Transmutor demo unit and thermal into electrical energy transformation problems

International Nuclear Information System (INIS)

Matal, O.; Fiedler, J.

1999-01-01

In the three circuits layout of the transmutor the heat is transferred from the primary through the secondary circuits by a favourable heat carrier into the tertiary circuit where the thermal into electrical energy transformation in turbo-generator comes into force. Properties as well as parameters of the heat carrier in the secondary circuit affect basically both the conceptual layout of the tertiary circuit and consequently investments costs for its realization and the effectiveness of the transformation of thermal into electrical energy. For several heat carriers considered for the transmutor secondary circuit particular tertiary circuit concepts for the demonstration transmutor unit of approx. 15 W thermal power rate are analyzed, layout features and possibilities of turbogenerator selection are commented and investment costs as well as effectiveness of thermal into electrical energy transformation are estimated. Some of the results are as follows: (i) Heat carrier properties influence thermodynamics of the TDU water/steam cycle substantially. One of the dominant parameters is the melting (freezing) temperature of the heat carrier. (ii) Heat carrier properties influence investment costs of components of the TDU tertiary circuit substantially. Dominantly influenced are costs of the steam generator, steam turbine and high pressure regeneration system. (iii) If the heat carrier has to be a molten salt than a salt with a low melting temperature is recommended to be selected, for example KHF2. (iv) Eutectic alloy Pb-Bi as the heat carrier serves changes to design the TDU with efficient thermodynamics, with acceptable low investment costs of the tertiary as well as secondary circuit components and with an acceptable level of the nuclear safety

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

Impact of a 1,000-foot thermal mixing zone on the steam electric power industry

International Nuclear Information System (INIS)

Veil, J.A.

1994-04-01

Thermal discharge requirements for power plants using once-through cooling systems are based on state water quality standards for temperatures that must be met outside of designated mixing zones. This study evaluates the impact of limiting the extent of thermal mixing zones. This study evaluates the impact of limiting the extent of thermal mixing zones to no more than 1,000 feet from the discharge point. Data were collected from 79 steam electric plants. Of the plants currently using once-through cooling systems, 74% could not meet current thermal standards at the edge of a 1,000-foot mixing zone. Of this total, 68% would retrofit cooling towers, and 6% would retrofit diffusers. The estimated nationwide capital cost for retrofitting plants that could not meet current thermal standards at the edge of a 1,000-foot mixing zone is $21.4 billion. Conversion of a plant from once-through cooling to cooling towers or addition of diffusers would result in a lower energy output from that plant. For the affected plants, the total estimated replacement cost would be $370 to $590 million per year. Some power companies would have to construct new generating capacity to meet the increased energy demand. The estimated nationwide cost of this additional capacity would be $1.2 to $4.8 billion. In addition to the direct costs associated with compliance with a 1,000-foot mixing zone limit, other secondary environmental impacts would also occur. Generation of the additional power needed would increase carbon dioxide emissions by an estimated 8.3 million tons per year. In addition, conversion from once-through cooling systems to cooling towers at affected plants would result in increased evaporation of about 2.7 million gallons of water per minute nationwide

thermal analysis of a small scale solid waste-fired steam boiler

African Journals Online (AJOL)

user

Thermal analysis of a small scale solid waste-fired steam generator is presented in this paper. The analysis was based on the chosen design specifications which are operating steam ... include: wind, bio-energy, geothermal, solar thermal,.

Thermal performance test for steam turbine of nuclear power plants

International Nuclear Information System (INIS)

Bu Yubing; Xu Zongfu; Wang Shiyong

2014-01-01

Through study of steam turbine thermal performance test of CPR1000 nuclear power plant, we solve the enthalpy calculation problems of the steam turbine in wet steam zone using heat balance method which can help to figure out the real overall heat balance diagram for the first time, and we develop a useful software for thermal heat balance calculation. Ling'ao phase II as an example, this paper includes test instrument layout, system isolation, risk control, data acquisition, wetness measurement, heat balance calculation, etc. (authors)

Optimisation of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

DEFF Research Database (Denmark)

Modi, Anish; Haglind, Fredrik

2014-01-01

Central receiver solar thermal power plants are regarded as one of the promising ways to generate electricity in near future. They offer the possibility of using high temperatures and pressures to achieve high efficiencies with standard power cycles. A direct steam generation approach can be used...

Environmental codes of practice for steam electric power generation

International Nuclear Information System (INIS)

1985-03-01

The Design Phase Code is one of a series of documents being developed for the steam electric power generation industry. This industry includes fossil-fuelled stations (gas, oil and coal-fired boilers), and nuclear-powered stations (CANDU heavy water reactors). In this document, environmental concerns associated with water-related and solid waste activities of steam electric plants are discussed. Design recommendations are presented that will minimize the detrimental environmental effects of once-through cooling water systems, of wastewaters discharged to surface waters and groundwaters, and of solid waste disposal sites. Recommendations are also presented for the design of water-related monitoring systems and programs. Cost estimates associated with the implementation of these recommendations are included. These technical guides for new or modified steam electric stations are the result to consultation with a federal-provincial-industry task force

Postfact phenomena of the wet-steam flow electrization in turbines

Science.gov (United States)

Tarelin, A. A.

2017-11-01

Physical processes occurring in a turbine with natural electrization of a humidity-steam flow and their effect on efficiency and reliability of the turbine operation has been considered. Causes of the electrical potential occurrence on a rotor shaft are analyzed. The wet steam's electrization exposure on the electrical potential that is one of the major factors of bearings' electroerosion has been demonstrated on the full-scale installation. Hydrogen formation in wheelspace of the turbine as a result of electrochemical processes and electric field exposure of the space charge has been considered. Hydrogen concentration dependence on a volume charge density in the steam flow has been determined. It is stated that the processes occurring behind the final stage of wet-steam turbines are similar to the ones in elaerosol ectrostatic generators. It has been demonstrated that this phenomenon causes the flow's temporal inhibition and starts pulsations. These factors' impact on power loss of the turbine has been evaluated and recommendations for their elimination have been offered. It has been determined that motions of charged drops can cause self-maintained discharges inside of the flow and between the flow and grounded surfaces that are accompanied by electromagnetic radiation of the wide spectrum. The integrated studies have shown that physical phenomena occurring due to natural electrization negatively affect efficiency and reliability of the turbine operation. Practical recommendations allowing one to minimize the negative effects of the flow natural electrization process have been offered.

Methane-steam reforming by molten salt - membrane reactor using concentrated solar thermal energy

International Nuclear Information System (INIS)

Watanuki, K.; Nakajima, H.; Hasegawa, N.; Kaneko, H.; Tamaura, Y.

2006-01-01

By utilization of concentrated solar thermal energy for steam reforming of natural gas, which is an endothermic reaction, the chemical energy of natural gas can be up-graded. The chemical system for steam reforming of natural gas with concentrated solar thermal energy was studied to produce hydrogen by using the thermal storage with molten salt and the membrane reactor. The original steam reforming module with hydrogen permeable palladium membrane was developed and fabricated. Steam reforming of methane proceeded with the original module with palladium membrane below the decomposition temperature of molten salt (around 870 K). (authors)

Model studies of the vertical steam generator thermal-hydraulic characteristics

International Nuclear Information System (INIS)

Desyatun, V.F.; Moskvichev, V.F.; Ulasov, V.M.; Morozov, V.G.; Burkov, V.K.; Grebennikov, V.N.

1984-01-01

Results of investigations conducted to clarify the calculation technique and to test the workability of the main elements and units of the PGV-250 vertical steam generator of saturated steam are considered. The steam generating capacity of the plant is 1486 t/h, thermal power is 792 MW. Steam generation follows a multiple circulation scheme. The heat surface comprises 330-shields. The investigations are carried out with a model which reproduces all the main elements of the steam generator xcluding the economizer section. The flow rates of feed water, generated steam and coolant of the first circuit as well as temperature, pressure and humidity of the generated steam past the separator are determined. The average heat transfer factors of the heat surface are calculated on the base of the data obtained and a conclusion is drawn on the correctness of the thermohydraulic calculation technique used in development of the PGV-250 steam generator design. Temperature pulsations and heat surface steaming are not observed. The steam humidity at the outlet and steam capture into sinking tubes are within permissible values

Optimum thermal sizing and operating conditions for once through steam generator

Energy Technology Data Exchange (ETDEWEB)

Yi, Kunwoo; Ju, Kyongin; Im, Inyoung; Kim, Eunkee [KEPCO Engineering and Construction Company., Inc., Daejeon (Korea, Republic of)

2014-10-15

The steam generator is designed to be optimized so as to remove heat and to produce steam vapor. Because of its importance, theoretical and experimental researches have been performed on forced convection boiling heat transfer. The purpose of this study is to predict the thermal behavior and to perform optimum thermal sizing of once through steam generator. To estimate the tube thermal sizing and operating conditions of the steam generator, the analytical modeling is employed on the basis of the empirical correlation equations and theory. The optimized algorithm model, Non-dominated Sorting Genetic Algorithm (NSGA)-II, uses for this analysis. This research is focused on the design of in-vessel steam generator. An one dimensional analysis code is developed to evaluate previous researches and to optimize steam generator design parameters. The results of one-dimensional analysis need to be verified with experimental data. Goals of multi-objective optimization are to minimize tube length, pressure drop and tube number. Feedwater flow rate up to 115.425kg/s is selected so as to have margin of feedwater temperature 20 ..deg. C. For the design of 200MWth once through steam generator, it is evaluated that the tube length shall be over 12.0m for the number of tubes, 2500ea, and the length of the tube shall be over 8.0m for the number of tubes, 4500ea. The parallel coordinates chart can be provided to determine the optimal combination of number of tube, pressure drop, tube diameter and length.

Influence of recycling ratio on steam generator thermal recycling

International Nuclear Information System (INIS)

Bassel, W.S.; Rodrigues, V.G.

1989-01-01

A mathematical model was developed to simulate thermal performance of steam generator. The simulation was done with 3 control volumes. The coupled non-linear algebric equations, where the heat transfer was calculated with logarithmic meam temperature difference, was solved by iterative method. The developed model is suitable for calculation the parameters which effect the performance of steam generator. (author) [pt

Thermal-Hydraulic Analysis of a Once-Through Steam Generator Considering Performance Degradation

International Nuclear Information System (INIS)

Han, Hun Sik; Kang, Han Ok; Yoon, Ju Hyeon; Kim, Young In; Song, Jae Seung; Kim, Keung Koo

2016-01-01

Several countries have entered into a global race for the commercialization of SMRs, and considerable research and development have been implemented. Among the various reactor designs, many SMRs have adopted an integral type pressurized water reactor (PWR) to enhance the nuclear safety and system reliability. In the integral reactor design, a single reactor pressure vessel contains primary system components such as fuel and core, steam generators, pumps, and a pressurizer. For the component integration into a reactor vessel, it is important to design each component as small as possible. Thus, it is a common practice to employ a once-through steam generator in the integral reactor design due to its advantages in compactness. In general, gradual degradation in thermal-hydraulic performance of the steam generator occurs with time, and it changes slowly the operating point of the steam generator during plant lifetime. Numerical solutions are acquired to evaluate the thermal-hydraulic performance of the steam generator at various AUFs. The design results obtained show that the average tube length of the steam generator is augmented with the increase of design margin to compensate for the design uncertainties and heat transfer area reduction by plugging, fouling, etc. A helically coiled tube once-through steam generator with 30% design margin is considered for comparison of thermal-hydraulic performances according to the degradation rate

Thermal-Hydraulic Analysis of a Once-Through Steam Generator Considering Performance Degradation

Energy Technology Data Exchange (ETDEWEB)

Han, Hun Sik; Kang, Han Ok; Yoon, Ju Hyeon; Kim, Young In; Song, Jae Seung; Kim, Keung Koo [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Several countries have entered into a global race for the commercialization of SMRs, and considerable research and development have been implemented. Among the various reactor designs, many SMRs have adopted an integral type pressurized water reactor (PWR) to enhance the nuclear safety and system reliability. In the integral reactor design, a single reactor pressure vessel contains primary system components such as fuel and core, steam generators, pumps, and a pressurizer. For the component integration into a reactor vessel, it is important to design each component as small as possible. Thus, it is a common practice to employ a once-through steam generator in the integral reactor design due to its advantages in compactness. In general, gradual degradation in thermal-hydraulic performance of the steam generator occurs with time, and it changes slowly the operating point of the steam generator during plant lifetime. Numerical solutions are acquired to evaluate the thermal-hydraulic performance of the steam generator at various AUFs. The design results obtained show that the average tube length of the steam generator is augmented with the increase of design margin to compensate for the design uncertainties and heat transfer area reduction by plugging, fouling, etc. A helically coiled tube once-through steam generator with 30% design margin is considered for comparison of thermal-hydraulic performances according to the degradation rate.

Application of waterproof breathable fabric in thermal protective clothing exposed to hot water and steam

Science.gov (United States)

Su, Y.; Li, R.; Song, G.; Li, J.

2017-10-01

A hot water and steam tester was used to examine thermal protective performance of waterproof and breathable fabric against hot water and steam hazards. Time to cause skin burn and thermal energy absorbed by skin during exposure and cooling phases was employed to characterize the effect of configuration, placing order and properties of waterproof and breathable fabric on the thermal protective performance. The difference of thermal protective performance due to hot water and steam hazards was discussed. The result showed that the configuration of waterproof and breathable fabric presented a significant effect on the thermal protective performance of single- and double-layer fabric system, while the difference between different configurations in steam hazard was greater than that in hot water hazard. The waterproof and breathable fabric as outer layer provided better protection than that as inner layer. Increasing thickness and moisture regain improved the thermal protective performance of fabric system. Additionally, the thermal energy absorbed by skin during the cooling phase was affected by configuration, thickness and moisture regain of fabric. The findings will provide technical data to improve performance of thermal protective clothing in hot water and steam hazards.

Thermal circuit and supercritical steam generator of the BGR-300 nuclear power plant

International Nuclear Information System (INIS)

Afanas'ev, B.P.; Godik, I.B.; Komarov, N.F.; Kurochnkin, Yu.P.

1979-01-01

Secondary coolant circuit and a steam generator for supercritical steam parameters of the BGR-300 reactor plant are described. The BGR-300 plant with a 300 MW(e) high-temperature gas-cooled fast reactor is developed as a pilot commercial plant. It is shown that the use of a supercritical pressure steam increases the thermal efficiency of the plant and descreases thermal releases to the environment, permits to use home-made commercial turbine plants of large unit power. The proposed supercritical pressure steam generator has considerable advantages from the viewpoint of heat transfer and hydrodynamical processes

A review of test results on parabolic dish solar thermal power modules with dish-mounted Rankine engines and for production of process steam

Science.gov (United States)

Jaffe, Leonard D.

1988-11-01

This paper presents results of development testing of various solar thermal parabolic dish modules and assemblies. Most of the tests were at modules and assemblies that used a dish-mounted, organic Rankine cycle turbine for production of electric power. Some tests were also run on equipment for production of process steam or for production of electricity using dish-mounted reciprocating steam engines. These tests indicate that early modules achieve efficiencies of about 18 percent in converting sunlight to electricity (excluding the inverter but including parasitics). A number of malfunctions occurred. The performance measurements, as well as the malfunctions and other operating experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

An autonomous nuclear power plant with integrated nuclear steam supply system designed for electric power and heat supply in remote areas with difficult access

International Nuclear Information System (INIS)

Adamovich, L.A.; Grechko, G.I.; Lapin, B.D.; Ulasevich, V.K.; Shishkin, V.A.

1997-01-01

The paper contains basic conceptual principles used to develop the technical assignment for an autonomous nuclear power plant with integrated nuclear steam supply system (NSSS) designed to provide heat and electricity for areas which are remote with difficult access. The paper also describes technical procedures and equipment, NPP thermal hydraulic flow chart, steam generator design, safety aspects as well as operational and maintenance procedures. (author)

Automation of steam generator services at public service electric & gas

Energy Technology Data Exchange (ETDEWEB)

Cruickshank, H.; Wray, J.; Scull, D. [Public Service Electric & Gas, Hancock`s Bridge, NJ (United States)

1995-03-01

Public Service Electric & Gas takes an aggressive approach to pursuing new exposure reduction techniques. Evaluation of historic outage exposure shows that over the last eight refueling outages, primary steam generator work has averaged sixty-six (66) person-rem, or, approximately tewenty-five percent (25%) of the general outage exposure at Salem Station. This maintenance evolution represents the largest percentage of exposure for any single activity. Because of this, primary steam generator work represents an excellent opportunity for the development of significant exposure reduction techniques. A study of primary steam generator maintenance activities demonstrated that seventy-five percent (75%) of radiation exposure was due to work activities of the primary steam generator platform, and that development of automated methods for performing these activities was worth pursuing. Existing robotics systems were examined and it was found that a new approach would have to be developed. This resulted in a joint research and development project between Westinghouse and Public Service Electric & Gas to develop an automated system of accomplishing the Health Physics functions on the primary steam generator platform. R.O.M.M.R.S. (Remotely Operated Managed Maintenance Robotics System) was the result of this venture.

Optimum thermal design of steam pipelines and its impact on environment pollution

International Nuclear Information System (INIS)

Abdallah, A.M.; Karameldin, A.

1999-01-01

The majority portion of electric power generated production all over the world - produced by conventional and nuclear fuels produced by steam. Moreover, steam is used extensively in electronic, food, seawater desalination, and many other industries. In the last fifty years, little improvements have been made on the thermal efficiency of steam boilers. The major developments have been carried out in the direction of maintaining this efficiency on low-grade fuel and reducing labor and maintenance charges. Because the annual cost of fuel (nuclear and non-nuclear) is often greater than the combined cost of other expenses in steam power plants, greater amount of money can be saved. Designing steam pipelines in such a way that minimizing the total annual cost of pipes can do this. This can be done by optimal design of the total annual cost of the pipe lines, which includes the cost of insulation material, the cost of burned fuel plus the cost of maintenance. To deal with such situation, a case study of a superheated main steam pipeline at Shobrah Elkhema power plant is investigated. A general simplified working formula for calculating the heat transfer coefficient round a tube has been correlated and verified to facilitate the development for of the heat transfer mathematical model together with the steam pipeline total cost algorithm. The total cost algorithm has been optimized and solved by a digital computer program derived specially for this study. Accordingly, the obtained results are presented in a graphical form and analyzed. The results revealed that the optimal steam pipeline insulation must be chosen carefully. The insulation thickness of 0.225 up to 0.235 m, covers the operating time of 10-20 years, and fuel price of 0.125 up to more than 0.2$/kg. The calculated optimized insulation thickness minimizes the emission of sulfur dioxide, nitrogen oxide and carbon dioxide from 375, 75 and 26,778 kg/m/y to less than 7, 1.7 and 590 kg/m.y respectively

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

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.

Impact on the steam electric power industry of deleting Section 316(a) of the Clean Water Act: Capital costs

International Nuclear Information System (INIS)

Veil, J.A.

1993-01-01

Many power plants discharge large volumes of cooling water. In some cases, the temperature of the discharge exceeds state thermal requirements. Section 316(a) of the Clean Water Act (CWA) allows a thermal discharger to demonstrate that less stringent thermal effluent limitations would still protect aquatic life. About 32% of total US steam electric generating capacity operates under Section 316(a) variances. In 1991, the US Senate proposed legislation that would delete Section 316(a) from the CWA. This study, presented in two companion reports, examines how this legislation would affect the steam electric power industry. This report describes alternatives available to nuclear and coal-fired plants currently operating under variances. Data from 38 plants representing 14 companies are used to estimate the national cost of implementing such alternatives. Although there are other alternatives, most affected plants would be retrofitted with cooling towers. Assuming that all plants currently operating under variances would install cooling towers, the national capital cost estimate for these retrofits ranges from $22.7 billion to $24.4 billion (in 1992 dollars). The second report quantitatively and qualitatively evaluates the energy and environmental impacts of deleting the variance. Little justification has been found for removing the Section 316(a) variance from the CWA

Thermal analysis of cylindrical natural-gas steam reformer for 5 kW PEMFC

Science.gov (United States)

Jo, Taehyun; Han, Junhee; Koo, Bonchan; Lee, Dohyung

2016-11-01

The thermal characteristics of a natural-gas based cylindrical steam reformer coupled with a combustor are investigated for the use with a 5 kW polymer electrolyte membrane fuel cell. A reactor unit equipped with nickel-based catalysts was designed to activate the steam reforming reaction without the inclusion of high-temperature shift and low-temperature shift processes. Reactor temperature distribution and its overall thermal efficiency depend on various inlet conditions such as the equivalence ratio, the steam to carbon ratio (SCR), and the fuel distribution ratio (FDR) into the reactor and the combustor components. These experiments attempted to analyze the reformer's thermal and chemical properties through quantitative evaluation of product composition and heat exchange between the combustor and the reactor. FDR is critical factor in determining the overall performance as unbalanced fuel injection into the reactor and the combustor deteriorates overall thermal efficiency. Local temperature distribution also influences greatly on the fuel conversion rate and thermal efficiency. For the experiments, the operation conditions were set as SCR was in range of 2.5-4.0 and FDR was in 0.4-0.7 along with equivalence ratio of 0.9-1.1; optimum results were observed for FDR of 0.63 and SCR of 3.0 in the cylindrical steam reformer.

Solar thermal electricity generation

Science.gov (United States)

Gasemagha, Khairy Ramadan

1993-01-01

This report presents the results of modeling the thermal performance and economic feasibility of large (utility scale) and small solar thermal power plants for electricity generation. A number of solar concepts for power systems applications have been investigated. Each concept has been analyzed over a range of plant power ratings from 1 MW(sub e) to 300 MW(sub e) and over a range of capacity factors from a no-storage case (capacity factor of about 0.25 to 0.30) up to intermediate load capacity factors in the range of 0.46 to 0.60. The solar plant's economic viability is investigated by examining the effect of various parameters on the plant costs (both capital and O & M) and the levelized energy costs (LEC). The cost components are reported in six categories: collectors, energy transport, energy storage, energy conversion, balance of plant, and indirect/contingency costs. Concentrator and receiver costs are included in the collector category. Thermal and electric energy transport costs are included in the energy transport category. Costs for the thermal or electric storage are included in the energy storage category; energy conversion costs are included in the energy conversion category. The balance of plant cost category comprises the structures, land, service facilities, power conditioning, instrumentation and controls, and spare part costs. The indirect/contingency category consists of the indirect construction and the contingency costs. The concepts included in the study are (1) molten salt cavity central receiver with salt storage (PFCR/R-C-Salt); (2) molten salt external central receiver with salt storage (PFCR/R-E-Salt); (3) sodium external central receiver with sodium storage (PFCR/RE-Na); (4) sodium external central receiver with salt storage (PFCR/R-E-Na/Salt); (5) water/steam external central receiver with oil/rock storage (PFCR/R-E-W/S); (6) parabolic dish with stirling engine conversion and lead acid battery storage (PFDR/SLAB); (7) parabolic dish

Electric power generating plant having direct-coupled steam and compressed-air cycles

Science.gov (United States)

Drost, M.K.

1981-01-07

An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

Electric power generating plant having direct coupled steam and compressed air cycles

Science.gov (United States)

Drost, Monte K.

1982-01-01

An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

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.

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.

Composite electric generator equipped with steam generator for heating reactor coolant

International Nuclear Information System (INIS)

Watabe, Masaharu; Soman, Yoshindo; Kawanishi, Kohei; Ota, Masato.

1997-01-01

The present invention concerns a composite electric generator having coolants, as a heating source, of a PWR type reactor or a thermonuclear reactor. An electric generator driving gas turbine is disposed, and a superheater using a high temperature exhaust gas of the gas turbine as a heating source is disposed, and main steams are superheated by the superheater to elevate the temperature at the inlet of the turbine. This can increase the electric generation capacity as well as increase the electric generation efficiency. In addition, since the humidity in the vicinity of the exit of the steam turbine is reduced, occurrence of loss and erosion can be suppressed. When cooling water of the thermonuclear reactor is used, the electric power generated by the electric generator driven by the gas turbine can be used upon start of the thermonuclear reactor, and it is not necessary to dispose a large scaled special power source in the vicinity, which is efficient. (N.H.)

Effect of thermal barrier coatings on the performance of steam and water-cooled gas turbine/steam turbine combined cycle system

Science.gov (United States)

Nainiger, J. J.

1978-01-01

An analytical study was made of the performance of air, steam, and water-cooled gas-turbine/steam turbine combined-cycle systems with and without thermal-barrier coatings. For steam cooling, thermal barrier coatings permit an increase in the turbine inlet temperature from 1205 C (2200 F), resulting in an efficiency improvement of 1.9 percentage points. The maximum specific power improvement with thermal barriers is 32.4 percent, when the turbine inlet temperature is increased from 1425 C (2600 F) to 1675 C (3050 F) and the airfoil temperature is kept the same. For water cooling, the maximum efficiency improvement is 2.2 percentage points at a turbine inlet temperature of 1683 C (3062 F) and the maximum specific power improvement is 36.6 percent by increasing the turbine inlet temperature from 1425 C (2600 F) to 1730 C (3150 F) and keeping the airfoil temperatures the same. These improvements are greater than that obtained with combined cycles using air cooling at a turbine inlet temperature of 1205 C (2200 F). The large temperature differences across the thermal barriers at these high temperatures, however, indicate that thermal stresses may present obstacles to the use of coatings at high turbine inlet temperatures.

Evaluation of material integrity on electricity generator water steam cycles component (Main Steam Pipe)

International Nuclear Information System (INIS)

Sudardjo; Histori; Triyadi, Ari

1998-01-01

The evaluation of material integrity on electricity generator component has been done. That component was main steam pipe of Unit II Suralaya Coal Fired Power Plant. evaluation was done by replication technique. The damage was found are two porosity's, from two point samples of six points sample population. Based on cavity evaluation in steels, which proposed by Neubauer and Wedel that porosity's still at class A damage. For class A damage, its means no remedial action would be required until next major scheduled maintenance outage. That porosity's was grouped on isolated cavities and not need ti repair that main steam pipe component less than three year after replication test

78 FR 41907 - Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point...

Science.gov (United States)

2013-07-12

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 423 [EPA-HQ-OW-2009-0819. FRL-9832-7; EPA-HQ-RCRA-2013-0209] RIN 2040-AF14 Effluent Limitations Guidelines and Standards for the Steam Electric Power... proposed rule entitled, ``Effluent Limitations Guidelines and Standards for the Steam Electric Power...

Evaluation of Waterford Steam Electric Station Unit 3 technical specifications

International Nuclear Information System (INIS)

Baxter, D.E.; Bruske, S.J.

1985-09-01

This document was prepared for the Nuclear Regulatory Commission (NRC) to assist them in determining whether the Waterford Steam Electric Station Unit 3 Technical Specifications (T/S), which govern plant systems configurations and operations, are in conformance with the requirements of the Final Safety Analysis Report (FSAR) as amended, and the requirements of the Safety Evaluation Report (SER) as supplemented. A comparative audit of the FSAR as amended, and the SER as supplemented was performed with the Waterford T/S. Several discrepancies were identified and subsequently resolved by the cognizant NRC reviewer. Pending completion of the resolutions noted in Part 3 of this report, the Waterford Steam Electric Station Unit 3 T/S, to the extent reviewed, are in conformance with the FSAR and SER

A global fouling factor methodology for analyzing steam generator thermal performance degradation

International Nuclear Information System (INIS)

Kreider, M.A.; White, G.A.; Varrin, R.D. Jr.

1998-06-01

Over the past few years, steam generator (SG) thermal performance degradation has led to decreased plant efficiency and power output at numerous PWR nuclear power plants with recirculating-type SGs. The authors have developed and implemented methodologies for quantitatively evaluating the various sources of SG performance degradation, both internal and external to the SG pressure boundary. These methodologies include computation of the global fouling factor history, evaluation of secondary deposit thermal resistance using deposit characterization data, and consideration of pressure loss causes unrelated to the tube bundle, such as hot-leg temperature streaming and SG moisture separator fouling. In order to evaluate the utility of the global fouling factor methodology, the authors performed case studies for a number of PWR SG designs. Key results from two of these studies are presented here. In tandem with the fouling-factor analyses, a study evaluated for each plant the potential causes of pressure loss. The combined results of the global fouling factor calculations and the pressure-loss evaluations demonstrated two key points: (1) that the available thermal margin against fouling, which can vary substantially from plant to plant, has an important bearing on whether a given plant exhibits losses in electrical generating capacity, and (2) that a wide variety of causes can result in SG thermal performance degradation

Steam generator replacement at Kansai Electric Power Co., Inc

International Nuclear Information System (INIS)

Kimura, S.; Dodo, Takashi; Negishi, Kazuo

1995-01-01

Eleven nuclear units are in operation at the Kansai Electric Power Co., Inc.. In seven of them, Mihama-1·2·3, Takahama-1·2, and Ohi-1·2, comparatively long duration for tube inspection and repair have been required during late annual outages. KEPCO decided to replace all steam generators in these 7 units with the latest model which was improved upon the past degradation experiences, as a result of comprehensive considerations including public confidence in nuclear power generation, maintenability, and economic efficiency. This report presents the design improvements in new steam generators, replacement techniques, and so on. (author)

Steam producing plant concept of 4S for oil sand extraction

International Nuclear Information System (INIS)

Matsuyama, Shinichiro; Nishiguchi, Youhei; Sakashita, Yoshiaki; Kasuga, Shoji; Kawashima, Masatoshi

2009-01-01

Plant concept of small fast reactor '4S' applying to continuous steam production for recovery of crude oil from oil sands was investigated. Assuming typical steam assisted gravity drainage (SAGD) plant whose production scale is 120,000 barrels per day of a crude oil, concept of nuclear steam supply system consisting of eight reactor modules for steam production and three reactor modules for electric generation of the 4S with a thermal rating of 135 MWt was established without any essential or significant design change from the preceding 4S with a thermal rating of 30 MWt. The 4S, provided for an oil sand extraction, will reduce greenhouse gas emission significantly, and has not much burden for development and licensing and has economic competitiveness. (author)

Safety evaluation report related to steam generator repair at H.B. Robinson Steam Electric Plant, Unit No. 2. Docket No. 50-261

International Nuclear Information System (INIS)

1983-11-01

A Safety Evaluation Report was prepared for the H.B. Robinson Steam Electric Plant Unit No. 2 by the Office of Nuclear Reactor Regulation. This report considers the safety aspects of the proposed steam generator repair at H.B. Robinson Steam Electric Plant Unit No. 2. The report focuses on the occupational radiation exposure associated with the proposed repair program. It concludes that there is reasonable assurance that the health and safety on the public will not be endangered by the conduct of the proposed action, such activities will be conducted in compliance with the Commission's regulations, and the issuance of this amendment will not be inimical to the common defense and security or the health and safety of the public

Impact on the steam electric power industry of deleting Section 316(a) of the Clean Water Act: Energy and environmental impacts

International Nuclear Information System (INIS)

Veil, J.A.; VanKuiken, J.C.; Folga, S.; Gillette, J.L.

1993-01-01

Many power plants discharge large volumes of cooling water. In some cases, the temperature of the discharge exceeds state thermal requirements. Section 316(a) of the Clean Water Act (CWA) allows a thermal discharger to demonstrate that less stringent thermal effluent limitations would still protect aquatic life. About 32% of the total steam electric generating capacity in the United States operates under Section 316(a) variances. In 1991, the US Senate proposed legislation that would delete Section 316(a) from the CWA. This study, presented in two companion reports, examines how this legislation would affect the steam electric power industry. This report quantitatively and qualitatively evaluates the energy and environmental impacts of deleting the variance. No evidence exists that Section 316(a) variances have caused any widespread environmental problems. Conversion from once-through cooling to cooling towers would result in a loss of plant output of 14.7-23.7 billion kilowatt-hours. The cost to make up the lost energy is estimated at $12.8-$23.7 billion (in 1992 dollars). Conversion to cooling towers would increase emission of pollutants to the atmosphere and water loss through evaporation. The second report describes alternatives available to plants that currently operate under the variance and estimates the national cost of implementing such alternatives. Little justification has been found for removing the 316(a) variance from the CWA

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.

Performance analysis of an integrated gas-, steam- and organic fluid-cycle thermal power plant

International Nuclear Information System (INIS)

Oko, C.O.C.; Njoku, I.H.

2017-01-01

This paper presents the performance analysis of an existing combined cycle power plant augmented with a waste heat fired organic Rankine cycle power plant for extra power generation. This was achieved by performing energy and exergy analysis of the integrated gas-, steam- and organic fluid-cycle thermal power plant (IPP). Heat source for the subcritical organic Rankine cycle (ORC) was the exhaust flue gases from the heat recovery steam generators of a 650 MW natural gas fired combined cycle power plant. The results showed that extra 12.4 MW of electricity was generated from the attached ORC unit using HFE7100 as working fluid. To select ORC working fluid, ten isentropic fluids were screened and HFE7100 produced the highest net power output and cycle efficiency. Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively. The rate of exergy destruction in the existing combined cycle plant was highest in the combustion chamber, 59%, whereas in the ORC, the highest rate of exergy destruction occurred in the evaporator, 62%. Simulations showed exergy efficiency of the IPP decreased with increasing ambient temperature. Exit stack flue gas temperature reduced from 126 °C in the combined cycle power plant to 100 °C in the integrated power plant. - Highlights: • Combined cycle plant retrofitted with ORC produced extra 12.4 MW electric power. • ORC is powered with low temperature flue gas from an existing combined cycle plant. • Exergy destruction rate in integrated plant(IPP) is less than in combined plant. • Exit stack temperature of the IPP has less environmental thermal pollution. • Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively.

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

Survey of solar thermal energy storage subsystems for thermal/electric applications

Energy Technology Data Exchange (ETDEWEB)

Segaser, C. L.

1978-08-01

A survey of the current technology and estimated costs of subsystems for storing the thermal energy produced by solar collectors is presented. The systems considered were capable of producing both electricity and space conditioning for three types of loads: a single-family detached residence, an apartment complex of 100 units, and a city of 30,000 residents, containing both single-family residences and apartments. Collector temperatures will be in four ranges: (1) 100 to 250/sup 0/F (used for space heating and single-cycle air conditioners and organic Rankine low-temperature turbines); (2) 300 to 400/sup 0/F (used for dual-cycle air conditioners and low-temperature turbines); (3) 400 to 600/sup 0/F (using fluids from parabolic trough collectors to run Rankine turbines); (4) 800 to 1000/sup 0/F (using fluids from heliostats to run closed-cycle gas turbines and steam Rankine turbines). The solar thermal energy subsystems will require from 60 to 36 x 10/sup 5/ kWhr (2.05 x 10/sup 5/ to 1.23 x 10/sup 10/ Btu) of thermal storage capacity. In addition to sensible heat and latent heat storage materials, several other media were investigated as potential thermal energy storage materials, including the clathrate and semiclathrate hydrates, various metal hydrides, and heat storage based on inorganic chemical reactions.

Assessment of the once-through cooling alternative for central steam-electric generating stations

Energy Technology Data Exchange (ETDEWEB)

Paddock, R. A.; Ditmars, J. D.

1978-12-01

The efficacy of the disposal of waste heat from steam-electric power generation by means of once-through cooling systems was examined in the context of the physical aspects of water quality standards and guidelines for thermal discharges. Typical thermal standards for each of the four classes of water bodies (rivers, lakes, estuaries, and coastal waters) were identified. The mixing and dilution characteristics of various discharge modes ranging from simple, shoreline surface discharges to long, submerged multiport diffusers were examined in terms of the results of prototype measurements, analytical model predictions, and physical model studies. General guidelines were produced that indicate, for a given plant capacity, a given type of receiving water body, and a given discharge mode, the likelihood that once-through cooling can be effected within the restrictions of typical thermal standards. In general, it was found that shoreline surface discharges would not be adequate for large power plants (greater than or equal to 500 MW) at estuarine and marine coastal sites, would be marginally adequate at lake sites, and would be acceptable only at river sites with large currents and river discharges. Submerged multiport diffusers were found to provide the greatest likelihood of meeting thermal standards in all receiving water environments.

Assessment of the once-through cooling alternative for central steam-electric generating stations

International Nuclear Information System (INIS)

Paddock, R.A.; Ditmars, J.D.

1978-12-01

The efficacy of the disposal of waste heat from steam-electric power generation by means of once-through cooling systems was examined in the context of the physical aspects of water quality standards and guidelines for thermal discharges. Typical thermal standards for each of the four classes of water bodies (rivers, lakes, estuaries, and coastal waters) were identified. The mixing and dilution characteristics of various discharge modes ranging from simple, shoreline surface discharges to long, submerged multiport diffusers were examined in terms of the results of prototype measurements, analytical model predictions, and physical model studies. General guidelines were produced that indicate, for a given plant capacity, a given type of receiving water body, and a given discharge mode, the likelihood that once-through cooling can be effected within the restrictions of typical thermal standards. In general, it was found that shoreline surface discharges would not be adequate for large power plants (greater than or equal to 500 MW) at estuarine and marine coastal sites, would be marginally adequate at lake sites, and would be acceptable only at river sites with large currents and river discharges. Submerged multiport diffusers were found to provide the greatest likelihood of meeting thermal standards in all receiving water environments

75 FR 82414 - Carolina Power & Light Company; H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption

Science.gov (United States)

2010-12-30

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-261; NRC-2010-0062] Carolina Power & Light Company; H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption 1.0 Background Carolina Power & Light... authorizes operation of the H.B. Robinson Steam Electric Plant, Unit 2 (HBRSEP). The license provides, among...

75 FR 11579 - Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption

Science.gov (United States)

2010-03-11

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-261; NRC-2010-0062] Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption 1.0 Background Carolina Power & Light... of the H. B. Robinson Steam Electric Plant, Unit 2 (HBRSEP). The license provides, among other things...

Development of a 1D thermal-hydraulic analysis code for once-through steam generator in SMRs using straight tubes

Energy Technology Data Exchange (ETDEWEB)

Park, Youngjae; Kim, Iljin; Kim, Hyungdae [Kyung Hee University, Yongin (Korea, Republic of)

2015-10-15

Diverse integral/small-modular reactors (SMRs) have been developed. Once-through steam generator (OTSG) which generates superheated steam without steam separator and dryer was used in the SMRs to reduce volume of steam generator. It would be possible to design a new steam generator with best estimate thermal-hydraulic codes such as RELAP and MARS. However, it is not convenience to use the general purpose thermal-hydraulic analysis code to design a specific component of nuclear power plants. A widely used simulation tool for thermal-hydraulic analysis of drum-type steam generators is ATHOS, which allows 3D analysis. On the other hand, a simple 1D thermal-hydraulic analysis code might be accurate enough for the conceptual design of OTSG. In this study, thermal-hydraulic analysis code for conceptual design of OTSG was developed using 1D homogeneous equilibrium model (HEM). A benchmark calculation was also conducted to verify and validate the prediction accuracy of the developed code by comparing with the analysis results with MARS. Finally, conceptual design of OTSG was conducted by the developed code. A simple 1D thermal-hydraulic analysis code was developed for the purpose of conceptual design OTSG for SMRs. A set of benchmark calculations was conducted to verify and validate the analysis accuracy of the developed code by comparing results obtained with a best-estimated thermal-hydraulic analysis code, MARS. Finally, analysis of two different OTSG design concepts with superheating and recirculation was demonstrated using the developed code.

Synergetic mechanism of methanol–steam reforming reaction in a catalytic reactor with electric discharges

International Nuclear Information System (INIS)

Kim, Taegyu; Jo, Sungkwon; Song, Young-Hoon; Lee, Dae Hoon

2014-01-01

Highlights: • Methanol–steam reforming was performed on Cu catalysts under an electric discharge. • Discharge had a synergetic effect on the catalytic reaction for methanol conversion. • Discharge lowered the temperature for catalyst activation or light off. • Discharge controlled the yield and selectivity of species in a reforming process. • Adsorption triggered by a discharge was a possible mechanism for a synergetic effect. - Abstract: Methanol–steam reforming was performed on Cu/ZnO/Al 2 O 3 catalysts under an electric discharge. The discharge occurred between the electrodes where the catalysts were packed. The electric discharge was characterized by the discharge voltage and electric power to generate the discharge. The existence of a discharge had a synergetic effect on the catalytic reaction for methanol conversion. The electric discharge provided modified reaction paths resulting in a lower temperature for catalyst activation or light off. The discharge partially controlled the yield and selectivity of species in a reforming process. The aspect of control was examined in view of the reaction kinetics. The possible mechanisms for the synergetic effect between the catalytic reaction and electric discharge on methanol–steam reforming were addressed. A discrete reaction path, particularly adsorption triggered by an electric discharge, was suggested to be the most likely mechanism for the synergetic effect. These results are expected to provide a guide for understanding the plasma–catalyst hybrid reaction

Procedure for estimating nonfuel operation and maintenance costs for large steam-electric power plants

International Nuclear Information System (INIS)

Myers, M.L.; Fuller, L.C.

1979-01-01

Revised guidelines are presented for estimating annual nonfuel operation and maintenance costs for large steam-electric power plants, specifically light-water-reactor plants and coal-fired plants. Previous guidelines were published in October 1975 in ERDA 76-37, a Procedure for Estimating Nonfuel Operating and Maintenance Costs for Large Steam-Electric Power Plants. Estimates for coal-fired plants include the option of limestone slurry scrubbing for flue gas desulfurization. A computer program, OMCOST, is also presented which covers all plant options

Investigation of thermal storage and steam generator issues

Energy Technology Data Exchange (ETDEWEB)

1993-08-01

A review and evaluation of steam generator and thermal storage tank designs for commercial nitrate salt technology showed that the potential exists to procure both on a competitive basis from a number of qualified vendors. The report outlines the criteria for review and the results of the review, which was intended only to assess the feasibility of each design, not to make a comparison or select the best concept.

Design and construction of a steam generator with feedback

International Nuclear Information System (INIS)

Camargo, Camila C.; Placco, Guilherme M.; Guimaraes, Lamartine N.F.

2013-01-01

The EARTH project aims to develop technologies to design and build systems that generate electricity in space, using microreactors. One of the activities within the TERRA project aims to build a closed thermal cycle Rankine type in order to test a Tesla turbine type. The objective of this work is to design and build a steam generator with feedback, which should ensure a satisfactory range of steam supply, security system, feedback system and heating system

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

Steam-treated wood pellets: Environmental and financial implications relative to fossil fuels and conventional pellets for electricity generation

International Nuclear Information System (INIS)

McKechnie, Jon; Saville, Brad; MacLean, Heather L.

2016-01-01

Highlights: • Steam-treated pellets can greatly reduce greenhouse gas emissions relative to coal. • Cost advantage is seen relative to conventional pellets. • Higher pellet cost is more than balanced by reduced retrofit capital requirements. • Low capacity factors further favour steam-treated pellets over conventional pellets. - Abstract: Steam-treated pellets can help to address technical barriers that limit the uptake of pellets as a fuel for electricity generation, but there is limited understanding of the cost and environmental impacts of their production and use. This study investigates life cycle environmental (greenhouse gas (GHG) and air pollutant emissions) and financial implications of electricity generation from steam-treated pellets, including fuel cycle activities (biomass supply, pellet production, and combustion) and retrofit infrastructure to enable 100% pellet firing at a generating station that previously used coal. Models are informed by operating experience of pellet manufacturers and generating stations utilising coal, steam-treated and conventional pellets. Results are compared with conventional pellets and fossil fuels in a case study of electricity generation in northwestern Ontario, Canada. Steam-treated pellet production has similar GHG impacts to conventional pellets as their higher biomass feedstock requirement is balanced by reduced process electricity consumption. GHG reductions of more than 90% relative to coal and ∼85% relative to natural gas (excluding retrofit infrastructure) could be obtained with both pellet options. Pellets can also reduce fuel cycle air pollutant emissions relative to coal by 30% (NOx), 97% (SOx), and 75% (PM 10 ). Lesser retrofit requirements for steam-treated pellets more than compensate for marginally higher pellet production costs, resulting in lower electricity production cost compared to conventional pellets ($0.14/kW h vs. $0.16/kW h). Impacts of retrofit infrastructure become increasingly

Steam process supply optimization for Arcelormittal Tubarao consumers; Otimizacao do sistema de fornecimento de vapor de processo para a usina (AMT)

Energy Technology Data Exchange (ETDEWEB)

Loss, Gecimar; Oliveira, Heron Domingues de; Silva, Jose Geraldo Lessa; Beccalli, Marcelo; Calente, Paulo Sergio Boni; Monteiro, Sergio Anderson [Companhia Siderurgica de Tubarao ArcelorMittal, Serra, ES (Brazil)

2010-07-01

The ArcelorMittal Tubarao Energy Production area is compounded by three units: Air Separation Units, Thermal Power Plants and Thermal Recovery Power Plants. The Thermo Power Plants are co-generated units responsible to generate electrical, mechanical (Blast Furnace blower) energy and also provide Steam to complement the facility internal consumption mainly provided by CDQ plant (CDQ - Coke Dry Quenching). Since RH2 (steel treatment process) start up, the steam consumption increased and the Thermal Power Plant contribution raised to attend this new demand. Solutions were needed to guarantee the steam supply by the Power Plant even in low steam header stoppages for maintenance, since the lack of steam caused by shortage in Power Plant steam supply resulting in steel production diminution in this new scenario. (author)

Preliminary results of thermal igniter experiments in H2-air-steam environments

International Nuclear Information System (INIS)

Lowry, W.

1981-01-01

Thermal igniters (glow plugs), proposed by the Tennessee Valley Authority for intentional ignition of hydrogen in nuclear reactor containment, have been tested for functionability in mixtures of air, hydrogen, and steam. Test environments included 6% to 16% hydrogen concentrations in air, and 8%, 10%, and 12% hydrogen in mixtures with 30% and 40% steam fractions. All were conducted in a 10.6 ft 3 insulated pressure vessel. For all of these tests the glow plug successfully initiated combustion. Dry air/hydrogen tests exhibited a distinct tendency for complete combustion at hydrogen concentrations between 8% and 9%. Steam suppressed both peak pressures and completeness of combustion. No combustion could be initiated at or above a 50% steam fraction. Circulation of the mixture with a fan increased the completeness of combustion. The glow plug showed no evidence of performance degradation throughout the program

Thermal and chemical analysis on steam reforming in an out-of-pile test facility (Contract research)

Energy Technology Data Exchange (ETDEWEB)

Haga, Katsuhiro [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Suyama, Kazumasa; Inagaki, Yoshiyuki; Hayashi, Kohji; Ogawa, Masuro

1999-08-01

An out-of-pile test facility of a hydrogen production system whose scale is 1/30th of the HTTR hydrogen production system is presently under construction at the Oarai Establishment of the Japan Atomic Energy Research Institute. In this system, a steam generator works as a thermal buffer for mitigating the heat consumption fluctuation in a steam reformer so as not to affect an operation of the reactor system. To control the thermal buffer system properly, it is important to evaluate the effect of the steam reforming parameters on the heat fluctuation in advance. So, using the mass and thermal balance analysis code developed for a simulation of the out-of-pile test facility, the heat consumption fluctuation in the steam reformer was analyzed by various changes of the process gas flow rate, the process gas inlet temperature, the process gas composition etc. From the analytical results, it was found that the heat transfer augmentation of the reformer tube by using repeated fins was effective in increasing the hydrogen production rate of up to 12.5%. Also, the fluctuation of the process gas flow rate tended to greatly affect the heat consumption rate for the steam reforming reaction, so that the helium gas temperature increased from 586degC to 718degC. (author)

Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

Directory of Open Access Journals (Sweden)

Fic Adam

2015-03-01

Full Text Available Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle, which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle. The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

Steam generator thermal sleeve reconstruction

Energy Technology Data Exchange (ETDEWEB)

Caton, E.; Askari, A.; Volder, P. [Babcock and Wilcox Canada Ltd., Cambridge, Ontario (Canada)]. E-mail: eecaton@babcock.com

2003-07-01

'Full text:' Successful implementation of a physically difficult repair program requires collaboration of the design and construction functions of an organization to ensure that goals are shared and rework or on-the-fly design changes are not required. Furthermore, in a nuclear facility this collaboration results in the optimal safety condition as dose uptake is minimized with a well planned job. The replacement of the degraded thermal sleeves in the Pickering A Steam Generator feedwater nozzles posed this type of problem. The project may be summarized as follows: i) problem analysis, ii) identification of design parameters and limitations, iii) integration of field engineering and design engineering solutions, iv) installation. Integration of the design engineering and field engineering design parameters ensured that the most effective solution was implemented. (author)

Using geophysical techniques to control in situ thermal remediation

International Nuclear Information System (INIS)

Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M.; Goldman, R.; Kayes, D.; Kenneally, K.; Udell, K.; Hunter, R.

1994-01-01

Monitoring the thermal and hydrologic processes that occur during thermal environmental remediation programs in near real-time provides essential information for controlling the process. Geophysical techniques played a crucial role in process control as well as for characterization during the recent Dynamic Underground Stripping Project demonstration in which several thousand gallons of gasoline were removed from heterogeneous soils both above and below the water table. Dynamic Underground Stripping combines steam injection and electrical heating for thermal enhancement with ground water pumping and vacuum extraction for contaminant removal. These processes produce rapid changes in the subsurface properties including changes in temperature fluid saturation, pressure and chemistry. Subsurface imaging methods are used to map the heated zones and control the thermal process. Temperature measurements made in wells throughout the field reveal details of the complex heating phenomena. Electrical resistance tomography (ERT) provides near real-time detailed images of the heated zones between boreholes both during electrical heating and steam injection. Borehole induction logs show close correlation with lithostratigraphy and, by identifying the more permeable gravel zones, can be used to predict steam movement. They are also useful in understanding the physical changes in the field and in interpreting the ERT images. Tiltmeters provide additional information regarding the shape of the steamed zones in plan view. They were used to track the growth of the steam front from individual injectors

Availability of steam generator against thermal disturbance of hydrogen production system coupled to HTGR

International Nuclear Information System (INIS)

Shibata, Taiju; Nishihara, Tetsuo; Hada, Kazuhiko; Shiozawa, Shusaku

1996-01-01

One of the safety issues to couple a hydrogen production system to an HTGR is how the reactor coolability can be maintained against anticipated abnormal reduction of heat removal (thermal disturbance) of the hydrogen production system. Since such a thermal disturbance is thought to frequently occur, it is desired against the thermal disturbance to keep reactor coolability by means other than reactor scram. Also, it is thought that the development of a passive cooling system for such a thermal disturbance will be necessary from a public acceptance point of view in a future HTGR-hydrogen production system. We propose a SG as the passive cooling system which can keep the reactor coolability during a thermal disturbance of a hydrogen production system. This paper describes the proposed steam generator (SG) for the HTGR-hydrogen production system and a result of transient thermal-hydraulic analysis of the total system, showing availability of the SG against a thermal disturbance of the hydrogen production system in case of the HTTR-steam reforming hydrogen production system. (author)

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.

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

Integrated gasification and Cu-Cl cycle for trigeneration of hydrogen, steam and electricity

Energy Technology Data Exchange (ETDEWEB)

Aghahosseini, S; Dincer, I; Naterer, G F [University of Ontario, Oshawa, ON (Canada). Institute of Technology

2011-02-15

This paper develops and analyzes an integrated process model of an Integrated Gasification Combined Cycle (IGCC) and a thermochemical copper-chlorine (Cu-Cl) cycle for trigeneration of hydrogen, steam and electricity. The process model is developed with Aspen HYSYS software. By using oxygen instead of air for the gasification process, where oxygen is provided by the integrated Cu-Cl cycle, it is found that the hydrogen content of produced syngas increases by about 20%, due to improvement of the gasification combustion efficiency and reduction of syngas NOx emissions. Moreover, about 60% of external heat required for the integrated Cu-Cl cycle can be provided by the IGCC plant, with minor modifications of the steam cycle, and a slight decrease of IGCC overall efficiency. Integration of gasification and thermochemical hydrogen production can provide significant improvements in the overall hydrogen, steam and electricity output, when compared against the processes each operating separately and independently of each other.

Investigation of thermodynamic cycle for generic 1200 MW{sub el} pressure channel reactor with nuclear steam superheat

Energy Technology Data Exchange (ETDEWEB)

Vincze, A.; Sidawi, K.; Abdullah, R.; Baldock, M.; Saltanov, E.; Pioro, I., E-mail: andrei.vincze@uoit.net, E-mail: khalil.sidawi@uoit.net, E-mail: rand.abdullah@uoit.net, E-mail: matthew.baldock@uoit.net, E-mail: eugene.saltanov@uoit.ca, E-mail: igor.pioro@uoit.ca [Univ. of Ontario Inst. of Tech., Oshawa, ON (Canada)

2014-07-01

Current Nuclear Power Plants (NPPs) play a significant role in energy production around the world. All NPPs operating today employ a Rankine steam cycle for the conversion of thermal power to electricity. This paper will examine the steam cycle arrangement an experimental pressure channel reactor using Nuclear Steam Superheat (NSS) and compare it to two advanced reactor designs, the Advanced CANDU Reactor 1000 (ACR-1000) and the Advanced Boiling Water Reactor (ABWR) designs. The thermodynamic cycle layout and thermal efficiencies of the three reactor types will be discussed. (author)

Aluminum-Enhanced Underwater Electrical Discharges for Steam Explosion Triggering

International Nuclear Information System (INIS)

HOGELAND, STEVE R.; NELSON, LLOYD S.; ROTH, THOMAS CHRISTOPHER

1999-01-01

For a number of years, we have been initiating steam explosions of single drops of molten materials with pressure and flow (bubble growth) transients generated by discharging a capacitor bank through gold bridgewires placed underwater. Recent experimental and theoretical advances in the field of steam explosions, however, have made it important to substantially increase these relatively mild transients in water without using high explosives, if possible. To do this with the same capacitor bank, we have discharged similar energies through tiny strips of aluminum foil submerged in water. By replacing the gold wires with the aluminum strips, we were able to add the energy of the aluminum-water combustion to that normally deposited electrically by the bridgewire explosion in water. The chemical enhancement of the explosive characteristics of the discharges was substantial: when the same electrical energies were discharged through the aluminum strips, peak pressures increased as much as 12-fold and maximum bubble volumes as much as 5-fold above those generated with the gold wires. For given weights of aluminum, the magnitudes of both parameters appeared to exceed those produced by the underwater explosion of equivalent weights of high explosives

Design and performance of General Electric boiling water reactor main steam line isolation valves

International Nuclear Information System (INIS)

Rockwell, D.A.; van Zylstra, E.H.

1976-08-01

An extensive test program has been completed by the General Electric Company in cooperation with the Commonwealth Edison Company on the basic design type of large main steam line isolation valves used on General Electric Boiling Water Reactors. Based on a total of 40 tests under simulated accident conditions covering a wide range of mass flows, mixture qualities, and closing times, it was concluded that the commercially available valves of this basic type will close completely and reliably as required. Analytical methods to predict transient effects in the steam line and valve after postulated breaks were refined and confirmed by the test program

Waste to Energy Conversion by Stepwise Liquefaction, Gasification and "Clean" Combustion of Pelletized Waste Polyethylene for Electric Power Generation---in a Miniature Steam Engine

Science.gov (United States)

Talebi Anaraki, Saber

The amounts of waste plastics discarded in developed countries are increasing drastically, and most are not recycled. The small fractions of the post-consumer plastics which are recycled find few new uses as their quality is degraded; they cannot be reused in their original applications. However, the high energy density of plastics, similar to that of premium fuels, combined with the dwindling reserves of fossil fuels make a compelling argument for releasing their internal energy through combustion, converting it to thermal energy and, eventually, to electricity through a heat engine. To minimize the emission of pollutants this energy conversion is done in two steps, first the solid waste plastics undergo pyrolytic gasification and, subsequently, the pyrolyzates (a mixture of hydrocarbons and hydrogen) are blended with air and are burned "cleanly" in a miniature power plant. This plant consists of a steam boiler, a steam engine and an electricity generator.

Elimination of feedwater heaters in steam turbines: Prospects for substantial energy savings

International Nuclear Information System (INIS)

Lorenzoni, G.

1992-01-01

This paper re-proposes the theory that thermal regeneration (RT) in steam turbine plants decreases thermodynamic efficiency. This theory is supported by the criterion of maximization of variation of exergy in the steam generator (CMVEG) and by an mathematical argumentation based on the first law of thermodynamics. Consequences of great importance are deduced: plant operating costs reductions and a new possibility for cogeneration, that indicates exceptional advantages for the whole power industry, since steam turbine plants are responsible for the greater part of global electric power production

Thermal-Hydraulic Design of the Modular Once Through Helical Steam Generator

International Nuclear Information System (INIS)

Mazufri, C.M

2000-01-01

The steam generator system of the CAREM reactor consists of twelve individual modules located in the annular place between the pressure vessel and barrel walls. Each steam generator module consists of a tube system, an upper header, an external shroud, a collector and a lower seal.The tube system is an arrangement of several multi-start cylindrical coils.In the present work the computation of the necessary heat transfer area to fulfill the heat removal requirements from the primary circuit, and the pressure drop in the primary and secondary side of the helical design of a modular steam generator is presented. Additionally, a first order estimation of the restriction to be used in the secondary side to assure the thermal-hydraulic stability is also made.It is concluded that an array of 6 concentric cylindrical coils fulfills the necessary design requirements

Thermal expansion measurement of turbine and main steam piping by using strain gages in power plants

International Nuclear Information System (INIS)

Na, Sang Soo; Chung, Jae Won; Bong, Suk Kun; Jun, Dong Ki; Kim, Yun Suk

2000-01-01

One of the domestic co-generation plants have undergone excessive vibration problems of turbine attributed to external force for years. The root cause of turbine vibration may be shaft alignment problem which sometimes is changed by thermal expansion and external force, even if turbine technicians perfectly performed it. To evaluate the alignment condition from plant start-up to full load, a strain measurement of turbine and main steam piping subjected to thermal loading is monitored by using strain gages. The strain gages are bonded on both bearing housing adjusting bolts and pipe stoppers which installed in the x-direction of left-side main steam piping near the turbine inlet in order to monitor closely the effect of turbine under thermal deformation of turbine casing and main steam piping during plant full load. Also in situ load of constant support hangers in main steam piping system is measured by strain gages and its results are used to rebalance the hanger rod load. Consequently, the experimental stress analysis by using strain gages turns out to be very useful tool to diagnose the trouble and failures of not only to stationary components but to rotating machinery in power plants

Electrically conductive carbon nanofiber/paraffin wax composites for electric thermal storage

International Nuclear Information System (INIS)

Zhang Kun; Han Baoguo; Yu Xun

2012-01-01

Highlights: ► Carbon nanofiber (CNF)/paraffin wax composite is found to be a promising electric thermal storage material. ► The thermal storage capacity of CNF/paraffin wax composite is five times of traditional electric thermal storage material. ► CNF is shown to be an effective conductive filler for the composite. - Abstract: The research of electric thermal storage (ETS) has attracted a lot of attention recently, which converts off-peak electrical energy into thermal energy and release it later at peak hours. In this study, new electric thermal storage composites are developed by employing paraffin wax as thermal storage media and carbon nanofiber (CNF) as conductive fillers. Electric heating and thermal energy release performances of the CNF/paraffin wax composites are experimentally investigated. Experimental results show that, when the composites are heated to about 70 °C, the developed electrically conductive CNF/paraffin wax composites present a thermal storage capacity of about 280 kJ/kg, which is five times of that of traditional thermal storage medium such as ceramic bricks (54 kJ/kg). The CNF/paraffin wax composites can also effectively store the thermal energy and release the thermal energy in later hours.

TG-MS analysis and kinetic study for thermal decomposition of six representative components of municipal solid waste under steam atmosphere.

Science.gov (United States)

Zhang, Jinzhi; Chen, Tianju; Wu, Jingli; Wu, Jinhu

2015-09-01

Thermal decomposition of six representative components of municipal solid waste (MSW, including lignin, printing paper, cotton, rubber, polyvinyl chloride (PVC) and cabbage) was investigated by thermogravimetric-mass spectroscopy (TG-MS) under steam atmosphere. Compared with TG and derivative thermogravimetric (DTG) curves under N2 atmosphere, thermal decomposition of MSW components under steam atmosphere was divided into pyrolysis and gasification stages. In the pyrolysis stage, the shapes of TG and DTG curves under steam atmosphere were almost the same with those under N2 atmosphere. In the gasification stage, the presence of steam led to a greater mass loss because of the steam partial oxidation of char residue. The evolution profiles of H2, CH4, CO and CO2 were well consistent with DTG curves in terms of appearance of peaks and relevant stages in the whole temperature range, and the steam partial oxidation of char residue promoted the generation of more gas products in high temperature range. The multi-Gaussian distributed activation energy model (DAEM) was proved plausible to describe thermal decomposition behaviours of MSW components under steam atmosphere. Copyright © 2015 Elsevier Ltd. All rights reserved.

A global fouling factor methodology for analyzing steam generator thermal performance degradation

International Nuclear Information System (INIS)

Kreider, M.A.; White, G.A.; Varrin, R.D.

1998-01-01

Over the past few years, steam generator (SG) thermal performance degradation has led to decreased plant efficiency and power output at numerous PWR nuclear power plants with recirculating-type SGs. The authors have developed and implemented methodologies for quantitatively evaluating the various sources of SG performance degradation, both internal and external to the SG pressure boundary. These methodologies include computation of the global fouling factor history, evaluation of secondary deposit thermal resistance using deposit characterization data, and consideration of pressure loss causes unrelated to the tube bundle, such as hot-leg temperature streaming and SG moisture separator performance. In order to evaluate the utility of the global fouling factor methodology, the authors performed case studies for a number of PWR SG designs. Key results from two of these studies are presented here. Uncertainty analyses were performed to determine whether the calculated fouling factor for each plant represented significant fouling or whether uncertainty in key variables (e.g., steam pressure or feedwater flow rate) could be responsible for calculated fouling. The methodology was validated using two methods: by predicting the SG pressure following chemical cleaning at San Onofre 2 and also by performing a sensitivity study with the industry-standard thermal-hydraulics code ATHOS to investigate the effects of spatially varying tube scale distributions. This study indicated that the average scale thickness has a greater impact on fouling than the spatial distribution, showing that the assumption of uniform resistance inherent to the global fouling factor is reasonable. In tandem with the fouling-factor analyses, a study evaluated for each plant the potential causes of pressure loss. The combined results of the global fouling factor calculations and the pressure loss evaluations demonstrated two key points: 1) that the available thermal margin against fouling, which can

Assessing the impact of primary measures for NOx reduction on the thermal power plant steam boiler

International Nuclear Information System (INIS)

Stupar, Goran; Tucaković, Dragan; Živanović, Titoslav; Belošević, Srdjan

2015-01-01

The European normatives prescribe content of 200 mg/Nm 3 NO x for pulverized coal combusting power plants. In order to reduce content of NO x in Serbian thermal power plant (TPP) 'Kostolac B' it's necessary to implement particular measures until 2016. The mathematical model of lignite combustion in the steam boiler furnace is defined and applied to analyze the possibility of implementing certain primary measures for reducing nitrogen oxides and their effects on the steam boiler operation. This model includes processes in the coal-fired furnace and defines radiating reactive two-phase turbulent flow. The model of turbulent flow also contains sub-model of fuel and thermal NO x formation and destruction. This complex mathematical model is related to thermal and aerodynamic calculations of the steam boiler within a unified calculation system in order to analyze the steam boiler overall work. This system provides calculations with a number of influential parameters. The steam boiler calculations for unit 1 (350 MWe) of TPP 'Kostolac B' are implemented for existing and modified combustion system in order to achieve effective, reliable and ecological facility work. The paper presents the influence analysis of large number of parameters on the steam boiler operation with an accepted concept of primary measures. Presented system of calculations is verified against measurements in TPP 'Kostolac B'. - Highlights: • Modern steam boilers need to operate according to ecological standards. • Possibility of applying some of the primary measures of NO x reduction. • Conventional calculations have no possibility to estimate sub-stoichiometric combustion. • Develop a new method of connecting the calculations. • Analysis shows the most favorable operation boiler regime (efficiency and ecology)

Ecotaxes and their impact in the cost of steam and electric energy generated by a steam turbine system

International Nuclear Information System (INIS)

Montero, Gisela

2006-01-01

Ecotaxes allow the internalization of costs that are considered externalities associated with polluting industrial process emissions to the atmosphere. In this paper, ecotaxes internalize polluting emissions negative impacts that are added to electricity and steam generated costs of a steam turbine and heat recovery systems from a utilities refinery plant. Steam costs were calculated by means of an exergy analysis tool and Aspen Plus simulation models. Ecotaxes were calculated for specific substances emitted in the refinery flue gases, based on a toxicity and pollution scale. Ecotaxes were generated from a model that includes damages produced to biotic and abiotic resources and considers the relative position of those substances in a toxicity and pollution scale. These ecotaxes were internalized by an exergoeconomic analysis resulting in an increase in the cost per kWh produced. This kind of ecotax is not applied in Mexico. The values of ecotaxes used in the cost determination are referred to the values currently applied by some European countries to nitrogen oxides emissions. (author)

Study on thermal and mechanical properties of U-tube materials for steam generator

International Nuclear Information System (INIS)

Rheu, Woo Suk; Kang, Young Hwan; Park, Jong Man; Joo, Ki Nam; Kim, Sung Soo; Maeng, Wan Young; Park, Se Jin

1993-01-01

Most of domestic nuclear plants have used I600 TT material for steam generator U-tube, and piled up the field experience. I600 HTMA and I690 TT, however, are recommended for an alternative of U-tube by ABB-CE since YK-3 and 4. Field experience of I600 HTMA and I690 TT have not compiled in the country, so it is concerned to select the future materials for U-tube. Thus, database on the thermal and mechanical properties of U-tube materials is very necessary for design documentations. In this study, the thermal, mechanical and metallugical properties were tested and evaluated to establish the database for steam generator U-tube. In addition, thermal conductivity of I600 and I690 was measured and compared statistically, providing a basic document for applying I690 to U-tube. The results will be used to improve the manufacturing process in order to increase the integrity of U-tube. (Author)

The supply of steam from Candu reactors for heavy water production

International Nuclear Information System (INIS)

Robertson, R.F.S.

1975-09-01

By 1980, Canada's energy needs for D 2 O production will be 420 MW of electrical energy and 3600 MW of thermal energy (as steam). The nature of the process demands that this energy supply be exceptionally stable. Today, production plants are located at or close to nuclear electricity generating sites where advantage can be taken of the low cost of both the electricity and steam produced by nuclear reactors. Reliability of energy supply is achieved by dividing the load between the multiple units which comprise the sites. The present and proposed means of energy supply to the production sites at the Bruce Heavy Water Plant in Ontario and the La Prade Heavy Water Plant in Quebec are described. (author)

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.

Draft environmental statement related to steam generator repair at H.B. Robinson Steam Electric Plant Unit No. 2, (Docket No. 50-261)

International Nuclear Information System (INIS)

1983-09-01

The staff has considered the environmental impacts and economic costs of the proposed steam generator repair at the H.B. Robinson Steam Electric Plant Unit No. 2 along with reasonable alternatives to the proposed action. The staff has concluded that the proposed repair will not significantly affect the quality of the human environment and that there are no preferable alternatives to the proposed action. Furthermore, any impacts from the repair program are outweighted by its benefits

Technical and economic studies of small reactors for supply of electricity and steam

International Nuclear Information System (INIS)

Spiewak, I.; Klepper, O.H.; Fuller, L.C.

1977-01-01

Several years ago conventional opinion held that nuclear power plants must be very large to be competitive with fossil fuels. This situation has changed markedly in most countries within recent years, as oil and gas supplies have become more scarce and costly. Studies have been carried out of several nuclear steam supply systems in the small and intermediate size range. Detail studies are reported of the Consolidated Nuclear Steam Generator (CNSG), a 313 MW(t) pressurized water reactor being developed by Babcock and Wilcox, as applied to industrial energy needs. Both conventional and barge-mounted nuclear steam supply systems are considered. Conceptual studies have been started of pressurized and boiling water reactors in the range of 1000 MW(t), which are envisioned for utility operation for supply of electric power and steam. Design studies of a 500 MW(t) high temperature reactor are also reported. The small reactors are expected to have higher unit costs than the large commercial plants, but to have compensating advantages in higher plant availability, shorter construction schedule and greater siting flexibility. Studies are also reported of power cycle parameters and cost allocations for extraction of steam from steam turbine plants. This steam could be used for industrial energy, district heating or desalination

Technical and economic studies of small reactors for supply of electricity and steam

International Nuclear Information System (INIS)

Spiewak, I.; Klepper, O.H.; Fuller, L.C.

1977-02-01

Several years ago conventional opinion held that nuclear power plants must be very large to be competitive with fossil fuels. This situation has changed markedly in most countries within recent years, as oil and gas supplies have become more scarce and costly. Studies have been carried out for several nuclear steam supply systems in the small and intermediate size range. Detail studies are reported of the Consolidated Nuclear Steam Generator (CNSG), a 365 MW(th) pressurized water reactor being developed by Babcock and Wilcox, as applied to industrial energy needs. Both conventional and barge-mounted nuclear steam supply systems are considered. Conceptual studies have been started of pressurized and boiling water reactors in the range of 1000 MW(th), which are envisioned for utility operation for supply of electric power and steam. Design studies of a 500 MW(th) high temperature reactor are also reported. The small reactors are expected to have higher unit costs than the large commercial plants, but to have compensating advantages in higher plant availability, shorter construction schedule, and greater siting flexibility. Studies are also reported of power cycle parameters and cost allocations for extraction of steam from steam turbine plants. This steam could be used for industrial energy, district heating, or desalination

Technical and economic studies of small reactors for supply of electricity and steam

International Nuclear Information System (INIS)

Spiewak, I.; Klepper, O.H.; Fuller, L.C.

1977-01-01

Several years ago conventional opinion held that nuclear power plants must be very large to be competitive with fossil fuels. This situation has changed markedly in most countries within recent years, as oil and gas supplies have become more scarce and costly. Studies have been carried out of several nuclear steam supply systems in the small and intermediate size range. Detail studies are reported of the Consolidated Nuclear Steam Generator (CNSG), a 313MW(th) pressurized water reactor being developed by Babcock and Wilcox, as applied to industrial energy needs. Both conventional and barge-mounted nuclear steam supply systems are considered. Conceptual studies have been started of pressurized and boiling water reactors in the range of 1000MW(th), which are envisioned for utility operation for supply of electric power and steam. Design studies of a 500MW(th) high temperature reactor are also reported. The small reactors are expected to have higher unit costs than the large commercial plants, but to have compensating advantages in higher plant availability, shorter construction schedule and greater siting flexibility. Studies are also reported of power cycle parameters and cost allocations for extraction of steam from steam turbine plants. This steam could be used for industrial energy, district heating or desalination. (author)

Thermal electric power production

International Nuclear Information System (INIS)

Boehmer, S.

2001-01-01

The basic principle of a thermal power plant is to heat up water in the pipe system of a boiler to generate steam, which exits the boiler with high pressure and releases its energy to a tandem-arranged turbine. This energy is transmitted to a generator over a common shaft. The generated electricity is fed into the power supply system. The processed steam is condensed to water by means of a condenser and transferred back into the pipe system of the boiler (feed water circuit). In general the following techniques are applied for the combustion of solid, liquid and gaseous fuels: dry bottom boiler, wet bottom boiler, grate firing, fluidized bed combustion, gasification systems - integrated gasification combined cycle (IGCC), oil firing technique, gas firing technique. Residues from power plants are generated by the following processes and emission reduction measures: separation of bottom ash or boiler slag in the boiler; separation of fly ash (particulate matter) by means of filters or electric precipitators; desulphurization through lime additive processes, dry sorption or spray absorption processes and lime scrubbing processes; desulphurization according to Wellmann-Lord and to the Walther process; reduction of NO x emissions by selective catalytic reduction (SCR). In this case spent catalyst results as a waste unless it is recycled. No residues are generated by the following measures to reduce NO x emissions: minimization of nitrogen by selective non-catalytic reduction (SNCR); adaptations of the firing technology to avoid emissions - primary measures (low-NO x burners, CO reduction). However, this may change the quality of fly ash by increasing unburnt carbon. Combustion of fossil fuels (with the exception of gaseous fuels) and biomass generates large quantities of residues - with coal being the greatest contributor - either from the fuel itself in the form of ashes, or from flue gas cleaning measures. In coal-fired power plants huge amounts of inorganic residues

900 MW CP1 nuclear steam turbine retrofit thermal effects on low pressure diaphragms

International Nuclear Information System (INIS)

Buguin, A.; Gruau, P.; Lamarque, F.; Huggett, J.

2015-01-01

The steam turbines of the Koeberg units 1 and 2 operated by ESKOM in South Africa have been retrofitted in order to mitigate the generic problems of stress corrosion cracking of the original shrunk-on disk rotor design. As already done in Belgium and France, the implementation of welded rotors improves the turbine reliability and availability. Moreover, the new technology implemented associated with a new steam path allows a significant performance improvement. With a wealth of experience in CP1 retrofit, ALSTOM has put in place new technical features in the steam path in order to further improve the heat rate. Among them, steam balance holes drilled in the rotor disks have exacerbated the thermal sensitivity of the LP diaphragms. During the commissioning of the Unit 1 LP turbines following the retrofit, the load increase led to unacceptable vibrations. An investigation program was launched to determine the root causes of the problem. This paper presents the findings following the turbine inspection, as well as the recommendations and modifications to allow a smooth return to service of the unit. In addition, the results of the root cause analysis of the vibration incident are explained. Based on finite element calculations and site measurements, ALSTOM has established that the diaphragm thermal behavior, intensified by the steam balance holes, has led to radial rubbing. It was also established that the phenomena had no effect on the diaphragms mechanical integrity. Design changes have been proposed to ensure a safe and reliable long term operation of the units. These modifications have been successfully implemented onto the Koeberg Unit 2 Nuclear Steam Turbine commissioned in November 2012. (authors)

Start-up support for New Brunswick Electric's Point Lepreau nuclear steam generators

International Nuclear Information System (INIS)

Schneider, W.; Leroux, A.

1983-05-01

The start-up of the 600 MW Point Lepreau reactor provided the opportunity for direct involvement in the important low and medium power start-up phase which was of particular interest because this was a first-of-a-kind reactor type incorporating a new steam generator design. Support included test assistance and test results interpretation for the thermal hydraulic performance of the steam generators and in particular, investigation of water level response to operating pressure, power and feed flow. This work resulted in both a greatly improved understanding of transient characteristics and in a number of beneficial refinements in the control methods

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.)

Solar energy thermally powered electrical generating system

Science.gov (United States)

Owens, William R. (Inventor)

1989-01-01

A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

Economic analysis of process steam and electricity generation by a 200 MW NHR

International Nuclear Information System (INIS)

Tian Li; Wang Yongqing

2000-01-01

New applications for low temperature nuclear heating reactors should be developed using economic analysis. This paper compares and analyzes the economics of the generation 1.5 MPa process steam and electricity by a 200 MW nuclear heating reactor (NHR-200) for industrial development. The project is very attractive economically with an internal rate of return of 19.61%, a net present worth (discount rate 10%) of 765 million yuan RMB and a capital recovery or payback period of about 5 years after construction is completed. Compared with only using the NHR-200 for in winter heating, the economic of process steam and electricity generation by NHR-200 are much better. In addition, the NHR-200 will significantly improve environmental pollution in cities and reduce the transport of coal from north to south in China

Local chemical and thermal-hydraulic analysis of U-tube steam generators

International Nuclear Information System (INIS)

Lee, J.Y.; No, H.C.

1990-01-01

In order to know how pH distribution affects corrosion in a U-tube steam generator, a study of the combination of water chemistry and thermal-hydraulic conditions is suggested. A two-fluid (unequal velocity and unequal temperature) formulation is proposed to describe the convective transport of volatile species in each phase, and a spherical bubble model is developed on the basis of the penetration theory to describe the interfacial mass transfer. The thermal-hydraulic local conditions are obtained by the U-tube steam generator design analysis code FAUST which is based on the three-dimensional two-fluid model. The results of the present study are compared with dynamic equilibrium model calculations. This study shows that, in contrast with dynamic equilibrium calculations, the pH is lower in the cold-leg side than in the hot-leg side because of liquid recirculation. Just above the tube sheet, however, the lower void fraction in this region than that in the hot-leg region results in higher pH, which agrees with the prediction of the dynamic equilibrium model. (orig.)

76 FR 77022 - In the Matter of Carolina Power & Light Company, H.B. Robinson Steam Electric Plant, Unit No. 2...

Science.gov (United States)

2011-12-09

... and 72-3] In the Matter of Carolina Power & Light Company, H.B. Robinson Steam Electric Plant, Unit No. 2, H. B. Robinson Steam Electric Plant, Unit 2, Independent Spent Fuel Storage Installation; Order Approving Indirect Transfer of Control of Licenses I. Carolina Power & Light Company (CP&L, the licensee) is...

Assessing the thermal-hydraulic behaviour of steam generators in a CANDU-6 type NPP in the event of MSSV blockage on the open-setting

International Nuclear Information System (INIS)

Dinca, Elena

2004-01-01

This work aims at achieving an analysis regarding the thermal-hydraulic behaviour of a CANDU-6 type NPP in the event of the blockage on open-setting of an MSSV (Main Steam Safety Valve) for steam relief from steam generators. The systems studied are main steam and feedwater mixture in the secondary circuit, particularly being analyzed the behaviour of the steam generators as well as the primary heat transfer and the control system of heavy water pressure and inventory in the primary system. One supposes that the MSSV blockage occurs directly after its opening in the event of an accident that led to the a steam pressure rise in the steam generators up to the threshold value of MSSV o penning. The analysis was applied to two events of initiation which lead to MSSV o penning, namely a Class IV loss of electric supply and loss of vacuum in turbine condenser. In the simulation of the events selected for analysis a long elapse of time is supposed (3600 seconds) and no operator intervention while the NPP is operating at rating power and equilibrium fuel regime. Each of the two events were analyzed for two distinct sets of conditions of event initiation and evolution. The study was focussed on the behaviour of NPP, particularly of the steam generators, and on the estimation of the amount of water in the secondary circuit released into the atmosphere during the event. The analysis is of deterministic type and supplies information required by the Probabilistic Safety Assessment (PSA) applied to nuclear facilities in establishing the operation procedures and documentation. The analysis was based on design data for a CANDU-6 NPP and the HYDN3 code for thermal-hydraulic computation in CANDU type NPPs. In the paper there are presented the analysis, methodology, models, hypotheses and the input data as well as the analyzed cases. Within the computing code some models were developed to allow simulating the event sequences chosen for analyses. The results are plotted and

Green Remediation Best Management Practices: Implementing In Situ Thermal Technologies

Science.gov (United States)

Over recent years, the use of in situ thermal technologies such as electrical resistance heating, thermal conductive heating, and steam enhanced extraction to remediate contaminated sites has notably increased.

Quantitative indexes of gas-steam thermo electrical power plants thermodynamical cycles; Indices quantitativos de ciclos termodinamicos de centrais termoeletricas de gas-vapor

Energy Technology Data Exchange (ETDEWEB)

Vlassov, D.; Vargas, J.V.C. [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Mecanica]. E-mails: vlassov@demec.ufpr.br; jvargas@demec.ufpr.br

2002-07-01

This paper analyses various thermal schemes of the world wide most used cycles in gas-steam thermoelectric power plants. The combination of gas turbine cycle with the steam-gas cycle in thermoelectric power plants is performed in several ways, resulting in different thermal schemes, used equipment and operation plant basic characteristics. The thermal scheme of a gas-steam power plant is a determinant factor for the definition of energetic, economic and ecological characteristics. For the comparative analysis various quantitative indexes are presented, as for example: the heat fraction supplied to the gas turbine cycle and the cycle binary rate.

Thermally-enhanced oil recovery method and apparatus

Science.gov (United States)

Stahl, Charles R.; Gibson, Michael A.; Knudsen, Christian W.

1987-01-01

A thermally-enhanced oil recovery method and apparatus for exploiting deep well reservoirs utilizes electric downhole steam generators to provide supplemental heat to generate high quality steam from hot pressurized water which is heated at the surface. A downhole electric heater placed within a well bore for local heating of the pressurized liquid water into steam is powered by electricity from the above-ground gas turbine-driven electric generators fueled by any clean fuel such as natural gas, distillate or some crude oils, or may come from the field being stimulated. Heat recovered from the turbine exhaust is used to provide the hot pressurized water. Electrical power may be cogenerated and sold to an electric utility to provide immediate cash flow and improved economics. During the cogeneration period (no electrical power to some or all of the downhole units), the oil field can continue to be stimulated by injecting hot pressurized water, which will flash into lower quality steam at reservoir conditions. The heater includes electrical heating elements supplied with three-phase alternating current or direct current. The injection fluid flows through the heater elements to generate high quality steam to exit at the bottom of the heater assembly into the reservoir. The injection tube is closed at the bottom and has radial orifices for expanding the injection fluid to reservoir pressure.

Thermal-hydraulic experiments for the PCHE type steam generator

International Nuclear Information System (INIS)

Shin, C. W.; No, H. C.

2015-01-01

Printed circuit heat exchanger (PCHE) manufactured by HEATRIC is a compact type of the mini-channel heat exchanger. The PCHE is manufactured by diffusion bonding of the chemically-etched plates, and has high heat transfer rate due to a large surface. Therefore, the size of heat exchanger can be reduced by 1/5 - 1/6 and PCHE can be operated under high pressure, high temperature and multi-phase flow. Under such merits, it is used as heat exchanger with various purposes of gas cycle and water cycle. Recently, it is newly suggested as an application of a steam generator. IRIS of MIT and FASES of KAIST conceptually adopted PCHE as a steam generator. When using boiling condition of micro-channel, flow instability is one of the critical issues. Instability may cause unstable mass flow rate, sudden temperature change and system control failure. However instability tests of micro channels using water are very limited because the previous studies were focused on a single tube or other fluid instead of water. In KAIST, we construct the test facility to study the thermal hydraulics and fluid dynamics of the heat exchanger, especially occurrence of instability. By inducing the pressure drop of inlet water, amplitude of oscillation declined by 90%. Finally, the throttling effect was experimentally confirmed that PCHE could be utilized as a steam generator

Accurate calibration of steam turbine speed control system and its influence on primary regulation at electric grid

Energy Technology Data Exchange (ETDEWEB)

Irrazabal Bohorquez, Washington Orlando; Barbosa, Joao Roberto [Technological Institute of Aeronautics (ITA/CTA), Sao Jose dos Campos, SP (Brazil). Center for Reference on Gas Turbine and Energy], E-mail: barbosa@ita.br

2010-07-01

In an interconnected electric system there are two very important parameters: the field voltage and the frequency system. The frequency system is very important for the primary regulation of the electric grid. Each turbomachine actuating as generator interconnected to the grid has an automatic speed regulator to keep the rotational speed and mechanical power of the prime machine operating at the set conditions and stable frequency. The electric grid is a dynamical system and in every moment the power units are exposed to several types of disturbances, which cause unbalance of the mechanical power developed by prime machine and the consumed electric power at the grid. The steam turbine speed control system controls the turbine speed to support the electric grid primary frequency at the same time it controls the frequency of the prime machine. Using a mathematical model for the speed control system, the transfer functions were calculated, as well as the proportionality constants of each element of the steam turbine automatic speed regulator. Among other parameters, the droop characteristic of steam turbine and the dynamic characteristics of the automatic speed regulator elements were calculated. Another important result was the determination of the behavior of the speed control when disturbances occur with the improvement of the calibration precision of the control system. (author)

Effect of steam thermal treatment on the drying process of Eucalyptus dunnii variables

Directory of Open Access Journals (Sweden)

Elias Taylor Durgante Severo

2013-12-01

Full Text Available The aim of this study was to evaluate the effect of steam treatment prior to drying on the initial moisture content, moisture gradient, and drying rate in Eucalyptus dunnii Maiden wood. Boards were steamed at 100ºC for 3 h after 1 h of heating-up. Part of these boards was dried in a drying electric oven at 50ºC, and part was dried at kiln. The results showed that the steaming prior to drying of wood: (1 significantly reduced by 9.2% the initial moisture content; (2 significantly increased by 6.2% the drying rate; (3 significantly decreased by 15.6 and 14.8% the moisture gradient between the outer layer and the center of boards and between the outer and intermediate layers of boards, respectively. Steamed boards when dried in an oven showed drying rate of 0.007065 whereas in kiln were 0.008200 and 0.034300 from green to 17 and 17 to 12% moisture content, respectively. It was demonstrated that the steaming prior to drying can be suitable for reduces the drying times of this kind of wood.

Thermal-hydraulics in recirculating steam generators

International Nuclear Information System (INIS)

Carver, M.B.; Carlucci, L.N.; Inch, W.W.R.

1981-04-01

This manual describes the THIRST code and its use in computing three-dimensional two-phase flow and heat transfer in a steam generator under steady state operation. The manual is intended primarily to facilitate the application of the code to the analysis of steam generators typical of CANDU nuclear stations. Application to other steam generator designs is also discussed. Details of the assumptions used to formulate the model and to implement the numerical solution are also included

Combined heat and power plants with parallel tandem steam turbines; Smaaskalig kraftvaerme med parallellkopplade tandemturbiner

Energy Technology Data Exchange (ETDEWEB)

Steinwall, Pontus; Norstroem, Urban; Pettersson, Camilla; Oesterlin, Erik

2004-12-01

We investigate the technical and economical conditions for a concept with parallel coupled tandem turbines in small scale combined heat and power plants fired with bio-fuel and waste. Performance and heat production costs at varying electricity prices for the concept with two smaller tandem coupled steam turbines has been compared to the traditional concept with one single multi-staged turbine. Three different types of plants have been investigated: - Bio fuelled CHP plant with thermal capacity of 15 MW{sub th}; - Waste fired CHP plant with thermal capacity of 20 MW{sub th}; - Bio fuelled CHP plant with thermal capacity of 25 MW{sub th}. The simple steam turbines (Curtis turbines) used in the tandem arrangement has an isentropic efficiency of about 49 to 53% compared to the multi-staged steam turbines with isentropic efficiency in the range of 59% to 81%. The lower isentropic efficiency for the single staged turbines is to some extent compensated at partial load when one of the two turbines can be shut down leading to better operational conditions for the one still in operation. For concepts with saturated steam at partial load below 50% the tandem arrangements presents higher electricity efficiency than the conventional single turbine alternative. The difference in annual production of electricity is therefore less than the difference in isentropic efficiency for the two concepts. Production of electricity is between 2% and 42% lower for the tandem arrangements in this study. Investment costs for the turbine island has been calculated for the two turbine concepts and when the costs for turbines, generator, power transmission, condensing system, piping system, buildings, assembling, commissioning and engineering has been added the sum is about the same for the two concepts. For the bio-fuelled plant with thermal capacity of 15 MW{sub th} the turbine island amount to about 10-12 MSEK and about 13-15 MSEK for the waste fired plant with a thermal capacity of 20 MW

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)

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

The Thermal Hydraulics of Tube Support Fouling in Nuclear Steam Generators

International Nuclear Information System (INIS)

Rummens, Helena E.C.; Rogers, J.T.; Turner, C.W.

2004-01-01

It is hypothesized that the thermal-hydraulic environment plays a role in the fouling of tube supports in nuclear steam generators. Experiments were performed to simulate the thermal-hydraulic environment near various designs of supports. Pressure loss, local velocity, turbulence intensity, and local void fraction were measured to characterize the effect of the support. Fouling mechanisms specific to supports were inferred from these experimental data and from actual steam generator inspection results. An analytical model was developed to predict the rate of particulate deposition on the supports, to better understand the complex processes involved.This paper presents the following set of tools for assessing the fouling propensity of a given support design: (1) proposed fouling mechanisms, (2) criteria for support fouling propensity, (3) correlation of fouling with parameters such as mass flux and quality, (4) descriptions of experimental tools such as flow visualization and measurement of pressure-loss profiles, and (5) analytical tools.An important conclusion from this and our previous work is that the fouling propensity is greater with broached support plates, both trefoil and quatrefoil, than with lattice bar supports and formed bar supports, in which significant cross flows occur

Steam generator thermal hydraulic design & functional architecture features and related operational and reliability issues requiring consideration

International Nuclear Information System (INIS)

Klarner, R.G.

2012-01-01

Proper thermal hydraulic design and functional architecture are critical to successful steam generator operation and long term reliability. The evolution of steam generators has been a gradual learning process that has benefited from continuous industry operational experience (OPEX). Inadequate thermal hydraulic design can lead to numerous degradation mechanisms such as excessive deposition, corrosion, flow and level instabilities, fluid-elastic instabilities and tube wear. The functional architecture determines the health of the tube bundle and the other internals during manufacturing, handling and operation. It also determines thermal performance as well as establishing global thermal-hydraulic characteristics such as water level shrink and swell response. This paper discusses the range of operational and reliability issues and relates them to the thermal hydraulic attributes and functional architecture of steam generators (many SG reliability issues are further discussed in other presentations at this conference). In pursuing such issues, the paper focuses on the four major features of the equipment, identifying in each case the goals and requirements such features must meet. Typical approaches and the means by which such requirements are addressed in current equipment are discussed. The four features are: 1. Tubing Material and Tube Bundle Heat Transfer Performance; a. Two materials are in current use – Alloy 690 TT and Alloy 800. Both are good materials with excellent performance records which serve their owners very well (the reliability attributes of Alloy 800 and 690 are discussed in other papers at this conference). Caution is advised in the supply of any material: – material quality is only assured by what is specified to material suppliers in procurement specifications – i.e. - all the knowledge and research in the world assures nothing if its findings are not reflected in procurement requirements. b. Heat transfer performance in addition to being

Effect of baking and steaming on physicochemical and thermal properties of sweet potato puree preserved by freezing and freeze-drying

Directory of Open Access Journals (Sweden)

Bernarda Svrakačić

2016-01-01

Full Text Available Thermal treatments could be one of the hurdles in applications of sweet potato purees for food different products formulation. Sweet potato purees (SPP were prepared from raw, baked and steamed roots and they were preserved by freezing and freeze-drying. The effects of baking and steaming on thermal properties (melting temperature-Tm, melting transition energy - ΔH, and glass transition temperatures - Tg of sweet potato (cultivar Beauregard, were measured by means of a Differential scanning calorimetry (DSC. The SPP made from baked roots had higher total and soluble solids (20.32 and 18.95%, respectively than SPP made from raw and steamed roots. It can be also noticed that starch content was reduced by steaming and baking which reflected on amount of total and reducing sugars. The increase of reducing sugars level in baked SPP for 3.78% and steamed for 0.86% SPP was the result of yielding the maltose. The chemical changes of SPP also influenced the thermal behavior such that SPP prepared from baked sweet potato roots had the lowest initial freezing point (-2.80 °C followed by SPP prepared from steamed (-2.63 °C and raw (-0.71 °C roots. The highest energy for melting (transition was needed for SPP prepared from raw potato roots followed by steamed and baked roots, -103.79, -103.63, and -102.90 J/g, respectively. The glass transition in freeze-dried SPP prepared from raw roots was not detected. However, in the freeze-dried SPP prepared from baked and steamed roots the glass transition was detected in the range of 39 and 42 °C but with no significant difference (p > 0.05.

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.)

Alternative method for steam generation for thermal oxidation of silicon

Science.gov (United States)

Spiegelman, Jeffrey J.

2010-02-01

Thermal oxidation of silicon is an important process step in MEMS device fabrication. Thicker oxide layers are often used as structural components and can take days or weeks to grow, causing high gas costs, maintenance issues, and a process bottleneck. Pyrolytic steam, which is generated from hydrogen and oxygen combustion, was the default process, but has serious drawbacks: cost, safety, particles, permitting, reduced growth rate, rapid hydrogen consumption, component breakdown and limited steam flow rates. Results from data collected over a 24 month period by a MEMS manufacturer supports replacement of pyrolytic torches with RASIRC Steamer technology to reduce process cycle time and enable expansion previously limited by local hydrogen permitting. Data was gathered to determine whether Steamers can meet or exceed pyrolytic torch performance. The RASIRC Steamer uses de-ionized water as its steam source, eliminating dependence on hydrogen and oxygen. A non-porous hydrophilic membrane selectively allows water vapor to pass. All other molecules are greatly restricted, so contaminants in water such as dissolved gases, ions, total organic compounds (TOC), particles, and metals can be removed in the steam phase. The MEMS manufacturer improved growth rate by 7% over the growth range from 1μm to 3.5μm. Over a four month period, wafer uniformity, refractive index, wafer stress, and etch rate were tracked with no significant difference found. The elimination of hydrogen generated a four-month return on investment (ROI). Mean time between failure (MTBF) was increased from 3 weeks to 32 weeks based on three Steamers operating over eight months.

Numerical Study of Thermal Hydraulics for Secondary side of Steam Generator by CUPID/MARS Coupled Simulation

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Ryong; Yoon, Han Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

As a thermal-hydraulic behavior in the secondary side of steam generator such as two-phase boiling flow, flow-induce vibration of U-tubes is quite complicated, the importance to numerically investigate the flow behavior has been arisen. Recently, multi-scale analyses have been developed to take into account the primary side as well. In this study, the coupled CUPID and MARS code was used for the simulation of boiler side of the PWR steam generator. Calculation results are compared with the existing code quantitatively. Coupled CUPID/MARS code was applied for the simulation of the steam generator. The primary side of the steam generator and other RCS was simulated by MARS and the secondary side was calculated by CUPID with porous media approach.

Mechanical design of a sodium heated steam generator

International Nuclear Information System (INIS)

Chetal, S.C.

1975-01-01

FBTR steam generator is a once through type unit consisting of four 12.5 MW thermal modules generating a total of 74 tons per hour of steam at 125 bar and 480 0 C. This paper outlines the mechanical design of such type of steam generator with emphasis on special design problems associated with this type of sodium to water steam heat exchanger, namely, thermal cycling of transition zone where nucleate boiling changes over to film boiling, application of pressure vessel design criteria for transient pressures, thermal stress evaluation resulting from differential expansion between shell and tube in this typical configuration, sodium headers support design, thermal sleeve, design, thermal shock analysis in thick tubes, thermal stress resulting from stratification and stability of expansion bends against vibration. Some of the possible design changes for the future large size steam generator are outlined. (author)

Electric Motor Thermal Management

Energy Technology Data Exchange (ETDEWEB)

Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-01

Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

Electrical power system integrated thermal/electrical system simulation

International Nuclear Information System (INIS)

Freeman, W.E.

1992-01-01

This paper adds thermal properties to previously developed electrical Saber templates and incorporates these templates into a functional Electrical Power Subsystem (EPS) simulation. These combined electrical and thermal templates enable the complete and realistic simulation of a vehicle EPS on-orbit. Applications include on-orbit energy balance determinations for system load changes, initial array and battery EPS sizing for new EPS development, and array and battery technology trade studies. This effort proves the versatility of the Saber simulation program in handling varied and complex simulations accurately and in a reasonable amount of computer time. 9 refs

Review of the Brunswick Steam Electric Plant Probabilistic Risk Assessment

International Nuclear Information System (INIS)

Sattison, M.B.; Davis, P.R.; Satterwhite, D.G.; Gilmore, W.E.; Gregg, R.E.

1989-11-01

A review of the Brunswick Steam Electric Plant probabilistic risk Assessment was conducted with the objective of confirming the safety perspectives brought to light by the probabilistic risk assessment. The scope of the review included the entire Level I probabilistic risk assessment including external events. This is consistent with the scope of the probabilistic risk assessment. The review included an assessment of the assumptions, methods, models, and data used in the study. 47 refs., 14 figs., 15 tabs

Electric Motor Thermal Management R&D. Annual Report

Energy Technology Data Exchange (ETDEWEB)

Bennion, Kevin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-04-01

With the push to reduce component volumes, lower costs, and reduce weight without sacrificing performance or reliability, the challenges associated with thermal management increase for power electronics and electric motors. Thermal management for electric motors will become more important as the automotive industry continues the transition to more electrically dominant vehicle propulsion systems. The transition to more electrically dominant propulsion systems leads to higher-power duty cycles for electric drive systems. Thermal constraints place significant limitations on how electric motors ultimately perform, and as thermal management improves, there will be a direct trade-off between motor performance, efficiency, cost, and the sizing of electric motors to operate within the thermal constraints. The goal of this research project is to support broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management. Work in FY15 focused on two areas related to motor thermal management: passive thermal performance and active convective cooling. Passive thermal performance emphasized the thermal impact of materials and thermal interfaces among materials within an assembled motor. The research tasks supported the publication of test methods and data for thermal contact resistances and direction-dependent thermal conductivity within an electric motor. Active convective cooling focused on measuring convective heat-transfer coefficients using automatic transmission fluid (ATF). Data for average convective heat transfer coefficients for direct impingement of ATF jets was published. Also, experimental hardware for mapping local-scale and stator-scale convective heat transfer coefficients for ATF jet impingement were developed.

CDIO – The steam engine powering the electric grid

DEFF Research Database (Denmark)

Træholt, Chresten; Holbøll, Joachim; Thomsen, Ole Cornelius

2011-01-01

In building the new DTU B.Eng programme [1] one of the pilots on the 4’th semester is the Design-build project course in Electric Energy Systems. In this course, which is the last Designbuild course many of the CDIO Syllabus bullets [2] are addressed starting with problem identification and formu......In building the new DTU B.Eng programme [1] one of the pilots on the 4’th semester is the Design-build project course in Electric Energy Systems. In this course, which is the last Designbuild course many of the CDIO Syllabus bullets [2] are addressed starting with problem identification...... and formulation, experimental inquiry and modelling, finally leading to planning and solution. The goal is to acquire the skills that are needed for an engineer within electric power engineering to analyse a given task, define the necessary steps to solve the task, organize him/her self and others and finally...... solve the task with success. The concrete work is built up around a miniaturized electric energy system powered by a steam engine. The system mimics an essential sub-section of a real electric power system. The process is realised with a combination of optional lectures, optional exercises, 3 set...

Mathematical modelling of a steam boiler room to research thermal efficiency

International Nuclear Information System (INIS)

Bujak, J.

2008-01-01

This paper introduces a mathematical model of a boiler room to research its thermal efficiency. The model is regarded as an open thermodynamic system exchanging mass, energy, and heat with the atmosphere. On those grounds, the energy and energy balance were calculated. Here I show several possibilities concerning how this model may be applied. Test results of the coefficient of thermal efficiency were compared to a real object, i.e. a steam boiler room of the Provincial Hospital in Wloclawek (Poland). The tests were carried out for 18 months. The results obtained in the boiler room were used for verification of the mathematical model

Control scheme for direct steam generation in parabolic troughs under recirculation operation mode

Energy Technology Data Exchange (ETDEWEB)

Valenzuela, L.; Zarza, E. [CIEMAT, Plataforma Solar de Almeria, Ctra. Senes s/n, P.O. Box 22, E-04200 Tabernas, Almeria (Spain); Berenguel, M. [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, E-04120 Almeria (Spain); Camacho, E.F. [Universidad de Sevilla, Dpto. de Ingenieria de Sistemas y Automatica, Camino de los Descubrimientos s/n, E-41092 Sevilla (Spain)

2006-01-15

Electricity production using solar thermal energy is one of the main research areas at present in the field of renewable energies, these systems being characterised by the need of reliable control systems aimed at maintaining desired operating conditions in the face of changes in solar radiation, which is the main source of energy. A new prototype of solar system with parabolic trough collectors was implemented at the Plataforma Solar de Almeria (PSA, South-East Spain) to investigate the direct steam generation process under real solar conditions in the parabolic solar collector field of a thermal power plant prototype. This paper presents details and some results of the application of a control scheme designed and tested for the recirculation operation mode, for which the main objective is to obtain steam at constant temperature and pressure at the outlet of the solar field, so that changes produced in the inlet water conditions and/or solar radiation will only affect the amount of steam produced by the solar field. The steam quality and consequently the nominal efficiency of the plant are thus maintained. (author)

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.

Three Dimensional Visualization for the Steam Injection into Water Pool using Electrical Resistance Tomography

International Nuclear Information System (INIS)

Khambampati, Anil Kumar; Lee, Jeong Seong; Kim, Sin; Kim, Kyung Youn

2010-01-01

The direct injection of steam into a water pool is a method of heat transfer used in many process industries. The amount of research in this area however is limited to the nuclear industry, with applications relating to reactor cooling systems. Electrical resistance tomography (ERT), a low cost, non-invasive and which has high temporal resolution characteristics, can be used as a visualization tool for the resistivity distribution for the steam injection into water pool such as IRWST. In this paper, three dimensional resistivity distribution of the process is obtained through ERT using iterative Gauss-Newton method. Numerical experiments are performed by assuming different resistive objects in the water pool. Numerical results show that ERT is successful in estimating the resistivity distribution for the injection of steam in the water pool

Production of Fischer–Tropsch fuels and electricity from bituminous coal based on steam hydrogasification

International Nuclear Information System (INIS)

Lu, Xiaoming; Norbeck, Joseph M.; Park, Chan S.

2012-01-01

A new thermochemical process for (Fischer–Tropsch) FT fuels and electricity coproduction based on steam hydrogasification is addressed and evaluated in this study. The core parts include (Steam Hydrogasification Reactor) SHR, (Steam Methane Reformer) SMR and (Fisher–Tropsch Reactor) FTR. A key feature of SHR is the enhanced conversion of carbon into methane at high steam environment with hydrogen and no need for catalyst or the use of oxygen. Facilities utilizing bituminous coal for coproduction of FT fuels and electricity with carbon dioxide sequestration are designed in detail. Cases with design capacity of either 400 or 4000 TPD (Tonne Per Day) (dry basis) are investigated with process modeling and cost estimation. A cash flow analysis is performed to determine the fuels (Production Cost) PC. The analysis shows that the 400 TPD case due to a FT fuels PC of 5.99 $/gallon diesel equivalent results in a plant design that is totally uneconomic. The 4000 TPD plant design is expected to produce 7143 bbl/day FT liquids with PC of 2.02 $/gallon and 2.27 $/gallon diesel equivalent at overall carbon capture ratio of 65% and 90%, respectively. Prospective commercial economics benefits with increasing plant size and improvements from large-scale demonstration efforts on steam hydrogasification. -- Highlights: ► We develop a new thermochemical method for synthetic fuels production. ► Detailed plant design and process modeling for the Coal-to-Liquid facilities are performed. ► Economic analysis has been carried out in determining the fuel production cost and IRR. ► The fuels produced in this study can compete with petroleum when crude oil price is 100 $/bbl. ► Further economic benefit comes with plant scale-up and process commercial demonstration efforts.

Comparing the steam and electric heat tracing solutions for petrochemical or refining facilities

Energy Technology Data Exchange (ETDEWEB)

Young, Joseph G.; McQueen, Greg [Tyco Thermal Controls, Belgie (Belgium)

2012-07-01

In this era of energy conservation and cost reduction, the ability to effectively select the optimal solution to meet the heat management system needs of petrochemical or refining facilities is becoming increasingly important. Depending on the type and location of the plant, a heat management system (HMS) can comprise a significant portion of the overall capital expenditure, as well as the ongoing operating and maintenance costs. Several important heat management system design decisions affect the financial operations of a facility, including the selection of the heat tracing technology, the utility distribution scheme, and the insulation system criteria, among others. However, most of these decisions are made early in the project life-cycle without thorough analysis of the various options available. From a high level perspective, numerous heat trace media should be considered, including electric, steam, tempered water, and glycol. These systems also have different impacts on piping systems within the plant battery limits (ISBL) and transfer lines outside of the battery limits (OSBL). This paper takes a careful look at two of the predominant heat tracing technologies - electric heat tracing and steam tracing - and compares these within the larger framework of the heat management system, and relative to petrochemical or refining facilities within the general Brazil geography. In the broader context, a heat management system is defined as the heat tracing technology itself, the utility distribution associated with that technology, the control and monitoring scheme associated with that technology, and the insulation system. We will evaluate the capital expenditure cost, operating expenditure cost, and overall reliability of the electric and steam tracing mediums in both the ISBL and OSBL environments within this broader context. (author)

Steam CFD simulation of injection in suppression pool

International Nuclear Information System (INIS)

Naveen Samad, A.M.; Ghosh, Sumana

2015-01-01

Boiling water reactor (BWR) is one of the common types of electricity generating nuclear reactor. Suppression pool system is a major component of the BWR which has to be designed efficiently for the safe operations. During some accidents like Loss of Coolant Accident (LOCA) large amount of steam are injected to the pressure suppression system resulting in increase in temperature of the pool and thereby increasing the pressure. The present work discuss about the Computational Fluid Dynamics (CFD) simulation of steam injected to the wet well of BWR through the blow down pipes and there by investigating the hydrodynamic and thermal characteristics of the system. The simulations were carried out for three different steam injection velocities. The numerical simulations were performed with ANSYS FLUENT using multiphase 3D Volume of Fluid (VOF) model and k-ε model was adopted for modelling turbulence flow. (author)

A two-fluid two-phase model for thermal-hydraulic analysis of a U-tube steam generator

International Nuclear Information System (INIS)

Hung, Huanjen; Chieng, Chingchang; Pei, Baushei; Wang, Songfeng

1993-01-01

The Advanced Thermal-Hydraulic Analysis Code for Nuclear Steam Generators (ATHANS) was developed on the basis of the THERMIT-UTSG computer code for U-tube steam generators. The main features of the ATHANS model are as follows: (a) the equations are solved in cylindrical coordinates, (b) the number and the arrangement of the control volumes inside the steam generator can be chosen by the user, (c) the virtual mass effect is incorporated, and (d) the conjugate gradient squared method is employed to accelerate and improve the numerical convergence. The performance of the model is successfully validated by comparison with the test data from a Westinghouse model F steam generator at the Maanshan nuclear power plant. Better agreement with the test data can be obtained by a finer grid system using a cylindrical coordinate system and the virtual mass effect. With these advanced features, ATHANS provides the basic framework for further studies on the problems of steam generators, such as analyses of secondary-side corrosion and tube ruptures

Thermal-hydraulic tests of steam-generator tube-support-plate crevices. Volume 2. Appendixes I through S. Final report

International Nuclear Information System (INIS)

Cassell, D.S.; Vroom, D.W.

1983-01-01

A test program was conducted to determine for selected steam generator tube supports the thermal/hydraulic conditions at the inception of dryout as indicated by a tube wall temperature excursion, to determine the pressure drop across the supports, and to obtain photographic documentation of the flow upstream and downstream of the supports. A multi-tube steam generator model was used and testing performed over the range of typcal PWR steam generator operating conditions. These appendices contain information on instrumentation calibration, test model and loop calibration, error analysis, test model thermal-hydraulic analyses, index of lab materials and log sheets, index of two-phase flow still photographs, index of high speed movies and video, test data printouts, test model and loop fabrication drawings, procedure for silver brazing tubewall thermocouples, and procedure for esablishing tube-tube support line contact

Severe transient tests on operation steam generators: Analysis of the fluid structure dynamic thermal interaction

International Nuclear Information System (INIS)

Billon, F.; David, J.; Procaccia, H.

1983-01-01

The operating efficiency of steam generators (S.G.s) and their structural integrity depend on the design configurations of the feedwater spray within the S.G., and on the operating procedure. To check the merit of some design modifications, and to verify the fluid-structure interaction with a view to preserve the S.G.s integrity during severe operating transients, a special instrumentation that admits the determination of the instantaneous thermal hydraulic characteristics of the flow in the secondary water and the S.G. tube sheet, has been installed by EDF on one steam generator of Tricastin unit 1 power plant. In parallel, FRAMATOME has developped a computer code, TEMPTRON, that allows the calculations of the thermal loads and the consequent stresses in the most sollicited zones of the steam generator during transient operation of the plant. This code divides the S.G. into three parts: - the first concerns the S.G.s region above the downcomer, zone where the mixing between hot water and cold feedwater occurs, - the second is the downcomer itself which is divided into n segments, - the third concerns the tube sheet zone which is also divided into n segments. The most severe transient test performed is the auxiliary cold feedwater injection into the steam generator during a hot standby of the plant: two levels of flow rate have been realised: 55 and 110 m 3 /h of 42 0 C feedwater. The tests have shown that if the cold feedwater injection occurs when the steam generator water level is below feedwater ring, the lowest fluid temperature reached at tube sheet inlet is about 230 0 C. (orig.)

Electricity costs in liberalized market

International Nuclear Information System (INIS)

Barkans, J.; Junghans, G.

2006-01-01

In the liberalized electricity market the flexible demand determines the operation of power plants. Under market conditions the producers are forced to compete, and their power plants are normally loaded in order of increasing prices. The electricity costs consist of fixed and variable components, and the competition among producers simulates minimization of both the components. Considering the fixed costs (including maintenance, depreciation, capital costs and other permanent costs not depending on production) to be known, the total electricity costs in different operating conditions are based on the economic characteristics and the equipment load of a power plant. The paper describes the method for determination of electricity costs for condensing thermal power plants with permanent steam take-off for regeneration purposes and adjustable steam take-off for the needs of local heat energy consumers. The marginal costs for CHP plants are determined considering a number of different steam take-off from a turbine. At the electricity cost determination, auxiliary services also are taken into account. These can be reduced by adjusting the rotational speed of electric motors. The paper also shows how to determine the electricity costs for gas turbines, combined cycle gas turbines, and nuclear power plants. The position of hydro power plants among other PPs in the free market is also analysed. (authors)

Design and performance of BWC replacement steam generators for PWR systems

International Nuclear Information System (INIS)

Klarner, R.; Steinmoeller, F.; Millman, J.; Schneider, W.

1998-01-01

In recent years, Babcock and Wilcox Canada (BWC) has provided a number of PWR Replacement Steam Generators (RSGS) to replace units that had experienced extensive Alloy 600 tube degradation. BWC RSG units are in operation at Northeast Utilities' Millstone Unit 2, Rochester Gas and Electric's Ginna Station, Duke Energy's Catawba Unit 1, McGuire Unit 1 and 2, Florida Power and Light's St. Lucie Unit 1 and Commonwealth Edison's Byron 1 Station. Extensive start-up performance characteristics have been obtained for Millstone 2, Ginna, McGuire 1, and Catawba 1 RSGS. The Millstone 2, Ginna and Catawba 1 RSGs have also undergone extensive inspections following their first cycle of operation. The design and start-up performance characteristics of these RSGs are presented. The BWC Replacement Steam generators were designed to fit the existing envelope of pressure boundary dimensions to ensure licensability and integration into the Nuclear Steam Supply System. The RSGs were provided with a tube bundle of Alloy 690TT tubing, sized to match or exceed the original steam generator (OSG) thermal performance including provision for the reduced thermal conductivity of Alloy 690 relative to Alloy 600. The RSG tube bundle configurations provide a higher circulation design relative to the OSG, and feature corrosion resistant lattice grid and U-bend tube supports which provide effective anti-vibration support. The tube bundle supports accommodate relatively unobstructed flow and allow unrestrained structural interactions during thermal transients. Efficient steam separators assure low moisture carryover as well as high circulation. Performance measurements obtained during start-up verify that the BWC RSGs meet or exceed the specified thermal and moisture carryover performance requirements. RSG water level stability results at nor-mal operation and during plant transients have been excellent. Visual and ECT inspections have confirmed minimal deposition and 100% tube integrity following

Steam gasification of oil palm trunk waste for clean syngas production

International Nuclear Information System (INIS)

Nipattummakul, Nimit; Ahmed, Islam I.; Kerdsuwan, Somrat; Gupta, Ashwani K.

2012-01-01

Highlights: ► Initial high values of syngas flow rate are attributed to rapid devolatilization. ► Over 50% of syngas generated was obtained during the first five minutes of the process. ► Increase in steam flow rate resulted in reduced gasification time. ► Variation in steam flow rate slightly affected the apparent thermal efficiency. ► Oil palm yielded more energy than that from mangrove wood, paper and food waste. -- Abstract: Waste and agricultural residues offer significant potential for harvesting chemical energy with simultaneous reduction of environmental pollution, providing carbon neutral (or even carbon negative) sustained energy production, energy security and alleviating social concerns associated with the wastes. Steam gasification is now recognized as one of the most efficient approaches for waste to clean energy conversion. Syngas generated during the gasification process can be utilized for electric power generation, heat generation and for other industrial and domestic uses. In this paper results obtained from the steam assisted gasification of oil palm trunk waste are presented. A batch type gasifier has been used to examine the syngas characteristics from gasification of palm trunk waste using steam as the gasifying agent. Reactor temperature was fixed at 800 °C. Results show initial high values of syngas flow rate, which is attributed to rapid devolatilization of the sample. Approximately over 50% of the total syngas generated was obtained during the first five minutes of the process. An increase in steam flow rate accelerated the gasification reactions and resulted in reduced gasification time. The effect of steam flow rate on the apparent thermal efficiency has also been investigated. Variation in steam flow rate slightly affected the apparent thermal efficiency and was found to be very high. Properties of the syngas obtained from the gasification of oil palm trunk waste have been compared to other samples under similar operating

Improvement of chemical control in the water-steam cycle of thermal power plants

International Nuclear Information System (INIS)

Rajakovic-Ognjanovic, Vladana N.; Zivojinovic, Dragana Z.; Grgur, Branimir N.; Rajakovic, Ljubinka V.

2011-01-01

A more effective chemical control in the water-steam cycle (WSC) of thermal power plants (TPP) is proposed in this paper. Minimization of corrosion effects by the production of ultra pure water and its strict control is the basis of all the investigated processes. The research involved the analysis of water samples in the WSC through key water quality parameters and by the most convenient analytical tools. The necessity for the stricter chemical control is demonstrated through a concrete example of the TPP Nikola Tesla, Serbia. After a thorough analysis of the chemical control system of the WSC, diagnostic and control parameters were chosen for continuous systematic measurements. Sodium and chloride ions were recognized as the ions which indicate the corrosion potential of the water and give insight into the proper production and maintenance of water within the WSC. Chemical transformations of crucial corrosion elements, iron and silica, were considered and related to their quantitative values. - Research highlights: → The more effective chemical control in the water-steam cycle of thermal power plant Nikola Tesla, Serbia. → In chemical control the diagnostic and control parameters were optimized and introduced for the systematic measurements in the water-steam cycle. → Sodium and chloride ions were recognized as ions which indicate corrosion potential of water and give insight to proper function of production and maintenance of water within water-team cycle. → Chemical transformations of crucial corrosion elements, iron and silica are considered and related with their quantitative values.

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...

Thermo-economic analysis of a micro-cogeneration system based on a rotary steam engine (RSE)

International Nuclear Information System (INIS)

Alanne, Kari; Saari, Kari; Kuosa, Maunu; Jokisalo, Juha; Martin, Andrew R.

2012-01-01

A rotary steam engine (RSE) is a simple, small, quiet and lubricant-free option for micro-cogeneration. It is capable of exploiting versatile thermal sources and steam temperatures of 150–180 °C, which allow operational pressures less than 10 bar for electrical power ranges of 1–20 kW e . An RSE can be easily integrated in commercially available biomass-fired household boilers. In this paper, we characterize the boiler-integrated RSE micro-cogeneration system and specify a two-control-volume thermodynamic model to conduct performance analyses in residential applications. Our computational analysis suggests that an RSE integrated with a 17 kW th pellet-fueled boiler can obtain an electrical output of 1.925 kW e, in the design temperature of 150 °C, the electrical efficiency being 9% (based on the lower heating value of the fuel, LHV) and the thermal efficiency 77% (LHV). In a single-family house in Finland, the above system would operate up to 1274 h/y, meeting 31% of the house's electrical demand. The amount of electricity delivered into the grid is 989 kW h/y. An economic analysis suggests that incremental costs not exceeding € 1500 are justifiable at payback periods less than five years, when compared to standard boilers. - Highlights: ► We characterize and model a micro-cogeneration system based on a rotary steam engine. ► We assess the performance of the above system in a residential building in Finland. ► The above system is capable of meeting 31% of the building's annual electrical demand. ► The above system may cost at most € 1500 more than a standard boiler system.

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

Characterization of a steam plasma jet at atmospheric pressure

International Nuclear Information System (INIS)

Ni Guohua; Zhao Peng; Cheng Cheng; Song Ye; Meng Yuedong; Toyoda, Hirotaka

2012-01-01

An atmospheric steam plasma jet generated by an original dc water plasma torch is investigated using electrical and spectroscopic techniques. Because it directly uses the water used for cooling electrodes as the plasma-forming gas, the water plasma torch has high thermal efficiency and a compact structure. The operational features of the water plasma torch and the generation of the steam plasma jet are analyzed based on the temporal evolution of voltage, current and steam pressure in the arc chamber. The influence of the output characteristics of the power source, the fluctuation of the arc and current intensity on the unsteadiness of the steam plasma jet is studied. The restrike mode is identified as the fluctuation characteristic of the steam arc, which contributes significantly to the instabilities of the steam plasma jet. In addition, the emission spectroscopic technique is employed to diagnose the steam plasma. The axial distributions of plasma parameters in the steam plasma jet, such as gas temperature, excitation temperature and electron number density, are determined by the diatomic molecule OH fitting method, Boltzmann slope method and H β Stark broadening, respectively. The steam plasma jet at atmospheric pressure is found to be close to the local thermodynamic equilibrium (LTE) state by comparing the measured electron density with the threshold value of electron density for the LTE state. Moreover, based on the assumption of LTE, the axial distributions of reactive species in the steam plasma jet are estimated, which indicates that the steam plasma has high chemical activity.

Thermal power blocks with ultra-super-critical steam parameters

Directory of Open Access Journals (Sweden)

Aličić Merim M.

2016-01-01

Full Text Available New generation of thermal power plants are required to have increased utilization rates, in addition to reduced emissions of pollutants, in order to reach optimal solutions, from both technical and economic point of view. One way to achieve greater utilization efficiency is operation of the plant at super critical (SC or ultra super critical steam parameters (USC. However, achieving high parameters depends on use of new materials, which have better properties at high temperatures and pressures, use of new welding technologies and by solving the problem of corrosion. The paper gives an overview of some of the plants with these parameters.

Thermal Inactivation of Listeria monocytogenes and Salmonella during Water and Steam Blanching of Vegetables.

Science.gov (United States)

Ceylan, Erdogan; McMahon, Wendy; Garren, Donna M

2017-09-01

Thermal inactivation of Listeria monocytogenes and Salmonella was evaluated on peas, spinach, broccoli, potatoes, and carrots that were treated with hot water and steam. One gram-positive bacterium, L. monocytogenes, and one gram-negative bacterium, Salmonella, were selected as pertinent human pathogens for evaluation. Samples were inoculated with a composite of five strains each of L. monocytogenes and Salmonella to achieve approximately 10 8 to 10 9 CFU/g. Inoculated samples were treated with hot water at 85 and 87.8°C and with steam at 85 and 96.7°C for up to 3.5 min. A greater than 5-log reduction of L. monocytogenes and Salmonella was achieved on all products within 0.5 min by hot water blanching at 85 and 87.8°C. Steam blanching at 85°C reduced Salmonella populations by greater than 5 log on spinach and peas within 2 min and on carrots and broccoli within 3.5 min. Populations of Salmonella were reduced by more than 5 log within 1 min on carrot, spinach, and broccoli and within 2 min on peas by steam blanching at 96.7°C. Steam blanching at 85°C reduced L. monocytogenes populations by more than 5 log on carrots and spinach within 2 min and on broccoli and peas within 3.5 min. L. monocytogenes populations were reduced more than 5 log within 1 min on carrot, spinach, peas and broccoli by steam blanching at 96.7°C. Longer treatment times and higher temperatures were required for steam-blanched samples than for samples blanched with hot water. Results suggest that hot water and steam blanching practices commonly used by the frozen vegetable industry will achieve the desired 5-log lethality of L. monocytogenes and Salmonella and will enhance microbiological safety prior to freezing.

Recruiting, Training, Retaining, and Promoting the Workforce of the Future at Comanche Peak Steam Electric Station

International Nuclear Information System (INIS)

Sunseri, M.

1999-01-01

TXU Electric expects to encounter a relatively high turnover in the workforce in the coming years. To prepare for this challenge and to maintain a high level of performance, a number of approaches are being implemented. These approaches involve recruiting experienced personnel, recruiting and developing local nonexperienced personnel, and developing current employees. Through these approaches, TXU Electric expects to maintain a high-quality workforce for the continued support of Comanche Peak Steam Electric Station

Thermal burn and electrical injuries among electric utility workers, 1995-2004.

Science.gov (United States)

Fordyce, Tiffani A; Kelsh, Michael; Lu, Elizabeth T; Sahl, Jack D; Yager, Janice W

2007-03-01

This study describes the occurrence of work-related injuries from thermal-, electrical- and chemical-burns among electric utility workers. We describe injury trends by occupation, body part injured, age, sex, and circumstances surrounding the injury. This analysis includes all thermal, electric, and chemical injuries included in the Electric Power Research Institute (EPRI) Occupational Health and Safety Database (OHSD). There were a total of 872 thermal burn and electric shock injuries representing 3.7% of all injuries, but accounting for nearly 13% of all medical claim costs, second only to the medical costs associated with sprain- and strain-related injuries (38% of all injuries). The majority of burns involved less than 1 day off of work. The head, hands, and other upper extremities were the body parts most frequently injured by burns or electric shocks. For this industry, electric-related burns accounted for the largest percentage of burn injuries, 399 injuries (45.8%), followed by thermal/heat burns, 345 injuries (39.6%), and chemical burns, 51 injuries (5.8%). These injuries also represented a disproportionate number of fatalities; of the 24 deaths recorded in the database, contact with electric current or with temperature extremes was the source of seven of the fatalities. High-risk occupations included welders, line workers, electricians, meter readers, mechanics, maintenance workers, and plant and equipment operators.

Water regime of steam power plants

International Nuclear Information System (INIS)

Oesz, Janos

2011-01-01

The water regime of water-steam thermal power plants (secondary side of pressurized water reactors (PWR); fossil-fired thermal power plants - referred to as steam power plants) has changed in the past 30 years, due to a shift from water chemistry to water regime approach. The article summarizes measures (that have been realised by chemists of NPP Paks) on which the secondary side of NPP Paks has become a high purity water-steam power plant and by which the water chemistry stress corrosion risk of heat transfer tubes in the VVER-440 steam generators was minimized. The measures can also be applied to the water regime of fossil-fired thermal power plants with super- and subcritical steam pressure. Based on the reliability analogue of PWR steam generators, water regime can be defined as the harmony of construction, material(s) and water chemistry, which needs to be provided in not only the steam generators (boiler) but in each heat exchanger of steam power plant: - Construction determines the processes of flow, heat and mass transfer and their local inequalities; - Material(s) determines the minimal rate of general corrosion and the sensitivity for local corrosion damage; - Water chemistry influences the general corrosion of material(s) and the corrosion products transport, as well as the formation of local corrosion environment. (orig.)

Prototype steam generator test at SCTI/ETEC. Acoustic program test plan

International Nuclear Information System (INIS)

Greene, D.A.; Thiele, A.; Claytor, T.N.

1981-10-01

This document is an integrated test plan covering programs at General Electric (ARSD), Rockwell International (RI) and Argonne National Laboratory (CT). It provides an overview of the acoustic leak detection test program which will be completed in conjunction with the prototype LMFBR steam generator at the Energy Technology Engineering Laboratory. The steam generator is installed in the Sodium Components Test Installation (SCTI). Two acoustic detection systems will be used during the test program, a low frequency system developed by GE-ARSD (GAAD system) and a high frequency system developed by RI-AI (HALD system). These systems will be used to acquire data on background noise during the thermal-hydraulic test program. Injection devices were installed during fabrication of the prototype steam generator to provide localized noise sources in the active region of the tube bundle. These injectors will be operated during the steam generator test program, and it will be shown that they are detected by the acoustic systems

A study on the thermal and mechanical properties of inconel for steam generator U-tube

International Nuclear Information System (INIS)

Ryu, Woo Seong; Kang, Young Hwan; Park, Jong Man; Choo, Kee Nam; Kim, Sung Soo; Maeng, Wan Young; Park, Se Jin

1993-12-01

A series of laboratory tests was conducted to obtain the thermal and mechanical properties of Inconel 600 and 690 for the design document of steam generator U-tube. The following properties were measured as a function of temperature, and treated statistically to establish a database: 1) heat capacity, RT ∼ 500 deg C, 2) thermal expansion, RT ∼ 500 deg C, 3) thermal diffusivity, RT ∼ 500 deg C, 4) thermal conductivity, RT ∼ 500 deg C, 5) tensile property, RT ∼ 700 deg C 6) ductility, RT ∼ 700 deg C, 7) Elastic modulii and Poission's ratio, RT, 8) Microhardness, 9) Oxidation rate. (Author)

Advanced technologies on steam generators

Energy Technology Data Exchange (ETDEWEB)

Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

1997-12-31

The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

Advanced technologies on steam generators

Energy Technology Data Exchange (ETDEWEB)

Sakata, Kaoru; Nakamura, Yuuki [Mitsubishi Heavy Industry Co., Takasago (Japan); Nakamori, Nobuo; Mizutani, Toshiyuki; Uwagawa, Seiichi; Saito, Itaru [Mitsubishi Heavy Industry Co., Kobe (Japan); Matsuoka, Tsuyoshi [Mitsubishi Heavy Industry Co., Yokohama (Japan)

1998-12-31

The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermalhydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (orig.). 3 refs.

Shiraz solar power plant operation with steam engine

International Nuclear Information System (INIS)

Yaghoubi, M.; Azizian, K.

2004-01-01

The present industrial developments and daily growing need of energy, as well as economical and environmental problem caused by fossil fuels consumption, resulted certain constraint for the future demand of energy. During the past two decades great attention has been made to use renewable energy for different sectors. In this regard for the first time in Iran, design and construction of a 250 K W Solar power plant in Shiraz, Iran is being carried out and it will go to operation within next year. The important elements of this power plant is an oil cycle and a steam cycle, and several studies have been done about design and operation of this power plant, both for steady state and transient conditions. For the steam cycle, initially a steam turbine was chosen and due to certain limitation it has been replaced by a steam engine. The steam engine is able to produce electricity with hot or saturated vapor at different pressures and temperatures. In this article, the effects of installing a steam engine and changing its vapor inlet pressure and also the effects of sending hot or saturated vapor to generate electricity are studied. Various cycle performance and daily electricity production are determined. The effects of oil cycle temperature on the collector field efficiency, and daily, monthly and annual amount of electricity production is calculated. Results are compared with the steam cycle output when it contains a steam turbine. It is found that with a steam engine it is possible to produce more annual electricity for certain conditions

Evaluation of thermal performance in fields subjected to steam injection (SW-SAGD mode), Orinoco oil belt, Venezuela

Energy Technology Data Exchange (ETDEWEB)

Armas, F.; Mago, R.; Franco, L.; Rodriguez, J.; Gil, E. [PDVSA EandP (Venezuela)

2011-07-01

The first well to operate the SW-SAGD process in the Orinoco oil belt in Venezuela was built in 2006 by Petroleos de Venezuela S.A (PDVSA). SW-SAGD is a thermal recovery process consisting in the injection of steam through a horizontal well pipe insulation. In order to follow the behavior of steam and the movement of heated fluids in such a process better, PDVSA installed a monitoring system composed of high temperature fiber optic and thermocouple type sensors. The aim of this paper is to assess the thermal behavior of reservoirs in wells under the SW-SAGD process. A pilot test has been conducted over the last 3 years. Results show an increase in production and estimations show a recovery factor twice as high as in other wells. This study demonstrated that SW-SAGD is an excellent alternative solution to stimulate reservoirs in the Orinoco oil belt and valuable information on the reservoir's thermal behavior was established.

Concentrating solar thermal power.

Science.gov (United States)

Müller-Steinhagen, Hans

2013-08-13

In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept.

Thermal and electrical conductivities of Cd-Zn alloys

International Nuclear Information System (INIS)

Saatci, B; Ari, M; Guenduez, M; Meydaneri, F; Bozoklu, M; Durmus, S

2006-01-01

The composition and temperature dependences of the thermal and electrical conductivities of three different Cd-Zn alloys have been investigated in the temperature range of 300-650 K. Thermal conductivities of the Cd-Zn alloys have been determined by using the radial heat flow method. It has been found that the thermal conductivity decreases slightly with increasing temperature and the data of thermal conductivity are shifting together to the higher values with increasing Cd composition. In addition, the electrical measurements were determined by using a standard DC four-point probe technique. The resistivity increases linearly and the electrical conductivity decreases exponentially with increasing temperature. The resistivity and electrical conductivity are independent of composition of Cd and Zn. Also, the temperature coefficient of Cd-Zn alloys has been determined, which is independent of composition of Cd and Zn. Finally, Lorenz number has been calculated using the thermal and electrical conductivity values at 373 and 533 K. The results satisfy the Wiedemann-Franz (WF) relation at T 373 K), the WF relation could not hold and the phonon component contribution of thermal conductivity dominates the thermal conduction

3D model of steam generator of nuclear power plant Krsko

International Nuclear Information System (INIS)

Ravnikar, I.; Petelin, S.

1995-01-01

The Westinghouse Electric Corporation D4 steam generator design was analyzed from a thermal-hydraulic point of view using the 3D PHOENICS computer code. Void fraction, velocity and enthalpy distributions were obtained in the U-tube riser. The boundary conditions of primary side were provided by SMUP 1D code. The calculations were carried out for present operating conditions of nuclear power plant Krsko. (author)

The market for steam turbine generators around the world

International Nuclear Information System (INIS)

Mandement, O.; Anglaret, P.; Ledermann, P.

2012-01-01

As a discrete market (in the mathematical meaning of the word) with irregular sales from one year to the next, the market for steam turbine generators in nuclear plants requires working out a strategy adapted to each project. The diversity of the reactors proposed (technology, thermal power, the thermodynamic characteristics of the steam supplied), the variety of the cold sources to be used (ranging from the Baltic Sea to the Indian Ocean) and the different frequencies of electricity grids (50 or 60 Hz) necessitate developing platforms of solutions. Furthermore, the requirement that local businesses have a share in contracts often entails partnerships. After pointing out the diversity of this market, the effort is made to point out its principal characteristics. (authors)

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.

Effects of electric current upon catalytic steam reforming of biomass gasification tar model compounds to syngas

International Nuclear Information System (INIS)

Tao, Jun; Lu, Qiang; Dong, Changqing; Du, Xiaoze; Dahlquist, Erik

2015-01-01

Highlights: • ECR technique was proposed to convert biomass gasification tar model compounds. • Electric current enhanced the reforming efficiency remarkably. • The highest toluene conversion reached 99.9%. • Ni–CeO 2 /γ-Al 2 O 3 exhibited good stability during the ECR performance. - Abstract: Electrochemical catalytic reforming (ECR) technique, known as electric current enhanced catalytic reforming technique, was proposed to convert the biomass gasification tar into syngas. In this study, Ni–CeO 2 /γ-Al 2 O 3 catalyst was prepared, and toluene was employed as the major feedstock for ECR experiments using a fixed-bed lab-scale setup where thermal electrons could be generated and provided to the catalyst. Several factors, including the electric current intensity, reaction temperature and steam/carbon (S/C) ratio, were investigated to reveal their effects on the conversion of toluene as well as the composition of the gas products. Moreover, toluene, two other tar model compounds (benzene and 1-methylnaphthalene) and real tar (tar-containing wastewater) were subjected to the long period catalytic stability tests. All the used catalysts were analyzed to determine their carbon contents. The results indicated that the presence of electric current enhanced the catalytic performance remarkably. The toluene conversion reached 99.9% under the electric current of 4 A, catalytic temperature of 800 °C and S/C ratio of 3. Stable conversion performances of benzene, 1-methylnaphthalene and tar-containing wastewater were also observed in the ECR process. H 2 and CO were the major gas products, while CO 2 and CH 4 were the minor ones. Due to the promising capability, the ECR technique deserves further investigation and application for efficient tar conversion

Functionalized Graphene Enables Highly Efficient Solar Thermal Steam Generation.

Science.gov (United States)

Yang, Junlong; Pang, Yunsong; Huang, Weixin; Shaw, Scott K; Schiffbauer, Jarrod; Pillers, Michelle Anne; Mu, Xin; Luo, Shirui; Zhang, Teng; Huang, Yajiang; Li, Guangxian; Ptasinska, Sylwia; Lieberman, Marya; Luo, Tengfei

2017-06-27

The ability to efficiently utilize solar thermal energy to enable liquid-to-vapor phase transition has great technological implications for a wide variety of applications, such as water treatment and chemical fractionation. Here, we demonstrate that functionalizing graphene using hydrophilic groups can greatly enhance the solar thermal steam generation efficiency. Our results show that specially functionalized graphene can improve the overall solar-to-vapor efficiency from 38% to 48% at one sun conditions compared to chemically reduced graphene oxide. Our experiments show that such an improvement is a surface effect mainly attributed to the more hydrophilic feature of functionalized graphene, which influences the water meniscus profile at the vapor-liquid interface due to capillary effect. This will lead to thinner water films close to the three-phase contact line, where the water surface temperature is higher since the resistance of thinner water film is smaller, leading to more efficient evaporation. This strategy of functionalizing graphene to make it more hydrophilic can be potentially integrated with the existing macroscopic heat isolation strategies to further improve the overall solar-to-vapor conversion efficiency.

Design and construction of a steam generator with feedback; Projeto e construcao de um gerador de vapor com realimentacao

Energy Technology Data Exchange (ETDEWEB)

Camargo, Camila C., E-mail: camilacamargo@outlook.com [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Placco, Guilherme M., E-mail: placco@ieav.cta.br [Instituto de Tecnologia Aeronautica (ITA/CTA), Sao Jose dos Campos, SP (Brazil); Guimaraes, Lamartine N.F., E-mail: guimarae@ieav.cta.br [Instituto de Estudos Avancado (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Departamento ENU

2013-07-01

The EARTH project aims to develop technologies to design and build systems that generate electricity in space, using microreactors. One of the activities within the TERRA project aims to build a closed thermal cycle Rankine type in order to test a Tesla turbine type. The objective of this work is to design and build a steam generator with feedback, which should ensure a satisfactory range of steam supply, security system, feedback system and heating system.

Technical Specifications, Comanche Peak Steam Electric Station, Unit 1 (Docket No. 50-445)

International Nuclear Information System (INIS)

1990-04-01

The Technical Specifications for Comanche Peak Steam Electric Station, Unit 1 were prepared by the US Nuclear Regulatory Commission. They set forth the limits, operating conditions, and other requirements applicable to a nuclear reactor facility, as set forth in Section 50.36 of Title 10 of the Code of Federal Regulations Part 50, for the protection of the health and safety of the public

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)

Base-Load and Peak Electricity from a Combined Nuclear Heat and Fossil Combined-Cycle Plant

International Nuclear Information System (INIS)

Conklin, Jim; Forsberg, Charles W.

2007-01-01

A combined-cycle power plant is proposed that uses heat from a high-temperature reactor and fossil fuel to meet base-load and peak electrical demands. The high-temperature gas turbine produces shaft power to turn an electric generator. The hot exhaust is then fed to a heat recovery steam generator (HRSG) that provides steam to a steam turbine for added electrical power production. A simplified computational model of the thermal power conversion system was developed in order to parametrically investigate two different steady-state operation conditions: base load nuclear heat only from an Advanced High Temperature Reactor (AHTR), and combined nuclear heat with fossil heat to increase the turbine inlet temperature. These two cases bracket the expected range of power levels, where any intermediate power level can result during electrical load following. The computed results indicate that combined nuclear-fossil systems have the potential to offer both low-cost base-load electricity and lower-cost peak power relative to the existing combination of base-load nuclear plants and separate fossil-fired peak-electricity production units. In addition, electric grid stability, reduced greenhouse gases, and operational flexibility can also result with using the conventional technology presented here for the thermal power conversion system coupled with the AHTR

Design and performance of BWC replacement steam generators for PWR systems

Energy Technology Data Exchange (ETDEWEB)

Klarner, R.; Steinmoeller, F.; Millman, J.; Schneider, W. [Babcock and Wilcox Canada, Cambridge, Ontario (Canada)

1998-07-01

In recent years, Babcock and Wilcox Canada (BWC) has provided a number of PWR Replacement Steam Generators (RSGS) to replace units that had experienced extensive Alloy 600 tube degradation. BWC RSG units are in operation at Northeast Utilities' Millstone Unit 2, Rochester Gas and Electric's Ginna Station, Duke Energy's Catawba Unit 1, McGuire Unit 1 and 2, Florida Power and Light's St. Lucie Unit 1 and Commonwealth Edison's Byron 1 Station. Extensive start-up performance characteristics have been obtained for Millstone 2, Ginna, McGuire 1, and Catawba 1 RSGS. The Millstone 2, Ginna and Catawba 1 RSGs have also undergone extensive inspections following their first cycle of operation. The design and start-up performance characteristics of these RSGs are presented. The BWC Replacement Steam generators were designed to fit the existing envelope of pressure boundary dimensions to ensure licensability and integration into the Nuclear Steam Supply System. The RSGs were provided with a tube bundle of Alloy 690TT tubing, sized to match or exceed the original steam generator (OSG) thermal performance including provision for the reduced thermal conductivity of Alloy 690 relative to Alloy 600. The RSG tube bundle configurations provide a higher circulation design relative to the OSG, and feature corrosion resistant lattice grid and U-bend tube supports which provide effective anti-vibration support. The tube bundle supports accommodate relatively unobstructed flow and allow unrestrained structural interactions during thermal transients. Efficient steam separators assure low moisture carryover as well as high circulation. Performance measurements obtained during start-up verify that the BWC RSGs meet or exceed the specified thermal and moisture carryover performance requirements. RSG water level stability results at nor-mal operation and during plant transients have been excellent. Visual and ECT inspections have confirmed minimal deposition and 100

Electrical and thermal conductivities in dense plasmas

Energy Technology Data Exchange (ETDEWEB)

Faussurier, G., E-mail: gerald.faussurier@cea.fr; Blancard, C.; Combis, P.; Videau, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

2014-09-15

Expressions for the electrical and thermal conductivities in dense plasmas are derived combining the Chester-Thellung-Kubo-Greenwood approach and the Kramers approximation. The infrared divergence is removed assuming a Drude-like behaviour. An analytical expression is obtained for the Lorenz number that interpolates between the cold solid-state and the hot plasma phases. An expression for the electrical resistivity is proposed using the Ziman-Evans formula, from which the thermal conductivity can be deduced using the analytical expression for the Lorenz number. The present method can be used to estimate electrical and thermal conductivities of mixtures. Comparisons with experiment and quantum molecular dynamics simulations are done.

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.)

75 FR 8753 - Carolina Power & Light Company, Brunswick Steam Electric Plant, Units 1 and 2; Environmental...

Science.gov (United States)

2010-02-25

... Dusenbury of the North Carolina Department of Environment and Natural Resources regarding the environmental... & Light Company, Brunswick Steam Electric Plant, Units 1 and 2; Environmental Assessment and Finding of No... identification of licensing and regulatory actions requiring environmental assessments,'' the NRC prepared an...

Electrical-thermal coupling of induction machine for improved ...

African Journals Online (AJOL)

Electrical-thermal coupling of induction machine for improved thermal performance. ... Nigerian Journal of Technology ... The interaction of its electrical and mechanical parts leads to an increase in temperature which if not properly monitored ...

Steampunk: Full Steam Ahead

Science.gov (United States)

Campbell, Heather M.

2010-01-01

Steam-powered machines, anachronistic technology, clockwork automatons, gas-filled airships, tentacled monsters, fob watches, and top hats--these are all elements of steampunk. Steampunk is both speculative fiction that imagines technology evolved from steam-powered cogs and gears--instead of from electricity and computers--and a movement that…

Steam separator-superheater with drawing of a fraction of the dried steam

International Nuclear Information System (INIS)

Bessouat, Roger; Marjollet, Jacques.

1976-01-01

This invention concerns a vertical separator-superheater of the steam from a high pressure expansion turbine before it is admitted to an expansion turbine at a lower pressure, by heat exchange with steam under a greater pressure, and drawing of a fraction of the dried steam before it is superheated. Such drawing off is necessary in the heat exchange systems of light water nuclear reactors. Its purpose is to provide a separator-superheater that provides an even flow of non superheated steam and a regular distribution of the steam to be superheated to the various superheating bundles, with a significantly uniform temperature of the casing, thereby preventing thermal stresses and ensuring a minimal pressure drop. The vertical separator-superheater of the invention is divided into several vertical sections comprising as from the central area, a separation area of the steam entrained water and a superheater area and at least one other vertical section with only a separation area of the steam entrained water [fr

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.).

Simulation of thermal stresses in anode-supported solid oxide fuel cell stacks. Part II: Loss of gas-tightness, electrical contact and thermal buckling

Science.gov (United States)

Nakajo, Arata; Wuillemin, Zacharie; Van herle, Jan; Favrat, Daniel

Structural stability issues in planar solid oxide fuel cells arise from the mismatch between the coefficients of thermal expansion of the components. The stress state at operating temperature is the superposition of several contributions, which differ depending on the component. First, the cells accumulate residual stresses due to the sintering phase during the manufacturing process. Further, the load applied during assembly of the stack to ensure electric contact and flatten the cells prevents a completely stress-free expansion of each component during the heat-up. Finally, thermal gradients cause additional stresses in operation. The temperature profile generated by a thermo-electrochemical model implemented in an equation-oriented process modelling tool (gPROMS) was imported into finite-element software (ABAQUS) to calculate the distribution of stress and contact pressure on all components of a standard solid oxide fuel cell repeat unit. The different layers of the cell in exception of the cathode, i.e. anode, electrolyte and compensating layer were considered in the analysis to account for the cell curvature. Both steady-state and dynamic simulations were performed, with an emphasis on the cycling of the electrical load. The study includes two different types of cell, operation under both thermal partial oxidation and internal steam-methane reforming and two different initial thicknesses of the air and fuel compressive sealing gaskets. The results generated by the models are presented in two papers: Part I focuses on cell cracking. In the present paper, Part II, the occurrences of loss of gas-tightness in the compressive gaskets and/or electrical contact in the gas diffusion layer were identified. In addition, the dependence on temperature of both coefficients of thermal expansion and Young's modulus of the metallic interconnect (MIC) were implemented in the finite-element model to compute the plastic deformation, while the possibilities of thermal buckling

Improving Thermal and Electrical Efficiency in Photovoltaic Thermal Systems for Sustainable Cooling System Integration

Directory of Open Access Journals (Sweden)

Mohammad Alobaid

2018-06-01

Full Text Available Research into photovoltaic thermal systems is important in solar technologies as photovoltaic thermal systems are designed to produce both electrical and thermal energy, this can lead to improved performance of the overall system. The performance of photovoltaic thermal systems is based on several factors that include photovoltaic thermal materials, design, ambient temperature, inlet and outlet fluid temperature and photovoltaic cell temperature. The aim of this study is to investigate the effect of photovoltaic thermal outlet water temperatures and solar cell temperature on both electrical and thermal efficiency for different range of inlet water temperature. To achieve this, a mathematical model of a photovoltaic thermal system was developed to calculate the anticipated system performance. The factors that affect the efficiency of photovoltaic thermal collectors were discussed and the outlet fluid temperature from the photovoltaic thermal is investigated in order to reach the highest overall efficiency for the solar cooling system. An average thermal and electrical efficiency of 65% and 13.7%, respectively, was achieved and the photovoltaic thermal mathematical model was validated with experimental data from literature.

Electric Motor Thermal Management R&D

Energy Technology Data Exchange (ETDEWEB)

Bennion, Kevin

2016-06-07

Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

The limits to solar thermal electricity

International Nuclear Information System (INIS)

Trainer, Ted

2014-01-01

The potential and limits of solar thermal power systems depend primarily on their capacity to meet electricity demand in mid-winter, and the associated cost, storage and other implications. Evidence on output and costs is analysed. Most attention is given to central receivers. Problems of low radiation levels, embodied energy costs, variability and storage are discussed and are found to set significant difficulties for large scale solar thermal supply in less than ideal latitudes and seasons. It is concluded that for solar thermal systems to meet a large fraction of anticipated global electricity demand in winter would involve prohibitive capital costs. - Highlights: • Output and capital cost data for various solar thermal technologies is examined. • Special attention is given to performance in winter. • Attention is also given to the effect of solar intermittency. • Implications for storage are considered. • It is concluded that there are significant limits to solar thermal power

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

Recent developments in numerical simulation techniques of thermal recovery processes

Energy Technology Data Exchange (ETDEWEB)

Tamim, M. [Bangladesh University of Engineering and Technology, Bangladesh (Bangladesh); Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, Al-Ain 17555 (United Arab Emirates); Farouq Ali, S.M. [University of Alberta, Alberta (Canada)

2000-05-01

Numerical simulation of thermal processes (steam flooding, steam stimulation, SAGD, in-situ combustion, electrical heating, etc.) is an integral part of a thermal project design. The general tendency in the last 10 years has been to use commercial simulators. During the last decade, only a few new models have been reported in the literature. More work has been done to modify and refine solutions to existing problems to improve the efficiency of simulators. The paper discusses some of the recent developments in simulation techniques of thermal processes such as grid refinement, grid orientation, effect of temperature on relative permeability, mathematical models, and solution methods. The various aspects of simulation discussed here promote better understanding of the problems encountered in the simulation of thermal processes and will be of value to both simulator users and developers.

Fish protection at steam-electric power plants: alternative screening devices

International Nuclear Information System (INIS)

Cannon, J.B.

1978-01-01

Since the enactment of the Federal Water Pollution Control Act Amendments of 1972, very few innovations have surfaced that advance the state of intake technology for fish protection at steam-electric power plants. After careful examination of basic hydrology, hydraulics, and ecology of the source water body is completed and after a suitable location for the intake is established, the design process reduces to the development of proper screening techniques and to the provision of a means of preventing resident and migratory species from entering the intake structure. As a result of this design process, three basic fish protection concepts have evolved: fish deterrence, fish collection and removal, and fish diversion. Intake screening devices that protect fish are discussed

Transient analysis of a U-tube natural circulation steam generator

Energy Technology Data Exchange (ETDEWEB)

Gaikwad, A J; Kumar, Rajesh; Bhadra, Anu; Chakraborty, G; Venkat Raj, V [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

A computer code has been developed, for transient thermal-hydraulic analysis of proposed 500 MWe PHWR steam generator. The transient behaviour of a nuclear power plant is very much dependent on the steam generator performance, as it provides a thermal linkage between the primary and secondary systems. Study of dynamics of steam generator is essential for over all power plant dynamics as well as design of control systems for steam generator. A mathematical model has been developed for the simulation of thermal-hydraulic phenomena in a U tube natural circulation steam generator. Fluid model is based on one dimensional, nonlinear, single fluid conservation equations of mass, momentum, energy and equation of state. This model includes coupled two phase flow heat transfer and natural circulation. The model accounts for both compressibility and thermal expansion effects. The process simulation and results obtained for transients such as step change in load and total loss of feed water are presented. (author). 5 refs., 7 figs.

Solar thermal energy conversion to electrical power

International Nuclear Information System (INIS)

Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

2014-01-01

The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

Gas--steam turbine combined cycle power plants

Energy Technology Data Exchange (ETDEWEB)

Christian, J.E.

1978-10-01

The purpose of this technology evaluation is to provide performance and cost characteristics of the combined gas and steam turbine, cycle system applied to an Integrated Community Energy System (ICES). To date, most of the applications of combined cycles have been for electric power generation only. The basic gas--steam turbine combined cycle consists of: (1) a gas turbine-generator set, (2) a waste-heat recovery boiler in the gas turbine exhaust stream designed to produce steam, and (3) a steam turbine acting as a bottoming cycle. Because modification of the standard steam portion of the combined cycle would be necessary to recover waste heat at a useful temperature (> 212/sup 0/F), some sacrifice in the potential conversion efficiency is necessary at this temperature. The total energy efficiency ((electric power + recovered waste heat) divided by input fuel energy) varies from about 65 to 73% at full load to 34 to 49% at 20% rated electric power output. Two major factors that must be considered when installing a gas--steam turbine combines cycle are: the realiability of the gas turbine portion of the cycle, and the availability of liquid and gas fuels or the feasibility of hooking up with a coal gasification/liquefaction process.

Continuous ultrasonic waves to detect steam bubbles in water under high pressure

Energy Technology Data Exchange (ETDEWEB)

Hulshof, H J.M.; Schurink, F

1985-01-01

Steam in the recirculation circuit of boilers may lead to unacceptable high thermal loads on the evaporator tubes. The ability to detect steam in the recirculation circuit during process transients is therefore important. A simple detector using continuous ultrasonic waves and able to detect bubbles in water contained in steel tubes is described in this paper. The variation of the transmitted wave caused by the bubbles was determined by demodulation. The results have met the objectives set for cold water with air bubbles. A clear indication of the presence of steam bubbles was found in fast-flowing hot water in a steel tube with a diameter of 60 mm. A change in the low-frequency region of the modulation was the only indication of the presence of steam bubbles in the large-diameter downcomer of the water-separator drum of a boiler in an electrical power plant. Possible causes of the differences in the results obtained are discussed on the basis of differences in bubble sizes and in focusing and reflection of the ultrasonic waves. (orig.). 11 refs.; 10 figs.

Continuous ultrasonic waves to detect steam bubbles in water under high pressure

International Nuclear Information System (INIS)

Hulshof, H.J.M.; Schurink, F.

1985-01-01

Steam in the recirculation circuit of boilers may lead to unacceptable high thermal loads on the evaporator tubes. The ability to detect steam in the recirculation circuit during process transients is therefore important. A simple detector using continuous ultrasonic waves and able to detect bubbles in water contained in steel tubes is described in this paper. The variation of the transmitted wave caused by the bubbles was determined by demodulation. The results have met the objectives set for cold water with air bubbles. A clear indication of the presence of steam bubbles was found in fast-flowing hot water in a steel tube with a diameter of 60 mm. A change in the low-frequency region of the modulation was the only indication of the presence of steam bubbles in the large-diameter downcomer of the water-separator drum of a boiler in an electrical power plant. Possible causes of the differences in the results obtained are discussed on the basis of differences in bubble sizes and in focusing and reflection of the ultrasonic waves. (orig.)

Vapor generator steam drum spray heat

International Nuclear Information System (INIS)

Fasnacht, F.A. Jr.

1978-01-01

A typical embodiment of the invention provides a combination feedwater and cooldown water spray head that is centrally disposed in the lower portion of a nuclear power plant steam drum. This structure not only discharges the feedwater in the hottest part of the steam drum, but also increases the time required for the feedwater to reach the steam drum shell, thereby further increasing the feedwater temperature before it contacts the shell surface, thus reducing thermal shock to the steam drum structure

76 FR 66333 - Carolina Power & Light Company, H.B. Robinson Steam Electric Plant, Unit No. 2; Environmental...

Science.gov (United States)

2011-10-26

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-261; NRC-2011-0247] Carolina Power & Light Company, H.B. Robinson Steam Electric Plant, Unit No. 2; Environmental Assessment and Finding of No Significant... Facility Operating License No. DPR-23, issued to Carolina Power & Light Company (the licensee), for...

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)

Thermal Hydraulic Design and Analysis of a Water-Cooled Ceramic Breeder Blanket with Superheated Steam for CFETR

Science.gov (United States)

Cheng, Xiaoman; Ma, Xuebin; Jiang, Kecheng; Chen, Lei; Huang, Kai; Liu, Songlin

2015-09-01

The water-cooled ceramic breeder blanket (WCCB) is one of the blanket candidates for China fusion engineering test reactor (CFETR). In order to improve power generation efficiency and tritium breeding ratio, WCCB with superheated steam is under development. The thermal-hydraulic design is the key to achieve the purpose of safe heat removal and efficient power generation under normal and partial loading operation conditions. In this paper, the coolant flow scheme was designed and one self-developed analytical program was developed, based on a theoretical heat transfer model and empirical correlations. Employing this program, the design and analysis of related thermal-hydraulic parameters were performed under different fusion power conditions. The results indicated that the superheated steam water-cooled blanket is feasible. supported by the National Special Project for Magnetic Confined Nuclear Fusion Energy of China (Nos. 2013GB108004, 2014GB122000 and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

Performance analysis of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

International Nuclear Information System (INIS)

Modi, Anish; Haglind, Fredrik

2014-01-01

Solar thermal power plants have attracted increasing interest in the past few years – with respect to both the design of the various plant components, and extending the operation hours by employing different types of storage systems. One approach to improve the overall plant efficiency is to use direct steam generation with water/steam as both the heat transfer fluid in the solar receivers and the cycle working fluid. This enables operating the plant with higher turbine inlet temperatures. Available literature suggests that it is feasible to use ammonia-water mixtures at high temperatures without corroding the equipment by using suitable additives with the mixture. The purpose of the study reported here was to investigate if there is any benefit of using a Kalina cycle for a direct steam generation, central receiver solar thermal power plant with high live steam temperature (450 °C) and pressure (over 100 bar). Thermodynamic performance of the Kalina cycle in terms of the plant exergy efficiency was evaluated and compared with a simple Rankine cycle. The rates of exergy destruction for the different components in the two cycles were also calculated and compared. The results suggest that the simple Rankine cycle exhibits better performance than the Kalina cycle when the heat input is only from the solar receiver. However, when using a two-tank molten-salt storage system as the primary source of heat input, the Kalina cycle showed an advantage over the simple Rankine cycle because of about 33 % reduction in the storage requirement. The solar receiver showed the highest rate of exergy destruction for both the cycles. The rates of exergy destruction in other components of the cycles were found to be highly dependent on the amount of recuperation, and the ammonia mass fraction and pressure at the turbine inlet. - Highlights: •Kalina cycle for a central receiver solar thermal power plant with direct steam generation. •Rankine cycle shows better plant exergy

Supercritical Water Nuclear Steam Supply System: Innovations In Materials, Neutronics and Thermal-Hydraulics

International Nuclear Information System (INIS)

Anderson, Mark; Corradini, M.L.; Sridharan, K.; Wilson, P.; Cho, D.; Kim, T.K.; Lomperski, S.

2004-01-01

In the 1990's supercritical light-water reactors were considered in conceptual designs. A nuclear reactor cooled by supercritical waster would have a much higher thermal efficiency with a once-through direct power cycle, and could be based on standardized water reactor components (light water or heavy water). The theoretical efficiency could be improved by more than 33% over that of other water reactors and could be simplified with higher reliability; e.g., a boiling water reactor without steam separators or dryers

Thermal-hydraulic behavior on break simulation of steam generator U-tube

International Nuclear Information System (INIS)

Seul, Kwang Won; Bang, Young Seok; Lee, Sukho; Kim, Hho Jung

1995-01-01

The thermal-hydraulic behavior depending on the break simulation in a steam generator U-tube was investigated and identified the code predictability on plant responses during SGTR accident. The calculated results were compared and assessed with LSTF SB-SG-06 test data. The RELAP5/MOD3.1 code well predicted the sequence of events and the significant phenomena, such as the asymmetric loop behavior, the RCS cooldown and heat transfer by the natural circulation, and system depressurization, even though there were some differences from the experimental data. The break flowrate was found to be sensitive to the break model and affected the system behavior

Electricity from geothermal steam

Energy Technology Data Exchange (ETDEWEB)

Wheatcroft, E L.E.

1959-01-01

The development of the power station at Wairakei geothermal field is described. Wairakei is located at the center of New Zealand's volcanic belt, which lies within a major graben which is still undergoing some degree of downfaulting. A considerable number of wells, some exceeding 610 m, have been drilled. Steam and hot water are produced from both deep and shallow wells, which produce at gauge pressures of 1.5 MPa and 0.6 MPa, respectively. The turbines are fed by low, intermediate, and high pressure mains. The intermediate pressure turbine bank was installed as a replacement for a heavy water production facility which had originally been planned for the development. Stage 1 includes a 69 MW plant, and stage 2 will bring the capacity to 150 MW. A third stage, which would bring the output up to 250 MW had been proposed. The second stage involves the installation of more high pressure steam turbines, while the third stage would be powered primarily by hot water flashing. Generation is at 11 kV fed to a two-section 500 MVA board. Each section of the board feeds through a 40 MVA transformer to a pair of 220 V transmission lines which splice into the North Island grid. Other transformers feed 400 V auxiliaries and provide local supply.

High thermal conductivity connector having high electrical isolation

Science.gov (United States)

Nieman, Ralph C.; Gonczy, John D.; Nicol, Thomas H.

1995-01-01

A method and article for providing a low-thermal-resistance, high-electrical-isolation heat intercept connection. The connection method involves clamping, by thermal interference fit, an electrically isolating cylinder between an outer metallic ring and an inner metallic disk. The connection provides durable coupling of a heat sink and a heat source.

Impact of steam generator start-up limitations on the performance of a parabolic trough solar power plant

DEFF Research Database (Denmark)

Ferruzza, Davide; Topel, Monika; Laumert, Björn

2018-01-01

typically start-up and shut down every day, so in order to maximize their profitability, it is necessary to increase their flexibility in transient operation and to initiate power generation as rapidly as possible. Two of the key components are the steam generator and steam turbine and the rates at which...... they can reach operational speed are limited by thermo-mechanical constraints. This paper presents an analysis of the effects of the thermal stress limitations of the steam generator and steam turbine on the power plant start-up, and quantifies their impact on the economy of the system. A dynamic model......-driven and peak-load. The results indicate that for steam generator hot start-ups, a 1.5% increase in peak-load electricity production would be achieved by doubling the maximum allowable heating rate of the evaporator. No useful increase would be achieved by increasing the rates beyond a limit of 7–8 K...

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 11: Advanced steam systems. [energy conversion efficiency for electric power plants using steam

Science.gov (United States)

Wolfe, R. W.

1976-01-01

A parametric analysis was made of three types of advanced steam power plants that use coal in order to have a comparison of the cost of electricity produced by them a wide range of primary performance variables. Increasing the temperature and pressure of the steam above current industry levels resulted in increased energy costs because the cost of capital increased more than the fuel cost decreased. While the three plant types produced comparable energy cost levels, the pressurized fluidized bed boiler plant produced the lowest energy cost by the small margin of 0.69 mills/MJ (2.5 mills/kWh). It is recommended that this plant be designed in greater detail to determine its cost and performance more accurately than was possible in a broad parametric study and to ascertain problem areas which will require development effort. Also considered are pollution control measures such as scrubbers and separates for particulate emissions from stack gases.

Integrated Gasification SOFC Plant with a Steam Plant

DEFF Research Database (Denmark)

Rokni, Masoud; Pierobon, Leonardo

2011-01-01

A hybrid Solid Oxide Fuel Cell (SOFC) and Steam Turbine (ST) plant is integrated with a gasification plant. Wood chips are fed to the gasification plant to produce biogas and then this gas is fed into the anode side of a SOFC cycle to produce electricity and heat. The gases from the SOFC stacks...... enter into a burner to burn the rest of the fuel. The offgases after the burner are now used to generate steam in a Heat Recovery Steam Generator (HRSG). The generated steam is expanded in a ST to produce additional power. Thus a triple hybrid plant based on a gasification plant, a SOFC plant...... and a steam plant is presented and studied. The plant is called as IGSS (Integrated Gasification SOFC Steam plant). Different systems layouts are presented and investigated. Electrical efficiencies up to 56% are achieved which is considerably higher than the conventional integrated gasification combined...

Steam turbines for the future

International Nuclear Information System (INIS)

Trassl, W.

1988-01-01

Approximately 75% of the electrical energy produced in the world is generated in power plants with steam turbines (fossil and nuclear). Although gas turbines are increasingly applied in combined cycle power plants, not much will change in this matter in the future. As far as the steam parameters and the maximum unit output are concerned, a certain consolidation was noted during the past decades. The standard of development and mathematical penetration of the various steam turbine components is very high today and is applied in the entire field: For saturated steam turbines in nuclear power plants and for steam turbines without reheat, with reheat and with double reheat in fossil-fired power plants and for steam turbines with and without reheat in combined cycle power plants. (orig.) [de

Comparison of the Effects of Thermal Pretreatment, Steam Explosion and Ultrasonic Disintegration on Digestibility of Corn Stover

Directory of Open Access Journals (Sweden)

Andras Dallos

2016-06-01

Full Text Available The energy demand of the corn-based bioethanol production could be reduced using the agricultural byproducts as bioenergy feedstock for biogas digesters. The release of lignocellulosic material and therefore the acceleration of degradation processes can be achieved using thermal and mechanical pretreatments, which assist to hydrolyze the cell walls and speed the solubilization of biopolymers in biogas feedstock. This study is focused on liquid hot water, steam explosion and ultrasonic pretreatments of corn stover. The scientific contribution of this paper is a comprehensive comparison of the performance of the pretreatments by fast analytical, biochemical, anaerobic digestibility and biomethane potential tests, extended by energy consumptions and energy balance calculations.The effectiveness of pretreatments was evaluated by means of soluble chemical oxygen demand, biochemical oxygen demand and by the biogas and methane productivities. The results have shown that the thermal pretreatment, steam explosion and ultrasonic irradiation of biogas feedstock disintegrated the lignocellulosic structure, increased and accelerated the methane production and increased the cumulative biogas and methane productivity of corn stover in reference to the control during mesophilic anaerobic digestion.The energy balance demonstrated that there is an economical basis of the application of the liquid hot-compressed water pretreatments in a biogas plant. However, the steam explosion and ultrasonication are energetically not profitable for corn stover pretreatment.

Design and modelling of an innovative three-stage thermal storage system for direct steam generation CSP plants

Science.gov (United States)

Garcia, Pierre; Vuillerme, Valéry; Olcese, Marco; El Mourchid, Nadim

2016-05-01

Thermal Energy Storage systems (TES) for a Direct Steam Generation (DSG) solar plant feature preferably three stages in series including a latent heat storage module so that steam can be recovered with a limited temperature loss. The storage system designed within the Alsolen Sup project is characterized by an innovative combination of sensible and latent modules. A dynamic model of this three-stage storage has been developed and applied to size the storage system of the Alsolen Sup® plant demonstrator at CEA Cadarache. Results of this simulation show that this promising concept is an efficient way to store heat in DSG solar plants.

Molten salt steam generator subsystem research experiment. Volume I. Phase 1 - Final report

Energy Technology Data Exchange (ETDEWEB)

None

1984-10-01

A study was conducted for Phase 1 of a two-phase project whose objectives were to develop a reliable, cost-effective molten salt steam generating subsystem for solar thermal plants, minimize uncertainty in capital, operating, and maintenance costs, and demonstrate the ability of molten salt to generate high-pressure, high-temperature steam. The Phase 1 study involved the conceptual design of molten salt steam generating subsystems for a nominal 100-MWe net stand-alone solar central receiver electric generating plant, and a nominal 100-MWe net hybrid fossil-fueled electric power generating plant that is 50% repowered by a solar central receiver system. As part of Phase 1, a proposal was prepared for Phase 2, which involves the design, construction, testing and evaluation of a Subsystem Research Experiment of sufficient size to ensure successful operation of the full-size subsystem designed in Phase 1. Evaluation of several concepts resulted in the selection of a four-component (preheater, evaporator, superheater, reheater), natural circulation, vertically oriented, shell and tube (straight) heat exchanger arrangement. Thermal hydraulic analysis of the system included full and part load performance, circulation requirements, stability, and critical heat flux analysis. Flow-induced tube vibration, tube buckling, fatigue evaluation of tubesheet junctions, steady-state tubesheet analysis, and a simplified transient analysis were included in the structural analysis of the system. Operating modes and system dynamic response to load changes were identified. Auxiliary equipment, fabrication, erection, and maintenance requirements were also defined. Installed capital costs and a project schedule were prepared for each design.

Coal consumption minimizing by increasing thermal energy efficiency at ROMAG-PROD Heavy Water Plant

International Nuclear Information System (INIS)

Preda, Marius Cristian

2006-01-01

ROMAG-PROD Heavy Water Plant is a large thermal energy consumer using almost all the steam output from ROMAG-TERMO Power Plant - the steam cost weight in the total heavy water price is about 40%. The steam consumption minimizing by modernization of isotopic exchange facilities and engineering development in ROMAG-PROD Heavy Water Plant results in an corresponding decrease of coal amount burned at ROMAG-TERMO boilers. This decrease could be achieved mainly by the followings ways: - Facility wrappings integrity; - High performance heat exchangers; - Refurbished heat insulations; - Modified condenser-collecting pipeline routes; - High performance steam traps; - Heat electric wire. When coal is burned in Power Plant burners to obtain thermal energy, toxic emissions results in flue gases, such as: - CO 2 and NO x with impact on climate warming; - SO 2 which results in ozone layer thinning effect and in acid rain falls. From the value of steam output per burned coal: 1 GCal steam = 1.41 tone steam = 0.86 thermal MW = 1.1911 tones burned coal (lignite), it is obvious that by decreasing the thermal energy consumption provided for ROMAG PROD, a coal amount decrease is estimated at about 45 t/h, or about 394,200 t/year coal, which means about 10% of the current coal consumption at ROMAG-TERMO PP. At the same time, by reducing the burned coal amount, an yearly decrease in emissions into air to about 400,000 tones CO 2 is expected

Electrical and thermal behavior of unsaturated soils: experimental results

Science.gov (United States)

Nouveau, Marie; Grandjean, Gilles; Leroy, Philippe; Philippe, Mickael; Hedri, Estelle; Boukcim, Hassan

2016-05-01

When soil is affected by a heat source, some of its properties are modified, and in particular, the electrical resistivity due to changes in water content. As a result, these changes affect the thermal properties of soil, i.e., its thermal conductivity and diffusivity. We experimentally examine the changes in electrical resistivity and thermal conductivity for four soils with different grain size distributions and clay content over a wide range of temperatures, from 20 to 100 °C. This temperature range corresponds to the thermal conditions in the vicinity of a buried high voltage cable or a geothermal system. Experiments were conducted at the field scale, at a geothermal test facility, and in the laboratory using geophysical devices and probing systems. The results show that the electrical resistivity decreases and the thermal conductivity increases with temperature up to a critical temperature depending on soil types. At this critical temperature, the air volume in the pore space increases with temperature, and the resulting electrical resistivity also increases. For higher temperatures , the thermal conductivity increases sharply with temperature up to a second temperature limit. Beyond it, the thermal conductivity drops drastically. This limit corresponds to the temperature at which most of the water evaporates from the soil pore space. Once the evaporation is completed, the thermal conductivity stabilizes. To explain these experimental results, we modeled the electrical resistivity variations with temperature and water content in the temperature range 20 - 100°C, showing that two critical temperatures influence the main processes occurring during heating at temperatures below 100 °C.

Variable electricity and steam from salt, helium and sodium cooled base-load reactors with gas turbines and heat storage - 15115

International Nuclear Information System (INIS)

Forsberg, C.; McDaniel, P.; Zohuri, B.

2015-01-01

Advances in utility natural-gas-fired air-Brayton combed cycle technology is creating the option of coupling salt-, helium-, and sodium-cooled nuclear reactors to Nuclear air-Brayton Combined Cycle (NACC) power systems. NACC may enable a zero-carbon electricity grid and improve nuclear power economics by enabling variable electricity output with base-load nuclear reactor operations. Variable electricity output enables selling more electricity at times of high prices that increases plant revenue. Peak power is achieved using stored heat or auxiliary fuel (natural gas, bio-fuels, hydrogen). A typical NACC cycle includes air compression, heating compressed air using nuclear heat and a heat exchanger, sending air through a turbine to produce electricity, reheating compressed air, sending air through a second turbine, and exhausting to a heat recovery steam generator (HRSG). In the HRSG, warm air produces steam that is used to produce added electricity. For peak power production, auxiliary heat (natural gas, stored heat) is added before the air enters the second turbine to raise air temperatures and power output. Like all combined cycle plants, water cooling requirements are dramatically reduced relative to other power cycles because much of the heat rejection is in the form of hot air. (authors)

Calculation Method of Steam Generator Level for swelling and shrinking effects in YGN 1/2 Simulator

International Nuclear Information System (INIS)

Hwang, Do Hyun; Seo, In Yong; Park, Weon Seo; Suh, Jae Seung

2007-01-01

In August 2006, the development of new simulator for YGN 1/2 Simulator was completed. The NSSS (Nuclear Steam Supply System) T/H(Thermal- Hydraulic) module in this simulator was developed with ARTS code based on RETRAN, which is a best estimate thermal-hydraulic code designed to analyze several operational transients by EPRI(Electric Power Research Institute). RETRAN, however, has some limitations in real-time calculation capability and its robustness to be used in the simulator for some transient conditions. To overcome these limitations, its robustness and real-time calculation capability have been improved with simplifications and removing of discontinuities of the physical correlations of the RETRAN code. And some supplements are also developed to extend its simulation scope of the ARTS code. In comparison to KNPEC(Kori Nuclear Power Education Center) no.2 simulator, the simulator based on Younggwang Unit 1 developed in the year 2001, the ARTS code was upgraded that it extended its calculating region to the steam line and common header before turbine while it had calculated to the steam generator exit before steam line in KNPEC no.2 simulator. Consequently, the number of volume and fill/normal junction in ARTS nodalization increased to 109 and 174 from 62 and 125, respectively

Development of ecologically safety technology for steam-thermal treatment of organic wastes

International Nuclear Information System (INIS)

Juravskij, J.

1997-01-01

The experience on mitigation of the consequences of the Chernobyl's nuclear power station accident proves that the treatment of large amounts of organic and mixed wastes containing radionuclides is a very urgent scientific and technical problem. In this connection a search for new ideas and development of highly efficient and ecologically safety technologies for treatment of organic radioactive wastes has been undertaken. This study is based on use of physico-mechanical properties of various organic materials (wood, rubber-containing composites, plastics, biomass) subjected to thermal decomposition in the overheated water steam medium. Under such conditions, there is a possibility, under relatively low temperatures (400 - 500 deg. C), to realize thermal decomposition and considerably (in 8 - 50 times) to reduce the amount of wastes, to obtain the main concentration of radionuclides in the solid residue and to prevent releases of gaseous products containing radionuclides to the environment. (author). 5 figs, 1 tab

An electrical method for the measurement of the thermal and electrical conductivity of reduced graphene oxide nanostructures.

Science.gov (United States)

Schwamb, Timo; Burg, Brian R; Schirmer, Niklas C; Poulikakos, Dimos

2009-10-07

This paper introduces an electrical four-point measurement method enabling thermal and electrical conductivity measurements of nanoscale materials. The method was applied to determine the thermal and electrical conductivity of reduced graphene oxide flakes. The dielectrophoretically deposited samples exhibited thermal conductivities in the range of 0.14-2.87 W m(-1) K(-1) and electrical conductivities in the range of 6.2 x 10(2)-6.2 x 10(3) Omega(-1) m(-1). The measured properties of each flake were found to be dependent on the duration of the thermal reduction and are in this sense controllable.

Thermodynamic analysis of pumped thermal electricity storage

International Nuclear Information System (INIS)

White, Alexander; Parks, Geoff; Markides, Christos N.

2013-01-01

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater need for electricity storage. Although there are many existing and emerging storage technologies, most have limitations in terms of geographical constraints, high capital cost or low cycle life, and few are of sufficient scale (in terms of both power and storage capacity) for integration at the transmission and distribution levels. This paper is concerned with a relatively new concept which will be referred to here as Pumped Thermal Electricity Storage (PTES), and which may be able to make a significant contribution towards future storage needs. During charge, PTES makes use of a high temperature ratio heat pump to convert electrical energy into thermal energy which is stored as ‘sensible heat’ in two thermal reservoirs, one hot and one cold. When required, the thermal energy is then converted back to electricity by effectively running the heat pump backwards as a heat engine. The paper focuses on thermodynamic aspects of PTES, including energy and power density, and the various sources of irreversibility and their impact on round-trip efficiency. It is shown that, for given compression and expansion efficiencies, the cycle performance is controlled chiefly by the ratio between the highest and lowest temperatures in each reservoir rather than by the cycle pressure ratio. The sensitivity of round-trip efficiency to various loss parameters has been analysed and indicates particular susceptibility to compression and expansion irreversibility

CHP in Switzerland from 1990 to 1998. Thermal power generation including combined heat and power

International Nuclear Information System (INIS)

Kaufmann, U.

1999-01-01

The results of a study on thermal power generation in Switzerland show that combined heat and power (CHP) systems have grown rapidly. Statistics are presented on the development of CHP-based power and also on thermal power stations without waste heat usage. Figures are given for gas and steam turbine installations, combined gas and steam turbine stations and motor-driven CHP units. Power production is categorised, separating small and large (over 1 Megawatt electrical) power generation facilities. On-site, distributed power generation at consumers' premises and the geographical distribution of plant is described

Amazing & extraordinary facts the steam age

CERN Document Server

Holland, Julian

2012-01-01

Respected transport author Julian Holland delves into the intriguing world of steam in his latest book, which is full of absorbing facts and figures on subjects ranging from Cornish beam engines, steam railway locomotives, road vehicles and ships through to traction engines, steam rollers and electricity generating stations and the people who designed and built them. Helped along the way by the inventive minds of James Watt, Richard Trevithick and George Stephenson, steam became the powerhouse that drove the Industrial Revolution in Britain in the late 18th and 19th centuries.

Thermochemical recuperative combined cycle with methane-steam reforming combustion; Tennengasu kaishitsu nensho ni yoru konbaindo saikuru hatsuden no kokoritsuka oyobi denryoku fuka heijunka taio

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, R.; Essaki, K.; Tsutsumi, A. [The University of Tokyo, Tokyo (Japan). Dept. of Chemical System Engineering; Kaganoi, S.; Kurimura, H. [Teikoku Sekiyu Co., Tokyo (Japan); Sasaki, T.; Ogawa, T. [Toshiba Co., Tokyo (Japan)

2000-03-10

Thermochemical recuperative combined cycles with methane-steam reforming are proposed for improving their thermal efficiency and for peak-load leveling. For targeting higher thermal efficiency, a cycle with methane-steam reforming reaction heated by gas turbine exhaust was analyzed. The inlet temperature of gas turbine was set at 1,350 degree C. Low-pressure steam extracted from a steam turbine is mixed with methane, and then this mixture is heated by part of the gas turbine exhaust to promote a reforming reaction. The rest of the exhaust heat is used to produce steam, which drives steam turbines to generate electricity. The effect of steam-to-methane ratio (S/C) on thermal efficiency of the cycle, as well as on methane conversion, is investigated by using the ASPEN Plus process simulator. The methane feed rate was fixed at constant and S/C ratio was varied from 2.25 to 4.75. Methane conversion shows an increasing trend toward the ratio and has a maximum value of 17.9 % at S/C=4.0. Thermal efficiency for the system is about 51 % higher than that calculated for a conventional 1,300 degree C class combined cycle under similar conditions. A thermochemical recuperative combined cycle is designed for peak-load leveling. In night-time operation from 20 : 00 to 8 : 00 it stores hydrogen produced by methane steam reforming at S/C=3.9 to save power generation. The gas turbine inlet temperature is 1,330 degree C. In daytime operation from 8 : 00 to 20 : 00 the chemically recuperated combined cycle operated at S/C=2.0 is driven by the mixture of a combined cycle operated at constant load with the same methane feed rate, whereas daytime operation generated power 1.26 times larger than that of the combined cycle. (author)

Steam generator of FBR type reactor

International Nuclear Information System (INIS)

Hashiguchi, Ko.

1992-01-01

Liquid metal (for example, mercury) which is scarcely reactive with metal sodium is contained and cover gases which are scarcely reactive with the liquid metal are filled in a steam generator of an FBR type reactor and it is closed. The heat of primary sodium is transferred to the liquid metal, which is not reactive with sodium, in a primary thermal conduction portion. Since the temperature of the primary thermal conduction portion is high, the density is extremely low. On the other hand, since a second thermal conduction portion is kept at a single phase and the temperature is lower compared with that of the first thermal conduction portion, the density is kept high. since the density difference and gas jetting speed generate a great circulating force to liquid metal passing the opening of a partition plate, heat can be conducted on the side of water without disposing pumps. The steam concentration in the liquid metal is low being in a single phase of steams, corrosion caused from the outside of pipes of the primary thermal conduction pipe is scarcely promoted. Even if sodium leaks should be caused, since the sodium concentration in the liquid metal is extremely low and the reactivity is low, the temperature of the liquid metal is not elevated. (N.H.)

Integrated Vehicle Thermal Management - Combining Fluid Loops in Electric Drive Vehicles (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Rugh, J. P.

2013-07-01

Plug-in hybrid electric vehicles and electric vehicles have increased vehicle thermal management complexity, using separate coolant loop for advanced power electronics and electric motors. Additional thermal components result in higher costs. Multiple cooling loops lead to reduced range due to increased weight. Energy is required to meet thermal requirements. This presentation for the 2013 Annual Merit Review discusses integrated vehicle thermal management by combining fluid loops in electric drive vehicles.

Solid waste processing experience at Susquehanna Steam Electric Station

International Nuclear Information System (INIS)

Phillips, J.W.; Granus, M.W.

1984-01-01

This paper reviews the first year's operation at the Susquehanna Steam Electric Station (SSES) with respect to the Westinghouse Hittman Nuclear Incorporated (Hittman) mobile solidification system and the dry activated waste generation, handling and processing. Experiences pertinent to the mobile solidification system are reviewed with emphasis on the integration of the system into the plant, problems associated with unexpected waste properties and the myriad of operating procedures that had to be prepared. The processing history for 1983 is reviewed in terms of the volume of waste, including solidified wastes, dewatered wastes an DAW. Factors that must be considered in evaluating processing alternatives, i.e., dewatering vs. solidification; steel liners vs. HICs, are discussed. Actions taken by Hittman and SSES to maximize the processing economics are also discussed. Finally, recommendations are provided to the utility considering implementing mobile solification services to ensure a smooth and timely integration of services into the plant

A study on improving the performance of steam generator using thermal analysis

International Nuclear Information System (INIS)

Li, Zhen Zhe; Heo, Kwang Su; Choi, Jun Hoo; Seol, Seoung Yun

2008-01-01

Steam generation mechanism is the key technology of domestic steam cleaner. Not only weight and price of steam cleaner but also the performance of steam generation mechanism must be considered to improve the competitive power of the products. In order to find out the mechanism which can be used to improve the performance of steam generator, the process of steam generation was studied at first. In the following step, possibility of control, safety of mechanism and etc were compared about the two candidated steam generation mechanism. Finally, the merit and drawback of each mechanism were summarized

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.

Improve the Anaerobic Biodegradability by Copretreatment of Thermal Alkali and Steam Explosion of Lignocellulosic Waste

Directory of Open Access Journals (Sweden)

Muhammad Abdul Hanan Siddhu

2016-01-01

Full Text Available Effective alteration of the recalcitrance properties like crystallization of cellulose, lignin shield, and interlinking of lignocellulosic biomass is an ideal way to utilize the full-scale potential for biofuel production. This study exhibited three different pretreatment effects to enhance the digestibility of corn stover (CS for methane production. In this context, steam explosion (SE and thermal potassium hydroxide (KOH-60°C treated CS produced the maximal methane yield of 217.5 and 243.1 mL/gvs, which were 40.0% and 56.4% more than untreated CS (155.4 mL/gvs, respectively. Copretreatment of thermal potassium hydroxide and steam explosion (CPTPS treated CS was highly significant among all treatments and improved 88.46% (292.9 mL/gvs methane yield compared with untreated CS. Besides, CPTPS also achieved the highest biodegradability up to 68.90%. Three kinetic models very well simulated dynamics of methane production yield. Moreover, scanning electron microscopy (SEM, Fourier transform infrared (FTIR, and X-ray diffraction (XRD analyses declared the most effective changes in physicochemical properties after CPTPS pretreatment. Thus, CPTPS might be a promising approach to deconstructing the recalcitrance of lignocellulosic structure to improve the biodegradability for AD.

Technical evaluation report on the monitoring of electric power to the reactor-protection system for the Brunswick Steam Electric Plant, Units 1 and 2

International Nuclear Information System (INIS)

Selan, J.C.

1982-01-01

This report documents the technical evaluation of the monitoring of electric power to the reactor protection system (RPS) at the Brunswick Steam Electric Plant, Units 1 and 2. The evaluation is to determine if the proposed design modification will protect the RPS from abnormal voltage and frequency conditions which could be supplied from the power supplies and will meet certain requirements set forth by the Nuclear Regulatory Commission. The proposed design modifications with time delays verified by GE, will protect the RPS from sustained abnormal voltage and frequency conditions from the supplying sources

General Electric Company analytical model for loss-of-coolant analysis in accordance with 10CFR50 appendix K, amendment No. 3: effect of steam environment on BWR core spray distribution

International Nuclear Information System (INIS)

1977-04-01

The core spray sparger designs of the BWR/2 through BWR/5 product lines were verified by means of full-scale mock-ups tested in air at various flow conditions. In 1974, an overseas technical partner of General Electric reported that a steam environment changed the individual core spray nozzle patterns when compared to patterns measured in air. This document describes preliminary findings of how a steam environment alters the core spray nozzle pattern, and the actions which General Electric is pursuing to quantify the steam effects

Development of a steam generator lancing system

International Nuclear Information System (INIS)

Jeong, Woo-Tae; Kim, Seok-Tae; Hong, Sung-Yull

2006-01-01

It is recommended to clean steam generators of nuclear power plants during plant outages. Under normal operations, sludge is created and constantly accumulates in the steam generators. The constituents of this sludge are different depending on each power plant characteristics. The sludge of the Kori Unit 1 steam generator, for example, was found to be composed of 93% ferrous oxide, 3% carbon and 1% of silica oxide and nickel oxide each. The research to develop a lancing system that would remove sludge deposits from the tubesheet of a steam generator was started in 1998 by the Korea Electric Power Research Institute (KEPRI) of the Korea Electric Power Corporation (KEPCO). The first commercial domestic lancing system in Korea, and KALANS-I Lancing System, was completed in 2000 for Kori Unit 1 for cleaning the tubesheet of its Westinghouse Delta-60 steam generator. Thereafter, the success of the development and site implementation of the KALANS-I lancing system for YGN Units 1 and 2 and Ulchin Units 3 and 4 was also realized in 2004 for sludge removal at those sites. The upper bundle cleaning system for Westinghouse model F steam generators is now under development

Tube sheet design for PFBR steam generator

International Nuclear Information System (INIS)

Chellapandi, P.; Chetal, S.C.; Bhoje, S.B.

1991-01-01

Top and bottom tube sheets of PFBR Steam Generators have been analysed with 3D and axisymmetric models using CASTEM Programs. Analysis indicates that the effects of piping reactions at the inlet/outlet nozzles on the primary stresses in the tube sheets are negligible and the asymmetricity of the deformation pattern introduced in the tube sheet by the presence of inlet/outlet and manhole nozzles is insignificant. The minimum tube sheet thicknesses for evaporator and reheater are 135 mm and 75 mm respectively. Further analysis has indicated the minimum fillet radius at the junction of tube sheet and dished end should be 20 mm. Simplified methodology has been developed to arrive at the number of thermal baffles required to protect the tube sheet against fatigue damage due to thermal transient. This method has been applied to PFBR steam generators to determine the required number of thermal baffles. For protecting the bottom tube sheet of evaporator against the thermal shock due to feed water and secondary pump trip, one thermal shield is found to be sufficient. Further analysis is required to decide upon the actual number to take care of the severe thermal transient, following the event of sudden dumping of water/steam, immediately after the sodium-water reaction. (author)

Development and validation of advanced oxidation protective coatings for super critical steam power plant

Energy Technology Data Exchange (ETDEWEB)

Henderson, M.B.; Scheefer, M. [Alstom Power Ltd., Rugby (United Kingdom); Agueero, A. [Instituto Nacional de Tecnica Aerospacial (INTA) (Spain); Allcock, B. [Monitor Coatings Ltd. (United Kingdom); Norton, B. [Indestructible Paints Ltd. (United Kingdom); Tsipas, D.N. [Aristotle Univ. of Thessaloniki (Greece); Durham, R. [FZ Juelich (Germany); Xiang, Z. [Northumbria Univ. (United Kingdom)

2006-07-01

Increasing the efficiency of coal-fired power plant by increasing steam temperatures and pressures brings benefits in terms of cheaper electricity and reduced emissions, particularly CO{sub 2}. In recent years the development of advanced 9%Cr ferritic steels with improved creep strength has enabled power plant operation at temperatures in excess of 600 C, such that these materials are being exploited to construct a new generation of advanced coalfired plant. However, the move to higher temperatures and pressures creates an extremely hostile oxidising environment. To enable the full potential of the new steels to be achieved, it is vital that protective coatings are developed, validated under high temperature steam and applied to candidate components from the steam path. This paper reviews recent work conducted within the Framework V project ''Coatings for Supercritical Steam Cycles'' (SUPERCOAT) to develop and demonstrate advanced slurry and thermal spray coatings capable of providing steam oxidation protection at temperatures in excess of 620 C and up to 300 bar. The programme of work has demonstrated the feasibility of applying a number of candidate coatings to steam turbine power plant components and has generated long-term steam oxidation rate and failure data that underpin the design and application work packages needed to develop and establish this technology for new and retrofit plant. (orig.)

Value of non-electric applications of nuclear energy beyond market potential

International Nuclear Information System (INIS)

Khamis, I.

2014-01-01

Providing process steam at different temperatures, Nuclear Power Plants (NPPs) could be coupled to various types of non-electric applications such as seawater desalination, hydrogen production, district heating or cooling, as well as any energy-demanding process heat industrial application. This will not only make nuclear power a more feasible option helping to accelerate its penetration into the the heat and transportation markets, but also helping to improve their overall thermal efficiencies. Typical thermal efficiencies of NPPs are about 33%. All existing reactor types can be coupled to non-electric application based on cogeneration i.e. the production of electricity and process heat. (authors)

Future aspects for liquid metal heated steam generators

International Nuclear Information System (INIS)

Jansing, W.; Ratzel, W.; Vinzens, K.

1975-01-01

The present status of steam generators is shown. The experience gained until now is expressed in form of basic points. The most important design criteria for steam generator systems are outlined. On the basis of these design criteria, two possible steam generator concepts are shown. Costs in relationship to the repair concepts of two modular steam generators (thermal output 156 and 625 MW) and a pool design of 625 MW are compared. (author)

Future aspects for liquid metal heated steam generators

Energy Technology Data Exchange (ETDEWEB)

Jansing, W; Ratzel, W; Vinzens, K

1975-07-01

The present status of steam generators is shown. The experience gained until now is expressed in form of basic points. The most important design criteria for steam generator systems are outlined. On the basis of these design criteria, two possible steam generator concepts are shown. Costs in relationship to the repair concepts of two modular steam generators (thermal output 156 and 625 MW) and a pool design of 625 MW are compared. (author)

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

Development of ecologically safety technology for steam-thermal treatment of organic wastes

Energy Technology Data Exchange (ETDEWEB)

Juravskij, J [Centre for Science, Technology and Industrial Applications, ` ` Tokema` ` , Minsk (Belarus)

1997-02-01

The experience on mitigation of the consequences of the Chernobyl`s nuclear power station accident proves that the treatment of large amounts of organic and mixed wastes containing radionuclides is a very urgent scientific and technical problem. In this connection a search for new ideas and development of highly efficient and ecologically safety technologies for treatment of organic radioactive wastes has been undertaken. This study is based on use of physico-mechanical properties of various organic materials (wood, rubber-containing composites, plastics, biomass) subjected to thermal decomposition in the overheated water steam medium. Under such conditions, there is a possibility, under relatively low temperatures (400 - 500 deg. C), to realize thermal decomposition and considerably (in 8 - 50 times) to reduce the amount of wastes, to obtain the main concentration of radionuclides in the solid residue and to prevent releases of gaseous products containing radionuclides to the environment. (author). 5 figs, 1 tab.

ECO steam explosion experiments on the conversion of thermal into mechanical energy

International Nuclear Information System (INIS)

Cherdron, W.; Kaiser, A.; Schuetz, W.; Will, H.

2001-01-01

In case of a steam explosion, e.g. as a consequence of a severe reactor accident, part of the thermal energy of the melt is transferred into mechanical energy. At Forschungszentrum Karlsruhe, so-called ECO experiments, are being directed to measure the conversion factor under well-defined conditions. In ECO, alumina from a thermite reaction is used as a simulating material instead of corium. Dimensions of the test facility as well as major test conditions, e.g. temperature and release mode of the melt, water inventory and test procedure, are based on the former PREMIX experimental series. In the paper, results of the first test, ECO 01, are given. (orig.)

Bony ankylosis following thermal and electrical injury

Energy Technology Data Exchange (ETDEWEB)

Balen, P.F.; Helms, C.A. [Dept. of Radiology, Duke University Medical Center, Durham, NC (United States)

2001-07-01

Objective. Bony ankylosis has been described following trauma, paralysis, psoriasis, Reiter's syndrome, ankylosing spondylitis, juvenile chronic arthritis and rheumatoid arthritis. Reports of bony ankylosis following thermal and electrical injury are limited.Design and patients. Thirteen cases of burn-related joint ankylosis in four patients are presented.Conclusion. Patients with burns from thermal or electrical injury may develop bony ankylosis among other radiographic manifestations. This bony ankylosis may result either from bridging extra-articular heterotopic ossification with preservation of the underlying joint or from intra-articular fusion due to joint destruction. (orig.)

Design and experimental investigation of a 1 kW organic Rankine cycle system using R245fa as working fluid for low-grade waste heat recovery from steam

International Nuclear Information System (INIS)

Muhammad, Usman; Imran, Muhammad; Lee, Dong Hyun; Park, Byung Sik

2015-01-01

Highlights: • A 1 kW organic Rankine cycle test rig for waste heat recovery was investigated for net electric power output. • Low grade steam (1–3 bar) was used directly in evaporator as heat source. • Effect of superheating of working fluid on system performance was studied. • The maximum electric power output and thermal efficiency is 1016 W and 5.75% respectively. - Abstract: This work presents an experimental investigation of a small scale (1 kW range) organic Rankine cycle system for net electrical power output ability, using low-grade waste heat from steam. The system was designed for waste steam in the range of 1–3 bar. After the organic Rankine cycle system was designed and thermodynamic simulation was performed, equipment selection and construction of test rig was carried out. R245fa was used as working fluid, a scroll type expansion directly coupled with electrical generator produced a maximum electrical power output of 1.016 kW with 0.838 kW of net electrical power output. The thermal efficiency of the system was 5.64%, net efficiency was 4.66% and expander isentropic efficiency was 58.3% at maximum power output operation point. Maximum thermal efficiency was 5.75% and maximum expander isentropic efficiency obtained was 77.74% during the experiment. Effect of superheating of working fluid at expander inlet was also investigated which show that an increase in the degree of superheating by 1 °C reduces thermal efficiency of system by 0.021% for current system. The results indicated that the measured electric power output and enthalpy determined power output (after accounting for isentropic efficiency) differed by 40%. Similarly, the screw pump converted 42.25% of electric power to the enthalpy determined pumping power delivered to the working fluid. Both expander and screw pump were losing power in electric and mechanical losses (generator/motor) presenting a need of further development of these components for better efficiency. Heat loss in

Steam atmosphere drying concepts using steam exhaust recompression

Energy Technology Data Exchange (ETDEWEB)

DiBella, F.A. (TECOGEN, Inc., Waltham, MA (United States))

1992-08-01

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg[sub evap] to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

Steam atmosphere drying concepts using steam exhaust recompression

Energy Technology Data Exchange (ETDEWEB)

DiBella, F.A. [TECOGEN, Inc., Waltham, MA (United States)

1992-08-01

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg{sub evap} to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

Hybrid systems to address seasonal mismatches between electricity production and demand in nuclear renewable electrical grids

International Nuclear Information System (INIS)

Forsberg, Charles

2013-01-01

A strategy to enable zero-carbon variable electricity production with full utilization of renewable and nuclear energy sources has been developed. Wind and solar systems send electricity to the grid. Nuclear plants operate at full capacity with variable steam to turbines to match electricity demand with production (renewables and nuclear). Excess steam at times of low electricity prices and electricity demand go to hybrid fuel production and storage systems. The characteristic of these hybrid technologies is that the economic penalties for variable nuclear steam inputs are small. Three hybrid systems were identified that could be deployed at the required scale. The first option is the gigawatt-year hourly-to-seasonal heat storage system where excess steam from the nuclear plant is used to heat rock a kilometer underground to create an artificial geothermal heat source. The heat source produces electricity on demand using geothermal technology. The second option uses steam from the nuclear plant and electricity from the grid with high-temperature electrolysis (HTR) cells to produce hydrogen and oxygen. Hydrogen is primarily for industrial applications; however, the HTE can be operated in reverse using hydrogen for peak electricity production. The third option uses variable steam and electricity for shale oil production. -- Highlights: •A system is proposed to meet variable hourly to seasonal electricity demand. •Variable solar and wind electricity sent to the grid. •Base-load nuclear plants send variable steam for electricity and hybrid systems. •Hybrid energy systems can economically absorb gigawatts of variable steam. •Hybrid systems include geothermal heat storage, hydrogen, and shale-oil production

Practical aspects of steam injection processes: A handbook for independent operators

Energy Technology Data Exchange (ETDEWEB)

Sarathi, P.S.; Olsen, D.K.

1992-10-01

More than 80% of the total steam injection process operating costs are for the production of steam and the operation of surface and subsurface equipment. The proper design and operation of the surface equipment is of critical importance to the success of any steam injection operation. However, the published monographs on thermal recovery have attached very little importance to this aspect of thermal oil recovery; hence, a definite need exists for a comprehensive manual that places emphasis on steam injection field practices and problems. This handbook is an attempt to fulfill this need. This handbook explores the concept behind steam injection processes and discusses the information required to evaluate, design, and implement these processes in the field. The emphasis is on operational aspects and those factors that affect the technology and economics of oil recovery by steam. The first four chapters describe the screening criteria, engineering, and economics of steam injection operation as well as discussion of the steam injection fundamentals. The next four chapters begin by considering the treatment of the water used to generate steam and discuss in considerable detail the design, operation and problems of steam generations, distribution and steam quality determination. The subsurface aspects of steamflood operations are addressed in chapters 9 through 12. These include thermal well completion and cementing practices, insulated tubulars, and lifting equipment. The next two chapters are devoted to subsurface operational problems encountered with the use of steam. Briefly described in chapters 15 and 16 are the steam injection process surface production facilities, problems and practices. Chapter 17 discusses the importance of monitoring in a steam injection project. The environmental laws and issues of importance to steam injection operation are outlined in chapter 18.

Steam generator tube integrity program

International Nuclear Information System (INIS)

Dierks, D.R.; Shack, W.J.; Muscara, J.

1996-01-01

A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given

Evolution of design of steam generator for sodium cooled reactors

International Nuclear Information System (INIS)

Chetal, S.C.; Vaidyanathan

1997-01-01

The first sodium cooled reactor was the experimental breeder reactor (EBR-I) in usa which was commissioned in 1951 and was incidentally the first nuclear reactor to generate electrical energy. This was followed by fast breeder reactors in USSR, UK, france, USA, japan, germany and India. The use of sodium as a coolant is due to its low moderation which helps in breeding fissile fuel from fertile materials and also its high heat transfer coefficient at comparatively low velocities. The good heat transfer properties introduce thermal stresses when there are rapid changes in the sodium temperatures. Also sodium has a chemical affinity with air and water. The steam generators for sodium cooled reactors have to allow for these novel conditions and in addition, unlike other components. Choices have to be made whether it is a recirculation type as in most fossil plants or an once through unit, the power rating, shape of the tube (straight, helical, U-tube), materials (Ferritic or austenitic), with free level of sodium or not, sodium on tube side or shell side and so on. With higher pressures and steam temperatures reheating steam after partial expansion in the turbine becomes essential as in conventional turbines. For this purpose the choice of reheating fluid viz sodium or live main steam has to be made. This paper traces the evolution of steam generator designs in the different sodium cooled reactors (chronologically) and the operation experience. 16 figs., 1 tab

Cleanliness criteria to improve steam generator performance

International Nuclear Information System (INIS)

Schwarz, T.; Bouecke, R.; Odar, S.

2005-01-01

High steam generator performance is a prerequisite for high plant availability and possible life time extension. The major opponent to that is corrosion and fouling of the heating tubes. Such steam generator degradation problems arise from the continuous ingress of non-volatile contaminants, i.e. corrosion products and salt impurities may accumulate in the steam generators. These impurities have their origin in the secondary side systems. The corrosion products generally accumulate in the steam generators and form deposits not only in the flow restricted areas, such as on top of tube sheet and tube support structure, but also build scales on the steam generator heating tubes. In addition, the tube scales in general affect the steam generator thermal performance, which ultimately causes a reduction of power output. The most effective ways of counteracting all these degradation problems, and thus of improving the steam generator performance is to keep them in clean conditions or, if judged necessary, to plan cleaning measures such as mechanical tube sheet lancing or chemical cleaning. This paper presents a methodology how to assess the cleanliness condition of a steam generator by bringing together all available operational and inspection data such as thermal performance and water chemistry data. By means of this all-inclusive approach the cleanliness condition is quantified in terms of a fouling index. The fouling index allows to monitor the condition of a specific steam generator, compare it to other plants and, finally, to serve as criterion for cleaning measures such as chemical cleaning. The application of the cleanliness criteria and the achieved field results with respect to improvements of steam generator performance will be presented. (author)

Steam injection : analysis of a typical application.

NARCIS (Netherlands)

Penning, F.M.; Lange, de H.C.

1996-01-01

A cardboard factory requires steam and electricity, which are produced in its own powerplant. Conventional cogeneration systems cannot cope with the large fluctuations in steam demand, inherent to the cardboard production process, while power demand remains almost constant. For this reason, two

Increasing economic benefits by load-shifting of electrical heat pumps

OpenAIRE

Laveyne, Joannes; Zwaenepoel, Brecht; Van Eetvelde, Greet; Vandevelde, Lieven

2014-01-01

Electrical heating is still widely used in the process industry. While the use of immersion heaters for the production of hot water or steam is declining, the adoption rate of electrical heat pumps is increasing rapidly. Heat pumps show great flexibility and potential for energy savings, e.g. through low temperature waste heat recuperation. In combination with thermal storage they also allow for load shifting. Because their main power source is electricity, which up to now cannot be stored ef...

Steam and hot air injection for thermal rehabilitation of contaminated sites; Wasserdampf- und Heissluftinjektion zur thermischen Sanierung kontaminierter Standorte

Energy Technology Data Exchange (ETDEWEB)

Schmidt, R

2001-07-01

Thermal in situ rehabilitation technologies are a promising alternative to conventional methods of cleaning up contaminated sites. The fact that an increase in temperature changes the physical properties of materials makes it possible, in principle, to release large quantities of pollutants within short time periods. The use of pure steam or steam/air mixtures as fluid thermal carriers permits converting subterranean non-aqueous-phase pollutants into the gas phase through increased vapour pressure and transporting them to the surface by means of soil air aspiration for further treatment. The purpose of the present two-stage research project was to systematically develop a thermal in situ rehabilitation technology using steam as fluid heat carrier and use it for land rehabilitation operations on a pilot basis. In the first, fundamental project phase aspects of heat transport (Faerber, 1997) and pollutant behaviour (Betz, 1998)in homogenous porous media upon pure steam injection were explored at a laboratory and technical scale using containers of different sizes (1D, 2D, 3D). The results were used to derive application criteria for this technology. [German] Thermische In-situ-Sanierungstechnologien stellen bei der Reinigung kontaminierter Standorte eine vielversprechende Alternative zu konventionellen Verfahren dar. Die Veraenderung physikalischer Stoffeigenschaften mit steigender Temperatur ermoeglicht grundsaetzlich hohe Schadstoffaustraege innerhalb kurzer Zeitraeume. Beim Einsatz von reinem Wasserdampf oder Wasserdampf-Luft-Gemischen als Waermetraegerfluid koennen im Untergrund in nicht waessriger Phase vorliegende Schadstoffe hauptsaechlich wegen der erhoehten Dampfdruecke in die Gasphase ueberfuehrt, ueber eine Bodenluftabsaugung an die Oberflaeche transportiert und dann einer weiteren Behandlung zugefuehrt werden. Zielsetzung eines zweistufigen Forschungsvorhabens war die systematische Entwicklung einer thermischen In-situ-Sanierungstechnologie unter

Radioactivity transport following steam generator tube rupture

International Nuclear Information System (INIS)

Hopenfeld, J.

1985-03-01

A review of the capabilities of the CITADEL computer code as well as plant experience to project radioactivity releases following a steam generator tube rupture in PWR's shows that certain experimental data are needed for reliable off-site dose predictions. This article defines five parameters which are the key for such predictions and discusses the functional dependence of these parameters on various operational variables. The above parameters can be used in conjunction with CITADEL or they can be inserted in the appropriate equations which then conveniently can be programmed as a subroutine in thermal-hydraulic system codes. A joint Westinghouse, Electric Power Research Institute and Nuclear Regulatory Commission Program aimed at obtaining the five parameters empirically is described

Thermal efficiency improvements - an imperative for nuclear generating stations

International Nuclear Information System (INIS)

Hassanien, S.; Rouse, S.

1997-01-01

A one and a half percent thermal performance improvement of Ontario Hydro's operating nuclear units (Bruce B, Pickering B, and Darlington) means almost 980 GWh are available to the transmission system (assuming an 80% capacity factor). This is equivalent to the energy consumption of 34,000 electrically-heated homes in Ontario, and worth more than $39 million in revenue to Ontario Hydro Nuclear Generation. Improving nuclear plant thermal efficiency improves profitability (more GWh per unit of fuel) and competitiveness (cost of unit energy), and reduces environmental impact (less spent fuel and nuclear waste). Thermal performance will naturally decrease due to the age of the units unless corrective action is taken. Most Ontario Hydro nuclear units are ten to twenty years old. Some common causes for loss of thermal efficiency are: fouling and tube plugging of steam generators, condensers, and heat exchangers; steam leaks in the condenser due to valve wear, steam trap and drain leaks; deposition, pitting, cracking, corrosion, etc., of turbine blades; inadequate feedwater metering resulting from corrosion and deposition. This paper stresses the importance of improving the nuclear units' thermal efficiency. Ontario Hydro Nuclear has demonstrated energy savings results are achievable and affordable. Between 1994 and 1996, Nuclear reduced its energy use and improved thermal efficiency by over 430,000 MWh. Efficiency improvement is not automatic - strategies are needed to be effective. This paper suggests practical strategies to systematically improve thermal efficiency. (author)

Electrical and thermal modeling of railguns

International Nuclear Information System (INIS)

Kerrisk, J.F.

1984-01-01

Electrical and thermal modeling of railguns at Los Alamos has been done for two purposes: (1) to obtain detailed information about the behavior of specific railgun components such as the rails, and (2) to predict overall performance of railgun tests. Detailed electrical and thermal modeling has concentrated on calculations of the inductance and surface current distribution of long parallel conductors in the high-frequency limit and on calculations of current and thermal diffusion in rails. Inductance calculations for various rail cross sections and for magnetic flux compression generators (MFCG) have been done. Inductance and current distribution results were compared with experimental measurements. Twodimensional calculations of current and thermal diffusion in rail cross sections have been done; predictions of rail heating and melting as a function of rail size and total current have been made. An overall performance model of a railgun and power supply has been developed and used to design tests at Los Alamos. The lumped-parameter circuit model uses results from the detailed inductance and current diffusion calculations along with other circuit component models to predict rail current and projectile acceleration, velocity, and position as a function of time

Determining an energy-optimal thermal management strategy for electric driven vehicles

Energy Technology Data Exchange (ETDEWEB)

Suchaneck, Andre; Probst, Tobias; Puente Leon, Fernando [Karlsruher Institut fuer Technology (KIT), Karlsruhe (Germany). Inst. of Industrial Information Technology (IIIT)

2012-11-01

In electric, hybrid electric and fuel cell vehicles, thermal management may have a significant impact on vehicle range. Therefore, optimal thermal management strategies are required. In this paper a method for determining an energy-optimal control strategy for thermal power generation in electric driven vehicles is presented considering all controlled devices (pumps, valves, fans, and the like) as well as influences like ambient temperature, vehicle speed, motor and battery and cooling cycle temperatures. The method is designed to be generic to increase the thermal management development process speed and to achieve the maximal energy reduction for any electric driven vehicle (e.g., by waste heat utilization). Based on simulations of a prototype electric vehicle with an advanced cooling cycle structure, the potential of the method is shown. (orig.)

Incorporating Water Boiling in the Numerical Modelling of Thermal Remediation by Electrical Resistance Heating

Science.gov (United States)

Molnar, I. L.; Krol, M.; Mumford, K. G.

2017-12-01

Developing numerical models for subsurface thermal remediation techniques - such as Electrical Resistive Heating (ERH) - that include multiphase processes such as in-situ water boiling, gas production and recovery has remained a significant challenge. These subsurface gas generation and recovery processes are driven by physical phenomena such as discrete and unstable gas (bubble) flow as well as water-gas phase mass transfer rates during bubble flow. Traditional approaches to multiphase flow modeling soil remain unable to accurately describe these phenomena. However, it has been demonstrated that Macroscopic Invasion Percolation (MIP) can successfully simulate discrete and unstable gas transport1. This has lead to the development of a coupled Electro Thermal-MIP Model2 (ET-MIP) capable of simulating multiple key processes in the thermal remediation and gas recovery process including: electrical heating of soil and groundwater, water flow, geological heterogeneity, heating-induced buoyant flow, water boiling, gas bubble generation and mobilization, contaminant mass transport and removal, and additional mechanisms such as bubble collapse in cooler regions. This study presents the first rigorous validation of a coupled ET-MIP model against two-dimensional water boiling and water/NAPL co-boiling experiments3. Once validated, the model was used to explore the impact of water and co-boiling events and subsequent gas generation and mobilization on ERH's ability to 1) generate, expand and mobilize gas at boiling and NAPL co-boiling temperatures, 2) efficiently strip contaminants from soil during both boiling and co-boiling. In addition, a quantification of the energy losses arising from steam generation during subsurface water boiling was examined with respect to its impact on the efficacy of thermal remediation. While this study specifically targets ERH, the study's focus on examining the fundamental mechanisms driving thermal remediation (e.g., water boiling) renders

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants

Science.gov (United States)

Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

1976-01-01

The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

Final environmental statement related to the operation of H.B. Robinson Nuclear Steam-Electric Plant, Unit 2: (Docket No. 50-261)

International Nuclear Information System (INIS)

1975-04-01

The proposed action is the continuation of Facility Operating License DPR-23 to Carolina Power and Light Company for H.B. Robinson Unit 2. Unit 2, located adjacent to Lake Robinson in Darlington County, near Hartsville, South Carolina, employs a pressurized water reactor to produce up to 2200 megawatts thermal (MWt). A steam turbine-generator uses this heat to provide 700 megawatts electric (MWe) of net electrical power capacity. A design power level of 2300 MWt (730 MWe) has been requested and is considered in the assessments contained in this statement. The exhaust steam is cooled by a flow of water obtained from the discharged to a 2250-acre cooling lake, Lake Robinson. Land areas disturbed during construction of the plant, but not used, have been seeded to native grasses, trees, and shrubs. Construction of a cooling water discharge canal extension resulted in alteration of about 100 acres of wildlife habitat. Subsequently, the canal banks were seeded with pines and legumes. Some erosion has taken place in the pine-seeded areas. Some small fish are killed by impingement on the water intake screens. Organisms passing through the screens very likely do not survive their passage through the circulating water system. Operation of the plant will cause an increase in the temperature of Black Creek below Lake Robinson. A small impact exists due to production and, after processing, disposal or release of sanitary and chemical wastes. Unit 2 may discharge up to 500 pounds/day of chemicals (primarily sulfates). Under conditions of low flow into and out of the lake, this increases the sulfate concentration in the lake by less than 1 ppM over the normal 7.7 ppM

Mechanical problems in turbomachines, steam and gas turbines. Large steam turbine manufacturing requirements to fulfill customer needs for electric power

International Nuclear Information System (INIS)

Brazzini, R.

1975-01-01

The needs of the customers in large steam turbines for electric power are examined. The choices and decisions made by the utility about the equipments are dealt with after considering the evolution of power demand on the French network. These decisions and choices mainly result from a technical and economic optimization of production equipments: choice of field-proven solutions, trend to lower steam characteristics, trend to higher output of the units (i.e. size effect), spreading out standardization of machines and components (policy of technical as well as technological levels, i.e. mass production effect). Standardization of external characteristics of units of same level of output and even standardization of some main components. The requirements turbine manufacturers have to meet may fall in two categories: on one side: gaining experience and know-how, capability of making high quality experiments, out put capacity, will to hold a high efficiency level; on the other side: meeting the technical requirements related to the contracts. Among these requirements, one can differentiate those dealing with the service expected from the turbine and that resulting in the responsibility limits of the manufacturer and those tending to gain interchangeability, to improve availability of the equipment, to increase safety, and to make operation and maintenance easier [fr

A Study on the Air Vent Valve of the Hydraulic Servo Actuator for Steam Control of Power Plants

International Nuclear Information System (INIS)

Lee, Yong Bum; Lee, Jong Jik

2016-01-01

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

A Study on the Air Vent Valve of the Hydraulic Servo Actuator for Steam Control of Power Plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Bum; Lee, Jong Jik [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2016-06-15

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

Concept of a utility scale dispatch able solar thermal electricity plant with an indirect particle receiver in a single tower layout

Science.gov (United States)

Schwaiger, Karl; Haider, Markus; Haemmerle, Martin; Steiner, Peter; Obermaier, Michael-Dario

2016-05-01

Flexible dispatch able solar thermal electricity plants applying state of the art power cycles have the potential of playing a vital role in modern electricity systems and even participating in the ancillary market. By replacing molten salt via particles, operation temperatures can be increased and plant efficiencies of over 45 % can be reached. In this work the concept for a utility scale plant using corundum as storage/heat transfer material is thermodynamically modeled and its key performance data are cited. A novel indirect fluidized bed particle receiver concept is presented, profiting from a near black body behavior being able to heat up large particle flows by realizing temperature cycles over 500°C. Specialized fluidized bed steam-generators are applied with negligible auxiliary power demand. The performance of the key components is discussed and a rough sketch of the plant is provided.

Thermal and electrical conductivities of high purity tantalum

International Nuclear Information System (INIS)

Archer, S.L.

1978-01-01

The electrical resistivity and thermal conductivity of three high purity tantalum samples have been measured as functions of temperature over a temperature range of 5K to 65K. Sample purities ranged up to a resistivity ratio of 1714. The highest purity sample had a residual resistivity of .76 x 10 -10 OMEGA-m. The intrinsic resistivity varied as T 3 . 9 from 10K to 31K. The thermal conductivity of the purest sample had a maximum of 840 W/mK at 9.8K. The intrinsic thermal resistivity varied as T 2 . 4 from 10K to 35K. At low temperatures electrons were scattered primarily by impurities and by phonons with both interband and intraband transitions observed. The electrical and thermal resistivity is departed from Matthiessen's rule at low temperatures

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)

Solar thermal power plants for heat and electricity generation; Presentacion de plantas termosolares para generacion de calor y energia electrica

Energy Technology Data Exchange (ETDEWEB)

Estrada Cajigal, V [Solartronic S. A. de C. V., Cuernavaca (Mexico); Manzini, F; Sanchez, A [Laboratorio de Energia Solar (IIM-UNAM), Temixco (Mexico)

1993-12-31

Solar thermal technology is presented for concentration into a point for the production of heat and energy in small and large scale, emphasis is made on the capacity for the combination with current technologies using fossil fuels for electricity generation and process steam, increasing the global efficiency of the power plants and notably reducing the pollutants emission to the air during the insolation hours. It is successfully compared with other solar-thermal technologies. [Espanol] Se presenta la tecnologia termosolar de concentracion puntual para produccion de calor y de energia en pequena y gran escala, se enfatiza su capacidad de combinacion con las tecnologias actuales que utilizan combustibles fosiles para produccion de electricidad y vapor de proceso, aumentando la eficiencia global de las plantas y reduciendo notablemente sus emisiones contaminantes a la atmosfera durante las horas de insolacion. Se le compara exitosamente con otras tecnologias termosolares.

Solar thermal power plants for heat and electricity generation; Presentacion de plantas termosolares para generacion de calor y energia electrica

Energy Technology Data Exchange (ETDEWEB)

Estrada Cajigal, V. [Solartronic S. A. de C. V., Cuernavaca (Mexico); Manzini, F.; Sanchez, A. [Laboratorio de Energia Solar (IIM-UNAM), Temixco (Mexico)

1992-12-31

Solar thermal technology is presented for concentration into a point for the production of heat and energy in small and large scale, emphasis is made on the capacity for the combination with current technologies using fossil fuels for electricity generation and process steam, increasing the global efficiency of the power plants and notably reducing the pollutants emission to the air during the insolation hours. It is successfully compared with other solar-thermal technologies. [Espanol] Se presenta la tecnologia termosolar de concentracion puntual para produccion de calor y de energia en pequena y gran escala, se enfatiza su capacidad de combinacion con las tecnologias actuales que utilizan combustibles fosiles para produccion de electricidad y vapor de proceso, aumentando la eficiencia global de las plantas y reduciendo notablemente sus emisiones contaminantes a la atmosfera durante las horas de insolacion. Se le compara exitosamente con otras tecnologias termosolares.

Mechanical design of the hot steam headers of the THTR-300 steam generators

International Nuclear Information System (INIS)

Blumer, U.; Stumpf, M.

1988-01-01

The high pressure steam headers of the THTR steam generators have been subject to special attention during the design phase due to the following reasons: these components are the pressure retaining parts with the heaviest wall thickness in the region of the steam generators; they therefore are sensitive to thermal transient conditions; they are operated in the elevated temperature regime, where creep effects cannot be neglected; there is almost no service experience from fossil steam generators with this type of material (Alloy 800). Safety consideration therefore have been rather extensive and have focussed on two main areas which will be treated in this paper: 1. Analytical investigations on the cyclic material behaviour under all specified operating conditions, taking into account the non-elastic response of the material. 2. Limitation of the consequences of a header rupture by installation of heavy whip restraints. Elastic-plastic-creep analyses: The analyses were performed in different stages and are explained in the corresponding order: Evaluation of the critical location on the header and establishment of a simplified model of a nozzle region for further analysis. Preliminary thermal analyses of all specified transient conditions on simplified procedures, in order to establish a severity ranking of the conditions. Establishment of representative loading blocks. Evaluation of the material properties for thermal and structural, especially non-elastic behaviour. Detailed thermal analyses. Detailed structural analyses of the non-elastic cyclic response. Extrapolation for all cycles and assessment of the results by design codes. Discussion of the results. Header whip restraint design: In addition to the above analysis efforts, heavy whip restraints were provided to assure limitation of the effects of a header failure. This pager shows the measures that were taken to restrain the movement in case of longitudinal and transverse breaks: The anti-whip designs are

Electricity in lieu of nautral gas and oil for industrial thermal energy: a preliminary survey

Energy Technology Data Exchange (ETDEWEB)

Tallackson, J. R.

1979-02-01

In 1974, industrial processors accounted for nearly 50% of the nation's natural gas consumption and nearly 20% of its consumption of petroleum. This report is a preliminary assessment of the potential capability of the process industries to substitute utility-generated electricity for these scarce fuels. It is tacitly assumed that virtually all public utilities will soon be relying on coal or nuclear fission for primary energy. It was concluded that the existing technology will permit substitution of electricity for approximately 75% of the natural gas and petroleum now being consumed by industrial processors, which is equivalent to an annual usage of 800 million barrels of oil and 9 trillion cubic feet of gas at 1974 levels. Process steam generation, used throughout industry and representing 40% of its energy usage, offers the best near-term potential for conversion to electricity. Electric boilers and energy costs for steam are briefly discussed. Electrically driven heat pumps are considered as a possible method to save additional low-grade energy. Electrical reheating at high temperatures in the primary metals sector will be an effective way to conserve gas and oil. A wholesale shift by industry to electricity to replace gas and oil will produce impacts on the public utilities and, perhaps, those of a more general socio-economic nature. The principal bar to large-scale electrical substitution is economics, not technology. 174 references.

Reversible temperature regulation of electrical and thermal conductivity using liquid–solid phase transitions

Science.gov (United States)

Zheng, Ruiting; Gao, Jinwei; Wang, Jianjian; Chen, Gang

2011-01-01

Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions. PMID:21505445

Reversible temperature regulation of electrical and thermal conductivity using liquid-solid phase transitions.

Science.gov (United States)

Zheng, Ruiting; Gao, Jinwei; Wang, Jianjian; Chen, Gang

2011-01-01

Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions.

Electrically Driven Thermal Management: Flight Validation, Experiment Development, Future Technologies

Science.gov (United States)

Didion, Jeffrey R.

2018-01-01

Electrically Driven Thermal Management is an active research and technology development initiative incorporating ISS technology flight demonstrations (STP-H5), development of Microgravity Science Glovebox (MSG) flight experiment, and laboratory-based investigations of electrically based thermal management techniques. The program targets integrated thermal management for future generations of RF electronics and power electronic devices. This presentation reviews four program elements: i.) results from the Electrohydrodynamic (EHD) Long Term Flight Demonstration launched in February 2017 ii.) development of the Electrically Driven Liquid Film Boiling Experiment iii.) two University based research efforts iv.) development of Oscillating Heat Pipe evaluation at Goddard Space Flight Center.

Final environmental statement related to the operation of Comanche Peak Steam Electric Station, Units 1 and 2: (Docket Nos. 50-445 and 50-446)

International Nuclear Information System (INIS)

1981-09-01

The proposed action is the issuance of operating licenses to the Texas Utilities Generating Company for the startup and operation of Units 1 and 2 of the Comanche Peak Steam Electric Station located on Squaw Creek Reservoir in Somervell County, Texas, about 7 km north-northeast of Glen Rose, Texas, and about 65 km southwest of Fort Worth in north-central Texas. The information in this environmental statement represents the second assessment of the environmental impact associated with the Comanche Peak Steam Electric Station pursuant to the guidelines of the National Environmental Policy Act of 1969 (NEPA) and 10 CFR Part 51 of the Commission's Regulations. After receiving an application to construct this station, the staff carried out a review of impact that would occur during its construction and operation. This evaluation was issued as a Final Environmental Statement -- Construction Phase. After this environmental review, a safety review, an evaluation by the Advisory Committee on Reactor Safeguards, and public hearings in Glen Rose, Texas, the US Atomic Energy Commission (now US Nuclear Regulatory Commission) issued construction permits for the construction of Units 1 and 2 of the Comanche Peak Steam Electric Station. 16 figs., 34 tabs

Study of the electrical and thermal performances of photovoltaic thermal collector-compound parabolic concentrated

Directory of Open Access Journals (Sweden)

Ahed Hameed Jaaz

2018-06-01

Full Text Available The importance of utilizing the solar energy as a very suitable source among multi-source approaches to replace the conventional energy is on the rise in the last four decades. The invention of the photovoltaic module (PV could be the corner stone in this process. However, the limited amount of energy obtained from PV was and still the main challenge of full utilization of the solar energy. In this paper, the use of the compound parabolic concentrator (CPC along with the thermal photovoltaic module (PVT where the cooling process of the CPC is conducted using a novel technique of water jet impingement has applied experimentally and physically tested. The test includes the effect of water jet impingement on the total power, electrical efficiency, thermal efficiency, and total efficiency on CPC-PVT system. The cooling process at the maximum irradiation by water jet impingement resulted in improving the electrical efficiency by 7%, total output power by 31% and the thermal efficiency by 81%. These results outperform the recent highest results recorded by the most recent work. Keywords: Photovoltaic thermal collectors, Electrical performance, Thermal performance, Compound parabolic concentrator, Jet impingement

Experience and modeling of radioactivity transport following steam generator tube rupture

International Nuclear Information System (INIS)

Hopenfeld, J.

1985-01-01

A review of the capabilities of the CITADEL computer code as well as plant experience to project radioactivity releases following a steam generator tube rupture in pressurized-water reactors shows that certain experimental data are needed for reliable offsite dose predictions. This article defines five parameters that are the key for such predictions and discusses the functional dependence of these parameters on various operational variables. The above parameters can be used in conjuction with CITADEL or they can be inserted in the appropriate equations, which then can be programmed conveniently as a subroutine in thermal-hydraulic system codes. A joint Westinghouse Electric Corporation, Electric Power Research Institute, and Nuclear Regulatory Commission program aimed at obtaining the five parameters empirically is described

Maximizing heavy-oil recovery by containing steam through optimized cementing

Energy Technology Data Exchange (ETDEWEB)

Ravi, K.; Hunter, B.; Kulakofsky, D [Halliburton Energy Services, Calgary, AB (Canada)

2008-10-15

As the world's oil and gas reserves decline, interest in unconventional sources, such as heavy oil, is increasing in response to global energy demand. Conventional methods are not sufficient to produce highly viscous heavy oil, and measures must be taken to decrease its viscosity. Although steam injection is an option, steam heats the casing and the cement sheath posing considerable thermal stress on the casing and the cement sheath. This paper described the design procedures that are required for evaluating the properties needed in the cement sheath in order to assist in withstanding thermal stresses. The steps needed to deliver an optimized cement system were presented. The paper presented an illustration of a typical wellbore for heavy-oil application and listed the parameters responsible for the extent of heat loss. These included formation properties; cement sheath thermal conductivity; steam-injection rate; and steam quality. The paper also described the Zhang unified mechanistic model which involved the temperature, pressure, steam quality, and heat loss changes as a function of the depth and the surroundings. Recommendations for withstanding well operations, hole cleaning, and slurry placement were also presented. Insurance for incomplete drilling fluid displacement and cement with the ability to react and respond were also proposed. It was concluded that in thermal recovery wells, energy loss to the surroundings could be reduced by lowering the thermal conductivity of the cement sheath. This could greatly improve the economics of such wells. 9 refs., 5 figs.

Third international seminar on horizontal steam generators

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.

Third international seminar on horizontal steam generators

International Nuclear Information System (INIS)

1995-01-01

The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues

Third international seminar on horizontal steam generators

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.

Integration of mixed conducting membranes in an oxygen–steam biomass gasification process

DEFF Research Database (Denmark)

Puig Arnavat, Maria; Soprani, Stefano; Søgaard, Martin

2013-01-01

. The two configurations demonstrating the highest efficiency are then thermally integrated into an oxygen– steam biomass gasification plant. The energy demand for oxygen production and the membrane area required for a 6 MWth biomass plant are calculated for different operating conditions. Increasing......Oxygen–steam biomass gasification produces a high quality syngas with a high H2/CO ratio that is suitable for upgrading to liquid fuels. Such a gas is also well suited for use in conjunction with solid oxide fuel cells giving rise to a system yielding high electrical efficiency based on biomass...... distillation, especially for small to medium scale plants. This paper examines different configurations for oxygen production using MIEC membranes where the oxygen partial pressure difference is achieved by creating a vacuum on the permeate side, compressing the air on the feed side or a combination of the two...

Comments on US LMFBR steam generator base technology

International Nuclear Information System (INIS)

Simmons, W.R.

1984-01-01

The development of steam generators for the LMFBR was recognized from the onset by the AEC, now DOE, as a difficult, challenging, and high-priority task. The highly reactive nature of sodium with water/steam requires that the sodium-water/steam boundaries of LMFBR steam generators possess a degree of leak-tightness reliability not normally attempted on a commercial scale. In addition, the LMFBR steam generator is subjected to high fluid temperatures and severe thermal transients. These requirements place great demand on materials, fabrication processes, and inspection methods; and even greater demands on the designer to provide steam generators that can meet these demanding requirements, be fabricated without unreasonable shop requirements, and tolerate off-normal effects

Electrical and thermal properties of graphite/polyaniline composites

Energy Technology Data Exchange (ETDEWEB)

Bourdo, Shawn E., E-mail: sxbourdo@ualr.edu [Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States); Warford, Brock A.; Viswanathan, Tito [Department of Chemistry, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States)

2012-12-15

A composite of a carbon allotrope (graphite) and an inherently conducting polymer, polyaniline (PANI), has been prepared that exhibits an electrical conductivity greater than either of the two components. An almost 2-fold increase in the bulk conductivity occurs when only a small mass fraction of polyaniline exists in the composite (91% graphite/ 9% polyaniline, by mass). This increase in dc electrical conductivity is curious since in most cases a composite material will exhibit a conductivity somewhere between the two individual components, unless a modification to the electronic nature of the material occurs. In order to elucidate the fundamental electrical properties of the composite we have performed variable temperature conductivity measurements to better understand the nature of conduction in these materials. The results from these studies suggest a change in the mechanism of conduction as the amount of polyaniline is increased in the composite. Along with superior electrical properties, the composites exhibit an increase in thermal stability as compared to the graphite. - Graphical abstract: (Left) Room temperature electrical conductivity of G-PANI composites at different mass ratios. (Right) Electrical conductivity of G-PANI composites at temperatures from 5 K to 300 K. Highlights: Black-Right-Pointing-Pointer Composites of graphite and polyaniline have been synthesized with unique electrical and thermal properties. Black-Right-Pointing-Pointer Certain G-PANI composites are more conductive and more thermally stable than graphite alone. Black-Right-Pointing-Pointer G-PANI composites exhibit a larger conductivity ratio with respect to temperature than graphite alone.

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

Effective electrical and thermal conductivity of multifilament twisted superconductors

International Nuclear Information System (INIS)

Chechetkin, V.R.

2013-01-01

The effective electrical and thermal conductivity of composite wire with twisted superconducting filaments embedded into normal metal matrix is calculated using the extension of Bruggeman method. The resistive conductivity of superconducting filaments is described in terms of symmetric tensor, whereas the conductivity of a matrix is assumed to be isotropic and homogeneous. The dependence of the resistive electrical conductivity of superconducting filaments on temperature, magnetic field, and current density is implied to be parametric. The resulting effective conductivity tensor proved to be non-diagonal and symmetric. The non-diagonal transverse–longitudinal components of effective electrical conductivity tensor are responsible for the redistribution of current between filaments. In the limits of high and low electrical conductivity of filaments the transverse effective conductivity tends to that of obtained previously by Carr. The effective thermal conductivity of composite wires is non-diagonal and radius-dependent even for the isotropic and homogeneous thermal conductivities of matrix and filaments.

Thermal Management of Power Electronics and Electric Motors for Electric-Drive Vehicles (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Narumanchi, S.

2014-09-01

This presentation is an overview of the power electronics and electric motor thermal management and reliability activities at NREL. The focus is on activities funded by the Department of Energy Vehicle Technologies Office Advanced Power Electronics and Electric Motors Program.

Strategic elements of steam cycle chemistry control practices at TXU's Comanche Peak steam electric station

International Nuclear Information System (INIS)

Fellers, B.; Stevens, J.; Nichols, G.

2002-01-01

Early industry experience defined the critical importance of Chemistry Control Practices to maintaining long-term performance of PWR steam generators. These lessons provided the impetus for a number of innovations and alternate practices at Comanche Peak. For example, advanced amine investigations and implementation of results provided record low iron transport and deposition. The benefits of the surface-active properties of dimethyl-amine exceeded initial expectations. Operation of pre-coat polishers and steam generator blowdown demineralizers in the amine cycle enabled optimization of amine concentrations and stable pH control. The strategy for coordinated control of oxygen and hydrazine dosing complemented the advanced amine program for protective oxide stabilization. Additionally, a proactive chemical cleaning was performed on Unit 1 to prevent degradations from general fouling of steam generator tube-tube support plate (TSP) and top-of-tubesheet (TTS) crevices. This paper shares the results of these innovations and practices. Also, the bases, theory, and philosophy supporting the strategic elements of program will be presented. (authors)

Steam generator reliability improvement project

International Nuclear Information System (INIS)

Blomgren, J.C.; Green, S.J.

1987-01-01

Upon successful completion of its research and development technology transfer program, the Electric Power Research Institute's Steam Generator Owners Group (SGOG II) will disband in December 1986 and be replaced in January 1987 by a successor project, the Steam Generator Reliability Project (SGRP). The new project, funded in the EPRI base program, will continue the emphasis on reliability and life extension that was carried forward by SGOG II. The objectives of SGOG II have been met. Causes and remedies have been identified for tubing corrosion problems, such as stress corrosion cracking and pitting, and steam generator technology has been improved in areas such as tube wear prediction and nondestructive evaluation (NDE). These actions have led to improved reliability of steam generators. Now the owners want to continue with a centrally managed program that builds on what has been learned. The goal is to continue to improve steam generator reliability and solve small problems before they become large problems

Steam generator reliability improvement project

International Nuclear Information System (INIS)

Blomgren, J.C.; Green, S.J.

1987-01-01

Upon successful completion of its research and development technology transfer program, the Electric Power Research Institute's (EPRI's) Steam Generator Owners Group (SGOG II) will disband in December 1986, and be replaced in January 1987, by a successor project, the Steam Generator Reliability Project (SGRP). The new project, funded in the EPRI base program, will continue to emphasize reliability and life extension, which were carried forward by SGOG II. The objectives of SGOG II have been met. Causes and remedies have been identified for tubing corrosion problems such as stress corrosion cracking and pitting, and steam generator technology has been improved in areas such as tube wear prediction and nondestructive evaluation. These actions have led to improved reliability of steam generators. Now the owners want to continue with a centrally managed program that builds on what has been learned. The goal is to continue to improve steam generator reliability and to solve small problems before they become large problems

Method for operating a steam turbine of the nuclear type with electronic reheat control of a cycle steam reheater

International Nuclear Information System (INIS)

Luongo, M.C.

1975-01-01

An electronic system is provided for operating a nuclear electric power plant with electronic steam reheating control applied to the nuclear turbine system in response to low pressure turbine temperatures, and the control is adapted to operate in a plurality of different automatic control modes to control reheating steam flow and other steam conditions. Each of the modes of control permit turbine temperature variations within predetermined constraints and according to predetermined functions of time. (Official Gazette)

Dancing with STEAM: Creative Movement Generates Electricity for Young Learners

Science.gov (United States)

Simpson Steele, Jamie; Fulton, Lori; Fanning, Lisa

2016-01-01

The integration of science, technology, engineering, arts, and mathematics (STEAM) serves to develop creative thinking and twenty-first-century skills in the classroom (Maeda 2012). Learning through STEAM promotes novelty, innovation, ingenuity, and task-specific purposefulness to solve real-world problems--all aspects that define creativity. Lisa…

Steam process cogeneration using nuclear energy

International Nuclear Information System (INIS)

Alonso, G.; Ramirez, R.

2010-10-01

Use of energy in a sustainable manner is to make processes more efficient. Oil industry requires of electricity and steam for refinery and petrochemical processes, nuclear energy can be a clean energy alternative. Cogeneration is an option to be assessed by Mexico to provide additional value to electricity generation. Mexico is a country with oil resources that requires process heat for gasoline production among other things. With the concern about the climate change and sustain ability policies it is adequate to use cogeneration as a way to optimize energy resources. Currently there is a national program that considers cogeneration for several Mexican refineries, and the first choices are combined cycle plants and thermo power plants using residual oil. This is long term program. The pebble bed modular reactor (PBMR) is a next generation reactors that works with very high temperatures that can be used to produce steam process along with electricity, in this work two different couplings are assessed for the PBMR reactor to produce steam process, the two couplings are compared for using in the Mexican refineries and some conclusions are given. (Author)

High-frequency thermal-electrical cycles for pyroelectric energy conversion

International Nuclear Information System (INIS)

Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna; Martin, Lane W.; King, William P.

2014-01-01

We report thermal to electrical energy conversion from a 150 nm thick BaTiO 3 film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10 5  kV/cm-s, and temperature change rates as high as 6 × 10 5  K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems

Continuous hydrino thermal power system

Energy Technology Data Exchange (ETDEWEB)

Mills, Randell L.; Zhao, Guibing; Good, William [BlackLight Power, Inc., 493 Old Trenton Road, Cranbury, NJ 08512 (United States)

2011-03-15

The specifics of a continuous hydrino reaction system design are presented. Heat from the hydrino reactions within individual cells provide both reactor power and the heat for regeneration of the reactants. These processes occur continuously and the power from each cell is constant. The conversion of thermal power to electrical power requires the use of a heat engine exploiting a cycle such as a Rankine, Brayton, Stirling, or steam-engine cycle. Due to the temperatures, economy goal, and efficiency, the Rankine cycle is the most practical and can produce electricity at 30-40% efficiency with a component capital cost of about $300 per kW electric. Conservatively, assuming a conversion efficiency of 25% the total cost with the addition of the boiler and chemical components is estimated at $1064 per kW electric. (author)

Continuous hydrino thermal power system

International Nuclear Information System (INIS)

Mills, Randell L.; Zhao, Guibing; Good, William

2011-01-01

The specifics of a continuous hydrino reaction system design are presented. Heat from the hydrino reactions within individual cells provide both reactor power and the heat for regeneration of the reactants. These processes occur continuously and the power from each cell is constant. The conversion of thermal power to electrical power requires the use of a heat engine exploiting a cycle such as a Rankine, Brayton, Stirling, or steam-engine cycle. Due to the temperatures, economy goal, and efficiency, the Rankine cycle is the most practical and can produce electricity at 30-40% efficiency with a component capital cost of about $300 per kW electric. Conservatively, assuming a conversion efficiency of 25% the total cost with the addition of the boiler and chemical components is estimated at $1064 per kW electric.

Comparison of the Effects of Thermal Pretreatment, Steam Explosion and Ultrasonic Disintegration on Digestibility of Corn Stover

OpenAIRE

Andras Dallos; Gyula Dörgő; Dániel Capári

2016-01-01

The energy demand of the corn-based bioethanol production could be reduced using the agricultural byproducts as bioenergy feedstock for biogas digesters. The release of lignocellulosic material and therefore the acceleration of degradation processes can be achieved using thermal and mechanical pretreatments, which assist to hydrolyze the cell walls and speed the solubilization of biopolymers in biogas feedstock. This study is focused on liquid hot water, steam explosion and ultrasonic pretrea...

Improvement of Thermal and Electrical Conductivity of Epoxy/boron Nitride/silver Nanoparticle Composite

Energy Technology Data Exchange (ETDEWEB)

Kim, Seungyong; Lim, Soonho [Korea Institute of Science and Technology, Wanju (Korea, Republic of)

2017-06-15

In this study, we investigated the effect of BN (boron nitride) on the thermal and the electrical conductivity of composites. In case of epoxy/BN composites, the thermal conductivity was increased as the BN contents were increased. Epoxy/AgNP (Ag nanoparticle) nanocomposites exhibited a slight change of thermal conductivity and showed a electrical percolation threshold at 20 vol% of Ag nanoparticles. At the fixed Ag nanoparticle content below the electrical percolation threshold, increasing the amount of BN enhanced the electrical conductivity as well as thermal conductivity for the epoxy/AgNP/BN composites.

An evaluation of the statistical variability in thermal expansion properties of steam generator tubesheet (SA-508) and tubing (Alloy-600TT)

International Nuclear Information System (INIS)

Riccardella, P.C.; Staples, J.F.; Kandra, J.T.

2009-01-01

Inspections of steam generator tubing are performed in U.S. PWRs as part of the Steam Generator Management Program. Westinghouse has recently completed a technical justification demonstrating that in steam generators with thermally treated Ni-Cr Alloy (Alloy 600TT) tubes that are hydraulically expanded into low alloy steel (SA-508) tubesheets, flaws in the region of the tubes below a certain distance from the top of the tubesheet, denoted H * , will not result in reactor coolant pressure boundary breach nor unacceptable primary-to-secondary leakage. This is because, even if a flaw in this region were to result in complete tube sever, if the length of undegraded tube in the tubesheet exceeds H*, neither operating nor accident loadings create sufficient pull-out forces to overcome the frictional forces between the tube and tubesheet. One key component of this technical justification is the differential thermal expansion between the tube and tubesheet, since a significant portion of the pullout strength of the hydraulically expanded tube-to-tubesheet joint is due to mechanical interference resulting from the larger expansion of the tubing relative to the tubesheet at a given temperature. To address this phenomenon, a detailed statistical evaluation of coefficient of thermal expansion (CTE) data for the tubesheet material (SA-508) and the tube material (thermally treated Alloy-600) was performed. Data used in the evaluation included existing test results obtained from a number of sources as well as extensive new laboratory data developed specifically for this purpose. The evaluation resulted in recommended statistical distributions of this property for the two materials including their means and probabilistic variability. In addition, it was determined that the CTE values reported in the ASME Code (Section II) represent reasonably conservative mean values for both the tubesheet and tubing material. (author)

Fluidelastic instability analysis of steam generator U-tubes at antivibration bar-inactive modes

International Nuclear Information System (INIS)

Lee, S.K.; Jo, J.C.

1995-01-01

This paper presents the results of thermal-hydraulic and fluidelastic U-tube instability analyses performed for the vertical type pressurized water reactor (PWR) steam generator model being employed at Kori units 2, 3 and 4, and Yonggwang units 1 and 2 in Korea. The thermal-hydraulic analysis for providing the detailed three-dimensional two-phase flow field in the secondary side of the steam generator was accomplished using the ATHOS3 steam generator thermal-hydraulic analysis code. The UTVA2 code designed for calculating both the free vibration responses and fluidelastic stability ratio of a specific U-tube under consideration was used to assess the potential for fluidelastic instability of the steam generator U-tubes at various conditions of antivibration bar (AVB)-inactive modes. The results of the fluidelastic instability analysis were discussed in comparison with those obtained for the steam generator U-tubes at AVB-active mode

Specific properties of the electrical equipment in the nuclear steam supply system; Specificnosti elektricne opreme u primarnom djelu nuklearne elektrane

Energy Technology Data Exchange (ETDEWEB)

Smiljanic, D [Rade Koncar Institut, Zagreb (Yugoslavia)

1979-07-01

The paper presents description of reactor coolant pump motor in the primary coolant loop. The motor is treated as a representative of all electrical equipment in the nuclear steam supply system that has to meet all the requirements concerning reliability, minimum maintenance, radiation, seismic etc. (author)

Selective hydrogenation processes in steam cracking

Energy Technology Data Exchange (ETDEWEB)

Bender, M.; Schroeter, M.K.; Hinrichs, M.; Makarczyk, P. [BASF SE, Ludwigshafen (Germany)

2010-12-30

Hydrogen is the key elixir used to trim the quality of olefinic and aromatic product slates from steam crackers. Being co-produced in excess amounts in the thermal cracking process a small part of the hydrogen is consumed in the ''cold part'' of a steam cracker to selectively hydrogenate unwanted, unsaturated hydrocarbons. The compositions of the various steam cracker product streams are adjusted by these processes to the outlet specifications. This presentation gives an overview over state-of-art selective hydrogenation technologies available from BASF for these processes. (Published in summary form only) (orig.)

Performance and thermal decomposition analysis of foaming agent NPL-10 for use in heavy oil recovery by steam injection

Directory of Open Access Journals (Sweden)

Zhao Fa-Jun

2018-02-01

Full Text Available Foaming agents, despite holding potential in steam injection technology for heavy oil recovery, are still poorly investigated. In this work, we analyzed the performance of the foaming agent NPL-10 in terms of foam height and half-life under various conditions of temperature, pH, salinity, and oil content by orthogonal experiments. The best conditions of use for NPL-10 among those tested are T=220°C, pH 7, salinity 10000 mg·L–1 and oil content 10 g·L–1. Thermal decomposition of NPL-10 was also studied by thermogravimetric and differential thermal analyses. NPL-10 decomposes above 220°C, and decomposition is a two-step process. The kinetic triplet (activation energy, kinetic function and pre-exponential factor and the corresponding rate law were calculated for each step. Steps 1 and 2 follow kinetics of different order (n = 2 and ½, respectively. These findings provide some criteria for the selection of foaming agents for oil recovery by steam injection.

Fourth international seminar on horizontal steam generators

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, H. [ed.] [IVO Group, Vantaa (Finland); Purhonen, H. [ed.] [VTT, Espoo (Finland); Kouhia, V. [ed.] [Lappeenranta Univ. of Technology (Finland)

1997-12-31

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

Fourth international seminar on horizontal steam generators

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, H [ed.; IVO Group, Vantaa (Finland); Purhonen, H [ed.; VTT, Espoo (Finland); Kouhia, V [ed.; Lappeenranta Univ. of Technology (Finland)

1998-12-31

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

Fourth international seminar on horizontal steam generators

International Nuclear Information System (INIS)

Tuomisto, H.; Purhonen, H.; Kouhia, V.

1997-01-01

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries

Electro-thermal analysis and integration issues of lithium ion battery for electric vehicles

International Nuclear Information System (INIS)

Saw, L.H.; Ye, Y.; Tay, A.A.O.

2014-01-01

Highlights: • We modeled the electrical and thermal behavior of the Li-ion battery. • We validated the simulation results with experimental studies. • We compared the thermal performance of different size of cylindrical cells. • We investigated the integration issues of cylindrical cells into battery pack. - Abstract: Electrical and thermal characteristics of lithium-ion battery packs in electric vehicles in different operating conditions are important in order to design the battery pack thermal management system. In this work, electrical and thermal behaviors of different size of LiFePO 4 cylindrical cells are investigated under various operating conditions. The simulation results show good agreement with the experimental data under various operating modes. Due to the large thermal resistance of layered active material in a Li-ion cell, the temperature difference in the radial direction is significantly correlated with a diameter of cell and I t -rates. Compared with natural convection, strong forced convection will reduce the temperature uniformity in the cell and accelerate the thermal aging rate. Lastly, integration issues of the cells into a battery pack are discussed from mechanical, electrical, thermal, control and monitoring, manufacturing and maintenance aspects. These issues could impact the performance, cost, driving range and life cycle of the battery pack in electric vehicles

Synthesis, structural and electrical characterizations of thermally ...

African Journals Online (AJOL)

Synthesis, structural and electrical characterizations of thermally evaporated Cu 2 SnS 3 thin films. ... The surface profilometer shows that the deposited films are rough. The XRD spectra identified the ... The electrical resistivity of the deposited Cu2SnS3 film is 2.55 x 10-3 Ωcm. The conductivity is in the order of 103 Ω-1cm-1.

Thermal performance of a linear Fresnel reflector solar concentrator PV/T energy systems

Energy Technology Data Exchange (ETDEWEB)

Gomaa, Mohamed R. [State Engineering University of Armenia (Armenia)], E-Mail: Dmoh_elbehary@yahoo.com

2011-07-01

This is a report on an investigation of photovoltaic/thermal (PV/T) collectors. Solar energy conversion efficiency was increased by taking advantage of PV/T collectors and low solar concentration technologies, combined into a PV/T system operated at elevated temperature. The main novelty is the coupling of a linear Fresnel mirror reflecting concentrator with a channel PV/T collector. Concentrator PV/T collectors can function at temperatures over 100 degrees celsius, and thus thermal energy can be made to drive processes such as refrigeration, desalination and steam production. Solar system analytical thermal performance gives efficiency values over 60%. Combined electric and thermal (CET) efficiency is high. A combined electric and heat power for the linear fresnel reflector approach that employs high performance CPV technology to produce both electricity and thermal energy at low to medium temperatures is presented. A well-functioning PV/T system can be designed and constructed with low concentration and a total efficiency of nearly 80% can be attained.

Thermal hydraulic aspects of steam drum level control philosophy for the natural circulation based heavy water reactor

International Nuclear Information System (INIS)

Gupta, S.K.; Gaikwad, A.J.; Kumar, Rajesh

2004-01-01

From safety considerations advanced nuclear reactors rely more and more on passive systems such as natural circulation for primary heat removal. A natural circulation based water reactor is relatively larger in size so as to reduce flow losses and channel type for proper flow distribution. From the size of steam drum considerations it has to be multi loop but has a common inlet header. Normally the turbine follows the reactor. This paper addresses the thermal hydraulic aspects of the steam drum pressure and level control philosophy for a four drum, natural circulation based, channel type boiling water advanced reactor. Three philosophies may be followed for drum control viz. individual drum control, one control drum approach and an average of all the four drums. For drum pressure control, the steam flow to the turbine is be regulated. A single point pressure control is better than individual drum pressure control. This is discussed in the paper. But the control point has to be at a place down steam the point where all steam line from individual drum meet. This may lead to different pressure in all the four drums depending on the power produced in the respective loops. The difference in pressure cannot be removed even if the four drums are directly connected through pipes. Also the pressure control scheme with/without interconnection is discussed. For level, the control of individual drum may not be normally possible because of common inlet header. As the frictional pressure drops in the large diameter downcomers are small as compared to elevation pressure drops, the level in all the steam drum tend to equalize. Consequently a single representative drum level may be chosen as a control variable for controlling level in all the four drums. But in case, where all the four loops are producing different powers and single point pressure control is effective, the scheme may not work satisfactorily. the level in a drum may depend on the power produced in the loop

Two-dimensional thermal analysis of radial heat transfer of monoliths in small-scale steam methane reforming

DEFF Research Database (Denmark)

Cui, Xiaoti; Kær, Søren Knudsen

2018-01-01

Monolithic catalysts have received increasing attention for application in the small-scale steam methane reforming process. The radial heat transfer behaviors of monolith reformers were analyzed by two-dimensional computational fluid dynamic (CFD) modeling. A parameter study was conducted...... by a large number of simulations focusing on the thermal conductivity of the monolith substrate, washcoat layer, wall gap, radiation heat transfer and the geometric parameters (cell density, porosity and diameter of monolith). The effective radial thermal conductivity of the monolith structure, kr......,eff, showed good agreement with predictions made by the pseudo-continuous symmetric model. This influence of the radiation heat transfer is low for highly conductive monoliths. A simplified model has been developed to evaluate the importance of radiation for monolithic reformers under different conditions...

Electricity storage using a thermal storage scheme

Energy Technology Data Exchange (ETDEWEB)

White, Alexander, E-mail: ajw36@cam.ac.uk [Hopkinson Laboratory, Cambridge University Engineering Department, Trumpington Street, Cambridge. CB2 1PZ (United Kingdom)

2015-01-22

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on “sensible heat” storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

CRBRP steam-generator design evolution

International Nuclear Information System (INIS)

Geiger, W.R.; Gillett, J.E.; Lagally, H.O.

1983-01-01

The overall design of the CRBRP Steam Generator is briefly discussed. Two areas of particular concern are highlighted and considerations leading to the final design are detailed. Differential thermal expansion between the shell and the steam tubes is accommodated by the tubes flexing in the curved section of the shell. Support of the tubes by the internals structure is essential to permit free movement and minimize tube wear. Special spacer plate attachment and tube hole geometry promote unimpeded axial movement of the tubes by allowing individual tubes to rotate laterally and by providing lateral movement of the spacer plates relative to the adjacent support structure. The water/steam heads of the CRBRP Steam Generator are spherical heads welded to the lower and upper tubesheets. They were chosen principally because they provide a positively sealed system and result in more favorable stresses in the tubesheets when compared to mechanically attached steamheads

Electricity pricing model in thermal generating stations under deregulation

International Nuclear Information System (INIS)

Reji, P.; Ashok, S.; Moideenkutty, K.M.

2007-01-01

In regulated public utilities with competitive power markets, deregulation has replaced the monopoly. Under the deregulated power market, the electricity price primarily depends on market mechanism and power demand. In this market, generators generally follow marginal pricing. Each generator fixes the electricity price based on their pricing strategy and it leads to more price volatility. This paper proposed a model to determine the electricity price considering all operational constraints of the plant and economic variables that influenced the price, for a thermal generating station under deregulation. The purpose of the model was to assist existing stations, investors in the power sector, regulatory authorities, transmission utilities, and new power generators in decision-making. The model could accommodate price volatility in the market and was based on performance incentive/penalty considering plant load factor, availability of the plant and peak/ off peak demand. The model was applied as a case study to a typical thermal utility in India to determine the electricity price. It was concluded that the case study of a thermal generating station in a deregulated environment showed that the electricity price mainly depended on the gross calorific value (GCV) of fuel, mode of operation, price of the fuel, and operating charges. 11 refs., 2 tabs., 1 fig

Analysis Of Electrical – Thermal Coupling Of Induction Machine ...

African Journals Online (AJOL)

The interaction of the Electrical and mechanical parts of Electrical machines gives rise to the heating of the machine's constituent parts. This consequently leads to an increase in temperature which if not properly monitored may lead to the breakdown of the machine. This paper therefore presents the Electrical and thermal ...

Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

Energy Technology Data Exchange (ETDEWEB)

Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-03-17

This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

Steam generator tube failures

International Nuclear Information System (INIS)

MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

1996-04-01

A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

How is Electricity Generated from Nuclear Power Plant

International Nuclear Information System (INIS)

Lajnef, D.

2015-01-01

Nuclear power is a proven, safe and clean source of power generation. A nuclear power plant is a thermal power station in which the heat source is a nuclear reactor. As is typical in all conventional thermal power stations the heat is used to generate steam which drives a steam turbine: the energy released from continuous fission of the atoms of the fuel is harnessed as heat in either a gas or water, and is used to produce steam. Nuclear Reactors are classified by several methods. It can be classified by type of nuclear reaction, by the moderator material, by coolant or by generation. There are several components common to most types of reactors: fuel, moderator, control rods, coolant, and containment. Nuclear reactor technology has been under continuous development since the first commercial exploitation of civil nuclear power in the 1950s. We can mention seven key reactor attributes that illuminate the essential differences between the various generations of reactors: cost effectiveness, safety, security and non-proliferation, fuel cycle, grid appropriateness and Economics. Today there are about 437 nuclear power reactors that are used to generate electricity in about 30 countries around the world. (author)

Final Environmental Statement related to the operation of Comanche Peak Steam Electric Station, Units 1 and 2 (Docket Nos. 50-445 and 50-446)

International Nuclear Information System (INIS)

1989-10-01

In September 1981, the staff of the Nuclear Regulatory Commission (NRC) issued its Final Environmental Statement (NUREG-0775) related to the operation of Comanche Peak Steam Electric Station, Units 1 and 2 (Docket Nos. 50-445 and 50-446), located in Somervell County, Texas, approximately 40 miles southwest of Fort Worth, Texas. The NRC has prepared this supplement to NUREG-0775 to present its evaluation of the alternative of operating Comanche Peak with the installation of further severe-accident-mitigation design features. The NRC has discovered no substantial changes in the proposed action as previously evaluated in the Final Environmental Statement that are relevant to environmental concerns and bearing on the licensing of Comanche Peak Steam Electric Station, Units 1 and 2. 6 refs., 3 tabs

A thermal study of an encapsulated electrical transformer

Energy Technology Data Exchange (ETDEWEB)

Garcia, A. [Unidad Geotermia, Temixco (Mexico). Instituto de Investigaciones Electricas; Espinosa-Paredes, G. [Universidad Autonoma Metropolitana, Vicentina (Mexico). Dpto. de Ingenieria de Procesos e Hidraulica; Hernandez, I. [Centro de Sistemas de Manufactura, Nuevo Leon (Mexico). Instituto Tecnologico y de Estudios Superiores de Monterrey

2002-11-01

A thermal study of a 45 KVA-prototype encapsulated transformer is described. Casting resin systems were used as insulating systems for encapsulated electric transformers. Normal transformer operation is at full load and, thus the conductor and insulating system becomes hot owing to current circulation through the winding. To determine the various temperature distributions throughout the transformer, the thermal properties of the insulating system and boundary conditions must be known, so that hot spots are located via numerical modelling and maximum permissible temperatures are not attained. Results presented herein include thermal conductivity, thermal diffusivity, and specific heat capacity. Thermal conductivity was obtained experimentally by means of the line-source technique at various temperatures, between room temperature and 155{sup o}C which is the thermal limit of class F insulators. The thermal diffusivity was obtained by parameter estimation by fitting an approximate analytical model to the temperature-time data of the thermal conductivity experiment. Specific heat capacity was obtained from the definition of thermal diffusivity and the insulating-system density. In order to improve the electrical performance of the transformer criteria, a numerical simulation of the different dielectric structures was made using computer program. The boundary conditions for the thermal simulation stage were also determined experimentally from temperature test runs. Finally, in order to obtain data for thermal design, a numerical simulation of the high tension winding was carried out. The thermal simulation stage was performed at different current densities in the conductor with and without electrostatic shields to determine the temperature field and maximum attainable temperatures. Maximum transformer temperature were found to be 15-20{sup o}C below its thermal limit and a correlation of maximum temperature as function of circulating current was developed for design

Large nuclear steam turbine plants

International Nuclear Information System (INIS)

Urushidani, Haruo; Moriya, Shin-ichi; Tsuji, Kunio; Fujita, Isao; Ebata, Sakae; Nagai, Yoji.

1986-01-01

The technical development of the large capacity steam turbines for ABWR plants was partially completed, and that in progress is expected to be completed soon. In this report, the outline of those new technologies is described. As the technologies for increasing the capacity and heightening the efficiency, 52 in long blades and moisture separating heaters are explained. Besides, in the large bore butterfly valves developed for making the layout compact, the effect of thermal efficiency rise due to the reduction of pressure loss can be expected. As the new technology on the system side, the simplification of the turbine system and the effect of heightening the thermal efficiency by high pressure and low pressure drain pumping-up method based on the recent improvement of feed water quality are discussed. As for nuclear steam turbines, the actual records of performance of 1100 MW class, the largest output at present, have been obtained, and as a next large capacity machine, the development of a steam turbine of 1300 MWe class for an ABWR plant is in progress. It can be expected that by the introduction of those new technologies, the plants having high economical efficiency are realized. (Kako, I.)

Rapid Generation of Superheated Steam Using a Water-containing Porous Material

Science.gov (United States)

Mori, Shoji; Okuyama, Kunito

Heat treatment by superheated steam has been utilized in several industrial fields including sterilization, desiccation, and cooking. In particular, cooking by superheated steam is receiving increased attention because it has advantages of reducing the salt and fat contents in foods as well as suppressing the oxidation of vitamin C and fat. In this application, quick startup and cut-off responses are required. Most electrically energized steam generators require a relatively long time to generate superheated steam due to the large heat capacities of the water in container and of the heater. Zhao and Liao (2002) introduced a novel process for rapid vaporization of subcooled liquid, in which a low-thermal-conductivity porous wick containing water is heated by a downward-facing grooved heating block in contact with the upper surface of the wick structure. They showed that saturated steam is generated within approximately 30 seconds from room-temperature water at a heat flux 41.2 kW⁄m2. In order to quickly generate superheated steam of approximately 300°C, which is required for cooking, the heat capacity of the heater should be as small as possible and the imposed heat flux should be so high enough that the porous wick is able to dry out in the vicinity of the contact with the heater and that the resulting heater temperature becomes much higher than the saturation temperature. The present paper proposes a simple structured generator to quickly produce superheated steam. Only a fine wire heater is contacted spirally on the inside wall in a hollow porous material. The start-up, cut-off responses and the rate of energy conversion for input power are investigated experimentally. Superheated steam of 300°C is produced in approximately 19 seconds from room-temperature water for an input power of 300 W. The maximum rate of energy conversion in the steady state is approximately 0.9.

Thermal and Electrical Analysis of Mars Rover RTGs

Energy Technology Data Exchange (ETDEWEB)

Schock, Alfred; Or, Chuen T; Skrabek, Emanuel A

2012-01-19

The RTG designs described in the preceding paper in these proceedings were analyzed for their thermal and electrical performance. Each analysis consisted of coupled thermal, thermoelectric, and electrical analyses, using Fairchild-generated specialized computer codes. These were supplemented with preliminary structural and mass analyses. For each design, various cases representing different operating conditions (water-cooled/radiation-cooled, BOM/EOM, summer/winter, day/night) and different thermoelectric performance assumptions (from conservative to optimistic) were analyzed; and for every case, the heat flow rates, temperatures and electrical performance of each layer of thermoelectric elements and of the overall RTG were determined. The analyses were performed in great detail, to obtain accurate answers permitting meaningful comparisons between different designs. The results presented show the RTG performance achievable with current technology, and the performance improvements that would be achievable with various technology developments.

The use of advanced scale conditioning agents for maintenance of the secondary side of nuclear plant steam generators

International Nuclear Information System (INIS)

Battaglia, P.J.; Rogosky, D.L.

2006-01-01

Maintaining the secondary side of steam generators within a pressurized water reactor (PWR) free of deposited corrosion products and corrosion-inducing contaminants is key to ensuring their long-term operation. New cleaning processes have become available to aid nuclear plant personnel in optimizing secondary side maintenance strategies. These strategies include both maintaining nuclear steam generators corrosion free while maintaining full power operation. The conference presentation will discuss ASCA use and the major field experience acquired in the last several years in the United States and in Japan. Hokkaido Electric, Dominion Engineering, Inc. and Westinghouse cosponsored the development of ASCAs for use in the Nuclear Utility industry, and all three are active in field use programs. Westinghouse owns the worldwide rights for ASCA implementation except in Japan where MHI and NEL have been granted licenses to apply ASCAs. Dominion Engineering Inc., owns the ASCA patents and performs the laboratory qualification testing associated with the ASCA programs, and Hokkaido Electric are joint patent holders for ASCAs and have been implementing their use at the Tomari plants for cleaning and thermal hydraulic performance enhancements. The specific experience discussed in the presentation will include: 1. Full Bundle Maintenance ASCAs at Vogtle Units 2 and 2 and Wolf Creek (USA). 2. Top of the Tubesheet ASCAs with high pressure sludge lancing at Wolf Creek and UEC at Vogtle Units 1 and 2 (USA). 3. Thermal Hydraulic Recovery and Maintenance ASCAs at the Hokkaido Electric Tomari Units 1 and 2 (Japan). (author)

Thermal and Electrical Conductivity Measurements of CDA 510 Phosphor Bronze

Science.gov (United States)

Tuttle, James E.; Canavan, Edgar; DiPirro, Michael

2009-01-01

Many cryogenic systems use electrical cables containing phosphor bronze wire. While phosphor bronze's electrical and thermal conductivity values have been published, there is significant variation among different phosphor bronze formulations. The James Webb Space Telescope (JWST) will use several phosphor bronze wire harnesses containing a specific formulation (CDA 510, annealed temper). The heat conducted into the JWST instrument stage is dominated by these harnesses, and approximately half of the harness conductance is due to the phosphor bronze wires. Since the JWST radiators are expected to just keep the instruments at their operating temperature with limited cooling margin, it is important to know the thermal conductivity of the actual alloy being used. We describe an experiment which measured the electrical and thermal conductivity of this material between 4 and 295 Kelvin.

Differential and directional effects of perfusion on electrical and thermal conductivities in liver.

Science.gov (United States)

Podhajsky, Ronald J; Yi, Ming; Mahajan, Roop L

2009-01-01

Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.

Problems associated with accelerated thermal aging of electrical equipment

International Nuclear Information System (INIS)

Isgro, J.R.

1984-01-01

This paper discusses the potential problems that may be experienced when accounting for aging mechanisms in organic polymers when utilizing accelerated thermal aging techniques for electrical equipment qualification. Included are discussions of actual experiences and problems encountered in the qualification of electrical and electronic equipment for a complete nuclear power plant. The wide variety of approaches to thermal accelerated aging by various manufacturers of diverse equipment types provides depth to the discussion. A description of how to account for aging mechanisms is also presented

Solar thermal electric power information user study

Energy Technology Data Exchange (ETDEWEB)

Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

1981-02-01

The results of a series of telephone interviews with groups of users of information on solar thermal electric power are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from five solar thermal electric power groups of respondents are analyzed: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Utilities, Electric Power Engineers, and Educators. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

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)

Steam generator life management

International Nuclear Information System (INIS)

Tapping, R.L.; Nickerson, J.; Spekkens, P.; Maruska, C.

1998-01-01

Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermal hydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. This report shows how recent advances in cleaning technology are integrated into a life management strategy, discusses downcomer flow measurement as a means of monitoring steam generator condition, and describes recent advances in hideout return as a life management tool. The research and development program, as well as operating experience, has identified

Electrically and Thermally Conducting Nanocomposites for Electronic Applications

Directory of Open Access Journals (Sweden)

Daryl Santos

2010-02-01

Full Text Available Nanocomposites made up of polymer matrices and carbon nanotubes are a class of advanced materials with great application potential in electronics packaging. Nanocomposites with carbon nanotubes as fillers have been designed with the aim of exploiting the high thermal, electrical and mechanical properties characteristic of carbon nanotubes. Heat dissipation in electronic devices requires interface materials with high thermal conductivity. Here, current developments and challenges in the application of nanotubes as fillers in polymer matrices are explored. The blending together of nanotubes and polymers result in what are known as nanocomposites. Among the most pressing current issues related to nanocomposite fabrication are (i dispersion of carbon nanotubes in the polymer host, (ii carbon nanotube-polymer interaction and the nature of the interface, and (iii alignment of carbon nanotubes in a polymer matrix. These issues are believed to be directly related to the electrical and thermal performance of nanocomposites. The recent progress in the fabrication of nanocomposites with carbon nanotubes as fillers and their potential application in electronics packaging as thermal interface materials is also reported.

On the evaluation of lifetime of evaporative tubes of once-through steam generators at steam-generating surface temperature oscillations in the burnout region

International Nuclear Information System (INIS)

Vorob'ev, V.A.; Loshchinin, V.M.; Remizov, O.V.

1978-01-01

Suggested is a method for evaluation of a stressed state of evaporation tubes of once-through steam generators at temperature oscillations in the burnout region. Calculated is the amplitude of steam-generating surface temperature oscillations in the burnout region depending on the frequency of a liquid-steam boundary transfer and on this basis determined are thermal stresses in a tube wall. Knowing a fatigue curve gives the possibility to evaluate a heat transfer tube lifetime

Steam explosions in light water reactors

International Nuclear Information System (INIS)

1981-01-01

The report deals with a postulated accident caused by molten fuel falling into the lower plenum of the containment of a reactor. The analysis which is presented in the report shows that the thermal energy released in the resulting steam explosion is not enough to destroy the pressure vessel or the containment. The report was prepared for the Swedish Governmental Committee on steam explosion in light water reactors. It includes statements issued by internationally well-known specialists. (G.B.)

Replacement of steam generators at arkansas nuclear one, unit-2 (ano-2)

International Nuclear Information System (INIS)

Wilson, R.M.; Buford, A.

2001-01-01

The Arkansas Nuclear One, Unit-2 steam generators, originally supplied by Combustion Engineering, began commercial operation in 1980 producing a gross electrical output of 958 MW. After several years of successful operation, the owner decided that the tube degradation rates of the original steam generators were too high for the plant to meet the performance requirements for the full 40-year license period. The contract to supply replacement steam generators (RSGs) was awarded to Westinghouse Electric Company in 1996. Installation of these RSGs took place in the last months of 2000. This paper compares the design features of the original and re-placement steam generators with emphasis on design and reliability enhancements achieved. (author)

Technical specifications: Susquehanna Steam Electric Station, Unit No. 2 (Docket No. 50-388). Appendix A to License No. NPF-22

International Nuclear Information System (INIS)

1984-03-01

Susquehanna Steam Electric Station, Unit 2 Technical Specifications were prepared by the US Nuclear Regulatory Commission to set forth the limits, operating conditions, and other requirements applicable to a nuclear reactor facility as set forth in Section 50.36 of 10 CFR Part 50 for the protection of the health and safety of the public

Steam gasification of acid-hydrolysis biomass CAHR for clean syngas production.

Science.gov (United States)

Chen, Guanyi; Yao, Jingang; Yang, Huijun; Yan, Beibei; Chen, Hong

2015-03-01

Main characteristics of gaseous product from steam gasification of acid-hydrolysis biomass CAHR have been investigated experimentally. The comparison in terms of evolution of syngas flow rate, syngas quality and apparent thermal efficiency was made between steam gasification and pyrolysis in the lab-scale apparatus. The aim of this study was to determine the effects of temperature and steam to CAHR ratio on gas quality, syngas yield and energy conversion. The results showed that syngas and energy yield were better with gasification compared to pyrolysis under identical thermal conditions. Both high gasification temperature and introduction of proper steam led to higher gas quality, higher syngas yield and higher energy conversion efficiency. However, excessive steam reduced hydrogen yield and energy conversion efficiency. The optimal value of S/B was found to be 3.3. The maximum value of energy ratio was 0.855 at 800°C with the optimal S/B value. Copyright © 2014 Elsevier Ltd. All rights reserved.

Double wall steam generator tubing

International Nuclear Information System (INIS)

Padden, T.R.; Uber, C.F.

1983-01-01

Double-walled steam generator tubing for the steam generators of a liquid metal cooled fast breeder reactor prevents sliding between the surfaces due to a mechanical interlock. Forces resulting from differential thermal expansion between the outer tube and the inner tube are insufficient in magnitude to cause shearing of base metal. The interlock is formed by jointly drawing the tubing, with the inside wall of the outer tube being already formed with grooves. The drawing causes the outer wall of the inner tube to form corrugations locking with the grooves. (author)

Doping dependence of electrical and thermal conductivity of nanoscale polyaniline thin films

Energy Technology Data Exchange (ETDEWEB)

Jin Jiezhu; Wang Qing [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Haque, M A [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

2010-05-26

We performed simultaneous characterization of electrical and thermal conductivity of 55 nm thick polyaniline (PANI) thin films doped with different levels of camphor sulfonic acids (CSAs). The effect of the doping level is more pronounced on electrical conductivity than on thermal conductivity of PANIs, thereby greatly affecting their ratio that determines the thermoelectric efficiency. At the 60% (the molar ratio of CSA to phenyl-N repeat unit of PANI) doping level, PANI exhibited the maximum electrical and thermal conductivity due to the formation of mostly delocalized structures. Whereas polarons are the charge carriers responsible for the electrical conduction, phonons are believed to play a dominant role in the heat conduction in nanoscale doped PANI thin films.

Solar-generated steam for oil recovery: Reservoir simulation, economic analysis, and life cycle assessment

International Nuclear Information System (INIS)

Sandler, Joel; Fowler, Garrett; Cheng, Kris; Kovscek, Anthony R.

2014-01-01

Highlights: • Integrated assessment of solar thermal enhanced oil recovery (TEOR). • Analyses of reservoir performance, economics, and life cycle factors. • High solar fraction scenarios show economic viability for TEOR. • Continuous variable-rate steam injection meets the benchmarks set by conventional steam flood. - Abstract: The viability of solar thermal steam generation for thermal enhanced oil recovery (TEOR) in heavy-oil sands was evaluated using San Joaquin Valley, CA data. The effectiveness of solar TEOR was quantified through reservoir simulation, economic analysis, and life-cycle assessment. Reservoir simulations with continuous but variable rate steam injection were compared with a base-case Tulare Sand steamflood project. For equivalent average injection rates, comparable breakthrough times and recovery factors of 65% of the original oil in place were predicted, in agreement with simulations in the literature. Daily cyclic fluctuations in steam injection rate do not greatly impact recovery. Oil production rates do, however, show seasonal variation. Economic viability was established using historical prices and injection/production volumes from the Kern River oil field. For comparison, this model assumes that present day steam generation technologies were implemented at TEOR startup in 1980. All natural gas cogeneration and 100% solar fraction scenarios had the largest and nearly equal net present values (NPV) of $12.54 B and $12.55 B, respectively. Solar fraction refers to the steam provided by solar steam generation. Given its large capital cost, the 100% solar case shows the greatest sensitivity to discount rate and no sensitivity to natural gas price. Because there are very little emissions associated with day-to-day operations from the solar thermal system, life-cycle emissions are significantly lower than conventional systems even when the embodied energy of the structure is considered. We estimate that less than 1 g of CO 2 /MJ of refined

Thermal acclimation and thyroxine treatment modify the electric organ discharge frequency in an electric fish, Apteronotus leptorhynchus.

Science.gov (United States)

Dunlap, K D; Ragazzi, M A

2015-11-01

In ectotherms, the rate of many neural processes is determined externally, by the influence of the thermal environment on body temperature, and internally, by hormones secreted from the thyroid gland. Through thermal acclimation, animals can buffer the influence of the thermal environment by adjusting their physiology to stabilize certain processes in the face of environmental temperature change. The electric organ discharge (EOD) used by weak electric fish for electrocommunication and electrolocation is highly temperature sensitive. In some temperate species that naturally experience large seasonal fluctuations in environmental temperature, the thermal sensitivity (Q10) of the EOD shifts after long-term temperature change. We examined thermal acclimation of EOD frequency in a tropical electric fish, Apteronotus leptorhynchus that naturally experiences much less temperature change. We transferred fish between thermal environments (25.3 and 27.8 °C) and measured EOD frequency and its thermal sensitivity (Q10) over 11 d. After 6d, fish exhibited thermal acclimation to both warming and cooling, adjusting the thermal dependence of EOD frequency to partially compensate for the small change (2.5 °C) in water temperature. In addition, we evaluated the thyroid influence on EOD frequency by treating fish with thyroxine or the anti-thyroid compound propylthiouricil (PTU) to stimulate or inhibit thyroid activity, respectively. Thyroxine treatment significantly increased EOD frequency, but PTU had no effect. Neither thyroxine nor PTU treatment influenced the thermal sensitivity (Q10) of EOD frequency during acute temperature change. Thus, the EOD of Apteronotus shows significant thermal acclimation and responds to elevated thyroxine. Copyright © 2015 Elsevier Inc. All rights reserved.

Hydrogen-based power generation from bioethanol steam reforming

Energy Technology Data Exchange (ETDEWEB)

Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

2015-12-23

This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

Hydrogen-based power generation from bioethanol steam reforming

International Nuclear Information System (INIS)

Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

2015-01-01

This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO 2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint

Hydrogen-based power generation from bioethanol steam reforming

Science.gov (United States)

Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

2015-12-01

This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

Dynamic simulation of steam generator failures

Energy Technology Data Exchange (ETDEWEB)

Meister, G [Institut fuer Nukleare Sicherheitsforschung, Kernforschungsanlage Juelich GmbH, Juelich (Germany)

1988-07-01

A computer program will be described which is capable to simulate severe transients in a gas heated steam generator. Such transients may arise in the safety analysis of accidents resulting from failures in the heat removal system of an HTGR power plant. Important failure modes which have to be considered are ruptures of one or more steam generator tubes leading to water or steam ejection into the primary system or anomalous operating conditions which my cause damage due to excessive thermal stress. Examples are the complete dryout as a consequence of feedwater interrupt in connection with continuing gas heating and the reflooding of the secondary channel with cold feedwater after dryout. The steam generator program which is capable to simulate accidents of this type is written as a module which can be implemented into a program system fur the simulation of the total heat rejection system. It based on an advanced mathematical model for the two phase flow taking deviations from thermal equilibrium into account. Mass, energy and momentum balances for the primary and secondary fluid and the heat diffusion equations for the heat exchanging wall form a system of coupled differential equations which is solved numerically by an algorithm which is stiffly stable and suppresses effectively oscillations of numerical origin. Results of the simulation of transients of the type mentioned above will be presented and discussed. (author)

Dynamic simulation of steam generator failures

International Nuclear Information System (INIS)

Meister, G.

1988-01-01

A computer program will be described which is capable to simulate severe transients in a gas heated steam generator. Such transients may arise in the safety analysis of accidents resulting from failures in the heat removal system of an HTGR power plant. Important failure modes which have to be considered are ruptures of one or more steam generator tubes leading to water or steam ejection into the primary system or anomalous operating conditions which my cause damage due to excessive thermal stress. Examples are the complete dryout as a consequence of feedwater interrupt in connection with continuing gas heating and the reflooding of the secondary channel with cold feedwater after dryout. The steam generator program which is capable to simulate accidents of this type is written as a module which can be implemented into a program system fur the simulation of the total heat rejection system. It based on an advanced mathematical model for the two phase flow taking deviations from thermal equilibrium into account. Mass, energy and momentum balances for the primary and secondary fluid and the heat diffusion equations for the heat exchanging wall form a system of coupled differential equations which is solved numerically by an algorithm which is stiffly stable and suppresses effectively oscillations of numerical origin. Results of the simulation of transients of the type mentioned above will be presented and discussed. (author)

Design of large steam turbines for PWR power stations

International Nuclear Information System (INIS)

Hobson, G.; Muscroft, J.

1983-01-01

The thermodynamic cycle requirements for use with pressurized water reactors are reviewed and the manner in which thermal efficiency is maximised is outlined. The special nature of the wet steam cycle associated with turbines for this type of reactor is discussed. Machine and cycle parameters are optimised to achieve high thermal efficiency, particular attention being given to arrangements for water separation and steam reheating and to provisions for feedwater heating. Principles and details of mechanical design are considered for a range of both full-speed turbines running at 3000 rpm on 50 Hz systems and half-speed turbines running at 1800 rpm on 60 Hz systems. The importance of service experience with nuclear wet steam turbines and its relevance to the design of modern turbines for pressurized water reactor applications is discussed. (author)

French steam generator design developments

International Nuclear Information System (INIS)

Ginier, R.; Campan, J.L.; Pontier, M.; Leridon, A.; Remond, A.; Castello, G.; Holcblat, A.; Paurobally, H.

1986-01-01

From the outset of the French nuclear power program, a significant R and D effort has been invested in improvement of the design and operation of Pressurized Water Reactors including a special committment to improving steam generators. The steam generator enhancement program has spawned a wide variety of specific R and D resources, e.g., low temperature hydraulic models for investigation of areas with single-phase flow, and freon-filled models for simulation of areas of steam generators experiencing two-phase flow (tube bundles and moisture separators). For the moisture separators, a large scale research program using freon-filled models and highly sophisticated instrumentation was used. Tests at reactor sites during startup of both 900 MWe and 1300 MWe have been used to validate the assumptions made on the basis of loop tests. These tests also demonstrated the validity of using freon to simulate two-phase flow conditions. The wealth of knowledge accumulated by the steam generator R and D program has been used to develop a new design of steam generators for the N4 plants. The current R and D effort is aimed at qualifying the N4 steam generator model and developing more comprehensive models. One prong of the R and D effort is the Megeve program. Megeve is a 25 MW steam generator which simulates operating conditions of the N4 model. The other prong is Clotaire, a freon-filled steam generator model which will be used to qualify thermal/hydraulic design codes used for multidimensional calculations for design of tube bundles

Performance results of a solar greenhouse combining electrical and thermal energy production

NARCIS (Netherlands)

Sonneveld, P.J.; Swinkels, G.L.A.M.; Campen, J.B.; Tuijl, van B.A.J.; Janssen, H.J.J.; Bot, G.P.A.

2010-01-01

Performance results are given of a new type of greenhouse, which combines reflection of near infrared radiation (NIR) with electrical power generation using hybrid photovoltaic cell/thermal collector modules. Besides the generation of electrical and thermal energy, the reflection of the NIR will

LPGC, Levelized Steam Electric Power Generator Cost

International Nuclear Information System (INIS)

Coen, J.J.; Delene, J.G.

1994-01-01

1 - Description of program or function: LPGC is a set of nine microcomputer programs for estimating power generation costs for large steam-electric power plants. These programs permit rapid evaluation using various sets of economic and technical ground rules. The levelized power generation costs calculated may be used to compare the relative economics of nuclear and coal-fired plants based on life-cycle costs. Cost calculations include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generation cost. These programs can be used for quick analyses of power generation costs using alternative economic parameters, such as interest rate, escalation rate, inflation rate, plant lead times, capacity factor, fuel prices, etc. The two major types of electric generating plants considered are pressurized-water reactor (PWR) and pulverized coal-fired plants. Data are also provided for the Large Scale Prototype Breeder (LSPB) type liquid metal reactor. Costs for plant having either one or two units may be obtained. 2 - Method of solution: LPGC consists of nine individual menu-driven programs controlled by a driver program, MAINPWR. The individual programs are PLANTCAP, for calculating capital investment costs; NUCLOM, for determining operation and maintenance (O and M) costs for nuclear plants; COALOM, for computing O and M costs for coal-fired plants; NFUEL, for calculating levelized fuel costs for nuclear plants; COALCOST, for determining levelized fuel costs for coal-fired plants; FCRATE, for computing the fixed charge rate on the capital investment; LEVEL, for calculating levelized power generation costs; CAPITAL, for determining capitalized cost from overnight cost; and MASSGEN, for generating, deleting, or changing fuel cycle mass balance data for use with NFUEL. LPGC has three modes of operation. In the first, each individual code can be executed independently to determine one aspect of the total

Coupling of a 2.5 kW steam reformer with a 1 kW el PEM fuel cell

Science.gov (United States)

Mathiak, J.; Heinzel, A.; Roes, J.; Kalk, Th.; Kraus, H.; Brandt, H.

The University of Duisburg-Essen has developed a compact multi-fuel steam reformer suitable for natural gas, propane and butane. This steam reformer was combined with a polymer electrolyte membrane fuel cell (PEM FC) and a system test of the process chain was performed. The fuel processor comprises a prereformer step, a primary reformer, water gas shift reactors, a steam generator, internal heat exchangers in order to achieve an optimised heat integration and an external burner for heat supply as well as a preferential oxidation step (PROX) as CO purification. The fuel processor is designed to deliver a thermal hydrogen power output from 500 W to 2.5 kW. The PEM fuel cell stack provides about 1 kW electrical power. In the following paper experimental results of measurements of the single components PEM fuel cell and fuel processor as well as results of the coupling of both to form a process chain are presented.

Experimental investigation on thermal management of electric vehicle battery with heat pipe

International Nuclear Information System (INIS)

Rao Zhonghao; Wang Shuangfeng; Wu Maochun; Lin Zirong; Li Fuhuo

2013-01-01

Highlights: ► The thermal management system of electric vehicle battery with heat pipes was designed. ► Temperature rise is a key factor for the design of power battery thermal management system. ► Temperature distribution is inevitable to reference for better design of heat pipes used for heat dissipation. ► Heat pipes are effective for power batteries thermal management within electric vehicles. - Abstract: In order to increase the cycle time of power batteries and decrease the overall cost of electric vehicles, the thermal management system equipped with heat pipes was designed according to the heat generated character of power batteries. The experimental result showed that the maximum temperature could be controlled below 50 °C when the heat generation rate was lower than 50 W. Coupled with the desired temperature difference, the heat generation rate should not exceed 30 W. The maximum temperature and temperature difference are kept within desired rang under unsteady operating conditions and cycle testing conditions. Applying heat pipes based power batteries thermal management is an effective method for energy saving in electric vehicles.

MINAC radiography performed on susquehanna Steam Electric Station Unit 1

International Nuclear Information System (INIS)

Bognet, J.C.

1986-01-01

Ten welds were volumetrically examined with a manual and automated ultrasonic (UT) system during a Susquehanna Steam Electric Station (SES) Unit 1 preservice inspection. The automated system had been recently developed and several problems were encountered in this first field application. The ten welds examined had a Sweepolet-to-Risor weld configuration, which further complicated the examination effort. This weld configuration has corrosion-resistant cladding applied to the outside and inside circumference and, as a result of an installation/removal/reinstallation sequence during plant construction, is often referred to as the double weld. After several attempts to obtain interpretable UT data failed (e.g., repeatable data), the examination effort was terminated. PP and L opted to pursue using the Miniature Linear Accelerator (MINAC) to perform radiographic examination. The results were referenced in the Susquehanna SES Unit 1 outage summary report and submitted to the NRC. The total effort was viewed as a complete success with no impact to the overall outage duration. All welds previously attempted by automated and manual UT were successfully examined using the MINAC

Thermal-hydraulics of wave propagation and pressure distribution under hypothetical steam explosion conditions in the ANS reactor

Energy Technology Data Exchange (ETDEWEB)

Taleyarkhan, R.P.; Georgevich, V.; N-Valenit, S.; Kim, S.H. [Oak Ridge National Lab., TN (United States)

1995-09-01

This paper describes salient aspects of the modeling and analysis framework for evaluation of dynamic loads, wave propagation, and pressure distributions (under hypothetical steam explosion conditions) around key structural boundaries of the Advanced Neutron Source (ANS) reactor core region. A staged approach was followed, using simple thermodynamic models for bounding loads and the CTH code for evaluating realistic estimates in a staged multidimensional framework. Effects of nodalization, melt dispersal into coolant during explosion, single versus multidirectional dissipation, energy level of melt, and rate of energy deposition into coolant were studied. The importance of capturing multidimensional effects that simultaneously account for fluid-structural interactions was demonstrated. As opposed to using bounding loads from thermodynamic evaluations, it was revealed that the ANS reactor system will not be vulnerable to vertically generated missiles that threaten containment if realistic estimates of energetics are used (from CTH calculations for thermally generated steam explosions without significant aluminum ignition).

Solar thermal power plants

International Nuclear Information System (INIS)

Schnatbaum, L.

2009-01-01

The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

Steam supply and power cogeneration at Yanshan Petrochemical Co., Ltd.

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of reducing greenhouse effect gas emissions, a project was studied for the improvement of cogeneration facilities with steam supply of 600t/h and electric output of 55MW at Beijing Yanshan Petrochemical Co., China. In Plan A, fuel is changed from heavy oil to natural gas, and two heavy oil boilers are replaced with two gas turbines and two exhaust heat recovery steam generators for steam supply of 241t/h per unit and electric output of 136.9MW per unit. In Plan B, the boilers are replaced with three gas turbines and three exhaust heat recovery steam generators for steam supply of 210t/h per unit and electric output of 79.5MW per unit. The initial investment is 700 million yuan {+-} 100 million yuan in Plan A, and 500 million yuan {+-} 100 million yuan in Plan B. The generating cost is 0.403 yuan/kWh in Plan A, and 0.455 yuan/kWh in Plan B. It was concluded that without Plan A, the project will not be economically successful. In Plan A, the energy conservation will be 887,847 toe/y heavy oil equivalent, which increases productivity. Further, the amount of greenhouse effect gas emissions will be 2,747,187 t-CO2/y. (NEDO)

Steam injection for the thermal plasma destruction of halons and chlorofluorocarbons

Energy Technology Data Exchange (ETDEWEB)

Murphy, A.B.; Farmer, A.J.D.; Horrigan, E.C. [CSIRO Telecomunications and Industrial Physics, Lindfield NSW (Australia); Mc Allister, T. [CSIRO Telecomunications and Industrial Physics, Clifton Hill Vic (Australia)

2001-07-01

The destruction of ozone-depleting substances, in particular chlorofluorocarbons and halons, in the PLASCON plasma process is investigated. In particular, the use of oxygen and steam as oxidising gases is compared. Measurements of the exhaust gas composition are compared with the results Of calculations performed using a comprehensive chemical kinetic scheme. It is found that significant interconversion of ozone-depleting substances occurs, particularly for chloro-fluorocarbon destruction Steam is found to be a superior oxidising gas to oxygen, with greatly reduced levels of ozone-depleting substances and CF{sub 4} in the exhaust gas, particularly if the steam is input at close to or greater than stoichiometric levels. (authors)

Steam-cured stabilised soil blocks for masonry construction

Energy Technology Data Exchange (ETDEWEB)

Venkatarama Reddy, B.V. [Indian Inst. of Science, Bangalore (India). Dept. of Civil Engineering; Lokras, S.S. [Indian Inst. of Science, Bangalore (India). ASTRA

1998-12-01

Energy-efficient, economical and durable building materials are essential for sustainable construction practices. The paper deals with production and properties of energy-efficient steam-cured stabilised soil blocks used for masonry construction. Problems of mixing expansive soil and lime, and production of blocks using soil-lime mixtures have been discussed briefly. Details of steam curing of stabilised soil blocks and properties of such blocks are given. A comparison of energy content of steam-cured soil blocks and burnt bricks is presented. It has been shown that energy-efficient steam cured soil blocks (consuming 35% less thermal energy compared to burnt clay bricks) having high compressive strength can be easily produced in a decentralised manner. (orig.)

Optimum fuel allocation in parallel steam generator systems

International Nuclear Information System (INIS)

Bollettini, U.; Cangioli, E.; Cerri, G.; Rome Univ. 'La Sapienza'; Trento Univ.

1991-01-01

An optimization procedure was developed to allocate fuels into parallel steam generators. The procedure takes into account the level of performance deterioration connected with the loading history (fossil fuel allocation and maintenance) of each steam generator. The optimization objective function is the system hourly cost, overall steam demand being satisfied. Costs are due to fuel and electric power supply and to plant depreciation and maintenance as well. In order to easily updata the state of each steam generator, particular care was put in the general formulation of the steam production function by adopting a special efficiency-load curve description based on a deterioration scaling parameter. The influence of the characteristic time interval length on the optimum operation result is investigated. A special implementation of the method based on minimum cost paths is suggested

Thermal modeling of secondary lithium batteries for electric vehicle/hybrid electric vehicle applications

Science.gov (United States)

Al-Hallaj, Said; Selman, J. R.

A major obstacle to the development of commercially successful electric vehicles (EV) or hybrid electric vehicles (HEV) is the lack of a suitably sized battery. Lithium ion batteries are viewed as the solution if only they could be "scaled-up safely", i.e. if thermal management problems could be overcome so the batteries could be designed and manufactured in much larger sizes than the commercially available near-2-Ah cells. Here, we review a novel thermal management system using phase-change material (PCM). A prototype of this PCM-based system is presently being manufactured. A PCM-based system has never been tested before with lithium-ion (Li-ion) batteries and battery packs, although its mode of operation is exceptionally well suited for the cell chemistry of the most common commercially available Li-ion batteries. The thermal management system described here is intended specifically for EV/HEV applications. It has a high potential for providing effective thermal management without introducing moving components. Thereby, the performance of EV/HEV batteries may be improved without complicating the system design and incurring major additional cost, as is the case with "active" cooling systems requiring air or liquid circulation.

Thermal energy storage for electricity-driven space heating in a day-ahead electricity market

DEFF Research Database (Denmark)

Pensini, Alessandro

2012-01-01

Thermal Energy Storage (TES) in a space heating (SH) application was investigated. The study aimed to determine the economic benefits of introducing TES into an electricity-driven SH system under a day-ahead electricity market. The performance of the TES was assessed by comparing the cost...... of electricity in a system with a TES unit to the case where no storage is in use and the entire heat requirement is fulfilled by purchasing electricity according to the actual load. The study had two goals: 1. Determining how the size – in terms of electricity input (Pmax) and energy capacity (Emax...

Thermal analysis experiment for elucidating sodium-water chemical reaction mechanism in steam generator of sodium-cooled fast reactor

International Nuclear Information System (INIS)

Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki

2012-01-01

For the purpose of elucidating the mechanism of the sodium-water surface reaction in a steam generator of sodium-cooled fast reactors, kinetic study of the sodium (Na)-sodium hydroxide (NaOH) reaction has been carried out by using Differential Thermal Analysis (DTA) technique. The parameters, including melting points of Na and NaOH, phase transition temperature of NaOH, Na-NaOH reaction temperature, and decomposition temperature of sodium hydride (NaH) have been identified from DTA curves. Based on the measured reaction temperature, rate constant of sodium monoxide (Na 2 O) generation was obtained. Thermal analysis results indicated that Na 2 O generation at the secondary overall reaction should be considered during the sodium-water reaction. (author)

Steam generator design for solar towers using solar salt as heat transfer fluid

Science.gov (United States)

González-Gómez, Pedro Ángel; Petrakopoulou, Fontina; Briongos, Javier Villa; Santana, Domingo

2017-06-01

Since the operation of a concentrating solar power plant depends on the intermittent character of solar energy, the steam generator is subject to daily start-ups, stops and load variations. Faster start-up and load changes increase the plant flexibility and the daily energy production. However, it involves high thermal stresses on thick-walled components. Continuous operational conditions may eventually lead to a material failure. For these reasons, it is important to evaluate the transient behavior of the proposed designs in order to assure the reliability. The aim of this work is to analyze different steam generator designs for solar power tower plants using molten salt as heat transfer fluid. A conceptual steam generator design is proposed and associated heat transfer areas and steam drum size are calculated. Then, dynamic models for the main parts of the steam generator are developed to represent its transient performance. A temperature change rate that ensures safe hot start-up conditions is studied for the molten salt. The thermal stress evolution on the steam drum is calculated as key component of the steam generator.

Steam trap importance at the energy efficiency industrial program; Importancia do purgador de vapor nos programas de conservacao de energia

Energy Technology Data Exchange (ETDEWEB)

Siqueira, Francisco E. de C. [ASCA Equipamentos Industriais Ltda., Rio de Janeiro, RJ (Brazil); Belchor, Carlos Rodrigues Pereira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

2004-07-01

The work approach a historical of problems connected to the steam traps losses, solutions in the past time and the actual reality. We started it reporting the worry with the correct drainage of equipment against to the steam pipes drain. We discoursed about the two basic types traps that are used. The first one and more traditional refers to the thermodynamic disk steam trap. We detailed its operational principle with steam losses. After that we presented the calorimetric test set, a device which values can be compared by thermal balance confirming steam losses. The second one, as a new tendency in petrochemical market, is the inverted bucket trap, more efficient than thermodynamic type, but working by mechanical and intermittent principles, not appropriated to this kind of drainage. After that we presented the definition of the steam traps and their waited characteristics inclusively the necessary deaeration that the two types listed above do not realize. We emphasized that Steam is a thermal fluid and must be controlled by thermal devices. We presented some alternates products that execute the correct drainage, e.g. thermal traps and thermal-thermodynamic traps. Finally, we propose to the market a reconsideration of the used concepts at the steam pipes. (author)

Numerical modeling of secondary side thermohydraulics of horizontal steam generator

Energy Technology Data Exchange (ETDEWEB)

Melikhov, V.I.; Melikhov, O.I.; Nigmatulin, B.I. [Research and Engineering Centre of LWR Nuclear Plants Safety, Moscow (Russian Federation)

1995-12-31

A mathematical model for the transient three-dimensional secondary side thermal hydraulics of the horizontal steam generator has been developed. The calculations of the steam generator PGV-1000 and PGV-4 nominal regimes and comparison of numerical and experimental results have been carried out. 7 refs.

Numerical modeling of secondary side thermohydraulics of horizontal steam generator

Energy Technology Data Exchange (ETDEWEB)

Melikhov, V I; Melikhov, O I; Nigmatulin, B I [Research and Engineering Centre of LWR Nuclear Plants Safety, Moscow (Russian Federation)

1996-12-31

A mathematical model for the transient three-dimensional secondary side thermal hydraulics of the horizontal steam generator has been developed. The calculations of the steam generator PGV-1000 and PGV-4 nominal regimes and comparison of numerical and experimental results have been carried out. 7 refs.

Thermal and Electrical Characterization of Alumina Substrate for Microelectronic Applications

International Nuclear Information System (INIS)

Ahmad, S.; Ibrahim, A.; Alias, R.; Shapee, S. M.; Ambak, Z.; Zakaria, S. Z.; Yahya, M. R.; Mat, A. F. A.

2010-01-01

This paper reports the effect of sintering temperature on thermal and electrical properties of alumina material as substrate for microelectronic devices. Alumina materials in the form of green sheet with 1 mm thickness were sintered at 1100 deg. C, 1300 deg. C and 1500 deg. C for about 20 hours using heating and cooling rates of 2 deg. C/min. The densities were measured using densitometer and the microstructures of the samples were analyzed using SEM micrographs. Meanwhile thermal and electrical properties of the samples were measured using flash method and impedance analyzer respectively. It was found that thermal conductivity and thermal diffusivity of the substrate increases as sintering temperature increases. It was found also that the dielectric constant of alumina substrate increases as the sintering temperature increases.

Thermal and Electrical Characterization of Alumina Substrate for Microelectronic Applications

Science.gov (United States)

Ahmad, S.; Ibrahim, A.; Alias, R.; Shapee, S. M.; Ambak, Z.; Zakaria, S. Z.; Yahya, M. R.; Mat, A. F. A.

2010-03-01

This paper reports the effect of sintering temperature on thermal and electrical properties of alumina material as substrate for microelectronic devices. Alumina materials in the form of green sheet with 1 mm thickness were sintered at 1100° C, 1300° C and 1500° C for about 20 hours using heating and cooling rates of 2° C/min. The densities were measured using densitometer and the microstructures of the samples were analyzed using SEM micrographs. Meanwhile thermal and electrical properties of the samples were measured using flash method and impedance analyzer respectively. It was found that thermal conductivity and thermal diffusivity of the substrate increases as sintering temperature increases. It was found also that the dielectric constant of alumina substrate increases as the sintering temperature increases.

Mechanical efficiency of the energy release during a steam explosion

International Nuclear Information System (INIS)

Krieg, R.

1997-01-01

The mechanical processes during the expansion phase of a steam explosion with intimately fragmented liquid particles is investigated based on elementary principles and analytical solutions. During a short load pulse, the different densities of the water and the melted particles lead to different velocities. After the load pulse, viscosity effects lead to a slow down of the higher velocities and to a corresponding reconversion of the kinetic energy of the mixture into thermal energy. It is shown that both effects are proportional to each other. The ratio between the residual and the applied mechanical energy is defined as the mechanical efficiency of the steam explosion. Using data typical for a steam explosion in a pressurized water reactor, mechanical efficiencies of <50% are estimated. Considering that the thermodynamic efficiencies are quite limited, the very low conversion rates from thermal energy into mechanical energy observed during steam explosion experiments can be more easily understood

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

Steam generators and furnaces

Energy Technology Data Exchange (ETDEWEB)

Swoboda, E

1978-04-01

The documents published in 1977 in the field of steam generators for conventional thermal power plants are classified according to the following subjects: power industry and number of power plants, planning and operation, design and construction, furnaces, environmental effects, dirt accumulation and corrosion, conservation and scouring, control and automation, fundamental research, and materials.

Steam generator tube integrity program. Phase I report

International Nuclear Information System (INIS)

Alzheimer, J.M.; Clark, R.A.; Morris, C.J.; Vagins, M.

1979-09-01

The results are presented of the pressure tests performed as part of Phase I of the Steam Generator Tube Integrity (SGTI) program at Battelle Pacific Northwest Laboratory. These tests were performed to establish margin-to-failure predictions for mechanically defected Pressurized Water Reactor (PWR) steam generator tubing under operating and accident conditions. Defect geometries tested were selected because they simulate known or expected defects in PWR steam generators. These defect geometries are Electric Discharge Machining (EDM) slots, elliptical wastage, elliptical wastage plus through-wall slot, uniform thinning, denting, denting plus uniform thinning, and denting plus elliptical wastage. All defects were placed in tubing representative of that currently used in PWR steam generators

Operating experiences with 1 MW steam generator

Energy Technology Data Exchange (ETDEWEB)

Sano, A; Kanamori, A; Tsuchiya, T

1975-07-01

1 MW steam generator, which was planned as the first stage of steam generator development in Power Reactor and Nuclear Fuel Corp. (PNC) in Japan, is a single-unit, once-through, integrated shell and tube type with multi-helical coil tubes. It was completed in Oarai Engineering Center of PNC in March of 1971, and the various performance tests were carried out up to April, 1972. After the dismantle of the steam generator for structural inspection and material test, it was restored with some improvements. In this second 1 MW steam generator, small leak occurred twice during normal operation. After repairing the failure, the same kind of performance tests as the first steam generator were conducted in order to verify the thermal insulation effect of argon gas in downcomer zone from March to June, 1974. In this paper the above operating experiences were presented including the outline of some performance test results. (author)

Repair technology for steam generator tubes

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

2001-02-01

The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating.

Repair technology for steam generator tubes

International Nuclear Information System (INIS)

Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

2001-02-01

The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating

Point of view regarding the antitrust policy related to the electricity and thermal power generation sector in Romania

International Nuclear Information System (INIS)

Alexe, Fl.; Ionescu, M.

1996-01-01

At present, generation, transmission and selling of power in Romania is actually a monopoly of RENEL (The Romanian Electricity Authority). Moreover, RENEL covers an important share of the heat required by the great district heat consumers and industry (steam). Medium and long term programs for RENEL restructuring aims at moving the power distribution and selling sectors out of RENEL and at restructuring the generation sector. The present papers focuses mainly on those issues related to power generation sector privatization meant to promote a real competition in the field of power generation. To reach this purpose new regulations are necessary to ensure the access to the power system of various consumers satisfying certain technical requirements. This regards also all the independent power producers of electricity and possibly of thermal power (for instance the cogeneration power plants with less than or close to 50 MW). At the same time new concepts such as 'contracted power' and 'transit (wiring) tax' should be implemented in the near future in the business relations. Competition in this field will lead to the development of power market and the enhancement of power investments. (author). 3 refs

Development of axial tomography technique for the study of steam explosion

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Young; Seo, S. W.; You, S. [Handong Golbal Univ., Pohang (Korea, Republic of)

2006-05-15

In this report, axial tomography applying to steam explosion is implemented. When steam explosion experiment is performed, we have seen the difficulty with physical modeling due to the complex phenomena of generated steam, propagation of shock wave and bubble breakup and coalescence. Hence, the uncertainty due to these phenomena is occurred. The fast and global measurement of the steam distribution is imperative to understand the complex phenomena performed during the steam explosion, KAERI have developed the fast and global measuring instrument to monitor such phenomena of axial steam distribution. Generally, X-ray is used as measuring method, but this method is very expensive and has limited measurement area. So we need new method that can substitute X-ray method and in this research, ECT method is replaced. The research is performed dividing within two parts: Software and Hardware. In the software part, the electric field analysis code and algorithm for inverse projection were developed. And, in the hardware part, capacitance measurement circuit is developed to measure up to fF level. Operable axial tomography was analyzed with concept design of axial tomography appropriate to steam explosion accident and analysis code for axial electric field analysis and inverse algorithm were developed, moreover, designing signal analysis system for axial tomography was performed.

Steam explosion triggering and efficiency studies

International Nuclear Information System (INIS)

Buxton, L.D.; Nelson, L.S.; Benedick, W.B.

1979-01-01

A program at Sandia Laboratories to provide relevant data on the interaction of molten LWR core materials with water is described. Two different subtasks were established. The first was the performance of laboratory-scale experiments to investigate the ability to trigger steam explosions for realistic LWR core melt simulants under a wide range of initial conditions. The second was the performance of field-scale experiments to investigate the efficiency of converting the thermal energy of the melt into mechanical work in much larger steam explosions

Three Mile Island Nuclear Station steam generator chemical cleaning

International Nuclear Information System (INIS)

Hansen, C.A.

1992-01-01

The Three Mile Island-1 steam generators were chemically cleaned in 1991 by the B and W Nuclear Service Co. (BWNS). This secondary side cleaning was accomplished through application of the EPRI/SGOG (Electric Power Research Institute - Steam Generator Owners Group) chemical cleaning iron removal process, followed by sludge lancing. BWNS also performed on-line corrosion monitoring. Corrosion of key steam generator materials was low, and well within established limits. Liquid waste, subsequently processed by BWNS was less than expected. 7 tabs

Mathematical modeling of control system for the experimental steam generator

Science.gov (United States)

Podlasek, Szymon; Lalik, Krzysztof; Filipowicz, Mariusz; Sornek, Krzysztof; Kupski, Robert; Raś, Anita

2016-03-01

A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units - quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics) are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

Steam explosion - physical foundations and relation to nuclear reactor safety

International Nuclear Information System (INIS)

Schumann, U.

1982-08-01

'Steam explosion' means the sudden evaporation of a fluid by heat exchange with a hotter material. Other terms are 'vapour explosion', 'thermal explosion', and 'energetic fuel-coolant interaction (FCI)'. In such an event a large fraction of the thermal energy initially stored in the hot material may possibly be converted into mechanical work. For pressurized water reactors one discusses (e.g. in risk analysis studies) a core melt-down accident during which molten fuel comes into contact with water. In the analysis of the consequences one has to investigate steam explosions. In this report an overview over the state of the knowledge is given. The overview is based on an extensive literature review. The objective of the report is to provide the basic knowledge which is required for understanding of the most important theories on the process of steam explosions. Following topics are treated: overview on steam explosion incidents, work potential, spontaneous nucleation, concept of detonation, results of some typical experiments, hydrodynamic fragmentation of drops, bubbles and jets, coarse mixtures, film-boiling, scenario of a core melt-down accident with possible steam-explosion in a pressurized water reactor. (orig.) [de

Materials choices for the advanced LWR steam generators

International Nuclear Information System (INIS)

Paine, J.P.N.; Shoemaker, C.E.; McIlree, A.R.

1987-01-01

Current light water reactor (LWR) steam generators have been affected by a variety of corrosion and mechanical damage degradation mechanisms. Included are wear caused by tube vibration, intergranular corrosion, pitting, and thinning or wastage of the steam generator tubing and accelerated corrosion of carbon steel supports (denting). The Electric Power Research Institute (EPRI) and the Steam Generator Owners Groups (I, II) have sponsored laboratory and field studies to provide ameliorative actions for the majority of the damage forms experienced to date. Some of the current corrosion mechanisms are aggravated or caused by unique materials choices or materials interactions. New materials have been proposed and at least partially qualified for use in replacement model steam generators, including an advanced LWR design. In so far as possible, the materials choices for the advanced LWR steam generator avoid the corrosion pitfalls seemingly inherent in the current designs. The EPRI Steam Generator Project staff has recommended materials and design choices for a new steam generator. Based on these recommendations we believe that the advanced LWR steam generators will be much less affected by corrosion and mechanical damage mechanisms than are now experienced

Characterization of Contact and Bulk Thermal Resistance of Laminations for Electric Machines

Energy Technology Data Exchange (ETDEWEB)

Cousineau, J. Emily [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bennion, Kevin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); DeVoto, Doug [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mihalic, Mark [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Narumanchi, Sreekant [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2015-06-30

The ability to remove heat from an electric machine depends on the passive stack thermal resistances within the machine and the convective cooling performance of the selected cooling technology. This report focuses on the passive thermal design, specifically properties of the stator and rotor lamination stacks. Orthotropic thermal conductivity, specific heat, and density are reported. Four materials commonly used in electric machines were tested, including M19 (29 and 26 gauge), HF10, and Arnon 7 materials.

Elevated-constant pH control assessment at TXU's Comanche peak steam electric station

International Nuclear Information System (INIS)

Fellers, B.; Perkins, D.; Bosma, J.; Deshon, J.

2002-01-01

Industry experience with axial offset anomaly (AOA) has raised the importance of crud management strategies. Elevated-constant pH control is recognized as one potential solution. Additionally, minimizing radiation fields remains a high industry goal which is supported by this strategy. An investigation of industry experience and experimental data has supported a strategy of constant at-temperature pH of 7.4, requiring as much as 6-ppm lithium at the beginning-of-cycle (BOC). This approach, in a modern high temperature plant with high boron requirements, necessitated a careful assessment of potential risk for increased susceptibility to corrosion for both fuel cladding and RCS structural materials. This paper presents results of the assessment for Comanche peak steam electric station (CPSES) and plans for a demonstration of this practice. (author)

Thermal electric effects and heat generation in polypyrrole coated PET fabrics

OpenAIRE

Avloni, J.; Florio, L.; Henn, A. R.; Sparavigna, A.

2007-01-01

Polypyrrole chemically synthesized on PET gives rise to textiles with a high electric conductivity, suitable for several applications from antistatics to electromagnetic interference shielding devices. Here, we discuss investigations on thermal electric performances of the polypyrrole coated PET in a wide range of temperatures above room temperature. The Seebeck coefficient turns out to be comparable with that of metal thermocouple materials. Since polypyrrole shows extremely low thermal diff...

Function analysis of steam isolation valves

International Nuclear Information System (INIS)

Persson, R.; Sjoeberg, A.; Aakesson, H.; Kilpi, K.; Noro, H.; Siikonen, T.; Wallen, G.

1981-01-01

Function analysis of system-medium-operated steam isolation valves has been the objective of the Swedish-Finnish IVLS project, the results of which are presented in this report. Theoretical models were to be verified against available experimental data, to some extent from the HDR blowdown experiments, which are part of a German reactor safety program. Finnish hydraulic measurements on a valve model (scale 1:2.15) have been performed to give complementary data. The analysis work has covered the thermal-hydraulic behaviour of steam isolation valves as well as phenomena related to structural mechanics. (Auth.)

A numerical study on thermal behavior of a D-type water-cooled steam boiler

International Nuclear Information System (INIS)

Moghari, M.; Hosseini, S.; Shokouhmand, H.; Sharifi, H.; Izadpanah, S.

2012-01-01

To achieve a precise assessment on thermal performance of a D-type water-cooled natural gas-fired boiler the present paper was aimed at determining temperature distribution of water and flue gas flows in its different heat exchange equipment. Using the zonal method to predict thermal radiation treatment in the boiler furnace and a numerical iterative approach, in which heat and fluid flow relations associated with different heat surfaces in the boiler convective zone were employed to estimate heat transfer characteristics, enabled this numerical study to obtain results in good agreement with experimental data measured in the utility site during steady state operation. A constant flow rate for a natural gas fuel of specified chemical composition was assumed to be mixed with a given excess ratio of air flow at a full boiler load. Significant results attributed to distribution of heat flux on different furnace walls and that of flue gas and water/steam temperature in different convective stages including superheater, evaporating risers and downcomers modules, and economizer were obtained. Besides the rate of heat absorption in every stage and other essential parameters in the boiler design too, inherent thermal characteristics like radiative and convective heat transfer coefficients as well as overall heat transfer conductance and effectiveness of convective stages considered as cross-flow heat exchangers were eventually presented for the given operating condition. - Highlights: ► Detailed distribution of heat flux on all of the boiler furnace walls was obtained. ► Flue gas and water thermal behaviors in different heating sections were evaluated. ► A good agreement was made between numerical results and experimental data. ► Contribution of the boiler furnace to the total thermal absorption was 39%. ► Contribution of the boiler tube banks to the total thermal absorption was 61%.

Thermal-hydraulic analysis of SMART steam generator tube rupture using TASS/SMR-S code

International Nuclear Information System (INIS)

Kim, Hee-Kyung; Kim, Soo Hyoung; Chung, Young-Jong; Kim, Hyeon-Soo

2013-01-01

Highlights: ► The analysis was performed from the viewpoint of primary coolant leakage. ► The thermal hydraulic responses and the maximum leakage have been identified. ► There is no direct release into the atmosphere caused by an SGTR accident. ► SMART safety system works well against an SGTR accident. - Abstract: A steam generator tube rupture (SGTR) accident analysis for SMART was performed using the TASS/SMR-S code. SMART with a rated thermal power of 330 MWt has been developed at the Korea Atomic Energy Research Institute. The TASS/SMR-S code can analyze the thermal hydraulic phenomena of SMART in a full range of reactor operating conditions. An SGTR is one of the most important accidents from a thermal hydraulic and radiological viewpoint. A conservative analysis against a SMART SGTR was performed. The major concern of this analysis is to find the thermal hydraulic responses and maximum leakage amount from a primary to a secondary side caused by an SGTR accident. A sensitivity study searching for the conservative thermal hydraulic conditions, break locations, reactivity and other conditions was performed. The dominant parameters related with the integral leak are the high RCS pressure, low core inlet coolant temperature and low break location of the SG cassette. The largest integral leak comes to 28 tons in the most conservative case during 1 h. But there is no direct release into the atmosphere because the secondary system pressure is maintained with a sufficient margin for the design pressure. All leaks go to the condenser. The analysis results show that the primary and secondary system pressures are maintained below the design pressure and the SMART safety system is working well against an SGTR accident

Solar thermal repowering systems integration. Final report

Energy Technology Data Exchange (ETDEWEB)

Dubberly, L. J.; Gormely, J. E.; McKenzie, A. W.

1979-08-01

This report is a solar repowering integration analysis which defines the balance-of-plant characteristics and costs associated with the solar thermal repowering of existing gas/oil-fired electric generating plants. Solar repowering interface requirements for water/steam and salt or sodium-cooled central receivers are defined for unit sizes ranging from 50 MWe non-reheat to 350 MWe reheat. Finally balance-of-plant cost estimates are presented for each of six combinations of plant type, receiver type and percent solar repowering.

Effect of liquid waste discharges from steam generating facilities

Energy Technology Data Exchange (ETDEWEB)

McGuire, H.E. Jr.

1977-09-01

This report contains a summary of the effects of liquid waste discharges from steam electric generating facilities on the environment. Also included is a simplified model for use in approximately determining the effects of these discharges. Four basic fuels are used in steam electric power plants: three fossil fuels--coal, natural gas, and oil; and uranium--presently the basic fuel of nuclear power. Coal and uranium are expected to be the major fuels in future years. The following power plant effluents are considered: heat, chlorine, copper, total dissolved solids, suspended solids, pH, oil and grease, iron, zinc, chrome, phosphorus, and trace radionuclides.

Effect of liquid waste discharges from steam generating facilities

International Nuclear Information System (INIS)

McGuire, H.E. Jr.

1977-09-01

This report contains a summary of the effects of liquid waste discharges from steam electric generating facilities on the environment. Also included is a simplified model for use in approximately determining the effects of these discharges. Four basic fuels are used in steam electric power plants: three fossil fuels--coal, natural gas, and oil; and uranium--presently the basic fuel of nuclear power. Coal and uranium are expected to be the major fuels in future years. The following power plant effluents are considered: heat, chlorine, copper, total dissolved solids, suspended solids, pH, oil and grease, iron, zinc, chrome, phosphorus, and trace radionuclides

On-line energy and battery thermal management for hybrid electric heavy-duty truck

NARCIS (Netherlands)

Pham, H.T.; Kessels, J.T.B.A.; Bosch, van den P.P.J.; Huisman, R.G.M.; Nevels, R.M.P.A.

2013-01-01

This paper discusses an integrated approach for energy and thermal management to minimize the fuel consumption of a hybrid electric heavy-duty truck. Conventional Energy Management Systems (EMS) operate separately from the Battery Thermal Management System (BTMS) in Hybrid Electric Vehicles (HEVs).

Steam explosions in sodium cooled breeder reactors

International Nuclear Information System (INIS)

Lundell, B.

1982-01-01

Steam explosion is considered a physical process which transport heat from molten fuel to liquid coolant so fast that the coolant starts boiling in an explosion-like manner. The arising pressure waves transform part of the thermal energy to mechanical energy. This can stress the reactor tank and threaten its hightness. The course of the explosion has not been theoretical explained. Experimental results indicate that the probability of steam explosions in a breeder reactor is small. The efficiency of the transformation of the heat of fusion into mechanical energy in substantially lower than the theoretical maximum value. The mechanical stress from the steam explosion on the reactor tank does not seem to jeopardize its tightness. (G.B.)

Electrical power systems for distributed generation

Energy Technology Data Exchange (ETDEWEB)

Robertson, T.A.; Huval, S.J. [Stewart & Stevenson Services, Inc., Houston, TX (United States)

1996-12-31

{open_quotes}Distributed Generation{close_quotes} has become the {open_quotes}buzz{close_quotes} word of an electric utility industry facing deregulation. Many industrial facilities utilize equipment in distributed installations to serve the needs of a thermal host through the capture of exhaust energy in a heat recovery steam generator. The electrical power generated is then sold as a {open_quotes}side benefit{close_quotes} to the cost-effective supply of high quality thermal energy. Distributed generation is desirable for many different reasons, each with unique characteristics of the product. Many years of experience in the distributed generation market has helped Stewart & Stevenson to define a range of product features that are crucial to most any application. The following paper will highlight a few of these applications. The paper will also examine the range of products currently available and in development. Finally, we will survey the additional services offered by Stewart & Stevenson to meet the needs of a rapidly changing power generation industry.

Kinetics study of ethanol steam reforming on Pt/CeO{sub 2} based catalysts

Energy Technology Data Exchange (ETDEWEB)

Qi, A. [Queen' s-RMC Fuel Cell Research Centre, Kingston, ON (Canada). Dept. of Chemistry and Chemical Engineering; Thurgood, C.; Amphlett, J. [Royal Military College of Canada, Kingston, ON (Canada). Dept. of Chemistry and Chemical Engineering; Peppley, B. [Queens Univ., Kingston, ON (Canada). Dept. of Chemical Engineering

2009-07-01

Interest in fuel cell systems operating on fuels derived from renewable energy sources is increasing because they have the potential to produce electricity with high efficiency and minimal emissions of carbon dioxide and other pollutants. Bioethanol is currently produced by the fermentation of non-edible biomass, through conventional means and also through advances in enzyme technology. The authors previously reported on the steam reforming of bioethanol with a stable ceria supported precious metal catalyst, developed in-house. The catalyst had good thermal stability and resisted carbon formation. This paper reported on a more recent kinetic study in which the influence of operating conditions were quantified. The operating conditions included temperature, steam/carbon ratios, and gas hourly velocities. The results of standard catalyst characterization techniques such as BET, TGA, SEM and TPR were also provided. The data was used to drive an empirical rate expression. The study also investigated a potential rate mechanism.

Some possible causes and probability of leakages in LMFBR steam generators

International Nuclear Information System (INIS)

Bolt, P.R.

1984-01-01

Relevant operational experience with steam generators for process and conventional plant and thermal and fast reactors is reviewed. Possible causes of water/steam leakages into sodium/gas are identified and data is given on the conditions necessary for failure, leakage probability and type of leakage path. (author)

Thermo-economic analysis of Shiraz solar thermal power plant

Energy Technology Data Exchange (ETDEWEB)

Yaghoubi, M. [Academy of Science, Tehran (Iran, Islamic Republic of); Mokhtari, A.; Hesami, R. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). School of Engineering

2007-07-01

The Shiraz solar thermal power plant in Iran has 48 parabolic trough collectors (PTCs) which are used to heat the working oil. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. Conventional energy analysis based on the first law of thermodynamics does qualitatively assess the various losses occurring in the components. Therefore, exergy analysis, based on the second law of thermodynamics, can be applied to better assess various losses quantitatively as well as qualitatively. This paper presented a newly developed exergy-economic model for the Shiraz solar thermal power plant. The objective was to find the minimum exergetic production cost (EPC), based on the second law of thermodynamics. The application of exergy-economic analysis includes the evaluation of utility supply costs for production plants, and the energy costs for process operations. The purpose of the analysis was to minimize the total operating costs of the solar thermal power plant by assuming a fixed rate of electricity production and process steam. 21 refs., 3 tabs., 8 figs.

Increase of Steam Moisture in the BWR-Facility KKP 1

International Nuclear Information System (INIS)

Noack, Volker

2002-01-01

Main steam moisture in a BWR facility is determined by steam quality at core outlet and efficiency of steam separators and steam dryers. Transport of water with steam is accompanied by transport of radionuclides out of RPV resulting in enhanced radiation level in the main steam system. A remarkable increase of main steam moisture started at KKP 1 in 1997. In the following years increase of steam outlet moisture started at lower and lower core mass flow rates. Dose rate in main steam system increased simultaneously. Core mass flow rate and thus thermal power had to be reduced during stretch out operation to keep the main steam moisture below the specified boundary of 0.2 %. This boundary also guarantees, that radiological exposure remains far below approved values. The increase of main steam moisture corresponds with the application of low leakage core loading. Low leakage core loading results in enhanced steam generation in the center and in reduced steam generation in the outer zones of the core. It can be shown, that the uneven steam generation in the core became stronger over the years. Therefore, steam quality at inlet of the outer steam separators was getting lower. This resulted in higher carry over of water in this steam separators and steam dryers, thus explaining the increasing main steam moisture. KKP 1 started in 2000 with spectral shift operation. As one should expect, this resulted in reduced steam moisture. It remains the question of steam moisture in case of stretch out operation. Countermeasures are briefly discussed. (authors)

Nuclear steam generator tubesheet shield

International Nuclear Information System (INIS)

Nickerson, J.H.D.; Ruhe, A.

1982-01-01

The invention involves improvements to a nuclear steam generator of the type in which a plurality of U-shaped tubes are connected at opposite ends to a tubesheet and extend between inlet and outlet chambers, with the steam generator including an integral preheater zone adjacent to the downflow legs of the U-shaped tubes. The improvement is a thermal shield disposed adjacent to an upper face of the tubesheet within the preheater zone, the shield including ductile cladding material applied directly to the upper face of the tubesheet, with the downflow legs of the U-shaped tubes extending through the cladding into the tubesheet

Mathematical modeling of control system for the experimental steam generator

Directory of Open Access Journals (Sweden)

Podlasek Szymon

2016-01-01

Full Text Available A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units – quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

Inverted Steam Generators for Sodium Cooled Fast Reactors

International Nuclear Information System (INIS)

Matal, Oldřich; Šimo, Tomáš; Matal, Oldřich Jr.

2013-01-01

Conclusions: Two inverted steam generators of the Czech industry provenience have still been in successful operation with no water into sodium leaks at BOR 60 (RIAR Dimitrovgrad, Russian Federation). Micromodular inverted steam generator (MMISG) since 1981 and modular inverted steam generator (MISG) since 1991. In the framework of the CP ESFR project predesign studies of 100 MW (thermal) ISG modules were performed with the consideration of MMISG and MISG design, operational and safety benefits and experience. Development of material and technology for sodium heated steam generators components reflecting contemporary domestic industrial conditions in the Czech Republic was restarted in the years 2003 to 2004 and supported in the years 2008 to 2011 by the European CP ESFR project and by the Ministry of Industry and Trade of the Czech Republic

Electrical and Thermal Conductivity and Conduction Mechanism of Ge2Sb2Te5 Alloy

Science.gov (United States)

Lan, Rui; Endo, Rie; Kuwahara, Masashi; Kobayashi, Yoshinao; Susa, Masahiro

2018-06-01

Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism.

Electrical and Thermal Conductivity and Conduction Mechanism of Ge2Sb2Te5 Alloy

Science.gov (United States)

Lan, Rui; Endo, Rie; Kuwahara, Masashi; Kobayashi, Yoshinao; Susa, Masahiro

2017-11-01

Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism.

Superheated steam annealing of pressurized water reactor vessel

International Nuclear Information System (INIS)

Porowski, J.S.

1993-01-01

Thermal annealing of an embrittled Reactor Pressure Shell is the only recognized means for recovering material properties lost due to long-term exposure of the reactor walls to radiation. Reduced toughness of the material during operation is a major concern in evaluations of structural integrity of older reactors. Extensive studies performed within programs related to life extension of nuclear plants have confirmed that the thermal treatment of 850 deg. F for 168 hours on irradiated material essentially recovers material properties lost due to neutron exposure. Dry and wet annealing methods have been considered. Wet annealing involves operating the reactor at near design temperatures and pressures. Since the temperature of wet annealing must be limited to vessel design temperature of 650 deg. F, only partial recovery of the lost properties is achieved. Thus dry annealing was selected as an alternative for future development and industrial implementation to extend the safe life of reactors. Dry thermal annealing consists of heating portions of the reactor vessel at a specific temperature for a given period of time using a high temperature heat source. The use of spent fuel assemblies, induction heating and resistance heating elements as well as the circulation of heated fluid were investigated as potential candidate methods. To date the use of resistance heating elements which are lowered into a dry empty reactor was considered to be the preferred method. In-depth research in the United States and practical applications of such a method in Russia have confirmed feasibility of the method. The method of using circulating superheated steam to anneal the vessel at 850 deg. F without complete removal of the reactor internals is described herein. After removing the reactor head and fuel, the core barrel along with the upper and lower core in PWRs is lifted to open an annular space between the reactor shell flange and the core barrel flange. The thermal shield can remain

Global freshwater thermal emissions from steam-electric power plants with once-through cooling systems

International Nuclear Information System (INIS)

Raptis, Catherine E.; Pfister, Stephan

2016-01-01

Large quantities of heat are rejected into freshwater bodies from power plants employing once-through cooling systems, often leading to temperature increases that disturb aquatic ecosystems. The objective of this work was to produce a high resolution global picture of power-related freshwater thermal emissions and to analyse the technological, geographical and chronological patterns behind them. The Rankine cycle was systematically solved for ∼2400 generating units with once-through cooling systems, distinguishing between simple and cogenerative cycles, giving the rejected heat as a direct output. With large unit sizes, low efficiencies, and high capacity factors, nuclear power plants reject 3.7 GW heat into freshwater on average, contrasting with 480 MW rejected from coal and gas power plants. Together, nuclear and coal-fuelled power plants from the 1970s and 1980s account for almost 50% of the rejected heat worldwide, offering motivation for their phasing out in the future. Globally, 56% of the emissions are rejected into rivers, pointing to potential areas of high thermal pollution, with the rest entering lakes and reservoirs. The outcome of this work can be used to further investigate the identified thermal emission hotspots, and to calculate regionalized water temperature increase and related impacts in environmental, energy-water nexus studies and beyond. - Highlights: • The thermodynamic cycles of ∼2400 power units with once-through cooling were solved. • Global freshwater heat emissions depend on technology, geography & chronology. • Half the global emissions come from nuclear and coal plants from the 70s & 80s. • Hotspots of freshwater thermal emissions were identified globally. • Global georeferenced emissions are available for use in water temperature models.

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.

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.

SWAAM code development, verification and application to steam generator design

International Nuclear Information System (INIS)

Shin, Y.W.; Valentin, R.A.

1990-01-01

This paper describes the family of SWAAM codes developed by Argonne National Laboratory to analyze the effects of sodium/water reactions on LMR steam generators. The SWAAM codes were developed as design tools for analyzing various phenomena related to steam generator leaks and to predict the resulting thermal and hydraulic effects on the steam generator and the intermediate heat transport system (IHTS). The theoretical foundations and numerical treatments on which the codes are based are discussed, followed by a description of code capabilities and limitations, verification of the codes by comparison with experiment, and applications to steam generator and IHTS design. (author). 25 refs, 14 figs

SO2 pollution of heavy oil-fired steam power plants in Iran

International Nuclear Information System (INIS)

Nazari, S.; Shahhoseini, O.; Sohrabi-Kashani, A.; Davari, S.; Sahabi, H.; Rezaeian, A.

2012-01-01

Steam power plants using heavy oil provided about 17.4%, equivalent to 35.49 TWh, of electricity in Iran in 2007. However, having 1.55–3.5 weight percentage of sulfur, heavy oil produces SO 2 pollutant. Utilization of Flue Gas Desulfurization systems (FGD) in Iran's steam power plants is not common and thereby, this pollutant is dispersed in the atmosphere easily. In 2007, the average emission factor of SO 2 pollutant for steam power plants was 15.27 g/kWh, which means regarding the amount of electricity generated by steam power plants using heavy oil, 541,000 Mg of this pollutant was produced. In this study, mass distribution of SO 2 in terms of Mg/yr is considered and dispersion of this pollutant in each of the 16 steam power plants under study is modeled using Atmospheric Dispersion Modeling System (ADMS). Details of this study are demonstrated using Geographical Information System (GIS) software, ArcGIS. Finally, the average emission factor of SO 2 and the emission of it in Iran's steam power plants as well as SO 2 emission reduction programs of this country are compared with their alternatives in Turkey and China.

Thermal recovery--special report No. 4. Steam becomes a production assist

Energy Technology Data Exchange (ETDEWEB)

Batter, W H.R.

1966-05-01

A base map shows the general area where experimentation with steam is going on. The area around Lloydminster has many reservoirs containing heavy crude (10-20API) and existing at a shallow enough depth to result in a bottomhole temperature of 65 to 75$F. The oil in place represented by the fields in this area approximates 650 million bbl. The oil recoverable by primary means would be something less than 10%, since several of the pools cannot be primarily produced. Steam is being used as one means to enhance the recovery in these fields to a possible 30-40%. Steam serves a twofold purpose when when applied to reservoir. Initially it works as a cleaning agent on the tubing, perforations, and sandface and can improve production for a short time. Primarily, however, steam acts as a heat-transporting agent which can reduce the viscosity of the crude in the reservoir to a point where it will flow much more readily to the well bore and can thus be more easily recovered. A graph indicates how the viscosity of crude oil changes with temperature. Since an increase in temperature can only have a beneficial effect on viscosity, the next step is to determine how to apply this feature to the reservoir.

Improvement of steam separator in boiling water reactors

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Jan Peter; Cremer, Ingo; Lorenz, Maik [AREVA GmbH, Erlangen (Germany)

2013-07-01

The potential to improve the function of the steam separator is identified and explored by scaled air-water tests and validated CFD calculations. It can be outlined that requirements on a modern steam separator for BWR plants will be fulfilled, combined with very good operational experience of the existing separator designs (e.g. material, layout). With the new steam separator design, modern high performance fuel assembly designs can be used for various core loading strategies (e.g. low leakage). This allows an increased thermal power of up to +50 % for the fuel element clusters in the center of the core with high radial peaking factors. In addition, any problems with unallowable high moisture at the turbine are solved with the new design, which have been identified for running BWR plants with the old steam separator design after applying new core loading patterns (e.g. after power uprates). A compatible steam separator design for all running BWRs is ready to launch. (orig.)

Testing improved steam separators in third energy block of Chernobyl AES

Energy Technology Data Exchange (ETDEWEB)

Novosel' skiy, O Yu; Karasev, V B; Sakovich, E V; Lyutov, M A; An' kov, V I

1984-12-01

Improved steam separating drums are described. These have a four-row arrangement of the pipe unions of the steam-water supply lines, with increased diameter. Two collectors 400 mm in diameter from adjacent separators drums go to a single steam line 600 mm in diameter, which goes to the turbine. Tests of the system were conducted at a pressure of 7 MPa and at thermal power of 65, 83, 93, and 100% of rated value to determine the dependence of the moisture content at the output from the separator drum on the mass level at constant thermal power of the block. The separator drums, 2600 mm in diameter, were found to have a reserve for maximum permissible moisture content, and the moisture content of the steam in the central pipe unions did not exceed 0.02% with a level in the drums 200 mm above the rated level. Thus maintenance of the level above the submerged perforated plate by 100 mm above the planned level permits an increase of the water reserve in the multiple forced circulation circuit by 28 m/sup 3/ and does not hinder an increase of the steam productivity of the block.

Value and cost analyses for solar thermal-storage systems

Energy Technology Data Exchange (ETDEWEB)

Luft, W.; Copeland, R.J.

1983-04-01

Value and cost data for thermal energy storage are presented for solar thermal central receiver systems for which thermal energy storage appears to be attractive. Both solar thermal electric power and industrial process heat applications are evaluated. The value of storage is based on the cost for fossil fuel and solar thermal collector systems in 1990. The costing uses a standard lifetime methodology with the storage capacity as a parameter. Both value and costs are functions of storage capacity. However, the value function depends on the application. Value/cost analyses for first-generation storage concepts for five central receiver systems (molten salt, water/steam, organic fluid, air, and liquid metal) established the reference against which new systems were compared. Some promising second-generation energy storage concepts have been identified, and some more advanced concepts have also been evaluated.

Improvement and evaluation of thermal, electrical, sealing and mechanical contacts, and their interface materials

Science.gov (United States)

Luo, Xiangcheng

Material contacts, including thermal, electrical, seating (fluid sealing and electromagnetic sealing) and mechanical (pressure) contacts, together with their interface materials, were, evaluated, and in some cases, improved beyond the state of the art. The evaluation involved the use of thermal, electrical and mechanical methods. For thermal contacts, this work evaluated and improved the heat transfer efficiency between two contacting components by developing various thermal interface pastes. Sodium silicate based thermal pastes (with boron nitride particles as the thermally conductive filler) as well as polyethylene glycol (PEG) based thermal pastes were developed and evaluated. The optimum volume fractions of BN in sodium silicate based pastes and PEG based pastes were 16% and 18% respectively. The contribution of Li+ ions to the thermal contact conductance in the PEG-based paste was confirmed. For electrical contacts, the relationship between the mechanical reliability and electrical reliability of solder/copper and silver-epoxy/copper joints was addressed. Mechanical pull-out testing was conducted on solder/copper and silver-epoxy/copper joints, while the contact electrical resistivity was measured. Cleansing of the copper surface was more effective for the reliability of silver-epoxy/copper joint than that of solder/copper joint. For sealing contacts, this work evaluated flexible graphite as an electromagnetic shielding gasket material. Flexible graphite was found to be at least comparable to conductive filled silicone (the state of the art) in terms of the shielding effectiveness. The conformability of flexible graphite with its mating metal surface under repeated compression was characterized by monitoring the contact electrical resistance, as the conformability is important to both electromagnetic scaling and fluid waling using flexible graphite. For mechanical contacts, this work focused on the correlation of the interface structure (such as elastic

Thermal Management and Reliability of Power Electronics and Electric Machines

Energy Technology Data Exchange (ETDEWEB)

Narumanchi, Sreekant

2016-06-13

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, and in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.

Electro-thermal analysis of Lithium Iron Phosphate battery for electric vehicles

Science.gov (United States)

Saw, L. H.; Somasundaram, K.; Ye, Y.; Tay, A. A. O.

2014-03-01

Lithium ion batteries offer an attractive solution for powering electric vehicles due to their relatively high specific energy and specific power, however, the temperature of the batteries greatly affects their performance as well as cycle life. In this work, an empirical equation characterizing the battery's electrical behavior is coupled with a lumped thermal model to analyze the electrical and thermal behavior of the 18650 Lithium Iron Phosphate cell. Under constant current discharging mode, the cell temperature increases with increasing charge/discharge rates. The dynamic behavior of the battery is also analyzed under a Simplified Federal Urban Driving Schedule and it is found that heat generated from the battery during this cycle is negligible. Simulation results are validated with experimental data. The validated single cell model is then extended to study the dynamic behavior of an electric vehicle battery pack. The modeling results predict that more heat is generated on an aggressive US06 driving cycle as compared to UDDS and HWFET cycle. An extensive thermal management system is needed for the electric vehicle battery pack especially during aggressive driving conditions to ensure that the cells are maintained within the desirable operating limits and temperature uniformity is achieved between the cells.

Fretting-wear characteristics of steam generator tubes contacting with foreign object

International Nuclear Information System (INIS)

Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung

2003-01-01

Fretting-wear characteristics of steam generator tubes contacting with foreign object has been investigated in this study. The operating steam generator shell-side flow field conditions are obtained from three-dimensional steam generator flow calculation using a well-validated steam generator thermal-hydraulic analysis computer code. Modal analyses are performed for the finite element modelings of tubes to get the natural frequency, corresponding mode shape and participation factor. The wear rate of a steam generator tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted. In addition, the effects of internal pressure and flow velocity on the remaining life of the tube are discussed in this paper