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Sample records for conventional steam drive

  1. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  2. Improved microwave steam distillation apparatus for isolation of essential oils. Comparison with conventional steam distillation.

    Science.gov (United States)

    Sahraoui, Naima; Vian, Maryline Abert; Bornard, Isabelle; Boutekedjiret, Chahrazed; Chemat, Farid

    2008-11-14

    Steam distillation (SD) is routinely used by analysts for the isolation of essential oils from herbs, flowers and spices prior to gas chromatographic analysis. In this work, a new process design and operation for an improved microwave steam distillation (MSD) of essential oils from aromatic natural products was developed. To demonstrate its feasibility, MSD was compared with the conventional technique, SD, for the analysis of volatile compounds from dry lavender flowers (Lavandula angustifolia Mill., Lamiaceae). Essential oils isolated by MSD were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained by SD, but MSD was better than SD in terms of rapidity (6 min versus 30 min for lavender flowers), thereby allowing substantial savings of costs in terms of time and energy. Lavender flowers treated by MSD and SD were observed by scanning electron microscopy. Micrographs provide evidence of more rapid opening of essential oil glands treated by MSD, in contrast to conventional SD.

  3. Aquathermolysis of conventional heavy oil with superheated steam

    Institute of Scientific and Technical Information of China (English)

    Song Guangshou; Zhou Tiyao; Cheng Linsong; Wang Yunxian; Tian Guoqing; Pi Jian; Zhang Zheng

    2009-01-01

    This paper presents a new aquathermolysis study of conventional heavy oil in superheated steam. A new high temperature autoclave was designed, where volume and pressure could be adjusted. Aquathermolysis was studied on two different conventional heavy oil samples under different reaction times and temperatures. Experimental results show that aquathermolysis does take place for conventional heavy oil. As reaction time increases, the oil viscosity reduces. However, the reaction will reach equilibrium after a certain period of time and won't be sensitive to any further reaction time any more. Analysis shows that, while resin and asphaltenes decrease, saturated hydrocarbons and the H/C ratio increase after reaction. The main mechanism of aquathermolysis includes hydrogenization, desulfuration reaction of resin and asphaltenes, etc.

  4. Second law analysis of a conventional steam power plant

    Science.gov (United States)

    Liu, Geng; Turner, Robert H.; Cengel, Yunus A.

    1993-01-01

    A numerical investigation of exergy destroyed by operation of a conventional steam power plant is computed via an exergy cascade. An order of magnitude analysis shows that exergy destruction is dominated by combustion and heat transfer across temperature differences inside the boiler, and conversion of energy entering the turbine/generator sets from thermal to electrical. Combustion and heat transfer inside the boiler accounts for 53.83 percent of the total exergy destruction. Converting thermal energy into electrical energy is responsible for 41.34 percent of the total exergy destruction. Heat transfer across the condenser accounts for 2.89 percent of the total exergy destruction. Fluid flow with friction is responsible for 0.50 percent of the total exergy destruction. The boiler feed pump turbine accounts for 0.25 percent of the total exergy destruction. Fluid flow mixing is responsible for 0.23 percent of the total exergy destruction. Other equipment including gland steam condenser, drain cooler, deaerator and heat exchangers are, in the aggregate, responsible for less than one percent of the total exergy destruction. An energy analysis is also given for comparison of exergy cascade to energy cascade. Efficiencies based on both the first law and second law of thermodynamics are calculated for a number of components and for the plant. The results show that high first law efficiency does not mean high second law efficiency. Therefore, the second law analysis has been proven to be a more powerful tool in pinpointing real losses. The procedure used to determine total exergy destruction and second law efficiency can be used in a conceptual design and parametric study to evaluate the performance of other steam power plants and other thermal systems.

  5. Second law analysis of a conventional steam power plant

    Science.gov (United States)

    Liu, Geng; Turner, Robert H.; Cengel, Yunus A.

    1993-11-01

    A numerical investigation of exergy destroyed by operation of a conventional steam power plant is computed via an exergy cascade. An order of magnitude analysis shows that exergy destruction is dominated by combustion and heat transfer across temperature differences inside the boiler, and conversion of energy entering the turbine/generator sets from thermal to electrical. Combustion and heat transfer inside the boiler accounts for 53.83 percent of the total exergy destruction. Converting thermal energy into electrical energy is responsible for 41.34 percent of the total exergy destruction. Heat transfer across the condenser accounts for 2.89 percent of the total exergy destruction. Fluid flow with friction is responsible for 0.50 percent of the total exergy destruction. The boiler feed pump turbine accounts for 0.25 percent of the total exergy destruction. Fluid flow mixing is responsible for 0.23 percent of the total exergy destruction. Other equipment including gland steam condenser, drain cooler, deaerator and heat exchangers are, in the aggregate, responsible for less than one percent of the total exergy destruction. An energy analysis is also given for comparison of exergy cascade to energy cascade. Efficiencies based on both the first law and second law of thermodynamics are calculated for a number of components and for the plant. The results show that high first law efficiency does not mean high second law efficiency. Therefore, the second law analysis has been proven to be a more powerful tool in pinpointing real losses. The procedure used to determine total exergy destruction and second law efficiency can be used in a conceptual design and parametric study to evaluate the performance of other steam power plants and other thermal systems.

  6. Reactivation of an Idle Lease to Increase Heavy Oil Recovery through Application of Conventional Steam Drive Technology in a Low Dip Slope and Basin Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Deo, M.; Forster, C.; Jenkins, C.; Schamel, S.; Sprinkel, D.; and Swain, R.

    1999-02-01

    This project reactivates ARCO's idle Pru Fee lease in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming was used to reestablish baseline production within the reservoir characterization phase of the project completed in December 1996. During the demonstration phase begun in January 1997, a continuous steamflood enhanced oil recovery is testing the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having simular producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially t o other producers in California, through an aggressive technology transfer program.

  7. Reactivation of an Idle Lease to Increase Heavy Oil Recovery through Application of Conventional Steam Drive Technology in a Low Dip Slope and Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, Steven

    1999-07-08

    This project reactivates ARCO's idle Pru Fee lease in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steam was used to reestablish baseline production within the reservoir characterization phase of the project completed in December 1996. During the demonstration phase begun in January 1997, a continuous steamflood enhanced oil recovery is testing the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objective of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program.

  8. Methanol steam reforming in a fuel cell drive system

    Science.gov (United States)

    Wiese, W.; Emonts, B.; Peters, R.

    Within the framework of the Joule III project a compact methanol reformer (CMR) with a specific weight of 2 kg/kW (lower heating value of H 2) was developed. This CMR contains a methanol and water vaporizer, a steam reformer, a heat carrier circuit and a catalytic burner unit. A laboratory fixed-bed reactor consisting of four tubes which could be filled with different amounts of catalyst was used to investigate the catalyst performance and the ageing behaviour. A hydrogen yield of 10 m N3/(h l Cat) can be achieved at 280°C. In this case, the methanol conversion rate is 95% and the dry product gas contains 0.9% CO. A linear decrease of the catalyst activity was observed which can be described by a loss of active catalyst mass of 5.5 mg/h. The catalyst was operated for more than 1000 h without having exhibited activity losses that made a catalyst change necessary. Besides, the stationary behaviour of the reforming reactor, the dynamic behaviour was studied. The time needed for start-up procedures has to be improved for reformers of a next generation. Moreover, the hydrogen production during reformer load changes will be discussed. Simulations of the power train in driving cycles show the different states of a reformer during dynamic operation.

  9. Electric and Conventional Vehicle Driving Patterns

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Torp, Kristian

    2014-01-01

    The electric vehicle (EV) is an interesting vehicle type that can reduce the dependence on fossil fuels, e.g., by using electricity from wind turbines. A significant disadvantage of EVs is a very limited range, typically less than 200 km. This paper compares EVs to conventional vehicles (CVs...

  10. Horizontal alternating steam drive process for the Orinoco heavy oil belt in eastern Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Edgar A. Fernandez R.; Bashbush, J.L. [Schlumberger, Sugar Land, TX (United States)

    2008-10-15

    Horizontal alternating steam drive (HASD) processes use single horizontal wells that cyclically switch between injection and production phases. The steam chambers generated by the wells are laterally driven by the pressure differentials created by adjacent producers to form a sweeping front between the wells. This feasibility study assessed the use of HASD processes at a heavy oil reservoir in Venezuela. The study used numerical simulations from a representative reservoir with a 5-horizontal well array to asses the HASD recovery technique under various scenarios. Sensitivity analyses were also conducted to consider the positioning of the horizontal well placement in the reservoir column; different injection sequences; variations in the duration of injection cycles; injection rates; and the lengths of the horizontal reach of the wells. Results of the study suggested that HASD is a suitable alternative for reservoirs with sands in the 20 foot to 50 foot thickness range. HASD achieved average recovery factors of above 20 per cent over a 15 year period, and required fewer wells than steam assisted gravity drainage (SAGD) processes. It was concluded that the wells must be designed to consider the additional thermal stresses resulting the repeated injection and production cycles associated with HASD processes. The 6 refs., 2 tabs., 16 figs.

  11. Wertheim's hypothesis on 'highway hypnosis': empirical evidence from a study on motorway and conventional road driving.

    Science.gov (United States)

    Cerezuela, Gemma Pastor; Tejero, Pilar; Chóliz, Mariano; Chisvert, Mauricio; Monteagudo, M José

    2004-11-01

    This paper aims to study the phenomenon known as 'highway hypnosis' or 'driving without attention mode', which has been defined as a state showing sleepiness signs and attention slip resulting from driving a motor vehicle for a long period in a highly predictable environment with low event occurrence, this being the case with motorways and very familiar roads [Highway hypnosis: a theoretical analysis. In: Gale, A.G., Brown, I.D., Haslegrave, C.M., Moorhead, I., Taylor, S. (Eds.), Vision in Vehicles-III. Elsevier, North-Holland, pp. 467-472]. According to Wertheim's hypothesis on 'highway hypnosis', long-term driving on motorways and conventional roads, e.g. main roads, secondary roads--implies differences in the predictability of the movement pattern of the visual stimulation, in the eye musculature activity and in the type of feedback used in visual information processing (mostly extra-retinal on motorways and retinal and extra-retinal on conventional roads). All this ultimately leads to alertness differences between both road types. Our research is intended to provide empirical evidence from the hypothesis, based on the data recorded during the actual driving experience of a group of subjects on a motorway and a conventional road. We studied whether or not significant alertness differences were found-measured by EEG data relative to time periods of on-target eye-tracking performance--between motorway and conventional road driving. Our results partially support the hypothesis, as drowsiness proved to be higher on motorways than on conventional roads during the final driving period but not during the starting stage, when the opposite trend was noticed. This result could be explained by the fact that during the first driving periods the effects of the stimulus movement predictability had not yet become apparent, since they tend to show after a long drive.

  12. Dynamic Analysis of Heavy Vehicle Medium Duty Drive Shaft Using Conventional and Composite Material

    Science.gov (United States)

    Kumar, Ashwani; Jain, Rajat; Patil, Pravin P.

    2016-09-01

    The main highlight of this study is structural and modal analysis of single piece drive shaft for selection of material. Drive shaft is used for torque carrying from vehicle transmission to rear wheel differential system. Heavy vehicle medium duty transmission drive shaft was selected as research object. Conventional materials (Steel SM45 C, Stainless Steel) and composite materials (HS carbon epoxy, E Glass Polyester Resin Composite) were selected for the analysis. Single piece composite material drive shaft has advantage over conventional two-piece steel drive shaft. It has higher specific strength, longer life, less weight, high critical speed and higher torque carrying capacity. The main criteria for drive shaft failure are strength and weight. Maximum modal frequency obtained is 919 Hz. Various harmful vibration modes (lateral vibration and torsional vibration) were identified and maximum deflection region was specified. For single-piece drive shaft the natural bending frequency should be higher because it is subjected to torsion and shear stress. Single piece drive shaft was modelled using Solid Edge and Pro-E. Finite Element Analysis was used for structural and modal analysis with actual running boundary condition like frictional support, torque and moment. FEA simulation results were validated with experimental literature results.

  13. The eco-driving effect of electric vehicles compared to conventional gasoline vehicles

    Directory of Open Access Journals (Sweden)

    Hideki Kato

    2016-10-01

    Full Text Available Eco-driving is attractive to the public, not only users of internal-combustion-engine vehicles (ICEVs including hybrid electric vehicles (HEVs but also users of electric vehicles (EVs have interest in eco-driving. In this context, a quantitative evaluation of eco-driving effect of EVs was conducted using a chassis dynamometer (C/D with an “eco-driving test mode.” This mode comprised four speed patterns selected from fifty-two real-world driving datasets collected during an eco-driving test-ride event. The four patterns had the same travel distance (5.2 km, but showed varying eco-driving achievement levels. Three ICEVs, one HEV and two EVs were tested using a C/D. Good linear relationships were found between the eco-driving achievement level and electric or fuel consumption rate of all vehicles. The reduction of CO2 emissions was also estimated. The CO2-reduction rates of the four conventional (including hybrid vehicles were 10.9%–12.6%, while those of two types of EVs were 11.7%–18.4%. These results indicate that the eco-driving tips for conventional vehicles are effective to not only ICEVs and HEVs but also EVs. Furthermore, EVs have a higher potential of eco-driving effect than ICEVs and HEVs if EVs could maintain high energy conversion efficiency at low load range. This study is intended to support the importance of the dissemination of tools like the intelligent speed adaptation (ISA to obey the regulation speed in real time. In the future, also in the development and dissemination of automated driving systems, the viewpoint of achieving the traveling purpose with less kinetic energy would be important.

  14. Comparative evaluation of surface and downhole steam-generation techniques

    Science.gov (United States)

    Hart, C.

    The application of heat to reservoirs containing high API gravity oils can substantially improve recovery. Although steam injection is currently the principal thermal recovery method, heat transmission losses associated with delivery of the steam from the surface generators to the oil bearing formation has limited conventional steam injection to shallow reservoirs. The objective of the Department of Energy's Project DEEP STEAM is to develop the technology required to economically produce heavy oil from deep reservoirs. The tasks included in this effort are the development and evaluation of thermally efficient delivery systems and downhole steam generation systems. The technical and economic performance of conventional surface steam drives, which are strongly influenced by heat losses are compared. The selection of a preferred technology based upon either total efficiency or cost is found to be strongly influenced by reservoir depth, steam mass flow rate, and sandface steam quality.

  15. Scaled physical model studies of the steam drive process. First annual report, September 1977-September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Doscher, T M

    1980-12-01

    Scaling laws of the heat transport mechanism in steam displacement processes are developed based upon an integral energy balance equation. Unlike the differential approach adopted by previous workers, the above scaling laws do not necessitate the use of any empirical correction factor as has been done in previous scaling calculations. The results provide a complete and consistent scale-down of the energy transport behavior, which is the critical mechanism for the success of a steam injection process. In the course of the study, the scaling problems associated with relative permeability and capillary pressure are also discussed. A method which has often been used in scaling nonthermal displacement processes is applied to reduce errors due to scaling in relative permeability. Both dimensional and inspectional analyses are applied to illustrate their use in steam processes. Scale-up laws appeared in the literature and those used in this study are compared and numerical examples are given.

  16. Technique of optimization of minimum temperature driving forces in the heaters of regeneration system of a steam turbine unit

    Science.gov (United States)

    Shamarokov, A. S.; Zorin, V. M.; Dai, Fam Kuang

    2016-03-01

    At the current stage of development of nuclear power engineering, high demands on nuclear power plants (NPP), including on their economy, are made. In these conditions, improving the quality of NPP means, in particular, the need to reasonably choose the values of numerous managed parameters of technological (heat) scheme. Furthermore, the chosen values should correspond to the economic conditions of NPP operation, which are postponed usually a considerable time interval from the point of time of parameters' choice. The article presents the technique of optimization of controlled parameters of the heat circuit of a steam turbine plant for the future. Its particularity is to obtain the results depending on a complex parameter combining the external economic and operating parameters that are relatively stable under the changing economic environment. The article presents the results of optimization according to this technique of the minimum temperature driving forces in the surface heaters of the heat regeneration system of the steam turbine plant of a K-1200-6.8/50 type. For optimization, the collector-screen heaters of high and low pressure developed at the OAO All-Russia Research and Design Institute of Nuclear Power Machine Building, which, in the authors' opinion, have the certain advantages over other types of heaters, were chosen. The optimality criterion in the task was the change in annual reduced costs for NPP compared to the version accepted as the baseline one. The influence on the decision of the task of independent variables that are not included in the complex parameter was analyzed. An optimization task was decided using the alternating-variable descent method. The obtained values of minimum temperature driving forces can guide the design of new nuclear plants with a heat circuit, similar to that accepted in the considered task.

  17. Hydrogen production by steam reforming of bio-alcohols. The use of conventional and membrane-assisted catalytic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Seelam, P. K.

    2013-11-01

    The energy consumption around the globe is on the rise due to the exponential population growth and urbanization. There is a need for alternative and non-conventional energy sources, which are CO{sub 2}-neutral, and a need to produce less or no environmental pollutants and to have high energy efficiency. One of the alternative approaches is hydrogen economy with the fuel cell (FC) technology which is forecasted to lead to a sustainable society. Hydrogen (H{sub 2}) is recognized as a potential fuel and clean energy carrier being at the same time a carbon-free element. Moreover, H{sub 2} is utilized in many processes in chemical, food, metallurgical, and pharmaceutical industry and it is also a valuable chemical in many reactions (e.g. refineries). Non-renewable resources have been the major feedstock for H{sub 2} production for many years. At present, {approx}50% of H{sub 2} is produced via catalytic steam reforming of natural gas followed by various down-stream purification steps to produce {approx}99.99% H{sub 2}, the process being highly energy intensive. Henceforth, bio-fuels like biomass derived alcohols (e.g. bio-ethanol and bio-glycerol), can be viable raw materials for the H{sub 2} production. In a membrane based reactor, the reaction and selective separation of H{sub 2} occur simultaneously in one unit, thus improving the overall reactor efficiency. The main motivation of this work is to produce H{sub 2} more efficiently and in an environmentally friendly way from bio-alcohols with a high H{sub 2} selectivity, purity and yield. In this thesis, the work was divided into two research areas, the first being the catalytic studies using metal decorated carbon nanotube (CNT) based catalysts in steam reforming of ethanol (SRE) at low temperatures (<450 deg C). The second part was the study of steam reforming (SR) and the water-gas-shift (WGS) reactions in a membrane reactor (MR) using dense and composite Pd-based membranes to produce high purity H{sub 2}. CNTs

  18. SPEED CONTROL OF PMBLDC DRIVE WITH GATE CONTROL METHOD USING CONVENTIONAL AND FUZZY CONTROLLER

    Directory of Open Access Journals (Sweden)

    T.V.NARMADHA,

    2010-11-01

    Full Text Available The paper presents simulation results of fuzzy logic and conventional proportional integral controller for the sensorless speed control of permanent magnet brushless dc (PMBLDC motor using Gate control method. Although conventional PI controllers are widely used in the industry due to its simple control structure and ease of implementation, these controllers pose difficulties under the conditions of nonlinearity, load disturbances and parametric variations. Moreover PI controllers require precise linear mathematical models. In the paper, the performance of the permanent magnet brushless dc motor drive is examined with the aid of the fuzzy logic controller. The fuzzy logic controller shows improved performance compared to the conventional PI speed controller. The module of the Three Phase inverter system controlled Permanent magnet Brushless DC motor is simulated using PI and Fuzzy Logic Controller and implemented in closed loop model. . By simulation, the characteristics of the PMBLDCM system are investigated. THD analysis for the methods is presented. The simulation results indicate FLC has improved performance.

  19. Hydraulic Hybrid and Conventional Parcel Delivery Vehicles' Measured Laboratory Fuel Economy on Targeted Drive Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lammert, M. P.; Burton, J.; Sindler, P.; Duran, A.

    2014-10-01

    This research project compares laboratory-measured fuel economy of a medium-duty diesel powered hydraulic hybrid vehicle drivetrain to both a conventional diesel drivetrain and a conventional gasoline drivetrain in a typical commercial parcel delivery application. Vehicles in this study included a model year 2012 Freightliner P100H hybrid compared to a 2012 conventional gasoline P100 and a 2012 conventional diesel parcel delivery van of similar specifications. Drive cycle analysis of 484 days of hybrid parcel delivery van commercial operation from multiple vehicles was used to select three standard laboratory drive cycles as well as to create a custom representative cycle. These four cycles encompass and bracket the range of real world in-use data observed in Baltimore United Parcel Service operations. The NY Composite cycle, the City Suburban Heavy Vehicle Cycle cycle, and the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) cycle as well as a custom Baltimore parcel delivery cycle were tested at the National Renewable Energy Laboratory's Renewable Fuels and Lubricants Laboratory. Fuel consumption was measured and analyzed for all three vehicles. Vehicle laboratory results are compared on the basis of fuel economy. The hydraulic hybrid parcel delivery van demonstrated 19%-52% better fuel economy than the conventional diesel parcel delivery van and 30%-56% better fuel economy than the conventional gasoline parcel delivery van on cycles other than the highway-oriented HHDDT cycle.

  20. Nonequilibrium steady states and transient dynamics of conventional superconductors under phonon driving

    Science.gov (United States)

    Murakami, Yuta; Tsuji, Naoto; Eckstein, Martin; Werner, Philipp

    2017-07-01

    We perform a systematic analysis of the influence of phonon driving on the superconducting Holstein model coupled to heat baths by studying both the transient dynamics and the nonequilibrium steady state (NESS) in the weak and strong electron-phonon coupling regimes. Our study is based on the nonequilibrium dynamical mean-field theory, and for the NESS we present a Floquet formulation adapted to electron-phonon systems. The analysis of the phonon propagator suggests that the effective attractive interaction can be strongly enhanced in a parametric resonant regime because of the Floquet side bands of phonons. While this may be expected to enhance the superconductivity (SC), our fully self-consistent calculations, which include the effects of heating and nonthermal distributions, show that the parametric phonon driving generically results in a suppression or complete melting of the SC order. In the strong coupling regime, the NESS always shows a suppression of the SC gap, the SC order parameter, and the superfluid density as a result of the driving, and this tendency is most prominent at the parametric resonance. Using the real-time nonequilibrium DMFT formalism, we also study the dynamics towards the NESS, which shows that the heating effect dominates the transient dynamics, and SC is weakened by the external driving, in particular at the parametric resonance. In the weak coupling regime, we find that the SC fluctuations above the transition temperature are generally weakened under the driving. The strongest suppression occurs again around the parametric resonances because of the efficient energy absorption.

  1. Less-Conventional Low-Consumption Galvanic Separated MOSFET-IGBT Gate Drive Supply

    Directory of Open Access Journals (Sweden)

    Jean Marie Vianney Bikorimana

    2017-01-01

    Full Text Available A simple half-bridge, galvanic separated power supply which can be short circuit proof is proposed for gate driver local supplies. The supply is made while hacking a common mode type filter as a transformer, as the transformer shows a good insulation, it has a very low parasitic capacitance between primary and secondary coils, and it is cost-effective. Very low standby losses were observed during lab experiments. This makes it compatible with energy efficient drives and solar inverters.

  2. Conventional control and fuzzy control of a dc-dc converter for machine drive

    Energy Technology Data Exchange (ETDEWEB)

    Radoi, C.; Florescu, A. [Department of Power Electronics `Politecnica` University Bucharest (Romania)

    1997-12-31

    Fuzzy logic or fuzzy set theory is recently getting increasing emphasis in process control applications. The paper describes an application of fuzzy logic in speed control system that uses a dc-dc converter. The fuzzy control is used to linearize the family of external characteristics of the converter in discontinuous-conduction mode occurring at light load and/or high speed. In order to compare the conventional control with the fuzzy logic control, algorithms have been developed in detail and verified by Microsoft Excel simulation. The simulation study indicates that fuzzy control is a good alternative for conventional control methods, being used particularly in non-linear complex systems ill defined or totally unknown. Where the mathematical model exists, it is useful. The applications of fuzzy set theory in power electronics are almost entirely new; fuzzy logic seems to have a lot of premises in the large industrial control field. (orig.) 2 refs.

  3. Synthetic biology for manufacturing chemicals: constraints drive the use of non-conventional microbial platforms.

    Science.gov (United States)

    Czajka, Jeffrey; Wang, Qinhong; Wang, Yechun; Tang, Yinjie J

    2017-09-07

    Genetically modified microbes have had much industrial success producing protein-based products (such as antibodies and enzymes). However, engineering microbial workhorses for biomanufacturing of commodity compounds remains challenging. First, microbes cannot afford burdens with both overexpression of multiple enzymes and metabolite drainage for product synthesis. Second, synthetic circuits and introduced heterologous pathways are not yet as "robust and reliable" as native pathways due to hosts' innate regulations, especially under suboptimal fermentation conditions. Third, engineered enzymes may lack channeling capabilities for cascade-like transport of metabolites to overcome diffusion barriers or to avoid intermediate toxicity in the cytoplasmic environment. Fourth, moving engineered hosts from laboratory to industry is unreliable because genetic mutations and non-genetic cell-to-cell variations impair the large-scale fermentation outcomes. Therefore, synthetic biology strains often have unsatisfactory industrial performance (titer/yield/productivity). To overcome these problems, many different species are being explored for their metabolic strengths that can be leveraged to synthesize specific compounds. Here, we provide examples of non-conventional and genetically amenable species for industrial manufacturing, including the following: Corynebacterium glutamicum for its TCA cycle-derived biosynthesis, Yarrowia lipolytica for its biosynthesis of fatty acids and carotenoids, cyanobacteria for photosynthetic production from its sugar phosphate pathways, and Rhodococcus for its ability to biotransform recalcitrant feedstock. Finally, we discuss emerging technologies (e.g., genome-to-phenome mapping, single cell methods, and knowledge engineering) that may facilitate the development of novel cell factories.

  4. COMPUTATIONAL FLUID DYNAMIC ANALYSIS OF INTERMEDIATE PRESSURE STEAM TURBINE

    OpenAIRE

    C RAJESH BABU

    2013-01-01

    a steam prime mover with rotary motion of the driving element, or rotor, and continuous operation. It converts the thermal energy of steam into mechanical work. The steam flow proceeds through directing devices and impinges on curved blades mounted along the periphery of the rotor. By exerting a force on the blades, the steam flow causes the rotor to rotate. Unlike the reciprocating steam engine, the steam turbine makes use of the kinetic rather than the potential energy of steam. The perform...

  5. Investigation of sulfur interactions on a conventional nickel-based solid oxide fuel cell anode during methane steam and dry reforming

    Science.gov (United States)

    Jablonski, Whitney S.

    Solid oxide fuel cells (SOFC) are an attractive energy source because they do not have undesirable emissions, are scalable, and are feedstock flexible, which means they can operate using a variety of fuel mixtures containing H2 and hydrocarbons. In terms of fuel flexibility, most potential fuel sources contain sulfur species, which severely poison the nickel-based anode. The main objective of this thesis is to systematically evaluate sulfur interactions on a conventional Ni/YSZ anode and compare sulfur poisoning during methane steam and dry reforming (SMR and DMR) to a conventional catalyst (Sud Chemie, Ni/K2O-CaAl2O4). Reforming experiments (SMR and DMR) were carried out in a packed bed reactor (PBR), and it was demonstrated that Ni/YSZ is much more sensitive to sulfur poisoning than Ni/K2O-CaAl2O4 as evidenced by the decline in activity to zero in under an hour for both SMR and DMR. Adsorption and desorption of H2S and SO2 on both catalysts was evaluated, and despite the low amount of accessible nickel on Ni/YSZ (14 times lower than Ni/K2O-CaAl2O4), it adsorbs 20 times more H2S and 50 times more SO2 than Ni/K 2O-CaAl2O4. A one-dimensional, steady state PBR model (DetchemPBED) was used to evaluate SMR and DMR under poisoning conditions using the Deutschmann mechanism and a recently published sulfur sub-mechanism. To fit the observed deactivation in the presence of 1 ppm H2S, the adsorption/desorption equilibrium constant was increased by a factor 16,000 for Ni/YSZ and 96 for Ni/K2O-CaAl2O4. A tubular SAE reactor was designed and fabricated for evaluating DMR in a reactor that mimics an SOFC. Evidence of hydrogen diffusion through a supposedly impermeable layer indicated that the tubular SAE reactor has a major flaw in which gases diffuse to unintended parts of the tube. It was also found to be extremely susceptible to coking which leads to cell failure even in operating regions that mimic real biogas. These problems made it impossible to validate the tubular SAE

  6. Modulation of Exciton Generation in Organic Active Planar pn Heterojunction: Toward Low Driving Voltage and High-Efficiency OLEDs Employing Conventional and Thermally Activated Delayed Fluorescent Emitters.

    Science.gov (United States)

    Chen, Dongcheng; Liu, Kunkun; Gan, Lin; Liu, Ming; Gao, Kuo; Xie, Gaozhan; Ma, Yuguang; Cao, Yong; Su, Shi-Jian

    2016-08-01

    Organic light-emitting diodes (OLEDs) combining low driving voltage and high efficiency are designed by employing conventional and thermally activated delayed fluorescence emitters through modulation of excitons generated at the planar p-n heterojunction region. To date, this approach enables the highest power efficiency for yellow-green emitting fluorescent OLEDs with a simplified structure.

  7. THERMODYNAMICAL ANALYSIS OF HIGH-PRESSURE FEED WATER HEATER IN STEAM PROPULSION SYSTEM DURING EXPLOITATION

    Directory of Open Access Journals (Sweden)

    Igor Poljak

    2017-01-01

    Full Text Available Nowadays diesel engines prevail as ship propulsion. However, steam propulsion is still primary drive for LNG carriers. In the presented paper high-pressure feed water heater was analyzed, as one of the essential components in LNG carrier steam propulsion system. Measurements of all operating parameters (fluid streams at the analyzed heat exchanger inlets and outlets were performed. Change of the operating parameters was measured at different steam system loads, not at full load as usual. Through these measurements was enabled the insight into the behaviour of the heat exchanger operating parameters during the whole exploitation. The numerical analysis was performed, based on the measured data. The changes in energy and exergy efficiency of the heat exchanger were analyzed. Energetic and exergetic power inputs and outputs were also calculated, which enabled an insight into the change of energetic and exergetic power losses of the heat exchanger at different steam system loads. Change in energetic and exergetic power losses and operating parameters, which have the strongest influence on the high-pressure feed water heater losses, were described. Analyzed heat exchanger was compared with similar heat exchangers in the base loaded conventional steam power plants. From the conducted analysis, it is concluded that the adjustment and control modes of these high-pressure heat exchangers are equal, regardless of whether they were mounted in the base loaded conventional steam power plants or marine steam systems, while their operating parameters and behaviour patterns differ greatly.

  8. 化学辅助蒸汽驱室内实验研究%Experimental Research of Chemical Auxiliary Steam Drive Theory

    Institute of Scientific and Technical Information of China (English)

    范英才; 董龙; 刘永建

    2011-01-01

    During the process of steam injection, application of novel chemical system MCA can control mobility, reduce the heavy oil viscosity, improve the steam viscosity and heavy oil recovery. The substances in the chemical system MCA precipitated at the steam or temperature front by conversion from the vaporized or liquid state into the solid crystalline form. The precipitated chemicals formed a temporary substance zone in which the permeability for steam and hot water was reduced. The crystallized chemicals were resublimed or dissolved by the spreading of steam or hot water front. The result of laboratory experiments show that the chemicals MCA improved the displacement efficiency of hot water and the sweep efficiency of steam and hot water.%在注蒸汽过程中,应用新型化学体系MCA可控制流度、降低稠油黏度及增加蒸汽黏度,可以提高稠油的采收率.其中,化学体系中MCA物质由气态或液态变成固态结晶体,析出在高温蒸汽前缘,从而提高原油采收率.析出的化学药品形成暂态的物质带.在这个物质带里,蒸汽和热水的渗透率减小.结晶化的化学药品由于蒸汽或热水前缘的扩展而重新升华或溶解.化学体系中室内实验结果表明,化学体系中MCA能提高热水的驱替效率以及蒸汽和热水的波及效率.

  9. Steam Turbines

    Science.gov (United States)

    1981-01-01

    Turbonetics Energy, Inc.'s steam turbines are used as power generating systems in the oil and gas, chemical, pharmaceuticals, metals and mining, and pulp and paper industries. The Turbonetics line benefited from use of NASA research data on radial inflow steam turbines and from company contact with personnel of Lewis Research Center, also use of Lewis-developed computer programs to determine performance characteristics of turbines.

  10. Characteristics Evaluation of a CO2-Caputuring Power Generation System with Reheat Cycle Utilizing Regenerative Oxygen-Combustion Steam-Superheater

    Science.gov (United States)

    Pak, Pyong Sik

    A new CO2-capturing power generation system is proposed that can be easily realized by applying conventional technologies. In the proposed system, the temperature of middle-pressure steam in a thermal power plant is raised by utilizing oxygen-combusting regenerative steam-superheater. The generated CO2 by combusting fuel in the superheater can be easily separated and captured from the exhaust gas at condenser outlet, and is liquefied. The superheated steam is used to drive a steam turbine power generation system. By adopting a high efficient combined cycle power generation system as an example, it has been shown that the proposed system can increase power output by 10.8%, decrease the CO2 emission amount of the total integrated system by 18.6% with power generation efficiency drop of 2.36% compared with the original power plant without CO2-capture, when superheated steam temperature is 750°C

  11. M 油田稠油油藏蒸汽驱数值模拟研究%Numerical Simulation of Steam Drive for the Heavy Oil Reservoirs of M Oilfield

    Institute of Scientific and Technical Information of China (English)

    张博; 陈军斌

    2014-01-01

    M 油田为一浅层特稠油油藏,目前已进入蒸汽开发后期,采出程度高,产量递减加快,开发效益下降。为挖掘油藏北部汽驱区潜力并提升开发效果,选择有代表性的井组,利用数值模拟的方法对其注汽速度、注汽干度进行优化设计,并对不同间歇汽驱开发方式的效果进行了对比研究,最后优选出适合目标区域的蒸汽驱开发方式。研究结果对相似油田蒸汽驱的开发具有一定的借鉴意义。%M oilfield belongs to shallow extra-heavy oil reservoir.It has come into later stage of steam drive and takes on characteristics as high degree of recovery, increasing decline of production and shrinking benefits.In order to exploit potentialities of northern reservoir and improve the reservoir development,typical well groups were chosen for numerical simulation to optimize injection rates,team quality and to compare development effect of different intermittent steam-flood.As a result,an optimal alternative was chosen for the target zone.This research approach provided a reference significance for steam-flood of similar oilfield.

  12. Steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, G.; Gilli, P.V.; Fritz, K.; Lippitsch, J.

    1975-12-02

    A steam generator is disclosed which is particularly adapted to be used in nuclear power plants. A casing is provided with an inlet and outlet to receive and discharge a primary heating fluid from which heat is to be extracted. A pair of tube plates extend across the interior of the casing at the region of the inlet and outlet thereof, and a plurality of tubes extend along the interior of the casing and are connected in parallel between the tube plates with all of the tubes having open ends communicating with the inlet and outlet of the casing so that the primary heating fluid will flow through the interior of the tubes while a fluid in the casing at the exterior of the tubes will extract heat from the primary fluid. The casing has between the tubes at the region of the inlet a superheating chamber and at the region of the outlet a preheating chamber and between the latter chambers an evaporating chamber, the casing receiving water through an inlet at the preheating chamber and discharging superheated steam through an outlet at the superheating chamber. A separator communicates with the evaporating chamber to receive a mixture of steam and water therefrom for separating the steam from the water and for delivering the separated steam to the superheating chamber.

  13. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  14. Steam Drum Design for Direct Steam Generation

    OpenAIRE

    Willwerth, Lisa; Müller, Svenja; Krüger, Joachim; Succo, Manuel; Feldhoff, Jan Fabian; Tiedemann, Jörg; Pandian, Juvaraj; Krüger, Dirk; Hennecke, Klaus

    2016-01-01

    For the direct steam generation in solar fields, the recirculation concept has been demonstrated in several installations. Water masses in the solar field vary during transient phases, such as passing clouds. The volume of the steam drum can serve as a buffer during such transients by taking in excess water and providing water storage. The saturated steam mass flow to the superheating section or the consumer can be maintained almost constant during short transients; therefore the steam drum p...

  15. Th40 cells (CD4+CD40+ Tcells) drive a more severe form of Experimental Autoimmune Encephalomyelitis than conventional CD4 T cells

    Science.gov (United States)

    Vaitaitis, Gisela M.; Yussman, Martin G.; Waid, Dan M.; Wagner, David H.

    2017-01-01

    CD40-CD154 interaction is critically involved in autoimmune diseases, and CD4 T cells play a dominant role in the Experimental Autoimmune Encephalomyelitis (EAE) model of Multiple Sclerosis (MS). CD4 T cells expressing CD40 (Th40) are pathogenic in type I diabetes but have not been evaluated in EAE. We demonstrate here that Th40 cells drive a rapid, more severe EAE disease course than conventional CD4 T cells. Adoptively transferred Th40 cells are present in lesions in the CNS and are associated with wide spread demyelination. Primary Th40 cells from EAE-induced donors adoptively transfer EAE without further in-vitro expansion and without requiring the administration of the EAE induction regimen to the recipient animals. This has not been accomplished with primary, non-TCR-transgenic donor cells previously. If co-injection of Th40 donor cells with Freund’s adjuvant (CFA) in the recipient animals is done, the disease course is more severe. The CFA component of the EAE induction regimen causes generalized inflammation, promoting expansion of Th40 cells and infiltration of the CNS, while MOG-antigen shapes the antigen-specific TCR repertoire. Those events are both necessary to precipitate disease. In MS, viral infections or trauma may induce generalized inflammation in susceptible individuals with subsequent disease onset. It will be important to further understand the events leading up to disease onset and to elucidate the contributions of the Th40 T cell subset. Also, evaluating Th40 levels as predictors of disease onset would be highly useful because if either the generalized inflammation event or the TCR-honing can be interrupted, disease onset may be prevented. PMID:28192476

  16. Steam Digest 2001

    Energy Technology Data Exchange (ETDEWEB)

    2002-01-01

    Steam Digest 2001 chronicles BestPractices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  17. Steam Digest Volume IV

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  18. The Invisibility of Steam

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2014-01-01

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

  19. Improvement of steam temperature control in supercritical once thru boilers

    OpenAIRE

    黒石, 卓司; 藤川, 卓爾

    2009-01-01

     New steam temperature control logic for supercritical once thru boilers was developed from the view point of simplicity similar to that of the conventional sub-critical drum type boilers. Water wall outlet steam temperature can be controlled more easily due to larger specific heat capacity of steam than super heater outlet steam temperature. By dividing temperature control into two parts, one at water wall outlet by fuel flow and the other at SH(super heater) outlet by SH spray flow, boiler ...

  20. Solar process steam for a pharmaceutical company in Jordan

    Science.gov (United States)

    Berger, M.; Mokhtar, M.; Zahler, C.; Al-Najami, M. M. R.; Krüger, D.; Hennecke, K.

    2016-05-01

    This paper presents details of the recent installation of a linear Fresnel collector to provide saturated steam for process heat usage through Direct Steam Generation (DSG) for industrial use in the Jordanian pharmaceuticals manufacturing company RAM Pharma, where first solar steam has been provided in March 2015. This commercial DSG project also represents the first solar DSG plant in MENA. During sunshine, the system achieves a solar fraction of 100 %, and the conventional steam boiler is not needed. In the evening the fossil fired backup takes over automatically and replaces the solar collector in operation. Operational experience, details of the control strategy, and measurement data are presented in the paper.

  1. 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)

  2. Integrated Gasification SOFC Plant with a Steam Plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Pierobon, Leonardo

    2011-01-01

    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......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...... 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...

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

    OpenAIRE

    Chen-Kuang Lin; Guang-Jer Lai; Yoshiyuki Kobayashi; Masahiro Matsuo; Min-Chie Chiu

    2015-01-01

    Steam is an essential medium used in the industrial process. To ensure steam quality, small and middle scale boilers are often adopted. However, because a higher steam pressure (compared to the necessary steam pressure) is generated, the boiler’s steam pressure will be reduced via a pressure regulator before the steam is directed through the process. Unfortunately, pressure is somewhat wasted during the reducing process. Therefore, in order to promote energy efficiency, a pressure regulator i...

  4. Heat Recovery Steam Generator by Using Cogeneration

    Directory of Open Access Journals (Sweden)

    P.Vivek, P. Vijaya kumar

    2014-01-01

    Full Text Available A heat recovery steam generator or HRSG is an energy recovery heat exchanger that recovers heat from a hot gas stream. It produces steam that can be used in a process (cogeneration or used to drive a steam turbine (combined cycle. It has been working with open and closed cycle. Both of cycles are used to increase the performance and also power on the cogeneration plant. If we are using closed cycle technology, we can recycle the waste heat from the turbine. in cogeneration plant, mostly they are using open cycle technology. additional, by using closed cycle technology, we can use the waste heat that converts into useful amount of work. In this paper, the exhaust gas will be sent by using proper outlet from cogen unit, we are using only waste heat that produce from turbine.

  5. Active acoustic leak detection for LMFBR steam generators. Pt. 6. Applicability to practical steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Kazuo; Kumagai, Hiromichi; Kinoshita, Izumi [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1998-03-01

    It is necessary to develop a reliable water leak detection system for steam generators of liquid metal reactors in order to prevent the expansion of damage and to maintain the structural integrity of the steam generators. The concept of the active acoustic method is to detect the change of the ultrasonic field due to the hydrogen gas bubbles generated by a sodium-water reaction. This method has the potential for improved detection performance compared with conventional passive methods, from the viewpoint of sensitivity, response time and tolerance against the background noise. A feasibility study of the active acoustic leak detection system is being carried out. This report predicts the performance of the active acoustic method in the practical steam generators from the results of the large scale in-water experiments. The results shows that the active acoustic system can detect a 10 g/s leak within a few seconds in large-scale steam generators. (author)

  6. Safety Picks up "STEAM"

    Science.gov (United States)

    Roy, Ken

    2016-01-01

    This column shares safety information for the classroom. STEAM subjects--science, technology, engineering, art, and mathematics--are essential for fostering students' 21st-century skills. STEAM promotes critical-thinking skills, including analysis, assessment, categorization, classification, interpretation, justification, and prediction, and are…

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

    Directory of Open Access Journals (Sweden)

    Chen-Kuang Lin

    2015-01-01

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

  8. Dehumidification System with Steam Permeability Films

    Science.gov (United States)

    Ishikwa, Masaaki; Sekimori, Souji; Ogiwara, Shigeaki; Ochiai, Tetsunari; Hirata, Tetsuo

    In a factory with a clean room facility in cold regions, dew-condensation on walls of the facility is one of the most serious problems in winter. In this study, a new dehumidification system in which a steam permeability film is located between humid air in a clean room and dry air from outside to exchange steam is proposed. This system can treat a lot of humid air with small energy only for driving fans to flow air. Some films are examined in two kinds of steam exchangers; double tube type and flat p1ate type. Steam permeability resistance and therma1 resistance of each film are first obtained in a double tube type exchanger. An analytica1 model for a flat plate type exchanger is then proposed, which shows good agreement with experimental data. Steam and heat transfer characteristics of a flat plate type exchanger are also evaluated experimentally. One film on a flat plate type exchanger shows dehumidification capacity of 0.033g/s(=120g/h )with its area of 2.232m2.

  9. Solar steam generation: Steam by thermal concentration

    Science.gov (United States)

    Shang, Wen; Deng, Tao

    2016-09-01

    The solar-driven generation of water steam at 100 °C under one sun normally requires the use of optical concentrators to provide the necessary energy flux. Now, thermal concentration is used to raise the vapour temperature to 100 °C without the need for costly optical concentrators.

  10. New ferritic steels for advanced steam plants

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H; Koenig, H. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    During the last 15-20 years ferritic-martensitic 9-12 % chromium steels have been developed under international research programmes which permit inlet steam temperatures up to approx. 625 deg C and pressures up to about 300 bars, thus leading to improvements in thermal efficiency of around 8 % and a CO{sub 2} reduction of about 20 % versus conventional steam parameters. These new steels are already being applied in 13 European and 34 Japanese power stations with inlet steam temperature up to 610 deg C. This presentation will give an account of the content, scope and results of the research programmes and of the experience gained during the production of components which have been manufactured from the new steels. (orig.) 13 refs.

  11. Steam injection in Colombia under challenging environment

    Energy Technology Data Exchange (ETDEWEB)

    Waghray, J.P. [Mansovar Energy Colombia Ltd (Colombia)

    2011-07-01

    Mansarovar Energy Columbia Ltd. is a company extracting heavy oil from its Colombian fields. In order to enhance the production and at the same time to contribute to the economic recovery, they are using the cyclic steam injection method. The aim of this presentation is to show what are the challenges facing heavy oil extraction in Colombia, what is the state of the art, and what needs to be improved. Heavy oil extraction in Colombia presents two sorts of challenges: operational ones related to sanding problems and diluents and gas availability; and commercial ones, related to low return rates. The use of steam injection in conventional wells can, however, increase both productivity and the rate of return while at the same time enhancing the recovery factor by 10 to 15%. For the future, improvement in drilling and completion, production, and steam efficiency will be necessary as well as the implementation of the appropriate enhanced oil recovery processes.

  12. Ukraine Steam Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Gurvinder Singh

    2000-02-15

    The Ukraine Steam Partnership program is designed to implement energy efficiency improvements in industrial steam systems. These improvements are to be made by the private plants and local government departments responsible for generation and delivery of energy to end-users. One of the activities planned under this program was to provide a two-day training workshop on industrial steam systems focusing on energy efficiency issues related to the generation, distribution, and consumption of steam. The workshop was geared towards plant managers, who are not only technically oriented, but are also key decision makers in their respective companies. The Agency for Rational Energy Use and Ecology (ARENA-ECO), a non-governmental, not-for-profit organization founded to promote energy efficiency and environmental protection in Ukraine, in conjunction with the Alliance staff in Kiev sent out invitations to potential participants in all the regions of Ukraine. The purpose of this report is the describe the proceedings from the workshop and provide recommendations from the workshop's roundtable discussion. The workshop was broken down into two main areas: (1) Energy efficient boiler house steam generation; and Energy efficient steam distribution and consumption. The workshop also covered the following topics: (1) Ukrainian boilers; (2) Water treatment systems; (3) A profile of UKRESCO (Ukrainian Energy Services Company); (4) Turbine expanders and electricity generation; (5) Enterprise energy audit basics; and (6) Experience of steam use in Donetsk oblast.

  13. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. 4-1BB Signaling in Conventional T Cells Drives IL-2 Production That Overcomes CD4+CD25+FoxP3+ T Regulatory Cell Suppression.

    Directory of Open Access Journals (Sweden)

    Hampartsoum B Barsoumian

    Full Text Available Costimulation with the recombinant SA-4-1BBL agonist of 4-1BB receptor on conventional CD4+ T cells (Tconvs overcomes the suppression mediated by naturally occurring CD4+CD25+FoxP3+ T regulatory cells (Tregs. The mechanistic basis of this observation has remained largely unknown. Herein we show that Tconvs, but not Tregs, are the direct target of SA-4-1BBL-mediated evasion of Treg suppression. IL-2 produced by Tconvs in response to 4-1BB signaling is both necessary and sufficient for overcoming Treg suppression. Supernatant from Tconvs stimulated with SA-4-1BBL contains high levels of IL-2 and overcomes Treg suppression in ex vivo Tconv:Treg cocultures. Removal of IL-2 from such supernatant restores Treg suppression and repletion of Tconv:Treg cocultures with exogenous recombinant IL-2 overcomes suppression. This study establishes 4-1BB signaling as a key circuit that regulates physical and functional equilibrium between Tregs and Tconvs with important implications for immunotherapy for indications where a fine balance between Tregs and Teffs plays a decisive role.

  15. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data......Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional lisp...

  16. Reactivation of an Idle Lease to Increase Heavy Oil Recovery through Application of Conventional Steam Drive Technology in a Low-Dip Slope and Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California, Class III

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, Steven; Deo, Milind; Deets, Mike

    2002-02-21

    The objective of the project is not just to commercially produce oil from the Pru Fee property, but rather to test which operational strategies best optimize total oil recovery at economically acceptable rates of production volumes and costs.

  17. Reactivation of an Idle Lease to Increase Heavy Oil Recovery through Application of Conventional Steam Drive Technology in a Low-Dip Slope and Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California, Class III

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, S.

    2001-01-09

    The objective of this project is not just to produce oil from the Pru Fee property, but rather to test which operational strategies best optimize total oil recovery at economically acceptable rates of production and production costs.

  18. FACTORS AFFECTING GLOBAL WARMING: ENVIRONMENTAL IMPACT OF SOLAR COOLING AND SOLAR STEAM GENERATION

    Energy Technology Data Exchange (ETDEWEB)

    Levent Colak [Dept. of Mechanical Engineering, Baskent University, Faculty of Engineering, Baglica Campus, Ankara (Turkey); Ali Durmaz [Dept. of Mechanical Engineering, Gazi University, Faculty of Engineering, Maltepe, Ankara (Turkey)

    2008-09-30

    Energy is the prime source of human activities in all sectors of life. Traditionally fossil fuel has been the primary energy resource. Extensive fossil fuel consumption in almost all human activities led to some undesirable phenomena such as atmospheric and environmental pollutions. Consequently, global warming, greenhouse effect, climate change, ozone layer depletion and acid rain terminologies started to appear in the literature frequently. In this study a comprehensive account of medium temperature solar energy applications, such as solar cooling and solar steam generation, on global warming were discussed. During the summer, the demand for electricity greatly increases because of the extensive use of air-conditioning systems. This is a source of major problems in the country's electricity supply and contributes to an increase of carbon dioxide emissions causing environmental pollution and global warming. On the other hand, vapor compression air conditioning systems have impacts on stratospheric ozone depletion because of the chlorofluorocarbons and hydrofluorocarbon refrigerants. The use of solar energy to drive cooling cycles is attractive since the cooling load is roughly in phase with solar energy availability. The main advantages of solar assisted refrigeration systems concern the reduction of peak loads for electricity utilities, the use of zero ozone depletion impact refrigerants, the decreased primary energy consumption and decreased global warming impact. Steam generation is the other most widespread thermal use of solar energy in industrial sectors, especially in textile industry where large amount of steam or hot water is required in dyeing process. Although conventional energy sources consequently have high environmental impacts, solar steam generation can not only be an economical choice but also can reduce the environmental impacts substantially.

  19. High performance steam development

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, T.; Schneider, P. [Solar Turbines Inc., San Diego, CA (United States)

    1995-10-01

    Over 30 years ago U.S. industry introduced the world`s highest temperature (1200{degrees}F at 5000 psig) and most efficient power plant, the Eddystone coal-burning steam plant. The highest alloy material used in the plant was 316 stainless steel. Problems during the first few years of operation caused a reduction in operating temperature to 1100{degrees}F which has generally become the highest temperature used in plants around the world. Leadership in high temperature steam has moved to Japan and Europe over the last 30 years.

  20. STEAM GENERATOR GROUP PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Clark, R. A.; Lewis, M

    1985-09-01

    This report is a summary of progress in the Surry Steam Generator Group Project for 1984. Information is presented on the analysis of two baseline eddy current inspections of the generator. Round robin series of tests using standard in-service inspection techniques are described along with some preliminary results. Observations are reported of degradation found on tubing specimens removed from the generator, and on support plates characterized in-situ. Residual stresses measured on a tubing specimen are reported. Two steam generator repair demonstrations are described; one for antivibration bar replacement, and one on tube repair methods. Chemical analyses are shown for sludge samples removed from above the tube sheet.

  1. Drive system failure control for distributed drive electric vehicles

    Science.gov (United States)

    Liu, Tao; Tang, Yuan; Wang, Jianfeng; Li, Yaou; Yang, Na; Liu, Yiqun

    2017-09-01

    Aiming at the failure problem of distributed electric drive vehicle, the conventional control strategy of drive system failure is designed according to the characteristics of each wheel torque independent control and the redundant configuration of the power unit. On this basis, combined with the traditional body stability control technology, the direct yaw moment control method is used. The simulation results show that the conventional control method designed of the drive system failure can effectively improve the driving condition of the vehicle. The driving stability of the vehicle is further improved after the direct yaw torque control is applied.

  2. INTEGRATION OF KRAFT PULPING ON A FOREST BIOREFINERY BY THE ADDITION OF A STEAM EXPLOSION PRETREATMENT

    OpenAIRE

    Raquel Martin-Sampedro; Maria E. Eugenio; Esteban Revilla; Juan A. Martin; J. Carlos Villar

    2011-01-01

    Steam explosion has been proposed for a wide range of lignocellulosic applications, including fractionation of biomass, pre-treatment of biomass for ethanol production, or as an alternative to conventional mechanical pulping. Nevertheless, a steam explosion process could also be used as pretreatment before chemical pulping, expecting a reduction in cooking time due to the open structure of the exploded chips. Thus, to evaluate the effect of steam explosion as a pretreatment in the kraft pulpi...

  3. Economic efficiency of a gas-turbine topping for steam reheating at heating turbo-installations

    OpenAIRE

    Romashova Olga; Belyaev Leonid; Tubolev Aleksandr; Skrebatun Egor

    2017-01-01

    The article considers the ways to improve the operating efficiency of conventional combined heat power plants using gas-turbine topping scheme allowing heat utilization of flue gases for steam reheating in the waste-heat steam boiler. The calculating analysis was performed for a steam-turbine power generating unit with a turbine of the Т-110/120-130 brand name intended for various modes of operation.

  4. Off-design analysis of a gas turbine powerplant augmented by steam injection using various fuels

    Science.gov (United States)

    Stochl, R. J.

    1980-01-01

    Results are compared using coal derived low and intermediate heating valve fuel gases and a conventional distillate. The results indicate that steam injection provides substantial increases in both power and efficiency within the available compressor surge margin. The results also indicate that these performance gains are relatively insensitive as to the type of fuel. Also, in a cogeneration application, steam injection could provide some degree of flexibility by varying the split between power and process steam.

  5. Economic efficiency of a gas-turbine topping for steam reheating at heating turbo-installations

    Directory of Open Access Journals (Sweden)

    Romashova Olga

    2017-01-01

    Full Text Available The article considers the ways to improve the operating efficiency of conventional combined heat power plants using gas-turbine topping scheme allowing heat utilization of flue gases for steam reheating in the waste-heat steam boiler. The calculating analysis was performed for a steam-turbine power generating unit with a turbine of the Т-110/120-130 brand name intended for various modes of operation.

  6. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  7. Steam-frothing of milk for coffee

    DEFF Research Database (Denmark)

    Münchow, Morten; Jørgensen, Leif; Amigo Rubio, Jose Manuel

    2015-01-01

    A method for evaluation of the foaming properties of steam-frothed milk, based on image analysis (feature extraction) carried out on a video taken immediately after foam formation, was developed. The method was shown to be able to analyse steam-frothed milk made using a conventional espresso...... machine, such as commonly used by baristas. Samples of milk, processed in a commercial dairy plant, were made with varying fat (0.5%, 0.9%, 1.5%, 2.6%, 3.5%) or protein (3.0%, 3.4%. 3.8%) content and analysed using the developed method. Increased protein content was shown to cause a delay in the formation...

  8. Feasibility of energy efficient steam drying of paper and textile including process integration

    NARCIS (Netherlands)

    Deventer, H.C. van

    1997-01-01

    This article deals with a feasibility study on superheated steam drying of paper and textile. Drying with superheated steam in direct contact with the paper or textile web offers great advantages over conventional ways of drying with respect to energy efficiency, drying rate and quality aspects. The

  9. Feasibility of energy efficient steam drying of paper and textile including process integration

    NARCIS (Netherlands)

    Deventer, H.C. van

    1997-01-01

    This article deals with a feasibility study on superheated steam drying of paper and textile. Drying with superheated steam in direct contact with the paper or textile web offers great advantages over conventional ways of drying with respect to energy efficiency, drying rate and quality aspects. The

  10. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  11. Wet steam wetness measurement in a 10 MW steam turbine

    OpenAIRE

    Kolovratník Michal; Bartoš Ondřej

    2014-01-01

    The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  12. Process for purifying geothermal steam

    Science.gov (United States)

    Li, C.T.

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

  13. Wet steam treatment with oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Ruehle, W.; Enkler, G. [EnBW Kraftwerke AG, Kernkraftwerk Philippsburg (Germany)

    1999-07-01

    After many years of excellent results using high all volatile treatment (HAVT) for operation of the secondary system of a PWR, flow assisted corrosion in the heating pipes of the intermediate steam reheaters has been experienced. Oxygen addition into the heating steam before the reheater is expected to improve the protective oxide layers formation. The reaction of oxygen with the alkalizing steam ingredients is described. (orig.)

  14. Regenerative superheated steam turbine cycles

    Science.gov (United States)

    Fuller, L. C.; Stovall, T. K.

    1980-01-01

    PRESTO computer program was developed to analyze performance of wide range of steam turbine cycles with special attention given to regenerative superheated steam turbine cycles. It can be used to model standard turbine cycles, including such features as process steam extraction, induction and feedwater heating by external sources, peaking, and high back pressure. Expansion line efficiencies, exhaust loss, leakages, mechanical losses, and generator losses are used to calculate cycle heat rate and generator output. Program provides power engineer with flexible aid for design and analysis of steam turbine systems.

  15. Nonuniformity of Temperatures in Microwave Steam Heating of Lobster Tail.

    Science.gov (United States)

    Fleischman, Gregory J

    2016-11-01

    The biennial Conference for Food Protection provides a formal process for all interested parties to influence food safety guidance. At a recent conference, an issue was raised culminating in a formal request to the U.S. Food and Drug Administration to change its Food Code recommendation for safe cooking of seafood using microwave energy when steaming was also employed. The request was to treat microwave steam cooked seafood as a conventionally cooked raw animal product rather than a microwave cooked product, for which the safe cooking recommendation is more extensive owing to the complex temperature distributions in microwave heating. The request was motivated by a literature study that revealed a more uniform temperature distribution in microwave steam cooked whole lobster. In that study, single-point temperatures were recorded in various sections of the whole lobster, but only one temperature was recorded in the tail, although the large size of the tail could translate to multiple hot and cold points. The present study was conducted to examine lobster tail specifically, measuring temperatures at multiple points during microwave steam cooking. Large temperature differences, greater than 60°C at times, were found throughout the heating period. To compensate for such differences, the Food Code recommends a more extensive level of cooking when microwave energy, rather than conventional heat sources, is used. Therefore, a change in the Food Code regarding microwave steam heating cannot be recommended.

  16. Steam refining as an alternative to steam explosion.

    Science.gov (United States)

    Schütt, Fokko; Westereng, Bjørge; Horn, Svein J; Puls, Jürgen; Saake, Bodo

    2012-05-01

    In steam pretreatment the defibration is usually achieved by an explosion at the end of the treatment, but can also be carried out in a subsequent refiner step. A steam explosion and a steam refining unit were compared by using the same raw material and pretreatment conditions, i.e. temperature and time. Smaller particle size was needed for the steam explosion unit to obtain homogenous slurries without considerable amounts of solid chips. A higher amount of volatiles could be condensed from the vapour phase after steam refining. The results from enzymatic hydrolysis showed no significant differences. It could be shown that, beside the chemical changes in the cell wall, the decrease of the particle size is the decisive factor to enhance the enzymatic accessibility while the explosion effect is not required.

  17. Drugged Driving

    Science.gov (United States)

    ... Parents & Educators Children & Teens Search Connect with NIDA : Google Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu ... misuse of prescription drugs can make driving a car unsafe—just like driving after drinking alcohol. Drugged ...

  18. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-11

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  19. Steam generator tube integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, D.R.; Shack, W.J. [Argonne National Laboratory, IL (United States); Muscara, J.

    1996-03-01

    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.

  20. Steam Oxidation Testing in the Severe Accident Test Station

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McMurray, Jake W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    Since 2011, Oak Ridge National Laboratory (ORNL) has been conducting high temperature steam oxidation testing of candidate alloys for accident tolerant fuel (ATF) cladding. These concepts are designed to enhance safety margins in light water reactors (LWR) during severe accident scenarios. In the US ATF community, the Severe Accident Test Station (SATS) has been evaluating candidate materials (including coatings) since 2012. Compared to the current UO2/Zr-based alloy fuel system, alternative cladding materials need to offer slower oxidation kinetics and a smaller enthalpy of oxidation in order to significantly reduce the rate of heat and hydrogen generation in the core during a coolant-limited severe accident. The steam oxidation behavior of candidate materials is a key metric in the evaluation of ATF concepts and also an important input into models. However, prior modeling work of FeCrAl cladding has used incomplete information on the physical properties of FeCrAl. Also, the steam oxidation data being collected at 1200°-1700°C is unique as no prior work has considered steam oxidation of alloys at such high temperatures. In some cases, the results have been difficult to interpret and more fundamental information is needed such as the stability of alumina in flowing steam at 1400°-1500°C. This report summarizes recent work to measure the steam oxidation kinetics of candidate alloys, the evaporation rate of alumina in steam and the development of integral data on FeCrAl compared to conventional Zr-based cladding.

  1. 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.

  2. General purpose steam table library :

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, John H.; Belcourt, Kenneth Noel; Nourgaliev, Robert

    2013-08-01

    Completion of the CASL L3 milestone THM.CFD.P7.04 provides a general purpose tabular interpolation library for material properties to support, in particular, standardized models for steam properties. The software consists of three parts, implementations of analytic steam models, a code to generate tables from those models, and an interpolation package to interface the tables to CFD codes such as Hydra-TH. Verification of the standard model is maintained through the entire train of routines. The performance of interpolation package exceeds that of freely available analytic implementation of the steam properties by over an order of magnitude.

  3. STEAM DALAM PEMBUATAN PAKAN UNTUK KOMODITAS AKUAKULTUR

    OpenAIRE

    Sukarman Sukarman

    2010-01-01

    Kualitas fisik pakan (pelet) untuk hewan akuakultur sangat penting, karena akan dimasukkan ke dalam air dan diharapkan tidak banyak mencemari lingkungan. Salah satu faktor yang berpengaruh dalam menjaga kualitas fisik pakan adalah penambahan dan pengaturan steam pada saat proses pembuatan pelet. Steam adalah aliran gas yang dihasilkan oleh air pada saat mendidih. Steam dibagi menjadi 3 jenis yaitu steam basah, saturated steam, dan superheated steam. Steam yang digunakan dalam proses pembuatan...

  4. Pile Driving

    Science.gov (United States)

    1987-01-01

    Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

  5. Toyota hybrid synergy drive

    Energy Technology Data Exchange (ETDEWEB)

    Gautschi, H.

    2008-07-01

    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  6. Toyota hybrid synergy drive

    Energy Technology Data Exchange (ETDEWEB)

    Gautschi, H.

    2008-07-01

    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  7. Roller/Gear Drives For Robotic Manipulators

    Science.gov (United States)

    Anderson, William J.; Shipitalo, William

    1995-01-01

    Pitch/yaw roller/gear drive and wrist-roll roller/gear drive designed to incorporate several features desirable in robotic-joint actuators. Includes zero backlash, high efficiency, smooth motion (little ripple in torque and in speed ratio), and high degree of back-drivability. Pitch/yaw drive is novel two-axis drive containing combination of gears, rollers, and springs acting together eliminating backlash and cogging. Wrist-roll drive more-conventional single-axis drive offering advantages like those of pitch/yaw drive.

  8. Steam jacket dynamics in underground coal gasification

    Science.gov (United States)

    Otto, Christopher; Kempka, Thomas

    2017-04-01

    Underground coal gasification (UCG) has the potential to increase the world-wide hydrocarbon reserves by utilization of deposits not economically mineable by conventional methods. In this context, UCG involves combusting coal in-situ to produce a high-calorific synthesis gas, which can be applied for electricity generation or chemical feedstock production. Apart from high economic potentials, in-situ combustion may cause environmental impacts such as groundwater pollution by by-product leakage. In order to prevent or significantly mitigate these potential environmental concerns, UCG reactors are generally operated below hydrostatic pressure to limit the outflow of UCG process fluids into overburden aquifers. This pressure difference effects groundwater inflow into the reactor and prevents the escape of product gas. In the close reactor vicinity, fluid flow determined by the evolving high reactor temperatures, resulting in the build-up of a steam jacket. Numerical modeling is one of the key components to study coupled processes in in-situ combustion. We employed the thermo-hydraulic numerical simulator MUFITS (BINMIXT module) to address the influence of reactor pressure dynamics as well as hydro-geological coal and caprock parameters on water inflow and steam jacket dynamics. The US field trials Hanna and Hoe Creek (Wyoming) were applied for 3D model validation in terms of water inflow matching, whereby the good agreement between our modeling results and the field data indicates that our model reflects the hydrothermal physics of the process. In summary, our validated model allows a fast prediction of the steam jacket dynamics as well as water in- and outflows, required to avoid aquifer contamination during the entire life cycle of in-situ combustion operations.

  9. Steam reforming of ethanol

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Dahl, Søren; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of oxygenated species like bio-oil or ethanol can be used to produce hydrogen or synthesis gas from renewable resources. However, deactivation due to carbon deposition is a major challenge for these processes. In this study, different strategies to minimize carbon deposition...... on Ni-based catalysts during SR of ethanol were investigated in a flow reactor. Four different supports for Ni were tested and Ce0.6Zr0.4O2 showed the highest activity, but also suffered from severe carbon deposition at 600 °C or below. Operation at 600 °C or above were needed for full conversion...... 400 ppm of the carbon in the feed at approx. 600 °C. The different promoters did not influence the product distribution to any significant extent. Selective poisoning with small amounts of K2SO4 on Ni–CeO2/MgAl2O4 at 600 °C decreased carbon deposition from 900 to 200 ppm of the carbon in the feed...

  10. Chemical-free Extraction of Cotton Stalk Bark Fibers by Steam Flash Explosion

    Directory of Open Access Journals (Sweden)

    Xiuliang Hou

    2014-10-01

    Full Text Available Cotton stalk bark fibers (CSBF were extracted by steam flash explosion, completed within 0.09 s, and the extracted fibers were compared with those obtained by conventional alkaline treatment. Results indicate that the optimum steam pressure was 2.5 MPa when steaming time was set to 2 min for extracting CSBF. Under the optimized conditions, the obtained CSBF had a cellulose content of 72%, length of 48 mm, fineness of 45 dtex, crystallinity index of 68, moisture regain of 8%, water retention of 98%, and tensile strength of 2.4 cN/dtex, which were similar to results obtained by conventional alkaline treatment. Compared with bark of cotton stalks, CSBF had lower moisture regain and water retention, and higher onset decomposition temperature. The results show that moderate steam flash explosion is a chemical-free, quick, and effective method for exploring the industrial applications of bark of cotton stalks as natural cellulose fibers.

  11. Advanced Eddy current NDE steam generator tubing.

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtiari, S.

    1999-03-29

    As part of a multifaceted project on steam generator integrity funded by the U.S. Nuclear Regulatory Commission, Argonne National Laboratory is carrying out research on the reliability of nondestructive evaluation (NDE). A particular area of interest is the impact of advanced eddy current (EC) NDE technology. This paper presents an overview of work that supports this effort in the areas of numerical electromagnetic (EM) modeling, data analysis, signal processing, and visualization of EC inspection results. Finite-element modeling has been utilized to study conventional and emerging EC probe designs. This research is aimed at determining probe responses to flaw morphologies of current interest. Application of signal processing and automated data analysis algorithms has also been addressed. Efforts have focused on assessment of frequency and spatial domain filters and implementation of more effective data analysis and display methods. Data analysis studies have dealt with implementation of linear and nonlinear multivariate models to relate EC inspection parameters to steam generator tubing defect size and structural integrity. Various signal enhancement and visualization schemes are also being evaluated and will serve as integral parts of computer-aided data analysis algorithms. Results from this research will ultimately be substantiated through testing on laboratory-grown and in-service-degraded tubes.

  12. Distracted Driving

    Science.gov (United States)

    ... What's this? Submit What's this? Submit Button Distracted Driving Recommend on Facebook Tweet Share Compartir Each day in the United States, over 8 people are killed and 1,161 injured in crashes ...

  13. DRIVING GREEN

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China is promoting environmentally friendly cars to save energy and protect the environment While people enjoy the pleasure and convenience of driving, they are also creating and breathing more and more toxic

  14. Steam Digest 2001: Office of Industrial Technologies

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-01-01

    Steam Digest 2001 chronicles Best Practices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  15. Continuous steam hydrolysis of tulip poplar

    Energy Technology Data Exchange (ETDEWEB)

    Fieber, C.A.; Roberts, R.S.; Faass, G.S.; Muzzy, J.D.; Colcord, A.R.; Bery, M.K.

    1982-01-01

    The continuous hydrolysis of poplar chips by steam at 300-350 psi resulted in the separation of hemicellulose (I) cellulose and lignin components. The I fraction was readily depolymerised by steam to acetic acid, furfural, methanol, and xylose.

  16. Steam pretreatment for coal liquefaction

    Science.gov (United States)

    Ivanenko, Olga

    The objectives of this work are to test the application of steam pretreatment to direct coal liquefaction, to investigate the reaction of model compounds with water, and to explore the use of zeolites in these processes. Previous work demonstrated the effectiveness of steam pretreatment in a subsequent flash pyrolysis. Apparently, subcritical steam ruptures nearly all of the ether cross links, leaving a partially depolymerized structure. It was postulated that very rapid heating of the pretreated coal to liquefaction conditions would be required to preserve the effects of such treatment. Accordingly, a method was adopted in which coal slurry is injected into a hot autoclave containing solvent. Since oxygen is capable of destroying the pretreatment effect, precautions were taken for its rigorous exclusion. Tests were conducted with Illinois No. 6 coal steam treated at 340sp°C, 750 psia for 15 minutes. Both raw and pretreated samples were liquified in deoxygenated tetralin at high severity (400sp°C, 30 min.) and low severity (a: 350sp°C, 30 min., and b: 385sp°C, 15 min.) conditions under 1500 psia hydrogen. Substantial improvement in liquid product quality was obtained and the need for rapid heating and oxygen exclusion demonstrated. Under low severity conditions, the oil yield was more than doubled, going from 12.5 to 29 wt%. Also chemistry of the pretreatment process was studied using aromatic ethers as model compounds. alpha-Benzylnaphthyl ether (alpha-BNE), alpha-naphthylmethyl phenyl (alpha-NMPE), and 9-phenoxyphenanthrene were exposed to steam and inert gas at pretreatment conditions and in some cases to liquid water at 315sp°C. alpha-BNE and alpha-NMPE showed little difference in conversion in inert gas and in steam. Hence, these compounds are poor models for coal in steam pretreatment. Thermally stable 9-phenoxyphenanthrene, however, was completely converted in one hour by liquid water at 315sp°C. At pretreatment conditions mostly rearranged starting

  17. STEAM DALAM PEMBUATAN PAKAN UNTUK KOMODITAS AKUAKULTUR

    Directory of Open Access Journals (Sweden)

    Sukarman Sukarman

    2010-12-01

    Full Text Available Kualitas fisik pakan (pelet untuk hewan akuakultur sangat penting, karena akan dimasukkan ke dalam air dan diharapkan tidak banyak mencemari lingkungan. Salah satu faktor yang berpengaruh dalam menjaga kualitas fisik pakan adalah penambahan dan pengaturan steam pada saat proses pembuatan pelet. Steam adalah aliran gas yang dihasilkan oleh air pada saat mendidih. Steam dibagi menjadi 3 jenis yaitu steam basah, saturated steam, dan superheated steam. Steam yang digunakan dalam proses pembuatan pelet adalah saturated steam. Pengaruh penambahan steam pada kualitas pelet bisa mencapai 20%. Penambahan steam dengan jumlah dan kualitas yang tepat akan menghasilkan pelet berkualitas. Sedangkan jika pengaturan dan penambahannya tidak tepat, maka kualitas fisik pelet akan rendah dan kemungkinan bisa merusak kandungan nutrisi seperti vitamin dan protein. Penambahan steam yang benar bisa dilakukan di dalam kondisioner dengan mengatur retention time, sudut kemiringan paddle conditioner, kecepatan putaran bearing dan menjaga kualitas steam dari mesin boiler sampai dengan kondisioner.

  18. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)

    1995-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  19. BWR Steam Dryer Alternating Stress Assessment Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Morante, R. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hambric, S. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ziada, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-01

    This report presents an overview of Boiling Water Reactor (BWR) steam dryer design; the fatigue cracking failures that occurred at the Quad Cities (QC) plants and their root causes; a history of BWR Extended Power Uprates (EPUs) in the USA; and a discussion of steam dryer modifications/replacements, alternating stress mechanisms on steam dryers, and structural integrity evaluations (static and alternating stress).

  20. Maintenance of Power Steam Turbine

    OpenAIRE

    Kapelovich, Boris; Khmelnik, Solomon; Kapelovich, David; Benenson, Evgeny

    2008-01-01

    The diagnostics system of the power steam turbine is offered. It can be executed also in the form of telediagnostic system. The system is presented on a site http://turbo.mic34.com/ System engineering can is ordered to authors.

  1. Steam-water relative permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)

    1997-12-31

    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  2. Death Drive

    OpenAIRE

    Stühler, Rebekka Hellstrøm

    2012-01-01

    The aim of this project is to investigate why the Freudian term Death Drive is not acknowledged in modern psychological therapy. On basis of psychoanalytical theory and through a literary analysis, the project will present a discussion of the significance and presence of the term within these practises.

  3. Exergo-Economic Fuel-Impact Analysis for Steam Turbines Sections in Power Plants

    Directory of Open Access Journals (Sweden)

    Javier Royo

    2003-09-01

    Full Text Available In this paper exergoeconomic fuel-impact models for steam turbines in power plants are proposed. They are applied to calculate the impact on the steam cycle when malfunctions are occurring during the operation of steam turbine sections. Concepts such as the exergetic consumption and the dissipation temperature are used to understand the proposed fuel-impact analysis. In order to validate these fuel-impact methods, well-known procedures, to simulate on- and off-design conditions of a steam power cycle, are used as references. Three different methods a ASME PTC-6, b existing fuel-impact formula, and c proposed exergoeconomic Fuel–Impact formulation, are compared with respect to the simulator results. The proposed models allow evaluating fuel-impact cost with more accurate results than conventional procedures. An example of a 158 MW conventional power plant is presented herein. The malfunction costs occurring in the steam turbines are inferred from the results. One perspective of this analysis is to establish an on-line monitoring system into power plants that permits to opportunely detect steam turbine malfunctions, without simulators.

  4. Topping PCFB combustion plant with supercritical steam pressure

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, A. [Foster Wheeler Development Corp., Livingston, NJ (United States); White, J. [Parsons Power Group Inc., Reading, PA (United States)

    1997-11-01

    Research is being conducted to develop a new type of coal fired plant for electric power generation. This new type of plant, called a second generation or topping pressurized circulating fluidized bed combustion (topping PCFB) plant, offers the promise of efficiencies greater than 46 percent (HHV), with both emissions and a cost of electricity that are significantly lower than conventional pulverized coal fired plants with scrubbers. The topping PCFB plant incorporates the partial gasification of coal in a carbonizer, the combustion of carbonizer char in a pressurized circulating fluidized bed combustor (PCFB), and the combustion of carbonizer fuel gas in a topping combustor to achieve gas turbine inlet temperatures of 2,300 F and higher. After completing pilot plant tests of a carbonizer, a PCFB, and a gas turbine topping combustor, all being developed for this new plant, the authors calculated a higher heating value efficiency of 46.2 percent for the plant. In that analysis, the plant operated with a conventional 2,400 psig steam cycle with 1,000 F superheat and reheat steam and a 2.5 inch mercury condenser back pressure. This paper identifies the efficiency gains that this plant will achieve by using supercritical pressure steam conditions.

  5. Methane production from steam-exploded bamboo.

    Science.gov (United States)

    Kobayashi, Fumihisa; Take, Harumi; Asada, Chikako; Nakamura, Yoshitoshi

    2004-01-01

    To convert unutilized plant biomass into a useful energy source, methane production from bamboo was investigated using a steam explosion pretreatment. Methane could not be produced from raw bamboo but methane production was enhanced by steam explosion. The maximum amount of methane produced, i.e., about 215 ml, was obtained from 1 g of exploded bamboo at a steam pressure of 3.53 MPa and a steaming time of 5 min. A negative correlation between the amount of methane produced and the amount of Klason lignin was observed in the methane fermentation of steam-exploded bamboo.

  6. Three years of experience with polyamines in the high pressure steam system of a naphtha cracker

    Energy Technology Data Exchange (ETDEWEB)

    Lier, Roy van; Janssen, Gerard [SABIC Europe BV, Geleen (Netherlands). Site Improvement, Competence Center Manufacturing; Savelkoul, Jo

    2008-12-15

    The design and operation of the high pressure steam system of a naphtha cracker pose specific problems which in some cases cannot be satisfactorily resolved with conventional water/steam treatment programs. Following a decade of operational experience with polyamine products at lower pressures at the Geleen (petro)chemical site in the Netherlands, the ammonia/morpholine treatment of the 12.5 MPa steam system of one of SABIC Europe's naphtha crackers was converted to a polyamine program in November 2005. In this paper, the characteristics of the cracker's steam system are first described. Particular aspects of the conversion are then discussed. Finally, the experience gained and insights obtained into the polyamine treatment during the first three years are elaborated. (orig.)

  7. Environmental assessment: tar sand in situ steam injection experiment

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    A field experiment is planned for the in situ recovery of bitumen from tar sand. The site is located on a ten acre site 6.5 miles West of Vernal, Utah, and the experiment will last about six months. The experiment will utilize steam to lower the viscosity of the bitumen and drive it into production wells where it is recovered. Due to the small scale of this experiment, the impact of the proposed action will be minimal. Impact on local biological life will be minimal. The experiment will have no effect on aquatic habitats. No rare or endangered biological species will be affected by the experiment.

  8. Steam treatment of zebra mussels

    Energy Technology Data Exchange (ETDEWEB)

    Tsou, J. [Electric Power Research Institute, Palo Alto, CA (United States); Rybarik, D.L.; Thiel, J. [Dairyland Power Cooperative, La Crosse, WI (United States); Mussalli, Y.G.; Collins, F. [Stone & Webster Environmental Technology & Services, Boston, MA (United States)

    1996-08-01

    Steam injection into intake bays is a nonchemical method to control zebra mussels. This technique was demonstrated at Dairyland Power Cooperative`s J.P. Madgett Station located in Alma, Wisconsin. The project was funded by the EPRI Zebra Mussel Consortium which includes: Dairyland Power Cooperative, Central Illinois Public Service, Duke Power, Illinois Power Company, PSI Energy, Public Service Electric & Gas, and Tennessee Valley Authority. This technique can be used by other power plants around the nation. The steam treatments were performed at the J.P. Madgen intake in Alma, Wisconsin, on September 14 and 18, 1994. The J.P. Madgen Station has two water intake bays with capacities of approximately 295,000 gallons and 265,000 gallons each. Each intake can be isolated, permitting either full or reduced generation depending on river temperature conditions. In addition to the intake bays, the outside fire protection loop and hydrants were also treated with the hot water from one of the bays. This paper presents the process design, piping and steam educator configurations, portable industrial boiler sizing and description, and the thermocouples to monitor the water temperature in the intake bay. The biological mortality and control test protocol and treatment results are also presented. Treatment effectiveness was 100%, however equipment installation and operation was more problematic than anticipated. 3 refs., 5 figs., 2 tabs.

  9. Modeling steam pressure under martian lava flows

    Science.gov (United States)

    Dundas, Colin M.; Keszthelyi, Laszlo P.

    2013-01-01

    Rootless cones on Mars are a valuable indicator of past interactions between lava and water. However, the details of the lava–water interactions are not fully understood, limiting the ability to use these features to infer new information about past water on Mars. We have developed a model for the pressurization of a dry layer of porous regolith by melting and boiling ground ice in the shallow subsurface. This model builds on previous models of lava cooling and melting of subsurface ice. We find that for reasonable regolith properties and ice depths of decimeters, explosive pressures can be reached. However, the energy stored within such lags is insufficient to excavate thick flows unless they draw steam from a broader region than the local eruption site. These results indicate that lag pressurization can drive rootless cone formation under favorable circumstances, but in other instances molten fuel–coolant interactions are probably required. We use the model results to consider a range of scenarios for rootless cone formation in Athabasca Valles. Pressure buildup by melting and boiling ice under a desiccated lag is possible in some locations, consistent with the expected distribution of ice implanted from atmospheric water vapor. However, it is uncertain whether such ice has existed in the vicinity of Athabasca Valles in recent history. Plausible alternative sources include surface snow or an aqueous flood shortly before the emplacement of the lava flow.

  10. An installation for steam conversion of gases

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, K.; Matsumoto, I.

    1983-01-28

    An installation is proposed for steam conversion of a hydrocarbon gas in order to produce an inorganic gas which chiefly consists of H2 and CO in which the line for feeding the hydrocarbon gas has a steam generator which has a microcapillary structure made of sponge metal, inorganic heat resistant fibers of glass, Si02, Al203 or carbon, inorganic heat resistant fibers twisted into a fiber or a cord of multipore ceramic material; the installation is equipped with a heater which regulates the water temperature, in which the steam generator is submerged. The installation is designed for converting natural gas, C3H8, other hydrocarbon gases and vapors of liquid hydrocarbons (Uv) into H2 and CO. The design and disposition of the steam generator simplify the design of the device, eliminating the pump for feeding the steam and the device for premixing of the steam and hydrocarbon gas.

  11. Determination of steam wetness in the steam-generating equipment of nuclear power plants

    Science.gov (United States)

    Gorburov, V. I.; Gorburov, D. V.; Kuz'min, A. V.

    2012-05-01

    Calculation and experimental methods for determining steam wetness in horizontal steam generators for nuclear power stations equipped with VVER reactors, namely, the classic salt technique and calculations based on operating parameters are discussed considered and compared.

  12. Analysis of performance for centrifugal steam compressor

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seung Hwan; Ryu, Chang Kook; Ko, Han Seo [Sungkyunkwan University, Suwon (Korea, Republic of)

    2016-12-15

    In this study, mean streamline and Computational fluid dynamics (CFD) analyses were performed to investigate the performance of a small centrifugal steam compressor using a latent heat recovery technology. The results from both analysis methods showed good agreement. The compression ratio and efficiency of steam were found to be related with those of air by comparing the compression performances of both gases. Thus, the compression performance of steam could be predicted by the compression performance of air using the developed dimensionless parameters.

  13. New features and applications of PRESTO, a computer code for the performance of regenerative, superheated steam turbine cycles

    Science.gov (United States)

    Choo, Y. K.; Staiger, P. J.

    1982-01-01

    The code was designed to analyze performance at valves-wide-open design flow. The code can model conventional steam cycles as well as cycles that include such special features as process steam extraction and induction and feedwater heating by external heat sources. Convenience features and extensions to the special features were incorporated into the PRESTO code. The features are described, and detailed examples illustrating the use of both the original and the special features are given.

  14. Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    In this study, oxide layers generated on aluminum alloy 6060(UNS A96060) using a steam-based process were compared with conventional chromate and chromate-phosphate conversion coatings. Chemical composition and microstructure of the conversion coatings were investigated and their corrosion perfor...

  15. Adjustable Speed Drives and Power Quality

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    This paper provides an overview and proposes cost-effective and efficient opportunities in improving power quality in Adjustable Speed Drive (ASD) systems. In particular, an Electronic Inductor (EI) technique has been used in single drives to overcome the existing challenges in conventional...

  16. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  17. Design of Multi Cleaning System Using Steam

    Directory of Open Access Journals (Sweden)

    Abhijeetsinh v Makwana

    2016-11-01

    Full Text Available The multi cleaning system is supposed to be system that uses steam which can clean up things that are used by human in day to day life. The commercial detergent washers are compared with the system and it was found that the washing is very convenient and soapy forms are not produced that made the washing very clumsy. The removal of bacterial populations formed on surface of any material would be totally eradicated. The surface to be cleaned are given bath with steam with high pressure from 3 bar to 7 bar by which removal of dirt and stain particles were washed off very comfortably. High pressure steam would be generated by heat the water in the tank which will mounted on the system itself. The reason behind using the steam for washing purpose is the less wastage of water and also its availability. The development of steam based cleaning system has revolutionized the process of washing. One can choose an appropriate type of high power steam cleaners for challenging cleaning applications in office, commercial and industrial settings. The steam does that thing that commercial washing system cannot do. A steam can remove grease and grime while for normal cleaning requires expensive detergents. The multi cleaning system cannot be only used for industrial use but also for the housework stuff. So our prime focus is to use the steam and make multiple cleaning

  18. 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.

  19. Steam Flooding after Steam Soak in Heavy Oil Reservoirs through Extended-reach Horizontal Wells

    Institute of Scientific and Technical Information of China (English)

    Ning Zhengfu; Liu Huiqing; Zhang Hongling

    2007-01-01

    This paper presents a new development scheme of simultaneous injection and production in a single horizontal well drilled for developing small block reservoirs or offshore reservoirs.It is possible to set special packers within the long completion horizontal interval to establish an injection zone and a production zone.This method can also be used in steam flooding after steam soak through a horizontal well.Simulation results showed that it was desirable to start steam flooding after six steam soaking cycles and at this time the oil/steam ratio was 0.25 and oil recovery efficiency was 23.48%.Steam flooding performance was affected by separation interval and steam injection rate.Reservoir numerical simulation indicated that maximum oil recovery would be achieved at a separation section of 40-50 m at steam injection rate of 100-180 t/d; and the larger the steam injection rate,the greater the water cut and pressure difference between injection zone and production zone.A steam injection rate of 120 t/d was suitable for steam flooding under practical injection-production conditions.All the results could be useful for the guidance of steam flooding projects.

  20. Steam and fuel oil supply and purge valve with cooling steam feature

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, B.F.; Buchanan, J.R.

    1991-09-17

    This patent describes a steam and fuel oil supply and purge valve. It comprises a valve body defining steam and oil inlet ports, at least one discharge port, a steam purge passageway interconnecting the steam inlet and discharge ports, an oil supply passageway interconnecting the oil inlet and discharge ports, a cooling steam passageway interconnecting the steam inlet and discharge ports, a steam valve and actuator member movable between first, second, third, and fourth positions in the valve body and operable to open and close the steam purge and cooling steam passageways, a small metering passageway in the steam valve and actuator member which is so dimensioned and located as to open prior to full opening movement of the valve member and actuator relative to its seat, an oil valve member movable between first and second positions to open and close the oil supply passageway, biasing means urging the oil valve member toward its second and closed positions, the steam valve and actuator member in its first and second positions respectively closing and opening the steam purge passageway.

  1. Ethanol production from steam-explosion pretreated wheat straw.

    Science.gov (United States)

    Ballesteros, Ignacio; Negro, Ma José; Oliva, José Miguel; Cabañas, Araceli; Manzanares, Paloma; Ballesteros, Mercedes

    2006-01-01

    Bioconversion of cereal straw to bioethanol is becoming an attractive alternative to conventional fuel ethanol production from grains. In this work, the best operational conditions for steam-explosion pretreatment of wheat straw for ethanol production by a simultaneous saccharification and fermentation process were studied, using diluted acid [H2SO4 0.9% (w/w)] and water as preimpregnation agents. Acid- or water-impregnated biomass was steam-exploded at different temperatures (160-200 degrees C) and residence times (5, 10, and 20 min). Composition of solid and filtrate obtained after pretreatment, enzymatic digestibility and ethanol production of pretreated wheat straw at different experimental conditions was analyzed. The best pretreatment conditions to obtain high conversion yield to ethanol (approx 80% of theoretical) of cellulose-rich residue after steam-explosion were 190 degrees C and 10 min or 200 degrees C and 5 min, in acid-impregnated straw. However, 180 degrees C for 10 min in acid-impregnated biomass provided the highest ethanol yield referred to raw material (140 L/t wheat straw), and sugars recovery yield in the filtrate (300 g/kg wheat straw).

  2. Steam reforming of low-level mixed waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    ThermoChem has successfully designed, fabricated and operated a nominal 90 pound per hour Process Development Unit (PDU) on various low-level mixed waste surrogates. The design, construction, and testing of the PDU as well as performance and economic projections for a 300-lb/hr demonstration and commercial system are described. The overall system offers an environmentally safe, non-incinerating, cost-effective, and publicly acceptable method of processing LLMW. The steam-reforming technology was ranked the No. 1 non-incineration technology for destruction of hazardous organic wastes in a study commissioned by the Mixed Waste Focus Area and published in April 1997. The ThermoChem steam-reforming system has been developed over the last 13 years culminating in this successful test campaign on LLMW surrogates. Six surrogates were successfully tested including a 750-hour test on material simulating a PCB- and Uranium-contaminated solid waste found at the Portsmouth Gaseous Diffusion Plant. The test results indicated essentially total (> 99.9999%) destruction of RCRA and TSCA hazardous halogenated organics, significant levels of volume reduction (> 400 to 1), and retention of radionuclides in the volume-reduced solids. Economic evaluations have shown the steam-reforming system to be very cost competitive with more conventional and other emerging technologies.

  3. Steam reforming of low-level mixed waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    ThermoChem has successfully designed, fabricated and operated a nominal 90 pound per hour Process Development Unit (PDU) on various low-level mixed waste surrogates. The design, construction, and testing of the PDU as well as performance and economic projections for a 300-lb/hr demonstration and commercial system are described. The overall system offers an environmentally safe, non-incinerating, cost-effective, and publicly acceptable method of processing LLMW. The steam-reforming technology was ranked the No. 1 non-incineration technology for destruction of hazardous organic wastes in a study commissioned by the Mixed Waste Focus Area and published in April 1997. The ThermoChem steam-reforming system has been developed over the last 13 years culminating in this successful test campaign on LLMW surrogates. Six surrogates were successfully tested including a 750-hour test on material simulating a PCB- and Uranium-contaminated solid waste found at the Portsmouth Gaseous Diffusion Plant. The test results indicated essentially total (> 99.9999%) destruction of RCRA and TSCA hazardous halogenated organics, significant levels of volume reduction (> 400 to 1), and retention of radionuclides in the volume-reduced solids. Economic evaluations have shown the steam-reforming system to be very cost competitive with more conventional and other emerging technologies.

  4. Topping gas turbines improve steam power plant efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Lezuo, A. (Siemens AG, Erlangen (Germany, F.R.). KWU Group)

    An interesting option for improving the efficiency and output of an existing conventional steam power plant is to convert it into a combined steam-and-gas cycle power plant by adding a topping gas turbine. The investment involved is relatively low, the payback period is short, and the low specific fuel consumption makes it possible to save on overall running costs. At the same time, the amount of residue for disposal and also pollutant emissions are drastically reduced. This article describes the configuration of a fully-fired combined-cycle power plant and discusses thermodynamic design and efficiency, operational aspects, emissions and residues and investment and economic viability. Both coal-fired and gas or oil-fired steam power plants can be converted by adding a topping cycle and the investment cost is about 20% of the cost of a new plant with the same output rating as the plant to be converted. Conversion reduces pollutant emission and residues produced (SO{sub 2}, NO{sub x}, CO{sub 2}, dust, ash, gypsum, waste heat). 4 figs.

  5. Steam Reforming of Acetic Acid over Co-supported Catalysts: Coupling Ketonization for Greater Stability

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Stephen D.; Spies, Kurt A.; Mei, Donghai; Kovarik, Libor; Kutnyakov, Igor V.; Li, Xiaohong S.; Dagle, Vanessa; Albrecht, Karl O.; Dagle, Robert A.

    2017-09-11

    We report on the markedly improved stability of a novel 2-bed catalytic system, as compared to a conventional 1-bed steam reforming catalyst, for the production of H2 from acetic acid. The 2-bed catalytic system comprises of i) a basic oxide ketonization catalyst for the conversion of acetic acid to acetone, and a ii) Co-based steam reforming catalyst, both catalytic beds placed in sequence within the same unit operation. Steam reforming catalysts are particularly prone to catalytic deactivation when steam reforming acetic acid, used here as a model compound for the aqueous fraction of bio-oil. Catalysts comprising MgAl2O4, ZnO, CeO2, and activated carbon (AC) both with and without Co-addition were evaluated for conversion of acetic acid and acetone, its ketonization product, in the presence of steam. It was found that over the bare oxide support only ketonization activity was observed and coke deposition was minimal. With addition of Co to the oxide support steam reforming activity was facilitated and coke deposition was significantly increased. Acetone steam reforming over the same Co-supported catalysts demonstrated more stable performance and with less coke deposition than with acetic acid feedstock. DFT analysis suggests that over Co surface CHxCOO species are more favorably formed from acetic acid versus acetone. These CHxCOO species are strongly bound to the Co catalyst surface and could explain the higher propensity for coke formation from acetic acid. Based on these findings, in order to enhance stability of the steam reforming catalyst a dual-bed (2-bed) catalyst system was implemented. Comparing the 2-bed and 1-bed (Co-supported catalyst only) systems under otherwise identical reaction conditions the 2-bed demonstrated significantly improved stability and coke deposition was decreased by a factor of 4.

  6. Production-log base model for carbonate permeability distribution and steam flood optimization

    Energy Technology Data Exchange (ETDEWEB)

    Ahamed, S.F.; Choudhry, M.A.; Abdulbaqi, J.B. [Kuwait Gulf Oil Co. (Kuwait)

    2008-10-15

    This paper presented a model for the effective management of primary and thermal oil recovery operations in the Wafra Field in Kuwait, where a small huff and puff project was carried out in 1998 to determine if steam injection was a feasible recovery option for the field. The Eocene heavy oil reservoirs of the Wafra Field are carbonate rock admixtures with gypsum and anhydrite. They are the shallowest of the field's productive horizons and exhibit a high degree of fluid flow heterogeneity. The assessment of vertical and lateral permeability variation is a key factor for success of the reservoir development plan. Steam injection began in 2006 in a small scale test (SST) to determine if the innovative technology could produce steam from effluent water and to test the viability of steam injection in carbonate reservoirs. Following the success of the SST, a large scale pilot (LSP) is schedule to start in 2009. It can be used for completion strategies of injectors and producers in steam injection. The model showed that the productivity of the Eocene wells could be correlated with common available logs to develop a log based-permeability model. A series of cross plots for the perforated intervals of high and low productivity wells were constructed to develop a relationship between well productivity and location of log parameters on the plots. A relationship between rock quality, productivity and conventional log parameters was established. It was concluded that the vertical permeability and interwell continuity in the Eocene wells can be used to optimize new well placement for horizontal and vertical infill drilling. The model is also an effective tool to predict the steam injectivity profile to understand the anomalies related to temperature-depth distribution. The model can be used to improve the efficiency of formation heating by optimizing the steam flood process and steam pattern well completion. 16 refs.

  7. RPV steam generator pressure boundary

    Energy Technology Data Exchange (ETDEWEB)

    Strosnider, J.

    1996-03-01

    As the types of SG tube degradation affecting PWR SGs has changed, and improvements in tube inspection and repair technology have occurred, current SG regulatory requirements and guidance have become increasingly out of date. This regulatory situation has been dealt with on a plant-specific basis, however to resolve this problem in the long term, the NRC has begun development of a performance-based rule. As currently structured, the proposed steam generator rule would require licensees to implement SG programs that monitor the condition of the steam generator tubes against accepted performance criteria to provide reasonable assurance that the steam generator tubes remain capable of performing their intended safety functions. Currently the staff is developing three performance criteria that will ensure the tubes can continue to perform their safety function and therefore satisfy the SG rule requirements. The staff, in developing the criteria, is striving to ensure that the performance criteria have the two key attributes of being (1) measurable (enabling the tube condition to be {open_quotes}measured{close_quotes} against the criteria) and (2) tolerable (ensuring that failures to meet the criteria do not result in unacceptable consequences). A general description of the criteria are: (1) Structural integrity criteria: Ensures that the structural integrity of the SG tubes is maintained for the operating cycle consistent with the margins intended by the ASME Code. (2) Leakage integrity criteria: Ensures that postulated accident leakages and the associated dose releases are limited relative to 10 CFR Part 50 guidelines and 10 CFR Part 50 Appendix A GDC 19. (3) Operational leakage criteria: Ensures that the operating unit will be shut down as a defense-in depth measure when operational SG tube leakage exceeds established leakage limits.

  8. Steam microturbines in distributed cogeneration

    CERN Document Server

    Kicinski, Jan

    2014-01-01

    This book presents the most recent trends and concepts in power engineering, especially with regard to prosumer and civic energy generation. In so doing, it draws widely on his experience gained during the development of steam microturbines for use in small combined heat and power stations based on the organic Rankine cycle (CHP-ORC). Major issues concerning the dynamic properties of mechanical systems, in particular rotating systems, are discussed, and the results obtained when using unconventional bearing systems, presented. Modeling and analysis of radial-flow and axial-flow microturbines a

  9. Steam Turbine Materials and Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, G.H.; Hsu, D.H.

    2008-07-01

    Ultra-supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760 °C. In prior years this project examined the steamside oxidation of alloys for use in high- and intermediate-pressure USC turbines. This steamside oxidation research is continuing and progress is presented, with emphasis on chromia evaporation.

  10. Development of in-vessel type control rod drive mechanism for a innovative small reactor (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Yoritsune, Tsutomu; Ishida, Toshihisa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Although the control rod drive mechanism of an existing large scale light water reactor is generally installed outside the reactor vessel, an in-vessel type control rod drive mechanism (INV-CRDM) is installed inside the reactor vessel. The INV-CRDM contributes to compactness and simplicity of the reactor system, and it can eliminate the possibility of a rod ejection accident. Therefore, INV-CRDM is an important technology adopted in an innovative small reactor. Japan Atomic Energy Research Institute (JAERI) has developed this type of CRDM driven by an electric motor, which can work under high temperature and high pressure water for the advanced marine reactor. On the basis of this research result, a driving motor coil and a bearing were developed to be used under the high temperature steam, severe condition for an innovative small reactor. About the driving motor, we manufactured the driving motor available for high temperature steam and carried out performance test under room temperature atmosphere to confirm the electric characteristic and coolability of the driving coil. With these test results and the past test results under high temperature water, we analyzed and evaluated the electric performance and coolability of the driving coil under high temperature steam. Concerning bearing, we manufactured the test pieces using some candidate material for material characteristic test and carried out the rolling wear test under high temperature steam to select the material. Consequently, we confirmed that performance of the driving coil for the advanced type driving motor, is enough to be used under high temperature steam. And, we evaluated the performance of the bearing and selected the material of the bearing, which can be used under high temperature steam. From these results, we have obtained the prospect that the INV-CRDM can be used for an innovative small reactor under steam atmosphere could be developed. (author)

  11. Development of in-vessel type control rod drive mechanism for a innovative small reactor (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Yoritsune, Tsutomu; Ishida, Toshihisa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Although the control rod drive mechanism of an existing large scale light water reactor is generally installed outside the reactor vessel, an in-vessel type control rod drive mechanism (INV-CRDM) is installed inside the reactor vessel. The INV-CRDM contributes to compactness and simplicity of the reactor system, and it can eliminate the possibility of a rod ejection accident. Therefore, INV-CRDM is an important technology adopted in an innovative small reactor. Japan Atomic Energy Research Institute (JAERI) has developed this type of CRDM driven by an electric motor, which can work under high temperature and high pressure water for the advanced marine reactor. On the basis of this research result, a driving motor coil and a bearing were developed to be used under the high temperature steam, severe condition for an innovative small reactor. About the driving motor, we manufactured the driving motor available for high temperature steam and carried out performance test under room temperature atmosphere to confirm the electric characteristic and coolability of the driving coil. With these test results and the past test results under high temperature water, we analyzed and evaluated the electric performance and coolability of the driving coil under high temperature steam. Concerning bearing, we manufactured the test pieces using some candidate material for material characteristic test and carried out the rolling wear test under high temperature steam to select the material. Consequently, we confirmed that performance of the driving coil for the advanced type driving motor, is enough to be used under high temperature steam. And, we evaluated the performance of the bearing and selected the material of the bearing, which can be used under high temperature steam. From these results, we have obtained the prospect that the INV-CRDM can be used for an innovative small reactor under steam atmosphere could be developed. (author)

  12. 2D-simulation of wet steam flow in a steam turbine with spontaneous condensation

    Institute of Scientific and Technical Information of China (English)

    SUN Lan-xin; ZHENG Qun; LIU Shun-long

    2007-01-01

    Removal of condensates from wet steam flow in the last stages of steam turbines significantly promotes stage efficiency and prevents erosion of rotors. In this paper, homogeneous spontaneous condensation in transonic steam flow in the 2-D rotor-tip section of a stage turbine is investigated.Calculated results agree with experimental data reasonably well. On the basis of the above work, a 2-D numerical simulation of wet steam flow in adjacent root sections of a complex steam turbine stage was carried out. Computational results were analyzed and provide insights into effective removal of humidity.

  13. Modelling 3D Steam Turbine Flow Using Thermodynamic Properties of Steam Iapws-95

    Directory of Open Access Journals (Sweden)

    Rusanow A.V.

    2016-01-01

    Full Text Available An approach to approximate equations of state for water and steam (IAPWS-95 for the calculation of three-dimensional flows of steam in turbomachinery in a range of operation of the present and future steam turbines is described. Test calculations of three-dimensional viscous flow in an LP steam turbine using various equations of state (perfect gas, Van der Waals equation, equation of state for water and steam IAPWS-95 are made. The comparison of numerical results with experimental data is also presented.

  14. Control of non-conventional synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

  15. Steam chemistry - interaction of chemical species with water, steam, and materials during evaporation, superheating, and condensation. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    Topics of this proceedings are: steam chemistry, supercritical water, effects of chemicals in steam (acetic acid, formic acid, phosphoric acid or other impurities); solubility and deposition, condensation processes and effect of impurities; nucleation; gas-liquid interfaces; steam treatment. (SR)

  16. Optimizing steam flood performance utilizing a new and highly accurate two phase steam measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Huff, B. D.; Warren, P. B. [CalResources LLC (Canada); Whorff, F. [ITT Barton (Canada)

    1995-11-01

    The development of a two phase steam measurement system was documented. The system consists of a `V` cone differential pressure device and a vortex meter velocity device in series through which the steam flows. Temperature and pressure sensors are electronically interfaced with a data logging system. The design was described as being very simple and rugged, consequently, well suited to monitoring in the field.. Steam quality measurements were made in the Kern River Field and the Coalinga Field thermal projects using a surface steam separator. In steam flood operations, steam cost is very high, hence appropriate distribution of the steam can result in significant cost reduction. This technology allows the measurement of steam flow and quality at any point in the steam distribution system. The metering system`s orifice meter was found to have a total average error of 45%, with 25% of that attributable to `cold leg` problem. Installation of the metering system was expected to result in a steam use reduction of 8%, without any impact on production. Steam re-distribution could result in a potential oil production increase of 10%. 12 refs., 8 tabs., 9 figs.

  17. 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.

  18. The Invention of the Steam Engine

    NARCIS (Netherlands)

    Van der Kooij, B.J.G.

    2015-01-01

    This casestudy is a historic analysis of the developments that resulted in the steam engine. The range of inventions that started with Savery's 'Miner's Friend' (a water pump to solve the dramatic water problem in the British eighteenth century mines) over a century culminated in the steam engine us

  19. Steam generated conversion coating on aluminium alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    pressure steam produced by an autoclave at a temperature of 107 – 121 °C and pressure of 15 -17 psi for 10 minutes to produce a thin coating of aluminium oxide. The aim of this study is to understand the effect of high pressure steam with and without different chemical additives on surface morphology...

  20. Future trends in steam coal utilization

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, G.A. [IEA Coal Research, London (United Kingdom)

    2000-07-01

    After reviewing the history of coal production in important regions of the world and the evolution of the international steam coal trade, the paper examines the main drivers behind the future use of steam coal and looks at, from past evidence and current perception, how these may shape the future. The four main drivers are social issues, strategic issues, competitiveness issues, and environmental issues.

  1. The Invention of the Steam Engine

    NARCIS (Netherlands)

    Van der Kooij, B.J.G.

    2015-01-01

    This casestudy is a historic analysis of the developments that resulted in the steam engine. The range of inventions that started with Savery's 'Miner's Friend' (a water pump to solve the dramatic water problem in the British eighteenth century mines) over a century culminated in the steam engine us

  2. Steam generator tubing NDE performance

    Energy Technology Data Exchange (ETDEWEB)

    Henry, G. [Electric Power Research Institute, Charlotte, NC (United States); Welty, C.S. Jr. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-02-01

    Steam generator (SG) non-destructive examination (NDE) is a fundamental element in the broader SG in-service inspection (ISI) process, a cornerstone in the management of PWR steam generators. Based on objective performance measures (tube leak forced outages and SG-related capacity factor loss), ISI performance has shown a continually improving trend over the years. Performance of the NDE element is a function of the fundamental capability of the technique, and the ability of the analysis portion of the process in field implementation of the technique. The technology continues to improve in several areas, e.g. system sensitivity, data collection rates, probe/coil design, and data analysis software. With these improvements comes the attendant requirement for qualification of the technique on the damage form(s) to which it will be applied, and for training and qualification of the data analysis element of the ISI process on the field implementation of the technique. The introduction of data transfer via fiber optic line allows for remote data acquisition and analysis, thus improving the efficiency of analysis for a limited pool of data analysts. This paper provides an overview of the current status of SG NDE, and identifies several important issues to be addressed.

  3. Steam reforming of light oxygenates

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Resasco, Daniel E; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of ethanol, acetic acid, acetone, acetol, 1-propanol, and propanal has been investigated over Ni/MgAl2O4 at temperatures between 400 and 700 degrees C and at a steam-to-carbon-ratio (S/C) of 6. The yield of H-2 and conversion increased with temperature, while the yield of by-products...... decreased with temperature in the SR of the investigated compounds. The yield of H2 approached the thermodynamic limit at the highest temperatures investigated. No significant differences in conversion as a function of temperature among the different model compounds were observed. However, the product...... distribution depended on the model compound, and C-3-oxygenates produced a larger fraction of by-products compared to C-2-oxygenates. Temperatures of 600 degrees C or above were generally needed to minimize the fraction of by-products and obtain a syngas containing mainly CO, CO2, H-2, and H2O with only traces...

  4. New low pressure exhaust modules for the MAN steam turbine product line. High performance bladings for highest efficiency levels; Neue Niederdruck-Module fuer die MAN-Dampfturbinenproduktlinie. Hochentwickelte Beschaufelungen fuer hoechste Leistungsdichten und Wirkungsgrade

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, M.A.; Behnke, K.; Klemm, H. [MAN TURBO AG, Oberhausen (Germany)

    2008-07-01

    Currently it can be observed that in the case of generator drives as well as 'mechanical drives' smaller units are demanded with a steam turbine capacity of up to 150 MW and clearly higher efficiencies. MAN TURBO is meeting the challenge through realisation of a comprehensive development project aiming at the extension of the application range of the current steam turbine series.

  5. Steam/fuel system optimization report: 6000-tpd SRC-I Demonstration Plant

    Energy Technology Data Exchange (ETDEWEB)

    Vakil, T.D.

    1983-07-01

    The design and configuration of the steam and fuel system for the 6000-ton-per-day (tpd) SRC-I Demonstration plant have been optimized, based on requirements for each area of the plant that were detailed in Area Baseline Designs of December 1982. The system was optimized primarily for the two most likely modes of plant operation, that is, when the expanded-bed hydrocracker (EBH) is operating at either high or low conversion, with all other units operating. However, the design, as such, is also operable under four other anticipated operating modes. The plant is self-sufficient in fuel except when the coker/calciner unit is not operating; then the required fuel oil import ranges from 80 to 125 MM Btu/h, lower heating value (LHV). The system affords stable operation under varying fuel gas availability and is reliable, flexible, and efficient. The optimization was based on maximizing overall efficiency of the steam system. The system was optimized to operate at five different steam-pressure levels, which are justifiable based on the plant's team requirements for process, heat duty, and power. All identified critical equipment drives will be run by steam turbines. Also part of the optimization was elimination of the steam evaporator in the wastewater treatment area. This minimized the impact on the steam system of operating in either the discharge of zero-discharge mode; the steam system remains essentially the same for either mode. Any further optimization efforts should be based on overall cost-effectiveness.

  6. Strategic maintenance plan for Cernavoda steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Cicerone, T. [CNE-PROD, Cernavoda (Romania); Dhar, D.; VandenBerg, J.P. [Babcock and Wilcox (Canada)

    2002-07-01

    Steam generators are among the most important pieces of equipment in a nuclear power plant. They are required full time during the plant operation and obviously no redundancy exists. Past experience has shown that those utilities which implemented comprehensive steam generator inspection and maintenance programs and strict water chemistry controls, have had good steam generator performance that supports good overall plant performance. The purpose of this paper is to discuss a strategic Life Management and Operational-monitoring program for the Cernavoda steam generators. The program is first of all to develop a base of expertise for the management of the steam generator condition; and that is to be supported by a program of actions to be accomplished over time to assess their condition, to take measures to avoid degradation and to provide for inspections, cleaning and modifications as necessary. (author)

  7. Hard sludge removal in steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Santibanez, M.; Stoss, J.

    2013-07-01

    One of the majors problems during the life of Nuclear power plants is the efficiency lost in steam generator due to, among issues, the plugging and therefore useless, of tubes which presented possibility of cracking in the future. The hard sludge produced in the steam generators secondary side and deposited on the tube sheet or around the tubes as collar shape are one of the main agent causing this problem, so their elimination is considered a major topic in order to keep the steam generators in an optimum condition along the whole plant life. AREVA is aware of this global problem, therefore a process and tools have been continuously developed since 1995 in order to eliminate the hard deposits in a effective way, with no damage to steam generator's components and adaptable for the different steam generators models existing in the market.

  8. Brush Seals for Improved Steam Turbine Performance

    Science.gov (United States)

    Turnquist, Norman; Chupp, Ray; Baily, Fred; Burnett, Mark; Rivas, Flor; Bowsher, Aaron; Crudgington, Peter

    2006-01-01

    GE Energy has retrofitted brush seals into more than 19 operating steam turbines. Brush seals offer superior leakage control compared to labyrinth seals, owing to their compliant nature and ability to maintain very tight clearances to the rotating shaft. Seal designs have been established for steam turbines ranging in size from 12 MW to over 1200 MW, including fossil, nuclear, combined-cycle and industrial applications. Steam turbines present unique design challenges that must be addressed to ensure that the potential performance benefits of brush seals are realized. Brush seals can have important effects on the overall turbine system that must be taken into account to assure reliable operation. Subscale rig tests are instrumental to understanding seal behavior under simulated steam-turbine operating conditions, prior to installing brush seals in the field. This presentation discusses the technical challenges of designing brush seals for steam turbines; subscale testing; performance benefits of brush seals; overall system effects; and field applications.

  9. Research on Mechanisms of Steam Breakthrough and Profile Control Design for Steam Soaking Well

    Institute of Scientific and Technical Information of China (English)

    Liu Huiqing; Zhang Hongling; Wang Shulin; Wang Han; Bao Shucheng

    2006-01-01

    Scaled physical model tests for steam breakthrough were conducted based on the analysis of mechanisms and influence factors of steam breakthrough. Physical simulation results showed that at the initial steam breakthrough, preferential flow channels were formed in narrow sand packs and most residual oil left in these channels was immobile. This shortened the steam breakthrough time of follow-up steam flooding and decreased the increment of oil recovery efficiency. Steam breakthrough occurred easily for a smaller producer-injector spacing, and a bigger difference in physical properties between fluids and rock. Steam breakthrough is more likely to occur at a larger formation permeability (k), greater steam displacement velocity (u) and smaller producer-injector spacing (L). Steam breakthrough time is a function of the parameter group (uk/L), i.e. tb=3.2151 (uk/L) -0.5142. A non piston-like displacement model was built based on steam breakthrough observation for a steam stimulated well in the Jinglou Oilfield, Henan Oilfield Company. The steam volume swept in different directions could be obtained from inter-well permeability capacity and breakthrough angle, and the steam swept pore volume (SSPV) was also determined. Numerical simulation showed that steam sweep efficiency reached its peak value when a slug of profile control agent (slug size 10%-15% SSPV) was set at one half of the inter-well spacing. Field test with 12.5% SSPV of profile control agents in the Jinglou Oilfield achieved success in sealing breakthrough channels and good production performance of adjacent producers.

  10. Microbial activity in soils following steam treatment.

    Science.gov (United States)

    Richardson, Ruth E; James, C Andrew; Bhupathiraju, Vishvesh K; Alvarez-Cohen, Lisa

    2002-01-01

    Steam enhanced extraction (SEE) is an aquifer remediation technique that can be effective at removing the bulk of non-aqueous phase liquid (NAPL) contamination from the subsurface, particularly highly volatile contaminants. However, low volatility compounds such as polynuclear aromatic hydrocarbons (PAHs) are less efficiently removed by this process. This research evaluated the effects of steam injection on soil microbial activity, community structure, and the potential for biodegradation of contaminants following steam treatment. Three different soils were evaluated: a laboratory-prepared microbially-enriched soil, soil from a creosote contaminated field site, and soil from a chlorinated solvent and waste oil contaminated field site. Results from field-scale steaming are also presented. Microbial activity before and after steam treatment was evaluated using direct epifluorescent microscopy (DEM) using the respiratory activity dye 5-cyano-2,3, ditolyl tetrazolium chloride (CTC) in conjunction with the fluorochrome 5-(4,6-dichlorotriazinyl) aminofluorescein (DTAF) to yield a quantitative assessment of active and total microbial numbers. DEM results indicate that steamed soils that were analyzed while still hot exhibited microbial activity levels that were below detection. However, soil samples that were slowly cooled, more closely reflecting the conditions of applied SEE, exhibited microbial activity levels that were comparable to presteamed soils. Samples from a field-site where steam was applied continuously for 6 weeks also showed high levels of microbial activity following cooling. The metabolic capabilities of the steamed communities were investigated by measuring cell growth in enrichment cultures on various substrates. These studies provided evidence that organisms capable of biodegradation were among the mesophilic populations that survived steam treatment. Fluorescent in situ hybridization (FISH) analysis of the soils with domain-level rRNA probes suggest

  11. Effects of superheated steam on the drying of rubberwood

    Directory of Open Access Journals (Sweden)

    Kanokwan Buaphud

    2006-07-01

    favorably to the conventional hot air drying process of 7-8 days. Moreover, results of the mechanical properties for the optimum condition showed that the shear-parallel-to-grain was 13.46 MPa and the compression strength parallel-to-grain was 37.73 MPa, both of which were higher than the literature values. Thus, using superheated steam in conjunction with hot air presents a substantial saving in operating time and energy consumption compared to the conventional method while retaining the desired mechanical properties of the wood.

  12. Steam oxidation scale growth and thermal insulation effect on creep life of creep strength enhanced ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Masuyama, Fujimitsu; Tokunaga, Tatsuya [Kyushu Inst. of Technology (Japan). Graduate School of Engineering; Takao, Mikito [Kyushu Inst. of Technology (Japan). Graduate School of Engineering; JFE Steel Corporation (Japan); Arakawa, Katsutoshi [Kyushu Inst. of Technology (Japan). Graduate School of Engineering; Kobe Steel Ltd. (Japan)

    2010-07-01

    Creep strength enhanced ferritic steels, such as T91 and T23 are extensively used worldwide for superheater and reheater tubes, not only in advanced power plants but also in plants with conventional steam conditions. However when these steel tubes are used at higher metal temperature, steam oxidation problems are recently experienced resulting in turbine side erosion, and overheating of tubes leading to creep rupture due to scale blockage in tube bends or scale insulation effect due to thick scale, and separation and exfoliation of the scale. In the present study, steam oxidation growth tests of T91, T92, T23 and T22 were conducted to develop steam oxidation growth rate and scale behavior. Then using the steam oxidation growth data measured the metal temperature changes with scale growth were calculated considering the insulation effect of steam oxidation scale. Consequently the creep lives affected by steam oxidation scale growth were predicted as a function of time and temperature increase for creep strength enhanced ferritic steels. (orig.)

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

    Science.gov (United States)

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

    2017-02-01

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

  14. Current Drive in a Ponderomotive Potential with Sign Reversal

    Energy Technology Data Exchange (ETDEWEB)

    N.J. Fisch; J.M. Rax; I.Y. Dodin

    2003-07-30

    Noninductive current drive can be accomplished through ponderomotive forces with high efficiency when the potential changes sign over the interaction region. The effect can practiced upon both ions and electrons. The current drive efficiencies, in principle, might be higher than those possible with conventional radio-frequency current-drive techniques, since different considerations come into play.

  15. Current Drive in a Ponderomotive Potential with Sign Reversal

    CERN Document Server

    Fisch, N J; Rax, J M

    2003-01-01

    Noninductive current drive can be accomplished through ponderomotive forces with high efficiency when the potential changes sign over the interaction region. The effect can practiced upon both ions and electrons. The current drive efficiencies, in principle, might be higher than those possible with conventional radio-frequency current-drive techniques, since different considerations come into play.

  16. Improving Steam System Performance: A Sourcebook for Industry, Second Edition (Book) (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    2012-10-01

    Improving Steam System Performance: A Sourcebook for Industry was developed for the U.S. Department of Energy's (DOE) Advanced Manufacturing Office (AMO), formerly the Industrial Technologies Program. AMO undertook this project as a series of sourcebook publications. Other topics in this series include: compressed air systems, pumping systems, fan systems, process heating and motor and drive systems. For more information about program resources, see AMO in the Where to Find Help section of this publication.

  17. Steam oxidation and the evaluation of coatings and material performance through collaborative research

    Energy Technology Data Exchange (ETDEWEB)

    Fry, A.T. [National Physical Lab., Teddington (United Kingdom); Aguero, A. [INTA, Madrid (Spain)

    2010-07-01

    Over the last five years through the COST 536 Programme researchers across Europe have been collaborating to better understand the phenomena of steam oxidation and to characterise coated and uncoated materials for use in power plants. During this period fundamental study of the oxidation mechanisms and changes in the oxidation kinetics caused by the presence of steam have been undertaken. Materials covering a range of high temperature plant applications have been studied, from low alloy martensitic alloys through to Ni-based superalloy materials, with investigations into the effect of increasing temperatures and pressures on the oxidation kinetics, oxide morphology and spallation characteristics. In addition conventional and novel coatings have been evaluated to assess their potential use in new USC plant. This paper will present an overview of these activities demonstrating the effect that steam has on the oxidation of alloys and coatings. (orig.)

  18. CLIC Drive Beam Position Monitor

    CERN Document Server

    Smith, S; Gudkov, D; Soby, L; Syratchev, I

    2011-01-01

    CLIC, an electron-positron linear collider proposed to probe the TeV energy scale, is based on a two-beam scheme where RF power to accelerate a high energy luminosity beam is extracted from a high current drive beam. The drive beam is efficiently generated in a long train at modest frequency and current then compressed in length and multiplied in frequency via bunch interleaving. The drive beam decelerator requires >40000 quadrupoles, each holding a beam position monitor (BPM). Though resolution requirements are modest (2 microns) these BPMs face several challenges. They must be compact and inexpensive. They must operate below waveguide cutoff to insure locality of position signals, ruling out processing at the natural 12 GHz bunch spacing frequency. Wakefields must be kept low. We find compact conventional stripline BPM with signals processed below 40 MHz can meet requirements. Choices of mechanical design, operating frequency, bandwidth, calibration and processing algorithm are presented. Calculations of wa...

  19. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  20. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others

    2005-04-15

    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  1. New type steam turbine for cogeneration

    Institute of Scientific and Technical Information of China (English)

    He Jianren; Yang Qiguo; Xu Damao

    2010-01-01

    A concept of energy saving & efficiency improving from cold source for cogeneration steam turbine was discussed herein.A new type"NCB"cogeneration steam turbine was proposed,which could considerably increase heat supply capacity,thermal efficiency and electric power.Taking 300 MW cogeneration steam turbine as an example,the results show that heat supply capacity reaches the maximum,i.e.increases by 30%,thermal efficiency is improved by12%,and electric power is enhanced by 15 MW during peak heat load.

  2. 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.)

  3. 49 CFR 230.21 - Steam locomotive number change.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive number change. 230.21 Section 230... Recordkeeping Requirements § 230.21 Steam locomotive number change. When a steam locomotive number is changed, the steam locomotive owner and/or operator must reflect the change in the upper right-hand corner...

  4. International water and steam quality standards on thermal power plants at all-volatile treatment

    Science.gov (United States)

    Petrova, T. I.; Orlov, K. A.; Dooley, R. B.

    2016-12-01

    One of the methods for the improvement of reliability and efficiency of the equipment at heat power plants is the decrease in the rate of corrosion of structural materials and sedimentation in water/steam circuit. These processes can be reduced to minimum by using the water with low impurity content and coolant treatment. For many years, water and steam quality standards were developed in various countries (United States, Germany, Japan, etc.) for specific types of equipment. The International Association for the Properties of Water and Steam (IAPWS), which brings together specialists from 21 countries, developed the water and steam quality standards for various types of power equipment based on theoretical studies and long-term operating experience of power equipment. Recently, various water-chemistry conditions are applied on heatpower equipment including conventional boilers and HRSGs with combined cycle power plants (Combined Cycle Power Plants (CCPP)). In paper, the maintenance conditions of water chemistry with ammonia or volatile amine dosing are described: reducing AVT(R), oxidizing AVT(O), and oxygen OT. Each of them is provided by the water and steam quality standards and recommendations are given on their maintenance under various operation conditions. It is noted that the quality control of heat carrier must be carried out with a particular care on the HPPs with combined cycle gas turbine units, where frequent starts and halts are performed.

  5. Simulation of Steam Gasification in a Fluidized Bed Reactor with Energy Self-Sufficient Condition

    Directory of Open Access Journals (Sweden)

    Ajaree Suwatthikul

    2017-03-01

    Full Text Available The biomass gasification process is widely accepted as a popular technology to produce fuel for the application in gas turbines and Organic Rankine Cycle (ORC. Chemical reactions of this process can be separated into three reaction zones: pyrolysis, combustion, and reduction. In this study, sensitivity analysis with respect to three input parameters (gasification temperature, equivalence ratio, and steam-to-biomass ratio has been carried out to achieve energy self-sufficient conditions in a steam gasification process under the criteria that the carbon conversion efficiency must be more than 70%, and carbon dioxide gas is lower than 20%. Simulation models of the steam gasification process have been carried out by ASPEN Plus and validated with both experimental data and simulation results from Nikoo & Mahinpey (2008. Gasification temperature of 911 °C, equivalence ratio of 0.18, and a steam-to-biomass ratio of 1.78, are considered as an optimal operation point to achieve energy self-sufficient condition. This operating point gives the maximum of carbon conversion efficiency at 91.03%, and carbon dioxide gas at 15.18 volumetric percentages. In this study, life cycle assessment (LCA is included to compare the environmental performance of conventional and energy self-sufficient gasification for steam biomass gasification.

  6. INTEGRATION OF KRAFT PULPING ON A FOREST BIOREFINERY BY THE ADDITION OF A STEAM EXPLOSION PRETREATMENT

    Directory of Open Access Journals (Sweden)

    Raquel Martin-Sampedro

    2011-02-01

    Full Text Available Steam explosion has been proposed for a wide range of lignocellulosic applications, including fractionation of biomass, pre-treatment of biomass for ethanol production, or as an alternative to conventional mechanical pulping. Nevertheless, a steam explosion process could also be used as pretreatment before chemical pulping, expecting a reduction in cooking time due to the open structure of the exploded chips. Thus, to evaluate the effect of steam explosion as a pretreatment in the kraft pulping of Eucalyptus globulus, steam exploded chips and control chips were subjected to kraft cookings. Steam exploded chips provided pulps with reductions of kappa number by up to 70% with no significant change in viscosity. Therefore, the cooking time could be shortened by 60%, increasing the productivity and obtaining pulps with similar delignification degree to those of the control pulp. Furthermore, not only the production rate could be increased, but also most of the hemicelluloses could be recovered before pulping and converted to a value-added product. Finally, although exploded pulp had inferior mechanical strength, the optical properties, which are more important in eucalyptus pulps, were found to be better.

  7. 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.

  8. An Improved Steam Injection Model with the Consideration of Steam Override

    Directory of Open Access Journals (Sweden)

    He Congge

    2017-01-01

    Full Text Available The great difference in density between steam and liquid during wet steam injection always results in steam override, that is, steam gathers on the top of the pay zone. In this article, the equation for steam override coefficient was firstly established based on van Lookeren’s steam override theory and then radius of steam zone and hot fluid zone were derived according to a more realistic temperature distribution and an energy balance in the pay zone. On this basis, the equation for the reservoir heat efficiency with the consideration of steam override was developed. Next, predicted results of the new model were compared with these of another analytical model and CMG STARS (a mature commercial reservoir numerical simulator to verify the accuracy of the new mathematical model. Finally, based on the validated model, we analyzed the effects of injection rate, steam quality and reservoir thickness on the reservoir heat efficiency. The results show that the new model can be simplified to the classic model (Marx-Langenheim model under the condition of the steam override being not taken into account, which means the Marx-Langenheim model is corresponding to a special case of this new model. The new model is much closer to the actual situation compared to the Marx-Langenheim model because of considering steam override. Moreover, with the help of the new model, it is found that the reservoir heat efficiency is not much affected by injection rate and steam quality but significantly influenced by reservoir thickness, and to ensure that the reservoir can be heated effectively, the reservoir thickness should not be too small.

  9. Study of Scaling Development on Tube Surfaces of Water Steam Loop in Steam Generator of CEFR

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Lu; LIU; Fu-chen; LUO; De-kang; WU; Qiang; ZHANG; Huan-qi

    2012-01-01

    <正>The steam generator worked as pressure boundary of Na-H2O loop in China Experimental FastReactor (CEFR), which was quite important for nuclear reactor safety. Once the tubes separating the water from steam leak because of corrosion by scaling, Na-H2O reaction would lead to severe accident. So it’s critically important to study how the scaling develops on the water-steam sides.

  10. US PWR steam generator management: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Welty, C.S. Jr. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-02-01

    This paper provides an overview on the status of steam generator management activities in US PWRs, and includes: (1) an overview of the impact of steam generator problems; (2) a brief discussion of historical damage trends and the current damage mechanism of most concern; (3) a discussion of the elements of {open_quotes}steam generator management{close_quotes}; and (4) a description of the approach being followed to implement a degradation-specific protocol for tubing inspection and repair. This paper was prepared in conjunction with another paper presented during the Plenary Session of this Conference, {open_quotes}Steam Generator Degradation: Current Mitigation Strategies for Controlling Corrosion{close_quotes}, and is provided as a supplement to that material.

  11. Pretreatment of Corn Stalk by Steam Explosion

    Institute of Scientific and Technical Information of China (English)

    邵自强; 田永生; 谭惠民

    2003-01-01

    A steam explosion pretreatment, which is one of the best ways of pretreating plant stalk, is applied at various severities to corn stalk. It could effectively modify the super-molecular structure of corn stalk and defibrating corn stalk into individual components. The relationship between yield of reducing sugar and the operating conditions, including temperature, pressure of steam explosion pretreatment and acidity, is also established. Experimental results prove that the steam explosion substantially increases the yield of reducing sugar, and the optimal condition for steam explosion is as follows: the pressure is 2.0 MPa, the pressure-retaining time 300 s, the initial acid concentration 1% and the acid treatment time 24 h.

  12. Biophysical Evaluation of SonoSteam®:

    DEFF Research Database (Denmark)

    Andersen, Ann Zahle; Duelund, Lars; Brewer, Jonathan R.;

    and safety evaluations. Our results show that there are no contradictions between data obtained by either approach. However, the biophysical methods draw a much more nuanced picture of the effects and efficiency of the investigated decontamination method, revealing e.g. an exponential dose/response...... relationship between SonoSteam treatment time and changes in collagen I, and a depth dependency in bacterial reduction, which points toward CFU counts overestimating total bacterial reduction. In conclusion the biophysical methods provide a less biased, reproducible and highly detailed system description......In this study we employ a biophysical and molecular approach for the investigation of qualitative and quantitative changes in both food surface and bacteria upon surface decontamination by SonoSteam®. SonoSteam® is a recently developed method of food surface decontamination, which employs steam...

  13. Thermodynamics of supersaturated steam: Molecular simulation results

    Science.gov (United States)

    Moučka, Filip; Nezbeda, Ivo

    2016-12-01

    Supersaturated steam modeled by the Gaussian charge polarizable model [P. Paricaud, M. Předota, and A. A. Chialvo, J. Chem. Phys. 122, 244511 (2005)] and BK3 model [P. Kiss and A. Baranyai, J. Chem. Phys. 138, 204507 (2013)] has been simulated at conditions occurring in steam turbines using the multiple-particle-move Monte Carlo for both the homogeneous phase and also implemented for the Gibbs ensemble Monte Carlo molecular simulation methods. Because of these thermodynamic conditions, a specific simulation algorithm has been developed to bypass common simulation problems resulting from very low densities of steam and cluster formation therein. In addition to pressure-temperature-density and orthobaric data, the distribution of clusters has also been evaluated. The obtained extensive data of high precision should serve as a basis for development of reliable molecular-based equations for properties of metastable steam.

  14. A small pelton turbine for steam turbocharger

    Energy Technology Data Exchange (ETDEWEB)

    Rautenberg, M.; Abdelkader, M.; Malobabic, M.; Mobarak, A.

    1984-08-01

    The use of exhaust gas turbocharger for internal combustion engines is usually accompanied by mechanical loss. This loss is due to the raise of exhaust gas back pressure with the increase of engine speed. This back pressure prevents the discharge of the exhaust gas from the engine and causes mechanical loss. To avoid this undesirable phenomenon, a Clausius-Rankine cycle is used. In this case the thermal energy in the exhaust gas is used to vaporise water in a steam generator. The generated steam expands in a steam turbocharger which supercharges the engine. A small Pelton steam turbine has been designed and fabricated. The expected output for this small turbine is 10 kW. A computer program has been prepared to estimate the values of optimum cycle parameters.

  15. Inhibition of lipid oxidation in pork bundles processing by superheated steam frying.

    Science.gov (United States)

    Huang, Tzou-Chi; Ho, Chi-Tang; Fu, Hui-Yin

    2004-05-19

    The effect of superheated steam treatment on the oxidative stability of lipids in packaged Zousoon (pork bundles) was investigated. The aroma quality of Zousoon samples was evaluated by sensory analysis and chromatographic analysis of volatiles. Results of this study indicated that oxidation of lipids occurred in pan-fried Zousoon after prolonged storage. Significant amounts of highly volatile compounds such as formaldehyde, acetaldehyde, acetone, and hexanal in Zousoon were identified by a modified method of cysteamine derivatization followed by gas chromatography-mass spectrometry (GC-MS) analysis. Superheated steam was found to be effective in suppressing lipid oxidation in canned Zousoon as compared with Zousoon fried by the conventional method in a frying pan. The superheated steam-fried samples had relatively low thiobarbituric acid reactive substance (TBARS) and peroxide (POV) values before and after storage, whereas samples prepared by pan frying had relatively high TBARS and POV values before and after storage. Superheated steam-fried Zousoon had superior lipid stability to that prepared by the conventional pan-frying method.

  16. Cogeneration steam turbines from Siemens: New solutions

    Science.gov (United States)

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

    2017-03-01

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

  17. Future trends in steam coal utilisation

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, G.A.

    1999-07-01

    The history of coal production in important regions of the world and the evolution of the international steam coal trade is reviewed. Then the four main drivers for the evolution of steam coal utilisation and how they may impact different regions of the world are discussed. These drivers are: social issues, including population, wealth and employment; strategic issues like energy security and balance of payments; competitiveness; and environment.

  18. Reciprocating wear in a steam environment

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.J.; Gee, M.G. [National Physical Laboratory, Teddington, Middlesex (United Kingdom)

    2010-07-01

    Tests to simulate the wear between sliding components in steam power plant have been performed using a low frequency wear apparatus at elevated temperatures under static load, at ambient pressure, in a steam environment. The apparatus was modified to accept a novel method of steam delivery. The materials tested were pre-exposed in a flowing steam furnace at temperature for either 500 or 3000 hours to provide some simulation of long term ageing. The duration of each wear test was 50 hours and tests were also performed on as-received material for comparison purposes. Data has been compared with results of tests performed on non-oxidised material for longer durations and also on tests without steam to examine the effect of different environments. Data collected from each test consists of mass change, stub height measurement and friction coefficient as well as visual inspection of the wear track. Within this paper, it is reported that both pre-ageing and the addition of steam during testing clearly influence the friction between material surfaces. (orig.)

  19. A comparison of essential oils obtained from lavandin via different extraction processes: Ultrasound, microwave, turbohydrodistillation, steam and hydrodistillation.

    Science.gov (United States)

    Périno-Issartier, Sandrine; Ginies, Christian; Cravotto, Giancarlo; Chemat, Farid

    2013-08-30

    A total of eight extraction techniques ranging from conventional methods (hydrodistillation (HD), steam distillation (SD), turbohydrodistillation (THD)), through innovative techniques (ultrasound assisted extraction (US-SD) and finishing with microwave assisted extraction techniques such as In situ microwave-generated hydrodistillation (ISMH), microwave steam distillation (MSD), microwave hydrodiffusion and gravity (MHG), and microwave steam diffusion (MSDf)) were used to extract essential oil from lavandin flowers and their results were compared. Extraction time, yield, essential oil composition and sensorial analysis were considered as the principal terms of comparison. The essential oils extracted using the more innovative processes were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained from the conventional techniques. The method which gave the best results was the microwave hydrodiffusion and gravity (MHG) method which gave reduced extraction time (30min against 220min for SD) and gave no differences in essential oil yield and sensorial perception.

  20. Magnetic Gearing Versus Conventional Gearing in Actuators for Aerospace Applications

    Science.gov (United States)

    Puchhammer, Gregor

    2014-01-01

    Magnetic geared actuators (MGA) are designed to perform highly reliable, robust and precise motion on satellite platforms or aerospace vehicles. The design allows MGA to be used for various tasks in space applications. In contrast to conventional geared drives, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. This paper describes the fundamentals of magnetic wobbling gears (MWG) and the deduced inherent characteristics, and compares conventional and magnetic gearing.

  1. Reliability of steam generator tubing

    Energy Technology Data Exchange (ETDEWEB)

    Kadokami, E. [Mitsubishi Heavy Industries Ltd., Hyogo-ku (Japan)

    1997-02-01

    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  2. The Hague Judgments Convention

    DEFF Research Database (Denmark)

    Nielsen, Peter Arnt

    2011-01-01

    The Hague Judgments Convention of 2005 is the first global convention on international jurisdiction and recognition and enforcement of judgments in civil and commercial matters. The author explains the political and legal background of the Convention, its content and certain crucial issues during...

  3. STEAM Enacted: A Case Study of a Middle School Teacher Implementing STEAM Instructional Practices

    Science.gov (United States)

    Herro, Danielle; Quigley, Cassie

    2016-01-01

    This paper examines the implementation practices of a 6th grade middle school teacher enacting STEAM (science, technology, engineering, art and math) teaching in his classroom after participating in a 45-hour STEAM professional development. Case study is used to detail the process, successes, and challenges. Project-based learning, technology…

  4. Synthesis and optimization of steam system networks. 2. Multiple steam levels

    CSIR Research Space (South Africa)

    Price, T

    2010-08-01

    Full Text Available The use of steam in heat exchanger networks (HENs) can be reduced by the application of heat integration with the intention of debottlenecking the steam boiler and indirectly reducing the water requirement [Coetzee and Majozi. Ind. Eng. Chem. Res...

  5. Modifikasi Alat Steam untuk Pembengkokan Rotan

    Directory of Open Access Journals (Sweden)

    Eustasia Sri Murwati

    2016-04-01

    Full Text Available ABSTRAKSelama ini pembengkokan rotan yang dilakukan oleh IKM Mebel Rotan dengan memanaskan di atas api kompor menggunakan alat pembengkok catok. Hasil yang diperoleh memberikan noda kehitaman. Cara lain dengan memasukkan rotan ke dalam alat steam dari besi, namun terdapat kendala persebaran uap yang tidak merata karena kurangnya rongga di antara tumpukan rotan selain terkena noda karat dari tabung steamer. Permasalahan tersebut dapat diatasi dengan modifikasi alat steam yang didesain multi guna, dapat melunakkan rotan dengan uap basah dalam tabung steamer dan uap kering yang disemprotkan pada permukaan rotan. Keunggulan alat ini adalah lebih efektif, tepat guna, multiguna, proses lebih cepat, konstruksi sederhana, mudah dan aman pengoperasiannya. Metode yang dilakukan yaitu survei lapangan dan literatur, perancangan desain, pengadaan bahan, pembuatan alat, uji coba alat, finishing alat, evaluasi dan pelaporan. Uji coba alat dengan variabel penampang rotan 2,4 cm, 2,8 cm, 3,2 cm dan waktu pengukusan 5 menit, 10 menit, dan 15 menit, dengan suhu ketel uap dan tabung steamer 110 o C, tekanan maksimum 2 bar (kg/cm2. Hasil yang diperoleh berupa 1 unit alat steam untuk pebengkok rotan terdiri dari: Pemanas, Ketel uap stainless steel spesifikasi standar JIS G 3116-2000, volume 118 lt, tabung steamer Grade SUS 340, bak perendaman dan meja bending. Hasil uji coba paling baik dengan waktu pengukusan 15 menit, rotan tidak pecah, tidak retak maupun tidak gembos, untuk semua  variabel diameter. Dapat membengkokkan rotan bentuk U, Ω,setengah lingkaran dan spiral. Uji coba uap kering memberikan hasil optimal dengan waktu penyemprotan lebih dari 20 menit. Kata kunci: alat steam, mebel, pembengkok, rotanABSTRACTAll this time rattan furniture SME’s bend the rattan by heating over a fire stove with a bending tool vise. The results obtained provide a blackish stain. Another way is putting the rattan into the iron steamer, but still has problems such as uneven

  6. Development of the large main steam safety relief valve

    Energy Technology Data Exchange (ETDEWEB)

    Takeshima, Kikuo [Hitachi Ltd., Tokyo (Japan); Takasaki, Kiyoshi; Hamada, Nobuyoshi

    2000-02-01

    In order to control rise of reactor pressure at formation of over-pressure transition accident in a boiling water (BWR) type nuclear power plant, the numbers of the main steam safety relief valve (MSSRV) installed in a storage vessel increases with out-put in the plant, and for 1.35 MkW class improved BWR (ABWR) 18 sets of MSSRV are installed. And, in an ABWR preparing of construction at Ohma-cho, Aomori prefecture by the Electric Power Development Co., Ltd., uranium-plutonium mixed oxides (MOX) fuel is planned to load, to tend to further increase required numbers of MSSRV. In order to control arrangement in a storage vessel and increase of conservative inspection work together with increase the required numbers of MSSRV, it was planned to develop a large volume of MSSRV (16% increase in volume on comparison with that of conventional one), to confirm its function and feature by its testing and to apply to an actual machine. Here was introduced on its developmental contents and testing results. As a result, it could be estimated that required numbers of MSSRV would be sixteen, and was confirmed that features such as correlation on flowing-out pressure between nitrogen and steam, durability, work stability, valve seat leakage resistance, and so forth were similar to those of present MSSRV. (G.K.)

  7. HARMONIC DRIVE SELECTION

    Directory of Open Access Journals (Sweden)

    Piotr FOLĘGA

    2014-03-01

    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  8. Computer modeling of a convective steam superheater

    Science.gov (United States)

    Trojan, Marcin

    2015-03-01

    Superheater is for generating superheated steam from the saturated steam from the evaporator outlet. In the case of pulverized coal fired boiler, a relatively small amount of ash causes problems with ash fouling on the heating surfaces, including the superheaters. In the convection pass of the boiler, the flue gas temperature is lower and ash deposits can be loose or sintered. Ash fouling not only reduces heat transfer from the flue gas to the steam, but also is the cause of a higher pressure drop on the flue gas flow path. In the case the pressure drop is greater than the power consumed by the fan increases. If the superheater surfaces are covered with ash than the steam temperature at the outlet of the superheater stages falls, and the flow rates of the water injected into attemperator should be reduced. There is also an increase in flue gas temperature after the different stages of the superheater. Consequently, this leads to a reduction in boiler efficiency. The paper presents the results of computational fluid dynamics simulations of the first stage superheater of both the boiler OP-210M using the commercial software. The temperature distributions of the steam and flue gas along the way they flow together with temperature of the tube walls and temperature of the ash deposits will be determined. The calculated steam temperature is compared with measurement results. Knowledge of these temperatures is of great practical importance because it allows to choose the grade of steel for a given superheater stage. Using the developed model of the superheater to determine its degree of ash fouling in the on-line mode one can control the activation frequency of steam sootblowers.

  9. Computer modeling of a convective steam superheater

    Directory of Open Access Journals (Sweden)

    Trojan Marcin

    2015-03-01

    Full Text Available Superheater is for generating superheated steam from the saturated steam from the evaporator outlet. In the case of pulverized coal fired boiler, a relatively small amount of ash causes problems with ash fouling on the heating surfaces, including the superheaters. In the convection pass of the boiler, the flue gas temperature is lower and ash deposits can be loose or sintered. Ash fouling not only reduces heat transfer from the flue gas to the steam, but also is the cause of a higher pressure drop on the flue gas flow path. In the case the pressure drop is greater than the power consumed by the fan increases. If the superheater surfaces are covered with ash than the steam temperature at the outlet of the superheater stages falls, and the flow rates of the water injected into attemperator should be reduced. There is also an increase in flue gas temperature after the different stages of the superheater. Consequently, this leads to a reduction in boiler efficiency. The paper presents the results of computational fluid dynamics simulations of the first stage superheater of both the boiler OP-210M using the commercial software. The temperature distributions of the steam and flue gas along the way they flow together with temperature of the tube walls and temperature of the ash deposits will be determined. The calculated steam temperature is compared with measurement results. Knowledge of these temperatures is of great practical importance because it allows to choose the grade of steel for a given superheater stage. Using the developed model of the superheater to determine its degree of ash fouling in the on-line mode one can control the activation frequency of steam sootblowers.

  10. Experimental investigation of the steam wetness in a 1000 MW steam turbine

    Science.gov (United States)

    Kolovratník, Michal; Bartoš, Ondřej

    2016-03-01

    The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement opportunity provided lots of new information for the manufacturer and operator of the steam turbine and valuable experimental data for the phase transition modelling in the wet steam flow. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  11. Experimental investigation of the steam wetness in a 1000 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2016-01-01

    Full Text Available The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement opportunity provided lots of new information for the manufacturer and operator of the steam turbine and valuable experimental data for the phase transition modelling in the wet steam flow. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  12. Warp Drive - From Imagination to Reality

    Science.gov (United States)

    Gardiner, J.

    The realisation of warp drive is far beyond current science and technology; nevertheless, setting out a timetable for the realisation of warp drive is instructive as this will set expectations for the progress of future research. It is proposed that a time scale for the realisation of warp drive can be estimated by historical analogy with the development of manned space travel to the Moon, using conventional project estimation techniques. A timeline for space travel to the Moon begins with Cyrano de Bergerac's Voyage dans la Lune in 1657 and culminates with the Apollo 11 Moon landing in 1969, a little over 300 years later. A similar timeline for warp drive begins with John W. Campbell's novel Islands of Space in 1930. Fictional conjecture on the warp drive has given way to serious scientific speculation following publication of Alcubierre's seminal warp drive paper in 1994. It is concluded that the realisation of warp drive might be achieved around the year 2180. A projected timetable for the realisation of warp drive through phases of conjecture , speculation , science , technology and application suggests that the warp drive proposal should enter the science phase around the year 2030.

  13. Parametric performance analysis of steam-injected gas turbine with a thermionic-energy-converter-lined combustor

    Science.gov (United States)

    Choo, Y. K.; Burns, R. K.

    1982-01-01

    The performance of steam-injected gas turbines having combustors lined with thermionic energy converters (STIG/TEC systems) was analyzed and compared with that of two baseline systems; a steam-injected gas turbine (without a TEC-lined combustor) and a conventional combined gas turbine/steam turbine cycle. Common gas turbine parameters were assumed for all of the systems. Two configurations of the STIG/TEC system were investigated. In both cases, steam produced in an exhaust-heat-recovery boiler cools the TEC collectors. It is then injected into the gas combustion stream and expanded through the gas turbine. The STIG/TEC system combines the advantage of gas turbine steam injection with the conversion of high-temperature combustion heat by TEC's. The addition of TEC's to the baseline steam-injected gas turbine improves both its efficiency and specific power. Depending on system configuration and design parameters, the STIG/TEC system can also achieve higher efficiency and specific power than the baseline combined cycle.

  14. Functioning efficiency of intermediate coolers of multistage steam-jet ejectors of steam turbines

    Science.gov (United States)

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

    2017-03-01

    Designs of various types of intermediate coolers of multistage ejectors are analyzed and thermal effectiveness and gas-dynamic resistance of coolers are estimated. Data on quantity of steam condensed from steam-air mixture in stage I of an ejector cooler was obtained on the basis of experimental results. It is established that the amount of steam condensed in the cooler constitutes 0.6-0.7 and is almost independent of operating steam pressure (and, consequently, of steam flow) and air amount in steam-air mixture. It is suggested to estimate the amount of condensed steam in a cooler of stage I based on comparison of computed and experimental characteristics of stage II. Computation taking this hypothesis for main types of mass produced multistage ejectors into account shows that 0.60-0.85 of steam amount should be condensed in stage I of the cooler. For ejectors with "pipe-in-pipe" type coolers (EPO-3-200) and helical coolers (EO-30), amount of condensed steam may reach 0.93-0.98. Estimation of gas-dynamic resistance of coolers shows that resistance from steam side in coolers with built-in and remote pipe bundle constitutes 100-300 Pa. Gas-dynamic resistance of "pipein- pipe" and helical type coolers is significantly higher (3-6 times) compared with pipe bundle. However, performance by "dry" (atmospheric) air is higher for ejectors with relatively high gas-dynamic resistance of coolers than those with low resistance at approximately equal operating flow values of ejectors.

  15. 低压蒸汽节能回收改造总结%Sum-Up of Renovation of Energy Saving and Recovery of Low-Pressure Steam

    Institute of Scientific and Technical Information of China (English)

    马飞跃; 陈隆

    2015-01-01

    Due to design flaws,there is an unbalanced byproduct low-pressure steam from waste heat boiler,and the surplus low-pressure steam has to vent directly.In order to reduce energy consumption and save production cost,the surplus low-pressure steam is used to drive steam turbine, and steam turbine drives circulating water pump,and the excess energy is used to generate electricity. The implementation of technological renovation measures,not only has recovered and utilized surplus low-pressure steam,but also has significant economic benefit.%由于设计上的缺陷,导致废热锅炉副产的低压蒸汽不平衡,富余的低压蒸汽只能直接放空。为了降低能耗、节约生产成本,采用富余的低压蒸汽作为汽轮机的动能,由汽轮机拖动循环水泵,多余的能量用于发电。改造措施实施后,不仅回收利用了富余的低压蒸汽,而且具有明显的经济效益。

  16. Solar steam supply: Initial operation of a plant

    OpenAIRE

    Krüger, Dirk; Lichtenthäler, Niels; Dersch, Jürgen; Schenk, Heiko; Hennecke, Klaus; Anthrakidis, Anette; Rusack, Markus; Lokurlu, Ahmet; Saidi, Karim; Walder, Marcus; Fischer, Stephan; Wirth, Hans Peter

    2011-01-01

    This paper describes experiences in operating a parabolic trough collector field for process heat supply by direct steam generation. The solar steam generator has been running automatically since its start in 2010 except for a winter pause up to now, August 2011, without any malfunction. It has supplied steam at 4 bar absolute and 143°C to the main production steam line on sunny days. Direct steam generation has proven to be a viable technology to supply saturated steam to an industrial st...

  17. A real explosion: the requirement of steam explosion pretreatment.

    Science.gov (United States)

    Yu, Zhengdao; Zhang, Bailiang; Yu, Fuqiang; Xu, Guizhuan; Song, Andong

    2012-10-01

    The severity factor is a common term used in steam explosion (SE) pretreatment that describes the combined effects of the temperature and duration of the pretreatment. However, it ignores the duration of the explosion process. This paper describes a new parameter, the explosion power density (EPD), which is independent of the severity factor. Furthermore, we present the adoption of a 5m(3) SE model for a catapult explosion mode, which completes the explosion within 0.0875 s. The explosion duration ratio of this model to a conventional model of the same volume is 1:123. The comparison between the two modes revealed a qualitative change by explosion speed, demonstrating that this real explosion satisfied the two requirements of consistency, and suggested a guiding mechanism for the design of SE devices.

  18. Steam vaporizers: A danger for paediatric burns.

    Science.gov (United States)

    Lonie, Sarah; Baker, Paul; Teixeira, Rodrigo

    2016-12-01

    Steam vaporizers are used to humidify air in dry environments. They are marketed to moisten children's airway secretions and thus to help relieve symptoms associated with upper respiratory tract infections. Unfortunately the steam emitted from the unit can also pose a significant risk of burns to children. Our study aimed to ascertain patterns of injury and treatment outcomes from steam burns resulting from these devices. Potential preventative measures are discussed. Children who had sustained vaporizer scald burns were identified at the outpatient burns clinic over a 10-month period (November 2014-August 2015). Medical records were reviewed retrospectively and data collected on pattern of injury, management and outcomes. Ten children were treated for vaporizer steam burns over the study period. The mean age was 1.6 years and 8 (80%) patients were male. Operative intervention was undergone in 5 (50%) cases; four acutely and one as a secondary reconstructive procedure. Hand burns accounted for 8 (80%) of cases. Steam vaporizers can cause significant burns in the paediatric population. Toddlers were most at risk, frequently sustaining hand burns that underwent skin grafting. Greater public awareness of the danger is indicated and measures to prevent such injuries should be addressed by appropriate authorities. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  19. HVOF coatings for steam oxidation protection

    Energy Technology Data Exchange (ETDEWEB)

    Agueero, A.; Muelas, R.; Gonzalez, V. [Instituto Nacional de Tecnica Aeroespacial (INTA), Area de Materiales Metalicos, Madrid (Spain)

    2008-05-15

    In the context of the European project 'Coatings for Supercritical Steam Cycles' (SUPERCOAT), the use of steam oxidation resistant coatings on currently available ferritic materials with high creep strength but poor oxidation resistance was investigated in order to allow increase in the operating temperature of steam power plants from 550 to 650 C. Among the explored coating techniques for this application, chosen on the basis of being potentially appropriate for coating steam turbine components, High Velocity Oxy Fuel (HVOF) thermal spray has resulted in one of the most successful techniques. Different alloyed materials such as FeCrAl, NiCrSiFeB, FeAl, NiCr and FeCr have been deposited, optimized and tested under flowing steam at 650 C. Characterization of as deposited and tested samples by metallography, SEM-EDS and XRD was carried out. Some of these coatings form protective pure chromium or aluminium oxides exhibiting excellent behaviour for at least 15 000 h of exposure, whereas others form less stable complex mixed oxides which nevertheless grow at considerably slower rates than the oxides formed on uncoated P92 (9 wt%Cr ferritic steel). (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  20. On Power Stream in Motor or Drive System

    Directory of Open Access Journals (Sweden)

    Paszota Zygmunt

    2016-12-01

    Full Text Available In a motor or a drive system the quantity of power increases in the direction opposite to the direction of power flow. Energy losses and energy efficiency of a motor or drive system must be presented as functions of physical quantities independent of losses. Such quantities are speed and load. But the picture of power stream in a motor or drive system is presented in the literature in the form of traditional Sankey diagram of power decrease in the direction of power flow. The paper refers to Matthew H. Sankey’s diagram in his paper „The Thermal Efficiency of Steam Engines“ of 1898. Presented is also a diagram of power increase in the direction opposite to the direction of power flow. The diagram, replacing the Sankey’s diagram, opens a new prospect for research into power of energy losses and efficiency of motors and drive systems.

  1. Adjustable control in the steam zone of a steam power plant; Control ajustable de la zona de vapor de una unidad termoelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Gallegos, Joaquin; Bourguet Diaz, Rafael Ernesto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    A general description is presented of self adjustable control systems, as well as of the design and its application for steam temperature regulation of a steam power plant unit model. The algorithm employed is a controller of minimum variance that ponders the output deviation as well as the control effort. The results are compared with the ones obtained in a conventional control scheme, showing in general a better performance in the conducted experiments. [Espanol] Se presenta una descripcion general de los sistemas de control autoajustable, asi como del diseno y su aplicacion para regular las temperaturas de vapor de un modelo de unidad termoelectrica. El algoritmo utilizado es un controlador de variancia minima que pondera tanto la desviacion de salida como el esfuerzo de control. Los resultados se comparan con los obtenidos en un esquema de control convencional, mostrando en general un mejor desempeno en los experimentos realizados.

  2. Three-phase drive for a DT3 motor-coach of the Hamburger Hochbahn AG

    Energy Technology Data Exchange (ETDEWEB)

    Gemmeke, K.; Mueller, E.; Runge, W.; Schulze, H.; Steimel, A.

    1980-01-01

    BBC equipped a three-car underground railway vehicle of the Hamburger Hochbahn AG with a static inverter and rugged three-phase squirrel-cage motors. Compared with conventional drive systems, the new drive concept features a high degree of reliability, energy savings and low maintenance costs. This article contains information on the drive equipment and proves its suitability for the drive system.

  3. Varieties of conventional implicature

    Directory of Open Access Journals (Sweden)

    Eric Scott McCready

    2010-07-01

    Full Text Available This paper provides a system capable of analyzing the combinatorics of a wide range of conventionally implicated and expressive constructions in natural language via an extension of Potts's (2005 L_CI logic for supplementary conventional implicatures. In particular, the system is capable of analyzing objects of mixed conventionally implicated/expressive and at-issue type, and objects with conventionally implicated or expressive meanings which provide the main content of their utterances. The logic is applied to a range of constructions and lexical items in several languages. doi:10.3765/sp.3.8 BibTeX info

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  5. Integrated vacuum absorption steam cycle gas separation

    Science.gov (United States)

    Chen, Shiaguo; Lu, Yonggi; Rostam-Abadi, Massoud

    2011-11-22

    Methods and systems for separating a targeted gas from a gas stream emitted from a power plant. The gas stream is brought into contact with an absorption solution to preferentially absorb the targeted gas to be separated from the gas stream so that an absorbed gas is present within the absorption solution. This provides a gas-rich solution, which is introduced into a stripper. Low pressure exhaust steam from a low pressure steam turbine of the power plant is injected into the stripper with the gas-rich solution. The absorbed gas from the gas-rich solution is stripped in the stripper using the injected low pressure steam to provide a gas stream containing the targeted gas. The stripper is at or near vacuum. Water vapor in a gas stream from the stripper is condensed in a condenser operating at a pressure lower than the stripper to concentrate the targeted gas. Condensed water is separated from the concentrated targeted gas.

  6. Market structure scenarios in international steam coal

    Energy Technology Data Exchange (ETDEWEB)

    Trueby, Johannes; Paulus, Moritz

    2011-04-15

    The seaborne steam coal market changed in recent years. Trade volumes grew dynamically, important players emerged and since 2007 prices increased significantly and remained relatively high since then. In this paper we analyse market equilibria in the years 2006 and 2008 by testing for two possible market structure scenarios in this market: perfect competition and an oligopoly setup with major exporters competing in quantities. We conclude from our results that international steam coal trade is not perfectly competitive as there is a large spread between marginal costs and prices and a low capacity utilisation in 2008. Further, trade flows are generally more diversified in reality than in the competitive scenario. However, also the Cournot scenarios fail to accurately explain real market outcomes. We conclude that only more sophisticated models of strategic behaviour can predict market equilibria in international steam coal trade. (orig.)

  7. Combined gas/steam turbine power plants with coal fired steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, H.J.; Weirich, P.H. [ABB Kraftwerke AG, Mannheim (Germany)

    1994-12-31

    The combination of coal fired steam power plants with natural gas fired gas turbines results in an essential efficiency increase, up to 50%, requiring a portion of around one third of the fuel heat input in form of natural gas. There are two basic types of circuit arrangements in this category: in a topping process the gas turbine is connected to the steam generator on the gas side, and in a compound cycle power plant gas turbine and steam circuit are connected to each other on the water/steam side via a heat recovery steam generator. If comparable design parameters are applied slightly higher plant efficiencies can be obtained with the topping process. With respect to a higher power plant availability it is possible to operate both types of circuit arrangement without gas turbine. The specific investment cost of such combined cycle power plants is lower than that of corresponding steam power plants. Hence, they can represent economical solutions as far as the price ratio between natural gas and coal is not extremely high. In ecological respects, the advantage of this combination is a reduction of the specific CO{sub 2} emission by around 20-25%, compared with pure steam power plants. 1 ref., 9 figs., 2 tabs.

  8. Mathematical modelling of methane steam reforming in a membrane reactor: an isothermal model

    Energy Technology Data Exchange (ETDEWEB)

    Assaf, E.M. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Dept. de Fisico-Quimica; Jesus, C.D.F.; Assaf, J.M. [Sao Carlos Univ., SP (Brazil). Dept. de Engenharia Quimica

    1998-06-01

    A mathematical modelling of one-dimensional, stationary and isothermic membrane reactor for methane steam reforming was developed to compare the maximum yield for methane conversion in this reactor with that in a conventional fixed-bed reactor. Fick`s first law was used to describe the mechanism of hydrogen permeation. The variables studied include: reaction temperature, hydrogen feed flow rate and membrane thickness. The results show that the membrane reactor presents a higher methane conversion yield than the conventional fixed-bed reactor. (author) 16 refs., 5 figs., 1 tab.; e-mail: eassaf at iqsc.sc.usp.br; mansur at power.ufscar.br

  9. MATHEMATICAL MODELLING OF METHANE STEAM REFORMING IN A MEMBRANE REACTOR: AN ISOTHERMIC MODEL

    Directory of Open Access Journals (Sweden)

    E.M. ASSAF

    1998-06-01

    Full Text Available A mathematical modelling of one-dimensional, stationary and isothermic membrane reactor for methane steam reforming was developed to compare the maximum yield for methane conversion in this reactor with that in a conventional fixed-bed reactor. Fick's first law was used to describe the mechanism of hydrogen permeation. The variables studied include: reaction temperature, hydrogen feed flow rate and membrane thickness. The results show that the membrane reactor presents a higher methane conversion yield than the conventional fixed-bed reactor.

  10. 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.

  11. Sintering of nickel steam reforming catalysts

    DEFF Research Database (Denmark)

    Sehested, Jens; Larsen, Niels Wessel; Falsig, Hanne;

    2014-01-01

    . In this paper, particle migration and coalescence in nickel steam reforming catalysts is studied. Density functional theory calculations indicate that Ni-OH dominate nickel transport at nickel surfaces in the presence of steam and hydrogen as Ni-OH has the lowest combined energies of formation and diffusion...... compared to other potential nickel transport species. The relation between experimental catalyst sintering data and the effective mass diffusion constant for Ni-OH is established by numerical modelling of the particle migration and coalescence process. Using this relation, the effective mass diffusion...

  12. Steam generator tubesheet waterlancing at Bruce B

    Energy Technology Data Exchange (ETDEWEB)

    Persad, R. [Babcock and Wilcox Canada, Cambridge, Ontario (Canada); Eybergen, D. [Bruce Power, Tiverton, Ontario (Canada)

    2006-07-01

    High pressure water cleaning of steam generator secondary side tubesheet surfaces is an important and effective strategy for reducing or eliminating under-deposit chemical attack of the tubing. At the Bruce B station, reaching the interior of the tube bundle with a high-pressure water lance is particularly challenging due to the requirement to setup on-boiler equipment within the containment bellows. This paper presents how these and other design constraints were solved with new equipment. Also discussed is the application of new high-resolution inter-tube video probe capability to the Bruce B steam generator tubesheets. (author)

  13. Experimental investigation of the steam wetness in a 1000 MW steam turbine

    OpenAIRE

    Kolovratník Michal; Bartoš Ondřej

    2016-01-01

    The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement ...

  14. Driving After a Stroke

    Science.gov (United States)

    ... Inspirational Stories Stroke Heroes Among Us Driving After Stroke Updated:Jul 23,2015 Can I drive after ... more tips for daily living . Let's Talk About Stroke Fact Sheets Our stroke fact sheets cover treatments, ...

  15. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading.......Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading....

  16. Dementia and driving

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia , deciding when they can no longer drive may ...

  17. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  18. Optimum sizing of steam turbines for concentrated solar power plants

    OpenAIRE

    Andreas Poullikkas, Constantinos Rouvas, Ioannis Hadjipaschalis, George Kourtis

    2012-01-01

    In this work, a selection of the optimum steam turbine type and size for integration in concentrated solar power (CSP) plants is carried out. In particular, the optimum steam turbine input and output interfaces for a range of CSP plant capacity sizes are identified. Also, efficiency and electricity unit cost curves for various steam turbine capacities are estimated by using a combination of the Steam Pro software module of the Thermoflow Suite 18 package and the IPP v2.1 optimization software...

  19. Research progress of the Superheated Steam Drying Technology

    OpenAIRE

    Shi, Yongchun; Li, Jie; Li, Xuanyou; Zhao, Gaiju; Wu, Maogang

    2012-01-01

    The superheated steam drying technology has lots of advantages such as safe, energy-saving, pollution-free and so on, so it causes more and more extensive concern. The superheated steam drying technology is introduced and its merits and faults are analyzed. The theoretical research progress of the superheated steam drying is summarized and the recent application of the materials including the food, wood, paper, sludge and lignite is stated. In brief, the superheated steam drying technol...

  20. Fixation of compressive deformation in wood by pre-steaming

    Science.gov (United States)

    M. Inoue; N. Sekino; T. Morooka; R.M. Rowell; M. Norimoto

    2008-01-01

    Wood block specimens pre-steamed at 120-220 °C for 5-20 min were compressed in the radial direction. The recovery of set decreased with increasing pre-steaming temperature and time. The reduction of set recovery correlated with the amount of weight loss in steaming irrespective of pre-steaming temperature and time. The weight loss for the highest level of...

  1. At A Glance: Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    2016-07-01

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. With the range of styles and options available, there is likely one to meet your needs. The vehicles can be divided into three categories: 1) Hybrid electric vehicles (HEVs), 2) Plug-in hybrid electric vehicles (PHEVs), and 3) All-electric vehicles (EVs).

  2. At A Glance: Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-07-13

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. With the range of styles and options available, there is likely one to meet your needs. The vehicles can be divided into three categories: 1) Hybrid electric vehicles (HEVs), 2) Plug-in hybrid electric vehicles (PHEVs), and 3) All-electric vehicles (EVs).

  3. 46 CFR 61.15-5 - Steam piping.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a.... If the covering of the piping is not removed, the test pressure shall be maintained on the piping...

  4. Recent trends in repair and refurbishing of steam turbine components

    Indian Academy of Sciences (India)

    A K Bhaduri; S K Albert; S K Ray; P Rodriguez

    2003-06-01

    The repair and refurbishing of steam generator components is discussed from the perspective of repair welding philosophy including applicable codes and regulations. Some case histories of repair welding of steam generator components are discussed with special emphasis on details of repair welding of cracked steam turbine blades and shrouds in some of the commercial nuclear power plants using procedures developed.

  5. Improving Steam System Performance: A Sourcebook for Industry, Second Edition

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-02-23

    This sourcebook is designed to provide steam system users with a reference that describes the basic steam system components, outlines opportunities for energy and performance improvements, and discusses the benefits of a systems approach in identifying and implementing these improvement opportunities. The sourcebook is divided into three main sections: steam system basics, performance improvement opportunities, and where to find help.

  6. 46 CFR 50.05-20 - Steam-propelled motorboats.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steam-propelled motorboats. 50.05-20 Section 50.05-20... Application § 50.05-20 Steam-propelled motorboats. (a) The requirements covering design of the propelling... than 40 feet in length and which are propelled by machinery driven by steam shall be in accordance...

  7. Partially Turboelectric Aircraft Drive Key Performance Parameters

    Science.gov (United States)

    Jansen, Ralph H.; Duffy, Kirsten P.; Brown, Gerald V.

    2017-01-01

    The purpose of this paper is to propose electric drive specific power, electric drive efficiency, and electrical propulsion fraction as the key performance parameters for a partially turboelectric aircraft power system and to investigate their impact on the overall aircraft performance. Breguet range equations for a base conventional turbofan aircraft and a partially turboelectric aircraft are found. The benefits and costs that may result from the partially turboelectric system are enumerated. A break even analysis is conducted to find the minimum allowable electric drive specific power and efficiency, for a given electrical propulsion fraction, that can preserve the range, fuel weight, operating empty weight, and payload weight of the conventional aircraft. Current and future power system performance is compared to the required performance to determine the potential benefit.

  8. Steam Pyrolysis of Polyimides: Effects of Steam on Raw Material Recovery.

    Science.gov (United States)

    Kumagai, Shogo; Hosaka, Tomoyuki; Kameda, Tomohito; Yoshioka, Toshiaki

    2015-11-17

    Aromatic polyimides (PIs) have excellent thermal stability, which makes them difficult to recycle, and an effective way to recycle PIs has not yet been established. In this work, steam pyrolysis of the aromatic PI Kapton was performed to investigate the recovery of useful raw materials. Steam pyrolysis significantly enhanced the gasification of Kapton at 900 °C, resulting in 1963.1 mL g(-1) of a H2 and CO rich gas. Simultaneously, highly porous activated carbon with a high BET surface area was recovered. Steam pyrolysis increased the presence of polar functional groups on the carbon surface. Thus, it was concluded that steam pyrolysis shows great promise as a recycling technique for the recovery of useful synthetic gases and activated carbon from PIs without the need for catalysts and organic solvents.

  9. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  10. Investigation of beryllium/steam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chekhonadskikh, A.M.; Vurim, A.D.; Vasilyev, Yu.S.; Pivovarov, O.S. [Inst. of Atomic Energy National Nuclear Center of the Republic of Kazakstan Semipalatinsk (Kazakhstan); Shestakov, V.P.; Tazhibayeva, I.L.

    1998-01-01

    In this report program on investigations of beryllium emissivity and transient processes on overheated beryllium surface attacked by water steam to be carried out in IAE NNC RK within Task S81 TT 2096-07-16 FR. The experimental facility design is elaborated in this Report. (author)

  11. The Geometry of Conventionality

    CERN Document Server

    Weatherall, James Owen

    2013-01-01

    Hans Reichenbach famously argued that the geometry of spacetime is conventional in relativity theory, in the sense that one can freely choose the spacetime metric so long as one is willing to postulate a "universal force field". Here we make precise a sense in which the field Reichenbach defines fails to be a "force". We then argue that there is an interesting and perhaps tenable sense in which geometry is conventional in classical spacetimes. We conclude with a no-go result showing that the variety of conventionalism available in classical spacetimes does not extend to relativistic spacetimes.

  12. Conventional Spinal Anaesthesia

    African Journals Online (AJOL)

    patients scheduled for clcctive unilateral lower limb surgery. ... the conventional group were turned supine immediately after injection. Blood pressure, heart rate, respiratory rate and oxygen .... Characteristic Type of spinal anaesthcsia P-value.

  13. A study of steam injection in fractured media

    Energy Technology Data Exchange (ETDEWEB)

    Dindoruk, M.D.S.; Aziz, K.; Brigham, W.; Castanier, L.

    1996-02-01

    Steam injection is the most widely used thermal recovery technique for unfractured reservoirs containing heavy oil. There have been numerous studies on theoretical and experimental aspects of steam injection for such systems. Fractured reservoirs contain a large fraction of the world supply of oil, and field tests indicate that steam injection is feasible for such reservoirs. Unfortunately there has been little laboratory work done on steam injection in such systems. The experimental system in this work was designed to understand the mechanisms involved in the transfer of fluids and heat between matrix rocks and fractures under steam injection.

  14. Study on mathematical model of steam coal blending

    Institute of Scientific and Technical Information of China (English)

    高洪阁; 李白英; 刘泽常; 尹增德

    2002-01-01

    It is necessary to set up a new mathematical model of steam coal blending instead of the old model. Indexes such as moisture content, ash content, volatile matter, sulfur content and heating value in the new mathematical model have linear relation. The new mathematical model can also predict ash-fusion temperature precisely by considering coal ash ratio in steam coal blending, therefore it is possible to obtain linear relation of ash-fusion temperature between single coal and steam coal blending. The new mathematical model can improve precision of steam coal blending and perfect the old mathematical model of steam coal blending.

  15. Westinghouse Small Modular Reactor nuclear steam supply system design

    Energy Technology Data Exchange (ETDEWEB)

    Memmott, M. J.; Harkness, A. W.; Van Wyk, J. [Westinghouse Electric Company LLC, 600 Cranberry Woods Drive, Cranberry Twp. PA 16066 (United States)

    2012-07-01

    The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the first in a series of four papers which describe the design and functionality of the Westinghouse SMR. Also described in this series are the key drivers influencing the design of the Westinghouse SMR and the unique passive safety features of the Westinghouse SMR. Several critical motivators contributed to the development and integration of the Westinghouse SMR design. These design driving motivators dictated the final configuration of the Westinghouse SMR to varying degrees, depending on the specific features under consideration. These design drivers include safety, economics, AP1000{sup R} reactor expertise and experience, research and development requirements, functionality of systems and components, size of the systems and vessels, simplicity of design, and licensing requirements. The Westinghouse SMR NSSS consists of an integral reactor vessel within a compact containment vessel. The core is located in the bottom of the reactor vessel and is composed of 89 modified Westinghouse 17x17 Robust Fuel Assemblies (RFA). These modified fuel assemblies have an active core length of only 2.4 m (8 ft) long, and the entirety of the core is encompassed by a radial reflector. The Westinghouse SMR core operates on a 24 month fuel cycle. The reactor vessel is approximately 24.4 m (80 ft) long and 3.7 m (12 ft) in diameter in order to facilitate standard rail shipping to the site. The reactor vessel houses hot and cold leg channels to facilitate coolant flow, control rod drive mechanisms (CRDM), instrumentation and cabling, an intermediate flange to separate flow and instrumentation and facilitate simpler refueling, a pressurizer, a straight tube, recirculating steam

  16. 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.

  17. 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.

  18. XPS and IGC characterization of steam treated triticale straw

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Liyan, E-mail: Liyan.zhao@albertainnovates.ca [Cellulose and Hemicellulose Program, Forest Products, Alberta Innovates-Technology Futures, 250 Karl Clark Road, Edmonton, AB T6N 1E4 (Canada); Boluk, Yaman [Cellulose and Hemicellulose Program, Forest Products, Alberta Innovates-Technology Futures, 250 Karl Clark Road, Edmonton, AB T6N 1E4 (Canada)

    2010-10-15

    The surface chemical composition and surface energy of native and steam treated triticale straws have been investigated by X-ray photoelectron spectroscopy (XPS) and inverse gas chromatography (IGC) to reveal the effect of steam treatment temperature and time. The XPS results show that the contents of C elements and C-C group on the exterior surface of native triticale straw are much higher than those on the interior surface, indicating that there was a high quantity of wax on the exterior surface of the native triticale straw. Upon steam treatment, both carbon levels and C-C groups reduce with increasing steam temperature and treatment time of the exterior surfaces. However, the effect of steam treatment on the interior surface is very limited. In terms of the surface acid and base properties, the steam treated samples exhibited higher acid and base properties than the native sample, indicating a more polar surface of the steam treated sample.

  19. XPS and IGC characterization of steam treated triticale straw

    Science.gov (United States)

    Zhao, Liyan; Boluk, Yaman

    2010-10-01

    The surface chemical composition and surface energy of native and steam treated triticale straws have been investigated by X-ray photoelectron spectroscopy (XPS) and inverse gas chromatography (IGC) to reveal the effect of steam treatment temperature and time. The XPS results show that the contents of C elements and C-C group on the exterior surface of native triticale straw are much higher than those on the interior surface, indicating that there was a high quantity of wax on the exterior surface of the native triticale straw. Upon steam treatment, both carbon levels and C-C groups reduce with increasing steam temperature and treatment time of the exterior surfaces. However, the effect of steam treatment on the interior surface is very limited. In terms of the surface acid and base properties, the steam treated samples exhibited higher acid and base properties than the native sample, indicating a more polar surface of the steam treated sample.

  20. Corrosion Evaluation and Corrosion Control of Steam Generators

    Energy Technology Data Exchange (ETDEWEB)

    Maeng, W. Y.; Kim, U. C.; Sung, K. W.; Na, J. W.; Lee, Y. H.; Lee, D. H.; Kim, K. M

    2008-06-15

    Corrosion damage significantly influences the integrity and efficiency of steam generator. Corrosion problems of steam generator are unsolved issues until now even though much effort is made around world. Especially the stress corrosion cracking of heat exchange materials is the first issue to be solved. The corrosion protection method of steam generator is important and urgent for the guarantee of nuclear plant's integrity. The objectives of this study are 1) to evaluate the corrosion properties of steam generator materials, 2) to optimize the water chemistry of steam generator and 3) to develop the corrosion protection method of primary and secondary sides of steam generator. The results will be reflected to the water chemistry guideline for improving the integrity and efficiency of steam generator in domestic power plants.

  1. System for Steam Leak Detection by using CCTV Camera

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Chul; Lee, Min Soo; Choi, Hui Ju [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Son, Ki Sung; Jeon, Hyeong Seop [SAEAN.Co., Seoul (Korea, Republic of)

    2012-05-15

    There are many pipes in the secondary cooling systems of nuclear power plants and coal-fired power plants. In these pipes, high pressure fluids are moving with at high velocity, which can cause steam leakage due to pipe thinning. Steam leakage is one of the major issues for the structural fracture of pipes. Therefore, a method to inspect a large area of piping systems quickly and accurately is needed. Steam leakage is almost invisible, because the flow has very high velocity and pressure. Therefore, it is very difficult to detect a steam leakage. In this paper, we proposed the method for detecting steam leakage using image signal processing. Our basic idea comes from a heat shimmer, which shines with a soft light that looks as if it is being shaken slightly. To test the performance of this technique, experiments have been performed for a steam generator. Results show that the proposed technique is quite powerful for steam leak detection

  2. Computerized operating cost model for industrial steam generation

    Energy Technology Data Exchange (ETDEWEB)

    Powers, T.D.

    1983-02-01

    Pending EPA regulations, establishing revised emission levels for industrial boilers are perceived to have an effect on the relative costs of steam production technologies. To aid in the comparison of competitive boiler technologies, the Steam Cost Code was developed which provides levelized steam costs reflecting the effects of a number of key steam cost parameters. The Steam Cost Code is a user interactive FORTRAN program designed to operate on a VAX computer system. The program requires the user to input a number of variables describing the design characteristics, capital costs, and operating conditions for a specific boiler system. Part of the input to the Steam Cost Code is the capital cost of the steam production system. The capital cost is obtained from a program called INDCEPT, developed by Oak Ridge National Laboratory under Department of Energy, Morgantown Energy Technology Center sponsorship.

  3. Experiences with industrial solar process steam generation in Jordan

    Science.gov (United States)

    Krüger, Dirk; Berger, Michael; Mokhtar, Marwan; Willwerth, Lisa; Zahler, Christian; Al-Najami, Mahmoud; Hennecke, Klaus

    2017-06-01

    At the Jordanian pharmaceuticals manufacturing company RAM Pharma a solar process heat supply has been constructed by Industrial Solar GmbH in March 2015 and operated since then (Figure 1). The collector field consists of 394 m² of linear Fresnel collectors supplying saturated steam to the steam network at RAM Pharma at about 6 bar gauge. In the frame of the SolSteam project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) the installation has been modified introducing an alternative way to separate water and steam by a cyclone. This paper describes the results of experiments with the cyclone and compares the operation with a steam drum. The steam production of the solar plant as well as the fuel demand of the steam boiler are continuously monitored and results are presented in this paper.

  4. Transmit-receive eddy current probes for defect detection and sizing in steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Obrutsky, L.S.; Cecco, V.S.; Sullivan, S.P. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    1997-02-01

    Inspection of steam generator tubes in aging Nuclear Generating Stations is increasingly important. Defect detection and sizing, especially in defect prone areas such as the tubesheet, support plates and U-bend regions, are required to assess the fitness-for-service of the steam generators. Information about defect morphology is required to address operational integrity issues, i.e., risk of tube rupture, number of tubes at risk, consequential leakage. A major challenge continues to be the detection and sizing of circumferential cracks. Utilities around the world have experienced this type of tube failure. Conventional in-service inspection, performed with eddy current bobbin probes, is ineffectual in detecting circumferential cracks in tubing. It has been demonstrated in CANDU steam generators, with deformation, magnetite and copper deposits that multi-channel probes with transmit-receive eddy current coils are superior to those using surface impedance coils. Transmit-receive probes have strong directional properties, permitting probe optimization according to crack orientation. They are less sensitive to lift-off noise and magnetite deposits and possess good discrimination to internal defects. A single pass C3 array transmit-receive probe developed by AECL can detect and size circumferential stress corrosion cracks as shallow as 40% through-wall. Since its first trial in 1992, it has been used routinely for steam generator in-service inspection of four CANDU plants, preventing unscheduled shutdowns due to leaking steam generator tubes. More recently, a need has surfaced for simultaneous detection of both circumferential and axial cracks. The C5 probe was designed to address this concern. It combines transmit-receive array probe technology for equal sensitivity to axial and circumferential cracks with a bobbin probe for historical reference. This paper will discuss the operating principles of transmit-receive probes, along with inspection results.

  5. Investigation of the steam-cooled blade in a steam turbine cascade

    Institute of Scientific and Technical Information of China (English)

    Dieter Bohn; Jing Ren; Karsten Kusterer

    2007-01-01

    With the increasing demand for electricity,an efficiency improvement and thereby reduced CO2 emissions of the coal-fired plants are expected in order to reach the goals set in the Kyoto protocol.It can be achieved by a rise of the process parameters.Currently,live steam pressures and temperatures up to 300 bars and 923 K are planned as the next step.Closed circuit steam cooling of blades and vanes in modern steam turbines is a promising technology in order to establish elevated live steam temperatures in future steam turbine cycles.In this paper,a steam-cooled test vane in a cascade with external hot steam flow is analyzed numerically with the in-house code CHTflow.A parametric analysis aiming to improve the cooling effectiveness is carried out by varying the cooling mass flow ratio.The results from two investigated cases show that the steam cooling technique has a good application potential in the steam turbine.The internal part of the vane is cooled homogeneously in both cases.With the increased cooling mass flow rate,there is a significant improvement of cooling efficiency at the leading edge.The results show that the increased cooling mass flow ratio can enhance the cooling effectiveness at the leading edge.With respect to trailing edge,there is no observable improvement of cooling effectiveness with the increased cooling mass flow.This implies that due to the limited dimension at the trailing edge,the thermal stress cannot be decreased by increasing the cooling mass flow rate.Therefore,impingement-cooling configuration at the trailing edge might be a solution to overcome the critical thermal stress there.It is also observed that the performance of the cooling effective differs on pressure side and suction side.It implicates that the equilibrium of the cooling effectiveness on two sides are influenced by a coupled relationship between cooling mass flow ratio and hole geometry.In future work,optimizing the hole geometry and cooling steam supply conditions might

  6. Bio-Fuel Production Assisted with High Temperature Steam Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Grant Hawkes; James O' Brien; Michael McKellar

    2012-06-01

    Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oil and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model

  7. Bio-Fuel Production Assisted with High Temperature Steam Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Grant Hawkes; James O' Brien; Michael McKellar

    2012-06-01

    Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oil and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model

  8. Thermoeconomic analysis of mixed gas-steam cycles

    Energy Technology Data Exchange (ETDEWEB)

    Traverso, A.; Massardo, A.F. [Universita di Genova (Italy). Dip. di Macchine, Sistemi Energetici e Trasporti

    2002-01-01

    In this paper the direct thermoeconomic analysis approach developed by the authors [ASME Paper 95-CTP-38; ASME Cogen Turbo Power Conference, Wien, 23/25 August, 1995] is applied to the assessment of the thermoeconomic performance of mixed gas-steam cycles such as the steam injected cycle (steam injected gas turbine, STIG), regenerated water injected (RWI) cycle, and humid air turbine (HAT) or evaporative cycle. All the simulations were carried using the thermo-economic modular program (TEMP) code developed at the University of Genoa [ASME Trans., J. Engng. Gas Turbine Power 119 (1997) 885; Thermo-economic and environmental optimisation of energy systems, Tesi di Dottorato, Universita di Genova (DIMSET),1997] and carefully tested here, mainly for the HAT cycle and saturator, using the experimental data provided by the HAT pilot-plant operating at the Lund University, Sweden [Theoretical and experimental evaluation of the EvGT-process, Thesis for Degree of Licentiate in Engineering, Lund Institute of Technology, Sweden, 1999; Evaporative cycles - in theory and in practice, Doctoral Thesis, Lund Institute of Technology, Sweden, 2000]. Three different mixed cycles (STIG, RWI, and HAT) are analysed in detail together with an additional fourth layout proposed by the authors [Thermodynamic analysis of STIG, RWI and HAT cycles with carbon dioxide (CO{sub 2}) emissions penalty, Tesi di laurea, Universita di Genova (DIMSET),2000], named HAWIT, humid air water injection turbine, that appears to be the most attractive solution. The thermoeconomic results of mixed cycles are presented here for the first time in open literature. These results are compared to the data of a conventional two-pressure level combined cycle considered as representative of the state of the art of high efficiency conversion systems. A new representation proposed by the authors [ASME Trans., J. Engng. Gas Turbine Power 122 (2000)] such as cost of electricity versus cycle efficiency or internal rate of

  9. EVALUATION OF STRUCTURAL AND VIBRATIONAL CHARACTERISTIC OF COMPOSITE DRIVE SHAFT FOR AUTOMOBILE USING FEM

    OpenAIRE

    2016-01-01

    In vehicle drive shaft is one of the most important component. It transmits torque from the engine to the differential gear of a rear wheel drive vehicle. Generally the drive shaft is made up of steel alloy but the use of conventional steel has disadvantages such as low specific stiffness and strength and high weight. Nowadays this steel drive shaft is replaced by composite material drive shaft. This advanced composite such as graphite, Kevlar, carbon, glass with suitable resin have advantage...

  10. Steam Methane Reforming System for Hydrogen Production: Advanced Exergetic Analysis

    Directory of Open Access Journals (Sweden)

    Tatiana Morosuk

    2012-02-01

    Full Text Available Steam methane reforming (SMR is one of the most promising processes for the production of hydrogen. Therefore, the overall thermodynamic efficiency of this process is of particular importance. The thermodynamic inefficiencies in a thermal system are related to exergy destruction and exergy loss. However, a conventional exergetic analysis cannot evaluate the mutual interdependencies among the system components nor the real potential for improving the energy conversion system being considered. One of the tools under development for the improvement of energy conversion systems from the thermodynamic viewpoint is the advanced exergetic analysis. In this paper, the avoidable part of the exergy destruction is estimated and the interactions among components of the overall system are evaluated in terms of endogenous and exogenous exergy destruction. The assumptions required for these calculations are discussed in detail, especially for those components that are typically used in chemical processes. Results of this paper suggest options for increasing the thermodynamic efficiency of hydrogen production by steam-methane reforming.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-08-01

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

  12. Optimum temperature policy for sorption enhanced steam methane reforming process for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Retnamma, Rajasree [National Laboratory of energy and Geology (LNEG), Lisbon (PT). Energy Systems Modeling and Optimization Unit (UMOSE); Ravi Kumar, V.; Kulkarni, B.D. [National Chemical Laboratory, Pune (India). Chemical Engineering and Process Development

    2010-07-01

    Sorption enhanced steam methane reforming (SE-SMR) process offers high potential for producing H{sub 2} in fuel cell applications compared to conventional catalytic steam methane reforming (SMR) process. The reactor temperature can significantly affect the performance of the SE-SMR reaction and simultaneous adsorption behavior of CO{sub 2}. Determination of an optimal temperature policy in SE-SMR reactor is therefore an important optimization issue. Multi-stage operation is a possible way to implement optimum temperature policies. In the present work, simulation study has been carried out for multi-stage operation using a mathematical model incorporating basic mechanisms operating in a fixed bed reactor with nonlinear reaction kinetic features of an SE-SMR process. Three cases were considered for implementing the multi-stage concept and the results show that increase in temperature based on a policy leads to considerable improvement in the process performance. (orig.)

  13. Ethanol production from industrial hemp: effect of combined dilute acid/steam pretreatment and economic aspects

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi; Svensson, Sven-Erik; Prade, Thomas;

    2014-01-01

    In the present study, combined steam (140-180 °C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis and etha......In the present study, combined steam (140-180 °C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis...... pretreated at the optimal conditions showed positive economic results. The type of hemp cultivation (organic or conventional) did not influence significantly the effectiveness of the pretreatment and subsequent enzymatic hydrolysis and ethanol fermentation....

  14. Dimensional stability of a polyvinylsiloxane impression material following ethylene oxide and steam autoclave sterilization.

    Science.gov (United States)

    Holtan, J R; Olin, P S; Rudney, J D

    1991-04-01

    Polyvinlsiloxane impressions were made from a stainless steel master die machined to stimulate five full veneer crown preparations symmetrically placed in an arch form. Three groups of 10 impressions each were made. Treatment groups were sterilized using an ethylene oxide gas and a conventional steam autoclave. Casts were poured and intrapreparation, height, and diameter measurements were made using a stereomicroscope, a digital electronic caliper, and a 1-inch travel dial indicator. Analysis of dimensional changes for the two groups showed that casts made from impressions sterilized by ethylene oxide are acceptable for use in the construction of fixed or removable prostheses. Casts made from impressions sterilized in a steam autoclave can be used for the fabrication of diagnostic casts and some transitional prostheses, but not for routine construction of crowns or fixed partial dentures.

  15. Open-Cycle Gas Turbine/Steam Turbine Combined Cycles with synthetic fuels from coal

    Science.gov (United States)

    Shah, R. P.; Corman, J. C.

    1977-01-01

    The Open-Cycle Gas Turbine/Steam Turbine Combined Cycle can be an effective energy conversion system for converting coal to electricity. The intermediate step in this energy conversion process is to convert the coal into a fuel acceptable to a gas turbine. This can be accomplished by producing a synthetic gas or liquid, and by removing, in the fuel conversion step, the elements in the fuel that would be harmful to the environment if combusted. In this paper, two open-cycle gas turbine combined systems are evaluated: one employing an integrated low-Btu gasifier, and one utilizing a semi-clean liquid fuel. A consistent technical/economic information base is developed for these two systems, and is compared with a reference steam plant burning coal directly in a conventional furnace.

  16. Response of flakeboard properties to changes in steam-injection-pressing environments. Forest Service research paper

    Energy Technology Data Exchange (ETDEWEB)

    Geimer, R.L.; Johnson, S.E.; Kamke, F.A.

    1992-01-01

    Mechanical strength properties and dimensional stability of composite wood products are determined to some extent by the environment within the mat during pressing. The objectives of the study were to define time-related temperature and vapor-pressure parameters occurring in a mat during different steam injection pressing (SIP) schedules and to relate these conditions to board properties. Acceptable boards, as measured by internal bond strength, were produced with the isocyanate resin at all steaming schedules. Press times could often be reduced to less than half of that needed to bond boards made with phenolic resins. Shear and thickness swelling properties followed the same trends measured for internal bond strength. However, bending properties of SIP boards were influenced by the reduced density gradient of the boards and were below the bending properties of boards pressed in a conventional manner.

  17. Lectures on magnetohydrodynamical drives

    Science.gov (United States)

    Loigom, Villem

    The paper deals with nonconventional types of electrical machines and drives - magnetohydrodynamical (MHD) machines and drives. In cardinal it is based on the research conducted with participation of the author in Tallinn Technical University at the Institute of Electrical Drives and Power Electronics, where the use of magnetohydrodynamical motors and drives in the metallurgical and casting industries have been studied for a long time. Major research interests include the qualities and applications of the induction MHD-drives for set in the motion (pumping, turning, dosing, mixing, etc.) non-ferrous molten metals like Al, Mg, Sn, Pb, Na, K, and their alloys. The first part of the paper describes induction MHD motors and their electrohydraulical qualities. In the second part energy conversion problems are described. Also, on the basis of the analogy between electromechanical and electrohydraulical phenomenas, static and dynamic qualities of MHD drives with induction MHD machines are discussed.

  18. The Analysis on Advantages of Superheated Steam Stimulation Technology in Thin Heavy Oil Reservoir%薄层稠油油藏过热蒸汽吞吐技术优势解析

    Institute of Scientific and Technical Information of China (English)

    崔连训; 庞占喜; 李媛媛; 路涛

    2012-01-01

    在过热蒸汽开发稠油油藏提高采收率机理分析基础上,利用数值模拟技术对1-3 m、3-5 m和5 m以上薄层稠油油藏实施过热蒸汽吞吐的开发效果进行了对比和分析.通过对比普通湿蒸汽、高温湿蒸汽和过热蒸汽的增油能力、节约蒸汽效果及油藏特征,分析了稠油油藏过热蒸汽吞吐的技术优势.研究结果表明,过热蒸汽吞吐的增油能力明显高于普通湿饱和蒸汽吞吐和高温湿蒸汽,但当过热度超过20℃后,增油幅度变缓;相同产油量时,过热蒸汽要比湿饱和蒸汽节约大量蒸汽.这是因为过热蒸汽携热量大,比容高,可以有效萃取稠油中的轻质组分,有效扩大波及体积,增加洗油效率.%Base on the mechanisms of superheated steam enhancing oil recovery in heavy oil reservoirs, numerical simulation was employed to analyze development effectiveness of superheated steam stimulation in thin heavy oil reservoirs with different net pay, such as 1-3 m, 3-5 m and over 5 m. By contrasting of incremental oil effect, steam-saving volume, reservoir features among conventional saturated steam, hot saturated steam and superheated steam, the technological advantages of superheated steam stimulation was analyzed to develop heavy oil reservoirs. The results show that incremental oil effect of superheated steam is much higher than conventional saturated steam and hot saturated steam, but it gradually increases slower when degree of superheat was over 20 ℃. When the same volume of heavy oil was produced by the three kinds of steams, superheated steam could save amount of steam. This is because that superheated steam has higher heat quantity and larger specific volume. Superheated steam can effectively extract light component in heavy oil, increase swept volume and enhance washing oil efficiency in heavy oil reservoirs.

  19. Practical achievements on biomass steam gasification in a rotary tubular coiled-downdraft reactor.

    Science.gov (United States)

    Andrew, Renny; Gokak, D T; Sharma, Pankaj; Gupta, Shalini

    2016-12-01

    Today, the impending stringent environmental norms and concerns about the depletion of fossil fuel reserves have added impetus on development of cutting edge technologies for production of alternative fuels from renewable sources, like biomass. The concept of biomass pyro-gasification offers a platform for production of (a) hydrogen, (b) hydrocarbons and (c) value added chemicals, etc. In this context, there exists potential for hydrogen production from biomass by superheated steam gasification. Apart from H2, gaseous products of biomass steam gasification contain CO, CH4 and other hydrocarbons that can be converted to hydrogen through cracking, steam reforming and water gas shift reactions. In the present work, the characteristics of biomass steam gasification in an indigenously designed rotary tubular coiled-downdraft reactor for high value gaseous fuel production from rice husk was studied through a series of experiments. The robust reactor system enhances biomass conversion to gaseous products by improved mass and heat transfer within the system induced by a coiled flow pattern with increased heat transfer area. Also, the system has improved upon the reliability of operation and offered greater continuity of the process and easier control in comparison with a conventional process by making use of an innovative gas cooler assembly and efficient venturi-mixing system for biomass and steam. Subsequently, the effects of reactor temperature, steam-to-biomass ratio and residence time on overall product gas yield and hydrogen yield were investigated. From the experimental results, it can be deduced that an optimum reactor temperature of 750 °C, steam-to-biomass ratio of 2.0 and a residence time of 3.0 min contributed highest gas yield (1.252 Nm(3) kg(-1) moisture-free biomass). Based on the obtained experimental results, a projected potential hydrogen yield of 8.6 wt% of the moisture-free biomass could be achieved, and is also practical for production of

  20. Impact of flow induced vibration acoustic loads on the design of the Laguna Verde Unit 2 steam dryer

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, D. R.; Wellstein, L. F.; Theuret, R. C.; Han, Y.; Rajakumar, C. [Westinghouse Electric Company LLC, Cranberry Township, PA 16066 (United States); Amador C, C.; Sosa F, W., E-mail: forsytdr@westinghouse.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Km 42.5 Carretera Cardel-Nautla, 91680 Alto Lucero, Veracruz (Mexico)

    2015-09-15

    Industry experience with Boiling Water Reactors (BWRs) has shown that increasing the steam flow through the main steam lines (MSLs) to implement an extended power up rate (EPU) may lead to amplified acoustic loads on the steam dryer, which may negatively affect the structural integrity of the component. The source of these acoustic loads has been found to be acoustic resonance of the side branches on the MSLs, specifically, coupling of the vortex shedding frequency and natural acoustic frequency of safety relief valves (SRVs). The resonance that results from this coupling can contribute significant acoustic energy into the MSL system, which may propagate upstream into the reactor pressure vessel steam dome and drive structural vibration of steam dryer components. This can lead to high-cycle fatigue issues. Lock-in between the vortex shedding frequency and SRV natural frequency, as well as the ability for acoustic energy to propagate into the MSL system, are a function of many things, including the plant operating conditions, geometry of the MSL/SRV junction, and placement of SRVs with respect to each other on the MSLs. Comision Federal de Electricidad and Westinghouse designed, fabricated, and installed acoustic side branches (ASBs) on the MSLs which effectively act in the system as an energy absorber, where the acoustic standing wave generated in the side-branch is absorbed and dissipated inside the ASB. These ASBs have been very successful in reducing the amount of acoustic energy which propagates into the steam dome. In addition, modifications to the Laguna Verde Nuclear Power Plant Unit 2 steam dryer have been completed to reduce the stress levels in critical locations in the dryer. The objective of this paper is to describe the acoustic side branch concept and the design iterative processes that were undertaken at Laguna Verde Unit 2 to achieve a steam dryer design that meets the guidelines of the American Society of Mechanical Engineers, Boiler and Pressure

  1. Combined steam and ultrasound treatment of broilers at slaughter: a promising intervention to significantly reduce numbers of naturally occurring campylobacters on carcasses.

    Science.gov (United States)

    Musavian, Hanieh S; Krebs, Niels H; Nonboe, Ulf; Corry, Janet E L; Purnell, Graham

    2014-04-17

    Steam or hot water decontamination treatment of broiler carcasses is hampered by process limitations due to prolonged treatment times and adverse changes to the epidermis. In this study, a combination of steam with ultrasound (SonoSteam®) was investigated on naturally contaminated broilers that were processed at conventional slaughter speeds of 8,500 birds per hour in a Danish broiler plant. Industrial-scale SonoSteam equipment was installed in the evisceration room, before the inside/outside carcass washer. The SonoSteam treatment was evaluated in two separate trials performed on two different dates. Numbers of naturally occurring Campylobacter spp. and TVC were determined from paired samples of skin excised from opposite sides of the breast of the same carcass, before and after treatments. Sampling was performed at two different points on the line: i) before and after the SonoSteam treatment and ii) before the SonoSteam treatment and after 80 min of air chilling. A total of 44 carcasses were examined in the two trials. Results from the first trial showed that the mean initial Campylobacter contamination level of 2.35 log₁₀ CFU was significantly reduced (n=12, psignificant reduction (n=11, psignificant reductions (n=10, pSignificant reductions (n=11, pnumbers analyzed before the SonoSteam treatment (2.02 log₁₀ CFU) and after the air chilling treatment (1.37 log₁₀ CFU). The effect of air chilling without SonoSteam treatment was determined using 12 carcasses pre- and postchill. Results showed insignificant reductions of 0.09 log₁₀ from a mean initial level of 2.19 log₁₀ CFU. Numbers of TVC before treatments ranged between 3.47 and 4.79 log₁₀ CFU. In all cases, TVC was significantly (psignificantly reduce numbers of Campylobacter on naturally contaminated broilers.

  2. Design of nonlinear adaptive steam valve controllers for a turbo-generator system

    Energy Technology Data Exchange (ETDEWEB)

    Bekiaris-Liberis, N.K.; Paraskevopoulos, P.N. [National Technical Univ. of Athens Zographou, Athens (Greece); Boglou, A.K. [Technology Education Inst. of Kavala Agios Loukas, Kavala (Greece); Arvanitis, K.G.; Pasgianos, G.D. [Agricultural Univ. of Athens, Athens (Greece)

    2008-07-01

    This paper reported on a study that investigated the control of power systems consisting of interconnected networks of transmission lines linking generators and loads. Improving both small and large perturbation stability and dynamic performance is important because power systems have become less stable in the past 15 years due to the use of controllers that have been designed on the basis of linearized synchronous generators and turbine models. The high nonlinear nature of power system models and the resulting disturbances render conventional linear controller design techniques obsolete for use in power systems control. Power system engineers are becoming aware of the role of turbine steam valves in improving the dynamic stability of power systems and damping low frequency oscillations. Advanced nonlinear control strategies are needed since the conventional steam valve control theory cannot guarantee transient stability in cases where operational conditions and parameters vary considerably. A design approach to a nonlinear adaptive control system with unknown parameters was developed and applied to the turbine main steam valve control of a power system. A fourth order machine model was used along with an adaptive backstepping method to construct the Lyapunov function in order to obtain a nonlinear adaptive controller to solve the turbine fast valving nonlinear control problem. The newly designed nonlinear adaptive controller can make the resulting adaptive system asymptotically stable. The proposed controller is accompanied by a dynamic estimator of parameters and includes nonlinear damping terms, which guarantee input-output stability even without the use of the adaptive law. Simulation results showed that the proposed nonlinear adaptive controller performs better than other turbine main steam valve control techniques. It can face large parametric uncertainty and results in a closed-loop system that is able to face large and smaller disturbances, providing a

  3. Universal Drive Train Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  4. 垂直管内音速蒸汽射流凝结汽羽形状研究%Investigation on the Steam Plume Shapes for Sonic Steam Jet Condensation in a Vertical Pipe Flow

    Institute of Scientific and Technical Information of China (English)

    徐强; 郭烈锦; 马科帅; 邹遂丰

    2012-01-01

    A series of experiments on sonic saturated steam injected into moving water in a vertical circular pipe were carried out. The inlet steam flow rate and the subcooled water temperature were in the range of 376-773 kg.m^-2-s^-1and 10-55℃, respectively. Four different steam plume shapes (contraction, expansion-contraction, double expansion-contraction, and unstable jet) were typically observed. The results indicated that the steam plume shapes were significantly influenced by the Reynolds number. The maximum expansion ratio and the steam plume length increased with the decrease of Reynolds number and the condensation driving potential, and the values were lower than that of sonic steam jet condensation in stagnant water. Empirical correlation for the dimensionless stemn plume length was established, and most of the measured data lay within the range of +10% and -8(%) of the correlation.%本文针对质量流量376-773kg^-2·s^-1的饱和蒸汽在温度变化范围为10-55℃流动水中形成的音速蒸汽射流凝结进行了实验研究。实验观察到了四种不同的汽羽形状,并且汽羽形状受Re影响较大。当Re与凝结驱动势减小时,最大膨胀比和汽羽喷射长度增大,其值小于蒸汽音速射流在静止水中的情况。本文给出了汽羽喷射长度实验关联式,大多数实验数据与预测值的误差小于10%。

  5. Steam generators, industrial power plants, and cogeneration plants. Lectures; Dampferzeuger, Industrie- und Heizkraftwerke 2010. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The proceedings of the meeting on steam generators, industrial power plants, and cogeneration plants include the following lectures: Assignments and scopes of the VGB working group ''industry and thermal power plants, BHKW''. Combustion power and process control - application of feed grate firing in industrial technology - experiences and perspectives. A new possibility of biomass co-combustion. Biomass co-combustion in Vattenfall Waerme AG. Biomass plant with optimized control. The new energy supply concept for the paper plant in Plattling. Efficient steam boiler facilities for industry and thermal power plants - case studies. Adaptation of flue gas purification for co-combustion with experiences of prototype plants. Modern risk and insurance management for power plants. Reliability oriented maintenance. Surrogate fuel IHKW Gersthofen - planning, construction and preliminary operational experiences. Assignments and scopes of the VGB working group ''steam generators''. New developments in process safety management of E.ON UK coal-fired power plants. Station-supply reduction by power drive reconstruction to frequency control - modern injection technology at high plant parameters. Self-optimizing control of fuel/air regulation. CO{sub 2} reduction by automatic power plant modeling. Virtual reality as QA tool in 3D planning. Thermodynamic studies in power plants using VDI 2048. Heating surface cleaning with explosion generators - an alternative to soot blowers. results of laboratory study on urgent material questions.

  6. Modelling the horizontal steam generator with APROS

    Energy Technology Data Exchange (ETDEWEB)

    Ylijoki, J. [VTT Energy, Espoo (Finland); Palsinajaervi, C.; Porkholm, K. [IVO International Ltd, Vantaa (Finland)

    1995-12-31

    In this paper the capability of the five- and six-equation models of the simulation code APROS to simulate the behaviour of the horizontal steam generator is discussed. Different nodalizations are used in the modelling and the results of the stationary state runs are compared. Exactly the same nodalizations have been created for the five- and six-equation models. The main simulation results studied in this paper are void fraction and mass flow distributions in the secondary side of the steam generator. It was found that quite a large number of simulation volumes is required to simulate the distributions with a reasonable accuracy. The simulation results of the different models are presented and their validity is discussed. (orig.). 4 refs.

  7. Thermodynamic properties of superheated and supercritical steam

    Energy Technology Data Exchange (ETDEWEB)

    Malhotra, A. [Indian Inst. of Technology, New Delhi (India). Dept. of Mechanical Engineering; Panda, D.M.R. [Dadri Gas Power Station, NTPC, Gautam Buddha Nagar (India)

    2001-07-01

    An existing formulation for steam properties is due to Irvine and Liley. Their equations are convenient to program and do not require excessive computational time to produce results. The properties computed from these equations compare favourably with standard data. An additional advantage of these equations is that they follow prescribed theoretical trends by reducing to perfect-gas behaviour away from the saturation dome. However, a difficulty with these equations is that, at pressures above 10 MPa and close to the saturation dome, unacceptably large errors (above 10%) are produced. These equations are examined in the present work with a view towards enhancing their range of application through the use of additional functions. It is shown that the errors may be reduced to within 1% over the entire range of pressures (both sub-critical and super-critical pressures) required in steam-plant calculations. (author)

  8. Steam Initiated Surface Modification of Aluminium Alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud

    -friendly alternative processes. In the present work high temperature steam-based process has been investigated as a possible chromate free conversion coating. Investigations in the thesis includes the effect of alloy type, substrate microstructure, surface finish, and various chemistries on the coating formation......, and interface structure of the coatings were analysed using SEM, FIB-SEM,TEM, GI-XRD, FTIR, XPS, AFM, contact angle, and boiling test. Chapter 1 of this thesis provides a background to the work and available literature information. Materials and experimental methods are outlined in chapter 2. The chapters 3...... using autoclave or using spray system, and with or without various chemistries as accelerators. In general, results show the formation of 650 nm – 3000 nm thick conversion coating, where the thickness depend on the treatment parameters and steam chemistry. Further, the formed coating provide good...

  9. Integration of torrefaction with steam power plant

    Energy Technology Data Exchange (ETDEWEB)

    Zakri, B.; Saari, J.; Sermyagina, E.; Vakkilainen, E.

    2013-09-01

    Torrefaction is one of the pretreatment technologies to enhance the fuel characteristics of biomass. The efficient and continuous operation of a torrefaction reactor, in the commercial scale, demands a secure biomass supply, in addition to adequate source of heat. Biorefinery plants or biomass-fuelled steam power plants have the potential to integrate with the torrefaction reactor to exchange heat and mass, using available infrastructure and energy sources. The technical feasibility of this integration is examined in this study. A new model for the torrefaction process is introduced and verified by the available experimental data. The torrefaction model is then integrated in different steam power plants to simulate possible mass and energy exchange between the reactor and the plants. The performance of the integrated plant is investigated for different configurations and the results are compared. (orig.)

  10. Continuous steam hydrolysis of tulip poplar

    Energy Technology Data Exchange (ETDEWEB)

    Fieber, C.; Colcord, A.R.; Faass, S.; Muzzy, J.D.; Roberts, R.S.

    1982-08-01

    To produce ethanol from hardwood it is desirable to fractionate the hardwood in order to produce a relatively pure cellulosic pulp for dilute acid hydrolysis. An experimental investigation of continuous steam hydrolysis of tulip poplar wood chips indicates that over 90% of the lignin present can be extracted by 0.1N sodium hydroxide, resulting in a cellulose pulp containing over 90% hexosan. The study was performed using a Stake Technology, Ltd., continuous digester rated at one oven dry ton per hour of wood chips. The yields of hexosans, hexoses, xylan, xylose, lignin, furfural, acetic acid and methanol were determined as a function of residence time and steam pressure in the digester. The information provides a basis for establishing a material and energy balance for a hardwood to ethanol plant.

  11. Solar steam generation by heat localization.

    Science.gov (United States)

    Ghasemi, Hadi; Ni, George; Marconnet, Amy Marie; Loomis, James; Yerci, Selcuk; Miljkovic, Nenad; Chen, Gang

    2014-01-01

    Currently, steam generation using solar energy is based on heating bulk liquid to high temperatures. This approach requires either costly high optical concentrations leading to heat loss by the hot bulk liquid and heated surfaces or vacuum. New solar receiver concepts such as porous volumetric receivers or nanofluids have been proposed to decrease these losses. Here we report development of an approach and corresponding material structure for solar steam generation while maintaining low optical concentration and keeping the bulk liquid at low temperature with no vacuum. We achieve solar thermal efficiency up to 85% at only 10 kW m(-2). This high performance results from four structure characteristics: absorbing in the solar spectrum, thermally insulating, hydrophilic and interconnected pores. The structure concentrates thermal energy and fluid flow where needed for phase change and minimizes dissipated energy. This new structure provides a novel approach to harvesting solar energy for a broad range of phase-change applications.

  12. Enhancement of enzymatic saccharification of Eucalyptus globulus: steam explosion versus steam treatment.

    Science.gov (United States)

    Martin-Sampedro, Raquel; Revilla, Esteban; Villar, Juan C; Eugenio, Maria E

    2014-09-01

    Steam explosion and steam pre-treatment have proved capable of enhancing enzymatic saccharification of lignocellulosic materials. However, until now, these methods had not been compared under the same operational conditions and using the same raw material. Both pre-treatments lead to increased yields in the saccharification of Eucalyptus globulus; but results have been better with steam pre-treatments, despite the more accessible surface of exploded samples. The reason for this finding could be enzymatic inhibition: steam explosion causes a more extensive extraction of hemicelluloses and releases a greater amount of degradation products which can inhibit enzymatic action. Enzymatic inhibition is also dependent on the amount and chemical structure of lignin, which was also a contributing factor to the lower enzymatic yields obtained with the most severe pre-treatment. Thus, the highest yields (46.7% glucose and 73.4% xylose yields) were obtained after two cycle of steam treatment, of 5 and 3 min, at 183°C.

  13. A Numerical Study on the Supersonic Steam Ejector Use in Steam Turbine System

    Directory of Open Access Journals (Sweden)

    Lin Cai

    2013-01-01

    Full Text Available Supersonic steam ejector is widely used in steam energy systems such as refrigeration, wood drying equipment, papermaking machine, and steam turbine. In this paper the Computational Fluids Dynamics (CFD method was employed to simulate a supersonic steam ejector, SST k-w turbulence model was adopted, and both real gas model and ideal gas model for fluid property were considered and compared. The mixing chamber angle, throat length, and nozzle exit position (NXP primary pressure and temperature effects on entrainment ratio were investigated. The results show that performance of the ejector is underestimated using ideal gas model, and the entrainment ratio is 20%–40% lower than that when using real gas model. There is an optimum mixing chamber angel and NXP makes the entrainment ratio achieve its maximum; as throat length is decreased within a range, the entrainment ratio remains unchanged. Primary fluid pressure has a critical value, and the entrainment ratio reaches its peak at working critical pressure; when working steam superheat degree increases, the entrainment ratio is increased.

  14. TRIO specification of a steam boiler controller

    Energy Technology Data Exchange (ETDEWEB)

    Gargantini, A. [Politecnico di Milano (Italy). Dipt. di Electronica e Informazione; Morzenti, A. [Politecnico di Milano (Italy). Dipt. di Electronica e Informazione

    1996-12-31

    We specify a controller for a steam boiler starting from an informal descriptions of its requirements. The specification is formalized in the temporal logic TRIO and its object-oriented extension TRIO+. To obtain a maximum of abstraction and reuse we make the specification parametric with respect to all equipment and hardware features, and we avoid to impose any particular strategy in the management of the available resources and in the control of the critical physical quantities. (orig.)

  15. Materials Performance in USC Steam Portland

    Energy Technology Data Exchange (ETDEWEB)

    G.R. Holcomb; J. Tylczak; R. Hu

    2011-04-26

    Goals of the U.S. Department of Energy's Advanced Power Systems Initiatives include power generation from coal at 60% efficiency, which requires steam conditions of up to 760 C and 340 atm, co-called advanced ultrasupercritical (A-USC) steam conditions. A limitation to achieving the goal is a lack of cost-effective metallic materials that can perform at these temperatures and pressures. Some of the more important performance limitations are high-temperature creep strength, fire-side corrosion resistance, and steam-side oxidation resistance. Nickel-base superalloys are expected to be the materials best suited for steam boiler and turbine applications above about 675 C. Specific alloys of interest include Haynes 230 and 282, Inconel 617, 625 and 740, and Nimonic 263. Further validation of a previously developed chromia evaporation model is shown by examining the reactive evaporation effects resulting from exposure of Haynes 230 and Haynes 282 to moist air environments as a function of flow rate and water content. These two alloys differ in Ti and Mn contents, which may form outer layers of TiO{sub 2} or Cr-Mn spinels. This would in theory decrease the evaporation of Cr{sub 2}O{sub 3} from the scale by decreasing the activity of chromia at the scale surface, and be somewhat self-correcting as chromia evaporation concentrates the Ti and Mn phases. The apparent approximate chromia activity was found for each condition and alloy that showed chromia evaporation kinetics. As expected, it was found that increasing the gas flow rate led to increased chromia evaporation and decreased chromia activity. However, increasing the water content in moist air increased the evaporation, but results were mixed with its effect on chromia activity.

  16. Heat treatment of scallop adductor muscle using superheated steam.

    Science.gov (United States)

    Abe, T; Miyashita, K

    2007-08-01

    Scallop (Patinopecten yessoensis) adductor muscles were heated using superheated steam (150 and 200 degrees C), boiling (98 degrees C), and normal steaming (95 degrees C). The amounts of amino acids, water-soluble peptides, and nucleotides, expressed as extractive nitrogen in scallop products, are very important elements of quality and taste. After 15-min heating of scallop muscles with normal steaming and boiling, respective losses of 50% and 64% of the extractive nitrogen were observed. However, most extractive nitrogen (> 86%) remained in the scallop muscles treated with superheated steam at 150 and 200 degrees C. Protective effects of superheated steam against elution loss of nitrogen compounds were also observed in amino acid analyses of the heated products. The scallop-muscle surface temperature during treatment with superheated steam increased more quickly than that with normal steaming and boiling. The rapid water loss and the surface protein denaturation engendered formation of a 30-mum-thick film covering the surface, which prevented extractive nitrogen loss from internal tissues. Superheated steam treatment at 200 degrees C caused browning, surface shrinkage, and 47% weight loss. In marked contrast, the appearance and the weight loss of sample treated at 150 degrees C were almost the same as those of normal steaming and boiling-treated samples. These results suggested that superheated steaming at 150 degrees C is an optimal heat treatment of scallop adductor muscles.

  17. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  18. Reliability design method for steam turbine blades

    Institute of Scientific and Technical Information of China (English)

    Jinyuan SHI

    2008-01-01

    Based on theories of probability and statistics, and taking static stresses, dynamic stresses, endurance strength, safety ratios, vibration frequencies and exciting force frequencies of blades as random variables, a reliabil-ity design method for steam turbine blades is presented. The purport and calculation method for blade reliability are expounded. The distribution parameters of random variables are determined after analysis and numerical cal-culation of test data. The fatigue strength and the vibra-tion design reliability of turbine blades are determined with the aid of a probabilistic design method and by inter-ference models for stress distribution and strength distri-bution. Some blade reliability design calculation formulas for a dynamic stress design method, a safety ratio design method for fatigue strength, and a vibration reliability design method for the first and second types of tuned blades and a packet of blades on a disk connected closely, are given together with some practical examples. With these methods, the design reliability of steam turbine blades can be guaranteed in the design stage. This research may provide some scientific basis for reliability design of steam turbine blades.

  19. Data analysis for steam generator tubing samples

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, C.V.

    1996-07-01

    The objective of the Improved Eddy-Current ISI for Steam Generators program is to upgrade and validate eddy-current inspections, including probes, instrumentation, and data processing techniques for inservice inspection of new, used, and repaired steam generator tubes; to improve defect detection, classification and characterization as affected by diameter and thickness variations, denting, probe wobble, tube sheet, tube supports, copper and sludge deposits, even when defect types and other variables occur in combination; to transfer this advanced technology to NRC`s mobile NDE laboratory and staff. This report provides a description of the application of advanced eddy-current neural network analysis methods for the detection and evaluation of common steam generator tubing flaws including axial and circumferential outer-diameter stress-corrosion cracking and intergranular attack. The report describes the training of the neural networks on tubing samples with known defects and the subsequent evaluation results for unknown samples. Evaluations were done in the presence of artifacts. Computer programs are given in the appendix.

  20. Rotor thermal stress monitoring in steam turbines

    Science.gov (United States)

    Antonín, Bouberle; Jan, Jakl; Jindřich, Liška

    2015-11-01

    One of the issues of steam turbines diagnostics is monitoring of rotor thermal stress that arises from nonuniform temperature field. The effort of steam turbine operator is to operate steam turbine in such conditions, that rotor thermal stress doesn't exceed the specified limits. If rotor thermal stress limits are exceeded for a long time during machine operation, the rotor fatigue life is shortened and this may lead to unexpected machine failure. Thermal stress plays important role during turbine cold startup, when occur the most significant differences of temperatures through rotor cross section. The temperature field can't be measured directly in the entire rotor cross section and standardly the temperature is measured by thermocouple mounted in stator part. From this reason method for numerical solution of partial differential equation of heat propagation through rotor cross section must be combined with method for calculation of temperature on rotor surface. In the first part of this article, the application of finite volume method for calculation of rotor thermal stress is described. The second part of article deals with optimal trend generation of thermal flux, that could be used for optimal machine loading.

  1. Catalytic glycerol steam reforming for hydrogen production

    Science.gov (United States)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-12-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H2. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al2O3. The catalyst was prepared by wet impregnation method and characterized through different methods: N2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H2, CH4, CO, CO2. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H2O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  2. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Monica, E-mail: monica.dan@itim-cj.ro; Mihet, Maria, E-mail: maria.mihet@itim-cj.ro; Lazar, Mihaela D., E-mail: diana.lazar@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj Napoca (Romania)

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  3. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  4. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  5. Electric vehicles: Driving range

    Science.gov (United States)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  6. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  7. Drive Around the World

    Institute of Scientific and Technical Information of China (English)

    Yang Wei

    2008-01-01

    @@ "It's so cool that I can drive on my own,and my own car,"Cao Gang,WOrking for a private company in Changsha,capital city of Hunan Province,mid-south China,said in excitement when he newly bought Ben Ben,a Chinese local auto brand of Chang'an,with his freshly-passed driving license.

  8. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  9. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  10. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't

  11. Novel metallic alloys as phase change materials for heat storage in direct steam generation applications

    Science.gov (United States)

    Nieto-Maestre, J.; Iparraguirre-Torres, I.; Velasco, Z. Amondarain; Kaltzakorta, I.; Zubieta, M. Merchan

    2016-05-01

    Concentrating Solar Power (CSP) is one of the key electricity production renewable energy technologies with a clear distinguishing advantage: the possibility to store the heat generated during the sunny periods, turning it into a dispatchable technology. Current CSP Plants use an intermediate Heat Transfer Fluid (HTF), thermal oil or inorganic salt, to transfer heat from the Solar Field (SF) either to the heat exchanger (HX) unit to produce high pressure steam that can be leaded to a turbine for electricity production, or to the Thermal Energy Storage (TES) system. In recent years, a novel CSP technology is attracting great interest: Direct Steam Generation (DSG). The direct use of water/steam as HTF would lead to lower investment costs for CSP Plants by the suppression of the HX unit. Moreover, water is more environmentally friendly than thermal oils or salts, not flammable and compatible with container materials (pipes, tanks). However, this technology also has some important challenges, being one of the major the need for optimized TES systems. In DSG, from the exergy point of view, optimized TES systems based on two sensible heat TES systems (for preheating of water and superheating vapour) and a latent heat TES system for the evaporation of water (around the 70% of energy) is the preferred solution. This concept has been extensively tested [1, 2, 3] using mainly NaNO3 as latent heat storage medium. Its interesting melting temperature (Tm) of 306°C, considering a driving temperature difference of 10°C, means TES charging steam conditions of 107 bar at 316°C and discharging conditions of 81bar at 296°C. The average value for the heat of fusion (ΔHf) of NaNO3 from literature data is 178 J/g [4]. The main disadvantage of inorganic salts is their very low thermal conductivity (0.5 W/m.K) requiring sophisticated heat exchanging designs. The use of high thermal conductivity eutectic metal alloys has been recently proposed [5, 6, 7] as a feasible alternative. Tms

  12. Thermodynamic wetness loss calculation in a steam turbine rotor tip section: nucleating steam flow

    Science.gov (United States)

    Joseph, Joby; Sathyanarayanan, S.; K, Vigney; Prasad, B. V. S. SS; Biswas, D.; Jimbo, T.

    2016-09-01

    Rapid expansion of steam in the last stages of a steam turbine causes condensation. The formation of liquid droplets due to condensation results in wetness losses, which include aerodynamic losses (due to friction between liquid droplets and the vapour), thermodynamic losses (due to irreversible heat addition), and braking losses (due to the impact of liquid droplets on the blade). The thermodynamic loss contributes up to 80% to the wetness losses when the diameter of the droplets formed is less than 1 μm. In this study, the thermodynamic loss in a two-dimensional steam turbine rotor tip section is numerically investigated for various operating and off-design conditions. A pressure based, Eulerian-Eulerian approach is used to model the non-equilibrium condensation process. The entropy change due to condensation is used to compute the thermodynamic losses.

  13. Steam oxidation resistant coatings for steam turbine components: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Agueero, A.; Garcia de Blas, J.; Muelas, R.; Sanchez, A.; Tsipas, S. [Instituto de Tecnica Aeroespacial, Madrid (Spain). Area de Materiales

    2001-07-01

    The principal objective of the COST Action 522 is to raise the operating temperatures of both gas and steam turbines in order to increase their efficiency to reduce fuel consumption and emissions. Concerning steam turbines, the operating temperature is expected to rise from 550 C to 650 C, and the use of oxidation resistant coatings is being considered for the first time in Europe. In this preliminary work, two deposition techniques have so far been explored: slurry paints and atmospheric plasma spray (APS). Commercially available materials, known to have good oxidation resistance, were selected for both deposition techniques: one aluminium slurry and three alloyed materials for thermal spray: AlFe, FeCrAl and NiAl. The coatings were characterised by SEM-EDS and steam oxidation testing was carried out at 650 C. The preliminary findings show that some of the studied coatings may offer adequate protection. (orig.)

  14. Thermal hydraulic studies in steam generator test facility

    Energy Technology Data Exchange (ETDEWEB)

    Vinod, V.; Suresh Kumar, V.A.; Noushad, I.B.; Ellappan, T.R.; Rajan, K.K.; Rajan, M.; Vaidyanathan, G. [Engineering Development Group Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India)

    2005-07-01

    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{sup 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

  15. Combination spindle-drive system for high precision machining

    Science.gov (United States)

    Gerth, Howard L.

    1977-07-26

    A combination spindle-drive is provided for fabrication of optical quality surface finishes. Both the spindle-and-drive utilize the spindle bearings for support, thereby removing the conventional drive-means bearings as a source of vibration. An airbearing spindle is modified to carry at the drive end a highly conductive cup-shaped rotor which is aligned with a stationary stator to produce torque in the cup-shaped rotor through the reaction of eddy currents induced in the rotor. This arrangement eliminates magnetic attraction forces and all force is in the form of torque on the cup-shaped rotor.

  16. Heliostat field cost reduction by `slope drive' optimization

    Science.gov (United States)

    Arbes, Florian; Weinrebe, Gerhard; Wöhrbach, Markus

    2016-05-01

    An algorithm to optimize power tower heliostat fields employing heliostats with so-called slope drives is presented. It is shown that a field using heliostats with the slope drive axes configuration has the same performance as a field with conventional azimuth-elevation tracking heliostats. Even though heliostats with the slope drive configuration have a limited tracking range, field groups of heliostats with different axes or different drives are not needed for different positions in the heliostat field. The impacts of selected parameters on a benchmark power plant (PS10 near Seville, Spain) are analyzed.

  17. Materials for advanced ultrasupercritical steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Purgert, Robert [Energy Industries Of Ohio Inc., Independence, OH (United States); Shingledecker, John [Energy Industries Of Ohio Inc., Independence, OH (United States); Saha, Deepak [Energy Industries Of Ohio Inc., Independence, OH (United States); Thangirala, Mani [Energy Industries Of Ohio Inc., Independence, OH (United States); Booras, George [Energy Industries Of Ohio Inc., Independence, OH (United States); Powers, John [Energy Industries Of Ohio Inc., Independence, OH (United States); Riley, Colin [Energy Industries Of Ohio Inc., Independence, OH (United States); Hendrix, Howard [Energy Industries Of Ohio Inc., Independence, OH (United States)

    2015-12-01

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have sponsored a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired power plants capable of operating at much higher efficiencies than the current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of advanced ultrasupercritical (A-USC) steam conditions. A limiting factor in this can be the materials of construction for boilers and for steam turbines. The overall project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760°C (1400°F)/35MPa (5000 psi). This final technical report covers the research completed by the General Electric Company (GE) and Electric Power Research Institute (EPRI), with support from Oak Ridge National Laboratory (ORNL) and the National Energy Technology Laboratory (NETL) – Albany Research Center, to develop the A-USC steam turbine materials technology to meet the overall project goals. Specifically, this report summarizes the industrial scale-up and materials property database development for non-welded rotors (disc forgings), buckets (blades), bolting, castings (needed for casing and valve bodies), casting weld repair, and casting to pipe welding. Additionally, the report provides an engineering and economic assessment of an A-USC power plant without and with partial carbon capture and storage. This research project successfully demonstrated the materials technology at a sufficient scale and with corresponding materials property data to enable the design of an A-USC steam turbine. The key accomplishments included the development of a triple-melt and forged Haynes 282 disc for bolted rotor construction, long-term property development for Nimonic 105 for blading and bolting, successful scale-up of Haynes 282 and Nimonic 263 castings using

  18. Numerical investigation of mass transfer in the flow path of the experimental model of the PGV-1500 steam generator's steam receiving section with two steam nozzles

    Science.gov (United States)

    Golibrodo, L. A.; Krutikov, A. A.; Nadinskii, Yu. N.; Nikolaeva, A. V.; Skibin, A. P.; Sotskov, V. V.

    2014-10-01

    The hydrodynamics of working medium in the steam volume model implemented in the experimental setup constructed at the Leipunskii Institute for Physics and Power Engineering was simulated for verifying the procedure of calculating the velocity field in the steam space of steam generators used as part of the reactor plants constructed on the basis of water-cooled water-moderated power-generating reactors (VVER). The numerical calculation was implemented in the environment of the STAR-CCM+ software system with its cross verification in the STAR-CD and ANSYS CFX software systems. The performed numerical investigation served as a basis for substantiating the selection of the computation code and parameters for constructing the computer model of the steam receiving device of the PGV-1500 steam generator experimental model, such as the quantization scheme, turbulence model, and mesh model.

  19. Steam turbines and operation of steam turbines 2010. Proceedings; Dampfturbinen und Dampfturbinenbetrieb 2010. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Within the VGB conference an 30th June to 1st July, 2010 in Luebeck (Federal Republic of Germany) the following lectures were held: (1) Application of rifled tubes in power plant heat exchangers (Andreas Grahl); (2) Improved efficiency and potential savings at the 'cool end' through tube cleaning and cooling water filtration (Wolfgang Czolkoss); (3) Material and process improvements in condenser tubing (Pascal Gerard); (4) Automatic eddy current testing of longitudinally welded austentic and titanium tubes for condensers and other heat exchanger (Werner Hannig); (5) Major steam turbine losses: causes, repair measures, recommissioning (Stefan Thumm); (6) Damage on industrial steam turbines (Hans-Guenter Busch); (7) Proper design of turbine draining systems (Ralph Semme); (8) VDMA - Contribution to functional safety of turbomachinery - Required risk reduction by safety functions for steam turbines (Bernhard Wuest); (9) Functional safety by MAN turbo on the example of SIL3 safety loop overspeed detection (Holger Buschmann); (10) Boiler feed pump monitoring, diagnostic and controlling loop (Sohail Ahmed); (11) Experimental investigation to the radial adjustment of brush seals for steam turbines (Heiko Schwarz); (12) The revised VGB guidelines for condenser tubes from copper alloys, stainless steels and titanium (Frank-Udo Leidich); (13) Modernization of HP and LP turbines in coal-fired power plant Bergkamen (Roland Sommer); (14) Mega-components made of cast steel for power plant technology (Reinhold Hanus); (15) Quality monitoring of steam turbine sets for new construction projects of the Vattenfall Europe Generation AG (Marco Rediess); (16) Weld repair of a cracked LP rotor (Andreas Nowi); (17) Steam turbines and CO{sub 2} sequestration (Juergen Klebes); (18) Advanced filter element construction for alleviating electrostatic discharge effects in turbine lubricating systems (John K. Duchowski).

  20. Condensation-Induced Steam Bubble Collapse in a Pipeline

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Steam bubbles often occur in pipelines due to the pipeline structure or operational errors. The water hammer force induced by the steam bubble collapse is a hidden safety concern. This paper experimentally and numerically investigates the conditions for steam bubble formation and collapse. A series of video pictures taken in the laboratory show that steam bubbles form and collapse over several cycles. The pressure history of the steam bubbles is measured in conjunction with the pictures. In the experiment, the liquid column cavitated at the low pressures and then the cavities collapsed due to condensation causing high pressure pulses. The process was also simulated numerically. The results suggest that coolant pipeline design and operation must include procedures to avoid steam bubble formation.

  1. Thermoelastic steam turbine rotor control based on neural network

    Science.gov (United States)

    Rzadkowski, Romuald; Dominiczak, Krzysztof; Radulski, Wojciech; Szczepanik, R.

    2015-12-01

    Considered here are Nonlinear Auto-Regressive neural networks with eXogenous inputs (NARX) as a mathematical model of a steam turbine rotor for controlling steam turbine stress on-line. In order to obtain neural networks that locate critical stress and temperature points in the steam turbine during transient states, an FE rotor model was built. This model was used to train the neural networks on the basis of steam turbine transient operating data. The training included nonlinearity related to steam turbine expansion, heat exchange and rotor material properties during transients. Simultaneous neural networks are algorithms which can be implemented on PLC controllers. This allows for the application neural networks to control steam turbine stress in industrial power plants.

  2. 49 CFR 230.63 - Smoke box, steam pipes and pressure parts.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Pipes § 230.63 Smoke box, steam pipes and pressure parts. The smoke box, steam pipes and... 49 Transportation 4 2010-10-01 2010-10-01 false Smoke box, steam pipes and pressure parts....

  3. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Science.gov (United States)

    2010-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  4. 49 CFR 230.65 - Steam blocking view of engine crew.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Leaks § 230.65 Steam blocking view of engine crew. The steam locomotive owner and/or... 49 Transportation 4 2010-10-01 2010-10-01 false Steam blocking view of engine crew. 230.65...

  5. A Novel Method for Measuring the Coarse Water Droplets in Wet Steam Flow in Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    Xiaoshu Cai; Lili Wang; Yongzhi Pan; Xin Ouyan; Jianqi Shen

    2001-01-01

    Some optical probes based on light extinction have been developed to measure wemess dominated with fine droplets in steam turbine. However, coarse water droplets (hereafter referred to as CWD) that are the main cause of erosion of blade and of wetness loss of steam turbine can't be detected by the extinction probes because of its large size. In this paper, a new method - the light fluctuation method is presented that is capable of measuring the size of CWD. A new probe based on this method was developed for measuring the size of CWD as well as its velocity and concentration.

  6. Steam thermolysis of tire shreds: modernization in afterburning of accompanying gas with waste steam

    Science.gov (United States)

    Kalitko, V. A.

    2010-03-01

    On the basis of experience in the commercial operation of tire-shred steam thermolysis in EnresTec Inc. (Taiwan) producing high-grade commercial carbon, liquid pyrolysis fuel, and accompanying fuel gas by this method, we have proposed a number of engineering solutions and calculated-analytical substantiations for modernization and intensification of the process by afterburning the accompanying gas with waste steam condensable in the scrubber of water gas cleaning of afterburning products. The condensate is completely freed of the organic pyrolysis impurities and the necessity of separating it from the liquid fuel, as is the case with the active process, is excluded.

  7. INFLUENCE OF STEAM EXPLOSION ON THECRYSTALLINITY OF CELLULOSE FIBER

    OpenAIRE

    Jacquet, Nicolas; Vanderghem, Caroline; Danthine, Sabine; Blecker, Christophe; Richel, Aurore

    2014-01-01

    The aim of the present study is to compare the effect of different steam explosion treatments on crystallinity properties of a pure bleached cellulose. Steam explosion process is composed of two distinct stages: vapocracking and explosive decompression. The treatment intensities is determined by a severity factor, established by a correlation between temperature process and retention time. The results show that steam explosion treatment has an impact on the crystallinity properties of pure ce...

  8. Steam-Electric Power-Plant-Cooling Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Sonnichsen, J.C.; Carlson, H.A.; Charles, P.D.; Jacobson, L.D.; Tadlock, L.A.

    1982-02-01

    The Steam-Electric Power Plant Cooling Handbook provides summary data on steam-electric power plant capacity, generation and number of plants for each cooling means, by Electric Regions, Water Resource Regions and National Electric Reliability Council Areas. Water consumption by once-through cooling, cooling ponds and wet evaporative towers is discussed and a methodology for computation of water consumption is provided for a typical steam-electric plant which uses a wet evaporative tower or cooling pond for cooling.

  9. Steam and air plasma gasification of bituminous coal and petrocoke

    OpenAIRE

    Vladimir Messerle; Alexander Ustimenko

    2012-01-01

    This paper presents a numerical analysis and experimental investigation of two very different solid fuels, low-rank bituminous coal of 40 % ash content and petrocoke of 3 % ash content, gasification under steam and air plasma conditions with an aim of producing synthesis gas. Numerical analysis was fulfilled using the software package TERRA for equilibrium computation. Using the results of the numerical simulation, experiments on plasma steam gasification of the petrocoke and air and steam ga...

  10. Condensation pool experiments with steam using DN200 blowdown pipe

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-08-01

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

  11. AUTOMATIC CONTROL SYSTEM OF THE DRUM BOILER SUPERHEATED STEAM TEMPERATURE.

    Directory of Open Access Journals (Sweden)

    Juravliov A.A.

    2006-04-01

    Full Text Available The control system of the temperature of the superheated steam of the drum boiler is examined. Main features of the system are the PI-controller in the external control loop and introduction of the functional component of the error signal of the external control loop with the negative feedback of the error signal between the prescribed value of steam flowrate and the signal of the steam flowrate in the exit of the boiler in the internal control loop.

  12. Program for the thermal design and simulation of the operation of a steam condenser for thermal and nuclear power stations and its application to the condenser at the Cofrentes nuclear power station

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Bartual, R.; Pallares Huici, E.

    A program is being developed for an IBM-PC or AT computer based on a calculation system which synthesises the heat transfer process which takes place in the steam condensors at conventional thermal power stations. The program incorporates a useful tool capable of representing characteristic operating curves for a given condensor. Describes its application to the steam condenser at the Cofrentes nuclear power station. 4 refs., 5 tabs., 8 figs.

  13. Conventional cerebrospinal fluid scanning

    Energy Technology Data Exchange (ETDEWEB)

    Schicha, H.

    1985-06-01

    Conventional cerebrospinal fluid scanning (CSF scanning) today is mainly carried out in addition to computerized tomography to obtain information about liquor flow kinetics. Especially in patients with communicating obstructive hydrocephalus, CSF scanning is clinically useful for the decision for shunt surgery. In patients with intracranial cysts, CSF scanning can provide information about liquor circulation. Further indications for CSF scanning include the assessment of shunt patency especially in children, as well as the detection and localization of cerebrospinal fluid leaks.

  14. Integrating a SOFC Plant with a Steam Turbine Plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Scappin, Fabio

    2009-01-01

    A Solid Oxide Fuel Cell (SOFC) is integrated with a Steam Turbine (ST) cycle. Different hybrid configurations are studied. The fuel for the plants is assumed to be natural gas (NG). Since the NG cannot be sent to the anode side of the SOFC directly, a desulfurization reactor is used to remove....... The off-gases 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. Different systems layouts are considered. Cyclic efficiencies up to 67% are achieved which is considerably higher than...

  15. Parametric Optimization of Biomass Steam-and-Gas Plant

    Directory of Open Access Journals (Sweden)

    V. Sednin

    2013-01-01

    Full Text Available The paper contains a parametric analysis of the simplest scheme of a steam-and gas plant for the conditions required for biomass burning. It has been shown that application of gas-turbine and steam-and-gas plants can significantly exceed an efficiency of steam-power supply units which are used at the present moment. Optimum thermo-dynamical conditions for application of steam-and gas plants with the purpose to burn biomass require new technological solutions in the field of heat-exchange equipment designs.

  16. Experimental research of heterogeneous nuclei in superheated steam

    Directory of Open Access Journals (Sweden)

    Bartoš Ondřej

    2016-01-01

    Full Text Available A mobile steam expansion chamber has been developed to investigate experimentally homogeneous and heterogeneous nucleation processes in steam, both in the laboratory and at power plants using the steam withdrawn from the steam turbine. The purpose of the device is to provide new insight into the physics of nonequilibrium wet steam formation, which is one of the factors limiting the efficiency and reliability of steam turbines. The expanded steam or a mixture of steam with a non-condensable gas rapidly expands in the expansion chamber. Due to adiabatic cooling, the temperature drops below the dew point of the steam at a given pressure. When reaching a sufficiently high supersaturation, droplets are nucleated. By tuning the supersaturation in the so-called nucleation pulse, particles of various size ranges can be activated. This fact is used in the present study to measure the aerosol particles present in the air. Homogeneous nucleation was negligible in this case. The experiment demonstrates the functionality of the device, data acquisition system and data evaluation methods.

  17. Experimental research of heterogeneous nuclei in superheated steam

    Science.gov (United States)

    Bartoš, Ondřej; Kolovratník, Michal; Šmíd, Bohuslav; Hrubý, Jan

    2016-03-01

    A mobile steam expansion chamber has been developed to investigate experimentally homogeneous and heterogeneous nucleation processes in steam, both in the laboratory and at power plants using the steam withdrawn from the steam turbine. The purpose of the device is to provide new insight into the physics of nonequilibrium wet steam formation, which is one of the factors limiting the efficiency and reliability of steam turbines. The expanded steam or a mixture of steam with a non-condensable gas rapidly expands in the expansion chamber. Due to adiabatic cooling, the temperature drops below the dew point of the steam at a given pressure. When reaching a sufficiently high supersaturation, droplets are nucleated. By tuning the supersaturation in the so-called nucleation pulse, particles of various size ranges can be activated. This fact is used in the present study to measure the aerosol particles present in the air. Homogeneous nucleation was negligible in this case. The experiment demonstrates the functionality of the device, data acquisition system and data evaluation methods.

  18. Numerical simulation in steam injection process by a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    De Souza, J.C.Jr.; Campos, W.; Lopes, D.; Moura, L.S.S. [Petrobras, Rio de Janeiro (Brazil)

    2008-10-15

    Steam injection is a common thermal recovery method used in very viscous oil reservoirs. The method involves the injection of heat to reduce viscosity and mobilize oil. A steam generation and injection system consists primarily of a steam source, distribution lines, injection wells and a discarding tank. In order to optimize injection and improve the oil recovery factor, one must determine the parameters of steam flow such as pressure, temperature and steam quality. This study focused on developing a unified mathematical model by means of a mechanistic approach for two-phase steam flow in pipelines and wells. The hydrodynamic and heat transfer mechanistic model was implemented in a computer simulator to model the parameters of steam injection while trying to avoid the use of empirical correlations. A marching algorithm was used to determine the distribution of pressure and temperature along the pipelines and wellbores. The mathematical model for steam flow in injection systems, developed by a mechanistic approach (VapMec) performed well when the simulated values of pressures and temperatures were compared with the values measured during field tests. The newly developed VapMec model was incorporated in the LinVap-3 simulator that constitutes an engineering supporting tool for steam injection wells operated by Petrobras. 23 refs., 7 tabs., 6 figs.

  19. Optimal operations and resilient investments in steam networks

    Directory of Open Access Journals (Sweden)

    Stephane Laurent Bungener

    2016-01-01

    Full Text Available Steam is a key energy vector for industrial sites, most commonly used for process heating and cooling, cogeneration of heat and mechanical power, as a motive fluid or for stripping. Steam networks are used to carry steam from producers to consumers and between pressure levels through letdowns and steam turbines. The steam producers (boilers, heat and power cogeneration units, heat exchangers, chemical reactors should be sized to supply the consumers at nominal operating conditions as well as peak demand.This paper firstly proposes an Mixed Integer Linear Programming formulation to optimise the operations of steam networks in normal operating conditions and exceptional demand (when operating reserves fall to zero, through the introduction of load shedding. Optimisation of investments based on operational and investment costs are included in the formulation.Though rare, boiler failures can have a heavy impact of steam network operations and costs, leading to undercapacity and unit shutdowns. A method is therefore proposed to simulate steam network operations when facing boiler failures. Key performance indicators are introduced to quantify the network's resilience.The proposed methods are applied and demonstrated in an industrial case study using industrial data. The results indicate the importance of oversizing key steam producing equipments and the value of industrial symbiosis to increase industrial site resilience.

  20. Status of steam generator tubing integrity at Jaslovske Bohunice NPP

    Energy Technology Data Exchange (ETDEWEB)

    Cepcek, S. [Nuclear Regulatory Authority of the Slovak Republic, Trnava (Slovakia)

    1997-02-01

    Steam generator represents one of the most important component of nuclear power plants. Especially, loss of tubing integrity of steam generators can lead to the primary coolant leak to secondary circuit and in worse cases to the unit shut down or to the PTS events occurrence. Therefore, to ensure the steam generator tubing integrity and the current knowledge about tube degradation propagation and development is of the highest importance. In this paper the present status of steam generator tubing integrity in operated NPP in Slovak Republic is presented.

  1. Turbulent current drive mechanisms

    Science.gov (United States)

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

    2017-08-01

    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  2. Polar Direct Drive

    Science.gov (United States)

    Skupsky, S.

    2003-10-01

    Direct drive offers the potential of higher target gain on the National Ignition Facility (NIF) than x-ray drive: The initial direct-drive target design had a 1-D gain of 45 and consisted primarily of a pure cryogenic DT shell. Using the expected levels of target and laser nonuniformities for the NIF, two-dimensional (2-D) hydrodynamic simulations predicted target gains around 30.(P.W. McKenty et al.), Phys. Plasmas 8, 2315 (2001). More-recent designs have shown that higher target gains could be obtained by replacing a portion of the DT shell with ``wetted'' CH foam and by using adiabat shaping: (1) Higher-Z material (C) in the foam increases laser absorption by about 40% (from 60% absorption to 85%).(S. Skupsky et al.), in Inertial Fusion Sciences and Applications 2001, edited by K. Tanaka et al. (Elsevier, Paris, 2002), p. 240. (2) Adiabat shaping allows the main portion of the fuel to be placed on a lower adiabat without compromising target stability.(V.N. Goncharov et al.), Phys. Plasmas 10, 1906 (2003). These direct-drive concepts can be tested on the NIF, long before that facility is converted to a direct-drive (spherically symmetric) irradiation configuration. Using the NIF x-ray-drive beam configuration, some of the near-polar beams could be pointed to better illuminate the target's equator. These more-oblique, equatorial beams will have lower absorption and reduced drive efficiency than the polar beams. One strategy to compensate for the difference in polar and equatorial drive is to reduce the irradiation at the poles and employ different pulse shapes to accommodate the time-dependent variations in drive and absorption. This concept of polar direct drive (PDD) has been studied using the 2-D hydrocode DRACO to determine the requirements for achieving ignition and moderate target gain for the NIF. Experiments on the OMEGA laser will examine the effects of oblique irradiation on target drive. Results of simulations for different direct-drive target designs

  3. Condensation heat transfer of pure steam and steam from gas-steam mixture in tubes of AES-2006 PHRS SG heat exchanger

    Science.gov (United States)

    Balunov, B. F.; Il'in, V. A.; Shcheglov, A. A.; Lychakov, V. D.; Alekseev, S. B.; Kuhtevich, V. O.; Svetlov, S. V.; Sidorov, V. G.

    2017-01-01

    Results of experimental determination of the average heat transfer coefficient upon condensation of pure steam αc and steam from air-steam mixture αas.m in tubes of a large-scale model of the emergency cooling heat exchanger in the system of passive heat removal through steam generators of AES-2006 project at Leningrad II NPP are presented. The model contained 16 parallel tubes with a diameter of 16 × 2 mm and a length of 2.9 m connected to the upper steam distributing and lower condensate gathering horizontal collectors; the distance between their axes was 2.28 m. The tube segments were vertical, horizontal, or inclined. The internal diameter of the collectors was 40 or 60 mm. The model was placed in the lower part of a tank with a height of 6.5 m and a volume of 5.85 m3 filled with boiling water at atmospheric pressure. The experimental parameters were as follows: pressure range 0.43-7.77 MPa, condensate Reynolds number Ref = (0.87-9.3) × 103, and average air volume fraction at the segment with air-steam mixture 0.18-0.85. The studies showed that nonuniformity of static pressure distribution along the steam-distributing collector strongly influences the reduction of αc value (ejecting effect). The agreement between experimental and calculated according to statutory guidelines values of αc for vertical tubes is achieved if the dynamic head of the steam flow at the input of the steam-distributing collector does not exceed 1 kPa. Equations for calculation of the diffusion heat transfer coefficient at steam condensation from the air-steam mixture αas.m on the internal tube surface are proposed. In the considered conditions, air is completely displaced by steam flow from the upper to the lower part of the tubes. The boundary between these regions is characterized by an average reduced steam velocity through this cross section of 1.6 ± 0.4 m/s. Above the boundary cross section, it is recommended to calculate αc. according to [1].

  4. Measuring of carbon dioxide in water/steam cycle

    Energy Technology Data Exchange (ETDEWEB)

    Daucik, Karol

    2004-12-01

    Prevention of corrosion of the water/steam cycle caused by anionic contamination is based on control of acid conductivity. The contribution of carbon dioxide to the corrosion is very limited and yet it contributes considerably to the acid conductivity as one of the most common contaminants. Monitoring of the dangerous anionic contamination has therefore been on the agenda for many years. Commercial monitors for this purpose are based on separation of carbon dioxide from stronger acids due to its high volatility. A systematic error in these monitors comes from high volatility of other anionic contaminants, e.g. formic and acetic acid. The aim of this investigation was to show that the separation could be made on a weak base anion exchanger working on the basis of differences in the strength of acids. This simple method was expected to give reliable results with low investment and low operating costs. The results showed that the separation is indeed effective. However, reliable data are received only if the anion exchange resin is in equilibrium with the actual concentration of carbon dioxide in the sample. It may take several hours to reach this equilibrium by natural flow of the sample through the anion exchange column. Changes in the concentration of carbon dioxide in the sample will therefore temporarily give false results until a new equilibrium is achieved. The simple monitoring method can be used only in places, where verification of carbon dioxide contamination is required by long-term operation with elevated and stable acid conductivity in the steam. For future design it is suggested to install a forced achievement of the new equilibrium by conditioning of the resin by means of short-lived additions of carbon dioxide or sodium hydroxide to the sample. In these periods the output from the monitor will be suspended. Output close to the equilibrium is expected to be reached within 10 minutes. This new suggested procedure will complicate the monitoring to such a

  5. A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

    Directory of Open Access Journals (Sweden)

    Jesper Graa Andreasen

    2017-04-01

    Full Text Available This paper presents a comparison of the conventional dual pressure steam Rankine cycle process and the organic Rankine cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt % and low-sulfur (0.5 wt % fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane, toluene, n-pentane, i-pentane and c-pentane. The results of the comparison indicate that the net power output of the steam Rankine cycle process is higher at high engine loads, while the performance of the organic Rankine cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit turbines compared to the steam turbines. When the efficiency of the c-pentane turbine was allowed to be 10% points larger than the steam turbine efficiency, the organic Rankine cycle unit reaches higher net power outputs than the steam Rankine cycle unit at all engine loads for the low-sulfur fuel case. The net power production from the waste heat recovery units is generally higher for the low-sulfur fuel case. The steam Rankine cycle unit produces 18% more power at design compared to the high-sulfur fuel case, while the organic Rankine cycle unit using MM produces 33% more power.

  6. Two-Phase Instability Characteristics of Printed Circuit Steam Generator for the Low Pressure Condition

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Han-Ok; Han, Hun Sik; Kim, Young-In; Kim, Keung Koo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall manufacturing cost for the components. A PCHE(Printed Circuit Heat Exchanger) is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. PCSG(Printed Circuit Steam Generator) is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. For the introduction of new steam generator, design requirement for the two-phase flow instability should be considered. This paper describes two-phase flow instability characteristics of PCSG for the low pressure condition. PCSG is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. Interconnecting flow path was developed to mitigate the two-phase flow instability in the cold side. The flow characteristics of two-phase flow instability at the PCSG is examined experimentally in this study.

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

    Directory of Open Access Journals (Sweden)

    Slobodan Laković

    2010-01-01

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

  8. Solar tower power plant using a particle-heated steam generator: Modeling and parametric study

    Science.gov (United States)

    Krüger, Michael; Bartsch, Philipp; Pointner, Harald; Zunft, Stefan

    2016-05-01

    Within the framework of the project HiTExStor II, a system model for the entire power plant consisting of volumetric air receiver, air-sand heat exchanger, sand storage system, steam generator and water-steam cycle was implemented in software "Ebsilon Professional". As a steam generator, the two technologies fluidized bed cooler and moving bed heat exchangers were considered. Physical models for the non-conventional power plant components as air- sand heat exchanger, fluidized bed coolers and moving bed heat exchanger had to be created and implemented in the simulation environment. Using the simulation model for the power plant, the individual components and subassemblies have been designed and the operating parameters were optimized in extensive parametric studies in terms of the essential degrees of freedom. The annual net electricity output for different systems was determined in annual performance calculations at a selected location (Huelva, Spain) using the optimized values for the studied parameters. The solution with moderate regenerative feed water heating has been found the most advantageous. Furthermore, the system with moving bed heat exchanger prevails over the system with fluidized bed cooler due to a 6 % higher net electricity yield.

  9. High temperature oxidation of fuel cladding candidate materials in steam-hydrogen environments

    Science.gov (United States)

    Pint, B. A.; Terrani, K. A.; Brady, M. P.; Cheng, T.; Keiser, J. R.

    2013-09-01

    Alternative fuel cladding materials to Zr alloys are being investigated for enhanced accident tolerance, which specifically involves oxidation resistance to steam or steam-H2 environments at ⩾1200 °C for short times. Based on a comparison of a range of commercial and model alloys, conventional austenitic steels do not have sufficient oxidation resistance with only ˜18Cr-10Ni. Higher alloyed type 310 stainless steel is protective but Ni is not a desirable alloy addition for this application. Results at 1350 °C indicated that FeCrAl alloys and CVD SiC remain oxidation resistant in steam. At 1200 °C, high (⩾25% Cr) ferritic alloys appear to be good candidates for this application. Higher pressures (up to 20.7 bar) and H2 additions appeared to have a limited effect on the oxidation behavior of the most oxidation resistant alloys, but higher pressures accelerated the maximum metal loss for less oxidation resistant steels and less metal loss was observed for type 317 L tubing in a H2-50%H2O environment at 10.3 bar compared to 100% H2O.

  10. MHD-steam thermal power plant electrical stations with zero stack emission

    Energy Technology Data Exchange (ETDEWEB)

    Borghi, C.A.; Botti, M.; Ribani, P.L. [Univ. of Bologna (Italy)

    1994-12-31

    In the present work a system study of a combined cycle MHD-steam thermal power plant electrical station with zero stack emission through recirculation of CO{sub 2}, is presented. The design of the MHD generator of the topper is done by means of a quasi-one-dimensional optimisation model. The thermodynamic of the combustion gas, typical of this cycle, is considered. The technology of the components is conventional. An overall efficiency larger than 41% for power plants with electrical power inputs above 600 MWe, are obtained.

  11. Removal of NAPLs from the unsaturated zone using steam: prevention of downward migration by injecting mixtures of steam and air

    DEFF Research Database (Denmark)

    Schmidt, R.; Gudbjerg, Jacob; Sonnenborg, Torben Obel

    2002-01-01

    Steam injection for remediation of porous media contaminated by nonaqueous phase liquids has been shown to be a potentially efficient technology. There is, however, concern that the technique may lead to downward migration of separate phase contaminant. In this work, a modification of the steam i......, three mechanisms were identified and it was demonstrated how the effectiveness of these mechanisms depended on the air-to-steam mixing ratio. D 2002 Elsevier Science B.V. All rights reserved....

  12. Assessment: A Driving Force.

    Science.gov (United States)

    Rakow, Steven J.

    1992-01-01

    Asserts that educational assessment drives the curriculum. Thus, assessment is very important in contemplating reform in science education. Assessment should be an integral part of the instructional process, utilizing diagnostic testing, monitoring, and summative evaluations. (PR)

  13. Driving in a womb

    NARCIS (Netherlands)

    Anonymous

    Drive thousands of kilometres on just a litre of fuel? During the annual Shell eco-marathon at the end of May, schoolchildren and students – including a team from TU Delft – demonstrated that it can indeed be done.

  14. Steam feed and effect of steam-thermal seal in thermolysis of tire shreds in a screw-type reactor

    Science.gov (United States)

    Kalitko, V. A.

    2010-05-01

    On the basis of experience in commercial operation, the effect of steam seal in tire-shred pyrolysis in a screw-type reactor with superheated steam has been considered and analytically substantiated; there, local steam feed produces the above effect at the total reduced pressure and keeps air from entering the reactor without sluices or valves used for hermetization of its loading and unloading. It has been shown that the increase in the production rate of pyrolysis due to the heating by steam amounts to 10-15% and is limited by the diffusion transfer in the reactor’s charge bed.

  15. The condensation of steam from steam-water mixture on water jets at high pressure

    Science.gov (United States)

    Somova, E. V.; Kisina, V. I.; Shvarts, A. L.; Kolbasnikov, A. V.; Kanishchev, V. P.

    2009-01-01

    A physical model for condensation of steam in water flow at high pressure is developed, and analytical dependences for calculating heat transfer are obtained, in particular as applied to the operation of a direct-contact feedwater heater for a new-generation reactor plant with lead coolant.

  16. Decay rate of critical fluctuations in steam and in dilute steam - NaCl mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Tufeu, R.; Desmarest, P.; Le Neindre, B. (Universite Paris-Nord, Villetaneuse (France))

    1989-03-01

    The decay rate of critical fluctuations in steam and in a steam - NaCl mixture has been investigated experimentally with the aid of photon correlation spectroscopy. For pure steam, the measurements have been performed along seven isochores (({absolute value of {rho} {minus} {rho}{sub c}})/{rho}{sub c} < 0.09) as a function of the temperature T for (T {minus} T{sub t}) < 1 K. The results have been compared with the values predicted by the renormalization-group theory written as a modification of the classical mode coupling theory. The agreement between experiment and theory is satisfactory along the critical isochore, but larger deviations are noted for {rho} {ne} {rho}{sub c} when approaching the transition temperature T{sub t}. The decay rate of a 0.1% (molar) dilute mixture of NaCl in H{sub 2}O has been measured along some near-critical isochores as a function of temperature. Its behavior, which is very different from that observed for pure steam, is discussed.

  17. Instant Google Drive starter

    CERN Document Server

    Procopio, Mike

    2013-01-01

    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  18. Marine winch drive systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, M.; Smith, P.M.

    1983-12-01

    In the design of marine winch drive systems, efficiency, controllability, compactness and component layout flexibility are major considerations. This paper discusses design concepts aimed at achieving the above considerations in the design of variable speed, hydrostatic, marine winch drive systems. These concepts utilize a high pressure, load sensing pump, and a low-speed, high-torque (LSHT), radial-piston, hydraulic motor. These components are then shown applied in several open circuit hydrostatic power transmission systems.

  19. Steam savings of 33% provided by vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Aslam, J.

    1979-04-01

    Abbott Laboratories needed a vacuum system for a batch distillation process used in the manufacture of an anticonvulsant known as Depakene. The system was to handle 10 lb/hr of air at a suction pressure of 2 torr. A vacuum system that was reliable and also one that used a minimum amount of energy was required. Another requirement was a low-level installation, and if possible, availability from one vendor so to achieve single-source responsibility. After considering various alternatives, the plant installed a 4-stage combination system consisting of a liquid-ring vacuum pump and a 2-stage steam-jet ejector unit. Materials of construction were all 316 stainless steel. The liquid ring vacuum pump provides the initial and major reduction in pressure down to 28'' Hg vacuum. The two ejector stages further decrease this pressure to 2 torr. This combination system has been shown to have a utility cost only 2/3 as great as one in which a conventional 4-stage ejector system is used. Hence, utility cost is reduced by 33%. No significant maintenance has been needed on vacuum system since it was installed in June 1978.

  20. Compatibility of gas turbine materials with steam cooling

    Energy Technology Data Exchange (ETDEWEB)

    Desai, V.; Tamboli, D.; Patel, Y. [Univ. of Central Florida, Orlando, FL (United States)

    1995-10-01

    Gas turbines had been traditionally used for peak load plants and remote locations as they offer advantage of low installation costs and quick start up time. Their use as a base load generator had not been feasible owing to their poor efficiency. However, with the advent of gas turbines based combined cycle plants (CCPs), continued advances in efficiency are being made. Coupled with ultra low NO{sub x} emissions, coal compatibility and higher unit output, gas turbines are now competing with conventional power plants for base load power generation. Currently, the turbines are designed with TIT of 2300{degrees}F and metal temperatures are maintained around 1700{degrees}F by using air cooling. New higher efficiency ATS turbines will have TIT as high as 2700{degrees}F. To withstand this high temperature improved materials, coatings, and advances in cooling system and design are warranted. Development of advanced materials with better capabilities specifically for land base applications are time consuming and may not be available by ATS time frame or may prove costly for the first generation ATS gas turbines. Therefore improvement in the cooling system of hot components, which can take place in a relatively shorter time frame, is important. One way to improve cooling efficiency is to use better cooling agent. Steam as an alternate cooling agent offers attractive advantages because of its higher specific heat (almost twice that of air) and lower viscosity.

  1. Electrosleeve process for in-situ nuclear steam generator repair

    Energy Technology Data Exchange (ETDEWEB)

    Barton, R.A. [Ontario Hydro Technologies, Toronto, ON (Canada); Moran, T.E. [Framatome Technologies Inc., Lynchburg, VA (United States); Renaud, E. [Babcock and Wilcox Industries Ltd., Cambridge, ON (Canada)

    1997-07-01

    Degradation of steam generator (SG) tubing by localized corrosion is a widespread problem in the nuclear industry that can lead to costly forced out-ages, unit de-rating, SG replacement or even the permanent shutdown of a reactor. In response to the onset of SG tubing degradation at Ontario Hydro's Pickering Nuclear Generating Station (PNGS) Unit 5, and the determined unsuitability of conventional repair methods (mechanically expanded or welded sleeves) for Alloy 400, an alternative repair technology was developed. Electrosleeve is a non-intrusive, low-temperature process that involves the electrodeposition of a nanocrystalline nickel microalloy forming a continuously bonded, structural layer over the internal diameter of the degraded region. This technology is designed to provide a long-term pressure boundary repair, fully restoring the structural integrity of the damaged region to its original state. This paper describes the Electrosleeve process for SG tubing repair and the unique properties of the advanced sleeve material. The successful installation of Electrosleeves that have been in service for more than three years in Alloy 400 SG tubing at the Pickering-5 CANDU unit, the more recent extension of the technology to Alloy 600 and its demonstration in a U.S. pressurized water reactor (PWR), is presented. A number of PWR operators have requested plant operating technical specification changes to permit Electrosleeve SG tube repair. Licensing of the Electrosleeve by the U.S. Nuclear Regulatory Commission (NRC) is expected imminently. (author)

  2. Optimization Methods of Superheated Steam Injection Pipelines%过热注汽管线优化方式探讨

    Institute of Scientific and Technical Information of China (English)

    孙运生; 胡筱波; 侯文刚; 王文; 潘海燕

    2016-01-01

    注蒸汽热采是稠油开发的主要技术手段,将注汽锅炉产生的高压蒸汽通过注汽管线注入到地下油层,以降低稠油黏度,便于开采。吞吐和汽驱要求井底蒸汽干度≥50%, SAGD要求井底蒸汽干度≥90%,随着采油新技术的应用,对注汽品质也提出了更高的要求,如何减少热量散失和压力损失、确保蒸汽高效注入地层,对超稠油开发尤为重要。在理论计算的基础上,通过多方案对比的方法,对过热注汽管线优化设计进行了系统的研究和分析,结合目前过热注汽管网现状,阐述了过热注汽管线的管材、保温和热补偿等方面的优化方式,大口径注汽管线材质选用Q345E,热补偿采用旋转补偿器更为合理,保温采用气凝胶隔热毡作为主体具有较好的节能效果。%Thermal steam injection recovery is the main technical means of heavy oil devel-opment. The high pressure steam produced by steam injection boiler can be injected into the underground oil layer through the steam injection pipeline to reduce the viscosity of the heavy oil, which is convenient for mining. Huff and puff and steam drive requires steam quality is not less than 50%,SAGD requires steam quality is not less than 90%.As long as the applica-tion of new production technologies, the higher requirement for the quality of injection steam is put forward. It’ s important to ensure the injection efficiency and reduce the heat loss and pressure loss for super heavy oil development. Based on the theoretical calculation, through the method of multi-scheme comparison, overheat steam injection pipeline optimi-zation design were systematic research and analysis in this paper.Combining the current situ-ation of overheat steam injection pipe network, optimization methods of the overheat steam injection pipeline material, insulation, thermal compensation were put forward. Q345E is the applicable material of large diameter steam

  3. On synthesis and optimization of steam system networks. 1. Sustained boiler efficiency

    CSIR Research Space (South Africa)

    Majozi, T

    2010-08-01

    Full Text Available The traditional steam system comprises a steam boiler and the associated heat exchanger network (HEN). Most research published in literature tends to address both the elements of the steam system as separate entities instead of analyzing...

  4. Wankel engines as steam expanders: design considerations

    Energy Technology Data Exchange (ETDEWEB)

    Badr, O.; Naik, S.; O' Callaghan, P.W.; Probert, S.D. (Cranfield Inst. of Tech., Bedford (GB). Dept. of Applied Energy)

    1991-01-01

    Rotary Wankel engines offer several advantages compared with turbines and other positive-displacement machines as the expansion devices in low-power-output Rankine-cycle systems. So a Wankel expander was selected as the most appropriate device for a steam Rankine-engine, operating principally as a mini combined heat-and-power unit, providing a mechanical output of 5-20 kW. A computer-aided-design technique for selecting the optimal geometry and location of the ports of the expander is described: the computer programs are available from the authors. Lubrication and possible material combinations are also discussed. (author).

  5. Lifetime Assessment of a Steam Pipeline

    Directory of Open Access Journals (Sweden)

    Jiří Janovec

    2012-01-01

    Full Text Available The aim of this paper is to design a method for assessing the life of steam pipes for Czech power plants. The most widely-used material in Czech power plants is steel 15 128. Our findings may also be applied for international equivalents of this steel. The paper shows the classification of cavitation damage and microstructure classification status, based on the German VGB Act, with references to EPRI law in the USA. Calculations of remaining life on the basis of Russian experience are also shown. The possibility of applying this method to increase the operating parameters for power plants is discussed.

  6. Lifetime Assessment of a Steam Pipeline

    OpenAIRE

    Jiří Janovec; Daniela Poláchová; Michal Junek

    2012-01-01

    The aim of this paper is to design a method for assessing the life of steam pipes for Czech power plants. The most widely-used material in Czech power plants is steel 15 128. Our findings may also be applied for international equivalents of this steel. The paper shows the classification of cavitation damage and microstructure classification status, based on the German VGB Act, with references to EPRI law in the USA. Calculations of remaining life on the basis of Russian experience are also sh...

  7. Lifetime Assessment of a Steam Pipeline

    OpenAIRE

    Jiří Janovec; Daniela Poláchová; Michal Junek

    2012-01-01

    The aim of this paper is to design a method for assessing the life of steam pipes for Czech power plants. The most widely-used material in Czech power plants is steel 15 128. Our findings may also be applied for international equivalents of this steel. The paper shows the classification of cavitation damage and microstructure classification status, based on the German VGB Act, with references to EPRI law in the USA. Calculations of remaining life on the basis of Russian experience are also sh...

  8. Thermoeconomic optimization of the steam power plant

    Directory of Open Access Journals (Sweden)

    Reşat Selbaş, Hilmi Yazıcı, Arzu Şencan

    2010-05-01

    Full Text Available In this study, thermoeconomic optimization of the steam power plant with Levelized-cost method was carried out. Aim of thermoeconomy is to minimize exergy cost. With this aim, the first law and the second law of thermodynamics to each component of system were performed. Irreversibility and exergy values were obtained. Economic analysis by using exergy values was carried out. Unit electric cost for each component of system was calculated. Optimum design and operating conditions for minimum exergy cost were obtained.

  9. Hydrogen production from biomass over steam gasification

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, R.; Potetz, A.; Hofbauer, H. [Vienna Univ. of Technology (Austria). Inst. of Chemical Engineering; Weber, G. [Bioenergy 2020+, Guessing (Austria)

    2010-12-30

    Renewable hydrogen is one option for a clean energy carrier in the future. There were several research programs in the past, to produce hydrogen on a renewable basis by electrolysis, direct conversion of water or by gasification of biomass. None of these options were developed to a stage, that they could be used on a commercial basis. At the moment almost all hydrogen is produced from fossil fuels and one main consumer of hydrogen are refineries. So a good option to demonstrate the production of renewable hydrogen and bring it later into the market is over refineries. The most economic option to produce renewable hydrogen at the moment is over gasification of biomass. In Austria an indirect gasification system was developed and is demonstrated in Guessing, Austria. The biomass CHP Guessing uses the allothermal steam dual fluidised bed gasifier and produces a high grade product gas, which is used at the moment for the CHP in a gas engine. As there is no nitrogen in the product gas and high hydrogen content, this gas can be also used as synthesis gas or for production of hydrogen. The main aim of this paper is to present the experimental and simulation work to convert biomass into renewable hydrogen. The product gas of the indirect gasification system is mainly hydrogen, carbon monoxide, carbon dioxide and methane. Within the ERA-Net project ''OptiBtLGas'' the reforming of methane and the CO-shift reaction was investigated to convert all hydrocarbons and carbon monoxide to hydrogen. On basis of the experimental results the mass- and energy balances of a commercial 100 MW fuel input plant was done. Here 3 different cases of complexity of the overall plant were simulated. The first case was without reforming and CO-shift, only by hydrogen separation. The second case was by including steam - reforming and afterwards separation of hydrogen. The third case includes hydrocarbon reforming, CO-shift and hydrogen separation. In all cases the off-gases (CO

  10. Duplex tube steam reformer development program

    Energy Technology Data Exchange (ETDEWEB)

    Lewe, C K; Nieto, J M; Papadopoulos, A

    1978-09-01

    Work done in partial fulfillment of Task 7 of the Duplex Steam Reformer Development Program is described. The DSR concept acts as a double barrier between a process heat high temperature reactor plant (PNP) and a closed loop chemical heat pipe (CHP) for the long distance transport of chemical energy to a remote industrial user. The current state of the DSR design is described as well as related systems and equipment. The PNP concept presented is based upon work currently underway in the Federal Republic of Germany.

  11. Dementia and driving.

    Science.gov (United States)

    O'Neill, D; Neubauer, K; Boyle, M; Gerrard, J; Surmon, D; Wilcock, G K

    1992-04-01

    Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

  12. Self-driving carsickness.

    Science.gov (United States)

    Diels, Cyriel; Bos, Jelte E

    2016-03-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels.

  13. Conventional and unconventional superconductivity

    Science.gov (United States)

    Fernandes, R. M.

    2012-02-01

    Superconductivity has been one of the most fruitful areas of research in condensed matter physics, bringing together researchers with distinct interests in a collaborative effort to understand from its microscopic basis to its potential for unprecedented technological applications. The concepts, techniques, and methods developed along its centennial history have gone beyond the realm of condensed matter physics and influenced the development of other fascinating areas, such as particle physics and atomic physics. These notes, based on a set of lectures given at the 2011 Advanced Summer School of Cinvestav, aim to motivate the young undergraduate student in getting involved in the exciting world of conventional and unconventional superconductors.

  14. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  15. Equations for calculating the properties of dissociated steam

    Science.gov (United States)

    Aminov, R. Z.; Gudym, A. A.

    2017-08-01

    The equations of state for dissociated steam have been developed in the temperature and pressure ranges of 1250-2300 K and 0.01-10.00 MPa for calculating thermodynamic processes in thermal power units operating on high-temperature steam. These equations are based on the property tables for dissociated steam derived at a reference temperature of 0 K. It is assumed that the initial substance is steam, the dissociation of which—in accordance with the most likely chemical reactions—results in formation of molecules of hydrogen, oxygen, steam, hydroxyl, and atoms of oxygen and hydrogen. Differential thermodynamic correlations, considering a change in the chemical potential and the composition of the mixture, during the steam dissociation are used. A reference temperature of 0.01°C used in the calculation of parameters of nondissociated steam has been adopted to predict processes in thermal power units without matching the reference temperatures and to account for transformation of dissociated steam into its usual form for which there is the international system of equations with the water triple point of 0.01°C taken as the reference. In the investigated region, the deviation of dissociated steam properties from those of nondissociated steam, which increases with decreasing the pressure or increasing the temperature, was determined. For a pressure of 0.02 MPa and a temperature of 2200 K, these deviations are 512 kJ/kg for the enthalpy, 0.2574 kJ/(kg K) for the entropy, and 3.431 kJ/(kg K) for the heat capacity at constant pressure. The maximum deviation of the dissociated steam properties calculated by the developed equations from the handbook values that these equations are based on does not exceed 0.03-0.05%.

  16. Plasma-chemical Synthesis and Regeneration of Catalysts for CH4 Steam Conversion

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We carried out experimental studies concerning the plasma-chemical synthesis(PCS) of a catalyst for CH4 steam conversion and designed and built the equipment for PCS and/ or regeneration of spent catalyst for CH4 steam conversion. Under the conditions of an electric-arc low-temperature plasma (LTP), we studied the Ni-O-Al system and performed a comprehensive physicochemical analysis of the ultradispersed product obtained. It's the first time worldwide when the conditions of plasma-chemical synthesis and/ or regeneration of CH4 steam conversion catalysts under the conditions of electric-arc LTP are investigated depending on the plasma-chemical process (PCP) parameters and the plasma-chemical reactor (PCP) type (with CW-"cold walls" Tw = 500 K or WW-"warm walls" Tw = 1500 K), samples with a specific surface of 120 m2/g are obtained. Plasma-chemically synthesized and/ or regenerated samples have a homogenous chemical composition similar to that the Girdller (USA) conventional industrial catalyst. It is empirically established that the optimal temperature range in PCR for synthesis of samples with maximum dispersity is (2000 ~ 3000) K. Results from investigation on dynamics and kinetics of plasma-chemically synthesized and / or regenerated catalysts for CH4 steam conversion show that under LTP conditions premises for the formation of catalyst compositions are established. They are reduced 3 to 4 times faster than their industrial analogues. High specific surface of the samples, homogenous composition, high rate of active chemical surface formed by reduction, faulty crystal lattice of catalytically active phases and mostly high catalytic activity make them a potential competitor with their industrial analogues for their probable production in catalyst shops.

  17. Conventional OTSG development for heavy liquid fuel firing in thermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Setchfield, W.P. [Mitchell Engineers Ltd., Glasgow, Scotland (United Kingdom); Roset, J.N. [Total S.A., Paris (France); Schaffer, M. [Total E and P Canada Ltd., Calgary, AB (Canada); O' Connor, D. [MEG Energy Inc., Calgary, AB (Canada); Kense, K. [TIW Western Inc., Calgary, AB (Canada)

    2008-10-15

    The demand for natural gas is expected to increase as a result of future expansion in Canadian extra heavy oil in-situ thermal production, such as steam assisted gravity drainage or SAGD projects. Natural gas is the current predominant fuel utilized for the associated steam generation. Potential natural gas shortages and related price volatility require that operators consider alternative fuels for the projected growth of in-situ thermal production in Alberta. This paper targeted the use of bitumen from upstream sites and derivative residues from upgrading activities as the most convenient alternative fuel sources for thermal operators of established horizontal type gas fired once through steam generators (OTSGs). The paper presented the methodology, the issues associated with bitumen or residue burning and the related technical solutions in developing a multi-fuel OTSG product. The paper provided background information on conventional OTSG design development, conventional OTSG existing deign, and general description of conventional OTSG. The paper also described the configuration of a radiant furnace, convection module, and theories and definitions such as heavy liquid fuels. A description and application of the equipment and processes as well as a presentation of the data and results was then offered. The multi fuel OTSG design is considered to be a practical and workable product capable of firing heavy liquid fuels. However, the design changes have had a significant impact when compared with conventional OTSG boilers. 11 figs.

  18. An Effective Continuum Model for the Gas Evolution in Internal Steam Drives

    Energy Technology Data Exchange (ETDEWEB)

    Tsimpanogiannis, Ioannis N.; Yortsos, Yanis C.

    2002-06-11

    This report examines the gas phase growth from a supersaturated, slightly compressible, liquid in a porous medium, driven by heat transfer and controlled by the application of a constant-rate decline of the system pressure.

  19. Development of Steam Turbine Inlet Control Valve for Supercritical Pressure at Siemens Industrial Turbomachinery AB

    OpenAIRE

    Sors, Felix; Holm, Patrik

    2010-01-01

    The development in the steam turbine business is heading for applications with much higher steam parameters since this enables a raised efficiency. Steam parameters refer to the pressure and the temperature of the steam. The aim of this study was to generate concepts for steam turbine inlet control valves designed for higher pressure and temperature in comparison with the present design. Future steam power plants using solar energy, based on tower technology, request this kind of performance ...

  20. 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.

  1. 49 CFR 230.106 - Steam locomotive frame.

    Science.gov (United States)

    2010-10-01

    ... Tenders Trucks, Frames and Equalizing System § 230.106 Steam locomotive frame. (a) Maintenance and inspection. Frames, decks, plates, tailpieces, pedestals, and braces shall be maintained in a safe and... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive frame. 230.106 Section...

  2. Modelling of a Coil Steam Generator for CSP applications

    DEFF Research Database (Denmark)

    Pelagotti, Leonardo; Sørensen, Kim; Condra, Thomas Joseph;

    2014-01-01

    The project investigates a new design for a CSP plant steam generation system, the Coil Steam Generator (CSG). This system allows faster start-ups and therefore higher daily energy production from the Sun. An analytical thermodynamic simulation model of the evaporator and a mechanical analysis...

  3. Study on Technology Solutions of CEFR Steam Generator

    Institute of Scientific and Technical Information of China (English)

    WU; Zhi-guang; YU; Hua-jin; LIAO; Zi-yu; ZHANG; Zhen-xing

    2012-01-01

    <正>The technology solutions of CFR1000 steam generator were researched which were compared and analyze with foreign fast reactor steam generator technology solutions. The comparative analysis included the integral/modular structure, the number of modules per loop, structure types, the

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

    NARCIS (Netherlands)

    Bruining, J.; Marchesin, D.

    2007-01-01

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

  5. Optimalisation of the process for manually operated jacket steam sterilisers

    NARCIS (Netherlands)

    Muis B; Bruijn ACP de; Drongelen AW van; Huys JFFM; LGM

    2001-01-01

    The aim of the research was to find an optimal process for a manually operated jacketed steam steriliser, which is mainly used in developing countries. The experiments were focussed on the steam penetration into a textile test pack and the drying procedure. The performance of the various test cycles

  6. Teachers' Perceptions and Practices of STEAM Education in South Korea

    Science.gov (United States)

    Park, HyunJu; Byun, Soo-yong; Sim, Jaeho; Han, Hyesook; Baek, Yoon Su

    2016-01-01

    This study examined teachers' perceptions and practices of science, technology, engineering, arts, and mathematics (STEAM) education in South Korea, drawing on a survey of teachers in STEAM model schools. Results showed that the majority of Korean teachers, especially experienced teachers and male teachers, had a positive view on the role of STEAM…

  7. Temperature Fluctuation Characteristics Analysis for Steam Generator of Fast Reactor

    Institute of Scientific and Technical Information of China (English)

    ZHU; Li-na; WU; Zhi-guang

    2015-01-01

    In the case of boiling heat transfer deterioration,temperature fluctuating may accelerate the corrosion of heat transfer tubes and can also lead to thermal stress on the tubes.In this paper,dryout-induced temperature fluctuation for the fast reactor steam generator is investigated.The impacts of water flow rate,sodium inlet temperature and the outlet steam

  8. Steam vacuum cleaning. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. The baseline technology currently used for washing debris is a high-pressure water cleaning (HPWC) system. The system used at the FEMP is the Hotsy{reg_sign} Model 550B HPWC. Although the HPWC technology has functioned satisfactorily, improvements are being sought in areas related to reduced liquid waste volume, increased productivity, increased washing effectiveness, and decreased airborne contamination. An innovative technology that offers potential improvements in these areas is a steam vacuum cleaning (SVC) system that integrates high-pressure steam cleaning with a vacuum recovery sub-system that simultaneously collects dislodged contaminants thereby reducing airborne contamination. The SVC system selected for demonstration at the FEMP was the Kelly{trademark} Decontamination System shown. This report provides comparative performance and cost analyses between the Hotsy HPWC system and the Kelly Decontamination System. Both technologies were demonstrated at the FEMP site located at Fernald, Ohio from July 29, 1996 through August 15, 1996. The demonstrations were conducted at the FEMP Plant 1 as part of the LSTD project sponsored by the Deactivation and Decommissioning Focus Area (DDFA) of the US DOE`s Office of Science and Technology.

  9. Full STEAM Ahead: From Earth to Ploonoids

    Science.gov (United States)

    Runyon, C. R.; Hall, C.; Blackman, C. L.; Royle, M.; Williams, M. N.

    2015-12-01

    What the heck is a plunoid, you ask? The NASA Solar System Exploration Research Virtual Institute's Education/Public Engagement (EPE) program,from two SSERVI teams (SEEED at Brown/MIT and CLASS at University of Central Florida), is moving full STEAM ahead, engaging the public in the exciting discoveries being made around small bodies, including PLanetary mOONs and asterOIDS (i.e ploonoids). The team has incorporated the arts, from visual representations, storytelling, and music into every facet of the program, to stimulate an affective and personal connection to the content. This past year, the SSERVI STEAM team has participated in numerous public science events, including International Observe the Moon Night, two Astronomy Nights at a local baseball venue, Dark Skies at the US and Canadian National Parks, and Space Day at Camp Happy Days, a camp for children with cancer. Through these events, the team reached over 10000 members of the general public, showcasing current NASA SSERVI research, dispelling myths about our landing and exploring the moon, demonstrating the excitement of STEM through hands-on interactive displays, and providing an outlet for creativity by having multiple ways of representing and explaining scientific information through the arts. Join us on our "ed"venture through the solar system ploonoids.

  10. Studies of catalytic coal gasification with steam

    Directory of Open Access Journals (Sweden)

    Porada Stanisław

    2016-09-01

    Full Text Available One of the promising processes, belonging to the so-called clean coal technologies, is catalytic coal gasification. The addition of a catalyst results in an increased process rate, in which synthesis gas is obtained. Therefore, the subject of this research was catalytic gasification of low-ranking coal which, due to a high reactivity, meets the requirements for fuels used in the gasification process. Potassium and calcium cations in an amount of 0.85, 1.7 and 3.4% by weight were used as catalytically active substances. Isothermal measurements were performed at 900°C under a pressure of 2 MPa using steam as a gasifying agent. On the basis of kinetic curves, the performance of main gasification products as well as carbon conversion degree were determined. The performed measurements allowed the determination of the type and amount of catalyst that ensure the most efficient gasification process of the coal ‘Piast’ in an atmosphere of steam.

  11. Kinetics of zeolite dealumination in steam

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, C.D.; Labouriau, A.; Crawford, S.N.; Romero, R.; Quirin, J.; Earl, W.L.

    1998-08-01

    Zeolite dealumination is a well known phenomenon that contributes to the deactivation or activation of catalysts in several different applications. The most obvious effect is in acid catalysis where dealumination under reaction conditions removes the Broensted sites, thus deactivating the catalyst. The authors are interested in the use of cation exchanged zeolites as selective reduction catalysts for removal of NO{sub x} from exhaust streams, particularly from automotive exhaust. In this case, copper exchanged ZSM-5 has been shown to be an effective catalyst for the generic reaction of NO{sub x} with hydrocarbons. However, high temperature and steam in combustion exhaust causes dealumination and consequent migration of copper out of the zeolite structure resulting in rapid deactivation of the catalyst. Dealumination of zeolites has been reported by many authors in uncountable papers and cannot be reviewed here. However, to the authors` knowledge there are no reports on the kinetics of dealumination under varying conditions of temperature and steam. By measuring the kinetics of dealumination with different zeolites and exchange cations they expect to develop working models of the dealumination process that will allow control of zeolite deactivation. This manuscript is a description of the basic techniques used and a progress report on the very beginning of this study.

  12. 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.

  13. Technical and Economic Advantages of Turbo-Drive Variant with TRB Turbines over Turbo-Generator Variant in Low Power Engineering

    OpenAIRE

    N. V. Panteley

    2008-01-01

    The paper contains a comparative analysis of turbo-driven variant application with TRB turbines and turbo-generator variant in the low power engineering. High efficiency of steam-turbine drive application with TRB turbines is proved by calculation which is made on the basis of a SE-1250-140 network pump at one of the boilers of the Republic of Belarus taken as an example. Calculation has been made for the following steam parameters: turbo-drive input – 12 kgs/cm and 250 and parameters behind ...

  14. COMPARATIVE STUDY OF EXHAUSTION AND PAD-STEAM METHODS FOR IMPROVEMENT OF HANDLE, DYE UPTAKE AND WATER ABSORPTION OF POLYESTER/COTTON FABRIC

    Directory of Open Access Journals (Sweden)

    Aminoddin Haji

    2011-09-01

    Full Text Available In this study, a pad-steam process for treatment of polyester/cotton fabric with sodium hydroxide is developed and the effects of process parameters on selected properties of the fabric are investigated. The results are compared with the conventional exhaustion process. Both processes improved the handle, dyeability and water absorption of the polyester/cotton fabric, but the pad-steam process has the advantages of less strength loss of the fibers, shorter treatment time, lower consumption of water and chemicals that make the process less hazardous to the environment.

  15. Steam reforming of technical bioethanol for hydrogen production

    DEFF Research Database (Denmark)

    Rass-Hansen, Jeppe; Johansson, Roger; Møller, Martin Hulbek;

    2008-01-01

    Essentially all work on ethanol steam reforming so far has been carried out using simulated bioethanol feedstocks, which means pure ethanol mixed with water. However, technical bioethanol consists of a lot of different components including sugars, which cannot be easily vaporized and steam reformed....... For ethanol steam reforming to be of practical interest, it is important to avoid the energy-intensive purification steps to fuel grade ethanol. Therefore, it is imperative to analyze how technical bioethanol, with the relevant impurities, reacts during the steam reforming process. We show how three different...... distillation fractions of technical 2nd generation bioethanol, produced in a pilot plant, influence the performance of nickel- and ruthenium-based catalysts during steam reforming, and we discuss what is required to obtain high activity and long catalyst lifetime. We conclude that the use of technical...

  16. LMFBR steam generator systems development program progress report

    Energy Technology Data Exchange (ETDEWEB)

    None

    The intent of this program is to investigate methods of producing 2-1/4 Cr-1Mo duplex tubing to meet the structural, thermal/hydraulic and leak detection design requirements of the duplex tube leak detection concept for application on the Demonstration Plant and/or prototype steam generator. The leak detection concept as envisioned for LMFBR steam generator application will be analyzed regarding response to credible leak situations. The results of testing will be used for this analysis. The third fluid system will be conceptually designed including the two plena design adaptations being considered and the advantages and disadvantages of each will be assessed. The test program for the single-tube steam generator model will be developed in accordance with the technical and schedular objectives of the LMFBR duplex tube steam generator development program. A conceptual steam generator configuration will be established for use as a reference in the on-going feasibility studies and Demo Plant system development.

  17. Modelling of Steam Generating Paraboloidal dish Solar Thermal Power System

    Energy Technology Data Exchange (ETDEWEB)

    Siangsukone, P.; Lovegrove, K.

    2006-07-01

    The Australian National University (ANU) has a 400m2 Paraboloidal dish solar concentrator system, informally named the Big Dish that produces superheated steam via a receiver mounted monotube boiler connected to 50kWe steam engine for electricity generation. This paper describes an investigation of the system and its components modelled using the TRNYSYS transient system simulation package. The system was modelled in the context of performance assessment for multiple dishes, central generation Rankine cycle power plants. Five new custom components; paraboloidal dish collector, steam cavity receiver, steam line or feedwater line, steam engine, and pressure drop calculator, were developed for the TRNSYS deck file constructed for this study. Validation tests were performed by comparing with the latest experimental results measured with a 1-minute time step and good agreement, with errors less than 10%, has been found. (Author)

  18. Biodiesel from conventional feedstocks.

    Science.gov (United States)

    Du, Wei; Liu, De-Hua

    2012-01-01

    At present, traditional fossil fuels are used predominantly in China, presenting the country with challenges that include sustainable energy supply, energy efficiency improvement, and reduction of greenhouse gas emissions. In 2007, China issued The Strategic Plan of the Mid-and-Long Term Development of Renewable Energy, which aims to increase the share of clean energy in the country's energy consumption to 15% by 2020 from only 7.5% in 2005. Biodiesel, an important renewable fuel with significant advantages over fossil diesel, has attracted great attention in the USA and European countries. However, biodiesel is still in its infancy in China, although its future is promising. This chapter reviews biodiesel production from conventional feedstocks in the country, including feedstock supply and state of the art technologies for the transesterification reaction through which biodiesel is made, particularly the enzymatic catalytic process developed by Chinese scientists. Finally, the constraints and perspectives for China's biodiesel development are highlighted.

  19. Driving anger in Malaysia.

    Science.gov (United States)

    Sullman, Mark J M; Stephens, Amanda N; Yong, Michelle

    2014-10-01

    The present study examined the types of situations that cause Malaysian drivers to become angry. The 33-item version of the driver anger scale (Deffenbacher et al., 1994) was used to investigate driver anger amongst a sample of 339 drivers. Confirmatory factor analysis showed that the fit of the original six-factor model (discourtesy, traffic obstructions, hostile gestures, slow driving, illegal driving and police presence), after removing one item and allowing three error pairs to covary, was satisfactory. Female drivers reported more anger, than males, caused by traffic obstruction and hostile gestures. Age was also negatively related to five (discourtesy, traffic obstructions, hostile gestures, slow driving and police presence) of the six factors and also to the total DAS score. Furthermore, although they were not directly related to crash involvement, several of the six forms of driving anger were significantly related to the crash-related conditions of: near misses, loss of concentration, having lost control of a vehicle and being ticketed. Overall the pattern of findings made in the present research were broadly similar to those from Western countries, indicating that the DAS is a valid measure of driving anger even among non-European based cultures.

  20. High Temperature and Pressure Steam-H2 Interaction with Candidate Advanced LWR Fuel Claddings

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A [ORNL

    2012-08-01

    This report summarizes the work completed to evaluate cladding materials that could serve as improvements to Zircaloy in terms of accident tolerance. This testing involved oxidation resistance to steam or H{sub 2}-50% steam environments at 800-1350 C at 1-20 bar for short times. A selection of conventional alloys, SiC-based ceramics and model alloys were used to explore a wide range of materials options and provide guidance for future materials development work. Typically, the SiC-based ceramic materials, alumina-forming alloys and Fe-Cr alloys with {ge}25% Cr showed the best potential for oxidation resistance at {ge}1200 C. At 1350 C, FeCrAl alloys and SiC remained oxidation resistant in steam. Conventional austenitic steels do not have sufficient oxidation resistance with only {approx}18Cr-10Ni. Higher alloyed type 310 stainless steel is protective but Ni is not a desirable alloy addition for this application and high Cr contents raise concern about {alpha}{prime} formation. Higher pressures (up to 20.7 bar) and H{sub 2} additions appeared to have a limited effect on the oxidation behavior of the most oxidation resistant alloys but higher pressures accelerated the maximum metal loss for less oxidation resistant steels and less metal loss was observed in a H{sub 2}-50%H{sub 2}O environment at 10.3 bar. As some of the results regarding low-alloyed FeCrAl and Fe-Cr alloys were unexpected, further work is needed to fundamentally understand the minimum Cr and Al alloy contents needed for protective behavior in these environments in order to assist in alloy selection and guide alloy development.

  1. What constitutes a convention? : implications for the coexistence of conventions

    OpenAIRE

    Kolstad, Ivar

    2002-01-01

    A model of repeated play of a coordination game, where stage games have a location in social space, and players receive noisy signals of the true location of their games, is reviewed. Sugden (1995) suggests that in such a model, there can be a stationary state of convention coexistence only if interaction is non-uniform across social space. This paper shows that an alternative definition of conventions, which links conventions to actions rather than expectations, permits convention coexistenc...

  2. Comparison of mechanical drive concepts for high power ac-traction locomotives; Vergleich mechanischer Antriebskonzepte fuer Drehstrom-Hochleistungslokomotiven

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, O. [Siemens AG, Nuernberg (Germany). A und D LD T D2

    2004-11-01

    Due to the recent progress with rare earth magnets, a direct drive based on a permanent magnetic synchronous machine could be employed in high power locomotives. An unsprung and a partially suspended direct drive are compared by the criteria of complexity, costs, vertical wheel-rail forces and dynamic loads on the drive with a conventional cardan hollow shaft drive and a nose suspended drive. (orig.)

  3. U.S. DRIVE

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-03-16

    U.S. DRIVE, which stands for United States Driving Research and Innovation for Vehicle efficiency and Energy sustainability, is an expanded government-industry partnership among the U.S. Department of Energy; USCAR, representing Chrysler Group LLC, Ford Motor Company and General Motors; Tesla Motors; five energy companies – BP America, Chevron Corporation, ConocoPhillips, ExxonMobil Corporation, and Shell Oil Products US; two utilities – Southern California Edison and Michigan-based DTE Energy; and the Electric Power Research Institute (EPRI). The U.S. DRIVE mission is to accelerate the development of pre-competitive and innovative technologies to enable a full range of affordable and clean advanced light-duty vehicles, as well as related energy infrastructure.

  4. Pulsation driving and convection

    Science.gov (United States)

    Antoci, Victoria

    2015-08-01

    Convection in stellar envelopes affects not only the stellar structure, but has a strong impact on different astrophysical processes, such as dynamo-generated magnetic fields, stellar activity and transport of angular momentum. Solar and stellar observations from ground and space have shown that the turbulent convective motion can also drive global oscillations in many type of stars, allowing to study stellar interiors at different evolutionary stages. In this talk I will concentrate on the influence of convection on the driving of stochastic and coherent pulsations across the Hertzsprung-Russell diagram and give an overview of recent studies.

  5. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  6. Microlinear piezo drive experiments

    Science.gov (United States)

    Azin, A. V.; Bogdanov, E. P.; Rikkonen, S. V.; Ponomarev, S. V.; Khramtsov, A. M.

    2017-02-01

    The article embraces the experimental description of the micro linear piezo drive intended for the peripheral cord tensioner in the reflecting surface shape regulator system for large-sized transformable spacecraft antenna reflectors. The research target is the experimental investigation of the micro linear piezo drive to determine the stable oscillatory system operating modes which would include improved energy conversion parameters. The following points are briefly presented: test stand construction-design of the peripheral cord tensioner; the determined frequency characteristics and the identified resonant and actual frequencies of an oscillatory system under inertia load. A series of experiments has been conducted for both different preliminary voltages and inertia mass values.

  7. Sliding Mode Predictive Control of Main Steam Pressure in Coal-fired Power Plant Boiler

    Institute of Scientific and Technical Information of China (English)

    史元浩; 王景成; 章云锋

    2012-01-01

    Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional integral derivative (PID) control scheme. For the characteristics of the main steam pressure in coal-fired power plant boiler, the sliding mode control system with Smith predictive structure is proposed to look for performance and robustness improvement. First, internal model control (IMC) and Smith predictor (SP) is used to deal with the time delay, and sliding mode controller (SMCr) is designed to overcome the model mismatch. Simulation results show the effectiveness of the proposed controller compared with conventional ones.

  8. Automatic analytical monitoring of water-steam cycles; Automatische analytische Ueberwachung von Wasser-Dampf-Kreislaeufen

    Energy Technology Data Exchange (ETDEWEB)

    Pflug, H.D. [PreussenElektra AG, Hannover (Germany); Lutat, A.; Schoenfelder, T. [Kraftwerks- und Netzgesellschaft mbH (KNG), Kraftwerk Rostock (Germany)

    1998-05-01

    Continuously operating analytical measuring instruments have, in the meantime, been introduced into power station chemistry, at least for the more recently installed units. Naturally, a breakthrough to systematic consistent processing of the volumes of data is to date still to be achieved. This instrumentation leads a more or less isolated existence compared with conventional analysis techniques. This paper explains the principles of a data processing system for water-steam cycles and the initial results of practical trials on a conventional unit with a once-through boiler. (orig.) [Deutsch] Kontinuierlich arbeitende analytische Messgeraete sind in der Kraftwerkschemie, zumindest bei den neueren Bloecken, inzwischen eingefuehrt. Allerdings ist der Durchbruch zu einer systematischen konsequenten Verarbeitung der Datenmengen bisher ausgeblieben. Die Geraete fuehren ein mehr oder weniger isoliertes Dasein neben der konventionellen Analysentechnik. In dem Beitrag sollen die Grundlagen eines Datenverarbeitungssystems fuer Wasser-Dampf-Kreislaeufe sowie erste Ergebnisse der praktischen Erprobung in einem konventionellen Block mit Durchlaufkessel erlaeutert werden. (orig.)

  9. Dangers of Texting While Driving

    Science.gov (United States)

    ... nhtsa.gov/risky-driving/distracted-driving . Print Out Texting While Driving Guide (pdf) File a Complaint with the FCC ... Office: Consumer and Governmental Affairs Tags: Consumers - Distracted Driving - Health and Safety - Texting Federal Communications Commission 445 12th Street SW, Washington, ...

  10. Steam generator corrosion 2007; Dampferzeugerkorrosion 2007

    Energy Technology Data Exchange (ETDEWEB)

    Born, M. (ed.)

    2007-07-01

    Between 8th and 9th November, 2007, SAXONIA Standortentwicklungs- und -verwertungsgesellschaft GmbH (Freiberg, Federal Republic of Germany) performed the 3rd Freiberger discussion conference ''Fireside boiler corrosion''. The topics of the lectures are: (a) Steam generator corrosion - an infinite history (Franz W. Alvert); (b) CFD computations for thermal waste treatment plants - a contribution for the damage recognition and remedy (Klaus Goerner, Thomas Klasen); (c) Experiences with the use of corrosion probes (Siegfried R. Horn, Ferdinand Haider, Barbara Waldmann, Ragnar Warnecke); (d) Use of additives for the limitation of the high temperature chlorine corrosion as an option apart from other measures to the corrosion protection (Wolfgang Spiegel); (e) Current research results and aims of research with respect to chlorine corrosion (Ragnar Warnecke); (f) Systematics of the corrosion phenomena - notes for the enterprise and corrosion protection (Thomas Herzog, Wolfgang Spiegel, Werner Schmidl); (g) Corrosion protection by cladding in steam generators of waste incinerators (Joerg Metschke); (h) Corrosion protection and wear protection by means of thermal spraying in steam generators (Dietmar Bendix); (i) Review of thick film nickelized components as an effective protection against high-temperature corrosion (Johann-Wilhelm Ansey); (j) Fireproof materials for waste incinerators - characteristics and profile of requirement (Johannes Imle); (k) Service life-relevant aspects of fireproof linings in the thermal recycling of waste (Till Osthoevener and Wolfgang Kollenberg); (l) Alternatives to the fireproof material in the heating space (Heino Sinn); (m) Cladding: Inconal 625 contra 686 - Fundamentals / applications in boiler construction and plant construction (Wolfgang Hoffmeister); (n) Thin films as efficient corrosion barriers - thermal spray coating in waste incinerators and biomass firing (Ruediger W. Schuelein, Steffen Hoehne, Friedrich

  11. Steam Oxidation and Chromia Evaporation in Ultra-Supercritical Steam Boilers and Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gordon H. Holcomb

    2009-01-01

    U.S. Department of Energy’s goals include power generation from coal at 60% efficiency, which requires steam conditions of up to 760 °C and 340 atm, so-called ultra-supercritical (USC) conditions. Evaporation of protective chromia scales is expected to be a primary corrosion mechanism. A methodology to calculate Cr evaporation rates from chromia scales was developed and combined with Cr diffusion calculations within the alloy (with a constant flux of Cr leaving the alloy from evaporation) to predict Cr concentration profiles and to predict the time until breakaway oxidation. At the highest temperatures and pressures, the time until breakaway oxidation was predicted to be quite short for the turbine blade, and of concern within the steam pipe and the higher temperature portions of the superheater tube. Alloy additions such as Ti may allow for a reduction in evaporation rate with time, mitigating the deleterious effects of chromia evaporation.

  12. Improvements in the simulation of a main steam line break with steam generator tube rupture

    Science.gov (United States)

    Gallardo, Sergio; Querol, Andrea; Verdú, Gumersindo

    2014-06-01

    The result of simultaneous Main Steam Line Break (MSLB) and a Steam Generator Tube Rupture (SGTR) in a Pressurized Water Reactor (PWR) is a depressurization in the secondary and primary system because both systems are connected through the SGTR. The OECD/NEA ROSA-2 Test 5 performed in the Large Scale Test Facility (LSTF) reproduces these simultaneous breaks in a Pressurized Water Reactor (PWR). A simulation of this Test 5 was made with the thermal-hydraulic code TRACE5. Some discrepancies found, such as an underestimation of SG-A secondary pressure during the depressurization and overestimation of the primary pressure drop after the first Power Operated Relief Valve (PORV) opening can be improved increasing the nodalization of the Upper Head in the pressure vessel and meeting the actual fluid conditions of Upper Head during the transient.

  13. Conventional mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Tobias Joseph

    2010-01-01

    Full Text Available The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU. Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas.

  14. Steam generator issues in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Strosnider, J.R. [NRC, Washington, DC (United States)

    1997-02-01

    Alloy 600 steam generator tubes in the US have exhibited degradation mechanisms similar to those observed in other countries. Effective programs have been implemented to address several degradation mechanisms including: wastage; mechanical wear; pitting; and fatigue. These degradation mechanisms are fairly well understood as indicated by the ability to effectively mitigate/manage them. Stress corrosion cracking (SCC) is the dominant degradation mechanism in the US. SCC poses significant inspection and management challenges to the industry and the regulators. The paper also addresses issues of research into SCC, inspection programs, plugging, repair strategies, water chemistry, and regulatory control. Emerging issues in the US include: parent tube cracking at sleeve joints; detection and repair of circumferential cracks; free span cracking; inspection and cracking of dented regions; and severe accident analysis.

  15. Flow studies in a wet steam turbine

    Science.gov (United States)

    Evans, D. H.; Pouchot, W. D.

    1974-01-01

    The design and test results of a four stage wet vapor turbine operating with slightly superheated inlet steam and expanding to 10% exit moisture are presented. High speed movies at 3000 frames per second of liquid movement on the pressure side and along the trailing edge of the last stator blade are discussed along with back lighted photographs of moisture drops as they were torn from the stator blade trailing edge. Movies at lower framing rates were also taken of the exit of the last rotating blade and the casing moisture removal slot located in line with the rotor blade shroud. Also moisture removal data are presented of casing slot removal at the exit of the third and fourth rotor blades and for slots located in the trailing edge of the last stator blade. Finally, the degradation of turbine thermodynamic performance due to condensation formation and movement is discussed.

  16. Water treatment processes for oilfield steam injection

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, A.; Pauley, J.C. [Chevron Canada Ltd., Vancouver, BC (Canada)

    2009-07-01

    Various water treatment processes are used within the oilfield industry. Processes tend to be common within one region of the world, but different between regions due to untreated water characteristics and treated water quality requirements. This paper summarized Chevron's view of water treatment requirements and processes for oilfield steam injection. It identified water treatment systems that have been used at thermal projects, where they are most commonly utilized, their purpose, and the limits of each process. The advantages and disadvantages of different water treatment systems were also reviewed. The paper focused on the treatment of fresh waters, low-TDS produced waters, high-hardness waters, and high-silica produced waters. Challenges and opportunities were also identified. It was concluded that the challenges created by high-silica, or by high-hardness produced waters lead to more costly processes. 25 refs., 5 tabs., 4 figs.

  17. Lower head integrity under steam explosion loads

    Energy Technology Data Exchange (ETDEWEB)

    Theofanous, T.G.; Yuen, W.W.; Angelini, S.; Freeman, K.; Chen, X.; Salmassi, T. [Center for Risk Studies and Safety, Univ. of California, Santa Barbara, CA (United States); Sienicki, J.J.

    1998-01-01

    Lower head integrity under steam explosion loads in an AP600-like reactor design is considered. The assessment is the second part of an evaluation of the in-vessel retention idea as a severe accident management concept, the first part (DOE/ID-10460) dealing with thermal loads. The assessment is conducted in terms of the Risk Oriented Accident Analysis Methodology (ROAAM), and includes the comprehensive evaluation of all relevant severe accident scenarios, melt conditions and timing of release from the core region, fully 3D mixing and explosion wave dynamics, and lower head fragility under local, dynamic loading. All of these factors and brought together in a ROAAM Probabilistic Framework to evaluate failure likelihood. The conclusion is that failure is `physically unreasonable`. (author)

  18. Modeling of Steam Distillation Mechanism during Steam Injection Process Using Artificial Intelligence

    Science.gov (United States)

    Ahadi, Arash; Kharrat, Riyaz

    2014-01-01

    Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulate the distillate recoveries of these sets of data. Thirteen sets of data were used to train the models and three sets were used to test the models. The developed models are highly compatible with respect to input oil properties and can predict the distillate yield with minimum entry. For showing the performance of the proposed models, simulation of steam distillation is also done using modified Peng-Robinson equation of state. Comparison between the calculated distillates by ANFIS and neural network models and also equation of state-based method indicates that the errors of the ANFIS model for training data and test data sets are lower than those of other methods. PMID:24883365

  19. Modeling of steam distillation mechanism during steam injection process using artificial intelligence.

    Science.gov (United States)

    Daryasafar, Amin; Ahadi, Arash; Kharrat, Riyaz

    2014-01-01

    Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulate the distillate recoveries of these sets of data. Thirteen sets of data were used to train the models and three sets were used to test the models. The developed models are highly compatible with respect to input oil properties and can predict the distillate yield with minimum entry. For showing the performance of the proposed models, simulation of steam distillation is also done using modified Peng-Robinson equation of state. Comparison between the calculated distillates by ANFIS and neural network models and also equation of state-based method indicates that the errors of the ANFIS model for training data and test data sets are lower than those of other methods.

  20. Simulation of a main steam line break with steam generator tube rupture using trace

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, S.; Querol, A.; Verdu, G. [Departamento de Ingenieria Quimica Y Nuclear, Universitat Politecnica de Valencia, Camino de Vera s/n, 46022, Valencia (Spain)

    2012-07-01

    A simulation of the OECD/NEA ROSA-2 Project Test 5 was made with the thermal-hydraulic code TRACE5. Test 5 performed in the Large Scale Test Facility (LSTF) reproduced a Main Steam Line Break (MSLB) with a Steam Generator Tube Rupture (SGTR) in a Pressurized Water Reactor (PWR). The result of these simultaneous breaks is a depressurization in the secondary and primary system in loop B because both systems are connected through the SGTR. Good approximation was obtained between TRACE5 results and experimental data. TRACE5 reproduces qualitatively the phenomena that occur in this transient: primary pressure falls after the break, stagnation of the pressure after the opening of the relief valve of the intact steam generator, the pressure falls after the two openings of the PORV and the recovery of the liquid level in the pressurizer after each closure of the PORV. Furthermore, a sensitivity analysis has been performed to know the effect of varying the High Pressure Injection (HPI) flow rate in both loops on the system pressures evolution. (authors)

  1. CSI: Hard Drive

    Science.gov (United States)

    Sturgeon, Julie

    2008-01-01

    Acting on information from students who reported seeing a classmate looking at inappropriate material on a school computer, school officials used forensics software to plunge the depths of the PC's hard drive, searching for evidence of improper activity. Images were found in a deleted Internet Explorer cache as well as deleted file space.…

  2. Chaos in drive systems

    Directory of Open Access Journals (Sweden)

    Kratochvíl C.

    2007-10-01

    Full Text Available The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions.

  3. Fresh Drive Against Corruption

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China’s government is making efforts to prevent corruption by taking harsh measures against the illegal selection and appointment of cadres on the 10th anniversary of China’s anti-corruption drive,President Hu Jintao called fogreater efforts to carry it out.

  4. Driving with a Goat

    Institute of Scientific and Technical Information of China (English)

    高素菊

    2006-01-01

    <正>A highway patrol officer was sitting in his car beside the road one day when he noticed a man driving with a goat in the back seat of his car.Turning on the lights,he pulled out,sped up, and pulled the man over.

  5. Drugs and driving

    NARCIS (Netherlands)

    Walsh, J. Michael; De Gier, Johan J.; Christopherson, Asbjørg S.; Verstraete, Alain G.

    2004-01-01

    The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence-which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for futu

  6. Drive-Through Training

    Science.gov (United States)

    Carter, Margie

    2010-01-01

    In this article, the author discusses how the early childhood field's approach to staff training reflects the drive-through, fast-food culture. Year after year directors send their teachers to workshops to get some quick refresher techniques. The author suggests that rather than focusing professional development on topics, focus on observing…

  7. The Drive to Influence

    Science.gov (United States)

    Rodriguez, Diego

    2017-01-01

    At the heart of the educational vocation is a drive to influence, to meaningfully affect the learning and development of others. For adult educators working in higher education, daily activities--from teaching classes to supervising student research to attending faculty meetings to sitting on advisory boards--are full of opportunities to…

  8. Driving While Intoxicated.

    Science.gov (United States)

    Brick, John

    Alcohol intoxication increases the risk of highway accidents, the relative risk of crash probability increasing as a function of blood alcohol content (BAC). Because alcohol use is more prevalent than use of other drugs, more is known about the relationship between alcohol use and driving. Most states presume a BAC of .10% to be evidence of drunk…

  9. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  10. 烟气-蒸汽辅助重力泄油模拟技术%Numerical simulation technology of flue gas-steam assisted gravity drainage

    Institute of Scientific and Technical Information of China (English)

    林日亿; 李魏; 李兆敏; 杨立强; 杨建平

    2012-01-01

    采用加拿大CMG软件公司的CMG-STARS模拟器,对烟气-蒸汽辅助重力泄油技术中烟气在蒸汽腔中的运移规律进行数值模拟.研究烟气注入后蒸汽腔的扩展速度及形态变化规律,分析含油饱和度、黏度、压力、温度的变化规律.在优化的注入参数下,对烟气-蒸汽辅助重力泄油和常规蒸汽辅助重力泄油(SAGD)技术的开发效果进行对比.研究结果表明:优化的蒸汽注入温度为280 ℃、注入速度为150 m3/d、烟气与蒸汽比为1.0.在优化的注入参数下,烟气-蒸汽辅助重力泄油比SAGD的累积采油量提高2.0 kt,采收率提高7%,油气比增加0.7%.烟气-蒸汽辅助重力泄油技术的开发效果更好.%By using the CMG-STARS simulator, the migration laws of flue gas in the steam chamber at flue gas-steam assisted gravity drainage technology were researched. The speed of the steam chamber expanding and the variation of the shape of the steam chamber were studied after flue gas injected. The change rules of oil saturation, viscosity, pressure and temperature were analyzed. The injection parameters of flue gas were optimized by reservoir numerical simulation. With the optimized injection parameters, the development effects of flue gas-steam assisted gravity drainage technology and conventional SAGD were compared. The results show that the optimized steam injection temperature is 280℃ , the injection rate is 150 m /d, and the flue gas and steam ratio is 1.0. With the optimized injection parameters, the cumulative oil production increases by 2. 0 kt, and oil recovery efficiency increases by 7% using the flue gas-steam assisted gravity drainage technology compared with conventional SAGD. The development effect of flue gas-steam assisted gravity drainage technology is better.

  11. ESD and the Rio Conventions

    Science.gov (United States)

    Sarabhai, Kartikeya V.; Ravindranath, Shailaja; Schwarz, Rixa; Vyas, Purvi

    2012-01-01

    Chapter 36 of Agenda 21, a key document of the 1992 Earth Summit, emphasised reorienting education towards sustainable development. While two of the Rio conventions, the Convention on Biological Diversity (CBD) and the United Nations Framework Convention on Climate Change (UNFCCC), developed communication, education and public awareness (CEPA)…

  12. Steam generator tube inspection in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Shigetaka [Japan Power Engineering and Inspection Corp., Tokyo (Japan)

    1997-02-01

    Steam generator tube inspection was first carried out in 1971 at Mihama Unit-1 that is first PWR plant in Japan, when the plant was brought into the first annual inspection. At that time, inspection was made on sampling basis, and only bobbin coil probe was used. After experiencing various kinds of tube degradations, inspection method was changed from sampling to all number of tubes, and various kinds of probes were used to get higher detectability of flaw. At present, it is required that all the tubes shall be inspected in their full length at each annual inspection using standard bobbin coil probe, and some special probes for certain plants that have susceptibility of occurrence of flaw. Sleeve repaired portion is included in this inspection. As a result of analyses of eddy current testing data, all indications that have been evaluated to be 20% wall thickness or deeper shall be repaired by either plugging or sleeving, where flaw morphology is to be a wastage or wear. Other types of flaw such as IGA/SCC are not allowed to be left inservice when those indications are detected. These inspections are performed according to inspection procedures that are approved by regulatory authority. Actual inspections are witnessed by the Japan Power engineering and inspection corporation (JAPEIC)`s inspectors during data acquisition and analysis, and they issue inspection report to authority for review and approval. It is achieved high safety performance of steam generator through this method of inspections, however. some tube leakage problems were experienced in the past. To prevent recurrence of such events, government is conducting development and verification test program for new eddy current testing technology.

  13. [Severe burns related to steam inhalation therapy].

    Science.gov (United States)

    Belmonte, J A; Domínguez-Sampedro, P; Pérez, E; Suelves, J M; Collado, J M

    2015-02-01

    Despite lack of proven effectiveness and its potential to cause severe burns, steam inhalation therapy (SIT) is still used as a treatment for benign respiratory conditions. To characterize cases of burns related to steam inhalation therapy (BRSIT) in order to formulate appropriate preventive criteria. A review was conducted on cases of BRSIT admitted to a Burns Unit between 2006 and 2012, analysing epidemiological data, clinical aspects, severity and course. A total of 530 patients were admitted; 375 (70%) with scalds, and 15 with BRSIT (2.8% of burns; 4% of scalds). SIT was indicated in most cases for mild upper airway infections. The median age of patients was 7 years (2.5m-14 y). The burned area (BA) was ≥10% in 60% of cases (max. BA 22%). Injuries involved trunk, genital area, and extremities; only in one case was the face affected. The mean hospital length-of-stay was 14 days (3-30 d). Five patients (33%) were admitted to the PICU, most of them (60%) younger than 3 years. Eight patients (53%) underwent surgical treatment (skin grafting). In a 12-year-old patient whooping cough was diagnosed in the Burns Unit, and a 2.5-year-old patient developed staphylococcal toxic shock syndrome. No patient died. The final course was satisfactory in all patients. BRSIT can be severe and cause significant use of health resources. Professionals caring for children, particularly paediatricians, should seriously consider their prevention, avoiding treatments with SIT, and educating parents in order not to use it on their own. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  14. FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-12-22

    Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

  15. Ultra high-temperature solids-free insulating packer fluid for oil and gas production, steam injection and geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Ezell, R.G.; Harrison, D.J. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Halliburton Energy Services, Calgary, AB (Canada)

    2008-10-15

    Uncontrolled heat transfer from production/injection tubing during thermal oil recovery via steam injection can be detrimental to the integrity of the casing and to the quality of the steam that is injected into the reservoir. An aqueous-based insulating packer fluid (IPF) was introduced to improve the steam injection process by controlling the total heat loss from the produced fluids to the surrounding wellbore, internal annuli and formation. The IPF was developed for elevated temperature environments through extensive investigation across multidisciplinary technology. The innovative system delivers performance beyond conventional systems of comparable thermal conductivity. Its density range and conductivity measurements were presented in this paper. High-temperature static aging tests showed superior gel integrity without any phase separation after exposure to temperatures higher than 260 degrees C. The new fluids are hydrate inhibitive, non-corrosive and pass oil and grease testing. They are considered to be environmentally sound by Gulf of Mexico standards. It was concluded that the new ultra high-performance insulating packer fluid (HTIPF) reduced the heat loss significantly by both conduction and convection. Heat transfer within the aqueous-based HTIPF was 97 per cent less than that of pure water. It was concluded that the HTIPF can be substituted for conventional packer fluids without compromising any well control issues. 21 refs., 1 tab., 4 figs.

  16. Optimum sizing of steam turbines for concentrated solar power plants

    Directory of Open Access Journals (Sweden)

    Andreas Poullikkas, Constantinos Rouvas, Ioannis Hadjipaschalis, George Kourtis

    2012-01-01

    Full Text Available In this work, a selection of the optimum steam turbine type and size for integration in concentrated solar power (CSP plants is carried out. In particular, the optimum steam turbine input and output interfaces for a range of CSP plant capacity sizes are identified. Also, efficiency and electricity unit cost curves for various steam turbine capacities are estimated by using a combination of the Steam Pro software module of the Thermoflow Suite 18 package and the IPP v2.1 optimization software tool. The results indicate that the estimated efficiency and the expected specific capital cost of the power block are very important criteria in choosing the best steam turbine size of a CSP plant. For capacity sizes of 10kWe up to 50MWe, the steam turbine efficiency increases and the steam turbine expected specific capital cost of the power block decreases at a high rate, whereas for larger sizes they remain almost constant. Thus, there is significant efficiency gains to be realized and large cost savings in increasing the turbine size up to 50MWe. Finally, although the cost of electricity of a CSP plant with capacities greater than 1MWe is significantly reduced to less than 1US$/kWh, currently such technology can only become economically viable through supporting schemes.

  17. Optimum sizing of steam turbines for concentrated solar power plants

    Energy Technology Data Exchange (ETDEWEB)

    Poullikkas, Andreas; Rouvas, Constantinos; Hadjipaschalis, Ioannis; Kourtis, Gorge [Electricity Authority of Cyprus, P.O. Box 24506, 1399 Nicosia (Cyprus)

    2012-07-01

    In this work, a selection of the optimum steam turbine type and size for integration in concentrated solar power (CSP) plants is carried out. In particular, the optimum steam turbine input and output interfaces for a range of CSP plant capacity sizes are identified. Also, efficiency and electricity unit cost curves for various steam turbine capacities are estimated by using a combination of the Steam Pro software module of the Thermoflow Suite 18 package and the IPP v2.1 optimization software tool. The results indicate that the estimated efficiency and the expected specific capital cost of the power block are very important criteria in choosing the best steam turbine size of a CSP plant. For capacity sizes of 10kWe up to 50MWe, the steam turbine efficiency increases and the steam turbine expected specific capital cost of the power block decreases at a high rate, whereas for larger sizes they remain almost constant. Thus, there is significant efficiency gains to be realized and large cost savings in increasing the turbine size up to 50MWe. Finally, although the cost of electricity of a CSP plant with capacities greater than 1MWe is significantly reduced to less than 1US$/kWh, currently such technology can only become economically viable through supporting schemes.

  18. EFFECT OF STEAMING ON THE COLOUR CHANGE OF SOFTWOODS

    Directory of Open Access Journals (Sweden)

    Laszlo Tolvaj,

    2012-05-01

    Full Text Available The heat treatment of softwood (i.e. spruce, pine, fir, and larch may result in significant colour changes. During this study Scots pine and spruce samples were steamed and analysed for their altered hue and lightness. Treatments included: 0 to 22 days of steaming time at a temperature range of 70 to 100°C. The outcome included a variety of colours between the initial hues and brownish tint. These new colours are similar to that of aged furniture and indoor wooden structures. Consequently, properly steamed softwood may be used to repair historical artefacts and relic furniture. Besides restoration, steamed stocks are excellent sources for manufacture of periodical furniture, where the aged appearance has aesthetical value. Results however, indicated that steaming at a temperature above 90 ˚C has a bleaching effect, i.e. the coloured chemical components formed by moderate steaming may be removed. Furthermore, we observed a linear correlation between lightness and colour hue at all steaming times and temperatures.

  19. Frustrated synchronization in competing drive-response coupled chaotic systems

    CERN Document Server

    Sinha, S

    1998-01-01

    Chaotic systems can be synchronized by linking them to a common signal, subject to certain conditions. However, the presence of multiple driving signals coming from different systems, give rise to novel behavior. The particular case of Lorenz systems, with two independent systems driving another system through drive-response coupling has been studied in this paper. This is the simplest arrangement which shows the effect of ``frustrated synchronization'' due to competition between the two driver systems. The resulting response system attractor deviates significantly from the conventional Lorenz attractor. A new measure of desynchronization is proposed, which shows a power-law scaling with the competition parameter.

  20. Digital Simulation of Space Vector Modulation Based Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    G.V. Siva Krishna Rao and T.S. Surendra

    2011-04-01

    Full Text Available This study deals with simulation of Space vector modulated inverter fed induction motor drive. The drive system is modeled using matlab simulink and the results are presented. This drive has advantages like reduced harmonics and heating. Fixed AC is converted into DC and this DC is converted into variable voltage and variable frequency AC using SVM inverter. The output of SVM is applied to the stator of induction motor. The simulation results are compared with the analytical results. The FFT analysis shows that the current spectrum has reduced harmonics compared to the conventional system.

  1. Novel drive mechanism for in-tube micro robots

    Institute of Scientific and Technical Information of China (English)

    CHEN Yangzhi; XING Guangquan; PENG Xuefei; LIU Wenguang; YAO Huaping

    2007-01-01

    The volume of an in-tube micro robot is small and its interior space is very limited. However, conventional transmission methods are unfit to drive in-tube micro robots. A novel micro drive mechanism called the micro-elastic- meshing-wheel is presented in this paper. It can be used for transmitting power and locomotion between two shafts, which are upright and cross in a micro space. The mechanical model of the novel drive mechanism is built, and the maximal trans- mission force is deduced. Then, sufficient experiments are carried out to test maximal transmission force produced by the novel drive mechanism. The calculation and experiment results show that the novel drive mechanism can transmit sufficient power to in-tube micro robots.

  2. The relative impact of work-related stress, life stress and driving environment stress on driving outcomes.

    Science.gov (United States)

    Rowden, Peter; Matthews, Gerald; Watson, Barry; Biggs, Herbert

    2011-07-01

    Previous research has shown the association between stress and crash involvement. The impact of stress on road safety may also be mediated by behaviours including cognitive lapses, errors, and intentional traffic violations. This study aimed to provide a further understanding of the impact that stress from different sources may have upon driving behaviour and road safety. It is asserted that both stress extraneous to the driving environment and stress directly elicited by driving must be considered part of a dynamic system that may have a negative impact on driving behaviours. Two hundred and forty-seven public sector employees from Queensland, Australia, completed self-report measures examining demographics, subjective work-related stress, daily hassles, and aspects of general mental health. Additionally, the Driver Behaviour Questionnaire (DBQ) and the Driver Stress Inventory (DSI) were administered. All participants drove for work purposes regularly, however the study did not specifically focus on full-time professional drivers. Confirmatory factor analysis of the predictor variables revealed three factors: DSI negative affect; DSI risk taking; and extraneous influences (daily hassles, work-related stress, and general mental health). Moderate intercorrelations were found between each of these factors confirming the 'spillover' effect. That is, driver stress is reciprocally related to stress in other domains including work and domestic life. Structural equation modelling (SEM) showed that the DSI negative affect factor influenced both lapses and errors, whereas the DSI risk-taking factor was the strongest influence on violations. The SEMs also confirmed that daily hassles extraneous to the driving environment may influence DBQ lapses and violations independently. Accordingly, interventions may be developed to increase driver awareness of the dangers of excessive emotional responses to both driving events and daily hassles (e.g. driving fast to 'blow off steam

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

    Energy Technology Data Exchange (ETDEWEB)

    Verma, A.K.

    1986-03-01

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

  4. Estimating probable flaw distributions in PWR steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Gorman, J.A.; Turner, A.P.L. [Dominion Engineering, Inc., McLean, VA (United States)

    1997-02-01

    This paper describes methods for estimating the number and size distributions of flaws of various types in PWR steam generator tubes. These estimates are needed when calculating the probable primary to secondary leakage through steam generator tubes under postulated accidents such as severe core accidents and steam line breaks. The paper describes methods for two types of predictions: (1) the numbers of tubes with detectable flaws of various types as a function of time, and (2) the distributions in size of these flaws. Results are provided for hypothetical severely affected, moderately affected and lightly affected units. Discussion is provided regarding uncertainties and assumptions in the data and analyses.

  5. Numerical analysis of helium-heated methane/steam reformer

    Science.gov (United States)

    Mozdzierz, M.; Brus, G.; Kimijima, S.; Szmyd, J. S.

    2016-09-01

    One of the most promising between many high temperature nuclear reactors applications is to produce hydrogen with heat gained. The simplest and the best examined method is steam reforming of methane. The fabricated hydrogen has wide range of use, for example can be electrochemically oxidized in fuel cells. However, heat management inside methane/steam reformer is extremely important because huge temperature gradients can cause catalyst deactivation. In this work the analysis of temperature field inside helium-heated methane/steam reformer is presented. The optimal system working conditions with respect to methane conversion rate are proposed.

  6. Sorption Properties of Steam Treated Wood and Plant Fibres

    DEFF Research Database (Denmark)

    Hoffmeyer, Preben; Jensen, Signe Kamp; Jones, Dennis;

    2003-01-01

    mechanism may be the gradual filling of such micropores by lignin made to flow by further steam treatment. As a result of these counteractive mechanisms, sorption at high RH in steam treated fibres was seen to first grow, then drop and ultimately settle at a level corresponding to pure sorption at primary...... sorption sites. The annual plant fibres proved less susceptible than wood fibres to chemical breakdown from steam treatment. The component most susceptible to chemical breakdown was hemicellulose. Beech, wheat and hemp showed only a modest decrease of cellulose content, even at high temperatures, whereas...

  7. Creation of surface defects on carbon nanofibers by steam treatment

    Institute of Scientific and Technical Information of China (English)

    Zhengfeng; Shao; Min; Pang; Wei; Xia; Martin; Muhler; Changhai; Liang

    2013-01-01

    A direct strategy for the creation of defects on carbon nanofibers (CNFs) has been developed by steam treatment.Nitrogen physisorption,XRD,Raman spectra,SEM and TEM analyses proved the existence of the new defects on CNFs.BET surface area of CNFs after steam treatment was enhanced from 20 to 378 m2/g.Pd catalysts supported on CNFs were also prepared by colloidal deposition method.The different activity of Pd/CNFs catalysts in the partial hydrogenation of phenylacetylene further demonstrated the diverse surfaces of CNFs could be formed by steam treatment.

  8. Methane Steam Reforming Kinetics for a Rhodium-Based Catalyst

    DEFF Research Database (Denmark)

    Jakobsen, Jon Geest; Jakobsen, M.; Chorkendorff, Ib

    2010-01-01

    Methane steam reforming is the key reaction to produce synthesis gas and hydrogen at the industrial scale. Here the kinetics of methane steam reforming over a rhodium-based catalyst is investigated in the temperature range 500-800 A degrees C and as a function of CH4, H2O and H-2 partial pressures....... The methane steam reforming reaction cannot be modeled without taking CO and H coverages into account. This is especially important at low temperatures and higher partial pressures of CO and H-2. For methane CO2 reforming experiments, it is also necessary to consider the repulsive interaction of CO...

  9. Development and design of advanced heat recovery steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Peral, V.; Roa, A. [Babcock & Wilcox Espanola (Spain)

    1998-12-31

    The work carried out investigated: cycle considerations, pressure dependence between superheater and reheater and the condenser vacuum pressure; boiler restrictions by pinch points and heat available; and boiler design. The starting point was based on design experience of IGCC power plant at Puertollano. In this case, the heat recovery boiler has been designed for two fuel types: mixed coal and natural gas. The design of the boiler is in agreement with these two cases achieving highest steam temperature with natural gas and due to high pressure steam imported, the steam flow and pressure to turbine is higher with mixed coal + petroleum coke. The last section provides the construction data. 6 figs.

  10. Use of reactor effluent water as steam plant boiler feed

    Energy Technology Data Exchange (ETDEWEB)

    Clukey, H.V.

    1953-12-08

    The radiological aspects of a proposal to recover some of the heat now wasted in cooling water from the Hanford reactors by using the hot water as boiler feed for the steam plants in the 100 Areas are evaluated. The radioactive material in the hot effluent water will contaminate the boiler feed water system, cause additional radiation exposure of personnel, and increase the cost of maintenance and radiation protection, but very little radioactive material will be carried over into the steam system. At present steam loads, this proposal is economically attractive; other proposals being considered may nullify any savings from this one. 21 refs., 1 fig., 10 tabs.

  11. Steam as turbine blade coolant: Experimental data generation

    Energy Technology Data Exchange (ETDEWEB)

    Wilmsen, B.; Engeda, A.; Lloyd, J.R. [Michigan State Univ., East Lansing, MI (United States)

    1995-10-01

    Steam as a coolant is a possible option to cool blades in high temperature gas turbines. However, to quantify steam as a coolant, there exists practically no experimental data. This work deals with an attempt to generate such data and with the design of an experimental setup used for the purpose. Initially, in order to guide the direction of experiments, a preliminary theoretical and empirical prediction of the expected experimental data is performed and is presented here. This initial analysis also compares the coolant properties of steam and air.

  12. Optimizing the Heat Exchanger Network of a Steam Reforming System

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

    2004-01-01

    gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...... steam reforming reaction and steam must be generated. The dependence of the temperature profiles on conversion in shift reactors for gas purification is also significant. The optimum heat integration in the system is thus imperative in order to minimize the need for hot and cold utilities. A rigorous 1D...

  13. SELECTION OF RUSSIAN STEAM TURBINES FOR THE VIETNAMESE COMBINED GASSTEAM PLANT. THE INFLUENCE OF THE EFFICIENCY OF HIGH-PRESSURE CYLINDER OF STEAM TURBINE K-300-240-2 ON THE POWER OF A GAS-STEAM PLANT IN VIETNAM

    Directory of Open Access Journals (Sweden)

    Pham A. H.

    2015-06-01

    Full Text Available The article looks at the current state of energy in Vietnam and the selection of new Russian steam turbines for operation in combined gas-steam plant in Vietnam. The calculated results of thermal performance scheme 3x1 with combined gas-steam plant 1090 MW based on the Russian steam turbines K-330-240-2 and on the steam turbines TS2A40 Mitsubishi (station PhuMy-1, Vietnam. It also looks at the influence of the efficiency of high-pressure cylinders of Russian steam turbine K-330-240-2 on the efficiency and power of a gas-steam plant 3x1 with 1090 MW, increasing the efficiency of high-pressure cylinder of steam turbine through the use of honeycomb seals in flow part

  14. 46 CFR 54.01-10 - Steam-generating pressure vessels (modifies U-1(g)).

    Science.gov (United States)

    2010-10-01

    ...)). (a) Pressure vessels in which steam is generated are classed as “Unfired Steam Boilers” except as required otherwise by paragraph (b) of this section. Unfired steam boilers must be fitted with an efficient... § 54.15-15. Unfired steam boilers must be constructed in accordance with this part other than when...

  15. A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Meroni, Andrea; Haglind, Fredrik

    2017-01-01

    This paper presents a comparison of the conventional dual pressure steam Rankine cycle process and the organic Rankine cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt %) and low-sulfur (0.5 wt...... %) fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane), toluene, n-pentane, i-pentane and c-pentane. The results of the comparison...... indicate that the net power output of the steam Rankine cycle process is higher at high engine loads, while the performance of the organic Rankine cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit...

  16. 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.

  17. Highly efficient, gearless drive; Hocheffizienter, getriebeloser Antrieb

    Energy Technology Data Exchange (ETDEWEB)

    Niederer, R.

    2004-07-01

    Highly efficient, gearless variable-speed drive systems for low-speed applications have been developed. These systems consist of an inverter with active switches (IGBTs, MOSFETs, resp.) and a synchronous machine excited with permanent magnets. Therefore, these systems can be used for drive as well as for generator applications. They operate very efficiently since a gearbox is obsolete, furthermore weight, dimensions, noise and maintenance can be reduced. The inverter controllers do not require any speed sensors, thus reliability is increased and costs are decreased. Application for low-speed variable-speed drive systems can be found in industrial applications, cable railways or wind turbines. Both systems have been optimized in several iterative loops, in what regards overall efficiency and material expenditure. For both systems, prototypes have been developed and tested. Both prototypes performed reliably and fulfilled the expectations. The high power system (1200 kW, 20 rpm) operated at rated load with an overall efficiency of 93.1%, the lower power system (3 kW, 60 rpm) with an overall efficiency of 85%. Thus the losses of these new systems are at rated load about 4% lower compared to conventional drive systems equipped with a mechanical gearbox. (author)

  18. 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

  19. The 700{sup o}C steam turbine power plant status of development and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Edelmann, Heiner; Effert, Martin; Wieghardt, Kai; Kirchner, Holger

    2007-08-15

    This paper appraises the current development status of the 700{sup o}C steam power plant under consideration of process optimisation as well as design aspects of the steam turbine and steam generator. The results for a compact arrangement of the steam turbine and steam generator are also presented. Based on a cycle analysis, a net efficiency between 49.3% and 51.4% can be achieved with the 700{sup o}C steam power plant depending on the implementation and based on an inland plant site. No competing development activities for the 700{sup o}C steam power plant are known from the USA or Japan.

  20. Features of steam turbine cooling by the example of an SKR-100 turbine for supercritical steam parameters

    Science.gov (United States)

    Arkadyev, B. A.

    2015-10-01

    Basic principles of cooling of high-temperature steam turbines and constructive solutions used for development of the world's first cooled steam turbine SKR-100 (R-100-300) are described. Principal differences between the thermodynamic properties of cooling medium in the steam and gas turbines and the preference of making flow passes of cooled cylinders of steam turbines as reactive are shown. Some of its operation results and their conclusions are given. This turbine with a power of 100 MW, initial steam parameters approximately 30 MPa and 650°C, and back pressure 3 MPa was made by a Kharkov turbine plant in 1961 and ran successfully at a Kashira GRES (state district power plant) up to 1979, when it was taken out of use in a still fully operating condition. For comparison, some data on construction features and operation results of the super-high pressure cylinder of steam turbines of American Philo 6 (made by General Electric Co.) and Eddystone 1 (made by Westinghouse Co.) power generating units, which are close to the SKR-100 turbine by design initial steam parameters and the implementation time, are given. The high operational reliability and effectiveness of the cooling system that was used in the super-high pressure cylinder of the SKR-100 turbine of the power-generating unit, which were demonstrated in operation, confirms rightfulness and expediency of principles and constructive solutions laid at its development. As process steam temperatures are increased, the realization of the proposed approach to cooling of multistage turbines makes it possible to limit for large turbine parts the application of new, more expensive high-temperature materials, which are required for making steam boilers, and, in some cases, to do completely away with their utilization.

  1. Lab assessment of Bruce Unit 4 steam generator top-of-tubesheet cracking

    Energy Technology Data Exchange (ETDEWEB)

    Jevec, J.; Sarver, J. [Babcock and Wilcox Research Center (United States); King, P.; Yu, J. [Babcock and Wilcox Canada Ltd., Cambridge, Ontario (Canada); Sedman, K.; Durance, D. [Bruce Power, Tiverton, Ontario (Canada)

    2009-07-01

    An increasing number of significant circumferential indications were detected at the roll transition zone (RTZ) of Bruce Power Unit 4 steam generator (SG) tubing (sensitized Alloy 600) during the 2006 and 2007 Spring outages. Metallurgical examination of removed tubes found significant IGA/SCC associated with these indications. However, no circumferential indications were detected on Unit 4 SG tubing during the subsequent Fall 2007 and Spring 2008 outages. Based on a review of outage layup conditions it was theorized that the observed degradation occurs during an outage when the steam generator is drained for maintenance in combination with the presence of detrimental contaminants such as sulfur and copper. This theory was tested in the laboratory using a series of electrochemical and simulated crevice exposure tests. The oxygen/hydrazine reaction at room temperature and the resultant effect on the electrochemical potential of the sensitized Alloy 600 tubing were also studied in this program. Results from this test program are presented in this paper. The results indicate that exposure of the solutions to air tends to keep the sample in the sludge at a more reducing condition as compared to the free span tubing above the sludge resulting in a larger driving force for corrosion of the sample in the sludge. The theory that the defects in the RTZ were caused during drain-down outage conditions was shown to be plausible. (author)

  2. Driving and engine cycles

    CERN Document Server

    Giakoumis, Evangelos G

    2017-01-01

    This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

  3. Driving on the Descartes

    Science.gov (United States)

    1972-01-01

    Astronaut John W. Young, Apollo 16 mission commander, drives the 'Rover', Lunar Roving Vehicle (LRV) to its final parking place near the end of the third extravehicular activity (EVA-3) at the Descartes landing site. Astronaut Charles M. Duke Jr., Lunar Module pilot, took this photograph looking southward. The flank of Stone Mountain can be seen on the horizon at left. The shadow of the Lunar Module 'Orion' is visible in the foreground.

  4. Effect of Steam Explosion Pretreatment on Bamboo for Enzymatic Hydrolysis and Ethanol Fermentation

    OpenAIRE

    Zhiqiang Li; Benhua Fei; Zehui Jiang

    2014-01-01

    Based on the steam explosion pretreatment that has been applied to other types of lignocellulosic biomass, the steam explosion pretreatment of bamboo, along with a study of the chemical compositions and enzymatic hydrolyzability of substrates, was conducted. The results show that steam explosion pretreatment can greatly enhance the cellulose-to-glucose conversion yield after enzymatic hydrolysis, which is sometimes affected by bamboo age and steam explosion conditions. When the steam explosio...

  5. INFLUENCE OF STEAM EXPLOSION PRETREATMENT ON THE COMPOSITION AND STRUCTURE OF WHEAT STRAW

    OpenAIRE

    Li Cui; Zhong Liu; Chuanling Si,; Lanfeng Hui; Neng Kang,; Ting Zhao

    2012-01-01

    Steam explosion pretreatment of wheat straw can solubilize a significant portion of the hemicellulosic component and enhance the enzymatic digestibility of the remaining cellulose for fermentation into ethanol. In this work, wheat straw was pretreated by steam explosion using different steam temperatures and retention times, and the chemical compositions of the raw and steam-exploded wheat straw were analyzed. Results showed that the content of hemicellulose decreased sharply at higher steam ...

  6. SG (steam generator) tube repair by explosive welding

    Energy Technology Data Exchange (ETDEWEB)

    Helmley, J.M. (Babcock and Wilcox Co., Lynchburg, VA (United States))

    1993-03-01

    Traditional joining techniques have limitations for bonding the ends of repair sleeves inside PWR cracked steam generator tubes. Explosive (kinetic) welding has been used as a successful alternative in over 5000 defective tubes. (author).

  7. Horizontal steam generator PGV-1000 thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O. [Skoda Company, Prague (Switzerland); Doubek, M. [Czech Technical Univ., Prague (Switzerland)

    1995-12-31

    A computer program for the steady state thermal-hydraulic analysis of horizontal steam generator PGV-1000 is presented. The program provides the capability to analyze steam generator PGV-1000 primary side flow and temperature distribution, primary side pressure drops, heat transfer between the primary and secondary sides and multidimensional heat flux distribution. A special attention is paid to the thermal-hydraulics of the secondary side. The code predicts 3-D distribution of the void fraction at the secondary side, mass redistribution under the submerged perforated sheet and the steam generator level profile. By means of developed computer program a detailed thermal-hydraulic study of the PGV-1000 has been carried out. A wide range of calculations has been performed and a set of important steam generator characteristics has been obtained. Some of them are presented in the paper. (orig.). 5 refs.

  8. 46 CFR 56.50-15 - Steam and exhaust piping.

    Science.gov (United States)

    2010-10-01

    ... must be provided for draining every steam pipe in which dangerous water hammer might otherwise occur. ... hot water for heating systems may not exceed 375 °F. (i) Where positive shutoff valves are fitted...

  9. Compatibility of gas turbine materials with steam cooling

    Energy Technology Data Exchange (ETDEWEB)

    Desai, V.; Tamboli, D.; Patel, Y. [University of Central Florida, Orlando, FL (United States). Dept. of Mechanical and Aerospace Engineering

    1995-12-31

    Objective is to investigate performance of gas turbine materials in steam environment and evaluate remedial measures for alleviating the severity of the problem. Three superalloys commonly used in gas turbines were exposed to 3 steam environments containing different impurity levels for 2 to 6 months. Results: Cr2O3-forming alloys containing 1-4% Al such as IN 738 are susceptible to heavy internal oxidation of Al. High Al (>5%) alloys in which continuous Al2O3 scale can be formed, may not be susceptible to such attack. Deposition of salts from steam will accentuate hot corrosion problems. Alloys with higher Cr content such as X-45 are generally less prone to hot corrosion. The greater damage observed in IN 617 make this alloy less attractive for gas turbines with steam cooling. Electrochemical impedance spectroscopy is a good nondestructive method to evaluate microstructural damage.

  10. C++ Implementation of IAPWS Water/Steam Properties

    Energy Technology Data Exchange (ETDEWEB)

    Ling Zou; Haihua Zhao; Hongbin Zhang; Qiyue Lu

    2014-02-01

    For the calculations of water-involved systems, such as safety analysis of light water reactors, it is essential to provide accurate water properties. The International Association for the Properties of Water and Steam is an international non-profit association of national organizations concerned with the properties of water and steam. It provides internationally accepted formulations of water/steam properties for scientific and industrial applications. The purpose of this work is to provide a stand-alone software package in C++ programming language to provide accurate and efficient water/steam properties evaluation, based on the latest IAPWS releases. The discussion on related IAPWS releases, code implementations and verifications are provided in details.

  11. A detection of the coarse water droplets in steam turbines

    Directory of Open Access Journals (Sweden)

    Bartoš Ondřej

    2014-03-01

    Full Text Available The aim of this paper is to introduce a novel method for the detection of coarse water droplets in a low pressure part of steam turbines. The photogrammetry method has been applied for the measurement of coarse droplets in the low-pressure part of a steam turbine. A new probe based on this measurement technique was developed and tested in the laboratory and in a steam turbine in the Počerady power-plant. The probe was equipped with state-of-the-art instrumentation. The paper contains results from laboratory tests and the first preliminary measurements in a steam turbine. Possible applications of this method have been examined.

  12. Mandarin peel wastes pretreatment with steam explosion for bioethanol production.

    Science.gov (United States)

    Boluda-Aguilar, María; García-Vidal, Lidia; González-Castañeda, Fayiny Del Pilar; López-Gómez, Antonio

    2010-05-01

    The mandarin (Citrus reticulata L.) citrus peel wastes (MCPW) were studied for bioethanol production, obtaining also as co-products: d-limonene, galacturonic acid, and citrus pulp pellets (CPP). The steam explosion pretreatment was analysed at pilot plant level to decrease the hydrolytic enzymes requirements and to separate and recover the d-limonene. The effect of steam explosion on MCPW lignocellulosic composition was analyzed by means thermogravimetric analysis. The d-limonene contents and their influence on ethanol production have been also studied, while concentration of sugars, galacturonic acid and ethanol have been analysed to measure the saccharification and fermentation (HF and SSF) processes efficiency obtained by MCPW steam explosion pretreatment. Ethanol contents of 50-60L/1000kg raw MCPW can be obtained and CPP yields can be regulated by means the control of enzymes dose and the steam explosion pretreatment which can significantly reduce the enzymes requirements.

  13. STEAM EXPLOSION : PROCESS AND IMPACT ON LIGNOCELLULOSIC MATERIAL

    OpenAIRE

    Jacquet, Nicolas; Vanderghem, Caroline; Danthine, Sabine; Blecker, Christophe; Paquot, Michel

    2012-01-01

    Steam explosion is a thermomechanochemical process which allows the breakdown of lignocellulosic structural components by steam heating, hydrolysis of glycosidic bonds by organic acid formed during the process and shearing forces due to the expansion of the moisture. The process is composed of two distinct stages: vapocracking and explosive decompression. Cumul effects of both phases include modification of the physical properties of the material (specific surface area, water retention capaci...

  14. Vortex Pressure-Reducing Desuperheating Plants and Steam Coolers

    Directory of Open Access Journals (Sweden)

    V. Kascheev

    2012-01-01

    Full Text Available The authors have developed and tested the entire device class that appeared as a result of fundamental investigations of multiphase flows in centrifugal force fields, understanding of process mechanism occurring in them and their mathematical description for optimization. Method for reduction of pressure and steam temperature in vortex pressure-reducing desuperheating plants and steam coolers has been proposed for the first time in the paper.

  15. Filmwise condensation of steam on low integral-finned tubes

    OpenAIRE

    Georgiadis, Ioannis V.

    1984-01-01

    Approved for public release; distribution is unlimited Filmwise condensation heat-transfer measurements if steam were made on horizontal tubes under vacuum and near-atmospheric pressures. Data were taken for a smooth tube and for 21 tubes which contained rectangularly-shaped, low integral fins. The fin geometry was systematically varied in order to investigate the dependence of the steam-side heat-transfer coefficient on fin spacing, thickness and height. The condensation process was fo...

  16. Development of data management system for steam generator inspection

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yong Moo; Im, Chang Jae; Lee, Yoon Sang; Kang, Soon Joo; An, Jong Kwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-06-01

    The data communications environment for transferring Nuclear Power Plant Steam Generator Eddy Current testing data was investigated and after connecting LAN to Hinet-F network, the remote data transfer with the speed of 56 kbps was tested successfully. Data management system for Steam Generator Eddy current testing was also developed by using HP-UX, RMB (Rock Mountain Basic) 21 figs, 13 tabs, 5 refs. (Author).

  17. Steam as turbine blade coolant: Experimental data generation

    Energy Technology Data Exchange (ETDEWEB)

    Wilmsen, B.; Engeda, A.; Lloyd, J.R. [Michigan State Univ., East Lansing, MI (United States). Dept. of Mechanical Engineering

    1995-12-31

    Steam as a coolant is a possible option to cool blades in high temperature gas turbines; however there is practically no experimental data. This work deals with an attempt to generate such data and with the design of an experimental setup used for the purpose. Initially, in order to guide the direction of experiments, a preliminary theoretical and empirical prediction of the expected experimental data is performed and is presented here. This initial analysis also compares the coolant properties of steam and air.

  18. Computer monitoring and optimization of the steam boiler performance

    OpenAIRE

    Sobota Tomasz

    2017-01-01

    The paper presents a method for determination of thermo-flow parameters for steam boilers. This method allows to perform the calculations of the boiler furnace chamber and heat flow rates absorbed by superheater stages. These parameters are important for monitoring the performance of the power unit. Knowledge of these parameters allows determining the degree of the furnace chamber slagging. The calculation can be performed in online mode and use to monitoring of steam boiler. The presented me...

  19. Nonlinear H-infinity control of nuclear steam generators

    Science.gov (United States)

    Ramalho, Fernando Pinto

    Motivated by the fact that problems related to the control of steam generators are responsible for a significant amount of downtime in nuclear power plants, this thesis investigates the applicability of linear and nonlinear Hinfinity theory to the control of nuclear steam generators. A nonlinear model based on mass, energy, and momentum balances was developed for a U-tube steam generator, with the water level and steam quality at the exit of the riser considered as state variables. In this model the steam flow to the turbines and the heat flow from the primary to the secondary side are represented as disturbances affecting the system, while the feedwater flow is used to compensate for changes in the water level. The performance specifications for the feedback loop are encoded using weight functions incorporated into an augmented plant, and the control problem is formulated to minimize the effects of disturbances on the controlled variables. The solution of the optimization problem is reduced to the solution of a set of differential equations, which, in the linear case, is equivalent to the solution of Riccati equations. The linear Hinfinity controller and filter were obtained for the U-tube steam generator with and without weight functions, and simulations for a 50 s ramp transient resulting in 50% decrease in the heat and steam flows were performed over 300 s. The use of weights provided less variation in the water level, and an excellent noise rejection capability was observed. For the nonlinear Hinfinity formulation a finite-difference method was used to solve the state and costate equations numerically for optimal feedwater flow minimizing water level variations. The combined solution of the state equation in the forward direction and the costate equations in the backward direction converged in 10 iteractions. The nonlinear controller results in less variation in the water level than the corresponding linear Hinfinity controller, demonstrating the feasibility

  20. K-65-12.8 condensing steam turbine

    Science.gov (United States)

    Valamin, A. E.; Kultyshev, A. Yu.; Gol'dberg, A. A.; Sakhnin, Yu. A.; Bilan, V. N.; Stepanov, M. Yu.; Polyaeva, E. N.; Shekhter, M. V.; Shibaev, T. L.

    2016-11-01

    A new condensing steam turbine K-65-12.8 is considered, which is the continuation of the development of the steam turbine family of 50-70 MW and the fresh steam pressure of 12.8 MPa, such as twocylinder T-50-12.8 and T-60/65-12.8 turbines. The turbine was developed using the modular design. The design and the main distinctive features of the turbine are described, such as a single two-housing cylinder with the steam flow loop; the extraction from the blading section for the regeneration, the inner needs, and heating; and the unification of some assemblies of serial turbines with shorter time of manufacture. The turbine uses the throttling steam distribution; steam from a boiler is supplied to a turbine through a separate valve block consisting of a central shut-off valve and two side control valves. The blading section of a turbine consists of 23 stages: the left flow contains ten stages installed in the inner housing and the right flow contains 13 stages with diaphragm placed in holders installed in the outer housing. The disks of the first 16 stages are forged together with a rotor, and the disks of the rest stages are mounted. Before the two last stages, the uncontrolled steam extraction is performed for the heating of a plant with the heat output of 38-75 GJ/h. Also, a turbine has five regenerative extraction points for feed water heating and the additional steam extraction to a collector for the inner needs with the consumption of up to 10 t/h. The feasibility parameters of a turbine plant are given. The main solutions for the heat flow diagram and the layout of a turbine plant are presented. The main principles and features of the microprocessor electro hydraulic control and protection system are formulated.

  1. Five-component propagation model for steam explosion analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Moriyama, Kiyofumi; Park, H.S.; Maruyama, Yu; Sugimoto, Jun [Severe Accident Research Laboratory, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    1999-07-01

    A five-field simulation code JASMINE-pro has been developed at JAERI for the calculation of the propagation and explosion phase of steam explosions. The basic equations and the constitutive relationships specifically utilized in the propagation models in the code are introduced in this paper. Some calculations simulating the KROTOS 1D and 2D steam explosion experiments are also stated in the paper to show the present capability of the code. (author)

  2. Steam separator modeling for various nuclear reactor transients

    Energy Technology Data Exchange (ETDEWEB)

    Paik, C Y; Mullen, G; Knoess, C; Griffith, P

    1987-06-01

    In a pressurized water reactor steam generator, a moisture separator is used to separate steam and liquid and to insure that essentially dry steam is supplied to the turbine. During a steam line break or combined steam line break plus tube rupture, a number of phenomena can occur in the separator which have no counterparts during steady-state operation. How the separator will perform under these circumstances is important for two reasons, it affects the carry-over of radioactive iodine and the water inventory in the secondary side. This study has as its goal the development of a simple separator model which can be applied to a variety of steam generator for off-design conditions. Experiments were performed using air and water on three different types of centrifugal separators: a cyclone as a generic separator, a Combustion Engineering type stationary swirl vane separator, and a Westinghouse type separator. The cyclone separator system has three stages of separation: first the cyclone, then a gravity separator, and finally a chevron plate separator. The other systems have only a centrifugal separator to isolate the effect of the primary separator. Experiments were also done in MIT blowdown rig, with and without a separator, using steam and water. The separators appear to perform well at flow rates well above the design values as long as the downcomer water level is not high. High downcomer water level rather than high flow rates appear to be the primary cause of degraded performance. Appreciable carry-over from the separator section of a steam generator occurs when the drain lines from three stages of separation are unable to carry off the liquid flow. Failure scenarios of the separator for extreme range of conditions from the quasi-steady state transient to the fast transients are presented. A general model structure and simple separator models are provided.

  3. MINET validation study using steam generator test data

    Energy Technology Data Exchange (ETDEWEB)

    Van Tuyle, G.J.; Guppy, J.G.

    1984-01-01

    Three steam generator transient test cases that were simulated using the MINET computer code are described, with computed results compared against experimental data. The MINET calculations closely agreed with the experiment for both the once-through and the U-tube steam generator test cases. The effort is part of an ongoing effort to validate the MINET computer code for thermal-hydraulic plant systems transient analysis, and strongly supports the validity of the MINET models.

  4. Hydraulic drag at the condensing steam flow in tubes

    Science.gov (United States)

    Leontiev, A. I.; Milman, O. O.

    2014-12-01

    The dependency of condensing steam flow parameters in tubes and channels was studied as a function of different flow modes for the coolant: counter-flow, co-flow, cross-flow. The drop for the total pressure of steam is higher for the counter-flow than for the co-flow or cross-flow modes. The pressure drop was estimated with different computation models as a function flow mode. Calculation results were compared with experimental data.

  5. Automated Diagnosis and Classification of Steam Generator Tube Defects

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Gabe V. Garcia

    2004-10-01

    A major cause of failure in nuclear steam generators is tube degradation. Tube defects are divided into seven categories, one of which is intergranular attack/stress corrosion cracking (IGA/SCC). Defects of this type usually begin on the outer surface of the tubes and propagate both inward and laterally. In many cases these defects occur at or near the tube support plates. Several different methods exist for the nondestructive evaluation of nuclear steam generator tubes for defect characterization.

  6. Development of data management system for steam generator inspection

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yong Moo; Im, Chang Jae; Lee, Yoon Sang; Kang, Soon Joo; An, Jong Kwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-06-01

    The data communications environment for transferring Nuclear Power Plant Steam Generator Eddy Current testing data was investigated and after connecting LAN to Hinet-F network, the remote data transfer with the speed of 56 kbps was tested successfully. Data management system for Steam Generator Eddy current testing was also developed by using HP-UX, RMB (Rock Mountain Basic) 21 figs, 13 tabs, 5 refs. (Author).

  7. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

  8. Steam generator deposit control program assessment at Comanche Peak

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, J.; Fellers, B. [TXU Electric (United States); Orbon, S. [Westinghouse (United States)

    2002-07-01

    Comanche Peak has employed a variety of methods to assess the effectiveness of the deposit control program. These include typical methods such as an extensive visual inspection program and detailed corrosion product analysis and trending. In addition, a recently pioneered technique, low frequency eddy current profile analysis (LFEC) has been utilized. LFEC provides a visual mapping of the magnetite deposit profile of the steam generator. Analysis of the LFEC results not only provides general area deposition rates, but can also provide local deposition patterns, which is indicative of steam generator performance. Other techniques utilized include trending of steam pressure, steam generator hideout-return, and flow assisted corrosion (FAC) results. The sum of this information provides a comprehensive assessment of the deposit control program effectiveness and the condition of the steam generator. It also provides important diagnostic and predictive information relative to steam generator life management and mitigative strategies, such as special cleaning procedures. This paper discusses the techniques employed by Comanche Peak Chemistry to monitor the effectiveness of the deposit control program and describes how this information is used in strategic planning. (authors)

  9. 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.

  10. Solubility of Rock in Steam Atmospheres of Planets

    Science.gov (United States)

    Fegley, Bruce, Jr.; Jacobson, Nathan S.; Williams, K. B.; Plane, J. M. C.; Schaefer, L.; Lodders, Katharina

    2016-06-01

    Extensive experimental studies show that all major rock-forming elements (e.g., Si, Mg, Fe, Ca, Al, Na, K) dissolve in steam to a greater or lesser extent. We use these results to compute chemical equilibrium abundances of rocky-element-bearing gases in steam atmospheres equilibrated with silicate magma oceans. Rocky elements partition into steam atmospheres as volatile hydroxide gases (e.g., Si(OH)4, Mg(OH)2, Fe(OH)2, Ni(OH)2, Al(OH)3, Ca(OH)2, NaOH, KOH) and via reaction with HF and HCl as volatile halide gases (e.g., NaCl, KCl, CaFOH, CaClOH, FAl(OH)2) in much larger amounts than expected from their vapor pressures over volatile-free solid or molten rock at high temperatures expected for steam atmospheres on the early Earth and hot rocky exoplanets. We quantitatively compute the extent of fractional vaporization by defining gas/magma distribution coefficients and show that Earth's subsolar Si/Mg ratio may be due to loss of a primordial steam atmosphere. We conclude that hot rocky exoplanets that are undergoing or have undergone escape of steam-bearing atmospheres may experience fractional vaporization and loss of Si, Mg, Fe, Ni, Al, Ca, Na, and K. This loss can modify their bulk composition, density, heat balance, and interior structure.

  11. A model for liquid film in steam turbine

    Science.gov (United States)

    Simon, Amelie; Marcelet, Meryem; Herard, Jean-Marc; Dorey, Jean-Marc; Lance, Michel

    2015-11-01

    Wetness in steam turbines induces losses and erosion. Drops are created due to the fast expansion of the steam (homogeneous nucleation) and the impurities in the steam (heterogeneous nucleation). The droplets grow and some among them settle on the blade leading to a thin liquid film. This film may then be atomized into coarse water drops which crash on the following blades. The liquid film configuration is a thin film on a curved surface, created by the drop deposit and under high steam friction. In steam turbines, the liquid film is subject to high rotational effect (rotor) and/or to negative gravity. Moreover, due to interfacial instabilities, some drops are torn off from the film. The retained approach is an integral formulation of the Navier-Stokes equation (or shallow water equation) with specific terms. The derivation of these equations requires some closure laws for the convection contributions, the Coriolis terms and for terms related to the additional mass coming from the drops deposit. Once chosen, mathematical and mechanical analyses are performed (hyperbolicity, entropy, galilean and rotational invariance). A two-dimensional code has been developed based on finite volume method to simulate numerically this liquid film model for steam turbines.

  12. Steam foam studies in the presence of residual oil

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.A.; Demiral, B.; Castanier, L.M.

    1992-05-01

    The lack of understanding regarding foam flow in porous media necessitates further research. This paper reports on going work at Stanford University aimed at increasing our understanding in the particular area of steam foams. The behavior of steam foam is investigated with a one dimensional (6 ft. {times} 2.15 in.) sandpack under residual oil conditions of approximately 12 percent. The strength of the in-situ generated foam, indicated by pressure drops, is significantly affected by injection procedure, slug size, and steam quality. The surfactant concentration effect is minor in the range studied. In the presence of residual oil the simultaneous injection of steam and surfactant fails to generate foam in the model even though the same procedure generates a strong foam in the absence of oil. Nevertheless when surfactant is injected as a slug ahead of the steam using a surfactant alternating (SAG) procedure, foam is generated. The suggested reason for the success of SAG is the increased phase mixing that results from steam continually having to reestablish a path through a slug of surfactant solution.

  13. A computationally efficient and accurate numerical representation of thermodynamic properties of steam and water for computations of non-equilibrium condensing steam flow in steam turbines

    Directory of Open Access Journals (Sweden)

    Hrubý Jan

    2012-04-01

    Full Text Available Mathematical modeling of the non-equilibrium condensing transonic steam flow in the complex 3D geometry of a steam turbine is a demanding problem both concerning the physical concepts and the required computational power. Available accurate formulations of steam properties IAPWS-95 and IAPWS-IF97 require much computation time. For this reason, the modelers often accept the unrealistic ideal-gas behavior. Here we present a computation scheme based on a piecewise, thermodynamically consistent representation of the IAPWS-95 formulation. Density and internal energy are chosen as independent variables to avoid variable transformations and iterations. On the contrary to the previous Tabular Taylor Series Expansion Method, the pressure and temperature are continuous functions of the independent variables, which is a desirable property for the solution of the differential equations of the mass, energy, and momentum conservation for both phases.

  14. Accelerated growth of oxide film on aluminium alloys under steam: Part II: Effects of alloy chemistry and steam vapour pressure on corrosion and adhesion performance

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Bordo, Kirill; Jellesen, Morten Stendahl

    2015-01-01

    The steam treatment of aluminium alloys with varying vapour pressure of steamresulted in the growth of aluminium oxyhydroxide films of thickness range between 450 - 825nm. The surface composition, corrosion resistance, and adhesion of the produced films was characterised by XPS, potentiodynamic...... of the vapour pressure of the steam. The accelerated corrosion and adhesion tests on steam generated oxide films with commercial powder coating verified that the performance of the oxide coating is highly dependent on the vapour pressure of the steam....

  15. Accelerated growth of oxide film on aluminium alloys under steam: Part II: Effects of alloy chemistry and steam vapour pressure on corrosion and adhesion performance

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Bordo, Kirill; Jellesen, Morten Stendahl;

    2015-01-01

    The steam treatment of aluminium alloys with varying vapour pressure of steamresulted in the growth of aluminium oxyhydroxide films of thickness range between 450 - 825nm. The surface composition, corrosion resistance, and adhesion of the produced films was characterised by XPS, potentiodynamic...... of the vapour pressure of the steam. The accelerated corrosion and adhesion tests on steam generated oxide films with commercial powder coating verified that the performance of the oxide coating is highly dependent on the vapour pressure of the steam....

  16. Steam injections wells: topics to consider in casing design of steam injection wells; Revestimento para pocos de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Antonio Carlos Farias [PETROBRAS, Recife, PE (Brazil). Gerencia de Perfuracao do Nordeste. Div. de Operacoes

    1994-07-01

    Steam injection is one of the processes used to increase production from very viscous oil reservoirs. A well is completed at a temperature of about 110 deg F and during steam injection that temperature varies around 600 deg F. Strain or breakdowns may occur to the casing, due to the critical conditions generated by the change of temperature. The usual casing design methods, do not take into account special environmental conditions, such as those which exist for steam injection. From the results of this study we come up to the conclusion that casing grade K-55, heavy weight with premium connections, without pre-stressing and adequately heated, is the best option for steam injection well completion for most of the fields in Brazil. (author)

  17. Analysis of Current Status of Steam Cracking Feed Production and Measures for Maximization of Steam Cracking Feed

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In recent years China has seen speedy development of its ethylene industry. Compared to other advanced countries the per capita ethylene consumption in China is still low. With successive startup of grassroots ethylene projects in China after 2006 and debottlenecking and expansion of existing ethylene units China will be confronted with the major issues related with increase of feedstocks for steam cracking. Naphtha is the main feedstock for producing ethylene, and the hydrocracked tail oil is increasing its share in the steam cracker feedstock pool over recent years. This article has analyzed the possibility for maximization of steam cracking feedstock and estimated steam cracker feedstock output based on processing 5 Mt/a of different crudes including the mixed crude transferred through Lu-Ning pipeline and Arabian light crude using corresponding process technologies at the refinery.

  18. GASFLOW Validation with Panda Tests from the OECD SETH Benchmark Covering Steam/Air and Steam/Helium/Air Mixtures

    Directory of Open Access Journals (Sweden)

    Peter Royl

    2009-01-01

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

  19. Processing of Advanced Cast Alloys for A-USC Steam Turbine Applications

    Science.gov (United States)

    Jablonski, Paul D.; Hawk, Jeffery A.; Cowen, Christopher J.; Maziasz, Philip J.

    2012-02-01

    The high-temperature components within conventional supercritical coal-fired power plants are manufactured from ferritic/martensitic steels. To reduce greenhouse-gas emissions, the efficiency of pulverized coal steam power plants must be increased to as high a temperature and pressure as feasible. The proposed steam temperature in the DOE/NETL Advanced Ultra Supercritical power plant is high enough (760°C) that ferritic/martensitic steels will not work for the majority of high-temperature components in the turbine or for pipes and tubes in the boiler due to temperature limitations of this class of materials. Thus, Ni-based superalloys are being considered for many of these components. Off-the-shelf forged nickel alloys have shown good promise at these temperatures, but further improvements can be made through experimentation within the nominal chemistry range as well as through thermomechanical processing and subsequent heat treatment. However, cast nickel-based superalloys, which possess high strength, creep resistance, and weldability, are typically not available, particularly those with good ductility and toughness that are weldable in thick sections. To address those issues related to thick casting for turbine casings, for example, cast analogs of selected wrought nickel-based superalloys such as alloy 263, Haynes 282, and Nimonic 105 have been produced. Alloy design criteria, melt processing experiences, and heat treatment are discussed with respect to the as-processed and heat-treated microstructures and selected mechanical properties. The discussion concludes with the prospects for full-scale development of a thick section casting for a steam turbine valve chest or rotor casing.

  20. Biomass-to-hydrogen via fast pyrolysis and catalytic steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Chornet, E.; Wang, D.; Czernik, S. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Pyrolysis of lignocellulosic biomass and reforming the pyroligneous oils is being studied as a strategy for producing hydrogen. Novel technologies for the rapid pyrolysis of biomass have been developed in the past decade. They provide compact and efficient systems to transform biomass into vapors that are condensed to oils, with yields as high as 75-80 wt.% of the anhydrous biomass. This {open_quotes}bio-oil{close_quotes} is a mixture of aldehydes, alcohols, acids, oligomers from the constitutive carbohydrates and lignin, and some water derived from the dehydration reactions. Hydrogen can be produced by reforming the bio-oil or its fractions with steam. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. The reforming facility can be designed to handle alternate feedstocks, such as natural gas and naphtha, if necessary. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. Existing catalytic data on the reforming of oxygenates have been studied to guide catalyst selection. Tests performed on a microreactor interfaced with a molecular beam mass spectrometer showed that, by proper selection of the process variables: temperature, steam-to-carbon ratio, gas hourly space velocity, and contact time, almost total conversion of carbon in the feed to CO and CO{sub 2} could be obtained. These tests also provided possible reaction mechanisms where thermal cracking competes with catalytic processes. Bench-scale, fixed bed reactor tests demonstrated high hydrogen yields from model compounds and carbohydrate-derived pyrolysis oil fractions. Reforming bio-oil or its fractions required proper dispersion of the liquid to avoid vapor-phase carbonization of the feed in the inlet to the reactor. A special spraying nozzle injector was designed and successfully tested with an aqueous fraction of bio-oil.

  1. A nonlinearity compensation method for a matrix converter drive

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Blaabjerg, Frede

    2005-01-01

    converter model using the direction of current. The proposed method does not need any additional hardware or complicated software and it is easy to realize by applying the algorithm to the conventional vector control. The proposed compensation method is applied for high-performance induction motor drives...

  2. Driving on Natural Gas, Greening the Gasunie Fleet

    NARCIS (Netherlands)

    Faber, Tom

    2008-01-01

    Driving on CNG is preferable to conventional fuels because of diversification of the energy mix, local availability of natural gas, the financial benefit and the transition function towards (sustain-able) biogas and emission reduction. Furthermore, the CNG technology is expected to be safer than con

  3. Personalised feedback and eco-driving : An explorative study

    NARCIS (Netherlands)

    Brouwer, R. F. T.; Stuiver, A.; Hof, T.; Kroon, L.; Pauwelussen, J.; Holleman, B.

    2015-01-01

    Conventional road transport has negative impact on the environment. Stimulating eco-driving through feedback to the driver about his/her energy conservation performance has the potential to reduce CO2 emissions and promote fuel cost savings. Not all drivers respond well to the same type of feedback.

  4. Personalised feedback and eco-driving: An explorative study

    NARCIS (Netherlands)

    Brouwer, R.F.T.; Stuiver, A.; Hof, T.; Kroon, L.; Pauwelussen, J.; Holleman, B.

    2015-01-01

    Conventional road transport has negative impact on the environment. Stimulating eco-driving through feedback to the driver about his/her energy conservation performance has the potential to reduce CO2 emissions and promote fuel cost savings. Not all drivers respond well to the same type o

  5. Personalised feedback and eco-driving: An explorative study

    NARCIS (Netherlands)

    Brouwer, R.F.T.; Stuiver, A.; Hof, T.; Kroon, L.; Pauwelussen, J.; Holleman, B.

    2015-01-01

    Conventional road transport has negative impact on the environment. Stimulating eco-driving through feedback to the driver about his/her energy conservation performance has the potential to reduce CO2 emissions and promote fuel cost savings. Not all drivers respond well to the same type

  6. Driving on Natural Gas, Greening the Gasunie Fleet

    NARCIS (Netherlands)

    Faber, Tom

    2008-01-01

    Driving on CNG is preferable to conventional fuels because of diversification of the energy mix, local availability of natural gas, the financial benefit and the transition function towards (sustain-able) biogas and emission reduction. Furthermore, the CNG technology is expected to be safer than con

  7. Driving on Natural Gas, Greening the Gasunie Fleet

    NARCIS (Netherlands)

    Faber, Tom

    2008-01-01

    Driving on CNG is preferable to conventional fuels because of diversification of the energy mix, local availability of natural gas, the financial benefit and the transition function towards (sustain-able) biogas and emission reduction. Furthermore, the CNG technology is expected to be safer than

  8. Investigations on catalyzed steam gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Mudge, L.K.; Weber, S.L.; Mitchell, D.H.; Sealock, L.J. Jr.; Robertus, R.J.

    1981-01-01

    The purpose of the study is to evaluate the technical and economic feasibility of producing specific gas products via the catalytic gasification of biomass. This report presents the results of research conducted from December 1977 to October 1980. The study was comprised of laboratory studies, process development, and economic analyses. The laboratory studies were conducted to develop operating conditions and catalyst systems for generating methane-rich gas, synthesis gases, hydrogen, and carbon monoxide; these studies also developed techniques for catalyst recovery, regeneration, and recycling. A process development unit (PDU) was designed and constructed to evaluate laboratory systems at conditions approximating commercial operations. The economic analyses, performed by Davy McKee, Inc. for PNL, evaluated the feasibility of adapting the wood-to-methane and wood-to-methanol processes to full-scale commercial operations. Plants were designed in the economic analyses to produce fuel-grade methanol from wood and substitute natural gas (SNG) from wood via catalytic gasification with steam.

  9. Steam generator tube integrity flaw acceptance criteria

    Energy Technology Data Exchange (ETDEWEB)

    Cochet, B. [FRAMATOME, Paris la Defense (France)

    1997-02-01

    The author discusses the establishment of a flaw acceptance criteria with respect to flaws in steam generator tubing. The problem is complicated because different countries take different approaches to the problem. The objectives in general are grouped in three broad areas: to avoid the unscheduled shutdown of the reactor during normal operation; to avoid tube bursts; to avoid excessive leak rates in the event of an accidental overpressure event. For each degradation mechanism in the tubes it is necessary to know answers to an array of questions, including: how well does NDT testing perform against this problem; how rapidly does such degradation develop; how well is this degradation mechanism understood. Based on the above information it is then possible to come up with a policy to look at flaw acceptance. Part of this criteria is a schedule for the frequency of in-service inspection and also a policy for when to plug flawed tubes. The author goes into a broad discussion of each of these points in his paper.

  10. Steam sterilization of air turbine dental handpieces.

    Science.gov (United States)

    Edwardsson, S; Svensäter, G; Birkhed, D

    1983-12-01

    The efficacy of autoclaving high-speed dental handpieces was tested in two types of downward displacement steam sterilizers (instrument autoclaves), commonly used in the dentist's office. Eight series of experiments were performed with various sterilization schedules. Lubrication oils with or without antimicrobial agent were used in four of the series. Each handpiece was inoculated with 1 ml of a suspension containing equal amounts of saliva and spores of Bacillus stearothermophilus (approx. 10(6) spores/ml). Neither sterilization at 120-124 degrees C for 20 min nor at 134-136 degrees C for 10 min resulted in complete inactivation of the spores in series in which the instruments were tested without oil or with oil containing no antimicrobial agent. However, when the handpieces were lubricated with oil containing isopropanol and formaldehyde and the schedule 134-136 degrees C/10 min was used, no growth was observed. The results indicate that instrument autoclaves with built-in programs of 120-124 degrees C/20 min and 134-136 degrees C/10 min could have insufficient capacity to sterilize lubricated or unlubricated dental handpieces. The use of oils containing an antimicrobial agent can overcome this problem.

  11. The Reasons of Steam Pipeline Elbow Rupture

    Directory of Open Access Journals (Sweden)

    Mesjasz A.

    2016-09-01

    Full Text Available In the paper the reasons for steam pipeline’s elbow material rupture, made of steel 13CrMo4-5 (15HM that is being used in the energetics. Based on the mechanical properties in the ambient temperature (Rm, Rp0,2 and elongation A5 and in the increased temperature (Rp0,2t it was found, that the pipeline elbow’s material sampled from the ruptured area has lower Rp0,2 i Rp0,2t by around 2% than it is a requirement for 13CrMo4-5 steel in it’s base state. The damage appeared as a result of complex stress state, that substantially exceeded the admissible tensions, what was the consequence of considerable structure degradation level. As a result of the microstructure tests on HITACHI S4200 microscope, the considerable development of the creeping process associates were found. Also the advances progress of the microstructure degradation was observed, which is substantial decomposition of bainite and multiple, with varied secretion size, and in most cases forming the micro cracks chains. With the use of lateral micro sections the creeping voids were observed, that creates at some places the shrinkage porosities clusters and micro pores.

  12. Estimation of Temperature Influence on Creep Rate of High-Temperature Elements in Steam Turbines and Steam Pipelines

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2011-01-01

    Full Text Available The paper considers a high temperature influence on strength characteristics of steam pipelines and steam turbine parts of high and medium pressure. The charts showing a decisive temperature importance in diffuse creep have been presented in the paper. The paper contains a calculation of steel self-diffusion coefficient. Dependence Dsd = f(t for more accurate assessment of  resource characteristics of the applied steel has been proposed in the paper.

  13. Speed Ratio Prediction and Performance Analysis of Single Ball Traction Drive for CVT

    Directory of Open Access Journals (Sweden)

    Kunal S. Marathe

    2014-06-01

    Full Text Available Drives are basically used to transmit power and speed from the prime mover to the machine. The power transmission and speed reduction between the prime-mover and the driven machine can be achieved by using conventional drives like Belt drive, Rope drive, Chain drive, Gears, etc. with their numerous advantages and disadvantages. There are many machines and mechanical units that under varying circumstances make it desirable to be able to drive at a barely perceptible speed, an intermediate speed or a high speed. Thus an infinitely variable (step less speed variation in which it is possible to get any desirable speed. Some mechanical, hydraulic, drives serve as such step less drives. However the torque versus speed characteristics of these drives do not match torque at low speeds. Hence the need of a step less or infinitely variable speed drive came into existence. The drive presented by the end of this research work is single ball traction drive for continuously variable transmission systems. Dissertation includes the brief history of existing drives, speed prediction methodology and performance analysis of the drive developed.

  14. In situ analysis of chemical components induced by steaming between fresh ginseng, steamed ginseng, and red ginseng.

    Science.gov (United States)

    In, Gyo; Ahn, Nam-Geun; Bae, Bong-Seok; Lee, Myoung-Woo; Park, Hee-Won; Jang, Kyoung Hwa; Cho, Byung-Goo; Han, Chang Kyun; Park, Chae Kyu; Kwak, Yi-Seong

    2017-07-01

    The chemical constituents of Panax ginseng are changed by processing methods such as steaming or sun drying. In the present study, the chemical change of Panax ginseng induced by steaming was monitored in situ. Samples were separated from the same ginseng root by incision during the steaming process, for in situ monitoring. Sampling was sequentially performed in three stages; FG (fresh ginseng) → SG (steamed ginseng) → RG (red ginseng) and 60 samples were prepared and freeze dried. The samples were then analyzed to determine 43 constituents among three stages of P. ginseng. The results showed that six malonyl-ginsenoside (Rg1, Rb1, Rb3, Rc, Rd, Rb2) and 15 amino acids were decreased in concentration during the steaming process. In contrast, ginsenoside-Rh1, 20(S)-Rg2, 20(S, R)-Rg3 and Maillard reaction product such as AF (arginine-fructose), AFG (arginine-fructose-glucose), and maltol were newly generated or their concentrations were increased. This study elucidates the dynamic changes in the chemical components of P. ginseng when the steaming process was induced. These results are thought to be helpful for quality control and standardization of herbal drugs using P. ginseng and they also provide a scientific basis for pharmacological research of processed ginseng (Red ginseng).

  15. Steam distillation extraction of ginger essential oil: Study of the effect of steam flow rate and time process

    Science.gov (United States)

    Fitriady, Muhammad Arifuddin; Sulaswatty, Anny; Agustian, Egi; Salahuddin, Aditama, Deska Prayoga Fauzi

    2017-01-01

    In Indonesia ginger was usually used as a seasoning for dishes, an ingredient for beverage and a source of herbal medicines. Beside raw usage, ginger can be processed to obtain the essential oil which has many advantages such as proven to be an active antimicrobial and having an antioxidant ability. There are a lot of methods to extract essential oil from ginger, one of which is steam distillation. The aim of the current study was to investigate the effect of variation of time process and steam flow rate in the yield on ginger essential oil steam distillation extraction process. It was found that the best operation condition was 0.35 ml/s as the steam flow rate which yields 2.43% oil. The optimum time process was predicted at 7.5 hours. The composition of the oil was varied depend on the flow rate and every flow rate has its own major component contained in the oil. Curcumene composition in the oil was increased as increased steam flow rate applied, but the composition of camphene was decreased along with the increasing steam flow rate.

  16. PURE DRIVE GT

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    在2004年奥林匹克赛事中,中国的李婷,孙甜甜取得了中国网球第一个金牌一女子双打冠军。忘记不了当时李婷挥动着她的BABOLAT(百保力)网拍Pure Drive Zylon 360°激动地拥抱着孙甜甜吵闹着,幸福地哭着的情景。

  17. Electric drive design methodology

    CERN Document Server

    Jufer, Marcel

    2013-01-01

    An electric drive that is designed or adapted to a specific application must take into account all the elements of the chain of constituent elements in its use and deployment. In addition to the motor, the transmission, power electronics, control, sensors, and electrical protection systems must be taken into account. The motor and the transmission can be optimized and designed to obtain the best energy efficiency assessment, in particular for dynamic nodes. An inventory and a characterization of these various components is proposed as part of this book's examination and explanation

  18. Electrical machines & drives

    CERN Document Server

    Hammond, P

    1985-01-01

    Containing approximately 200 problems (100 worked), the text covers a wide range of topics concerning electrical machines, placing particular emphasis upon electrical-machine drive applications. The theory is concisely reviewed and focuses on features common to all machine types. The problems are arranged in order of increasing levels of complexity and discussions of the solutions are included where appropriate to illustrate the engineering implications. This second edition includes an important new chapter on mathematical and computer simulation of machine systems and revised discussions o

  19. Electrical machines and drives

    CERN Document Server

    Hindmarsh, John

    2002-01-01

    Recent years have brought substantial developments in electrical drive technology, with the appearance of highly rated, very-high-speed power-electronic switches, combined with microcomputer control systems.This popular textbook has been thoroughly revised and updated in the light of these changes. It retains its successful formula of teaching through worked examples, which are put in context with concise explanations of theory, revision of equations and discussion of the engineering implications. Numerous problems are also provided, with answers supplied.The third edition in

  20. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes power stages and bias configurations suitable for driving an electrostatic transducer. Measurement results of a 300 V prototype amplifier are shown. Measuring THD across a high impedance source is discussed......, and a high voltage attenuation interface for an audio analyzer is presented. THD below 0:1% is reported....