WorldWideScience

Sample records for condensers steam

  1. Steam condenser

    International Nuclear Information System (INIS)

    Masuda, Fujio

    1980-01-01

    Purpose: To enable safe steam condensation by providing steam condensation blades at the end of a pipe. Constitution: When high temperature high pressure steam flows into a vent pipe having an opening under water in a pool or an exhaust pipe or the like for a main steam eacape safety valve, non-condensable gas filled beforehand in the steam exhaust pipe is compressed, and discharged into the water in the pool. The non-condensable gas thus discharged from the steam exhaust pipe is introduced into the interior of the hollow steam condensing blades, is then suitably expanded, and thereafter exhausted from a number of exhaust holes into the water in the pool. In this manner, the non-condensable gas thus discharged is not directly introduced into the water in the pool, but is suitable expanded in the space of the steam condensing blades to suppress extreme over-compression and over-expansion of the gas so as to prevent unstable pressure vibration. (Yoshihara, H.)

  2. Condensation of steam

    International Nuclear Information System (INIS)

    Prisyazhniuk, V.A.

    2002-01-01

    An equation for nucleation kinetics in steam condensation has been derived, the equation taking into account the concurrent and independent functioning of two nucleation mechanisms: the homogeneous one and the heterogeneous one. The equation is a most general-purpose one and includes all the previously known condensation models as special cases. It is shown how the equation can be used in analyzing the process of steam condensation in the condenser of an industrial steam-turbine plant, and in working out new ways of raising the efficiency of the condenser, as well as of the steam-turbine plant as a whole. (orig.)

  3. Steam generators, turbines, and condensers. Volume six

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Volume six covers steam generators (How steam is generated, steam generation in a PWR, vertical U-tube steam generators, once-through steam generators, how much steam do steam generators make?), turbines (basic turbine principles, impulse turbines, reaction turbines, turbine stages, turbine arrangements, turbine steam flow, steam admission to turbines, turbine seals and supports, turbine oil system, generators), and condensers (need for condensers, basic condenser principles, condenser arrangements, heat transfer in condensers, air removal from condensers, circulating water system, heat loss to the circulating water system, factors affecting condenser performance, condenser auxiliaries)

  4. Maintaining steam/condensate lines

    International Nuclear Information System (INIS)

    Russum, S.A.

    1992-01-01

    Steam and condensate systems must be maintained with the same diligence as the boiler itself. Unfortunately, they often are not. The water treatment program, critical to keeping the boiler at peak efficiency and optimizing operating life, should not stop with the boiler. The program must encompass the steam and condensate system as well. A properly maintained condensate system maximizes condensate recovery, which is a cost-free energy source. The fuel needed to turn the boiler feedwater into steam has already been provided. Returning the condensate allows a significant portion of that fuel cost to be recouped. Condensate has a high heat content. Condensate is a readily available, economical feedwater source. Properly treated, it is very pure. Condensate improves feedwater quality and reduces makeup water demand and pretreatment costs. Higher quality feedwater means more reliable boiler operation

  5. High-efficiency condenser of steam from a steam-gas mixture

    Science.gov (United States)

    Milman, O. O.; Krylov, V. S.; Ptakhin, A. V.; Kondratev, A. V.; Yankov, G. G.

    2017-12-01

    The design of a module for a high-efficiency condenser of steam with a high content (up to 15%) of noncondensable gases (NCGs) with a nearly constant steam-gas mixture (SGM) velocity during the condensation of steam has been developed. This module provides the possibility to estimate the operational efficiency of six condenser zones during the motion of steam from the inlet to the SGM suction point. Some results of the experimental tests of the pilot high-efficiency condenser module are presented. The dependence of the average heat transfer coefficient k¯ on the volumetric NCG concentration v¯ has been derived. It is shown that the high-efficiency condenser module can provide a moderate decrease in k¯ from 4400-4600 to 2600-2800 W/(m2 K) at v¯ ≈ 0.5-9.0%. The heat transfer coefficient distribution over different module zones at a heat duty close to its nominal value has been obtained. From this distribution, it can be seen that the average heat transfer coefficient decreases to 2600 W/(m2 K) at an NCG concentration v¯ = 7.5%, but the first condenser sections ( 1- 3) retain high values of k¯ at a level of no lower than 3200 W/(m2 K), and the last sections operate less well, having k¯ at a level of 1700 W/(m2 K). The dependence of the average heat transfer coefficient on the water velocity in condenser tubes has been obtained at a nearly nominal duty such that the extrapolation of this dependence to the water velocity of 2 m/s may be expected to give k¯ = 5000 W/(m2 K) for relatively pure steam, but an increase in k¯ at v¯ = 8% will be smaller. The effect of the gas removal device characteristic on the operation of the high-efficiency condenser module is described. The design developed for the steam condenser of a gas-turbine plant with a power of 25 MW, a steam flow rate of 40.2 t/h, and a CO2 concentration of up to 12% with consideration for the results of performed studies is presented.

  6. Effects of non-condensable gas on the condensation of steam

    International Nuclear Information System (INIS)

    Jackson, J.D.; An, P.; Reinert, A.; Ahmadinejad, M.

    2000-01-01

    The experimental work reported here was undertaken with the aim of extending the database currently available on the condensation of steam in the presence of non-condensable gases and thereby improving the empirical input to thermal-hydraulic codes which might be used for design and safety assessment of advanced water-cooled nuclear reactors. Heat was removed from flowing mixtures of steam and air in a test section by means of a water-cooled condensing plate. The test facility constructed for the study incorporates a degassing unit which supplies water to a boiler. This delivers steam steadily to a mixing chamber where it joins with a flow of preheated air. The mixture of steam and air is supplied to the bottom of a cylindrical test section in which it flows upwards over a double sided condensing plate which can be vertical, inclined or horizontal, The rate at which heat is removed by cooling water flowing through internal passages in the plate can de determined calorimetrically knowing the flow rate of the water and its temperature rise. After commissioning experiments had shown that reliable measurements of condensation heat transfer rate could be made using the test facility, a programme of development work followed in the course of which three different designs of condensing plate were evaluated in turn. The version eventually used in the main programme of experiments which followed was made from copper. However, its surfaces were coated with a thin layer of nickel and then with one of chromium. It was found that such a surface consistently promoted dropwise condensation and showed no signs of deterioration after lengthy periods of use. The rate of heat removal from pure steam and from mixtures of steam and air in varying proportions was measured as a function of plate sub-cooling for a variety of plate orientations. (author)

  7. Review of steam jet condensation in a water pool

    International Nuclear Information System (INIS)

    Kim, Y. S.; Song, C. H.; Park, C. K.; Kang, H. S.; Jeon, H. G.; Yoon, Y. J.

    2002-01-01

    In the advanced nuclear power plants including APR1400, the SDVS is adopted to increase the plant safety using the concept of feed-and-bleed operation. In the case of the TLOFW, the POSRV located at the top of the pressurizer is expected to open due to the pressurization of the reactor coolant system and discharges steam and/or water mixture into the water pool, where the mixture is condensed. During the condensation of the mixture, thermal-hydraulic loads such as pressure and temperature variations are induced to the pool structure. For the pool structure design, such thermal-hydraulic aspects should be considered. Understanding the phenomena of the submerged steam jet condensation in a water pool is helpful for system designers to design proper pool structure, sparger, and supports etc. This paper reviews and evaluates the steam jet condensation in a water pool on the physical phenomena of the steam condensation including condensation regime map, heat transfer coefficient, steam plume, steam jet condensation load, and steam jet induced flow

  8. Effect on non-condensable gas on steam injector

    International Nuclear Information System (INIS)

    Kawamoto, Y.; Abe, Y.; Iwaki, C.; Narabayashi, T.; Mori, M.; Ohmori, S.

    2004-01-01

    Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. Although non-condensable gases are well known for reducing heat transfer, the effect of the non-condensable gas on the condensation of supersonic steam on high-speed water jet has not been cleared. The present paper presents an experimental study of condensation of supersonic steam around turbulent water jet with model steam injector made by transparent plastic. The experimental apparatus is described. The visual observation was carried out by using high-speed camera. The non-condensable gas effect on the pump performance and flow characteristics are clarified by the image processing technique for the jet shape and gas-liquid interface behavior. (authors)

  9. Condensation induced water hammer in steam supply system

    International Nuclear Information System (INIS)

    Andrews, P.B.; Antaki, G.A.; Rawls, G.B.; Gutierrez, B.J.

    1995-01-01

    The accidental mixing of steam and water usually leads to condensation induced water hammer. This phenomenon is not uncommon in the power and process industries, and is of particular concern due to the high energies which accompany steam transients. The paper discusses the conditions which lead to a recent condensation induced water hammer in a 150 psig steam supply header. The ensuing structural damage, inspection and repairs are described. Finally, a list of design, maintenance and operational cautions are presented to help minimize the potential for condensation induced water hammer in steam lines

  10. Condensation induced water hammer in steam supply system

    International Nuclear Information System (INIS)

    Andrews, P.B.; Antaki, G.A.; Rawls, G.B.; Gutierrez, B.J.

    1995-01-01

    The accidental mixing of steam and water usually leads to condensation induced water hammer. THis phenomenon is not uncommon in the power and process industries, and is of particular concern due to the high energies which accompany steam transients. The paper discusses the conditions which lead to a recent condensation induced water hammer in a 150 psig steam supply header. The insuing structural damage, inspection and repairs are described. Finally, a list of design cautions are presented to help minimize the potential for condensation induced water hammer in steam lines

  11. Effect of flow velocity on the process of air-steam condensation in a vertical tube condenser

    Science.gov (United States)

    Havlík, Jan; Dlouhý, Tomáš

    2018-06-01

    This article describes the influence of flow velocity on the condensation process in a vertical tube. For the case of condensation in a vertical tube condenser, both the pure steam condensation process and the air-steam mixture condensation process were theoretically and experimentally analyzed. The influence of steam flow velocity on the value of the heat transfer coefficient during the condensation process was evaluated. For the condensation of pure steam, the influence of flow velocity on the value of the heat transfer coefficient begins to be seen at higher speeds, conversely, this effect is negligible at low values of steam velocity. On the other hand, for the air-steam mixture condensation, the influence of flow velocity must always be taken into account. The flow velocity affects the water vapor diffusion process through non-condensing air. The presence of air significantly reduces the value of the heat transfer coefficient. This drop in the heat transfer coefficient is significant at low velocities; on the contrary, the decrease is relatively small at high values of the velocity.

  12. Deliberate ignition of hydrogen-air-steam mixtures in condensing steam environments

    International Nuclear Information System (INIS)

    Blanchat, T.K.; Stamps, D.W.

    1997-05-01

    Large scale experiments were performed to determine the effectiveness of thermal glow plug igniters to burn hydrogen in a condensing steam environment due to the presence of water sprays. The experiments were designed to determine if a detonation or accelerated flame could occur in a hydrogen-air-steam mixture which was initially nonflammable due to steam dilution but was rendered flammable by rapid steam condensation due to water sprays. Eleven Hydrogen Igniter Tests were conducted in the test vessel. The vessel was instrumented with pressure transducers, thermocouple rakes, gas grab sample bottles, hydrogen microsensors, and cameras. The vessel contained two prototypic engineered systems: (1) a deliberate hydrogen ignition system and (2) a water spray system. Experiments were conducted under conditions scaled to be nearly prototypic of those expected in Advanced Light Water Reactors (such as the Combustion Engineering (CE) System 80+), with prototypic spray drop diameter, spray mass flux, steam condensation rates, hydrogen injection flow rates, and using the actual proposed plant igniters. The lack of any significant pressure increase during the majority of the burn and condensation events signified that localized, benign hydrogen deflagration(s) occurred with no significant pressure load on the containment vessel. Igniter location did not appear to be a factor in the open geometry. Initially stratified tests with a stoichiometric mixture in the top showed that the water spray effectively mixes the initially stratified atmosphere prior to the deflagration event. All tests demonstrated that thermal glow plugs ignite hydrogen-air-steam mixtures under conditions with water sprays near the flammability limits previously determined for hydrogen-air-steam mixtures under quiescent conditions. This report describes these experiments, gives experimental results, and provides interpretation of the results. 12 refs., 127 figs., 16 tabs

  13. Condensation of the steam in the horizontal steam line during cold water flooding

    International Nuclear Information System (INIS)

    Strubelj, L.; Tiselj, I.

    2006-01-01

    Direct contact condensation and condensation induced water-hammer in a horizontal pipe was experimentally investigated at PMK-2 test facility of the Hungarian Atomic Energy Research Institute KFKI. The experiment is preformed in the horizontal section of the steam line of the PMK-2 integral test facility. As liquid water floods the horizontal part of the pipeline, the counter current horizontally stratified flow is being observed. During the flooding of the steam line, the vapour-liquid interface area increases and therefore the vapour condensation rate and the vapour velocity also increase. Similar phenomena can occur in the cold/hot leg of the primary loop of PWR nuclear power plant during loss of coolant accident, when emergency core cooling system is activated. Water level at one cross-section and four local void fraction and temperature at the top of steam line was measured and compared with simulation. Condensed steam increases the water temperature that is why the local temperature measurements are the most important information, from which condensation rate can be estimated, since mass of condensed steam was not measured. Free surface simulation of the experiment with thermal phase change model is presented. Surface renewal concept with small eddies is used for calculation of heat transfer coefficient. With surface renewal theory we did not get results similar to experiment, that is why heat transfer coefficient was increased by factor 20. In simulation with heat transfer coefficient calculated with surface renewal concept bubble entrapment is due to reflection of the wave from the end of the pipe. When heat transfer coefficient is increased, condensation rate and steam velocity are also increased, bubble entrapment is due to Kelvin-Helmholtz instability of the free surface, and the results become similar to the measurements. (author)

  14. Modelling of steam condensation in the primary flow channel of a gas-heated steam generator

    International Nuclear Information System (INIS)

    Kawamura, H.; Meister, G.

    1982-10-01

    A new simulation code has been developed for the analysis of steam ingress accidents in high temperatures reactors which evaluates the heat transfer in a steam generator headed by a mixture of helium and water steam. Special emphasis is laid on the analysis of steam condensation in the primary circuit of the steam generator. The code takes wall and bulk condensation into account. A new method is proposed to describe the entrainment of water droplets in the primary gas flow. Some typical results are given. Steam condensation in the primary channel may have a significant effect on temperature distributions. The effect on the heat transferred by the steam generator, however, is found to be not so prominent as might be expected. The reason is discussed. A simplified code will also be described, which gives results with reasonable accuracy within much shorter execution times. This code may be used as a program module in a program simulating the total primary circuit of a high temperature reactor. (orig.) [de

  15. Method for extending the unrestricted operating range of condensing steam turbines

    International Nuclear Information System (INIS)

    Csaba, G.; Bannerth, Cs.

    2009-01-01

    The allowed condenser temperature of the condensing steam turbines is determined by the design parameters of the steam turbine (casing geometry, exhaust area, blade length, blade angle, blade profile etc.). The fluctuations of condenser temperature may lead to reduced power output of the condensing steam turbine. Solutions where the low pressure turbine casings have the same exhaust area can be kept in operation at narrow condenser temperature range without restrictions. Exceeding the mentioned temperature range the exhaust hood temperature restriction, undergoing the temperature range choking point restriction appears causing increased operation cost. The aim of the paper is to present a condensing steam turbine - direct-contact condenser system that can extend the unrestricted operating range. The examined system consists of more parallelly connected low pressure turbine casings so-called diabolo that having at least two exhausts separated at the steam side. The exhausts, utilizing varying input-temperature coolant, are connected to the condensers that are separated at the steam side and serially connected at the coolant side. The casings have the same inlet areas while the exhausts have different areas resulting different volume flows and temperature operating range. The economic advantage of this solution approaches the savings between the serially connected direct-contact condensers and condensers in parallel of a dry cooling system. It can be proven by a simple calculation using the ambient air temperature duration diagram that is presented in the paper. (author)

  16. Condensate polisher application for PWR steam generator corrosion control

    International Nuclear Information System (INIS)

    Sawochka, S.G.; Leibovitz, J.; Siegwarth, D.P.; Pearl, W.L.

    1981-01-01

    The evolution of corrosion attack modes particularly in recirculating U-tube PWR steam generators has dictated a thorough review of the advantages and disadvantages of condensate polishing. Analytical modeling techniques to qualitatively predict crevice chemistry variations resulting from steam generator bulk water variations have allowed valuable insights to be developed. Modeling results complemented by steam generator and laboratory corrosion data will be employed to set condensate demineralizer effluent specifications consistent with control of steam generator corrosion. Laboratory and plant studies are being performed to demonstrate achievability of necessary effluent specifications. (author)

  17. Steam blowdown experiments with the condensation pool test rig

    International Nuclear Information System (INIS)

    Purhonen, H.; Puustinen, M.; Laine, J.; Raesaenen, A.; Kyrki-Rajamaeki, R.; Vihavainen, J.

    2005-01-01

    During a possible loss-of-coolant accident (Local) a large amount of non-condensable (nitrogen) and condensable (steam) gas is blown from the upper drywell of the containment to the condensation pool through the blowdown pipes at the boiling water reactors (BWRs). The wet well pool serves as the major heat sink for condensation of steam. The blowdown causes both dynamic and structural loads to the condensation pool. There might also be a risk that the gas discharging to the pool could push its way to the emergency core cooling systems (ECCS) and undermine their performance. (author)

  18. A condenser for very high power steam turbines

    International Nuclear Information System (INIS)

    Gardey, Robert.

    1973-01-01

    The invention relates to a condenser for very high power steam turbines under the masonry-block supporting the low-pressure stages of the turbine, that condenser comprises two horizontal aligned water-tube bundles passing through the steam-exhaust sleeves of the low-pressure stages, on both sides of a common inlet water box. The invention can be applied in particular to the 1000-2000 MW turbines of light water nuclear power stations [fr

  19. Improvement of degradation with non-condensable gas in micro steam injector

    International Nuclear Information System (INIS)

    Saihara, Atsushi; Horiki, Sachiyo; Osakabe, Masahiro; Ohmori, Shuichi

    2007-01-01

    Effect of non-condensable gas on a micro steam injector (MSI) to obtain a vacuum was experimentally studied. When a pure steam was used in the MSI, the high vacuum condition was obtained. However when the mass fraction of air included in the steam was larger than a cartain value, the MSI became unstable and the vacuum condition could not be obtained. It is considered that the malfunction is due to the instability triggered with the uncondensed steam remained at the throat in downstream of the condensing region. The water nozzle was expected to be a key component to mitigate the effect of non-condensable gas. Three kinds of water nozzle whose flow areas were round, star and screw shapes were used in the present experiment. The star-shaped nozzle where the increased surface area could be expected to compensate the degradation of condensation failed to improve the malfunction of MSI with the non-condensable gas. The screw nozzle expected to drive air away outside the condensing surface could mitigate the effect of non-condensable gas. (author)

  20. Condensation pool experiments with steam using DN200 blowdown pipe

    International Nuclear Information System (INIS)

    Laine, J.; Puustinen, M.

    2005-08-01

    This report summarizes the results of the condensation pool experiments with steam using a DN200 blowdown pipe. Altogether five experiment series, each consisting of several steam blows, were carried out in December 2004 with a scaled-down test facility designed and constructed at Lappeenranta University of Technology. The main purpose of the experiments was to increase the understanding of different phenomena in the condensation pool during steam discharge. (au)

  1. Experimental investigation of non-condensable gases effect on operation of VVER steam generator in condensation mode

    International Nuclear Information System (INIS)

    Efanov, A. D.; Kalyakin, S. G.; Morozov, A. V.; Remizov, O. V.; Tsyganok, A. A.; Generalov, V. N.; Berkovich, V. M.; Taranov, G. S.

    2008-01-01

    To provide the safety in new Russian NPP designs, protection passive systems which don't depend upon human errors are widely used. In terms of safety, the design of NPP of new generation (NPP-2006) falls into the class of advanced NPPs. In the event of an beyond design basis accident with the rupture of the reactor primary circuit and accompanied by the loss of ac sources, the use of passive safety systems are provided for necessary core cooling. Among these is passive heat removal system (PHRS). In the case of leakage in the primary circuit this system ensures the transition of steam generators (SG) to operation in the mode of condensation of the primary circuit steam coming to SG piping from the reactor. As a result, the condensate from steam generators arrives at the core providing its additional cooling. The SG condensation capacity can be adversely affected by the presence of non-condensable gases in the primary circuit of the reactor. Their main sources are nitrogen arriving at the circuit, as hydro accumulators actuate, products of radiolysis of water and air drawn in from the containment through the pipeline rupture. The accumulation of non-condensable gases in SG piping can result in degradation of its condensation capacity to the extent that condensation completely terminates. In this case, the core cooling conditions may be impaired. To experimental investigation of the condensation mode of operation of WER steam generator, a large scale HA2M-SG test rig was constructed at the SSC RF IPPE. The test rig incorporates: buffer tank, equipped by steam supply system; SG model with volumetric-power scale is 1:46; PHRS heat exchanger imitator, cooling by process water. The rig main equipment connected by pipelines and equipped by valves. The elevations of the main equipment correspond to those of reactor project. The rig maximum operating parameters: steam pressure - 1.6 MPa, temperature - 200 Celsius degrees. Experiments at the HA2M-SG test rig have been

  2. Technological investigations and efficiency analysis of a steam heat exchange condenser: Conceptual design of a hybrid steam condenser

    OpenAIRE

    Kapooria, R K; Kumar, S; Kasana, K S

    2008-01-01

    Most of the electricity being produced throughout the world today is from steam power plants. At the same time, many other competent means of generating electricity have been developed viz. electricity from natural gas, MHD generators, biogas, solar cells, etc. But steam power plants will continue to be competent because of the use of water as the main working fluid which is abundantly available and is also reusable. The condenser remains among one of the key components of a steam power plant...

  3. Computational fluid dynamics validation study of steam condensation on the containment walls

    International Nuclear Information System (INIS)

    Gera, B.; Sharma, P.K.; Singh, R.K.; Vaze, K.K.

    2012-01-01

    In water cooled power reactors, significant quantities of hydrogen could be produced following a severe accident (loss-of-coolant-accident along with non availability of emergency core cooling system). A sound understanding of dispersion, stratification and diffusion of released hydrogen during severe accidents is, therefore, of practical importance and use to better understand the possibility of ignition, combustion and explosion of such releases within the context of containment safety. The presence of air and steam in the containment atmosphere also affects the hydrogen distribution as steam condensation takes place at containment walls in presence of non condensable and bulk of the mixture diffuses towards wall. The application of general purpose CFD codes for the analysis of the hydrogen behaviour within NPP containments during severe accidents has been increasing over past few years. The commercial CFD codes generally do not have built-in steam condensations models. In the present work, the adaptation of a commercial multipurpose code to this kind of problem is explained, i.e. by the implementation of models for steam condensation onto walls in presence of non-condensable gases. Steam condensation was modeled using the Uchida correlation, which was originally developed to be used for 'lumped' (volume-averaged) modeling of steam condensation in the presence of non-condensable gases. The Uchida correlation is based on experiments on natural convection from relatively small vertical plates. The present methodology has been validated against experimental data from the TOSQAN and COPAIN experimental facilities. (orig.)

  4. Steam generator and condenser design of WWER-1000 type of nuclear power plant

    International Nuclear Information System (INIS)

    Zare Shahneh, Abolghasem.

    1995-03-01

    Design process of steam generator and condenser at Russian nuclear power plant type WWER-1000 is identified. The four chapter of the books are organized as nuclear power plant, types of steam generators specially horizontal steam generator, process of steam generator design and the description of condenser and its process design

  5. Condensation Analysis of Steam/Air Mixtures in Horizontal Tubes

    International Nuclear Information System (INIS)

    Lee, Kwon Yeong; Bae, Sung Won; Kim, Moo Hwan

    2008-01-01

    Perhaps the most common flow configuration in which a convective condensation occurs is a flow in a horizontal circular tube. This configuration is encountered in air-conditioning and refrigeration condensers as well as condensers in Rankine power cycles. Although a convective condensation is also sometimes contrived to occur in a co-current vertical downward flow, a horizontal flow is often preferred because the flow can be repeatedly passed through the heat exchanger core in a serpentine fashion without trapping liquid or vapor in the return bends. Many researchers have investigated a in-tube condensation for horizontal heat exchangers. However, almost all of them obtained tube section-averaged data without a noncondensable gas. Recently, Wu and Vierow have experimentally studied the condensation of steam in a horizontal heat exchanger with air present. In order to measure the condenser tube inner surface temperatures and to calculate the local heat fluxes, they developed an innovative thermocouple design that allowed for nonintrusive measurements. Here we developed a theoretical model using the heat and mass analogy to analyze a steam condensation with a noncondensable gas in horizontal tubes

  6. Experimental study of steam condensation regime map for simplified spargers

    International Nuclear Information System (INIS)

    Kim, Y. S.; Yoon, Y. J.; Song, C. H.; Park, C. K.; Kang, H. S.; Jun, H. K.

    2003-01-01

    An experimental study was conducted to produce a condensation regime map for single-hole and 4-hole steam spargers using GIRLS facility. The regime map for a single-hole sparger was derived using parameters such as the frequency and magnitude of the dynamic pressure. For 4-hole sparager, the regime map was derived using the trends of sound and dynamic pressure. Using the single-hole and 4-hole data, a steam jet condensation regime map was suggested with respect to pool temperature and steam mass flux

  7. Steam condensation modelling in aerosol codes

    International Nuclear Information System (INIS)

    Dunbar, I.H.

    1986-01-01

    The principal subject of this study is the modelling of the condensation of steam into and evaporation of water from aerosol particles. These processes introduce a new type of term into the equation for the development of the aerosol particle size distribution. This new term faces the code developer with three major problems: the physical modelling of the condensation/evaporation process, the discretisation of the new term and the separate accounting for the masses of the water and of the other components. This study has considered four codes which model the condensation of steam into and its evaporation from aerosol particles: AEROSYM-M (UK), AEROSOLS/B1 (France), NAUA (Federal Republic of Germany) and CONTAIN (USA). The modelling in the codes has been addressed under three headings. These are the physical modelling of condensation, the mathematics of the discretisation of the equations, and the methods for modelling the separate behaviour of different chemical components of the aerosol. The codes are least advanced in area of solute effect modelling. At present only AEROSOLS/B1 includes the effect. The effect is greater for more concentrated solutions. Codes without the effect will be more in error (underestimating the total airborne mass) the less condensation they predict. Data are needed on the water vapour pressure above concentrated solutions of the substances of interest (especially CsOH and CsI) if the extent to which aerosols retain water under superheated conditions is to be modelled. 15 refs

  8. The effect of non-condensable gas on direct contact condensation of steam/air mixture

    International Nuclear Information System (INIS)

    Lee, H. C.; Park, S. K.; Kim, M. H.

    1998-01-01

    To investigate the effects of noncondensable gas on the direct contact film condensation of vapor mixture, a series of experiments has been carried out. The rectangular duct inclined 87.deg. to the horizontal plane was used for this experiment. The average heat transfer coefficient of the steam-air mixture was obtained at the atmospheric pressure with four main parameters, air-mass fraction, vapor velocity, film Reynolds number,and the degree of water film subcooling having an influence on the condensation heat transfer coefficient. With the analysis on 88 cases of experiments, a correlation of the average Nusselt number for direct contact film condensation of steam-air mixture at a vertical wall proposed as functions of film Reynolds number, mixture Reynolds number, air mass fraction, and Jacob number. The average heat transfer coefficient for steam-air mixture condensation decreased significantly while air mass fraction increases with the same inlet mixture velocity and inlet film temperature. The average heat transfer coefficients also decreased with the degree of film subcooling increasing and were scarcely affected by film Reynolds number below the mixture Reynolds number about 30,000

  9. Two-fluid model with droplet size distribution for condensing steam flows

    International Nuclear Information System (INIS)

    Wróblewski, Włodzimierz; Dykas, Sławomir

    2016-01-01

    The process of energy conversion in the low pressure part of steam turbines may be improved using new and more accurate numerical models. The paper presents a description of a model intended for the condensing steam flow modelling. The model uses a standard condensation model. A physical and a numerical model of the mono- and polydispersed wet-steam flow are presented. The proposed two-fluid model solves separate flow governing equations for the compressible, inviscid vapour and liquid phase. The method of moments with a prescribed function is used for the reconstruction of the water droplet size distribution. The described model is presented for the liquid phase evolution in the flow through the de Laval nozzle. - Highlights: • Computational Fluid Dynamics. • Steam condensation in transonic flows through the Laval nozzles. • In-house CFD code – two-phase flow, two-fluid monodispersed and polydispersed model.

  10. How to compute the power of a steam turbine with condensation, knowing the steam quality of saturated steam in the turbine discharge

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Albarran, Manuel Jaime; Krever, Marcos Paulo Souza [Braskem, Sao Paulo, SP (Brazil)

    2009-07-01

    To compute the power and the thermodynamic performance in a steam turbine with condensation, it is necessary to know the quality of the steam in the turbine discharge and, information of process variables that permit to identifying with high precision the enthalpy of saturated steam. This paper proposes to install an operational device that will expand the steam from high pressure point on the shell turbine to atmosphere, both points with measures of pressure and temperature. Arranging these values on the Mollier chart, it can be know the steam quality value and with this data one can compute the enthalpy value of saturated steam. With the support of this small instrument and using the ASME correlations to determine the equilibrium temperature and knowing the discharge pressure in the inlet of surface condenser, the absolute enthalpy of the steam discharge can be computed with high precision and used to determine the power and thermodynamic efficiency of the turbine. (author)

  11. Condensate induced water hammer in a steam distribution system results in fatality

    International Nuclear Information System (INIS)

    Debban, H.L.; Eyre, L.E.

    1996-02-01

    Water hammer event s in steam distribution piping interrupt service and have the potential to cause serious injury and property damage. Conditions of condensation induced water hammer are discussed and recommendations aimed to improve safety of steam systems are presented. Condensate induced water hammer events at Hanford, a DOE facility, are examined

  12. Steam condensation process in a power production cycle and heat exchanger for it

    International Nuclear Information System (INIS)

    Tondeur, Gerard; Andro, Jean; Marjollet, Jacques; Pouderoux, Pierre.

    1982-01-01

    Steam condensation process in a power production cycle by expansion in turbines, characterized by the fact that this condensation is performed by the vaporization of a coolant with a vaporization temperature at atmospheric pressure lower than that of water, and that the vaporized coolant fluid is expanded in a turbine and then condensed by heat exchange with cold water being heated, while the liquefied coolant is recompressed and used for heat exchange with the steam to be condensed [fr

  13. Patchouli Oil Production for Fixative Aromatheraphy: A Case Study Design of Condenser for Steam Distillation

    Directory of Open Access Journals (Sweden)

    Egi Agustian

    2015-06-01

    Full Text Available Patchouli oil is an important material for aromatherapy industries and made from patchouli leaves by steam distillation. The important parts of steam distillation is condenser. The problem is process of farmer's patchouli based on experience not used chemical process of steam distillation cause not effective and efficient. The study was designed of condensers on steam distillation for patchouli leaves. Specification of condenser type is shell and tube, stainless steel material and water as coolant. Tubing sized is ¼ inch with 500 mm of length and 24 pieces. Shell measuring 2.5 inch and 600 mm of length. The performance of condenser gave the efficiency at 94.51%. The process condition of ratio stems to leaves is 5:6 and 4.5 hours was considered ideal for steam distillation. The used of energy is lowest cause the efficiency condenser and yield will be higher. Patchouli oil yield of 2.39% and patchouli alcohol content is 35.65%.

  14. Dynamic Modeling of Steam Condenser and Design of PI Controller Based on Grey Wolf Optimizer

    OpenAIRE

    Shu-Xia Li; Jie-Sheng Wang

    2015-01-01

    Shell-and-tube condenser is a heat exchanger for cooling steam with high temperature and pressure, which is one of the main kinds of heat exchange equipment in thermal, nuclear, and marine power plant. Based on the lumped parameter modeling method, the dynamic mathematical model of the simplified steam condenser is established. Then, the pressure PI control system of steam condenser based on the Matlab/Simulink simulation platform is designed. In order to obtain better performance, a new meta...

  15. Transonic flow of steam with non-equilibrium and homogenous condensation

    Science.gov (United States)

    Virk, Akashdeep Singh; Rusak, Zvi

    2017-11-01

    A small-disturbance model for studying the physical behavior of a steady transonic flow of steam with non-equilibrium and homogeneous condensation around a thin airfoil is derived. The steam thermodynamic behavior is described by van der Waals equation of state. The water condensation rate is calculated according to classical nucleation and droplet growth models. The current study is based on an asymptotic analysis of the fluid flow and condensation equations and boundary conditions in terms of the small thickness of the airfoil, small angle of attack, closeness of upstream flow Mach number to unity and small amount of condensate. The asymptotic analysis gives the similarity parameters that govern the problem. The flow field may be described by a non-homogeneous transonic small-disturbance equation coupled with a set of four ordinary differential equations for the calculation of the condensate mass fraction. An iterative numerical scheme which combines Murman & Cole's (1971) method with Simpson's integration rule is applied to solve the coupled system of equations. The model is used to study the effects of energy release from condensation on the aerodynamic performance of airfoils operating at high pressures and temperatures and near the vapor-liquid saturation conditions.

  16. Test for Jet Flow Induced by Steam Jet Condensation Using the GIRLS Facility

    International Nuclear Information System (INIS)

    Kim, Yeon Sik; Yoon, Y. J.; Song, C. H.

    2007-03-01

    To investigate the characteristics of the turbulent jet induced by steam jet condensation in a water tank through a single-hole sparger an experimental investigation was performed using the GIRLS facility. The experiments were conducted with respect to two cases, e.g. horizontal and vertical upward injections. For the measurements, pitot tube and thermocouples were used for turbulent flow velocity and temperatures, respectively. Overall flow shapes of the turbulent jet by the steam jet condensation are similar to those of axially symmetric turbulent jet flows. The angular coefficients of turbulent rays are quantitatively comparable between the traditional turbulent jet flows and the turbulent jet flows induced by the steam jet condensation in this work. Although the turbulent flows were induced by the horizontally injected steam jet condensation, general theory of turbulent jets was found to be applicable to the turbulent flows of this work. But for the vertically upward injection case, experimental data were quite deviated from the theoretical ones, which is considered due to the buoyancy effect

  17. Enhancement of Condensation Heat Transfer Rate of the Air-Steam Mixture on a Passive Condenser System Using Annular Fins

    Directory of Open Access Journals (Sweden)

    Yeong-Jun Jang

    2017-11-01

    Full Text Available This paper presents an experimental investigation on the enhancement of the heat transfer rate of steam condensation on the external surfaces of a vertical tube with annular fins. A cylindrical condenser tube, which is 40 mm in outer diameter and 1000 mm in length, with annular disks of uniform cross-sectional area is fabricated in the manner of ensuring perfect contact between the base surface and fins. A total of 13 annular fins of 80 mm diameter were installed along the tube height in order to increase the effective heat transfer area by 85%. Through a series of condensation tests for the air-steam mixture under natural convection conditions, the heat transfer data was measured in the pressure range of between 2 and 5 bar, and the air mass fraction from 0.3 to 0.7. The rates of heat transfer of the finned tube are compared to those that are measured on a bare tube to demonstrate the enhanced performance by extended surfaces. In addition, based on the experimental results and the characteristics of steam condensation, the applicability of finned tubes to a large condenser system with a bundle layout is evaluated.

  18. Preparatory studies for modelling steam condensation on soluble aerosols

    International Nuclear Information System (INIS)

    Dunbar, I.H.

    1988-01-01

    Of the fission products which would be released from the core of an LWR in the event of a severe accident, only the noble gases and possibly some of the iodine (depending on chemical form) are likely not to be in the form of aerosols when they reach the containment building atmosphere. Therefore in order to predict the extent of fission product retention on containment building internal structures, one needs to have a good understanding of aerosol deposition processes and of the factors which affect them. Following a severe accident in an LWR, a major component of the containment atmosphere will be steam. If the thermodynamic conditions allow condensation of this steam, this condensation is most likely to occur on the aerosol particles. A major component of the aerosol formed during the in-vessel release following a severe reactor accident will be fission product caesium. It is believed that much of this will enter the containment in the form of the hydroxide which has a great affinity for water, so particle growth due to steam condensation is likely to be a very important mechanism for retaining radioactive caesium within the containment builing. The author provides a systematic review of the basic chemical and physical issues which must be addressed if the phenomena are to be modelled accurately, and gives recommendations on how computer models of condensation onto soluble aerosols should be constructed. He proposes also to perform a systematic review of the existing literature and to perform small-scale thermodynamic experiments wherever important gaps in the data base are discovered

  19. Amorphous bimetallic alloys prepared by steam condensation

    International Nuclear Information System (INIS)

    Drago, V.

    1988-01-01

    Amorphous alloys of MnSn are prepared by steam condensation, in a substratum with a temperature near of the liquid helium. The magnetic and paramagnetic hyperfine spectrum and the ordination temperature by Moessbauer effect 119Sn are measured. A diagram of magnetic phase is proposed, basing on the measures of Moessbauer effect. (C.G.C.) [pt

  20. An integrated approach to steam condensation studies inside reactor containments: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Mahesh Kumar [Department of Mechanical Engineering, Indian Institute of Technology Kanpur, 208016 (India); Khandekar, Sameer, E-mail: samkhan@iitk.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Kanpur, 208016 (India); Sharma, Pavan K. [Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-04-15

    Occurrence of severe accidents, such as the Fukushima incident in 2011, is unlikely with a probability of 10{sup −5} per reactor per year. However, such kinds of accidents have serious consequences on both, short term as well as on long term public health, environment and energy policy and security. They also adversely affect the progress of nuclear power industry. Thus, despite such a low probability of occurrence, a need arises to review the safety standards of nuclear power plants, especially in the light of the Fukushima accident. Apart from other systems, a review of thermal-hydraulics and safety system for the reactor containment is vital, as it is the last barrier to radioactive leakage. Main threats to the containment integrity include over-pressurization, not only due to steam alone, but its coupling with the possibility of local hydrogen combustion, depending on the local mixture composition of steam-air-hydrogens. It must be emphasized that steam condensation rate affects the local mixture composition and presence of hydrogen significantly deteriorates the condensation rate. This intrinsic coupling needs to be understood. In this paper, steam condensation and related issues, including basics of condensation, modeling approaches, parameters affecting condensation and experiments performed (in both separate effect and integral test facilities) are critically reviewed, in the light of coupled issues of hydrogen transport and combustion. Such studies are necessary for correlation development and/or to find out the local distribution of steam-hydrogen-air mixture within the containment to locate the possible hydrogen combustion location(s) and hence, deployment of active/passive safety systems. In addition, it is important that future studies, both experimental and numerical modeling, focus on the coupled nature of the problem in a comprehensive manner for ensuring long term safety.

  1. An experimental and numerical study into turbulent condensing steam jets in air

    Energy Technology Data Exchange (ETDEWEB)

    Oerlemans, S. [Faculty of Applied Physics Eindhoven, Univ. of Technology Eindhoven (Netherlands); Badie, R. [Philips Research Laboratories Eindhoven (Netherlands); Dongen, M.E.H. van [Faculty of Applied Physics, Eindhoven Univ. of Technology (Netherlands)

    2001-07-01

    Temperatures, velocities, and droplet sizes are measured in turbulent condensing steam jets produced by a facial sauna, for varying nozzle diameters and varying initial velocities (Re=3,600-9,200). The release of latent heat due to droplet condensation causes the temperature in the two-phase jet to be significantly higher than in a single-phase jet. At some distance from the nozzle, droplets reach a maximum size and start to evaporate again, which results in a change in sign of latent heat release. The distance of maximum size is determined from droplet size measurements. The experimental results are compared with semi-analytical expressions and with a fully coupled numerical model of the turbulent condensing steam jet. The increase in centreline temperature due to droplet condensation is successfully predicted. (orig.)

  2. Measurement of condensation heat transfer coefficients in a steam chamber using a variable conductance heat pipe

    International Nuclear Information System (INIS)

    Robinson, J.A.; Windebank, S.R.

    1988-01-01

    Condensation heat transfer coefficients have been measured in a pressurised chamber containing a mixture of saturated steam and air. They were determined as a function of the air-steam ratio in nominally stagnant conditions. The effect of pressure is assessed and preliminary measurements with a forced convective component of velocity are presented. A novel measurement technique was adopted, namely to use a vertical heat pipe whose conductance could easily be varied. It transported heat from an evaporator located inside the chamber to a condenser section outside, at which the heat flow was measured. Heat flux at the evaporator could then be determined and a condensation heat transfer coefficient derived. The range of coefficients covered was from 150 W/m 2 0 K at high air-steam ratios to 20,000 W/m 2 0 K in pure steam. Results show that increasing either total pressure or velocity enhances condensation heat transfer over the range of air/steam ratios considered. (author)

  3. Specification of steam generator, condenser and regenerative heat exchanger materials for nuclear applications

    International Nuclear Information System (INIS)

    Jovasevic, J.V.; Stefanovic, V.M.; Spasic, Z.LJ.

    1977-01-01

    The basic standards specifications of materials for nuclear applications are selected. Seamless Ni-Cr-Fe alloy Tubes (Inconel-600) for steam generators, condensers and other heat exchangers can be employed instead of austenitic stainless steal or copper alloys tubes; supplementary requirements for these materials are given. Specifications of Ni-Cr-Fe alloy plate, sheet and strip for steam generator lower sub-assembly, U-bend seamless copper-alloy tubes for heat exchanger and condensers are also presented. At the end, steam generator channel head material is proposed in the specification for carbon-steel castings suitable for welding

  4. Simulation of steam condensation in the presence of noncondensable gases in horizontal condenser tubes using RELAP5 for advanced nuclear reactors

    International Nuclear Information System (INIS)

    Macedo, Luiz Alberto; Torres, Walmir Maximo

    2009-01-01

    Horizontal heat exchangers are used in advanced light water nuclear reactors in their passive cooling systems, such as residual heat removal (RHRS) and passive containment cooling system (PCCS). Condensation studies of steam and noncondensable gases mixtures in these heat exchangers are very important due to the phenomena multidimensional nature and the condensate stratification effects. This work presents a comparison between simulation results and experimental data in steady state conditions for some inlet pressure, steam and noncondensable gases (air) inlet mass fractions. The test section is three meters long and consists of two concentric tubes containing pressure, temperature and flow rate sensors. The internal tube, called condenser, contains steam-air mixture flow and external tube is a counter current cooler with water flow rate at low temperature. This test section was modeled and simulations were performed with RELAP5 code. Experimental tests were carried out for 200 to 400 kPa inlet pressure and 5, 10, 15 and 20% of inlet air mass fractions. Comparisons between experimental data and simulation results are presented for 200 and 400 kPa pressure conditions and showed good agreement. However, for 400 kPa inlet steam pressure and inlet air mass fractions above 5%, the simulated temperatures are lower than the experimental data at the final third from the inlet condenser tube, indicating a code overestimation of heat transfer coefficient. New correlations for heat transfer coefficient in these steam-air conditions must be theoretical and experimentally studied and implemented in RELAP5 code for better representing the condensation phenomena. (author)

  5. Use of steam condensate exchange process for recovery of deuterium from condensate of ammonia plant as adopted at Heavy Water Plant, Talcher (Paper No. 2.5)

    International Nuclear Information System (INIS)

    Saha, S.; Saha, P.

    1992-01-01

    This paper highlights the use of steam-condensate exchange system for recovery of deuterium from condensate of ammonia plant, which is adopted at Heavy Water Plant, Talcher. Deuterium concentration in the condensate leaving the steam-condensate exchange column can be brought down very close to the deuterium concentration in water thereby achieving practically complete deuterium recovery. (author). 2 tabs., 1 fig

  6. Why extraction lines and heaters in the turbine-condenser steam space should be lagged

    Energy Technology Data Exchange (ETDEWEB)

    Burns, J.M.; Haynes, C.J.

    1998-07-01

    Deregulated utilities face conditions today that necessitate their nuclear and fossil steam plants have the best possible heat rates. The low pressure turbine exhaust and condenser areas are known to be particularly sensitive to betterment. One relatively modest but cost effective heat rate improvement and one whose function and design is often misunderstood is the insulation of the extraction lines and heaters that are located within the turbine-condenser steam space. This paper discusses the dynamic environment of that turbine exhaust region and quantifies the application and benefit of stainless steel lagging to the extraction lines and heater shells within. The paper first focuses on the high energy, non-uniform steam flows of the turbine exhaust and how that impacts the heat losses, mechanical design and support of any components located inside that space. It then examines and quantifies the varieties of heat transfer from the heaters and extraction lines to the passing lower temperature, moist, high velocity turbine exhaust steam as it travels to the condenser. A new relationship is developed that defines the predominantly evaporative heat transfer mechanism on the exterior surfaces in contact with the exhaust steam. For a typical 630 MW fossil plant with three heater of different temperature levels in the steam space as exemplified by the US Generation fossil fired Brayton Point 3, the paper determined the additional condenser heat load and extra extraction steam. The paper lastly concluded that in this case, lagging the larger diameter lines of the lowest pressure heater and the heater itself is likely not cost-effective.

  7. Simulation of a flow spontaneously condensed moist steam in Laval nozzles

    International Nuclear Information System (INIS)

    Avetisyan, A.R.; Alipchenkov, V.M.; Zajchik, L.I.

    2002-01-01

    The method for simulating the evolution of the drops distribution by size in the course of commonly proceeding processes of nucleation (spontaneous condensation), heterogeneous condensation) evaporation and coagulation is proposed. The results of the analysis of the initial moisture effect on the steam spontaneous condensation in the transonic nozzles are presented. The availability of the minima in the output moisture dependences on the drops initial moisture and size is the most interesting result of the initial moisture effect on the spontaneous condensation in the Laval nozzles [ru

  8. Preliminary condensation pool experiments with steam using DN80 and DN100 blowdown pipes

    International Nuclear Information System (INIS)

    Laine, J.; Puustinen, M.

    2004-03-01

    The report summarizes the results of the preliminary steam blowdown experiments. Altogether eight experiment series, each consisting of several steam blows, were carried out in autumn 2003 with a scaled-down condensation pool test rig designed and constructed at Lappeenranta University of Technology. The main purpose of the experiments was to evaluate the capabilities of the test rig and the needs for measurement and visualization devices. The experiments showed that a high-speed video camera is essential for visual observation due to the rapid condensation of steam bubbles. Furthermore, the maximum measurement frequency of the current combination of instrumentation and data acquisition system is inadequate for the actual steam tests in 2004. (au)

  9. A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianmao, E-mail: xm-wang11@mails.tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Chang, Huajian, E-mail: changhj@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Corradini, Michael, E-mail: corradini@engr.wisc.edu [Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2016-08-15

    Highlights: • A condensation model is incorporated in the ANSYS FLUENT. • Different turbulence models are evaluated for flows over wavy surfaces. • Wavy surfaces with and without moving velocities are used to model the wave. • Various wavy surfaces with different wave heights and wavelengths are selected. • Wave influence on film steam condensation is investigated. - Abstract: Steam condensation plays an important role in removing heat from the containment of a nuclear plant during postulated accidents. However, due to the presence of non-condensable gases such as air and hydrogen in the containment, the condensation rate can decrease dramatically. Under certain conditions, the condensate film on the cold containment walls can affect the overall heat transfer rate. The wavy interface of the condensate film is a factor and is usually believed to enhance the condensation rate, since the waves can both increase the interfacial area and disturb the non-condensable gas boundary layer. However, it is not clear how to properly account for this factor and what is its quantitative influence in experiments. In this work, a CFD approach is applied to study the wave effects on film condensation in the presence of non-condensable gas. Wavy surfaces with and without moving velocities are used to replace the wavy interface of the falling film. A condensation model is incorporated in the ANSYS FLUENT simulation and a realizable k–ε turbulence model is applied. Various wavy surfaces with different wave heights and wavelengths are selected to conduct numerical experiments with a wide range of gas velocities. The results show that the wave structure can enhance condensation rate up to ten percent mainly due to the alteration of local flow structures in the gas phase. The increments of the condensation rate due to the wavy interface can vary with different gas velocities. The investigation shows that a multiplication factor accounts for the wave effects on film

  10. A calculation and measurement of the flow field in a steam condenser external to the tube nest

    International Nuclear Information System (INIS)

    Stastny, M.; Feistauer, M.

    1989-01-01

    The suggested physical and mathematical model is used to solve the flow of steam normal to the cooling tubes of condenser cross-sections in the region external to the nests. Numerical calculations are carried out by means of a multipurpose system of programmes for the finite element method and a programme for the boundary layer calculation. The results of the calculations are compared with measurements on the condenser of a 500MW steam turbine. The calculations of the flow field in a double pass condenser for the 1000MW saturated steam turbine are described. (author)

  11. Effect of non-condensation gas on pressure oscillation of submerged steam jet condensation

    International Nuclear Information System (INIS)

    Zhao, Quanbin; Cong, Yuelei; Wang, Yingchun; Chen, Weixiong; Chong, Daotong; Yan, Junjie

    2016-01-01

    Highlights: • Oscillation intensity of steam–air jet increases with rise of water temperature. • Oscillation intensity reduces obviously when air is mixed. • Both first and second dominant frequencies decrease with rise of air mass fraction. • Air has little effect on power of 1st & 2nd frequency bands under low temperature. • The maximum oscillation power occurs under case of A = 1% and T ⩾ 50 °C. - Abstract: The effect of air with low mass fraction on the oscillation intensity and oscillation frequency of a submerged steam jet condensation is investigated under stable condensation region. With air mixing in steam, an obvious dynamic pressure peak appears along the jet direction. The intensity peak increases monotonously with the rise of steam mass flux and water temperature. Peak position moves downstream with the rise of air mass fraction. Moreover, when compared with that of pure steam jet, the oscillation intensity clearly decreases as air is mixed. However, when water temperature is lower than approximately 45 °C, oscillation intensity increases slightly with the rise of air mass fraction, and when water temperature is higher than 55 °C, the oscillation intensity decreases greatly with the rise of air mass fraction. Both the first and second dominant frequencies decrease with rise of air mass fraction. Finally, effect of air mass fractions on the oscillation power of the first and second dominant frequency bands shows similar trends. Under low water temperature, the mixed air has little effect on the oscillation power of both first and second frequency bands. However, when water temperature is high, the oscillation power of both first and second frequency bands appears an obvious peak when air mass fraction is about 1%. With further rise of air mass fraction, the oscillation power decreases gradually.

  12. Interfacial condensation heat transfer for countercurrent steam-water wavy flow in a horizontal circular pipe

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Won; Chun, Moon Hyun [Korea Advanced Institute of Science and Technolgy, Taejon (Korea, Republic of); Chu, In Cheol [KAERI, Taejon (Korea, Republic of)

    2000-10-01

    An experimental study of interfacial condensation heat transfer has been performed for countercurrent steam-water wavy flow in a horizontal circular pipe. A total of 105 local interfacial condensation heat transfer coefficients have been obtained for various combinations of test parameters. Two empirical Nusselt number correlations were developed and parametric effects of steam and water flow rates and the degree of water subcooling on the condensation heat transfer were examined. For the wavy interface condition, the local Nusselt number is more strongly sensitive to the steam Reynolds number than water Reynolds number as opposed to the case of smooth interface condition. Comparisons of the present circular pipe data with existing correlations showed that existing correlations developed for rectangular channels are not directly applicable to a horizontal circular pipe flow.

  13. Analysis of experiments for vertical out-tube steam condensation in presence of non-condensable gases

    International Nuclear Information System (INIS)

    Su Jiqiang; Sun Zhongning; Fan Guangming; Guo Zixuan

    2014-01-01

    In order to investigate the influence of various parameters in the steam condensation heat transfer process with non-condensable gas, and to get a more suitable empirical correlation, the wall under-cooling, pressure and the content of non-condensable gas were studied outside a vertical tube by experiments. The results showed that: at the same pressure, the relationship between wall sub-cooling and HTC is exponential, and helium stratification does not happen within the experimental range. Based on the analysis of various experimental variables, combined with a large number of experimental data, a wider scope of application of the empirical correlation associated is obtained with the experimental value of the error within ±20%. (authors)

  14. Theory of the spontaneous condensation of steam during expansion

    International Nuclear Information System (INIS)

    Kleitz, Alain

    1978-01-01

    When steam expands in a nozzle or turbine, it cools and, at a certain pressure level, the saturation limit is exceeded. The appearance of moisture does not comply with the simple laws of thermodynamic balance. The liquid phase appears only as from a certain sub-cooling of the steam, at which stage it forms suddenly as a finely dispersed mist. On the basis of the kinetic theory of gases and the critical radius concept, Oswatitch produced a theory on spontaneous condensation which was checked by tests in nozzles. On the other hand, this theory does not fully explain that which is observed in turbines or manifolds fed with fluids other than steam. Modifications have been made to the conventional theory in an endeavour to corroborate the experimental results [fr

  15. Computational Fluid Dynamics Modeling of Steam Condensation on Nuclear Containment Wall Surfaces Based on Semiempirical Generalized Correlations

    Directory of Open Access Journals (Sweden)

    Pavan K. Sharma

    2012-01-01

    Full Text Available In water-cooled nuclear power reactors, significant quantities of steam and hydrogen could be produced within the primary containment following the postulated design basis accidents (DBA or beyond design basis accidents (BDBA. For accurate calculation of the temperature/pressure rise and hydrogen transport calculation in nuclear reactor containment due to such scenarios, wall condensation heat transfer coefficient (HTC is used. In the present work, the adaptation of a commercial CFD code with the implementation of models for steam condensation on wall surfaces in presence of noncondensable gases is explained. Steam condensation has been modeled using the empirical average HTC, which was originally developed to be used for “lumped-parameter” (volume-averaged modeling of steam condensation in the presence of noncondensable gases. The present paper suggests a generalized HTC based on curve fitting of most of the reported semiempirical condensation models, which are valid for specific wall conditions. The present methodology has been validated against limited reported experimental data from the COPAIN experimental facility. This is the first step towards the CFD-based generalized analysis procedure for condensation modeling applicable for containment wall surfaces that is being evolved further for specific wall surfaces within the multicompartment containment atmosphere.

  16. Analysis of the characteristics of heat transfer enhancement in steam condensers

    International Nuclear Information System (INIS)

    Yan Changqi; Sun Zhongning

    2001-01-01

    The influence of main factors on overall heat transfer was analyzed, and the effects of fouling factors on heat transfer characteristics in steam condenser were clarified. It was proposed that the tube outside enhancement is the most important attribute, when outside heat transfer coefficient increased there will be a big increase in condenser efficiency. The characteristics of heat transfer enhancement by spirally indented tube were investigated. It was proposed that condenser heat transfer efficiency will be raised when the low fin tube or the spirally indented tube with special treated surface were used

  17. Dynamic Modeling of Steam Condenser and Design of PI Controller Based on Grey Wolf Optimizer

    Directory of Open Access Journals (Sweden)

    Shu-Xia Li

    2015-01-01

    Full Text Available Shell-and-tube condenser is a heat exchanger for cooling steam with high temperature and pressure, which is one of the main kinds of heat exchange equipment in thermal, nuclear, and marine power plant. Based on the lumped parameter modeling method, the dynamic mathematical model of the simplified steam condenser is established. Then, the pressure PI control system of steam condenser based on the Matlab/Simulink simulation platform is designed. In order to obtain better performance, a new metaheuristic intelligent algorithm, grey wolf optimizer (GWO, is used to realize the fine-tuning of PI controller parameters. On the other hand, the Z-N engineering tuning method, genetic algorithm, and particle swarm algorithm are adopted for tuning PI controller parameters and compared with GWO algorithm. Simulation results show that GWO algorithm has better control performance than other four algorithms.

  18. Condensation heat transfer coefficient in horizontal stratified cocurrent flow of steam and cold water

    International Nuclear Information System (INIS)

    Kim, Kap; Kim, Hho Jung

    1986-01-01

    Some studies on direct-contact condensation in cocurrent stratified flow of steam and subcooled water were reviewed. Several approaches have been performed to develop the condensation heat transfer coefficient relationship. The local Nusselt number is correlated in terms of the local water Reynolds and Prandtl numbers as well as the steam Froude number. In addition, a turbulence-centered model, developed principally for gas absorption in several geometries, is modified by using calculated interfacial parameters for the turbulent velocity and length scales. These approaches result in a fairly good agreement with the data, whereas, the turbulence-centered model is here recommended since it is based on the turbulent properties which may be closely related to the condensation phenomena. (Author)

  19. Experimental investigation of reflux condensation heat transfer in PWR steam generator tubes in the presence of noncondensible gases

    Energy Technology Data Exchange (ETDEWEB)

    Vierow, Karen; Wu, Tiejun [Purdue Univ., West Lafayette (United States); Nagae, Takashi [Institute of Nuclear Safety System, Tokyo (Japan)

    2003-07-01

    Under certain circumstances in a Pressurized Water Reactor (PWR), the coolant system may be in a partially drained state and reflux condensation in the steam generator U-tubes can be the major heat removal mechanism. Noncondensable gases may be present and would degrade the heat transfer rate. If heat removal rates are insufficient, this situation could lead to core boil-off, fuel rod heatup, and eventually core damage. The Institute of Nuclear Safety System, Inc. (INSS) and the Nuclear Heat Transfer Systems Laboratory at Purdue University have begun a cooperative research program to investigate the effectiveness of reflux condensation in PWR steam generator U-tubes in the presence of noncondensable gases. The final objectives are to provide local heat transfer data for development of methods to analyze reflux condensation in PWR steam generator U-tubes and to investigate the potential for flooding. Key features of the experimental data reported herein are that they are local data under laminar steam/gas mixture and condensate film flow and they are taken from a test section with dimensions similar to an actual steam generator tube. Steady state data were obtained under various steam and air inlet flow rates and pressures. The data show the significant degrading effect of noncondensable gas on heat transfer coefficients. From the data, correlations for the reflux condensation local heat transfer coefficient and the local Nusselt number under laminar conditions were derived. These experiments are providing essential and unique fundamental data for development of methods to analyze reflux condensation.

  20. Steam condensation on finned tubes, in the presence of non-condensable gases and aerosols: Influence of impaction, diffusiophoresis and settling on aerosol deposition

    International Nuclear Information System (INIS)

    Munoz-Cobo, J.L.; Pena, J.; Herranz, L.E.; Perez-Navarro, A.

    2005-01-01

    This paper presents a mechanistic model to predict the steam condensation on containment finned tube heat exchangers in the presence of non-condensable gases (NC) and aerosols. The total thermal resistance from the bulk gas to the coolant is formulated as a parallel combination of the convective and condensation gas resistances coupled in series to those of condensate layer, the aerosol fouling layer, the wall, and the coolant. The condensate layer thermal resistance is calculated by means of an Adamek-based condensation model. The aerosol fouling layer is computed based on diffusiophoresis, settling and impaction mechanisms. The gas mixture (steam plus NC) thermal resistance is formulated based on a diffusion layer modeling. Finally, this paper presents a Montecarlo method implemented in the FORTRAN code TAEROSOL that is able to compute the amount of aerosol mass that is deposited by impaction on the top of the finned tubes. The model results are compared with the available experimental data of the CONGA European project

  1. Analysis of steam condensation in APR1400 IRWST for loss of coolant accident

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Young Suk

    2006-02-15

    The In-Containment Refueling Water Storage Tank (IRWST) of APR1400 is installed at the bottom of containment building to promote the plant safety functions during an accident. This design feature brings about uncertainty factors which may necessitate conventional prediction of temperature and pressure of containment building improved or revised when an accident occurs. The hot steam which is released from RCS break enters the IRWST through four Pressure Relief Dampers (PRDs). It is expected to be condensed with water stored in IRWST, in which water is colder than incoming steam. The purpose of this study is to investigate the influence of IRWST and pressure relief damper on back pressure and temperature in APR1400 containment codes such as CONTEMPT-LT and GOTHIC. The comparison of codes showed that GOTHIC code be more appropriate for the prediction of containment pressure and temperature under the condition of steam condensation occurring in confined water pool. Especially, the GOTHIC has superior capability to treat multi-compartmentalized geometry This study developed one-compartment (single) model, two-compartment (separated) model, and three-dimension (3-D) model, respectively. Two compartment model separates the IRWST from the other containment compartments. In 3-D model, only the IRWST is nodalized with Cartesian modeling. The single model is developed for comparison with two-compartment model which can analyze PRD's influence. The separated model for predicting PRD's influence divides the space between containment and IRWST. 3-D model for IRWST was generated because it is not symmetric considering location of sparger, pump, and suction sump. Therefore, IRWST is simulated with not only detailed three-dimensional behavior but also independent flow paths for four PRDs. Many experimental studies for the direct-contact heat transfer in stratified steam water flows, cocurrent or countercurrent, have been performed (Segev et al., 1981; Lim et al., 1981

  2. Analysis of steam condensation in APR1400 IRWST for loss of coolant accident

    International Nuclear Information System (INIS)

    Oh, Young Suk

    2006-02-01

    The In-Containment Refueling Water Storage Tank (IRWST) of APR1400 is installed at the bottom of containment building to promote the plant safety functions during an accident. This design feature brings about uncertainty factors which may necessitate conventional prediction of temperature and pressure of containment building improved or revised when an accident occurs. The hot steam which is released from RCS break enters the IRWST through four Pressure Relief Dampers (PRDs). It is expected to be condensed with water stored in IRWST, in which water is colder than incoming steam. The purpose of this study is to investigate the influence of IRWST and pressure relief damper on back pressure and temperature in APR1400 containment codes such as CONTEMPT-LT and GOTHIC. The comparison of codes showed that GOTHIC code be more appropriate for the prediction of containment pressure and temperature under the condition of steam condensation occurring in confined water pool. Especially, the GOTHIC has superior capability to treat multi-compartmentalized geometry This study developed one-compartment (single) model, two-compartment (separated) model, and three-dimension (3-D) model, respectively. Two compartment model separates the IRWST from the other containment compartments. In 3-D model, only the IRWST is nodalized with Cartesian modeling. The single model is developed for comparison with two-compartment model which can analyze PRD's influence. The separated model for predicting PRD's influence divides the space between containment and IRWST. 3-D model for IRWST was generated because it is not symmetric considering location of sparger, pump, and suction sump. Therefore, IRWST is simulated with not only detailed three-dimensional behavior but also independent flow paths for four PRDs. Many experimental studies for the direct-contact heat transfer in stratified steam water flows, cocurrent or countercurrent, have been performed (Segev et al., 1981; Lim et al., 1981; Kim and

  3. Preliminary condensation pool experiments with steam using DN80 and DN100 blowdown pipes[VIDEO CAMERAS

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M. [Lappeenranta University of Technology (Finland)

    2004-03-01

    The report summarizes the results of the preliminary steam blowdown experiments. Altogether eight experiment series, each consisting of several steam blows, were carried out in autumn 2003 with a scaled-down condensation pool test rig designed and constructed at Lappeenranta University of Technology. The main purpose of the experiments was to evaluate the capabilities of the test rig and the needs for measurement and visualization devices. The experiments showed that a high-speed video camera is essential for visual observation due to the rapid condensation of steam bubbles. Furthermore, the maximum measurement frequency of the current combination of instrumentation and data acquisition system is inadequate for the actual steam tests in 2004. (au)

  4. Estimation of the Influence of Operational Factors on the Oxygen Content of the Turbine Condensate at the Outlet from the Condenser of Steam Turbine

    Directory of Open Access Journals (Sweden)

    Shempelev A. G.

    2017-08-01

    Full Text Available The aim of the article is to analyze the influence of different factors on the oxygen content in the condensate using the example of the condenser of the steam turbine unit T-110/120-130. For the first time, the authors of the article analyze in details how the basic parameters of the condenser's operation (the condenser heat load, the flow and temperature of the cooling water, the air inflow in the condenser, the condition of the heat exchange surface influence the oxygen content of the condensate. The authors come to the conclusion that with standard air inflow in the vacuum system, the equilibrium oxygen content, which corresponds to the norms in the condensate at the condenser outlet, is only possible in its operation modes when the steam flow to the condenser is more than 50% of the nominal flow and cooling water temperatures are equal to or greater than calculated for this type of condenser. The conclusions are confirmed by the experimental material. The results of the research are the basis for the development of measures aimed to increase the deaerating capacity of condensers depending on specific operating conditions.

  5. Effect of condenser water in-leakage on steam generator water chemistry

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.

    1978-01-01

    Corrosive environments may be generated within steam genrators from condenser cooling water in-leakage. Theoretical as well as experimental evaluation of the aggressiveness of such environments is being carried out for the condenser-cooling waters used at CANDU-PHW nuclear power stations. Calculations have shown that highly concentrated chloride solutions - acidic in the case of sea-water in-leakage, and alkaline in the rest of the cases considered - would be produced within the steam generator. Experiments in a model boiler showed that sea-water in-leakage caused rapid corrosion of carbon steel components when only AVT (all volatile treatment) was used for water chemistry control. Use of a non-volatile reagent, as in the congruent phosphate treatment, avoided the rapid corrosion of carbon steel. On the basis of our studies, congruent phosphate treatment during sea water in-leakage appears desirable. (author)

  6. Condensation of steam in horizontal pipes: model development and validation

    International Nuclear Information System (INIS)

    Szijarto, R.

    2015-01-01

    This thesis submitted to the Swiss Federal Institute of Technology ETH in Zurich presents the development and validation of a model for the condensation of steam in horizontal pipes. Condensation models were introduced and developed particularly for the application in the emergency cooling system of a Gen-III+ boiling water reactor. Such an emergency cooling system consists of slightly inclined horizontal pipes, which are immersed in a cold water tank. The pipes are connected to the reactor pressure vessel. They are responsible for a fast depressurization of the reactor core in the case of accident. Condensation in horizontal pipes was investigated with both one-dimensional system codes (RELAP5) and three-dimensional computational fluid dynamics software (ANSYS FLUENT). The performance of the RELAP5 code was not sufficient for transient condensation processes. Therefore, a mechanistic model was developed and implemented. Four models were tested on the LAOKOON facility, which analysed direct contact condensation in a horizontal duct

  7. Cold leg condensation tests. Task C. Steam--water interaction tests

    International Nuclear Information System (INIS)

    Brodrick, J.R.; Loiselle, V.

    1974-03-01

    A report is presented of tests to determine the condensation efficiency of ECC water injected into a quality fluid mixture flowing through the cold leg. In particular, a specific objective was to determine if the mixture of ECC water and quality fluid reached thermodynamic equilibrium before exiting the cold leg. Further, the stability of the ECC water/quality fluid interaction would be assessed by interpretation of thermocouple records and utilization of a section of cold leg piping with view ports to film the interaction whenever possible. The cold leg condensation tests showed complete condensation of the 5 lbm/sec steam quality mixtures in the cold leg by the ECC water flows of the test matrix. The cold leg exit fluid temperature remained below the saturation temperature and had good agreement with the predicted cold leg outlet temperature, calculated assuming total condensation. (U.S.)

  8. Steam condenser optimization using Real-parameter Genetic Algorithm for Prototype Fast Breeder Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jayalal, M.L., E-mail: jayalal@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Kumar, L. Satish, E-mail: satish@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Jehadeesan, R., E-mail: jeha@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Rajeswari, S., E-mail: raj@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Satya Murty, S.A.V., E-mail: satya@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Balasubramaniyan, V.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India)

    2011-10-15

    Highlights: > We model design optimization of a vital reactor component using Genetic Algorithm. > Real-parameter Genetic Algorithm is used for steam condenser optimization study. > Comparison analysis done with various Genetic Algorithm related mechanisms. > The results obtained are validated with the reference study results. - Abstract: This work explores the use of Real-parameter Genetic Algorithm and analyses its performance in the steam condenser (or Circulating Water System) optimization study of a 500 MW fast breeder nuclear reactor. Choice of optimum design parameters for condenser for a power plant from among a large number of technically viable combination is a complex task. This is primarily due to the conflicting nature of the economic implications of the different system parameters for maximizing the capitalized profit. In order to find the optimum design parameters a Real-parameter Genetic Algorithm model is developed and applied. The results obtained are validated with the reference study results.

  9. Steam condenser optimization using Real-parameter Genetic Algorithm for Prototype Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Jayalal, M.L.; Kumar, L. Satish; Jehadeesan, R.; Rajeswari, S.; Satya Murty, S.A.V.; Balasubramaniyan, V.; Chetal, S.C.

    2011-01-01

    Highlights: → We model design optimization of a vital reactor component using Genetic Algorithm. → Real-parameter Genetic Algorithm is used for steam condenser optimization study. → Comparison analysis done with various Genetic Algorithm related mechanisms. → The results obtained are validated with the reference study results. - Abstract: This work explores the use of Real-parameter Genetic Algorithm and analyses its performance in the steam condenser (or Circulating Water System) optimization study of a 500 MW fast breeder nuclear reactor. Choice of optimum design parameters for condenser for a power plant from among a large number of technically viable combination is a complex task. This is primarily due to the conflicting nature of the economic implications of the different system parameters for maximizing the capitalized profit. In order to find the optimum design parameters a Real-parameter Genetic Algorithm model is developed and applied. The results obtained are validated with the reference study results.

  10. Steam condensation heat transfer in the presence of noncondensables in a vertical tube of passive containment cooling system

    International Nuclear Information System (INIS)

    Park, Hyun Sik

    1999-02-01

    A database for laminar condensation heat transfer is constructed from the previous experimental data at various condensation conditions. Based on the database, the condensation models in the standard RELAP5/MOD3.2 code are assessed and improved. Two wall film condensation models, the default and the alternative, are used in RELAP5/MOD3.2. The default model of the laminar film condensation in RELAP5/MOD3.2 does not give any reliable predictions, and its alternative model always predicts higher values than the experimental data. Therefore, it is needed to develop a new correlation based on the experimental data of various operating ranges. A set of condensation experiments in the presence of noncondensable gas in a vertical tube of the passive containment cooling system of the CP-1300 are performed. The experimental results show that the heat transfer coefficients (HTCs) increase as the inlet air mass fraction decreases and the inlet saturated steam temperature decreases. However, the dependence of the inlet mixture Reynolds number on the HTC is small for the operating range. An empirical correlation is developed, and its predictions are compared with experimental data to show good agreement with the standard deviation of 22.3%. The experimental HTCs are also compared with the predictions from the default and the alternative models used in RELAP5/MOD3.2. The experimental apparatus is modeled with two wall-film condensation models in RELAP5/MOD3.2 and the empirical correlation, and simulations are performed for several subtests to be compared with the experimental results. Overall, the simulation results show that the default model of RELAP5/MOD3.2 underpredicts the HTCs, and the alternative model overpredicts them, while the empirical correlation predicts them well throughout the condensing tube. Both the nodalization study and the sensitivity study are also performed. The nodalization study shows that the variation of the node number does not change both modeling

  11. Experimental investigation of condensation and mixing during venting of a steam / non-condensable gas mixture into a pressure suppression pool

    Energy Technology Data Exchange (ETDEWEB)

    De Walsche, C.; Cachard, F. de

    2000-07-01

    Experiments have been performed in the LINX facility to investigate condensation and mixing phenomena in pressure Suppression Pools (SPs), in the context of the European Simplified Boiling Water Reactor (ESBWR) study. As a contribution to the TEPSS project of the 4th European Framework Programme, eight medium-scale, separate-effect tests were carried out in which constant steam/air flow rates were injected below the surface of a two-metre diameter water pool, maintained at constant pressure, through a large downward vent. The vessel pressure was regulated, the pool temperature rising until equilibrium conditions with the incoming gas were reached. The SP temperature distribution was measured, as well as the inlet and outlet gas flow rates, and the overall condensation rate was estimated using mass and heat balances. The test matrix was based on steam mass floret and air mass fraction of the injected gas, the vent immersion depth, and the vessel pressure. Overall, the condensation was shown to be efficient for all tests performed, even for high non-condensable gas concentrations of the injected gas. Thermal stratification above the vent outlet was shown to be moderate. The tests performed allowed a better understanding to be gained of the mechanisms of condensation and mixing in the SP and Wetwell, and results were incorporated into an ORACLE database, to be used for further model development. (authors)

  12. Visualization of cross-sectional flow structure during condensation of steam in a slightly inclined horizontal tube

    Energy Technology Data Exchange (ETDEWEB)

    Puseya, Andree; Kim, H. [Kyung Hee University, Yongin (Korea, Republic of); Kwon, T. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    These flow characteristics called flow patterns still depend on a proper visualization technique in order to identify such local distribution. These proper distributions will have a dependence on the inclination of the tube as well, as it was demonstrated by Lips and Mayer. This work is focused on presenting an experimental investigation to visualize the cross sectional two-phase flow structure for condensation of steam in a horizontal tube and identify the liquid-gas interface using the axial-viewing technique. This innovative technique developed by Hewitt and more recently used in visualization works by Badie, permits the achievement to identify those systems in the area of interest by looking directly into the two-phase flow system during condensation of steam inside a pipe with technology such a high speed camera. An experimental work to visualize and locate the liquid-gas interface for steam condensation in horizontal tubes with slightly inclination was developed on this research The experimental results shows that the axial viewing technique works well with condensation phenomena and can be used for further developments in the field such as determination of liquid film geometry and calculation of void fraction.

  13. Statistical evaluation of steam condensation loads in pressure suppression pool, (1)

    International Nuclear Information System (INIS)

    Kukita, Yutaka; Takeshita, Isao; Namatame, Ken; Shiba, Masayoshi; Kato, Masami; Moriya, Kumiaki.

    1981-10-01

    The LOCA steam condensation loads in the BWR pressure suppression pool was evaluated with use of the test data obtained in the first eight tests of the JAERI Full-Scale Mark II CRT Program. Through this evaluation, finite desynchronization between the vent pressures during the chugging and the condensation oscillation phases was identified and quantified. The characteristics of the pressure oscillation propagation through the vent pipe and in the pool water, the fluid-structure-interaction (FSI) effects on the pool pressure loads, and the characteristics of the vent lateral loads were also investigated. (author)

  14. Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (13) Study on Heat Transfer of Direct Condensation of Steam on Subcooled Water Jet

    International Nuclear Information System (INIS)

    Yuhki Takahashi; Yasuo Koizumi; Hiroyasu Ohtake; Tohru Miyashita; Michitsugu Mori

    2006-01-01

    Characteristics of thermal-hydraulic phenomena in the steam injector were examined. In experiments, a water jet from a nozzle of 5 mm diameter flowed into the condensing test section pipe concentrically. The inner diameter of the condensing section was 7, 10, or 20 mm and the length was 105 mm. Steam flowed into the peripheral space between the water jet and the inner wall of the test section and condensed on the ware jet surface. The radial and the axial distributions of velocity and temperature of the water jet were measured. Analyses by using the STAR-CD code were also performed. The temperature measured in the central portion of the water jet was higher than the predicted assuming the ordinary turbulent flow in a pipe. The temperature measured in the peripheral region was lower than the predicted. The radial temperature distribution measured was flatter than the predicted. When the steam condensation rate was large, the measured radial velocity distribution in the water jet was flatter than the predicted. In the case that the steam velocity was quite high, the velocity measured in the peripheral region was higher than that in the center portion. These results implied that the steam condensing on the water jet brought momentum in the water jet to result in more effective radial transport of heat and momentum. The STAR-CD code analyses to allow the interface between the wall that simulated the steam flow part and the water flow that stood for the water jet to move, i.e. creating momentum in-flux at the water jet interface, provided better results to support the experimental results. To increase the interfacial friction had a minor effect on the radial velocity distribution in the tested range. (authors)

  15. Experimental and analytical study of intermittency in direct contact condensation of steam in a cross-flow of water

    NARCIS (Netherlands)

    Clerx, N.; Geld, van der C.W.M.

    2009-01-01

    The topology of a condensing steam jet, at low steam mass fluxes, injected in a cross-flow of water has been investigatedexperimentally for various conditions (system pressure around 3 bar). The intermittent character of the steam pocket growthand collapse clearly appeared from the high speed

  16. Check of condition of steam generators, volume compensators and turbine condensers in nuclear power plants

    International Nuclear Information System (INIS)

    Matal, O.; Klinga, J.; Holy, F.; Sobotka, J.

    1989-01-01

    A negative pressure leak detector is described designed for leak testing of tubes in steam generators and steam turbine condensers. The principle, operation and use are described of inflatable bags and an inflatable platform. The bags are designed for insulating and sealing spaces in nuclear reactor components while the inflatable platform is used in pressurizer inspections and repairs. Their properties, and other facilities for detecting leaks in steam generator tubes are briefly described. (M.D.). 3 figs

  17. Study of condensation heat transfer following a main steam line break inside containment

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J.H.; Elia, F.A. Jr.; Lischer, D.J. [Stone & Webster Engineering Corporation, Boston, MA (United States)

    1995-09-01

    An alternative model for calculating condensation heat transfer following a main stream line break (MSLB) accident is proposed. The proposed model predictions and the current regulatory model predictions are compared to the results of the Carolinas Virginia Tube Reactor (CVTR) test. The very conservative results predicted by the current regulatory model result from: (1) low estimate of the condensation heat transfer coefficient by the Uchida correlation and (2) neglecting the convective contribution to the overall heat transfer. Neglecting the convection overestimates the mass of steam being condensed and does not permit the calculation of additional convective heat transfer resulting from superheated conditions. In this study, the Uchida correlation is used, but correction factors for the effects of convection an superheat are derived. The proposed model uses heat and mass transfer analogy methods to estimate to convective fraction of the total heat transfer and bases the steam removal rate on the condensation heat transfer portion only. The results predicted by the proposed model are shown to be conservative and more accurate than those predicted by the current regulatory model when compared with the results of the CVTR test. Results for typical pressurized water reactors indicate that the proposed model provides a basis for lowering the equipment qualification temperature envelope, particularly at later times following the accident.

  18. Theoretical modeling of steam condensation in the presence of a noncondensable gas in horizontal tubes

    International Nuclear Information System (INIS)

    Lee, Kwon-Yeong; Kim, Moo Hwan; Kim, Moo Hwan

    2008-01-01

    A theoretical model was developed to investigate a steam condensation with a noncondensable gas in a horizontal tube. The heat transfer through the vapor/noncondensable gas mixture boundary layer consists of the sensible heat transfer and the latent heat transfer given up by the condensing vapor, and it must equal that from the condensate film to the tube wall. Therefore, the total heat transfer coefficient is given by the film, condensation and sensible heat transfer coefficients. The film heat transfer coefficients of the upper and lower portions of the tube were calculated separately from Rosson and Meyers (1965) correlation. The heat and mass transfer analogy was used to analyze the steam/noncondensable gas mixture boundary layer. Here, the Nusselt and Sherwood numbers in the gas phase were modified to incorporate the effects of condensate film roughness, suction, and developing flow. The predictions of the theoretical model for the experimental heat transfer coefficients at the top and bottom of the tube were reasonable. The calculated heat transfer coefficients at the top of the tube were higher than those at the bottom of it, as experimental results. As the temperature potential at the top of tube was lower than that at the bottom of it, the heat fluxes at the upper and lower portions of the tube were similar to each other. Generally speaking, however, the model predictions showed a good agreement with experimental data. The new empirical correlation proposed by Lee and Kim (2008) for the vertical tube was applied to the condensation of steam/noncondensable mixture in a horizontal tube. Nusselt theory and Chato correlation were used to calculate the heat transfer coefficients at top and bottom of the horizontal tube, respectively. The predictions of the new empirical correlation were good and very similar with the theoretical model. (author)

  19. Alkalization of steam and condensate with 2-amino-1-butanol and hydrazine; Alkalisering av aanga och kondensat med butanolamin och hydrazin

    Energy Technology Data Exchange (ETDEWEB)

    Falk, I [Studsvik Material AB, Nykoeping (Sweden)

    1996-04-01

    To maintain a low corrosion level in steam- and condensate systems at power and industrial plants, an alkalization of the steam is needed. A low corrosion level lowers the risk of operation disturbances and reduces the cost of the condensate clean up. A better knowledge in the behavior of the alkalis will improve the possibilities to avoid the corrosion attacks. In this work experimental measurements have been carried out during steam boiler conditions as temperature, continuous steam generation and condensation. It has been found that the volatility of 2-amino-1-butanol is very low during stationary dynamic conditions at 250 deg C and 120 deg C. To achieve a high ph-value in the final condensate a very high concentration of 2-amino-1-butanol is thus needed especially when the steam contains acidic compounds. The alkalization effect is obtained from ammonia which is created by thermal decomposition of hydrazine in the boiler water. It is necessary to carry out experimental investigations showing the thermal stability of organic compounds in boiler water before it is possible to recommend them as better volatile alkalis than ammonia and hydrazine. 6 refs, 13 figs

  20. Condensation induced water hammer in steam generators

    International Nuclear Information System (INIS)

    Jones, O.C. Jr.; Saha, P.; Wu, B.J.C.; Ginsberg, T.

    1979-06-01

    The case of condensation induced water hammer in nuclear steam generators is summarized, including both feed ring-type and economizer-type geometries. A slug impact model is described and used to demonstrate the parametric dependence of the impact pressures on heat transfer rates, initial pressures, and relative initial slug and void lengths. The results of the parametric study are related also to the economizer geometry and a suggested alternative model is presented. The importance of concerns regarding attenuation of shocks in two-phase media is delineated, and a simple experiment is described which was used to determine negligible attenuation within the accuracy of the experiment for void fractions up to over 30% in bubbly and slug flows

  1. MELCOR simulation of steam condensation effect on hydrogen behavior in THAI HM-2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seongnyeon; Lee, Jung-Jae; Cho, Yong-Jin [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of)

    2015-10-15

    In this study, MELCOR simulation was carried out for THAI HM-2 experiment of OECD. As a results, stratification of hydrogen cloud was reasonably captured in MELCOR simulation. Furthermore, the pressure from simulation results in cases where mass transfer coefficient of MELCOR condensation model was modified was good agreement with the experimental results. Containment Filtered Ventilation System (CFVS) has been introduced as facility to prevent containment failure during severe accident. However, possibility of hydrogen risk has been issued due to inflow of hydrogen, condensation and removal of steam and complicated inner structure in CFVS. Preferentially benchmark work for THAI HM-2 experiment of OECD was decided to validate the methodology before detailed assessment of hydrogen risk in CFVS. The objectives of THAI HM-2 experiment were evaluation of hydrogen behavior, verification of numerical analysis tools and so on. In this paper, therefore, MELCOR simulation was carried out in comparison with the experiment results. Additionally, steam condensation effect was considered for detailed simulation. Hydrogen concentration from MELCOR results was underestimated in comparison to the experimental results.

  2. Determination of moisture content in steams and variation in moisture content with operating boiler level by analyzing sodium content in steam generator water and steam condensate of a nuclear power plant using ion chromatographic technique

    International Nuclear Information System (INIS)

    Pal, P.K.; Bohra, R.C.

    2015-01-01

    Dry steam with moisture content less than <1% is the stringent requirements in a steam generator for good health of the turbine. In order to confirm the same, determination of sodium is done in steam generator water and steam condensate using Flame photometer in ppm level and ion chromatograph in ppb level. Depending on the carry over of sodium in steam along with the water droplet (moisture), the moisture content in steam was calculated and was found to be < 1% which is requirements of the system. The paper described the salient features of a PHWR, principle of Ion Chromatography, chemistry parameters of Steam Generators and calculation of moisture content in steam on the basis of sodium analysis. (author)

  3. Preventive testing and leakage detection in pipe-lines of steam condensers and generators of a PWR type reactor

    International Nuclear Information System (INIS)

    Canalini, A.; Carvalho, N.C. de

    1985-01-01

    The non-destructive methods: Spum, Helium and Hydrostatic used in leakage detection in condenser pipelines for PWR type reactors are presented. The time, costs, sensitivity, resources necessary and personnel development factors are considered to choose adequated method, in function of nuclear power plant conditions. The leakage tests are applied in pressurized systems or vacuum. Eddy Current testing is used in condensers and steam generators aiming to avoid leakage in these equipments. The spume testing for leakage detection in condenser pipelines - which operation - and hydrostatic testing for leakage detection through reaming with shutdown - were most efficients. The Helium testing applied in pressurized systems or submitted to vacuum systems presented satisfactory results. The Eddy Current testing in condenser and steam generator pipelines reached desired objective, reducing leakage in the first and preserving the integrity in the second. (M.C.K.) [pt

  4. Transition from annular flow to plug/slug flow in condensation of steam in microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Xiaojun; Cheng, Ping; Wu, Huiying [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2008-02-15

    A visualization study has been conducted to investigate the transition from annular flow to plug/slug flow in the condensation of steam in two different sets of parallel microchannels, having hydraulic diameters of 90 {mu}m and 136 {mu}m, respectively. The steam in the parallel microchannels was cooled on the bottom by forced convection of water and by natural convection of air from the top. It is found that the location, where the transition from annular flow to plug/slug flow takes place, depends on mass flux and cooling rate of steam. The effects of mass flux and cooling rate on the occurrence frequency of the injection flow in a single microchannel, having a hydraulic diameter of 120 {mu}m and 128 {mu}m, respectively, are investigated. It is found that two different shapes of injection flow occur in the smooth annular flow in microchannels: injection flow with unsteady vapor ligament occurring at low mass flux (or high cooling rate) and injection flow with steady vapor ligament occurring at high mass flux (or low cooling rate). It is also found that increase of steam mass flux, decrease of cooling rate, or decrease of the microchannel diameter tends to enhance instability of the condensate film on the wall, resulting in occurrence of the injection flow further toward the outlet with an increase in occurrence frequency. (author)

  5. The once-through mode of steam generator reflux condensation in loss of coolant accident scenarios

    International Nuclear Information System (INIS)

    Liao, Y.; Guentay, S.; Suckow, D.

    2009-01-01

    The once-through mode of steam generator reflux condensation in the presence of noncondensable gases and/or aerosols for LOCA scenarios is introduced. This phenomenon is planned to be investigated at Paul Scherrer Institute in the ARTIST/RFLX experimental program. The plausible accident scenarios associated with the once-through reflux condensation are analyzed with MELCOR to study the safety significance and the boundary conditions of this phenomenon. This work presents the recent PSI experimental and analytical work on reflux condensation: the progress of modification to the ARTIST test facility for the purpose to study reflux condensation, and the analytical model for the once-through reflux condensation in the presence of noncondensable gas using the heat and mass transfer analogy approach. Future experimental and analytical work on reflux condensation is also outlined. (author)

  6. Comparison of Heat Transfer Coefficients of Silver Coated and Chromium Coated Copper Tubes of Condenser in Dropwise Condensation

    OpenAIRE

    Er. Shivesh Kumar; Dr. Amit Kumar

    2016-01-01

    Since centuries steam is being used in power generating system. The steam leaving the power unit is reconverted into water in a condenser designed to transfer heat from the steam to the cooling water as rapidly and as efficiently as possible. The efficiency of condenser depends on rate of condensation and mode of condensation of steam in the condenser. The increase in efficiency of the condenser enhances the heat transfer co-efficient which in turn results in economic design of condenser and ...

  7. Process and device for accelerating condensation of the steam produced during an accident from the pressure vessel of a water cooled nuclear reactor

    International Nuclear Information System (INIS)

    Schnitker, W.

    1980-01-01

    In case of an accident, the steam from the PWR is taken away via lances under the water surface of the condensation area. In order to accelerate condensation, water is added via pipes projecting sideways into the lances. The kinetic energy of the steam carries the water over and produces a fog. (DG) [de

  8. Process and device for accelerating condensation of the steam produced during an accident from the pressure vessel of a water cooled nuclear reactor

    International Nuclear Information System (INIS)

    Schnitker, W.

    1981-01-01

    In case of an accident, the steam from the PWR is taken away via lances under the water surface of the condensation area. In order to accelerate condensation, water is added via pipes projecting sideways into the lances. The kinetic energy of the steam carries the water over and produces a fog. (orig./PW)

  9. Device for the condensation of pressurized steam and its application to the cooling of a nuclear reactor after an incident

    International Nuclear Information System (INIS)

    Dagard, P.; Couturier, M.

    1989-01-01

    This document describes an invention which relates to a device for condensation of pressurized water which is at a pressure considerably above atmospheric pressure, such as the steam produced by the steam generator of a pressurized-water nuclear reactor during the cooling of the reactor after an incident. The purpose of the invention is therefore to propose a device for the condensation of steam which is under a pressure which is considerably higher than atmospheric pressure by cooling this circulating steam as a result of contact with a heat-exchange wall which is cooled by water; such a device should be easy to install in a nuclear power plant to ensure passive cooling of the reactor, it should have a very good efficiency because of efficient heat exchangers, and it should require only a limited amount of cooling water in the equipment itself

  10. Description of steam condensation phenomena during the loss-of-coolant accident

    International Nuclear Information System (INIS)

    McCauley, E.W.; Holman, G.S.; Aust, E.; Furst, H.; Schwan, H.; Vollbrandt, J.

    1981-01-01

    Study of results from the full scale multivent pressure suppression experiment conducted by the GKSS Laboratory has developed an improved understanding of the dynamic, oscillatory steam condensation events and related loading functions which occur during the hypothetical loss-of-coolant accident in a boiling water nuclear reactor. Due to the unique measurements systems which combines both cinematic and digital data, qualified correlation between the dynamic physical variables and the associated two-phase thermo-hydraulic phenomena has been obtained

  11. Steam purity in PWRs

    International Nuclear Information System (INIS)

    Hopkinson, J.

    1982-01-01

    Impurities enter the secondary loop of the PWR through both makeup water from lake or well and cooling-water leaks in the condenser. These impurities can be carried to the steam generator, where they cause corrosion deposits to form. Corrosion products in steam are swept further through the system and become concentrated at the point in the low-pressure turbine where steam begins to condense. Several plants have effectively reduced impurities, and therefore corrosion, by installing a demineralizer for the makeup water, a resin-bed system to clean condensed steam from the condenser, and a deaerator to remove oxygen from the water and so lower the risk of system metal oxidation. 5 references, 1 figure

  12. Tamarugite in the Steam-Condensate Alteration Paragenesis in Diana Cave (SW Romania)

    Science.gov (United States)

    Puscas, C. M.; Onac, B. P.; Effenberger, H. S.; Povară, I.

    2012-12-01

    The double-salt hydrate tamarugite [NaAl(SO4)2 6H2O] is an uncommon mineral in the cave environment, forming as a result of chemical reactions between water and bedrock only under very specific conditions. The Diana Cave hosts a unique tamarugite occurrence, the first one to be reported from a typical karst environment. The cave is located within the limits of Băile Herculane township in the Cerna Mountains, SW Romania. It consists of a 14 m long, westward-oriented single passage, developed along the Diana Fault. In 1974 a concrete-clad mine gallery was created to channel the thermal water (Diana 1+2 Spring) flowing through the cave to a pumping station. The spring's chemical and physical parameters fluctuated through time, averaging 51.98° C, discharge of 0.96 Ls-1, pH of 7.46, 5768.66 ppm TDS, 9303 μScm-1 conductivity, 5.02 salinity. The major chemical components of the thermo-mineral water in Diana Cave are, Na+ (1392.57 ppm), K+ (58.55 ppm), Ca2+ (725.16 ppm), Mg2+ (10.78 ppm), Cl- (3376.83 ppm), and SO42- (92.27 ppm), and H2S (24.05 ppm), with traces of Si, Fe2+, Br+, I-, and Li+. The general air circulation pattern within the cave is fairly simple: cold air from the outside sweeps into the cave along the floor, heats up at the contact with the thermo-mineral water, ascends, and exists the cave along the ceiling. At the contact with the cold walls of the Diana Cave, the hot steam condenses and gives rise to a rich and exotic sulfate-mineral paragenesis (including halotrichite-series minerals, gypsum, bassanite, anhydrite, epsomite, alunite, halite, native sulfur, etc.). The most exotic minerals precipitate at or below the contact between the Tithonic - Neocomian limestone and the overlaying Cretaceous shaly limestone, as a result of steam-condensate alteration. Minerogenetic mechanisms responsible for the peculiar sulfate mineral assemblage in Diana Cave are evaporation, oxidation, hydrolysis, double exchange reactions, and deposition from vapours or

  13. An analysis direct-contact condensation in horizontal cocurrent stratified flow of steam and cold water

    International Nuclear Information System (INIS)

    Lee, Suk Ho; Kim, Hho Jung

    1992-01-01

    The physical benchmark problem on the direct-contact condensation under the horizontal cocurrent stratified flow was analyzed using the RELAP5/MOD2 and /MOD3 one-dimensional model. Analysis was performed for the Northwestern experiments, which involved condensing steam/water flow in a rectangular channel. The study showed that the RELAP5 interfacial heat transfer model, under the horizontal stratified flow regime, predicted the condensation rate well though the interfacial heat transfer area was underpredicted. However, some discrepancies in water layer thickness and local heat transfer coefficient with experimental results were found especially when there is a wavy interface, and those were satisfied only within the range. (Author)

  14. Experimental Investigation of Operation of VVER Steam Generator in Condensation Mode in the Event of the Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Andrey [Institute for Physics and Power Engineering by A.I. Leypunsky, 1 Bondarenko sq. Obninsk, 249033 (Russian Federation)

    2008-07-01

    For new Russian nuclear power plants with VVER-1200 reactor in the event of a beyond design basis accident, provision is made for the use of passive safety systems for necessary core cooling. These safety systems include the passive heat removal system (PHRS). In the case of leakage in the primary circuit this system assures the transition of steam generators (SG) to operation in the mode of condensation of the primary circuit steam. As a result, the condensate from SG arrives at the core providing its additional cooling. To investigate the condensation mode of VVER SG operation, a large scale HA2M-SG test facility was constructed. The rig incorporates: buffer tank, SG model with scale is 1:46, PHRS heat exchanger. Experiments at the test facility have been performed to investigate condensation mode of operation of SG model at the pressure 0.4 MPa, correspond to VVER reactor pressure at the last stage of the beyond design basis accident. The report presents the test procedure and the basic obtained test results. (authors)

  15. A Study on Condensation Heat Transfer at the Exterior Surface of S.A.M. Coated Titanium Tube Using in Steam Condensers

    Energy Technology Data Exchange (ETDEWEB)

    Im, Sung-Gu; Lee, Sang-Hyup; Ji, Dae-Yun; Park, Hyun-Gyu; Lee, Kwon-Yeong [Handong Global University, Pohang (Korea, Republic of)

    2016-10-15

    Condensation occurs when the temperature of a steam is reduced below its saturation temperature. There exist two forms of condensation on cooling surface: dropwise, and film condensations. Usually, dropwise condensation has a better heat transfer performance than film condensation, but it has limit of short period. Ma et al. executed heat transfer experiment in dropwise condensation with non-condensable gas, and studied how the amount of air and pressure difference affect condensation heat transfer coefficient. The more non-condensable gas exist, the condensation heat transfer coefficient is decreased. As a result, surface modified brass tube and stainless tube showed higher condensation heat transfer coefficient as much as 1.3 and 1.4 times comparing with their bare tubes in 70 kPa vacuum condition respectively. Most of power plants use sea water as coolant, so the surface of metal tubes could be corroded by the coolant. We had researched an experimental study related to condensation heat transfer on surface modified titanium tube. Our experimental facility was designed to show how two kinds of tube's heat transfer performances are different in a same condition. We changed the range of saturation pressure and coolant flow rate to observe tube's performance change. When saturation pressure and coolant flow rate increase, overall heat transfer coefficients were increased. When residue of non-condensable gases was decreased, the overall heat transfer coefficients were increased. S.A.M. coated tube's overall heat transfer coefficients were lower than those of bare tube, because the droplets didn't have a tendency of frequently falling down.

  16. Wireless Monitoring of the Height of Condensed Water in Steam Pipes

    Science.gov (United States)

    Lee, Hyeong Jae; Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Dingizian, Arsham; Takano, Nobuyuki; Blosiu, Julian O.

    2014-01-01

    A wireless health monitoring system has been developed for determining the height of water condensation in the steam pipes and the data acquisition is done remotely using a wireless network system. The developed system is designed to operate in the harsh environment encountered at manholes and the pipe high temperature of over 200 °C. The test method is an ultrasonic pulse-echo and the hardware includes a pulser, receiver and wireless modem for communication. Data acquisition and signal processing software were developed to determine the water height using adaptive signal processing and data communication that can be controlled while the hardware is installed in a manhole. A statistical decision-making tool is being developed based on the field test data to determine the height of in the condensed water under high noise conditions and other environmental factors.

  17. Effect of non-condensable gas on heat transfer in steam turbine condenser and modelling of ejector pump system by controlling the gas extraction rate through extraction tubes

    International Nuclear Information System (INIS)

    Strušnik, Dušan; Golob, Marjan; Avsec, Jurij

    2016-01-01

    Graphical abstract: Control of the amount of the pumped gases through extraction tubes. The connecting locations interconnect the extraction tubes for STC gas pumping. The extraction tubes are fitted with 3 control valves to control the amount of the pumped gas depending on the temperature of the pumped gas. The amount of the pumped gas increases through the extraction tubes, where the pumped gases are cooler and decreases, at the same time, through the extraction tubes, where the pumped gases are warmer. As a result, pumping of a larger amount of NCG is ensured and of a smaller amount of CG, given that the NCG concentration is the highest on the colder places. This way, the total amount of the pumped gases from the STC can be reduced, the SEPS operates more efficiently and consumes less energy for its operation. - Highlights: • Impact of non-condensable gas on heat transfer in a steam turbine condenser. • The ejector system is optimised by selecting a Laval nozzle diameter. • Simulation model of the control of the amount of pumped gases through extraction tubes. • Neural network and fuzzy logic systems used to control gas extraction rate. • Simulation model was designed by using real process data from the thermal power plant. - Abstract: The paper describes the impact of non-condensable gas (NCG) on heat transfer in a steam turbine condenser (STC) and modelling of the steam ejector pump system (SEPS) by controlling the gas extraction rate through extraction tubes. The ideal connection points for the NCG extraction from the STC are identified by analysing the impact of the NCG on the heat transfer and measuring the existing system at a thermal power plant in Slovenia. A simulation model is designed using the Matlab software and Simulink, Neural Net Work, Fuzzy Logic and Curve Fitting Toolboxes, to control gas extraction rate through extraction tubes of the gas pumped from the STC, thus optimising the operation of the steam ejector pump system (SEPS). The

  18. A Novel Method for Preparing Auxetic Foam from Closed-cell Polymer Foam Based on Steam Penetration and Condensation (SPC) Process.

    Science.gov (United States)

    Fan, Donglei; Li, Minggang; Qiu, Jian; Xing, Haiping; Jiang, Zhiwei; Tang, Tao

    2018-05-31

    Auxetic materials are a class of materials possessing negative Poisson's ratio. Here we establish a novel method for preparing auxetic foam from closed-cell polymer foam based on steam penetration and condensation (SPC) process. Using polyethylene (PE) closed-cell foam as an example, the resultant foams treated by SPC process present negative Poisson's ratio during stretching and compression testing. The effect of steam-treated temperature and time on the conversion efficiency of negative Poisson's ratio foam is investigated, and the mechanism of SPC method for forming re-entrant structure is discussed. The results indicate that the presence of enough steam within the cells is a critical factor for the negative Poisson's ratio conversion in the SPC process. The pressure difference caused by steam condensation is the driving force for the conversion from conventional closed-cell foam to the negative Poisson's ratio foam. Furthermore, the applicability of SPC process for fabricating auxetic foam is studied by replacing PE foam by polyvinyl chloride (PVC) foam with closed-cell structure or replacing water steam by ethanol steam. The results verify the universality of SPC process for fabricating auxetic foams from conventional foams with closed-cell structure. In addition, we explored potential application of the obtained auxetic foams by SPC process in the fabrication of shape memory polymer materials.

  19. High Temperature Monitoring the Height of Condensed Water in Steam Pipes

    Science.gov (United States)

    Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Widholm, Scott; Ostlund, Patrick; Blosiu, Julian

    2011-01-01

    An in-service health monitoring system is needed for steam pipes to track through their wall the condensation of water. The system is required to measure the height of the condensed water inside the pipe while operating at temperatures that are as high as 250 deg. C. The system needs to be able to make real time measurements while accounting for the effects of cavitation and wavy water surface. For this purpose, ultrasonic wave in pulse-echo configuration was used and reflected signals were acquired and auto-correlated to remove noise from the data and determine the water height. Transmitting and receiving the waves is done by piezoelectric transducers having Curie temperature that is significantly higher than 250 deg. C. Measurements were made at temperatures as high as 250 deg. C and have shown the feasibility of the test method. This manuscript reports the results of this feasibility study.

  20. Procedure for generating steam and steam generator for operating said procedure

    International Nuclear Information System (INIS)

    Chlique, Bernard.

    1975-01-01

    This invention concerns the generation of steam by bringing the water to be vaporised into indirect thermal exchange relation with the heating steam which condenses when passing in series, along alternate routes, through bundles of tubes immersed in a vaporising chamber. A number of steam generators working on this principle already exist. The purpose of the invention is to modify the operating method of these steam generators by means of a special disposition making it possible to build a compact unit including an additional bundle of tubes heated by the condensates collected at the outlet of each bundle through which the heating steam passes [fr

  1. Condensation heat transfer of steam on a single horizontal tube

    Science.gov (United States)

    Graber, K. A.

    1983-06-01

    An experimental apparatus was designed, constructed and instrumented in an effort to systematically and carefully study the condensation heat-transfer coefficient on a single, horizontal tube. A smooth, thick-walled copper tube of length 133.5 mm, with an outside diameter of 15.9 mm and an inside diameter of 12.7 mm was instrumented with six wall thermocouples. The temperature rise across the test section was measured accurately using quartz crystal thermometers. The inside heat-transfer coefficient was determined using the Sieder-Tate correlation with leading coefficient of 0.029. Initial steam side data were taken at atmospheric pressure to test the data acquisition/reduction computer programs.

  2. Investigations on the Steam Condensation in a Vertical Tube Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji-Hwan; Jerng, Dong-wook [Chung-Ang University, Seoul (Korea, Republic of)

    2016-10-15

    In case of accidents that threats containment integrity, such as Station Black Out (SBO), it is able to depressurize containment using exterior-surface condensation in presence of non-condensable gases, which is named as Passive Containment Cooling System (PCCS). It is very important to precisely predict heat removal capability PCCS, as it affects safety and economics. The effect of curvature is not yet experimentally and numerically studied. It is reported that the effect of curvature exists at single-phase condition, yet it is not studied that if it can applicable to two-phase condensation in presence of non-condensables. In this paper, various experimental data are collected to analyze if it is able to observe curvature effect. However, it is hard to analyze experimental data, as the geometry, experimental conditions and means of measurement differs. To check if the differences between experiments are curvature effect, each experiment is compared with CFD simulation result using a commercial CFD code, STAR-CCM+. In this paper, with correlations derived from prior studies, we found the existence of curvature effect under PCCS operating condition. However, it is unable to find out a clear curvature effect at experiment data as they scatter much. As a means of comparison reference between experiment, CFD code is used. From comparison between CFD and experiment, we could confirm the existence of curvature effect. However, measured heat transfer coefficients of Kawakubo’s experiment are relatively low, whereas Dehbi’s measurement data are relatively high. Also, considering that usage of eq. overly supplies steam to condensing shell region, heat transfer coefficients of Pan Tong’s measured relatively high, but not as much that of Dehbi’s. A further experimental identification is needed for evaluation. Currently, CFD code calculates the curvature effect. Overall trend versus air mass fraction is similar with average of experiment.

  3. Preventing freezing of condensate inside tubes of air cooled condenser

    International Nuclear Information System (INIS)

    Joo, Jeong A; Hwang, In Hwan; Lee, Dong Hwan; Cho, Young Il

    2012-01-01

    An air cooled condenser is a device that is used for converting steam into condensate by using ambient air. The air cooled condenser is prone to suffer from a serious explosion when the condensate inside the tubes of a heat exchanger is frozen; in particular, tubes can break during winter. This is primarily due to the structural problem of the tube outlet of an existing conventional air cooled condenser system, which causes the backflow of residual steam and noncondensable gases. To solve the backflow problem in such condensers, such a system was simulated and a new system was designed and evaluated in this study. The experimental results using the simulated condenser showed the occurrence of freezing because of the backflow inside the tube. On the other hand, no backflow and freezing occurred in the advanced new condenser, and efficient heat exchange occurred

  4. Steam condensation induced water hammer simulations for different pipelines

    International Nuclear Information System (INIS)

    Barna, I.F.; Ezsol, G.

    2011-01-01

    We investigate steam condensation induced water hammer (CIWH) phenomena and present theoretical results for different kind of pipelines. We analyze the process with the WAHA3 model based on two-phase flow six first-order partial differential equations that present one dimensional, surface averaged mass, momentum and energy balances. A second order accurate high-resolution shock-capturing numerical scheme was applied with different kind of limiters in the numerical calculations. At first, we present calculations for various pipelines in the VVER-440-312 type nuclear reactor. Our recent calculation clearly shows that the six conditions of Griffith are only necessary conditions for CIWH but not sufficient. As second results we performed calculations for various geometries and compare with the theory of Chun. (author)

  5. Effect of pool turbulence on direct contact condensation at a steam/water interface

    International Nuclear Information System (INIS)

    Jackson, J.D.; Zhao, C.L.; Doerffer, S.; Byrne, J.E.; Falaki, H.

    2000-01-01

    Measurements of direct contact condensation beat transfer have been made for the case where the process takes place at the horizontal interface between saturated steam and a pool of water in a vertical cylindrical test section. A submerged vertical jet of subcooled water was injected upwards on the axis to promote the condensation and water was withdrawn at the same rate from the bottom of the pool. In conjunction with the above study, measurements of the turbulent velocity fluctuations just below a free surface produced by the injection of a vertical submerged jet have been measured using hot film anemometry on an isothermal air-water test facility of similar geometry for similar flow conditions at ambient temperature. A correlation is proposed in terms of a Stanton number based on turbulent velocity fluctuation near the interface on the liquid-side. Our results are in good agreement with those of others for similar configurations when compared in terms of condensation Stanton number. (author)

  6. Purification method for condensate

    International Nuclear Information System (INIS)

    Shimoda, Akiyoshi.

    1996-01-01

    Condensates generated in secondary coolant circuits of a PWR type reactor are filtered using a hollow thread separation membranes comprising aromatic polyether ketone. Preferably, condensates after passing through a turbine are filtered at a place between a condensator and a steam generator at high temperature as close as a temperature of the steam generator. As the hollow thread membrane, partially crystalline membrane comprising aromatic polyether ketone is used. When it is used at high temperature, the crystallinity is preferably not less than 15wt%. Since a hollow thread membrane comprising the aromatic polyether ketone of excellent heat resistance is used, it can filter and purify the condensates at not lower than 70degC. Accordingly, impurities such as colloidal iron can be removed from the condensates, and the precipitation of cruds in the condensates to a steam generator and a turbine can be suppressed. (I.N.)

  7. Reduction in the specific consumption of heat by the thermal circuit, achieved by rationalization of the steam turbine condensation at nuclear power plants of the WWER-440 type

    International Nuclear Information System (INIS)

    Kubacek, A.

    1992-01-01

    Specific consumption of heat needed for the production of a net electricity unit is a criterion for assessing the efficiency of conversion of thermal energy into mechanical energy in the steam turbine. Based on theoretical calculations and analyses, a way of evaluating the specific heat consumption is demonstrated for the thermal circuit of the steam-engine equipment with one turbogenerator. The dependence of the specific heat consumption on the steam condensation temperature and on the amount of cooling water flowing through the condenser is calculated, as is the dependence of the limiting pressure on the relative loss of vacuum of the condenser and on the cooling water temperature. Such dependences can be used to upgrade the thermal circuit condensation regime. (M.D.). 2 figs., 12 refs

  8. Wet-steam erosion of steam turbine disks and shafts

    International Nuclear Information System (INIS)

    Averkina, N. V.; Zheleznyak, I. V.; Kachuriner, Yu. Ya.; Nosovitskii, I. A.; Orlik, V. G.; Shishkin, V. I.

    2011-01-01

    A study of wet-steam erosion of the disks and the rotor bosses or housings of turbines in thermal and nuclear power plants shows that the rate of wear does not depend on the diagrammed degree of moisture, but is determined by moisture condensing on the surfaces of the diaphragms and steam inlet components. Renovating the diaphragm seals as an assembly with condensate removal provides a manifold reduction in the erosion.

  9. Numerical investigation of convective condensation with the presence of non-condensable gases in a vertical tube

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Wen [Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Li, Xiaowei, E-mail: lixiaowei@tsinghua.edu.cn [Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wu, Xinxin [Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Corradini, Michael L. [Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2016-02-15

    Highlights: • Gas mixture convective condensation in vertical tubes were simulated using FLUENT code. • The simulation results matched well with experimental data. • The detailed velocity field and species distribution were investigated. • The suction factors predicted by CFD models were compared with the classical correlations. • The effects of air and helium on steam condensation were compared. - Abstract: Steam condensation is degraded when non-condensable gases are present. Convective condensation of steam–air mixture and steam–helium mixture in vertical tubes were simulated using the CFD code FLUENT. The condensation process was modeled by defining source terms for the mass, momentum, species and energy conservation equations. Several cases with various steam mass fractions were simulated, the results matched well with the experimental data. Detailed velocity field and species distribution were investigated. The radial velocity was clearly represented, and the suction effect was modeled, which needs to be accounted for when using the heat and mass transfer analogy theory. The Nusselt and Sherwood numbers predicted by CFD models were compared with the classical correlations, and the suction effects were analyzed. The suction effect is proportional to steam mass fraction, while the suction factor is little affected by the Reynolds number. For forced convection flow in this work, the buoyant force can be neglected, so the larger diffusion coefficient of steam–helium mixture would improve the steam condensation compared to steam–air mixture. The condensation mass fluxes of steam–helium mixture and steam–air mixture are almost the same at relatively high steam inlet molar fraction (≥90%).

  10. Performance of evaporative condensers

    Energy Technology Data Exchange (ETDEWEB)

    Ettouney, Hisham M.; El-Dessouky, Hisham T.; Bouhamra, Walid; Al-Azmi, Bader

    2001-07-01

    Experimental investigation is conducted to study the performance of evaporative condensers/coolers. The analysis includes development of correlations for the external heat transfer coefficient and the system efficiency. The evaporative condenser includes two finned-tube heat exchangers. The system is designed to allow for operation of a single condenser, two condensers in parallel, and two condensers in series. The analysis is performed as a function of the water-to-air mass flow rate ratio (L/G) and the steam temperature. Also, comparison is made between the performance of the evaporative condenser and same device as an air-cooled condenser. Analysis of the collected data shows that the system efficiency increases at lower L/G ratios and higher steam temperatures. The system efficiency for various configurations for the evaporative condenser varies between 97% and 99%. Lower efficiencies are obtained for the air-cooled condenser, with values between 88% and 92%. The highest efficiency is found for the two condensers in series, followed by two condensers in parallel and then the single condenser. The parallel condenser configuration can handle a larger amount of inlet steam and can provide the required system efficiency and degree of subcooling. The correlation for the system efficiency gives a simple tool for preliminary system design. The correlation developed for the external heat transfer coefficient is found to be consistent with the available literature data. (Author)

  11. The condensation of steam on the external surfaces of the shells of HIFAR heavy water heat exchangers during a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Chapman, A.G.

    1987-03-01

    A study of steam condensation rates on the HIFAR heavy water heat exchangers was undertaken to predict thermohydraulic conditions in the HIFAR containment during a postulated loss-of-coolant accident (LOCA). The process of surface condensation from a mixture of air and steam, and methods for calculating the rate of condensation, are briefly reviewed. Suitable experimental data are used to estimate coefficients of condensation heat transfer to cool surfaces in a reactor containment during a LOCA. The relevance of the available data to a LOCA in the HIFAR materials testing reactor is examined, and two sets of data are compared. The differences between air/H 2 O and air/D 2 O mixtures are discussed. Formulae are derived for the estimation of the coefficient of heat transfer from the heat exchanger shells to the cooling water, and a method of calculating the rate of condensation per unit area of surface is developed

  12. Moisture separator for steam generator level measurement system

    International Nuclear Information System (INIS)

    Cantineau, B.J.

    1987-01-01

    A steam generator level measurement system having a reference leg which is kept full of water by a condensation pot, has a liquid/steam separator in the connecting line between the condensation pot and the steam phase in the steam generator to remove excess liquid from the steam externally of the steam generator. This ensures that the connecting line does not become blocked. The separator pot has an expansion chamber which slows down the velocity of the steam/liquid mixture to aid in separation, and a baffle, to avoid liquid flow into the line connected to the condensate pot. Liquid separated is returned to the steam generator below the water level through a drain line. (author)

  13. Energy efficiency analysis of steam ejector and electric vacuum pump for a turbine condenser air extraction system based on supervised machine learning modelling

    International Nuclear Information System (INIS)

    Strušnik, Dušan; Marčič, Milan; Golob, Marjan; Hribernik, Aleš; Živić, Marija; Avsec, Jurij

    2016-01-01

    Highlights: • Steam ejector pump and electric liquid ring vacuum pump are analysed and modelled. • A supervised machine learning models by using real process data are applied. • The equation of ejector pumped mass flow from steam turbine condenser was solved. • The loss of specific energy capable of work in a SEPS or LRVP component was analysed. • The economic efficiency analysis per different coal heating values was made. - Abstract: This paper compares the vapour ejector and electric vacuum pump power consumptions with machine learning algorithms by using real process data and presents some novelty guideline for the selection of an appropriate condenser vacuum pump system of a steam turbine power plant. The machine learning algorithms are made by using the supervised machine learning methods such as artificial neural network model and local linear neuro-fuzzy models. The proposed non-linear models are designed by using a wide range of real process operation data sets from the CHP system in the thermal power plant. The novelty guideline for the selection of an appropriate condenser vacuum pumps system is expressed in the comparative analysis of the energy consumption and use of specific energy capable of work. Furthermore, the novelty is expressed in the economic efficiency analysis of the investment taking into consideration the operating costs of the vacuum pump systems and may serve as basic guidelines for the selection of an appropriate condenser vacuum pump system of a steam turbine.

  14. Temperature fields induced by direct contact condensation of steam in a cross-flow in a channel

    NARCIS (Netherlands)

    Clerx, N.; van Deurzen, L.G.M.; Pecenko, A.; Liew, R.; van der Geld, C.W.M.; Kuerten, Johannes G.M.

    2011-01-01

    The temperature fields in the center plane of a channel with a square cross-section have been measured. Steam injected at relatively low mass fluxes through a small hole in one of the walls of the channel condensed intermittently in a small area close to the inlet. The upstream temperature of the

  15. Condensation of steam on the underside of a horizontal surface in the presence of air and helium

    International Nuclear Information System (INIS)

    Stein, R.P.; Cho, D.H.; Lambert, G.A.

    1987-01-01

    Experiments and data analysis for the condensation of steam on the underside of a horizontal surface in a closed vessel are described. Previously reported results for film condensation with air as a noncondensable gas are reviewed and compared with new data with helium as the noncondensable in the same apparatus. Observations, including photographs of the condensate configurations, related to the occurrence of dropwise condensation are also discussed. It is noted that data reproducibility over long periods of time were possible only with film condensation and that with dropwise condensation condensing surface temperatures exhibited large nonuniformities and random fluctuations with time. The well known mass transfer calculational model for accounting for the presence of noncondensable gases had been shown previously to be successful with air. The same model when applied to the helium data was not successful except for small gas contents. It appears that the suppression of convection that would be expected to occur with the less dense gas is counteracted by convection induced by fog or mist formation

  16. Numerical Analysis on Transient of Steam-gas Pressurizer

    International Nuclear Information System (INIS)

    Kim, Jong-Won; Lee, Yeon-Gun; Park, Goon-Cherl

    2008-01-01

    In nuclear reactors, various pressurizers are adopted to satisfy their characteristics and uses. The additional active systems such as heater, pressurizer cooler, spray and insulator are essential for a steam or a gas pressurizer. With a steam-gas pressurizer, additional systems are not required due to the use of steam and non-condensable gas as pressure-buffering materials. The steam-gas pressurizer in integrated small reactors experiences very complicated thermal-hydraulic phenomena. To ensure the integrity of this pressurizer type, the analysis on the transient behavior of the steam-gas pressure is indispensable. For this purpose, the steam-gas pressurizer model is introduced to predict the accurate system pressure. The proposed model includes bulk flashing, rainout, inter-region heat and mass transfer and wall condensation with non-condensable gas. However, the ideal gas law is not applied because of significant interaction at high pressure between steam and non-condensable gas. The results obtained from this proposed model agree with those from pressurizer tests. (authors)

  17. Modelling of film condensation in presence of non condensable gases

    International Nuclear Information System (INIS)

    Genevieve Geffraye; Dominique Bestion; Vladimir Kalitvianski

    2005-01-01

    Full text of publication follows: This paper presents recent developments in the modelling of the condensation due to heat removal from a wall with a possible presence of hydrogen, nitrogen, or air. This work is mainly concerned with nuclear reactor safety with particular reference to situations related to new reactor design, cold shutdown state and severe accident analysis. Film condensation of steam in presence of nitrogen and helium in a tube has been investigated in the COTURNE experiment in a rather large range of parameters, pressure (from 0.1 to 7 Mpa), heat flux (0.1 to 6 W/cm 2 ), mass fraction of noncondensable gas (0 to 1) and also in presence of superheated steam. The experiment represents a Steam Generator tube of a Pressurised Water Reactor and can simulate both co-current or countercurrent flow of steam and water.The models are implemented in the CATHARE code used for nuclear reactor thermal-hydraulics. The code uses two mass balance equations for liquid and gas, two momentum balance equations for liquid and gas and two energy balance equations for liquid and gas. Additional mass transport equations can be added for each non condensable gas. Heat transfers from wall to liquid film, from liquid to interface and gas to interface are modelled. The liquid film heat transfer coefficient is first investigated in pure saturated steam conditions in the pressure range from 0.1 to 7 Mpa. The CATHARE film condensation model in pure steam conditions is derived from Chen's correlation. Chen proposes a general correlation for the film condensation, covering the wavy-laminar and the turbulent film regimes and taking into account the interfacial friction effect. A large data base of laminar film regime was used including COTURNE data other available data found in the literature. The analysis of these data base suggests an influence of the liquid Reynolds number, according to the Nusselt theory, and also of the Eoetvoes number, with surface tension effects. A

  18. An assessment of structural response of condensation pool columns in a BWR/MARK II containment to loads resulting from steam explosions

    International Nuclear Information System (INIS)

    Frid, W.

    1989-01-01

    The objective is to estimate the amount of molten core debris participating in a postulated propagating large-scale steam explosion that could threaten the integrity of the condensation pool columns in a BWR/MARK II containment. This objective was achieved by examination of the structural response of the columns to shock wave loadings and comparison, on the shock wave energy basis, of a propagating steam explosion to a detonation of TNT. In this connection the fraction of the steam explosion energy which appears in the form of a pressure shock wave was estimated. (orig.)

  19. Current experience and a new modeling on water hammer due to steam condensation in PWR secondary system

    International Nuclear Information System (INIS)

    Kawanishi, K.; Kasahara, J.; Ueno, T.; Suzuta, T.

    1998-01-01

    There have been possibilities to occur water hammer in pipelines of turbine system for nuclear or fossil fuel power plants. According to the NUREG report, approximately 150 events have been reported since 1969, we also have an experience recently. Water hammer occurs due to sudden steam condensation with pressure pulse. This kind of pressure pulses has been made by alternative producing and condensing of steam slug in the pipe and its frequency relates subcooling and pipe structures. This paper presents our current experience on water hammer with some experimental studies. The present experiment has been performed to obtain the data base for evaluating the pressure pulses. The test pipe was horizontal tubes with dead end connected to vertical tube which simulating drain line in PWR secondary system. The main results are shown as follows; Magnitude of pressure pulse depends drain velocity and initial subcooling. Pipe structure effects on the frequency and continual time of water hammer phenomenon. A new modeling for quantitative explanation of the phenomena is also presented

  20. Cleaning device for steam units in a nuclear power plant

    International Nuclear Information System (INIS)

    Sasamuro, Takemi.

    1978-01-01

    Purpose: To prevent radioactive contamination upon dismantling and inspection of steam units such as a turbine to a building containing such units and the peripheral area. Constitution: A steam generator indirectly heated by steam supplied from steam generating source in a separate system containing no radioactivity is provided to produce cleaning steam. A cleaning steam pipe is connected by way of a stop valve between separation valve of a nuclear power plant steam pipe and a high pressure turbine. Upon cleaning, the separation valve is closed, and steam supplied from the cleaning steam pipe is flown into a condenser. The water thus condensated is returned by way of a feed water heater and a condenser to a water storage tank. (Nakamura, S.)

  1. CFD Modeling of Wall Steam Condensation: Two-Phase Flow Approach versus Homogeneous Flow Approach

    International Nuclear Information System (INIS)

    Mimouni, S.; Mechitoua, N.; Foissac, A.; Hassanaly, M.; Ouraou, M.

    2011-01-01

    The present work is focused on the condensation heat transfer that plays a dominant role in many accident scenarios postulated to occur in the containment of nuclear reactors. The study compares a general multiphase approach implemented in NEPTUNE C FD with a homogeneous model, of widespread use for engineering studies, implemented in Code S aturne. The model implemented in NEPTUNE C FD assumes that liquid droplets form along the wall within nucleation sites. Vapor condensation on droplets makes them grow. Once the droplet diameter reaches a critical value, gravitational forces compensate surface tension force and then droplets slide over the wall and form a liquid film. This approach allows taking into account simultaneously the mechanical drift between the droplet and the gas, the heat and mass transfer on droplets in the core of the flow and the condensation/evaporation phenomena on the walls. As concern the homogeneous approach, the motion of the liquid film due to the gravitational forces is neglected, as well as the volume occupied by the liquid. Both condensation models and compressible procedures are validated and compared to experimental data provided by the TOSQAN ISP47 experiment (IRSN Saclay). Computational results compare favorably with experimental data, particularly for the Helium and steam volume fractions.

  2. Gas chromatographic determination of residual hydrazine and morpholine in boiler feed water and steam condensates

    International Nuclear Information System (INIS)

    Vatsala, S.; Bansal, V.; Tuli, D.K.; Rai, M.M.; Jain, S.K.; Srivastava, S.P.; Bhatnagar, A.K.

    1994-01-01

    Hydrazine, an oxygen scavenger in boiler water, was derivatised to the corresponding acetone azine and determined at the ng ml -1 level by gas chromatography. Morpholine, a corrosion inhibitor used in steam boilers, was estimated either directly (if >2.0 μg ml -1 ) or by quantitative preconcentration (0.1 ng-2.0 μg ml -1 ). To obtain symmetrical peaks for these amines, the column packing was coated with KOH. Use of a nitrogen-specific detector improved accuracy of estimation of hydrazine and morpholine, giving a RSD of 1.9-3.6%. Chromatographic analysis of these amines in boiler feed water and steam condensate samples collected from boilers servicing a pertroleum refinery is described. Environmental safety regulations calls for monitoring of hydrazine and the methods developed can easily be adapted for this purpose. (orig.)

  3. Entropy generation in a condenser and related correlations

    Directory of Open Access Journals (Sweden)

    Askowski Rafał

    2015-06-01

    Full Text Available The paper presents an analysis of relations describing entropy generation in a condenser of a steam unit. Connections between entropy generation, condenser ratio, and heat exchanger effectiveness, as well as relations implied by them are shown. Theoretical considerations allowed to determine limits of individual parameters which describe the condenser operation. Various relations for average temperature of the cold fluid were compared. All the proposed relations were verified against data obtained using a simulator and actual measurement data from a 200 MW unit condenser. Based on data from a simulator it was examined how the sum of entropy rates, steam condenser effectiveness, terminal temperature difference and condenser ratio vary with the change in the inlet cooling water temperature, mass flow rate of steam and the cooling water mass flow rate.

  4. An experimental investigation of the interfacial condensation heat transfer in steam/water countercurrent stratified flow in a horizontal pipe

    Energy Technology Data Exchange (ETDEWEB)

    Chu, In Cheol; Yu, Seon Oh; Chun, Moon Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Byong Sup; Kim, Yang Seok; Kim, In Hwan; Lee, Sang Won [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    An interfacial condensation heat transfer phenomenon in a steam/water countercurrent stratified flow in a nearly horizontal pipe has been experimentally investigated. The present study has been focused on the measurement of the temperature and velocity distributions within the water layer. In particular, the water layer thickness used in the present work is large enough so that the turbulent mixing is limited and the thermal stratification is established. As a result, the thermal resistance of the water layer to the condensation heat transfer is increased significantly. An empirical correlation of the interfacial condensation heat transfer has been developed. The present correlation agrees with the data within {+-} 15%. 5 refs., 6 figs. (Author)

  5. Experimental study of condensate subcooling with the use of a model of an air-cooled condenser

    Science.gov (United States)

    Sukhanov, V. A.; Bezukhov, A. P.; Bogov, I. A.; Dontsov, N. Y.; Volkovitsky, I. D.; Tolmachev, V. V.

    2016-01-01

    Water-supply deficit is now felt in many regions of the world. This hampers the construction of new steam-turbine and combined steam-and-gas thermal power plants. The use of dry cooling systems and, specifically, steam-turbine air-cooled condensers (ACCs) expands the choice of sites for the construction of such power plants. The significance of condensate subcooling Δ t as a parameter that negatively affects the engineering and economic performance of steam-turbine plants is thereby increased. The operation and design factors that influence the condensate subcooling in ACCs are revealed, and the research objective is, thus, formulated properly. The indicated research was conducted through physical modeling with the use of the Steam-Turbine Air-Cooled Condenser Unit specialized, multipurpose, laboratory bench. The design and the combined schematic and measurement diagram of this test bench are discussed. The experimental results are presented in the form of graphic dependences of the condensate subcooling value on cooling ratio m and relative weight content ɛ' of air in steam at the ACC inlet at different temperatures of cooling air t ca ' . The typical ranges of condensate subcooling variation (4 ≤ Δ t ≤ 6°C, 2 ≤ Δ t ≤ 4°C, and 0 ≤ Δ t ≤ 2°C) are identified based on the results of analysis of the attained Δ t levels in the ACC and numerous Δ t reduction estimates. The corresponding ranges of cooling ratio variation at different temperatures of cooling air at the ACC inlet are specified. The guidelines for choosing the adjusted ranges of cooling ratio variation with account of the results of experimental studies of the dependences of the absolute pressure of the steam-air mixture in the top header of the ACC and the heat flux density on the cooling ratio at different temperatures of cooling air at the ACC inlet are given.

  6. Steam generation: fossil-fired systems: utility boilers; industrial boilers; boiler auxillaries; nuclear systems: boiling water; pressurized water; in-core fuel management; steam-cycle systems: condensate/feedwater; circulating water; water treatment

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    A survey of development in steam generation is presented. First, fossil-fired systems are described. Progress in the design of utility and industrial boilers as well as in boiler auxiliaries is traced. Improvements in coal pulverizers, burners that cut pollution and improve efficiency, fans, air heaters and economisers are noted. Nuclear systems are then described, including the BWR and PWR reactors, in-core fuel management techniques are described. Finally, steam-cycle systems for fossil-fired and nuclear power plants are reviewed. Condensate/feedwater systems, circulating water systems, cooling towers, and water treatment systems are discussed

  7. RELAP5 analysis of reflux condensation behavior in heat transfer tube bundle of a steam generator

    International Nuclear Information System (INIS)

    Minami, Noritoshi; Chikusa, Toshiaki; Nagae, Takashi; Murase, Michio

    2007-01-01

    In case of loss of the residual heat removal system and other alternative cooling methods under mid-loop operation during shutdown of the pressurized water reactor plant, reflux condensation in the steam generator (SG) may be an effective heat removal mechanism. In reflux condensation experiments 7.2c with injection of nitrogen gas using the BETHSY facility in France, which is a scale model of a pressurized water reactor plant, 34 heat transfer tubes were divided into two kinds of flow patterns, which were steam forward flow and nitrogen reverse flow. In this study, we simulated the BETHSY experiments using the transient analysis code RELAP5. Modifying calculation equations for interfacial friction force and wall friction force between the inlet plenum and heat transfer tubes, nitrogen reverse flow was successfully simulated. In calculations with alteration of the flow area ratio to two flow channels for the heat transfer tube bundle, the number of active tubes with the maximum nitrogen recirculation flow rate agreed rather well with the observed number of active tubes. In calculations with three flow channels for the heat transfer tube bundle, the average number of active tubes in several calculations with different flow area ratios of the three flow channels predicted the number of active tubes well. (author)

  8. Analysis of experimental characteristics of multistage steam-jet electors of steam turbines

    Science.gov (United States)

    Aronson, K. E.; Ryabchikov, A. Yu.; Brodov, Yu. M.; Brezgin, D. V.; Zhelonkin, N. V.; Murmanskii, I. B.

    2017-02-01

    A series of questions for specification of physical gas dynamics model in flow range of steam-jet unit and ejector computation methodology, as well as functioning peculiarities of intercoolers, was formulated based on analysis of experimental characteristics of multistage team-jet steam turbines. It was established that coefficient defining position of critical cross-section of injected flow depends on characteristics of the "sound tube" zone. Speed of injected flow within this tube may exceed that of sound, and pressure jumps in work-steam decrease at the same time. Characteristics of the "sound tube" define optimal axial sizes of the ejector. According to measurement results, the part of steam condensing in the first-stage coolant constitutes 70-80% of steam amount supplied into coolant and is almost independent of air content in steam. Coolant efficiency depends on steam pressure defined by operation of steam-jet unit of ejector of the next stage after coolant of steam-jet stage, temperature, and condensing water flow. As a rule, steam entering content of steam-air mixture supplied to coolant is overheated with respect to saturation temperature of steam in the mixture. This should be taken into account during coolant computation. Long-term operation causes changes in roughness of walls of the ejector's mixing chamber. The influence of change of wall roughness on ejector characteristic is similar to the influence of reverse pressure of the steam-jet stage. Until some roughness value, injection coefficient of the ejector stage operating in superlimiting regime hardly changed. After reaching critical roughness, the ejector switches to prelimiting operating regime.

  9. Steam cleaning device

    International Nuclear Information System (INIS)

    Karaki, Mikio; Muraoka, Shoichi.

    1985-01-01

    Purpose: To clean complicated and long objects to be cleaned having a structure like that of nuclear reactor fuel assembly. Constitution: Steams are blown from the bottom of a fuel assembly and soon condensated initially at the bottom of a vertical water tank due to water filled therein. Then, since water in the tank is warmed nearly to the saturation temperature, purified water is supplied from a injection device below to the injection device above the water tank on every device. In this way, since purified water is sprayed successively from below to above and steams are condensated in each of the places, the entire fuel assembly elongated in the vertical direction can be cleaned completely. Water in the reservoir goes upward like the steam flow and is drained together with the eliminated contaminations through an overflow pipe. After the cleaning has been completed, a main steam valve is closed and the drain valve is opened to drain water. (Kawakami, Y.)

  10. Conversion of thermall energy to mechanical work in the oscillations with steam condensation in pool water

    International Nuclear Information System (INIS)

    Aya, Izuo; Nariai, Hideki.

    1988-01-01

    Pressure and fluid oscillations with steam injection into pool water were discussed from the view point of the conversion of thermal energy into mechanical work. When the change of fluid state moves clockwise in the p-V diagram, the oscillation sustains since the thermal energy changes into positive work. The equations difining the mechanical work at the condensation oscillations were presented. The oscillation threshold determined by the condition that mechanical work became zero, coincided with the values derived by the linear oscillation theory. The changes of pressure and specific volume during chugging were also shown with one dimensional simulation analysis. The p-V diagrams at various chugging modes were presented with the movement of steam water interface, and the conversion efficiency of thermal energy to mechanical work was also discussed. (author)

  11. Condensing heat transfer following a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Krotiuk, W.J.; Rubin, M.B.

    1978-01-01

    A new method for calculating the steam mass condensation energy removal rates on cold surfaces in contact with an air-steam mixture has been developed. This method is based on the principles of mass diffusion of steam from an area of high concentration to the condensing surface, which is an area of low steam concentration. This new method of calculating mass condensation has been programmed into the CONTEMPT-LT Mod 26 computer code, which calculates the pressure and temperature transients inside a light water reactor containment following a loss-of-coolant accident. The condensing heat transfer coefficient predicted by the mass diffusion method is compared to existing semi-empirical correlations and to the experimental results of the Carolinas Virginia Tube Reactor Containment natural decay test. Closer agreement with test results is shown in the calculation of containment pressure, temperature, and heat sink surface temperature using the mass diffusion condensation method than when using any existing semi-empirical correlation

  12. The Invisibility of Steam

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2014-01-01

    Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature…

  13. Emergency condensator for BWR type reactor

    International Nuclear Information System (INIS)

    Ubakai, Yoichi; Narumi, Yuichi; Sakata, Yuji.

    1992-01-01

    An emergency condensator is constituted with heat transfer pipes, a steam chamber, an upper pipe plate, a lower pipe plate and a condensate chamber. The upper pipe plate is secured by supports, and a steam pipe is connected to the upper pipe plate. A condensate pipeline and a incondensible gas vent pipe are disposed to the condensate chamber. Taking thermal expansion of the steam pipes and thermal expansion of the heat transfer pipes into consideration, the heat transfer pipe is made as an L-shaped pipe having a vertical portion and a horizontal portion so as to absorb each of the thermal expansion smoothly. The L-shaped heat transfer pipes are constituted as a bundle of pipes having the end portions thereof secured to the upper pipe plate and the lower pipe plate. The emergency condensator is disposed in a emergency condensator pool chamber. Cooling water in contact with the outer side of the L-shaped heat transfer pipes is the pool water in the pool chamber, and the condensator chamber is disposed in concrete walls of the pool chamber. With such a constitution, stress due to thermal expansion of the heat transfer pipes is mitigated, and heat transfer performance, earth quake resistance and maintenancability are improved. (I.N.)

  14. Experimental studies on condensation of steam mixed with noncondensable gas inside the vertical tube in a pool filled with subcooled water

    International Nuclear Information System (INIS)

    Maheshwari, N.K.; Saha, D.; Sinha, R.K.; Aritomi, M.

    2003-01-01

    A passive containment cooling system with immersed condensers has been proposed as one of the alternatives for the advanced heavy water reactor (AHWR) being designed in India. The system removes residual/decay heat released into the containment through the immersed condensers kept in a pool of water following loss of coolant accident. An important aspect of the immersed condensers is the potential degradation of its performance due to the presence of noncondensable gases. Experiments are performed to obtain reliable data on condensation phenomena in presence of air. These experiments are conducted on full-scale tubes of condensers immersed in a pool of water maintaining similar conditions as in the prototype of AHWR. A method has been proposed for the determination of the local heat transfer rate using correlations given in literature. The parametric effects of air mass fraction, pressure, steam flow, etc. on condensation heat transfer in presence of noncondensable gas have been studied. The experimental results are compared with the correlations given in literature. (orig.)

  15. A theoretical model of air and steam co-injection to prevent the downward migration of DNAPLs during steam-enhanced extraction

    Science.gov (United States)

    Kaslusky, Scott F.; Udell, Kent S.

    2002-04-01

    When steam is injected into soil containing a dense volatile non-aqueous phase liquid contaminant the DNAPL vaporized within the heated soil region condenses and accumulates ahead of the steam condensation front. If enough DNAPL accumulates, gravitational forces can overcome trapping forces allowing the liquid contaminant to flow downward. By injecting air with steam, a portion of the DNAPL vapor remains suspended in equilibrium with the air, decreasing liquid contaminant accumulation ahead of the steam condensation front, and thus reducing the possibility of downward migration. In this work, a one-dimensional theoretical model is developed to predict the injection ratio of air to steam that will prevent the accumulation of volatile DNAPLs. The contaminated region is modeled as a one-dimensional homogeneous porous medium with an initially uniform distribution of a single component contaminant. Mass and energy balances are combined to determine the injection ratio of air to steam that eliminates accumulation of the contaminant ahead of the steam condensation front, and hence reduces the possibility of downward migration. The minimum injection ratio that eliminates accumulation is defined as the optimum injection ratio. Example calculations are presented for three DNAPLs, carbon tetrachloride (CCl 4), trichloroethylene (TCE), and perchloroethylene (PCE). The optimum injection ratio of air to steam is shown to depend on the initial saturation and the volatility of the liquid contaminant. Numerical simulation results are presented to validate the model, and to illustrate downward migration for ratios less than optimum. Optimum injection ratios determined from numerical simulations are shown to be in good agreement with the theoretical model.

  16. Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (12) Evaluations of Spatial Distributions of Flow and Heat Transfer in Steam Injector

    International Nuclear Information System (INIS)

    Yutaka Abe; Yujiro Kawamoto; Chikako Iwaki; Tadashi Narabayashi; Michitsugu Mori; Shuichi Ohmori

    2006-01-01

    Next-generation nuclear reactor systems have been under development aiming at simplified system and improvement of safety and credibility. One of the innovative technologies is the supersonic steam injector, which has been investigated as one of the most important component of the next-generation nuclear reactor. The steam injector has functions of a passive pump without large motor or turbo-machinery and a high efficiency heat exchanger. The performances of the supersonic steam injector as a pump and a heat exchanger are dependent on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. In previous studies of the steam injector, there are studies about the operating characteristics of steam injector and about the direct contact condensation between static water pool and steam in atmosphere. However, there is a little study about the turbulent heat transfer and flow behavior under the great shear stress. In order to examine the heat transfer and flow behavior in supersonic steam injector, it is necessary to measure the spatial temperature distribution and velocity in detail. The present study, visible transparent supersonic steam injector is used to obtain the axial pressure distributions in the supersonic steam injector, as well as high speed visual observation of water jet and steam interface. The experiments are conducted with and without non-condensable gas. The experimental results of the interfacial flow behavior between steam and water jet are obtained. It is experimentally clarified that an entrainment exists on the water jet surface. It is also clarified that discharge pressure is depended on the steam supply pressure, the inlet water flow rate, the throat diameter and non-condensable flow rate. Finally a heat flux is estimated about 19 MW/m 2 without non-condensable gas condition in steam. (authors)

  17. An investigation of condensation from steam-gas mixtures flowing downward inside a vertical tube

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, S.Z.; Schrock, V.E.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States)

    1995-09-01

    Previous experiments have been carried out by Vierow, Ogg, Kageyama and Siddique for condensation from steam/gas mixtures in vertical tubes. In each case the data scatter relative to the correlation was large and there was not close agreement among the three investigations. A new apparatus has been designed and built using the lessons learned from the earlier studies. Using the new apparatus, an extensive new data base has been obtained for pure steam, steam-air mixtures and steam-helium mixtures. Three different correlations, one implementing the degradation method initially proposed by Vierow and Schrock, a second diffusion layer theory initially proposed by Peterson, and third mass transfer conductance model are presented in this paper. The correlation using the simple degradation factor method has been shown, with some modification, to give satisfactory engineering accuracy when applied to the new data. However, this method is based on very simplified arguments that do not fully represent the complex physical phenomena involved. Better representation of the data has been found possible using modifications of the more complex and phenomenologically based method which treats the heat transfer conductance of the liquid film in series with the conductance on the vapor-gas side with the latter comprised of mass transfer and sensible heat transfer conductance acting in parallel. The mechanistic models, based on the modified diffusion layer theory or classical mass transfer theory for mass transfer conductance with transpiration successfully correlate the data for the heat transfer of vapor-gas side. Combined with the heat transfer of liquid film model proposed by Blangetti, the overall heat transfer coefficients predicted by the correlations from mechanistic models are in close agreement with experimental values.

  18. Millstone 3 condensate dissolved gas monitoring

    International Nuclear Information System (INIS)

    Burns, T.F.; Grondahl, E.E.; Snyder, D.T.

    1988-01-01

    Condensate dissolved oxygen problems at Millstone Point Unit 3 (MP3) were investigated using the Dissolved Gas Monitoring System developed by Radiological and Chemical Technology, Inc. under EPRI sponsorship. Argon was injected into the turbine exhaust basket tips to perform a dissolved gas transport analysis and determine steam jet air ejector gas removal efficiency. The operating configuration of the steam jet air ejector system was varied to determine the effect on gas removal efficiency. Following circulating water chlorination, the gas removal efficiency was determined to evaluate the effect of condenser tube fouling on steam jet air ejector performance

  19. Study on corrosion of thermal power plant condenser tubes

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Abdolreza Rashidi; Zhaam, Ali Akbar [Niroo Research Institute, end of Poonak Bakhtari blvd., Shahrak Ghods, Tehran (Iran)

    2004-07-01

    The aim of this investigation is to study kinds of corrosion mechanisms in thermal power plant condenser tubes. Condenser is a shell and tube heat exchanger in which cooling water flows through its tubes. While the steam from low pressure turbine passes within condenser tubes, it is condensed by cooling water. The exhausted steam from low pressure turbine is condensed on external surface of condenser tubes and heat is transferred to cooling water which flow into tubes. Tubes composition is usually copper-based alloys, stainless steel or titanium. Annual damages due to corrosion cause much cost for replacement and repairing metallic equipment and installations in electric power industry. Because of existence of different contaminants in water and steam cycle, condenser tubes surfaces are exposed to corrosion. Contaminants like oxygen, carbon dioxide, chloride ion and ammonia in water and steam cycle originate several damages such as pitting and crevice corrosion, erosion, galvanic attack, SCC, condensed corrosion, de-alloying in thermal power plant condenser. The paper first states how corrosion damage takes place in condensers and then introduces types of usual alloys used in condensers and also their corrosion behavior. In continuation, a brief explanation is presented about kinds of condenser failures due to corrosion. Then, causes and locations of different mechanisms of corrosion events on condenser tubes and effects of different parameters such as composition, temperature, chloride and sulfide ion concentration, pH, water velocity and biological precipitation are examined and finally protection methods are indicated. Also some photos of tubes specimens related to power plants are studied and described in each case of mentioned mechanisms. (authors)

  20. Steam condensation behavior of high pressure water's blow down directly into water in containment under LOCA

    International Nuclear Information System (INIS)

    Kusunoki, Tsuyoshi; Ishida, Toshihisa; Yoritsune, Tsutomu; Kasahara, Y.

    1995-01-01

    JAERI has been conducting a design study of an advanced type Marine Reactor X (MRX) for merchant ships. By employing 'Integral type PWR', In-vessel type control rod drive systems', 'Water filled containment system' and 'Decay heat removal system by natural convection', MRX achieved a compact, light weight and highly safe plant. Experiments on steam condensation behavior of high pressure water's blow down into water have been conducted in order to investigate a major safety issue related to the design decision of 'Water filled containment system'. (author)

  1. Organic evaporator steam valve failure

    International Nuclear Information System (INIS)

    Jacobs, R.A.

    1992-01-01

    Defense Waste Processing Facility (DWPF) Technical has requested an analysis of the capacity of the Organic Evaporator (OE) condenser (OEC) be performed to determine its capability in the case where the OE steam flow control valve fails open. Calculations of the OE boilup and the OEC heat transfer coefficient indicate the OEC will have more than enough capacity to remove the heat at maximum OE boilup. In fact, the Salt Cell Vent Condenser (SCVC) should also have sufficient capacity to handle the maximum OE boilup. Therefore, it would require simultaneous loss of OEC and/or SCVC condensing capacity for the steam valve failure to cause high benzene in the Process Vessel Vent System (PVVS)

  2. Local properties of countercurrent stratified steam-water flow

    International Nuclear Information System (INIS)

    Kim, H.J.

    1985-10-01

    A study of steam condensation in countercurrent stratified flow of steam and subcooled water has been carried out in a rectangular channel/flat plate geometry over a wide range of inclination angles (4 0 -87 0 ) at several aspect ratios. Variables were inlet water and steam flow rates, and inlet water temperature. Local condensation rates and pressure gradients were measured, and local condensation heat transfer coefficients and interfacial shear stress were calculated. Contact probe traverses of the surface waves were made, which allowed a statistical analysis of the wave properties. The local condensation Nusselt number was correlated in terms of local water and steam Reynolds or Froude numbers, as well as the liquid Prandtl number. A turbulence-centered model developed by Theofanous, et al. principally for gas absorption in several geometries, was modified. A correlation for the interfacial shear stress and the pressure gradient agreed with measured values. Mean water layer thicknesses were calculated. Interfacial wave parameters, such as the mean water layer thickness, liquid fraction probability distribution, wave amplitude and wave frequency, are analyzed

  3. Computations for a condenser. Experimental results

    International Nuclear Information System (INIS)

    Walden, Jean.

    1975-01-01

    Computations for condensers are presented with experimental results. The computations are concerned with the steam flux at the condenser input, and inside the tube bundle. Experimental results are given for the flux inside the condenser sleeve and the flow passing through the tube bundle [fr

  4. An Isothermal Steam Expander for an Industrial Steam Supplying System

    Directory of Open Access Journals (Sweden)

    Chen-Kuang Lin

    2015-01-01

    Full Text Available Steam is an essential medium used in the industrial process. To ensure steam quality, small and middle scale boilers are often adopted. However, because a higher steam pressure (compared to the necessary steam pressure is generated, the boiler’s steam pressure will be reduced via a pressure regulator before the steam is directed through the process. Unfortunately, pressure is somewhat wasted during the reducing process. Therefore, in order to promote energy efficiency, a pressure regulator is replaced by a steam expander. With this steam expander, the pressure will be transformed into mechanical energy and extracted during the expansion process. A new type of isothermal steam expander for an industrial steam supplying system will be presented in the paper. The isothermal steam expander will improve the energy efficiency of a traditional steam expander by replacing the isentropic process with an isothermal expansion process. With this, steam condensation will decrease, energy will increase, and steam quality will be improved. Moreover, the mathematical model of the isothermal steam expander will be established by using the Schmidt theory, the same principle used to analyze Stirling engines. Consequently, by verifying the correctness of the theoretical model for the isothermal steam expander using experimental data, a prototype of 100 c.c. isothermal steam expander is constructed.

  5. Condensate treatment and oxygen control in power plants

    International Nuclear Information System (INIS)

    Sakai, Toshiaki; Iida, Kei; Ohashi, Shinichi.

    1997-01-01

    In thermal and nuclear power stations, the steam that operated turbines is cooled and condensed with condensers. The condensate is heated again with boilers, nuclear reactors or steam generators, but if corrosion products or impurities are contained in the condensate, corrosion and scale formation occur in boilers and others. The filtration facility and the desalting facility for condensate are installed to remove impurities, but water quality control is different in thermal, BWR and PWR plants, therefore, the treatment facilities corresponding to respective condensates have been adopted. In order to reduce the amount of clud generation, the treatment of injecting a small quantity of oxygen into condensate has been adopted. In thermal power plants, all volatile treatment is carried out, in which corrosion is prevented by the addition of ammonia and hydrazine to boiler feedwater. The condensate filters of various types and the NH 4 type condensate desalter for thermal power plants are described. In BWR power plants, steam is generated in nuclear reactors, therefore, the addition of chemicals into water is never carried out, and high purity neutral water is used. In PWR power plants, the addition of chemicals to water is done in the primary system, and AVT is adopted in the secondary system. Also the condensate treatment facilities are different for both reactors. (K.I.)

  6. Effect of Low Pressure End Conditions on Steam Power Plant Performance

    Directory of Open Access Journals (Sweden)

    Ali Syed Haider

    2014-07-01

    Full Text Available Most of the electricity produced throughout the world today is from steam power plants and improving the performance of power plants is crucial to minimize the greenhouse gas emissions and fuel consumption. Energy efficiency of a thermal power plant strongly depends on its boiler-condenser operating conditions. The low pressure end conditions of a condenser have influence on the power output, steam consumption and efficiency of a plant. Hence, the objective this paper is to study the effect of the low pressure end conditions on a steam power plant performance. For the study each component was modelled thermodynamically. Simulation was done and the results showed that performance of the condenser is highly a function of its pressure which in turn depends on the flow rate and temperature of the cooling water. Furthermore, when the condenser pressure increases both net power output and plant efficiency decrease whereas the steam consumption increases. The results can be used to run a steam power cycle at optimum conditions.

  7. Reflux condensation behavior in SBLOCA tests of ATLAS facility

    International Nuclear Information System (INIS)

    Kim, Yeon-Sik; Park, Hyun-Sik; Cho, Seok; Choi, Ki-Yong; Kang, Kyoung-Ho

    2017-01-01

    Highlights: • Behavior of a reflux condensation heat transfer was investigated for SBLOCA tests. • Behavior of the reflux condensate in HL, SG inlet plenum, and U-tubes were evaluated. • Concept of a steam moisturizing phenomenon was introduced and discussed. • Test data and MARS calculations were compared and discussed on the reflux condensate. - Abstract: The behavior of the reflux condensation heat transfer in a hot side steam generator (SG) U-tubes during a cold leg (CL) pipe and a direct vessel injection (DVI) line break in small break loss-of-coolant accident (SBLOCA) tests of the ATLAS facility was investigated including MARS code calculations. Among the SBLOCA tests, a 6″-CL pipe and 50%-DVI line break SBLOCA test were selected to investigate the behavior of the reflux condensation. A reflux condensation heat transfer seemed to occur from the time the SG U-tubes were half-empty to near the loop seal clearing (LSC). It was found that a transition regime existed between the reflux condensation heat transfer and reverse heat transfer. The remaining reflux condensate in SG U-tubes owing to the counter-current flow limit (CCFL) phenomenon and a separating effect of liquid carry-over and/or entrainment with steam moisturizing seemed to affect the thermal-hydraulic behavior of the transition regime. It was also found that the steam flowrate of the loop pipings and SG U-tubes seemed to have a strong effect on the duration time of the transition regime, e.g., a larger steam flowrate results in a longer duration. From a comparison of the reflux condensation behavior between the ATLAS tests and MARS code calculations, overall qualitative agreements were found between the two cases. The largest discrepancies were found in the SG inlet plenum water level between the two cases, and the authors suggest that the combination effects of the remaining reflux condensate in SG U-tubes and a separating effect of liquid carry-over and/or entrainment with steam

  8. Description of steam-condensation phenomena during the loss-of-coolant accident

    International Nuclear Information System (INIS)

    McCauley, E.W.; Holman, G.S.; Aust, E.; Schwan, H.; Vollbrandt, J.; Fuerst, H.

    1980-01-01

    The development and verification of advanced computer models which describe the boiling water reactor (BWR) pressure suppression process for a hypothetical loss-of-coolant accident (LOCA) require a clear description of basic steam condensation phenomena. The GKSS Research Center, in coordination with interested institutions of West Germany and the United States, is currently conducting a test program for such basic research on a multivent BWR-related pressure suppression system. The Lawrence Livermore National Laboratory (LLNL) acts as the principal US NRC liaison for this test program, with particular emphasis on development of GKSS data for confirmatory use regarding US Mark II nuclear power plants as well as to advanced code development. The multivent test facility, placed in operation in February 1979, is a three-pipe full-scale vent system modelling main features of both the West German KWU and United States G.E. Mk II BWR pressure suppression systems. The test facility and testing programs are described

  9. Experimental and theoretical study of steam condensation induced water hammer phenomena

    International Nuclear Information System (INIS)

    Barna, Imre Ferenc; Baranyai, Gabor; Ezsoel, Gyoergy

    2009-01-01

    We investigate steam condensation induced water hammer (waha) phenomena and present experimental and theoretical results. Some of the experiments were performed in the PMK-2 facility, which is a full-pressure thermohydraulic model of the nuclear power plant of VVER-440/312 type and located in the Atomic Energy Research Institute Budapest, Hungary. Other experiments were done in the ROSA facility in Japan. On the theoretical side waha is studied and analyzed with the WAHA3 model based on two-phase flow six first-order partial differential equations that present one dimensional, surface averaged mass, momentum and energy balances. A second order accurate high-resolution shock-capturing numerical scheme was applied with different kind of limiters in the numerical calculations. The applied two-fluid model shows some similarities to Relap5 which is widely used in the nuclear industry to simulate nuclear power plant accidents. Experimentally measured and theoretically calculated waha pressure peaks are in qualitative agreement. (author)

  10. A generalized correlation for steam condensation rates in the presence of air under turbulent free convection - 15549

    International Nuclear Information System (INIS)

    Dehbi, A.

    2015-01-01

    In the past several decades, experimentalists have proposed a large number of correlations to estimate steam condensation rates in the presence of noncondensable gases in free convection regimes. These correlations are largely empirical, and usually of limited scope, which often leads to their use outside their range of validity, thus incurring the risk of significant errors. In this investigation, we disregard the correlations altogether, and instead go back to their underlying original data, consolidate them in a single set, and propose a generalized correlation that is compatible with the heat and mass transfer analogy. This best-estimate correlation for steam-air mixtures, based on six different investigations and 350 data points, covers two orders of magnitude in the heat transfer coefficient, and is valid for pressures up to 20 bars and steam mass fraction from 0.1 to 0.95. The consolidated raw data are self-consistent and collapse around a curve with a standard deviation of 16 %, thus well within typical experimental error bands. This demonstrates that there is no physical justification for the large deviations (factor 2 or more) observed sometimes when one compares the heat transfer coefficients predicted by different empirical correlations. (author)

  11. TRACE assessment on local condensation heat transfer in presence of non-condensable gas inside a vertical tube

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Jin; Ahn, Seung Hoon; Kim, Kap; Kim, Hho Jung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2009-07-01

    TRACE assessment was performed to investigate local condensation heat transfer coefficients in the presence of a noncondensable gas inside a vertical tube. The data obtained from pure steam and steam/nitrogen mixture condensation experiments were compared to study the effects of noncondensable nitrogen gas on the annular film condensation phenomena. The condenser tube had a small inner diameter of 13mm (about 1/2-in.) and this experiment had been performed to prove the effectiveness of the a Passive Residual Heat Removal System (PRHRS) of SMART (System-integrated Modular Advanced ReacTor), which is a small modular integral-type pressurized water reactor that is developed for the dual purposes of seawater desalination and small-scaled power generation. In the case of nitrogen presence, TRACE results show the converged results but the prediction is different from experimental data. The candidate reasons can be focused on several models, such as the film thickness calculation, surface area, and condensation heat transfer correlations, etc. In the case of pure steam condensation case, TRACE results shows large oscillations and do not converge. This should be investigated in detail to identify the reason. Until now, the oscillation in thermal hydraulic parameters results from the film thickness calculation and surface area calculation. For future works, the whole sets of the experiment will be assessed and the improvement of TRACE will be performed.

  12. TRACE assessment on local condensation heat transfer in presence of non-condensable gas inside a vertical tube

    International Nuclear Information System (INIS)

    Cho, Yong Jin; Ahn, Seung Hoon; Kim, Kap; Kim, Hho Jung

    2009-01-01

    TRACE assessment was performed to investigate local condensation heat transfer coefficients in the presence of a noncondensable gas inside a vertical tube. The data obtained from pure steam and steam/nitrogen mixture condensation experiments were compared to study the effects of noncondensable nitrogen gas on the annular film condensation phenomena. The condenser tube had a small inner diameter of 13mm (about 1/2-in.) and this experiment had been performed to prove the effectiveness of the a Passive Residual Heat Removal System (PRHRS) of SMART (System-integrated Modular Advanced ReacTor), which is a small modular integral-type pressurized water reactor that is developed for the dual purposes of seawater desalination and small-scaled power generation. In the case of nitrogen presence, TRACE results show the converged results but the prediction is different from experimental data. The candidate reasons can be focused on several models, such as the film thickness calculation, surface area, and condensation heat transfer correlations, etc. In the case of pure steam condensation case, TRACE results shows large oscillations and do not converge. This should be investigated in detail to identify the reason. Until now, the oscillation in thermal hydraulic parameters results from the film thickness calculation and surface area calculation. For future works, the whole sets of the experiment will be assessed and the improvement of TRACE will be performed

  13. Steam turbines for nuclear power plants

    International Nuclear Information System (INIS)

    Kosyak, Yu.F.

    1978-01-01

    Considered are the peculiarities of the design and operation of steam turbines, condensers and supplementary equipment of steam turbines for nuclear power plants; described are the processes of steam flow in humid-steam turbines, calculation and selection principles of main parameters of heat lines. Designs of the turbines installed at the Charkov turbine plant are described in detail as well as of those developed by leading foreign turbobuilding firms

  14. Protected air-cooled condenser for the Clinch River Breeder Reactor Plant

    International Nuclear Information System (INIS)

    Louison, R.; Boardman, C.E.

    1981-01-01

    The long term residual heat removal for the Clinch River Breeder Reactor Plant (CRBRP) is accomplished through the use of three protected air-cooled condensers (PACC's) each rated at 15M/sub t/ following a normal or emergency shutdown of the reactor. Steam is condensed by forcing air over the finned and coiled condenser tubes located above the steam drums. The steam flow is by natural convection. It is drawn to the PACC tube bundle for the steam drum by the lower pressure region in the tube bundle created from the condensing action. The concept of the tube bundle employs a unique patented configuration which has been commercially available through CONSECO Inc. of Medfore, Wisconsin. The concept provides semi-parallel flow that minimizes subcooling and reduces steam/condensate flow instabilities that have been observed on other similar heat transfer equipment such as moisture separator reheaters (MSRS). The improved flow stability will reduce temperature cycling and associated mechanical fatigue. The PACC is being designed to operate during and following the design basis earthquake, depressurization from the design basis tornado and is housed in protective building enclosure which is also designed to withstand the above mentioned events

  15. Condensation induced water hammer driven sterilization

    Science.gov (United States)

    Kullberg, Craig M.

    2004-05-11

    A method and apparatus (10) for treating a fluid or materials therein with acoustic energy has a vessel (14) for receiving the fluid with inner walls shaped to focus acoustic energy to a target zone within the vessel. One or more nozzles (26) are directed into the vessel (14) for injecting a condensable vapor, such as steam, into the vessel (14). The system may include a steam source (18) for providing steam as the condensable vapor from an industrial waste heat source. Steam drums (88) are disposed between the steam source (18) and nozzles (26) to equalize and distribute the vapor pressure. A cooling source (30) provides a secondary fluid for maintaining the liquid in the vessel (14) in subcooled conditions. A heating jacket (32) surrounds the vessel (14) to heat the walls of the vessel (14) and prevent biological growth thereon. A pressurizer (33) may operate the system at elevated pressures.

  16. Contribution to the study of unsteady condensation in transonic flow

    International Nuclear Information System (INIS)

    Collignan, B.; Laali, A.R.

    1993-12-01

    The aim of this thesis is the study of transonic steam flows with condensation, especially at high pressure. This study includes a numerical part an experimental one. The modelling has consisted of introducing a spontaneous condensation model in a one-dimensional Euler code using steam-water thermodynamic tables. Calculations, performed with this code, are in good agreement with experimental results at low pressure. The experimental study has been undertaken on a high pressure experimental loop installed at the Bugey nuclear power plant. We have studied steam flows in nozzles. The results obtained show that a partial heterogeneous condensation occurs in these flows. This proportion is stronger if the expansion rate of the flow is low and if the inlet pressure is high. However, a correction factor is obtained for high pressure nucleation rate model from experimental results. No unsteady condensation has been observed for flows between 15 bars and 50 bars with the steam available at Bugey power plant. (authors). figs., 71 refs., 6 annexes

  17. Flow characteristics in nuclear steam turbine blade passage

    International Nuclear Information System (INIS)

    Ahn, H.J.; Yoon, W.H.; Kwon, S.B.

    1995-01-01

    The rapid expansion of condensable gas such as moist air or steam gives rise to nonequilibrium condensation. As a result of irreversibility of condensation process in the nuclear steam turbine blade passage, the entropy of the flow increases, and the efficiency of the turbine decreases. In the present study, in order to investigate the flow characteristics of moist air in two-dimensional turbine blade passage which is made from the configuration of the last stage tip section of the actual nuclear steam turbine moving blade, the static pressures along both pressure and suction sides of blade are measured by static pressure taps and the distribution of Mach number on both sides of the blade are obtained by using the measured static pressure. Also, the flow field is visualized by a Schlieren system. From the experimental results, the effects of the stagnation temperature and specific humidity on the flow properties in the two dimensional steam turbine blade passage are clearly identified

  18. CFD modeling of condensation process of water vapor in supersonic flows

    DEFF Research Database (Denmark)

    Yang, Yan; Walther, Jens Honore; Yan, Yuying

    2017-01-01

    The condensation phenomenon of vapor plays an important role in various industries, such as the steam flow in turbines and refrigeration system. A mathematical model is developed to predict the spontaneous condensing phenomenon in the supersonic flows using the nucleation and droplet growth...... theories. The numerical approach is validated with the experimental data, which shows a good agreement between them. The condensation characteristics of water vapor in the Laval nozzle are described in detail. The results show that the condensation process is a rapid variation of the vapor-liquid phase...... change both in the space and in time. The spontaneous condensation of water vapor will not appear immediately when the steam reaches the saturation state. Instead, it occurs further downstream the nozzle throat, where the steam is in the state of supersaturation....

  19. Leak detection in turbo group condensers using helium

    International Nuclear Information System (INIS)

    Gomez Cores, C.; Lloret, J.

    1997-01-01

    This method allows a rapid location of leaks (small or not) in the pipelines of a turbo group condenser, before opening the condenser boxes and no need of stooping the turbo group operation. This operation can last two hours maximum depending on the volume of the box or semi box. The technique consists of injecting helium into the water side and detecting it in the steam side, in the outlet of not condensable gases of the ejector. In the same way, probable air inlet to the condenser can be proved (auxiliary systems, turbo group joints to the condenser, etc.) in order to improve the vacuum and/or reduce the quantity of oxygen dissolved in the water of the steam side. (author) [es

  20. Investigation of the effect of pressure increasing in condensing heat-exchanger

    Science.gov (United States)

    Murmanskii, I. B.; Aronson, K. E.; Brodov, Yu M.; Galperin, L. G.; Ryabchikov, A. Yu.; Brezgin, D. V.

    2017-11-01

    The effect of pressure increase was observed in steam condensation in the intermediate coolers of multistage steam ejector. Steam pressure increase for ejector cooler amounts up to 1.5 kPa in the first ejector stage, 5 kPa in the second and 7 kPa in the third one. Pressure ratios are equal to 2.0, 1.3 and 1.1 respectively. As a rule steam velocities at the cooler inlets do not exceed 40…100 m/s and are subsonic in all regimes. The report presents a computational model that describes the effect of pressure increase in the cooler. The steam entering the heat exchanger tears the drops from the condensate film flowing down vertical tubes. At the inlet of heat exchanger the steam flow capturing condensate droplets forms a steam-water mixture in which the sound velocity is significantly reduced. If the flow rate of steam-water mixture in heat exchanger is greater than the sound velocity, there occurs a pressure shock in the wet steam. On the basis of the equations of mass, momentum and energy conservation the authors derived the expressions for calculation of steam flow dryness degree before and after the shock. The model assumes that droplet velocity is close to the velocity of the steam phase (slipping is absent); drops do not come into thermal interaction with the steam phase; liquid phase specific volume compared to the volume of steam is neglected; pressure shock is calculated taking into account the gas-dynamic flow resistance of the tube bundle. It is also assumed that the temperature of steam after the shock is equal to the saturation temperature. The calculations have shown that the rise of steam pressure and temperature in the shock results in dryness degree increase. For calculated flow parameters the velocity value before the shock is greater than the sound velocity. Thus, on the basis of generally accepted physics knowledge the computational model has been formulated for the effect of steam pressure rise in the condensing heat exchanger.

  1. Development of technologies on innovative-simplified nuclear power plant using high-efficiency steam injectors. (6) Operating characteristics of center water jet type supersonic steam injector

    International Nuclear Information System (INIS)

    Kawamoto, Yujiro; Abe, Yutaka; Iwaki, Chikako; Narabayashi, Tadashi; Mori, Michitsugu; Ohmori, Shuichi

    2004-01-01

    One of the most interesting devices for next generation reactor systems aiming at simplified system and improvement of safety and credibility is the steam injector which is a passive pump without large motor or turbo-machinery. One of the applications of the steam injector is the passive water injection system to inject the coolant water into the core. The system can be started up merely by injecting the steam without any outer power supply. Since the steam injector is a simple, compact and passive device for water injection, if the steam injector is applied to the actual reactor, it is expected to make the system simple and to reduce the construction cost. Although non-condensable gases are well known for reducing heat transfer between water and steam, the effect of the non-condensable gas on the condensation of supersonic steam on high-speed water jet has not been cleared. The present paper reports about the experimental apparatus, measurement instrument and experimental results of observing the phenomenon inside the test section supplying water and steam to the test by using both the high-speed camera and the video camera and measuring the temperature and the pressure distribution n the test section. (author)

  2. GENERATION, TRANSPORT AND DEPOSITION OF TUNGSTEN-OXIDE AEROSOLS AT 1000 C IN FLOWING AIR-STEAM MIXTURES.

    Energy Technology Data Exchange (ETDEWEB)

    GREENE,G.A.; FINFROCK,C.C.

    2001-10-01

    Experiments were conducted to measure the rates of oxidation and vaporization of pure tungsten rods in flowing air, steam and air-steam mixtures in laminar flow. Also measured were the downstream transport of tungsten-oxide condensation aerosols and their region of deposition, including plateout in the superheated flow tube, rainout in the condenser and ambient discharge which was collected on an array of sub-micron aerosol filters. The nominal conditions of the tests, with the exception of the first two tests, were tungsten temperatures of 1000 C, gas mixture temperatures of 200 C and wall temperatures of 150 C to 200 C. It was observed that the tungsten oxidation rates were greatest in all air and least in all steam, generally decreasing non-linearly with increasing steam mole fraction. The tungsten oxidation rates in all air were more than five times greater than the tungsten oxidation rates in all steam. The tungsten vaporization rate was zero in all air and increased with increasing steam mole fraction. The vaporization rate became maximum at a steam mole fraction of 0.85 and decreased thereafter as the steam mole fraction was increased to unity. The tungsten-oxide was transported downstream as condensation aerosols, initially flowing upwards from the tungsten rod through an 18-inch long, one-inch diameter quartz tube, around a 3.5-inch radius, 90{sup o} bend and laterally through a 24-inch horizontal run. The entire length of the quartz glass flow path was heated by electrical resistance clamshell heaters whose temperatures were individually controlled and measured. The tungsten-oxide plateout in the quartz tube was collected, nearly all of which was deposited at the end of the heated zone near the entrance to the condenser which was cold. The tungsten-oxide which rained out in the condenser as the steam condensed was collected with the condensate and weighed after being dried. The aerosol smoke which escaped the condenser was collected on the sub

  3. Cogeneration steam turbines from Siemens: New solutions

    Science.gov (United States)

    Kasilov, V. F.; Kholodkov, S. V.

    2017-03-01

    The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions.

  4. Water jet behavior in center water jet type supersonic steam injector

    International Nuclear Information System (INIS)

    Kawamoto, Y.; Abe, Y.

    2005-01-01

    Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. As previous studies of the steam injector, there are studies about formulation of operating characteristic of steam injector and analysis of jet structure in steam injector by Narabayashi etc. And as previous studies of the direct contact condensation, there is the study about the direct contact condensation in steam atmosphere. However the study about the turbulent heat transfer under the great shear stress is not enough investigated. Therefore it is necessary to examine in detail about the operating characteristic of the steam injector. The present paper reports the observation results of the water jet behavior in the super sonic steam injector by using the video camera and the high-speed video camera. And the measuring results of the temperature and the pressure distribution in the steam injector are reported. From observation results by video camera, it is cleared that the water jet is established at the center of the steam injector right after steam supplied and the operation of the steam injector depends on the throat diameter. And from observation results by high-speed video camera, it is supposed that the columned water jet surface is established in the mixing nozzle and the water jet surface movement exists. Furthermore and effect of the non-condensable gas on the steam injector is investigated by measuring the radial temperature distributions in the water jet. From measuring results, it is supposed the more the air included in the steam, the more the temperature fluctuation of both steam and discharge water

  5. Code-experiment comparison on wall condensation tests in the presence of non-condensable gases-Numerical calculations for containment studies

    Energy Technology Data Exchange (ETDEWEB)

    Malet, J., E-mail: jeanne.malet@irsn.fr [Institut de Radioprotection et de Surete Nucleaire (IRSN), PSN-RES, SCA, BP 68, 91192 Gif-sur-Yvette (France); Porcheron, E.; Dumay, F.; Vendel, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN), PSN-RES, SCA, BP 68, 91192 Gif-sur-Yvette (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Steam condensation on walls has been investigated in the TOSQAN vessel. Black-Right-Pointing-Pointer Experiments on 7 different tests have been performed. Black-Right-Pointing-Pointer Different steam injections and wall temperatures are used. Black-Right-Pointing-Pointer Simulations are performed in 2D using the TONUS code. Black-Right-Pointing-Pointer Code-experiments comparisons at many different locations show a good agreement. - Abstract: During the course of a severe Pressurized Water Reactor accident, pressurization of the containment occurs and hydrogen can be produced by the reactor core oxidation and distributed in the containment according to convection flows and wall condensation. Filmwise wall condensation in the presence of non-condensable gases is a subject of many interests and extensive studies have been performed in the past. Some empirical correlations have demonstrated their limit for extrapolation under different thermal-hydraulic conditions and at different geometries/scales. The French Institute for Radiological Protection and Nuclear Safety (IRSN) has developed a numerical tool and an experimental facility in order to investigate free convection flows in the presence of condensation. The objective of this paper is to present numerical results obtained on different wall condensation tests in 7 m{sup 3} volume vessel (TOSQAN facility), and to compare them with the experimental ones. Over eight tests are considered here, and code-experiment comparison is performed on many different locations, giving an extensive insight of the code assessment for air-steam mixture flows involving wall condensation in the presence of non-condensable gases.

  6. Use of fundamental condensation heat transfer experiments for the development of a sub-grid liquid jet condensation model

    Energy Technology Data Exchange (ETDEWEB)

    Buschman, Francis X., E-mail: Francis.Buschman@unnpp.gov; Aumiller, David L.

    2017-02-15

    Highlights: • Direct contact condensation data on liquid jets up to 1.7 MPa in pure steam and in the presence of noncondensable gas. • Identified a pressure effect on the impact of noncondensables to suppress condensation heat transfer not captured in existing data or correlations. • Pure steam data is used to develop a new correlation for condensation heat transfer on subcooled liquid jets. • Noncondensable data used to develop a modification to the renewal time estimate used in the Young and Bajorek correlation for condensation suppression in the presence of noncondensables. • A jet injection boundary condition, using a sub-grid jet condensation model, is developed for COBRA-IE which provides a more detailed estimate of the condensation rate on the liquid jet and allows the use of jet specific closure relationships. - Abstract: Condensation on liquid jets is an important phenomenon for many different facets of nuclear power plant transients and analyses such as containment spray cooling. An experimental facility constructed at the Pennsylvania State University, the High Pressure Liquid Jet Condensation Heat Transfer facility (HPLJCHT), has been used to perform steady-state condensation heat transfer experiments in which the temperature of the liquid jet is measured at different axial locations allowing the condensation rate to be determined over the jet length. Test data have been obtained in a pure steam environment and with varying concentrations of noncondensable gas. This data extends the available jet condensation data from near atmospheric pressure up to a pressure of 1.7 MPa. An empirical correlation for the liquid side condensation heat transfer coefficient has been developed based on the data obtained in pure steam. The data obtained with noncondensable gas were used to develop a correlation for the renewal time as used in the condensation suppression model developed by Young and Bajorek. This paper describes a new sub-grid liquid jet

  7. Use of fundamental condensation heat transfer experiments for the development of a sub-grid liquid jet condensation model

    International Nuclear Information System (INIS)

    Buschman, Francis X.; Aumiller, David L.

    2017-01-01

    Highlights: • Direct contact condensation data on liquid jets up to 1.7 MPa in pure steam and in the presence of noncondensable gas. • Identified a pressure effect on the impact of noncondensables to suppress condensation heat transfer not captured in existing data or correlations. • Pure steam data is used to develop a new correlation for condensation heat transfer on subcooled liquid jets. • Noncondensable data used to develop a modification to the renewal time estimate used in the Young and Bajorek correlation for condensation suppression in the presence of noncondensables. • A jet injection boundary condition, using a sub-grid jet condensation model, is developed for COBRA-IE which provides a more detailed estimate of the condensation rate on the liquid jet and allows the use of jet specific closure relationships. - Abstract: Condensation on liquid jets is an important phenomenon for many different facets of nuclear power plant transients and analyses such as containment spray cooling. An experimental facility constructed at the Pennsylvania State University, the High Pressure Liquid Jet Condensation Heat Transfer facility (HPLJCHT), has been used to perform steady-state condensation heat transfer experiments in which the temperature of the liquid jet is measured at different axial locations allowing the condensation rate to be determined over the jet length. Test data have been obtained in a pure steam environment and with varying concentrations of noncondensable gas. This data extends the available jet condensation data from near atmospheric pressure up to a pressure of 1.7 MPa. An empirical correlation for the liquid side condensation heat transfer coefficient has been developed based on the data obtained in pure steam. The data obtained with noncondensable gas were used to develop a correlation for the renewal time as used in the condensation suppression model developed by Young and Bajorek. This paper describes a new sub-grid liquid jet

  8. Flue gas condensation in oxyfuel power plants. Heat- and mass transfer measurements and experimental validation of an efficient condensation concept; Rauchgaskondensation in Oxyfuel-Kraftwerken. Waerme- und Stoffuebergangsmessungen sowie experimentelle Validierung eines effizienten Kondensationskonzepts

    Energy Technology Data Exchange (ETDEWEB)

    Raindl, Markus

    2010-12-06

    Condensation of a steam-inert gas mixture in an Oxyfuel condenser differs significantly from condensation of pure steam: condenser pressure and rest gas content increase dramatically, heat- and mass transfer coefficients are lower and oversaturation of the steam-inert gas mixture yields to fog formation. In the context of this thesis, therefore, at first the optimal ranges of working parameters for Oxyfuel processes calculated. In the following some heat flux measurements were carried out on a horizontal, crossflow pipe to validate various heat- and mass transfer theories. Building on these results a new, efficient condensation concept was developed to reduce fog formation. The final results of the measurements with a laboratory model show great performance regarding fog reduction and condensation efficiency. (orig.)

  9. High Temperatures Health Monitoring of the Condensed Water Height in Steam Pipe Systems

    Science.gov (United States)

    Lih, Shyh-Shiuh; Bar-Cohen, Yoseph; Lee, Hyeong Jae; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Takano, Nobuyuki; Ostlund, Patrick; Blosiu, Julian

    2013-01-01

    Ultrasonic probes were designed, fabricated and tested for high temperature health monitoring system. The goal of this work was to develop the health monitoring system that can determine the height level of the condensed water through the pipe wall at high temperature up to 250 deg while accounting for the effects of surface perturbation. Among different ultrasonic probe designs, 2.25 MHz probes with air backed configuration provide satisfactory results in terms of sensitivity, receiving reflections from the target through the pipe wall. A series of tests were performed using the air-backed probes under irregular conditions, such as surface perturbation and surface disturbance at elevated temperature, to qualify the developed ultrasonic system. The results demonstrate that the fabricated air-backed probes combined with advanced signal processing techniques offer the capability of health monitoring of steam pipe under various operating conditions.

  10. Development of high performance condensers for thermal and nuclear power plants

    International Nuclear Information System (INIS)

    Okouchi, Isao; Takahashi, Sankichi; Tomita, Akira.

    1980-01-01

    As the trend toward the large capacity of thermal and nuclear power plants advances, condensers also become large, and from the viewpoint of energy saving in whole plants, the maintenance of high performance and reliability is strongly desired. Hitachi Ltd. responded to this demand, and repeated the basic investigation with a model condenser on the selection of condenser cooling tubes and their arrangement. As the result, balanced downflow type tube arrangement was developed, which enables smooth steam flow and the improvement of condenser performance by forming the intense flow of turbine exhaust from the upper part of tube nest downward and making the steam flow in the lower part of tube nest into radial form toward air ejecting port. This tube arrangement has been applied to actual machines, and the excellent results have been obtained. In particular, the improvement of the degree of vacuum due to the reduction of steam flow loss is advantageous for increasing the power output of turbines. Thereupon, based on the basic experiment with various models of tube arrangement and the consideration on the operational results of actual machines using this tube arrangement, the features of this technique are reported. The basic construction of tube arrangement, the steam flow in tube nest, the vacuum in condensers, the supercooling of condensate, and actual balanced downflow type condensers are described. (Kako, I.)

  11. Condensation phenomena in BWR-pressure suppression containments under LOCA conditions

    International Nuclear Information System (INIS)

    Aust, E.; McCauley, E.W.; Niemann, H.R.

    1983-01-01

    Experimental studies on condensation phenomena in pressure suppression systems (PSS) have shown, that chugging produces the major dynamic loads in a PSS. Time correlation of digital and visual data have produced understanding of the essential physics of this phenomenon: chugging events are characterized by pipe outside and pipe inside condensation. Pipe outside condensation is smooth, sometimes accompanied by vent pipe acoustic frequency. Pipe inside condensation is ring-like and induces a strong pressure pulse with ringdown frequency. The steam ring is caused by the retreating steam front in the pipe exit, which acts as a BORDA-mouth. (orig.) [de

  12. Optimization of steam-vortex plasma-torch start-up

    Science.gov (United States)

    Mikhailov, B. I.

    2011-12-01

    We propose a new optimal method of steam-vortex plasma-torches start-up; this method completely prevents the danger of water steam condensation in the arc chamber and all undesirable consequences of it.

  13. Effect of steam condensation on pressure and temperature under hydrogen jet fire in a vented enclosure

    International Nuclear Information System (INIS)

    Kuznetsov, Mike; Xiao, Jianjun; Travis, Jack

    2017-01-01

    Hydrogen release through leaks due to the LOCA and MCCI accidents and its immediate ignition leads to formation of hydrogen jet fire in a containment of reactor building. An experimental study of hydrogen jet fire in a chamber of 1x1x1 m 3 volume with different vent position, vent areas from 1 to 90 cm 2 and hydrogen mass flow rates from 0.027 to 1.087 g/s were performed in current work. Depending on hydrogen mass flow rate and vent area a well-ventilated or under-ventilated jet fire regime may occur. In the case of relatively small hydrogen release rate and large vent area, relatively stable jet fire behaviour for well-ventilated jet fire leading to over-pressure not more than 0.8 mbar was found. Three different scenarios of under-ventilated jet fire behaviour with self-extinction, re-ignition and external flame leading to relatively high overpressure of 10-100 mbar were found experimentally and numerically. Numerical simulations with GASFLOW-MPI code were performed with/without modelling heat conduction in solid walls, steam condensation, convective heat transfer and thermal radiation. With heat transfer modelling, both initial pressure peak and pressure decay were very well predicted compared to the experimental data. Numerical simulations were then compared with experimental Background Oriented Schlieren (BOS) images obtained to visualize the hydrogen combustion process. Self-extinction and re-ignition events were captured in the numerical simulation as well. An adiabatic case indicates that heat transfer and steam condensation must be included into the combustion model to accurately predict the physical phenomena of turbulent hydrogen jet flames in a vented enclosure. (author)

  14. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    Tavast, J.

    1988-03-01

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  15. Dry coolers and air-condensing units (Review)

    Science.gov (United States)

    Milman, O. O.; Anan'ev, P. A.

    2016-03-01

    The analysis of factors affecting the growth of shortage of freshwater is performed. The state and dynamics of the global market of dry coolers used at electric power plants are investigated. Substantial increase in number and maximum capacity of air-cooled condensers, which have been put into operation in the world in recent years, are noted. The key reasons facilitating the choice of developers of the dry coolers, in particular the independence of the location of thermal power plant from water sources, are enumerated. The main steam turbine heat removal schemes using air cooling are considered, their comparison of thermal efficiency is assessed, and the change of three important parameters, such as surface area of heat transfer, condensate pump flow, and pressure losses in the steam exhaust system, are estimated. It is shown that the most effective is the scheme of direct steam condensation in the heat-exchange tubes, but other schemes also have certain advantages. The air-cooling efficiency may be enhanced much more by using an air-cooling hybrid system: a combination of dry and wet cooling. The basic applied constructive solutions are shown: the arrangement of heat-exchange modules and the types of fans. The optimal mounting design of a fully shopassembled cooling system for heat-exchange modules is represented. Different types of heat-exchange tubes ribbing that take into account the operational features of cooling systems are shown. Heat transfer coefficients of the plants from different manufacturers are compared, and the main reasons for its decline are named. When using evaporative air cooling, it is possible to improve the efficiency of air-cooling units. The factors affecting the faultless performance of dry coolers (DC) and air-condensing units (ACU) and the ways of their elimination are described. A high velocity wind forcing reduces the efficiency of cooling systems and creates preconditions for the development of wind-driven devices. It is noted that

  16. Combined gas and steam power plant

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, D T; Davis, J P

    1977-06-02

    The invention concerns a combination of internal combustion engine and steam turbine, where not only the heat of the hot exhaust gases of the internal combustion engine, but also the heat in the coolant of the internal combustion engine is used for power generation. The working fluid of the steam turbine is an organic fluid of low boiling point. A mixture of 85 mol% of tri-fluoro ethanol and 15 mol% of water is the most suitable fluid. The combustion engine (a Diesel engine is the most suitable), drives a working machine, e.g. a generator. The hot combustion exhaust gases produce evaporation of the working fluid in an HP evaporator. The superheated steam gives up its energy in the HP turbine stage, flows through the feed preheater of the fluid, and is condensed in the condenser. A pump pumps the fluid via control valve to heat the feed preheater of the fluid, from which it returns to the HP evaporator. At the same time evaporated coolant flows into an LP evaporator in counter-flow to the working fluid, condenses, and is returned to the cooling circuit of the combustion engine. The working fluid in the LP evaporator is heated to its boiling point, gives up its energy in the LP stage of the steam turbine is condensed, pumped to the preheater and returns to the LP evaporator. The two rotors of the turbine stages (HP and LP stages) are mounted on the same shaft, which drives a working machine or a generator.

  17. Numerical Simulation on Forced Convective Condensation of Steam Upward Flow in a Vertical Pipe

    Directory of Open Access Journals (Sweden)

    Guo-Dong Qiu

    2014-05-01

    Full Text Available A transient three-dimensional volume of fluid (VOF simulation on condensation of upward flow of wet steam inside a 12 mm i.d. vertical pipe is presented. The effect of gravity and surface tension are taken into account. A uniform wall temperature has been fixed as boundary conditions. The mass flux is 130~6400 kg m−2's−1 and the turbulence inside the vapor phase and liquid phase have been handled by Reynolds stress model (RSM. The vapor quality of fluid is 0~0.4. The numerical simulation results show that, in all the simulation conditions, the bubbly flow, slug flow, churn flow, wispy annular flow, and annular flow are observed; in addition, the results of flow pattern are in good agreement with the regime map from Hewitt and Roberts. The typical velocity field characteristic of each flow pattern and the effect of velocity field on heat transfer of condensation are analyzed, indicating that the slug flow and churn flow have obvious local eddy. However, no obvious eddy is observed in other flow patterns and the streamlines are almost parallel to the flow direction. The simulation results of heat transfer coefficients and frictional pressure drop show good agreement with the correlations from existing literatures.

  18. Numerical Research of Steam and Gas Plant Efficiency of Triple Cycle for Extreme North Regions

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2016-01-01

    Full Text Available The present work shows that temperature decrease of heat rejection in a cycle is necessary for energy efficiency of steam turbine plants. Minimum temperature of heat rejection at steam turbine plant work on water steam is 15°C. Steam turbine plant of triple cycle where lower cycle of steam turbine plant is organic Rankine cycle on low-boiling substance with heat rejection in air condenser, which safely allows rejecting heat at condensation temperatures below 0°C, has been offered. Mathematical model of steam and gas plant of triple cycle, which allows conducting complex researches with change of working body appearance and parameters defining thermodynamic efficiency of cycles, has been developed. On the basis of the model a program of parameters and index cycles design of steam and gas plants has been developed in a package of electron tables Excel. Numerical studies of models showed that energy efficiency of steam turbine plants of triple cycle strongly depend on low-boiling substance type in a lower cycle. Energy efficiency of steam and gas plants net 60% higher can be received for steam and gas plants on the basis of gas turbine plant NK-36ST on pentane and its condensation temperature below 0°C. It was stated that energy efficiency of steam and gas plants net linearly depends on condensation temperature of low-boiling substance type and temperature of gases leaving reco very boiler. Energy efficiency increases by 1% at 10% decrease of condensation temperature of pentane, and it increases by 0.88% at 15°C temperature decrease of gases leaving recovery boiler.

  19. Theoretical modeling of condensation of steam outside different vertical geometries (tube, flat plates) in the presence of noncondensable gases like air and helium

    International Nuclear Information System (INIS)

    Ganguli, Arijit; Patel, A.G.; Maheshwari, N.K.; Pandit, A.B.

    2008-01-01

    Condensation of steam coming out from the coolant pipe during a loss of coolant accident (LOCA) plays a key role in removing heat from the primary containment of the advanced nuclear reactor (ANR). The presence of large mass fractions of air (W air = 0.25-0.9) and a small mass fraction of helium (W He = 0.017-0.083) reduces the overall heat transfer coefficient (HTC) substantially. The present work emphasizes on the issue that modeling the diffusion of water-vapor through the gas-liquid interface is the key to give good predictions in HTC. In this, condensation conductivity and effective diffusivity plays a key role. Therefore, modifications have been made in the derivation for calculation of condensation conductivity in the case of steam-air mixture and effective diffusivity (in the case of multicomponent mixture). The model validation has been done with the experimental data of Dehbi et al. [Dehbi, A.A., Golay, M.W., Kazimi, M.S., 1991. National Conference of Heat Transfer AIChE Symposium Series, pp. 19-28] and Anderson et al. [Anderson, M.H., Herranz, L.E., Corradini, M.L., 1998. Experimental analysis of heat transfer within the AP600 containment under postulated accident conditions. Nucl. Eng. Des. 185, 153-172] and other analytical models available in the literature [Herranz, L.E., Anderson, M.H., Corradini, M.H., 1998a. The effect of light gases in noncondensable mixtures on condensation heat transfer. Nucl. Eng. Des. 183, 133-150; Herranz, L.E., Anderson, M.H., Corradini, M.L., 1998b. A diffusion layer model for steam condensation within the AP600 containment. Nucl. Eng. Des. 185, 153-172; Peterson, P.F., Schrock, Y.E., Kageyama, T., 1993. Diffusion layer theory for turbulent vapor condensation with noncondensable gases. J. Heat Transf., 115; Dehbi, A.A., Golay, M.W., Kazimi, M.S., 1991. National Conference of Heat Transfer AIChE Symposium Series, pp. 19-28]. Since the validations of the results were found satisfactory, the datasets [Dehbi, A.A., Golay, M

  20. Experimental study on the unstable direct contact condensation regimes

    International Nuclear Information System (INIS)

    Damasio, C.; Del Tin, G.; Fiegna, G.; Malandrone, M.

    1985-01-01

    Vapour-liquid interface fluctuation frequencies have been measured by means of electrical resistive probes. Frequency data from these probes have been compared with measured frequencies from a Kistler piezoelectric pressure transducer in the pool near the steam-water interaction region. An attempt has been made to correlate measured frequencies to the observed condensation regimes. Experimental data concerning ''steam chugging'' and condensation oscillation regimes have been correlated in terms of dimensionless parameters

  1. Gas Flow Validation with Panda Tests from the OECD SETH Benchmark Covering Steam/Air and Steam/Helium/Air Mixtures

    International Nuclear Information System (INIS)

    Royl, P.; Travis, J.R.; Breitung, W.; Kim, J.; Kim, S.B.

    2009-01-01

    The CFD code GASFLOW solves the time-dependent compressible Navier-Stokes Equations with multiple gas species. GASFLOW was developed for nonnuclear and nuclear applications. The major nuclear applications of GASFLOW are 3D analyses of steam/hydrogen distributions in complex PWR containment buildings to simulate scenarios of beyond design basis accidents. Validation of GASFLOW has been a continuously ongoing process together with the development of this code. This contribution reports the results from the open posttest GASFLOW calculations that have been performed for new experiments from the OECD SETH Benchmark. Discussed are the steam distribution tests 9 and 9 bis, 21 and 21 bis involving comparable sequences with and without steam condensation and the last SETH test 25 with steam/helium release and condensation. The latter one involves lighter gas mixture sources like they can result in real accidents. The helium is taken as simulant for hydrogen

  2. Evaporation and condensation heat transfer with a noncondensable gas present

    International Nuclear Information System (INIS)

    Murase, M.; Kataoka, Y.; Fujii, T.

    1993-01-01

    To evaluate the system pressure of an external water wall type containment vessel, which is one of the passive systems for containment cooling, the evaporation and condensation behavior under a noncondensable gas presence has been experimentally examined. In the system, steam evaporated from the suppression pool surface into the wetwell, filled with noncondensable gas, and condensed on the containment vessel wall. The system pressure was the sum of the noncondensable gas pressure and saturated steam pressure in the wetwell. The wetwell temperature was, however, lower than the suppression pool temperature and depended on the thermal resistance on the suppression pool surface. The evaporation and condensation heat transfer coefficients in the presence of air as noncondensable gas were measured and expressed by functions of steam/air mass ratio. The evaporation heat transfer coefficients were one order higher than the condensation heat transfer coefficients because the local noncondensable gas pressure was much lower on the evaporating pool surface than on the condensing liquid surface. Using logal properties of the heat transfer surfaces, there was a similar trend between evaporation and condensation even with a noncondensable gas present. (orig.)

  3. Condensers for measuring steam quality at the inlet of back-pressure units of the Los Azufres, Mich., geothermal field; Condensadores para medir la calidad del vapor a la entrada de las turbinas a contrapresion del campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval Medina, Fernando; Gonzalez Gonzalez, Rubi; Reyes Delgado, Lisette; Medina Martinez, Moises [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres (Mexico)]. E-mail: fernando.sandoval@cfe.gob.mx

    2007-01-15

    Electrical conductivity is an indirect measurement of the quality of the steam supplied to power units. In the Los Azufres, Mich., geothermal field, the electrical conductivity once was measured in a discrete and periodic way by condensing steam samples through a water-cooled condenser. In an attempt to continuously measure conductivity, conductivity meters were installed where the units discharged, but the values proved unstable and unrepresentative. Thereafter, taking into account that steam quality should be measured at the steam delivery-reception point, equipment was designed and tested for continuously condensing steam. Finally it was possible to get an air-cooled condenser able to condense 500 milliliters per minute, enough to collect a representative flow of the steam and to measure its electrical conductivity. The equipment was installed in all seven back-pressure units operating in the field and to date has been operating in an optimal manner. [Spanish] La conductividad electrica es una medida indirecta de la calidad del vapor que se suministra a las unidades turbogeneradoras. En el campo geotermico de Los Azufres, Mich., la conductividad electrica se media en forma puntual y periodica, condensando muestras de vapor por medio de un serpentin enfriado con agua. Despues, ante la necesidad de medirla en forma continua, se instalaron conductivimetros en las descargas de las unidades, pero los valores resultaron muy inestables y poco representativos. Considerando, ademas, que la calidad del vapor debe medirse en el punto de entrega-recepcion, se disenaron y probaron equipos para condensar vapor de manera continua, lograndose construir un condensador enfriado por aire que logra condensar un flujo de 500 mililitros por minuto, cantidad suficiente para tener un flujo representativo del vapor que alimenta a las turbinas y medirle su conductividad electrica. Se instalaron estos equipos en las siete unidades turbogeneradoras a contrapresion que funcionan en el campo

  4. The Effect of Condensing Steam Turbine Exhaust Hood Body Geometry on Exhaust Performance Efficiency

    Science.gov (United States)

    Gribin, V. G.; Paramonov, A. N.; Mitrokhova, O. M.

    2018-06-01

    The article presents data from combined numerical and experimental investigations of the effect that the overall dimensions of the exhaust hood of a steam turbine with an underslung condenser has on the aerodynamic losses in the hood. Owing to the properly selected minimum permissible overall dimensions of the exhaust hood, more efficient operation of this turbine component is achieved, better vibration stability of the turbine set shaft line is obtained, and lower costs are required for arranging the steam turbine plant in the turbine building. Experiments have shown that the main overall dimensions of the hood body have a determining effect on the exhaust hood flow path profile and on its aerodynamic performance. Owing to properly selected ratios between the exhaust hood body main sizes without a diffuser, a total loss coefficient equal to approximately unity has been obtained. By using an axial-radial diffuser, the energy loss can be decreased by 30-40% depending on the geometrical parameters and level of velocities in the inlet section of a hood having the optimal overall dimensions. By using the obtained results, it becomes possible to evaluate the overall dimensions necessary for achieving the maximal aerodynamic hood efficiency and, as a consequence, to obtain better technical and economic indicators of the turbine plant as a whole already at the initial stage of its designing. If a need arises to select overall dimensions smaller than their optimal values, the increase of energy loss can be estimated using the presented dependences. The cycle of investigations was carried out on the experimental setups available in the fundamental research laboratory of the Moscow Power Engineering Institute National University's Department of Steam and Gas Turbines with due regard to the operating parameters and similarity criteria.

  5. Thermal stability of chloroform in the steam condensate cycle of CANDU-PHW nuclear power plant

    International Nuclear Information System (INIS)

    Lepine, Louis; Gilbert, Roland; Ouellet, Lorenzo

    1992-01-01

    Analysis of samples taken at the Gentilly 2 (Quebec) CANDU-PHW (CANadian Deuterium Uranium - Pressurized Heavy Water) plant after chlorination and demineralization revealed the presence of all four trihalomethanes (THMs) (CHCl 3 , CHBrCl 2 , CHBr 2 Cl and CHBr 3 ) and other unidentified halogenated volatile compounds. Among the THMs, chloroform was the major contaminant. A study of its thermal stability in water at different temperatures confirmed the degradation of the CHCl 3 molecule according to the equation CHCl 3 + H2O → CO + 3 HCl. The reaction follows first order kinetics and has an activation energy of 100 kJ/mol. The estimated half-life is six seconds at 260 deg C, the maximum temperature of the steam condensate cycle

  6. Air-cooled steam condensers non-freeze warranties

    Energy Technology Data Exchange (ETDEWEB)

    Larinoff, M.W.

    1995-09-01

    What this paper is suggesting is the seller quote a condenser package with a LIMITED NON-FREEZE WARRANTY. Relieve the inexperienced buyer of the responsibility for selecting freeze protection design options. The seller cannot afford to over-design because of the added costs and the need for a competitive price. Yet he cannot under-design and allow the condenser tubes to freeze periodically and then pay the repair bills in accordance with the warranty.

  7. Boilers, evaporators, and condensers

    International Nuclear Information System (INIS)

    Kakac, S.

    1991-01-01

    This book reports on the boilers, evaporators and condensers that are used in power plants including nuclear power plants. Topics included are forced convection for single-phase side heat exchangers, heat exchanger fouling, industrial heat exchanger design, fossil-fuel-fired boilers, once through boilers, thermodynamic designs of fossil fuel-first boilers, evaporators and condensers in refrigeration and air conditioning systems (with respect to reducing CFC's) and nuclear steam generators

  8. Condensation induced non-condensable accumulation in a non-vented horizontal pipe connected with an elbow and a vertical pipe

    International Nuclear Information System (INIS)

    Stevanovic, V.D.; Stosic, Z.V.; Stoll, U.

    2005-01-01

    In this paper the radiolytic gases (hydrogen and oxygen) accumulation is investigated numerically for the pipe geometry consisting of a horizontal pipe closed at one end, and connected via a downward directed elbow with a vertical pipe open at its bottom end. This configuration is a typical part of many pipeline systems or measuring lines. The steam inside the pipes is condensed due to heat losses to the surrounding atmosphere, the condensate is drained and the concentration of the remaining noncondensable radiolytic gases is increased. Three dimensional numerical simulations are performed with the thermal-hydraulic and physico-chemical code HELIO, especially developed for the simulation and analyses of radiolytic gases accumulation in pipelines. The HELIO code model is based on the mass, momentum and energy conservation equations for the gas mixture and wall condensate film flow, as well as on the transport equations for non-condensable diffusion and convection. At the liquid film surface, the phases are coupled through the no-slip velocity condition and the mass transfer due to steam condensation and non-condensable absorption and degassing. Obtained numerical results show the gas mixture and condensate liquid film flow fields. In case of here analyzed geometry, the gas mixture circulates in the elbow and the horizontal pipe due to buoyancy forces induced by concentration and related density differences. The circulation flow prevents the formation of the radiolytic gases concentration front. The non-condensable radiolytic gases are transported from the pipe through the open end by the mechanisms of diffusion and convection. The analyzed geometry is the same as in case of venting pipe mounted on the steam pipeline. The results are of practical importance since they show that radiolytic gases accumulation does not occur in the geometry of the venting pipes. (authors)

  9. Assessment of Condenser Design in the Cooling System of PWR

    International Nuclear Information System (INIS)

    Sukmanto Dibyo

    2008-01-01

    This paper explains various cases related to the problem of condenser design principle. Condenser equipment is circuit component of cooling that is very important. Steam that goes down from the turbine, flowing to the condenser and the steam is condensate to be water. Step of design is beginning from identification of problem until mechanic design. Usually, the condenser is designed by conservative certain levels, as well as thermal aspect or mechanic. Beside that, the design analysis is also anticipated to the existing of degradation due to aging therefore safety aspect and requirement are accepted. The assessment that related to the condenser design has been discussed. Most important aspect is obtaining of performances. Beside that, the discussion is also described about design method and that complication should consider aspect of thermal design, physics, economic, aspect of corrosion and others factors. (author)

  10. Condensation heat transfer with noncondensable gas for passive containment cooling of nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Leonardi, Tauna [Schlumberger, 14910 Airline Rd., Rosharon, TX 77583 (United States)]. E-mail: Tleonardi@slb.com; Ishii, Mamoru [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)]. E-mail: Ishii@ecn.purdue.edu

    2006-09-15

    Noncondensable gases that come from the containment and the interaction of cladding and steam during a severe accident deteriorate a passive containment cooling system's performance by degrading the heat transfer capabilities of the condensers in passive containment cooling systems. This work contributes to the area of modeling condensation heat transfer with noncondensable gases in integral facilities. Previously existing correlations and models are for the through-flow of the mixture of steam and the noncondensable gases and this may not be applicable to passive containment cooling systems where there is no clear passage for the steam to escape. This work presents a condensation heat transfer model for the downward cocurrent flow of a steam/air mixture through a condenser tube, taking into account the atypical characteristics of the passive containment cooling system. An empirical model is developed that depends on the inlet conditions, including the mixture Reynolds number and noncondensable gas concentration.

  11. Integrated steam generation process and system for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Betzer-Zilevitch, M. [Ex-Tar Technologies Inc., Calgary, AB (Canada)

    2010-07-01

    A method of producing steam for the extraction of heavy bitumens was presented. The direct contact steam generation (DCSG) method is used for the direct heat transfer between combustion gas and contaminated liquid phase water to generate steam. This paper presented details of experimental and field studies conducted to demonstrate the DCSG. Results of the study demonstrated that pressure and temperature are positively correlated. As pressure increases, the flow rate of the discharged mass decreases and the steam ratio decreases. As pressure increases, the condensate and distillate flow rates increases while water vapor losses in the non-condensable gases decrease. The study indicated that for a 10 bar pressurized system producing 9.6 mt per hour of 10,000 kpa steam and 9.6 mt per hour of distillate BFW, 70 percent of the combustion energy should be recovered to generate 10,000 kpa pressure steam for EOR. Combustion energy requirements were found to decrease when pressure decreases. 11 refs., 5 tabs., 8 figs.

  12. Experimental and theoretical investigations on condensation heat transfer at very low pressure to improve power plant efficiency

    International Nuclear Information System (INIS)

    Berrichon, J.D.; Louahlia-Gualous, H.; Bandelier, Ph.; Bariteau, N.

    2014-01-01

    Highlights: • Theoretical model for condensation heat transfer at very low pressure is developed using only one iterative loop. • Experimental results on steam and air steam condensation heat transfer at very low pressure are presented. • The developed model gives the good predictions for local condensation heat transfer at low pressure. • A maximal deterioration of 50% in condensation heat transfer is obtained at low pressure for air fraction of 4%. • A new correlation including effect of a wavy film surface for steam condensation at low pressure is suggested. - Abstract: This paper presents experimental investigation on the influence of very low pressure on local and average condensation heat transfer in a vertical tube. Furthermore, this paper develops an analytical study for film condensation heat transfer coefficient in the presence of non-condensable gas inside a vertical tube. The condensate film thickness is calculated for each location in a tube using mass and heat transfer analogy. The effects of interfacial shear stress and waves on condensate film surface are included in the model. The comparative studies show that the present model well predicts the experimental data of Khun et al. [1]for local condensation of steam air mixture at high pressure. Different correlations defined for condensation heat transfer are evaluated. It is found that the correlations of Cavallini and Zecchin [2] and Shah [3] are the closest to the calculated steam condensation local heat transfer coefficient. The model gives a satisfactory accuracy with the experimental results for condensation heat transfer at very low pressure. The mean deviation between the predictions of the theoretical model with the measurements for pure saturated vapor is 12%. Experimental data show that the increase of air fraction to 4% deteriorates condensation heat transfer at low pressure up to 50%

  13. Research progress of control of condensate depression for condenser

    Science.gov (United States)

    Liu, Ying; Liang, Run; Li, Fengyu

    2017-08-01

    It is introduced that significance and structure of the condensate depression control system. In accordance with controller devised procedure, we analyze and elaborate how to construct the lumped parameter and dynamic mathematical model which possesses distinct physics significance. Neural network model being called black-box model is also introduced. We analyze and contrast the control technique of condensate depression as conventional PI control, fuzzy PI control and fuzzy control. It is indicated that if the controller of condensate depression were devised inappropriate, while the steam discharged of turbine varying by a large margin, would result in the rotation rate of cooling water circulating pump accelerating at a great lick even to trigger the galloping danger which is less impressive for the units operating safely.

  14. Numerical simulation of condensation phase change flow in an inclined tube with bend

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Shin, Byung Soo; Do, Kyu Sik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Lee, Yong Kap [Anflux Co., Seoul (Korea, Republic of)

    2012-10-15

    The new PWR design named APR+ incorporates a passive auxiliary feedwater system (PAFS) as shown in Fig.1. The PAFS consists of two separate divisions. Each division is equipped with one passive condensation heat exchanger (PCHX), isolation or drain or vent valves, check valves, instrumentation and control, and pipes. It is aligned to feed condensed water to its corresponding steam generator (SG). During the PAFS normal operation, steam being produced in the SG secondary side by the residual heat moves up due to buoyancy force and then flows into the PCHX where steam is condensed on the inner surface of the tubes of which the outer surfaces are cooled by the water stored in the passive condensation cooling tank (PCCT). The condensate is passively fed into the SG economizer by gravity. Because the thermal hydraulic characteristics in the PCHT determine the condensation mass rate and the possibility of system instability and water hammer, it is important to understand the condensation phase change flow in the PCHT. This paper presents a numerical simulation of the condensation phase change flow in the PCHX adopted for the APR+ PAFS.

  15. Development of technologies on innovative-simplified nuclear power plant using high-efficiency steam injectors (5) operating characteristics of center water jet type supersonic steam injector

    International Nuclear Information System (INIS)

    Abe, Y.; Kawamoto, Y.; Iwaki, C.; Narabayashi, T.; Mori, M.; Ohmori, S.

    2005-01-01

    Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. As previous studies of the steam injector, there are studies about formulation of operating characteristic of steam injector and analysis of jet structure in steam injector by Narabayashi etc. And as previous studies of the direct contact condensation, there is the study about the direct contact condensation in steam atmosphere. However the study about the turbulent heat transfer under the great shear stress is not enough investigated. Therefore it is necessary to examine in detail about the operating characteristic of the steam injector. The present paper reports the observation results of the water jet behavior in the super sonic steam injector by using the video camera and the high-speed video camera. And the measuring results of the temperature and the pressure distribution in the steam injector are reported. From observation results by video camera, it is cleared that the water jet is established at the center of the steam injector right after steam supplied and the operation of the steam injector depends on the throat diameter. And from observation results by high-speed video camera, it is supposed that the columned water jet surface is established in the mixing nozzle and the water jet surface movement exists. And from temperature measuring results, it is supposed that the steam temperature at the mixing nozzle is changed between about 80 degree centigrade and about 60 degree centigrade. Then from the pressure measuring results, it is confirmed that the pressure at the diffuser depends on each the throat diameter and

  16. Control-volume-based model of the steam-water injector flow

    Science.gov (United States)

    Kwidziński, Roman

    2010-03-01

    The paper presents equations of a mathematical model to calculate flow parameters in characteristic cross-sections in the steam-water injector. In the model, component parts of the injector (steam nozzle, water nozzle, mixing chamber, condensation wave region, diffuser) are treated as a series of connected control volumes. At first, equations for the steam nozzle and water nozzle are written and solved for known flow parameters at the injector inlet. Next, the flow properties in two-phase flow comprising mixing chamber and condensation wave region are determined from mass, momentum and energy balance equations. Then, water compression in diffuser is taken into account to evaluate the flow parameters at the injector outlet. Irreversible losses due to friction, condensation and shock wave formation are taken into account for the flow in the steam nozzle. In two-phase flow domain, thermal and mechanical nonequilibrium between vapour and liquid is modelled. For diffuser, frictional pressure loss is considered. Comparison of the model predictions with experimental data shows good agreement, with an error not exceeding 15% for discharge (outlet) pressure and 1 K for outlet temperature.

  17. Method to detect steam generator tube leakage

    International Nuclear Information System (INIS)

    Watabe, Kiyomi

    1994-01-01

    It is important for plant operation to detect minor leakages from the steam generator tube at an early stage, thus, leakage detection has been performed using a condenser air ejector gas monitor and a steam generator blow down monitor, etc. In this study highly-sensitive main steam line monitors have been developed in order to identify leakages in the steam generator more quickly and accurately. The performance of the monitors was verified and the demonstration test at the actual plant was conducted for their intended application to the plants. (author)

  18. US NRC/LLL liaison with the Federal Republic of Germany for the GKSS-PSS steam condensation tests. Progress report No. 1

    International Nuclear Information System (INIS)

    McCauley, E.W.

    1979-01-01

    This progress report for the USNRC/LLL Liaison program with the Federal Republic of Germany regarding boiling water reactor containment multivent steam condensation tests being conducted by GKSS (Gesellschaft fuer Kernenergieverwertung in Schiffbau und Schiffahrt) address program activity during the period of May-June 1979. During this period the program scope was defined, initial contacts between LLL and GKSS were established, and the first trip by an LLL representative to the GKSS test facility was taken

  19. Treating bituminous minerals. [use of superheated steam

    Energy Technology Data Exchange (ETDEWEB)

    MacIvor, G

    1880-12-21

    In this new procedure, the superheated steam is the agent by which the heat is directly applied to the rock; the superheated steam is made to pass between the rocks and into the vessel or retort in which the rock is contained and where the extraction of the bitumen or the distillation of the mineral oils is carried out. The temperature of the heating apparatus in which the steam is superheated, is easily regulated at will in accord with the desired result. When one wishes to extract only bitumen, the temperature of the steam is raised to a point sufficiently high to loosen and separate the bitumen without permitting any condensation of water inside the retort. When it is desired to produce a mineral oil, the temperature is increased in such a way that all the volatile products are distilled from the rock and come into the condenser. By means of this process, any temperature up to a full red heat, can be maintained in the retort, making possible many variations in the kind of products obtainable from the rock.

  20. Maximal oil recovery by simultaneous condensation of alkane and steam

    NARCIS (Netherlands)

    Bruining, J.; Marchesin, D.

    2007-01-01

    This paper deals with the application of steam to enhance the recovery from petroleum reservoirs. We formulate a mathematical and numerical model that simulates coinjection of volatile oil with steam into a porous rock in a one-dimensional setting. We utilize the mathematical theory of conservation

  1. Cheaper power generation from surplus steam generating capacities

    International Nuclear Information System (INIS)

    Gupta, K.

    1996-01-01

    Prior to independence most industries had their own captive power generation. Steam was generated in own medium/low pressure boilers and passed through extraction condensing turbines for power generation. Extraction steam was used for process. With cheaper power made available in Nehru era by undertaking large hydro power schemes, captive power generation in industries was almost abandoned except in sugar and large paper factories, which were high consumers of steam. (author)

  2. Specific features of steam turbine design at LMZ

    International Nuclear Information System (INIS)

    Pichugin, I.I.; Tsvetkov, A.M.; Simkin, M.S.

    1993-01-01

    General structural layouts of the condensation steam turbines produced by the Leningrad metalworks (LM) are considered. Currently LM produced 50 types and modifications of steam turbines with the capacity from 30 up to 1200 MW. Problems of turbine efficiency and ways of the flow section improvement are discussed

  3. Studies and solutions of steam turbines for nuclear heating power stations

    International Nuclear Information System (INIS)

    Drahy, J.

    1979-01-01

    The possibilities of combined generation of heat and electric power and special features of the corresponding equipment for WWER type reactors are considered. Condensing steam turbines with bled steam points and the constructional solution of bled points are presented for heating the network water to 110 0 C, 120 0 C, and 160 0 C, respectively. The dimensions of the low pressure final stage of the turbine are given. Problems concerning condensing and bleeding turbines and combination types of back-pressure and condensing turbines as well as solutions to the design of 250 MW and 500 MW turbines are discussed

  4. On synthesis and optimization of steam system networks. 3. Pressure drop consideration

    CSIR Research Space (South Africa)

    Price, T

    2010-08-01

    Full Text Available Heat exchanger networks in steam systems are traditionally designed to operate in parallel. Coetzee and Majozi (Ind. Eng. Chem. Res. 2008, 47, 4405-4413) found that by reusing steam condensate within the network the steam flow rate could be reduced...

  5. The effect of the number of condensed phases modeled on aerosol behavior during an induced steam generator tube rupture sequence

    International Nuclear Information System (INIS)

    Bixler, N.E.; Schaperow, J.H.

    1998-06-01

    VICTORIA is a mechanistic computer code designed to analyze fission product behavior within a nuclear reactor coolant system (RCS) during a severe accident. It provides detailed predictions of the release of radioactive and nonradioactive materials from the reactor core and transport and deposition of these materials within the RCS. A recently completed independent peer review of VICTORIA, while confirming the overall adequacy of the code, recommended a number of modeling improvements. One of these recommendations, to model three rather than a single condensed phase, is the focus of the work reported here. The recommendation has been implemented as an option so that either a single or three condensed phases can be treated. Both options have been employed in the study of fission product behavior during an induced steam generator tube rupture sequence. Differences in deposition patterns and mechanisms predicted using these two options are discussed

  6. Theoretical study of steam condensation induced water hammer phenomena in horizontal pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Barna, Imre Ferenc [Hungarian Academy of Sciences, Budapest (Hungary). Wigner Research Center; ELI-HU Nonprofit Kft., Szeged (Hungary); Pocsai, Mihaly Andras [Hungarian Academy of Sciences, Budapest (Hungary). Wigner Research Center; Pecs Univ. (Hungary). Inst. of Physics; Guba, Attila [Hungarian Academy of Sciences, Budapest (Hungary). Energy Research Center; Imre, Attila Rikard [Hungarian Academy of Sciences, Budapest (Hungary). Energy Research Center; Budapest University of Technology and Economics (Hungary). Dept. of Energy Engineering

    2015-11-15

    Steam condensation induced water hammer (CIWH) phenomena are investigated and new theoretical results are presented. We use the WAHA3 model based on two-phase flow six first-order partial differential equations that present one dimensional, surface averaged mass, momentum and energy balances. A second order accurate high-resolution shock-capturing numerical scheme was applied with different kind of limiters in the numerical calculations. The applied two-fluid model shows some similarities to RELAP5 which is widely used in the nuclear industry to simulate nuclear power plant accidents. This model was validated with different CIWH experiments which were performed in the PMK-2 facility, which is a full-pressure thermohydraulic model of the nuclear power plant of VVER-440/312 type in the Energy Research Center of the Hungarian Academy of Sciences and in the Rosa facility of the Japan Atomic Energy Agency. In our present study we show the first part of a planned large database which will give us the upper and lower flooding mass flow rates for various pipe geometries where CIWH can happen. Such a reliable database would be a great help for future reactor constructions and scheming.

  7. Theoretical study of steam condensation induced water hammer phenomena in horizontal pipelines

    International Nuclear Information System (INIS)

    Barna, Imre Ferenc; Pocsai, Mihaly Andras; Pecs Univ.; Guba, Attila; Imre, Attila Rikard; Budapest University of Technology and Economics

    2015-01-01

    Steam condensation induced water hammer (CIWH) phenomena are investigated and new theoretical results are presented. We use the WAHA3 model based on two-phase flow six first-order partial differential equations that present one dimensional, surface averaged mass, momentum and energy balances. A second order accurate high-resolution shock-capturing numerical scheme was applied with different kind of limiters in the numerical calculations. The applied two-fluid model shows some similarities to RELAP5 which is widely used in the nuclear industry to simulate nuclear power plant accidents. This model was validated with different CIWH experiments which were performed in the PMK-2 facility, which is a full-pressure thermohydraulic model of the nuclear power plant of VVER-440/312 type in the Energy Research Center of the Hungarian Academy of Sciences and in the Rosa facility of the Japan Atomic Energy Agency. In our present study we show the first part of a planned large database which will give us the upper and lower flooding mass flow rates for various pipe geometries where CIWH can happen. Such a reliable database would be a great help for future reactor constructions and scheming.

  8. Dimensional analysis of small-scale steam explosion experiments

    International Nuclear Information System (INIS)

    Huh, K.; Corradini, M.L.

    1986-01-01

    Dimensional analysis applied to Nelson's small-scale steam explosion experiments to determine the qualitative effect of each relevant parameter for triggering a steam explosion. According to experimental results, the liquid entrapment model seems to be a consistent explanation for the steam explosion triggering mechanism. The three-dimensional oscillatory wave motion of the vapor/liquid interface is analyzed to determine the necessary conditions for local condensation and production of a coolant microjet to be entrapped in fuel. It is proposed that different contact modes between fuel and coolant may involve different initiation mechanisms of steam explosions

  9. The influence of surface-active agents in gas mixture on the intensity of jet condensation

    Science.gov (United States)

    Yezhov, YV; Okhotin, VS

    2017-11-01

    The report presents: the methodology of calculation of contact condensation of steam from the steam-gas mixture into the stream of water, taking into account: the mass flow of steam through the boundary phase, particularly the change in turbulent transport properties near the interface and their connection to the interface perturbations due to the surface tension of the mixture; the method of calculation of the surface tension at the interface water - a mixture of fluorocarbon vapor and water, based on the previously established analytical methods we calculate the surface tension for simple one - component liquid-vapor systems. The obtained analytical relation to calculate the surface tension of the mixture is a function of temperature and volume concentration of the fluorocarbon gas in the mixture and is true for all sizes of gas molecules. On the newly created experimental stand is made verification of experimental studies to determine the surface tension of pure substances: water, steam, C3F8 pair C3F8, produced the first experimental data on surface tension at the water - a mixture of water vapor and fluorocarbon C3F8. The obtained experimental data allow us to refine the values of the two constants used in the calculated model of the surface tension of the mixture. Experimental study of jet condensation was carried out with the flow in the zone of condensation of different gases. The condensation process was monitored by measurement of consumption of water flowing from the nozzle, and the formed condensate. When submitting C3F8, there was a noticeable, intensification condensation process compared with the condensation of pure water vapor. The calculation results are in satisfactory agreement with the experimental data on surface tension of the mixture and steam condensation from steam-gas mixture. Analysis of calculation results shows that the presence of surfactants in the condensation zone affects the partial vapor pressure on the interfacial surface, and

  10. To the generalization of experimental data on heat and mass transfer in evaporation and condensation

    International Nuclear Information System (INIS)

    Berman, L.D.

    1980-01-01

    Similarity equations for heat-and-mass transfer in binary gas or steam-gas layers in the processes of liquid evaporation, condensation and desublimation of vapours, desorption and absorption and porous body cooling are considered. It is accepted that steam-gas components obey to the equation of ideal gas state and that evaporation and condensation condititons permit to neglect the influence of compressability of gas (steam-gas) mixture, non-isothermality of boundary layer and interphase kinetic resistance to mass transfer onto the interfaces. It is concluded that the results of considered experimental and theoretical investigations of the above processes are in a satisfactory agreement and show insignificance of the effect of hydrodynamic conditions determining the regime of main steam-gas mixture flow on relative heat-and-mass transfer coefficients. According to the theoretical calculation results with increase of the factor of M steam-gas mixture non-uniformity mass transfer intensity in evaporation decreases, while in condensation it grows, but M effect on the mass transfer coefficient is rather small and sowhat increases in the case of a turbulent boundary layer evaporation. In condensation it is less than in evaporation

  11. Parametric and scaling studies of condensation oscillation in subcooled water of the in-containment refueling water storage tank

    International Nuclear Information System (INIS)

    Lee, Jun Hyung; No, Hee Cheon

    1999-01-01

    Condensation oscillation by jetting the steam into subcooled water through spargers is studied. To provide a suitable guideline for oscillation phenomena in the IRWST of the next generation reactor, scaling methodology is introduced. Through scaling methodology and subsequent tests, it shows that the volume of steam cavity determines the dynamic characteristics of condensation oscillation. The second-order linear differential equation for frequency analysis is derived and its results are compared with those from the test data. Two types of condensation phenomena exist according to steam flow rates. At subsonic jet, condensation interface becomes irregular in shape and upper system volumes affect the dynamic characteristics of condensation oscillation. At sonic jet, a regular steam cavity forms at the exit of discharge holes. Parametric effects and subsequent dynamic responses of the pool tank are investigated through experiments in applicable test ranges. When the temperature of pool water becomes lower, the amplitude becomes larger. Critical parameters are derived from the scaling methodology and are system volume, cavity volume, discharge hole area, and density ration. It is found that system friction factors affect frequency components of condensation oscillation. Oscillations of a steam cavity occur mainly on the face of the axial direction and pressure amplitudes become larger than that of the lateral direction

  12. Relationship between thermal stratification and flow patterns in steam-quenching suppression pool

    International Nuclear Information System (INIS)

    Song, Daehun; Erkan, Nejdet; Jo, Byeongnam; Okamoto, Koji

    2015-01-01

    Highlights: • Thermal stratification mechanism by direct contact condensation is investigated. • Thermal stratification condition changes according to the flow pattern. • Thermal stratification depends on the force balance between buoyancy and momentum. • Flow pattern change was observed even in the same regime. • Flow pattern is affected by the sensitive force balance. - Abstract: This study aims to examine the relationship between thermal stratification and flow patterns in a steam-quenching suppression pool using particle image velocimetry. Thermal stratification was experimentally evaluated in a depressurized water pool under different steam mass flux conditions. The time evolution of the temperature profile of the suppression pool was presented with the variation of condensation regimes, and steam condensation processes were visualized using a high-speed camera. The thermal stratification condition was classified into full mixing, gradual thermal stratification, and developed thermal stratification. It was found that the condition was determined by the flow patterns depending on the force balance between buoyancy and momentum. The force balance affected both the condensation regime and the flow pattern, and hence, the flow pattern was changed with the condensation regime. However, the force balance had a sensitive influence on the flow in the pool; therefore, distinct flow patterns were observed even in the same condensation regime.

  13. Signal characteristics of guided wave for condenser tube of NPP

    International Nuclear Information System (INIS)

    Min, Lee Dong; Hoon, Choi Sang; Yeong, Yang Tae

    2012-01-01

    A Condenser is a large heat exchanger of the shell and tube type. Cooling water enters through the water box, through the tubesheet and into the tubes(about 80,000 tubes/unit). The shell side of the condenser receives steam from the low pressure turbines exhaust. The steam is cooled to a liquid by passing over the tubes where the cooling water is circulated. Because seawater is used as a coolant, condenser tubes are easily damaged. For such a reason, nondestructive testing conducted periodically. But nondestructive testing takes a lot of manpower and time. Guided wave technique can overcome these shortcomings. In this study, we made an effort evaluating a guided wave defect signal

  14. Feed water pre-heater with two steam spaces

    International Nuclear Information System (INIS)

    Tratz, H.; Kelp, F.; Netsch, E.

    1976-01-01

    A feed water pre-heater for the two stage heating of feed water by condensing steam, having a low installed height is described, which can be installed in the steam ducts of turbines of large output, as in LWRs in nuclear power stations. The inner steam space is closed on one side by the water vessel, while the tubes of the inner steam space go straight from the water vessel, and the tubes of the outer steam space are bent into a U shape and open out into the water vessel. The two-stage preheater is thus surrounded by feedwater in two ways. (UWI) [de

  15. A parametric study of condensation-induced water hammer in nuclear power plants

    International Nuclear Information System (INIS)

    Shon, Young Uk; Chun, Moon Hyun

    1990-01-01

    Condensation-induced water hammer (CIWH), which may occur in systems involving steam and water simultaneously, has a series of processes such as formation of water slug, trapping a steam cavity, depressurization due to steam condensation, accelerating slug caused pressure difference over it and final slug impact. These processes are dependent on water flow rate in a pipe, water temperature, water subcooling, steam pressure, size of slug and cavity, and heat transfer coefficient at interface between steam and water. In the present work, the prediction of conditions to initiate water hammer has been made with full scale by applying the open channel flow theory. These conditions are expressed in terms of water flow rate according to changes of steam pressure, water subcooling, and pipe diameter. Under these conditions that induce CIWH, the effect of parameters which influence on slug impact pressure and cavity collapse rate have been studied with full scale. Also, the impact loads that may be applied to piping design were evaluated under various system conditions

  16. Condensation induced water hammer safety

    International Nuclear Information System (INIS)

    Gintner, M.A.

    1997-01-01

    Condensation induced water hammer events in piping systems can cause catastrophic steam system failures which can result in equipment damage, personal injury, and even death. As an industry, we have learned to become accustomed to the ''banging'' that we often hear in our steam piping systems, and complacent in our actions to prevent it. It is unfortunate that lives are lost needlessly, as this type of water hammer event is preventable if one only applies some basic principles when operating and maintaining their steam systems. At the U. S. Department of Energy's Hanford Site where I work, there was one such accident that occurred in 1993 which took the life of a former co-worker and friend of mine. Hanford was established as part of the Manhattan Project during World War II. it is a 560 square mile complex located along the banks of the Columbia River in Southeastern Washington State. For almost 45 years, hanford's mission was to produce weapons grade plutonium for our nations defense programs. Today, Hanford no longer produces plutonium, but is focused on site clean-up and economic diversification. Hanford still uses steam for heating and processing activities, utilizing over 20 miles of piping distribution systems similar to those found in industry. Although these aging systems are still sound, they cannot stand up to the extreme pressure pulses developed by a condensation induced water hammer

  17. Liquid-phase problems in steam turbine LP stages

    International Nuclear Information System (INIS)

    Blanc-Feraud, P.

    1978-01-01

    Wet steam formation owing to incipient condensation in final steam turbine pressure stages results in a loss of efficiency and possible rotor blading erosion. The effects of erosion are now clearly understood and quite easily counteracted, but loss of thermodynamics, mechanical and aerodynamic efficiency is still a problem. Only the final LP stages of conventional power station plant operate with wet steam, whereas nuclear plant turbines use it to produce most of their total output [fr

  18. Assessment of TRACE Condensation Model Against Reflux Condensation Tests with Noncondensable Gases

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Won; Cheong, Ae Ju; Shin, Andong; Suh, Nam Duk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    The TRACE is the latest in a series of advanced, best-estimated reactor systems code developed by U.S. Nuclear Regulatory Commission for analyzing transient and steady-state neutronic-thermal-hydraulic behavior in light water reactors. This special model is expected to replace the default model in a future code release after sufficient testing has been completed. This study assesses the special condensation model of TRACE 5.0-patch4 against the counter-current flow configuration. For this purpose, the predicted results of special model are compared to the experimental and to those of default model. The KAST reflux condensation test with NC gases are used in this assessment. We assessed the special model for film condensation of TRACE 5.0-patch4 against the data of the reflux condensation test in the presence of NC gases. The special condensation model of TRACE provides a reasonable estimate of HTC with good agreement at the low inlet steam flow rate.

  19. Assessment of TRACE Condensation Model Against Reflux Condensation Tests with Noncondensable Gases

    International Nuclear Information System (INIS)

    Lee, Kyung Won; Cheong, Ae Ju; Shin, Andong; Suh, Nam Duk

    2015-01-01

    The TRACE is the latest in a series of advanced, best-estimated reactor systems code developed by U.S. Nuclear Regulatory Commission for analyzing transient and steady-state neutronic-thermal-hydraulic behavior in light water reactors. This special model is expected to replace the default model in a future code release after sufficient testing has been completed. This study assesses the special condensation model of TRACE 5.0-patch4 against the counter-current flow configuration. For this purpose, the predicted results of special model are compared to the experimental and to those of default model. The KAST reflux condensation test with NC gases are used in this assessment. We assessed the special model for film condensation of TRACE 5.0-patch4 against the data of the reflux condensation test in the presence of NC gases. The special condensation model of TRACE provides a reasonable estimate of HTC with good agreement at the low inlet steam flow rate

  20. Performance analysis of a potassium-steam two stage vapour cycle

    International Nuclear Information System (INIS)

    Mitachi, Kohshi; Saito, Takeshi

    1983-01-01

    It is an important subject to raise the thermal efficiency in thermal power plants. In present thermal power plants which use steam cycle, the plant thermal efficiency has already reached 41 to 42 %, steam temperature being 839 K, and steam pressure being 24.2 MPa. That is, the thermal efficiency in a steam cycle is facing a limit. In this study, analysis was made on the performance of metal vapour/steam two-stage Rankine cycle obtained by combining a metal vapour cycle with a present steam cycle. Three different combinations using high temperature potassium regenerative cycle and low temperature steam regenerative cycle, potassium regenerative cycle and steam reheat and regenerative cycle, and potassium bleed cycle and steam reheat and regenerative cycle were systematically analyzed for the overall thermal efficiency, the output ratio and the flow rate ratio, when the inlet temperature of a potassium turbine, the temperature of a potassium condenser, and others were varied. Though the overall thermal efficiency was improved by lowering the condensing temperature of potassium vapour, it is limited by the construction because the specific volume of potassium in low pressure section increases greatly. In the combinatipn of potassium vapour regenerative cycle with steam regenerative cycle, the overall thermal efficiency can be 58.5 %, and also 60.2 % if steam reheat and regenerative cycle is employed. If a cycle to heat steam with the bled vapor out of a potassium vapour cycle is adopted, the overall thermal efficiency of 63.3 % is expected. (Wakatsuki, Y.)

  1. A study on passive containment cooling condensers in SBWR

    International Nuclear Information System (INIS)

    Kuran, S.; Soekmen; C. N.

    2001-01-01

    The passive containment cooling condensers (PCCC) are the crucial part of several new reactor designs, like European Simplified Boiling Water Reactor (ESBWR) and the SBWR. In a hypothetical accident, the pressurised steam non-condensable mixture from drywell is condensed in PCCCs, and condensate is returned to reactor vessel while non-condensable is vented through wet well. In this study, in order to examine the performance of PCCCs, condensation with presence of noncondensable is investigated. Condensation with different noncondensable types and conditions is studied on a PCCC model, which is developed by using RELAP5 Mod3.2 computer code

  2. A three-dimensional laboratory steam injection model allowing in situ saturation measurements. [Comparing steam injection and steam foam injection with nitrogen and without nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Demiral, B.M.R.; Pettit, P.A.; Castanier, L.M.; Brigham, W.E.

    1992-08-01

    The CT imaging technique together with temperature and pressure measurements were used to follow the steam propagation during steam and steam foam injection experiments in a three dimensional laboratory steam injection model. The advantages and disadvantages of different geometries were examined to find out which could best represent radial and gravity override flows and also fit the dimensions of the scanning field of the CT scanner. During experiments, steam was injected continuously at a constant rate into the water saturated model and CT scans were taken at six different cross sections of the model. Pressure and temperature data were collected with time at three different levels in the model. During steam injection experiments, the saturations obtained by CT matched well with the temperature data. That is, the steam override as observed by temperature data was also clearly seen on the CT pictures. During the runs where foam was present, the saturation distributions obtained from CT pictures showed a piston like displacement. However, the temperature distributions were different depending on the type of steam foam process used. The results clearly show that the pressure/temperature data alone are not sufficient to study steam foam in the presence of non-condensible gas.

  3. Optimal design of marine steam turbine

    International Nuclear Information System (INIS)

    Liu Chengyang; Yan Changqi; Wang Jianjun

    2012-01-01

    The marine steam turbine is one of the key equipment in marine power plant, and it tends to using high power steam turbine, which makes the steam turbine to be heavier and larger, it causes difficulties to the design and arrangement of the steam turbine, and the marine maneuverability is seriously influenced. Therefore, it is necessary to apply optimization techniques to the design of the steam turbine in order to achieve the minimum weight or volume by means of finding the optimum combination of design parameters. The math model of the marine steam turbine design calculation was established. The sensitivities of condenser pressure, power ratio of HP turbine with LP turbine, and the ratio of diameter with height at the end stage of LP turbine, which influence the weight of the marine steam turbine, were analyzed. The optimal design of the marine steam turbine, aiming at the weight minimization while satisfying the structure and performance constraints, was carried out with the hybrid particle swarm optimization algorithm. The results show that, steam turbine weight is reduced by 3.13% with the optimization scheme. Finally, the optimization results were analyzed, and the steam turbine optimization design direction was indicated. (authors)

  4. Study on the characteristics of the supersonic steam injector

    International Nuclear Information System (INIS)

    Abe, Yutaka; Shibayama, Shunsuke

    2014-01-01

    Steam injector is a passive jet pump which operates without power source or rotating machinery and it has high heat transfer performance due to the direct-contact condensation of supersonic steam flow onto subcooled water jet. It has been considered to be applied to the passive safety system for the next-generation nuclear power plants. The objective of the present study is to clarify operating mechanisms of the steam injector and to determine the operating ranges. In this study, temperature and velocity distribution in the mixing nozzle as well as flow directional pressure distribution were measured. In addition, flow structure in whole of the injector was observed with high-speed video camera. It was confirmed that there were unsteady interfacial behavior in mixing nozzle which enhanced heat transfer between steam flow and water jet with calculation of heat transfer coefficient. Discharge pressure at diffuser was also estimated with a one-dimensional model proposed previously. Furthermore, it was clarified that steam flow did not condense completely in mixing nozzle and it was two-phase flow in throat and diffuser, which seemed to induce shock wave. From those results, several discussions and suggestions to develop a physical model which predicts the steam injectors operating characteristics are described in this paper

  5. Condensation: the new deal; Condensation: la nouvelle donne

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-06-01

    The principle of condensation boilers is based on the recovery of the latent heat of the steam generated by the combustion of natural gas. This technology was introduced in France at the end of the 80's but failed in its promise because of the complexity of the equipments available at that time. Today, constructors' offer is more mature and reliable and the context has changed. This technology can conciliate three goals: a mastery of energy consumptions, the comfort of the user and the respect of environment. This meeting organized by the research center of Gaz de France (Cegibat), was a good opportunity to makes a status of the market of individual condensation systems in France and in Europe, to present the situation of this technology today and the 10 golden rules for the fitting and maintenance of individual condensation boilers, and to present some technical references, examples and results of today's offer. (J.S.)

  6. A non-conventional interpretation of thermal regeneration in steam cycles

    International Nuclear Information System (INIS)

    Bracco, Stefano; Damiani, Lorenzo

    2012-01-01

    Highlights: ► A better understanding of the concept of thermal regeneration in steam cycles. ► Use of a system composed by a non-regenerative cycle and several reverse cycles. ► Calculation of the heat pumps coefficients of performance. ► New interesting formulations of the regenerative cycle efficiency. -- Abstract: The paper aims to contribute to a better understanding of the thermodynamic concept of heat regeneration in steam power plants with a finite number of bleedings. A regenerative Rankine cycle is compared to a complex system (CHC – complete hybrid cycle) composed by one non-regenerative Rankine cycle (HEC – hybrid engine cycle) and more reverse cycles (RCs – reverse cycles), as many as the number of the bleedings, able to pump heat from the condenser to a series of surface feedwater heaters, disposed upstream of the steam plant boiler. The COPs (coefficients of performance) of the heat pumps are evaluated, and new interesting formulations of the efficiency of the regenerative steam cycle are proposed. In particular a steam cycle with two bleedings is analyzed, neglecting heat losses and pressure drops in the boiler and considering irreversibility only along the expansion line of the steam turbine and into the feedwater heaters. The efficiency and the work of the regenerative cycle are compared to the analogous values of the CHC cycle composed by one simple steam cycle (HEC) and two heat pump cycles (RCs), with steam as the working fluid. The two reverse cycles are considered completely reversible and raising heat from the condenser temperature to the bled steam condensing temperature. The paper shows the most significant results of the study in order to analyze the regenerative cycle and the CHC cycle in comparison with the non-regenerative Rankine cycle; in particular, the analysis is focused on the evaluation of the useful work, the heat supplied and the heat rejected for the examined cycles.

  7. Assessment of GOTHIC and TRACE codes against selected PANDA experiments on a Passive Containment Condenser

    Energy Technology Data Exchange (ETDEWEB)

    Papini, Davide, E-mail: davide.papini@psi.ch; Adamsson, Carl; Andreani, Michele; Prasser, Horst-Michael

    2014-10-15

    Highlights: • Code comparison on the performance of a Passive Containment Condenser. • Simulation of separate effect tests with pure steam and non-condensable gases. • Role of the secondary side and accuracy of pool boiling models are discussed. • GOTHIC and TRACE predict the experimental performance with slight underestimation. • Recirculatory flow pattern with injection of light non-condensable gas is inferred. - Abstract: Typical passive safety systems for ALWRs (Advanced Light Water Reactors) rely on the condensation of steam to remove the decay heat from the core or the containment. In the present paper the three-dimensional containment code GOTHIC and the one-dimensional system code TRACE are compared on the calculation of a variety of phenomena characterizing the response of a passive condenser submerged in a boiling pool. The investigation addresses the conditions of interest for the Passive Containment Cooling System (PCCS) proposed for the ESBWR (Economic Simplified Boiling Water Reactor). The analysis of selected separate effect tests carried out on a PCC (Passive Containment Condenser) unit in the PANDA large-scale thermal-hydraulic facility is presented to assess the code predictions. Both pure steam conditions (operating pressure of 3 bar, 6 bar and 9 bar) and the effect on the condensation heat transfer of non-condensable gases heavier than steam (air) and lighter than steam (helium) are considered. The role of the secondary side (pool side) heat transfer on the condenser performance is examined too. In general, this study shows that both the GOTHIC and TRACE codes are able to reasonably predict the heat transfer capability of the PCC as well as the influence of non-condensable gas on the system. A slight underestimation of the condenser performance is obtained with both codes. For those tests where the experimental and simulated efficiencies agree better the possibility of compensating errors among different parts of the heat transfer

  8. Steam purity in PWRs

    International Nuclear Information System (INIS)

    Hopkinson, J.; Passell, T.

    1982-01-01

    Reports that 2 EPRI studies of PWRs prove that impure steam triggers decay of turbine metals. Reveals that EPRI is attempting to improve steam monitoring and analysis, which are key steps on the way to deciding the most cost-effective degree of steam purity, and to upgrade demineralizing systems, which can then reliably maintain that degree of purity. Points out that 90% of all cracks in turbine disks have occurred at the dry-to-wet transition zone, dubbed the Wilson line. Explains that because even very clean water contains traces of chemical impurities with concentrations in the parts-per-billion range, Crystal River-3's secondary loop was designed with even more purification capability; a deaerator to remove oxygen and prevent oxidation of system metals, and full-flow resin beds to demineralize 100% of the secondary-loop water from the condenser. Concludes that focusing attention on steam and water chemistry can ward off cracking and sludge problems caused by corrosion

  9. Steam chugging in a boiling water reactor pressure-suppression system

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1980-01-01

    Results of a transient analysis predicting the general characteristics of steam chugging compare well with the results of two large scale experiments: GKM II, test 21 and GKSS, test 16. Predicted fundamental periods of chugging are within 5 and 16 per cent of the respective experimental values. The results of the analysis include effects of air in the drywell, momentum loss and heat transfer in the condensation pipe, direct contact condensation heat transfer at the gas-water interface and momentum and heat transfer in the wetwell water pool. Bubble shape is calculated in two-dimensional cylindrical coordinates. Required inputs to the analysis include the geometry, initial conditions and constants to determine both the steam inlet mass flowrate to the drywell as a function of time and conduction heat transfer through the wall of the condensation pipe. There are no arbitrary free parameters which must be specified to predict specific experiments. Rather, the analysis is based on fundamental physical phenomena, experimental coefficients documented for general heat transfer and fluid mechanics characteristics and standard analytical techniques. The random nature of steam chugging observed in some experiments is partially explained by predicted regimes of chugging and changes in the maximum extent of a bubble below the condensation pipe exit during each regime. (orig.)

  10. An expert system for diagnostics and estimation of steam turbine components condition

    Science.gov (United States)

    Murmansky, B. E.; Aronson, K. E.; Brodov, Yu. M.

    2017-11-01

    The report describes an expert system of probability type for diagnostics and state estimation of steam turbine technological subsystems components. The expert system is based on Bayes’ theorem and permits to troubleshoot the equipment components, using expert experience, when there is a lack of baseline information on the indicators of turbine operation. Within a unified approach the expert system solves the problems of diagnosing the flow steam path of the turbine, bearings, thermal expansion system, regulatory system, condensing unit, the systems of regenerative feed-water and hot water heating. The knowledge base of the expert system for turbine unit rotors and bearings contains a description of 34 defects and of 104 related diagnostic features that cause a change in its vibration state. The knowledge base for the condensing unit contains 12 hypotheses and 15 evidence (indications); the procedures are also designated for 20 state parameters estimation. Similar knowledge base containing the diagnostic features and faults hypotheses are formulated for other technological subsystems of turbine unit. With the necessary initial information available a number of problems can be solved within the expert system for various technological subsystems of steam turbine unit: for steam flow path it is the correlation and regression analysis of multifactor relationship between the vibration parameters variations and the regime parameters; for system of thermal expansions it is the evaluation of force acting on the longitudinal keys depending on the temperature state of the turbine cylinder; for condensing unit it is the evaluation of separate effect of the heat exchange surface contamination and of the presence of air in condenser steam space on condenser thermal efficiency performance, as well as the evaluation of term for condenser cleaning and for tube system replacement and so forth. With a lack of initial information the expert system enables to formulate a diagnosis

  11. Thermal hydraulics-I. 5. Local Heat Transfer and Flow Transition in U-Tubes During a Reflux Condensation Mode

    International Nuclear Information System (INIS)

    Chun, Moon-Hyun; Lee, Kyung-Won; Chu, In-Cheol

    2001-01-01

    For the safety analysis of nuclear power plant (NPP) mid-loop operation, it is very important to determine the mechanisms governing heat transfer and to investigate the factors affecting the onset of flooding in steam generator U-tubes during a reflux condensation mode. The main purpose of this work is to evaluate the local condensation heat transfer with and without non-condensable gases (air) and to investigate the effect of multiple U-tubes on the onset of flooding during a reflux condensation. A schematic diagram of the experimental apparatus is shown in Fig. 1. In the present study, five U-tubes with the same inner diameter of 0.0162 m are installed in a rectangular pool to simulate the geometry of the pressurized water reactor steam generator U-tubes of the Korea standard NPP (KSNPP) (Ulchin Units 3 and 4, inner diameter≅0.01692 m). One central U-tube (2.8 m high) is fully equipped with 32 thermocouples to evaluate the heat transfer coefficients (HTCs), whereas the others (i.e., two short tubes 2.5 m high and two long tubes 3.3 m high) are used to investigate the effect of multiple U-tubes on the flooding phenomena. The local heat flux through a U-tube wall was evaluated from the temperature gradient of the U-tube wall. The onset of flooding, on the other hand, was determined by measuring the change in pressure difference between the bottom and the top of the U-tubes. A total of 512 data for local condensation HTCs (108 for pure steam flow and 404 for steam-air flow conditions, respectively) have been obtained for various flow rates of steam and air under atmospheric conditions. The experimental results for a pure steam flow, in general, agree with the classical Nusselt theory, as shown in Fig. 2. At a relatively high-steam Reynolds number (i.e., >3500), however, the present data are slightly higher than the values predicted by Nusselt theory because of the influence of interfacial shear. In the case of pure steam condensation, the condensate film acts as

  12. An experimental study of high pressure steam condensation in a vertical tube of passive secondary condensation system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Jae; No, Hee Cheon [KAIST, Taejon (Korea, Republic of)

    1998-07-01

    To investigate the physical parameters of PSCS (Passive Secondary Condensation System) which is a passive residual heat removal system of CP-1300, the high pressure condensation experiments are performed in a small scale experimental facility. The experimental parameters are the local heat flux and the transfer coefficient and the pressure drop in a condensation heat trasnfer. The film condensation heat transfer coefficients in a vertical tube are calculated from the measured wall temperature difference and compared with the analytical models. A new analytical condensation model is developed based on the annular film flow model. The present model gives marginally better results than those from the Shah model in comparison with the experimental data in the database. Also, experimental data are compared with the results of the RELAP5/MOD3.2 thermal hydraulic code. The RELAP5/MOD3.2 underpredicts the condensation heat transfer coefficients of the present experiment by 50 %.

  13. Keeping condensers clean

    Energy Technology Data Exchange (ETDEWEB)

    Wicker, K.

    2006-04-15

    The humble condenser is among the biggest contributors to a steam power plant's efficiency. But although a clean condenser can provide great economic benefit, a dirty one can raise plant heat rate, resulting in large losses of generation revenue and/or unnecessarily high fuel bills. Conventional methods for cleaning fouled tubes range form chemicals to scrapers to brushes and hydro-blasters. This article compares the available options and describes how one power station, Omaha Public Power District's 600 MW North Omaha coal-fired power station, cleaned up its act. The makeup and cooling water of all its five units comes from the Missouri River. 6 figs.

  14. Steam generating system in LMFBR type reactors

    International Nuclear Information System (INIS)

    Kurosawa, Katsutoshi.

    1984-01-01

    Purpose: To suppress the thermal shock loads to the structures of reactor system and secondary coolant system, for instance, upon plant trip accompanying turbine trip in the steam generation system of LMFBR type reactors. Constitution: Additional feedwater heater is disposed to the pipeway at the inlet of a steam generator in a steam generation system equipped with a closed loop extended from a steam generator by way of a gas-liquid separator, a turbine and a condensator to the steam generator. The separated water at high temperature and high pressure from a gas-liquid separator is heat exchanged with coolants flowing through the closed loop of the steam generation system in non-contact manner and, thereafter, introduced to a water reservoir tank. This can avoid the water to be fed at low temperature as it is to the steam generator, whereby the thermal shock loads to the structures of the reactor system and the secondary coolant system can be suppressed. (Moriyama, K.)

  15. Exergy and exergoeconomic analysis of a petroleum refinery utilities plant using the condensing to power method

    Energy Technology Data Exchange (ETDEWEB)

    Mendes da Silva, Julio Augusto; Pellegrini, Luiz Felipe; Oliveira Junior, Silvio [Polytechnic School of the University of Sao Paulo, SP (Brazil)], e-mails: jams@usp.br, luiz.pellegrini@usp.br, soj@usp.br; Plaza, Claudio; Rucker, Claudio [Petrobras - Petroleo Brasileiro S.A., Rio de Janeiro, RJ (Brazil)], e-mails: claudioplaza@petrobras.com.br, rucker@petrobras.com.br

    2010-07-01

    In this paper a brief description of the main processes present in a modern high capacity refinery is done. The methodology used to evaluate, through exergy analysis, the performance of the refinery's utilities plant since it is responsible for a very considerable amount of the total exergy destruction in a refinery is presented. The utilities plant products: steam, electricity, shaft power and high pressure water had their exergy unit cost determined using exergoeconomic approach. A simple and effective method called condensing to power was used to define the product of the condensers in exergy basis. Using this method it is possible to define the product of the condenser without the use of negentropy concept nor the aggregation of condensers to the steam turbines. By using this new approach, the costs obtained for the plant's products are exactly the same costs obtained when the condenser is aggregated to the steam turbine but with the advantage that the information about the stream between condenser and the steam turbine is not lost and the condenser can be evaluated singly. The analysis shows that the equipment where attention and resources should be focused are the boilers followed by the gas turbine, that together, are responsible for 80% of total exergy destruction in the utilities plant. The total exergy efficiency found for the utilities plant studied is 35% while more than 280 MW of exergy is destroyed in the utilities processes. (author)

  16. Condensation induced water hammer safety

    Energy Technology Data Exchange (ETDEWEB)

    Gintner, M.A.

    1997-03-10

    Condensation induced water hammer events in piping systems can cause catastrophic steam system failures which can result in equipment damage, personal injury, and even death. As an industry, we have learned to become accustomed to the ''banging'' that we often hear in our steam piping systems, and complacent in our actions to prevent it. It is unfortunate that lives are lost needlessly, as this type of water hammer event is preventable if one only applies some basic principles when operating and maintaining their steam systems. At the U. S. Department of Energy's Hanford Site where I work, there was one such accident that occurred in 1993 which took the life of a former co-worker and friend of mine. Hanford was established as part of the Manhattan Project during World War II. it is a 560 square mile complex located along the banks of the Columbia River in Southeastern Washington State. For almost 45 years, hanford's mission was to produce weapons grade plutonium for our nations defense programs. Today, Hanford no longer produces plutonium, but is focused on site clean-up and economic diversification. Hanford still uses steam for heating and processing activities, utilizing over 20 miles of piping distribution systems similar to those found in industry. Although these aging systems are still sound, they cannot stand up to the extreme pressure pulses developed by a condensation induced water hammer.

  17. A simple modelling of mass diffusion effects on condensation with noncondensable gases for the CATHARE Code

    Energy Technology Data Exchange (ETDEWEB)

    Coste, P.; Bestion, D. [Commissariat a l Energie Atomique, Grenoble (France)

    1995-09-01

    This paper presents a simple modelling of mass diffusion effects on condensation. In presence of noncondensable gases, the mass diffusion near the interface is modelled using the heat and mass transfer analogy and requires normally an iterative procedure to calculate the interface temperature. Simplifications of the model and of the solution procedure are used without important degradation of the predictions. The model is assessed on experimental data for both film condensation in vertical tubes and direct contact condensation in horizontal tubes, including air-steam, Nitrogen-steam and Helium-steam data. It is implemented in the Cathare code, a french system code for nuclear reactor thermal hydraulics developed by CEA, EDF, and FRAMATOME.

  18. Purification of condenser water in thermal power station by superconducting magnetic separation

    International Nuclear Information System (INIS)

    Ha, D.W.; Kwon, J.M.; Baik, S.K.; Lee, Y.J.; Han, K.S.; Ko, R.K.; Sohn, M.H.; Seong, K.C.

    2011-01-01

    Magnetic separation using cryo-cooled Nb-Ti superconducting magnet was applied for the purification of condenser water. Iron oxides in condenser water were effectively removed by superconducting magnetic separation. The effect of magnetic field strength and filter size was determined. Thermal power station is made up of a steam turbine and a steam condenser which need a lot of water. The water of steam condenser should be replaced, since scales consisting of iron oxide mainly are accumulated on the surface of condenser pipes as it goes. Superconducting high gradient magnetic separation (HGMS) system has merits to remove paramagnetic substance like iron oxides because it can generate higher magnetic field strength than electromagnet or permanent magnet. In this paper, cryo-cooled Nb-Ti superconducting magnet that can generate up to 6 T was used for HGMS systems. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The result of X-ray analysis showed contaminants were mostly α-Fe 2 O 3 (hematite) and γ-Fe 2 O 3 (maghemite). The higher magnetic field was applied up to 6 T, the more iron oxides were removed. As the wire diameter of magnetic filter decreased, the turbidity removal of the sample was enhanced.

  19. Modelling of film condensation on the reactor containment walls

    International Nuclear Information System (INIS)

    Leduc, Christian

    1995-01-01

    A containment code used in nuclear plant safety analysis must be able to predict evolutions of steam, air and hydrogen concentrations and pressure in the containment of a pressurized water reactor in an accidental situation. Steam condensation on cold walls is an essential factor for these evolutions as it allows the release of an important heat flow, and locally reduces steam concentration. In this research thesis, the author proposes a film condensation model in presence of un-condensable gases. The film flow is supposed to be laminar. Three different approaches are used to model transfers in boundary layers: global correlations in which a hybrid Grashof number is used which expresses the mass and thermal nature of convection, a boundary layer calculation using wall rules for a forced convection regime, and a boundary layer calculation using a k-epsilon model with a low Reynolds number for a natural convection regime. Each approach requires very different mesh fineness at the vicinity of the wall. Models are implemented in the 3-D TRIO-VF thermo-hydraulic code. The obtained theoretical heat transfer coefficients are compared with experimental results [fr

  20. The steam condensate alteration mineralogy of Ruatapu cave, Orakei Korako geothermal field, Taupo Volcanic Zone, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, K.A.; Hamlin, K.A.; Browne, P.R.L.; Campbell, K.A. [Aukland Univ., Dept. of Geology, Auckland (New Zealand); Martin, R.

    2000-02-01

    Ruatapu cave has developed beneath a block of hydrothermally altered quaternary vitric tuff in the active Orakei Korako geothermal field. The cave extends {approx}45 m, with a vertical drop of 23 m, to a shallow pool of clear, sulfate-rich ({approx}450 {mu}g/g), warm (T = 43-48degC), acid (pH 3.0) water. Steam, accompanied by H{sub 2}S, rises from the pool surface, from a second pool nearby, and from fumaroles and joints in the ignimbrite, to condense on surfaces within the cave. Oxidation of the H{sub 2}S to H{sub 2}SO{sub 4} produces acid sulfate fluids which react with the surficial rocks to generate three principal and distinct assemblages of secondary minerals. Kaolinite {+-} opal-A {+-} cristobalite {+-} alunite {+-} alunogen dominate the assemblage at the cave mouth; the essential Al, K and Si are derived from the tuffs and Na, Ca, Fe and Mg removed. In the main body of the cave the highly limited throughflow of water results in the more soluble of the leached constituents, notably Na and K, being retained in surface moisture and becoming available to form tamarugite and potash alum as efflorescences, in part at the expense of kaolin, along with lesser amounts of alunogen, meta-alunogen, mirabilite, halotrichite, kalinite, gypsum and, possibly, tschermigite; the particular species being determined by the prevailing physico-chemical conditions. Heat and moisture assist in moving Fe out of the rock to the air-water interface but, unlike typical surficial acid alteration systems elsewhere in the TVZ, there is an insufficient flow of water, of appropriate Eh-pH, to continue to move Fe out of the cave system. Much becomes locally immobilised as Fe oxides and oxyhydroxides that mottle the side and roof of the cave. Jarosite crusts have developed where acid sulfate pool waters have had protracted contact with ignimbrite wallrock coated with once-living microbial mats. Subsequent lowering of the waters has caused the porous jarositic crusts to alter to potatsh alum

  1. Process for resuperheating steam coming from the high-pressure stage of a turbine and device to bring into use this process

    International Nuclear Information System (INIS)

    Pacault, P.H.

    1977-01-01

    A process is described for resuperheating steam coming from the high pressure stage of a turbine fed by a steam generator, itself heated from a base thermal source. The resuperheating is done by desuperheating at least a part of the steam coming from the generator, taken from the inflow of the turbine high pressure stage, the desuperheated steam being condensed, partially at least, in a condensation exchanger forming a preliminary resuperheater [fr

  2. Following trends in steam sterilizer performance by quantitative monitoring of non-condensable gases

    NARCIS (Netherlands)

    van Wezel, R.A.C.; van Gastel, A.; de Ranitz, A.; van Doornmalen Gomez Hoyos, J.P.C.M.

    2017-01-01

    Standards require a daily steam penetration test before starting production with a steam sterilizer. In many cases the results of steam penetration tests are not used for improvements or optimization of processes. This study aimed to detect whether trend analysis with an objective and quantifying

  3. Effects of phase transformation of steam-water relative permeabilities

    Energy Technology Data Exchange (ETDEWEB)

    Verma, A.K.

    1986-03-01

    A combined theoretical and experimental study of steam-water relative permeabilities (RPs) was carried out. First, an experimental study of two-phase concurrent flow of steam and water was conducted and a set of RP curves was obtained. These curves were compared with semi-empirical and experimental results obtained by other investigators for two-phase, two-component flow (oil/gas; gas/water; gas/oil). It was found that while the wetting phase RPs were in good agreement, RPs for the steam phase were considerably higher than the non-wetting phase RPs in two-component systems. This enhancement of steam RP is attributed to phase transformation effects at the pore level in flow channels. The effects of phase transformation were studied theoretically. This study indicates that there are two separate mechanisms by which phase transformation affects RP curves: (1) Phase transformation is converging-diverging flow channels can cause an enhancement of steam phase RP. In a channel dominated by steam a fraction of the flowing steam condenses upstream from the constriction, depositing its latent heat of condensation. This heat is conducted through the solid grains around the pore throat, and evaporation takes place downstream from it. Therefore, for a given bulk flow quality; a smaller fraction of steam actually flows through the throat segments. This pore-level effect manifests itself as relative permeability enhancement on a macroscopic level; and (2) phase transformation along the interface of a stagnant phase and the phase flowing around it controls the irreducible phase saturation. Therefore, the irreducible phase saturation in steam-water flow will depend, among other factors, on the boundary conditions of the flow.

  4. Development and preliminary assessment of the wall condensation heat transfer models for the SPACE code

    International Nuclear Information System (INIS)

    Park, Hyun Sik; Choi, Ki Yong; Moon, Sang Ki; Kim, Jung Woo; Kim, Kyung Doo

    2009-01-01

    The wall condensation heat transfer models are developed for the SPACE code and are assessed for various condensation conditions. Both default and alternative models were selected through an extensive literature survey. For a pure steam condensation, a maximum value among the Nusselt, Chato, and Shah's correlations is used in order to consider the geometric and turbulent effects. In the presence of non-condensable gases, the Colburn-Hougen's diffusion model was used as a default model and a non-iterative condensation model proposed by No and Park was selected as an alternative model. The wall condensation heat transfer models were assessed preliminarily by using arbitrary test conditions. Both wall condensation models could simulate the heat transfer coefficients and heat fluxes in the vertical, horizontal and turbulent conditions quite reasonably for a pure steam condensation. Both the default and alternative wall condensation models were also verified for the condensation heat transfer coefficient and heat flux in the presence of noncondensable gas. However, some improvements and further detailed verification are necessary for the condensation phenomena in the presence of noncondensable gas

  5. Analysis study of the condensation heat transfer coefficient in the presence of noncondensable on PCCS vertical condenser tube using MARS-KS

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dong jae; Jang, Yeong jun; Lee, Yeon-Gun [Jeju National University, Jeju (Korea, Republic of); Kim, Sin [Chung-Ang University, Seoul (Korea, Republic of)

    2015-10-15

    The Passive Containment Cooling System (PCCS) to be introduced in advanced LWRs removes released energy to an external heat sink by a naturally driven flow. Containment through the condensation heat transfer phenomenon in the event of the loss of coolant accident (LOCA) or main steam line break (MSLB). As the released steam pressurizes the containment, the PCCS will activate to transport the decay heat In this study, a numerical analysis of the condensation heat transfer coefficients on the PCCS condenser tube is conducted using the MARS-KS code. The condensation heat transfer coefficients are obtained from JNU condensation tests performed on a 1000 long and 40 mm O.D. tube. The analysis condition covers 2 and 4 bar for the air mass fraction ranging from 0.1 to 0.8. The JNU single vertical condensation experimental results, Uchida's and Dehbi's correlation compared with the MARS-KS code's results at 2 and 4 bar. Experimental results and MARS-KS predicted heat transfer coefficient is different from the thermal resistances and Wall subcooling. An average relative error is 18.8% and 15% at 2 and 4 bar, respectively. Uchida's correlation is considered the noncondensable gas mass fraction only. Therefore, that is lower than MARS-KS results at 4 bar. Dehbi's correlation affected by ratio of the height-to-diameter, so its results are higher condensation heat transfer coefficient than MARS-KS predicted results.

  6. Direct-contact condensation regime map for core makeup tank of passive reactors

    International Nuclear Information System (INIS)

    Lee, Sang Il; No, Hee Cheon

    1998-01-01

    The condensation regime map in the core makeup tank of passive reactors is experimentally investigated. The condensation regimes identified through the experiments are divided into three distinct ones: sonic jet, subsonic jet, and steam cavity. The steam cavity regime is a unique regime of downward injection with the present geometry not previously observed in other experiments. The condensation regime map is constructed using Froude number and Jacob number. It turns out that the buoyancy force has a large influence on the regime transition because the regime map using the Froude number better fits data with different geometries than other dimensionless parameters. Simple correlations for the regime boundaries are proposed using the Froude number and the Jacob number

  7. Water hammer caused by rapid steam production in a severe accident in a light water reactor

    International Nuclear Information System (INIS)

    Inasaka, Fujio; Adachi, Masaki; Murata, Hiroyuki; Aya, Izuo

    2007-01-01

    We conducted the experimental studies on the water hammer caused by striking of a water mass pushed up by a rapidly growing steam bubble, using a cylindrical model containment vessel of 0.4286 m in diameter. In the experiments, a rapid gas growth was simulated by injecting high-pressure steam into a water pool. It was clarified that coherency of the water mass movement and its water hammer caused by the condensable gas production considerably decreased in comparison with the case of the non-condensable gas production because the rising velocity of the water mass was suppressed due to the steam bubble condensation. On the basis of the data, experimental correlations for estimating the water hammer on the structures in the containment vessel were proposed. (author)

  8. W-007H B Plant Process Condensate Treatment Facility. Revision 3

    International Nuclear Information System (INIS)

    Rippy, G.L.

    1995-01-01

    B Plant Process Condensate (BCP) liquid effluent stream is the condensed vapors originating from the operation of the B Plant low-level liquid waste concentration system. In the past, the BCP stream was discharged into the soil column under a compliance plan which expired January 1, 1987. Currently, the BCP stream is inactive, awaiting restart of the E-23-3 Concentrator. B Plant Steam Condensate (BCS) liquid effluent stream is the spent steam condensate used to supply heat to the E-23-3 Concentrator. The tube bundles in the E-23-3 Concentrator discharge to the BCS. In the past, the BCS stream was discharged into the soil column. Currently, the BCS stream is inactive. This project shall provide liquid effluent systems (BCP/BCS/BCE) capable of operating for a minimum of 20 years, which does not include the anticipated decontamination and decommissioning (D and D) period

  9. W-007H B Plant Process Condensate Treatment Facility. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Rippy, G.L.

    1995-01-20

    B Plant Process Condensate (BCP) liquid effluent stream is the condensed vapors originating from the operation of the B Plant low-level liquid waste concentration system. In the past, the BCP stream was discharged into the soil column under a compliance plan which expired January 1, 1987. Currently, the BCP stream is inactive, awaiting restart of the E-23-3 Concentrator. B Plant Steam Condensate (BCS) liquid effluent stream is the spent steam condensate used to supply heat to the E-23-3 Concentrator. The tube bundles in the E-23-3 Concentrator discharge to the BCS. In the past, the BCS stream was discharged into the soil column. Currently, the BCS stream is inactive. This project shall provide liquid effluent systems (BCP/BCS/BCE) capable of operating for a minimum of 20 years, which does not include the anticipated decontamination and decommissioning (D and D) period.

  10. Study on steam pressure characteristics in various types of nozzles

    Science.gov (United States)

    Firman; Anshar, Muhammad

    2018-03-01

    Steam Jet Refrigeration (SJR) is one of the most widely applied technologies in the industry. The SJR system was utilizes residual steam from the steam generator and then flowed through the nozzle to a tank that was containing liquid. The nozzle converts the pressure energy into kinetic energy. Thus, it can evaporate the liquid briefly and release it to the condenser. The chilled water, was produced from the condenser, can be used to cool the product through a heat transfer process. This research aims to study the characteristics of vapor pressure in different types of nozzles using a simulation. The Simulation was performed using ANSYS FLUENT software for nozzle types such as convergent, convrgent-parallel, and convergent-divergent. The results of this study was presented the visualization of pressure in nozzles and was been validated with experiment data.

  11. 1D models for condensation induced water hammer in pipelines

    International Nuclear Information System (INIS)

    Bloemeling, Frank; Neuhas, Thorsten; Schaffrath, Andreas

    2013-01-01

    Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)

  12. 1D models for condensation induced water hammer in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Bloemeling, Frank; Neuhas, Thorsten; Schaffrath, Andreas [TUEV NORD SysTec GmbH und Co. KG, Hamburg (Germany)

    2013-03-15

    Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)

  13. Geysers advanced direct contact condenser research

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, J.; Bahning, T.; Bharathan, D.

    1997-12-31

    The first geothermal application of the Advanced Direct Contact Condenser (ADCC) technology developed by the National Renewable Energy Laboratory (NREL) is now operational and is being tested at The Geysers Power Plant Unit 11. This major research effort is being supported through the combined efforts of NREL, The Department of Energy (DOE), and Pacific Gas and Electric (PG&E). NREL and PG&E have entered into a Cooperative Research And Development Agreement (CRADA) for a project to improve the direct-contact condenser performance at The Geysers Power Plant. This project is the first geothermal adaptation of an advanced condenser design developed for the Ocean Thermal Energy Conversion (OTEC) systems. PG&E expects this technology to improve power plant performance and to help extend the life of the steam field by using steam more efficiently. In accordance with the CRADA, no money is transferred between the contracting parties. In this case the Department of Energy is funding NREL for their efforts in this project and PG&E is contributing funds in kind. Successful application of this technology at The Geysers will provide a basis for NREL to continue to develop this technology for other geothermal and fossil power plant systems.

  14. Pressure distribution due to steam bubble collapse in a BWR suppression chamber

    International Nuclear Information System (INIS)

    Giencke, E.

    1979-01-01

    For the pressure time history at the walls of a suppression chamber due to a steam bubble collaps at the condenser pipes interests, expecially the influence of the wall elasticity and the position of the condenser pipes. Two problems are to solve: the pressure time history in the steam bubble and at the walls during the collaps and the pressure distribution at the walls. Both problems are coupled with each other, but the influence of the wall elasticity on the pressure time history in the steam bubble is usually small. Thus the two problems may be solved one after each other. For simplifying the analysis the steam bubble surface may be idealized as a sphere during the whole collaps time. Then the resulting pressure time history is be put on the fluid-structure-system. To show the influence of the containment-elasticity it is favourable to investigate both the rigid and the elastic containment. Because the condenser pipes are arranged in a regular scheme, two limit loading cases are to distinguish. Collapses occur simultaneously with the same intensity at all condenser pipes and a strong collaps occurs only at one condenser pipe or a small group of pipes. When including wall elasticity first the modes of the fluid-structure-system are to analyse and then the dynamical responses of the modes. The coupling effects between the pressure time history in the bubble and at the walls are discussed and then how the membrane and bending stiffness of the walls and the buttomstructure influence the pressure distribution, both for steel and concrete structure. Finally simple models for the analysis are derived and the analytical results are compared with experiments. (orig.)

  15. Transient direct-contact condensation on liquid droplets

    International Nuclear Information System (INIS)

    Pasamehmetoglu, K.O.; Nelson, R.A.

    1987-01-01

    In this paper, direct-contact condensation on subcooled liquid droplets is studied in two parts. In the first part, simple design correlations for the condensation in a steady environment are developed based upon a conduction model. These correlations include the convective heat-transfer coefficient, condensation rate, total condensation, and the droplet-thermalization time. In the second part of the paper, the effect of a time-dependent saturation temperature on the condensation process is investigated. A rapid decrease in saturation temperature is typical of condensation environments in which the steam-supply rate is limited and condensation-induced depressurization becomes important. Design correlations are developed for condensation in an environment in which the saturation temperature decreases linearly with time. These correlations are graphically compared to the design correlations of the first part through a quasi-steady approach. The error associated with this approach is quantified as a function of the rate of change of the saturation temperature

  16. Influence of the loop design of the feedwater- and steam quality in a power plant with pressurized water reactor

    International Nuclear Information System (INIS)

    Bennert, J.; Becher, L.

    1977-01-01

    At nuclear power plants with pressurized water reactors, condensate occurs on the high pressure part of the water-steam circuit, caused by the operation with low steam parameters. The behaviour of the electrolytes which entered into the circuit (solubility, distribution in water and/or steam) shows that these electrolytes (salts) are to be found mainly in the condensate. The insinuated electrolytes are reconcentrated during the common arrangements with 'Small Circuit' - consisting of steam generator, high pressure turbine, water separator, feedwater vessel, and have a negative influence on the feedwater - boiler water - and the steam quality. Remedy is possible by modified arrangements, during which these electrolyte-containing condensates will be treated and traced back into the main circuit. Nevertheless that the efficiency decrease is insignificant and additional efforts are necessary, a change over to these arrangements is recommendable, due to the fact that the feedwater quality, the boiler water quality, the steam quality in front of the turbine, and finally also the operational safety, as well as the availability will be improved. (orig.) [de

  17. The role of flooding in the design of vent and reflux condensers

    International Nuclear Information System (INIS)

    Sacramento, Julio C.; Heggs, Peter J.

    2009-01-01

    Reflux and vent condensers are vertical separators where film condensation occurs. A vapour mixture is supplied at the bottom of the tubes and encounters vertical cold surfaces. A falling film forms and exits from the bottom of the tubes, flowing counter-current to the vapour, but co-current to the coolant on the shell side. Flooding occurs when the condensate flow moves from a gravity regime to a shear regime. Vapour velocities at or above the flooding velocity will cause the liquid to exit from the top of the tubes rather than from the bottom. The main disadvantage of these condensers is the limited flooding velocity allowed. Several investigators propose correlations to predict the flooding velocity. In most cases these correlations come from isothermal experiments data, thus the general recommendation of using safety factors of at least 30%. This work compares these correlations to new experimental values of flooding in steam/air vent condensation. The experimental apparatus is a 3 m long, double-pipe condenser with an internal diameter of 0.028 m. The conclusions presented here will aid the design engineer to understand better the applicability of the discussed correlations in the design of steam/air vent condensers

  18. Investigation of condensation implosion by changing configurations of water and steam inlets

    International Nuclear Information System (INIS)

    Seporaitis, Marijus; Pabarcius, Raimondas; Almenas, Kazys

    2003-01-01

    A previous paper (Seporaitis, 2002) presented experimental results, which showed that it is possible to induce condensation implosion events in a horizontal cylindrical pulser solely by varying the introduction rate of sub-cooled liquid. Interface disruption is triggered when an increasing liquid-vapor inter-face generates a growing condensation rate that leads to larger vapor flows. Vapor flow and condensation induced shear initiate surface waves and when these exceed a 'critical' growth rate complete interface disruption leading to a rapid condensation pulse. Although initial experimental success-generation of condensation implosion events in a controlled manner-was achieved it was determined that the range of the liquid introduction rate is fairly narrow. To avoid a high liquid heat up (negative factor for initiation of condensation implosion events) during it inducing into pulser and to expend range of the controlling variable the internal flow configurations in the further tests were used. The experimental studies presented in this paper have shown that trace amount of non-condensable gas have a larger effect on the initiation of a controlled condensation implosion event then was initially assumed. The influence of non-condensable gas is shown to be of an equivalent importance as the liquid side turbulence that is modulated by the rate of liquid introduction. (author)

  19. Numerical analyses of a water pool under loadings caused by a condensation induced water hammer

    Energy Technology Data Exchange (ETDEWEB)

    Timperi, A.; Paettikangas, T.; Calonius, K.; Tuunanen, J.; Poikolainen, J.; Saarenheimo, A. [VTT Industrial Systems (Finland)

    2004-03-01

    Three-dimensional simulations of a rapidly condensing steam bubble in a water pool have been performed by using the commercial computational fluid dynamics (CFD) code Star-CD. The condensing bubble was modelled by using a mass sink in a single-phase calculation. The pressure load on the wall of the pool was determined and transferred to the structural analyses code ABAQUS. The analyses were done for a test pool at Lappeenranta University of Technology. The structural integrity of the pool during steam experiments was investigated by assuming as a test load the rapid condensation of a steam bubble with a diameter of 20 cm. The mass sink for modelling the collapse of the bubble was deter-mined from the potential theory of incompressible fluid. The rapid condensation of the bubble within 25 ms initiated a strong condensation water hammer. The maximum amplitude of the pressure load on the pool wall was approximately 300 kPa. The loads caused by the high compression waves lasted only about 0.4 ms. The loadings caused by larger bubbles or more rapid collapse could not be calculated with the present method. (au)

  20. Condensation heat transfer on natural convection at the high pressure

    International Nuclear Information System (INIS)

    Jong-Won, Kim; Hyoung-Kyoun, Ahn; Goon-Cherl, Park

    2007-01-01

    The Regional Energy Research Institute for the Next Generation is to develop a small scale electric power system driven by an environment-friendly and stable small nuclear reactor. REX-10 has been developed to assure high system safety in order to be placed in densely populated region and island. REX-10 adopts the steam-gas pressurizer to assure the inherent safety. The thermal-hydraulic phenomena in the steam-gas pressurizer are very complex. Especially, the condensation heat transfer with noncondensable gas on the natural convection is important to evaluate the pressurizer behavior. However, there have been few investigations on the condensation in the presence of noncondensable gas at the high pressure. In this study, the theoretical model is developed to estimate the condensation heat transfer at the high pressure using heat and mass transfer analogy. The analysis results show good agreement with correlations and experimental data. It is found that the condensation heat transfer coefficient increases as the total pressure increases or the mass fraction of the non-condensable gas decreases. In addition, the heat transfer coefficient no more increases over the specific pressure

  1. Corrosion cracking of rotor steels of steam turbines

    International Nuclear Information System (INIS)

    Melekhov, R.K.; Litvintseva, E.N.

    1994-01-01

    Results of investigation of stress corrosion cracking of steam turbine materials in nuclear, fossil and geothermal power plants have been analysed. The role of factors that cause damage to rotor discs, mono block and welding rotors of steam turbines has been shown. These are yield stress and steel composition, stress intensity coefficient and crack growth rate, composition and temperature of the condensed steam and water, electrochemical conditions. The conclusion has been made about the state of stress corrosion cracking of the rotors materials, and main investigation trends which are necessary to solve this problem have been listed

  2. Comparison of european computer codes relative to the aerosol behavior in PWR containment buildings during severe core damage accidents. (Modelling of steam condensation on the particles)

    International Nuclear Information System (INIS)

    Bunz, H.; Dunbar, L.H.; Fermandjian, J.; Lhiaubet, G.

    1987-11-01

    An aerosol code comparison exercise was performed within the framework of the Commission of European Communities (Division of Safety of Nuclear Installations). This exercise, focused on the process of steam condensation onto the aerosols occurring in PWR containment buildings during severe core damage accidents, has allowed to understand the discrepancies between the results obtained. These discrepancies are due, in particular, to whether the curvature effect is modelled or not in the codes

  3. Effects of surface roughness on deviation angle and performance losses in wet steam turbines

    International Nuclear Information System (INIS)

    Bagheri Esfe, H.; Kermani, M.J.; Saffar Avval, M.

    2015-01-01

    In this paper, effects of turbine blade roughness and steam condensation on deviation angle and performance losses of the wet stages are investigated. The steam is assumed to obey non-equilibrium thermodynamic model, in which abrupt formation of liquid droplets produces condensation shocks. An AUSM-van Leer hybrid scheme is used to solve two-phase turbulent transonic steam flow around turbine rotor tip sections. The dominant solver of the computational domain is taken to be the AUSM scheme (1993) that in regions with large gradients smoothly switches to van Leer scheme (1979). This guarantees a robust hybrid scheme throughout the domain. It is observed that as a result of condensation, the aerothermodymics of the flow field changes. For example for a supersonic wet case with exit isentropic Mach number M e,is  = 1.45, the deviation angle and total pressure loss coefficient change by 65% and 200%, respectively, when compared with dry case. It is also observed that losses due to surface roughness in subsonic regions are much larger than those in supersonic regions. Hence, as a practical guideline for maintenance sequences, cleaning of subsonic parts of steam turbines should be considered first. - Highlights: • Two-phase turbulent transonic steam flow is numerically studied in this paper. • As a result of condensation, aerothermodynamics of the flow field changes. • Surface roughness has almost negligible effect on deviation angle. • Surface roughness plays an important role in performance losses. • Contribution of different loss mechanisms for smooth and rough blades are computed.

  4. Surry Power Station secondary water chemistry improvement since steam generator replacement and the unit two feedwater pipe rupture

    International Nuclear Information System (INIS)

    Swindell, E.T.

    1988-01-01

    Surry Power Station has two Westinghouse-designed three-loop PWRs of 811 MWe design rating. The start of commercial operation was in July, 1972 in No.1 plant, and May, 1973 in No.2 plant. Both plants began the operation using controlled phosphate chemistry for the steam generators. In 1975, both plants were converted to all volatile treatment on the secondary side due to the tube wall thinning corrosion in the steam generators, which was associated with the phosphate sludge that was building up on the tube sheets and created acidic condition. Thereafter, condenser and air leakage and steam generator denting occurred, and after the operation of 8 years 2 month of No.1 plant and 5 years 9 months of No.2 plant, the steam generators were replaced. A major plant improvement program was designed and implemented from 1979 to 1980. The improvement in new steam generators, the modification for preventing corrosion, the addition of a steam generator blowdown recovery system, the reconstruction of condensers, the installation of full flow, deep bed condensate polishers, the addition of Dionex 8,000 on-line ion chromatograph, a long term maintenance agreement with Westinghouse and so on are reported. (Kako, I.)

  5. Analysis for a PRHRS Condensation Heat Exchanger of the SMART-P Plant

    International Nuclear Information System (INIS)

    Lee, Kwon-Yeong; Kim, Moo Hwan

    2007-01-01

    When an emergency such as the unavailability of feedwater or the loss of off-site power arises with SMART-P, the PRHRS passively removes the core decay heat via natural convection. The system is connected to the feedwater and steam pipes and consists of a heat exchanger submerged in a refueling water tank, a compensation tank, and check and isolation valves. The heat exchanger removes the heat from the reactor coolant system through a steam generator via condensation heat transfer to water in the refueling water tank. The compensating tank is pressurized using a nitrogen gas to make up the water volume change in the PRHRS. Before PRHRS operation, nitrogen may be dissolved in the cooling water of the PRHRS. Therefore, during PRHRS operation, nitrogen gas might be generated due to evaporation in the steam generator, which will act as a noncondensable gas in the condensation heat exchanger. The main objective of the present study was to assess the design of a PRHRS condensation heat exchanger (PRHRS HX) by investigating its heat transfer characteristics

  6. High-power condensation turbine application to district heating

    International Nuclear Information System (INIS)

    Virchenko, M.A.; Arkad'ev, B.A.; Ioffe, V.Yu.

    1982-01-01

    In general outline the role of condensation turbines in NPP district heating is considered. The expediency of expansion of central heating loading of turbines of operating as well as newly designed condensation power plants on the basis of the WWER-1000-type reactors is shown. The principle heat flowsheet of the 1000 MW power turbine is given. An advantage in using turbines with uncontrolled steam bleeding is pointed out [ru

  7. Assessment of RELAP5/MOD3 with condensation experiment for pure steam condensation in a vercal tube

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Jae; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1999-12-31

    The film condensation models in RELAP5/MOD3.1 and RELAP5/MOD3.2 are assessed with the data of experiment performed in the scaled down condensation experimental facility with a single vertical tube of inner diameter of 46 mm in the range of pressure 0.1 {approx} 7.5 MPa for the PSCS(Passive Secondary Condenser System). Both MOD3.1 and MOD3.2 don`t shows any reliable predictions of the experimental data. The RELAP5/MOD3.1 overpredicts the heat transfer coefficients of experiment, whereas the RELAP5/MOD3.2 underpredicts those data. It is recommended that the film condensation model in RELAP5/MOD3.2 should be modified to have a larger heat transfer coefficient than those of the present model to give the reliable predictions. 7 refs., 6 figs., 1 tab. (Author)

  8. Assessment of RELAP5/MOD3 with condensation experiment for pure steam condensation in a vercal tube

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Jae; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    The film condensation models in RELAP5/MOD3.1 and RELAP5/MOD3.2 are assessed with the data of experiment performed in the scaled down condensation experimental facility with a single vertical tube of inner diameter of 46 mm in the range of pressure 0.1 {approx} 7.5 MPa for the PSCS(Passive Secondary Condenser System). Both MOD3.1 and MOD3.2 don`t shows any reliable predictions of the experimental data. The RELAP5/MOD3.1 overpredicts the heat transfer coefficients of experiment, whereas the RELAP5/MOD3.2 underpredicts those data. It is recommended that the film condensation model in RELAP5/MOD3.2 should be modified to have a larger heat transfer coefficient than those of the present model to give the reliable predictions. 7 refs., 6 figs., 1 tab. (Author)

  9. Topflow-experiments on direct condensation and bubble entrainment. Technical report

    International Nuclear Information System (INIS)

    Seidel, Tobias; Lucas, Dirk; Beyer, Matthias

    2016-01-01

    Direct Contact Condensation between steam and water as well as bubble entrainment below the water surface play an important role in different accident scenarios for light water reactors. One example is the emergency core cooling water injection into a two-phase mixture. It has to be considered for example to evaluate potential pressurized thermal shock phenomena. This report documents experiments conducted in flat basin inside the TOPFLOW pressure chamber aiming on the generation of a database useful for CFD model development and validation. It comprises 3 different setups: condensation at a stratified flow of sub-cooled water, condensation at a sub-cooled water jet and a combination of both phenomena with steam bubble entrainment. The documentation includes all details on the experimental set up, on experimental conditions (experimental matrices), on the conduction of the experiments, on measuring techniques used and on data evaluation procedures. In addition, selected results are presented.

  10. BWR Passive Containment Cooling System by condensation-driven natural circulation

    International Nuclear Information System (INIS)

    Vierow, K.M.; Townsend, H.E.; Fitch, J.R.; Andersen, J.G.M.; Alamgir, M.; Schrock, V.E.

    1991-01-01

    A method of long-term decay heat removal which is safe, reliable, and passive has been incorporated into the design of the Simplified Boiling Water Reactor (SBWR). The primary functions of the Passive Containment Cooling System (PCCS) are to remove heat and maintain the containment pressure below allowable levels following a LOCA. A key component of the PCCS is the PCC condenser unit (PCC). By natural circulation, a steam-nitrogen mixture flows into the PCC heat exchanger, condensate drains to the reactor pressure vessel (RPV), and noncondensables are vented to the suppression chamber (S/C). This analysis focuses on three significant thermal-hydraulic phenomena which occur in the system. Specifically, steam condensation in the presence of a noncondensable, the PCC noncondensable venting and the natural circulation are discussed. Results of TRACG simulations are presented which show that the PCCS performs its intended functions. (author)

  11. Analytical model for power plant condenser for transients and off-normal operating conditions

    International Nuclear Information System (INIS)

    Thangamani, I.; Dutta, Anu; Chakraborty, G.; Ghosh, A.K.

    2006-11-01

    A computer code for power plant condenser dynamic analysis has been developed based on a lumped parameter approach considering time dependent mass and energy conservation equations over the control volumes for the shell side as well as tube side fluids. Effects of heat transfer on condenser structure and hot well level transients were considered in the analysis. Suitable heat transfer coefficient recommended by various standards and codes were employed. The code was used to analyze the condenser performance during steady state as well as transient (load rejection or turbine trip) conditions. The condenser performance is predicted in terms of condenser back pressure, shell side steam temperature and tube side coolant exit temperature with respect to time. As a part of parametric studies, the effect of change in tube side coolant flow rate and inlet temperature was also studied. The analysis predicted that up to 47% of rated coolant flow rate on the tube side (for design conditions), the steam dumping can be continued without condenser isolation. The paper describes the detailed methodology adopted for the condenser modeling and presents the results obtained from the different parametric studies and code validation. (author)

  12. A numerical analysis on the effect of inlet parameters for condensation induced water hammer

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Priyankan [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); Chakravarty, Aranyak [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); School of Nuclear Studies & Application, Jadavpur University, Kolkata (India); Ghosh, Koushik, E-mail: kghosh@mech.jdvu.ac.in [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); Mukhopadhyay, Achintya; Sen, Swarnendu [Department of Mechanical Engineering, Jadavpur University, Kolkata (India); Dutta, Anu; Goyal, Priyanshu [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai (India)

    2016-08-01

    Highlights: • Condensation induced water hammer phenomenon is analysed with RELAP5/Mod 3.4. • Effect of various inlet conditions on the occurrence of CIWH are investigated. • Pressure peak amplitude and location has strong dependency on water subcooling. • Superheated steam does not have significant impact on pressure amplitude. • Presence of dry saturated steam is the necessary condition for CIWH. - Abstract: Direct contact condensation (DCC) is almost an inevitable phenomenon during accidental condition for all LWRs. Rapid condensation caused by the direct contact of steam and subcooled water can lead to condensation induced water hammer (CIWH). The present work explores the underlying physics of CIWH phenomenon in a horizontal pipe under different inlet conditions such as inlet water temperature, pressure difference between steam and water section, steam superheating, steam quality and duration of valve opening using RELAP5/Mod 3.4. This work emphasises on the prediction of pressure peak magnitude in conjunction with its location of occurrence under different parametric conditions. The stratified to slug flow transition is presented in terms of the ‘flow regime map’ which is identified as the primary cause for pressure wave generation. The strongest pressure wave amplitude due to CIWH is found to be 116.6 bar for ΔP = 10 bar. Observation reveals that peak pressure location shifts towards the subcooled water injection point for higher inlet water temperature. For the lowest inlet water temperature (T{sub in} = 20 °C), the peak pressure is found at a distance of 47.5 cm away from the water inlet whereas, for the high water temperature (T{sub in} = 120 °C), peak pressure is observed at 6.25 cm away from the injection point. It is also observed that the duration of valve opening significantly affects the location of peak pressure occurrence. This study also reveals that the presence of superheated or wet steam could possibly avoid the occurrence of

  13. Analysis of LOCV(Loss Of Condenser Vacuum) for OPR1000 using the SPACE

    Energy Technology Data Exchange (ETDEWEB)

    Youn, Bum-Soo; Kim, Se-Yun; Lee, Dong-Hyuk [KHNP CRI, Daejeon (Korea, Republic of)

    2015-10-15

    For validation of SPACE code developed by KHNP, the LOCV(loss of condenser vacuum) accident for OPR1000 is analyzed with SPACE code and results are compared with those from RETRAN code. The LOCV can occur from break in the circulation system, break in the condenser vacuum system, etc. The analysis assumes turbine trip at the beginning of the accident. In the actual plant, the steam bypass control system and the reactor power cutback system reduce the pressure increase of the pressurizer and steam generator from turbine trip. However, in this analysis, steam bypass system and reactor cutback system are not used. The LOCV result in stopping of steam flow to turbine and feed water flow to steam generator. This reduces heat removal to the secondary side and causes pressure increase in primary and secondary side. Using the SPACE, the thermal hydraulic behavior of the LOCV accident for OPR1000 was analyzed. The results are compared with RETRAN code. The results of two codes were very similar. From these results, SPACE has the ability to simulation LOCV for OPR1000.

  14. Advanced on-line monitoring of power plant water/steam quality

    Energy Technology Data Exchange (ETDEWEB)

    Perboni, G.; Rocchini, G.; Sigon, F. [Ente Nazionale per l`Energia Elettrica, Milan (Italy)

    1995-03-01

    To improve the behaviour and resistance of materials in the water-steam cycle critical components (steam generator, condensate heaters, turbine) it is necessary to adopt proper actions for promoting formation and integrity of surface protective oxide layers and preventing general and localised corrosion and transport processes of corrosion products throughout the cycle. In this report two important topics are reported: steam side corrosion in the low pressure turbines induced by the `first condensate` in the final stages of the turbine, and the stability of the oxides layers as a function of the condensate chemistry, with particular attention to the transport of corrosion products to the boiler. Furthermore an innovative technique for monitoring some physico-chemical parameters at the actual fluid temperature (150-300C) using new electrochemical sensors improved by ENEL/CRAM is studied: pH, conductivity, corrosion rate, corrosion and redox potentials.ENEL/CRAM validated on lab-scale testing loops these sensors and carried out the following programs: calibration procedures, reliability of the response, long-term stability and assessment of a reduced maintenance. Applications of the electrochemical methods to fossil fired units have demonstrated their validity for monitoring the cycle chemistry and the resistance to corrosion of structural materials in real time.

  15. Assessment and improvement of condensation model in RELAP5/MOD3

    Energy Technology Data Exchange (ETDEWEB)

    Rho, Hui Cheon; Choi, Kee Yong; Park, Hyeon Sik; Kim, Sang Jae [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Lee, Sang Il [Korea Power Engineering Co., Inc., Seoul (Korea, Republic of)

    1997-07-15

    The objective of this research is to remove the uncertainty of the condensation model through the assessment and improvement of the various heat transfer correlations used in the RELAP5/MOD3 code. The condensation model of the standard RELAP5/MOD3 code is systematically arranged and analyzed. A condensation heat transfer database is constructed from the previous experimental data on various condensation phenomena. Based on the constructed database, the condensation models in the code are assessed and improved. An experiment on the reflux condensation in a tube of steam generator in the presence of noncondensable gases is planned to acquire the experimental data.

  16. Simulation of main steam and feedwater system of full scope simulator for Qinshan 300 MW Nuclear Power Unit

    International Nuclear Information System (INIS)

    Zhao Xiaoyu

    1996-01-01

    The simulation of main steam and feedwater system is the most important and maximal part in secondary circuit model, including all of main steam and feedwater's thermal-hydraulic properties, except heat-exchange of secondary side of steam generator. It simulates main steam header, steam power in each stage of turbine, moisture separator-reheater, deaerator, condenser, high pressure and low pressure heater, auxiliary feedwater and main steam bypass in full scope

  17. Steam turbines for nuclear power plants

    International Nuclear Information System (INIS)

    Stastny, M.

    1983-01-01

    A three-cylinder 220 MW saturated steam turbine was developed for WWER reactors by the Skoda concern. Twenty four of these turbines are currently in operation, in production or have been ordered. A 1000 MW four-cylinder turbine is being developed. The disign of the turbines has had to overcome difficulties connected with the unfavourable effects of wet steam at extreme power values. Great attention had to be devoted to the aerodynamics of control valves and to the prevention of flow separation areas. The problem of corrosion-erosion in guide wheels and the high pressure section was resolved by the use of ferritic stainless steels. For the low pressure section it was necessary to separate the moisture and to reheat the steam in the separator-reheater. Difficulties caused by the generation of wet steam in the low pressure section by spontaneous condensation were removed. Also limited was the erosion caused by droplets resulting from the disintegration of water films on the trailing edges. (A.K.)

  18. Thermodynamic effects when utilizing waste heat from condensation in cases of a reduced vacuum in steam turbine plants of thermal power stations, to provide heat at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Vasiljevic, N.; Savic, B.; Stojakovic, M.

    1986-01-01

    There is an interesting variant of cogeneration in the steam turbine system of a thermal power plant, i.e. the utilisation of the waste heat of condensation with a reduced vacuum without reconstruction of the thermal power plant. The thermodynamic effect in cogeneration was calculated in consideration of the dynamics of heat consumption. This cogeneration process has the advantage of saving primary energy without reconstruction of the thermal power plant.

  19. Dimensioning of emergency condensers in accordance with safety requirements

    Energy Technology Data Exchange (ETDEWEB)

    Palavecino, C [SIEMENS, Energieerzeugung, Offenbach (Germany)

    1996-12-01

    The emergency condensers are heat exchangers consisting of a parallel arrangement of horizontal U-tubes between two common heads. The tope header is connected via piping to the reactor vessel steam space, while the lower header is connected to the reactor vessel below the reactor vessel water level. The heat exchangers are located in a pool filled with cold water. The emergency condensers and the reactor vessel thus form a system of communicating pipes. At normal reactor water level, the emergency condensers are flooded with cold, non-flowing water. No heat transfer takes place in this condition. If there is a drop in the reactor water level, the heat exchanging surfaces are gradually uncovered and the incoming steam condenses on the cold surfaces. The cold condensate in returned to the reactor vessel. In this way, heat is removed from the reactor vessel and water simultaneously supplied to the reactor vessel. This means that the emergency condensers function as a heat removal system while at the same time serving as HP and LP coolant injection systems. The emergency condensers operate with the highest possible degree of passivity imaginable, namely through a drop in the reactor vessel water level alone, requiring neither control systems nor power supply. The design of the emergency condensers must meet the requirements dictated by the thermal and the hydraulic conditions. Taking into consideration a redundancy degree of N + 2, a specific thermal rating of 63 MW per emergency condenser results for a reactor with an output of 2778 MW. The total performance of the emergency condenser system in thus 252 MW, or 9.1% of reactor output. The probability of failure of the emergency condenser of Siemens SWR 1000 is approximately 10{sup -4} per demand, while that of the older emergency condenser designs is approximately 2 to 3 x 10{sup -3} per demand. (author). 7 figs, 2 tabs.

  20. A Preliminary Study of Transverse Curvature Effects on Condensation Heat Transfer on Vertical Tube in the Presence of Non-condensable Gas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yeon Gun; Kim, Sin [Jeju National Univ., Jeju (Korea, Republic of); Jerng, Dong Wook [Chung Ang Univ., Seoul (Korea, Republic of)

    2013-10-15

    In this study, the effect of the transverse curvature on the condensation HTC on a vertical tube in the presence of air is preliminarily investigated by using the analysis of boundary layer for free convective heat transfer. The results indicate that the heat transfer performance can be enhanced as the outer diameter of condenser tubes is small. To confirm this curvature effect, an experimental program to obtain the condensation heat transfer data for various values of tube diameter is indispensable. Currently, by a joint research project of Jeju National University and Chung-Ang University, a condensation test facility is being designed and constructed to acquire the condensation HTC data as shown in Fig. 3. From a series of experiment on a single vertical tube, the effects of not only the tube diameter but the inclination, the existence of fins and the local velocity of a bulk mixture by natural circulation will be evaluated precisely. An empirical correlation for the condensation heat transfer of a steam-air mixture will also be developed for design optimization and performance evaluation of the PCCS. The Passive Containment Cooling System (PCCS) provides passive means to remove the decay heat and protect the integrity of the containment during severe accidents. Korea, in which all the NPPs employ the concrete containment, may adopt a PCCS using internal condensers. In the event of the loss-of-coolant accident (LOCA), steam released from the reactor coolant system is mixed with air inside the containment and condensed on the outer surface of inclined condenser tubes. It is noted that, among previous theoretical and empirical models for condensation on outer wall in the presence of non-condensable gas, no one took into account the effect of a tube diameter. Though the condensation heat transfer coefficient may vary with transverse curvature of condenser tubes, such a curvature effect has not been reported so far. In this study, a preliminary analysis is conducted

  1. A Preliminary Study of Transverse Curvature Effects on Condensation Heat Transfer on Vertical Tube in the Presence of Non-condensable Gas

    International Nuclear Information System (INIS)

    Lee, Yeon Gun; Kim, Sin; Jerng, Dong Wook

    2013-01-01

    In this study, the effect of the transverse curvature on the condensation HTC on a vertical tube in the presence of air is preliminarily investigated by using the analysis of boundary layer for free convective heat transfer. The results indicate that the heat transfer performance can be enhanced as the outer diameter of condenser tubes is small. To confirm this curvature effect, an experimental program to obtain the condensation heat transfer data for various values of tube diameter is indispensable. Currently, by a joint research project of Jeju National University and Chung-Ang University, a condensation test facility is being designed and constructed to acquire the condensation HTC data as shown in Fig. 3. From a series of experiment on a single vertical tube, the effects of not only the tube diameter but the inclination, the existence of fins and the local velocity of a bulk mixture by natural circulation will be evaluated precisely. An empirical correlation for the condensation heat transfer of a steam-air mixture will also be developed for design optimization and performance evaluation of the PCCS. The Passive Containment Cooling System (PCCS) provides passive means to remove the decay heat and protect the integrity of the containment during severe accidents. Korea, in which all the NPPs employ the concrete containment, may adopt a PCCS using internal condensers. In the event of the loss-of-coolant accident (LOCA), steam released from the reactor coolant system is mixed with air inside the containment and condensed on the outer surface of inclined condenser tubes. It is noted that, among previous theoretical and empirical models for condensation on outer wall in the presence of non-condensable gas, no one took into account the effect of a tube diameter. Though the condensation heat transfer coefficient may vary with transverse curvature of condenser tubes, such a curvature effect has not been reported so far. In this study, a preliminary analysis is conducted

  2. Improvements in steam cycle electric power generating plants

    International Nuclear Information System (INIS)

    Bienvenu, Claude.

    1973-01-01

    The invention relates to a steam cycle electric energy generating plants of the type comprising a fossil or nuclear fuel boiler for generating steam and a turbo alternator group, the turbine of which is fed by the boiler steam. The improvement is characterized in that use is made of a second energy generating group in which a fluid (e.g. ammoniac) undergoes a condensation cycle the heat source of said cycle being obtained through a direct or indirect heat exchange with a portion of the boiler generated steam whereby it is possible without overloading the turbo-alternator group, to accomodate any increase of the boiler power resulting from the use of another fuel while maintaining a maximum energy output. This can be applied to electric power stations [fr

  3. Operative behaviour of a condenser tube under ETA chemistry

    International Nuclear Information System (INIS)

    Chocron, Mauricio; Burkart, Arturo; Rodriguez, Ivanna; Raul, Manera; Diego, Quinteros

    2012-09-01

    Among the various recommendations for the surveillance of the integrity of the materials of the Secondary Cycle (Balance of Plant) it is the periodic removal of a steam generator tube and a condenser tube and their analysis. It considers assessment of the water chemistry, corrosion and the reciprocal effect on or from other components of the cycle. Embalse N.P.P. is a CANDU 6 type, Pressurized Heavy Water Reactor, located in Cordoba Province, Argentina. Previous papers have shown results on tubes removed from the steam generators (Bordoni et al., NPC'08, September 15-18, 2008, Berlin, Germany; 6 th Canadian Nuclear Society - Steam Generators Conference, November 8-11, 2009, Toronto, Canada). Considering that the Embalse BOP has mixed metallurgy, i.e., steam generator tubes made of A800, piping made of ferrous alloys and condenser tubes made of Admiralty Brass and also taking into account that the chemistry has been modified from Morpholine control to ETA control (Fernandez et. al, NPC'2010, October 3-7, Quebec City, Canada), it has been decided to remove and analyze a condenser tube that has been placed in operation coincidently with the establishment of the ETA chemical control. The extraction is dated along with the November 2011 Plant Programmed Outage. Objectives are assessing the operative behavior of the tube performing visual and optical microscope inspection, SEM analysis of the oxides and deposits in exposed surfaces and occluded locations like tube sheet and other tests as well. Results are compared to the same analysis performed on a new tube in storage and integrated with the chemical operative figures of the cycle during the period: chemical data and corrosion products transport. (authors)

  4. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    This NEUP funded project, NEUP 12-3630, is for experimental, numerical and analytical studies on high-pressure steam condensation phenomena in a steel containment vessel connected to a water cooling tank, carried out at Oregon State University (OrSU) and the University of Wisconsin at Madison (UW-Madison). In the three years of investigation duration, following the original proposal, the planned tasks have been completed: (1) Performed a scaling study for the full pressure test facility applicable to the reference design for the condensation heat transfer process during design basis accidents (DBAs), modified the existing test facility to route the steady-state secondary steam flow into the high pressure containment for controllable condensation tests, and extended the operations at negative gage pressure conditions (OrSU). (2) Conducted a series of DBA and quasi-steady experiments using the full pressure test facility to provide a reliable high pressure condensation database (OrSU). (3) Analyzed experimental data and evaluated condensation model for the experimental conditions, and predicted the prototypic containment performance under accidental conditions (UW-Madison). A film flow model was developed for the scaling analysis, and the results suggest that the 1/3 scaled test facility covers large portion of laminar film flow, leading to a lower average heat transfer coefficient comparing to the prototypic value. Although it is conservative in reactor safety analysis, the significant reduction of heat transfer coefficient (50%) could under estimate the prototypic condensation heat transfer rate, resulting in inaccurate prediction of the decay heat removal capability. Further investigation is thus needed to quantify the scaling distortion for safety analysis code validation. Experimental investigations were performed in the existing MASLWR test facility at OrST with minor modifications. A total of 13 containment condensation tests were conducted for pressure

  5. Implementation and validation of a condensation model in ANSYS

    International Nuclear Information System (INIS)

    Lehmkuhl, J.; Kelm, S.; Allelein, H.J.; Forschungszentrum Juelich

    2012-01-01

    During design-based beyond-design accidents large amounts of steam and hydrogen are released onto the containment. The knowledge on the local distribution of gases and atmospheric conditions is therefore necessary for the design of safety systems or emergency measures. Condensation processes have a significant influence on the thermal hydraulics, the hydrogen combustion and the aerosol behavior in the containment. The presented one-phase condensation model was developed for an effective CFD modeling of condensation processes in ANSYS CFX for accident analyses. Based on the assumption that wall condensation is mainly determined by the mass transport the assumption of thermal equilibrium can be used for one-phase calculations. The modeling concept is applicable for wall and volume condensation and has been implemented.

  6. Condensate-polisher resin-leakage quantification and resin-transport studies

    International Nuclear Information System (INIS)

    Stauffer, C.C.; Doss, P.L.

    1983-04-01

    The objectives of this program were to: (1) determine the extent of resin leakage from current generation condensate polisher systems, both deep bed and powdered resin design, during cut-in, steady-state and flow transient operation, (2) analyze moisture separator drains and other secondary system samples for resin fragments and (3) document the level of organics in the secondary system. Resin leakage samples were obtained from nine-power stations that have either recirculating steam generators or once through steam generators. Secondary system samples were obtained from steam generator feedwater, recirculating steam generator blowdown and moisture separator drains. Analysis included ultraviolet light examination, SEM/EDX, resin quantification and infrared analysis. Data obtained from the various plants were compared and factors affecting resin leakage were summarized

  7. Advanced Signal Processing for High Temperatures Health Monitoring of Condensed Water Height in Steam Pipes

    Science.gov (United States)

    Lih, Shyh-Shiuh; Bar-Cohen, Yoseph; Lee, Hyeong Jae; Takano, Nobuyuki; Bao, Xiaoqi

    2013-01-01

    An advanced signal processing methodology is being developed to monitor the height of condensed water thru the wall of a steel pipe while operating at temperatures as high as 250deg. Using existing techniques, previous study indicated that, when the water height is low or there is disturbance in the environment, the predicted water height may not be accurate. In recent years, the use of the autocorrelation and envelope techniques in the signal processing has been demonstrated to be a very useful tool for practical applications. In this paper, various signal processing techniques including the auto correlation, Hilbert transform, and the Shannon Energy Envelope methods were studied and implemented to determine the water height in the steam pipe. The results have shown that the developed method provides a good capability for monitoring the height in the regular conditions. An alternative solution for shallow water or no water conditions based on a developed hybrid method based on Hilbert transform (HT) with a high pass filter and using the optimized windowing technique is suggested. Further development of the reported methods would provide a powerful tool for the identification of the disturbances of water height inside the pipe.

  8. Mitigation of caustic stress corrosion cracking of steam generator tube materials by blowdown -a case study

    International Nuclear Information System (INIS)

    Dutta, Anu; Patwegar, I.A.; Chaki, S.K.; Venkat Raj, V.

    2000-01-01

    The vertical U-tube steam generators are among the most important equipment in nuclear power plants as they form the vital link between the reactor and the turbogenerator. Over ∼ 35 years of operating experience of water cooled reactor has demonstrated that steam generator tubes are susceptible to various forms of degradation. This degradation leads to failure and outages of the power plant. A majority of these failures have been attributed to concentrated alkali attacks in the low flow areas such as crevices in the tube to tube sheet joints, baffle plate location and the areas of sludge deposits. Free hydroxides can be produced by improper maintenance of phosphate chemical control in the secondary side of the steam generators and also by the thermal decomposition of impurities present in the condenser cooling water which may leak into the feed water through the condenser tubes. The free hydroxides concentrate in the low flow areas. This buildup of free hydroxide in combination with residual stress leads to caustic stress corrosion cracking. In order to mitigate caustic stress corrosion cracking of Inconel 600 tubes, the trend is to avoid phosphate dosing. Instead All Volatile Treatment (AVT) for secondary water is used backed by full flow condensate polishing. Sodium hydroxide concentration is now being considered as the basis for steam generator blowdown. A methodology has been established for determining the blowdown requirement in order to mitigate caustic stress corrosion cracking in the secondary side of the vertical U-tube natural circulation steam generator. A case study has been carried out for zero solid treatment (AVT coupled with full flow condensate polishing plant) water chemistry. Only continuous blowdown schemes have been studied based on maximum caustic concentration permissible in the secondary side of the steam generator. The methodology established can also be used for deciding concentration of any other impurities

  9. Numerical modeling of counter-current condensation in a Black Liquor Gasification plant

    International Nuclear Information System (INIS)

    Risberg, Mikael; Gebart, Rikard

    2013-01-01

    Pressurized Entrained flow High Temperature Black Liquor Gasification is a novel technique to recover the inorganic chemicals and available energy in black liquor originating from kraft pulping. The gasifier has a direct quench that quickly cools the raw syngas when it leaves the hot reactor by spraying the gas with a water solution. As a result, the raw syngas becomes saturated with steam. Typically the gasifier operates at 30 bar which corresponds to a dew point of about 235 °C and a steam concentration in the saturated syngas that is about 3 times higher than the total concentration of the other species in the syngas. After the quench cooler the syngas is passed through a counter-current condenser where the raw syngas is cooled and most of the steam is condensed. The condenser consists of several vertical tubes where reflux condensation occurs inside the tubes due to water cooling of the tubes on the shell-side. A large part of the condensation takes place inside the tubes on the wall and results in a counterflow of water driven by gravity through the counter current condenser. In this study a computational fluid dynamics model is developed for the two-phase fluid flow on the tube-side of the condenser and for the single phase flow of the shell-side. The two-phase flow was treated using an Euler–Euler formulation with closure correlations for heat flux, condensation rate and pressure drop inside the tubes. The single-phase model for the shell side uses closure correlations for the heat flux and pressure drop. Predictions of the model are compared with results from experimental measurements in a condenser used in a 3 MW Black Liquor Gasification development plant. The results are in good agreement with the limited experimental data that has been collected in the experimental gasifier. However, more validation data is necessary before a definite conclusion can be drawn about the predictive capability of the code. -- Highlights: • A multi-phase model for a

  10. THE DETECTION OF THE NECESSARY CONDITIONS OF EFFECTIVE FUNCTIONING OF THE BALL CLEANING SYSTEM OF THE TUBES OF STEAM TURBINE CONDENSERS. Part 1

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2017-01-01

    Full Text Available A problem of an increase of the power of turbine by improving heat transfer in condensers of steam turbines is considered in the article as a topical one. The analysis of contamination of the internal surfaces of cooling tubes and of the influence of pollution on the process of heat transfer in turbine condensers has been fulfilled. The existing method of cleaning of condenser tubes with the use of porous elastic balls of sponge rubber that is implemented on a number of large thermal power plants and state region power plants of the Republic of Belarus is examined. In the operation of the ball cleaning system a significant drawback has been revealed, viz. a low efficiency of this method due to the failure to comply with preparation the system of circulating water for operation. Also, a certain imperfection of ball cleaning system technology has been determined. One of the prerequisites for the effective functioning of the ball cleaning system is a certain degree of purity of the pipe system of the condenser, characterized by the coefficient of purity. To determine the effectiveness of ball cleaning system a series of experiments on the launching of porous rubber balls in the pipe system of the main and the embedded bunches of the T-250/300-240 UTMZ turbine has been produced. Immediately before the experiments hydraulic cleaning of the tubes of the condenser by a high-pressure installation were carried out. During the experiments, records of the number of downloaded porous rubber balls, of the number of rubber balls captured in a loading chamber, and of the number of rubber balls that remained in a calibration device were kept. A large proportion of default of the balls caused by the presence of residues of the carbonate sediments, that obstruct the movement of porous rubber balls in the tubes of the condenser, was determined. The presence of carbonate deposits in the tubes of the condenser indicates a lack of effectiveness of antiscale treatment

  11. Gas-steam turbine plant for cogenerative process at 'Toplifikacija' - Skopje (Joint-Stock Co. for district heating - Macedonia)

    International Nuclear Information System (INIS)

    Cvetkovski, Andrijan

    2003-01-01

    The gas-steam power plant for combined heat and electric power production at A.D. 'Toplifikacija' Skopje - TO 'Zapad' is analyzed and determined. The analyzed plant is consisted of gas turbine, heat recovery steam generator (HRSG) and condensate steam turbine with controlled steam extraction. It operates on natural gas as a main fuel source. The heating of the water for the district heating is dine in the heat exchanger, with // heat of controlled extraction from condensate turbine. The advantages of the both binary plant and centralized co generative production compared with the individual are analyzed. The natural gas consumption of for both specific heating and electrical capacity in join production as well as fuel savings compared to the separate production of the same quantity of energy is also analyzed. (Original)

  12. Turbulence production by a steam-driven jet in a water vessel

    Energy Technology Data Exchange (ETDEWEB)

    Wissen, R.J.E. van; Schreel, K.R.A.M.; Geld, C.W.M. van der [Eindhoven Univ. of Technology (Netherlands). Dept. of Mechanical Engineering; Wieringa, J. [Unilever Research and Development, Vlaardingen (Netherlands)

    2004-04-01

    Direct steam injection is an efficient means of heating a volume of liquid. Usually the steam is injected via a nozzle, yielding a strong jet that condenses rapidly and transforms into a self-similar single phase jet. In the experiments reported in this paper, superheated steam is injected, centrally, at the bottom of a vertical, cylindrical water vessel. The resulting jet is turbulent (Re=7.9 x 10{sup 4}-18.1 x 10{sup 4} with the length scale based on the width of the jet, r{sub 1/2} and the velocity scale based on the centerline velocity, U{sub 0}). Using PIV in a vertical plane through the central axis, instantaneous velocity fields have been measured at a rate of 15 Hz. Near the inlet, the jet is mainly steam that rapidly condenses. Further downstream, the jet is essentially single phase, although some residual air is present as microscopically small bubbles. In the area directly downstream of the steam part, the ratio of r{sub 1/2} to the vessel radius R (32.5 cm) is about 1/14. The production of turbulent kinetic energy has been quantified for the main process conditions. Its dependencies on temperature, nozzle opening and inlet steam pressure have been determined. This production of energy is related to the stresses exerted on small particles in the mixture, and break-up of particles is discussed. (author)

  13. Assessment of a potential rapid condensation induced water hammer in a passive auxiliary feedwater system

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Shin, Byung Soo; Do, Kyu Sik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Moody, Frederick J. [General Electric (Retired), CA (United States)

    2012-10-15

    A passive auxiliary feedwater system (PAFS) which is incorporated in the APR+ system is a kind of closed natural circulation loop. The PAFS has no operating functions during normal plant operation, but it has a dedicated safety function of the residual heat removal following initiating events, including the unlikely event of the most limiting single failure occurring coincident with a loss of offsite power, when the feedwater system becomes inoperable or unavailable. Even in the unlikely event of a station blackout, the isolation valves can be opened either by DC power or manual operation and then the PAFS can also provide adequate condensate to the steam generator (SG). The PAFS piping in the vicinity of each of the two SGs is designed to minimize the potential for destructive water hammer during start up operation by setting the stroke time for full close or full open of the condensate isolation valves upon receipt of a passive auxiliary feedwater actuation signal. The temperature of the stagnant condensate water and its surrounding tubes and piping during the reactor normal operation modes may fall to the ambient temperature. A possible concern is the introduction of saturated steam into the PAFS recirculation pipe downstream of the PCHX in the beginning of the PAFS operation. Although the steam introduction rate is expected to be slow, a rapid condensation rate is expected due to the initial cold surrounding temperature in the pipe, which could result in a localized pressure reduction and the propagation of decompression and velocity disturbances into the condensate water leg, which might cause the sudden closure of check valves and associated water hammer. Thus, it is requisite for the licensing review of the PAFS design to confirm if destructive water hammers will not be produced due to such rapid condensation induced decompressions in the system. This paper addresses an assessment of the potential local decompressions which could result from the steam

  14. IMPACT OF THE COLD END OPERATING CONDITIONS ON ENERGY EFFICIENCY OF THE STEAM POWER PLANTS

    Directory of Open Access Journals (Sweden)

    Slobodan Laković

    2010-01-01

    Full Text Available The conventional steam power plant working under the Rankine Cycle and the steam condenser as a heat sink and the steam boiler as a heat source have the same importance for the power plant operating process. Energy efficiency of the coal fired power plant strongly depends on its turbine-condenser system operation mode. For the given thermal power plant configuration, cooling water temperature or/and flow rate change generate alterations in the condenser pressure. Those changes have great influence on the energy efficiency of the plant. This paper focuses on the influence of the cooling water temperature and flow rate on the condenser performance, and thus on the specific heat rate of the coal fired plant and its energy efficiency. Reference plant is working under turbine-follow mode with an open cycle cooling system. Analysis is done using thermodynamic theory, in order to define heat load dependence on the cooling water temperature and flow rate. Having these correlations, for given cooling water temperature it is possible to determine optimal flow rate of the cooling water in order to achieve an optimal condensing pressure, and thus, optimal energy efficiency of the plant. Obtained results could be used as useful guidelines in improving existing power plants performances and also in design of the new power plants.

  15. Counter-current flow limitation at hot leg pipe during reflux condensation cooling after small-break LOCA

    International Nuclear Information System (INIS)

    Jeong, Hae Yong; Ha, Sang Jun; Jo, Yung Jo; Jun, Hwang Yong

    1999-01-01

    The possibility of hot leg flooding is evaluated in case of a small-break loss-of-coolant accident in Korean Next Generation Reactor (KNGR) operating at the core power of 3983 MW normally. The vapor and liquid velocities in hot leg and steam generator tubes are calculated during reflux condensation cooling with the accident scenarios of three typical break sizes, 0.13 %, 1.02 % and 10.19 % cold leg break. The calculated results are compared with the existing flooding correlations. It is predicted that the hot leg flooding is excluded when two steam generators are available. It is also shown that the possibility of hot leg flooding under the operation with one steam generator is very low. Therefore, it can be said that the occurrence of hot leg flooding is unexpected when the reflux condensation cooling is maintained in steam generator tubes

  16. Study on thermal-hydraulic behavior in supersonic steam injector

    International Nuclear Information System (INIS)

    Abe, Yutaka; Fukuichi, Akira; Kawamoto, Yujiro; Iwaki, Chikako; Narabayashi, Tadashi; Mori, Michitsugu; Ohmori, Shuichi

    2007-01-01

    Supersonic steam injector is the one of the most possible devices aiming at simplifying system and improving the safety and the credibility for next-generation nuclear reactor systems. The supersonic steam injector has dual functions of a passive jet pump without rotating machine and a compact and high efficiency heat exchanger, because it is operated by the direct contact condensation between supersonic steam and subcooled water jet. It is necessary to clarify the flow behavior in the supersonic steam injector which is governed by the complicated turbulent flow with a great shear stress of supersonic steam. However, in previous study, there is little study about the turbulent heat transfer and flow behavior under such a great shear stress at the gas-liquid interface. In the present study, turbulent flow behavior including the effect of the interface between water jet and supersonic steam is developed based on the eddy viscosity model. Radial velocity distributions and the turbulent heat transfer are calculated with the model. The calculation results are compared with the experimental results done with the transparent steam injector. (author)

  17. Evaporation and condensation heat transfer in a suppression chamber of the water wall type passive containment cooling system

    International Nuclear Information System (INIS)

    Fujii, Tadashi; Kataoka, Yoshiyuki; Murase, Michio

    1996-01-01

    To evaluate the system pressure response of a water wall type containment cooling system, which is one of the passive safety systems, the evaporation and condensation behaviors in a suppression chamber have been experimentally examined. In the system, the suppression pool water evaporates from the pool surface, passing into the wetwell due to pool temperature rise, while steam in the wetwell condenses on the steel containment vessel wall due to the heat release through the wall. The wetwell is a gas phase region in the suppression chamber and its pressure, which is expressed as the sum of the noncondensable gas pressure and saturated steam pressure, is strongly affected by the evaporation heat transfer from the suppression pool surface and condensation heat transfer on the containment vessel wall. Based on the measured temperature profiles near the heat transfer surface and the wetwell pressure using two apparatuses, evaporation and condensation heat transfer coefficients were evaluated. The following results were obtained. (1) Both heat transfer coefficients increased as the ratio of the steam partial pressure to the total pressure increased. (2) Comparison of the results from two types of test apparatuses confirmed that the size of the heat transfer surface did not affect the heat transfer characteristics within these tests. (3) The heat transfer coefficients were expressed by the ratio of the steam to noncondensable gas logarithmic mean concentration, which considered the steam and gas concentration gradient from the heat transfer surface to the wetwell bulk. (author)

  18. Development of balanced downflow type surface condensers, (2)

    International Nuclear Information System (INIS)

    Tomida, Akira; Oshima, Yoshikuni; Okochi, Isao; Izumi, Kenkichi.

    1976-01-01

    As the size of the condensers for power generation plants grew large, the new balanced downflow type condenser was developed and completed on the basis of the experiment on steam flow according to the two-dimensional flow model, the analysis of the performance in a tube nest with a computer, and the studies on the effect of outside liquid film and the reheating deaeration of condensate. When the balanced downflow type condensers were adopted for actual plants, the construction, strength and production method were examined, and the reliability of the new condenser was confirmed by the thermal characteristic experiment with the model similar to the actual machine. The condenser comprises a condenser body, supporting plates, cooling tubes, tube plates, water chambers, and reinforcements, and the cooling tubes are arranged so as to exchange heat effectively. The arrangement of tubes is divided into three regions, namely radiation portion, densely arranged portion, and air cooling portion. In the balanced downflow type condensers, the dilution by utilizing condensate is provided against ammonia attack. The apparatuses for the thermal characteristic experiment and the experimental results, and the results of the performance test on the actual balanced downflow type condenser are reported. (Kako, I.)

  19. Optimisation of condenser design in waste immobilisation plants (WIP`s)

    Energy Technology Data Exchange (ETDEWEB)

    Rajani, G; Ozarde, P D; Gandhi, P M [Waste Management Projects Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    The situation under study is vertical heat exchanger with steam as the condensing vapour and NO{sub x} gases as the non condensible gas. The presence of even a small quantity of non-condensible gas in the condensible vapour has a profound influence on the resistance to heat transfer in the region of liquid-vapour heat transfer. Heat transfer coefficients go on reducing progressively, making condensers prohibitively bulky and hence optimisation of condensers is necessary for carrying out design calculations. The condenser has been divided into segments and for each segment, momentum and energy equations have been established and solved. Finally the average value for overall mass transfer coefficients has been calculated. Parametric studies giving the influence of sub cooling gases, water temperature, exit temperature etc. have been studied. (author). 5 refs., 5 figs., 2 tabs.

  20. Steam generator tube failures: experience with water-cooled nuclear power reactors during 1976

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1978-02-01

    A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author)

  1. Dew point measurements of flue gases in steam generators with brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schinkel, W.

    1980-01-01

    This paper examines empirical data on sulfuric acid condensation and resulting internal corrosion in brown coal fired steam generators. Due to the high sulfur content in brown coal (0.5% to 5.0%) and relative short duration of the gases in the combustion chamber the concentrations of sulfur trioxide present in the flue gases can condense at the heat exchange surfaces of the steam generators. A number of diagrams show sulfuric acid dew point temperatures depending on brown coal sulfur content, the influence of combustion air supply on the dew point, and condensing speed and the rate of corrosion in relation to different heat exchange surface temperatures. The conclusion is made that a five-fold increase in corrosion can be caused by a 10 K higher flue gas dew point, a 5 K cooling of heating surfaces can also cause heavy corrosion at a certain dew point. Maximum corrosion results at 20 to 50 K differences between flue gas dew point and heat exchange surfaces. Optimum operation of steam generators with minimal internal corrosion requires the consideration of flue gas and heating surface temperatures as well as flue gas sulfur acid dew points. (10 refs.) (In German)

  2. A mathematical model of steam-drum dynamics

    International Nuclear Information System (INIS)

    Moeck, E.O.; Hinds, H.W.

    1976-12-01

    Mathematical equations describing the dynamic behaviour of pressure, water mass, etc. in a steam drum are derived from basic principles. The resultant model includes such effects as steam superheating and water subcooling as well as spontaneous flashing of liquid and condensation of vapour. Experimental data from a pressurizer are adequately predicted by the model. The pressure rise following a turbine trip can be predicted by the isentropic-compression model but not by the thermodynamic-equilibrium model. The equations are individually linearized and implemented on an analog computer in such a way that their non-linear behaviour is retained for small-perturbation studies. (author)

  3. A condensation experiment in the accumulated conditions of noncondensable gas in a vertical tube

    International Nuclear Information System (INIS)

    Lee, Kwon Yeong; Kim, Moo Hwan

    2005-01-01

    Full text of publication follows: It has been well known that the presence of noncondensable gases in vapors can greatly inhibit the condensation process. Many analytical and experimental studies were conducted to investigate the effect of noncondensable gases on steam condensation for both stagnant and forced-convective situations either over a plate or outside a horizontal tube. Recently, several researches have been performed for the condensation in the presence of noncondensable gases taken place inside the vertical tube in order to give the information to design the passive containment cooling system (PCCS) in Simplified Boiling Water Reactor (SBWR). Generally, the experimental results showed that the heat transfer coefficient depends on inlet noncondensable gas mass fraction, inlet saturated steam temperature related with system pressure and inlet mixture Reynolds number. This research was performed for the System-integrated Modular Advanced ReacTor-Pilot (SMART-P), in which the remaining heat is removed from the core passively by Passive Residual Heat Removal System (PRHRS) condenser in a period of serious accident. The PRHRS is separated from working fluid loop, and pressurized by a nitrogen gas during the normal operation of SMART-P. But when the PRHRS starts operating, the nitrogen gas acts as a noncondensable gas and affects the heat transfer characteristics of the PRHRS. The experimental conditions of this study were almost similar with those of previous researches except the noncondensable gas was accumulated and remained inside the vertical tube. In the previous researches, the noncondensable gas was flowing with constant flow rate. Because of the condensate inside condenser tube, the accumulation of noncondensable gas could be developed inside the vertical tube. At steady-state condition the local temperatures and system pressure were measured to obtain heat transfer characteristics. This study also gave the information about the distribution of the

  4. Apparatus and method for depressurizing, degassing, and affording decay of the radioactivity of weakly radioactive condensates in nuclear power plants

    International Nuclear Information System (INIS)

    Gross, R.; Plotz, J.

    1976-01-01

    Described is an apparatus for depressurizing, degassing and affording decay of weakly radioactive condensates in nuclear power plants having a turbine and a main condenser turbine wherein exhaust steam of the turbine is condensed and forms a main condensate, and includes a collecting tank for the condensate situated below the condenser. A plurality of horizontal degassing channels, each having a lateral overflow, are disposed in the upper part of the condensate collecting tank and are filled with the main condensate up to the level of the overflow. At least one feedwater preheater which is heated by bleeder steam from the turbine provides a secondary condensate. Below the overflow height of the degassing channels extend horizontal feed pipes for the secondary condensate. The feed pipes are connected to the output of pressure relieving expanding devices and are provided on their underside with discharge openings for the bubbling of the secondary condensate into the main condensate to thereby degass the main condensate. The condensate collecting tank has mutually offset partitions therein providing an adequately long path for the decay of the main and secondary condensates. The condensate which is discharged from the condensate collecting tank is returned into the cycle as feedwater. Also disclosed is a method of operating the foregoing apparatus

  5. Analysis of experimental routines of high enthalpy steam discharge in subcooled water

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Rafael R., E-mail: Rafael.rade@ctmsp.mar.mil.br [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil); Andrade, Delvonei A., E-mail: delvonei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The discharge of high enthalpy steam through safety release valves out from pressurizers in PWR's needs to be condensed in order to allow the treatment of possibly present radwaste within. The Direct Contact Condensation is used in a relief tank to achieve the condensation. Care must be taken to avoid the bypass of the steam through the subcooled water, what would increase the peak of pressure and the necessity of structural reinforcement of the relief tank. An experiment to determine the optimal set up of the relief tank components and their characteristics (type of sprinkler, level of water, volume of tank, discharge direction, pressure in the pressurizer among others) was executed in 2000, in the CTE 150 facility, in CTMSP. In a total, 144 routines varying its components and characteristics were made, although no comprehensive analysis of its results were yet made, since the mass of data was too big to be readily analyzed. In order to comprehensively analyze it, a VBA program is being made to compile and graphically represent the mass of data. The current state of this program allowed conclusions over the peak pressure, adiabatic assumption of the experiment, and the quality of the steam generated due to the discharge. (author)

  6. Analysis of experimental routines of high enthalpy steam discharge in subcooled water

    International Nuclear Information System (INIS)

    Pacheco, Rafael R.; Andrade, Delvonei A.

    2015-01-01

    The discharge of high enthalpy steam through safety release valves out from pressurizers in PWR's needs to be condensed in order to allow the treatment of possibly present radwaste within. The Direct Contact Condensation is used in a relief tank to achieve the condensation. Care must be taken to avoid the bypass of the steam through the subcooled water, what would increase the peak of pressure and the necessity of structural reinforcement of the relief tank. An experiment to determine the optimal set up of the relief tank components and their characteristics (type of sprinkler, level of water, volume of tank, discharge direction, pressure in the pressurizer among others) was executed in 2000, in the CTE 150 facility, in CTMSP. In a total, 144 routines varying its components and characteristics were made, although no comprehensive analysis of its results were yet made, since the mass of data was too big to be readily analyzed. In order to comprehensively analyze it, a VBA program is being made to compile and graphically represent the mass of data. The current state of this program allowed conclusions over the peak pressure, adiabatic assumption of the experiment, and the quality of the steam generated due to the discharge. (author)

  7. The common project for completion of Bubbler Condenser Qualification (Bohunice, Mochovce, Dukovany and Paks NPPs)

    International Nuclear Information System (INIS)

    Jaroslav, H.; Pavol, B.

    2003-01-01

    Described is the common project for completion of bubbler condenser qualification for nuclear power plants in Bohunice, Mochovice, Dukovany and Paks. Functionality of the bubbler condenser was elaborated during the simulation of the main steam line brake, medium break and small break LOCA. On this basis the appropriate operation of bubbler condenser containment under accident conditions can be positively confirmed

  8. Influence of the distribution of non-condensables on passive containment condenser performance in PANDA

    International Nuclear Information System (INIS)

    Bandurski, Th.; Huggenberger, M.; Dreier, J.; Aubert, C.; Putz, F.; Gamble, R.E.; Yadigaroglu, G.

    2001-01-01

    Recently passive cooling systems have been designed for the long-term decay heat removal from the containment of Advanced Light Water Reactors. In particular, the long-term LOCA response of the Passive Containment Cooling System (PCCS) for the General Electric European Simplified Boiling Water Reactor (ESBWR) has been tested in the large-scale PANDA facility. The PANDA tests achieved the dual objectives of improving confidence in the performance of the passive heat removal mechanisms underlying the design of the system, and extending the database available for containment analysis code qualification. The tests conducted subject the PCCS to a variety of conditions representing design-basis and beyond-design-basis accident conditions. These include operation in the presence of both heavier and lighter than steam non-condensable gases, as well as a variety of asymmetric and challenging start-up conditions. The present paper addresses the transient distribution of non-condensables in PANDA, and their effect on (passive) condenser performance. (author)

  9. Influence of the distribution of non-condensables on passive containment condenser performance in PANDA

    Energy Technology Data Exchange (ETDEWEB)

    Bandurski, Th.; Huggenberger, M.; Dreier, J.; Aubert, C.; Putz, F.; Gamble, R.E.; Yadigaroglu, G

    2001-03-01

    Recently passive cooling systems have been designed for the long-term decay heat removal from the containment of Advanced Light Water Reactors. In particular, the long-term LOCA response of the Passive Containment Cooling System (PCCS) for the General Electric European Simplified Boiling Water Reactor (ESBWR) has been tested in the large-scale PANDA facility. The PANDA tests achieved the dual objectives of improving confidence in the performance of the passive heat removal mechanisms underlying the design of the system, and extending the database available for containment analysis code qualification. The tests conducted subject the PCCS to a variety of conditions representing design-basis and beyond-design-basis accident conditions. These include operation in the presence of both heavier and lighter than steam non-condensable gases, as well as a variety of asymmetric and challenging start-up conditions. The present paper addresses the transient distribution of non-condensables in PANDA, and their effect on (passive) condenser performance. (author)

  10. Simulating the transient regime for main condensate system at Cernavoda NPP

    International Nuclear Information System (INIS)

    Nita, Iulian; Gheorghiu, Mihai; Prisecaru, Ilie; Dupleac, Daniel

    2005-01-01

    The purpose of this project is to make a Thermal Hydraulic Analysis of Main Condensate System for getting real-time answer of installation during regimes occurring during normal and abnormal operation. To obtain the analyses the MMS code was used. The boundaries of the systems analysis are extended to Main Feedwater System in order to get a realistic response of Deaerator equipment which are situated between those two systems and have entrances from both systems. In this way we made a complex analysis with main condenser and steam generators as boundaries. We obtained a model for the entire chain of condensate and feedwater preheater with interface just turbine bleed steam. From that we could reduce the number of assumptions necessary to make the analysis. The analyses consist in hydraulics and thermal hydraulics analyses, respectively. For the first case analysed are: - the nominal operation regime with main condensate pumps; - start-up regime with total circulate of condensate to condenser; - 25% MCR (Maximum Continuous Rate) regime (this regime was used in designing the condensate regulating valves at low flow; - 40% MCR regime (with circulate of some condensate flow to condenser); - operating regime of 60% MCR with one main condensate pump operating; - operating regime with auxiliary condensate pump; - operating regime with discharging a condensate flow to condensate storage tank. The thermal hydraulic analyses deal with normal and abnormal operating regimes, respectively. In the first case analysed are the following regimes: - nominal operating regime with main condensate pump operating 100% MCR; - transient regime, 100-80% MCR; - transient regime, 100-80-60% MCR with two pumps in operation and 60 % MCR with one main condensate pump in operation; - transient regime, 100-80-60-60-40 % MCR; - shut-down regime; - start-up regime from Hot zero power to rated power regime. Finally, for the abnormal operating regimes the analyses concerned: - transient regime 100

  11. Profile Septa cut out condensate crud

    International Nuclear Information System (INIS)

    Poschmann, T.

    1991-01-01

    Secondary side corrosion is a major factor leading to steam generator tube plugging. Large quantities of steam generator sludge can harden, prolonging system maintenance during an outage. However, eliminating the ingress of solids to the PWR steam generators can reduce the need for sludge lancing and increase the life of the steam generator tubes. The Pall Corporation has developed an improved filter demineralizer septum for retrofitting traditional yarn-wound elements without having to modify hardware. In November 1990, operators at Turkey Point installed 496 2in x 70in Pall's Profile Septa in one of the four filter demineralizer vessels on unit 3. After installation of the Profile Septa, samples of filter influent and effluent were taken and analyzed over a one-month period - these showed a particulate removal rate of 96-99%. Contaminant analysis by Pall Corporation identified the vast majority of particulates to be iron oxides. This is as was expected, since Turkey Point has titanium condenser tubes which reduce the source of copper oxides. The success of Profile Septa at Turkey Point has encouraged the other utilities to look at using the septa at their own plants. The cost for these retrofits would be recouped through savings in maintenance costs, due to faster steam generator lancing (fewer solids), reduced radiation exposure and, ultimately, longer steam generator life. (author)

  12. Steam turbine chemistry in light water reactor plants

    International Nuclear Information System (INIS)

    Svoboda, Robert; Haertel, Klaus

    2008-01-01

    Steam turbines in boiling water reactor (BWR) and pressurized water reactor (PWR) power plants of various manufacturers have been affected by corrosion fatigue and stress corrosion cracking. Steam chemistry has not been a prime focus for related research because the water in nuclear steam generating systems is considered to be of high purity. Steam turbine chemistry however addresses more the problems encountered in fossil fired power plants on all volatile treatment, where corrosive environments can be formed in zones where wet steam is re-evaporated and dries out, or in the phase transition zone, where superheated steam starts to condense in the low-pressure (LP) turbine. In BWR plants the situation is aggravated by the fact that no alkalizing agents are used in the cycle, thus making any anionic impurity immediately acidic. This is illustrated by case studies of pitting corrosion of a 12 % Cr steel gland seal and of flow-oriented corrosion attack on LP turbine blades in the phase transition zone. In PWR plants, volatile alkalizing agents are used that provide some buffering of acidic impurities, but they also produce anionic decomposition products. (orig.)

  13. Air condensation plants

    International Nuclear Information System (INIS)

    Kelp, F.; Pohl, H.H.

    1978-01-01

    In this plant the steam is distributed by a ventilator from the bottom to symmetrically fixed, inclined cooling elements with tubes. The upper part of the current side of the cooling elements as well as the bottom part of the outflow side can be covered by cover plates via a control circuit. This way, part of the air amount is deviated and in case of unfavourable atmospheric conditions (cold) the air is heated. This heating is enough to prevent freezing of the condensate on the cooling tubes. (DG) [de

  14. Determination of heat transfer coefficient with vapor condensation inside the tubes diesel’s radiator sections

    Directory of Open Access Journals (Sweden)

    Y.K.Sklifus

    2012-12-01

    Full Text Available The article presents the calculation of heat transfer coefficient during condensation of steam, the mathematical model of temperature distribution in the gas and liquid phases of the coolant and the model of the formation of the condensate film on the walls of the tubes.

  15. The use of titanium for condenser tube bundles

    International Nuclear Information System (INIS)

    Dobrovitch, N.

    2002-01-01

    In a power plant, the condenser is a strategic heat exchanger with regards to the efficiency of the steam turbine and its reliability guarantees the performance and continuous operation of the plant. Until the early 1980's, copper alloys were routinely used in condenser tubes, thanks to their high heat transfer rates. Yet numerous problems arose from the use of this material, such as stress cracking corrosion, ammoniacal corrosion, fouling, erosion, dezincification, abrasion, erosion-corrosion,... and lately the problem of inadequateness of copper with nuclear steam generators (in nuclear power plant the abrasion problem of the copper alloy tubes created a deposit problem in the steam generator conducting to the replacement of all the condensers). The trend was then to consider new tube materials, such stainless steel and titanium, firstly for particular operating conditions and now for most of the projects, with several objectives, such as: 1) improve the reliability (titanium in particular can bring major improvements such as higher water velocities promoting better heat coefficients, excellent resistance to abrasion, erosion and corrosion thereby improving resistance to fouling; 2) find more cost-effective solutions. The first investment is higher but money is saved on maintenance costs and on time reliability of the material. Titanium tube manufacturing has greatly evolved for the last 20 years. Tubes are mostly welded tubes from ASTM SB 338 grade 1 made on a continuous manufacturing line. All manufacturing operations (welding, annealing, non-destructive testing) are fully automated to produce high quality tubes in large quantities. The most common way to attach tubes to a tubesheet is to roller expand them. (A.C.)

  16. Study on the behavior of moisture droplets in low pressure steam turbines

    International Nuclear Information System (INIS)

    Kimura, Y.; Kuramoto, Y.; Yoshida, K.; Etsu, M.

    1978-01-01

    Low pressure stages of fossil turbines and almost all stages of nuclear and geothermal turbines operate on wet steam. Turbine operating on wet steam have the following two disadvantages: decrease of efficiency and erosion of blades. Decrease of efficiency results from an increase in profile loss caused by water films on the blade surface; loss of steam energy in breaking up the films and accelerating moisture droplets; undercooling and condensation shocks associated with it; velocity difference between water and steam phases and consequent decelerating action of moisture droplets in the rotating blades, etc. Impingement of moisture droplets on the rotating blades also causes quick erosion of the blades. In this paper, the behavior of moisture droplets in wet steam flow is described and the correlation between their behavior and the abovementioned two disadvantages of turbines operating on wet steam is clarified. (author)

  17. Characteristics of flow in turbine-condenser connections

    International Nuclear Information System (INIS)

    Yasugahira, Norio; Sato, Takeshi; Mukai, Yasuteru; Otake, Katsumoto; Miyai, Masahiko

    1981-01-01

    It is important to save energy in thermal and nuclear power plants, and Hitachi Ltd. has exerted efforts on this subject. The performance of condensers depends largely on the condition of steam flow into the tube nests, and is affected by the state of steam flow in the connecting parts between LP turbines and the condensers. It is desirable to give turbines low exhaust pressure by minimizing the resistance of the obstacles in the diffuser paths and increasing the restoration of static pressure. But in the connecting parts, feed water heaters, bleeding pipes and stiffeners are placed, and if these re arranged inadequately, the performance of condensers and the efficiency of turbines are lowered by pressure loss. In this study, the flow in the connecting parts was reproduced with models, and the detailed state of internal flow was grasped. Also the influence of the form of the connecting parts, feed water heaters and bleeding pipes on pressure loss was examined, and the measures to reduce the pressure loss were sought. The cases of the connecting parts containing one feed water heater and four feed water heaters were examined. The experimental setup, the structure of the tested models, and the test results are reported. The velocity distribution and flow pattern of the internal flow were obtained, and the arrangement of feed water heaters which reduces pressure loss was clarified. (Kako, I.)

  18. Exergy Steam Drying and Energy Integration

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Prem; Muenter, Claes (Exergy Engineering and Consulting, SE-417 55 Goeteborg (Sweden)). e-mail: verma@exergyse.com

    2008-10-15

    Exergy Steam Drying technology has existed for past 28 years and many new applications have been developed during this period. But during past few years the real benefits have been exploited in connection with bio-fuel production and energy integration. The steam dryer consists of a closed loop system, where the product is conveyed by superheated and pressurised carrier steam. The carrier steam is generated by the water vapours from the product being dried, and is indirectly superheated by another higher temperature energy source such as steam, flue gas, thermal oil etc. Besides the superior heat transfer advantages of using pressurised steam as a drying medium, the energy recovery is efficient and simple as the recovered energy (80-90%) is available in the form of steam. In some applications the product quality is significantly improved. Examples presented in this paper: Bio-Combine for pellets production: Through integration of the Exergy Steam Dryer for wood with a combined heat and power (CHP) plant, together with HP steam turbine, the excess carrier steam can be utilised for district heating and/or electrical power production in a condensing turbine. Bio-ethanol production: Both for first and second generation of ethanol can the Exergy process be integrated for treatment of raw material and by-products. Exergy Steam Dryer can dry the distillers dark grains and solubles (DDGS), wood, bagasse and lignin. Bio-diesel production: Oil containing seeds and fruits can be treated in order to improve both the quality of oil and animal feed protein, thus minimizing further oil processing costs and increasing the sales revenues. Sewage sludge as bio-mass: Municipal sewage sludge can be considered as a renewable bio-fuel. By drying and incineration, the combustion heat value of the sludge is sufficient for the drying process, generation of electrical energy and production of district heat. Keywords; Exergy, bio-fuel, bio-mass, pellets, bio-ethanol, biodiesel, bio

  19. Removal of fine particles in wet flue gas desulfurization system by heterogeneous condensation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, L.J.; Bao, J.J.; Yan, J.P.; Liu, J.H.; Song, S.J.; Fan, F.X. [Southeast University, Nanjing (China). School of Energy & Environment

    2010-01-01

    A novel process to remove fine particles with high efficiency by heterogeneous condensation in a wet flue gas desulfurization (WFGD) system is presented. A supersaturated vapor phase, necessary for condensational growth of fine particles, was achieved in the SO{sub 2} absorption zone and at the top of the wet FGD scrubber by adding steam in the gas inlet and above the scrubbing liquid inlet of the scrubber, respectively. The condensational grown droplets were then removed by the scrubbing liquid and a high-efficiency demister. The results show that the effectiveness of the WFGD system for removal of fine particles is related to the SO{sub 2} absorbent employed. When using CaCO{sub 3} and NH{sub 3} {center_dot} H{sub 2}O to remove SO{sub 2} from flue gas, the fine particle removal efficiencies are lower than those for Na2CO{sub 3} and water, and the morphology and elemental composition of fine particles are changed. This effect can be attributed to the formation of aerosol particles in the limestone and ammonia-based FGD processes. The performance of the WFGD system for removal of fine particles can be significantly improved for both steam addition cases, for which the removal efficiency increases with increasing amount of added steam. A high liquid to gas ratio is beneficial for efficient removal of fine particles by heterogeneous condensation of water vapor.

  20. CFD simulation on condensation inside a Hybrid SIT

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Byong Guk; Ryu, Sung Uk; Kim, Seok; Euh, Dong Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The concept of Hybrid Safety Injection Tank system (Hybrid SIT) was proposed by Korea Atomic Energy Research Institute (KAERI) aiming at Advanced Power Reactor Plus. The main advantage of the system is the ready injection of coolant into the reactor coolant system at high pressure. In this paper, a CFD simulation is conducted as a preliminary study. In Hybrid SITs, condensation inside the tank affects its pressure rise and injection time. In an attempt to explore the condensation in detail, we manufactured a dedicated experimental facility for visualization of condensation-induced thermal mixing and conducted a preliminary CFD simulation. Its condensation models were validated first and then computational domain was constructed. The water region was modeled as a solid for stable calculation. The CFD results gave less condensation and excessive pressurization because of lack of steam penetration into the water. In the future, the water region will be modeled as liquid using a VOF model.

  1. A model for the performance of a vertical tube condenser in the presence of noncondensable gases

    Energy Technology Data Exchange (ETDEWEB)

    Guentay, A.D.S.

    1995-09-01

    Some proposed vertical tube condensers are designed to operate at high noncondensable fractions, which warrants a simple model to predict their performance. Models developed thus far are usually non self-contained as they require the specification of the wall temperature to predict the local condensation rate. The present model attempts to fill this gap by addressing the secondary side heat transfer as well. Starting with momentum balance which includes the effect of interfacial shear stress, a Nusselt-type algebraic equation is derived for the film thickness as a function of flow and geometry parameters. The heat and mass transfer analogy relations are then invoked to deduce the condensation rate of steam onto the tube wall. Lastly, the heat transfer to the secondary side is modelled to include cooling by forced, free or mixed convection flows. The model is used for parametric simulations to determine the impact on the condenser performance of important factors such as the inlet gas fraction, the mixture inlet flowrate, the total pressure, and the molecular weight of the noncondensable gas. The model performed simulations of some experiments with pure steam and air-steam mixtures flowing down a vertical tube. The model predicts the data quite well.

  2. Nuclear power plant and apparatus for superheating steam

    International Nuclear Information System (INIS)

    Schluderberg, D.C.

    1983-01-01

    The invention consists of an apparatus for superheating steam, the apparatus comprising a horizontally disposed generally cylindrical elongate shell, inlet means in the shell for receiving steam, outlet means in the shell for discharching the steam, and a bundle of inclined tubes positioned in the flow path of the steam, each of the tubes having a length which is less than the diameter of the shell and opening into and extending in an upward direction from an outlet header to an inlet header, the inlet header beeing connected to a source of vapor, and the outlet header beeing connected to a condensate drain, characterised in that the test bundle comprises two banks of the tubes, the angle at which each of the tubes of one of the banks extends relative to a vertical longitudinal centerplane, the tubes of one of the banks terminate at and open into the inlet header, and the tubes of the other banks terminate at an open into another inlet header

  3. Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria.

    Science.gov (United States)

    Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

    2003-03-01

    Steam classification is a process for treatment of solid waste that allows recovery of volatile organic compounds from the waste via steam condensate and off-gases. A mixed culture of aromatic hydrocarbon-degrading bacteria was used to degrade the contaminants in the condensate, which contained approx. 60 hydrocarbons, of which 38 were degraded within 4 d. Many of the hydrocarbons, including styrene, 1,2,4-trimethylbenzene, naphthalene, ethylbenzene, m-/p-xylene, chloroform, 1,3-dichloropropene, were completely or nearly completely degraded within one day, while trichloroethylene and 1,2,3-trichloropropane were degraded more slowly.

  4. Steam chugging in pressure suppression containment

    International Nuclear Information System (INIS)

    Lee, C.K.B.; Chan, C.K.

    1978-01-01

    The condensation of steam flow in subcooled water was studied by injecting a quasi-steady stream of saturated steam into a pool water at different temperature. From the movies, it was observed that chugging occurred at a frequency on the order of 1 to 2 times a second. In between each chug over a period of approximately half a second, a few bubbles formed and collapsed at the exit of the downcomer. At a mass flow rate of approximately 5.02 Kg/m 2 sec., the chugging process is found to be strongly affected by the bubble formation. At pool temperatures below 50 0 C, the chugging process is dominated by internal chugging which is characterized by high water slug exit velocity, detached steam bubble and lhigh chugging level. Above 50 0 C, the external chugging mode is dominant. The external chugging mode is characterized by pancake bubble shape, low water slug exit velocity, and low chugging level. (author)

  5. A preliminary study on HTGR with air-cooled condenser at Riyadh, Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jonghwa; Lee, Wonjae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    N GNP reactor plant adopted a Rank in steam cycle for early deployment and for reducing R and D risk and cost. Original plant design is based on a wet cooling tower with wet bulb temperature of 34 .deg. C. This cooling environment may be sufficient for most area in North America. However, we should consider air temperature of 45 .deg. C and no available cooling water for any site near Riyadh, Saudi Arabia. A plausible option in such arid area is using an air-cooled condenser(ACC) which is widely used in a combined cycle plant in arid region. ACC is also suitable for freezing area such as northern territory or high elevation remote area. We have studied impact of the cooling method on the power generation efficiency and the annual average power production referencing N GNP steam turbine. Even though condenser split is assumed to be the same between ACC and wet cooling tower, large difference in air temperature and wet bulb temperature makes large efficiency loss in the ACC. The ACC efficiency is lower than that of the wet cooling tower by 1.12%. To make up this loss, we proposed the variable steam extraction rates operation. An air cooled condenser is a practical.

  6. Experimental and computational analysis of steam condensation in the presence of air and helium

    International Nuclear Information System (INIS)

    Bucci, M.

    2010-01-01

    Among the different phenomena expected to occur within nuclear reactor containments during a postulated loss of coolant accident, condensation on containment walls plays a major role, since it represents an important heat sink for evacuating the energy released by the discharge of the primary water. Nevertheless, condensation strongly affects other relevant phenomena, like containment atmosphere mixing, that influences the distribution of non-condensable gases hypothetically delivered in severe accident conditions. In this scenario, the role of condensation is not obvious, since it can locally aid the hydrogen produced by the oxidation of the core claddings to concentrate and reach flammability limits, providing a dangerous effect instead of a positive one. The understanding of condensation in the presence of air and hydrogen is therefore a fundamental task for the safety analyses of reactor containments. This research has been carried out with the aim to contribute to the understanding of these phenomena. A double strategy has been adopted, including complementary experimental and computational activities. Novel data have been made available by the CONAN facility, investigating the effects induced by light non-condensable gases in experimental configurations that were scarcely investigated in past studies. Computational fluid dynamics (CFD) condensation models have been developed and validated. The suitability of helium as a substitute for hydrogen in experimental activities has been investigated by theoretical and computational analyses allowing to establish simple criteria for the scaling of condensation tests in the presence of a light non-condensable gas. (authors)

  7. A study of the condensation of a high-velocity vapor jet on a coflowing turbulent liquid jet

    Science.gov (United States)

    Ovsiannikov, V. A.; Levin, A. A.

    A method for the experimental determination of the local value of the heat transfer coefficient under conditions of jet condensation is proposed which employs a heat balance expression in differential form. The method is used in an experimental study of the heat transfer characteristics of the condensation of a high-velocity coaxial jet of a slightly superheated (3 percent) steam on a coflowing cylindrical turbulent water jet. In the experiment, the relative velocities reach hundreds of m/s; the temperature nonequilibrium of the phases is high, as is the steam flow mass density during the initial contact; heat transfer between the phases is significant. The results can be used as the basis for determining experimental criterial dependences for jet condensation.

  8. Unsteady coupling effects of wet steam in steam turbines flows

    International Nuclear Information System (INIS)

    Blondel, Frederic

    2014-01-01

    In addition to conventional turbomachinery problems, both the behavior and performances of steam turbines are highly dependent on the vapour thermodynamic state and the presence of a liquid phase. EDF, the main French electricity producer, is interested in further developing its' modelling capabilities and expertise in this area to allow for operational studies and long-term planning. This PhD thesis explores the modelling of wetness formation and growth in a steam turbine and an analysis of the coupling between the liquid phase and the main flow unsteadiness. To this end, the work in this thesis took the following approach. Wetness was accounted for using a homogeneous model coupled with transport equations to take into account the effects of non-equilibrium phenomena, such as the growth of the liquid phase and nucleation. The real gas attributes of the problem demanded adapted numerical methods. Before their implementation in the 3D elsA solver, the accuracy of the chosen models was tested using a developed one-dimensional nozzle code. In this manner, various condensation models were considered, including both poly-dispersed and monodispersed behaviours of the steam. Finally, unsteady coupling effects were observed from several perspectives (1D, 1D - 3D, 3D), demonstrating the ability of the method of moments to sustain unsteady phenomena which were not apparent in a simple monodispersed model. (author)

  9. Numerical Study of Condensation Heat Exchanger Design in a Cooling jacket: Correlation Investigation

    International Nuclear Information System (INIS)

    Kim, Myoung Jun; Lee, Hee Joon; Kang, Han Ok; Lee, Tae Ho; Park, Cheon Tae

    2013-01-01

    In this study, condensing heat transfer correlation of TSCON is evaluated with the existing experimental data set to design condensation heat exchanger without noncondensable gas effect (pure steam condensation) in a cooling jacket. From the investigation of the existing condensation heat transfer correlation to the existing experimental data, the improved Shah's correlation showed most satisfactory result for the condensation heat transfer coefficient with experimental data of Khun in a cooling jacket, whereas the Shah's correlation with experimental data of Lee. Lee et al. reported the improved Shah correlation gave us the best predictor for the condensation heat transfer data of Kim and Henderson in a subcooled and saturated water pool. They suggested the improved Shah correlation should be adopted as condensation heat transfer module in TSCON(Thermal Sizing of CONdenser) to design condensation heat exchanger in secondary passive cooling system of nuclear plant

  10. Development of a condenser for the dual catalyst water recovery system

    Science.gov (United States)

    Budinikas, P.; Rasouli, F.; Rabadi, N.

    1983-01-01

    Conceptual evaporation/condensation systems suitable for integration with the catalytic water recovery method were evaluated. The primary requirements for each concept were its capability to operate under zero-gravity conditions, condense recovered water from a vapor-noncondensable gas mixture, and integrate with the catalytic system. Specific energy requirements were estimated for concepts meeting the primary requirements, and the concept most suitable for integration with the catalytic system was proposed. A three-man rate condenser capable of integration with the proposed system, condensing water vapor in presence of noncondensables and transferring the heat of condensation to feed urine was designed, fabricated, and tested. It was treated with steam/air mixtures at atmospheric and elevated pressures and integrated with an actual catalytic water recovery system. The condenser has a condensation efficiency exceeding 90% and heat transfer rate of approximately 85% of theoretical value at coolant temperature ranging from 7 to 80 deg C.

  11. Assessment of horizontal in-tube condensation models using MARS code. Part I: Stratified flow condensation

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Seong-Su [Department of Engineering Project, FNC Technology Co., Ltd., Bldg. 135-308, Seoul National University, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Department of Nuclear Engineering, Seoul National University, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Hong, Soon-Joon, E-mail: sjhong90@fnctech.com [Department of Engineering Project, FNC Technology Co., Ltd., Bldg. 135-308, Seoul National University, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Park, Ju-Yeop; Seul, Kwang-Won [Korea Institute of Nuclear Safety, 19 Kuseong-dong, Yuseong-gu, Daejon (Korea, Republic of); Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer This study collected 11 horizontal in-tube condensation models for stratified flow. Black-Right-Pointing-Pointer This study assessed the predictive capability of the models for steam condensation. Black-Right-Pointing-Pointer Purdue-PCCS experiments were simulated using MARS code incorporated with models. Black-Right-Pointing-Pointer Cavallini et al. (2006) model predicts well the data for stratified flow condition. Black-Right-Pointing-Pointer Results of this study can be used to improve condensation model in RELAP5 or MARS. - Abstract: The accurate prediction of the horizontal in-tube condensation heat transfer is a primary concern in the optimum design and safety analysis of horizontal heat exchangers of passive safety systems such as the passive containment cooling system (PCCS), the emergency condenser system (ECS) and the passive auxiliary feed-water system (PAFS). It is essential to analyze and assess the predictive capability of the previous horizontal in-tube condensation models for each flow regime using various experimental data. This study assessed totally 11 condensation models for the stratified flow, one of the main flow regime encountered in the horizontal condenser, with the heat transfer data from the Purdue-PCCS experiment using the multi-dimensional analysis of reactor safety (MARS) code. From the assessments, it was found that the models by Akers and Rosson, Chato, Tandon et al., Sweeney and Chato, and Cavallini et al. (2002) under-predicted the data in the main condensation heat transfer region, on the contrary to this, the models by Rosson and Meyers, Jaster and Kosky, Fujii, Dobson and Chato, and Thome et al. similarly- or over-predicted the data, and especially, Cavallini et al. (2006) model shows good predictive capability for all test conditions. The results of this study can be used importantly to improve the condensation models in thermal hydraulic code, such as RELAP5 or MARS code.

  12. Water separator for a steam turbine for nuclear power stations

    International Nuclear Information System (INIS)

    Herzog, J.; Hubble, W.S.; Woods, K.K.

    1976-01-01

    The invention concerns a water separator for the condensation of humidity from steam of the inertia type, which has an improved flow distribution and can therefore be built for large dimensions. This is achieved by variation of the dimensions of the components of the liquid separator, particularly by the configuration of the drain trough, and by the fixing of suitable impact sheets, which produce turbulence and distribute the wet steam evenly over the separator elements. There is a detailed representation with drawings. (UW) [de

  13. Thermal hydraulic studies in steam generator test facility

    International Nuclear Information System (INIS)

    Vinod, V.; Suresh Kumar, V.A.; Noushad, I.B.; Ellappan, T.R.; Rajan, K.K.; Rajan, M.; Vaidyanathan, G.

    2005-01-01

    Full text of publication follows: A 500 MWe fast breeder reactor is being constructed at Kalpakkam, India. This is a sodium cooled reactor with two primary and two secondary sodium loops with total 8 steam generators. The typical advantage of fast breeder plants is the high operating temperature of steam cycles and the high plant efficiency. To produce this high pressure and high temperature steam, once through straight tube vertical sodium heated steam generators are used. The steam is generated from the heat produced in the reactor core and being transported through primary and secondary sodium circuits. The steam generator is a 25 m high middle supported steam generator with expansion bend and 23 m heat transfer length. Steam Generator Test Facility (SGTF) constructed at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam aims at performing various tests on a 5.5 MWt steam generator. This vertically simulated test article is similar in all respects to the proposed 157 MWt steam generator module for the Prototype Fast Breeder Reactor (PFBR), with reduced number of tubes. Heat transfer performance tests are done with this 19 tube steam generator at various load conditions. Sodium circuit for the SGTF is equipped with oil fired heater as heat source and centrifugal sodium pump, to pump sodium at 105 m 3 /hr flow rate. Other typical components like sodium to air heat exchanger, sodium purification system and hydrogen leak detection system is also present in the sodium circuit. High pressure steam produced in the steam generator is dumped in a condenser and recycled. Important tests planned in SGTF are the heat transfer performance test, stability test, endurance test and performance test of steam generator under various transients. The controlled operation of steam generator will be studied with possible control schemes. A steady state simulation of the steam generator is done with a mathematical model. This paper gives the details of heat transfer

  14. Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (11) Visualization Study on the Start-Up of the Steam Injector

    International Nuclear Information System (INIS)

    Koji Okamoto; Tadashi Narabayashi; Chikako Iwaki; Shuichi Ohmori; Michitsugu Mori

    2006-01-01

    The Steam Injector is the superior system to pump the fluid without rotating machine. Because the water column is surrounded by the saturated steam, very high heat transfer is also expected with direct condensation. The inside of the Steam Injector is very complicated. To improve the efficiency of the Steam Injector, the water column behavior inside the Injector is visualized using the Dynamic PIV system. Dynamic PIV system consists of the high-speed camera and lasers. In this study, 384 x 180 pixel resolution with 30,000 fps camera is used to visualize the flow. For the illumination CW green laser with 300 mW is applied. To view inside the Injector, relay lens system is set at the Injector wall. Very high speed water column during the starting up of Steam Injector had been clearly visualized with 30,000 fps. The wave velocity on the water column had been analyzed using PIV technique. The instability of the water column is also detected. (authors)

  15. Investigation of the Condensation Effect at IRWST Pool Surface on Containment Back Pressure in APR1400 Containment

    International Nuclear Information System (INIS)

    Lee, Eui Jong; Lee, Jin Yong; Lee, Byung Chul

    2006-01-01

    The APR1400 has several new design concepts in order to improve the plant safety functions during a postulated accident. The In-Containment Refueling Water Storage Tank (IRWST) is one of the new design concepts of APR1400 and installed at the bottom of containment building to promote the plant safety functions by simplifying emergency core cooling water source and preventing release of the fission product during an accidents. This design feature, however, brings about uncertainty factors which may necessitate conventional prediction of temperature and pressure of containment building improved or revised under accident conditions. The hot steam which is released from RCS break enters into the IRWST through four Pressure Relief Dampers (PRDs). It is expected to be condensed with water stored in IRWST, colder than incoming steam. The purpose of this study is to examine closely the influence of the condensation effect at IRWST on containment back pressure in APR1400 containment building using the GOTHIC code which can predict the steam condensation on IRWST pool surface

  16. Modeling of condensation, stratification, and mixing phenomena in a pool of water

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Kudinov, P.; Villanueva, W. (Royal Institute of Technology (KTH). Div. of Nuclear Power Safety, Stockholm (Sweden))

    2010-12-15

    This work pertains to the research program on Containment Thermal-Hydraulics at KTH. The objective is to evaluate and improve performance of methods, which are used to analyze thermal-hydraulics of steam suppression pools in a BWR plant under different abnormal transient and accident conditions. As a passive safety system, the function of steam pressure suppression pools is paramount to the containment performance. In the present work, the focus is on apparently-benign but intricate and potentially risk-significant scenarios in which thermal stratification could significantly impede the pool's pressure suppression capacity. For the case of small flow rates of steam influx, the steam condenses rapidly in the pool and the hot condensate rises in a narrow plume above the steam injection plane and spreads into a thin layer at the pool's free surface. When the steam flow rate increases significantly, momentum introduced by the steam injection and/or periodic expansion and shrink of large steam bubbles due to direct contact condensation can cause breakdown of the stratified layers and lead to mixing of the pool water. Accurate prediction of the pool thermal-hydraulics in such scenarios presents a computational challenge. Lumped-parameter models have no capability to predict temperature distribution of water pool during thermal stratification development. While high-order-accurate CFD (RANS, LES) methods are not practical due to excessive computing power needed to calculate 3D high-Rayleighnumber natural circulation flow in long transients. In the present work, a middleground approach is used, namely CFD-like model of the general purpose thermalhydraulic code GOTHIC. Each cell of 3D GOTHIC grid uses lumped parameter volume type closures for modeling of various heat and mass transfer processes at subgrid scale. We use GOTHIC to simulate POOLEX/PPOOLEX experiment, in order to (a) quantify errors due to GOTHIC's physical models and numerical schemes, and (b

  17. Characteristics of steam jet impingement on annulus

    International Nuclear Information System (INIS)

    Yoon, Sang H.; Kim, Won J.; Suh, Kune Y.; Song, Chul H.

    2004-01-01

    The steam jet impingement occurs when the steam through the cold leg from the steam generator strikes the inner reactor barrel during the reflood phase of a loss-of-coolant accident (LOCA), which is a characteristic behavior for the APR1400 (Advanced Power Reactor 1400 MWe). In the cold leg break LOCA, the steam and water flows in the downcomer are truly multidimensional. The azimuthal velocity distribution of the steam flow has an important bearing on the thermal hydraulic phenomena such as the emergency coolant water direct bypass, sweepout, steam condensation, and so forth. The investigation of jet flow is required to determine the steam path and momentum reduction rate after the impingement. For the observation of the steam behavior near the break, the computational fluid dynamic (CFD) analysis has been carried out using CFX5.6. The flow visualization and analysis demonstrate the velocity profiles of the steam flow in the annulus region for the same boundary conditions. Pursuant to the CFD results, the micro-Pitot tubes were positioned at varying angles, and corrected for their sensitivity. The experiments were carried out to directly measure the pressure differential and to visualize the flow utilizing a smoke injection method. Results from this study are slated to be applied to MARS, which is a thermal hydraulic system code for the best-estimate analysis. The current one- or two-dimensional analysis in MARS was known to distort the local flow behavior. To enhance prediction capability of MARS, it is necessary to inspect the steam path in the break flow and mechanically simulate the momentum variation. The present experimental and analytical results can locally be applied to developing the engineering models of specific and essential phenomena. (author)

  18. Numerical Study of Condensation Heat Exchanger Design in a Subcooled Pool: Correlation Investigation

    International Nuclear Information System (INIS)

    Lee, Hee Joon; Ju, Yun Jae; Kang, Han Ok; Lee, Tae Ho; Park, Cheon Tae

    2012-01-01

    Generally the condensation heat exchanger has higher heat transfer coefficient compared to the single phase heat exchanger, so has been widely applied to the cooling systems of energy plant. Recently vertical or horizontal type condensation heat exchangers are being studied for the application to secondary passive cooling system of nuclear plants. Lee and Lee investigated the existing condensation correlation to the experiment for heat exchanger in saturated pool. They concluded Traviss' correlation showed most satisfactory results for the heat transfer coefficient and mass flow rate in a saturated water pool. In this study, a thermal sizing program of vertical condensation heat exchanger to design, TSCON(Thermal Sizing of CONdenser) was validated with the existing experimental data of condensation heat exchanger in a subcooled pool for pure steam condensation

  19. Optimization design for drain to nuclear power condenser

    International Nuclear Information System (INIS)

    Ding Jiapeng; Jiang Chengren

    2010-01-01

    Characters and varieties of drain to nuclear power condenser are discussed in this paper. Take the main steam system of a nuclear power as an example, normal and detailed optimization design are introduced, related expatiate are used as a reference for the drain of other systems. According to the characters of nuclear power instant operation, the influence and needed actions related with the optimization design are also analyzed. Based on the above research, the scheme has been carried out in a nuclear power station and safety for the condenser operation of the nuclear power has been improved largely. (authors)

  20. The use of titanium for condenser tube bundles

    International Nuclear Information System (INIS)

    Dobrowitch, Nicolas

    2003-01-01

    In a power plant, the condenser is a strategic heat exchanger with regards to the efficiency of the steam turbine and its reliability guarantees the performance and continuous operation of the plant. Until the early 1980s, copper alloys were routinely used in condenser tubes, thanks to their high heat transfer rates. Yet, numerous problems arose from the use of this material, such as stress corrosion cracking, ammoniacal corrosion, fouling, erosion, dezincification, abrasion, erosion-corrosion, etc. and lately the problem of the inadequacy of copper with nuclear steam generators. The trend was then to consider new tube materials, such as stainless steel and titanium, at first for particular operating conditions and now for most of the projects, with several objectives, such as: improving reliability (titanium in particular can bring major improvements including higher water velocities promoting better heat transfer coefficients, and excellent resistance to abrasion, erosion and corrosion thereby improving resistance to fouling); finding more cost-effective solutions. The first investment is higher but money is saved on maintenance costs and on time reliability of the material. (orig.)

  1. Methods of increasing thermal efficiency of steam and gas turbine plants

    Science.gov (United States)

    Vasserman, A. A.; Shutenko, M. A.

    2017-11-01

    Three new methods of increasing efficiency of turbine power plants are described. Increasing average temperature of heat supply in steam turbine plant by mixing steam after overheaters with products of combustion of natural gas in the oxygen. Development of this idea consists in maintaining steam temperature on the major part of expansion in the turbine at level, close to initial temperature. Increasing efficiency of gas turbine plant by way of regenerative heating of the air by gas after its expansion in high pressure turbine and before expansion in the low pressure turbine. Due to this temperature of air, entering combustion chamber, is increased and average temperature of heat supply is consequently increased. At the same time average temperature of heat removal is decreased. Increasing efficiency of combined cycle power plant by avoiding of heat transfer from gas to wet steam and transferring heat from gas to water and superheated steam only. Steam will be generated by multi stage throttling of the water from supercritical pressure and temperature close to critical, to the pressure slightly higher than condensation pressure. Throttling of the water and separation of the wet steam on saturated water and steam does not require complicated technical devices.

  2. Hybrid dry cooling. Enhanced energy efficiency in steam turbines. Hybride Trockenkuehlung. Bessere Energienutzung bei Dampfturbinen

    Energy Technology Data Exchange (ETDEWEB)

    Stucki, R. (Colenco Power Consulting AG, Baden (Switzerland)); Mueller, W. (Jaeggi AG, Bern (Switzerland)); Haltiner, E.W.

    1992-09-11

    Condensation turbo groups facilitate the utilization of thermal energy from vapor production plants, for example from garbage incineration. Through an optimum design of the cooling system, the profitable electric energy can be increased through the maximum spreading of the condensation temperature and the live steam temperature. The hybrid dry cooling guarantees unsurpassable operating conditions. (orig.).

  3. Improvements to TRAC models of condensing stratified flow. Pt. 1

    International Nuclear Information System (INIS)

    Zhang, Q.; Leslie, D.C.

    1991-12-01

    Direct contact condensation in stratified flow is an important phenomenon in LOCA analyses. In this report, the TRAC interfacial heat transfer model for stratified condensing flow has been assessed against the Bankoff experiments. A rectangular channel option has been added to the code to represent the experimental geometry. In almost all cases the TRAC heat transfer coefficient (HTC) over-predicts the condensation rates and in some cases it is so high that the predicted steam is sucked in from the normal outlet in order to conserve mass. Based on their cocurrent and countercurrent condensing flow experiments, Bankoff and his students (Lim 1981, Kim 1985) developed HTC models from the two cases. The replacement of the TRAC HTC with either of Bankoff's models greatly improves the predictions of condensation rates in the experiment with cocurrent condensing flow. However, the Bankoff HTC for countercurrent flow is preferable because it is based only on the local quantities rather than on the quantities averaged from the inlet. (author)

  4. Comparative assessment of condensation models for horizontal tubes

    International Nuclear Information System (INIS)

    Schaffrath, A.; Kruessenberg, A.K.; Lischke, W.; Gocht, U.; Fjodorow, A.

    1999-01-01

    The condensation in horizontal tubes plays an important role e.g. for the determination of the operation mode of horizontal steam generators of VVER reactors or passive safety systems for the next generation of nuclear power plants. Two different approaches (HOTKON and KONWAR) for modeling this process have been undertaken by Forschungszentrum Juelich (FZJ) and University for Applied Sciences Zittau/Goerlitz (HTWS) and implemented into the 1D-thermohydraulic code ATHLET, which is developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH for the analysis of anticipated and abnormal transients in light water reactors. Although the improvements of the condensation models are developed for different applications (VVER steam generators - emergency condenser of the SWR1000) with strongly different operation conditions (e.g. the temperature difference over the tube wall in HORUS is up to 30 K and in NOKO up to 250 K, the heat flux density in HORUS is up to 40 kW/m 2 and in NOKO up to 1 GW/m 2 ) both models are now compared and assessed by Forschungszentrum Rossendorf FZR e.V. Therefore, post test calculations of selected HORUS experiments were performed with ATHLET/KONWAR and compared to existing ATHLET and ATHLET/HOTKON calculations of HTWS. It can be seen that the calculations with the extension KONWAR as well as HOTKON improve significantly the agreement between computational and experimental data. (orig.) [de

  5. Collecting and recirculating condensate in a nuclear reactor containment

    International Nuclear Information System (INIS)

    Schultz, T.L.

    1993-01-01

    An arrangement passively cools a nuclear reactor in the event of an emergency, condensing and recycling vaporized cooling water. The reactor is surrounded by a containment structure and has a storage tank for cooling liquid, such as water, vented to the containment structure by a port. The storage tank preferably is located inside the containment structure and is thermally coupleable to the reactor, e.g. by a heat exchanger, such that water in the storage tank is boiled off to carry away heat energy. The water is released as a vapor (steam) and condenses on the cooler interior surfaces of the containment structure. The condensed water flows downwardly due to gravity and is collected and routed back to the storage tank. One or more gutters are disposed along the interior wall of the containment structure for collecting the condensate from the wall. Piping is provided for communicating the condensate from the gutters to the storage tank. 3 figures

  6. Collecting and recirculating condensate in a nuclear reactor containment

    Science.gov (United States)

    Schultz, Terry L.

    1993-01-01

    An arrangement passively cools a nuclear reactor in the event of an emergency, condensing and recycling vaporized cooling water. The reactor is surrounded by a containment structure and has a storage tank for cooling liquid, such as water, vented to the containment structure by a port. The storage tank preferably is located inside the containment structure and is thermally coupleable to the reactor, e.g. by a heat exchanger, such that water in the storage tank is boiled off to carry away heat energy. The water is released as a vapor (steam) and condenses on the cooler interior surfaces of the containment structure. The condensed water flows downwardly due to gravity and is collected and routed back to the storage tank. One or more gutters are disposed along the interior wall of the containment structure for collecting the condensate from the wall. Piping is provided for communicating the condensate from the gutters to the storage tank.

  7. Numerical Study of Condensation Heat Exchanger Design in a Cooling jacket: Correlation Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Hee Joon [Kookmin Univ., Seoul (Korea, Republic of); Kang, Han Ok; Lee, Tae Ho; Park, Cheon Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In this study, condensing heat transfer correlation of TSCON is evaluated with the existing experimental data set to design condensation heat exchanger without noncondensable gas effect (pure steam condensation) in a cooling jacket. From the investigation of the existing condensation heat transfer correlation to the existing experimental data, the improved Shah's correlation showed most satisfactory result for the condensation heat transfer coefficient with experimental data of Khun in a cooling jacket, whereas the Shah's correlation with experimental data of Lee. Lee et al. reported the improved Shah correlation gave us the best predictor for the condensation heat transfer data of Kim and Henderson in a subcooled and saturated water pool. They suggested the improved Shah correlation should be adopted as condensation heat transfer module in TSCON(Thermal Sizing of CONdenser) to design condensation heat exchanger in secondary passive cooling system of nuclear plant.

  8. Vaporization of tungsten-metal in steam at high temperatures

    International Nuclear Information System (INIS)

    Greene, G.A.; Finfrock, C.C.

    2000-01-01

    The vaporization of tungsten from the APT spallation target dominates the radiological source term for unmitigated target overheating accidents. Chemical reactions of tungsten with steam which persist to tungsten temperatures as low as 800 C result in the formation of a hydrated tungsten-oxide which has a high vapor pressure and is readily convected in a flowing atmosphere. This low-temperature vaporization reaction essentially removes the oxide film that forms on the tungsten-metal surface as soon as it forms, leaving behind a fresh metallic surface for continued oxidation and vaporization. Experiments were conducted to measure the oxidative vaporization rates of tungsten in steam as part of the effort to quantify the MT radiological source term for severe target accidents. Tests were conducted with tungsten rods (1/8 inch diameter, six inches long) heated to temperatures from approximately 700 C to 1350 C in flowing steam which was superheated to 140 C. A total of 19 experiments was conducted. Fifteen tests were conducted by RF induction heating of single tungsten rods held vertical in a quartz glass retort. Four tests were conducted in a vertically-mounted tube furnace for the low temperature range of the test series. The aerosol which was generated and transported downstream from the tungsten rods was collected by passing the discharged steam through a condenser. This procedure insured total collection of the steam along with the aerosol from the vaporization of the rods. The results of these experiments revealed a threshold temperature for tungsten vaporization in steam. For the two tests at the lowest temperatures which were tested, approximately 700 C, the tungsten rods were observed to oxidize without vaporization. The remainder of the tests was conducted over the temperature range of 800 C to 1350 C. In these tests, the rods were found to have lost weight due to vaporization of the tungsten and the missing weight was collected in the downstream condensate

  9. Numerical Simulation of Non-Equilibrium Two-Phase Wet Steam Flow through an Asymmetric Nozzle

    Directory of Open Access Journals (Sweden)

    Miah Md Ashraful Alam

    2017-11-01

    Full Text Available The present study reported of the numerical investigation of a high-speed wet steam flow through an asymmetric nozzle. The spontaneous non-equilibrium homogeneous condensation of wet steam was numerically modeled based on the classical nucleation theory and droplet growth rate equation combined with the field conservations within the computational fluid dynamics (CFD code of ANSYS Fluent 13.0. The equations describing droplet formations and interphase change were solved sequentially after solving the main flow conservation equations. The calculations were carried out assuming the flow two-dimensional, compressible, turbulent, and viscous. The SST k-ω model was used for modeling the turbulence within an unstructured mesh solver. The validation of numerical model was accomplished, and the results showed a good agreement between the numerical simulation and experimental data. The effect of spontaneous non-equilibrium condensation on the jet and shock structures was revealed, and the condensation shown a great influence on the jet structure.

  10. Contact condensation effects in the main coolant pipe

    International Nuclear Information System (INIS)

    Haefner, W.; Fischer, K.

    1990-01-01

    Contact condensation effects may occur in a pressurized water reactor (PWR) after a loss of coolant accident (LOCA) when emergency core cooling (ECC) water is injected contact with escaping steam which is generated within the core. The condensation which takes place may cause a sudden depressurization leading to the formation of water slugs. The interaction between the transient condensation and the inertia of the flow may also result in large amplitude flow and pressure oscillations. These contact condensation effects are of great importance for the mass flow distribution and the coolant water supply to the reactor core. To examine those complex processes, large computer codes are necessary. The development and verification of analytical models requires greatly simplified flow boundary conditions from experiments and a sufficiently large base of experimental data. Separate models have been developed for interfacial exchange of mass, momentum and energy with respect to the associated flow regime. Therefore, an adequate description of the condensation process requires the modeling of two different topics: the prediction of the flow regime and the calculation of the interfacial exchange. (author)

  11. Exergy Analysis of a Subcritical Reheat Steam Power Plant with Regression Modeling and Optimization

    Directory of Open Access Journals (Sweden)

    MUHIB ALI RAJPER

    2016-07-01

    Full Text Available In this paper, exergy analysis of a 210 MW SPP (Steam Power Plant is performed. Firstly, the plant is modeled and validated, followed by a parametric study to show the effects of various operating parameters on the performance parameters. The net power output, energy efficiency, and exergy efficiency are taken as the performance parameters, while the condenser pressure, main steam pressure, bled steam pressures, main steam temperature, and reheat steam temperature isnominated as the operating parameters. Moreover, multiple polynomial regression models are developed to correlate each performance parameter with the operating parameters. The performance is then optimizedby using Direct-searchmethod. According to the results, the net power output, energy efficiency, and exergy efficiency are calculated as 186.5 MW, 31.37 and 30.41%, respectively under normal operating conditions as a base case. The condenser is a major contributor towards the energy loss, followed by the boiler, whereas the highest irreversibilities occur in the boiler and turbine. According to the parametric study, variation in the operating parameters greatly influences the performance parameters. The regression models have appeared to be a good estimator of the performance parameters. The optimum net power output, energy efficiency and exergy efficiency are obtained as 227.6 MW, 37.4 and 36.4, respectively, which have been calculated along with optimal values of selected operating parameters.

  12. Nuclear steam power plant cycle performance calculations supported by power plant monitoring and results computer

    International Nuclear Information System (INIS)

    Bettes, R.S.

    1984-01-01

    The paper discusses the real time performance calculations for the turbine cycle and reactor and steam generators of a nuclear power plant. Program accepts plant measurements and calculates performance and efficiency of each part of the cycle: reactor and steam generators, turbines, feedwater heaters, condenser, circulating water system, feed pump turbines, cooling towers. Presently, the calculations involve: 500 inputs, 2400 separate calculations, 500 steam properties subroutine calls, 200 support function accesses, 1500 output valves. The program operates in a real time system at regular intervals

  13. Effectiveness of thermal ignition devices in lean hydrogen-air-steam mixtures

    International Nuclear Information System (INIS)

    Tamm, H.; McFarlane, R.; Liu, D.D.S.

    1985-03-01

    Deliberate ignition of hydrogen at low concentrations in reactor containment systems is one method of controlling hydrogen during degraded core accidents. Since many postulated accident conditions have substantial amounts of steam present, experiments have been performed to determine the hydrogen-air-steam concentration regimes in which ignitors would be effective. In these experiments, both a GM AC 7G thermal flow plug and a Tayco Model 3442 ignitor have been used. These ignitors have been installed in PWR containments with ice condensers and in BWR Mark III containments. This report presents the results of these ignitor effectiveness experiments, and gives the ignition limits and the effect of steam on the ignitor surface temperatures required for ignition

  14. Steam generator for PWR type reactor

    International Nuclear Information System (INIS)

    Baba, Iwao; Hiyama, Nobuyuki.

    1994-01-01

    A steam generator of the present invention comprises a primary coolant chamber having primary coolants circulating therein, a secondary coolants chamber having secondary coolants and steams circulating therein, which are isolated from each other by a partition wall, and heat pipes disposed being passed through the partition wall. The heat pipes are disposed having an evaporation portion in the primary coolants chamber, a condensation portion in the secondary coolants chamber, and an intermediate heat insulating portion in the partition wall. Since the primary coolants containing radioactivity and the secondary coolants not containing radioactivity does not transfer heat directly by a heat transfer wall, a leakage accident of radioactivity to the secondary coolants can be prevented. Moreover, since the heat pipes are used, a great amount of heat can be transferred by a slight temperature difference by using steams of the heat transfer medium itself, latent heat due to coagulation, and capillary phenomenon. Since neither transferring power nor pumps are required, heat of the primary coolants can effectively be transferred to the secondary coolants. (N.H.)

  15. Evaluation of EDTA based chemical formulations for the cleaning of monel-400 tubed steam generators

    International Nuclear Information System (INIS)

    Velmurugan, S.; Rufus, A.L.; Sathyaseelan, V.S.; Kumar, P.S.; Veena, S.N.; Srinivasan, M.P.; Narasimhan, S.V.

    1998-01-01

    The Steam Generator (SG) is an important component in any nuclear power plant which contributes significantly for the over all performance of the reactor. The failure of SG tubes occurs mainly by corrosion under accelerated conditions caused by fouling. There is continuous ingress of the corrosion products and ionic impurities from the condenser and feed train of the secondary heat transfer system. The corrosion products accumulate in the stagnant areas near the tube sheet, over the tube support plates and in the tube to tube support plate crevices. These accumulated deposits help to concentrate the aggressive impurities and induce a variety of corrosion processes affecting the structural materials and finally leading to failure of the SG tube. Scale forming impurities can deposit over the tube surfaces and result in reduction of heat transfer efficiency and over heating of the surfaces. Every effort is being made to control the transport of impurities to the steam generator. Increased blow down, installation of condensate polishers and use of all volatile amines have helped to reduce the corrosion product and ionic impurities input into the steam generators of PHWRs. Despite these efforts, failures of SG tubes in PHWRs have been reported. Hence, attempts are being made to develop chemical formulations to clean the deposits accumulated in the steam generators. The EPRI-SGOG chemical cleaning process has been tried with good success in steam generators of different designs including the steam generators of PHWRs. This paper discusses the work on the evaluation of EDTA based chemical cleaning formulations for monel-400 tubed steam generators of PHWRs. (author)

  16. Computations of steam flow and heat transfer in nuclear power plant condensers

    International Nuclear Information System (INIS)

    Yuan, A.

    1997-01-01

    To improve performance of its PWR nuclear power plants, Electricite de France has developed a performance monitoring system that checks simultaneously the operation of the components of the secondary system. The performance monitoring system is based on a computational software CITER for steady state runs. A one-dimensional condenser model has been developed. Application of this code to a nuclear power plant condenser shows that predicted values in good agreement with the design values

  17. Numerical analysis of water hammer induced by injection of subcooled water into steam flow in a horizontal pipe

    International Nuclear Information System (INIS)

    Minato, Akihiko; Nagoyoshi, Takuji; Nakamura, Akira; Fujii, Yuzo; Aya, Izuo; Yamane, Kenji

    2004-01-01

    Subcooled water injection into steam flow in piping systems may generate a water column containing a large steam slug. The steam slug collapses due to rapid condensation and interfaces on both sides collides with each other. Water hammer takes place and sharp pressure pulse propagates through the pipe. The purpose of this study is to show capability of the present numerical simulation method for predictions of pressure transient and loads on a piping system following steam slug collapse. A three-dimensional computer code for transient gas-liquid two-phase flow was applied to simulate an experiment of steam-condensation-induced water hammer with a horizontal polycarbonate pipe. The code was based on the extended two-fluid model, which treated interface motion using the VOF (Volume of Fluid) technique. The Godunov scheme of highly compressible single-phase flow was modified for application to the Riemann problem solution of gas-liquid mixture. Analysis of local steam slug collapse resulted in comparable peak pressure and pulse width of pressure transients with the observation. The calculation of pressure pulse propagation and impact load on piping system showed the quasi-steady pressure load was imposed especially on elbow at 1/10 of water hammer peak pressure. (author)

  18. Water spray interaction with air-steam mixtures under containment spray conditions: experimental study in the TOSQAN facility

    Energy Technology Data Exchange (ETDEWEB)

    Porcheron, E.; Lemaitre, P.; Malet, J.; Nuboer, A.; Brun, P.; Bouilloux, L.; Vendel, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Direction de la Surete des Usines, des laboratoires, des transports et des dechets, Saclay, BP 68 - 91192 Gif-sur-Yvette cedex (France)

    2005-07-01

    Full text of publication follows: During the course of an hypothetical severe accident in a Pressurized Water Reactor (PWR), hydrogen can be produced by the reactor core oxidation and distributed into the reactor containment according to convection flows and steam wall condensation. In order to assess the risk of detonation generated by a high local hydrogen concentration, hydrogen distribution in the containment has to be known. The TOSQAN experimental program has been created to simulate typical accidental thermal hydraulic flow conditions in the reactor containment. The present work is devoted to study the interaction of a water spray injection used as a mitigation mean in order to reduce containment pressure and to produce a mixing of air, steam and hydrogen induced by spray entrainment and condensation on droplet. In order to have a better understanding of physical phenomena, we need to make a detailed characterization of the spray and the gas. The TOSQAN facility that is highly instrumented with non-intrusive diagnostics consists in a closed cylindrical vessel (7 m{sup 3} volume, 4 m high, 1.5 m i.d.) into which steam is injected. Water droplets size is measured in the vessel by the Interferometric Laser Imaging for Droplet Sizing technique. Droplet velocity is obtained by Particle Image Velocimetry and Laser Doppler Velocimetry, and droplet temperature is measured by global rainbow refractometry. Gas concentration measurements are performed by Spontaneous Raman Scattering. The walls of the vessel are thermostatically controlled by heated oil circulation. Inner spray system that is located on the top of the enclosure on the vertical axis, is composed of a single nozzle producing a full cone water spray. Spray test scenario consists of water spray injection in TOSQAN that is first pressurized with a steam injection (steam injection is stopped before spray injection). Water spray falling into the sump is removed to avoid accumulation and evaporation

  19. Removal of decay heat by specially designed isolation condensers for advanced heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, M L; Bhatia, S K [Reactor Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    For Advanced Heavy Water Reactor (AHWR), removal of decay heat and containment heat is being considered by passive means. For this, special type of isolation condensers are designed. Isolation condensers when submerged in a pool of water, are the best choice because condensation of high temperature steam is an extremely efficient heat transfer mechanism. By the use of isolation condensers, not only heat is removed but also pressure and temperature of the system are automatically controlled without losing the coolant and without using conventional safety relief valves. In this paper, design optimisation studies of isolation condensers of different types with natural circulation for the removal of core decay heat for AHWR is presented. (author). 8 refs., 2 figs.

  20. The Effect of Condensate Inundation on Steam Condensation Heat Transfer to Wire-Wrapped Tubing.

    Science.gov (United States)

    1983-06-01

    my Thesis Advisor, for his support and patient guidance throughout the project. My sincere appreciation to Dr. A.S. Wanniarachchi, my Second Reader...and perforated tube installation. The tubes were positioned using nylon tube sheets that were attached to the exterior of the condenser end plates. To...Co Tco #5 014 Tt 015 Tsat 016 Tcond 017 T 018 vap 53 IV. PROCEDURES A. INSTALLATION AND OPERATING PROCEDURES 1. 2-r-eparat inDfCndes ubu Prior to

  1. Heat exchanger with intermediate evaporating and condensing fluid

    International Nuclear Information System (INIS)

    Fraas, A.P.

    1978-01-01

    A shell and tube-type heat exchanger, such as a liquid sodium-operated steam generator for use in nuclear reactors, comprises a shell containing a primary fluid tube bundle, a secondary fluid tube bundle at higher elevation, and an intermediate fluid vaporizing at the surface of the primary fluid tubes and condensing at the surface of the secondary fluid tubes

  2. Field Test of a Steam Condenser Heat Sink Concept

    Science.gov (United States)

    1974-01-01

    stored underground for a specified time. A functional and economical heat rejection system is an important design consideration for such...per- mits the use of tunnels for other than just heat sink purposes. If existing tunnels can be used, the concept becomes economically attractive...that the water meter readings aie a valid indication of the mpu ! and that condensate was lost bv seepage thionuli the lock and or ballast into the

  3. Steam generators and waste heat boilers for process and plant engineers

    CERN Document Server

    Ganapathy, V

    2014-01-01

    Incorporates Worked-Out Real-World ProblemsSteam Generators and Waste Heat Boilers: For Process and Plant Engineers focuses on the thermal design and performance aspects of steam generators, HRSGs and fire tube, water tube waste heat boilers including air heaters, and condensing economizers. Over 120 real-life problems are fully worked out which will help plant engineers in evaluating new boilers or making modifications to existing boiler components without assistance from boiler suppliers. The book examines recent trends and developments in boiler design and technology and presents novel idea

  4. Experimental investigation on improving the removal effect of WFGD system on fine particles by heterogeneous condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Jingjing; Yang, Linjun; Yan, Jinpei; Xiong, Guilong; Shen, Xianglin [Southeast Univ., Nanjing (China). School of Energy and Environment

    2013-07-01

    Heterogeneous condensation of water vapor as a preconditioning technique for the removal of fine particles from flue gas was investigated experimentally in a wet flue gas desulfurization (WFGD) system. A supersaturated vapor phase, necessary for condensational growth of fine particles, was achieved in the SO{sub 2} absorption zone and at the top of the wet FGD scrubber by adding steam in the gas inlet and above the scrubbing liquid inlet of the scrubber, respectively. The condensational grown droplets were then removed by the scrubbing liquid and a high-efficiency demister. The results show that the effectiveness of the WFGD system for removal of fine particles is related to the SO{sub 2} absorbent and the types of scrubber employed. Despite a little better effectiveness for the removal of fine particles in the rotating-stream-tray scrubber at the same liquid-to-gas ratio, The similar trends are obtained between the spray scrubber and rotating-stream-tray scrubber. Due to the formation of aerosol particles in the limestone and ammonia-based FGD processes, the fine particle removal efficiencies are lower than those for Na{sub 2}CO{sub 3} and water. The performance of the WFGD system for removal of fine particles can be significantly improved for both steam addition cases, for which the removal efficiency increases with increasing amount of added steam. A high liquid to gas ratio is beneficial for efficient removal of fine particles by heterogeneous condensation of water vapor.

  5. Workshop proceedings: U-bend tube cracking in steam generators

    Science.gov (United States)

    Shoemaker, C. E.

    1981-06-01

    A design to reduce the rate of tube failure in high pressure feedwater heaters, a number of failed drawn and stress relieved Monel 400 U-bend tubes removed from three high pressure feedwater heaters was examined. Steam extracted from the turbine is used to preheat the boiler feedwater in fossil fuel fired steam plants to improve thermal efficiency. This is accomplished in a series of heaters between the condenser hot well and the boiler. The heaters closest to the boiler handle water at high pressure and temperature. Because of the severe service conditions, high pressure feedwater heaters are frequently tubed with drawn and stress relieved Monel 400.

  6. A three-dimensional laboratory steam injection model allowing in situ saturation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Demiral, B.M.R.; Pettit, P.A.; Castanier, L.M.; Brigham, W.E.

    1992-08-01

    The CT imaging technique together with temperature and pressure measurements were used to follow the steam propagation during steam and steam foam injection experiments in a three dimensional laboratory steam injection model. The advantages and disadvantages of different geometries were examined to find out which could best represent radial and gravity override flows and also fit the dimensions of the scanning field of the CT scanner. During experiments, steam was injected continuously at a constant rate into the water saturated model and CT scans were taken at six different cross sections of the model. Pressure and temperature data were collected with time at three different levels in the model. During steam injection experiments, the saturations obtained by CT matched well with the temperature data. That is, the steam override as observed by temperature data was also clearly seen on the CT pictures. During the runs where foam was present, the saturation distributions obtained from CT pictures showed a piston like displacement. However, the temperature distributions were different depending on the type of steam foam process used. The results clearly show that the pressure/temperature data alone are not sufficient to study steam foam in the presence of non-condensible gas.

  7. One-dimensional three-field model of condensation in horizontal countercurrent flow with supercritical liquid velocity

    International Nuclear Information System (INIS)

    Trewin, Richard R.

    2011-01-01

    Highlights: → CCFL in the hot leg of a PWR with ECC Injection. → Three-Field Model of counter flowing water film and entrained droplets. → Flow of steam can cause a hydraulic jump in the supercritical flow of water. → Condensation of steam on subcooled water increases the required flow for hydraulic jump. → Better agreement with UPTF experimental data than Wallis-type correlation. - Abstract: A one-dimensional three-field model was developed to predict the flow of liquid and vapor that results from countercurrent flow of water injected into the hot leg of a PWR and the oncoming steam flowing from the upper plenum. The model solves the conservation equations for mass, momentum, and energy in a continuous-vapor field, a continuous-liquid field, and a dispersed-liquid (entrained-droplet) field. Single-effect experiments performed in the upper plenum test facility (UPTF) of the former SIEMENS KWU (now AREVA) at Mannheim, Germany, were used to validate the countercurrent flow limitation (CCFL) model in case of emergency core cooling water injection into the hot legs. Subcooled water and saturated steam flowed countercurrent in a horizontal pipe with an inside diameter of 0.75 m. The flow of injected water was varied from 150 kg/s to 400 kg/s, and the flow of steam varied from 13 kg/s to 178 kg/s. The subcooling of the liquid ranged from 0 K to 104 K. The velocity of the water at the injection point was supercritical (greater than the celerity of a gravity wave) for all the experiments. The three-field model was successfully used to predict the experimental data, and the results from the model provide insight into the mechanisms that influence the flows of liquid and vapor during countercurrent flow in a hot leg. When the injected water was saturated and the flow of steam was small, all or most of the injected water flowed to the upper plenum. Because the velocity of the liquid remained supercritical, entrainment of droplets was suppressed. When the injected

  8. Titanium condenser tubes. Problems and their solution for wider application to large surface condensers. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S; Sugiyama, S; Nagata, K; Nanba, K; Shimono, M [Sumitomo Light Metal Industries Ltd., Tokyo (Japan)

    1977-06-01

    The corrosion resistance of titanium in sea water is extremely excellent, but titanium tubes are expensive, and the copper alloy tubes resistant in polluted sea water were developed, therefore they were not used practically. In 1970, ammonia attack was found on the copper alloy tubes in the air-cooled portion of condensers, and titanium tubes have been used as the countermeasure. As the result of the use, the galvanic attack on copper alloy tube plates with titanium tubes as cathode and the hydrogen absorption at titanium tube ends owing to excess electrolytic protection was observed, but the corrosion resistance of titanium tubes was perfect. These problems can be controlled by the application of proper electrolytic protection. The condensers with all titanium tubes adopted recently in USA are intended to realize perfectly no-leak condensers as the countermeasure to the corrosion in steam generators of PWR plants. Regarding large condensers of nowadays, three problems are pointed out, namely the vibration of condenser tubes, the method of joining tubes and tube plates, and the tubes of no coolant leak. These three problems in case of titanium tubes were studied, and the problem of the fouling of tubes was also examined. The intervals of supporting plates for titanium tubes should be narrowed. The joining of titanium tubes and titanium tube plates by welding is feasible and promising. The cleaning with sponge balls is effective to control fouling.

  9. Investigation of Condensation Heat Transfer Correlation of Heat Exchanger Design in Secondary Passive Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yun Jae; Lee, Hee Joon [Kookmin Univ., Seoul (Korea, Republic of); Kang, Hanok; Lee, Taeho; Park, Cheontae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-12-15

    Recently, condensation heat exchangers have been studied for applications to the passive cooling systems of nuclear plants. To design vertical-type condensation heat exchangers in secondary passive cooling systems, TSCON (Thermal Sizing of CONdenser), a thermal sizing program for a condensation heat exchanger, was developed at KAERI (Korea Atomic Energy Research Institute). In this study, the existing condensation heat transfer correlation of TSCON was evaluated using 1,157 collected experimental data points from the heat exchanger of a secondary passive cooling system for the case of pure steam condensation. The investigation showed that the Shah correlation, published in 2009, provided the most satisfactory results for the heat transfer coefficient with a mean absolute error of 34.8%. It is suggested that the Shah correlation is appropriate for designing a condensation heat exchanger in TSCON.

  10. A theoretical and experimental investigation into the thermodynamic performance of a 50 MW power plant with a novel modular air-cooled condenser

    International Nuclear Information System (INIS)

    O'Donovan, Alan; Grimes, Ronan

    2014-01-01

    Economic and environmental restrictions have resulted in an increase in the installation of air-cooled condensers (ACCs) in thermoelectric power plants located in arid regions. The traditional A-frame design is installed most frequently, despite an array of empirical evidence that shows it to suffer from significant inefficiencies. As a result, there is scope for improvement in condenser design and this paper presents one such approach – a novel modular air-cooled condenser (MACC). It is suggested that the unique ability of the MACC to continually vary fan speed could result in efficiency gains over a plant operating with existing state-of-the-art fixed speed ACCs. To determine the impact of installing the MACC on plant output, the steam-side characteristics were established through a series of experimental measurements taken on a full-scale prototype. The experimental arrangement and measurement technique ensured that conditions representative of an operational ACC were maintained throughout. The steam-side characteristics are quantified in terms of temperature, pressure and thermal resistance. Predicted values of these quantities are also presented, calculated from established theory. Both the measurements and predictions were used in a thermodynamic analysis to determine the performance of a 50 MW power plant. Results show that, for a given steam flow rate, increasing fan speed leads to a reduction in condenser pressure which ultimately, results in increased plant output. This occurs up until a certain point, at which further increases in output are offset by larger fan power consumption rates. Thus, an optimum operating point is shown to exist. The results from the thermodynamic analysis demonstrate discrepancies between the plant output evaluated from the measurements and that predicted from theory. In some cases, a difference as large as 1.5% was observed, equating to a 0.8 MW over-prediction by the theory. - Highlights: • A novel modular air

  11. Assessment of MELCOR condensation models with the presence of noncondensable gas in natural convection flow regime

    International Nuclear Information System (INIS)

    Yoon, Dhongik S; Jo, HangJin; Corradini, Michael L

    2017-01-01

    Condensation of steam vapor is an important mode of energy removal from the reactor containment. The presence of noncondensable gas complicates the process and makes it difficult to model. MELCOR, one of the more widely used system codes for containment analyses, uses the heat and mass transfer analogy to model condensation heat transfer. To investigate previously reported nodalization-dependence in natural convection flow regime, MELCOR condensation model as well as other models are studied. The nodalization-dependence issue is resolved by using physical length from the actual geometry rather than node size of each control volume as the characteristic length scale for MELCOR containment analyses. At the transition to turbulent natural convection regime, the McAdams correlation for convective heat transfer produces a better prediction compared to the original MELCOR model. The McAdams correlation is implemented in MELCOR and the prediction is validated against a set of experiments on a scaled AP600 containment. The MELCOR with our implemented model produces improved predictions. For steam molar fractions in the gas mixture greater than about 0.58, the predictions are within the uncertainty margin of the measurements. The simulation results still underestimate the heat transfer from the gas-steam mixture, implying that conservative predictions are provided.

  12. Dynamic load in suppression pool during BWR main steam safety relief valve actuation

    International Nuclear Information System (INIS)

    Tsukada, Hiroshi; Yamaguchi, Hirokatsu; Morita, Terumichi

    1979-01-01

    BWRs are so designed that the exhaust steam from main steam safety relief valves is led to pressure suppression pools, and the steam is condensed in pool water, but at this time, dynamic load seems to arise in the pool water. In Tokai No. 2 Power Station, a Mark-2 containment vessel was adopted to improve the reliability as much as possible and to obtain the design with margin. In this report, the result of actual machine test in Tokai No. 2 Power Station and the method of reducing the load are described. When a relief valve works, the discharge of water in exhaust pipes into a suppression pool, the exhaust of air in exhaust pipes and repeated expansion and contraction of bubbles in pool water, and the exhaust of steam and condensation occur. As for the construction of the suppression pool in Tokai No. 2 Power Station, cross-shaped quencher and the structure with jet deflector were installed. The test plan and the test result with an actual machine are reported. The soundness of the Mark-2 containment vessel and the structures in the pool was proved. The differential pressure acting on the structures was negligibly small. The measured pulsating pressure was in the range from 0.84 to -0.39 kg/cm 2 . (Kako, I.)

  13. Research on simulation of supercritical steam turbine system in large thermal power station

    Science.gov (United States)

    Zhou, Qiongyang

    2018-04-01

    In order to improve the stability and safety of supercritical steam turbine system operation in large thermal power station, the body of the steam turbine is modeled in this paper. And in accordance with the hierarchical modeling idea, the steam turbine body model, condensing system model, deaeration system model and regenerative system model are combined to build a simulation model of steam turbine system according to the connection relationship of each subsystem of steam turbine. Finally, the correctness of the model is verified by design and operation data of the 600MW supercritical unit. The results show that the maximum simulation error of the model is 2.15%, which meets the requirements of the engineering. This research provides a platform for the research on the variable operating conditions of the turbine system, and lays a foundation for the construction of the whole plant model of the thermal power plant.

  14. Steam stable mesoporous silica MCM-41 stabilized by trace amounts of Al.

    Science.gov (United States)

    Tompkins, Jordan T; Mokaya, Robert

    2014-02-12

    Evaluation of low and ultralow Al content (Si/Al between 50 and 412) aluminosilicate Al-MCM-41 materials synthesized via three contrasting alumination routes, namely, direct mixed-gel synthesis, post-synthesis wet grafting, and post-synthesis dry grafting, indicates that trace amounts of Al introduced via dry grafting can stabilize mesoporous silica MCM-41 to steaming at 900 °C for 4 h. It was found that trace amounts of Al (Si/Al > 400) introduced via so-called dry grafting of Al stabilize the virtually purely siliceous MCM-41 to steaming, whereas Al incorporated via other methods that involve aqueous media such as direct mixed gel synthesis or wet grafting of Al offer only limited protection at low Al content. It is particularly remarkable that a post-synthesis dry grafted Al-MCM-41 material possessing trace amounts of Al (i.e., Si/Al ratio of 412) and surface area and pore volume of 1112 m(2)/g and 1.20 cm(3)/g, respectively, retains 90% (998 m(2)/g) of the surface area and 85% (1.03 cm(3)/g) of the pore volume after exposure to steaming at 900 °C for 4 h. Under similar steam treatment conditions, the mesostructure of pure silica Si-MCM-41 is virtually destroyed and undergoes a 93% reduction in surface area (958 m(2)/g to 69 m(2)/g) and 88% decrease in pore volume (0.97 cm(3)/g to 0.12 cm(3)/g). The steam stable ultralow (i.e., trace) Al containing MCM-41 materials is found to be virtually similar to mesoporous pure silica Si-MCM-41 with hardly any detectable acidity. The improvement in steam stability arises from not only the presence of trace amounts of Al, but also from an apparent increase in the level of silica condensation that is specific to dry grafted alluminosilicate MCM-41 materials. The more highly condensed framework has fewer silanol groups and therefore is more resistant to hydrolysis under steaming conditions.

  15. Methods for calculating the speed-up characteristics of steam-water turbines

    International Nuclear Information System (INIS)

    Golovach, E.A.

    1981-01-01

    The methods of approximate and specified calculations of speed- up characteristics of steam-water turbines are considered. The specified non-linear method takes into account change of thermal efficiency, heat drop and losses in the turbine as well as vacuum break-up the condenser. Speed-up characteristics of the K-1000-60-1500 turbine are presented. The calculational results obtained by the non-linear method are compared with the calculations conducted by the approximate linearized method. Differences in the frequency speed up of the turbine rotor rotation calculated by the two methods constitute only 0.5-2.0%. That is why it is necessary to take into account in the specified calculations first of all the most important factors following the rotor speed- up in the following consequence: valve shift of the high pressure cylinder (HPC); steam volume in front of the HPC; shift of the valves behind the separator-steam superheater (SSS); steam volumes and moisture boiling in the SSS; steam consumption for regenerating heating of feed water, steam volumes at the intermediate elements of the turbine, losses in the turbine, heat drop and thermal efficiency [ru

  16. Commercially Available Activated Carbon Fiber Felt Enables Efficient Solar Steam Generation.

    Science.gov (United States)

    Li, Haoran; He, Yurong; Hu, Yanwei; Wang, Xinzhi

    2018-03-21

    Sun-driven steam generation is now possible and has the potential to help meet future energy needs. Current technologies often use solar condensers to increase solar irradiance. More recently, a technology for solar steam generation that uses heated surface water and low optical concentration is reported. In this work, a commercially available activated carbon fiber felt is used to generate steam efficiently under one sun illumination. The evaporation rate and solar conversion efficiency reach 1.22 kg m -2 h -1 and 79.4%, respectively. The local temperature of the evaporator with a floating activated carbon fiber felt reaches 48 °C. Apart from the high absorptivity (about 94%) of the material, the evaporation performance is enhanced thanks to the well-developed pores for improved water supply and steam escape and the low thermal conductivity, which enables reduced bulk water temperature increase. This study helps to find a promising material for solar steam generation using a water evaporator that can be produced economically (∼6 $/m 2 ) with long-term stability.

  17. Surface property effects on dropwise condensation heat transfer from flowing air-steam mixtures to promote drainage

    International Nuclear Information System (INIS)

    Grooten, M.H.M.; Van der Geld, C.W.M.

    2012-01-01

    In this study, the effect of a partially structured Ti-coated plate surface on droplet drainage and heat transfer in dropwise condensation in a compact plate heat exchanger is investigated. In the presence of high concentrations of inert gases, heat transfer is governed by vapor diffusion and condensate drainage is of major importance. A structured coating of the condenser plates is applied to create two coexisting dropwise condensation patterns. The structured Ti-coating constrains drainage and introduces directed surface energy 'gradients', 1-D binary patterns. The condenser with the partially structured coating is compared with two equally sized condensers: a full PVDF and a fully Ti-coated PVDF condenser. It is found that drop drainage is promoted by oriented Ti-coated tracks with a width of approximately the diameter of the maximum drop size to such a degree that the heat transfer performance is practically the same as that of a fully Ti-coated exchanger. Design recommendations are given. (authors)

  18. Steam-moderated oxy-fuel combustion

    International Nuclear Information System (INIS)

    Seepana, Sivaji; Jayanti, Sreenivas

    2010-01-01

    The objective of the present paper is to propose a new variant of the oxy-fuel combustion for carbondioxide (CO 2 ) sequestration in which steam is used to moderate the flame temperature. In this process, pure oxygen is mixed with steam and the resulting oxidant mixture is sent to the boiler for combustion with a fossil fuel. The advantage of this method is that flue gas recirculation is avoided and the volumetric flow rates through the boiler and auxiliary components is reduced by about 39% when compared to the conventional air-fired coal combustion power plant leading to a reduction in the size of the boiler. The flue gas, after condensation of steam, consists primarily of CO 2 and can be sent directly for compression and sequestration. Flame structure analysis has been carried out using a 325-step reaction mechanism of methane-oxidant combustion to determine the concentration of oxygen required to ensure a stable flame. Thermodynamic exergy analysis has also been carried out on SMOC-operated CO 2 sequestration power plant and air-fired power plant, which shows that though the gross efficiency increases the absolute power penalty of ∼8% for CO 2 sequestration when compared to air-fired power plant.

  19. Steam-moderated oxy-fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Seepana, Sivaji; Jayanti, Sreenivas [Department of Chemical Engineering, IIT Madras, Adyar, Chennai 600 036 (India)

    2010-10-15

    The objective of the present paper is to propose a new variant of the oxy-fuel combustion for carbondioxide (CO{sub 2}) sequestration in which steam is used to moderate the flame temperature. In this process, pure oxygen is mixed with steam and the resulting oxidant mixture is sent to the boiler for combustion with a fossil fuel. The advantage of this method is that flue gas recirculation is avoided and the volumetric flow rates through the boiler and auxiliary components is reduced by about 39% when compared to the conventional air-fired coal combustion power plant leading to a reduction in the size of the boiler. The flue gas, after condensation of steam, consists primarily of CO{sub 2} and can be sent directly for compression and sequestration. Flame structure analysis has been carried out using a 325-step reaction mechanism of methane-oxidant combustion to determine the concentration of oxygen required to ensure a stable flame. Thermodynamic exergy analysis has also been carried out on SMOC-operated CO{sub 2} sequestration power plant and air-fired power plant, which shows that though the gross efficiency increases the absolute power penalty of {proportional_to}8% for CO{sub 2} sequestration when compared to air-fired power plant. (author)

  20. Nuclear steam turbines for power production in combination with heating

    International Nuclear Information System (INIS)

    Frilund, B.; Knudsen, K.

    1977-01-01

    The general operating conditions for nuclear steam turbines in district heating system are briefly outlined. The turbine plant can consist of essentially the same types of machines as in conventional district heating systems. Some possible arrangements of back-pressure turbines, back-pressure turbines with condensing tails, or condensing turbines with heat extraction are considered for nuclear power and heat stations. Principles of control for hot water temperature and electrical output are described. Optimization of the plant, considering parallel variations during the year between heat load, cooling water temperature, and required outgoing temperature is discussed. (U.K.)

  1. Fluid dynamic simulation of the non homogeneous steam-air mixture motion in the dome of MARS safety core cooling system

    International Nuclear Information System (INIS)

    Said, S.A.; Caira, M.; Gramiccia, L.; Naviglio, A.

    1992-01-01

    One of the main features of the MARS, an inherently safe nuclear reactor of the new generation, is the innovative decay heat removal system. This has a high inherent reliability thanks to the complete absence of active components. The core decay heat is removed by the vaporization of the water in an emergency reservoir; then the steam collected in the dome over the pool condenses in the air condenser and returns back to the reservoir creating a heat sink of nearly infinite capacity. The transient fluid dynamic numerical simulation of the steam-air mixture flow in the dome is presented. This allows an assessment to be made of the time required for the uncondensable gases to be evacuated. After that time the condenser works at its rated capacity. (4 figures) (Author)

  2. Erosion-corrosion of structural materials of wet steam turbines

    International Nuclear Information System (INIS)

    Tomarov, G.V.

    1989-01-01

    A model of erosion-corrosion wear of elements of a wet steam zone and a condensate-feeding path of turbines is considered. It is shown that diffusion of impurities and corrosion products in pores of an oxide layer is the control mechanism under conditions of laminar flow of a media. Processes of mass transfer are controlling factors in turbulent flow

  3. Flow oscillations on the steam control valve in the middle opening condition. Clarification of the phenomena by steam flow experiment and CFD calculation

    International Nuclear Information System (INIS)

    Morita, Ryo; Inada, Fumio

    2006-01-01

    A steam control valve might cause vibrations of piping when the valve opening is in a middle condition. For rationalization of maintenance and management of the plant, the valve should be improved, but it is difficult to understand flow characteristics in detail by experiment because flow around the valve is complex 3D structure and becomes supersonic (M>1). Therefore, it is necessary to clarify the cause of the vibrations and to develop improvements by Computational Fluid Dynamics (CFD) technology. In previous researches, we clarified a mechanism of the pressure fluctuations in the middle opening condition and suggested the way to prevent the pressure fluctuations by experiments and CFD calculations. But, as we used air as a working fluid in our previous research instead of steam that is used in the power plant, we couldn't consider effects of condensation and difference of change of the quantity of state between air and steam. In this report, we have conducted steam flow experiments by multi-purpose steam experiment apparatus 'WISSH' and CFD calculations by steam flow code 'MATIS-SC' to clarify those effects. As a result, in the middle opening condition, we have observed rotating pressure fluctuations in the experiment and valve-attached flow and local high-pressure region in the CFD result. These results show the pressure fluctuations in steam experiments and CFD is same kind of the fluctuations found in air experiment and CFD. (author)

  4. Evaporation and condensation of steam-water in a vertical tube

    International Nuclear Information System (INIS)

    Sun, G.; Hewitt, G.F.

    2001-01-01

    Heat Transfer data have been obtained for water from single-phase flow to two-phase annular flow at 0.07-0.09 MPa in a 9.5 mm vertical bore tube under conditions of evaporation and condensation in the same test section. The main aim of the experiments was to elucidate the mechanism of heat transfer in annular flow by distinguishing between the conventional explanation of a purely convective mechanism at high quality region and the alternative hypothesis in which heat transfer is enhanced by secondary nucleation in the region. To avoid ambiguities in local hydrodynamic conditions the experiments were carried out under the same conditions (namely equilibrium annular flow) for both evaporation and condensation in the same test section. The results indicated a forced convective mechanism of the conventional type rather than the alternative thin film boiling mechanism (secondary nucleation) as suggested by Mesler (AIChE, 23 (1977) 448). The heat transfer coefficients in single-phase flow and annular flow regimes are compared with literature correlations. The results show that the present data are in reasonable agreement with existing correlations

  5. PORST: a computer code to analyze the performance of retrofitted steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.; Hwang, I.T.

    1980-09-01

    The computer code PORST was developed to analyze the performance of a retrofitted steam turbine that is converted from a single generating to a cogenerating unit for purposes of district heating. Two retrofit schemes are considered: one converts a condensing turbine to a backpressure unit; the other allows the crossover extraction of steam between turbine cylinders. The code can analyze the performance of a turbine operating at: (1) valve-wide-open condition before retrofit, (2) partial load before retrofit, (3) valve-wide-open after retrofit, and (4) partial load after retrofit.

  6. DESIGNING AND EFFICIENCY EFFECT OF AUTOMATIC BALL-CLEANING SYSTEM FOR CONDENSER 180-KTsS-1 OF TURBINE Т-180/210-130-1 LMZ. Part 2

    Directory of Open Access Journals (Sweden)

    Yu. A. Zenovich-Leshkevich-Ol’pinskiy

    2015-01-01

    Full Text Available The authors elaborate the economical efficiency evaluation technique that could be universal and applied for technical-and-economic feasibility study of the ball-cleaning system installation on the steam turbines of the electric power plants. Besides the effect from reducing the exhaust steam pressure in the condenser by means of the ball-cleaning system implementation, this technique also accounts for the effect of lowering the condenser hydraulic pressure.The article refers to the practical results of the ball-cleaning system introduction on the steam turbines of Gomel CHP-2. As a result of regular application of the ball-cleaning system the temperature difference of the condensers of all blocks Т-180/210-130-1 confined into the regulatory values and the cleanness coefficient of all three turbine units reached 0,85. The authors consider the working results, implementation experience of the ball-cleaning system at Gomel CHP-2 and its efficiency evaluation technique to be worth disseminating when introducing the analogous systems at the plants of Belarusian power network.The authors suggest measures on the condenser automatic-cleaning system improvement with the turbine mathematical-simulation model employment that will make it possible to optimize the condenser cleaning regimes and to increase the ball-cleaning system effectiveness with the condenser cleanness coefficient growing up to 0,90–0,92.

  7. The numerical and experimental study of two passes power plant condenser

    Directory of Open Access Journals (Sweden)

    Rusowicz Artur

    2017-01-01

    Full Text Available The steam condenser is one of the most important element in whole power plant installation. Their proper design and operation makes a significant contribution to the efficiency of electricity production. The purpose of this article is to propose a two-dimensional mathematical model that allows modeling condenser work. In the model, the tube bundle is treated as a porous bed. The analysis has been subjected to a two passes power condenser with a capacity of 50 MW. The mathematical analysis was compared with the results of experimental studies. The average error between the model and the experiment for difference of cooling water temperatures was 5.15% and 11.60% for the first and second pass respectively. This allows to conclude that the proposed model is good enough to optimize future work of the condenser.

  8. Exergoeconomic analysis of small-scale biomass steam cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Sotomonte, Cesar Adolfo; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba, MG (Brazil)], e-mails: c.rodriguez32@unifei.edu.br, electo@unifei.edu.br; Venturini, Osvaldo Jose; Escobar, Jose Carlos [Universidad Federal de Itajuba, MG (Brazil)], e-mail: osvaldo@unifei.edu.br

    2010-07-01

    The principal objective of this work is to develop a calculation process, based on the second law of thermodynamics, for evaluating the thermoeconomic potential of a small steam cogeneration plant using waste from pulp processing and/or sawmills as fuel. Four different configurations are presented and assessed. The exergetic efficiency of the cycles that use condensing turbines is found to be around 11%, which has almost 3 percent higher efficiency than cycles with back pressure turbines. The thermoeconomic equations used in this paper estimated the production costs varying the fuel price. The main results show that present cost of technologies in a small-scale steam cycle cogeneration do not justify the implementation of more efficient systems for biomass prices less than 100 R$/t. (author)

  9. On the reliability of steam generator performance at nuclear power plants with WWER type reactors

    International Nuclear Information System (INIS)

    Styrikovich, M.A.; Margulova, T.Kh.

    1974-01-01

    The problem of ensuring reliable operation of steam generators in a nuclear power plant with a water-cooled, water-moderated reactor (WWER) was studied. At a nuclear power plant with a vertical steam generator (specifically, a Westinghouse product) the steam generator tubes were found to have been penetrated. Shutdown was due to corrosion disintegration of the austenitic stainless steel, type 18/8, used as pipe material for the heater surface. The corrosion was the result of the action of chlorine ions concentrated in the moisture contained in the iron oxide films deposited in low parts of the tube bundle, directly at the tube plate. Blowing through did not ensure complete removal of the film, and in some cases the construction features of the steam generator made removal of the film practically impossible. Replacement of type 18/8 stainless steel by other construction material, e.g., Inconel, did not give good results. To ensure reliable operation of vertical steam generators in domestic practice, the generators are designed without a low tube plate (a variant diagram of the vertical steam generator of such construction for the water-cooled, water-moderated reactor 1000 is presented). When low tube plates are used the film deposition is intolerable. For organization of a non-film regime a complex treatment of the feed water is used, in which the amount of complexion is calculated from the stoichmetric ratios with the composition of the feed water. It is noted that, if 100% condensate purification is used with complexon processing of the feed water to the generator, we can calculate the surface of the steam-generator heater without considering the outer placement on the tubes. In this the cost of the steam generator and all the nuclear power plants with WWER type reactors is decreased even with installation of a 100% condensate purification. It is concluded that only simultaneous solution of construction and water-regime problems will ensure relaible operation of

  10. Modeling of Kerena Emergency Condenser

    Science.gov (United States)

    Bryk, Rafał; Schmidt, Holger; Mull, Thomas; Wagner, Thomas; Ganzmann, Ingo; Herbst, Oliver

    2017-12-01

    KERENA is an innovative boiling water reactor concept equipped with several passive safety systems. For the experimental verification of performance of the systems and for codes validation, the Integral Test Stand Karlstein (INKA) was built in Karlstein, Germany. The emergency condenser (EC) system transfers heat from the reactor pressure vessel (RPV) to the core flooding pool in case of water level decrease in the RPV. EC is composed of a large number of slightly inclined tubes. During accident conditions, steam enters into the tubes and condenses due to the contact of the tubes with cold water at the secondary side. The condensed water flows then back to the RPV due to gravity. In this paper two approaches for modeling of condensation in slightly inclined tubes are compared and verified against experiments. The first approach is based on the flow regime map. Depending on the regime, heat transfer coefficient is calculated according to specific semi-empirical correlation. The second approach uses a general, fully-empirical correlation. The models are developed with utilization of the object-oriented Modelica language and the open-source OpenModelica environment. The results are compared with data obtained during a large scale integral test, simulating loss of coolant accident performed at Integral Test Stand Karlstein (INKA). The comparison shows a good agreement.Due to the modularity of models, both of them may be used in the future in systems incorporating condensation in horizontal or slightly inclined tubes. Depending on his preferences, the modeller may choose one-equation based approach or more sophisticated model composed of several exchangeable semi-empirical correlations.

  11. Method and apparatus for enhanced heat recovery from steam generators and water heaters

    Science.gov (United States)

    Knight, Richard A.; Rabovitser, Iosif K.; Wang, Dexin

    2006-06-27

    A heating system having a steam generator or water heater, at least one economizer, at least one condenser and at least one oxidant heater arranged in a manner so as to reduce the temperature and humidity of the exhaust gas (flue gas) stream and recover a major portion of the associated sensible and latent heat. The recovered heat is returned to the steam generator or water heater so as to increase the quantity of steam generated or water heated per quantity of fuel consumed. In addition, a portion of the water vapor produced by combustion of fuel is reclaimed for use as feed water, thereby reducing the make-up water requirement for the system.

  12. Steam turbines for nuclear power stations in Czechoslovakia and their use for district heating

    International Nuclear Information System (INIS)

    Drahy, J.

    1989-01-01

    The first generation of nuclear power stations in Czechoslavakia is equipped with 440 MW e pressurized water reactors. Each reactor supplies two 220 MW, 3000 rpm condensing type turbosets operating with saturated steam. After the completion of heating water piping systems, all of the 24 units of 220 MW in Czechoslovak nuclear power stations will be operated as dual purpose units, delivering both electricity and heat. At the present time, second-generation nuclear power stations, with 1000 MW e PWRs, are being built. Each such plant is equipped with one 1000 MW full-speed saturated steam turbine. The turbine is so designed as to permit the extraction of steam corresponding to the following quantities of heat: 893 MJ/s with three-stage water heating (150/60 0 C); and 570 MJ/s with two-stage water heating (120/60 0 C). The steam is taken from uncontrolled steam extraction points. (author)

  13. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1984-10-01

    A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization

  14. Intentional back flow effects on ruptured steam generator cooldown during a SGTR event for KSNP

    International Nuclear Information System (INIS)

    Kim, C.W.; Park, S.J.; Choi, C.J.; Seo, J.T.

    2004-01-01

    For an optimum recovery from a steam generator tube rupture (SGTR) event, the operators are directed to isolate the steam generator (SG) with ruptured tube as early as possible to minimize the radioactive material release. However, the reactor coolant system (RCS) cooldown and depressurization to the shutdown cooling system (SCS) operation conditions using the intact SG only are hard to achieve unless the ruptured SG is properly cooled since the ruptured SG, which is isolated by operator, remains at high temperature even though the RCS has been cooled down. The effects of intentional back flow from the SG secondary side to the RCS through the ruptured U-tube on the the ruptured SG cooldown were evaluated for the pressurized light water reactor, especially for the Korean standard nuclear power plant (KSNP). In order to evaluate the back flow effect, a series of analyses was conducted using the RELAP5/MOD3 computer code. For the first stage of the analysis, the cooldown process by natural circulation in the SG secondary side was simulated for the initial conditions of the ruptured SG cooldown. In the next analysis stage, two methods of the ruptured SG cooldown by using back flow after RCS cooldown were evaluated. One utilizes the steam condensation on the uncovered U-tube surface, and the other is a SG drain and fill. In the former method, SG tubes are exposed to the steam space by draining SG secondary water into the RCS in order to condense the steam directly onto the uncovered tubes. This method showed that the steam condensation decreased SG secondary pressure and temperature rapidly, demonstrating its effectiveness for cooling. However, this process has a limited applicability if the rupture is located at the lower region. The latter method, draining by back flow and filling using the feedwater system was also found to be effective in ruptured SG cooldown and depressurization even if the rupture occurred at the top of the U-tube. It is concluded that the

  15. Interfacial heat transfer in countercurrent flows of steam and water

    International Nuclear Information System (INIS)

    Megahed, M.M.

    1987-04-01

    A study was conducted to examine the departure from equilibrium conditions with respect to direct contact condensation. A simple analytical model, which used an equilibrium factor, K, was derived. The model was structured to represent the physical dimensions of a nuclear reactor downcomer annulus, water subcooling, wall temperature, and water flow rate. In a two step process the model was first used to isolate the average interfacial heat transfer coefficient from vertical countercurrent steam/water data of Cook et al., with the aid of a Stanton number correlation. In the second step the model was assessed by regeneration of measured steam flow rates in the experiments by Cook et al., and an additional experiment of Kim. This report documents the analytical model, the derived Stanton number correlation, and the comparison of the calculated and measured steam flow rates by which the accuracy of the model was assessed

  16. The deterministic prediction of failure of low pressure steam turbine disks

    International Nuclear Information System (INIS)

    Liu, Chun; Macdonald, D.D.

    1993-01-01

    Localized corrosion phenomena, including pitting corrosion, stress corrosion cracking, and corrosion fatigue, are the principal causes of corrosion-induced damage in electric power generating facilities and typically result in more than 50% of the unscheduled outages. Prediction of damage, so that repairs and inspections can be made during scheduled outages, could have an enormous impact on the economics of electric power generation. To date, prediction of corrosion damage has been made on the basis of empirical/statistical methods that have proven to be insufficiently robust and accurate to form the basis for the desired inspection/repair protocol. In this paper, we describe a deterministic method for predicting localized corrosion damage. We have used the method to illustrate how pitting corrosion initiates stress corrosion cracking (SCC) for low pressure steam turbine disks downstream of the Wilson line, where a thin condensed liquid layer exists on the steel disk surfaces. Our calculations show that the SCC initiation and propagation are sensitive to the oxygen content of the steam, the environment in the thin liquid condensed layer, and the stresses that the disk experiences in service

  17. Calculational model for condensation of water vapor during an underground nuclear detonation

    International Nuclear Information System (INIS)

    Knox, R.J.

    1975-01-01

    An empirally derived mathematical model was developed to calculate the pressure and temperature history during condensation of water vapor in an underground-nuclear-explosion cavity. The condensation process is non-isothermal. Use has been made of the Clapeyron-Clausius equation as a basis for development of the model. Analytic fits to the vapor pressure and the latent heat of vaporization for saturated-water vapor, together with an estimated value for the heat-transfer coefficient, have been used to describe the phenomena. The calculated pressure-history during condensation has been determined to be exponential, with a time constant somewhat less than that observed during the cooling of the superheated steam from the explosion. The behavior of the calculated condensation-pressure compares well with the observed-pressure record (until just prior to cavity collapse) for a particular nuclear-detonation event for which data is available

  18. Accident localization system with jet condensers for VVER 440-V 230 NPP at Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Murani, J.

    1995-01-01

    The operational safety of the V1 nuclear power plant (NPP) is unsatisfactory and does not correspond to present requirements as to nuclear safety. Further NPP operation after 1995 is conditional on nuclear safety enhancement to a level comparable with that in West European countries. This aim should be achieved by a principal reconstruction involving in addition to others also backfitting the V1 NPP with technical facilities aimed at coping with a design basis accident (DBA).To cope with such an accident the Power Equipment Research Institute (VUEZ) designed an accident localization system with jet condensers. This system consists of (a) an air trap (one for each unit, mutually interconnected) with an expansion bell enclosed within, placed on a plate with 200 pipes of jet condensers passing through, and (b) a connecting duct between the hermetic zone and the air trap. The vertical jet condenser is an essential element of the system designed for steam condensation. Apart from condensation it serves as a water seal separating units 1 and 2.Demonstration tests of the jet condenser (model 1:1) condensing function were carried out at the testing unit of the All-Union Research Institute for NPP Operation (VNIIAES), Moscow in Kashir, 11-22 September 1992. These experiments proved the jet condenser ability to ensure complete condensation of the steam produced. Experimental verification of the sealing function (model 1:1) was carried out at the testing unit of the VUEZ Tlmace. These experiments concerning the dynamics and overpressure in the free space above the pool were close to the conditions in the air trap during DBA. The jet condenser height was proved to be sufficient to ensure the sealing function. Design and experimental work has been implemented in close cooperation with Russian experts Mr. V.N. Bulynin from the VNIIAES, Moscow, and Mr. M.V. Kuznecov from the Scientific and Engineering Center for Nuclear and Radiological Safety, Moscow. (orig.)

  19. Separate effects tests for GOTHIC condensation and evaporative heat transfer models

    International Nuclear Information System (INIS)

    George, T.L.; Singh, A.

    1994-01-01

    The GOTHIC computer program, under development at EPRI/NAI, is a general purpose thermal hydraulics computer program for design, licensing, safety and operating analysis of nuclear containments and other confinement buildings. The code solves a nine equation model for three dimensional multiphase flow with separate mass, momentum and energy equations for vapor, liquid and drop phases. The vapor phase can be a gas mixture of steam and non-condensing gases. The phase balance equations are coupled by mechanistic and empirical models for interface mass, energy and momentum transfer that cover the entire flow regime from bubbly flow to film/drop flow. A variety of heat transfer correlations are available to model the fluid coupling to active and passive solid conductors. This paper focuses on the application of GOTHIC to two separate effects tests; condensation heat transfer on a vertical flat plate with varying bulk velocity, steam concentration and temperature, and evaporative heat transfer from a hot pool to a dry (superheated) atmosphere. Comparisons with experimental data is included for both tests. Results show the validity of two condensation heat transfer correlations as incorporated into GOTHIC and the interfacial heat and mass transfer models for the range of the experimental test conditions. Comparisons are also made for lumped versus multidimensional modeling for buoyancy controlled flow with evaporative heat transfer. (author). 13 refs., 1 tab., 10 figs

  20. Separate effects tests for GOTHIC condensation and evaporative heat transfer models

    International Nuclear Information System (INIS)

    George, T.L.; Singh, A.

    1996-01-01

    The GOTHIC computer program, under development at NAI for EPRI, is a general purpose thermal hydraulics computer program for design, licensing, safety and operating analysis of nuclear containments and other confinement buildings. The code solves a nine-equation model for three-dimensional multiphase flow with separate mass, momentum and energy equations for vapor, liquid and drop phases. The vapor phase can be a gas mixture of steam and non-condensing gases. The phase balance equations are coupled by mechanistic and empirical models for interface mass, energy and momentum transfer that cover the entire flow regime from bubbly flow to film-drop flow. A variety of heat transfer correlations are available to model the fluid coupling to active and passive solid conductors. This paper focuses on the application of GOTHIC to two separate effects tests: condensation heat transfer on a vertical flat plate with varying bulk velocity, steam concentration and temperature, and evaporative heat transfer from a hot pool to a dry (superheated) atmosphere. Comparisons with experimental data are included for both tests. Results show the validity of two condensation heat transfer correlations as incorporated into GOTHIC and the interfacial heat and mass transfer models for the range of the experimental test conditions. Comparisons are also made for lumped vs. multidimensional modeling for buoyancy-controlled flow with evaporative heat transfer. (orig.)

  1. An automated eddy current in-service inspection system for nuclear steam generator tubing

    International Nuclear Information System (INIS)

    Wells, N.S.

    1981-06-01

    A prototype steam generator in-service inspection system incorporating remotely-controlled instrumentation linked by a digital transmission line to an instrument and control trailer outside the reactor containment has been designed and manufactured and is presently undergoing field tests. The (Monel 400) steam generator tubes are scanned two at a time using absolute eddy current probes controlled by two remotely-operated probe drives at a scanning speed of 0.5 m/s. The probes are positioned on the tubesheet by a light-weight (1.5 kg) microprocessor-operated tubesheet walker mechanism. Digitized control and data signals are transmitted up to 300 m to the control trailer. There the control and analysis computers extract the relevant signal information and present it in condensed form as labelled graphics on CRT consoles for on-line visual assessment. Hard copy output is also provided for each tube scanned (one per minute). Condensed data is archived on magnetic tapes for additional off-line analysis and comparisons with other inspections

  2. Modeling of Kerena Emergency Condenser

    Directory of Open Access Journals (Sweden)

    Bryk Rafał

    2017-12-01

    Full Text Available KERENA is an innovative boiling water reactor concept equipped with several passive safety systems. For the experimental verification of performance of the systems and for codes validation, the Integral Test Stand Karlstein (INKA was built in Karlstein, Germany. The emergency condenser (EC system transfers heat from the reactor pressure vessel (RPV to the core flooding pool in case of water level decrease in the RPV. EC is composed of a large number of slightly inclined tubes. During accident conditions, steam enters into the tubes and condenses due to the contact of the tubes with cold water at the secondary side. The condensed water flows then back to the RPV due to gravity. In this paper two approaches for modeling of condensation in slightly inclined tubes are compared and verified against experiments. The first approach is based on the flow regime map. Depending on the regime, heat transfer coefficient is calculated according to specific semi-empirical correlation. The second approach uses a general, fully-empirical correlation. The models are developed with utilization of the object-oriented Modelica language and the open-source OpenModelica environment. The results are compared with data obtained during a large scale integral test, simulating loss of coolant accident performed at Integral Test Stand Karlstein (INKA. The comparison shows a good agreement.Due to the modularity of models, both of them may be used in the future in systems incorporating condensation in horizontal or slightly inclined tubes. Depending on his preferences, the modeller may choose one-equation based approach or more sophisticated model composed of several exchangeable semi-empirical correlations.

  3. Analysis of loads and fluid-structure interactions in a condensation pool

    Energy Technology Data Exchange (ETDEWEB)

    Timperi, A.; Paettikangas, T.; Niemi, J. [VTT, Technical Research Centre of Finland (Finland)

    2007-04-15

    A simplified direct contact condensation model was implemented into the Volume of Fluid model of the Fluent CFD code. Transient three-dimensional test runs for the POOLEX experiments, where steam is blown into a water pool were performed. The model was found to provide too small condensation rate for steam when compared to experiments. In addition, the calculated back and forth oscillation of the steam water interface was much smaller than in the experiments. The model was found to be numerically quite robust. The discrepancies of the simulation, such as the too small condensation rate, could be to some extent cured by making improvements into the condensation model. As an alternative estimation method of thermohydraulic loads in condensation pools, the SILA code based on potential flow theory, was taken into use. SILA solves the pressure distribution caused by oscillating bubbles in a pool, and is easier to use and more flexible than Method of Images studied earlier. SILA has been modified for pools without an inner cylinder and test simulations for the POOLEX water pool were performed. The MpCCI FSI coupling software employs an explicit coupling scheme, which results in numerical instability in the case of the POOLEX facility. In order to improve stability, ways for implementing an implicit coupling scheme with MpCCI were examined. It was found that such a scheme is difficult to achieve without access to the source codes. An implicit coupling scheme is expected to be available with MpCCI in forthcoming years. A method was developed which can be used for analysing two-way FSI problems realistically by using only one-way coupling of CFD and structural analysis codes. In the method, the mass of the fluid is accounted for in the structural motion by adding the fluid to the structural model as an acoustic medium. Validity of the method was examined with promising results mathematically by an order of magnitude analysis and by comparing numerical results with a full

  4. An experimental and analytical investigation of glow plug performance in ignition and flame propagation through low concentrations of H2 in a steam/fog environment

    International Nuclear Information System (INIS)

    Davis, B.W.

    1982-01-01

    Thermal igniters proposed by the Tennessee Valley Authority for intentional ignition of hydrogen in nuclear reactor containments have been tested in mixtures of air, hydrogen, and steam. The igniters, conventional diesel engine glow plugs, were tested in a 10.6 ft 3 pressure vessel with dry hydrogen concentrations from 4% to 29%, and in steam fractions of up to 50%. Dry tests indicated complete combustion consistently occurred at H 2 fractions above 8% with no combustion for concentrations below 5%. Combustion tests in the presence of steam were conducted with hydrogen volume fractions of 8%, 10%, and 12%. Steam concentrations of up to 30% consistently resulted in ignition. Most of the 40% steam fraction tests indicated a pressure rise. Circulation of the mixture improved combustion in both the dry and the steam tests, most notably at low H 2 concentrations. An analysis of the high steam fraction test data yielded evidence of the presence of small, suspended, water droplets in the combustion mixture. The suppressive influence of condensation-generated fog on combustion is evaluated. Analysis of experimental results along with results derived from analytic models have provided consistent evidence of the strong influence of mass condensation rates and fog on experimentally observed ignition and flame propagation phenomena

  5. Results of Steam-Water-Oxygen Treatment of the Inside of Heating Surfaces in Heat-Recovery Steam Generators of the PGU-800 Power Unit at the Perm' District Thermal Power Station

    Science.gov (United States)

    Ovechkina, O. V.; Zhuravlev, L. S.; Drozdov, A. A.; Solomeina, S. V.

    2018-05-01

    Prestarting, postinstallation steam-water-oxygen treatment (SWOT) of the natural circulation/steam reheat heat-recovery steam generators (HRSG) manufactured by OAO Krasny Kotelshchik was performed at the PGU-800 power unit of the Perm District Thermal Power Station (GRES). Prior to SWOT, steam-oxygen cleaning, passivation, and preservation of gas condensate heaters (GCH) of HRSGs were performed for 10 h using 1.3MPa/260°C/70 t/h external steam. After that, test specimens were cut out that demonstrated high strength of the passivating film. SWOT of the inside of the heating surfaces was carried out during no-load operation of the gas turbine unit with an exhaust temperature of 280-300°C at the HRSG inlet. The steam turbine was shutdown, and the generated steam was discharged into the atmosphere. Oxygen was metered into the discharge pipeline of the electricity-driven feed pumps and downcomers of the evaporators. The behavior of the concentration by weight of iron compounds and the results of investigation of cutout specimens by the drop or potentiometric method indicate that the steam-water-oxygen process makes it possible to remove corrosion products and reduce the time required to put a boiler into operation. Unlike other processes, SWOT does not require metal-intensive cleaning systems, temporary metering stations, and structures for collection of the waste solution.

  6. Radioactivity release vs probability for a steam generator tube rupture accident

    International Nuclear Information System (INIS)

    Buslik, A.J.; Hall, R.E.

    1978-01-01

    A calculation of the probability of obtaining various radioactivity releases from a steam generator tube rupture (SGTR) is presented. The only radioactive isotopes considered are Iodine-131 and Xe-133. The particular accident path considered consists of a double-ended guillotine SGTR followed by loss of offsite power (LOSP). If there is no loss of offsite power, and no system fault other than the SGTR, it is judged that the consequences will be minimal, since the amount of iodine released through the condenser air ejector is expected to be quite small; this is a consequence of the fact that the concentration of iodine in the vapor released from the condenser air ejector is very small compared to that dissolved in the condensate water. In addition, in some plants the condenser air ejector flow is automatically diverted to containment or a high-activity alarm. The analysis presented here is for a typical Westinghouse PWR such as described in RESAR-3S

  7. Interfacial Dynamics of Condensing Vapor Bubbles in an Ultrasonic Acoustic Field

    Science.gov (United States)

    Boziuk, Thomas; Smith, Marc; Glezer, Ari

    2016-11-01

    Enhancement of vapor condensation in quiescent subcooled liquid using ultrasonic actuation is investigated experimentally. The vapor bubbles are formed by direct injection from a pressurized steam reservoir through nozzles of varying characteristic diameters, and are advected within an acoustic field of programmable intensity. While kHz-range acoustic actuation typically couples to capillary instability of the vapor-liquid interface, ultrasonic (MHz-range) actuation leads to the formation of a liquid spout that penetrates into the vapor bubble and significantly increases its surface area and therefore condensation rate. Focusing of the ultrasonic beam along the spout leads to ejection of small-scale droplets from that are propelled towards the vapor liquid interface and result in localized acceleration of the condensation. High-speed video of Schlieren images is used to investigate the effects of the ultrasonic actuation on the thermal boundary layer on the liquid side of the vapor-liquid interface and its effect on the condensation rate, and the liquid motion during condensation is investigated using high-magnification PIV measurements. High-speed image processing is used to assess the effect of the actuation on the dynamics and temporal variation in characteristic scale (and condensation rate) of the vapor bubbles.

  8. Students' construction of a simple steam distillation apparatus and development of creative thinking skills: A project-based learning

    Science.gov (United States)

    Diawati, Chansyanah; Liliasari, Setiabudi, Agus; Buchari

    2017-05-01

    This project-based learning combined the chemistry of separation process using steam distillation with engineering design process in an undergraduate chemistry course. Students built upon their knowledge of phase changes, immiscible mixture, and the relationship between vapor pressure and boiling point to complete a project of modifications steam distillation apparatus. The research method is a qualitative case study, which aims to describe how (1) the creative thinking skills of students emerged during six weeks of theproject, (2) students built steam distillation apparatus characteristics as the project product and (3) students response to the project-based learning model. The results showed that the students had successfully constructed a steam distillation apparatus using plastic kettle as steam generator and distillation flask. A Plastic tubewas used to drain water vapor from steam generator to distillation flask and to drain steam containing essential oil to the condenser. A biscuit tin filled with ice was used as a condenser. The time required until resulting distillate was fifteen minutes. The production of essential was conductive qualitatively by a very strong smell typical of essential oil and two phases of distillate. Throughout the project, students formulated the relevant and varied problem, formulated the goals, proposed the ideas of the apparatus and materials, draw apparatus design, constructed apparatus, tested apparatus, evaluated, and reported the project. Student response was generally positive. They were pleased, interested, more understanding the concepts and work apparatus principles, also implemented new ideas. These results indicate that project-based learning can develop students' creative thinking skills. Based on these results, it is necessary to conduct research and implemented project-based learning to other concepts.

  9. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1982-04-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. The number of failed tubes was also lower, 0.14% of the tubes in service in 1980 compared with 0.20% of those in service in 1979. Analysis of the causes of these failures indicates that stress corrosion cracking was the leading failure mechanism. Reactors that used all-volatile treatment of secondary water, with or without full-flow condensate demineralization since start-up showed the lowest incidence of corrosion-related defects

  10. Mixed convection heat transfer between a steam / non-condensable gas mixture and an inclined finned tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    Cachard, F. de; Lomperski, S.; Monauni, G.R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. for Thermal-Hydraulics

    1999-07-01

    An experimental and analytical program was performed at PSI to study the performance of a finned-tube condenser in the presence of non-condensable gases at low gas mass fluxes. The model developed for this application includes mixed convection heat transfer between the vapour/non-condensable mixture and the finned-tubes, heat conduction through the fins and tubes, and evaporative heat transfer inside the tubes. The finned-tubes condenser model has been assessed against data obtained at the PSI LINX facility with two test condensers. For the 62 LINX experiments performed, the model predictions are very good, i.e., less than 10 % standard deviation between experimental and predicted results. (authors)

  11. Steam Explosions in Slurry-fed Ceramic Melters

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J.T.

    2001-03-28

    This report assesses the potential and consequences of a steam explosion in Slurry Feed Ceramic Melters (SFCM). The principles that determine if an interaction is realistically probable within a SFCM are established. Also considered are the mitigating effects due to dissolved, non-condensable gas(es) and suspended solids within the slurry feed, radiation, high glass viscosity, and the existence of a cold cap. The report finds that, even if any explosion were to occur, however, it would not be large enough to compromise vessel integrity.

  12. Experimental investigation on enhanced heat transfer of vertical condensers with trisection helical baffles

    International Nuclear Information System (INIS)

    Wu, Jiafeng; Zhou, Jiahao; Chen, Yaping; Wang, Mingchao; Dong, Cong; Guo, Ya

    2016-01-01

    Highlights: • Trisection helical baffles are introduced for vertical condenser enhancement. • Condensation in short-section and intermediate drainage is applied in new schemes. • Helical baffles with liquid dam and drainage gaps can promote condenser performance. • Dual-thread baffle scheme is superior to that of single-thread one by about 19%. • Condensation enhancement ratio of helical schemes is 1.5–2.5 over segment one. - Abstract: The vertical condensers have advantages of small occupation area, convenient in assemble or dismantle tube bundle and simple structure etc. However, the low heat transfer performance limits their applications. To enhance the heat transfer, a novel type of vertical condensers was designed by introducing trisection helical baffles with liquid dams and gaps for facilitating condensate drainage. Four configurations of vertical condensers with trisection helical baffle are experimentally studied and compared to a traditional segment baffle condenser. The enhancement ratio of trisection helical baffle schemes is about 1.5–2.5 and the heat transfer coefficient of the dual-thread trisection helical baffle scheme is superior to that of the single-thread one by about 19%. Assistant by the theoretical study, the experimental data is simulated and the condensation enhancement mechanisms by applying trisection helical baffle in vertical condenser are summarized as condensate drainage, short tube construct and reduce steam dead zone functions of the helical baffles.

  13. A fast response miniature probe for wet steam flow field measurements

    International Nuclear Information System (INIS)

    Bosdas, Ilias; Mansour, Michel; Abhari, Reza S; Kalfas, Anestis I

    2016-01-01

    Modern steam turbines require operational flexibility due to renewable energies’ increasing share of the electrical grid. Additionally, the continuous increase in energy demand necessitates efficient design of the steam turbines as well as power output augmentation. The long turbine rotor blades at the machines’ last stages are prone to mechanical vibrations and as a consequence time-resolved experimental data under wet steam conditions are essential for the development of large-scale low-pressure steam turbines. This paper presents a novel fast response miniature heated probe for unsteady wet steam flow field measurements. The probe has a tip diameter of 2.5 mm, and a miniature heater cartridge ensures uncontaminated pressure taps from condensed water. The probe is capable of providing the unsteady flow angles, total and static pressure as well as the flow Mach number. The operating principle and calibration procedure are described in the current work and a detailed uncertainty analysis demonstrates the capability of the new probe to perform accurate flow field measurements under wet steam conditions. In order to exclude any data possibly corrupted by droplets’ impact or evaporation from the heating process, a filtering algorithm was developed and implemented in the post-processing phase of the measured data. In the last part of this paper the probe is used in an experimental steam turbine test facility and measurements are conducted at the inlet and exit of the last stage with an average wetness mass fraction of 8.0%. (paper)

  14. Construction of the blowdown and condensation loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon Kyung; Song, Chul Kyung; Cho, Seok; Chun, S. Y.; Chung, Moon Ki

    1997-12-01

    The blowdown and condensation loop (B and C loop) has been constructed to get experimental data for designing the safety depressurization system (SDS) and steam sparger which are considered to implement in the Korea Next Generation Reactor (KNGR). In this report, system description on the B and C loop is given in detail, which includes the drawings and technical specification of each component, instrumentation and control system, and the operational procedures and the results of the performance testing. (author). 7 refs., 11 tabs., 48 figs.

  15. Improving the thermodynamic efficiency of steam turbine condensers with partial tube replacement and an advanced tube bundle design

    International Nuclear Information System (INIS)

    Drosdziok, A.; Zorner, W.

    1989-01-01

    Many different problems have been experienced with power plant condensers all over the world. It has become apparent that plant availability and cost-effectiveness are significantly influenced by the thermodynamic design of the condensers and the materials selected. This paper reports that by refitting older condensers in operating plants it has proven possible to improve thermodynamic efficiency by changing the tube bundle design. In conjunction with the replacement of the cooper-bearing tubing in these condensers, which became necessary because of the introduction of high AVT (All Volatile Treatment) conditioning in the secondary circuit, it has generally been possible to fulfil the requirements imposed on the condensers without a deterioration of plant efficiency. By experience, best results have been obtained by replacing the condenser bundle with an advanced tube bundle design. Apart from solving all problems, this further improves the thermodynamic efficiency of the condensers. In nuclear power plants constructed by the Siemens KWU Group the condensers are tailored to present-day requirements

  16. Hydrogen distribution in a containment with a high-velocity hydrogen-steam source

    International Nuclear Information System (INIS)

    Bloom, G.R.; Muhlestein, L.D.; Postma, A.K.; Claybrook, S.W.

    1982-09-01

    Hydrogen mixing and distribution tests are reported for a modeled high velocity hydrogen-steam release from a postulated small pipe break or release from a pressurizer relief tank rupture disk into the lower compartment of an Ice Condenser Plant. The tests, which in most cases used helium as a simulant for hydrogen, demonstrated that the lower compartment gas was well mixed for both hydrogen release conditions used. The gas concentration differences between any spatial locations were less than 3 volume percent during the hydrogen/steam release period and were reduced to less than 0.5 volume percent within 20 minutes after termination of the hydrogen source. The high velocity hydrogen/steam jet provided the dominant mixing mechanism; however, natural convection and forced air recirculation played important roles in providing a well mixed atmosphere following termination of the hydrogen source. 5 figures, 4 tables

  17. Scaling and Parametric Studies of Condensation Oscillation in an In-Containment Refueling Water Storage Tank

    International Nuclear Information System (INIS)

    Lee, Jun Hyung; No, Hee Cheon

    2003-01-01

    The purpose of this paper is to study the condensation oscillation phenomena by steam-jetting into subcooled water through a multihole sparger, implementing a scaling methodology and the similarity correlation between the test facility and model prototype. To corroborate the scaling methodology, various experimental tests were conducted. The thickness of the boundary layer that encloses the steam cavity was found to be equal to the maximum length of the steam cavity formed. Three key scaling parameters were identified and correlated with the maximum amplitude of pressure oscillation: flow restriction coefficient, area ratio of discharge hole to steam cavity, and density ratio of water to steam. Variations of the oscillation amplitude were small when steam-jetting directions were altered. The concept of a reduction factor was introduced for estimating the oscillation amplitude of the multihole sparger with test data from a single-hole sparger. The results of this study can provide suitable guidelines for sparger design utilized in the in-containment refueling water storage tank for the Advanced Power Reactor 1400

  18. Critical review of use of high pressure saturated steam turbine economizers in nuclear power plants

    International Nuclear Information System (INIS)

    Urbanek, J.

    1981-01-01

    In the high-pressure part of the turbine drops of moisture condensate, which causes erosion and has negative impact on the service-life of the turbine and on its thermodynamic efficiency. Various designs have been put forward to eliminate moisture. A good combination is moisture separation combined with the offtake of steam for the regeneration of feed water or for the steam re-heater. As concerns the high-pressure component of the turbine it is best to offtake steam for the feed water heater and for heating the steam between the high- and low-pressure components of the turbine. The connections of the heater and re-heater in diagrams of various manufacturers are evaluated and compared. It appears to be uneconomical to use the heater in cases where feed water would be heated to temperature considerably below its optimal value. (M.D.)

  19. Preliminary Analysis of Rapid Condensation Experiment with MARS-KS Code

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Ho; Jun, Hwang Yong; Jeong, Hae Yong [Sejong University, Seoul (Korea, Republic of)

    2016-05-15

    In the present study, the rapid condensation experiment performed in MANOTEA facility is analyzed with the MARS-KS code. It is known that there exists some limitation with a system code to predict this kind of a very active condensation due to direct mixing of cold injection flow and steam. Through the analysis we investigated the applicability of MARS-KS code for the design of various passive safety systems in the future. The configuration of the experimental facility MANOTEA, which has been constructed at the University of Maryland - United States Naval Academy, is described and the modeling approach using the MARS-KS code is also provided. The preliminary result shows that the MARS-KS predicts the general trend of pressure and temperature in the condensing part correctly. However, it is also found that there exist some limitations in the simulation such as an unexpected pressure peak or a sudden temperature change.

  20. QA practice for online analyzers in water steam cycles

    International Nuclear Information System (INIS)

    Staub, L.

    2010-01-01

    The liberalization of power markets throughout the world has resulted in more and more power stations being operated in cycling mode, with frequent load changes and multiple daily start-up and shut-down cycles. This more flexible operation also calls for better automation and poses new challenges to water chemistry in water steam cycles, to avoid subsequent damage to vital plant components such as turbines, boilers or condensers. But automation for the most important chemistry control tool, the sampling and online analyzer system, is only possible if chemists can rely on their online analysis equipment. Proof of plausibility as well as reliability and availability of online analysis results becomes a major focus. While SOP and standard QA procedures for laboratory equipment are well established and daily practice, such measures are widely neglected for online process analyzers. This paper is aiming to establish a roadmap for the implementation of SOP and QA/QC procedures for online instruments in water steam cycles, leading to reliable chemical information that is trustworthy for process automation and chemistry control in water steam cycles. (author)

  1. QA practice for online analyzers in water steam cycles

    International Nuclear Information System (INIS)

    Staub Lukas

    2009-01-01

    The liberalization of power markets throughout the world has resulted in more and more power stations being operated in cycling mode, with frequent load changes and multiple daily start-up and shut-down cycles. This more flexible operation also calls for better automation and poses new challenges to water chemistry in water steam cycles, to avoid subsequent damage to vital plant components such as turbines, boilers or condensers. But automation for the most important chemistry control tool, the sampling and online analyzer system, is only possible if chemists can rely on their online analysis equipment. Proof of plausibility as well as reliability and availability of online analysis results becomes a major focus. While SOP and standard QA procedures for laboratory equipment are well established and daily practice, such measures are widely neglected for online process analyzers. This paper is aiming to establish a roadmap for the implementation of SOP and QA/QC procedures for online instruments in water steam cycles, leading to reliable chemical information that is trustworthy for process automation and chemistry control in water steam cycles. (author)

  2. Saturated steam turbines for power reactors of WWER-type

    International Nuclear Information System (INIS)

    Czwiertnia, K.

    1978-01-01

    The publication deals with design problems of large turbines for saturated steam and with problem of output limitations of single shaft normal speed units. The possibility of unification of conventional and nuclear turbines, which creates the economic basis for production of both types of turbines by one manufacturer based on standarized elements and assemblies is underlined. As separate problems the distribution of nuclear district heating power systems are considered. The choice of heat diagram for district heating saturated steam turbines, the advantages of different diagrams and evaluaton for further development are presented. On this basis a program of unified turbines both condensing and district heating type suitable for Soviet reactors of WWER-440 and WWER-1000 type for planned development of nuclear power in Poland is proposed. (author)

  3. Recent technology for nuclear steam turbine-generator units

    International Nuclear Information System (INIS)

    Moriya, Shin-ichi; Kuwashima, Hidesumi; Ueno, Takeshi; Ooi, Masao

    1988-01-01

    As the next nuclear power plants subsequent to the present 1,100 MWe plants, the technical development of ABWRs was completed, and the plan for constructing the actual plants is advanced. As for the steam turbine and generator facilities of 1,350 MWe output applied to these plants, the TC6F-52 type steam turbines using 52 in long blades, moisture separation heaters, butterfly type intermediate valves, feed heater drain pumping-up system and other new technologies for increasing the capacity and improving the thermal efficiency were adopted. In this paper, the outline of the main technologies of those and the state of examination when those are applied to the actual plants are described. As to the technical fields of the steam turbine system for ABWRs, the improvement of the total technologies of the plants was promoted, aiming at the good economical efficiency, reliability and thermal efficiency of the whole facilities, not only the main turbines. The basic specification of the steam turbine facilities for 50 Hz ABWR plants and the main new technologies applied to the turbines are shown. The development of 52 in long last stage blades, the development of the analysis program for the coupled vibration of the large rotor system, the development of moisture separation heaters, the turbine control system, condensate and feed water system, and the generators are described. (Kako, I.)

  4. Troubleshooting vacuum systems steam turbine surface condensers and refinery vacuum towers

    CERN Document Server

    Lieberman, Norman P

    2012-01-01

    Vacuum systems are in wide spread use in the petrochemical plants, petroleum refineries and power generation plants. The existing texts on this subject are theoretical in nature and only deal with how the equipment functions when in good mechanical conditions, from the viewpoint of the equipment vendor.  In this much-anticipated volume, one of the most well-respected and prolific process engineers in the world takes on troubleshooting vacuum systems, and especially steam ejectors, an extremely complex and difficult subject that greatly effects the profitability of the majority of the world'

  5. Effects of steam-heating processes on a stratified volcanic aquifer: Stable isotopes and dissolved gases in thermal waters of Vulcano Island (Aeolian archipelago)

    Science.gov (United States)

    Federico, C.; Capasso, G.; Paonita, A.; Favara, R.

    2010-05-01

    We report on a comprehensive study of major-ion chemistry, dissolved gases, and stable isotopes measured in water wells at Vulcano Island since 1988. The work focuses on a quantitative model describing steam condensation and boiling phenomena in shallow water bodies. The model is based on the differences in partition coefficients between liquid water and vapor characterizing oxygen and hydrogen isotopes, as well as volcanic gases (CO 2, S species, and HCl). Based on both physical conditions of aquifers identified during drilling campaigns and the composition of the volcanic vapor, mass and enthalpy balances are applied in a multistep process of steam separation and condensation in shallower aquifers. By comparing the model results with measured data, we infer that (i) strong isotope enrichment observed in some shallow thermal waters can result from an increasing mass rate of condensing deep vapor, even in water meteoric in origin; (ii) the high CO 2 content measured in the fumarolic vapor during 1988-1993 affected the δ18O value of the steam-heated water due to CO 2-H 2O isotope exchange; (iii) the high pCO 2 measured in the coldest and peripheral waters are explained by the progressive enrichment of this gas in the vapor phase during multistep boiling; and (iv) the high Cl - and SO 42-contents in the hottest waters can be attributed to the direct condensation (single-step) of volcanic vapor. The model also takes into account both the mass fluxes and the compositions of the involved endmembers (steam and shallow groundwater), which provides important inferences on the modifications observed or expected during periods of increasing mass and heat input from depth.

  6. The chemical kinetics of the reactions of lithium with steam-air mixtures

    International Nuclear Information System (INIS)

    Barnett, D.S.; Kazimi, M.S.

    1989-04-01

    This work involved the experimental and analytical determination of the consequences of lithium fires in the presence of steam. Experiments were performed to characterize the chemical reactions of lithium with steam-nitrogen and steam-air mixtures. Models were introduced in the LITFIRE code to describe lithium fires in the presence of steam inside the containment building and plasma chamber of a hypothetical fusion reactor. The code was also equipped with the capability to determine the effects of decay heat and lithium fire on the temperature response of the reactor first wall in the event of a coolant disturbance. Forty-two kinetics experiments were performed in which a stream of steam-nitrogen or steam-air was passed over and reacted with approximately three grams of lithium heated to a predetermined temperature. The lithium reaction rates with the constituent gases were measured and characterized for a wide range of lithium temperatures and gas compositions. Experiments were performed with steam molar concentrations of 5, 15 and 30% and lithium temperatures ranging from 400 to 1100 degree C, inclusive. The LITFIRE code was modified to enable it to model the interactions of lithium with steam-air atmospheres. Results of the reaction kinetics experiments were used in the reaction model, and the heat transfer model was expanded to allow it to handle condensible atmospheres. Three groups of accidents were investigated: a spill on the containment building floor, a spill inside the reactor plasma chamber, and a spill inside the plasma chamber with steam injection to the containment building simulating a steam line break. The results were compared to dry air cases under the same conditions. 23 refs., 66 figs., 18 tabs

  7. Physical-chemistry aspects of water in steam turbines associated with material stress and electrochemical assessment of the AISI 403 to simulate real condition

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, D S; Franco, C V; Godinho, J F; Frech, W A; Sonai, G G [Univ. Federal de Santa Catarina, Florianopolis (Brazil); Torres, L A.M.; Ellwanger, A R.F. [Tractebel Energia, Capivari de Baixo (Brazil)

    2009-07-01

    This study described a methodology developed to prevent the occurrence of corrosion failure in steam turbines. The methodology was developed after the failure of a turbine blade at a plant in Brazil. Deposits were collected from various locations along the turbine blade path and analyzed. A turbine deposit collector and simulator was installed to determine the concentrations of steam impurities. Samples were collected from the low pressure turbine at the crossover point and from the polishing station and analyzed using inductive coupled plasma-mass spectrometry (ICP-MS) in order to determine if sodium levels exceeded 3 ppb. Filters were weighed in order to determine the accumulation of impurities. A 3-electrode system was used to determine the influence of chloride ions. The design of the system's condensate polisher beds was modified in order to improve condensate effluent conductivity. The condensate treatment procedure lowered the concentrations of salt impurities and established a monitoring methodology for water and steam used at the plant. It was concluded that the methodology can be used to to reduce inspection intervals and increase system reliability. 10 refs., 1 tab., 7 figs.

  8. Measures against the adverse impact of natural wind on air-cooled condensers in power plant

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant.It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers.Based on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed.The physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD simulation.The back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled condensers.The results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind.

  9. Mixed convection heat transfer between a steam/non-condensable gas mixture and an inclined finned tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    De Cachard, F.; Lompersky, S.; Monauni, G.R. [Paul Scherrer Institute, Villigen (Switzerland). Thermal Hydraulic Lab.

    1999-07-01

    An experimental and analytical program was performed at PSI (Paul Scherrer Institute) to study the performance of a finned-tube condenser in the presence of non-condensable gases at low gas mass fluxes. The model developed for this application includes mixed convection heat transfer between the vapour/non-condensable mixture and the finned tubes, heat conduction through the fins and tubes, and evaporative heat transfer inside the tubes. On the gas, heat transfer correlations are used, and the condensation rate is calculated using the heat/mass transfer analogy. A combination of various available correlations for forced convection in staggered finned tube bundles is used, together with a correction accounting for superimposed natural convection. For the condensate heat transfer resistance, the beatty and Katz model for gravity driven liquid films on the tubes is used. The fine efficiency is accounted for using classical iterative calculations. Evaporative heat transfer inside the tubes is predicted using the Chen correlation. The finned tube condenser model has been assessed against data obtained at the PSI LINX facility with two test condensers. For the 62 LINX experiments performed, the model predictions are very good, i.e., less then 10% standard deviation between experimental and predicted results.

  10. Thermodynamic Analysis of a Steam Power Plant with Double Reheat and Feed Water Heaters

    Directory of Open Access Journals (Sweden)

    M. M. Rashidi

    2014-03-01

    Full Text Available A steam cycle with double reheat and turbine extraction is presented. Six heaters are used, three of them at high pressure and the other three at low pressure with deaerator. The first and second law analysis for the cycle and optimization of the thermal and exergy efficiencies are investigated. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. The exergy and irreversibility analyses of each component of the cycle are determined. Effects of turbine inlet pressure, boiler exit steam temperature, and condenser pressure on the first and second laws' efficiencies are investigated. Also the best turbine extraction pressure on the first law efficiency is obtained. The results show that the biggest exergy loss occurs in the boiler followed by the turbine. The results also show that the overall thermal efficiency and the second law efficiency decrease as the condenser pressure increases for any fixed outlet boiler temperature, however, they increase as the boiler temperature increases for any condenser pressure. Furthermore, the best values of extraction pressure from high, intermediate, and low pressure turbine which give the maximum first law efficiencies are obtained based on the required heat load corresponding to each exit boiler temperature.

  11. Implementation and validation of the condensation model for containment hydrogen distribution studies

    International Nuclear Information System (INIS)

    Ravva, Srinivasa Rao; Iyer, Kannan N.; Gupta, S.K.; Gaikwad, Avinash J.

    2014-01-01

    Highlights: • A condensation model based on diffusion was implemented in FLUENT. • Validation of a condensation model for the H 2 distribution studies was performed. • Multi-component diffusion is used in the present work. • Appropriate grid and turbulence model were identified. - Abstract: This paper aims at the implementation details of a condensation model in the CFD code FLUENT and its validation so that it can be used in performing the containment hydrogen distribution studies. In such studies, computational fluid dynamics simulations are necessary for obtaining accurate predictions. While steam condensation plays an important role, commercial CFD codes such as FLUENT do not have an in-built condensation model. Therefore, a condensation model was developed and implemented in the FLUENT code through user defined functions (UDFs) for the sink terms in the mass, momentum, energy and species balance equations together with associated turbulence quantities viz., kinetic energy and dissipation rate. The implemented model was validated against the ISP-47 test of TOSQAN facility using the standard wall functions and enhanced wall treatment approaches. The best suitable grid size and the turbulence model for the low density gas (He) distribution studies are brought out in this paper

  12. Improvement of reliability of heater and condenser

    International Nuclear Information System (INIS)

    Yamagishi, Hiroki

    1988-01-01

    Recently, the diversification of the operation modes of power plants has advanced as well as daily start and stop and weekly start and stop operations, as the result, the needs for the reliability improvement of various heat exchangers around steam turbines heighten. In newly constructed plants, the design to meet this demand is carried out, but also in existing platns, the application of the latest technology is investigated. As for the reliability of condensers, aluminum brass cooling tubes have been used by doing the optimal maintenance and taking the measures against deposit attack. In the case of requiring high reliability, the examples of adopting titanium cooling tubes increased. The technology of titanium tube condensers, completely assembled condensers, the replacement of existing brass tubes with titanium tubes and so on are discussed. In the case of feed heaters, the deterioration phenomena due to the lapse of long years, such as the attack of steel tube inlet, the drain attack on the external surfaces of steel tubes, the ammonia attack of aluminum brass tubes and the adhesion of scale to heaters, are explained, and the countermeasures are shown. (Kako, I.)

  13. A theoretical analysis of flow through the nucleating stage in a low pressure steam turbine

    International Nuclear Information System (INIS)

    Skillings, S.A.; Walters, P.T.; Jackson, R.

    1989-01-01

    In order to improve steam turbine efficiency and reliability, the phenomena associated with the formation and growth of water droplets must be understood. This report describes a theoretical investigation into flow behaviour in the nucleating stage, where the predictions of a one-dimensional theory are compared with measured turbine data. Results indicate that droplet sizes predicted by homogeneous condensation theory cannot be reconciled with measurements unless fluctuating shock waves arise. Heterogeneous effects and flow turbulence are also discussed along with their implications for the condensation process. (author)

  14. DESIGNING AND EFFICIENCY EFFECT OF AUTOMATIC BALL-CLEANING SYSTEM FOR CONDENSER 180-KTsS-1 OF TURBINE Т-180/210-130-1 LMZ. Part 1

    Directory of Open Access Journals (Sweden)

    Yu. A. Zenovich-Leshkevich-Ol’pinskiy

    2015-01-01

    Full Text Available In order to reduce losses in the cooling source (condenser and to increase effectiveness of fuel-and-power resources utilization, the authors present a modern automatic ball-cleaning system for the pipes of condenser 180-KTsS-1 of turbine unit Т-180/210-130-1 LMZ of Gomel CHP-2. The article examines exploitation challenges of the steam turbine condensers and methods of clearing them from sedimentations. Depending on the sedimentation character and composition, and the quality of cooling water at the power plant, they apply various methods of the condenser tubes clearing: heat drying, vacuum dehydration, acid-washing, pipes-shooting with water and water-air pistols, ablution with high-pressure water jet etc. All the applied cleaning methods are the periodical means to fight the sedimentations and require the turbine halting or unloading, predetermine the equipment operating between clearings with constantly smearing cooling surfaces of the condensers, i.e. with reduced efficiency of equipment operation.The installation of the ball-cleaning system practically excludes defects of the chemical and mechanical cleaning methods, which leads to the condenser pipes life-in-service increase, the full-flow condensate quality improvement, reliability and efficient performance enhancement of the steam turbines equipment. The authors consider developed algorithms of data processing and designed system control of the condenser cleaning that allowed realizing its operation in automatic mode.

  15. Evaluation of Advanced Models for PAFS Condensation Heat Transfer in SPACE Code

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Byoung-Uhn; Kim, Seok; Park, Yu-Sun; Kang, Kyung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ahn, Tae-Hwan; Yun, Byong-Jo [Pusan National University, Busan (Korea, Republic of)

    2015-10-15

    The PAFS (Passive Auxiliary Feedwater System) is operated by the natural circulation to remove the core decay heat through the PCHX (Passive Condensation Heat Exchanger) which is composed of the nearly horizontal tubes. For validation of the cooling and operational performance of the PAFS, PASCAL (PAFS Condensing Heat Removal Assessment Loop) facility was constructed and the condensation heat transfer and natural convection phenomena in the PAFS was experimentally investigated at KAERI (Korea Atomic Energy Research Institute). From the PASCAL experimental result, it was found that conventional system analysis code underestimated the condensation heat transfer. In this study, advanced condensation heat transfer models which can treat the heat transfer mechanisms with the different flow regimes in the nearly horizontal heat exchanger tube were analyzed. The models were implemented in a thermal hydraulic safety analysis code, SPACE (Safety and Performance Analysis Code for Nuclear Power Plant), and it was evaluated with the PASCAL experimental data. With an aim of enhancing the prediction capability for the condensation phenomenon inside the PCHX tube of the PAFS, advanced models for the condensation heat transfer were implemented into the wall condensation model of the SPACE code, so that the PASCAL experimental result was utilized to validate the condensation models. Calculation results showed that the improved model for the condensation heat transfer coefficient enhanced the prediction capability of the SPACE code. This result confirms that the mechanistic modeling for the film condensation in the steam phase and the convection in the condensate liquid contributed to enhance the prediction capability of the wall condensation model of the SPACE code and reduce conservatism in prediction of condensation heat transfer.

  16. Furfural production by 'acidic steam stripping' of lignocellulose.

    Science.gov (United States)

    van Buijtenen, Jeroen; Lange, Jean-Paul; Espinosa Alonso, Leticia; Spiering, Wouter; Polmans, Rob F; Haan, Rene J

    2013-11-01

    Furfural and acetic acid are produced with approximately 60 and 90 mol % yield, respectively, upon stripping bagasse with a gaseous stream of HCl/steam and condensing the effluent to water/furfural/acetic acid. The reaction kinetics is 1(st)  order in furfural and 0.5(th)  order in HCl. A process concept with full recycling of the reaction effluents is proposed to reduce the energy demand to furfural-rich phase. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Steam 80 steam generator instrumentation

    International Nuclear Information System (INIS)

    Carson, W.H.; Harris, H.H.

    1980-01-01

    This paper describes two special instrumentation packages in an integral economizer (preheater) steam generator of one of the first System 80 plants scheduled to go into commercial operation. The purpose of the instrumentation is to obtain accurate operating information from regions of the secondary side of the steam generator inaccessible to normal plant instrumentation. In addition to verification of the System 80 steam generator design predictions, the data obtained will assist in verification of steam generator thermal/hydraulic computer codes developed for generic use in the industry

  18. Ice-condenser aerosol tests

    International Nuclear Information System (INIS)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K.

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between ∼0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m 3 /s resulted in stable thermal stratification whereas flows less than 0.1 m 3 /s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs

  19. Gas manufacture, processes for: condensers

    Energy Technology Data Exchange (ETDEWEB)

    Young, W

    1876-11-29

    In the production of illuminating gas from coal, shale, hydrocarbon oil, or other substance used in the production of gas, the volatile products inside the retort are agitated by means of moving pistons or jets of compressed gas, steam, or vapor in order to decompose them into permanent gases, and in some cases to increase the volume of gas by the decomposition of the injected gas, etc. or by blending or carburetting this gas with the decomposition products of the volatile matters. To separate the condensible hydrocarbons from the crude gas it is passed through heated narrow tortuous passages or is caused to impinge on surfaces. If the crude gases are cold these surfaces are heated and vice versa.

  20. Scaling and parametric studies of condensation oscillation in an in-containment refueling water storage tank

    International Nuclear Information System (INIS)

    Lee, Jun Hyung; No, Hee Cheon

    2001-01-01

    The purpose of this paper is to study the condensation oscillation phenomena by steam-jetting into subcooled water through a sparger, implementing a scaling methodology and the similarity correlation between the test facility and model prototype. In additon, the results of this study can provide suitable guidelines for sparger design utilized in the IRWST for the Advanced Passive Reactor 1400 (APR 1400). To corroborate the scaling methodology, various experimental tests were conducted. The scaling-related parameters experimentally considered were water temperatures, mass flux, discharge system volumes, tank sizes, source pressure, steam-jetting directions, and numbers of sparger discharge holes. To preserve the scaling similarity, the thickness of the minimum water volume created by the boundary layer that encloses the steam cavity was found to be equal to the maximum length of the steam cavity formed. Four key scaling parameters were identified and empirically correlated with the maximum amplitude of pressure oscillation. They are as follows: Volume of the steam cavity, flow restriction coefficient, discharge hole area, and density ratio of steam to water. Variations of the oscillation amplitude were small when steam-jetting directions were altered. The concept of a reduction factor was introduced for estimating the oscillation amplitude of the multi-hole sparger with test data from a single-hole sparger

  1. Nanoparticles found in superheated steam: a quantitative analysis of possible heterogeneous condensation nuclei

    Czech Academy of Sciences Publication Activity Database

    Kolovratník, M.; Hrubý, Jan; Ždímal, Vladimír; Bartoš, Ondřej; Jiříček, I.; Moravec, Pavel; Zíková, Naděžda

    2014-01-01

    Roč. 228, č. 2 (2014), s. 186-193 ISSN 0957-6509 R&D Projects: GA ČR GA101/09/1633 Institutional support: RVO:61388998 ; RVO:67985858 Keywords : heterogeneous nucleation * steam turbine * ultrafine aerosol particles Subject RIV: BJ - Thermodynamics; CF - Physical ; Theoretical Chemistry (UCHP-M) Impact factor: 0.645, year: 2014 http://pia.sagepub.com/content/early/2013/12/10/0957650913512816

  2. Structural Changes of Lignin from Wheat Straw by Steam Explosion and Ethanol Pretreatments

    Directory of Open Access Journals (Sweden)

    Cheng Pan

    2016-06-01

    Full Text Available Effects of the pretreatment of wheat straw by steam explosion and ethanol were evaluated relative to the structural changes of lignin from the pretreated pulp. The lignin from steam explosion pulp (LS, lignin from steam blasting residual liquid (LL, lignin from ethanol pretreatment pulp (LE, lignin from black liquor (LB, and lignin from wheat straw (LW were separated, and the structural characteristics of the lignin fractions were compared based on analyses of Fourier transform-infrared, ultraviolet, thermogravimetric, and 1H and 13C nuclear magnetic resonance spectra. The proportions of the three structural units in all lignin fractions clearly changed during the pretreatment process because of inter-conversion reactions. The conjugated structure of lignin was destroyed in the pretreatment process and was also affected by the alkali extraction process. The alcoholic hydroxyl links on the aliphatic side chain were partly transformed into carbonyl groups during ethanol pretreatment. Demethoxylation occurred in all lignin fractions during the ethanol pretreatment and steam explosion process. The thermal stability of the LB fraction was relatively high because of the condensation reaction.

  3. Steam relief valve control system for a nuclear reactor

    International Nuclear Information System (INIS)

    Torres, J.M.

    1976-01-01

    Described is a turbine follow system and method for Pressurized Water Reactors utilizing load bypass and/or atmospheric dump valves to provide a substitute load upon load rejection by bypassing excess steam to a condenser and/or to the atmosphere. The system generates a variable pressure setpoint as a function of load and applies an error signal to modulate the load bypass valves. The same signal which operates the bypass valves actuates a control rod automatic withdrawal prevent to insure against reactor overpower

  4. MELCOR 1.8.1 assessment: PNL Ice Condenser Aerosol Experiments

    International Nuclear Information System (INIS)

    Gross, R.J.

    1993-06-01

    The MELCOR code was used to simulate PNL's Ice Condenser Experiments 11-6 and 16-11. In these experiments, ZnS was injected into a mixing chamber, and the combined steam/air/aerosol mixture flowed into an ice condenser which was l4.7m tall. Experiment 11-6 was a low flow test; Experiment l6-1l was a high flow test. Temperatures in the ice condenser region and particle retention were measured in these tests. MELCOR predictions compared very well to the experimental data. The MELCOR calculations were also compared to CONTAIN code calculations for the same tests. A number of sensitivity studies were performed. It as found that simulation time step, aerosol parameters such as the number of MAEROS components and sections used and the particle density, and ice condenser parameters such as the energy capacity of the ice, ice heat transfer coefficient multiplier, and ice heat structure characteristic length all could affect the results. Thermal/hydraulic parameters such as control volume equilibrium assumptions, flow loss coefficients, and the bubble rise model were found to affect the results less significantly. MELCOR results were not machine dependent for this problem

  5. Theoretical studying the stability of steady-state regime of a channel with a coolant condensation

    International Nuclear Information System (INIS)

    Savikhin, O.G.

    1987-01-01

    Based on the boiling channel stability theory, the channel steady-state stability with the coolant condensation is studied. Condensable coolants are used in the NPP steam-separator superheaters as well as in cryogenic technique. Under certain conditions the coolant flow rate and temperature fluctuations may be excited in the parallel channel system with coolant condensation, which produce a sufficient effect on the heat exchange equipment operation reliability. To describe unsteady processes of heat and mass transfer in the channel, a homogeneous two-phase flow one dimensional model is used. The results obtained allow one to make a conclusion concerning the effect of some parameters on condensing channel steady-state regime stability: reduction of inlet and outlet unheated communication length, pressure drop increase at the outlet plate and its reduction at the inlet one lead to the increase of stability margin

  6. Simulation and design of distillation units for treatment of sulfite pulping condensates to recover methanol and furfural. Part II. Applicability of multiple-effect distillation using live steam

    Energy Technology Data Exchange (ETDEWEB)

    Aly, G.; Zacchi, G.

    1979-06-01

    A distillation unit has been designed for a capacity of 73 t/h of condensate and for at least 90% recovery of the contaminating organics. This unit consists of three columns: a primary stripper to remove volatile organics and two upgrading columns to purify the methanol and furfural byproducts. Three different energy-saving alternatives for satisfying the energy requirements have been studied: utilisation of secondary steam from the evaporation plant, and application of the principle of multi-effect distillation in one-stripper and in two-stripper configurations. Investment cost needed in all alternatives amounts to 5.5 to 6.0 MCr (millions of Swedish Crowns) while operating cost varies between 0.8 to 3.1 MCr. The first design alternative has a payoff period of 2.3 years while the two multi-effect distillation alternatives have a payoff period of about 3 years.

  7. Corrosion Product Measurements to ensure integrity of the Steam Generators in Beznau NPP

    International Nuclear Information System (INIS)

    Mailand, Irene; Franz, Patrick; Venz, Hartmut

    2012-09-01

    The Nuclear Power Plant Beznau comprises two identical 380 MWe PWR units with two loops each, commissioned in 1969 and 1971. Westinghouse was responsible for the primary part of the plant and BBC/ABB for the secondary circuit. The original materials used in the secondary systems were made of several copper-based alloys, such as for the Condensers, the Low Pressure Pre-heaters and the Moisture Separator Re-heater. The original Steam Generator Tubes were made of Inconel 600 MA. Regarding its age, the NPP Beznau has to be qualified as an old plant. However, in fact particularly in the last 20 years the plant has undergone an extensive modernisation programme in which about 1.5 billion Swiss Francs have been invested. Important measures were the replacements of the Steam Generators with tubes comprising Inconel 690 TT which was realized at unit 1 in 1993 and at unit 2 in 1999. Copper was completely banished from the secondary system and replaced by stainless and chromium steel. The Condensers were fitted with titanium tubes. The secondary water chemistry had to be changed by these replacements and moved step by step from Low-AVT with a pH of about 9.3 to High-AVT with a pH of 9.8 to 9.9, currently. To ensure the integrity of the new Steam Generators as well as of the whole Secondary System a corrosion product programme was introduced at the end of the Nineties. Several investigations which are performed periodically are represented by analyses of corrosion products, measurements of sludge mass and composition in the Steam Generators, Hide-Out-Return- and mass balance measurements of corrosion products in the whole circuit. Objectives of these investigations are assessments of the efficiency of the water chemistry and trend considerations regarding to the transport of corrosion products and pollutants into the Steam Generator, as well as of the potential danger of deposits and stored or absorbed pollutants. The main target of all measures is to avoid any chemical

  8. Dynamic underground stripping: steam and electric heating for in situ decontamination of soils and groundwater

    Science.gov (United States)

    Daily, William D.; Ramirez, Abelardo L.; Newmark, Robin L.; Udell, Kent; Buetnner, Harley M.; Aines, Roger D.

    1995-01-01

    A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary. Geophysical imaging methods can be used to map the boundary between the hot, dry, contamination-free underground zone and the cool, damp surrounding areas to help monitor the dynamic stripping process.

  9. Study of steam condensation at sub-atmospheric pressure: setting a basic research using MELCOR code

    Science.gov (United States)

    Manfredini, A.; Mazzini, M.

    2017-11-01

    One of the most serious accidents that can occur in the experimental nuclear fusion reactor ITER is the break of one of the headers of the refrigeration system of the first wall of the Tokamak. This results in water-steam mixture discharge in vacuum vessel (VV), with consequent pressurization of this container. To prevent the pressure in the VV exceeds 150 KPa absolute, a system discharges the steam inside a suppression pool, at an absolute pressure of 4.2 kPa. The computer codes used to analyze such incident (eg. RELAP 5 or MELCOR) are not validated experimentally for such conditions. Therefore, we planned a basic research, in order to have experimental data useful to validate the heat transfer correlations used in these codes. After a thorough literature search on this topic, ACTA, in collaboration with the staff of ITER, defined the experimental matrix and performed the design of the experimental apparatus. For the thermal-hydraulic design of the experiments, we executed a series of calculations by MELCOR. This code, however, was used in an unconventional mode, with the development of models suited respectively to low and high steam flow-rate tests. The article concludes with a discussion of the placement of experimental data within the map featuring the phenomenon characteristics, showing the importance of the new knowledge acquired, particularly in the case of chugging.

  10. Microfabricated rankine cycle steam turbine for power generation and methods of making the same

    Science.gov (United States)

    Frechette, Luc (Inventor); Muller, Norbert (Inventor); Lee, Changgu (Inventor)

    2009-01-01

    In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

  11. HTCC - a heat transfer model for gas-steam mixtures

    International Nuclear Information System (INIS)

    Papadimitriou, P.

    1983-01-01

    The mathematical model HTCC (Heat Transfer Coefficient in Containment) has been developed for RALOC after a loss-of-coolant accident in order to determine the local heat transfer coefficients for transfer between the containment atmosphere and the walls of the reactor building. The model considers the current values of room and wall temperature, the concentration of steam and non-condensible gases, geometry data and those of fluid dynamics together with thermodynamic parameters and from these determines the heat transfer mechanisms due to convection, radiation and condensation. The HTCC is implemented in the RALOC program. Comparative analyses of computed temperature profiles, for HEDL Standard problems A and B on hydrogen distribution, and of computed temperature profiles determined during the heat-up phase in the CSE-A5 experiment show a good agreement with experimental data. (orig.) [de

  12. Arrangement for the analysis of feed water- and condensate samples of power plants

    International Nuclear Information System (INIS)

    Mostofin, A.A.; Sorokina, N.S.

    1979-01-01

    The analysis of the feedwater- and condensate sample of condensation heat power plants and nuclear power plants results from the determination of the concentrations of salt and NH 3 . The sample is led through a multistep concentrator with evaporators. On the outlet of the evaporator are throttles for the outlet of the steam-gas-mixture. The throttle on the first evaporator is designed in a way that carbonic acid escapes from the sample, which is measured by a conductivity transmitter. A conductivity transmitter with an outlet signal that is proportional to the NH 3 content is also located on the throttle of the second evaporator. (RW) [de

  13. Test facility of the VVER-440 condensation-type pressure suppression system

    International Nuclear Information System (INIS)

    Wolff, H.; Arndt, S.

    2004-01-01

    Since the early nineties, GRS has supported regulatory authorities in Central and Eastern Europe in performing safety assessments of nuclear power plants. Especially studies of the condensation-type pressure suppression system of VVER-440/V-213-type plants have been important in this respect. Major steps in demonstrating complete functioning of the condensation-type pressure suppression system under accident conditions by experiments run in the Russian large scale test facility, BC V-213, have been completed in the past two years within the framework of various international experimental programs. The test results were used to validate specifically for power plants with VVER-400/V-213 reactors the COCOSYS GRS computer code, which is used in the safety assessments. The results of recalculations of the C02 EREC test, which simulates a break of a main steam pipe, demonstrate the present state of validation of COCOSYS for VVER condensation-type pressure suppression systems. (orig.) [de

  14. Determination of optimum fin profile for a zero-G capillary drained condenser

    Science.gov (United States)

    Mccormick, John A.; Valenzuela, Javier A.; Choudhury, Dipanker

    1990-01-01

    This paper presents the analytical formulation and numerical results for heat transfer in a high heat flux condenser that relies on capillary flow along shaped fins (Gregorig surfaces) and a drainage network embedded in the condenser walls. Results are shown for a variety of fin profile shapes in order to show the geometric trade-offs involved in seeking a maximum effective heat transfer coefficient for the fin. Predictions of the model show excellent agreement with previously reported measurements for steam. Based on this work, a profile has been selected for a 2 kW ammonia condenser currently under development for use in space. In that design the fin half width is 0.5 mm and the model predicts a heat transfer coefficient referred to the base of the fin of 9 W/sq cm deg C for a heat flux of 10/W sq cm at the base.

  15. Analysis of Ruptured Heater Tube of Degasser Condenser in Wolsong Unit 4

    International Nuclear Information System (INIS)

    Kim, Hong Pyo; Kim, J. S.; Lim, Y. S.; Kim, S. S.; Hwang, S. S.; Kim, D. J.; Kim, S. W.; Jeong, M. K.; Hong, J. H.

    2007-08-01

    In a degasser condenser in Wolsong unit 4, the cracks were found in the heater tube no. 6 and no. 7. To avoid additional damages in the specimen during a decontamination process for the previous analysis, the cracks were analyzed without any decontamination process in this work. We performed the investigation of the ruptured surface morphology, the EDS analysis of the ruptured surface, the microstructural analysis of Alloy 800H sheath tube and literature survey to find the failure mechanism. From the results, it was expected that the sheath tube has been exposed in a steam condition as the coolant level was decreased in the degasser condenser, leading to the rupture of the sheath tube

  16. Optimization of Design of Steam Turbine Exhaust Conduits

    Directory of Open Access Journals (Sweden)

    A. S. Goldin

    2014-01-01

    Full Text Available Improving effectiveness turbine was and remains a key issue for today. In order to improve the efficiency of the turbine is necessary to reduce losses in the steam turbine exhaust conduit.This paper presents the design optimization exhaust conduit steam turbine K-27-2.9 produced by JSC «KTW» at the design stage. The aims of optimizing the design were: decreasing hydraulic resistance of the conduit, reduction of non-uniformity of the flow at the outlet of the conduit, equalizing steam flow ahead of the condenser tube bundle.The conduit models were made and flows in it were simulated in environment of the Solid Works and its application COSMOS Flo Works.As the initial conduit model was selected exhaust conduit of turbine PT-25/34-3.4 produced by JSC «KTW». Was obtained by the calculated velocity field at the outlet of the conduit. The analysis of the calculation results revealed the necessity of changes to the initial design of the conduit. The changes were accompanied by calculating currents flow in the conduit, and assessed the impact of design changes on the nature of the course. Further transformation of the construction of the conduit was held on the results of these calculations. Construction changes are not touched by the outer geometry of the conduit, and were introduced to meet technological.According to calculation results, conclusions were drawn and selected three versions of the conduit.Given are the research results for the initial conduit model and modified design versions. In order to evaluate the flow degree of irregularity the momentum factor (Bussinesku factor for outlet crosssection of the selected conduit design version. Analysis of the research results made it possible to determine optimum design of the exhaust conduit.Introducing the suggested alterations in the conduit design will result in improvement of heat exchange in the condenser, an increase in reliability of the tube bundle operation, a decrease in noise and

  17. EVALUASI KINERJA TURBINE CONDENSER E-2302 SEBELUM DAN SESUDAH DILAKSANAKAN TURN AROUND 2016

    Directory of Open Access Journals (Sweden)

    Herdyana Yanunda Putri

    2017-04-01

    Full Text Available PT. Kaltim Parna Industri (KPI is an ammonia plant with a capacity of 1,500 MPTD. The purity of the products produced 99.95% by weight. The process that is used in PT. KPI is Haldor Topsoe Process. The raw material used to produce ammonia is natural gas (as a source of H2 and air (as a source of N2. PT. Kaltim Parna Industri has two main units of production processes and utilities. In the production process of the unit there are several major units, unit desulphurizer, reforming system consists of primary and secondary reformer, CO Converter unit consisting of High and Low Temperature CO Converter (HTS and LTS, CO2 units, unit methanator, and ammonia converter. In the unit utility has main units, there are units of sea water intake, units of desalination, demineralization, daerator, Package Boilers, Water Heat Boiler, sea water cooling towers, waste water treatment system, chlorination, STG and emergency diesel denerator, N2 generator, instrument water, and storage tanks. Turbine Condenser E-2302 has the main function to condense steam low to utilize the latent heat which is then used to drive a steam turbine-pump (TS / P-2301A / B. Overall heat transfer coefficient of turbine condenser E-2302 prior to Turn Around (TA has an efficiency of 88.964% and afterTurn Around (TA of 94 928% with heat transfer coefficient calculation technique overalls using calor compared with area and LMTD (Log Mean Temperature Difference.

  18. Reverse primary-side flow in steam generators during natural circulation cooling

    International Nuclear Information System (INIS)

    Stumpf, H.; Motley, F.; Schultz, R.; Chapman, J.; Kukita, Y.

    1987-01-01

    A TRAC model of the Large Scale Test Facility with a 3-tube steam-generator model was used to analyze natural-circulation test ST-NC-02. For the steady state at 100% primary mass inventory, TRAC was in excellent agreement with the natural-circulation flow rate, the temperature distribution in the steam-generator tubes, and the temperature drop from the hot leg to the steam-generator inlet plenum. TRAC also predicted reverse flow in the long tubes. At reduced primary mass inventories, TRAC predicted the three natural-circulation flow regimes: single phase, two phase, and reflux condensation. TRAC did not predict the cyclic fill-and-dump phenomenon seen briefly in the test. TRAC overpredicted the two-phase natural-circulation flow rate. Since the core is well cooled at this time, the result is conservative. An important result of the analysis is that TRAC was able to predict the core dryout and heatup at approximately the same primary mass inventory as in the test. 4 refs., 8 figs., 2 tabs

  19. Film condensation on a porous vertical surface in a porous media

    International Nuclear Information System (INIS)

    Ebinuma, C.D.; Liu, C.Y.; Ismail, K.A.R.

    1983-01-01

    The problem of dry saturated steam film condensation by natural convection on a porous surface in a porous medium is presented. Through the classical Darcy law for flow in porous medium and the approximations considered in the Boundary layer theory, it is shown that the analytical solution exists only when the normal velocity to the porous wall is inversly proportional to the square root of the distance along the plate. (E.G.) [pt

  20. To the choice of the regeneration system of the K-1000-68/1500 turbine plant for the NPP with a vertical-type steam generator

    International Nuclear Information System (INIS)

    Kuznetsov, N.M.; Piskarev, A.A.; Grinman, M.I.; Kruglikov, P.A.

    1985-01-01

    Several variants of the heat regeneration system for the NPP with WWER-1000 type reactors using vertical steam generator (SG) generating saturated steam at 7.2 MPa pressure and 200 deg C feed water temperature at the SG inlet are considered. The results of comparison of variants in water and steam circuits of turbine plants are greatly influenced by integral economy account, i.e. efficiency indexes account under variable conditions of power unit operation. From variants of water and steam circuits of the K-1000-68/1500 turbine plant considered preference is given to the variant with four low pressure heaters with increased up to 1.25 MPa pressure in a deacrator without high pressure heater with pumping intermediate steam superheater condensate into feedwater circuit

  1. Steam condensation induced water hammer in a vertical up-fill configuration within an integral test facility. Experiments and computational simulations

    Energy Technology Data Exchange (ETDEWEB)

    Dirndorfer, Stefan

    2017-01-17

    Condensation induced water hammer is a source of danger and unpredictable loads in pipe systems. Studies concerning condensation induced water hammer were predominantly made for horizontal pipes, studies concerning vertical pipe geometries are quite rare. This work presents a new integral test facility and an analysis of condensation induced water hammer in a vertical up-fill configuration. Thanks to the state of the art technology, the phenomenology of vertical condensation induced water hammer can be analysed by means of sufficient high-sampled experimental data. The system code ATHLET is used to simulate UniBw condensation induced water hammer experiments. A newly developed and implemented direct contact condensation model enables ATHLET to calculate condensation induced water hammer. Selected experiments are validated by the modified ATHLET system code. A sensitivity analysis in ATHLET, together with the experimental data, allows to assess the performance of ATHLET to compute condensation induced water hammer in a vertical up-fill configuration.

  2. Steam condensation induced water hammer in a vertical up-fill configuration within an integral test facility. Experiments and computational simulations

    International Nuclear Information System (INIS)

    Dirndorfer, Stefan

    2017-01-01

    Condensation induced water hammer is a source of danger and unpredictable loads in pipe systems. Studies concerning condensation induced water hammer were predominantly made for horizontal pipes, studies concerning vertical pipe geometries are quite rare. This work presents a new integral test facility and an analysis of condensation induced water hammer in a vertical up-fill configuration. Thanks to the state of the art technology, the phenomenology of vertical condensation induced water hammer can be analysed by means of sufficient high-sampled experimental data. The system code ATHLET is used to simulate UniBw condensation induced water hammer experiments. A newly developed and implemented direct contact condensation model enables ATHLET to calculate condensation induced water hammer. Selected experiments are validated by the modified ATHLET system code. A sensitivity analysis in ATHLET, together with the experimental data, allows to assess the performance of ATHLET to compute condensation induced water hammer in a vertical up-fill configuration.

  3. ORCENT-2, Full Load Steam Turbine Cycle Thermodynamics for LWR Power Plant

    International Nuclear Information System (INIS)

    Fuller, L.C.

    1979-01-01

    1 - Description of problem or function: ORCENT-2 performs heat and mass balance calculations at valves-wide-open design conditions, maximum guaranteed rating conditions, and an approximation of part-load conditions for steam turbine cycles supplied with throttle steam, characteristic of contemporary light-water reactors. The program handles both condensing and back-pressure turbine exhaust arrangements. Turbine performance calculations are based on the General Electric Company method for 1800-rpm large steam turbine- generators operating with light-water-cooled nuclear reactors. Output includes all information normally shown on a turbine-cycle heat balance diagram. 2 - Method of solution: The turbine performance calculations follow the procedures outlined in General Electric report GET-6020. ORCENT-2 utilizes the 1967 American Society of Mechanical Engineers (ASME) formulations and procedures for calculating the properties of steam, adapted for ORNL use by D.W. Altom. 3 - Restrictions on the complexity of the problem: Maxima of: 12 feed-water heaters, 5 moisture removal stages in the low-pressure turbine section. ORCENT-2 is limited to 1800-rpm tandem-compound turbine-generators with single- or double-flow high pressure sections and one, two, or three double-flow low-pressure turbine sections. Steam supply for LWR cycles should be between 900 and 1100 psia and slightly wet to 100 degrees F of initial superheat. Generator rating should be greater than 100 MVA

  4. Numerical simulation of gas-liquid two-phase flow behavior with condensation heat transfer

    International Nuclear Information System (INIS)

    Takamori, Kazuhide; Murase, Michio; Baba, Yoshikazu; Aihara, Tsuyoshi.

    1995-01-01

    In this study, condensation heat transfer experiments were performed in order to verify a condensation heat transfer model coupled with a three-dimensional two-phase flow analysis. In the heat transfer model, the liquid film flow rate on the heat transfer tubes was calculated by a mass balance equation and the liquid film thickness was calculated from the liquid film flow rate using Nusselt's laminar flow model and Fujii's equation for steam velocity effect. In the experiments, 112 horizontal staggered tubes with an outer diameter of 16 mm and length of 0.55 m were used. Steam and spray water were supplied to the test section, and inlet quality was controlled by the spray water flow rate. The temperature was 100degC and the pressure was 0.1 MPa. The overall heat transfer coefficients were measured for inlet quality of 13-100%. From parameter calculations for the falling liquid film ratio from the upper tubes to the lower tubes, the calculated overall heat transfer coefficients agreed with the data to within ±5% at the falling liquid film ratio of 0.7. (author)

  5. Stable-isotope geochemistry of the Pierina high-sulfidation Au-Ag deposit, Peru: Influence of hydrodynamics on SO42--H2S sulfur isotopic exchange in magmatic-steam and steam-heated environments

    Science.gov (United States)

    Fifarek, R.H.; Rye, R.O.

    2005-01-01

    The Pierina high-sulfidation Au-Ag deposit formed 14.5 my ago in rhyolite ash flow tuffs that overlie porphyritic andesite and dacite lavas and are adjacent to a crosscutting and interfingering dacite flow dome complex. The distribution of alteration zones indicates that fluid flow in the lavas was largely confined to structures but was dispersed laterally in the tuffs because of a high primary and alteration-induced permeability. The lithologically controlled hydrodynamics created unusual fluid, temperature, and pH conditions that led to complete SO42--H2S isotopic equilibration during the formation of some magmatic-steam and steam-heated alunite, a phenomenon not previously recognized in similar deposits. Isotopic data for early magmatic hydrothermal and main-stage alunite (??34S=8.5??? to 31.7???; ??18 OSO4=4.9??? to 16.5???; ??18 OOH=2.2??? to 14.4???; ??D=-97??? to -39???), sulfides (??34 S=-3.0??? to 4.3???), sulfur (??34S=-1.0??? to 1.1???), and clay minerals (??18O=4.3??? to 12.5???; ??D=-126??? to -81???) are typical of high-sulfidation epithermal deposits. The data imply the following genetic elements for Pierina alteration-mineralization: (1) fluid and vapor exsolution from an I-type magma, (2) wallrock buffering and cooling of slowing rising vapors to generate a reduced (H2S/SO4???6) highly acidic condensate that mixed with meteoric water but retained a magmatic ??34S???S signature of ???1???, (3) SO2 disproportionation to HSO4- and H2S between 320 and 180 ??C, and (4) progressive neutralization of laterally migrating acid fluids to form a vuggy quartz???alunite-quartz??clay???intermediate argillic???propylitic alteration zoning. Magmatic-steam alunite has higher ??34S (8.5??? to 23.2???) and generally lower ??18OSO4 (1.0 to 11.5???), ??18OOH (-3.4 to 5.9???), and ??D (-93 to -77???) values than predicted on the basis of data from similar occurrences. These data and supporting fluid-inclusion gas chemistry imply that the rate of vapor ascent for this

  6. Development of a test device to characterize thermal protective performance of fabrics against hot steam and thermal radiation

    International Nuclear Information System (INIS)

    Su, Yun; Li, Jun

    2016-01-01

    Steam burns severely threaten the life of firefighters in the course of their fire-ground activities. The aim of this paper was to characterize thermal protective performance of flame-retardant fabrics exposed to hot steam and low-level thermal radiation. An improved testing apparatus based on ASTM F2731-11 was developed in order to simulate the routine fire-ground conditions by controlling steam pressure, flow rate and temperature of steam box. The thermal protective performance of single-layer and multi-layer fabric system with/without an air gap was studied based on the calibrated tester. It was indicated that the new testing apparatus effectively evaluated thermal properties of fabric in hot steam and thermal radiation. Hot steam significantly exacerbated the skin burn injuries while the condensed water on the skin’s surface contributed to cool down the skin tissues during the cooling. Also, the absorbed thermal energy during the exposure and the cooling was mainly determined by the fabric’s configuration, the air gap size, the exposure time and the existence of hot steam. The research provides a effective method to characterize the thermal protection of fabric in complex conditions, which will help in optimization of thermal protection performance of clothing and reduction of steam burn. (paper)

  7. Natural draft dry-type cooling tower for steam power plants

    International Nuclear Information System (INIS)

    Nasser, G.

    1976-01-01

    The task to build natural-draught dry cooling towers for large steam power plants as simple, compact, and economical as possible may be achieved by a combination of known features with the aid of the present application: the condenser elements built as piles of corrugated plates are arranged in the form of a truncated pyramid widened towards the top. For the cooling-air flow inlet openings for hot gas supplied from the lower part of the dome are provided. (UWI) [de

  8. Prediction of Heat Removal Capacity of Horizontal Condensation Heat Exchanger submerged in Pool

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Seong-Su; Hong, Soon-Joon [FNC Tech., Yongin (Korea, Republic of); Cho, Hyoung-Kyu [Seoul National University, Seoul (Korea, Republic of); Park, Goon-Cherl [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    As representative passive safety systems, there are the passive containment cooling system (PCCS) of ESBWR, the emergency condenser system (ECS) of the SWR-1000, the passive auxiliary feed-water system (PAFS) of the APR+ and etc. During the nuclear power plant accidents, these passive safety systems can cool the nuclear system effectively via the heat transfer through the steam condensation, and then mitigate the accidents. For the optimum design and the safety analysis of the passive safety system, it is essential to predict the heat removal capacity of the heat exchanger well. The heat removal capacity of the horizontal condensation heat exchanger submerged in a pool is determined by a combination of a horizontal in-tube condensation heat transfer and a boiling heat transfer on the horizontal tube. Since most correlations proposed in the previous nuclear engineering field were developed for the vertical tube, there is a certain limit to apply these correlations to the horizontal tube. Therefore, this study developed the heat transfer model for the horizontal Ushaped condensation heat exchanger submerged in a pool to predict well the horizontal in-tube condensation heat transfer, the boiling heat transfer on the horizontal tube and the overall heat removal capacity of the heat exchanger using the best-estimate system analysis code, MARS.

  9. 3D PORFLO simulations of Loviisa steam generator

    International Nuclear Information System (INIS)

    Hovi, V.; Ilvonen, M.

    2010-01-01

    PORFLO is a 3-dimensional two-phase flow solver for porous media, developed at VTT originally by Jaakko Miettinen and now mainly by the author Ville Hovi. It is targeted at applications where 3D phenomena may be significant, but geometrical complexity does not allow for a CFD-style structure-fitted grid, such as steam generators and other heat exchangers, reactor cores or core debris beds. Basic features of PORFLO include staggered Cartesian grid and iterative solution of pressure and phase velocities (phase-coupled SIMPLE) based on 3D momentum equations, together with mass and energy equations, all for both liquid and vapour. A PORFLO model of the secondary side of a WWER-440 horizontal steam generator was developed and some preliminary simulations of its steady state operation were performed. To generate the necessary boundary condition on the primary tubes, an APROS system code model was used, from which a simple unidirectional transfer brings the tube surface temperatures to PORFLO. Feedwater is modelled by mass sources at the injection tube, with no consideration of its momentum. In the interphasial mass transfer, evaporation and condensation are considered in the bulk sense and due to the primary tubes. In momentum transfer, the interphasial drag and the drag caused by the tube bundles are modelled according to. Results of the PORFLO simulations presented here, typically in a 109 x 30 x 30 grid, include liquid and vapour velocities, void fractions and evaporation / condensation rates. Furthermore, some comparisons of PORFLO and Fluent results were made. (Authors)

  10. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

  11. On the adequacy of wall functions to predict condensation rates from steam-noncondensable gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Dehbi, A., E-mail: abdel.dehbi@psi.ch

    2013-12-15

    Highlights: • Work investigates the effect of near-wall mesh resolution on CFD predictions. • Case study: turbulent condensation in the presence of noncondensable gases. • Wall functions largely underpredict condensation rates at boundary layer onset. • When boundary layer is developed, wall functions predictions are reasonable. • Prescribed wall functions must be compatible with prevailing flow regime. - Abstract: As one looks forward to applying CFD based methods to simulate turbulent flows in larger volumes up to containment scales, the mesh resolution, especially near the walls, becomes one of the main issues dictating the feasibility of the simulation. The wall-function approach is a natural choice to minimize the computational size of the problem and make it tractable. In the current investigation, we compare the wall-function to the fully resolved boundary layer approaches for the prediction of vapor condensation rates on cold walls in the presence of noncondensable gases. We simulate three sets of geometric configurations. The first two sets relate to domains which are small (height of 2 m) and medium (height 4.8 m), and for which experimental heat transfer data are available. In the third set, we look at a hypothetical large 2D rectangular domain in which the condenser height is comparable to that of typical NPP containments (20 m). In the developing region of the boundary layer, it is found that the wall function treatment leads to substantial deviations from the wall resolved approach and available experimental data. Further downstream, however, when the boundary layer is fully developed, the discrepancy is greatly reduced. It is therefore concluded that the wall-function formulation is able to provide predictions of condensation rates that are similar to wall-resolved treatments in simple forced flows for which fully developed boundary layers can be assumed over most of the domain. Care must however be exercised to ensure the chosen wall

  12. Researches of a thermodynamic behaviour of bubbling vacuum system bubble condenser NPP 'Mochovce'

    International Nuclear Information System (INIS)

    Rjeznikov, Iu.V.; Lifshitz, E.V.; Kouznetsov, M.V.; Antropov, V. N.; Doulepov, U. N.; Suchanek, M.

    1997-01-01

    During joint development and designing of the bubbling vacuum system (BVS) equipment for localization of under-loss of coolant accident (LOCA) consequences on NPPs with WWER 440/213, a large volume of experimental and calculational activities have been performed by VTI and SverdNIIchimmash for the substantiation of functionality of this system, and in particular, for bubbler-condenser (BC) design, as a part of BVS. However, not looking on broad introduction of BVS on 16-th NPP units with WWER 440/213, its functionality was subjected to a doubt from experts of different countries. Sequentially, that promoted issue of the IAEA, document and OECD document. Therefore, before commissioning of the NPP 'Mochovce' unit 1 it was decided to execute additional experimental and computational researches for Safety Analysis Report preparation. Within the framework of these BVS thermodynamic behavior researches, in particular the following problems were chosen: (1) The check of a capability of valves DN 250 blocking in an opened position, as a result of return pressure differential on BC, during vent clearing process of the hydro-lock, that can sequentially result in an a drop of efficiency of stem condensation in BC pool; (2) To provide by direct measurements the absence of pressure oscillations dangerous for strength of a BC design in different modes of steam condensation in BC and to execute computational researches of instability of steam condensation processes (for such mode as 'chugging'); (3) Study influences of pool swell and water carry over through check valves DN 500 in the air traps on a BVS functionality; (4) To determine by a computational way the maximum pressure in NPP premises during LOCA, with taking into consideration additional failures of the BC equipment: absence of a water on two and more BC plates and DN 250 valves have blocked in an opened position (conservative conditions). (authors)

  13. Methods of Thermal Calculations for a Condensing Waste-Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Rączka Paweł

    2014-12-01

    Full Text Available The paper presents the algorithms for a flue gas/water waste-heat exchanger with and without condensation of water vapour contained in flue gas with experimental validation of theoretical results. The algorithms were used for calculations of the area of a heat exchanger using waste heat from a pulverised brown coal fired steam boiler operating in a power unit with a capacity of 900 MWe. In calculation of the condensing part, the calculation results obtained with two algorithms were compared (Colburn-Hobler and VDI algorithms. The VDI algorithm allowed to take into account the condensation of water vapour for flue gas temperatures above the temperature of the water dew point. Thanks to this, it was possible to calculate more accurately the required heat transfer area, which resulted in its reduction by 19 %. In addition, the influence of the mass transfer on the heat transfer area was taken into account, which contributed to a further reduction in the calculated size of the heat exchanger - in total by 28% as compared with the Colburn-Hobler algorithm. The presented VDI algorithm was used to design a 312 kW pilot-scale condensing heat exchanger installed in PGE Belchatow power plant. Obtained experimental results are in a good agreement with calculated values.

  14. Modeling bubble condenser containment with computer code COCOSYS: post-test calculations of the main steam line break experiment at ELECTROGORSK BC V-213 test facility

    International Nuclear Information System (INIS)

    Lola, I.; Gromov, G.; Gumenyuk, D.; Pustovit, V.; Sholomitsky, S.; Wolff, H.; Arndt, S.; Blinkov, V.; Osokin, G.; Melikhov, O.; Melikhov, V.; Sokoline, A.

    2005-01-01

    Containment of the WWER-440 Model 213 nuclear power plant features a Bubble Condenser, a complex passive pressure suppression system, intended to limit pressure rise in the containment during accidents. Due to lack of experimental evidence of its successful operation in the original design documentation, the performance of this system under accidents with ruptures of large high-energy pipes of the primary and secondary sides remains a known safety concern for this containment type. Therefore, a number of research and analytical studies have been conducted by the countries operating WWER-440 reactors and their Western partners in the recent years to verify Bubble Condenser operation under accident conditions. Comprehensive experimental research studies at the Electrogorsk BC V-213 test facility, commissioned in 1999 in Electrogorsk Research and Engineering Centre (EREC), constitute essential part of these efforts. Nowadays this is the only operating large-scale facility enabling integral tests on investigation of the Bubble Condenser performance. Several large international research projects, conducted at this facility in 1999-2003, have covered a spectrum of pipe break accidents. These experiments have substantially improved understanding of the overall system performance and thermal hydraulic phenomena in the Bubble Condenser Containment, and provided valuable information for validating containment codes against experimental results. One of the recent experiments, denoted as SLB-G02, has simulated steam line break. The results of this experiment are of especial value for the engineers working in the area of computer code application for WWER-440 containment analyses, giving an opportunity to verify validity of the code predictions and identify possibilities for model improvement. This paper describes the results of the post-test calculations of the SLB-G02 experiment, conducted as a joint effort of GRS, Germany and Ukrainian technical support organizations for

  15. Calculation of Steam Volume Fraction in Subcooled Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, S Z

    1967-06-15

    An analysis of subcooled boiling is presented. It is assumed that heat is removed by vapor generation, heating of the liquid that replaces the detached bubbles, and to some extent by single phase heat transfer. Two regions of subcooled boiling are considered and a criterion is provided for obtaining the limiting value of subcooling between the two regions. Condensation of vapor in the subcooled liquid is analysed and the relative velocity of vapor with respect to the liquid is neglected in these regions. The theoretical arguments result in some equations for the calculation of steam volume fraction and true liquid subcooling.

  16. Condensation during gravity driven ECC: Experiments with PACTEL

    Energy Technology Data Exchange (ETDEWEB)

    Munther, R.; Kalli, H. [Lappeenranta Univ. of Technology (Finland); Kouhia, J. [Technical Research Centre of Finland, Lappeenranta (Finland)

    1995-09-01

    This paper provides the results of the second series of gravity driven emergency core cooling (ECC) experiments with PACTEL (Parallel Channel Test Loop). The simulated accident was a small break loss-of-coolant accident (SBLOCA) with a break in a cold leg. The ECC flow was provided from a core makeup tank (CMT) located at a higher elevation than the main part of the primary system. The CMT was pressurized with pipings from the pressurizer and a cold leg. The tests indicated that steam condensation in the CMT can prevent ECC and lead to core uncovery.

  17. Calculations of condensed moisture escape from a NPP spray pond

    International Nuclear Information System (INIS)

    Bratuta, Eh. G.; Yaroshenko, T.I.

    1988-01-01

    A method for calculating water losses due to condensed moisture escape with a wind away from a spray pond used for cooling steam turbine condensator water and emergency nuclear reactor cooling is developed. The method is based on solving a three-dimensional equation of single drop motion, assuming that during the whole flight only gravity and aerodynamic resistance forces act on a drop. The basic parameter variation ranges are the following: 0-18 m/s wind velocity, 0.04-0.12 MPa pressure drop at the nozzle output, 1-2 m height of sprayers above the pond mirror. The given method permits to determine both the amount of circulation water loss and the local liquid flow rate distribution pattern as well as the area around the pond receiving the escaped moisture that is necessary for estimating the ecological situation near a NPP

  18. Steam turbine cycle

    International Nuclear Information System (INIS)

    Okuzumi, Naoaki.

    1994-01-01

    In a steam turbine cycle, steams exhausted from the turbine are extracted, and they are connected to a steam sucking pipe of a steam injector, and a discharge pipe of the steam injector is connected to an inlet of a water turbine. High pressure discharge water is obtained from low pressure steams by utilizing a pressurizing performance of the steam injector and the water turbine is rotated by the high pressure water to generate electric power. This recover and reutilize discharged heat of the steam turbine effectively, thereby enabling to improve heat efficiency of the steam turbine cycle. (T.M.)

  19. Transient Performance of Air-cooled Condensing Heat Exchanger in Long-term Passive Cooling System during Decay Heat Load

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Hee Joon [Kookmin University, Seoul (Korea, Republic of); Moon, Joo Hyung; Bae, Youngmin; Kim, Young-In [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    In the event of a 'loss of coolant accident'(LOCA) and a non-LOCA, the secondary passive cooling system would be activated to cool the steam in a condensing heat exchanger that is immersed in an emergency cooldown tank (ECT). Currently, the capacities of these ECTs are designed to be sufficient to remove the sensible and residual heat from the reactor coolant system for 72 hours after the occurrence of an accident. After the operation of a conventional passive cooling system for an extended period, however, the water level falls as a result of the evaporation from the ECT, as steam is emitted from the open top of the tank. Therefore, the tank should be refilled regularly from an auxiliary water supply system when the system is used for more than 72 hours. Otherwise, the system would fail to dissipate heat from the condensing heat exchanger due to the loss of the cooling water. Ultimately, the functionality of the passive cooling system would be seriously compromised. As a passive means of overcoming the water depletion in the tank, Kim et al. applied for a Korean patent covering the concept of a long-term passive cooling system for an ECT even after 72 hours. This study presents transient performance of ECT with installing air-cooled condensing heat exchanger under decay heat load. The cooling capacity of an air-cooled condensing heat exchanger was evaluated to determine its practicality.

  20. Evaluation of anticipatory signal to steam generator pressure control program for 700 MWe Indian pressurized heavy water reactor

    International Nuclear Information System (INIS)

    Pahari, S.; Hajela, S.; Rammohan, H. P.; Malhotra, P. K.; Ghadge, S. G.

    2012-01-01

    700 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is horizontal channel type reactor with partial boiling at channel outlet. Due to boiling, it has a large volume of vapor present in the primary loops. It has two primary loops connected with the help of pressurizer surge line. The pressurizer has a large capacity and is partly filled by liquid and partly by vapor. Large vapor volume improves compressibility of the system. During turbine trip or load rejection, pressure builds up in Steam Generator (SG). This leads to pressurization of Primary Heat Transport System (PHTS). To control pressurization of SG and PHTS, around 70% of the steam generated in SG is dumped into the condenser by opening Condenser Steam Dump Valves (CSDVs) and rest of the steam is released to the atmosphere by opening Atmospheric Steam Discharge Valves (ASDVs) immediately after sensing the event. This is accomplished by adding anticipatory signal to the output of SG pressure controller. Anticipatory signal is proportional to the thermal power of reactor and the proportionality constant is set so that SG pressure controller's output jacks up to ASDV opening range when operating at 100% FP. To simulate this behavior for 700 MWe IPHWR, Primary and secondary heat transport system is modeled. SG pressure control and other process control program have also been modeled to capture overall plant dynamics. Analysis has been carried out with 3-D neutron kinetics coupled thermal hydraulic computer code ATMIKA.T to evaluate the effect of the anticipatory signal on PHT pressure and over all plant dynamics during turbine trip in 700 MWe IPHWR. This paper brings out the results of the analysis with and without considering anticipatory signal in SG pressure control program during turbine trip. (authors)

  1. Flow-induced vibration analysis of heat exchanger and steam generator designs

    International Nuclear Information System (INIS)

    Pettigrew, M.J.; Sylvestre, Y.; Campagna, A.O.

    1977-08-01

    Tube and shell heat exchange components such as steam generators, heat exchangers and condensers are essential parts of CANDU nuclear power stations. Excessive flow-induced vibration may cause tube failures by fatigue or more likely by fretting-wear. Such failures may lead to station shutdowns that are very undesirable in terms of lost production. Hence good performance and reliability dictate a thorough flow-induced vibration analysis at the design stage. This paper presents our approach and techniques in this respect. (author)

  2. Energy Analysis of Cascade Heating with High Back-Pressure Large-Scale Steam Turbine

    Directory of Open Access Journals (Sweden)

    Zhihua Ge

    2018-01-01

    Full Text Available To reduce the exergy loss that is caused by the high-grade extraction steam of traditional heating mode of combined heat and power (CHP generating unit, a high back-pressure cascade heating technology for two jointly constructed large-scale steam turbine power generating units is proposed. The Unit 1 makes full use of the exhaust steam heat from high back-pressure turbine, and the Unit 2 uses the original heating mode of extracting steam condensation, which significantly reduces the flow rate of high-grade extraction steam. The typical 2 × 350 MW supercritical CHP units in northern China were selected as object. The boundary conditions for heating were determined based on the actual climatic conditions and heating demands. A model to analyze the performance of the high back-pressure cascade heating supply units for off-design operating conditions was developed. The load distributions between high back-pressure exhaust steam direct supply and extraction steam heating supply were described under various conditions, based on which, the heating efficiency of the CHP units with the high back-pressure cascade heating system was analyzed. The design heating load and maximum heating supply load were determined as well. The results indicate that the average coal consumption rate during the heating season is 205.46 g/kWh for the design heating load after the retrofit, which is about 51.99 g/kWh lower than that of the traditional heating mode. The coal consumption rate of 199.07 g/kWh can be achieved for the maximum heating load. Significant energy saving and CO2 emission reduction are obtained.

  3. Condensation induced water hammer (CIWH). Relevance in the nuclear industry and state of science and technology

    Energy Technology Data Exchange (ETDEWEB)

    Swidersky, Harald [TUeV Sued Industrie Service GmbH, Muenchen (Germany)

    2013-03-15

    Condensation-induced water hammers (CIWH) are consequences of rapid condensation of steam in partially filled pipes. They present a particular hazard potential, as they seem to occur spontaneously and out of stagnation. The entire process still eludes a secured analytical or numerical predictability and determination of the fluid dynamic loads. The simulation of these processes is one of the most difficult tasks of thermal hydraulic transient analyses. Condensation induced water hammers in plants - mostly power plants - can lead to significant costs if they result in long downtimes, detailed analyses and upgrades. In this contribution, the phenomenon CIWH is explained and the relevance for nuclear engineering will be discussed. An outlook on the actual requirements of regulatory guidelines and the state of science and technology will be given. (orig.)

  4. Condensation induced water hammer (CIWH). Relevance in the nuclear industry and state of science and technology

    International Nuclear Information System (INIS)

    Swidersky, Harald

    2013-01-01

    Condensation-induced water hammers (CIWH) are consequences of rapid condensation of steam in partially filled pipes. They present a particular hazard potential, as they seem to occur spontaneously and out of stagnation. The entire process still eludes a secured analytical or numerical predictability and determination of the fluid dynamic loads. The simulation of these processes is one of the most difficult tasks of thermal hydraulic transient analyses. Condensation induced water hammers in plants - mostly power plants - can lead to significant costs if they result in long downtimes, detailed analyses and upgrades. In this contribution, the phenomenon CIWH is explained and the relevance for nuclear engineering will be discussed. An outlook on the actual requirements of regulatory guidelines and the state of science and technology will be given. (orig.)

  5. Steam generator tube performance: world experience with water-cooled nuclear power reactors during 1979

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1981-01-01

    The performance of steam generator tubes in water-cooled nuclear power reactors is reviewed for 1979. Tube failures occurred at 38 of the 93 reactors surveyed. The causes of these failures and the procedures designed to deal with them are described. The defect rate, although higher than that in 1978, was still lower than the rates of the two previous years. Methods being employed to detect defects include the increased use of multifrequency eddy-current testing and a trend to full-length inspection of all tubes. To reduce the incidence of tube failure by corrosion, plant operators are turning to full-flow condensate demineralization and more leak-resistant condenser tubes. 10 tables

  6. Corrosion of the CANDU steam generator tubesheet due to aqueous environment pH

    International Nuclear Information System (INIS)

    Lucan, D.; Fulger, M.; Velciu, L.

    2009-01-01

    There is a side environment that is known to be affected significantly by several factors dependent on the balance of plant conditions (condenser leaks, condensate polishing, and coolant system materials) as well on the operational conditions, particularly through their thermal-hydraulic effects. The presence of tube-tubesheet crevices and restricted flow areas within sludge or surface deposits provides for local concentration sites for various impurities, including the acidic ones. The generalized corrosion can occur and can affect the steam generator performances. It is very important to understand the generalized corrosion mechanism with the purpose of evaluating the amount of corrosion products which exist in the steam generator after a determined period of operation. The purpose of this work consists in the assessment of corrosion behavior of the tubesheet material (carbon steel SA508 cl.2) at normal secondary circuit parameters (temperature, 260 deg. C, pressure, 5.1 MPa). The testing environment was the demineralized water without impurities, at different pH values regulated with morpholine and cyclohexylamine (all volatile treatment - AVT). The results are presented like micrographs, potentiodynamic curves and graphics representing loss of metal by corrosion, corrosion rate, the total corrosion products, the adherent corrosion products, the released corrosion products and the release of the metal. (authors)

  7. Simulation of the condensation experiment for the SG primary of SMART with MIDAS/SMR

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Hwa; Kim, Dong Ha; Chung, Young Jong; Park, Sun Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seong Won [Korea Radiation Technology Institute Co., Daejeon (Korea, Republic of)

    2012-05-15

    SMART is new concept of reactor that all the main components such as the steam generator, the coolant pumps and the pressurizer are located inside the reactor vessel. MIDAS/SMR V1.0.3 code has been used for estimating the severe accident from SMART. SMART has the SG tube with helical shape that is different from that of PWR. MIDAS code has the condensation model for the both sides of surfaces from the various kinds of geometry. But it does not have the condensation model for the helical type of tube. In this study, the condensation experiment for the outer surface of the SG tube in SMART that was performed by Po-Hang university was simulated with MIDAS/SMR under the assumption of straight pipe. The simulation results showed well predictions of the amount of heat removal from the SG tube primary side and thermal hydraulic parameters

  8. Simulation of the condensation experiment for the SG primary of SMART with MIDAS/SMR

    International Nuclear Information System (INIS)

    Park, Jong Hwa; Kim, Dong Ha; Chung, Young Jong; Park, Sun Hee; Cho, Seong Won

    2012-01-01

    SMART is new concept of reactor that all the main components such as the steam generator, the coolant pumps and the pressurizer are located inside the reactor vessel. MIDAS/SMR V1.0.3 code has been used for estimating the severe accident from SMART. SMART has the SG tube with helical shape that is different from that of PWR. MIDAS code has the condensation model for the both sides of surfaces from the various kinds of geometry. But it does not have the condensation model for the helical type of tube. In this study, the condensation experiment for the outer surface of the SG tube in SMART that was performed by Po-Hang university was simulated with MIDAS/SMR under the assumption of straight pipe. The simulation results showed well predictions of the amount of heat removal from the SG tube primary side and thermal hydraulic parameters

  9. The status of the Bubbler Condenser Containment System for the Reactors of the VVER-440/213 Type

    International Nuclear Information System (INIS)

    Karwat, H.; Rosinger, H.E.

    1998-01-01

    VVER-440/213 Pressurized Water Reactors have a pressure-suppression containment structure called a 'Bubbler Condenser' tower which can reduce the design pressure of the entire containment following a design basis accident (DBA), such as a loss-of-coolant accident (LOCA). The bubbler condenser pressure suppression system provides reduction of the LOCA containment pressure by the condensation of released steam in a water pool. World-wide there are 14 nuclear power plants of the VVER-440/213 type in Eastern Europe and Russia. One of the safety concerns for the VVER-440/213 reactors relates to the ability of the bubbler condenser containment system to function satisfactorily and to maintain its integrity following certain postulated accidents and thus limit the release of radioactive material to the environment. The complicated geometry of the bubbler condenser unit, and the dependence on several moving devices and interlocks are the main doubts expressed by different specialists with regard to the design. General description of the bubbler condenser containment system, the physical processes, concerns and design assessment of the bubbler condenser containment system, presentation of the OECD's Unified Bubbler Condenser Research Project (UBCRP) and the European Commission PHARE/TACIS project. Recent utility investigations are also discussed

  10. Study of the Dynamics of a Condensing Bubble Using Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    Shahnawaz Ahmed

    2015-06-01

    Full Text Available Mesoscopic lattice Boltzmann method (LBM is used to discretize the governing equations for a steam bubble inside a tube filled with water. The bubbles are kept at higher temperature compared to its boiling point while the liquid is kept subcooled. Heat transfer is allowed to take place between the two phases by virtue of which the bubble will condense. Three separate probability distribution functions are used in LBM to handle continuity, momentum and energy equations separately. The interface is considered to be diffused within a narrow zone and it has been modeled using convective Cahn-Hillard equation. Combined diffused interface-LBM framework is adapted accordingly to handle complex interface separating two phases having high density ratio. Developed model is validated with respect to established correlations for instantaneous equivalent radius of a spherical condensing bubble. Numerical snapshots of the simulation depict that the bubble volume decreases faster for higher degree of superheat. The degrees of superheat are varied over a wide range to note its effect on bubble shape and size. Effect of initial volume of the bubble on the condensation rate is also studied. It has been observed that for a fixed degree of superheat, the condensation rate is not exactly proportional to its volume. Due to the variation in interfacial configuration for different sized bubbles, condensation rate changes drastically. Influence of gravity on the rate of condensation is also studied using the developed methodology.

  11. An Improved Steam Injection Model with the Consideration of Steam Override

    OpenAIRE

    He , Congge; Mu , Longxin; Fan , Zifei; Xu , Anzhu; Zeng , Baoquan; Ji , Zhongyuan; Han , Haishui

    2017-01-01

    International audience; The great difference in density between steam and liquid during wet steam injection always results in steam override, that is, steam gathers on the top of the pay zone. In this article, the equation for steam override coefficient was firstly established based on van Lookeren’s steam override theory and then radius of steam zone and hot fluid zone were derived according to a more realistic temperature distribution and an energy balance in the pay zone. On this basis, th...

  12. A porous media calculation for the isolation condenser heat transfer and circulation

    International Nuclear Information System (INIS)

    Jaakko, Miettinen; Ismo, Karppinen

    2003-01-01

    In the development of advanced light water reactors, thermohydraulic phenomena are versatile in comparison with the present concepts. The new features include, for example, passive safety systems, where energy transport takes place by natural circulation instead of forced flow. In the isolation condenser, the steam generated in the reactor vessel is conduced into the heat transfer tubes. The tube bundle has been submerged into a large water pool, where the heat flux through the tube wall initially is heating the subcooled water, but rather soon boiling take place. The temperature differences and void fraction in the pool create large two-phase circulation. For modeling of the entire condenser a combined application of two types of simulation models has been selected. For the whole geometry, a porous media solution has been developed, where the existence of the heat transfer tubes in the water pool and their heat generation is described by the porous media approach. The 3-dimensional solution of two-phase equations is based on the drift-flux formalism. The condensation and liquid film generation inside the heat transfer tube is modelled using a 1-dimensional model considering the steam core, liquid film and heat transfer tube. The heat flux through the tube wall defines the boundary conditions for the water pool. Parallel to the porous media development for the entire process facility, the phase change models have been improved for Fluent 6 mixture model, and the code is used for analysing in detail the heat transfer around the tubing. The purpose in the analyses is to obtain more detailed information of the flow field and vapour distribution around the tube bundle. By combining the porous media model for the entire facility, with the CFD models for the two-phase flow details around the heat transfer tubes and experimental studies the most important mechanisms around the condensation pool can be gathered. In this context the porous media model is considered. (author)

  13. Possibility of revitalization of control system of steam turbine 210 MW LMZ

    International Nuclear Information System (INIS)

    Racki, Branko

    2004-01-01

    It is a one-shaft, three casing condensing turbine, type K-210-130. A rigid coupling connects it directly to the electric energy generator. There is one intermediate superheat of steam and seven non regulated blending for regenerative condensate heating. A considerate number of such turbines have been used on the territory of the Eastern Europe. There are two blocks installed in TP Sisak, Croatia. There is a survey of the existing control system of turbine, power 210 MW. It points out and describes problems appearing during exploitation. Technical solutions according to complexity of realization have been described. It gives an overview of minimum range of modification with utilization of the existing oil system and maximum range by adding separate high pressure oil system with new solutions for performing segments. (Author)

  14. Imaging optical probe for pressurized 6200K steam-water environment

    International Nuclear Information System (INIS)

    Donaldson, M.R.; Pulfrey, R.E.; Merrill, S.K.

    1979-01-01

    An air-cooled imaging optical probe, 0.3 m long with a 25.4-mm outside diameter, has been built to provide high resolution viewing of flow regimes in a steam-water environment at 620 0 K and 15.5 MPa. The probe consists of a 3.5-mm-diameter rod lens borescope, surrounded by two coaxial coolant flow channels and two coaxial insulating dead air spaces. With air flowing through the probe at 5.7 g/s, thermal analysis shows that no part of the optical borescope will exceed 366 0 K when the probe is immersed in a 620 0 K environment. The objective lens is protected by a sapphire window which tests have shown can survive over 200 hours in 620 0 K water or steam with negligible loss of resolution and contrast. Condensation on the protective window is boiled off by electrically heating the window. Computer stress analysis, plus actual tests, shows that the probe can operate successfully with conservative safety factors

  15. Computer calculations of air and steam blowdown suppression

    International Nuclear Information System (INIS)

    Norris, D.M. Jr.; McMaster, W.H.; Landram, C.S.; Quinones, D.F.; Gong, E.Y.; Macken, N.A.

    1980-01-01

    We describe a computer code that combines an Eulerian incompressible-fluid algorithm (SOLA) with a Lagrangian finite-element shell algorithm. The former models the fluid and the latter models the containing structure in an analysis of pressure suppression in boiling-water reactors. The code (PELE-IC) calculates loads and structural response from air blow-down and from the oscillatory condensation of steam bubbles in a water pool. The fluid, structure, and coupling algorithms are tested by recalculating problems that have known analytical solutions, including tank drainage, spherical bubble growth, coupling for circular plates, and submerged cylinder vibration. Code calculations are also compared with the results of small-scale blowdown experiments. (orig.)

  16. Steam turbine installations

    International Nuclear Information System (INIS)

    Bainbridge, A.

    1976-01-01

    The object of the arrangement described is to enable raising steam for driving steam turbines in a way suited to operating with liquid metals, such as Na, as heat transfer medium. A preheated water feed, in heat transfer relationship with the liquid metals, is passed through evaporator and superheater stages, and the superheated steam is supplied to the highest pressure stage of the steam turbine arrangement. Steam extracted intermediate the evaporator and superheater stages is employed to provide reheat for the lower pressure stage of the steam turbine. Only a major portion of the preheated water feed may be evaporated and this portion separated and supplied to the superheater stage. The feature of 'steam to steam' reheat avoids a second liquid metal heat transfer and hence represents a simplification. It also reduces the hazard associated with possible steam-liquid metal contact. (U.K.)

  17. The steam generator repair project of the Donald C. Cook Nuclear Plant, Unit 2

    International Nuclear Information System (INIS)

    White, J.D.

    1993-01-01

    Donald C. Cook Nuclear Plant Unit 2 is part of a two unit nuclear complex located in southwestern Michigan and owned and operated by the Indiana Michigan Power Company. The Cook Nuclear Plant is a pressurized water reactor (PWR) plant with four Westinghouse Series 51 steam generators housed in an ice condenser containment. This paper describes the program undertaken by Indiana Michigan Power and the American Electric Power Service Corporation (AEPSC) to repair the Unit 2 steam generators. (Both Indiana Michigan Power and AEPSC arc subsidiaries of American Electric Power Company, Incorporated (AEP). AEPSC provides management and technical support services to Indiana Michigan Power and the other AEP operating companies.) Eddy current examinations, in a series of refueling and forced outages between November 1983 and July 1986 resulted in 763 (5.6%) plugged tubes. In order to maintain adequate reactor core cooling, a limit of 10% is placed on the allowable percentage of steam generator tubes that can be removed from service by plugging. Additionally, sections of tubes were removed for metallurgical analysis and confirmed that the degradation was due to intergranular stress corrosion cracking. In developing the decision on how to repair the steam generators, four alternative actions were considered for addressing these problems: retubing in place, sleeving, operating at 80% reactor power to lower temperature and thus reduce the rate of corrosion, replacing steam generator lower assemblies

  18. New Czechoslovak detector of leaking condenser tubes usable in both shutdown and reduced output operation of power unit

    International Nuclear Information System (INIS)

    Matal, O.; Klinga, J.; Varvarovsky, F.; Zachar, J.; Fratric, D.

    1986-01-01

    The main reason for penetration of undesirable admixtures from cooling water in the condensate is the inleakage of steam turbine condensers. Briefly assessed are the means and methods of detecting and locating condenser leaks used in the world and in power facilities in Czechoslovakia. Equipment was developed based on measuring the difference between the pressure in a temporarily closed condenser tube and ambient pressure, for leak testing of condenser tubes during operation and during shutdown of WWER-440 units. Two types of the equipment were tested in practice. Type VUEZ-PHN 85P meets the requirements of objective leak tests and those of leak location in condenser tubes and of leak detection in tube expansion in the tube plates of WWER-440 unit condensers, this as concerns sensitivity, the objectivity of results, the cost of tests, and minimal losses of power during the test. Type VUEZ-PHN 85P can be used for leak location in all tube type heat exchangers with access to tube outlets in which under- or overpressure can be achieved in the space between the tubes relative to ambient pressure during the test. (Z.M.) 5 figs., 4 tabs., 11 refs

  19. Generalized modeling of multi-component vaporization/condensation phenomena for multi-phase-flow analysis

    International Nuclear Information System (INIS)

    Morita, K.; Fukuda, K.; Tobita, Y.; Kondo, Sa.; Suzuki, T.; Maschek, W.

    2003-01-01

    A new multi-component vaporization/condensation (V/C) model was developed to provide a generalized model for safety analysis codes of liquid metal cooled reactors (LMRs). These codes simulate thermal-hydraulic phenomena of multi-phase, multi-component flows, which is essential to investigate core disruptive accidents of LMRs such as fast breeder reactors and accelerator driven systems. The developed model characterizes the V/C processes associated with phase transition by employing heat transfer and mass-diffusion limited models for analyses of relatively short-time-scale multi-phase, multi-component hydraulic problems, among which vaporization and condensation, or simultaneous heat and mass transfer, play an important role. The heat transfer limited model describes the non-equilibrium phase transition processes occurring at interfaces, while the mass-diffusion limited model is employed to represent effects of non-condensable gases and multi-component mixture on V/C processes. Verification of the model and method employed in the multi-component V/C model of a multi-phase flow code was performed successfully by analyzing a series of multi-bubble condensation experiments. The applicability of the model to the accident analysis of LMRs is also discussed by comparison between steam and metallic vapor systems. (orig.)

  20. Condensation model for the ESBWR passive condensers

    International Nuclear Information System (INIS)

    Revankar, S. T.; Zhou, W.; Wolf, B.; Oh, S.

    2012-01-01

    In the General Electric's Economic simplified boiling water reactor (GE-ESBWR) the passive containment cooling system (PCCS) plays a major role in containment pressure control in case of an loss of coolant accident. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure following a design basis accident. There are three PCCS condensation modes depending on the containment pressurization due to coolant discharge; complete condensation, cyclic venting and flow through mode. The present work reviews the models and presents model predictive capability along with comparison with existing data from separate effects test. The condensation models in thermal hydraulics code RELAP5 are also assessed to examine its application to various flow modes of condensation. The default model in the code predicts complete condensation well, and basically is Nusselt solution. The UCB model predicts through flow well. None of condensation model in RELAP5 predict complete condensation, cyclic venting, and through flow condensation consistently. New condensation correlations are given that accurately predict all three modes of PCCS condensation. (authors)