WorldWideScience

Sample records for ejector cooling powered

  1. Evaluation of ejector performance for an organic Rankine cycle combined power and cooling system

    International Nuclear Information System (INIS)

    Zhang, Kun; Chen, Xue; Markides, Christos N.; Yang, Yong; Shen, Shengqiang

    2016-01-01

    Highlights: • The performance of an ejector in an Organic Rankine Cycle and ejector refrigeration cycle (EORC) was evaluated. • The achieved entrainment ratio and COP of an EORC system is affected significantly by the evaporator conditions (such as temperature, pressure and flow rate). • An optimum distance of 6 mm nozzle position was found that ensures a maximum entrainment ratio, the best efficiency and lowest loss in the ejector. • A reduced total pressure loss between the nozzle inlet and exit leads to a lower energy loss, a higher entrainment ratio and better overall ejector performance. - Abstract: Power-generation systems based on organic Rankine cycles (ORCs) are well suited and increasingly employed in the conversion of thermal energy from low temperature heat sources to power. These systems can be driven by waste heat, for example from various industrial processes, as well as solar or geothermal energy. A useful extension of such systems involves a combined ORC and ejector-refrigeration cycle (EORC) that is capable, at low cost and complexity, of producing useful power while having a simultaneous capacity for cooling that is highly desirable in many applications. A significant thermodynamic loss in such a combined energy system takes place in the ejector due to unavoidable losses caused by irreversible mixing in this component. This paper focuses on the flow and transport processes in an ejector, in order to understand and quantify the underlying reasons for these losses, as well as their sensitivity to important design parameters and operational variables. Specifically, the study considers, beyond variations to the geometric design of the ejector, also the role of changing the external conditions across this component and how these affect its performance; this is not only important in helping develop ejector designs in the first instance, but also in evaluating how the performance may shift (in fact, deteriorate) quantitatively when the device

  2. Performance test of solar-assisted ejector cooling system

    KAUST Repository

    Huang, Bin-Juine

    2014-03-01

    A solar-assisted ejector cooling/heating system (SACH-2k) is built and test result is reported. The solar-driven ejector cooling system (ECS) is connected in series with an inverter-type air conditioner (IAC). Several advanced technologies are developed in SACH-k2, including generator liquid level control in ECS, the ECS evaporator temperature control, and optimal control of fan power in cooling tower of ECS. From the field test results, the generator liquid level control performs quite well and keeps stable performance of ejector. The ECS evaporator temperature control also performs satisfactorily to keep ejector performance normally under low or fluctuating solar radiation. The fan power control system cooling tower performs stably and reduces the power consumption dramatically without affecting the ECS performance. The test results show that the overall system COPo including power consumptions of peripheral increases from 2.94-3.3 (IAC alone) to 4.06-4.5 (SACH-k2), about 33-43%. The highest COPo is 4.5. © 2013 Elsevier Ltd and IIR. All rights reserved.

  3. CFD analysis of ejector in a combined ejector cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Rusly, E.; Aye, Lu [International Technologies Centre (IDTC), Department of Civil and Environmental Engineering, The University of Melbourne, Melbourne, Vic. 3010 (Australia); Charters, W.W.S.; Ooi, A. [Department of Mechanical and Manufacturing Engineering, The University of Melbourne, Melbourne, Vic. 3010 (Australia)

    2005-11-01

    One-dimensional ejector analyses often use coefficients derived from experimental data for a set of operating conditions with limited functionality. In this study, several ejector designs were modelled using finite volume CFD techniques to resolve the flow dynamics in the ejectors. The CFD results were validated with available experimental data. Flow field analyses and predictions of ejector performance outside the experimental range were also carried out. During validation, data from CFD predicted the entrainment ratios with greater accuracy on definite area ratios, although no shock was recorded in the ejector. Predictions outside the experimental range-at operating conditions in a combined ejector-vapour compression system-and flow conditions resulting from ejector geometry variations are discussed. It is found that the maximum entrainment ratio happens in the ejector just before a shock occurs and that the position of the nozzle is an important ejector design parameter. (author)

  4. Theoretical studies of a hybrid ejector CO2 compression cooling system for vehicles and preliminary experimental investigations of an ejector cycle

    International Nuclear Information System (INIS)

    Chen, Xiangjie; Worall, Mark; Omer, Siddig; Su, Yuehong; Riffat, Saffa

    2013-01-01

    Highlights: ► Waste heat from vehicle exhausted gas was used as heat source for ejector. ► Ejector acts as the main interface between ejector and CO 2 VC sub-system. ► The effect of sub-cooling was analyzed. ► COP of ejector cooling system was measured between 0.2 and 0.5 during experiments. ► Enhanced ejector and vapour compression system. -- Abstract: This paper presents theoretical investigations into a hybrid ejector and CO 2 vapour compression (VC) system for road transport cooling. The purpose is to utilise the waste heat from exhaust gas and the VC sub-system to drive the ejector system, whose cooling effect will be employed to subcool the VC sub-system. Exploitation of the energy consumption ratio between ejector sub-system and CO 2 VC sub-system indicated that the more energy obtained from exhausted gas, the better system performance could be achieved for CO 2 VC sub-system, and hence higher cooling capacity of the VC sub-system at the same compression power. Thermodynamic simulations of two sub-systems and the hybrid system were presented. The results indicated that, at boiler temperature of 120 °C, evaporator temperature of 10 °C, a COP of 0.584 was achieved for hybrid system, with 22% improvement over a single ejector cycle. Preliminary experimental studies were carried out on a single ejector cycle, with boiler temperatures between 115 °C and 130 °C, and evaporator temperatures between 5 °C and 10 °C. The effects of various operation conditions on the overall ejector operation were coherently analysed. The COP of the ejector sub-system from experimental results was approximately 85% compared with simulation results, which showed a good agreement between theoretical analysis and experimental results.

  5. Efficiency analysis of alternative refrigerants for ejector cooling cycles

    International Nuclear Information System (INIS)

    Gil, Bartosz; Kasperski, Jacek

    2015-01-01

    Highlights: • Advantages of using alternative refrigerants as ejector refrigerants were presumed. • Computer software basing on theoretical model of Huang et al. (1999) was prepared. • Optimal temperature range of primary vapor for each working fluid was calculated. - Abstract: Computer software, basing on the theoretical model of Huang et al. with thermodynamic properties of selected refrigerants, was prepared. Investigation was focused on alternative refrigerants that belong to two groups of substances: common solvents (acetone, benzene, cyclopentane, cyclohexane and toluene) and non-flammable synthetic refrigerants applied in Organic Rankine Cycle (ORC) (R236ea, R236fa, R245ca, R245fa, R365mfc and RC318). Refrigerants were selected to detect a possibility to use them in ejector cooling system powered by a high-temperature heat source. A series of calculations were carried out for the generator temperature between 70 and 200 °C, with assumed temperatures of evaporation 10 °C and condensation 40 °C. Investigation revealed that there is no single refrigerant that ensures efficient operation of the system in the investigated temperature range of primary vapor. Each substance has its own maximum entrainment ratio and COP at its individual temperature of the optimum. The use of non-flammable synthetic refrigerants allows obtaining higher COP in the low primary vapor temperature range. R236fa was the most beneficial among the non-flammable synthetic refrigerants tested. The use of organic solvents can be justified only for high values of motive steam temperature. Among the solvents, the highest values of entrainment ratio and COP throughout the range of motive temperature were noted for cyclopentane. Toluene was found to be an unattractive refrigerant from the ejector cooling point of view

  6. Ejectors of power plants turbine units efficiency and reliability increasing

    Science.gov (United States)

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

    2017-11-01

    The functioning of steam turbines condensation systems influence on the efficiency and reliability of a power plant a lot. At the same time, the condensation system operating is provided by basic ejectors, which maintain the vacuum level in the condenser. Development of methods of efficiency and reliability increasing for ejector functioning is an actual problem of up-to-date power engineering. In the paper there is presented statistical analysis of ejector breakdowns, revealed during repairing processes, the influence of such damages on the steam turbine operating reliability. It is determined, that 3% of steam turbine equipment breakdowns are the ejector breakdowns. At the same time, about 7% of turbine breakdowns are caused by different ejector malfunctions. Developed and approved design solutions, which can increase the ejector functioning indexes, are presented. Intercoolers are designed in separated cases, so the air-steam mixture can’t move from the high-pressure zones to the low-pressure zones and the maintainability of the apparatuses is increased. By U-type tubes application, the thermal expansion effect of intercooler tubes is compensated and the heat-transfer area is increased. By the applied nozzle fixing construction, it is possible to change the distance between a nozzle and a mixing chamber (nozzle exit position) for operating performance optimization. In operating conditions there are provided experimental researches of more than 30 serial ejectors and also high-efficient 3-staged ejector EPO-3-80, designed by authors. The measurement scheme of the designed ejector includes 21 indicator. The results of experimental tests with different nozzle exit positions of the ejector EPO-3-80 stream devices are presented. The pressure of primary stream (water steam) is optimized. Experimental data are well-approved by the calculation results.

  7. Performance study of ejector cooling cycle at critical mode under superheated primary flow

    International Nuclear Information System (INIS)

    Tashtoush, Bourhan; Alshare, Aiman; Al-Rifai, Saja

    2015-01-01

    Highlights: • The ECC is modeled using EES Software and it is validated with published data. • Detailed analysis of the ECC with different refrigerants is conducted. • The constant pressure mixing is better than constant area mixing ejectors. • R134a is the selected refrigerant for the best cooling cycle performance. • The superheated primary flow at critical mode is achieved with EJ2 ejector used. - Abstract: In this work the performance of the ejector cooling cycle is investigated at critical mode, where, the effects of ejector geometry, refrigerant type, and operating condition are studied. The ejector cooling cycle is modeled with EES Software. The mass, momentum, and energy conservation principles are applied to the secondary and primary flows to investigate the performance of the ejector cooling cycle under superheated primary flow. The refrigerant R134 a is selected based on the merit of its environmental and performance characteristics. The primary working fluid in the refrigeration cycle is maintained at superheated conditions for optimal ejector performance. The solar generator temperature ranges are 80–100 °C. The operating temperature of evaporator range is 8–12 °C and the optimal condensation temperature is in the range of 28–40 °C. It is found that constant-pressure mixing ejector generates higher backpressure than constant-area mixing ejector for the same entrainment ratio and COP. The type of ejector is selected based on the performance criteria of the critical backpressure and choking condition of the primary flow, the so called EJ2 type ejector meets the criteria. The COP is found to be in the range of 0.59–0.67 at condenser backpressure of 24 bar due to higher critical condenser pressure and higher generator temperature

  8. Effects of ejector geometries on performance of ejector-expansion R410A air conditioner considering cooling seasonal performance factor

    International Nuclear Information System (INIS)

    Jeon, Yongseok; Jung, Jongho; Kim, Dongwoo; Kim, Sunjae; Kim, Yongchan

    2017-01-01

    Highlights: •The performance of an ejector-expansion R410A air conditioner is measured. •The effect of ejector geometries on the COP and CSPF is analyzed. •The mixing-section diameter of the ejector is optimized based on the CSPF. •The mixing-section diameter is optimized based on the climatic conditions. -- Abstract: The objective of this study was to investigate the effects of ejector geometries on the performance of an ejector-expansion air conditioner (EEAC) considering the cooling seasonal performance factor (CSPF). The performance of the EEAC using R410A was measured and analyzed by varying the compressor speed, outdoor-bin temperature, operating pressures, nozzle-throat diameter, and mixing-section diameter. The EEAC in the medium-capacity mode exhibited maximum coefficient of performance (COP) improvement, i.e., 7.5%, over the baseline (conventional) cycle. The optimum mixing-section diameter was determined to be 9 mm based on the CSPF. In addition, the optimum mixing-section diameter increased with an increase in the annual average outdoor temperature. The CSPF of the EEAC with the optimized mixing-section diameter improved in the range of 16.0–20.3% over the baseline cycle depending on the climatic conditions.

  9. Design-theoretical study of cascade CO2 sub-critical mechanical compression/butane ejector cooling cycle

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    In this paper an innovative micro-trigeneration system composed of a cogeneration system and a cascade refrigeration cycle is proposed. The cogeneration system is a combined heat and power system for electricity generation and heat production. The cascade refrigeration cycle is the combination of a CO2 mechanical compression refrigerating machine (MCRM), powered by generated electricity, and an ejector cooling machine (ECM), driven by waste heat and using refrigerant R600. Effect of the cycle operating conditions on ejector and ejector cycle performances is studied. Optimal geometry of the ejector and performance characteristics of ECM are determined at wide range of the operating conditions. The paper also describes a theoretical analysis of the CO2 sub-critical cycle and shows the effect of the MCRM evaporating temperature on the cascade system performance. The obtained data provide necessary information to design a small-scale cascade system with cooling capacity of 10 kW for application in micro-trigeneration systems. © 2010 Elsevier Ltd and IIR. All rights reserved.

  10. Development and Performance of an Advanced Ejector Cooling System for a Sustainable Built Environment

    Directory of Open Access Journals (Sweden)

    Paulo ePereira

    2015-06-01

    Full Text Available Ejector refrigeration is a promising technology for the integration into solar driven cooling systems because of its relative simplicity and low initial cost. The major drawback of such a system is associated to its relatively low coefficient of performance (COP under variable operating conditions. In order to overcome this problem, an advanced ejector was developed that changes its geometrical features depending on the upstream and downstream conditions. This paper provides a short overview of the development process and results of a small cooling capacity (1.5 kW solar driven cooling system using a variable geometry ejector. During the design steps, a number of theoretical works have been carried out, including the selection of the working fluid, the determination of the geometrical requirements and prototype design. Based on the analysis, R600a was selected as working fluid. A prototype was constructed with two independent variable geometrical factors: the area ratio and the nozzle exit position. A test rig was also assembled in order to test the ejector performance under controlled laboratory conditions and to elaborate a control algorithm for the variable geometry. Ejector performance was assessed by calculation of cooling cycle COP, entrainment ratio and critical back pressure. The results show that for a condenser pressure of 3 bar, an 80% increase in the COP was obtained when compared to the performance of a fixed geometry ejector. Experimental COP values varied between 0.4 and 0.8, depending on operating conditions. Currently the cooling cycle is being integrated into a solar driven demonstration site for long term in situ assessment.

  11. Performance evaluation of combined ejector LiBr/H2O absorption cooling cycle

    Directory of Open Access Journals (Sweden)

    Hasan Sh. Majdi

    2016-03-01

    Full Text Available The objective of this work is to develop a computer simulation program to evaluate the performance of solar-assited combined ejector absorption (single-effect cooling system using LiBr/H2O as a working fluid and operating under steady-state conditions. The ejector possess no moving parts and is simple and reliable, which makes it attractive for combination with single-stage absorption cycle for further improvement to the system's performance. In this research, improvement to the system is achieved by utilizing the potential kinetic energy of the ejector to enhance refrigeration efficiency. The effects of the entrainment ratio of the ejector, operating temperature, on the thermal loads, and system performance have been investigated. The results showed that the evaporator and condenser loads, post-addition of the ejector, is found to be permanently higher than that in the basic cycle, which indicates a significant enhancement of the proposed cycle and the cooling capacity of the system increasing with the increase in evaporator temperature and entrainment ratio. The COP of the modified cycle is improved by up to 60 % compared with that of the basic cycle at the given condition. This process stabilizes the refrigeration system, enhanced its function, and enabled the system to work under higher condenser temperatures.

  12. Performance test of solar-assisted ejector cooling system

    KAUST Repository

    Huang, Bin-Juine; Ton, Wei-Zhe; Wu, Chen-Chun; Ko, Hua-Wei; Chang, Hsien-Shun; Hsu, Hang-Yuen; Liu, Jen-Hao; Wu, Jia-Hung; Yen, Rue-Her

    2014-01-01

    are developed in SACH-k2, including generator liquid level control in ECS, the ECS evaporator temperature control, and optimal control of fan power in cooling tower of ECS. From the field test results, the generator liquid level control performs quite well

  13. Initial ratio optimization for the ejector cooling system with thermal pumping effect (ECSTPE)

    International Nuclear Information System (INIS)

    He, Yijian; Sun, Yongjun; Zhang, Sheng; Lyu, Yuanli; Chen, Guangming

    2016-01-01

    Graphical abstract: The existing ejector cooling systems with thermal pumping effect (ECSTPEs) have severe problems of thermal energy and chilling load waste. The deviations of the initial ratio from its optimal value would lead to the deviations of the time length of cooling stage (TLCS), and finally, result in the performance deteriorations of the ECSTPEs. The results of the case study showed that, for an ECSTPE with R134a, a 10-second deviation from the optimal TLCS led to a decrease of 5.6% in the COP value and an increase of 23.7% in the chilling load, when the generation temperature, the condensing temperature and the evaporation temperature were 85 °C, 35 °C and 10 °C, respectively. Therefore, accurately controlling the TLCS corresponding to the optimal TLCS, which is derived on the basis of the optimal initial ratio, can effectively improve the performance of ECSPTEs. - Highlights: • ECSTPEs encounter challenges for a great waste of heat and chilling water. • Initial ratio optimization is proposed to improve the performance of ECSTPEs. • Based on the optimal initial ratio, the optimal TLCS control strategy is obtained. • With the optimal TLCS control, COP values of the ECSTPEs are effectively enhanced. • Accordingly, the chilling loads of the ECSTPEs are greatly reduced. - Abstract: An ejector cooling system with thermal pumping effect (ECSTPE) could operate without consumption of electric power, but it discards a great amount of thermal energy, which generally results in a lower COP value and a greater chilling load. An innovative concept for the optimal initial ratio is therefore proposed to develop the optimal time length of cooling stage (TLCS) control method. The optimal TLCS control method effectively improves the ECSTPE performance. First, in this context, it was theoretically proven that the optimal initial ratio could be used to reduce the energy loss and the chilling load. Second, it was formulated how to achieve the optimal initial

  14. Parametric analysis for a new combined power and ejector-absorption refrigeration cycle

    International Nuclear Information System (INIS)

    Wang Jiangfeng; Dai Yiping; Zhang Taiyong; Ma Shaolin

    2009-01-01

    A new combined power and ejector-absorption refrigeration cycle is proposed, which combines the Rankine cycle and the ejector-absorption refrigeration cycle, and could produce both power output and refrigeration output simultaneously. This combined cycle, which originates from the cycle proposed by authors previously, introduces an ejector between the rectifier and the condenser, and provides a performance improvement without greatly increasing the complexity of the system. A parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the cycle performance. It is shown that heat source temperature, condenser temperature, evaporator temperature, turbine inlet pressure, turbine inlet temperature, and basic solution ammonia concentration have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. It is evident that the ejector can improve the performance of the combined cycle proposed by authors previously.

  15. Exergoeconomic analysis and multi-objective optimization of an ejector refrigeration cycle powered by an internal combustion (HCCI) engine

    International Nuclear Information System (INIS)

    Sadeghi, Mohsen; Mahmoudi, S.M.S.; Khoshbakhti Saray, R.

    2015-01-01

    Highlights: • Ejector refrigeration systems powered by HCCI engine is proposed. • A new two-dimensional model is developed for the ejector. • Multi-objective optimization is performed for the proposed system. • Pareto frontier is plotted for multi-objective optimization. - Abstract: Ejector refrigeration systems powered by low-grade heat sources have been an attractive research subject for a lot of researchers. In the present work the waste heat from exhaust gases of a HCCI (homogeneous charge compression ignition) engine is utilized to drive the ejector refrigeration system. Considering the frictional effects on the ejector wall, a new two-dimensional model is developed for the ejector. Energy, exergy and exergoeconomic analysis performed for the proposed system using the MATLAB software. In addition, considering the exergy efficiency and the product unit cost of the system as objective functions, a multi-objective optimization is performed for the system to find the optimum design variables including the generator, condenser and evaporator temperatures. The product unit cost is minimized while the exergy efficiency is maximized using the genetic algorithm. The optimization results are obtained as a set of optimal points and the Pareto frontier is plotted for multi-objective optimization. The results of the optimization show that ejector refrigeration cycle is operating at optimum state based on exergy efficiency and product unit cost when generator, condenser and evaporator work at 94.54 °C, 33.44 °C and 0.03 °C, respectively

  16. Power electronics cooling apparatus

    Science.gov (United States)

    Sanger, Philip Albert; Lindberg, Frank A.; Garcen, Walter

    2000-01-01

    A semiconductor cooling arrangement wherein a semiconductor is affixed to a thermally and electrically conducting carrier such as by brazing. The coefficient of thermal expansion of the semiconductor and carrier are closely matched to one another so that during operation they will not be overstressed mechanically due to thermal cycling. Electrical connection is made to the semiconductor and carrier, and a porous metal heat exchanger is thermally connected to the carrier. The heat exchanger is positioned within an electrically insulating cooling assembly having cooling oil flowing therethrough. The arrangement is particularly well adapted for the cooling of high power switching elements in a power bridge.

  17. Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

    International Nuclear Information System (INIS)

    Dai Yiping; Wang Jiangfeng; Gao Lin

    2009-01-01

    A new combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the ejector refrigeration cycle. This combined cycle produces both power output and refrigeration output simultaneously. It can be driven by the flue gas of gas turbine or engine, solar energy, geothermal energy and industrial waste heats. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. And a parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the performance of the combined cycle. In addition, a parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The results show that the biggest exergy loss due to the irreversibility occurs in heat addition processes, and the ejector causes the next largest exergy loss. It is also shown that the turbine inlet pressure, the turbine back pressure, the condenser temperature and the evaporator temperature have significant effects on the turbine power output, refrigeration output and exergy efficiency of the combined cycle. The optimized exergy efficiency is 27.10% under the given condition.

  18. Theoretical analysis of a combined power and ejector refrigeration cycle using zeotropic mixture

    International Nuclear Information System (INIS)

    Yang, Xingyang; Zhao, Li; Li, Hailong; Yu, Zhixin

    2015-01-01

    Highlights: • A combined power and refrigeration cycle using zeotropic mixture is analyzed. • The cycle performances with different mixture compositions are compared. • Both exergy and parametric analysis of the combined cycle are conducted. - Abstract: A theoretical study on a combined power and ejector refrigeration cycle using zeotropic mixture isobutane/pentane is carried out. The performances of different mixture compositions are compared. An exergy analysis is conducted for the cycle. The result reveals that most exergy destruction happens in the ejector, where more than 40% exergy is lost. The heat exchange in generator causes the second largest exergy loss, larger than 28%. As the mass fraction of isobutane changes ranges from 100% to 0%, the relative exergy destruction of each component is also changing. And mixture isobutane/pentane (50/50) has the maximum exergy efficiency of 7.83%. The parametric analysis of generator temperature, condenser temperature and evaporator temperature for all the mixtures shows that, all these three thermodynamic parameters have a strong effect on the cycle performance.

  19. Theoretical study and design of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane and intended for cooling of gas transported in a gas-main pipeline

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    This paper describes the construction and performance of a novel combined system intended for natural gas transportation and power production, and for cooling of gas transported in a gas-main pipeline. The proposed system includes a gas turbine compressor, a combined electrogenerating plant and an ejector refrigeration unit operating with a hydrocarbon refrigerant. The combined electrogenerating plant consists of a high-temperature steam-power cycle and a low-temperature hydrocarbon vapor power cycle, which together comprise a binary vapor system. The combined system is designed for the highest possible effectiveness of power generation and could find wide application in gas-transmission systems of gas-main pipelines. Application of the proposed system would enable year-round power generation and provide cooling of natural gas during periods of high ambient temperature operation. This paper presents the main results of a theoretical study and design performance specifications of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane. © 2010 Elsevier Ltd and IIR. All rights reserved.

  20. CFD Analysis of Nozzle Exit Position Effect in Ejector Gas Removal System in Geothermal Power Plant

    Directory of Open Access Journals (Sweden)

    Setyo Nugroho

    2015-06-01

    Full Text Available The single stage ejector is used to extract the Non CondensableGas (NCG in the condenser using the working principle of the Venturi tube. Three dimensional computational simulation of the ejector according to the operating conditions was conducted to determine the flow in the ejector. Motive steam entering through the convergent – divergent nozzle with increasing flow velocity so that the low pressure exist around the nozzle. Comparison is done also in a two dimensional simulation to know the differences occurring phenomena and flow inside ejector. Different simulation results obtained between two dimensional and three dimensional simulation. Reverse flow which occurs in the mixing chamber made the static pressure in the area has increased dramatically. Then the variation performed on Exit Nozzle Position (NXP to determine the changes of the flow of the NCG and the vacuum level of the ejector. Keywords: Ejector, NCG, CFD, Compressible flow.

  1. Technology of power plant cooling

    International Nuclear Information System (INIS)

    Maulbetsch, J.S.; Zeren, R.W.

    1976-01-01

    The following topics are discussed: the thermodynamics of power generation and the need for cooling water; the technical, economic, and legislative constraints within which the cooling problem must be solved; alternate cooling methods currently available or under development; the water treatment requirements of cooling systems; and some alternatives for modifying the physical impact on aquatic systems

  2. Thermodynamic analysis of a novel ejector expansion transcritical CO_2/N_2O cascade refrigeration (NEETCR) system for cooling applications at low temperatures

    International Nuclear Information System (INIS)

    Megdouli, K.; Ejemni, N.; Nahdi, E.; Mhimid, A.; Kairouani, L.

    2017-01-01

    Natural substances are becoming very promising for long term alternative for refrigeration purposes. In this paper, two natural refrigerants have been proposed and analyzed for a novel ejector expansion transcritical cascade refrigeration (NEETCR) system. Nitrous oxide (N_2O) is used in the low temperature circuit (LTC) whereas carbon dioxide (CO_2) is used in the high temperature circuit (HTC) of the NEETCR system. The reject of refrigerant vapor heat in the HTC is carried out through the use of transcritical carbon dioxide Rankine cycle. This produces work, which will be used to reduce the consumption work of compressors and feed pump thereby resulting in the improvement of the energy efficiency of the whole system. The simulation results were obtained by a computer FORTRAN program, where REFPROP 9 database was used to get the refrigerant thermodynamic properties. The simulation results showed that the (NEETCR) system had higher coefficient of performance and higher system second law efficiency compared to the EETCR system. An enhancement more than 9% in the COP and exergy efficiency of NEETCR system was found in comparison with EETCR system, when the cooling capacity and operating conditions of the two systems were the same. The increase of COP of NEETCR system and its efficiency along with the reduction of power consumption make it more practical for the use in cooling applications. - Highlights: • Exergy-energy analysis of two cascade refrigeration systems is conducted. • The input power of the NEETCR system is lower than that of the EETCR system. • The COP of the NEETCR system is higher than that of the EETCR system. • The NEETCR system is promise in cascade refrigeration system.

  3. Direct cooled power electronics substrate

    Science.gov (United States)

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  4. Power ramp rate capabilities of a 5 kW proton exchange membrane fuel cell system with discrete ejector control

    Science.gov (United States)

    Nikiforow, K.; Pennanen, J.; Ihonen, J.; Uski, S.; Koski, P.

    2018-03-01

    The power ramp rate capabilities of a 5 kW proton exchange membrane fuel cell (PEMFC) system are studied theoretically and experimentally for grid support service applications. The fuel supply is implemented with a fixed-geometry ejector and a discrete control solution without any anode-side pressure fluctuation suppression methods. We show that the stack power can be ramped up from 2.0 kW to 4.0 kW with adequate fuel supply and low anode pressure fluctuations within only 0.1 s. The air supply is implemented with a centrifugal blower. Air supply ramp rates are studied with a power increase executed within 1 and 0.2 s after the request, the time dictated by grid support service requirements in Finland and the UK. We show that a power ramp-up from 2.0 kW to 3.7 kW is achieved within 1 s with an initial air stoichiometry of 2.5 and within 0.2 s with an initial air stoichiometry of 7.0. We also show that the timing of the power ramp-up affects the achieved ancillary power capacity. This work demonstrates that hydrogen fueled and ejector-based PEMFC systems can provide a significant amount of power in less than 1 s and provide valuable ancillary power capacity for grid support services.

  5. Cooling power technology at a turning point

    International Nuclear Information System (INIS)

    Hese, L.H.

    1978-01-01

    From freshwater cooling and efflux condenser cooling to wet recirculation cooling, hybrid and dry cooling towers, cooling tower technology has seen a development characterized by higher cooling tower costs and reduced power plant efficiency. Therefore, all research work done at the moment concentrates on making up for the economic losses connected with improved environmental protection. (orig.) [de

  6. Atmospheric emissions from power plant cooling towers

    International Nuclear Information System (INIS)

    Micheletti, W.

    2006-01-01

    Power plant recirculated cooling systems (cooling towers) are not typically thought of as potential sources of air pollution. However, atmospheric emissions can be important considerations that may influence cooling tower design and operation. This paper discusses relevant U.S. environmental regulations for potential atmospheric pollutants from power plant cooling towers, and various methods for estimating and controlling these emissions. (orig.)

  7. Power semiconductor device adaptive cooling assembly

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to a power semiconductor device (100) cooling assembly for cooling a power semiconductor device (100), wherein the assembly comprises an actively cooled heat sink (102) and a controller (208; 300), wherein the controller (208; 300) is adapted for adjusting the cooling

  8. Study of an innovative ejector heat pump-boosted district heating system

    International Nuclear Information System (INIS)

    Zhang, Bo; Wang, Yuanchao; Kang, Lisha; Lv, Jinsheng

    2013-01-01

    An Ejector heat pump-boosted District Heating (EDH) system is proposed to improve the heating capacity of existing district heating systems with Combined Heat and Power (CHP). In the EDH, two ejector heat pumps are installed: a primary heat pump (HP 1 ) at the heating station and a secondary heat pump (HP 2 ) at the heating substation. With the EDH, the low-grade waste heat from circulating cooling water in the CHP is recycled and the temperature difference between the water supply and the return of the primary heating network is increased. A thermodynamic model was provided. An experimental study was carried out for both HP 1 and HP 2 to verify the predicting performance. The results show that the COP of HP 1 can reach 1.5–1.9, and the return water temperature of the primary heating network could be decreased to 35 °C with HP 2 . A typical case study for the EDH was analyzed. -- Highlights: • An ejector heat pump-boosted district heating (EDH) is proposed. • The 1st ejector heat pump in EDH recycles heat from cooling water of the CHP. • The 2nd ejector heat pump in EDH boosts the thermal energy utilization of the primary heating network. • Modeling and experimental studies are presented

  9. Cooling towers for thermal power plants

    International Nuclear Information System (INIS)

    Chaboseau, J.

    1987-01-01

    After a brief recall on cooling towers testing and construction, this paper presents four examples of very large French nuclear power plant cooling towers, and one of an Australian thermal power plant [fr

  10. Thermo-economic analysis and optimization of a combined cooling and power (CCP) system for engine waste heat recovery

    International Nuclear Information System (INIS)

    Xia, Jiaxi; Wang, Jiangfeng; Lou, Juwei; Zhao, Pan; Dai, Yiping

    2016-01-01

    Highlights: • A combined cooling and power system was proposed for engine waste heat recovery. • Effects of key parameters on thermodynamic performance of the system were studied. • Exergoeconomic parameter analysis was performed for the system. • A single-objective optimization by means of genetic algorithm was carried out. - Abstract: A combined cooling and power (CCP) system is developed, which comprises a CO 2 Brayton cycle (BC), an organic Rankine cycle (ORC) and an ejector refrigeration cycle for the cascade utilization of waste heat from an internal combustion engine. By establishing mathematical model to simulate the overall system, thermodynamic analysis and exergoeconomic analysis are conducted to examine the effects of five key parameters including the compressor pressure ratio, the compressor inlet temperature, the BC turbine inlet temperature, the ORC turbine inlet pressure and the ejector primary flow pressure on system performance. What’s more, a single-objective optimization by means of genetic algorithm (GA) is carried out to search the optimal system performance from viewpoint of exergoeconomic. Results show that the increases of the BC turbine inlet temperature, the ORC turbine inlet pressure and the ejector primary flow pressure are benefit to both thermodynamic and exergoeconimic performances of the CCP system. However, the rises in compressor pressure ratio and compressor inlet temperature will lead to worse system performances. By the single-objective optimization, the lowest average cost per unit of exergy product for the overall system is obtained.

  11. Solar-powered cooling system

    Science.gov (United States)

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  12. A Summary/Overview of Ejector Augmentor Theory and Performance. Volume 2. Bibliography

    Science.gov (United States)

    1979-09-01

    229. 1/3 DPDF A, E,T Brown, G. A., and Levy, E. K., "Liquid Metal Magnetohydrodynamic SS F, Power Generation with Condensing Ejector Cycles’’, Paper SM ...SPSF C, Duvvuri, T., and Raghunath , B., "Theoretical Study of Turbulent SS F Mixing Along Curved Jet Boundaries", Duvvuri Research Associates Tech. Rep...Engine Cooling System for a Turbojet Powered Aircraft, Report No. SM -14020, Douglas Aircraft Company, Incorporated, Santa Monica, California, May

  13. Cooling towers of nuclear power plants

    International Nuclear Information System (INIS)

    Mikyska, L.

    1986-01-01

    The specifications are given of cooling towers of foreign nuclear power plants and a comparison is made with specifications of cooling towers with natural draught in Czechoslovak nuclear power plants. Shortcomings are pointed out in the design of cooling towers of Czechoslovak nuclear power plants which have been derived from conventional power plant design. The main differences are in the adjustment of the towers for winter operation and in the designed spray intensity. The comparison of selected parameters is expressed graphically. (J.B.)

  14. Cooling methods for power plants

    International Nuclear Information System (INIS)

    Gaspersic, B.; Fabjan, L.; Petelin, S.

    1977-01-01

    There are some results of measurements carried out on the wet cooling tower 275 MWe at TE Sostanj and on the experimental cooling tower at Jozef Stefan Institute, as well. They are including: the measurements of the output air conditions, the measurements of the cross current of water film and vapour-air flowing through two plates, and the distribution of velocity in boundary layer measured by anemometer

  15. Thermoelectric self-cooling for power electronics: Increasing the cooling power

    International Nuclear Information System (INIS)

    Martinez, Alvaro; Astrain, David; Aranguren, Patricia

    2016-01-01

    Thermoelectric self-cooling was firstly conceived to increase, without electricity consumption, the cooling power of passive cooling systems. This paper studies the combination of heat pipe exchangers and thermoelectric self-cooling, and demonstrates its applicability to the cooling of power electronics. Experimental tests indicate that source-to-ambient thermal resistance reduces by around 30% when thermoelectric self-cooling system is installed, compared to that of the heat pipe exchanger under natural convection. Neither additional electric power nor cooling fluids are required. This thermal resistance reaches 0.346 K/W for a heat flux of 24.1 kW/m"2, being one order of magnitude lower than that obtained in previous designs. In addition, the system adapts to the cooling demand, reducing this thermal resistance for increasing heat. Simulation tests have indicated that simple system modifications allow relevant improvements in the cooling power. Replacement of a thermoelectric module with a thermal bridge leads to 33.54 kW/m"2 of top cooling power. Likewise, thermoelectric modules with shorter legs and higher number of pairs lead to a top cooling power of 44.17 kW/m"2. These results demonstrate the applicability of thermoelectric self-cooling to power electronics. - Highlights: • Cooling power of passive systems increased. • No electric power consumption. • Applicable for the cooling of power electronics. • Up to 44.17 kW/m"2 of cooling power, one order of magnitude higher. • Source-to-ambient thermal resistance reduces by 30%.

  16. Design-theoretical study of cascade CO2 sub-critical mechanical compression/butane ejector cooling cycle

    KAUST Repository

    Petrenko, V.O.; Huang, B.J.; Ierin, V.O.

    2011-01-01

    In this paper an innovative micro-trigeneration system composed of a cogeneration system and a cascade refrigeration cycle is proposed. The cogeneration system is a combined heat and power system for electricity generation and heat production

  17. Cooling water requirements and nuclear power plants

    International Nuclear Information System (INIS)

    Rao, T.S.

    2010-01-01

    Indian nuclear power programme is poised to scuttle the energy crisis of our time by proposing joint ventures for large power plants. Large fossil/nuclear power plants (NPPs) rely upon water for cooling and are therefore located near coastal areas. The amount of water a power station uses and consumes depends on the cooling technology used. Depending on the cooling technology utilized, per megawatt existing NPPs use and consume more water (by a factor of 1.25) than power stations using other fuel sources. In this context the distinction between 'use' and 'consume' of water is important. All power stations do consume some of the water they use; this is generally lost as evaporation. Cooling systems are basically of two types; Closed cycle and Once-through, of the two systems, the closed cycle uses about 2-3% of the water volumes used by the once-through system. Generally, water used for power plant cooling is chemically altered for purposes of extending the useful life of equipment and to ensure efficient operation. The used chemicals effluent will be added to the cooling water discharge. Thus water quality impacts on power plants vary significantly, from one electricity generating technology to another. In light of massive expansion of nuclear power programme there is a need to develop new ecofriendly cooling water technologies. Seawater cooling towers (SCT) could be a viable option for power plants. SCTs can be utilized with the proper selection of materials, coatings and can achieve long service life. Among the concerns raised about the development of a nuclear power industry, the amount of water consumed by nuclear power plants compared with other power stations is of relevance in light of the warming surface seawater temperatures. A 1000 MW power plant uses per day ∼800 ML/MW in once through cooling system; while SCT use 27 ML/MW. With the advent of new marine materials and concrete compositions SCT can be constructed for efficient operation. However, the

  18. Secondary Flow Patterns of Liquid Ejector with Computational Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kwisung; Yun, Jinwon; Yu, Sangseok [Chungnam National University, Daejeon (Korea, Republic of); Sohn, Inseok [COAVIS, Sejong (Korea, Republic of); Seo, Yongkyo [Korea Automotive Technology Institute, Cheonan (Korea, Republic of)

    2015-02-15

    An ejector is a type of non-powered pump that is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for fueling the vehicle because of less failures and simple structure. Since most of ejectors in industry are gas-to-gas and liquid to gas ejector, many research activities have been reported in optimization of gas ejector. On the other hand, the liquid ejector is also applied in many industry but few research has been reported. The liquid ejector occurs cavitation, and it causes damage of parts. Cavitation has bees observed at the nozzle throat at the specified pressure. In this study, a two-dimensional axisymmetric simulation of a liquid-liquid ejector was carried out using five different parameters. The angle of the nozzle plays an important role in the cavitation of a liquid ejector, and the performance characteristics of the flow ratio showed that an angle of 35° was the most advantageous. The simulation results showed that the performance of the liquid ejector and the cavitation effect have to be considered simultaneously.

  19. Developments in power plant cooling systems

    International Nuclear Information System (INIS)

    Agarwal, N.K.

    1993-01-01

    A number of cooling systems are used in the power plants. The condenser cooling water system is one of the most important cooling systems in the plant. The system comprises a number of equipment. Plants using sea water for cooling are designed for the very high corrosion effects due to sea water. Developments are taking place in the design, materials of construction as well as protection philosophies for the various equipment. Power optimisation of the cycle needs to be done in order to design an economical system. Environmental (Protection) Act places certain limitations on the effluents from the plant. An attempt has been made in this paper to outline the developing trends in the various equipment in the condenser cooling water systems used at the inland as well as coastal locations. (author). 5 refs., 6 refs

  20. Investigation of an experimental ejector refrigeration machine operating with refrigerant R245fa at design and off-design working conditions. Part 1. Theoretical analysis

    KAUST Repository

    Shestopalov, K.O.; Huang, B.J.; Petrenko, V.O.; Volovyk, O.S.

    2015-01-01

    , which enable its wide application in the production of cooling. In this paper the theoretical analysis of ejector design and ejector refrigeration cycle performance is presented. It is shown that ERM performance characteristics depend strongly

  1. Small high cooling power space cooler

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E. [Northrop Grumman Aerospace Systems Redondo Beach, Ca, 90278 (United States)

    2014-01-29

    The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

  2. Power electronics substrate for direct substrate cooling

    Science.gov (United States)

    Le, Khiet [Mission Viejo, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA; Yankoski, Edward P [Corona, CA; Smith, Gregory S [Woodland Hills, CA

    2012-05-01

    Systems and apparatus are provided for power electronics substrates adapted for direct substrate cooling. A power electronics substrate comprises a first surface configured to have electrical circuitry disposed thereon, a second surface, and a plurality of physical features on the second surface. The physical features are configured to promote a turbulent boundary layer in a coolant impinged upon the second surface.

  3. Designing and simulating a nitinol-based micro ejector

    Directory of Open Access Journals (Sweden)

    Yesid Mora Sierra

    2012-01-01

    Full Text Available This paper describes pico-droplet ejector design and simulation. The actuation system was based on two interconnected nitinol membranes’ shape memory effect. Ejected volume was 12pL and it operated at 30°C to 64°C. Ejecting excitation voltage was 12V and the ejecting energy required by actuator operation was 26µJ per drop. These pico-liter ejectors could have applications in making, lubricating and cooling integrated circuits.

  4. Vapour recompression by ejectors

    Energy Technology Data Exchange (ETDEWEB)

    Krejci, S; Komurka, J; Gemza, E; Kaspar, J; Wergner, F

    1985-01-01

    Thermodynamic analyses using the concept of exergy are considered very important in analysing the energy balances of processes. The way in which such a technique can be applied to ejectors is discussed. (author).

  5. Smart Control System to Optimize Time of Use in a Solar-Assisted Air-Conditioning by Ejector for Residential Sector

    Directory of Open Access Journals (Sweden)

    Giovanna Avedian-González

    2018-02-01

    Full Text Available The present work provides a series of theoretical improvements of a control strategy in order to optimize the time of use of solar air-conditioning by an ejector distributed in multiple solar collectors of vacuum tubes for the residential sector, which will allow us to reduce carbon-dioxide emissions, costs and electrical energy consumption. In a solar ejector cooling system, the instability of the solar source of energy causes an operational conflict between the solar thermal system and ejector cooling cycle. A fuzzy control structure for the supervisory ejector cycle and multi-collector control system is developed: the first control is applied to control the mass flow of the generator and the evaporator for different cooling capacities (3, 3.5, 4, 4.5 and 5 kW and set a temperature reference according to the operating conditions; the second is applied to keep a constant temperature power source that feeds the low-grade ejector cooling cycle using R134aas refrigerant. For the present work, the temperature of the generator oscillates between 65 °C and 90 °C, a condenser temperature of 30 °C and an evaporator temperature of 10 °C. For the purpose of optimization, there are different levels of performance for time of use: the Mode 0 (economic gives a performance of 17.55 h, Mode 5 (maximum cooling power 14.86 h and variable mode (variable mode of capacities 16.25 h, on average. Simulations are done in MATLAB-Simulink applying fuzzy logic for a mathematical model of the thermal balance. They are compared with two different types of solar radiation: real radiation and disturbed radiation.

  6. Heat pipe cooling of power processing magnetics

    Science.gov (United States)

    Hansen, I. G.; Chester, M.

    1979-01-01

    The constant demand for increased power and reduced mass has raised the internal temperature of conventionally cooled power magnetics toward the upper limit of acceptability. The conflicting demands of electrical isolation, mechanical integrity, and thermal conductivity preclude significant further advancements using conventional approaches. However, the size and mass of multikilowatt power processing systems may be further reduced by the incorporation of heat pipe cooling directly into the power magnetics. Additionally, by maintaining lower more constant temperatures, the life and reliability of the magnetic devices will be improved. A heat pipe cooled transformer and input filter have been developed for the 2.4 kW beam supply of a 30-cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. This paper presents the design details along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor.

  7. Power plant cooling systems: trends and challenges

    International Nuclear Information System (INIS)

    Rittenhouse, R.C.

    1979-01-01

    A novel design for an intake and discharge system at the Belle River plant is described followed by a general discussion of water intake screens and porous dikes for screening fish and zooplankton. The intake system for the San Onofre PWR plant is described and the state regulations controlling the use of water for power plants is discussed. The use of sewage effluent as a source of cooling water is mentioned with reference to the Palo Verde plant. Progress in dry cooling and a new wet/dry tower due to be installed at the San Juan plant towards the end of this year, complete the survey

  8. Combined cold compressor/ejector helium refrigerator cycle

    International Nuclear Information System (INIS)

    Schlafke, A.P.; Brown, D.P.; Wu, K.C.

    1984-01-01

    This chapter demonstrates how the use of a cold compressor in series with an ejector is an effective way to produce the desired low pressure in a helium refrigeration system. The cold compressor is tentatively located at the low pressure side below the J-T heat exchanger. The ejector is the first stage and the cold compressor is the second stage of the two-stage pumping system. A centrifugal, oil-bearing type compressor was installed on the R and D refrigerator at the Brookhaven National Laboratory. It is determined that the combined cold compressor and ejector system produces a lower temperature on the same load or more cooling at the same temperature compared with a system which uses an ejector alone. Results of the test showed a gain of 20%

  9. Optimal control and performance test of solar-assisted cooling system

    KAUST Repository

    Huang, B.J.

    2010-10-01

    The solar-assisted cooling system (SACH) was developed in the present study. The ejector cooling system (ECS) is driven by solar heat and connected in parallel with an inverter-type air conditioner (A/C). The cooling load can be supplied by the ECS when solar energy is available and the input power of the A/C can be reduced. In variable weather, the ECS will probably operate at off-design condition of ejector and the cooling capability of the ECS can be lost completely. In order to make the ejector operate at critical or non-critical double-choking condition to obtain a better performance, an electronic expansion valve was installed in the suction line of the ejector to regulate the opening of the expansion valve to control the evaporator temperature. This will make the SACH always produce cooling effect even at lower solar radiation periods while the ejector performs at off-design conditions. The energy saving of A/C is experimentally shown 50-70% due to the cooling performance of ECS. The long-term performance test results show that the daily energy saving is around 30-70% as compared to the energy consumption of A/C alone (without solar-driven ECS). The total energy saving of A/C is 52% over the entire test period. © 2010 Elsevier Ltd. All rights reserved.

  10. Study of an ejector-absorption refrigeration cycle with an adaptable ejector nozzle for different working conditions

    International Nuclear Information System (INIS)

    Vereda, C.; Ventas, R.; Lecuona, A.; Venegas, M.

    2012-01-01

    Highlights: ► An absorption refrigeration cycle with an ejector device at the absorber inlet is presented. ► This cycle is able to reduce up to 9 °C the temperature of onset of refrigerant generation without extra energy consumption. ► At very low driving temperatures it allows increasing the cooling capacity. ► The ejector device proposed has a partially variable geometry and we study its influence on the cycle performances. -- Abstract: This paper presents a numerical model of an ejector-absorption (single-effect) refrigeration cycle with ammonia–lithium nitrate solution as working fluid, operating under steady-state conditions. In this cycle, the ejector is located at the absorber inlet replacing the solution expansion valve. The liquid–gas ejector entrains refrigerant vapor from the evaporator; this way the absorber pressure becomes higher than the evaporator pressure without any additional energy consumption. The objective of this numerical model is to evaluate the influence of the ejector geometry on the cycle performances and to determine the range of the heat source temperature in which it is convenient to use a practical ejector in the absorption cycle. The simulation is based on UA-ΔT lm models for separate heat transfer regions in a novel implementation using plate-type heat exchangers and this way the results are offered as a function of the external temperatures. This study focuses on evaluating the feasibility of an ejector whose nozzle area is adjustable while the rest of the ejector dimensions are fixed, thus being more feasible than complete variable geometry ejectors. The cycle performance is reported for different mixing tube constant diameters. Results of the simulation show that the use of an ejector allows, among others, to decrease the activation temperature approximately 9 °C in respect to the conventional single-effect absorption cycle and increasing the COP for moderate temperatures. The variable ejector nozzle geometry is

  11. Noise from cooling towers of power parks

    International Nuclear Information System (INIS)

    Zakaria, J.; Moore, F.K.

    1975-01-01

    A study is presented of the noise pollution problem for large power parks proposed for the future. Such parks might have an area of about 75 sq. miles, and a generating capacity up to 48000 MW. A comparative analysis has been done for natural and mechanical-draft wet towers as the major sources of acoustic power. Noise radiation from single isolated towers as well as from a dispersed array of towers has been considered for both types of cooling systems. Major noise attenuation effects considered are due to the atmospheric absorption and A-weighting. Conditions of 60F and 70 percent relative humidity in a still atmosphere have been assumed

  12. Subsonic Performance of Ejector Systems

    Science.gov (United States)

    Weil, Samuel

    Combined cycle engines combining scramjets with turbo jets or rockets can provide efficient hypersonic flight. Ejectors have the potential to increase the thrust and efficiency of combined cycle engines near static conditions. A computer code was developed to support the design of a small-scale, turbine-based combined cycle demonstrator with an ejector, built around a commercially available turbojet engine. This code was used to analyze the performance of an ejector system built around a micro-turbojet. With the use of a simple ejector, net thrust increases as large as 20% over the base engine were predicted. Additionally the specific fuel consumption was lowered by 10%. Increasing the secondary to primary area ratio of the ejector lead to significant improvements in static thrust, specific fuel consumption (SFC), and propulsive efficiency. Further ejector performance improvements can be achieved by using a diffuser. Ejector performance drops off rapidly with increasing Mach number. The ejector has lower thrust and higher SFC than the turbojet core at Mach numbers above 0.2. When the nozzle chokes a significant drop in ejector performance is seen. When a diffuser is used, higher Mach numbers lead to choking in the mixer and a shock in the nozzle causing a significant decrease in ejector performance. Evaluation of different turbo jets shows that ejector performance depends significantly on the properties of the turbojet. Static thrust and SFC improvements can be achieved with increasing ejector area for all engines, but size of increase and change in performance at higher Mach numbers depend heavily on the turbojet. The use of an ejector in a turbine based combined cycle configuration also increases performance at static conditions with a thrust increase of 5% and SFC decrease of 5% for the tested configuration.

  13. Design and implementation of ejector driven micropump

    International Nuclear Information System (INIS)

    Chuech, S.G.; Chen, C.-C.; Lu, J.-C.; Yan, M.-M.

    2007-01-01

    The working principle of the ejector, which converts fluid energy into suction power, was utilized for designing the miniaturized pump. The present micropump with the structure scale in the size range of microns to millimeters was fabricated through the MEMS manufacturing processes. The pump may offer portable convenience and requires no electrical power; especially it can be used in many applications where electricity is unsafe or impractical. To optimize the design, the size of the diffuser throat in the micropump was varied and used as a design parameter. The optimization results indicate that there exists an optimal width for the diffuser throat, which is critically important to the design of an ejector driven micropump. For testing the pump, the fabricated micropump was driven by compressed air from a portable can to pump water and air. In the experimental tests, the pumping flow rates of water and air were measured and compared for design optimization

  14. Cooling facility of nuclear power plant

    International Nuclear Information System (INIS)

    Arai, Kenji; Nagasaki, Hideo.

    1992-01-01

    In a cooling device of a nuclear power plant, an exhaust pipe for an incondensible gas is branched. One of the branched exhaust pipes is opened in a pressure suppression pool water in a suppression chamber containing pool water and the other is opened at a lower portion of a dry well incorporating a pressure vessel. In a state where the pressure in the dry well is higher than that in the suppression chamber, an off-gas is exhausted effectively by way of the exhaustion pipe in communication with the suppression chamber. In a state where there is no difference between the pressures and the opening end of the exhaustion pipe in communication with the suppression chamber is sealed with water, off-gas is exhausted by way of the exhaustion pipe in communication with the lower portion of the dry well. Then, since the incondensible gas in a heat transfer pipe is not accumulated, after-heat can be removed efficiently. Satisfactory cooling is maintained even after the coincidence of the pressures in the dry well with that in the suppression chamber, to decrease a pressure in a reactor container. (N.H.)

  15. Performance Analysis of XCPC Powered Solar Cooling Demonstration Project

    Science.gov (United States)

    Widyolar, Bennett K.

    A solar thermal cooling system using novel non-tracking External Compound Parabolic Concentrators (XCPC) has been built at the University of California, Merced and operated for two cooling seasons. Its performance in providing power for space cooling has been analyzed. This solar cooling system is comprised of 53.3 m2 of XCPC trough collectors which are used to power a 23 kW double effect (LiBr) absorption chiller. This is the first system that combines both XCPC and absorption chilling technologies. Performance of the system was measured in both sunny and cloudy conditions, with both clean and dirty collectors. It was found that these collectors are well suited at providing thermal power to drive absorption cooling systems and that both the coinciding of available thermal power with cooling demand and the simplicity of the XCPC collectors compared to other solar thermal collectors makes them a highly attractive candidate for cooling projects.

  16. Auxiliary cooling device for power plant

    International Nuclear Information System (INIS)

    Yamanoi, Kozo.

    1996-01-01

    An auxiliary cooling sea water pipeline for pumping up cooling sea water, an auxiliary cooling sea water pipeline and a primary side of an auxiliary cooling heat exchanger are connected between a sea water taking vessel and a sea water discharge pit. An auxiliary cooling water pump is connected to an auxiliary water cooling pipeline on the second side of the auxiliary cooling heat exchanger. The auxiliary cooling water pipeline is connected with each of auxiliary equipments of a reactor system and each of auxiliary equipments of the turbine system connected to a turbine auxiliary cooling water pipeline in parallel. During ordinary operation of the reactor, heat exchange for each of the auxiliary equipments of the reactor and heat exchange for each of the equipments of the turbine system are conducted simultaneously. Since most portions of the cooling devices of each of the auxiliary equipments of the reactor system and each of the auxiliary equipments of the turbine system can be used in common, the operation efficiency of the cooling device is improved. In addition, the space for the pipelines and the cost for the equipments can be reduced. (I.N.)

  17. World's first ejector cycle for mobile refrigerators to stop global warming

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Hirotsugu [Denso Corporation, Kariya (Japan); Gyoeroeg, Tibor [DENSO AUTOMOTIVE Deutschland GmbH, Eching (Germany)

    2010-07-01

    The development of energy-saving technologies is in great demand recently to stop global warming. We are committed to developing the Ejector Cycle as an energy-saving technology for refrigerators and air conditioners. The ejector, which is an energy-saving technological innovation, improves the efficiency of the refrigeration cycle by effectively using the expansion energy that is lost in the conventional vapor-compression cycle, and is applicable to almost all vapor-compression refrigerating air conditioners, thus improving the efficiency of the refrigeration cycle. Concerning the application of the Ejector Cycle in truck-transport refrigerators, we released Ejector Cycle products for large and medium-size freezer trucks, which have been favorably accepted by customers in 2003. Simultaneously we also developed the domestic water supply system using heat pump with natural refrigerant (CO{sub 2}). We developed a new Ejector Cycle, completed in 2007 a cool box which uses the refrigeration cycle of the mobile air-conditioning system to cool drinks and the commercial compact refrigerator. In 2008 a domestic water supply heat pump system using a heat pump with the natural refrigerant CO{sub 2} and the next-generation Ejector Cycle II that substantially improves performance was brought to the market. A new generation of Ejector Cycle is under development which will significantly improve the efficiency of mobile air conditioning systems (orig.)

  18. The atmospheric cooling of nuclear power stations

    International Nuclear Information System (INIS)

    Leuenberger, J.M.; Mayor, J.C.; Gassmann, F.; Lieber, K.

    1978-08-01

    Four different types of nuclear reactor are considered: light water reactors, high temperature reactors with steam circulation and with direct gas turbine circulation, and fast breeder reactors. Wet and dry cooling towers are described and experimental studies carried out using cooling tower models are presented. (G.T.H.)

  19. Integrated systems for power plant cooling and wastewater management

    International Nuclear Information System (INIS)

    Haith, D.A.

    1975-01-01

    The concept of integrated management of energy and water resources, demonstrated in hydropower development, may be applicable to steam-generated power, also. For steam plants water is a means of disposing of a waste product, which is unutilized energy in the form of heat. One framework for the evolution of integrated systems is the consideration of possible technical linkages between power plant cooling and municipal wastewater management. Such linkages include the use of waste heat as a mechanism for enhancing wastewater treatment, the use of treated wastewater as make-up for evaporative cooling structures, and the use of a pond or reservoir for both cooling and waste stabilization. This chapter reports the results of a systematic evaluation of possible integrated systems for power plant cooling and waste water management. Alternatives were analyzed for each of three components of the system--power plant cooling (condenser heat rejection), thermally enhanced waste water treatment, and waste water disposal. Four cooling options considered were evaporative tower, open cycle, spray pond, and cooling pond. Three treatment alternatives considered were barometric condenser-activated sludge, sectionalized condenser-activated sludge, and cooling/stabilization pond. Three disposal alternatives considered were ocean discharge, land application (spray irrigation), and make-up (for evaporative cooling). To facilitate system comparisons, an 1100-MW nuclear power plant was selected. 31 references

  20. Inverter power module with distributed support for direct substrate cooling

    Science.gov (United States)

    Miller, David Harold [San Pedro, CA; Korich, Mark D [Chino Hills, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA

    2012-08-21

    Systems and/or methods are provided for an inverter power module with distributed support for direct substrate cooling. An inverter module comprises a power electronic substrate. A first support frame is adapted to house the power electronic substrate and has a first region adapted to allow direct cooling of the power electronic substrate. A gasket is interposed between the power electronic substrate and the first support frame. The gasket is configured to provide a seal between the first region and the power electronic substrate. A second support frame is adapted to house the power electronic substrate and joined to the first support frame to form the seal.

  1. Dry cooling with night cool storage to enhance solar power plants performance in extreme conditions areas

    International Nuclear Information System (INIS)

    Muñoz, J.; Martínez-Val, J.M.; Abbas, R.; Abánades, A.

    2012-01-01

    Highlights: ► Solar thermo-electric power plants with thermal storage for condenser cooling. ► Technology to mitigate the negative effect on Rankine cycles of the day-time high temperatures in deserts. ► Electricity production augmentation in demand-peak hours by the use of day-night temperature difference. -- Abstract: Solar thermal power plants are usually installed in locations with high yearly average solar radiation, often deserts. In such conditions, cooling water required for thermodynamic cycles is rarely available. Moreover, when solar radiation is high, ambient temperature is very high as well; this leads to excessive condensation temperature, especially when air-condensers are used, and decreases the plant efficiency. However, temperature variation in deserts is often very high, which drives to relatively low temperatures during the night. This fact can be exploited with the use of a closed cooling system, so that the coolant (water) is chilled during the night and store. Chilled water is then used during peak temperature hours to cool the condenser (dry cooling), thus enhancing power output and efficiency. The present work analyzes the performance improvement achieved by night thermal cool storage, compared to its equivalent air cooled power plant. Dry cooling is proved to be energy-effective for moderately high day–night temperature differences (20 °C), often found in desert locations. The storage volume requirement for different power plant efficiencies has also been studied, resulting on an asymptotic tendency.

  2. Theoretical study and design of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane and intended for cooling of gas transported in a gas-main pipeline

    KAUST Repository

    Petrenko, V.O.; Volovyk, O.S.

    2011-01-01

    This paper describes the construction and performance of a novel combined system intended for natural gas transportation and power production, and for cooling of gas transported in a gas-main pipeline. The proposed system includes a gas turbine

  3. Comprehensive analysis and parametric optimization of a CCP (combined cooling and power) system driven by geothermal source

    International Nuclear Information System (INIS)

    Zhao, Yajing; Wang, Jiangfeng; Cao, Liyan; Wang, Yu

    2016-01-01

    A CCP (combined cooling and power) system, which integrated a flash-binary power generation system with a bottom combined cooling and power subsystem operating through the combination of an organic Rankine cycle and an ejector refrigeration cycle, was developed to utilize geothermal energy. Thermodynamic and exergoeconomic analyses were performed on the system. A performance indicator, namely the average levelized costs per unit of exergy products for the overall system, was developed to assess the exergoeconomic performance of the system. The effects of four key parameters including flash pressure, pinch point temperature difference in the vapor generator, inlet pressure and back pressure of the ORC turbine on the system performance were evaluated through a parametric analysis. Two single-objective optimizations were conducted to reach the maximum exergy efficiency and the minimum average levelized costs per unit of exergy products for the overall system, respectively. The optimization results implied that the most exergoeconomically effective system couldn't obtain the best system thermodynamic performance and vice versa. An exergy analysis based on the thermodynamic optimization result revealed that the biggest exergy destruction occurred in the vapor generator and the next two largest exergy destruction were respectively caused by the steam turbine and the flashing device. - Highlights: • A CCP (combined cooling and power) system driven by geothermal source is developed. • Levelized costs per unit of exergy product is used as the exergoeconomic indicator. • Parametric analyses are performed from thermodynamic and exergoeconomic viewpoints. • The optimal exergoeconomic design cannot obtain the best thermodynamic performance. • Exergy analysis is carried out based on the thermodynamic optimization result.

  4. Determination of the ejector dimensions of a bus air-conditioning system using analytical and numerical methods

    International Nuclear Information System (INIS)

    Ünal, Şaban

    2015-01-01

    Comfortable journey with commercial buses is an essential goal of transportation companies. An air-conditioning system can play an important role for this comfortable journey but it can put extra load on the engine and extra cost in the fuel consumption. The purpose of this work is to increase the performance of air-conditioning system of the buses by reducing the load on the engine and fuel consumption. Using a two-phase ejector as an expansion valve can increase the coefficient of performance (COP) of the air-conditioning system. An improvement in the COP can reduce the empty vehicle weight and fuel consumption of buses. Two-phase ejector dimensions can be determined using the empirical methods available in the literature. In this paper, the two-phase ejector dimensions of air conditioning system for a bus are calculated using the analytical and numerical methods. First of all, the thermodynamic analysis of the vapor-compression refrigeration cycle with a two-phase ejector is performed, and then the ejector dimensions are subsequently determined. The cooling loads of the midibus and bus with R134a as a refrigerant are assumed to be 14 kW and 32 kW, respectively. The total length of the two-phase ejector for the midibuses and buses due to these cooling loads, are computed to be 480.8 mm and 793.1 mm, respectively. Also, an experimental setup is installed on a midibus air conditioner to turn it into the ejector air conditioning system to validate theoretical results with the experimental study. - Highlights: • Determination of two-phase ejector dimensions of a bus air-conditioning system. • Thermodynamic analysis of the two-phase ejector cooling system. • Experimental study on a midibus air conditioner using two-phase ejector.

  5. Passive cooling systems in power reactors

    International Nuclear Information System (INIS)

    Aharon, J.; Harrari, R.; Weiss, Y.; Barnea, Y.; Katz, M.; Szanto, M.

    1996-01-01

    This paper reviews several R and D activities associated with the subject of passive cooling systems, conducted by the N.R.C.Negev thermohydraulic group. A short introduction considering different types of thermosyphons and their applications is followed by a detailed description of the experimental work, its results and conclusions. An ongoing research project is focused on the evaluation of the external dry air passive containment cooling system (PCCS) in the AP-600 (Westinghouse advanced pressurized water reactor). In this context some preliminary theoretical results and planned experimental research are for the fature described

  6. Kaiseraugst nuclear power station: meteorological effects of the cooling towers

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Considerations of water conservation persuaded the German Government in 1971 not to allow the use of the Aar and Rhine for direct cooling of nuclear power stations. The criticism is often made that the Kaiseraugst cooling towers were built without full consideration of the resulting meteorological effects. The criticism is considered unjustified because the Federal Cooling Tower Commission considered all the relevant aspects before making its recommendations in 1972. Test results and other considerations show that the effect of the kaiseraugst cooling towers on meteorological and climatic conditions is indeed minimal and details are given. (P.G.R.)

  7. Cooling water in the study of nuclear power plants sites

    International Nuclear Information System (INIS)

    Martinez, J.J.C.

    1990-01-01

    The location of an electric power plant has its limitations as regards the availability of apt sites. The radiosanitary risk, seismic risk and the overload capacity of the ground can be generically enumerated, being the cooling water availability for an electric power plant a basic requirement. Diverse cooling systems may be employed but the aim must always be that thermal contamination in the immediate environment be the least possible. (Author) [es

  8. ''Novel'' types of cooling towers for the power industry

    International Nuclear Information System (INIS)

    Mikyska, L.

    1991-01-01

    New types of cooling towers are beginning to be used abroad for the cooling circuits of nuclear power plants employing power generation units rated at 1,300 to 1,400 MW. These so-called water recovery cooling towers make use of natural draught without a droplet section. They are actually upgraded designs which were built in Europe as far back as 70 years ago. Because of the unsuitable materials then employed, these cooling towers fell into oblivion. Today, however, they are undergoing a renaissance. An upgraded design of these towers is described and compared with existing cooling towers with a droplet section. The feasibility of using these towers in Czechoslovak conditions is considered. (author)

  9. Numerical approach to solar ejector-compression refrigeration system

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2016-01-01

    Full Text Available A model was established for solar ejector-compression refrigeration system. The influence of generator temperature, middle-temperature, and evaporator temperature on the performance of the refrigerant system was analyzed. An optimal generator temperature is found for maximal energy efficiency ratio and minimal power consumption.

  10. A Numerical and Experimental Study of Ejector Internal Flow Structure and Geometry Modification for Maximized Performance

    Science.gov (United States)

    Falsafioon, Mehdi; Aidoun, Zine; Poirier, Michel

    2017-12-01

    A wide range of industrial refrigeration systems are good candidates to benefit from the cooling and refrigeration potential of supersonic ejectors. These are thermally activated and can use waste heat recovery from industrial processes where it is abundantly generated and rejected to the environment. In other circumstances low cost heat from biomass or solar energy may also be used in order to produce a cooling effect. Ejector performance is however typically modest and needs to be maximized in order to take full advantage of the simplicity and low cost of the technology. In the present work, the behavior of ejectors with different nozzle exit positions has been investigated using a prototype as well as a CFD model. The prototype was used in order to measure the performance advantages of refrigerant (R-134a) flowing inside the ejector. For the CFD model, it is assumed that the ejectors are axi-symmetric along x-axis, thus the generated model is in 2D. The preliminary CFD results are validated with experimental data over a wide range of conditions and are in good accordance in terms of entrainment and compression ratios. Next, the flow patterns of four different topologies are studied in order to discuss the optimum geometry in term of ejector entrainment improvement. Finally, The numerical simulations were used to find an optimum value corresponding to maximized entrainment ratio for fixed operating conditions.

  11. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

    Full Text Available Using DPSSL (Diode Pumped Solid State Lasers as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz. The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K–170 K with a heat flux of 1 MW*m−2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  12. Cooling water recipients for nuclear power plants

    International Nuclear Information System (INIS)

    Dahl, F.-E.; Saetre, H.J.

    1971-10-01

    The hydrographical and hydrological conditions at 17 prospective nuclear power plant sites in the Oslofjord district are evaluated with respect to their suitability as recipients for thermal discharges from nuclear power plants. No comparative evaluations are made. (JIW)

  13. Modern cooling systems in thermal power plants relieve environmental pollution. Pt. 2

    International Nuclear Information System (INIS)

    Brosche, D.

    1983-01-01

    Direct and indirect dry recirculation cooling, wet cooling tower, natural-draught wet cooling tower, combined cooling processes, hybrid cooling systems, cell cooling systems, auxiliary water preparation, cooling process design, afterheat removal in nuclear power plants, environmental effects, visible plumes as a function of weather conditions, environmental protection and energy supply assurance. (orig.) [de

  14. Investigation of an experimental ejector refrigeration machine operating with refrigerant R245fa at design and off-design working conditions. Part 1. Theoretical analysis

    KAUST Repository

    Shestopalov, K.O.

    2015-07-01

    © 2015 Elsevier Ltd and IIR.All rights reserved. The ejector refrigeration machine (ERM) offers several advantages over other heat-driven refrigeration machine, including simplicity in design and operation, high reliability and low installation cost, which enable its wide application in the production of cooling. In this paper the theoretical analysis of ejector design and ejector refrigeration cycle performance is presented. It is shown that ERM performance characteristics depend strongly on the operating conditions, the efficiency of the ejector used, and the thermodynamic properties of the refrigerant used. A 1-D model for the prediction of the entrainment ratio ω, and an optimal design for ejectors with cylindrical and conical-cylindrical mixing chambers are presented in this paper. In order to increase ERM performance values, it is necessary first of all to improve the performance of the ejector.

  15. Cryogenic system with the sub-cooled liquid nitrogen for cooling HTS power cable

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Y.F. [Chinese Academy of Sciences, Beijing (China). Technical Institute of Physics and Chemistry; Graduate School of Chinese Academy of Sciences, Beijing (China); Gong, L.H.; Xu, X.D.; Li, L.F.; Zhang, L. [Chinese Academy of Sciences, Beijing (China). Technical Institute of Physics and Chemistry; Xiao, L.Y. [Chinese Academy of Sciences, Beijing (China). Institute of Electrical Engineering

    2005-04-01

    A 10 m long, three-phase AC high-temperature superconducting (HTS) power cable had been fabricated and tested in China August 2003. The sub-cooled liquid nitrogen (LN{sub 2}) was used to cool the HTS cable. The sub-cooled LN{sub 2} circulation was built by means of a centrifugal pump through a heat exchanger in the sub-cooler, the three-phase HTS cable cryostats and a LN{sub 2} gas-liquid separator. The LN{sub 2} was cooled down to 65 K by means of decompressing, and the maximum cooling capacity was about 3.3 kW and the amount of consumed LN{sub 2} was about 72 L/h at 1500 A. Cryogenic system design, test and some experimental results would be presented in this paper. (author)

  16. Passive Two-Phase Cooling of Automotive Power Electronics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

    2014-08-01

    Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

  17. Steam jet ejectors are examined automatically

    International Nuclear Information System (INIS)

    Lardiere, C.

    2013-01-01

    Steam jet ejectors are used in the nuclear industry particularly for the transfer of radioactive fluids. Their working is based on the Venturi effect and the conservation of energy. A steam ejector can be considered as a thermodynamical pump without mobile parts. The Descote enterprise manufactures a broad range of steam jet ejectors and the characterization and testing of the steam ejectors was made manually and empirically so far. A new test bench has been designed, the tests are led automatically and allow a more accurate characterization and optimization of the steam jet ejectors. (A.C.)

  18. A study on the flow characteristics in ejector by PIV and CFD

    International Nuclear Information System (INIS)

    Lee, Haeng Nam; Park, Gil Moon; Park, Ji Man; Lee, Duk Gu; Sul, Jae Lim

    2003-01-01

    The ejector is used to get low pressure, and it has been applied to a lot of industry field like the heat engine, the fluid instrument power plant, the food industry, environment industry etc... because there are not any problem even it is mixed with a any kind of liquid, gas, and solid. The flow characteristics in ejector are investigated by PIV and CFD. The experiment using PIV measurement for mixing pipe's flow characteristics acquired velocity distribution, kinetic energy distribution, and whirlpool. Based on the PIV and the CFD results, the flow characteristics in ejector are discussed, and it shows the validity of this study

  19. Dry-type cooling systems in electric power production

    International Nuclear Information System (INIS)

    Li, K.W.

    1973-01-01

    This study indicates that the dry-type cooling tower could be adopted in this country as an alternative method for removing waste heat from power plants. The use of dry cooling towers would not only lead to a change of cooling system design, but also to a change of overall thermal design in a power generating system. The principal drawbacks to using dry cooling towers in a large steam-turbine plant are the generating capacity loss, increased fuel consumption and the high capital cost of the dry cooling towers. These economic penalties must be evaluated in each specific case against the benefits that may result from the use of dry cooling towers. The benefits are principally these: (1) Fewer constraints in the selection of power plant sites, (2) No thermal discharge to the natural water bodies, (3) Elimination of vapor plumes and water evaporation loss, and (4) Freedom of adding new units to an existing facility where inadequate water supply may otherwise rule out this possibility

  20. Trends in HPC and Data Center Power, Packaging, and Cooling

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    air vs liquid-cooling, and metrics to track it all will be discussed. About the speaker Michael K. Patterson is a Senior Principal Engineer in the Technical Computing Group - Systems Architecture & Pathfinding at the Intel Corporation, in Dupont, Washington, where he works in the power, thermal, and energy-efficient-performance areas of High Performance Computing. The work covers silicon level activity, through platform and rack-level solutions, and on up to interface with Data Center power and cooling technologies. He did his undergraduate work at Purdue University, received his MS degree in Management from Rensselaer Polytechnic Institute, an...

  1. Effects of power plant cooling on aquatic biota

    International Nuclear Information System (INIS)

    Moeller, H.

    1978-01-01

    Several bibliographies and reviews on 'ecological consequences of power plant cooling' have been published. Other reports compile additional data, but are not available to the public. Altogether, more than 3,000 literature citations have been gathered until now, too many to be studied by an individual scientist. The bibliography becomes more comprehensible if only titles are accepted that deal with power plant cooling itself, neglecting the influence of temperature and other stress factors on organisms as examined under laboratory conditions. Among these 600 remaining titles, about 370 are published in journals and periodicals available to the public. They are presented in this bibliography. (orig./RW) [de

  2. Thermodynamic analysis of cooling systems for nuclear power stations condenser

    International Nuclear Information System (INIS)

    Beck, A.

    1985-06-01

    This work is an attempt to concentrate on the thermodynamic theory, the engineering solution and the quantities of water needed for the operation of a wet as well as a wet/dry cooling towers coupled to a nuclear turbine condenser,. About two hundred variables are needed for the design of a condenser - cooling tower system. In order to make the solution fast and handy, a computer model was developed. The amount of water evaporation from cooling towers is a function of the climate conditions prevailing around the site. To achieve an authentic analysis, the meteorological data of the northern Negev was used. The total amount of water necessary to add to the system in a year time of operation is large and is a function of both the blow-down rate and the evaporation. First estimations show that the use of a combined system, wet/dry cooling tower, is beneficial in the northern Negev area. Such a system can reduce significantly the amount of wasted fresh water. Lack of international experience is the major problem in the acceptability of wet/dry cooling towers. The technology of a wet cooling tower using sea water is also discussed where no technical or engineering limitations were found. This work is an attempt to give some handy tools for making the choice of cooling systems for nuclear power plants easier

  3. Design and optimization of geothermal power generation, heating, and cooling

    Science.gov (United States)

    Kanoglu, Mehmet

    Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the

  4. Lower parts of Temelin nuclear power plant cooling towers

    International Nuclear Information System (INIS)

    Sebek, J.

    1988-01-01

    The progress of work is described in detail on the foundations and lower parts of the cooling towers of the Temelin nuclear power plant. The cooling tower is placed on a reinforced concrete footing of a circular layout. Support pillars are erected on the reinforced concrete continuous footing. They consists of oblique shell stanchions. Inside, the footing joins up to monolithic wall and slab structures of the cooling tower tub. The tub bottom forms a foundation plate supporting prefab structures of the cooling tower inner structural systems. The framed support of the chimney shell consists of 56 pairs of prefabricated oblique stanchions. Following their erection into the final position and anchoring in the continuous footing, the concreting of the casing can start of the reinforced conrete chimney. (Z.M.). 3 figs

  5. Organohalogens in chlorinated cooling waters discharged from nuclear power stations

    International Nuclear Information System (INIS)

    Bean, R.M.; Mann, D.C.; Neitzel, D.A.

    1983-01-01

    For the power plant discharges studied to date, measured concentrations of trihalomethanes are lower than might be expected, particularly in cooling tower water, which can lose THMs to the atmosphere. In the cooling towers, where chlorine was added in higher concentrations and for longer residence times, halogenated phenols can contribute significantly to the total organic halogen content of the discharge. The way in which cooling towers are operated may also influence the production of halogenated phenols because they concentrate the incoming water by a factor of 4 or 5. In addition, the phenols, which act as a substrate for the halogenating agent, are also probably concentrated by the cooling tower operation and may be prevented from being biodegraded by addition of the same biocide that produces the halogenated phenols. 8 references, 4 tables

  6. Status of helium-cooled nuclear power systems. [Development potential

    Energy Technology Data Exchange (ETDEWEB)

    Melese-d' Hospital, G.; Simnad, M

    1977-09-01

    Helium-cooled nuclear power systems offer a great potential for electricity generation when their long-term economic, environmental, conservation and energy self-sufficiency features are examined. The high-temperature gas-cooled reactor (HTGR) has the unique capability of providing high-temperature steam for electric power and process heat uses and/or high-temperature heat for endothermic chemical reactions. A variation of the standard steam cycle HTGR is one in which the helium coolant flows directly from the core to one or more closed cycle gas turbines. The effective use of nuclear fuel resources for electric power and nuclear process heat will be greatly enhanced by the gas-cooled fast breeder reactor (GCFR) currently being developed. A GCFR using thorium in the radial blanket could generate sufficient U-233 to supply the fuel for three HTGRs, or enough plutonium from a depleted uranium blanket to fuel a breeder economy expanding at about 10% per year. The feasibility of utilizing helium to cool a fusion reactor is also discussed. The status of helium-cooled nuclear energy systems is summarized as a basis for assessing their prospects. 50 references.

  7. Water cooled type nuclear power plant

    International Nuclear Information System (INIS)

    Arai, Shigeki.

    1981-01-01

    Purpose: To construct high efficiency a PWR type nuclear power plant with a simple structure by preparing high temperature and pressure water by a PWR type nuclear reactor and a pressurizer, converting the high temperature and high pressure water into steam with a pressure reducing valve and introducing the steam into a turbine, thereby generating electricity. Constitution: A pressurizer is connected downstream of a PWR type nuclear reactor, thereby maintaining the reactor at high pressure. A pressure-reducing valve is provided downstream of the pressurizer, the high temperature and pressure water is reduced in pressure, thereby producing steam. The steam is fed to a turbine, and electric power is generated by a generator connected to the turbine. The steam exhausted from the turbine is condensed by a condenser into water, and the water is returned through a feedwater heater to the reactor. Since the high temperature and pressure water in thus reduced in pressure thereby evaporating it, the steam can be more efficiently produced than by a steam generator. (Sekiya, K.)

  8. Development of a higher power cooling system for lithium targets.

    Science.gov (United States)

    Phoenix, B; Green, S; Scott, M C; Bennett, J R J; Edgecock, T R

    2015-12-01

    The accelerator based Boron Neutron Capture Therapy beam at the University of Birmingham is based around a solid thick lithium target cooled by heavy water. Significant upgrades to Birmingham's Dynamitron accelerator are planned prior to commencing a clinical trial. These upgrades will result in an increase in maximum achievable beam current to at least 3 mA. Various upgrades to the target cooling system to cope with this increased power have been investigated. Tests of a phase change coolant known as "binary ice" have been carried out using an induction heater to provide a comparable power input to the Dynamitron beam. The experimental data shows no improvement over chilled water in the submerged jet system, with both systems exhibiting the same heat input to target temperature relation for a given flow rate. The relationship between the cooling circuit pumping rate and the target temperature in the submerged jet system has also been tested. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. A thermosyphon heat pipe cooler for high power LEDs cooling

    Science.gov (United States)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  10. High power density reactors based on direct cooled particle beds

    Science.gov (United States)

    Powell, J. R.; Horn, F. L.

    Reactors based on direct cooled High Temperature Gas Cooled Reactor (HTGR) type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out along the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBRs) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed.

  11. Emergency core cooling systems in CANDU nuclear power plants

    International Nuclear Information System (INIS)

    1981-12-01

    This report contains the responses by the Advisory Committee on Nuclear Safety to three questions posed by the Atomic Energy Control Board concerning the need for Emergency Core Cooling Systems (ECCS) in CANDU nuclear power plants, the effectiveness requirement for such systems, and the extent to which experimental evidence should be available to demonstrate compliance with effectiveness standards

  12. Cooling off South Africa's power outage fever

    Energy Technology Data Exchange (ETDEWEB)

    Schlichtung, D. [GEA Thermal Engineering Division (Germany)

    2008-10-15

    The 6 x 790 MW coal-fired Medupi power station, currently under construction, forms a strategic part to South Africa's energy policy to meet its growing electricity demand. It is a project of large dimensions, not least its air-cooled condenser, which once constructed will cover an area equivalent to ten football pitches. 3 photos.

  13. Gas-cooled reactor power systems for space

    International Nuclear Information System (INIS)

    Walter, C.E.

    1987-01-01

    Efficiency and mass characteristics for four gas-cooled reactor power system configurations in the 2- to 20-MWe power range are modeled. The configurations use direct and indirect Brayton cycles with and without regeneration in the power conversion loop. The prismatic ceramic core of the reactor consists of several thousand pencil-shaped tubes made from a homogeneous mixture of moderator and fuel. The heat rejection system is found to be the major contributor to system mass, particularly at high power levels. A direct, regenerated Brayton cycle with helium working fluid permits high efficiency and low specific mass for a 10-MWe system

  14. Optimization of the cooling power distribution in a superconducting linac

    International Nuclear Information System (INIS)

    Wendl, C.M.; Noe, J.W.

    1996-01-01

    The benefits of setting the resonators in a superconducting heavy-ion linac to a certain optimum distribution of cooling power have been evaluated in terms of the total acceleration such a distribution may produce, compared to a distribution in which each resonator dissipates power equally. The optimum power distribution can be expressed in closed form in certain simplified cases, but the general case is solved by equalizing the 'marginal power cost' of the resonators by iteration in a computer simulation. For the Stony Brook linac an additional possible acceleration of several percent is thus predicted for typical beams. (author)

  15. Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

    Directory of Open Access Journals (Sweden)

    Mishra Shubham

    2016-12-01

    Full Text Available Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%, which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle. Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

  16. Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

    Science.gov (United States)

    Mishra, Shubham; Sarkar, Jahar

    2016-12-01

    Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene) is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP) for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%), which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle). Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

  17. Power shift -- Cool solutions to global warming

    International Nuclear Information System (INIS)

    2000-11-01

    The argument advanced in this paper by the Suzuki Foundation is that Canada, a rich, industrialized nation that has often led the world in technological advances, including advances in the energy sector, is lagging behind Europe and Japan in utilizing new energy-efficient technologies and techniques, despite the fact that these new approaches could reduce energy costs, improve air quality and public health stimulate new industries and create jobs. The paper describes an analytical model created by Ralph Torrie, one of Canada's foremost sustainable energy experts, which shows that based on population and economic growth, Canada's emissions will continue to grow to 30 percent above today's levels by 2010, instead of being reduced to 94 per cent of 1990 levels as required by the Kyoto Protocol. The end-use model created by Torrie runs various scenarios regarding the level and mix of activity, technological efficiency and fuel shares showing their effect of GHG emissions levels. Beginning with 1995 as the base-year, and assuming population growth of 19 per cent and a growth in transportation of 38 per cent over the next 30 years, GHG emission reduction scenarios are produced for people and freight transportation, residential and commercial buildings, industrial energy use, power production and non-energy sources. The GHG savings described in the model show that a 50 per cent reduction by 2030 is conceivable even with technologies that are already available. To get there, however, will require wholehearted effort by both the public and private sectors. Regulation, public investment, innovative market mechanisms and behavioral changes will all have significant roles to play if GHG emission levels of this magnitude are to be achieved

  18. Exergy analysis of a combined power and cooling cycle

    International Nuclear Information System (INIS)

    Fontalvo, Armando; Pinzon, Horacio; Duarte, Jorge; Bula, Antonio; Quiroga, Arturo Gonzalez; Padilla, Ricardo Vasquez

    2013-01-01

    This paper presents a comprehensive exergy analysis of a combined power and cooling cycle which combines a Rankine and absorption refrigeration cycle by using ammonia–water mixture as working fluid. A thermodynamic model was developed in Matlab ® to find out the effect of pressure ratio, ammonia mass fraction at the absorber and turbine efficiency on the total exergy destruction of the cycle. The contribution of each cycle component on the total exergy destruction was also determined. The results showed that total exergy destruction decreases when pressure ratio increases, and reaches a maximum at x ≈ 0.5, when ammonia mass fraction is varied at absorber. Also, it was found that the absorber, the boiler and the turbine had the major contribution to the total exergy destruction of the cycle, and the increase of the turbine efficiency reduces the total exergy destruction. The effect of rectification cooling source (external and internal) on the cycle output was investigated, and the results showed that internal rectification cooling reduces the total exergy destruction of the cycle. Finally, the effect of the presence or absence of the superheater after the rectification process was determined and it was obtained that the superheated condition reduces the exergy destruction of the cycle at high turbine efficiency values. Highlights: • A parametric exergy analysis of a combined power and cooling cycle is performed. • Two scenarios for rectifier cooling (internal and external) were studied. • Internal cooling source is more exergetic efficient than external cooling source. • The absorber and boiler have the largest total exergy destruction. • Our results show that the superheater reduces the exergy destruction of the cycle

  19. Simplified ejector model for control and optimization

    International Nuclear Information System (INIS)

    Zhu Yinhai; Cai Wenjian; Wen Changyun; Li Yanzhong

    2008-01-01

    In this paper, a simple yet effective ejector model for a real time control and optimization of an ejector system is proposed. Firstly, a fundamental model for calculation of ejector entrainment ratio at critical working conditions is derived by one-dimensional analysis and the shock circle model. Then, based on thermodynamic principles and the lumped parameter method, the fundamental ejector model is simplified to result in a hybrid ejector model. The model is very simple, which only requires two or three parameters and measurement of two variables to determine the ejector performance. Furthermore, the procedures for on line identification of the model parameters using linear and non-linear least squares methods are also presented. Compared with existing ejector models, the solution of the proposed model is much easier without coupled equations and iterative computations. Finally, the effectiveness of the proposed model is validated by published experimental data. Results show that the model is accurate and robust and gives a better match to the real performances of ejectors over the entire operating range than the existing models. This model is expected to have wide applications in real time control and optimization of ejector systems

  20. Averthermodynamic analysis of waste heat recovery for cooling systems in hybrid and electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Javani, N.; Dincer, I.; Naterer, G.F. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology (Canada)], email: nader.javani@uoit.ca

    2011-07-01

    The transportation sector is a heavy consumer of energy and better energy use is needed to reduce fuel consumption. One way to improve energy usage is to recover waste heat for cabin heating, cooling, or to produce electricity. The aim of this paper is to examine the use of waste heat in hybrid electric vehicles (HEV) and electric vehicles for cooling purposes using an ejector cooling cycle and an absorption cooling cycle. Energy and exergy analyses were conducted using waste heat from the battery pack and the exhaust gases to power the boiler and generator. Results showed that waste energy from the battery pack does not provide enough energy to produce cabin cooling but that exhaust gases can produce 7.32 kW and 7.91 kW cooling loads in the ejector and absorption systems. This study demonstrated that both ejector and absorption systems can reduce energy consumption in vehicles through the use of waste heat from exhaust gases.

  1. Specific power of liquid-metal-cooled reactors

    International Nuclear Information System (INIS)

    Dobranich, D.

    1987-10-01

    Calculations of the core specific power for conceptual space-based liquid-metal-cooled reactors, based on heat transfer considerations, are presented for three different fuel types: (1) pin-type fuel; (2) cermet fuel; and (3) thermionic fuel. The calculations are based on simple models and are intended to provide preliminary comparative results. The specific power is of interest because it is a measure of the core mass required to produce a given amount of power. Potential problems concerning zero-g critical heat flux and loss-of-coolant accidents are also discussed because these concerns may limit the core specific power. Insufficient experimental data exists to accurately determine the critical heat flux of liquid-metal-cooled reactors in space; however, preliminary calculations indicate that it may be a concern. Results also indicate that the specific power of the pin-type fuels can be increased significantly if the gap between the fuel and the clad is eliminated. Cermet reactors offer the highest specific power because of the excellent thermal conductivity of the core matrix material. However, it may not be possible to take fuel advantage of this characteristic when loss-of-coolant accidents are considered in the final core design. The specific power of the thermionic fuels is dependent mainly on the emitter temperature. The small diameter thermionic fuels have specific powers comparable to those of pin-type fuels. 11 refs., 12 figs, 2 tabs

  2. Hybrid Cooling for Geothermal Power Plants: Final ARRA Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.

    2013-06-01

    Many binary-cycle geothermal plants use air as the heat rejection medium. Usually this is accomplished by using an air-cooled condenser (ACC) system to condense the vapor of the working fluid in the cycle. Many air-cooled plants suffer a loss of production capacity of up to 50% during times of high ambient temperatures. Use of limited amounts of water to supplement the performance of ACCs is investigated. Deluge cooling is found to be one of the least-cost options. Limiting the use of water in such an application to less than one thousand operating hours per year can boost plant output during critical high-demand periods while minimizing water use in binary-cycle geothermal power plants.

  3. Reactor core cooling device for nuclear power plant

    International Nuclear Information System (INIS)

    Tsuda, Masahiko.

    1992-01-01

    The present invention concerns a reactor core cooling facility upon rupture of pipelines in a BWR type nuclear power plant. That is, when rupture of pipelines should occur in the reactor container, an releasing safety valve operates instantly and then a depressurization valve operates to depressurize the inside of a reactor pressure vessel. Further, an injection valve of cooling water injection pipelines is opened and cooling water is injected to cool the reactor core from the time when the pressure is lowered to a level capable of injecting water to the pressure vessel by the static water head of a pool water as a water source. Further, steams released from the pressure vessel and steams in the pressure vessel are condensed in a high pressure/low pressure emergency condensation device and the inside of the reactor container is depressurized and cooled. When the reactor is isolated, since the steams in the pressure vessel are condensed in the state that the steam supply valve and the return valve of a steam supply pipelines are opened and a vent valve is closed, the reactor can be maintained safely. (I.S.)

  4. Thermodynamic performance optimization of a combined power/cooling cycle

    International Nuclear Information System (INIS)

    Pouraghaie, M.; Atashkari, K.; Besarati, S.M.; Nariman-zadeh, N.

    2010-01-01

    A combined thermal power and cooling cycle has already been proposed in which thermal energy is used to produce work and to generate a sub-ambient temperature stream that is suitable for cooling applications. The cycle uses ammonia-water mixture as working fluid and is a combination of a Rankine cycle and absorption cycle. The very high ammonia vapor concentration, exiting turbine under certain operating conditions, can provide power output as well as refrigeration. In this paper, the goal is to employ multi-objective algorithms for Pareto approach optimization of thermodynamic performance of the cycle. It has been carried out by varying the selected design variables, namely, turbine inlet pressure (P h ), superheater temperature (T superheat ) and condenser temperature (T condensor ). The important conflicting thermodynamic objective functions that have been considered in this study are turbine work (w T ), cooling capacity (q cool ) and thermal efficiency (η th ) of the cycle. It is shown that some interesting and important relationships among optimal objective functions and decision variables involved in the combined cycle can be discovered consequently. Such important relationships as useful optimal design principles would have not been obtained without the use of a multi-objective optimization approach.

  5. Thermodynamic analysis of the two-phase ejector air-conditioning system for buses

    International Nuclear Information System (INIS)

    Ünal, Şaban; Yilmaz, Tuncay

    2015-01-01

    Air-conditioning compressors of the buses are usually operated with the power taken from the engine of the buses. Therefore, an improvement in the air-conditioning system will reduce the fuel consumption of the buses. The improvement in the coefficient of performance (COP) of the air-conditioning system can be provided by using the two-phase ejector as an expansion valve in the air-conditioning system. In this study, the thermodynamic analysis of bus air-conditioning system enhanced with a two-phase ejector and two evaporators is performed. Thermodynamic analysis is made assuming that the mixing process in ejector occurs at constant cross-sectional area and constant pressure. The increase rate in the COP with respect to conventional system is analyzed in terms of the subcooling, condenser and evaporator temperatures. The analysis shows that COP improvement of the system by using the two phase ejector as an expansion device is 15% depending on design parameters of the existing bus air-conditioning system. - Highlights: • Thermodynamic analysis of the two-phase ejector refrigeration system. • Analysis of the COP increase rate of bus air-conditioning system. • Analysis of the entrainment ratio of the two-phase ejector refrigeration system

  6. Power Conversion Study for High Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    Chang Oh; Richard Moore; Robert Barner

    2005-01-01

    The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gas cooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language

  7. Experimental investigation on motive nozzle throat diameter for an ejector expansion refrigeration system

    International Nuclear Information System (INIS)

    Bilir Sag, Nagihan; Ersoy, H. Kursad

    2016-01-01

    Highlights: • Effects of nozzle throat diameter and its location on performance were investigated. • The nozzle has an optimum throat diameter under the experiment condition. • The maximum performance has been achieved by using optimum nozzle throat diameter. • The variation of nozzle throat diameter with condenser water inlet temperature was examined. • Motive nozzle has no optimum position in the ejector refrigeration system. - Abstract: In this study, ejector was used to reduce throttling losses in a vapour compression refrigeration system. Effects on system performance of throat diameter and position of motive nozzle of ejector were investigated experimentally. An ejector was designed based on the established mathematical model and manufactured. The experiments were carried out by using different primary nozzle throat diameters. The experiments were further conducted by changing condenser water inlet temperature, which is one of the external parameters. The experimental results of the ejector system and those of the classic system were compared under same external operating conditions and for the same cooling capacity. In order to obtain same external operating conditions in both systems, the inlet conditions of the brine supplied to the evaporator and inlet water conditions (flow rate and temperature) to the condenser were kept constant. Maximum performance was obtained when the primary nozzle throat diameter was 2.3 mm within the areas considered in this study. When compared, it was experimentally determined that the ejector system that uses the optimum motive nozzle throat diameter exhibits higher COP than the classic system by 5–13%. Furthermore, it was found that the variation of coefficient of performance based on position of motive nozzle in two-phase ejector expander refrigeration cycle is lower than 1%.

  8. Performance evaluation of an ejector subcooled vapor-compression refrigeration cycle

    International Nuclear Information System (INIS)

    Xing, Meibo; Yan, Gang; Yu, Jianlin

    2015-01-01

    Highlights: • An ejector subcooled vapor-compression refrigeration cycle is proposed. • The performance of the cycle with ejector subcooling is evaluated theoretically. • Increase in refrigeration capacity can be achieved by the ejector subcooled cycle. • The new cycle exhibits higher COP compared to the basic single-stage cycle. • Performance of the new cycle depends on the operation pressures of the ejector. - Abstract: In this study, a novel vapor-compression refrigeration cycle with mechanical subcooling using an ejector is proposed to improve the performance of a conventional single-stage vapor-compression refrigeration cycle. In the theoretical study, a mathematical model is developed to predict the performance of the cycle by using R404A and R290, and then compared with that of the conventional refrigeration cycle. The simulation results show that the performance of the ejector subcooled cycle is better than that of the conventional cycle. When the evaporator temperature ranges from −40 to −10 °C and the condenser temperature is 45 °C, the novel cycle displays volumetric refrigeration capacity improvements of 11.7% with R404A and 7.2% with R290. And the novel cycle achieves COP improvements of 9.5% with R404A and 7.0% with R290. In addition, the improvement of the COP and cooling capacity of this novel cycle largely depends on the operation pressures of the ejector. The potential practical advantages offered by the cycle may be worth further attention in future studies

  9. Linear Dynamics Model for Steam Cooled Fast Power Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vollmer, H

    1968-04-15

    A linear analytical dynamic model is developed for steam cooled fast power reactors. All main components of such a plant are investigated on a general though relatively simple basis. The model is distributed in those parts concerning the core but lumped as to the external plant components. Coolant is considered as compressible and treated by the actual steam law. Combined use of analogue and digital computer seems most attractive.

  10. Legionella control in power station cooling towers using oxidising biocides

    Energy Technology Data Exchange (ETDEWEB)

    Sailer, Christian; Rawlinson, Julia; Killeen, Paul [Ecolab PTY LTD, Ascot, WA (Australia)

    2009-02-15

    Power stations have used oxidising biocides such as chlorine or bromine for many years to control microbial growth in their cooling towers. In this paper Ecolab trademark looks at the direct effect halogen concentration has on Legionella populations in order to determine the most effective halogenation rate required to ensure that the site key performance indicator (KPI) of < 100 colony-forming units (cfu) per mL can be maintained. (orig.)

  11. Delayed gamma power measurement for sodium-cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, R., E-mail: romain.coulon@cea.f [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); Normand, S., E-mail: stephane.normand@cea.f [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); Ban, G., E-mail: ban@lpccaen.in2p3.f [ENSICAEN, 6 Boulevard Marechal Juin, F-14050 Caen Cedex 4 (France); Barat, E.; Montagu, T.; Dautremer, T. [CEA, LIST, Laboratoire Modelisation Simulation et Systemes, F-91191 Gif-sur-Yvette (France); Brau, H.-P. [ICSM, Centre de Marcoule, BP 17171 F-30207 Bagnols sur Ceze (France); Dumarcher, V. [AREVA NP, SET, F-84500 Bollene (France); Michel, M.; Barbot, L.; Domenech, T.; Boudergui, K.; Bourbotte, J.-M. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); Jousset, P. [CEA, LIST, Departement des Capteurs, du Signal et de l' Information, F-91191 Gif-sur-Yvette (France); Barouch, G.; Ravaux, S.; Carrel, F. [CEA, LIST, Laboratoire Modelisation Simulation et Systemes, F-91191 Gif-sur-Yvette (France); Saurel, N. [CEA, DAM, Laboratoire Mesure de Dechets et Expertise, F-21120 Is-sur-Tille (France); Frelin-Labalme, A.-M.; Hamrita, H. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France)

    2011-01-15

    Graphical abstract: Display Omitted Research highlights: {sup 20}F and {sup 23}Ne tagging agents are produced by fast neutron flux. {sup 20}F signal has been measured at the SFR Phenix prototype. A random error of only 3% for an integration time of 2 s could be achieved. {sup 20}F and {sup 23}Ne power measurement has a reduced temperature influence. Burn-up impact could be limited by simultaneous {sup 20}F and {sup 23}Ne measurement. - Abstract: Previous works on pressurized water reactors show that the nitrogen 16 activation product can be used to measure thermal power. Power monitoring using a more stable indicator than ex-core neutron measurements is required for operational sodium-cooled fast reactors, in order to improve their economic efficiency at the nominal operating point. The fluorine 20 and neon 23 produced by (n,{alpha}) and (n,p) capture in the sodium coolant have this type of convenient characteristic, suitable for power measurements with low build-up effects and a potentially limited temperature, flow rate, burn-up and breeding dependence. This method was tested for the first time during the final tests program of the French Phenix sodium-cooled fast reactor at CEA Marcoule, using the ADONIS gamma pulse analyzer. Despite a non-optimal experimental configuration for this application, the delayed gamma power measurement was pre-validated, and found to provide promising results.

  12. Simulation of solar-powered absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Atmaca, I.; Yigit, A. [Uludag Univ., Bursa (Turkey). Dept. of Mechanical Engineering

    2003-07-01

    With developing technology and the rapid increase in world population, the demand for energy is ever increasing. Conventional energy will not be enough to meet the continuously increasing need for energy in the future. In this case, renewable energy sources will become important. Solar energy is a very important energy source because of its advantages. Instead of a compressor system, which uses electricity, an absorption cooling system, using renewable energy and kinds of waste heat energy, may be used for cooling. In this study, a solar-powered, single stage, absorption cooling system, using a water-lithium bromide solution, is simulated. A modular computer program has been developed for the absorption system to simulate various cycle configurations and solar energy parameters for Antalya, Turkey. So, the effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling components are studied. In addition, reference temperatures which are the minimum allowable hot water inlet temperatures are determined and their effect on the fraction of the total load met by non-purchased energy (FNP) and the coefficient of performance are researched. Also, the effects of the collector type and storage tank mass are investigated in detail. (author)

  13. Cooling and heating facility for nuclear power plant

    International Nuclear Information System (INIS)

    Kakuta, Atsuro

    1994-01-01

    The present invention concerns a cooling and heating facility for a nuclear power plant. Namely, a cooling water supply system supplies cooling water prepared by a refrigerator for cooling the inside of the plant. A warm water supply system supplies warm water having its temperature elevated by using an exhausted heat from a reactor water cleanup system. The facility comprises a heat pump-type refrigerator disposed in a cold water supply system for producing cold water and warm water, and warm water pipelines for connecting the refrigerator and the warm water supply system. With such a constitution, when the exhaust heat from the reactor water cleanup system can not be used, warm water prepared by the heat pump type refrigerator is supplied to the warm water supply system by way of the warm water pipelines. Accordingly, when the exhaust heat from the reactor water cleanup system can not be used such as upon inspection of the plant, a portion of the refrigerators in a not-operated state can be used for heating. Supply of boiler steams in the plant is no more necessary or extremely reduced. (I.S.)

  14. High power density reactors based on direct cooled particle beds

    International Nuclear Information System (INIS)

    Powell, J.R.; Horn, F.L.

    1985-01-01

    Reactors based on direct cooled HTGR type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out long the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBR's) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed. 12 figs

  15. A gas-cooled reactor surface power system

    International Nuclear Information System (INIS)

    Lipinski, R.J.; Wright, S.A.; Lenard, R.X.; Harms, G.A.

    1999-01-01

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars. copyright 1999 American Institute of Physics

  16. A gas-cooled reactor surface power system

    International Nuclear Information System (INIS)

    Lipinski, Ronald J.; Wright, Steven A.; Lenard, Roger X.; Harms, Gary A.

    1999-01-01

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars

  17. A Gas-Cooled Reactor Surface Power System

    Energy Technology Data Exchange (ETDEWEB)

    Harms, G.A.; Lenard, R.X.; Lipinski, R.J.; Wright, S.A.

    1998-11-09

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life- cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitide clad in Nb 1 %Zr, which has been extensively tested under the SP-I 00 program The fiel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fbel and stabilizing the geometty against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality cannot occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.

  18. An optimal multivariable controller for transcritical CO2 refrigeration cycle with an adjustable ejector

    International Nuclear Information System (INIS)

    He, Yang; Deng, Jianqiang; Yang, Fusheng; Zhang, Zaoxiao

    2017-01-01

    Highlights: • Dynamic model for transcritical CO 2 ejector refrigeration system is developed. • A model-driven optimal multivariable controller is proposed. • Gas cooler pressure and cooling capacity are tracked independently. • Maximal performance for a given load is achieved by the optimal controller. - Abstract: The fixed ejector has to work under a restricted operating condition to keep its positive effectiveness on the transcritical CO 2 refrigeration cycle, and a controllable ejector will be helpful. In this paper, an optimal multivariable controller based on the dynamic model is proposed to improve transcritical CO 2 refrigeration cycle with an adjustable ejector (TCRAE). A nonlinear dynamic model is first developed to model the dynamic characteristic of TCRAE. The corresponding model linearization is carried out and the simulation results reproduce transient behavior of the nonlinear model very well. Based on the developed model, an optimal multivariable controller with a tracker based linear quadratic state feedback algorithm and a predictor using steepest descent method is designed. The controller is finally applied on the experimental apparatus and the performance is verified. Using the tracker only, the gas cooler pressure and chilled water outlet temperature (cooling capacity) are well tracked rejecting the disturbances from each other. Furthermore, by the predictor, the optimal gas cooler pressure for a constant cooling capacity is actually approached on the experimental apparatus with a settling time about 700 s.

  19. Complete indium-free CW 200W passively cooled high power diode laser array using double-side cooling technology

    Science.gov (United States)

    Wang, Jingwei; Zhu, Pengfei; Liu, Hui; Liang, Xuejie; Wu, Dihai; Liu, Yalong; Yu, Dongshan; Zah, Chung-en; Liu, Xingsheng

    2017-02-01

    High power diode lasers have been widely used in many fields. To meet the requirements of high power and high reliability, passively cooled single bar CS-packaged diode lasers must be robust to withstand thermal fatigue and operate long lifetime. In this work, a novel complete indium-free double-side cooling technology has been applied to package passively cooled high power diode lasers. Thermal behavior of hard solder CS-package diode lasers with different packaging structures was simulated and analyzed. Based on these results, the device structure and packaging process of double-side cooled CS-packaged diode lasers were optimized. A series of CW 200W 940nm high power diode lasers were developed and fabricated using hard solder bonding technology. The performance of the CW 200W 940nm high power diode lasers, such as output power, spectrum, thermal resistance, near field, far field, smile, lifetime, etc., is characterized and analyzed.

  20. Modular He-cooled divertor for power plant application

    International Nuclear Information System (INIS)

    Diegele, Eberhard; Kruessmann, R.; Malang, S.; Norajitra, P.; Rizzi, G.

    2003-01-01

    Gas cooled divertor concepts are regarded as a suitable option for fusion power plants because of an increased thermal efficiency for power conversion systems and the use of a coolant compatible with all blanket systems. A modular helium cooled divertor concept is proposed with an improved heat transfer. The concept employs small tiles made of tungsten and brazed to a finger-like structure made of Mo-alloy (TZM). Design goal was a heat flux of at least 15 MW/m 2 and a minimum temperature of the structure of 600 deg.C. The divertor has to survive a number of cycles (100-1000) between operating temperature and room temperature even for the steady state operation assumed. Thermo-hydraulic design requirements for the concepts include to keep the pumping power below 10% of the thermal power to the divertor plates, and simultaneously achieving a heat transfer coefficient in excess of 60 kW/m 2 K. Inelastic stress analysis indicates that design allowable stress limits on primary and secondary (thermal) stresses as required by the ITER structural design criteria are met even under conservative assumptions. Finally, critical issues for future development are addressed

  1. Solar-powered Rankine heat pump for heating and cooling

    Science.gov (United States)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  2. The Design of the Trading Mechanism to Adapt the Development of Mixed Cooling Heating and Power

    Science.gov (United States)

    Liu, D. N.; Li, Z. H.; Zhou, H. M.; Zhao, Q.; Xu, X. F.

    2017-08-01

    The enterprise who has combined cooling heating and power system has both the customer group and the power generation resources. Therefore, it can be used as a power user, and can also be used as a power generation enterprise to participate in the direct purchase of electricity. This paper combines characteristics of mixed cooling heating and power, designs application business model of mixed cooling heating and power, and puts forward to the scene of cooling heating and power trading scheme, helping the enterprise according to the power supply and demand situation in the region adjust their positions and participate in the electricity market.

  3. Parallel Work of CO2 Ejectors Installed in a Multi-Ejector Module of Refrigeration System

    Science.gov (United States)

    Bodys, Jakub; Palacz, Michal; Haida, Michal; Smolka, Jacek; Nowak, Andrzej J.; Banasiak, Krzysztof; Hafner, Armin

    2016-09-01

    A performance analysis on of fixed ejectors installed in a multi-ejector module in a CO2 refrigeration system is presented in this study. The serial and the parallel work of four fixed-geometry units that compose the multi-ejector pack was carried out. The executed numerical simulations were performed with the use of validated Homogeneous Equilibrium Model (HEM). The computational tool ejectorPL for typical transcritical parameters at the motive nozzle were used in all the tests. A wide range of the operating conditions for supermarket applications in three different European climate zones were taken into consideration. The obtained results present the high and stable performance of all the ejectors in the multi-ejector pack.

  4. Exergetic comparison of two different cooling technologies for the power cycle of a thermal power plant

    International Nuclear Information System (INIS)

    Blanco-Marigorta, Ana M.; Victoria Sanchez-Henriquez, M.; Pena-Quintana, Juan A.

    2011-01-01

    Exergetic analysis is without any doubt a powerful tool for developing, evaluating and improving an energy conversion system. In the present paper, two different cooling technologies for the power cycle of a 50 MWe solar thermal power plant are compared from the exergetic viewpoint. The Rankine cycle design is a conventional, single reheat design with five closed and one open extraction feedwater heaters. The software package GateCycle is used for the thermodynamic simulation of the Rankine cycle model. The first design configuration uses a cooling tower while the second configuration uses an air cooled condenser. With this exergy analysis we identify the location, magnitude and the sources or thermodynamic inefficiencies in this thermal system. This information is very useful for improving the overall efficiency of the power system and for comparing the performance of both technologies.

  5. Review on Water Distribution of Cooling Tower in Power Station

    Science.gov (United States)

    Huichao, Zhang; Lei, Fang; Hao, Guang; Ying, Niu

    2018-04-01

    As the energy sources situation is becoming more and more severe, the importance of energy conservation and emissions reduction gets clearer. Since the optimization of water distribution system of cooling tower in power station can save a great amount of energy, the research of water distribution system gets more attention nowadays. This paper summarizes the development process of counter-flow type natural draft wet cooling tower and the water distribution system, and introduces the related domestic and international research situation. Combining the current situation, we come to the conclusion about the advantages and disadvantages of the several major water distribution modes, and analyze the problems of the existing water distribution ways in engineering application, furthermore, we put forward the direction of water distribution mode development on the basis knowledge of water distribution of cooling tower. Due to the water system can hardly be optimized again when it’s built, choosing an appropriate water distribution mode according to actual condition seems to be more significant.

  6. A powerful way of cooling computer chip using liquid metal with low melting point as the cooling fluid

    Energy Technology Data Exchange (ETDEWEB)

    Li Teng; Lv Yong-Gang [Chinese Academy of Sciences, Beijing (China). Cryogenic Lab.; Chinese Academy of Sciences, Beijing (China). Graduate School; Liu Jing; Zhou Yi-Xin [Chinese Academy of Sciences, Beijing (China). Cryogenic Lab.

    2006-12-15

    With the improvement of computational speed, thermal management becomes a serious concern in computer system. CPU chips are squeezing into tighter and tighter spaces with no more room for heat to escape. Total power-dissipation levels now reside about 110 W, and peak power densities are reaching 400-500 W/mm{sup 2} and are still steadily climbing. As a result, higher performance and greater reliability are extremely tough to attain. But since the standard conduction and forced-air convection techniques no longer be able to provide adequate cooling for sophisticated electronic systems, new solutions are being looked into liquid cooling, thermoelectric cooling, heat pipes, and vapor chambers. In this paper, we investigated a novel method to significantly lower the chip temperature using liquid metal with low melting point as the cooling fluid. The liquid gallium was particularly adopted to test the feasibility of this cooling approach, due to its low melting point at 29.7 C, high thermal conductivity and heat capacity. A series of experiments with different flow rates and heat dissipation rates were performed. The cooling capacity and reliability of the liquid metal were compared with that of the water-cooling and very attractive results were obtained. Finally, a general criterion was introduced to evaluate the cooling performance difference between the liquid metal cooling and the water-cooling. The results indicate that the temperature of the computer chip can be significantly reduced with the increasing flow rate of liquid gallium, which suggests that an even higher power dissipation density can be achieved with a large flow of liquid gallium and large area of heat dissipation. The concept discussed in this paper is expected to provide a powerful cooling strategy for the notebook PC, desktop PC and large computer. It can also be extended to more wide area involved with thermal management on high heat generation rate. (orig.)

  7. Seawater for the cooling of decay power. Partial report 1

    International Nuclear Information System (INIS)

    Poern, K.; Agnedal, P.O.; Evans, S.; Sundblad, B.

    1980-11-01

    It is stated that there should be provisions made for to cool down the decay power of a reactor. The intake of coolant should be kept clean of hindrances. The variations of the obstacles in the coolant intake of the Ringhals power plant has been investigated during the period 1976-78 in order to find the correlation of simultaneous conditions of wind, water flow, water level and temperature in relation to the blocking up. If one considers the dredged matter as typical for a medusae season, the amount of the substance can be considered having lognormal distribution. An estimate of the probability of the substance to exceed a critical limit at a given coolant flow can be made.(G.B.)

  8. Shock circle model for ejector performance evaluation

    International Nuclear Information System (INIS)

    Zhu, Yinhai; Cai, Wenjian; Wen, Changyun; Li, Yanzhong

    2007-01-01

    In this paper, a novel shock circle model for the prediction of ejector performance at the critical mode operation is proposed. By introducing the 'shock circle' at the entrance of the constant area chamber, a 2D exponential expression for velocity distribution is adopted to approximate the viscosity flow near the ejector inner wall. The advantage of the 'shock circle' analysis is that the calculation of ejector performance is independent of the flows in the constant area chamber and diffuser. Consequently, the calculation is even simpler than many 1D modeling methods and can predict the performance of critical mode operation ejectors much more accurately. The effectiveness of the method is validated by two experimental results reported earlier. The proposed modeling method using two coefficients is shown to produce entrainment ratio, efficiency and coefficient of performance (COP) accurately and much closer to experimental results than those of 1D analysis methods

  9. Two-phase Flow Ejector as Water Refrigerant by Using Waste Heat

    International Nuclear Information System (INIS)

    Yamanaka, H; Nakagawa, M

    2013-01-01

    Energy saving and the use of clean energy sources have recently become significant issues. It is expected that clean energy sources such as solar panels and fuel cells will be installed in many private dwellings. However, when electrical power is generated, exhaust heat is simultaneously produced. Especially for the summer season, the development of refrigeration systems that can use this waste heat is highly desirable. One approach is an ejector that can reduce the mechanical compression work required in a normal refrigeration cycle. We focus on the use of water as a refrigerant, since this can be safely implemented in private dwellings. Although the energy conversion efficiency is low, it is promising because it can use heat that would otherwise be discarded. However, a steam ejector refrigeration cycle requires a large amount of energy to change saturated water into vapour. Thus, we propose a more efficient two-phase flow ejector cycle. Experiments were carried out in which the quality of the two-phase flow from a tank was varied, and the efficiency of the ejector and nozzle was determined. The results show that a vacuum state can be achieved and suction exerted with a two-phase flow state at the ejector nozzle inlet.

  10. Non-Cooled Power System for Venus Lander

    Science.gov (United States)

    Salazar, Denise; Landis, Geoffrey A.; Colozza, Anthony J.

    2014-01-01

    The Planetary Science Decadal Survey of 2013-2022 stated that the exploration of Venus is of significant interest. Studying the seismic activity of the planet is of particular importance because the findings can be compared to the seismic activity of Earth. Further, the geological and atmospheric properties of Venus will shed light into the past and future of Earth. This paper presents a radioisotope power system (RPS) design for a small low-power Venus lander. The feasibility of the new power system is then compared to that of primary batteries. A requirement for the power source system is to avoid moving parts in order to not interfere with the primary objective of the mission - to collect data about the seismic activity of Venus using a seismometer. The target mission duration of the lander is 117 days, a significant leap from Venera 13, the longest-lived lander on the surface of Venus, which survived for 2 hours. One major assumption for this mission design is that the power source system will not provide cooling to the other components of the lander. This assumption is based on high-temperature electronics technology that will enable the electronics and components of the lander to operate at Venus surface temperature. For the proposed RPS, a customized General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHSRTG) is designed and analyzed. The GPHS-RTG is chosen primarily because it has no moving parts and it is capable of operating for long duration missions on the order of years. This power system is modeled as a spherical structure for a fundamental thermal analysis. The total mass and electrical output of the system are calculated to be 24 kilograms and 26 Watts, respectively. An alternative design for a battery-based power system uses Sodium Sulfur batteries. To deliver a similar electrical output for 117 days, the battery mass is calculated to be 234 kilograms. Reducing mission duration or power required will reduce the required battery mass

  11. Advanced applications of water cooled nuclear power plants

    International Nuclear Information System (INIS)

    2008-07-01

    By August 2007, there were 438 nuclear power plants (NPPs) in operation worldwide, with a total capacity of 371.7 GW(e). Further, 31 units, totaling 24.1 GW(e), were under construction. During 2006 nuclear power produced 2659.7 billion kWh of electricity, which was 15.2% of the world's total. The vast majority of these plants use water-cooled reactors. Based on information provided by its Member States, the IAEA projects that nuclear power will grow significantly, producing between 2760 and 2810 billion kWh annually by 2010, between 3120 and 3840 billion kWh annually by 2020, and between 3325 and 5040 billion kWh annually by 2030. There are several reasons for these rising expectations for nuclear power: - Nuclear power's lengthening experience and good performance: The industry now has more than 12 000 reactor years of experience, and the global average nuclear plant availability during 2006 reached 83%; - Growing energy needs: All forecasts project increases in world energy demand, especially as population and economic productivity grow. The strategies are country dependent, but usually involve a mix of energy sources; - Interest in advanced applications of nuclear energy, such as seawater desalination, steam for heavy oil recovery and heat and electricity for hydrogen production; - Environmental concerns and constraints: The Kyoto Protocol has been in force since February 2005, and for many countries (most OECD countries, the Russian Federation, the Baltics and some countries of the Former Soviet Union and Eastern Europe) greenhouse gas emission limits are imposed; - Security of energy supply is a national priority in essentially every country; and - Nuclear power is economically competitive and provides stability of electricity price. In the near term most new nuclear plants will be evolutionary water cooled reactors (Light Water Reactors (LWRs) and Heavy Water Reactors (HWRs), often pursuing economies of scale. In the longer term, innovative designs that

  12. Optimal scheduling of biocide dosing for seawater-cooled power and desalination plants

    KAUST Repository

    Mahfouz, Abdullah Bin; Atilhan, Selma; Batchelor, Bill; Linke, Patrick; Abdel-Wahab, Ahmed; El-Halwagi, Mahmoud M.

    2011-01-01

    Thermal desalination systems are typically integrated with power plants to exploit the excess heat resulting from the power-generation units. Using seawater in cooling the power plant and the desalination system is a common practice in many parts

  13. Emission operational strategy for combined cooling, heating, and power systems

    International Nuclear Information System (INIS)

    Fumo, Nelson; Mago, Pedro J.; Chamra, Louay M.

    2009-01-01

    Integrated Energy Systems (IES), as technology that use thermal activated components to recover waste heat, are energy systems that offer key solution to global warming and energy security through high overall energy efficiency and better fuel use. Combined Cooling, Heating, and Power (CCHP) Systems are IES that use recovered thermal energy from the prime mover to produce heating and cooling for the building. The CCHP operational strategy is critical and it has to be considered in a well designed system since it defines the ultimate goal for the benefits expected from the system. One of the most common operational strategies is the cost-oriented strategy, which allows the system to operate at the lowest cost. A primary energy strategy (PES) optimizes energy consumption instead of cost. However, as a result of the worldwide concern about global warming, projects that target reduction of greenhouse gas (GHG) emissions have gained a lot of interest. Therefore, for a CCHP system, an emission strategy (ES) would be an operational strategy oriented to minimize emission of pollutants. In this study, the use of an ES is proposed for CCHP systems targeted to reduce emission of pollutants. The primary energy consumption (PEC) reduction and carbon dioxide (CO 2 ) emission reduction obtained using the proposed ES are compared with results obtained from the use of a PES. Results show that lower emission of CO 2 is achieved with the ES when compared with the PES, which prove the advantage of the ES for the design of CCHP systems targeted to emissions reduction.

  14. Tests of cooling water pumps at Dukovany nuclear power plant

    International Nuclear Information System (INIS)

    Travnicek, J.

    1986-01-01

    Tests were performed to examine the operating conditions of the 1600 BQDV cooling pumps of the main coolant circuit of unit 1 of the Dukovany nuclear power plant. For the pumps, the performance was tested in the permissible operating range, points were measured below this range and the guaranteed operating point was verified. Pump efficiency was calculated from the measured values. The discussion of the measurement of parameters has not yet been finished because the obtained values of the amount delivered and thus of the pump efficiency were not up to expectation in all detail. It was also found that for obtaining the guaranteed flow the pump impeller had to be opened to 5deg -5.5deg instead of the declared 3deg. Also tested were pump transients, including the start of the pump, its stop, the operation and failure of one of the two pumps. In these tests, pressures were also measured at the inlet and the outlet of the inner part of the TG 11 turbine condenser. It was shown that the time course and the pressure course of the processes were acceptable. In addition to these tests, pressure losses in the condenser and the cooling water flow through the feed pump electromotor cooler wre tested for the case of a failure of one of the two pumps. (E.S.)

  15. Venturi Air-Jet Vacuum Ejector For Sampling Air

    Science.gov (United States)

    Hill, Gerald F.; Sachse, Glen W.; Burney, L. Garland; Wade, Larry O.

    1990-01-01

    Venturi air-jet vacuum ejector pump light in weight, requires no electrical power, does not contribute heat to aircraft, and provides high pumping speeds at moderate suctions. High-pressure motive gas required for this type of pump bled from compressor of aircraft engine with negligible effect on performance of engine. Used as source of vacuum for differential-absorption CO-measurement (DACOM), modified to achieve in situ measurements of CO at frequency response of 10 Hz. Provides improvement in spatial resolution and potentially leads to capability to measure turbulent flux of CO by use of eddy-correlation technique.

  16. Low grade heat driven adsorption system for cooling and power generation using advanced adsorbent materials

    International Nuclear Information System (INIS)

    Al-Mousawi, Fadhel Noraldeen; Al-Dadah, Raya; Mahmoud, Saad

    2016-01-01

    Highlights: • Adsorption system based on water and advanced physical adsorbents has the potential of producing cooling and power. • Adding an expander to physisorption system enhances efficiency by up to 11%. • MIL101Cr MOF can produce 95 W/kg and 1357 W/kg of specific power and cooling. • AQSOA Z02 can produce 73 W/kg and 640 W/kg of specific power and cooling. - Abstract: Globally there is abundance of low grade heat sources (around 150 °C) from renewables like solar energy or from industrial waste heat. The exploitation of such low grade heat sources will reduce fossil fuel consumption and CO_2 emissions. Adsorption technology offers the potential of using such low grade heat to generate cooling and power. In this work, the effect of using advanced adsorbent materials like AQSOA-Z02 (SAPO-34) zeolite and MIL101Cr Metal Organic Framework (MOF) at various operating conditions on power and cooling performance compared to that of commonly used silica-gel was investigated using water as refrigerant. A mathematical model for a two bed adsorption cooling cycle has been developed with the cycle modified to produce power by incorporating an expander between the desorber and the condenser. Results show that it is possible to produce power and cooling at the same time without affecting the cooling output. Results also show that for all adsorbents used as the heat source temperature increases, the cooling effect and power generated increase. As for increasing the cold bed temperature, this will decrease the cooling effect and power output except for SAPO-34 which shows slightly increasing trend of cooling and power output. As the condenser cooling temperature increases, the cooling effect and power output will decrease while for the chilled water temperature, the cooling load and power generated increased as the temperature increased. The maximum values of average specific power generation (SP), specific cooling power (SCP) and cycle efficiency are 73 W

  17. Gas-cooled reactor for space power systems

    International Nuclear Information System (INIS)

    Walter, C.E.; Pearson, J.S.

    1987-05-01

    Reactor characteristics based on extensive development work on the 500-MWt reactor for the Pluto nuclear ramjet are described for space power systems useful in the range of 2 to 20 MWe for operating times of 1 y. The modest pressure drop through the prismatic ceramic core is supported at the outlet end by a ceramic dome which also serves as a neutron reflector. Three core materials are considered which are useful at temperatures up to about 2000 K. Most of the calculations are based on a beryllium oxide with uranium dioxide core. Reactor control is accomplished by use of a burnable poison, a variable-leakage reflector, and internal control rods. Reactivity swings of 20% are obtained with a dozen internal boron-10 rods for the size cores studied. Criticality calculations were performed using the ALICE Monte Carlo code. The inherent high-temperature capability of the reactor design removes the reactor as a limiting condition on system performance. The low fuel inventories required, particularly for beryllium oxide reactors, make space power systems based on gas-cooled near-thermal reactors a lesser safeguard risk than those based on fast reactors

  18. Control of cooling of an oil-immersed power transformer by varying speed of fans

    OpenAIRE

    Đorđević, Nikola Z.; Žakula, Dane M.; Jevtić, Milica M.; Tomašević, Radojica Ž.; Radaković, Zoran R.

    2016-01-01

    The paper presents a prototype system for speed control of cooling fans for a small oil-immersed 6.6 kVA transformer, implemented on a standard PLC. Generally, the potential for optimization of the cooling process depends on the accessible cooling modes and construction of the transformer; basically the aim of the cooling system control is reduction in power consumption of the fans / pumps and keeping the top-oil temperature at constant value (to reduce transformer 'breathing' and infiltratio...

  19. Cooling of nuclear power stations with high temperature reactors and helium turbine cycles

    International Nuclear Information System (INIS)

    Foerster, S.; Hewing, G.

    1977-01-01

    On nuclear power stations with high temperature reactors and helium turbine cycles (HTR-single circuits) the residual heat from the energy conversion process in the primary and intermediate coolers is removed from cycled gas, helium. Water, which is circulated for safety reasons through a closed circuit, is used for cooling. The primary and intermediate coolers as well as other cooling equipment of the power plant are installed within the reactor building. The heat from the helium turbine cycle is removed to the environment most effectively by natural draught cooling towers. In this way a net plant efficiency of about 40% is attainable. The low quantities of residual heat thereby produced and the high (in comparison with power stations with steam turbine cycles) cooling agent pressure and cooling water reheat pressure in the circulating coolers enable an economically favourable design of the overall 'cold end' to be expected. In the so-called unit range it is possible to make do with one or two cooling towers. Known techniques and existing operating experience can be used for these dry cooling towers. After-heat removal reactor shutdown is effected by a separate, redundant cooling system with forced air dry coolers. The heat from the cooling process at such locations in the power station is removed to the environment either by a forced air dry cooling installation or by a wet cooling system. (orig.) [de

  20. Design for micro-combined cooling, heating and power systems stirling engines and renewable power systems

    CERN Document Server

    2015-01-01

    ‘Design for Micro-Combined Cooling, Heating & Power Systems’ provides a manual for the technical and structural design of systems for supplying decentralised energy in residential buildings. It presents the micro-combined cooling, heating & power systems Stirling engines & renewable energy sources (mCCHP-SE-RES) systems in an accessible manner both for the public at large, and for professionals who conceive, design or commercialise such systems or their components.  The high performance levels of these systems are demonstrated within the final chapter by the results of an experiment in which a house is equipped with a mCCHP-SE-RES system. The reader is also familiarized with the conceptual, technical and legal aspects of modern domestic energy systems; the components that constitute these systems; and advanced algorithms for achieving the structural and technical design of such systems. In residential buildings, satisfying demands of durable development has gradually evolved from necessity to...

  1. Deuterium- and 18O-content in the cooling water of power station cooling towers

    International Nuclear Information System (INIS)

    Heimbach, H.; Dongmann, G.

    1976-09-01

    The 0-18/0-16 and D/H isotope ratios of water from two different cooling towers were determined by mass spectrometry. The observed isotope fractionation corresponds to that known from natural evaporation or transpiration processes: cooling tower I: delta(D) = 46.8 per thousand, delta( 18 O) = 7.6 per thousand cooling tower II: delta(D) = 33.9 per thousand delta( 18 O) = 5.7 per thousand Evaluation of simple compartment models of a cooling tower and a distillation device suggests that there exists some isotope discrimination within the open trickling unit of a cooling tower analogous to that in a rectification column. In a real cooling tower, however, this effect is compensated largely by the recycling of the cooling water, resulting only in a small enrichment of the heavy isotopes. This can be understood as the result of three partial effects: 1) a fractionation in the vapor pressure equilibrium, 2) a kinetic effect due to diffusion of the water vapor into a turbulent atmosphere, and 3) an exchange effect which is proportional to relative humidity. This low enrichment of the heavy isotope excludes the technical use of cooling towers as isotope separation devices. (orig.) [de

  2. Evaluation of the performance of combined cooling, heating, and power systems with dual power generation units

    International Nuclear Information System (INIS)

    Knizley, Alta A.; Mago, Pedro J.; Smith, Amanda D.

    2014-01-01

    The benefits of using a combined cooling, heating, and power system with dual power generation units (D-CCHP) is examined in nine different U.S. locations. One power generation unit (PGU) is operated at base load while the other is operated following the electric load. The waste heat from both PGUs is used for heating and for cooling via an absorption chiller. The D-CCHP configuration is studied for a restaurant benchmark building, and its performance is quantified in terms of operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE). Cost spark spread, PEC spark spread, and CDE spark spread are examined as performance indicators for the D-CCHP system. D-CCHP system performance correlates well with spark spreads, with higher spark spreads signifying greater savings through implementation of a D-CCHP system. A new parameter, thermal difference, is introduced to investigate the relative performance of a D-CCHP system compared to a dual PGU combined heat and power system (D-CHP). Thermal difference, together with spark spread, can explain the variation in savings of a D-CCHP system over a D-CHP system for each location. The effect of carbon credits on operational cost savings with respect to the reference case is shown for selected locations. - Highlights: • We investigate benefits from using combined cooling, heating, and power systems. • A dual power generation unit configuration is considered for CCHP and CHP. • Spark spreads for cost, energy, and emissions correlate with potential savings. • Thermal difference parameter helps to explain variations in potential savings. • Carbon credits may increase cost savings where emissions savings are possible

  3. The early history of high-temperature helium gas-cooled nuclear power reactors

    International Nuclear Information System (INIS)

    Simnad, M.T.; California Univ., San Diego, La Jolla, CA

    1991-01-01

    The original concepts in the proposals for high-temperature helium gas-cooled power reactors by Farrington Daniels, during the decade 1944-1955, are summarized. The early research on the development of the helium gas-cooled power reactors is reviewed, and the operational experiences with the first generation of HTGRs are discussed. (author)

  4. 77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Science.gov (United States)

    2012-12-07

    ... Plants AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide; request for comment... (DG), DG-1259, ``Initial Test Programs for Water-Cooled Nuclear Power Plants.'' This guide describes... (ITPs) for light water cooled nuclear power plants. DATES: Submit comments by January 31, 2013. Comments...

  5. Optimization Tool for Direct Water Cooling System of High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Blaabjerg, Frede

    2016-01-01

    important issue for thermal design engineers. This paper aims to present a user friendly optimization tool for direct water cooling system of a high power module which enables the cooling system designer to identify the optimized solution depending on customer load profiles and available pump power. CFD...

  6. Hydrogen in water-cooled nuclear power reactors

    International Nuclear Information System (INIS)

    1992-01-01

    The Commission of the European Community (CEC) and the International Atomic Energy Agency (IAEA) decided in 1989 to update the state of the art concerning hydrogen in water cooled nuclear power reactors by commissioning a report which would review, all the available information to-date and make recommendations for the future. This joint report was prepared by committees formed by the IAEA and by the CEC. The aim of this report is to review the current understanding on the areas in which the research on hydrogen in LWR is conventionally presented, taking into account the results of the latest reported research developments. The main reactions through which hydrogen is produced are assessed together with their timings. An estimation of the amount of hydrogen produced by each reaction is given, in order to reckon their relative contribution to the hazard. An overview is then given of the state of knowledge of the most important phenomena taking place during its transport from the place of production and the phenomena which control the hydrogen combustion and the consequences of combustion under various conditions. Specific research work is recommended in each sector of the presented phenomena. The last topics reviewed in this report are the hydrogen detection and the prevent/mitigation of pressure and temperature loads on containment structures and structures and safety related equipment caused by hydrogen combustion

  7. Development Project of Supercritical-water Cooled Power Reactor

    International Nuclear Information System (INIS)

    Kataoka, K.; Shiga, S.; Moriya, K.; Oka, Y.; Yoshida, S.; Takahashi, H.

    2002-01-01

    A Supercritical-water Cooled Power Reactor (SCPR) development project (Feb. 2001- Mar. 2005) is being performed by a joint team consisting of Japanese universities and nuclear venders with a national fund. The main objective of this project is to provide technical information essential to demonstration of SCPR technologies through concentrating three sub-themes: 'plant conceptual design', 'thermohydraulics', and 'material and water chemistry'. The target of the 'plant conceptual design sub-theme' is simplify the whole plant systems compared with the conventional LWRs while achieving high thermal efficiency of more than 40 % without sacrificing the level of safety. Under the 'thermohydraulics sub-theme', heat transfer characteristics of supercritical-water as a coolant of the SCPR are examined experimentally and analytically focusing on 'heat transfer deterioration'. The experiments are being performed using fron-22 for water at a fossil boiler test facility. The experimental results are being incorporated in LWR analytical tools together with an extended steam/R22 table. Under the 'material and water chemistry sub-theme', material candidates for fuel claddings and internals of the SCPR are being screened mainly through mechanical tests, corrosion tests, and simulated irradiation tests under the SCPR condition considering water chemistry. In particular, stress corrosion cracking sensitivity is being investigated as well as uniform corrosion and swelling characteristics. Influences of water chemistry on the corrosion product characteristics are also being examined to find preferable water condition as well as to develop rational water chemistry controlling methods. (authors)

  8. Performance analysis for minimally nonlinear irreversible refrigerators at finite cooling power

    Science.gov (United States)

    Long, Rui; Liu, Zhichun; Liu, Wei

    2018-04-01

    The coefficient of performance (COP) for general refrigerators at finite cooling power have been systematically researched through the minimally nonlinear irreversible model, and its lower and upper bounds in different operating regions have been proposed. Under the tight coupling conditions, we have calculated the universal COP bounds under the χ figure of merit in different operating regions. When the refrigerator operates in the region with lower external flux, we obtained the general bounds (0 present large values, compared to a relative small loss from the maximum cooling power. If the cooling power is the main objective, it is desirable to operate the refrigerator at a slightly lower cooling power than at the maximum one, where a small loss in the cooling power induces a much larger COP enhancement.

  9. The application of gas ejector for road transport air conditioning system

    Science.gov (United States)

    Sumeru, Nasution, Henry; Ani, Farid Nasir

    2012-06-01

    The depletion of fossil fuel supply requires fuel and energy saving in energy utilization system. Therefore, these required the development of new and efficient technologies as to reduce fuel consumption especially in air conditioning of road vehicles. Currently, the air conditioning for road vehicles uses vapor compression system. Although the vapor compression system has high COP, the compressor is driven by vehicle engines, which take additional fuel consumption when the air conditioning system is in operation. In this study, the waste heat of radiator drives the ejector refrigeration for air conditioning. Although the ejector refrigeration system has low COP, the use of heat driven air conditioning will reduce the fuel consumption as compared with conventional system. This is because the systems do not use the mechanical engine load. The analysis of this study is based on the ejector refrigeration system using natural refrigerant (isobutene). The evaporation temperature is 10°C, condensation temperature is 35°C, generator temperature is 90°C with ejector isentropic efficiency of 0.7, and the COP system is 0.25. The heat released by the radiator of typical small road vehicles is between 60 to 100 kW and if the generator absorbs 20% of the heat, the heat contained in the generator is 12 to 20 kW. When the ejector air conditioning system has a COP 0.25, it will generate cooling capacity between 3 to 5 kW, compared with the conventional air conditioning of similar vehicles, which is approximately 2 to 4.4 kW.

  10. Cooling system for auxiliary systems of a nuclear power plant

    International Nuclear Information System (INIS)

    Maerker, W.; Mueller, K.; Roller, W.

    1981-01-01

    From the reactor auxiliary and ancillary systems of a nuclear facility heat has to be removed without the hazard arising that radioactive liquids or gases may escape from the safe area of the nuclear facility. A cooling system is described allowing at every moment to make available cooling fluid at a temperature sufficiently low for heat exchangers to be able to remove the heat from such auxiliary systems without needing fresh water supply or water reservoirs. For this purpose a dry cooling tower is connected in series with a heat exchanger that is cooled on the secondary side by means of a refrigerating machine. The cooling pipes are filled with a nonfreezable fluid. By means of a bypass a minimum temperature is guaranteed at cold weather. (orig.) [de

  11. Valves for condenser-cooling-water circulating piping in thermal power station and nuclear power station

    International Nuclear Information System (INIS)

    Kondo, Sumio

    1977-01-01

    Sea water is mostly used as condenser cooling water in thermal and nuclear power stations in Japan. The quantity of cooling water is 6 to 7 t/sec per 100,000 kW output in nuclear power stations, and 3 to 4 t/sec in thermal power stations. The pipe diameter is 900 to 2,700 mm for the power output of 75,000 to 1,100,000 kW. The valves used are mostly butterfly valves, and the reliability, economy and maintainability must be examined sufficiently because of their important role. The construction, number and arrangement of the valves around a condenser are different according to the types of a turbine and the condenser and reverse flow washing method. Three types are illustrated. The valves for sea water are subjected to the electrochemical corrosion due to sea water, the local corrosion due to stagnant water, the fouling by marine organisms, the cavitation due to valve operation, and the erosion by earth and sand. The fundamental construction, use and features of butterfly valves are described. The cases of the failure and repair of the valves after their delivery are shown, and they are the corrosion of valve bodies and valve seats, and the separation of coating and lining. The newly developed butterfly valve with overall water-tight rubber lining is introduced. (Kako, I.)

  12. Marginal costs of water savings from cooling system retrofits: a case study for Texas power plants

    Science.gov (United States)

    Loew, Aviva; Jaramillo, Paulina; Zhai, Haibo

    2016-10-01

    The water demands of power plant cooling systems may strain water supply and make power generation vulnerable to water scarcity. Cooling systems range in their rates of water use, capital investment, and annual costs. Using Texas as a case study, we examined the cost of retrofitting existing coal and natural gas combined-cycle (NGCC) power plants with alternative cooling systems, either wet recirculating towers or air-cooled condensers for dry cooling. We applied a power plant assessment tool to model existing power plants in terms of their key plant attributes and site-specific meteorological conditions and then estimated operation characteristics of retrofitted plants and retrofit costs. We determined the anticipated annual reductions in water withdrawals and the cost-per-gallon of water saved by retrofits in both deterministic and probabilistic forms. The results demonstrate that replacing once-through cooling at coal-fired power plants with wet recirculating towers has the lowest cost per reduced water withdrawals, on average. The average marginal cost of water withdrawal savings for dry-cooling retrofits at coal-fired plants is approximately 0.68 cents per gallon, while the marginal recirculating retrofit cost is 0.008 cents per gallon. For NGCC plants, the average marginal costs of water withdrawal savings for dry-cooling and recirculating towers are 1.78 and 0.037 cents per gallon, respectively.

  13. A homogeneous cooling scheme investigation for high power slab laser

    Science.gov (United States)

    He, Jianguo; Lin, Weiran; Fan, Zhongwei; Chen, Yanzhong; Ge, Wenqi; Yu, Jin; Liu, Hao; Mo, Zeqiang; Fan, Lianwen; Jia, Dan

    2017-10-01

    The forced convective heat transfer with the advantages of reliability and durability is widely used in cooling the laser gain medium. However, a flow direction induced temperature gradient always appears. In this paper, a novel cooling configuration based on longitudinal forced convective heat transfer is presented. In comparison with two different types of configurations, it shows a more efficient heat transfer and more homogeneous temperature distribution. The investigation of the flow rate reveals that the higher flow rate the better cooling performance. Furthermore, the simulation results with 20 L/min flow rate shows an adequate temperature level and temperature homogeneity which keeps a lower hydrostatic pressure in the flow path.

  14. Analysis of the evaporative towers cooling system of a coal-fired power plant

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2012-01-01

    Full Text Available The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system.

  15. Optimization of ejector design and operation

    Directory of Open Access Journals (Sweden)

    Kuzmenko Konstantin

    2016-01-01

    Full Text Available The investigation aims at optimization of gas ejector operation. The goal consists in the improvement of the inflator design so that to enable 50 liters of gas inflation within ~30 milliseconds. For that, an experimental facility was developed and fabricated together with the measurement system to study pressure patterns in the inflator path.

  16. Air-cooling viability to increase the power in the thermal power stations of gas: Colombian case

    International Nuclear Information System (INIS)

    Amell, Andres; Bedoya, H. A

    2000-01-01

    Thermal power decreases as air temperature increases, which reduce both efficiency and projects yielding. Technologically it is possible to eliminate the environment temperature incidence on reduction of power and efficiency, cooling the input air to the turbine, obtaining important power and efficiency improvements. In this work, the technical and economical viability, when applying air cooling technologies (evaporative cooling, steam compression, and production and ice storage (TES) were studied, having in mind meteorological conditions and Colombian electric marketing features, in which, nearly 2800 MW of natural gas thermal power have been installed in the last decade. as a result of applying these cooling technologies the study determined: the mean potential of recoverable power at the second peak of the national demand curve, shows several schemes in which they are technically and economically viable in the Colombian context

  17. Closed-cycle cooling systems for nuclear power plants

    International Nuclear Information System (INIS)

    Santini, Lorenzo

    2006-01-01

    The long experience in the field of closed-cycle cooling systems and high technological level of turbo machines and heat exchangers concurs to believe in the industrial realizability of nuclear systems of high thermodynamic efficiency and intrinsic safety [it

  18. Conductive cooling of high-power RIB targets

    International Nuclear Information System (INIS)

    Talbert, W.L.; Drake, D.M.; Wilson, M.T.; Lenz, J.W.; Hsu, H.-H.

    2002-01-01

    A short review is presented of target cooling approaches suggested for targets irradiated by intense high-energy proton beams to produce radioactive species for use in a broad range of physics studies. This work reports on conductive cooling approaches for operation at temperatures lower than effective for radiative cooling. The possibilities for conductive cooling are discussed, and a prototype test target is described. This target was constructed for an experiment, designed to validate the numerical analysis approaches, at the TRIUMF/ISAC facility. Fabrication issues and the results of the experiment are presented, followed by a discussion of the implications of the experiment outcome for future development of targets to produce intense beams of radioactive ions

  19. Engineering Design Handbook. Military Vehicle Power Plant Cooling

    Science.gov (United States)

    1975-06-01

    conductivity of steel and, Indirect cooling is achieved by an interme- therefore, has a much higher heat transfer diary fluid that absorbs heat from...PROBABLZ - -- - - N PERFOEUMACE 0 t0 4 8 21 is s0 24 AIR DELIVEY,. CPU flo 1000-0- U.=rWIM-YEC0*4CAL " AYA OM". 7-6-59 F-igure 8-40. Cooling Fin

  20. Concept of electric power output control system for atomic power generation plant utilizing cool energy of stored snow

    International Nuclear Information System (INIS)

    Kamimura, Seiji; Toita, Takayuki

    2003-01-01

    A concept of the SEAGUL system (Snow Enhancing Atomic-power Generation UtiLity) is proposed in this paper. Lowering the temperature of sea water for cooling of atomic-power plant will make a efficiency of power generation better and bring several ten MW additional electric power for 1356 MW class plant. The system concept stands an idea to use huge amount of seasonal storage snow for cooling water temperature control. In a case study for the Kashiwazaki-Kariwa Nuclear Power Station, it is estimated to cool down the sea water of 29degC to 20degC by 80 kt snow for 3 hours in a day would brought 60 MWh electric power per a day. Annually 38.4 Mt of stored snow will bring 1800 MWh electric power. (author)

  1. Optimum selection of solar collectors for a solar-driven ejector air conditioning system by experimental and simulation study

    International Nuclear Information System (INIS)

    Zhang Wei; Ma Xiaoli; Omer, S.A.; Riffat, S.B.

    2012-01-01

    Highlights: ► Three solar collectors have been compared to drive ejector air conditioning system. ► A simulation program was constructed to study the effect parameters. ► The outdoor test were conducted to validate the solar collector modeling. ► Simulation program was found to predict solar collector performance accurately. ► The optimal design of solar collector system was carried out. - Abstract: In this paper, three different solar collectors are selected to drive the solar ejector air conditioning system for Mediterranean climate. The performance of the three selected solar collector are evaluated by computer simulation and lab test. Computer model is incorporated with a set of heat balance equations being able to analyze heat transfer process occurring in separate regions of the collector. It is found simulation and test has a good agreement. By the analysis of the computer simulation and test result, the solar ejector cooling system using the evacuated tube collector with selective surface and high performance heat pipe can be most economical when operated at the optimum generating temperature of the ejector cooling machine.

  2. Biological effects from discharge of cooling water from thermal power plants

    International Nuclear Information System (INIS)

    1976-12-01

    Results are reported for a Danish project on biological effects from discharge of cooling water from thermal power plants. The purpose of the project was to provide an up-to-date knowledge of biological effects of cooling water discharge and of organization and evaluation of recipient investigations in planned and established areas. (BP)

  3. Macrophytes in the cooling ponds of Ukrainian nuclear and thermal power plants

    International Nuclear Information System (INIS)

    D'yachenko, T.N.

    2013-01-01

    Attention is focused at the macrophytes role in the functioning of the natural-technological cooling ponds ecosystems, at the features of aquatic plants and station water supply system interaction. It was considered the degree of macrophytes scrutiny and it was pointed out the necessity of monitoring and controlling their condition in the cooling ponds of Ukrainian power plants.

  4. Conceptual design and simulation investigation of an electronic cooling device powered by hot electrons

    International Nuclear Information System (INIS)

    Su, Guozhen; Zhang, Yanchao; Cai, Ling; Su, Shanhe; Chen, Jincan

    2015-01-01

    Most electronic cooling devices are powered by an external bias applied between the cold and the hot reservoirs. Here we propose a new concept of electronic cooling, in which cooling is achieved by using a reservoir of hot electrons as the power source. The cooling device incorporates two energy filters with the Lorentzian transmission function to respectively select low- and high-energy electrons for transport. Based on the proposed model, we analyze the performances of the device varying with the resonant levels and half widths of two energy filters and establish the optimal configuration of the cooling device. It is believed that such a novel device may be practically used in some nano-energy fields. - Highlights: • A new electronic cooling device powered by hot electrons is proposed. • Two energy filters are employed to select the electrons for transport. • The effects of the resonant levels and half widths of two filters are discussed. • The maximum cooling power and coefficient of performance are calculated. • The optimal configuration of the cooling device is determined.

  5. Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

    Energy Technology Data Exchange (ETDEWEB)

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2010-06-01

    Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be built at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic

  6. Saving of drinking water in cooling system at Aq aba Thermal Power Station

    International Nuclear Information System (INIS)

    Al-Nsour, A.F.

    2001-01-01

    This paper discussing a new modification, design and implementation to the existing cooling water system of boiler drum continuous blow down water at Aq aba Thermal Power Stations to eliminate drinking water consumption as a coolant medium

  7. Integrated packaging of multiple double sided cooling planar bond power modules

    Science.gov (United States)

    Liang, Zhenxian

    2018-04-10

    An integrated double sided cooled power module has one or multiple phase legs configuration including one or more planar power packages, each planar power package having an upper power switch unit and a lower power switch unit directly bonded and interconnected between two insulated power substrates, and further sandwiched between two heat exchangers via direct bonds. A segmented coolant manifold is interposed with the one or more planar power packages and creates a sealed enclosure that defines a coolant inlet, a coolant outlet and a coolant flow path between the inlet and the outlet. A coolant circulates along the flow path to remove heat and increase the power density of the power module.

  8. Method to operate power reactors with light water cooling

    International Nuclear Information System (INIS)

    Aleite, W.; Bock, H.W.

    1976-01-01

    The invention provides a possibility to 'condition' the fuel of a power plant used in base load operation, i.e. to bring it to such a high power density level that the local excesses arising with the occasional total power changes, remain below the power densities reached in normal operation (conditioning level). (orig./RW) [de

  9. Measures against the adverse impact of natural wind on air-cooled condensers in power plant

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant.It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers.Based on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed.The physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD simulation.The back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled condensers.The results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind.

  10. Reliability Model of Power Transformer with ONAN Cooling

    OpenAIRE

    M. Sefidgaran; M. Mirzaie; A. Ebrahimzadeh

    2010-01-01

    Reliability of a power system is considerably influenced by its equipments. Power transformers are one of the most critical and expensive equipments of a power system and their proper functions are vital for the substations and utilities. Therefore, reliability model of power transformer is very important in the risk assessment of the engineering systems. This model shows the characteristics and functions of a transformer in the power system. In this paper the reliability model...

  11. Solar heating cooling. Preparation of possible participation in IEA, Solar Heating Cooling Task 25

    International Nuclear Information System (INIS)

    2001-03-01

    For the Danish solar heating industries it is interesting to discuss the domestic market possibilities and the export possibilities for solar heating cooling systems. The Danish solar heating sector also wants to participate in the international collaboration within IEA Solar Heating and Cooling Task 25 'Solar Assisted Air Conditioning of Buildings'. The Danish Energy Agency therefore has granted means for this project to discuss: The price of cooling for 3 different solar cooling methods (absorption cooling, desiccant cooling and ejector cooling); Market possibilities in Denmark and abroad; The advantages by Danish participation in IEA Task 25. The task has been solved through literature studies to establish status for the 3 technologies. It turned out that ejector cooling by low temperatures (85 deg. C from the solar collector) exists as pilot plants in relation to district heating, but is still not commercial accessible. Desiccant cooling, where the supplied heat has temperatures down to 55 deg. C is a well-developed technology. However only a handful of pilot plants with solar heating exists, and thus optimization relating to operation strategy and economy is on the experimental stage. Absorption cooling plants driven by solar heating are found in a large number in Japan and are also demonstrated in several other countries. The combination of absorption heating pump and solar heating is considered to be commercial accessible. Solar heating is interesting as heat source of to the extent that it can replace other sources of heat without the economy being depreciated. This can be the case in South Europe if: 1) oil or natural gas is used for heating; 2) a solar heating system already exists, e.g. for domestic water supply, and is installed so that the marginal costs by solar heating supply of the ventilation plant is reduced. All in all the above conditions mean that the market for solar heating for cooling is very limited in Europe, where almost everybody are

  12. Development of hybrid solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.; Wu, J.H.; Hsu, H.Y.; Wang, J.H.

    2010-01-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  13. Development of hybrid solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.

    2010-08-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  14. Economical Efficiency of Combined Cooling Heating and Power Systems Based on an Enthalpy Method

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2017-11-01

    Full Text Available As the living standards of Chinese people have been improving, the energy demand for cooling and heating, mainly in the form of electricity, has also expanded. Since an integrated cooling, heating and power supply system (CCHP will serve this demand better, the government is now attaching more importance to the application of CCHP energy systems. Based on the characteristics of the combined cooling heating and power supply system, and the method of levelized cost of energy, two calculation methods for the evaluation of the economical efficiency of the system are employed when the energy production in the system is dealt with from the perspective of exergy. According to the first method, fuel costs account for about 75% of the total cost. In the second method, the profits from heating and cooling are converted to fuel costs, resulting in a significant reduction of fuel costs, accounting for 60% of the total cost. Then the heating and cooling parameters of gas turbine exhaust, heat recovery boiler, lithium-bromide heat-cooler and commercial tariff of provincial capitals were set as benchmark based on geographic differences among provinces, and the economical efficiency of combined cooling heating and power systems in each province were evaluated. The results shows that the combined cooling heating and power system is economical in the developed areas of central and eastern China, especially in Hubei and Zhejiang provinces, while in other regions it is not. The sensitivity analysis was also made on related influencing factors of fuel cost, demand intensity in heating and cooling energy, and bank loans ratio. The analysis shows that the levelized cost of energy of combined cooling heating and power systems is very sensitive to exergy consumption and fuel costs. When the consumption of heating and cooling energy increases, the unit cost decreases by 0.1 yuan/kWh, and when the on-grid power ratio decreases by 20%, the cost may increase by 0.1 yuan

  15. Increasing photovoltaic panel power through water cooling technique

    Directory of Open Access Journals (Sweden)

    Calebe Abrenhosa Matias

    2017-02-01

    Full Text Available This paper presents the development of a cooling apparatus using water in a commercial photovoltaic panel in order to analyze the increased efficiency through decreased operating temperature. The system enables the application of reuse water flow, at ambient temperature, on the front surface of PV panel and is composed of an inclined plane support, a perforated aluminum profile and a water gutter. A luminaire was specially developed to simulate the solar radiation over the module under test in a closed room, free from the influence of external climatic conditions, to carry out the repetition of the experiment in controlled situations. The panel was submitted to different rates of water flow. The best water flow rate was of 0.6 L/min and net energy of 77.41Wh. Gain of 22.69% compared to the panel without the cooling system.

  16. Ejector device for returning incomplete combustion products

    Energy Technology Data Exchange (ETDEWEB)

    Szule, T.; Minas, E.; Pietrowski, K.

    1977-12-19

    A device is proposed for separating the fine fraction of incompletely burned clinker and delivering it to the firebox for combustion. The clinker is fed into the two-chambered device from the top through an open gate. The inside chamber of the device consists of a side enclosure with an inspection hole and a hatch, and a gate with a screen on top. An ejector is located in the chamber. The case of the outside chamber, also with an inspection hole and hatch, forms a bypass channel with the enclosure of the inside chamber. Fine clinker is poured through the screen into the inside chamber, and some of it is removed by the ejector for combustion; the coarser fraction builds up on top of the gate, and is periodically passed through it. Large pieces of clinker which do not fit through the screen pass down through the bypass channel.

  17. Environmental impact of cooling towers of large nuclear power plants

    International Nuclear Information System (INIS)

    Nester, K.

    1975-01-01

    The computer program for the calculation of the rise of cooling tower plumes (3-dimensional) was extented. In addition to the distributions of the vertical velocity, the temperatures and the specific humidity, it yields now the distribution of the rain droplets in the plume, too. The treatment of the cloud physics was based on the theory of Kessler (E. Kessler, Meteorological Monographs, 10 (1969) No. 32). (orig.) [de

  18. Utilization of municipal wastewater for cooling in thermoelectric power plants

    Energy Technology Data Exchange (ETDEWEB)

    Safari, Iman [Illinois Inst. of Technology, Chicago, IL (United States); Walker, Michael E. [Illinois Inst. of Technology, Chicago, IL (United States); Hsieh, Ming-Kai [Carnegie Mellon Univ., Pittsburgh, PA (United States); Dzombak, David A. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Liu, Wenshi [Univ. of Pittsburgh, PA (United States); Vidic, Radisav D. [Univ. of Pittsburgh, PA (United States); Miller, David C. [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Abbasian, Javad [Illinois Inst. of Technology, Chicago, IL (United States)

    2013-09-01

    A process simulation model has been developed using Aspen Plus® with the OLI (OLI System, Inc.) water chemistry model to predict water quality in the recirculating cooling loop utilizing secondary- and tertiary-treated municipal wastewater as the source of makeup water. Simulation results were compared with pilot-scale experimental data on makeup water alkalinity, loop pH, and ammonia evaporation. The effects of various parameters including makeup water quality, salt formation, NH3 and CO2 evaporation mass transfer coefficients, heat load, and operating temperatures were investigated. The results indicate that, although the simulation model can capture the general trends in the loop pH, experimental data on the rates of salt precipitation in the system are needed for more accurate prediction of the loop pH. It was also found that stripping of ammonia and carbon dioxide in the cooling tower can influence the cooling loop pH significantly. The effects of the NH3 mass transfer coefficient on cooling loop pH appear to be more significant at lower values (e.g., kNH3 < 4×10-3 m/s) when the makeup water alkalinity is low (e.g., <90 mg/L as CaCO3). The effect of the CO2 mass transfer coefficient was found to be significant only at lower alkalinity values (e.g., kCO2<4×10-6 m/s).

  19. Monolayer graphene dispersion and radiative cooling for high power LED

    Science.gov (United States)

    Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

    2013-10-01

    Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1 ° C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation.

  20. Monolayer graphene dispersion and radiative cooling for high power LED

    International Nuclear Information System (INIS)

    Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

    2013-01-01

    Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1 ° C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation. (paper)

  1. Thermal Management of Power Semiconductor Packages - Matching Cooling Technologies with Packaging Technologies (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, K.; Moreno, G.

    2010-04-27

    Heat removal for power semiconductor devices is critical for robust operation. Because there are different packaging options, different thermal management technologies, and a range of applications, there is a need for a methodology to match cooling technologies and package configurations to target applications. To meet this need, a methodology was developed to compare the sensitivity of cooling technologies on the overall package thermal performance over a range of power semiconductor packaging configurations. The results provide insight into the trade-offs associated with cooling technologies and package configurations. The approach provides a method for comparing new developments in power semiconductor packages and identifying potential thermal control technologies for the package. The results can help users select the appropriate combination of packaging configuration and cooling technology for the desired application.

  2. Performance Analysis of an Updraft Tower System for Dry Cooling in Large-Scale Power Plants

    Directory of Open Access Journals (Sweden)

    Haotian Liu

    2017-11-01

    Full Text Available An updraft tower cooling system is assessed for elimination of water use associated with power plant heat rejection. Heat rejected from the power plant condenser is used to warm the air at the base of an updraft tower; buoyancy-driven air flows through a recuperative turbine inside the tower. The secondary loop, which couples the power plant condenser to a heat exchanger at the tower base, can be configured either as a constant-pressure pump cycle or a vapor compression cycle. The novel use of a compressor can elevate the air temperature in the tower base to increases the turbine power recovery and decrease the power plant condensing temperature. The system feasibility is evaluated by comparing the net power needed to operate the system versus alternative dry cooling schemes. A thermodynamic model coupling all system components is developed for parametric studies and system performance evaluation. The model predicts that constant-pressure pump cycle consumes less power than using a compressor; the extra compression power required for temperature lift is much larger than the gain in turbine power output. The updraft tower system with a pumped secondary loop can allow dry cooling with less power plant efficiency penalty compared to air-cooled condensers.

  3. Thermodynamic, Environmental and Economic Analyses of Solar Ejector Refrigeration System Application for Cold Storage

    Directory of Open Access Journals (Sweden)

    İbrahim ÜÇGÜL

    2009-02-01

    Full Text Available The refrigeration processes have been widely applied for especially in cold storages. In these plants, the systems working with compressed vapour cooling cycles have been used as a classical method. In general, electrical energy is used for compressing in these processes. Although, mainly the electricity itself has no pollution effect on the environment, the fossil fuels that are widely used to produce electricity in the most of the world, affect the nature terribly. In short, these refrigeration plants, because of the source of the electricity pollute the nature indirectly. However, for compression an ejector refrigeration system requires one of the important renewable energy sources with negligible pollution impact on the environment, namely solar energy from a thermal source. Thermodynamical, environmental and economical aspects of the ejector refrigeration system working with solar energy was investigated in this study. As a pilot case, apple cold storage plants widely used in ISPARTA city, which 1/5 th of apple production of TURKEY has been provided from, was chosen. Enviromental and economical advantages of solar ejector refrigeration system application for cold storage dictated by thermodynamic, economic and enviromental analyses in this research.

  4. Custom design of a hanging cooling water power generating system applied to a sensitive cooling water discharge weir in a seaside power plant: A challenging energy scheme

    International Nuclear Information System (INIS)

    Tian, Chuan Min; Jaffar, Mohd Narzam; Ramji, Harunal Rejan; Abdullah, Mohammad Omar

    2015-01-01

    In this study, an innovative design of hydro-electricity system was applied to an unconventional site in an attempt to generate electricity from the exhaust cooling water of a coal-fired power plant. Inspired by the idea of micro hydro, present study can be considered new in three aspects: design, resource and site. This system was hung at a cooling water discharge weir, where all sorts of civil work were prohibited and sea water was used as the cooling water. It was designed and fabricated in the university's mechanical workshop and transported to the site for installation. The system was then put into proof run for a three-month period and achieved some success. Due to safety reasons, on-site testing was prohibited by the power plant authority. Hence, most data was acquired from the proof run. The driving system efficiency was tested in the range of 25% and 45% experimentally while modeling results came close to experimental results. Payback period for the system is estimated to be about 4.23 years. Result obtained validates the feasibility of the overall design under the sensitive site application. - Highlights: • Challenging energy scheme via a hanging cooling water power generating system. • Driving system efficiency was tested in the range of 25% and 45%. • Payback period for the system is estimated to be about 4.2 years

  5. A dilution refrigerator combining low base temperature, high cooling power and low heat leak for use with nuclear cooling

    International Nuclear Information System (INIS)

    Bradley, D.I.; Guenault, A.M.; Keith, V.; Miller, I.E.; Pickett, G.R.; Bradshaw, T.W.; Locke-Scobie, B.G.

    1982-01-01

    The design philosophy, design, construction and performance of a dilution refrigerator specifically intended for nuclear cooling experiments in the submillikelvin regime is described. Attention has been paid from the outset to minimizing sources of heat leaks, and to achieving a low base temperature and relatively high cooling power below 10 mK. The refrigerator uses sintered silver heat exchangers similar to those developed at Grenoble. The machine has a base temperature of 3 mK or lower and can precool a copper nuclear specimen in 6.8 T to 8 mK in 70 h. The heat leak to the innermost nuclear stage is < 30 pW after only a few days' running. (author)

  6. Numerical Study of an Ejector as an Expansion Device in Split-type Air Conditioners for Energy Savings

    Directory of Open Access Journals (Sweden)

    Kasni Sumeru

    2013-07-01

    Full Text Available The present study describes a numerical approach for determining both the motive nozzle and constant-area diameters of an ejector as an expansion device, based on the cooling capacity of a split-type air-conditioner using R290 as refrigerant. Previous studies have shown that replacement of HCFC R22 with HC290 (propane in the air conditioner can improve the coefficient of performance (COP. The purpose of replacing the capillary tube with an ejector as an expansion device in a split-type air conditioner using HC290 is to further improve the COP. In developing the model, conservation laws of mass, momentum and energy equations were applied to each part of the ejector. The numerical results show that the motive nozzle diameter remains constant (1.03 mm under varying condenser temperatures, whereas the diameter of the constant-area decreases as the condenser temperature increases. It was also found that improvement of the COP can reach 32.90% at a condenser temperature of 55 °C. From the results mentioned above, it can be concluded that the use of an ejector can further improve the COP of a split-type air conditioner using HC290 as working fluid.

  7. Thermodynamic investigation of a booster-assisted ejector refrigeration system

    International Nuclear Information System (INIS)

    Zhao, Hongxia; Zhang, Ke; Wang, Lei; Han, Jitian

    2016-01-01

    Highlights: • COP based on thermal input increases with booster outlet pressure. • Both entrainment ratio and area ratio increase with booster outlet pressure. • COP based on work is larger than compressor-based refrigeration system. • An optimum booster outlet pressure obtains maximum COP based on work. • Exergy destruction occurs mainly in ejector, condenser, evaporator and generator. - Abstract: In order to improve performance of ejector refrigeration system, a booster is added before an ejector to enhance secondary flow pressure, which is called a booster assisted refrigeration system. Based on mass, momentum and energy conservation, a 1D model of ejector for optimal performance prediction was presented and validated with experimental data. A detailed study of working characteristics of the booster assisted ejector refrigeration system was carried out and compared against conventional ejector refrigeration system and compressor based refrigeration system, on the basis of first and second laws of thermodynamics. Effects of booster outlet pressure on COP_t_h based on thermal energy and COP_w based on work input, and also on entrainment ratio and area ratio of ejector were studied. The exergy destruction rates were also computed and analyzed for components of the booster-assisted ejector refrigeration system. Ways to reduce exergy destruction were discussed.

  8. Evaluation of Control and Protection System for Loss of Electrical Power Supply System of Water-Cooling Nuclear Power Plant

    International Nuclear Information System (INIS)

    Suhaemi, Tjipta; Djen Djen; Setyono; Jambiar, Riswan; Rozali, Bang; Setyo P, Dwi; Tjahyono, Hendro

    2000-01-01

    Evaluation of control and protection system for loss of electrical power supply system of water-cooled nuclear power plant has been done. The loss of electrical power supply. The accident covered the loss of external electrical load and loss of ac power to the station auxiliaries. It is analysed by studying and observing the mechanism of electrical power system and mechanism of related control and protection system. The are two condition used in the evaluation i e without turbine trip and with turbine trip. From the evaluation it is concluded that the control and protection system can handled the failure caused by the loss of electrical power system

  9. Startup of Pumping Units in Process Water Supplies with Cooling Towers at Thermal and Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Berlin, V. V., E-mail: vberlin@rinet.ru; Murav’ev, O. A., E-mail: muraviov1954@mail.ru; Golubev, A. V., E-mail: electronik@inbox.ru [National Research University “Moscow State University of Civil Engineering,” (Russian Federation)

    2017-03-15

    Aspects of the startup of pumping units in the cooling and process water supply systems for thermal and nuclear power plants with cooling towers, the startup stages, and the limits imposed on the extreme parameters during transients are discussed.

  10. Optimum operating conditions for a combined power and cooling thermodynamic cycle

    International Nuclear Information System (INIS)

    Sadrameli, S.M.; Goswami, D.Y.

    2007-01-01

    The combined production of thermal power and cooling with an ammonia-water based cycle proposed by Goswami is under intensive investigation. In the cycle under consideration, simultaneous cooling output is produced by expanding an ammonia-rich vapor in an expander to sub-ambient temperatures and subsequently heating the cool exhaust. When this mechanism for cooling production is considered in detail, it is apparent that the cooling comes at some expense to work production. To optimize this trade-off, a very specific coefficient-of-performance has been defined. In this paper, the simulation of the cycle was carried out in the process simulator ASPEN Plus. The optimum operating conditions have been found by using the Equation Oriented mode of the simulator and some of the results have been compared with the experimental data obtained from the cycle. The agreement between the two sets proves the accuracy of the optimization results

  11. Improving the performance of power-limited transverse stochastic cooling systems

    International Nuclear Information System (INIS)

    Goldberg, D.A.; Lambertson, G.R.

    1989-08-01

    We present the formulas relevant to the behavior of (transverse) stochastic cooling systems which operate under the not uncommon condition that performance is limited by available output power, and contrast the operation of such systems with non-power-limited ones. In particular, we show that for power-limited systems, the two most effective improvements are the use of pickups/kickers which operate in both planes simultaneously and/or plunging of the cooling system electrodes, and present an example where increasing bandwidth is counter-productive. We apply our results to the proposed upgrade of the Fermilab bar p source. 4 refs., 1 fig., 2 tabs

  12. Thermoelectric cooling of microelectronic circuits and waste heat electrical power generation in a desktop personal computer

    International Nuclear Information System (INIS)

    Gould, C.A.; Shammas, N.Y.A.; Grainger, S.; Taylor, I.

    2011-01-01

    Thermoelectric cooling and micro-power generation from waste heat within a standard desktop computer has been demonstrated. A thermoelectric test system has been designed and constructed, with typical test results presented for thermoelectric cooling and micro-power generation when the computer is executing a number of different applications. A thermoelectric module, operating as a heat pump, can lower the operating temperature of the computer's microprocessor and graphics processor to temperatures below ambient conditions. A small amount of electrical power, typically in the micro-watt or milli-watt range, can be generated by a thermoelectric module attached to the outside of the computer's standard heat sink assembly, when a secondary heat sink is attached to the other side of the thermoelectric module. Maximum electrical power can be generated by the thermoelectric module when a water cooled heat sink is used as the secondary heat sink, as this produces the greatest temperature difference between both sides of the module.

  13. 78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Science.gov (United States)

    2013-06-12

    ... Plants AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory guide; issuance. SUMMARY: The U.S... Programs for Water-Cooled Nuclear Power Plants.'' This guide describes the general scope and depth that the... power plants. ADDRESSES: Please refer to Docket ID NRC-2012-0293 about the availability of information...

  14. Integrated three-dimensional module heat exchanger for power electronics cooling

    Science.gov (United States)

    Bennion, Kevin; Lustbader, Jason

    2013-09-24

    Embodiments discussed herein are directed to a power semiconductor packaging that removes heat from a semiconductor package through one or more cooling zones that are located in a laterally oriented position with respect to the semiconductor package. Additional embodiments are directed to circuit elements that are constructed from one or more modular power semiconductor packages.

  15. Subtask 5.10 - Testing of an Advanced Dry Cooling Technology for Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Christopher L. [Univ. of Oklahoma, Norman, OK (United States); Pavlish, John H. [Univ. of Oklahoma, Norman, OK (United States)

    2013-09-30

    The University of North Dakota’s Energy & Environmental Research Center (EERC) is developing a market-focused dry cooling technology that is intended to address the key shortcomings of conventional dry cooling technologies: high capital cost and degraded cooling performance during daytime temperature peaks. The unique aspect of desiccant dry cooling (DDC) is the use of a hygroscopic working fluid—a liquid desiccant—as a heat-transfer medium between a power plant’s steam condenser and the atmosphere. This configuration enables a number of beneficial features for large-scale heat dissipation to the atmosphere, without the consumptive use of cooling water. The overall goal of this project was to accurately define the performance and cost characteristics of DDC to determine if further development of the concept is warranted. A balanced approach of modeling grounded in applied experimentation was pursued to substantiate DDC-modeling efforts and outline the potential for this technology to cool full-scale power plants. The resulting analysis shows that DDC can be a lower-cost dry cooling alternative to an air-cooled condenser (ACC) and can even be competitive with conventional wet recirculating cooling under certain circumstances. This project has also highlighted the key technological steps that must be taken in order to transfer DDC into the marketplace. To address these issues and to offer an extended demonstration of DDC technology, a next-stage project should include the opportunity for outdoor ambient testing of a small DDC cooling cell. This subtask was funded through the EERC–U.S. Department of Energy (DOE) Joint Program on Research and Development for Fossil Energy-Related Resources Cooperative Agreement No. DE-FC26-08NT43291. Nonfederal funding was provided by the Wyoming State Legislature under an award made through the Wyoming Clean Coal Technologies Research Program.

  16. Development in cooling water intake and outfall systems for atomic or steam power stations

    International Nuclear Information System (INIS)

    Wada, Akira

    1987-01-01

    The condenser cooling water channel, in its functional aspects, is an important structure for securing a stable supply of cooling water. In its design it is necessary to give a thorough-going study to a reduction of ranges affected by discharged warm water and minimizing the effect of discharged water on navigating ships, and in its functional aspects as a structure for power generation, avoiding the recirculation of discharged warm water as well as to maintaining the operation of power stations in case of abnormalities (concentration of dirts owing to typhoons and floods, outbreak of a large amount of jellyfishes, etc.), and all these aspects must be reflected in the design of cooling water channel systems. In this paper, the present situation relating to the design of cooling water intake and outfall systems in Japan is discussed. (author). 10 figs

  17. 3D Analysis of Cooling Performance with Loss of Offsite Power Using GOTHIC Code

    International Nuclear Information System (INIS)

    Oh, Kye Min; Heo, Gyun Young; Na, In Sik; Choi, Yu Jung

    2010-01-01

    GOTHIC code enables to analyze one-dimensional or multi-dimensional problems for evaluating the cooling performance of loss of offsite power. The conventional GOTHIC code analysis performs heat transfer between plant containment and the outside of the fan cooler tubes by modeling each of fan cooler part model and component cooling water inside tube each to analyze boiling probability. In this paper, we suggest a way which reduces the multi-procedure of the cooling performance with loss of offsite power or the heat transfer states with complex geometrical structure to a single-procedure and verify the applicability of the heat transfer differences from the containment atmosphere humidity changes by the multi-nodes which component cooling water of tube or air of Reactor Containment Fan Cooler in the containment, otherwise the component model uses only one node

  18. Cooling unit for a superconducting power cable. Two years successful operation

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Friedhelm [Messer Group GmbH, Krefeld (Germany); Kutz, Thomas [Messer Industriegase GmbH, Bad Soden (Germany); Stemmle, Mark [Nexans Deutschland GmbH, Hannover (Germany); Kugel, Torsten [Westnetz GmbH, Essen (Germany)

    2016-07-01

    High temperature super conductors (HTS) can efficiently be cooled with liquid nitrogen down to a temperature of 64 K (-209 C). Lower temperatures are not practical, because nitrogen becomes solid at 63 K (-210 C). To achieve this temperature level the coolant has to be vaporized below atmospheric pressure. Messer has developed a cooling unit with an adequate vacuum subcooler, a liquid nitrogen circulation system, and a storage vessel for cooling an HTS power cable. The cooling unit was delivered in 2013 for the German AmpaCity project of RWE Deutschland AG, Nexans and Karlsruhe Institute of Technology. Within this project RWE and Nexans installed the worldwide longest superconducting power cable in the city of Essen, Germany. The cable is in operation since March 10th, 2014.

  19. COOLING WATER ISSUES AND OPPORTUNITIES AT U.S. NUCLEAR POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Gary Vine

    2010-12-01

    This report has been prepared for the Department of Energy, Office of Nuclear Energy (DOE-NE), for the purpose of providing a status report on the challenges and opportunities facing the U.S. commercial nuclear energy industry in the area of plant cooling water supply. The report was prompted in part by recent Second Circuit and Supreme Court decisions regarding cooling water system designs at existing thermo-electric power generating facilities in the U.S. (primarily fossil and nuclear plants). At issue in the courts have been Environmental Protection Agency regulations that define what constitutes “Best Technology Available” for intake structures that withdraw cooling water that is used to transfer and reject heat from the plant’s steam turbine via cooling water systems, while minimizing environmental impacts on aquatic life in nearby water bodies used to supply that cooling water. The report was also prompted by a growing recognition that cooling water availability and societal use conflicts are emerging as strategic energy and environmental issues, and that research and development (R&D) solutions to emerging water shortage issues are needed. In particular, cooling water availability is an important consideration in siting decisions for new nuclear power plants, and is an under-acknowledged issue in evaluating the pros and cons of retrofitting cooling towers at existing nuclear plants. Because of the significant ongoing research on water issues already being performed by industry, the national laboratories and other entities, this report relies heavily on ongoing work. In particular, this report has relied on collaboration with the Electric Power Research Institute (EPRI), including its recent work in the area of EPA regulations governing intake structures in thermoelectric cooling water systems.

  20. COOLING WATER ISSUES AND OPPORTUNITIES AT U.S. NUCLEAR POWER PLANTS

    International Nuclear Information System (INIS)

    Vine, Gary

    2010-01-01

    This report has been prepared for the Department of Energy, Office of Nuclear Energy (DOE-NE), for the purpose of providing a status report on the challenges and opportunities facing the U.S. commercial nuclear energy industry in the area of plant cooling water supply. The report was prompted in part by recent Second Circuit and Supreme Court decisions regarding cooling water system designs at existing thermo-electric power generating facilities in the U.S. (primarily fossil and nuclear plants). At issue in the courts have been Environmental Protection Agency regulations that define what constitutes 'Best Technology Available' for intake structures that withdraw cooling water that is used to transfer and reject heat from the plant's steam turbine via cooling water systems, while minimizing environmental impacts on aquatic life in nearby water bodies used to supply that cooling water. The report was also prompted by a growing recognition that cooling water availability and societal use conflicts are emerging as strategic energy and environmental issues, and that research and development (R and D) solutions to emerging water shortage issues are needed. In particular, cooling water availability is an important consideration in siting decisions for new nuclear power plants, and is an under-acknowledged issue in evaluating the pros and cons of retrofitting cooling towers at existing nuclear plants. Because of the significant ongoing research on water issues already being performed by industry, the national laboratories and other entities, this report relies heavily on ongoing work. In particular, this report has relied on collaboration with the Electric Power Research Institute (EPRI), including its recent work in the area of EPA regulations governing intake structures in thermoelectric cooling water systems.

  1. Rotary wave-ejector enhanced pulse detonation engine

    Science.gov (United States)

    Nalim, M. R.; Izzy, Z. A.; Akbari, P.

    2012-01-01

    The use of a non-steady ejector based on wave rotor technology is modeled for pulse detonation engine performance improvement and for compatibility with turbomachinery components in hybrid propulsion systems. The rotary wave ejector device integrates a pulse detonation process with an efficient momentum transfer process in specially shaped channels of a single wave-rotor component. In this paper, a quasi-one-dimensional numerical model is developed to help design the basic geometry and operating parameters of the device. The unsteady combustion and flow processes are simulated and compared with a baseline PDE without ejector enhancement. A preliminary performance assessment is presented for the wave ejector configuration, considering the effect of key geometric parameters, which are selected for high specific impulse. It is shown that the rotary wave ejector concept has significant potential for thrust augmentation relative to a basic pulse detonation engine.

  2. Cooling System for the Merit High-Power Target Experiment

    CERN Document Server

    Haug, F; Silva, P; Pezzeti, M; Pavlov, O; Pirotte, O; Metselaar, J; Efthymiopoulos, I; Fabich, A; Lettry, J; Kirk, H G; McDonald, K T; Titus, P; Bennett, J R J

    2010-01-01

    MERIT is a proof-of-principle experiment of a target station suitable as source for future muon colliders or neutrino factories. When installed at the CERN (European Organization for Nuclear Research) PS (Proton Synchrotron)complex fast-extracted high-intensity proton beams intercepted a free mercury jet inside a normal-conducting, pulsed 15-T capture solenoid magnet cooled with liquid nitrogen. Up to 25 MJ of Joule heat was dissipated in the magnet during a pulse. The fully automated, remotely controlled cryogenic system of novel design permitted the transfer of nitrogen by the sole means of differential pressures inside the vessels. This fast cycling system permitted several hundred tests in less than three weeks during the 2007 data taking campaign.

  3. Procedure for operating a heavy water cooled power reactor

    International Nuclear Information System (INIS)

    Rau, P.; Kumpf, H.

    1981-01-01

    Nuclear reactors cooled by heavy water usually have equipment for fuel element exchange during operation, with the primary circuit remaining contained. This fuel element exchange equipment is expensive and complicated in many respects. According to the invention, the heavy water is therefore replaced by light water after a certain time of operation in such way that light water is led in and heavy water is led off. After the replacement, at least a quarter of the fuel elements of the reactor core is exchanged with the reactor pressure vessel being open. Then the light water serving as a shielding is replaced by heavy water, with the reactor pressure vessel being closed. The invention is of interest particularly for high-conversion reactors. (orig.) [de

  4. Natural draft dry-type cooling tower for steam power plants

    International Nuclear Information System (INIS)

    Nasser, G.

    1976-01-01

    The task to build natural-draught dry cooling towers for large steam power plants as simple, compact, and economical as possible may be achieved by a combination of known features with the aid of the present application: the condenser elements built as piles of corrugated plates are arranged in the form of a truncated pyramid widened towards the top. For the cooling-air flow inlet openings for hot gas supplied from the lower part of the dome are provided. (UWI) [de

  5. Dry cooling for coal fired power plants: the new state-of-the-art

    Energy Technology Data Exchange (ETDEWEB)

    Souvenir, C.; Nagel, P. [SPX Cooling Technologies (Belgium)

    2008-07-01

    In the first part of this paper an update is provided regarding the use of dry cooling in power plants. The evolution of the reasons leading to this technical solution, the trends in the market place, and the growth over the last 15 years are described. In the second part, the use of current advanced dry cooling technologies for coal-fired plants in China is illustrated. 34 figs.

  6. Power sources involving ~ 300W PEMFC fuel cell stacks cooled by different media

    Directory of Open Access Journals (Sweden)

    Dudek Magdalena

    2017-01-01

    Full Text Available Two constructions of ~300W PEMFC stacks, cooled by different media, were analysed. An open-cathode ~300W PEMFC stack cooled by air (Horizon, Singapore and a PEMFC F-42 stack cooled by a liquid medium (Schunk, Germany were chosen for all of the investigations described in this paper. The potential for the design and construction of power sources involving fuel cells, as well as of a hybrid system (fuel cell-lithium battery for mobile and stationary applications, is presented and discussed. The impact of certain experimental parameters on PEMFC stack performance is analysed and discussed.

  7. Enhancement of LNG plant propane cycle through waste heat powered absorption cooling

    International Nuclear Information System (INIS)

    Rodgers, P.; Mortazavi, A.; Eveloy, V.; Al-Hashimi, S.; Hwang, Y.; Radermacher, R.

    2012-01-01

    In liquefied natural gas (LNG) plants utilizing sea water for process cooling, both the efficiency and production capacity of the propane cycle decrease with increasing sea water temperature. To address this issue, several propane cycle enhancement approaches are investigated in this study, which require minimal modification of the existing plant configuration. These approaches rely on the use of gas turbine waste heat powered water/lithium bromide absorption cooling to either (i) subcool propane after the propane cycle condenser, or (ii) reduce propane cycle condensing pressure through pre-cooling of condenser cooling water. In the second approach, two alternative methods of pre-cooling condenser cooling water are considered, which consist of an open sea water loop, and a closed fresh water loop. In addition for all cases, three candidate absorption chiller configurations are evaluated, namely single-effect, double-effect, and cascaded double- and single-effect chillers. The thermodynamic performance of each propane cycle enhancement scheme, integrated in an actual LNG plant in the Persian Gulf, is evaluated using actual plant operating data. Subcooling propane after the propane cycle condenser is found to improve propane cycle total coefficient of performance (COP T ) and cooling capacity by 13% and 23%, respectively. The necessary cooling load could be provided by either a single-effect, double-effect or cascaded and single- and double-effect absorption refrigeration cycle recovering waste heat from a single gas turbine operated at full load. Reducing propane condensing pressure using a closed fresh water condenser cooling loop is found result in propane cycle COP T and cooling capacity enhancements of 63% and 22%, respectively, but would require substantially higher capital investment than for propane subcooling, due to higher cooling load and thus higher waste heat requirements. Considering the present trend of short process enhancement payback periods in the

  8. Enhancing the efficiency of a three-lobe roots blower by means of by-passing gas to the working cavity through an ejector adaptor

    Science.gov (United States)

    Vizgalov, S. V.; Volkov, M. V.; Chekushkin, G. N.; Khisameev, I. G.

    2017-08-01

    A positive displacement Roots blower with two- or three-lobe straight-tooth or twisted rotors demonstrates high performance with small specific dimensions and is used to boost internal combustion engines, aerate tanks of treatment facilities, is employed in air and gas transport systems in the food, petrochemical and metallurgical industry. It is common knowledge that several solutions have been implemented in Roots blower designs with straight-tooth with three-lobe or more-lobes rotors. It is more practical to bypass a portion of the compressed gas to the working cavity of the blower through an ejector. The purpose of developing a mathematical model for a blower working in conjunction with an ejector adapter and the further research is to determine the efficiency of this scheme un-der different discharge pressure conditions and different ejector active flow temperatures (the gas cooling effect before the nozzle).

  9. Solar heating cooling. Preparation of possible participation in IEA, Solar Heating Cooling Task 25; Solvarmedrevet koeling. Forberedelse af evt. deltagelse i IEA, Solar Heating Cooling Task 25

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the Danish solar heating industries it is interesting to discuss the domestic market possibilities and the export possibilities for solar heating cooling systems. The Danish solar heating sector also wants to participate in the international collaboration within IEA Solar Heating and Cooling Task 25 'Solar Assisted Air Conditioning of Buildings'. The Danish Energy Agency therefore has granted means for this project to discuss: The price of cooling for 3 different solar cooling methods (absorption cooling, desiccant cooling and ejector cooling); Market possibilities in Denmark and abroad; The advantages by Danish participation in IEA Task 25. The task has been solved through literature studies to establish status for the 3 technologies. It turned out that ejector cooling by low temperatures (85 deg. C from the solar collector) exists as pilot plants in relation to district heating, but is still not commercial accessible. Desiccant cooling, where the supplied heat has temperatures down to 55 deg. C is a well-developed technology. However only a handful of pilot plants with solar heating exists, and thus optimization relating to operation strategy and economy is on the experimental stage. Absorption cooling plants driven by solar heating are found in a large number in Japan and are also demonstrated in several other countries. The combination of absorption heating pump and solar heating is considered to be commercial accessible. Solar heating is interesting as heat source of to the exent that it can replace other sources of heat without the economy being depreciated. This can be the case in South Europe if: 1) oil or natural gas is used for heating; 2) a solar heating system already exists, e.g. for domestic water supply, and is installed so that the marginal costs by solar heating supply of the ventilation plant is reduced. All in all the above conditions mean that the market for solar heating for cooling is very limited in Europe, where almost

  10. Effect of dc-power-system reliability on reactor-shutdown cooling

    International Nuclear Information System (INIS)

    Kolaczkowski, A.M.; Baranowsky, P.W.; Hickman, J.W.

    1981-01-01

    The DC power systems in a nuclear power plant provide control and motive power to valves, instrumentation, emergency diesel generators, and many other components and systems during all phases of plant operation including abnormal shutdowns and accident situations. A specific area of concern is the adequacy of the minimum design requirements for DC power systems, particularly with regard to multiple and common cause failures. This concern relates to the application of the single failure criterion for assuring a reliable DC power supply which may be required for the functionability of shutdown cooling systems. The results are presented of a reliability based study performed to assess the adequacy of DC power supply design requirements for currently operating light water reactors with particular attention to shutdown cooling requirements

  11. Water cooling thermal power measurement in a vacuum diffusion pump

    Directory of Open Access Journals (Sweden)

    Luís Henrique Cardozo Amorin

    2012-04-01

    Full Text Available Diffusion vacuum pumps are used both in industry and in laboratory science for high vacuum production. For its operation they must be refrigerated, and it is done by circulating water in open circuit. Considering that, vacuum systems stays operating by hours, the water consumption may be avoided if the diffusion vacuum pumps refrigeration were done in closed circuit. However, it is necessary to know the diffusion vacuum pump thermal power (the heat transferred to circulate water by time units to implement one of these and get in the refrigeration system dimension. In this paper the diffusion vacuum pump thermal power was obtained by measuring water flow and temperature variation and was calculated through the heat quantity variation equation time function. The thermal power value was 935,6 W, that is 397 W smaller and 35 W bigger than, respectively, the maximum and minimum diffusion pump thermal power suggested by its operation manual. This procedure have been shown useful to precisely determine the diffusion pump thermal power or of any other system that needs to be refrigerated in water closed circuit.

  12. Mitigation of hydrogen hazards in water cooled power reactors

    International Nuclear Information System (INIS)

    2001-02-01

    Past considerations of hydrogen generated in containment buildings have tended to focus attention on design basis accidents (DBAs) where the extent of the in-core metal-water reaction is limited at low values by the operation of the emergency core cooling systems (ECCS). The radiolysis of water in the core and in the containment sump, together with the possible corrosion of metals and paints in the containment, are all relatively slow processes. Therefore, in DBAs the time scale involved for the generation of hydrogen allows sufficient time for initiation of measures to control the amount of hydrogen in the containment atmosphere and to prevent any burning. Provisions have been made in most plants to keep the local hydrogen concentration below its flammability limit (4% of volume) by means of mixing devices and thermal recombiners. Severe accidents, involving large scale core degradation and possibly even core concrete interactions, raise the possibility of hydrogen release rates greatly exceeding the capacity of conventional DBA hydrogen control measures. The accident at Three Mile Island illustrated the potential of unmitigated hydrogen accumulation to escalate the potential consequences of a severe accident. In a severe accident scenario, local high hydrogen concentrations can be reached in a short time, leading to flammable gas mixtures in containment. Another possibility is that local high steam concentrations will initially create an inert atmosphere and prevent burning for a limited time. While such temporary inerting provides additional time for mixing (dilution) of the hydrogen with containment air, depending on the quantity of hydrogen released, it prevents early intervention by deliberate ignition and sets up conditions for more severe combustion hazards after steam condensation eventually occurs, e.g., by spray initiation or the long term cooling down of the containment atmosphere. As the foregoing example indicates, analysis of the hydrogen threat in

  13. Power oscillation and stability in water cooled reactors

    International Nuclear Information System (INIS)

    Por, G.; Kis, G.

    1998-01-01

    Periodic oscillation in measured temperature fluctuation was observed near to surface of a heated rod in certain heat transfer range. The frequency of the peak found in power spectral density of temperature fluctuation and period estimated from the cross correlation function for two axially placed thermocouples change linearly with linear energy (or surface heat) production. It was concluded that a resonance of such surface (inlet) temperature oscillation with the pole of the reactor transfer function can be responsible for power oscillation in BWR and PWR, thus instability is not solely due to reactor transfer function. (author)

  14. Steam water cycle chemistry of liquid metal cooled innovative nuclear power reactors

    International Nuclear Information System (INIS)

    Yurmanov, Victor; Lemekhov, Vadim; Smykov, Vladimir

    2012-09-01

    The Federal Target Program (FTP) of Russian Federation 'Nuclear Energy Technologies of the New Generation for 2010-2015 and for Perspective up to 2020' is aimed at development of advanced nuclear energy technologies on the basis of closed fuel cycle with fast reactors. There are advanced fast reactor technologies of the 4. generation with liquid metal cooled reactors. Development stages of maturity of fast sodium cooled reactor technology in Russia includes experimental reactors BR-5/10 (1958-2002) and BOR-60 (since 1969), nuclear power plants (NPPs) with BN-350 (1972-1999), BN-600 (since 1980), BN-800 (under construction), BN-1200 (under development). Further stage of development of fast sodium cooled reactor technology in Russia is commercialization. Lead-bismuth eutectic fast reactor technology has been proven at industrial scale for nuclear submarines in former Soviet Union. Lead based technology is currently under development and need for experimental justification. Current status and prospects of State Corporation 'Rosatom' participation in GIF activities was clarified at the 31. Meeting of Policy Group of the International Forum 'Generation-IV', Moscow, May 12-13, 2011. In June, 2010, 'Rosatom' joined the Sodium Fast Reactor Arrangement as an authorized representative of the Russian Government. It was also announced the intention of 'Rosatom' to sign the Memorandum on Lead Fast Reactor based on Russia's experience with lead-bismuth and lead cooled fast reactors. In accordance with the above FTP some innovative liquid metal cooled reactors of different design are under development in Russia. Gidropress, well known as WER designer, develops innovative lead-bismuth eutectic cooled reactor SVBR-100. NIKIET develops innovative lead cooled reactor BRESTOD-300. Some other nuclear scientific centres are also involved in this activity, e.g. Research and Development Institute for Power Engineering (RDIPE). Optimum

  15. Biocide usage in cooling towers in the electric power and petroleum refining industries

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J.; Rice, J.K.; Raivel, M.E.S.

    1997-11-01

    Cooling towers users frequently apply biocides to the circulating cooling water to control growth of microorganisms, algae, and macroorganisms. Because of the toxic properties of biocides, there is a potential for the regulatory controls on their use and discharge to become increasingly more stringent. This report examines the types of biocides used in cooling towers by companies in the electric power and petroleum refining industries, and the experiences those companies have had in dealing with agencies that regulate cooling tower blowdown discharges. Results from a sample of 67 electric power plants indicate that the use of oxidizing biocides (particularly chlorine) is favored. Quaternary ammonia salts (quats), a type of nonoxidizing biocide, are also used in many power plant cooling towers. The experience of dealing with regulators to obtain approval to discharge biocides differs significantly between the two industries. In the electric power industry, discharges of any new biocide typically must be approved in writing by the regulatory agency. The approval process for refineries is less formal. In most cases, the refinery must notify the regulatory agency that it is planning to use a new biocide, but the refinery does not need to get written approval before using it. The conclusion of the report is that few of the surveyed facilities are having any difficulty in using and discharging the biocides they want to use.

  16. A passive cooling system proposal for multifunction and high-power displays

    Science.gov (United States)

    Tari, Ilker

    2013-03-01

    Flat panel displays are conventionally cooled by internal natural convection, which constrains the possible rate of heat transfer from the panel. On one hand, during the last few years, the power consumption and the related cooling requirement for 1080p displays have decreased mostly due to energy savings by the switch to LED backlighting and more efficient electronics. However, on the other hand, the required cooling rate recently started to increase with new directions in the industry such as 3D displays, and ultra-high-resolution displays (recent 4K announcements and planned introduction of 8K). In addition to these trends in display technology itself, there is also a trend to integrate consumer entertainment products into displays with the ultimate goal of designing a multifunction device replacing the TV, the media player, the PC, the game console and the sound system. Considering the increasing power requirement for higher fidelity in video processing, these multifunction devices tend to generate very high heat fluxes, which are impossible to dissipate with internal natural convection. In order to overcome this obstacle, instead of active cooling with forced convection that comes with drawbacks of noise, additional power consumption, and reduced reliability, a passive cooling system relying on external natural convection and radiation is proposed here. The proposed cooling system consists of a heat spreader flat heat pipe and aluminum plate-finned heat sink with anodized surfaces. For this system, the possible maximum heat dissipation rates from the standard size panels (in 26-70 inch range) are estimated by using our recently obtained heat transfer correlations for the natural convection from aluminum plate-finned heat sinks together with the surface-to-surface radiation. With the use of the proposed passive cooling system, the possibility of dissipating very high heat rates is demonstrated, hinting a promising green alternative to active cooling.

  17. Dry well cooling systems in BWR type nuclear power plants

    International Nuclear Information System (INIS)

    Hanamura, Ikuo; Tada, Kenji.

    1986-01-01

    Purpose: To prevent the damages of pipeways due to salt damages at the surface of control rod drives in BWR type reactors. Constitution: In control rod drives and the lowermost area in the dry well in which surface corrosion and pitching have been resulted by the salt contents in air due to the increase in the humidity accompanying the lowering of the temperature, a blower is disposed to the upstream of the cooling coils and a portion of high temperature air returned to the lower cooler is replaced with a low temperature feed air to increase the feed temperature in the area. Further, by upwardly turning the downwarded feed air drawing port in which cold feed air has so far been descended as it is, the descendance of the cold air is suppressed. As a result, temperature lowering in the driving mechanisms and the lower area can be prevented to obtain a predetermined temperature, whereby the dewing on the surface can be prevented and thereby preventing the occurrence of corrosion and pitching. (Horiuchi, T.)

  18. Environmental effects of large discharges of cooling water. Experiences from Swedish nuclear power plants

    International Nuclear Information System (INIS)

    Ehlin, Ulf; Lindahl, Sture; Neuman, Erik; Sandstroem, Olof; Svensson, Jonny

    2009-07-01

    Monitoring the environmental effects of cooling water intake and discharge from Swedish nuclear power stations started at the beginning of the 1960s and continues to this day. In parallel with long-term monitoring, research has provided new knowledge and methods to optimise possible discharge locations and design, and given the ability to forecast their environmental effects. Investigations into the environmental effects of cooling-water are a prerequisite for the issuing of power station operating permits by the environmental authorities. Research projects have been carried out by scientists at universities, while the Swedish Environmental Protection Agency, the Swedish Board of Fisheries, and the Swedish Meteorological and Hydrological Institute, SMHI, are responsible for the greater part of the investigations as well as of the research work. The four nuclear power plants dealt with in this report are Oskarshamn, Ringhals, Barsebaeck and Forsmark. They were taken into operation in 1972, 1975, 1975 and 1980 resp. - a total of 12 reactors. After the closure of the Barsebaeck plants in 2005, ten reactors remain in service. The maximum cooling water discharge from the respective stations was 115, 165, 50 and 135 m 3 /s, which is comparable to the mean flow of an average Swedish river - c:a 150 m 3 /s. The report summarizes studies into the consequences of cooling water intake and discharge. Radiological investigations made at the plants are not covered by this review. The strategy for the investigations was elaborated already at the beginning of the 1960s. The investigations were divided into pre-studies, baseline investigations and monitoring of effects. Pre-studies were partly to gather information for the technical planning and design of cooling water intake and outlet constructions, and partly to survey the hydrographic and ecological situation in the area. Baseline investigations were to carefully map the hydrography and ecology in the area and their natural

  19. A novel nuclear combined power and cooling system integrating high temperature gas-cooled reactor with ammonia–water cycle

    International Nuclear Information System (INIS)

    Luo, Chending; Zhao, Fuqiang; Zhang, Na

    2014-01-01

    Highlights: • We propose a novel nuclear ammonia–water power and cooling cogeneration system. • The high temperature reactor is inherently safe, with exhaust heat fully recovered. • The thermal performances are improved compared with nuclear combined cycle. • The base case attains an energy efficiency of 69.9% and exergy efficiency of 72.5%. • Energy conservation and emission reduction are achieved in this cogeneration way. - Abstract: A nuclear ammonia–water power and refrigeration cogeneration system (NAPR) has been proposed and analyzed in this paper. It consists of a closed high temperature gas-cooled reactor (HTGR) topping Brayton cycle and a modified ammonia water power/refrigeration combined bottoming cycle (APR). The HTGR is an inherently safe reactor, and thus could be stable, flexible and suitable for various energy supply situation, and its exhaust heat is fully recovered by the mixture of ammonia and water in the bottoming cycle. To reduce exergy losses and enhance outputs, the ammonia concentrations of the bottoming cycle working fluid are optimized in both power and refrigeration processes. With the HTGR of 200 MW thermal capacity and 900 °C/70 bar reactor-core-outlet helium, the system achieves 88.8 MW net electrical output and 9.27 MW refrigeration capacity, and also attains an energy efficiency of 69.9% and exergy efficiency of 72.5%, which are higher by 5.3%-points and 2.6%-points as compared with the nuclear combined cycle (NCC, like a conventional gas/steam power-only combined cycle while the topping cycle is a closed HTGR Brayton cycle) with the same nuclear energy input. Compared with conventional separate power and refrigeration generation systems, the fossil fuel saving (based on CH 4 ) and CO 2 emission reduction of base-case NAPR could reach ∼9.66 × 10 4 t/y and ∼26.6 × 10 4 t/y, respectively. The system integration accomplishes the safe and high-efficiency utilization of nuclear energy by power and refrigeration

  20. EXPERIMENTAL VERIFICATION OF COMPUTER MODEL OF COOLING SYSTEM FOR POWERFUL SEMI- CONDUCTOR DEVICE

    Directory of Open Access Journals (Sweden)

    I. A. Khorunzhii

    2007-01-01

    Full Text Available A cooling system for powerful semi-conductor device (power -1 kW consisting of a pin-type radiator and a body is considered in the paper. Cooling is carried out by forced convection of a coolant. Calculated values of temperatures on the radiator surface and experimentally measured values of temperatures in the same surface points have been compared in the paper. It has been shown that the difference between calculated and experimentally measured temperatures does not exceed 0,1-0,2 °C and it is comparable with experimental error value. The given results confirm correctness of a computer model.

  1. High power cable with internal water cooling 400 kV

    Energy Technology Data Exchange (ETDEWEB)

    Rasquin, W; Harjes, B

    1982-08-01

    The project was planned for a duration of 4 years. Afterwards it has been extended over 6 years and finally stopped after 3 1/2 years. Therefore, of course results of field tests with an internally cooled 400 kV cable are not available. Nevertheless, this conductor cooled high power cable has been developed to such an extend, that this manufactured cable could withstand type tests according to IEC/VDE recommendations. Even by missing field tests it is obvious that a high power cable for 400 kV is available.

  2. Cooling intensification during quenching of power plant components - the way to increase reliability

    International Nuclear Information System (INIS)

    Borisov, I.A.

    1989-01-01

    To enchance the complex of mechanical properties and to increase operation time of large components of power facilities, regimes of accelerated cooling are developed. Results of heat treatment with accelerated cooling of turbine rotor of steel 26KhN3M2FAA, disks of turbine welded rotor of steel 20KhN2MFAA, components of steel 35KhN3MFA, are given. Special steels with carbon content less than 0.30% for details of power machine-building are developed

  3. Enhanced Passive Cooling for Waterless-Power Production Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Salvador B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-06-14

    Recent advances in the literature and at SNL indicate the strong potential for passive, specialized surfaces to significantly enhance power production output. Our exploratory computational and experimental research indicates that fractal and swirl surfaces can help enable waterless-power production by increasing the amount of heat transfer and turbulence, when compared with conventional surfaces. Small modular reactors, advanced reactors, and non-nuclear plants (e.g., solar and coal) are ideally suited for sCO2 coolant loops. The sCO2 loop converts the thermal heat into electricity, while the specialized surfaces passively and securely reject the waste process heat in an environmentally benign manner. The resultant, integrated energy systems are highly suitable for small grids, rural areas, and arid regions.

  4. Liquid metal cooling concepts in solar power application

    International Nuclear Information System (INIS)

    Deegan, P.B.; Mangus, J.D.; Whitlow, G.A.

    1978-01-01

    The thermodynamic and thermophysical properties and proven technology of a liquid sodium heat transport system provide numerous advantages and benefits for application in a central receiver solar thermal power plant concept. The major advantages of utilizing liquid sodium are: attainment of high thermodynamic cycle efficiencies, reduced relative costs, and achievement of these goals by the mid-1980's through the utilization of proven liquid metal technology developed in the power industry, without the need for extensive development programs. The utilization of liquid sodium reduces the complexity of the design of these systems, thus providing confidence in system reliability. The implementation of the proven technology in liquid metal systems also provides assurance of reliability. In addition, the ease of transition from liquid metal breeder reactor systems to solar application provides immediate availability of this technology

  5. Cooling problems of thermal power plants. Physical model studies

    International Nuclear Information System (INIS)

    Neale, L.C.

    1975-01-01

    The Alden Research Laboratories of Worcester Polytechnic Institute has for many years conducted physical model studies, which are normally classified as river or structural hydraulic studies. Since 1952 one aspect of these studies has involved the heated discharge from steam power plants. The early studies on such problems concentrated on improving the thermal efficiency of the system. This was accomplished by minimizing recirculation and by assuring full use of available cold water supplies. With the growing awareness of the impact of thermal power generation on the environment attention has been redirected to reducing the effect of heated discharges on the biology of the receiving body of water. More specifically the efforts of designers and operators of power plants are aimed at meeting or complying with standards established by various governmental agencies. Thus the studies involve developing means of minimizing surface temperatures at an outfall or establishing a local area of higher temperature with limits specified in terms of areas or distances. The physical models used for these studies have varied widely in scope, size, and operating features. These models have covered large areas with both distorted geometric scales and uniform dimensions. Instrumentations has also varied from simple mercury thermometers to computer control and processing of hundreds of thermocouple indicators

  6. Numerical modelling of series-parallel cooling systems in power plant

    Directory of Open Access Journals (Sweden)

    Regucki Paweł

    2017-01-01

    Full Text Available The paper presents a mathematical model allowing one to study series-parallel hydraulic systems like, e.g., the cooling system of a power boiler's auxiliary devices or a closed cooling system including condensers and cooling towers. The analytical approach is based on a set of non-linear algebraic equations solved using numerical techniques. As a result of the iterative process, a set of volumetric flow rates of water through all the branches of the investigated hydraulic system is obtained. The calculations indicate the influence of changes in the pipeline's geometrical parameters on the total cooling water flow rate in the analysed installation. Such an approach makes it possible to analyse different variants of the modernization of the studied systems, as well as allowing for the indication of its critical elements. Basing on these results, an investor can choose the optimal variant of the reconstruction of the installation from the economic point of view. As examples of such a calculation, two hydraulic installations are described. One is a boiler auxiliary cooling installation including two screw ash coolers. The other is a closed cooling system consisting of cooling towers and condensers.

  7. Adaptive Environmentally Contained Power and Cooling IT Infrastructure for the Data Center

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Ron; Chavez, Miguel, E.

    2012-06-27

    The objectives of this program were to research and develop a fully enclosed Information Technology (IT) rack system for 100 kilowatts (KW) of IT load that provides its own internal power and cooling with High Voltage Alternating Current (HVAC defined as 480 volt) and chilled water as the primary inputs into the system and accepts alternative energy power sources such as wind and solar. For maximum efficiency, internal power to the IT equipment uses distributed High Voltage Direct Current power (HVDC defined as 360-380 volt) from the power source to the IT loads. The management scheme aggressively controls energy use to insure the best utilization of available power and cooling resources. The solution incorporates internal active management controls that not only optimizes the system environment for the given dynamic IT loads and changing system conditions, but also interfaces with data center Building Management Systems (BMS) to provide a complete end-to-end view of power and cooling chain. This technology achieves the goal of a Power Usage Effectiveness (PUE) of 1.25, resulting in a 38% reduction in the total amount of energy needed to support a 100KW IT load compared to current data center designs.

  8. Control of cooling of an oil-immersed power transformer by varying speed of fans

    Directory of Open Access Journals (Sweden)

    Đorđević Nikola Z.

    2016-01-01

    Full Text Available The paper presents a prototype system for speed control of cooling fans for a small oil-immersed 6.6 kVA transformer, implemented on a standard PLC. Generally, the potential for optimization of the cooling process depends on the accessible cooling modes and construction of the transformer; basically the aim of the cooling system control is reduction in power consumption of the fans / pumps and keeping the top-oil temperature at constant value (to reduce transformer 'breathing' and infiltration of moisture. The following constraints should be taken into account: hot-spot temperature, its current value and the one which would appear for planned overloads must not exceed the allowed limit. Based on the results in steady state, the paper offers the quantitative determination of transformer thermal characteristics depending on the fan speed.

  9. Cooling tower make-up water processing for nuclear power plants: a comparison

    Energy Technology Data Exchange (ETDEWEB)

    Andres, O; Flunkert, F; Hampel, G; Schiffers, A [Rheinisch-Westfaelisches Elektrizitaetswerk A.G., Essen (Germany, F.R.)

    1977-01-01

    In water-cooled nuclear power plants, 1 to 2% of the total investment costs go to cooling tower make-up water processing. The crude water taken from rivers or stationary waters for cooling must be sufficiently purified regarding its content of solids, carbonate hardness and corrosive components so as to guarantee an operation free of disturbances. At the same time, the processing methods must be selected for operational-economic reasons in such a manner that waste water and waste problems are kept small regarding environmental protection. The various parameters described have a decisive influence on the processing methods of the crude water, individual processes (filtration, sedimentation, decarbonization) are described, circuit possibilities for cooling water systems are compared and the various processes are analyzed and compared with regard to profitableness and environmental compatability.

  10. Water cooling of high power light emitting diode

    DEFF Research Database (Denmark)

    Sørensen, Henrik

    2012-01-01

    The development in light technologies for entertainment is moving towards LED based solutions. This progress is not without problems, when more than a single LED is used. The amount of generated heat is often in the same order as in a conventional discharge lamp, but the allowable operating...... temperature is much lower. In order to handle the higher specific power (W/m3) inside the LED based lamps cold plates were designed and manufactured. 6 different designs were analyzed through laboratory experiments and their performances were compared. 5 designs cover; traditional straight mini channel, S...

  11. New methods for analyzing transport phenomena in supersonic ejectors

    International Nuclear Information System (INIS)

    Lamberts, Olivier; Chatelain, Philippe; Bartosiewicz, Yann

    2017-01-01

    Highlights: • Simulation of a supersonic ejector with the open source software for CFD OpenFOAM. • Validation of the numerical tool based on flow structures obtained by schlieren. • Application of the momentum and energy tube analysis tools to a supersonic ejector. • Extension of this framework to exergy to construct exergy transport tubes. • Quantification of local transfers and losses of exergy within the ejector. - Abstract: This work aims at providing novel insights into the quantification and the location of the transfers and the irreversibilities within supersonic ejectors, and their connection with the entrainment. In this study, we propose two different and complementary approaches. First of all, recent analysis tools based on momentum and energy tubes (Meyers and Meneveau (2013)) are extended to the present compressible flow context and applied to the mean-flow structure of turbulent flow within the ejector. Furthermore, the transport equation for the mean-flow total exergy is derived and exergy transport tubes are proposed as a tool for the investigation of transport phenomena within supersonic ejectors. In addition to this topological approach, an analysis based on classical stream tubes is performed in order to quantitatively investigate transfers between the primary and the secondary streams all along the ejector. Finally, the present work identifies the location of exergy losses and their origins. Throughout this analysis, new local and cumulative parameters related to transfers and irreversibilities are introduced. The proposed methodology sheds light on the complex phenomena at play and may serve as a basis for the analysis of transport phenomena within supersonic ejectors. For the ejector under consideration, although global transfers are more important in on-design conditions, it is shown that the net gain in exergy of the secondary stream is maximum for a value of the back pressure that is close to the critical back pressure, as

  12. A design study of high electric power for fast reactor cooled by supercritical light water

    International Nuclear Information System (INIS)

    Koshizuka, Seiichi

    2000-03-01

    In order to evaluate the possibility to achieve high electric power by a fast reactor with supercritical light water, the design study was carried out on a large fast reactor core with high coolant outlet temperature (SCFR-H). Since the reactor coolant circuit uses once-through direct cycle where all feedwater flows through the core to the turbine at supercritical pressure, it is possible to design much simpler and more compact reactor systems and to achieve higher thermal efficiency than those of current light water reactors. The once-through direct cycle system is employed in current fossil-fired power plants. In the present study, three types of core were designed. The first is SCFR-H with blankets cooled by ascending flow, the second is SCFR-H with blankets cooled by descending flow and the third is SCFR-H with high thermal power. Every core was designed to achieve the thermal efficiency over 43%, positive coolant density reactivity coefficient and electric power over 1600 MW. Core characteristics of SCFR-Hs were compared with those of SCLWR-H (electric power: 1212 MW), which is a thermal neutron spectrum reactor cooled and moderated by supercritical light water, with the same diameter of the reactor pressure vessel. It was shown that SCFR-H could increase the electric power about 1.7 times maximally. From the standpoint of the increase of a reactor thermal power, a fast reactor has advantages as compared with a thermal neutron reactor, because it can increase the power density by adopting tight fuel lattices and eliminating the moderator region. Thus, it was concluded that a reactor cooled by supercritical light water could further improve the cost competitiveness by using a fast neutron spectrum and achieving a higher thermal power. (author)

  13. Analysis of an Electrostatic MEMS Squeeze-film Drop Ejector

    Directory of Open Access Journals (Sweden)

    Edward P. Furlani

    2009-10-01

    Full Text Available We present an analysis of an electrostatic drop-on-demand MEMS fluid ejector. The ejector consists of a microfluidic chamber with a piston that is suspended a few microns beneath a nozzle plate. A drop is ejected when a voltage is applied between the orifice plate and the piston. This produces an electrostatic force that moves the piston towards the nozzle. The moving piston generates a squeeze-film pressure distribution that causes drop ejection. We discuss the operating physics of the ejector and present a lumped-element model for predicting its performance. We calibrate the model using coupled structural-fluidic CFD analysis.

  14. A portable solar-powered air-cooling system based on phase-change materials for a vehicle cabin

    International Nuclear Information System (INIS)

    Qi, Lingfei; Pan, Hongye; Zhu, Xin; Zhang, Xingtian; Salman, Waleed; Zhang, Zutao; Li, Li; Zhu, Miankuan; Yuan, Yanping; Xiang, Bo

    2017-01-01

    Graphical abstract: This paper proposed a portable solar-powered air cooling system for a vehicle cabin based on Phase-change Materials. The cooling system contains three main parts: a solar-energy collection module, an energy-storage module and a phase-change cooling module. The operating principle can be described as follows. For energy input, the solar-energy-collection module harvests solar energy and converts it to electricity. The power-storage module stores the electrical energy in the supercapacitor to power the electrical equipment, mainly the air pump (AP) and water pump (WP) of the phase-change cooling module. Finally, the phase-change cooling module provides cold air for the vehicle cabin to create a comfortable vehicle interior in a hot summer. The proposed system is demonstrated through thermal simulations, which show the long-duration cooling effect of the system. Temperature drops of were obtained in field tests, predicting that the proposed cooling system is beneficial and practical for cooling vehicle cabins. - Highlights: • A novel portable air cooling system based on PCMs is presented. • Solar energy was adopted to power the proposed air cooling system. • This proposed system is used for cooling vehicle cabins exposed to the sun. • Experimental results show that the proposed system has a good cooling effect. - Abstract: In summer, the temperature is very high inside vehicles parked under the hot sun. This causes consuming more fossil energy to power the air conditioner and generation of harmful gases. There is currently no effective method to address this problem in an energy-saving and environmentally friendly manner. In this paper, a novel solar-powered air-cooling system for vehicle cabins is proposed based on Phase-change Materials (PCMs); the system prevents the temperature inside a vehicle cabin from rising too high when the vehicle is parked outdoor exposure to the sun. The proposed system consists of three main parts: a solar

  15. Design of a low parasitic inductance SiC power module with double-sided cooling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fei [The University of Tennessee, Knoxville; Liang, Zhenxian [Cree Inc.; Wang, Fei [ORNL; Wang, Zhiqiang [ORNL

    2017-03-01

    In this paper, a low-parasitic inductance SiC power module with double-sided cooling is designed and compared with a baseline double-sided cooled module. With the unique 3D layout utilizing vertical interconnection, the power loop inductance is effectively reduced without sacrificing the thermal performance. Both simulations and experiments are carried out to validate the design. Q3D simulation results show a power loop inductance of 1.63 nH, verified by the experiment, indicating more than 60% reduction of power loop inductance compared with the baseline module. With 0Ω external gate resistance turn-off at 600V, the voltage overshoot is less than 9% of the bus voltage at a load of 44.6A.

  16. Optimization of regional water - power systems under cooling constraints and climate change

    DEFF Research Database (Denmark)

    Payet-burin, Raphaël; Bertoni, Federica; Davidsen, Claus

    2018-01-01

    Thermo-electric generation represents 70% of Europe's electricity production and 43% of water withdrawals, and is therefore a key element of the water-energy nexus. In 2003, 2006 and 2009, several thermal power plants had to be switched off in Europe because of heat waves, showing the need...... to assess the impact of climate change on cooling constraints of thermal power plants. An integrated water-power model of the Iberian Peninsula was developed in this study. It includes a physical hydrologic representation, spatially and temporally resolved water demands, management of water infrastructure...... and a simple power system model. The system was evaluated under present and future climatic conditions using different climate change scenarios. The cost of cooling constraints is found to increase by 220–640 million €/year, for the period 2046–2065 depending on the climate change scenario. Average available...

  17. Power distribution monitoring system in the boiling water cooled reactor core

    International Nuclear Information System (INIS)

    Leshchenko, Yu.I.; Sadulin, V.P.; Semidotskij, I.I.

    1987-01-01

    Consideration is being given to the system of physical power distribution monitoring, used during several years in the VK-50 tank type boiling water cooled reactor. Experiments were conducted to measure the ratios of detector prompt and activation currents, coefficients of detector relative sensitivity with respect to neutrons and effective cross sections of 103 Rh interaction with thermal and epithermal neutrons. Mobile self-powered detectors (SPD) with rhodium emitters are used as the power distribution detectors in the considered system. All detectors move simultaneously with constant rate in channels, located in fuel assembly central tubes, when conducting the measurements. It is concluded on the basis of analyzing the obtained data, that investigated system with calibrated SPD enables to monitor the absolute power distribution in fuel assemblies under conditions of boiling water cooled reactor and is independent of thermal engineering measurements conducted by in core instruments

  18. Loss of cooling accident simulation of nuclear power station spent-fuel pool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.; Liang, K-S., E-mail: mlee@ess.nthu.edu.tw, E-mail: ksliang_1@hotmail.com [National Tsing Hua Univ., Hsinchu, Taiwan (China); Lin, K-Y., E-mail: syrup760914@gmail.com [Taiwan Power Company, Taiwan (China)

    2014-07-01

    The core melt down accident of Fukushima Nuclear Power Station on March 11th, 2011 alerted nuclear industry that the long term loss of cooling of spent fuel pool may need some attention. The target plant analyzed is the Chinshan Nuclear Power Station of Taiwan Power Company. The 3-Dimensional RELAP5 input deck of the spent fuel pool of the station is built. The results indicate that spent fuel of Chinshan Nuclear Power Station is uncovered at 6.75 days after an accident of loss cooling takes place and cladding temperature rises above 2,200{sup o}F around 8 days. The time is about 13 hours earlier than the results predicted using simple energy balance method. The results also show that the impact of Counter Current Flow Limitation (CCFL) and radiation heat transfer model is marginal. (author)

  19. Burst failures of water cooling rubber pipes of TRISTAN MR magnet power supplies and magnets

    International Nuclear Information System (INIS)

    Kubo, Tadashi

    1994-01-01

    In 1992, from June to September, the rubber pipes of magnet and magnet power supply for water cooling burst in succession. All the rubber pipes to be dangerous to leave as those were had been replaced to new rubber pipes before the end of the summer accelerator shutdown. (author)

  20. Account of External Cooling Medium Temperature while Modeling Thermal Processes in Power Oil-Immersed Transformers

    OpenAIRE

    Yu. A. Rounov; O. G. Shirokov; D. I. Zalizny; D. M. Los

    2004-01-01

    The paper proposes a thermal model of a power oil-immersed transformer as a system of four homogeneous bodies: winding, oil, core and cooling medium. On the basis of experimental data it is shown that such model describes more precisely actual thermal processes taking place in a transformer than the thermal model accepted in GOST 14209-85.

  1. Account of External Cooling Medium Temperature while Modeling Thermal Processes in Power Oil-Immersed Transformers

    Directory of Open Access Journals (Sweden)

    Yu. A. Rounov

    2004-01-01

    Full Text Available The paper proposes a thermal model of a power oil-immersed transformer as a system of four homogeneous bodies: winding, oil, core and cooling medium. On the basis of experimental data it is shown that such model describes more precisely actual thermal processes taking place in a transformer than the thermal model accepted in GOST 14209-85.

  2. Analysis of power and cooling cogeneration using ammonia-water mixture

    International Nuclear Information System (INIS)

    Padilla, Ricardo Vasquez; Demirkaya, Goekmen; Goswami, D. Yogi; Stefanakos, Elias; Rahman, Muhammad M.

    2010-01-01

    Development of innovative thermodynamic cycles is important for the efficient utilization of low-temperature heat sources such as solar, geothermal and waste heat sources. This paper presents a parametric analysis of a combined power/cooling cycle, which combines the Rankine and absorption refrigeration cycles, uses ammonia-water mixture as the working fluid and produces power and cooling simultaneously. This cycle, also known as the Goswami Cycle, can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using solar or geothermal energy. A thermodynamic study of power and cooling cogeneration is presented. The performance of the cycle for a range of boiler pressures, ammonia concentrations and isentropic turbine efficiencies are studied to find out the sensitivities of net work, amount of cooling and effective efficiencies. The roles of rectifier and superheater on the cycle performance are investigated. The cycle heat source temperature is varied between 90-170 o C and the maximum effective first law and exergy efficiencies for an absorber temperature of 30 o C are calculated as 20% and 72%, respectively. The turbine exit quality of the cycle for different boiler exit scenarios shows that turbine exit quality decreases when the absorber temperature decreases.

  3. Biofouling in the condenser cooling conduits of Madras Atomic Power Station

    International Nuclear Information System (INIS)

    Thiyagarajan, V.; Subramoniam, T.; Venugopalan, V.P.; Nair, K.V.K.

    1995-01-01

    The present paper deals with various aspects fouling organisms collected from the condenser cooling water circuit of Madras Atomic Power Station (MAPS II) their biomass, thickness, composition and length frequency distribution of one of the major species namely, B. reticulatus. (author). 8 refs., 1 tab., 2 figs

  4. Calculations on heavy-water moderated and cooled natural uranium fuelled power reactors

    International Nuclear Information System (INIS)

    Pinedo V, J.L.

    1979-01-01

    One of the codes that the Instituto Nacional de Investigaciones Nucleares (Mexico) has for the nuclear reactors design calculations is the LEOPARD code. This work studies the reliability of this code in reactors design calculations which component materials are the same of the heavy water moderated and cooled, natural uranium fuelled power reactors. (author)

  5. Steam-generator tube failures: world experience in water-cooled nuclear power reactors in 1974

    International Nuclear Information System (INIS)

    Hare, M.G.

    1976-01-01

    Steam-generator tube failures were reported at 25 of 59 water-cooled nuclear power reactors surveyed in 1974, compared to 11 of 49 in 1973. A summary is presented of these failures, most of which, where the cause is known, were the result of corrosion. Water chemistry control, inspection and repair procedures, and failure rates are discussed

  6. High-power frequency-stabilized laser for laser cooling of metastable helium at 389 nm

    NARCIS (Netherlands)

    Koelemeij, J.C.J.; Hogervorst, W.; Vassen, W.

    2005-01-01

    A high-power, frequency-stabilized laser for cooling of metastable helium atoms using the 2 S13 →3 P23 transition at 389 nm has been developed. The 389 nm light is generated by frequency doubling of a titanium:sapphire laser in an external enhancement cavity containing a lithium-triborate nonlinear

  7. An experimental investigation on a novel ejector enhanced refrigeration cycle applied in the domestic refrigerator-freezer

    International Nuclear Information System (INIS)

    Wang, Xiao; Yu, Jianlin

    2015-01-01

    This paper presents an experimental investigation on a NERC (novel ejector enhanced refrigeration cycle) applied in the domestic refrigerator-freezer (BCD-249). Experimental studies were conducted to validate the NERC system feasibility in a practical NERC based refrigerator-freezer prototype. The system performances of energy consumption, ejector pressure lift ratio and compressor power were compared under different combinations of system configuration parameters. The results showed that the NERC system could effectively reduce the thermodynamic losses in the throttle processing. The minimum energy consumption of 0.520 kWh 24 h"−"1 was obtained for the NERC prototype, indicating 5.45% energy consumption reduction compared with the conventional domestic refrigerator-freezer. Furthermore, the effects of system configuration parameters including the refrigerant charge amount, the compressor displacement and the length of capillary tube were investigated. This study aims at providing deep insight into ejector-expansion technology applied in domestic refrigerator-freezers. - Highlights: • A NERC (novel ejector enhanced refrigeration cycle) was experimentally studied. • 73 experimental data points with different system configuration were acquired. • Energy consumption could be reduced with optimum system configuration. • 5.45% energy consumption reduction is obtained compared with the conventional system.

  8. First and Second Law Analyses of Trans-critical N2O Refrigeration Cycle Using an Ejector

    Directory of Open Access Journals (Sweden)

    Damoon Aghazadeh Dokandari

    2018-04-01

    Full Text Available An ejector-expansion refrigeration cycle using nitrous oxide was assessed. Thermodynamic analyses, including energy and exergy analyses, were carried out to investigate the effects on performance of several key factors in the system. The results show that the ejector-expansion refrigeration cycle (EERC has a higher maximum coefficient of performance and exergy efficiency than the internal heat exchanger cycle (IHEC, by 12% and 15%, respectively. The maximum coefficient of performance and exergy efficiency are 14% and 16.5% higher than the corresponding values for the vapor-compression refrigeration cycle (VCRC, respectively. The total exergy destruction for the N2O ejector-expansion cycle is 63% and 53% less than for IHEC and VCRC, respectively. Furthermore, the highest COPs for the vapor-compression refrigeration, the internal heat exchanger and the ejector-expansion refrigeration cycles correspond to a high side pressure of 7.3 MPa, and the highest COPs for the three types of CO2 refrigeration cycles correspond to a high side pressure of 8.5 MPa. Consequently, these lead to a lower electrical power consumption by the compressor.

  9. Fundamental design bases for independent core cooling in Swedish nuclear power reactors

    International Nuclear Information System (INIS)

    Jelinek, Tomas

    2015-01-01

    New regulations on design and construction of nuclear power plants came into force in 2005. The need of an independent core cooling system and if the regulations should include such a requirement was discussed. The Swedish Radiation Safety authority (SSM) decided to not include such a requirement because of open questions about the water balance and started to investigate the consequences of an independent core cooling system. The investigation is now finished and SSM is also looking at the lessons learned from the accident in Fukushima 2011. One of the most important measures in the Swedish national action plan is the implementation of an independent core cooling function for all Swedish power plants. SSM has investigated the basic design criteria for such a function where some important questions are the level of defence in depth and the acceptance criteria. There is also a question about independence between the levels of defence in depth that SSM have included in the criteria. Another issue that has to be taken into account is the complexity of the system and the need of automation where independence and simplicity are very strong criteria. In the beginning of 2014 a memorandum was finalized regarding fundamental design bases for independent core cooling in Swedish nuclear power reactors. A decision based on this memorandum with an implementation plan will be made in the first half of 2014. Sweden is also investigating the possibility to have armed personnel on site, which is not allowed currently. The result from the investigation will have impact on the possibility to use mobile equipment and the level of protection of permanent equipment. In this paper, SSM will present the memorandum for design bases for independent core cooling in Swedish nuclear power reactors that was finalized in March 20147 that also describe SSM's position regarding independence and automation of the independent core cooling function. This memorandum describes the Swedish

  10. Nuclear Power Station Kalkar, 300 MWe Prototype Nuclear Power Plant with Fast Sodium Cooled Reactor (SNR-300), Plant description

    International Nuclear Information System (INIS)

    1984-06-01

    The nuclear power station Kalkar (SNR-300) is a prototype with a sodium cooled fast reactor and a thermal power of 762 MW. The present plant description has been made available in parallel to the licensing procedure for the reactor plant and its core Mark-Ia as supplementary information for the public. The report gives a detailed description of the whole plant including the prevention measures against the impact of external and plant internal events. The radioactive materials within the reactor cooling system and the irradiation protection and surveillance measures are outlined. Finally, the operation of the plant is described with the start-up procedures, power operation, shutdown phases with decay heat removal and handling procedures

  11. Thermal optimization of the helium-cooled power leads for the SSC

    International Nuclear Information System (INIS)

    Demko, J.A.; Schiesser, W.E.; Carcagno, R.; McAshan, M.; McConeghy, R.

    1992-03-01

    The optimum thermal design of the power leads for the Superconducting Super Collider (SSC) will minimize the amount of Carnot work (which is a combination of refrigeration and liquefaction work) required. This optimization can be accomplished by the judicious selection of lead length and diameter. Even though an optimum set of dimensions is found, the final design must satisfy other physical constraints such as maximum allowable heat leak and helium vapor mass flow rate. A set of corresponding lengths and diameters has been determined that meets these requirements for the helium vapor-cooled, spiral-fin power lead design of the SSC. Early efforts by McFee and Mallon investigated optimizing power leads for cryogenic applications with no convection cooling. Later designs utilized the boiled-off helium vapor to cool the lead. One notable design for currents up to several thousand amps is presented by Efferson based on a series of recommendations discussed by Deiness. Buyanov presents many theoretical models and design formulate but does not demonstrate an approach to thermally optimizing the design of a vapor-cooled lead. A method for optimizing superconducting magnet current leads is described by Maehata et al. The approach assumes that the helium boil-off caused by heat conduction along with power lead into the low-temperature helium is used to cool the lead. The optimum solution is found when the heat flow at the cold end is minimized.. In this study, a detailed numerical thermal model of a power lead design for the SSC has been developed. It was adapted from the dynamic model developed by Schiesser. This model was used to determine the optimum dimensions that minimize the Carnot refrigeration and liquefaction work due to the leads

  12. Full scale experimental study of a small natural draft dry cooling tower for concentrating solar thermal power plant

    International Nuclear Information System (INIS)

    Li, Xiaoxiao; Duniam, Sam; Gurgenci, Hal; Guan, Zhiqiang; Veeraragavan, Anand

    2017-01-01

    Highlights: • A 20 m high natural draft dry cooling tower is designed and tested. • The cooling tower model is refined and validated with the experimental data. • The performance of the cooling tower utilized in a CST power plant is investigated. • Ambient temperature effect on Rankine cycle and Brayton cycle is discussed. - Abstract: Concentrating solar thermal power system can provide low carbon, renewable energy resources in countries or regions with strong solar irradiation. For this kind of power plant which is likely to be located in the arid area, natural draft dry cooling tower is a promising choice. To develop the experimental studies on small cooling tower, a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence. The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 °C to 32 °C. The cooling tower numerical model was refined and validated with the experimental data. The model of 1 MW concentrating solar thermal supercritical CO_2 power cycle was developed and integrated with the cooling tower model. The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated. The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO_2 Brayton cycle were analysed and discussed.

  13. The design of a new coaxial water cooling structure for APS high power BM front end photon shutters

    International Nuclear Information System (INIS)

    Chang, J.; Shu, D.; Collins, J.; Ryding, D.; Kuzay, T.

    1993-01-01

    A new UHV compatible coaxial water cooling structure has been designed for Advanced Photon Source (APS) high power bending magnet front end photon shutters. Laser-beam-thermal-simulation test results show that this new cooling structure can provide more than 1.56 kW total power cooling capacity with 12.3 W/mm 2 maximum surface heat flux. The maximum surface temperature will be lower than 116 degree C

  14. The behaviour of a hybrid compressor and ejector refrigeration system with refrigerants 134a and 142b

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J.I.; Best, R.; Estrada, C.A. [UNAM, Morelos (Mexico). Centro de Investigacion en Energia; Dorantes, R.J. [UAM Azcapotzalco, Reynosa Tamaulipas (Mexico). Dpto. de Energia

    2004-09-01

    A complete theoretical analysis on the thermodynamic behaviour of a HYbrid Compressor and Ejector Refrigeration System - HYCERS - is carried out. An ejector under optimum performance is employed. Two working fluids were selected: refrigerant 142b (HCFC 142b) which has shown very good characteristics in air conditioning applications of ejector systems and refrigerant 134a (HFC134a) which is widely used in refrigeration applications and readily available in most countries. The variation of the generator and condenser temperatures as well as the intercooler pressure were considered for an evaporator temperature of 10{sup o}C and a unitary cooling capacity of 1 kW. The ideal efficiency, the enthalpy-based coefficient of performance, the exergy efficiency and the supplied energy ratio are obtained. With this information, at a moderate condenser and generator temperature of 30 and 85{sup o}C, respectively, the HYCERS working with R134a had the best operation with a highest coefficient of performance of 0.48 and an exergy efficiency of 0.25. On the other hand, if a higher condenser temperature is imposed, the HYCERS with 142b had its best performance at a higher generator temperature. In selecting a working fluid the ejector subsystem behaviour is determinant in system performance. If a working fluid is badly selected, despite having high entrainment ratios, the system will not function properly. Therefore, the methodology here defined becomes an effective tool for selecting adequate working fluids and optimum system design conditions. Also, the employment of a unitary cooling load allows system scaling at any capacity as it increases linearly. (author)

  15. Control-Volume Analysis Of Thrust-Augmenting Ejectors

    Science.gov (United States)

    Drummond, Colin K.

    1990-01-01

    New method of analysis of transient flow in thrust-augmenting ejector based on control-volume formulation of governing equations. Considered as potential elements of propulsion subsystems of short-takeoff/vertical-landing airplanes.

  16. Emergency Cooling of Nuclear Power Plant Reactors With Heat Removal By a Forced-Draft Cooling Tower

    Energy Technology Data Exchange (ETDEWEB)

    Murav’ev, V. P., E-mail: murval1@mail.ru

    2016-07-15

    The feasibility of heat removal during emergency cooling of a reactor by a forced-draft cooling tower with accumulation of the peak heat release in a volume of precooled water is evaluated. The advantages of a cooling tower over a spray cooling pond are demonstrated: it requires less space, consumes less material, employs shorter lines in the heat removal system, and provides considerably better protection of the environment from wetting by entrained moisture.

  17. Methods and technologies for cost reduction in the design of water cooled reactor power plants

    International Nuclear Information System (INIS)

    1991-05-01

    The Specialists Meeting was organized in the framework of the IAEA International Working Group on Advanced Technologies for Water-Cooled Reactors. Its purpose was to provide an international forum for review and discussion on recent results in research and development on different methods and technologies of current and advanced water-cooled reactor power plants, which can lead to reduced investment and operation, maintenance and fuel-cycle costs of the plants. 27 specialists representing 10 countries and the IAEA took part in the meeting. 10 papers were presented. A separate abstract was prepared for each of these papers. Refs, figs and tabs

  18. Ecological investigations at power plant cooling lakes, reservoirs, and ponds: an annotated bibliography. Final report

    International Nuclear Information System (INIS)

    Yost, F.E.; Talmage, S.S.

    1981-06-01

    Presented as an annotated bibliography are 541 references dealing with ecological investigations at power plants which use cooling lakes, ponds, or reservoirs. The references were obtained from open literature and from environmental reports and impact statements prepared for or by the electric utility industry. The literature covers the period 1950 through mid-1980. Topics covered include site-specific studies at facilities using cooling lakes, ponds, or reservoirs, as well as special studies, engineering studies, and general studies. References are arranged alphabetically by author and indexes are provided to personal and corporate authors, facility names, regions, and taxonomic names

  19. Organohalogen products from chlorination of cooling water at nuclear power stations

    International Nuclear Information System (INIS)

    Bean, R.M.

    1983-10-01

    Eight nuclear power units at seven locations in the US were studied to determine the effects of chlorine, added as a biocide, on the composition of cooling water discharge. Water, sediment and biota samples from the sites were analyzed for total organic halogen and for a variety of organohalogen compounds. Haloforms were discharged from all plants studied, at concentrations of a few μg/L (parts-per-billion). Evidence was obtained that power plants with cooling towers discharge a significant portion of the haloforms formed during chlorination to the atmosphere. A complex mixture of halogenated phenols was found in the cooling water discharges of the power units. Cooling towers can act to concentrate halogenated phenols to levels approaching those of the haloforms. Examination of samples by capillary gas chromatography/mass spectrometry did not result in identification of any significant concentrations of lipophilic base-neutral compounds that could be shown to be formed by the chlorination process. Total concentrations of lipophilic (Bioabsorbable) and volatile organohalogen material discharged ranged from about 2 to 4 μg/L. Analysis of sediment samples for organohalogen material suggests that certain chlorination products may accumulate in sediments, although no tissue bioaccumulation could be demonstrated from analysis of a limited number of samples. 58 references, 25 figures, 31 tables

  20. High power cable with internal water cooling 400 kV

    Science.gov (United States)

    Rasquin, W.; Harjes, B.

    1982-08-01

    Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal laboratory, testing of test cable, field testing of test cable, fabrication of industrial cable laboratory, testing of industrial cable, field testing of industrial cable, and system analysis for optimization were prepared. The field testing was impossible to realize. However, it is proved that a cable consisting of an internal stainless steel water cooled tube, covered by stranded copper profiles, insulated with heavy high quality paper, and protected by an aluminum cover can be produced, withstand tests accordingly to IEC/VDE recommendations, and is able to fulfill all exploitation conditions.

  1. Resource-Saving Cleaning Technologies for Power Plant Waste-Water Cooling Ponds

    Directory of Open Access Journals (Sweden)

    Zakonnova Lyudmila

    2017-01-01

    Full Text Available One of the frequently encountered problems of power plant small cooling ponds is rapid eutrophication and related intensified development of phytoplankton (“hyperflow” and overgrowing of ponds by higher aquatic vegetation. As a result of hyper-flowering, an enormous amount of detritus settles on the condenser tubes, reducing the efficiency of the power plant operation. The development of higher aquatic vegetation contributes to the appearing of the shoals. As a result the volume, area and other characteristics of the cooling ponds are getting changed. The article describes the environmental problems of small manmade ponds of power plants and coal mines in mining regions. Two approaches to the problem of eutrophication are considered: technological and ecological. The negative effects of herbicides application to aquatic organisms are experimentally proved. An ecological approach to solving the problem by fish-land reclamation method is shown.

  2. Analysis of combustion turbine inlet air cooling systems applied to an operating cogeneration power plant

    International Nuclear Information System (INIS)

    Chacartegui, R.; Jimenez-Espadafor, F.; Sanchez, D.; Sanchez, T.

    2008-01-01

    In this work, combustion turbine inlet air cooling (CTIAC) systems are analyzed from an economic outlook, their effects on the global performance parameters and the economic results of the power plant. The study has been carried out on a combined cogeneration system, composed of a General Electric PG 6541 gas turbine and a heat recovery steam generator. The work has been divided into three parts. First, a revision of the present CTIAC technologies is shown, their effects on power plant performance and evaluation of the associated investment and maintenance costs. In a second phase of the work, the cogeneration plant was modelled with the objective of evaluating the power increase and the effects on the generated steam and the thermal oil. The cogeneration power plant model was developed, departing from the recorded operational data of the plant in 2005 and the gas turbine model offered by General Electric, to take into consideration that, in 2000, the gas turbine had been remodelled and the original performance curves should be corrected. The final objective of this model was to express the power plant main variables as a function of the gas turbine intake temperature, pressure and relative humidity. Finally, this model was applied to analyze the economic interest of different intake cooling systems, in different operative ranges and with different cooling capacities

  3. Chlorination for biofouling control in power plant cooling water system - a review

    International Nuclear Information System (INIS)

    Satpathy, K.K.; Ruth Nithila, S.D.

    2008-01-01

    Fresh water is becoming a rare commodity day by day and thus power plant authorities are turning into sea to make use of the copious amount of seawater available at an economical rate for condenser cooling. Unfortunately, biofouling; the growth and colonization of marine organisms affect the smooth operation of power plant cooling water systems. This is more so, if the plant is located in tropical climate having clean environment, which enhances the variety and density of organisms. Thus, biofouling needs to be controlled for efficient operation of the power plant. Biocide used for biofouling control is decided based on three major criteria viz: it should be economically, operationally and environmentally acceptable to the power plant authorities. Chlorine among others stands out on the top and meets all the above requirements in spite of a few shortcomings. Therefore it is no wonder that still chlorine rules the roost and chlorination remains the most common method of biofouling control in power plant cooling water system all over the world. Although, it is easier said than done, a good amount of R and D work is essential before a precise chlorination regime is put into pragmatic use. This paper discusses in details the chemistry of chlorination such as chlorine demand, chlorine decay, break point chlorination, speciation of chlorine residual and role of temperature and ammonia on chlorination in biofouling control. Moreover, targeted and pulse chlorination are also discussed briefly. (author)

  4. Theoretical analysis of ejector refrigeration system performance under overall modes

    International Nuclear Information System (INIS)

    Chen, Weixiong; Shi, Chaoyin; Zhang, Shuangping; Chen, Huiqiang; Chong, Daotong; Yan, Junjie

    2017-01-01

    Highlights: • Real gas theoretical model is used to get ejector performance at critical/sub-critical modes. • The model has a better accuracy against the experiment results compared to ideal gas model. • The overall performances of two refrigerants are analyzed based on the parameter analysis. - Abstract: The ejector refrigeration integrated in the air-conditioning system is a promising technology, because it could be driven by the low grade energy. In the present study, a theoretical calculation based on the real gas property is put forward to estimate the ejector refrigeration system performance under overall modes (critical/sub-critical modes). The experimental data from literature are applied to validate the proposed model. The findings show that the proposed model has higher accuracy compared to the model using the ideal gas law, especially when the ejector operates at sub-critical mode. Then, the performances of the ejector refrigeration circle using different refrigerants are analyzed. R290 and R134a are selected as typical refrigerants by considering the aspects of COP, environmental impact, safety and economy. Finally, the ejector refrigeration performance is investigated under variable operation conditions with R290 and R134a as refrigerants. The results show that the R290 ejector circle has higher COP under critical mode and could operate at low evaporator temperature. However, the performance would decrease rapidly at high condenser temperature. The performance of R134a ejector circle is the opposite, with relatively lower COP, and higher COP at high condenser temperature compared to R290.

  5. Thermal optimization of the helium-cooled power leads for the SSC

    International Nuclear Information System (INIS)

    Demko, J.A.; Schiesser, W.E.; Carcagno, R.; McAshan, M.; McConeghy, R.

    1992-01-01

    The optimum thermal design of the power leads for the Superconducting Super Collider (SSC) will minimize the amount of Carnot work (which is a combination of refrigeration and liquefaction work) required. This optimization can be accomplished by the judicious selection of lead length and diameter. Even though an optimum set of dimensions is found, the final design must satisfy other physical constraints such as maximum allowable heat leak and helium vapor mass flow rate. A set of corresponding lengths and diameters has been determined that meets these requirements for the helium vapor-cooled, spiral-fin power lead design of the SSC. Early efforts by McFee and Mallon investigated optimizing power leads for cryogenic applications with no convection cooling. Later designs utilized the boiled-off helium vapor to cool the lead. One notable design for currents up to several thousand amps is presented by Efferson based on a series of recommendations discussed by Deiness. Buyanov presents many theoretical models and design formulae but does not demonstrate an approach to thermally optimizing the design of a vapor-cooled lead. In this study, a detailed numerical thermal model of a power lead design for the SSC has been developed. It was adapted from the dynamic model developed by Schiesser. This model was used to determine the optimum dimensions that minimize the Carnot refrigeration and liquefaction work due to the leads. Since the SSC leads will be cooled by supercritical helium, the flow of vapor is regulated by a control valve. These leads include a superconducting portion at the cold end. All of the material properties in the model are functions of temperature, and for the helium are functions of pressure and temperature. No pressure drop calculations were performed as part of this analysis. The diameter that minimizes the Carnot work was determined for four different lengths at a design current of 6600 amps

  6. The surface roughness effect on the performance of supersonic ejectors

    Science.gov (United States)

    Brezgin, D. V.; Aronson, K. E.; Mazzelli, F.; Milazzo, A.

    2017-07-01

    The paper presents the numerical simulation results of the surface roughness influence on gas-dynamic processes inside flow parts of a supersonic ejector. These simulations are performed using two commercial CFD solvers (Star- CCM+ and Fluent). The results are compared to each other and verified by a full-scale experiment in terms of global flow parameters (the entrainment ratio: the ratio between secondary to primary mass flow rate - ER hereafter) and local flow parameters distribution (the static pressure distribution along the mixing chamber and diffuser walls). A detailed comparative study of the employed methods and approaches in both CFD packages is carried out in order to estimate the roughness effect on the logarithmic law velocity distribution inside the boundary layer. Influence of the surface roughness is compared with the influence of the backpressure (static pressure at the ejector outlet). It has been found out that increasing either the ejector backpressure or the surface roughness height, the shock position displaces upstream. Moreover, the numerical simulation results of an ejector with rough walls in the both CFD solvers are well quantitatively agreed with each other in terms of the mean ER and well qualitatively agree in terms of the local flow parameters distribution. It is found out that in the case of exceeding the "critical roughness height" for the given boundary conditions and ejector's geometry, the ejector switches to the "off-design" mode and its performance decreases considerably.

  7. Power-Cooling-Mismatch Test Series Test PCM-7. Experiment operating specifications

    International Nuclear Information System (INIS)

    Sparks, D.T.; Smith, R.H.; Stanley, C.J.

    1979-02-01

    The experiment operating specifications for the Power-Cooling-Mismatch (PCM) Test PCM-7 to be conducted in the Power Burst Facility are described. The PCM Test Series was designed on the basis of a parametric evaluation of fuel behavior response with cladding temperature, rod internal pressure, time in film boiling, and test rod power being the variable parameters. The test matrix, defined in the PCM Experiment Requirements Document (ERD), encompasses a wide range of situations extending from pre-CHF (critical heat flux) PCMs to long duration operation in stable film boiling leading to rod failure

  8. Tube failures due to cooling process problem and foreign materials in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, J. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200 (Malaysia); Purbolaksono, J., E-mail: judha@uniten.edu.m [Department of Mechanical Engineering, Universiti Tenaga Nasional, Km 7 Jalan Kajang-Puchong, Kajang 43009, Selangor (Malaysia); Beng, L.C. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200 (Malaysia)

    2010-07-15

    Cooling process which uses water for heat transfer is an essential factor in coal-fired and nuclear plants. Loss of cooling upset can force the plants to shut down. In particular, this paper reports visual inspections and metallurgical examinations on the failed SA210-A1 right-hand side (RHS) water wall tube of a coal-fired plant. The water wall tube showed the abnormal outer surface colour and has failed with wide-open ductile rupture and thin edges indicating typical signs of short-term overheating. Metallurgical examinations confirmed the failed tube experiencing higher temperature operation. Water flow starvation due to restriction inside the upstream tube is identified as the main root cause of failure. The findings are important to take failure mitigation actions in the future operation. Discussion on the typical problems related to the cooling process in nuclear power plants is also presented.

  9. Study on extreme high temperature of cooling water in Chinese coastal nuclear power plant

    International Nuclear Information System (INIS)

    Yu Fan; Jiang Ziying

    2012-01-01

    In order to protect aquatic life from the harmful effects of thermal discharge, the appropriate water temperature limits or the scope of the mixing zone is a key issue in the regulatory control of the environmental impact of thermal discharge. Based on the sea surface temperature in the Chinese coastal waters, the extreme value of the seawater temperature change was analyzed by using the Gumbel model. The limit of the design temperature rise of cooling water in the outfall is 9 ℃, and the limit of the temperature rise of cooling water in the edge of the mixing zone is 4 ℃. The extreme high temperature of the cooling water in Chinese coastal nuclear power plant is 37 ℃ in the Bohai Sea, Yellow Sea, and is 40 ℃ in East China Sea, South China Sea. (authors)

  10. Theoretical Models for the Cooling Power and Base Temperature of Dilution Refrigerators

    CERN Document Server

    Wikus, Patrick

    2010-01-01

    He-3/He-4 dilution refrigerators are widely used for applications requiring continuous cooling at temperatures below approximately 300 mK. Despite of the popularity of these devices in low temperature physics, the thermodynamic relations underlying the cooling mechanism of He-3/He-4 refrigerators are very often incorrectly used. Several thermodynamic models of dilution refrigeration have been published in the past, sometimes contradicting each other. These models are reviewed and compared with each other over a range of different He-3 flow rates. In addition, a new numerical method for the calculation of a dilution refrigerator's cooling power at arbitrary flow rates is presented. This method has been developed at CERN's Central Cryogenic Laboratory. It can be extended to include many effects that cannot easily be accounted for by any of the other models, including the degradation of heat exchanger performance due to the limited number of step heat exchanger elements, which can be considerable for some design...

  11. Building concept of cooling towers for WWER-1000 nuclear power plants

    International Nuclear Information System (INIS)

    Bucha, V.; David, M.

    1984-01-01

    A project is described of cooling towers with natural draught for the Temelin nuclear power plant. The concept proceeds from the classical design of the so-called Itterson type, i.e., the outer cladding of the draught stack is made of a monolithic reinforced concrete unit in the shape of a hyperboloid of revolution supported by a system of oblique supports mounted along the edge of the cooled water tank. The procedure is explained of the thermal calculation for the given operating conditions. The basic alternatives are considered of the choice of material and design of the cooling system. Questions are discussed relating to the design of the eliminator, the windwart wall and the shape of the shell of the draught stack and its loading by wind and seismic effects. (E.S.)

  12. Tube failures due to cooling process problem and foreign materials in power plants

    International Nuclear Information System (INIS)

    Ahmad, J.; Purbolaksono, J.; Beng, L.C.

    2010-01-01

    Cooling process which uses water for heat transfer is an essential factor in coal-fired and nuclear plants. Loss of cooling upset can force the plants to shut down. In particular, this paper reports visual inspections and metallurgical examinations on the failed SA210-A1 right-hand side (RHS) water wall tube of a coal-fired plant. The water wall tube showed the abnormal outer surface colour and has failed with wide-open ductile rupture and thin edges indicating typical signs of short-term overheating. Metallurgical examinations confirmed the failed tube experiencing higher temperature operation. Water flow starvation due to restriction inside the upstream tube is identified as the main root cause of failure. The findings are important to take failure mitigation actions in the future operation. Discussion on the typical problems related to the cooling process in nuclear power plants is also presented.

  13. Integrated application of combined cooling, heating and power poly-generation PV radiant panel system of zero energy buildings

    Science.gov (United States)

    Yin, Baoquan

    2018-02-01

    A new type of combined cooling, heating and power of photovoltaic radiant panel (PV/R) module was proposed, and applied in the zero energy buildings in this paper. The energy system of this building is composed of PV/R module, low temperature difference terminal, energy storage, multi-source heat pump, energy balance control system. Radiant panel is attached on the backside of the PV module for cooling the PV, which is called PV/R module. During the daytime, the PV module was cooled down with the radiant panel, as the temperature coefficient influence, the power efficiency was increased by 8% to 14%, the radiant panel solar heat collecting efficiency was about 45%. Through the nocturnal radiant cooling, the PV/R cooling capacity could be 50 W/m2. For the multifunction energy device, the system shows the versatility during the heating, cooling and power used of building utilization all year round.

  14. Design and Thermodynamic Analysis of a Steam Ejector Refrigeration/Heat Pump System for Naval Surface Ship Applications

    Directory of Open Access Journals (Sweden)

    Cüneyt Ezgi

    2015-12-01

    Full Text Available Naval surface ships should use thermally driven heating and cooling technologies to continue the Navy’s leadership role in protecting the marine environment. Steam ejector refrigeration (SER or steam ejector heat pump (SEHP systems are thermally driven heating and cooling technologies and seem to be a promising technology to reduce emissions for heating and cooling on board naval surface ships. In this study, design and thermodynamic analysis of a seawater cooled SER and SEHP as an HVAC system for a naval surface ship application are presented and compared with those of a current typical naval ship system case, an H2O-LiBr absorption heat pump and a vapour-compression heat pump. The off-design study estimated the coefficient of performances (COPs were 0.29–0.11 for the cooling mode and 1.29–1.11 for the heating mode, depending on the pressure of the exhaust gas boiler at off-design conditions. In the system operating at the exhaust gas boiler pressure of 0.2 MPa, the optimum area ratio obtained was 23.30.

  15. Solar cooling systems. Classification and energetic evaluation; Solare Kuehlsysteme. Klassifizierung und energetische Bewertung

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Jakob [Technische Univ. Bergakademie Freiberg (Germany); Hafner, Armin [SINTEF Energy Research, Trondheim (Norway); Eikevik, Trygve M. [NTNU, Trondheim (Norway)

    2012-07-01

    The investigation of alternative, sustainable concepts for cold production is worthwhile in times of increasing energy demand for cooling and air conditioning applications. Energy sources such as solar radiation can help to reduce the burden on the environment and energy networks. Solar electricity from photovoltaic cells or solar power from solar collectors can be used in refrigerating equipment (such as cold vapor compression chiller, absorption chiller, adsorption chillers, open systems, thermo-mechanical systems or ejector-based systems) are fed in order to produce the desired coldness. In many cases, the temporal coincidence of radiation supply and cooling requirements makes the solar cooling to a promising concept, especially at sites with a high solar radiation, large cooling demand, high energy prices, or insufficient access to public power grids. A model-based investigation of different solar cooling systems with an equivalent cooling capacity was carried out. The results show that the performance potential strongly depends on the selected technology and the site of the system. A balanced daily energy balance can be achieved with an appropriately dimensioned solar power plant with cooling concept. Depending on the system and interpretation, primary energy savings or a primary energy overhead can be achieved within a year in comparison to a conventional system.

  16. Physical parameters of effluent from nuclear power station cooling towers; Fizicki parametri efluenata iz rashladnih tornjeva nuklearne elektrane

    Energy Technology Data Exchange (ETDEWEB)

    Vehauc, A [Institute of Nuclear Sciences VINCA, Belgrade (Yugoslavia)

    1992-07-01

    Physical parameters of the effluent dispersed from the wet cooling towers, i.e. mixture of the warm moist air with the entrained droplets are analysed. Understanding of the effluent physical parameters at the exit of cooling tower is important for prediction of the effluent dispersion in the environment. Mass and droplet diameter distributors of the drifted cooling water are measured in situ and also, drift eliminators are characterised experimentally. A new numerical method for heat and mass transfer evaluation in the cooling tower packing (fill) was developed, that leads to more accurate prediction for outlet air parameters in relation of plant power rate, cooling tower characteristics and atmospheric conditions. (author)

  17. The discussion of nuclear power plant's cooling chain design for freezing site

    International Nuclear Information System (INIS)

    Hu Jian; Yang Ting; Jiang Xulun

    2014-01-01

    The Component cooling water system (RRI) and Essential service water system (SEC) are composed of Nuclear Power Plant's (NPP) cooling chain, which has its special requirement for freezing site from system design and safety point of view. The feature and difficulty of cooling chain design at freezing condition (when the intake water temperature is below O ℃) are represented. At present, several NPPs are in operation or under construction at freezing site in the world, including Pressurized Water Reactor (PWR) and Canadian Deuterium Uranium reactor (CANDU). By analyzing the thoughts and applicability of different kinds of cooling chain design at freezing site, one solution called 'SEC thermal discharge reflux' is proposed to remove the residual heat from Nuclear Island (NI) into heat sink safely in winter. The solution has been approved by National Nuclear Safety Administration (NNSA) in China and applied in one of CPR NPP in the north of China, which is able to solve several problems compared with the traditional solutions, such as 'Reactor low power operation', 'Reactor start-up for the first time', and 'Changeover of RRI/SEC trains in winter'. The solution is also able to prevent RRI/SEC heat exchanger from icing and avoid low flowrate in SEC pipes. Besides, considering of the economical efficiency, simple operation and control strategy is designed. (authors)

  18. Ecology of Legionella within water cooling circuits of nuclear power plants along the French Loire River

    International Nuclear Information System (INIS)

    Jakubek, Delphine

    2012-01-01

    The cooling circuits of nuclear power plants, by their mode of operating, can select thermophilic microorganisms including the pathogenic organism Legionella pneumophila. To control the development of this genus, a disinfection treatment of water cooling systems with monochloramine can be used. To participate in the management of health and environmental risks associated with the physico-chemical and microbiological modification of water collected from the river, EDF is committed to a process of increasing knowledge about the ecology of Legionella in cooling circuits and its links with its environment (physical, chemical and microbiological) supporting or not their proliferation. Thus, diversity and dynamics of culturable Legionella pneumophila were determined in the four nuclear power plants along the Loire for a year and their links with physico-chemical and microbiological parameters were studied. This study revealed a high diversity of Legionella pneumophila subpopulations and their dynamic seems to be related to the evolution of a small number of subpopulations. Legionella subpopulations seem to maintain strain-specific relationships with biotic parameters and present different sensitivities to physico-chemical variations. The design of cooling circuits could impact the Legionella community. The use of monochloramine severely disrupts the ecosystem but does not select biocide tolerant subpopulations. (author)

  19. Method of inhibiting concentration of radioactive corrosion products in cooling water or nuclear power plants

    International Nuclear Information System (INIS)

    Takabayashi, Jun-ichi; Hishida, Mamoru; Ishikura, Takeshi.

    1979-01-01

    Purpose: To suppress the increase in the concentration of the radioactive corrosion products in cooling water, which increase is accompanied by the transference of the corrosion products activated and accumulated in the core due to dissolution and exfoliation into the core water, and inhibit the flowing of said products out of the core and the diffusion thereof into the cooling system, thereby to prevent the accumulation of said products in the cooling system and prevent radioactive contaminations. Method: In a nuclear power plant of a BWR type light water reactor, when the temperature of the pile water is t 0 C, hydrogen is injected in cooling water in a period of time from immediately before starting of the drive stopping operation of the nuclear power plant to immediately after the termination of restarting operation, whereby the concentration of hydrogen in the reactor water through said period is maintained at a value more than 2exp (0.013 t) cm 3 N.T.P./kg H 2 O. (Aizawa, K.)

  20. Design and analysis of new prestressed concrete containment and its passive cooling system for nuclear power plants

    International Nuclear Information System (INIS)

    Tan Xiaoshi; Li Xiaowei; Li Xiaotian; He Shuyan

    2014-01-01

    A new nuclear power plant prestressed concrete containment and its passive cooling system design were proposed for CAP1700 nuclear power plant as an example. The thermal-hydraulic calculation method for the new passive containment cooling system of CAP1700 was introduced and the operating parameters in accident condition were obtained. The result shows that the design of passive containment cooling system for CAP1700 is feasible and can meet the cooling demand in accident condition. Reservoir capacity of tank has a big margin and can be further optimized by calculation. (authors)

  1. An investigation of heat recovery of submarine diesel engines for combined cooling, heating and power systems

    International Nuclear Information System (INIS)

    Daghigh, Roonak; Shafieian, Abdellah

    2016-01-01

    Highlights: • The power output of the cycle is about 53 kW in the mass flow rate of 0.6 kg/s. • The output cooling water temperature of evaporator is 3.64 °C. • The absorption chiller has a coefficient of performance equal to 0.94. - Abstract: High temperature and mass flow rate of the exhaust gases of submarine diesel engines provide an appropriate potential for their thermal recovery. The current study introduces a combined cooling, heating and power system for thermal recovery of submarine diesel engines. The cooling system is composed of a mixed effect absorption chiller with two high and low pressure generators. The exhaust of the diesel engine is used in the high pressure generator, and the low pressure generator was divided into two parts. The required heat for the first and second compartments is supplied by the cooling water of the engine and condensation of the vapor generated in the high pressure generator, respectively. The power generation system is a Rankine cycle with an organic working fluid, which is considered a normal thermal system to supply hot water. The whole system is encoded based on mass stability, condensation and energy equations. The obtained findings showed that the maximum heat recovery for the power cycle occurs in exhaust gas mass ratio of 0.23–0.29 and working fluid mass flow rate of 0.45–0.57 kg/s. Further, for each specific mass ratio of exhaust gas, only a certain range of working fluid mass flow rate is used. In the refrigerant mass flow rate of 0.6 kg/s and exhaust gas mass ratio of 0.27, the power output of the cycle is 53 kW, which can also be achieved by simultaneous increase of refrigerant mass flow rate and exhaust gas mass ratio in a certain range of higher powers. In the next section, the overall distribution diagram of output water temperature of the thermal system is obtained according to the exhaust gas mass ratio in various mass flow rates, which can increase the potential of designing and controlling the

  2. Feasibility Study on Dual-Cooled Annular Fuel for OPR-1000 Power Uprate

    International Nuclear Information System (INIS)

    Chun, Tae Hyun; In, Wang Kee; Oh, Dong Suck

    2010-04-01

    A dual-cooled annular fuel (DCAF) is a highly promising concept as a high power density fuel for PWR power-uprate. The purpose of this study is to assess a feasibility of 120% core power for OPR-1000 with the DCAF. So the feasibility study were done through the code establishments for annular fuel analysis, evaluations of core physics, thermal-hydraulics and safety analyses at a 120% power with OPR-1000 and the preliminary economic benefits of 20% power-uprate. As results of the analyses, DCAF at 120% power showed sufficient margins available on DNB, PCT and fuel pellet temperature relative to the solid fuel at 100% power. However, judging from an anticipated wide range of the gap conductance variation in inner and outer clearances as fuel burn-up in the reactor core, irradiation behavior of DCAF has to be observed through research reactor test. On the other hand, the nuclear physics parameters like moderator temperature coefficient, power coefficient and so on comply with the technical specifications. An impact of 20% power-uprate on NSSS and BOP was also investigated, and accordingly some components and parts need to be changed were identified. Moreover, the economical benefits from the power-uprate was roughly estimated. It turned out that the power-uprating with DCAF could give an enormous profit even considering the expenses of components and parts to be replaced, additional fuel cycle cost and extended overhaul period

  3. Strainer device for an emergency cooling system in a nuclear power plant

    International Nuclear Information System (INIS)

    Trybom, J.

    1997-01-01

    The invention relates to a strainer device for separating contaminants from water in an emergency cooling system for a nuclear power plant. The nuclear power plant has a wet-well for water in the emergency cooling system and the strainer device comprises at least one strainer device, which is arranged in the wet-well. According to the invention the strainer is suspended in a desired position in the wet-well by means of at least a group of at least three tie rods arranged at angles to each other, each tie rod being fixed at one end to the strainer and its other end to the container or an anchor ring joined thereto. (author) figs

  4. Accumulation of 137Cs in commercial fish of the Belyarsk nuclear power station cooling supply

    International Nuclear Information System (INIS)

    Trapeznikova, V.N.; Kulikov, N.V.; Trapeznikov, A.V.

    1984-01-01

    Results are presented of a comparative study of the accumulation of 137 Cs in basic species of commercial fish of the Beloyarsk reservoir which is used as the cooling supply for the Beloyarsk nuclear power station. Possible reasons for interspecies differences in accumulation of the radionuclide are indicated, and the increased accumulation of 137 Cs by free-living fish in the zone of heated water effluent from the station and the reduced accumulation of the emitter in carp, which are cultivated on artificial food in cages, are noted. Levels of the content of the radionuclide are compared in roach and farm carp from the cooling supplies of the Beloyarsk station and the Reftinsk power plant in the Urals

  5. System performance and economic analysis of solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.; Wu, J.H.; Yen, R.H.; Wang, J.H.; Hsu, H.Y.; Hsia, C.J.; Yen, C.W.; Chang, J.M.

    2011-01-01

    The long-term system simulation and economic analysis of solar-assisted cooling/heating system (SACH-2) was carried out in order to find an economical design. The solar heat driven ejector cooling system (ECS) is used to provide part of the cooling

  6. Nuclear closed-cycle gas turbine (HTGR-GT): dry cooled commercial power plant studies

    International Nuclear Information System (INIS)

    McDonald, C.F.; Boland, C.R.

    1979-11-01

    Combining the modern and proven power conversion system of the closed-cycle gas turbine (CCGT) with an advanced high-temperature gas-cooled reactor (HTGR) results in a power plant well suited to projected utility needs into the 21st century. The gas turbine HTGR (HTGR-GT) power plant benefits are consistent with national energy goals, and the high power conversion efficiency potential satisfies increasingly important resource conservation demands. Established technology bases for the HTGR-GT are outlined, together with the extensive design and development program necessary to commercialize the nuclear CCGT plant for utility service in the 1990s. This paper outlines the most recent design studies by General Atomic for a dry-cooled commercial plant of 800 to 1200 MW(e) power, based on both non-intercooled and intercooled cycles, and discusses various primary system aspects. Details are given of the reactor turbine system (RTS) and on integrating the major power conversion components in the prestressed concrete reactor vessel

  7. Steam-generator tube performance: world experience with water-cooled nuclear power reactors during 1978

    International Nuclear Information System (INIS)

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

    1980-01-01

    The performance of steam-generator tubes in water-cooled nuclear power reactors during 1978 is reviewed. Tube failures occurred at 31 of the 86 reactors surveyed. The causes of these failures and the procedures designed to deal with them are described. The number of tubes plugged has decreased dramatically in 1978 compared to the previous year. This is attributed to the diligent application of techniques developed through in-plant experience and research and development programs over the past several years

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

    International Nuclear Information System (INIS)

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

    1978-02-01

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

  9. Steam generator tube failures: world experience in water-cooled nuclear power reactors in 1975

    International Nuclear Information System (INIS)

    Hare, M.G.

    1976-11-01

    Steam generator tube failures were reported in 22 out of 62 water-cooled nuclear power plants surveyed in 1975. This was less than in 1974, and the number of the tubes affected was noticeably less. This report summarizes these failures, most of which were due to corrosion. Secondary-water chemistry control, procedures for inspection and repair, tube materials, and failure rates are discussed. (author)

  10. Steam generator tube performance: experience with water-cooled nuclear power reactors during 1977

    International Nuclear Information System (INIS)

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

    1979-02-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1977. Failures were reported in 34 of the 79 reactors surveyed. Causes of these failures and inspection and repair procedures designed to deal with them are presented. Although corrosion remained the leading cause of tube failures, specific mechanisms have been identified and methods of dealing with them developed. These methods are being applied and should lead to a reduction of corrosion failures in future. (author)

  11. Internal-external flow integration for a thin ejector-flapped wing section

    Science.gov (United States)

    Woolard, H. W.

    1979-01-01

    Thin airfoil theories of an ejector flapped wing section are reviewed. The global matching of the external airfoil flow with the ejector internal flow and the overall ejector flapped wing section aerodynamic performance are examined. Mathematical models of the external and internal flows are presented. The delineation of the suction flow coefficient characteristics are discussed. The idealized lift performance of an ejector flapped wing relative to a jet augmented flapped wing are compared.

  12. Thermoeconomic analysis and optimization of an ammonia–water power/cooling cogeneration cycle

    International Nuclear Information System (INIS)

    Zare, V.; Mahmoudi, S.M.S.; Yari, M.; Amidpour, M.

    2012-01-01

    The performance of an ammonia–water power/cooling cogeneration cycle is investigated and optimized paying more attention on the economic point of view. Thermodynamic and thermoeconomic models are developed in order to investigate the thermodynamic performance of the cycle and assess the unit cost of products. A parametric study is carried out and the cycle performance is optimized based on the thermal and exergy efficiencies as well as the sum of the unit costs of the system products. The results show that the sum of the unit cost of the cycle products obtained through thermoeconomic optimization is less than by around 18.6% and 25.9% compared to the cases when the cycle is optimized from the viewpoints of first and second laws of thermodynamics, respectively. It is also concluded that for each increase of $3/ton in unit cost of the steam as the heat source, the unit cost of the output power and cooling is increased by around $7.6/GJ and $15–19/GJ, respectively. -- Highlights: ► The theory of exergetic cost is applied to the case of ammonia–water power/cooling cycle. ► The cycle is optimized from the viewpoints of thermodynamics and economics. ► The economic optimization leads to a considerable reduction in the system product costs.

  13. Thermodynamic analysis of a new combined cooling and power system using ammonia–water mixture

    International Nuclear Information System (INIS)

    Wang, Jiangfeng; Wang, Jianyong; Zhao, Pan; Dai, Yiping

    2016-01-01

    Highlights: • A new combined cooling and power system is proposed. • Exergy destruction analysis is used to identify irreversibility of components in system. • Thermodynamic parameter analysis is performed for system. - Abstract: In order to achieve both power and cooling supply for users, a new combined cooling and power system using ammonia–water mixture is proposed to utilizing low grade heat sources, such as industrial waste heat, solar energy and geothermal energy. The proposed system combines a Kalina cycle and an ammonia–water absorption refrigeration cycle, in which the ammonia–water turbine exhaust is delivered to a separator to extract purer ammonia vapor. The purer ammonia vapor enters an evaporator to generate refrigeration output after being condensed and throttled. Mathematical models are established to simulate the combined system under steady-state conditions. Exergy destruction analysis is conducted to display the exergy destruction distribution in the system qualitatively and the results show that the major exergy destruction occurs in the heat exchangers. Finally a thermodynamic sensitivity analysis is performed and reveals that with an increase in the pressure of separator I or the ammonia mass fraction of basic solution, thermal efficiency and exergy efficiency of the system increase, whereas with an increase in the temperature of separator I, the ammonia–water turbine back pressure or the condenser II pressure, thermal efficiency and exergy efficiency of the system drop.

  14. IAEA activities in technology development for advanced water-cooled nuclear power plants

    International Nuclear Information System (INIS)

    Juhn, Poong Eil; Kupitz, Juergen; Cleveland, John; Lyon, Robert; Park, Je Won

    2003-01-01

    As part of its Nuclear Power Programme, the IAEA conducts activities that support international information exchange, co-operative research and technology assessments and advancements with the goal of improving the reliability, safety and economics of advanced water-cooled nuclear power plants. These activities are conducted based on the advice, and with the support, of the IAEA Department of Nuclear Energy's Technical Working Groups on Advanced Technologies for Light Water Reactors (LWRs) and Heavy Water Reactors (HWRs). Assessments of projected electricity generation costs for new nuclear plants have shown that design organizations are challenged to develop advanced designs with lower capital costs and short construction times, and sizes, including not only large evolutionary plants but also small and medium size plants, appropriate to grid capacity and owner financial investment capability. To achieve competitive costs, both proven means and new approaches should be implemented. The IAEA conducts activities in technology development that support achievement of improved economics of water-cooled nuclear power plants (NPPs). These include fostering information sharing and cooperative research in thermo-hydraulics code validation; examination of natural circulation phenomena, modelling and the reliability of passive systems that utilize natural circulation; establishment of a thermo-physical properties data base; improved inspection and diagnostic techniques for pressure tubes of HWRs; and collection and balanced reporting from recent construction and commissioning experiences with evolutionary water-cooled NPPs. The IAEA also periodically publishes Status Reports on global development of advanced designs. (author)

  15. Determination Of Maximum Power Of The RSG-Gas At Power Operation Mode Using One Line Cooling System

    International Nuclear Information System (INIS)

    Hastuti, Endiah Puji; Kuntoro, Iman; Darwis Isnaini, M.

    2000-01-01

    In the frame of minimizing the operation-cost, operation mode using one line cooling system is being evaluated. Maximum reactor power shall be determined to assure that the existing safety criteria are not violated. The analysis was done by means of a core thermal hydraulic code, COOLOD-N. The code solves core thermal hydraulic equation at steady state conditions. By varying the reactor power as the input, thermal hydraulic parameters such as fuel cladding and fuel meat temperatures as well as safety margin against flow instability were calculated. Imposing the safety criteria to the results, maximum permissible power for this operation was obtained as much as 17.1 MW. Nevertheless, for operation the maximum power is limited to 15MW

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

    International Nuclear Information System (INIS)

    Raptis, Catherine E.; Pfister, Stephan

    2016-01-01

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

  17. IAEA'S study on advanced applications of water cooled nuclear power plants

    International Nuclear Information System (INIS)

    Cleveland, J.; McDonald, A.; Rao, A.; )

    2008-01-01

    About one-fifth of the world's energy consumption is used for electricity generation, with nuclear power contributing approximately 15.2% of this electricity. However; most of the world's energy consumption is for heat and transportation. Nuclear energy has considerable potential to penetrate these energy sectors now served by fossil fuels that are characterized by price volatility and finite supply. Advanced applications of nuclear energy include seawater desalination, district heating, and heat for industrial processes. Nuclear energy also has potential to provide a near-term, greenhouse gas free, source of energy for transportation. These applications rely on a source of heat and electricity. Nuclear energy from water-cooled reactors, of course, is not unique in this sense. Indeed, higher temperature heat can be produced by burning natural gas and coal, or through the use of other nuclear technologies such as gas-cooled or liquid-metal-cooled reactors. Water-cooled reactors, however; are being deployed today while other reactor types have had considerably less operational and regulatory experience and will take still some time to be widely accepted in the market. Both seawater desalination and district heating with nuclear energy are well proven, and new seawater desalination projects using water-cooled reactors will soon be commissioned. Provision of process heat with nuclear energy can result in less dependence on fossil fuels and contribute to reductions of greenhouse gases. Importantly, because nuclear power produces base-load electricity at stable and predictable prices, it provides a greenhouse gas free source of electricity for transportation systems (trains and subways), and for electric and plug-in hybrid vehicles, and in the longer term nuclear energy could produce hydrogen for fuel cell vehicles, as well as for other components of a hydrogen economy. These advanced applications can play an important role in enhancing public acceptance of nuclear

  18. High-Temperature Air-Cooled Power Electronics Thermal Design: Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Waye, Scot [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-01

    Power electronics that use high-temperature devices pose a challenge for thermal management. With the devices running at higher temperatures and having a smaller footprint, the heat fluxes increase from previous power electronic designs. This project overview presents an approach to examine and design thermal management strategies through cooling technologies to keep devices within temperature limits, dissipate the heat generated by the devices and protect electrical interconnects and other components for inverter, converter, and charger applications. This analysis, validation, and demonstration intends to take a multi-scale approach over the device, module, and system levels to reduce size, weight, and cost.

  19. Behavior of a nine-rod PWR bundle under power-cooling-mismatch conditions

    International Nuclear Information System (INIS)

    Gunnerson, F.S.; Sparks, D.T.

    1979-01-01

    An experiment to characterize the behavior of a nine-rod pressurized water reactor (PWR) fuel bundle operating during power-cooling-mismatch (PCM) conditions has been conducted in the Power Burst Facility (PBF) at the Idaho National Engineering Laboratory (INEL). The experiment, designated Test PCM-5, is part of a series of PCM experiments designed to evaluate light water reactor (LWR) fuel rod response under postulated accident conditions. Test PCM-5 was the first nine-rod bundle experiment in the PCM test series. The primary objectives and the results of the experiment are described

  20. Design measures to facilitate implementation of safeguards at future water cooled nuclear power plants

    International Nuclear Information System (INIS)

    1999-01-01

    The report is intended to present guidelines to the State authorities, designers and prospective purchasers of future water cooled power reactors which, if taken into account, will minimize the impact of IAEA safeguards on plant operation and ensure efficient and effective acquisition of safeguards data to the mutual benefit of the Member State, the plant operator and the IAEA. These guidelines incorporate the IAEA's experience in establishing and carrying out safeguards at currently operating nuclear power plants, the ongoing development of safeguards techniques and feedback of experience from plant operators and designers on the impact of IAEA safeguards on plant operation. The following main subjects are included: The IAEA's safeguards function for current and future nuclear power plants; summary of the political and legal foundations of the IAEA's safeguards system; the technical objective of safeguards and the supply and use of required design information; safeguards approaches for nuclear power plants; design implications of experience in safeguarding nuclear power plants and guidelines for future water cooled reactors to facilitate the implementation of safeguards

  1. Optimal scheduling of biocide dosing for seawater-cooled power and desalination plants

    KAUST Repository

    Mahfouz, Abdullah Bin

    2011-02-13

    Thermal desalination systems are typically integrated with power plants to exploit the excess heat resulting from the power-generation units. Using seawater in cooling the power plant and the desalination system is a common practice in many parts of the world where there is a shortage of freshwater. Biofouling is one of the major problems associated with the usage of seawater in cooling systems. Because of the dynamic variation in the power and water demands as well as the changes in the characteristics of seawater and the process, there is a need to develop an optimal policy for scheduling biocide usage and cleaning maintenance of the heat exchangers. The objective of this article is to introduce a systematic procedure for the optimization of scheduling the dosing of biocide and dechlorination chemicals as well as cleaning maintenance for a power production/thermal desalination plant. A multi-period optimization formulation is developed and solved to determine: the optimal levels of dosing and dechlorination chemicals; the timing of maintenance to clean the heat-exchange surfaces; and the dynamic dependence of the biofilm growth on the applied doses, the seawater-biocide chemistry, the process conditions, and seawater characteristics for each time period. The technical, economic, and environmental considerations of the system are accounted for. A case study is solved to elucidate the applicability of the developed optimization approach. © 2011 Springer-Verlag.

  2. Operating characteristics of a single-stage Stirling cryocooler capable of providing 700 W cooling power at 77 K

    Science.gov (United States)

    Xu, Ya; Sun, Daming; Qiao, Xin; Yu, Yan S. W.; Zhang, Ning; Zhang, Jie; Cai, Yachao

    2017-04-01

    High cooling capacity Stirling cryocooler generally has hundreds to thousands watts of cooling power at liquid nitrogen temperature. It is promising in boil-off gas (BOG) recondensation and high temperature superconducting (HTS) applications. A high cooling capacity Stirling cryocooler driven by a crank-rod mechanism was developed and studied systematically. The pressure and frequency characteristics of the cryocooler, the heat rejection from the ambient heat exchanger, and the cooling performance are studied under different charging pressure. Energy conversion and distribution in the cryocooler are analyzed theoretically. With an electric input power of 10.9 kW and a rotating speed of 1450 r/min of the motor, a cooling power of 700 W at 77 K and a relative Carnot efficiency of 18.2% of the cryocooler have been achieved in the present study, and the corresponding pressure ratio in the compression space reaches 2.46.

  3. Multi-criteria decision analysis of concentrated solar power with thermal energy storage and dry cooling.

    Science.gov (United States)

    Klein, Sharon J W

    2013-12-17

    Decisions about energy backup and cooling options for parabolic trough (PT) concentrated solar power have technical, economic, and environmental implications. Although PT development has increased rapidly in recent years, energy policies do not address backup or cooling option requirements, and very few studies directly compare the diverse implications of these options. This is the first study to compare the annual capacity factor, levelized cost of energy (LCOE), water consumption, land use, and life cycle greenhouse gas (GHG) emissions of PT with different backup options (minimal backup (MB), thermal energy storage (TES), and fossil fuel backup (FF)) and different cooling options (wet (WC) and dry (DC). Multicriteria decision analysis was used with five preference scenarios to identify the highest-scoring energy backup-cooling combination for each preference scenario. MB-WC had the highest score in the Economic and Climate Change-Economy scenarios, while FF-DC and FF-WC had the highest scores in the Equal and Availability scenarios, respectively. TES-DC had the highest score for the Environmental scenario. DC was ranked 1-3 in all preference scenarios. Direct comparisons between GHG emissions and LCOE and between GHG emissions and land use suggest a preference for TES if backup is require for PT plants to compete with baseload generators.

  4. Electromagnetic and thermal analysis of distributed cooled high power millimeter wave windows

    International Nuclear Information System (INIS)

    Nelson, S.D.; Reitter, T.; Caplan, M.; Moeller, C.

    1996-01-01

    The sectional high-frequency internally-cooled window, as proposed by General Atomics(1), has unique potential for allowing microwave sources to reach multi-megawatt CW levels with application to ECRH. Designs are being investigated using computational electromagnetic (EM), thermal, and mechanical codes at 110 GHz and 170 GHz to examine the design tradeoffs between RF performance and thermal mechanical safety margins. The EM analyses are for the window, under vacuum at one MW and includes variations in the shapes of the cooling fins, the surface treatment of the window elements themselves, the cooling fin tip treatment, the window pitch angle, and the waveguide effects. One advantage of the distributed cooled window is it close-quote s extensibility to higher power levels. Results in the modeling efforts are presented showing the EM field concentrations (which then will feed into the thermal analysis), the energy scattering/reflection, the transmitted launch angle variation as a function of physical geometry, and the spatial energy distribution and loss as a function of time and position. copyright 1996 American Institute of Physics

  5. Activities of passive cooling applications and simulation of innovative nuclear power plant design

    International Nuclear Information System (INIS)

    Aglar, F.; Tanrykut, A.

    2002-01-01

    This paper gives a general insight on activities of the Turkish Atomic Energy Authority (TAEA) concerning passive cooling applications and simulation of innovative nuclear power plant design. The condensation mode of heat transfer plays an important role for the passive heat removal application in advanced water-cooled reactor systems. But it is well understood that the presence of noncondesable (NC) gases can greatly inhibit the condensation process due to the build up of NC gas concentration at the liquid/gas interface. The isolation condenser of passive containment cooling system of the simplified boiling water reactors is a typical application area of in-tube condensation in the presence of NC. The test matrix of the experimental investigation undertaken at the METU-CTF test facility (Middle East Technical University, Ankara) covers the range of parameters; Pn (system pressure) : 2-6 bar, Rev (vapor Reynolds number): 45,000-94,000, and Xi (air mass fraction): 0-52%. This experimental study is supplemented by a theoretical investigation concerning the effect of mixture flow rate on film turbulence and air mass diffusion concepts. Recently, TAEA participated to an international standard problem (OECD ISP-42) which covers a set of simulation of PANDA test facility (Paul Scherrer Institut-Switzerland) for six different phases including different natural circulation modes. The concept of condensation in the presence of air plays an important role for performance of heat exchangers, designed for passive containment cooling, which in turn affect the natural circulation behaviour in PANDA systems. (author)

  6. Contingency power for small turboshaft engines using water injection into turbine cooling air

    Science.gov (United States)

    Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

    1987-01-01

    Because of one engine inoperative requirements, together with hot-gas reingestion and hot day, high altitude takeoff situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stresses is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  7. Contingency power for a small turboshaft engine by using water injection into turbine cooling air

    Science.gov (United States)

    Biesiadny, Thomas J.; Klann, Gary A.

    1992-01-01

    Because of one-engine-inoperative (OEI) requirements, together with hot-gas reingestion and hot-day, high-altitude take-off situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation by using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stress is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  8. Biofouling evaluation in the seawater cooling circuit of an operating coastal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, P.S.; Veeramani, P.; Ershath, M.I.M.; Venugopalan, V.P. [BARC Facilities, Water and Steam Chemistry Div., Kalpakkam, Tamil Nadu (India)

    2010-07-01

    Chlorination is the most commonly used method of biofouling control in cooling water systems of coastal power stations. In the present study, we report results of extensive sampling in different sections of the cooling water system of an operating power station undertaken during three consecutive maintenance shutdowns. The power plant employed continuous low level chlorination (0.2 ± 0.1 mg L{sup -1} TRO) with twice-a-week booster dosing (0.4 ± 0.1 mg L-1 TRO for 8 hours). In addition, the process seawater heat exchangers received supplementary dosing of bromide treatment (0.2 ± 0.1 mg L{sup -1} TRO for 1 hour in every 8 h shift). Biofouling samples were collected from the cooling water conduits, heat exchanger water boxes, pipelines, heated discharge conduits and outfall section during the annual maintenance shutdown of the plant in the years 2007, 2008 and 2009. Simultaneous monitoring of biofouling on test coupons in coastal waters enabled direct comparison of fouling situation on test panels and that in the cooling system. The data showed significant reduction in biofouling inside the cooling circuit as compared to the coastal waters. However, significant amount of fouling was still evident at several places, indicating inadequacy of the biocide treatment regime. The maximum load of 31.3 kg m{sup 2} y{sup -1} was observed in the conduits leading to the process seawater heat exchangers (PSW-HX) and the minimum of 1.3 kg m{sup 2} y{sup -1} was observed in the outfall section. Fouling loads of 12.2 - 14.7 kg m{sup 2} y{sup -1} were observed in the concrete conduits feeding the main condensers. Bromide treatment ahead of the PSW-HX could marginally reduce the fouling load in the downstream section of the dosing point; the HX inlets still showed good biofouling. Species diversity across the cooling water system showed the pre-condenser section to be dominated by green mussels (Perna viridis), pearl oysters (Pinctada sp.) and edible oysters (Crassostrea sp

  9. Biofouling evaluation in the seawater cooling circuit of an operating coastal power plant

    International Nuclear Information System (INIS)

    Murthy, P.S.; Veeramani, P.; Ershath, M.I.M.; Venugopalan, V.P.

    2010-01-01

    Chlorination is the most commonly used method of biofouling control in cooling water systems of coastal power stations. In the present study, we report results of extensive sampling in different sections of the cooling water system of an operating power station undertaken during three consecutive maintenance shutdowns. The power plant employed continuous low level chlorination (0.2 ± 0.1 mg L -1 TRO) with twice-a-week booster dosing (0.4 ± 0.1 mg L-1 TRO for 8 hours). In addition, the process seawater heat exchangers received supplementary dosing of bromide treatment (0.2 ± 0.1 mg L -1 TRO for 1 hour in every 8 h shift). Biofouling samples were collected from the cooling water conduits, heat exchanger water boxes, pipelines, heated discharge conduits and outfall section during the annual maintenance shutdown of the plant in the years 2007, 2008 and 2009. Simultaneous monitoring of biofouling on test coupons in coastal waters enabled direct comparison of fouling situation on test panels and that in the cooling system. The data showed significant reduction in biofouling inside the cooling circuit as compared to the coastal waters. However, significant amount of fouling was still evident at several places, indicating inadequacy of the biocide treatment regime. The maximum load of 31.3 kg m 2 y -1 was observed in the conduits leading to the process seawater heat exchangers (PSW-HX) and the minimum of 1.3 kg m 2 y -1 was observed in the outfall section. Fouling loads of 12.2 - 14.7 kg m 2 y -1 were observed in the concrete conduits feeding the main condensers. Bromide treatment ahead of the PSW-HX could marginally reduce the fouling load in the downstream section of the dosing point; the HX inlets still showed good biofouling. Species diversity across the cooling water system showed the pre-condenser section to be dominated by green mussels (Perna viridis), pearl oysters (Pinctada sp.) and edible oysters (Crassostrea sp.), whereas the post-condenser section and heat

  10. Compact modeling of a telecom back-up unit powered by air-cooled proton exchange membrane fuel cell

    DEFF Research Database (Denmark)

    Gao, Xin; Kær, Søren Knudsen

    2018-01-01

    Applications of proton exchange membrane fuel cells (PEMFC’s) are expanding in portable, automotive and stationary markets. One promising application is the back-up power for telecommunication applications in remote areas where usually air-cooled PMEFC’s are used. An air-cooled PEMFC system is much...

  11. Analysis of Refrigeration Cycle Performance with an Ejector

    Directory of Open Access Journals (Sweden)

    Wani J. R.

    2016-01-01

    Full Text Available A conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses during the expansion process. A refrigeration cycle with ejector is a promising modification to improve the performance of conventional refrigeration cycle. The ejector is used to recover some of the available work so that the compressor suction pressure increases. To investigate the enhancement a model with R134a refrigerant was developed. To solve the set of equations and simulate the cycle performance a subroutine was written on engineering equation solver (EES environment. At specific conditions, the refrigerant properties are obtained from EES. At the design conditions the ejector refrigeration cycle achieved 5.141 COP compared to 4.609 COP of the conventional refrigeration cycle. This means that ejector refrigeration cycle offers better COP with 10.35% improvement compared to conventional refrigeration cycle. Parametric analysis of ejector refrigeration cycle indicated that COP was influenced significantly by evaporator and condenser temperatures, entrainment ratio and diffuser efficiency.

  12. Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond

    International Nuclear Information System (INIS)

    Farfan, E. B.; Jannik, G. T.; Marra, J. C.; Oskolkov, B. Ya.; Bondarkov, M. D.; Gaschak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.

    2009-01-01

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning

  13. Energy and environmental evaluation of combined cooling heating and power system

    Science.gov (United States)

    Bugaj, Andrzej

    2017-11-01

    The paper addresses issues involving problems of implementing combined cooling, heating and power (CCHP) system to industrial facility with well-defined demand profiles of cooling, heating and electricity. The application of CCHP system in this particular industrial facility is being evaluated by comparison with the reference system that consists of three conventional methods of energy supply: (a) electricity from external grid, (b) heat from gas-fired boilers and (c) cooling from vapour compression chillers run by electricity from the grid. The CCHP system scenario is based on the combined heat and power (CHP) plant with gas turbine-compressor arrangement and water/lithium bromide absorption chiller of a single-effect type. Those two scenarios are analysed in terms of annual primary energy usage as well as emissions of CO2. The results of the analysis show an extent of primary energy savings of the CCHP system in comparison with the reference system. Furthermore, the environmental impact of the CCHP usage, in the form of greenhouse gases emission reductions, compares quite favourably with the reference conventional option.

  14. Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E. B.; Jannik, G. T.; Marra, J. C.; Oskolkov, B. Ya.; Bondarkov, M. D.; Gaschak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.

    2009-11-09

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  15. ENVIRONMENTAL PROBLEMS ASSOCIATED WITH DECOMMISSIONING THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.

    2009-09-30

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  16. AP1000{sup R} nuclear power plant safety overview for spent fuel cooling

    Energy Technology Data Exchange (ETDEWEB)

    Gorgemans, J.; Mulhollem, L.; Glavin, J.; Pfister, A.; Conway, L.; Schulz, T.; Oriani, L.; Cummins, E.; Winters, J. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)

    2012-07-01

    The AP1000{sup R} plant is an 1100-MWe class pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance, safety and costs. The AP1000 design uses passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems such as AC power, component cooling water, service water or HVAC. Furthermore, these passive features 'fail safe' during a non-LOCA event such that DC power and instrumentation are not required. The AP1000 also has simple, active, defense-in-depth systems to support normal plant operations. These active systems provide the first level of defense against more probable events and they provide investment protection, reduce the demands on the passive features and support the probabilistic risk assessment. The AP1000 passive safety approach allows the plant to achieve and maintain safe shutdown in case of an accident for 72 hours without operator action, meeting the expectations provided in the U.S. Utility Requirement Document and the European Utility Requirements for passive plants. Limited operator actions are required to maintain safe conditions in the spent fuel pool via passive means. In line with the AP1000 approach to safety described above, the AP1000 plant design features multiple, diverse lines of defense to ensure spent fuel cooling can be maintained for design-basis events and beyond design-basis accidents. During normal and abnormal conditions, defense-in-depth and other systems provide highly reliable spent fuel pool cooling. They rely on off-site AC power or the on-site standby diesel generators. For unlikely design basis events with an extended loss of AC power (i.e., station blackout) or loss of heat sink or both, spent fuel cooling can still be provided indefinitely: - Passive systems, requiring minimal or no operator actions, are sufficient for at least 72 hours under all

  17. Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

    Science.gov (United States)

    Foley, T. Q.; Oskolkov, B. Y.; Bondarkov, M. D.; Gashchak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.; Jannik, G. T.; Farfan, E. B.; Marra, J. C.

    2009-12-01

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination is a fairly pressing issue. Significant problems may result from decommissioning of cooling ponds. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained bodies of water in the Chernobyl Region and Ukrainian Polesye with a water surface area of 22.9 km2. The major hydrological feature of the ChNPP Cooling Pond is that its water level is 6-7 m higher than the water level in the Pripyat River and water losses due to seepage and evaporation are replenished by pumping water from the Pripyat River. In 1986, the accident at the ChNPP #4 Reactor Unit significantly contaminated the ChNPP Cooling Pond. According to the 2001 data, the total radionuclide inventory in the ChNPP Cooling Pond bottom deposits was as follows: 16.28 ± 2.59 TBq for 137Cs; 2.4 ± 0.48 TBq for 90Sr, and 0.00518 ± 0.00148 TBq for 239+240Pu. Since ChNPP is being decommissioned, the ChNPP Cooling Pond of such a large size will no longer be needed and cost effective to maintain. However, shutdown of the water feed to the Pond would expose the contaminated bottom deposits and change the hydrological features of the area, destabilizing the radiological and environmental situation in the entire region in 2007 - 2008, in order to assess potential consequences of draining the ChNPP Cooling Pond, the authors conducted preliminary radio-ecological studies of its shoreline ecosystems. The radioactive contamination of the ChNPP Cooling Pond shoreline is fairly variable and ranges from 75 to 7,500 kBq/m2. Three areas with different contamination levels were selected to sample soils, vegetation, small mammals, birds, amphibians, and reptilians in order to measure their 137Cs and 90Sr content. Using the ERICA software, their dose exposures were estimated. For the 2008 conditions, the estimated dose rates were found to be as follows: amphibians - 11

  18. Computer optimization of dry and wet/dry cooling tower systems for large fossil and nuclear power plants

    International Nuclear Information System (INIS)

    Choi, M.; Glicksman, L.R.

    1979-02-01

    This study determined the cost of dry cooling compared to the conventional cooling methods. Also, the savings by using wet/dry instead of all-dry cooling were determined. A total optimization was performed for power plants with dry cooling tower systems using metal-finned-tube heat exchangers and surface condensers. The optimization minimizes the power production cost. The program optimizes the design of the heat exchanger and its air and water flow rates. In the base case study, the method of replacing lost capacity assumes the use of gas turbines. As a result of using dry cooling towers in an 800 MWe fossil plant, the incremental costs with the use of high back pressure turbine and conventional turbine over all-wet cooling are 11 and 15%, respectively. For a 1200 MWe nuclear plant, these are 22 and 25%, respectively. Since the method of making up lost capacity depends on the situation of a utility, considerable effort has been placed on testing the effects of using different methods of replacing lost capacity at high ambient temperatures by purchased energy. The results indicate that the optimization is very sensitive to the method of making up lost capacity. It is, therefore, important to do an accurate representation of all possible methods of making up capacity loss when optimizating power plants with dry cooling towers. A solution for the problem of losing generation capability by a power plant due to the use of a dry cooling tower is to supplement the dry tower during the hours of peak ambient temperatures by a wet tower. A separate wet/dry cooling tower system with series tower arrangement was considered in this study, and proved to be an economic choice over all-dry cooling where some water is available but supplies are insufficient for a totally evaporative cooling tower

  19. European development of He-cooled divertors for fusion power plants

    International Nuclear Information System (INIS)

    Norajitra, P.; Giniyatulin, R.; Kuznetsov, V.; Mazul, I.; Ovchinnikov, I.; Ihli, T.; Janeschitz, G.; Krauss, W.; Kruessmann, R.; Karditsas, P.; Maisonnier, D.; Sardain, P.; Nardi, C.; Papastergiou, S.; Pizzuto, A.

    2005-01-01

    Helium-cooled divertor concepts are considered suitable for use in fusion power plants for safety reasons, as they enable the use of a coolant compatible with any blanket concept, since water would not be acceptable e.g. in connection with ceramic breeder blankets using large amounts of beryllium. Moreover, they allow for a high coolant exit temperature for increasing the efficiency of the power conversion system. Within the framework of the European power plant conceptual study (PPCS), different helium-cooled divertor concepts based on different heat transfer mechanisms are being investigated at ENEA Frascati, Italy, and Forschungszentrum Karlsruhe, Germany. They are based on a modular design which helps reduce thermal stresses. The design goal is to withstand a high heat flux of about 10-15 MW/m 2 , a value which is considered relevant to future fusion power plants to be built after ITER. The development and optimisation of the divertor concepts require an iterative design approach with analyses, studies of materials and fabrication technologies, and the execution of experiments. These issues and the state of the art of divertor development shall be the subject of this report. (author)

  20. Stochastic study on entrainment of floating particles with intake of cooling water of a power plant

    International Nuclear Information System (INIS)

    Kadoyu, Masatake; Wada, Akira

    1979-01-01

    The mortality of ichthyoplanktons, contained in the sea water passing through the cooling water systems of a power plant, may be associated with rising temperature and mechanical effect. In this study, the range and the rate of entrainment of the organisms like ichthyoplanktons floating in the sea caused by the intake of cooling water were stochastically investigated by simulating the average current as well as the flow caused by the intake of water and by taking into consideration random velocity fluctuation without these flows, using a mathematical model. An intake was set along the straight coastline in semi-infinite sea, and the rate of inflow of particles into the intake was simulated by a mathematical model. In the numerical simulation, the average flow as coastal current component and the flow caused by the intake of water were obtained with the hydrodynamic equations of motion and continuity, and the rate of entrainment of floating particles was examined by giving turbulence to the particles in the sea and by calculating the position of each particle every moment. The results are as follows; 1) The range of entrainment of floating particles by the intake of cooling water and its probability were obtained in consideration of the flow rate of cooling water, coast current velocity and diffusion coefficient as parameters. 2) The extent of inflow of floating particles considerably varied with tidal amplitude, diffusion coefficient and the flow rate of cooling water in the sea where the coastal flow has clear periodicity. 3) The extent of entrainment was considerably influenced by the steady current velocity, the velocity distribution in offshore direction and the intake volume in the sea where periodicity is not observed. (Nakai, Y.)

  1. Seismic assessment of air-cooled type emergency electric power supply system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    JNES initiated seismic assessment programs to develop seismic review criterions for the air-cooled system (diesel generator, gas turbine generator), which will be newly installed for enhancing the diversity of emergency electric power supply system. Five principal subjects are involved in the programs: two subjects for fiscal 2011 and three ones for fiscal 2012 and 2013. The summary of outcomes is as follows: 1) Past capacity test data and related technical issues (2011). Seismic capacity data obtained from past seismic shaking tests were investigated. 2) Test programs based on the investigation of system specification (2011). Design specifications for the air-cooled system were investigated. 3) Large Air Fin Cooler (AFC) one unit model seismic capacity test and quantitative seismic capacity evaluation. AFC one unit model seismic capacity tests were conducted and quantitative seismic capacities were evaluated. (author)

  2. Design and analysis on super-critical water cooled power reactors

    International Nuclear Information System (INIS)

    Ishiwatari, Yuki

    2005-01-01

    The Super-Critical Water Cooled Power Reactors (SCPR) is cooled by 25 MPa supercritical water of 280degC at reactor inlet and greater than 500degC at reactor outlet and directly connected with turbine/generators with high energy conversion efficiency. This corresponds to the deletion of recirculation system and steam-water separation system of BWR type reactors or of pressurizer and steam generator of PWR type reactors. In addition to the design study of the university of Tokyo, technology development of the SCPR for practical use has started under the collaboration of industry and academia since 2000. Mockup single tube and bundle tests for heat transfer/fluid flow characteristics of the design have been conducted with 3D heat transfer analysis. Materials compatible with coolant conditions for fuel cans and reactor internals are also assessed. Overall evaluation of the reactor concept is under way. (T. Tanaka)

  3. Seismic assessment of air-cooled type emergency electric power supply system

    International Nuclear Information System (INIS)

    2013-01-01

    JNES initiated seismic assessment programs to develop seismic review criterions for the air-cooled system (diesel generator, gas turbine generator), which will be newly installed for enhancing the diversity of emergency electric power supply system. Five principal subjects are involved in the programs: two subjects for fiscal 2011 and three ones for fiscal 2012 and 2013. The summary of outcomes is as follows: 1) Past capacity test data and related technical issues (2011). Seismic capacity data obtained from past seismic shaking tests were investigated. 2) Test programs based on the investigation of system specification (2011). Design specifications for the air-cooled system were investigated. 3) Large Air Fin Cooler (AFC) one unit model seismic capacity test and quantitative seismic capacity evaluation. AFC one unit model seismic capacity tests were conducted and quantitative seismic capacities were evaluated. (author)

  4. Method and apparatus for emergency cooling of a nuclear power plant

    International Nuclear Information System (INIS)

    Naito, Masanori; Chino, Koichi; Sato, Chikara; Inoue, Hisamichi.

    1978-01-01

    Purpose: To improve the cooling effect of spray water by eliminating the flow control effect for spray water due to increase in the steam pressure and flowing the entire spray water into the reactor core. Constitution: Upon emergency cooling of a reactor core by spraying coolants from above at the loss of coolant accident in a nuclear power plant, coolant is sprayed in a state where the temperature upon flowing into the reactor core is below the saturated temperature after heat exchange with vapors rising from the core. This enables to apply spray water always at a temperature and a flow rate in the range of whole volume falling irrespective of the water temperature in a pressure suppression pool. (Furukawa, Y.)

  5. The influence of cooling water outlet of the Ringhals power plant on the coastal fish colony

    International Nuclear Information System (INIS)

    Neuman, E.

    1988-03-01

    Fish abundance has been monitored with fyke nets in 1976-1987 at the cooling-water outlet from the Ringhals nuclear power plant at the Swedish west coast and in a reference area. Judging from the dependence of the catches on temperature, Myoxocephalus scorpius, Zoarces viviparus, Gadus morhua and Platichtys flesus can be classified as cold-water species and Symphodus melops, Ctenolabrus rupestris, Carci nus maenas and Anguilla anguilla as warm-water species. As a rule the warm-water species were more and the cold-water fishes less abundant in the outlet area than in the reference area. The catch of the economically important Anguilla was about three times greater in the heated area. A lower abundance than expected of Ctenolabrus and Myoxocephalus at the outlet may be caused by a loss of eggs and larvae in the cooling-water system. (author)

  6. Kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems

    International Nuclear Information System (INIS)

    Lietzke, M.H.

    1977-01-01

    A kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems has been developed. The model incorporates the most important chemical reactions that are known to occur when chlorine is added to natural fresh waters. The simultaneous differential equations, which describe the rates of these chemical reactions, are solved numerically to give the composition of the water as a function of time. A listing of the computer program is included, along with a description of the input variables. A worked-out example illustrates the application of the program to an actual cooling system. An appendix contains a compilation of the known equilibrium and kinetic data for many of the chemical reactions that might be encountered in chlorinating natural fresh waters

  7. Steam generator tube performance: experience with water-cooled nuclear power reactors during 1983 and 1984

    International Nuclear Information System (INIS)

    Tatone, O.S.; Meindl, P.; Taylor, G.F.

    1986-06-01

    A review of the performance of steam generator tubes in water-cooled nuclear power reactors showed that tubes were plugged at 47 (35.6%) of the reactors in 1983 and at 63 (42.6%) of the reactors during 1984. In 1983 and 1984 3291 and 3335 tubes, respectively, were removed from service, about the same as in 1982. The leading causes assigned to tube failure were stress corrosion cracking from the primary side and stress corrosion cracking or intergranular attack from the secondary side. In addition 5668 tubes were repaired for further service by installation of internal sleeves. Most of these were believed to have deteriorated by one of the above mechanisms or by pitting. There is a continuing trend towards high-integrity condenser tube materials at sites cooled by brackish or sea water. 31 refs

  8. Numerical modeling for the retrofit of the hydraulic cooling subsystems in operating power plant

    Science.gov (United States)

    AlSaqoor, S.; Alahmer, A.; Al Quran, F.; Andruszkiewicz, A.; Kubas, K.; Regucki, P.; Wędrychowicz, W.

    2017-08-01

    This paper presents the possibility of using the numerical methods to analyze the work of hydraulic systems on the example of a cooling system of a power boiler auxiliary devices. The variety of conditions at which hydraulic system that operated in specific engineering subsystems requires an individualized approach to the model solutions that have been developed for these systems modernizing. A mathematical model of a series-parallel propagation for the cooling water was derived and iterative methods were used to solve the system of nonlinear equations. The results of numerical calculations made it possible to analyze different variants of a modernization of the studied system and to indicate its critical elements. An economic analysis of different options allows an investor to choose an optimal variant of a reconstruction of the installation.

  9. Design and simulation of liquid cooled system for power battery of PHEV

    Science.gov (United States)

    Wang, Jianpeng; Xu, Haijun; Xu, Xiaojun; Pan, Cunyun

    2017-09-01

    Various battery chemistries have different responses to failure, but the most common failure mode of a cell under abusive conditions is the generation of heat and gas. To prevent battery thermal abuse, a battery thermal management system is essential. An excellent design of battery thermal management system can ensure that the battery is working at a suitable temperature and keeps the battery temperature diffenence at 2-3 °C. This paper presents a thermal-elcetric coupling model for a 37Ah lithium battery using AMESim. A liquid cooled system of hybrid electric vehicle power battery is designed to control the battery temperature.A liquid cooled model of thermal management system is built using AMESim, the simulation results showed that the temperature difference within 3°C of cell in the pack.

  10. Natural-draught wet-type cooling tower of the Philippsburg 1 nuclear power plant

    International Nuclear Information System (INIS)

    Ernst, G.; Schnabel, G.; Bhargava, N.; Brog, P.; Caneill, J.Y.; Carhart, R.A.; Dorwarth, G.; Egler, W.; Fiedler, F.; Gassmann, F.; Haschke, D.; Hodin, A.; Hofmann, W.; Huebschmann, W.; Nester, K.; Policastro, A.J.; Rudolf, B.; Schatzmann, M.; Tinguely, M.; Vignolo, C.; Zaidineraite, M.

    1984-01-01

    In spring 1980, comprehensive field measurements were performed on the natural-draught wet type, cooling tower of Philippsburg I nuclear power plant. Performance in service and emission of cooling tower, condition of ambient atmosphere and spread of plume were studied in seven subprojects. The report on hand contains the results of the 8th subproject within which plume spreading was calculated by means of mathematical models. Efforts were made to win the participation of as large as circle of scientists as possible in order to obtain an overview on the efficiencies of the existing models. The size of visible plumes were calculated by means of emission data and ambient data and were compared with those dimensions resulting from photograph. The models and the results are described in individual reports. Results were summarized for B models. Complete data on the 16'Philippsburg incidents' are contained in the annex to the program report. (orig./HP) [de

  11. Optimization of fog inlet air cooling system for combined cycle power plants using genetic algorithm

    International Nuclear Information System (INIS)

    Ehyaei, Mehdi A.; Tahani, Mojtaba; Ahmadi, Pouria; Esfandiari, Mohammad

    2015-01-01

    In this research paper, a comprehensive thermodynamic modeling of a combined cycle power plant is first conducted and the effects of gas turbine inlet fogging system on the first and second law efficiencies and net power outputs of combined cycle power plants are investigated. The combined cycle power plant (CCPP) considered for this study consist of a double pressure heat recovery steam generator (HRSG) to utilize the energy of exhaust leaving the gas turbine and produce superheated steam to generate electricity in the Rankine cycle. In order to enhance understanding of this research and come up with optimum performance assessment of the plant, a complete optimization is using a genetic algorithm conducted. In order to achieve this goal, a new objective function is defined for the system optimization including social cost of air pollution for the power generation systems. The objective function is based on the first law efficiency, energy cost and the external social cost of air pollution for an operational system. It is concluded that using inlet air cooling system for the CCPP system and its optimization results in an increase in the average output power, first and second law efficiencies by 17.24%, 3.6% and 3.5%, respectively, for three warm months of year. - Highlights: • To model the combined cycle power plant equipped with fog inlet air cooling method. • To conduct both exergy and economic analyses for better understanding. • To conduct a complete optimization using a genetic algorithm to determine the optimal design parameters of the system

  12. Entrainment and impingement of aquatic fauna at cooling water system of Madras Atomic Power Station (MAPS)

    International Nuclear Information System (INIS)

    Barath Kumar, S.; Das, N.P.I.; Satpathy, K.K.

    2015-01-01

    Marine organisms get impinged to the intake screens of Madras Atomic Power Station (MAPS) due to the suction force of the cooling water system of the power plant. The present work has studied the loss of aquatic organism at MAPS due to impingement at cooling water screens. In total 67 species of marine faunas impinged on the water intake screens of MAPS during the study. The proportion of fish, shrimp, crab, jellyfish and others, with respect to the total biomass of impinged organisms are 1.59 % (33 species), 0.30% (9), 2.77 % (16), 95.10% (3) and 0.24% (4), respectively. Jellyfishes were observed to be the largest entrained group covering around 44.85% of individual and constituting almost 94.82 % of biomass recorded during the study period and sea nettle jelly (Chrysaora quinquecirrha) was impinged with highest frequency. The diel study shows higher impingement occurred during night time, on full moon day and at low tides in contrast to their counterparts. Fishes accounts for 14.84 % of individual count and mere 1.67 % of biomass. Totally 33 number of fish species were observed. The highest impinged species were pony fishes (Secutor ruconius, Secutor insidiator, Photopectoralis bindus, Alepes kleinii and Leiognathus equulus) (21% occurrence). These few entrained fishes are mostly very small in size and have less commercial value. The total loss of marine fauna by impingement during study period was estimated to be 4779 (or 463.46 kg). The present data when compared with the impingement data from other coastal power plants, shows that the impinged fish biomass at MAPS cooling water system is much less than the other temperate and tropical power plants. (author)

  13. The development of emergency core cooling systems in the PWR, BWR, and HWR Candu type of nuclear power plants

    International Nuclear Information System (INIS)

    Mursid Djokolelono.

    1976-01-01

    Emergency core cooling systems in the PWR, BWR, and HWR-Candu type of nuclear power plant are reviewed. In PWR and BWR the emergency cooling can be catagorized as active high pressure, active low pressure, and a passive one. The PWR uses components of the shutdown cooling system: whereas the BWR uses components of pressure suppression contaiment. HWR Candu also uses the shutdown cooling system similar to the PWR except some details coming out from moderator coolant separation and expensive cost of heavy water. (author)

  14. Cooling Tower Optimization A Simple Way to Generate Green Megawatts and to Increase the Efficiency of a Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Strohmer, F.

    2014-07-01

    The profitability of nuclear power plants is worldwide challenged by low electricity prices. One hand low cost shale gas is offering a low price electricity production , other hand additional taxes on fuel are reducing the operating income of nuclear power stations. The optimization of cooling towers can help to increase the efficiency and profit of a nuclear power plant. (Author)

  15. ANN based optimization of a solar assisted hybrid cooling system in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ozgur, Arif; Yetik, Ozge; Arslan, Oguz [Mechanical Eng. Dept., Engineering Faculty, Dumlupinar University (Turkey)], email: maozgur@dpu.edu.tr, email: ozgeyetik@dpu.edu.tr, email: oarslan@dpu.edu.tr

    2011-07-01

    This study achieved optimization of a solar assisted hybrid cooling system with refrigerants such as R717, R141b, R134a and R123 using an artificial neural network (ANN) model based on average total solar radiation, ambient temperature, generator temperature, condenser temperature, intercooler temperature and fluid types. ANN is a new tool; it works rapidly and can thus be a solution for design and optimization of complex power cycles. A unique flexible ANN algorithm was introduced to evaluate the solar ejector cooling systems because of the nonlinearity of neural networks. The conclusion was that the best COPs value obtained with the ANN is 1.35 and COPc is 3.03 when the average total solar radiation, ambient temperature, generator temperature, condenser temperature, intercooler temperature and algorithm are respectively 674.72 W/m2, 17.9, 80, 15 and 13 degree celsius and LM with 14 neurons in single hidden layer, for R717.

  16. Natural circulation in water cooled nuclear power plants: Phenomena, models, and methodology for system reliability assessments

    International Nuclear Information System (INIS)

    2005-11-01

    In recent years it has been recognized that the application of passive safety systems (i.e. those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. Further, the IAEA Conference on The Safety of Nuclear Power: Strategy for the Future which was convened in 1991 noted that for new plants 'the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate'. Considering the weak driving forces of passive systems based on natural circulation, careful design and analysis methods must be employed to assure that the systems perform their intended functions. To support the development of advanced water cooled reactor designs with passive systems, investigations of natural circulation are an ongoing activity in several IAEA Member States. Some new designs also utilize natural circulation as a means to remove core power during normal operation. In response to the motivating factors discussed above, and to foster international collaboration on the enabling technology of passive systems that utilize natural circulation, an IAEA Coordinated Research Project (CRP) on Natural Circulation Phenomena, Modelling and Reliability of Passive Systems that Utilize Natural Circulation was started in early 2004. Building on the shared expertise within the CRP, this publication presents extensive information on natural circulation phenomena, models, predictive tools and experiments that currently support design and analyses of natural circulation systems and highlights areas where additional research is needed. Therefore, this publication serves both to provide a description of the present state of knowledge on natural circulation in water cooled nuclear power plants and to guide the planning and conduct of the CRP in

  17. Exergy Flows inside a One Phase Ejector for Refrigeration Systems

    Directory of Open Access Journals (Sweden)

    Mohammed Khennich

    2016-03-01

    Full Text Available The evaluation of the thermodynamic performance of the mutual transformation of different kinds of exergy linked to the intensive thermodynamic parameters of the flow inside the ejector of a refrigeration system is undertaken. Two thermodynamic metrics, exergy produced and exergy consumed, are introduced to assess these transformations. Their calculation is based on the evaluation of the transiting exergy within different ejector sections taking into account the temperature, pressure and velocity variations. The analysis based on these metrics has allowed pinpointing the most important factors affecting the ejector’s performance. A new result, namely the temperature rise in the sub-environmental region of the mixing section is detected as an important factor responsible for the ejector’s thermodynamic irreversibility. The overall exergy efficiency of the ejector as well as the efficiencies of its sections are evaluated based on the proposed thermodynamic metrics.

  18. Design of an ejector cycle refrigeration system

    International Nuclear Information System (INIS)

    Grazzini, G.; Milazzo, A.; Paganini, D.

    2012-01-01

    Highlights: ► A design procedure is presented for an ejection refrigeration system. ► Properties of applicable operating fluids are presented and R245fa is selected. ► Real gas properties are used. ► The diffuser is designed with a profile that controls momentum change. ► Fluid friction is accounted for along all main components. - Abstract: A design procedure, based on a one-dimensional simulation, is presented for an ejection refrigeration system. Heat exchangers are included in the calculation, accounting for temperature differences between the fluids and for pressure losses. The ideal gas assumption, which is quite common in the literature concerning ejector systems, is avoided. Furthermore, the supersonic diffuser is designed with a continuous profile, without cylindrical piece, controlling the variation of momentum along the flow path and accounting for friction. At design conditions, this should reduce the irreversibility due to the normal shock. A comparison between different operating fluids is presented and R245fa is selected. The results of the design procedure and the expected performance, in terms of first and second law efficiency, are presented.

  19. Formation of secondary inorganic aerosols by power plant emissions exhausted through cooling towers in Saxony.

    Science.gov (United States)

    Hinneburg, Detlef; Renner, Eberhard; Wolke, Ralf

    2009-01-01

    The fraction of ambient PM10 that is due to the formation of secondary inorganic particulate sulfate and nitrate from the emissions of two large, brown-coal-fired power stations in Saxony (East Germany) is examined. The power stations are equipped with natural-draft cooling towers. The flue gases are directly piped into the cooling towers, thereby receiving an additionally intensified uplift. The exhausted gas-steam mixture contains the gases CO, CO2, NO, NO2, and SO2, the directly emitted primary particles, and additionally, an excess of 'free' sulfate ions in water solution, which, after the desulfurization steps, remain non-neutralized by cations. The precursor gases NO2 and SO2 are capable of forming nitric and sulfuric acid by several pathways. The acids can be neutralized by ammonia and generate secondary particulate matter by heterogeneous condensation on preexisting particles. The simulations are performed by a nested and multi-scale application of the online-coupled model system LM-MUSCAT. The Local Model (LM; recently renamed as COSMO) of the German Weather Service performs the meteorological processes, while the Multi-scale Atmospheric Transport Model (MUSCAT) includes the transport, the gas phase chemistry, as well as the aerosol chemistry (thermodynamic ammonium-sulfate-nitrate-water system). The highest horizontal resolution in the inner region of Saxony is 0.7 km. One summer and one winter episode, each realizing 5 weeks of the year 2002, are simulated twice, with the cooling tower emissions switched on and off, respectively. This procedure serves to identify the direct and indirect influences of the single plumes on the formation and distribution of the secondary inorganic aerosols. Surface traces of the individual tower plumes can be located and distinguished, especially in the well-mixed boundary layer in daytime. At night, the plumes are decoupled from the surface. In no case does the resulting contribution of the cooling tower emissions to PM10

  20. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    Energy Technology Data Exchange (ETDEWEB)

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to

  1. Experimental study on the thermal management of high-power LED headlight cooling device integrated with thermoelectric cooler package

    International Nuclear Information System (INIS)

    Wang, Jing; Zhao, Xin-Jie; Cai, Yi-Xi; Zhang, Chun; Bao, Wei-Wei

    2015-01-01

    Highlights: • A novel TEC cooling system for multi-chip LED module was successfully developed. • Influences of liquid velocity on the system thermal performance were investigated. • TEC system is more sensitive to the input current than that of the mere air cooling. • The junction temperature can be maintained below 61.8 °C (liquid cooling & TEC). - Abstract: In view of the characteristics of high power light-emitting diodes (LEDs), such as strict junction temperature (T j ) control, the enhanced cooling models based on the thermoelectric cooler (TEC) were presented to meet the thermal demand of high-power LED headlight. The cooling performance of different devices (air cooling & TEC, liquid cooling & TEC) was evaluated and compared by measuring the LED case temperature. Details of the heat transfer performance, particularly, the start-up performances of the TEC cooler, as well as the influence of the fan rotate speed or liquid velocity on the system thermal performance were obtained. It was found that the thermal performance had been elevated dramatically due to the reduction of the hot side temperature, and the thermoelectric cooler was more sensitive to the external fan speed or liquid velocity than purely air cooling or liquid cooling. In addition, the optimal current for air cooling & TEC was 3A, and 5A for liquid cooling + TEC. Investigations of the simulated ambient temperature on junction temperature, forward voltage, and output light were conducted. Results indicated that the case temperature changed linear basically with the increase in heating power or the simulated ambient temperature. When the ambient temperature was within its severe level (60–65 °C), the junction temperature could be calculated to 59.5 °C, and the corresponding output light was 1607.3 lm

  2. Computational study of variable area ejector rocket flowfields

    Science.gov (United States)

    Etele, Jason

    Access to space has always been a scientific priority for countries which can afford the prohibitive costs associated with launch. However, the large scale exploitation of space by the business community will require the cost of placing payloads into orbit be dramatically reduced for space to become a truly profitable commodity. To this end, this work focuses on a next generation propulsive technology called the Rocket Based Combined Cycle (RBCC) engine in which rocket, ejector, ramjet, and scramjet cycles operate within the same engine environment. Using an in house numerical code solving the axisymmetric version of the Favre averaged Navier Stokes equations (including the Wilcox ko turbulence model with dilatational dissipation) a systematic study of various ejector designs within an RBCC engine is undertaken. It is shown that by using a central rocket placed along the axisymmetric axis in combination with an annular rocket placed along the outer wall of the ejector, one can obtain compression ratios of approximately 2.5 for the case where both the entrained air and rocket exhaust mass flows are equal. Further, it is shown that constricting the exit area, and the manner in which this constriction is performed, has a significant positive impact on the compression ratio. For a decrease in area of 25% a purely conical ejector can increase the compression ratio by an additional 23% compared to an equal length unconstricted ejector. The use of a more sharply angled conical section followed by a cylindrical section to maintain equivalent ejector lengths can further increase the compression ratio by 5--7% for a total increase of approximately 30%.

  3. Response of unirradiated and irradiated PWR fuel rods tested under power-cooling-mismatch conditions

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Quapp, W.J.; Martinson, Z.R.; McCardell, R.K.; Mehner, A.S.

    1978-01-01

    This report summarizes the results from the single-rod power-cooling-mismatch (PCM) and irradiation effects (IE) tests conducted to date in the Power Burst Facility (PBF) at the U.S. DOE Idaho National Engineering Laboratory. This work was performed for the U.S. NRC under contact to the Department of Energy. These tests are part of the NRC Fuel Behavior Program, which is designed to provide data for the development and verification of analytical fuel behavior models that are used to predict fuel response to abnormal or postulated accident conditions in commercial LWRs. The mechanical, chemical and thermal response of both previously unirradiated and previously irradiated LWR-type fuel rods tested under power-cooling-mismatch condition is discussed. A brief description of the test designs is presented. The results of the PCM thermal-hydraulic studies are summarized. Primary emphasis is placed on the behavior of the fuel and cladding during and after stable film boiling. (orig.) [de

  4. Custom ceramic microchannel-cooled array for high-power fiber-coupled application

    Science.gov (United States)

    Junghans, Jeremy; Feeler, Ryan; Stephens, Ed

    2018-03-01

    A low-SWaP (Size, Weight and Power) diode array has been developed for a high-power fiber-coupled application. High efficiency ( 65%) diodes enable high optical powers while minimizing thermal losses. A large amount of waste heat is still generated and must be extracted. Custom ceramic microchannel-coolers (MCCs) are used to dissipate the waste heat. The custom ceramic MCC was designed to accommodate long cavity length diodes and micro-lenses. The coolers provide similar thermal performance as copper MCCs however they are not susceptible to erosion and can be cooled with standard filtered water. The custom ceramic micro-channel cooled array was designed to be a form/fit replacement for an existing copperbased solution. Each array consisted of three-vertically stacked MCCs with 4 mm CL, 976 nm diodes and beamshaping micro-optics. The erosion and corrosion resistance of ceramic array is intended to mitigate the risk of copperbased MCC corrosion failures. Elimination of the water delivery requirements (pH, resistivity and dissolved oxygen control) further reduces the system SWaP while maintaining reliability. The arrays were fabricated and fully characterized. This work discusses the advantages of the ceramic MCC technology and describes the design parameters that were tailored for the fiber-coupled application. Additional configuration options (form/fit, micro-lensing, alternate coolants, etc.) and on-going design improvements are also discussed.

  5. Feasibility of maintaining natural convection mode core cooling in research reactor power upgrades

    International Nuclear Information System (INIS)

    Ha, J.J.; Belhadj, M.; Aldemir, T.; Christensen, R.N.

    1987-01-01

    Two operational concerns for natural convection coooled research reactors using plate type fuels are: 1) pool top 16 N activity (PTNA), and 2) nucleate boiling in core channels. The feasibility assessment of a power upgrade while maintaining natural convection mode core cooling requires addressing these operational concerns. Previous studies have shown that: a) The conventional technique for reducing PTNA by plume dispersion may not be effective in a large power upgrade of research reactors with small pools. b) Currently used correlations to predict onset of nucleate boiling (ONB) in thin, rectangular core channels are not valid for low-velocity, upward flows such as encountered in natural convection cooling. The PTNA depends on the velocity distribution in the reactor pool. COMMIX-1A code is used to determine the three-dimensional velocity fields in The Ohio State University Research Reactor (OSURR) pool as a function of varying design conditions, following a power upgrade to 500 kW with LEU fuel. It is shown that a sufficiently deep stagnant water layer can be created below the pool top by properly choosing the disperser flow rate. The ONB heat flux is experimentally determined for channel gaps and upward flow velocities in the range 2mm-4mm and 3-16 cm/sec., respectively. Two alternatives to plume dispersion for reducing PTNA and a new correlation to determine the ONB heat flux in thin, rectangular channels under low-velocity, upward flow conditions are proposed. (Author)

  6. Enhancement of energy performance in a boil-off gas re-liquefaction system of LNG carriers using ejectors

    International Nuclear Information System (INIS)

    Tan, Hongbo; Zhao, Qingxuan; Sun, Nannan; Li, Yanzhong

    2016-01-01

    Highlights: • An ejector-enhanced LNG boil-off gas (BOG) re-liquefaction system is proposed. • The new system has an improvement of 28% in COP over the existing system. • The specific energy consumption of the new system is reduced to 0.59 kW h/kg(BOG). • The power consumption of 754.1 kW is saved in the case study. - Abstract: An ejector-enhanced Liquefied Natural Gas (LNG) boil-off gas (BOG) re-liquefaction system is proposed to improve the energy efficiency of the existing system. In the new system, two ejectors are respectively used to reduce the energy loss in the expansion of the pressurized BOG and inject a part of fuel BOG into the compression system, and a recuperator is employed to recover the cold energy of the BOG exited from LNG tank. The performance improvement of the proposed system is analysed on the basis of the simulation in Aspen HYSYS. In the case of the re-liquefaction capacity of 4557.6 kg/h, the coefficient of performance (COP) and exergy efficiency can be increased by 28%, and the specific energy consumption (SEC) reduced from 0.756 to 0.59 kW h/kg(BOG) compared to the conventional BOG re-liquefaction system. Correspondingly, the power consumption of 754.1 kW is saved. This means that applying ejectors can effectively improve the energy efficiency of the existing BOG re-liquefaction system for LNG carriers.

  7. Air ejector augmented compressed air energy storage system

    Science.gov (United States)

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  8. Liquid metal versus gas cooled reactor concepts for a turbo electric powered space vehicle

    International Nuclear Information System (INIS)

    Carre, F.; Proust, E.; Schwartz, J.P.

    1985-01-01

    Recent CNES/CEA prospective studies of an orbit transfer vehicule to be launched by ARIANE V, emphasize the advantage of the Brayton cycle over the thermionics and thermoelectricity, in minimizing the total mass of 100 to 300 kWsub(e) power systems under the constraint specific to ARIANE of a radiator area limited to 95 m 2 . The review of candidate reactor concepts for this application, finally recommends both liquid metal and gas cooled reactors, for their satisfactory adaptation to a reference Brayton cycle and for the available experience from the terrestrial operation of comparable systems

  9. Steam generator tube performance: experience with water-cooled nuclear power reactors during 1978

    International Nuclear Information System (INIS)

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

    1980-02-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1978. Tube failures occurred at 31 of the 86 reactors surveyed. Causes of these failures and procedures designed to deal with them are described. A dramatic decrease in the number of tubes plugged was evident in 1978 compared to the previous year. This is attributed to diligent application of techniques developed from in-plant experience and research and development programs over the past several years. (auth)

  10. Outbreak of legionnaires' disease from a cooling water system in a power station (Heysham)

    International Nuclear Information System (INIS)

    Morton, S.; Dyer, J.V.; Bartlett, C.L.R.; Bibby, L.F.; Hutchinson, D.N.; Dennis, P.J.

    1986-01-01

    In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures. (author)

  11. Boost Converter Fed High Performance BLDC Drive for Solar PV Array Powered Air Cooling System

    Directory of Open Access Journals (Sweden)

    Shobha Rani Depuru

    2017-01-01

    Full Text Available This paper proposes the utilization of a DC-DC boost converter as a mediator between a Solar Photovoltaic (SPV array and the Voltage Source Inverters (VSI in an SPV array powered air cooling system to attain maximum efficiency. The boost converter, over the various common DC-DC converters, offers many advantages in SPV based applications. Further, two Brushless DC (BLDC motors are employed in the proposed air cooling system: one to run the centrifugal water pump and the other to run a fan-blower. Employing a BLDC motor is found to be the best option because of its top efficiency, supreme reliability and better performance over a wide range of speeds. The air cooling system is developed and simulated using the MATLAB/Simulink environment considering the steady state variation in the solar irradiance. Further, the efficiency of BLDC drive system is compared with a conventional Permanent Magnet DC (PMDC motor drive system and from the simulated results it is found that the proposed system performs better.

  12. The effects of age on nuclear power plant containment cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A. [Brookhaven National Lab., Upton, NY (United States); Davis, J. [Science Applications International Corp., New York, NY (United States)

    1994-04-01

    A study was performed to assess the effects of aging on the performance and availability of containment cooling systems in US commercial nuclear power plants. This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. The effects of age were characterized for the containment cooling system by reviewing and analyzing failure data from national databases, as well as plant-specific data. The predominant failure causes and aging mechanisms were identified, along with the components that failed most frequently. Current inspection, surveillance, and monitoring practices were also examined. A containment cooling system unavailability analysis was performed to examine the potential effects of aging by increasing failure rates for selected components. A commonly found containment spray system design and a commonly found fan cooler system design were modeled. Parametric failure rates for those components in each system that could be subject to aging were accounted for in the model to simulate the time-dependent effects of aging degradation, assuming no provisions are made to properly manage it. System unavailability as a function of increasing component failure rates was then calculated.

  13. Economic analysis of multiple-module high temperature gas-cooled reactor (MHTR) nuclear power plants

    International Nuclear Information System (INIS)

    Liu Yu; Dong Yujie

    2011-01-01

    In recent years, as the increasing demand of energy all over the world, and the pressure on greenhouse emissions, there's a new opportunity for the development of nuclear energy. Modular High Temperature Gas-cooled Reactor (MHTR) received recognition for its inherent safety feature and high outlet temperature. Whether the Modular High Temperature Gas-cooled Reactor would be accepted extensively, its economy is a key point. In this paper, the methods of qualitative analysis and the method of quantitative analysis, the economic models designed by Economic Modeling Working Group (EMWG) of the Generation IV International Forum (GIF), as well as the HTR-PM's main technical features, are used to analyze the economy of the MHTR. A prediction is made on the basis of summarizing High Temperature Gas-cooled Reactor module characteristics, construction cost, total capital cost, fuel cost and operation and maintenance (O and M) cost and so on. In the following part, comparative analysis is taken measures to the economy and cost ratio of different designs, to explore the impacts of modularization and standardization on the construction of multiple-module reactor nuclear power plant. Meanwhile, the analysis is also adopted in the research of key factors such as the learning effect and yield to find out their impacts on the large scale development of MHTR. Furthermore, some reference would be provided to its wide application based on these analysis. (author)

  14. The effects of age on nuclear power plant containment cooling systems

    International Nuclear Information System (INIS)

    Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A.; Davis, J.

    1994-04-01

    A study was performed to assess the effects of aging on the performance and availability of containment cooling systems in US commercial nuclear power plants. This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. The effects of age were characterized for the containment cooling system by reviewing and analyzing failure data from national databases, as well as plant-specific data. The predominant failure causes and aging mechanisms were identified, along with the components that failed most frequently. Current inspection, surveillance, and monitoring practices were also examined. A containment cooling system unavailability analysis was performed to examine the potential effects of aging by increasing failure rates for selected components. A commonly found containment spray system design and a commonly found fan cooler system design were modeled. Parametric failure rates for those components in each system that could be subject to aging were accounted for in the model to simulate the time-dependent effects of aging degradation, assuming no provisions are made to properly manage it. System unavailability as a function of increasing component failure rates was then calculated

  15. Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

    Energy Technology Data Exchange (ETDEWEB)

    Apfelbaum, Steven L. [Applied Ecological Services Inc., Brodhead, WI (United States); Duvall, Kenneth W. [Sterling Energy Services, LLC, Atlanta, GA (United States); Nelson, Theresa M. [Applied Ecological Services Inc., Brodhead, WI (United States); Mensing, Douglas M. [Applied Ecological Services Inc., Brodhead, WI (United States); Bengtson, Harlan H. [Sterling Energy Services, LLC, Atlanta, GA (United States); Eppich, John [Waterflow Consultants, Champaign, IL (United States); Penhallegon, Clayton [Sterling Energy Services, LLC, Atlanta, GA (United States); Thompson, Ry L. [Applied Ecological Services Inc., Brodhead, WI (United States)

    2013-12-01

    Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive

  16. Mathematical Modeling – The Impact of Cooling Water Temperature Upsurge on Combined Cycle Power Plant Performance and Operation

    Science.gov (United States)

    Indra Siswantara, Ahmad; Pujowidodo, Hariyotejo; Darius, Asyari; Ramdlan Gunadi, Gun Gun

    2018-03-01

    This paper presents the mathematical modeling analysis on cooling system in a combined cycle power plant. The objective of this study is to get the impact of cooling water upsurge on plant performance and operation, using Engineering Equation Solver (EES™) tools. Power plant installed with total power capacity of block#1 is 505.95 MWe and block#2 is 720.8 MWe, where sea water consumed as cooling media at two unit condensers. Basic principle of analysis is heat balance calculation from steam turbine and condenser, concern to vacuum condition and heat rate values. Based on the result shown graphically, there were impact the upsurge of cooling water to increase plant heat rate and vacuum pressure in condenser so ensued decreasing plant efficiency and causing possibility steam turbine trip as back pressure raised from condenser.

  17. Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System.

    Science.gov (United States)

    Lee, Chengming; Chen, Rongshun

    2015-05-20

    Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.

  18. Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System

    Directory of Open Access Journals (Sweden)

    Chengming Lee

    2015-05-01

    Full Text Available Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID controller, combining a PID neural network (PIDNN with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server’s fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.

  19. Thermal tests of large recirculation cooling installations for nuclear power plants

    Science.gov (United States)

    Balunov, B. F.; Lychakov, V. D.; Il'in, V. A.; Shcheglov, A. A.; Maslov, O. P.; Rasskazova, N. A.; Rakhimov, R. Z.; Boyarov, R. A.

    2017-11-01

    The article presents the results from thermal tests of some recirculation installations for cooling air in nuclear power plant premises, including the volume under the containment. The cooling effect in such installations is produced by pumping water through their heat-transfer tubes. Air from the cooled room is blown by a fan through a bundle of transversely finned tubes and is removed to the same room after having been cooled. The finning of tubes used in the tested installations was made of Grade 08Kh18N10T and Grade 08Kh18N10 stainless steels or Grade AD1 aluminum. Steel fins were attached to the tube over their entire length by means of high-frequency welding. Aluminum fins were extruded on a lathe from the external tube sheath into which a steel tube had preliminarily been placed. Although the fin extrusion operation was accompanied by pressing the sheath inner part to the steel tube, tight contact between them over the entire surface was not fully achieved. In view of this, the air gap's thermal resistance coefficient was introduced in calculating the heat transfer between the heat-transferring media. The air gap average thickness was determined from the test results taking into account the gap variation with temperature due to different linear expansion coefficients of steel and aluminum. These tests, which are part of the acceptance tests of the considered installations, were carried out at the NPO TsKTI test facility and were mainly aimed at checking if the obtained thermal characteristics were consistent with the values calculated according to the standard recommendations with introduction, if necessary, of modifications to those recommendations.

  20. Performance analysis of ejector absorption heat pump using ozone safe fluid couple through artificial neural networks

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol; Oezalp, Mehmet

    2004-01-01

    Thermodynamic analysis of absorption thermal systems is too complex because the analytic functions calculating the thermodynamic properties of fluid couples involve the solution of complex differential equations and simulation programs. This study aims at easing this complex situation and consists of three cases: (i) A special ejector, located at the absorber inlet, instead of the common location at the condenser inlet, to increase overall performance was used in the ejector absorption heat pump (EAHP). The ejector has two functions: Firstly, it aids the pressure recovery from the evaporator and then upgrades the mixing process and pre-absorption by the weak solution of the methanol coming from the evaporator. (ii) Use of artificial neural networks (ANNs) has been proposed to determine the properties of the liquid and two phase boiling and condensing of an alternative working fluid couple (methanol/LiCl), which does not cause ozone depletion. (iii) A comparative performance study of the EAHP was performed between the analytic functions and the values predicted by the ANN for the properties of the couple. The back propagation learning algorithm with three different variants and logistic sigmoid transfer function were used in the network. In order to train the neural network, limited experimental measurements were used as training and test data. In the input layer, there are temperature, pressure and concentration of the couples. Specific volume is in the output layer. After training, it was found that the maximum error was less than 3%, the average error was less than 1.2% and the R 2 values were about 0.9999. Additionally, in comparison of the analysis results between analytic equations obtained by using experimental data and by means of the ANN, the deviations of the refrigeration effectiveness of the system for cooling (COP r ), exergetic coefficient of performance of the system for cooling (ECOP r ) and circulation ratio (F) for all working temperatures were

  1. Cooling towers

    International Nuclear Information System (INIS)

    Boernke, F.

    1975-01-01

    The need for the use of cooling systems in power plant engineering is dealt with from the point of view of a non-polluting form of energy production. The various cooling system concepts up to the modern natural-draught cooling towers are illustrated by examples. (TK/AK) [de

  2. Wind tunnel experimental study on effect of inland nuclear power plant cooling tower on air flow and dispersion of pollutant

    International Nuclear Information System (INIS)

    Qiao Qingdang; Yao Rentai; Guo Zhanjie; Wang Ruiying; Fan Dan; Guo Dongping; Hou Xiaofei; Wen Yunchao

    2011-01-01

    A wind tunnel experiment for the effect of the cooling tower at Taohuajiang nuclear power plant on air flow and dispersion of pollutant was introduced in paper. Measurements of air mean flow and turbulence structure in different directions of cooling tower and other buildings were made by using an X-array hot wire probe. The effects of the cooling tower and its drift on dispersion of pollutant from the stack were investigated through tracer experiments. The results show that the effect of cooling tower on flow and dispersion obviously depends on the relative position of stack to cooling towers, especially significant for the cooling tower parallel to stack along wind direction. The variation law of normalized maximum velocity deficit and perturbations in longitudinal turbulent intensity in cooling tower wake was highly in accordance with the result of isolated mountain measured by Arya and Gadiyaram. Dispersion of pollutant in near field is significantly enhanced and plume trajectory is changed due to the cooling towers and its drift. Meanwhile, the effect of cooling tower on dispersion of pollutant depends on the height of release. (authors)

  3. Diffusion-cooled high-power single-mode waveguide CO2 laser for transmyocardial revascularization

    Science.gov (United States)

    Berishvili, I. I.; Bockeria, L. A.; Egorov, E. N.; Golubev, Vladimir S.; Galushkin, Michail G.; Kheliminsky, A. A.; Panchenko, Vladislav Y.; Roshin, A. P.; Sigaev, I. Y.; Vachromeeva, M. N.; Vasiltsov, Victor V.; Yoshina, V. I.; Zabelin, Alexandre M.; Zelenov, Evgenii V.

    1999-01-01

    The paper presents the results on investigations and development of multichannel waveguide CO2 laser with diffusion cooling of active medium excited by discharge of audio-frequency alternating current. The description of high-power single-mode CO2 laser with average beam power up to 1 kW is presented. The result of measurement of the laser basic parameters are offered, as well as the outcomes of performances of the laser head with long active zone, operating in waveguide mode. As an example of application of these laser, various capabilities a description of the developed medical system 'Genom' used in the transmyocardial laser revascularization (TMLR) procedure and clinical results of the possibilities of the TMLR in the surgical treatment are presented.

  4. Gas cooled solar tower power plant (GAST) KWU approach to a 20 MW hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Martin

    1980-07-01

    The gas cooled solar tower powerplant with a hybrid solar-fossil heating system in the form given here represents a significant step towards the industrial use of solar energy. The transition from fossil fuels to solar energy can be facilitated for the power plant operators if the transition is gradual and if conventional technology is used. Using solar energy and with a turbine inlet temperature of 800/sup 0/C the GAST power plant reaches an output of approximately 20 MW and a thermal efficiency of approximately 40% reference to the heat supplied by the receiver. In the absence of solar radiation the plant can be operated exclusively on fossil fuel. Increasing the turbine inlet temperature to 1000/sup 0/C enables an efficiency of about 47% to be reached in the GUD cycle.

  5. Effect of cooling tower vapours on agriculture in the environment of power plants

    International Nuclear Information System (INIS)

    Seemann, J.

    1976-01-01

    The effect of cooling tower vapours according to investigations made so far are mainly noticeable regarding solar radiation, and this is practically merely in the immediate neighbourhood of the power plant. The effective influence on photosynthesis should be hardly detectable even in this limited area around the power plant. The effect on the temperature is minimum, the influence on the relative moisture is so small that it lies within the margin of error of measuring, with the exception of the few cases in which the vapours are pressed down to the ground. One need not reckon with an increased fungoid growth and bad drying conditions. Rainfall could be additionally increased if the weather situation is likely to rain or if it is raining anyway. Regarding fog frequency, one may assume that there might be a certain increase in fog. So far no cases are known in which fog would occur where there is no general tendency for fog formation. (orig.) [de

  6. R744 ejector technology future perspectives

    Science.gov (United States)

    Hafner, Armin; Banasiak, Krzysztof

    2016-09-01

    Carbon Dioxide, CO2 (R744) was one of the first commonly applied working fluids in the infancy of refrigeration more than 100 years ago. In contrast to ammonia it mainly disappeared after the first generation of synthetic refrigerants have been introduced to the market after 1930. One reason was that the transition from low-rpm belt driven compressors towards the direct electrical motor driven compressors (50-60 Hz) was not performed for CO2 compressors before the revival introduced by Gustav Lorentzen in the 90is of last century. Since 1988 an enormous R & D effort has been made to further develop CO2 refrigeration technology in spite of the opposition from the chemical industry. Today CO2 refrigeration and heat pumping technologies are accepted as viable and sustainable alternatives for several applications like commercial refrigeration, transport refrigeration, vehicle air conditioning & heat pumping, domestic hot water heat pumps and industrial applications. For some applications, the current threshold to introduce R744 technology can be overcome when the system design takes into account the advantage of the thermo dynamical- and fluid properties of CO2. I.e. the system is designed for transcritical operation with all it pros and cons and takes into consideration how to minimize the losses, and to apply the normally lost expansion work. Shortcut-designs, i.e. drop in solutions, just replacing the H(C)FC refrigeration unit with an CO2 systems adapted for higher system pressures will not result in energy efficient products. CO2 systems do offer the advantage of enabling flooded evaporators supported with adapted ejector technology. These units offer high system performances at low temperature differences and show low temperature air mal-distributions across evaporators. This work gives an overview for the development possibilities for several applications during the next years. Resulting in a further market share increase of CO2 refrigeration and heat pump

  7. Method for controlling a coolant liquid surface of cooling system instruments in an atomic power plant

    International Nuclear Information System (INIS)

    Monta, Kazuo.

    1974-01-01

    Object: To prevent coolant inventory within a cooling system loop in an atomic power plant from being varied depending on loads thereby relieving restriction of varied speed of coolant flow rate to lowering of a liquid surface due to short in coolant. Structure: Instruments such as a superheater, an evaporator, and the like, which constitute a cooling system loop in an atomic power plant, have a plurality of free liquid surface of coolant. Portions whose liquid surface is controlled and portions whose liquid surface is varied are adjusted in cross-sectional area so that the sum total of variation in coolant inventory in an instrument such as a superheater provided with an annulus portion in the center thereof and an inner cylindrical portion and a down-comer in the side thereof comes equal to that of variation in coolant inventory in an instrument such as an evaporator similar to the superheater. which is provided with an overflow pipe in its inner cylindrical portion or down-comer, thereby minimizing variation in coolant inventory of the entire coolant due to loads thus minimizing variation in varied speed of the coolant. (Kamimura, M.)

  8. Thermodynamic performance analysis and optimization of a solar-assisted combined cooling, heating and power system

    International Nuclear Information System (INIS)

    Wang, Jiangjiang; Lu, Yanchao; Yang, Ying; Mao, Tianzhi

    2016-01-01

    This study aims to present a thermodynamic performance analysis and to optimize the configurations of a hybrid combined cooling, heating and power (CCHP) system incorporating solar energy and natural gas. A basic natural gas CCHP system containing a power generation unit, a heat recovery system, an absorption cooling system and a storage tank is integrated with solar photovoltaic (PV) panels and/or a heat collector. Based on thermodynamic modeling, the thermodynamic performance, including energy and exergy efficiencies, under variable work conditions, such as electric load factor, solar irradiance and installation ratio, of the solar PV panels and heat collector is investigated and analyzed. The results of the energy supply side analysis indicate that the integration of solar PV into the CCHP system more efficiently improves the exergy efficiency, whereas the integration of a solar heat collector improves the energy efficiency. To match the building loads, the optimization method combined with the operation strategy is employed to optimize the system configurations to maximize the integrated benefits of energy and economic costs. The optimization results of demand–supply matching demonstrate that the integration of a solar heat collector achieves a better integrated performance than the solar PV integration in the specific case study. - Highlights: • Design a CCHP system integrated with solar PV and heat collector. • Present the energy and exergy analyses under variable work conditions. • Propose an optimization method of CCHP system for demand-supply matching.

  9. Numerical Hydraulic Study on Seawater Cooling System of Combined Cycle Power Plant

    Science.gov (United States)

    Kim, J. Y.; Park, S. M.; Kim, J. H.; Kim, S. W.

    2010-06-01

    As the rated flow and pressure increase in pumping facilities, a proper design against surges and severe cavitations in the pipeline system is required. Pressure surge due to start-up, shut-down process and operation failure causes the water hammer in upstream of the closing valve and the cavitational hammer in downstream of the valve. Typical cause of water hammer is the urgent closure of valves by breakdown of power supply and unexpected failure of pumps. The abrupt changes in the flow rate of the liquid results in high pressure surges in upstream of the valves, thus kinetic energy is transformed into potential energy which leads to the sudden increase of the pressure that is called as water hammer. Also, by the inertia, the liquid continues to flow downstream of the valve with initial speed. Accordingly, the pressure decreases and an expanding vapor bubble known as column separation are formed near the valve. In this research, the hydraulic study on the closed cooling water heat exchanger line, which is the one part of the power plant, is introduced. The whole power plant consists of 1,200 MW combined power plant and 220,000 m3/day desalination facility. Cooling water for the plant is supplied by sea water circulating system with a capacity of 29 m3/s. The primary focus is to verify the steady state hydraulic capacity of the system. The secondary is to quantify transient issues and solutions in the system. The circuit was modeled using a commercial software. The stable piping network was designed through the hydraulic studies using the simulation for the various scenarios.

  10. TWO-PHASE EJECTOR of CARBON DIOXIDE HEAT PUMP CALCULUS

    Directory of Open Access Journals (Sweden)

    Sit B.M.

    2010-12-01

    Full Text Available It is presented the calculus of the two-phase ejector for carbon dioxide heat pump. The method of calculus is based on the method elaborated by S.M. Kandil, W.E. Lear, S.A. Sherif, and is modified taking into account entrainment ratio as the input for the calculus.

  11. A Multidisciplinary Approach to Mixer-Ejector Analysis and Design

    Science.gov (United States)

    Hendricks, Eric, S.; Seidel, Jonathan, A.

    2012-01-01

    The design of an engine for a civil supersonic aircraft presents a difficult multidisciplinary problem to propulsion system engineers. There are numerous competing requirements for the engine, such as to be efficient during cruise while yet quiet enough at takeoff to meet airport noise regulations. The use of mixer-ejector nozzles presents one possible solution to this challenge. However, designing a mixer-ejector which will successfully address both of these concerns is a difficult proposition. Presented in this paper is an integrated multidisciplinary approach to the analysis and design of these systems. A process that uses several low-fidelity tools to evaluate both the performance and acoustics of mixer-ejectors nozzles is described. This process is further expanded to include system-level modeling of engines and aircraft to determine the effects on mission performance and noise near airports. The overall process is developed in the OpenMDAO framework currently being developed by NASA. From the developed process, sample results are given for a notional mixer-ejector design, thereby demonstrating the capabilities of the method.

  12. Mechanical and experimental study on freeze proof solar powered adsorption cooling tube using active carbon/methanol working pair

    International Nuclear Information System (INIS)

    Zhao Huizhong; Zhang Min; Liu Zhenyan; Liu Yanling; Ma Xiaodong

    2008-01-01

    The freeze proof solar cooling tube, which can produce cooling capacity with the refrigerant temperature below 0 deg. C using solar light as energy and active carbon-methanol as working pair, was firstly designed and made in this research. This paper focused on mechanical and experimental study on a freeze proof solar powered adsorption cooling tube. The following experimental results could be concluded: at the solar radiation value between 15.3 and 17.1 MJ m -2 , the highest adsorbent bed temperature is below 110 deg. C. The freeze proof solar cooling tube's cooling capacity was about 87-99 kJ, and the coefficient of performance (COP) was more than 0.11 when the evaporation temperature was about -4 deg. C

  13. Passive safety systems and natural circulation in water cooled nuclear power plants

    International Nuclear Information System (INIS)

    2009-11-01

    Nuclear power produces 15% of the world's electricity. Many countries are planning to either introduce nuclear energy or expand their nuclear generating capacity. Design organizations are incorporating both proven means and new approaches for reducing the capital costs of their advanced designs. In the future most new nuclear plants will be of evolutionary design, often pursuing economies of scale. In the longer term, innovative designs could help to promote a new era of nuclear power. Since the mid-1980s it has been recognized that the application of passive safety systems (i.e. those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially improve economics of new nuclear power plant designs. The IAEA Conference on The Safety of Nuclear Power: Strategy for the Future, which was convened in 1991, noted that for new plants 'the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate'. Some new designs also utilize natural circulation as a means to remove core power during normal operation. The use of passive systems can eliminate the costs associated with the installation, maintenance, and operation of active systems that require multiple pumps with independent and redundant electric power supplies. However, considering the weak driving forces of passive systems based on natural circulation, careful design and analysis methods must be employed to ensure that the systems perform their intended functions. To support the development of advanced water cooled reactor designs with passive systems, investigations of natural circulation are conducted in several IAEA Member States with advanced reactor development programmes. To foster international collaboration on the enabling technology of passive systems that utilize natural circulation, the IAEA

  14. Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Verma, V., E-mail: vasudha.verma@physics.uu.se [Division of Applied Nuclear Physics, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-lez-Durance (France); Barbot, L.; Filliatre, P. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-lez-Durance (France); Hellesen, C. [Division of Applied Nuclear Physics, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Jammes, C. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-lez-Durance (France); Svärd, S. Jacobsson [Division of Applied Nuclear Physics, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)

    2017-07-11

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor. Diverse possibilities of detector system installation must be studied for various locations in the reactor vessel in order to detect any perturbations in the core. Results from a previous paper indicated that it is possible to detect changes in neutron source distribution initiated by an inadvertent withdrawal of outer control rod with in-vessel fission chambers located azimuthally around the core. It is, however, not possible to follow inner control rod withdrawal and precisely know the location of the perturbation in the core. Hence the use of complimentary in-core detectors coupled with the peripheral fission chambers is proposed to enable robust core monitoring across the radial direction. In this paper, we assess the feasibility of using self-powered neutron detectors (SPNDs) as in-core detectors in fast reactors for detecting local changes in the power distribution when the reactor is operated at nominal power. We study the neutron and gamma contributions to the total output current of the detector modelled with Platinum as the emitter material. It is shown that this SPND placed in an SFR-like environment would give a sufficiently measurable prompt neutron induced current of the order of 600 nA/m. The corresponding induced current in the connecting cable is two orders of magnitude lower and can be neglected. This means that the SPND can follow in-core power fluctuations. This validates the operability of an SPND in an SFR-like environment. - Highlights: • Studied possibility of using SPNDs as in-core detectors in SFRs. • Study done to detect local power profile changes when reactor is at nominal power. • SPND with a Pt-emitter gives measurable prompt current of the order of 600 nA/m. • Dominant proportion of prompt response is maintained throughout the operation. • Detector signal gives dynamic information on the power fluctuations.

  15. Conditioning of cooling water in power stations. Feedback from twenty years of experience with acid feeding

    Energy Technology Data Exchange (ETDEWEB)

    Goffin, C.; Duvivier, L.; Girasa, E. [LABORELEC, Chemistry of Water (Belgium); Brognez, J. [ELECTRABEL, TIHANGE Nuclear Power Station (Belgium)

    2002-07-01

    In the late 1970's and early 1980's, with the development of the nuclear programme in many European countries, the recirculation of cooling water in power stations became an issue which required urgent attention. The concentration of several plants of 1000 MW or more on sites along inland waterways actually made simple once-through cooling impossible, owing to the risk of an unacceptable rise in the river's water temperature. The chemical composition of natural freshwater in western European waterways is such that when it becomes slightly concentrated, scale is rapidly formed. The relatively low solubility of calcium carbonate and the degassing of the carbon dioxide during close contact between the water and air in the heat exchangers of the cooling tower explain this precipitation tendency. Fairly soon, experts in the electricity power generation companies highlighted the need for on-site, pilot loop simulations, in order to foresee the physico-chemical phenomena that could arise in industrial installations. The number of financially justifiable processing possibilities could be briefly summarised by the following three solutions: to adapt the concentration factor in order to be under the calcium carbonate solubility limit and thereby avoid the need for any water conditioning; to accept concentration factors of between 1.4 and 1.9 and control the calcium carbonate precipitation through controlled acid injection in the circulation water; to raise the concentration factor over 5 and soften the makeup water through the addition of lime and flocculant. The last of these solutions was rarely ever used in Belgium and France. It was however widely used in Germany. Its application requires a greater investment and leads to higher operating costs than acid injection. Furthermore, it leads to the problem of daily drying and disposal of several dozen tonnes of sludge, which have to be recycled or dumped. In an increasingly stringent environmental context, this

  16. Conditioning of cooling water in power stations. Feedback from twenty years of experience with acid feeding

    International Nuclear Information System (INIS)

    Goffin, C.; Duvivier, L.; Girasa, E.; Brognez, J.

    2002-01-01

    In the late 1970's and early 1980's, with the development of the nuclear programme in many European countries, the recirculation of cooling water in power stations became an issue which required urgent attention. The concentration of several plants of 1000 MW or more on sites along inland waterways actually made simple once-through cooling impossible, owing to the risk of an unacceptable rise in the river's water temperature. The chemical composition of natural freshwater in western European waterways is such that when it becomes slightly concentrated, scale is rapidly formed. The relatively low solubility of calcium carbonate and the degassing of the carbon dioxide during close contact between the water and air in the heat exchangers of the cooling tower explain this precipitation tendency. Fairly soon, experts in the electricity power generation companies highlighted the need for on-site, pilot loop simulations, in order to foresee the physico-chemical phenomena that could arise in industrial installations. The number of financially justifiable processing possibilities could be briefly summarised by the following three solutions: to adapt the concentration factor in order to be under the calcium carbonate solubility limit and thereby avoid the need for any water conditioning; to accept concentration factors of between 1.4 and 1.9 and control the calcium carbonate precipitation through controlled acid injection in the circulation water; to raise the concentration factor over 5 and soften the makeup water through the addition of lime and flocculant. The last of these solutions was rarely ever used in Belgium and France. It was however widely used in Germany. Its application requires a greater investment and leads to higher operating costs than acid injection. Furthermore, it leads to the problem of daily drying and disposal of several dozen tonnes of sludge, which have to be recycled or dumped. In an increasingly stringent environmental context, this solution is no

  17. Kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems

    International Nuclear Information System (INIS)

    Lietzke, M.H.

    1977-01-01

    The results of applying a kinetic model to the chlorination data supplied by Commonwealth Edison on the once-through cooling system at the Quad Cities Nuclear Station provide a validation of the model. The two examples given demonstrate that the model may be applied to either once-through cooling systems or to cooling systems involving cooling towers

  18. Optimal control and performance test of solar-assisted cooling system

    KAUST Repository

    Huang, B.J.; Yen, C.W.; Wu, J.H.; Liu, J.H.; Hsu, H.Y.; Petrenko, V.O.; Chang, J.M.; Lu, C.W.

    2010-01-01

    temperature. This will make the SACH always produce cooling effect even at lower solar radiation periods while the ejector performs at off-design conditions. The energy saving of A/C is experimentally shown 50-70% due to the cooling performance of ECS

  19. Study on a heat recovery system for the thermal power plant utilizing air cooling island

    International Nuclear Information System (INIS)

    Sun, Jian; Fu, Lin; Sun, Fangtian; Zhang, Shigang

    2014-01-01

    A new heat recovery system for CHP (combined heat and power) systems named HRU (heat recovery unit) is presented, which could recover the low grade heat of exhausted steam from the turbine at the thermal power plant directly. Heat recovery of exhausted steam is often accomplished by recovering the heat of cooling water in current systems. Therefore, two processes of heat transfer is needed at least. However, exhausted steam could be condensed in the evaporator of HRU directly, which reduce one process of heat transfer. A special evaporator is designed condense the exhausted steam directly. Simulated results are compared to experiments, which could include the calculation of heat transfer coefficients of different parts of HRU. It is found that about 25Mw of exhausted steam is recovered by this system. HRU could be promising for conventional CHP systems, which could increase the total energy efficiency obviously and enlarge the heating capacity of a built CHP system. - Highlights: • A new heat recovery system for thermal power plant is presented. • A mathematical model including heat transfer coefficients calculation is given. • This heat recovery system is experimented at a thermal power plant. • Performances of this system under different working conditions are simulated

  20. Workshop on cooling of x-ray monochromators on high power beamlines

    International Nuclear Information System (INIS)

    Matsushita, T.; Ishikawa, T.

    1989-03-01

    This report is a Workshop on Cooling of X-ray Monochromators on High Power Beamlines held on August 31, 1988 at the Photon Factory during the Third International Conference on Synchrotron Radiation Instrumentation (SRI88). On high power beamlines, especially on insertion device beamlines, heating of crystal monochromators is becoming a serious problem: Researchers observe that the intensity of the X-ray beam on the sample is not proportional to the source intensity because of thermal distortion of the monochromator crystal. This problem will be even more serious on beamlines for the next generation X-ray rings. In the very tight program of the SRI88 conference, only 2 speakers were able to give invited talks closely related to this problem in the session of OPTICAL COMPONENTS FOR HIGH POWER BEAMLINES on Wednesday morning of August 31, 1988. We held this workshop in the afternoon of the same day with the intention of offering further opportunities to exchange information on efforts underway at various laboratories and to discuss ideas how to solve this problem. We also intended that the workshop would be a 'follow-up' to the X-ray optics workshop held at ESRF, Grenoble in September 1987, where the importance of crystal cooling was strongly pointed out. There were 32 participants from 7 countries. 12 people represented their experiences and ideas for reducing thermal distortion of crystal monochromators. Following those presentations, there were discussions on collaborations for solving this important problem. The attendees agreed that exchange of information should be continued by holding such meetings at reasonable intervals. (J.P.N.)

  1. Numerical solution of compressible flow equations inside an ejector

    International Nuclear Information System (INIS)

    Omid khah, M. R.; Navid Famili, M. H.; Jalili Keshtiban, E.

    2002-01-01

    Ejector is important equipment in the chemical industry. It is mainly used for vaccuming and mixing of flows. In the present work a computer modeling of the flow inside an ejector is used to give a better understanding of the principle of the operation of an ejector. Since the fluid inside an ejector passes through subsonic, sonic and supersonic regimens, the pressure field is used as the controlling variable and the density is found through the constitutive equations. The control volume method with a co-location grid, attached to the boundary is used to discretize the domain. The overall solution is obtained by the SIMPLEC method and to dissociate the pressure and the velocity grid Rhie-Chow interpolation method is employed. A central difference approximation method is used to approximate the density on the elements borders and the upwind approximation is used to correct the density correction factors. Both upwind, quick and minimum gradient methods were used to approximate the momentum variables on the control volumes. The resultant matrices are solved with the tri-diagonal method. The accuracy of the model is checked by simulating a flow regiment in a converging-diverging nozzle, and comparing the results with the available experimental data. The results show that for an inviscid the first order approximation produce as an accurate results as the higher order approximations while it has a better stability. However, for the viscous fluid the second order approximation produces a better understanding of the physics of the problem. The solution also showes that the flow field inside an ejector is a complex one and the shock wave has a great influence on the pressure field especially close to the walls. The upper convective quick method did not converge well in the shock calculations while the slowest descent method had a very stable behavior in the analysis of the shock behavior

  2. Structural optimization of a microjet based cooling system for high power LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Liu; Zhiyin Gan [Institute for Microsystems, School of Mechanical Engineering, Huazhong University of Science and Technology, Wuhan (China); Wuhan National Lab of Optoelectronics, Huazhong University of Science and Technology, Wuhan (China); Jianghui Yang [School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan (China); Xiaobing Luo [Wuhan National Lab of Optoelectronics, Huazhong University of Science and Technology, Wuhan (China); School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan (China)

    2008-08-15

    Based on the previous experiments and simulations reported by the present authors, it was found the cooling system could be optimized to obtain better performance. In this paper, the microjet cooling systems with three different microjet structures were numerically investigated. The numerical model was proven by the experiments. The optimization results demonstrate that the microjet structure with one single inlet but two outlets can achieve better cooling performance. The simulation results show that the maximum temperature of the LED substrate cooled by the optimized microjet cooling device was 23 K lower than that of the LED substrate cooled by the present experimental cooling system. (author)

  3. A charge regulating system for turbo-generator gas-cooled high-temperature reactor power stations

    International Nuclear Information System (INIS)

    Braytenbah, A.S.; Jaegtnes, K.O.

    1975-01-01

    The invention relates to a regulating system for gas-cooled high-temperature reactors power stations (helium coolant), equipped with several steam-boilers, each of which deriving heat from a corresponding cooling-gas flow circulating in the reactor, so as to feed superheated steam into a main common steam-manifold and re-superheated steam into a re-superheated hot common manifold [fr

  4. The ring-stiffened shell of the ISAR II nuclear power plant natural-draught cooling tower

    International Nuclear Information System (INIS)

    Form, J.

    1986-01-01

    The natural-draught cooling tower of the ISAR II nuclear power plant is one of the largest in the world. The bid specifications provided for an unstiffened cooling tower shell. For the execution, however, it was decided to adopt a shell with three additional stiffening rings. The present contribution deals with the static and dynamic calculations of the execution and, in particular, with the working technique employed for the construction of the rings. (author)

  5. Test of a cryogenic set-up for a 10 meter long liquid nitrogen cooled superconducting power cable

    DEFF Research Database (Denmark)

    Træholt, Chresten; Rasmussen, Carsten; Kühle (fratrådt), Anders Van Der Aa

    2000-01-01

    High temperature superconducting power cables may be cooled by a forced flow of sub-cooled liquid nitrogen. One way to do this is to circulate the liquid nitrogen (LN2) by means of a mechanical pump through the core of the cable and through a sub-cooler.Besides the cooling station, the cryogenics...... cable. We report on our experimental set-up for testing a 10 meter long high temperature superconducting cable with a critical current of 3.2 kA at 77K. The set-up consists of a custom designed cable end termination, current lead, coolant feed-through, liquid nitrogen closed loop circulation system...

  6. Construction and commissioning experience of evolutionary water cooled nuclear power plants

    International Nuclear Information System (INIS)

    2004-04-01

    Electricity market liberalization is an established fact in several countries and there is a trend to adopt it in other countries. The essential aim of market liberalization is to improve the overall economic efficiency. In order that nuclear power remains a viable option for electricity generation, its costs should be competitive with alternative sources while, at the same time, it should have a safe and reliable operation record. The capital cost of nuclear power plants (NPPs) generally accounts for 43-70% of the total nuclear electricity generation costs, compared to 26-48% for coal plants and 13-32% for gas plants. Most of these expenditures are incurred during the construction phase of a NPP. The achievement of shorter construction periods using improved technology and construction methods has a significant benefit on the costs incurred prior to any production of electricity. This document is intended to make the recent worldwide experience on construction and commissioning of evolutionary water cooled NPPs available to Member States and especially to those with nuclear power plants under construction/planning, and to those seriously considering nuclear power projects in the future. The final aim is to assist utilities and other organizations in Member States to improve the construction of nuclear power plants and achieve shortened schedules and reduced costs without compromising quality and safety. This document aims to provide an overview of the most advanced technologies, methods and processes used in construction and commissioning of recent nuclear projects. To better achieve this objective the presentation is selectively focused more on the new developments rather than providing a full review of all issues related to construction and commissioning. The experience described in this TECDOC applies to managers, engineers, supervisors, technicians and workers in various organizations dealing with the site construction and commissioning of nuclear power plants

  7. Future needs for dry or peak shaved dry/wet cooling and significance to nuclear power plants. Final report

    International Nuclear Information System (INIS)

    Clukey, H.V.; McNelly, M.J.; Mitchell, R.C.

    1976-02-01

    U.S. requirements for uncommitted nuclear installations in water scarce areas that might require dry cooling tower systems are minimal through the year 2000 (6 to 23 GWe). In these areas it appears that peak-shaved dry/wet cooling systems are more attractive than all-dry tower cooling unless water costs were to approach the high level of several cents per gallon. The differential cooling system evaluated cost of peak-shaved dry/wet cooling systems above wet towers is typically $20 to $30/kWe for steam turbines; whereas, dry towers can represent an incremental burden of as much as $80/kWe. Gas turbine (Brayton Cycle) systems show similar benefits from an evaporative heat sink to those for steam turbine cycles--lower cooling system evaluated costs for peak-shaved dry/wet cooling systems than for conventional wet towers. These cooling system cost differentials do not reflect total costs for Brayton Cycle gas turbine plants. Together these added costs and uncertainties may substantially exceed the dollar incentives available for development of the Brayton Cycle for power generation needs for water deficient sites

  8. Condensation nuclear power plants with water-cooled graphite-moderated channel type reactors and advances in their development

    International Nuclear Information System (INIS)

    Boldyrev, V.M.; Mikhaj, V.I.

    1985-01-01

    Consideration is being given to results of technical and economical investigations of advisability of increasing unit power by elevating steam generating capacity as a result of inserting numerous of stereotype sectional structural elements of the reactor with similar thermodynamic parameters. It is concluded that construction of power units of condensation nuclear power plants with water-cooled graphite-moderated channel type reactors of 2400-3200 MWe and higher unit power capacity represents the real method for sharp growth of efficiency and labour productivity in power industry. It can also provide the required increase of the rate of putting electrogenerating powers into operation

  9. Feasibility analysis of gas turbine inlet air cooling by means of liquid nitrogen evaporation for IGCC power augmentation

    International Nuclear Information System (INIS)

    Morini, Mirko; Pinelli, Michele; Spina, Pier Ruggero; Vaccari, Anna; Venturini, Mauro

    2015-01-01

    Integrated Gasification Combined Cycles (IGCC) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, an Air Separation Unit (ASU) is also part of the plant. In this paper, a system for power augmentation in IGCC is evaluated. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first liquefied to be used for inlet air cooling or stored for later use. This system is not characterized by the limits of water evaporative cooling systems (the lower temperature is limited by air saturation) and refrigeration cooling (the effectiveness is limited by the pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for energy conversion system simulation. A sensitivity analysis on the main parameters is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year and by comparing to traditional inlet air cooling strategies. - Highlights: • Gas turbine inlet air cooling by means of liquid nitrogen spray. • Humidity condensation may form a fog which provides further power augmentation. • High peak and off peak electric energy price ratios make the system profitable

  10. Passive residual energy utilization system in thermal cycles on water-cooled power reactors

    International Nuclear Information System (INIS)

    Placco, Guilherme M.; Guimaraes, Lamartine N.F.; Santos, Rubens S. dos

    2013-01-01

    This work presents a concept of a residual energy utilization in nuclear plants thermal cycles. After taking notice of the causes of the Fukushima nuclear plant accident, an idea arose to adapt a passive thermal circuit as part of the ECCS (Emergency Core Cooling System). One of the research topics of IEAv (Institute for Advanced Studies), as part of the heat conversion of a space nuclear power system is a passive multi fluid turbine. One of the main characteristics of this device is its passive capability of staying inert and be brought to power at moments notice. During the first experiments and testing of this passive device, it became clear that any small amount of gas flow would generate power. Given that in the first stages of the Fukushima accident and even during the whole event there was plenty availability of steam flow that would be the proper condition to make the proposed system to work. This system starts in case of failure of the ECCS, including loss of site power, loss of diesel generators and loss of the battery power. This system does not requires electricity to run and will work with bleed steam. It will generate enough power to supply the plant safety system avoiding overheating of the reactor core produced by the decay heat. This passive system uses a modified Tesla type turbine. With the tests conducted until now, it is possible to ensure that the operation of this new turbine in a thermal cycle is very satisfactory and it performs as expected. (author)

  11. Performance power evaluation of DC fan cooling system for PV panel by using ANSYS CFX

    Science.gov (United States)

    Syafiqah, Z.; Amin, N. A. M.; Irwan, Y. M.; Irwanto, M.; Leow, W. Z.; Amelia, A. R.

    2017-09-01

    A research has been conducted to find the optimum combination for DC fan air cooling system of photovoltaic (PV) panel. During normal operation of PV panel, it is estimated that only 15 % of solar radiation is converted into electrical energy. Meanwhile, the rest of the solar radiation is converted into heat energy which affects the performance of the PV panel. Therefore, the aim of this research is to investigate the performance power evaluation of DC fan cooling system for PV panel by using ANSYS CFX. The effect of airflow configuration of DC fan has been investigated. This is to analyze whether the airflow circulation of DC fan cause a change towards the maximum temperature of PV panel. Besides, the impact of varying number of DC fans attached at the back of PV panel is evaluated. The result of airflow circulation of DC fan has been discussed. Meanwhile, with the increment number of DC fans, the PV panel temperature drops significantly. As a conclusion, the optimum number of DC fans is two with the combination of inlet airflow.

  12. Solar-Enhanced Air-Cooled Heat Exchangers for Geothermal Power Plants

    Directory of Open Access Journals (Sweden)

    Kamel Hooman

    2017-10-01

    Full Text Available This paper focuses on the optimization of a Solar-Enhanced Natural-Draft Dry-Cooling Tower (SENDDCT, originally designed by the Queensland Geothermal Energy Centre of Excellence (QGECE, as the air-cooled condenser of a geothermal power plant. The conventional method of heat transfer augmentation through fin-assisted area extension is compared with a metal foam-wrapped tube bundle. Both lead to heat-transfer enhancement, albeit at the expense of a higher pressure drop when compared to the bare tube bundle as our reference case. An optimal design is obtained through the use of a simplified analytical model and existing correlations by maximizing the heat transfer rate with a minimum pressure drop goal as the constraint. Sensitivity analysis was conducted to investigate the effect of sunroof diameter, as well as tube bundle layouts and tube spacing, on the overall performance of the system. Aiming to minimize the flow and thermal resistances for a SENDDCT, an optimum design is presented for an existing tower to be equipped with solar panels to afterheat the air leaving the heat exchanger bundles, which are arranged vertically around the tower skirt. Finally, correlations are proposed to predict the total pressure drop and heat transfer of the extended surfaces considered here.

  13. Hydrogen co-production from subcritical water-cooled nuclear power plants in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Gnanapragasam, N.; Ryland, D.; Suppiah, S., E-mail: gnanapragasamn@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-06-15

    Subcritical water-cooled nuclear reactors (Sub-WCR) operate in several countries including Canada providing electricity to the civilian population. The high-temperature-steam-electrolysis process (HTSEP) is a feasible and laboratory-demonstrated large-scale hydrogen-production process. The thermal and electrical integration of the HTSEP with Sub-WCR-based nuclear-power plants (NPPs) is compared for best integration point, HTSEP operating condition and hydrogen production rate based on thermal energy efficiency. Analysis on integrated thermal efficiency suggests that the Sub-WCR NPP is ideal for hydrogen co-production with a combined efficiency of 36%. HTSEP operation analysis suggests that higher product hydrogen pressure reduces hydrogen and integrated efficiencies. The best integration point for the HTSEP with Sub-WCR NPP is upstream of the high-pressure turbine. (author)

  14. Surveillance tests for light-water cooled nuclear power reactor vessels in IMEF

    International Nuclear Information System (INIS)

    Choo, Yong-Sun; Ahn, Sang-Bok; Park, Dae-Gyu; Jung, Yang-Hong; Yoo, Byung-Ok; Oh, Wan-Ho; Baik, Seung-Je; Koo, Dae-Seo; Lee, Key-Soon

    1999-01-01

    The surveillance tests for light-water cooled nuclear power reactor vessels were established to monitor the radiation-induced changes in the mechanical properties of ferritic materials in the beltline according to US NRC 10 CFR 50 App. G, US NRC RG1.99-rev.2, ASTM E185-82 and E185-94 in Irradiated Materials Examination Facility(IMEF). The surveillance capsule was transported from NPPs pool sites to KAERI IMEF by using a shipping cask. The capsule was cut and dismantled by capsule cutting machine and milling machine in M2 hot cell. Charpy tests and tension tests were performed in M5a and M5b hot cells respectively. Especially the EPMA located at hot lab was used to analyze the Ni and Cu wt% composition of base metal and weld for predicting the adjusted reference temperature(ART). The established process and test results were summarized in this paper. (author)

  15. BRENDA: a dynamic simulator for a sodium-cooled fast reactor power plant

    International Nuclear Information System (INIS)

    Hetrick, D.L.; Sowers, G.W.

    1978-06-01

    This report is a users' manual for one version of BRENDA (Breeder Reactor Nuclear Dynamic Analysis), which is a digital program for simulating the dynamic behavior of a sodium-cooled fast reactor power plant. This version, which contains 57 differential equations, represents a simplified model of the Clinch River Breeder Reactor Project (CRBRP). BRENDA is an input deck for DARE P (Differential Analyzer Replacement, Portable), which is a continuous-system simulation language developed at the University of Arizona. This report contains brief descriptions of DARE P and BRENDA, instructions for using BRENDA in conjunction with DARE P, and some sample output. A list of variable names and a listing for BRENDA are included as appendices

  16. Experience of Electricite de France in the use of sea water for cooling thermal power stations

    International Nuclear Information System (INIS)

    Boyer, R.M.E.; Malherbe, C.

    1979-01-01

    The sea is a practically unlimited reserve of water for cooling conventional or nuclear thermal power stations. On the other hand, its use gives rise to numerous problems relating to the design and operation of the equipment. The main problems encountered at EDF are associated with filter screens (clogging, corrosion), the distribution ducts (encrusted organisms), the water boxes, the tube plates, and above all, the condenser tubes (corrosion, corrosion-erosion). The site-construction of several PWR nuclear sets has caused EDF to dispense with the use of cuprous alloys for the tubes of condensers using sea water; these are now of thin-walled seam-welded titanium. In order to reduce further the risks of leakage, these tubes are expanded into double tube plates between which fresh water is trapped under pressure. (author)

  17. Post-LOCA long term cooling performance in Korean standard nuclear power plants

    International Nuclear Information System (INIS)

    Bang, Young Seok; Jung, Jae Won; Seul, Kwang Won; Kim, Hho Jung

    1999-01-01

    The post-LOCA long term cooling (LTC) performance of the Korean Standard Nuclear Power Plant (KSNPP) is analyzed for both small break LOCA and large break LOCA. The RELAP5/MOD3.2.2 code is used to calculate the LTC sequences based on the LTC plan of the KSNPP. A standard input model is developed such that LOCA and the followed LTC sequence can be calculated in a single run for both small break LOCA and large break LOCA. A spectrum of small break LOCA ranging from 0.02 to 0.5 ft 2 of break area and a double-ended guillotine break are analyzed. Through the code calculations, the thermal-hydraulic behavior and the boron behavior are evaluated and the effect of the important manual action including the safety injection tank isolation in LTC procedure is investigated

  18. Digital simulation of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant

    International Nuclear Information System (INIS)

    Ray, A.; Bowman, H.F.

    1978-01-01

    A nonlinear dynamic model of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant was derived in state-space form from fundamental principles. The plant model is 40th order, time-invariant, deterministic and continuous-time. Numerical results were obtained by digital simulation. Steady-state performance of the nonlinear model was verified with plant heat balance data at 100, 75 and 50 percent load levels. Local stability, controllability and observability were examined in this range using standard linear algorithms. Transfer function matrices for the linearized models were also obtained. Transient response characteristics of 6 system variables for independent step distrubances in 2 different input variables are presented as typical results

  19. Steam generator tube performance: world experience with water-cooled nuclear power reactors during 1979

    International Nuclear Information System (INIS)

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

    1981-01-01

    The performance of steam generator tubes in water-cooled nuclear power reactors is reviewed for 1979. Tube failures occurred at 38 of the 93 reactors surveyed. The causes of these failures and the procedures designed to deal with them are described. The defect rate, although higher than that in 1978, was still lower than the rates of the two previous years. Methods being employed to detect defects include the increased use of multifrequency eddy-current testing and a trend to full-length inspection of all tubes. To reduce the incidence of tube failure by corrosion, plant operators are turning to full-flow condensate demineralization and more leak-resistant condenser tubes. 10 tables

  20. Solar energy powering up aerial misting systems for cooling surroundings in Saudi Arabia

    International Nuclear Information System (INIS)

    Atieh, Ahmad; Al Shariff, Samir

    2013-01-01

    Highlights: ► Demonstrate solar energy misting system for the first time to our knowledge. ► Return on investment for such a system is recovered within two and half years. ► Solar panel tilt position is 25° due south in Medina Munawarah. ► The misting system is capable of lowering ambient temperature over 10 °C. - Abstract: We demonstrated for the first time to our knowledge a misting system that is powered by solar energy. The system was used to cool down an open area in Medina, Saudi Arabia. The ambient and surrounding temperatures were measured and compared for different timing signals that were applied to the misting system. The used solar panel performance is evaluated for different loads, and tilting settings. The return on investment for the misting system is found to be about two years and half.

  1. Development of an innovative polygeneration process in hybrid solar-biomass system for combined power, cooling and desalination

    International Nuclear Information System (INIS)

    Sahoo, U.; Kumar, R.; Pant, P.C.; Chaudhary, R.

    2017-01-01

    Highlights: • Heat utilization from solar and biomass resources are considered for hybridization. • Modeling of polygeneration process in hybrid solar-biomass power plant is considered. • Thermodynamic evaluation are performed to identify the effect of various parameters. • Primary Energy Saving of polygeneration process is determined. - Abstract: In the polygeneration process simultaneous production of power, vapor absorption refrigeration (VAR) cooling and multi-effect humidification and dehumidification (MEHD) desalination system from different heat sources in hybrid solar-biomass (HSB) system with higher energy efficiency take place. It is one of the solutions to fulfill energy requirements from renewable sources and also helps in the reduction of carbon dioxide emissions. The VAR cooling system operates using the extracted heat taken from turbine and condenser heat of the VAR cooling system is used in desalination system for production of drinking water as per demand requirement. Though the production of electricity decreases due to extraction of heat from turbine for VAR cooling and desalination, the complete system meets the energy requirements & increases the primary energy savings (PES). The thermodynamic evaluation and optimization of HSB system in polygeneration process for combined power, cooling and desalination is investigated to identify the effects of various operating parameters. Primary energy savings (PES) of polygeneration process in HSB system is achieved to 50.5%. The energy output is increased to 78.12% from this system as compared to simple power plant.

  2. Performance of water cooled nuclear power reactor fuels in India – Defects, failures and their mitigation

    International Nuclear Information System (INIS)

    Ganguly, Chaitanyamoy

    2015-01-01

    Water cooled and moderated nuclear power reactors account for more than 95% of the operating reactors in the world today. Light water reactors (LWRs) consisting of pressurized water reactor (PWR), their Russian counterpart namely VVER and boiling water reactor (BWR) will continue to dominate the nuclear power market. Pressurized heavy water reactor (PHWR), also known as CANDU, is the backbone of the nuclear power program in India. Updates on LWR and PHWR fuel performance are being periodically published by IAEA, OECD-NEA and the World Nuclear Association (WNA), highlighting fuel failure rate and the mitigation of fuel defects and failures. These reports clearly indicate that there has been significant improvement in in – pile fuel performance over the years and the present focus is to achieve zero fuel failure in high burn up and high performance fuels. The present paper summarizes the status of PHWR and LWR fuel performance in India, highlighting the manufacturing and the related quality control and inspection steps that are being followed at the PHWR fuel fabrication plant in order to achieve zero manufacturing defect which could contribute to achieving zero in – pile failure rate in operating and upcoming PHWR units in India. (author)

  3. High power RF test of an 805 MHz RF cavity for a muon cooling channel

    International Nuclear Information System (INIS)

    Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

    2002-01-01

    We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q 0 of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons

  4. Safe corrosion inhibitor for treating cooling water on heat power engineering plants

    Science.gov (United States)

    Nikolaeva, L. A.; Khasanova, D. I.; Mukhutdinova, E. R.; Safin, D. Kh.; Sharifullin, I. G.

    2017-08-01

    Heat power engineering (HPE) consumes significant volumes of water. There are, therefore, problems associated with corrosion, biological fouling, salt deposits, and sludge formation on functional surfaces of heat power equipment. One of the effective ways to solve these problems is the use of inhibitory protection. The development of new Russian import-substituting environmentally friendly inhibitors is very relevant. This work describes experimental results on the OPC-800 inhibitor (TU 2415-092-00206 457-2013), which was produced at Karpov Chemical Plant and designed to remove mineral deposits, scale, and biological fouling from the surfaces of water-rotation node systems on HPE objects. This reagent is successfully used as an effective corrosion inhibitor in the water recycling systems of Tatarstan petrochemical enterprises. To save fresh make-up water, the circulating system is operated in a no-blow mode, which is characterized by high evaporation and salt content coefficients. It was experimentally found that corrosion rate upon treatment of recycled water with the OPC-800 inhibitor is 0.08-0.10 mm/year. HPE mainly uses inhibitors based on oxyethylidene diphosphonic (OEDPA) and nitrilotrimethylphosphonic (NTMPA) acids. The comparative characteristic of inhibition efficiency for OPC-800 and OEDF-Zn-U2 is given. The results obtained indicate that OPC-800 can be used as an inhibitor for treatment of cooling water in HPE plants. In this case, it is necessary to take into account the features of water rotation of a thermal power plant.

  5. Solid-Core, Gas-Cooled Reactor for Space and Surface Power

    International Nuclear Information System (INIS)

    King, Jeffrey C.; El-Genk, Mohamed S.

    2006-01-01

    The solid-core, gas-cooled, Submersion-Subcritical Safe Space (S and 4) reactor is developed for future space power applications and avoidance of single point failures. The Mo-14%Re reactor core is loaded with uranium nitride fuel in enclosed cavities, cooled by He-30%Xe, and sized to provide 550 kWth for seven years of equivalent full power operation. The beryllium oxide reflector disassembles upon impact on water or soil. In addition to decreasing the reactor and shadow shield mass, Spectral Shift Absorber (SSA) materials added to the reactor core ensure that it remains subcritical in the worst-case submersion accident. With a 0.1 mm thick boron carbide coating on the outside surface of the core block and 0.25 mm thick iridium sleeves around the fuel stacks, the reflector outer diameter is 43.5 cm and the combined reactor and shadow shield mass is 935.1 kg. With 12.5 atom% gadolinium-155 added to the fuel, 2.0 mm diameter gadolinium-155 sesquioxide intersititial pins, and a 0.1 mm thick gadolinium-155 sesquioxide coating, the S and 4 reactor has a slightly smaller reflector outer diameter of 43.0 cm, and a total reactor and shield mass of 901.7 kg. With 8.0 atom% europium-151 added to the fuel, 2.0 mm diameter europium-151 sesquioxide interstitial pins, and a 0.1 mm thick europium-151 sesquioxide coating, the reflector's outer diameter and the total reactor and shield mass are further reduced to 41.5 cm and 869.2 kg, respectively

  6. Cleaning of porous filters in fluidized bed reactors. Use of one ejector for various filters

    International Nuclear Information System (INIS)

    Sancho Rod, J.; Rodrigo Otero, A.

    1966-01-01

    Tests to know the efficiency of a porous filters cleaning system by blow-back that uses on ejector for each set of simultaneously cleaned filters were carried out. A Calculation method to obtain the optimum ejector for this system was shown, taking n=2, as optimum number of working for the fluidized bed reactors belonging to the Pilot plant of the Materials Division at JEN. That is two filters for each ejector. (Author)

  7. Simulation and performance enhancement of the air cooling system in a DC/AC power converter station

    Energy Technology Data Exchange (ETDEWEB)

    Lozowy, R.; El-Shaboury, A.; Soliman, H.; Ormiston, S. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Mechanical and Manufacturing Engineering

    2010-07-01

    This study analyzed the flow structure and heat transfer in a large 3-dimensional domain with turbulence, mixed convection, an impinging jet, and flow over heated blocks. The objective was to better understand turbulent mixed-convection cooling of heat-generating bodies in 3-dimensional enclosures, which is important to industry. The cooling of 2 thyristor valve halls was simulated. Each valve hall housed 3 towers that contained electronics used in DC/AC power conversion. The simulation results included the magnitudes of the net air flows for all the inter-block gaps and the maximum temperature in each gap. A parametric study was also performed to investigate the effects of the air inlet location, size and aspect ratio. The effects of the air injection angle on cooling effectiveness was also examined. The study showed that for fixed inlet mass flow rate, significant improvement in the cooling effectiveness can be obtained by changing the injection angle of the inlet air jet, the location of the inlet grill, or the size of the inlet grill. It was concluded that these study results may be relevant to other applications, such as the design of power transformers, the design of cooling systems for spent nuclear fuel and computer server cooling racks. 13 refs., 12 figs.

  8. Power maximization method for land-transportable fully passive lead–bismuth cooled small modular reactor systems

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jaehyun, E-mail: chojh@kaeri.re.kr [Korea Atomic Energy Research Institute, 1405 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Shin, Yong-Hoon; Hwang, Il Soon [Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

    2015-08-15

    Highlights: • The power maximization method for LBE natural circulation cooled SMRs was developed. • The two powers in view of neutronics and thermal-hydraulics were considered. • The limitations for designing of LBE natural circulation cooled SMRs were summarized. • The necessary conditions for safety shutdown in accidents were developed. • The maximized power in the case study is 206 MW thermal. - Abstract: Although current pressurized water reactors (PWRs) have significantly contributed to global energy supply, PWR technology has not been considered a trustworthy energy solution owing to its problems of spent nuclear fuels (SNFs), nuclear safety, and nuclear economy. In order to overcome these problems, a lead–bismuth eutectic (LBE) fully passive cooling small modular reactor (SMR) system is suggested. This technology can not only provide the solution for the problems of SNFs through the transmutation feature of the LBE coolant, but also strengthen safety and economy through the concept of natural circulation cooling SMRs. It is necessary to maximize the advantages, namely safety and economy, of this type of nuclear power plants for broader applications in the future. Accordingly, the objective of this study is to maximize the reactor core power while satisfying the limitations of shipping size, materials endurance, and criticality of a long-burning core as well as safety under beyond design basis events. To achieve these objectives, the design limitations of natural circulating LBE-cooling SMRs are derived. Then, the power maximization method is developed based on obtaining the design limitations. The results of this study are expected to contribute to the effectiveness of the reactor design stage by providing insights to designers, as well as by formulating methods for the power maximization of other types of SMRs.

  9. Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors

    Science.gov (United States)

    Verma, V.; Barbot, L.; Filliatre, P.; Hellesen, C.; Jammes, C.; Svärd, S. Jacobsson

    2017-07-01

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor. Diverse possibilities of detector system installation must be studied for various locations in the reactor vessel in order to detect any perturbations in the core. Results from a previous paper indicated that it is possible to detect changes in neutron source distribution initiated by an inadvertent withdrawal of outer control rod with in-vessel fission chambers located azimuthally around the core. It is, however, not possible to follow inner control rod withdrawal and precisely know the location of the perturbation in the core. Hence the use of complimentary in-core detectors coupled with the peripheral fission chambers is proposed to enable robust core monitoring across the radial direction. In this paper, we assess the feasibility of using self-powered neutron detectors (SPNDs) as in-core detectors in fast reactors for detecting local changes in the power distribution when the reactor is operated at nominal power. We study the neutron and gamma contributions to the total output current of the detector modelled with Platinum as the emitter material. It is shown that this SPND placed in an SFR-like environment would give a sufficiently measurable prompt neutron induced current of the order of 600 nA/m. The corresponding induced current in the connecting cable is two orders of magnitude lower and can be neglected. This means that the SPND can follow in-core power fluctuations. This validates the operability of an SPND in an SFR-like environment.

  10. Feasibility study of self sustaining capability on water cooled thorium reactors for different power reactors

    International Nuclear Information System (INIS)

    Permana, S.; Takaki, N.; Sekimoto, H.

    2007-01-01

    Thorium fuel cycle can maintain the sustainable system of the reactor for self sustaining system for future sustainable development in the world. Some characteristics of thorium cycle show some advantages in relation to higher breeding capability, higher performance of burn-up and more proliferation resistant. Several investigations was performed to improve the breeding capability which is essential for maintaining the fissile sustainability during reactor operation in thermal reactor such as Shippingport reactor and molten salt breeder reactor (MSBR) project. The preliminary study of breeding capability on water cooled thorium reactor has been investigated for various power output. The iterative calculation system is employed by coupling the equilibrium fuel cycle burn-up calculation and cell calculation of PIJ module of SRAC2000. In this calculation, 1238 fission products and 129 heavy nuclides are employed. In the cell calculation, 26 heavy metals and 66 fission products and 1 pseudo FP are employed. The employed nuclear data library was JENDL 3.2. The reactor is fueled by 2 33U-Th Oxide and it has used the light water coolant as moderator. Some characteristics such as conversion ratio and void reactivity coefficient performances are evaluated for the systems. The moderator to fuel ratio (MFR) values and average burnups are studied for survey parameter. The parametric survey for different power outputs are employed from 10 MWt to 3000 MWt for evaluating the some characteristics of core size and leakage effects to the spectra profile, required enrichment, breeding capability, fissile inventory condition, and void reactivity coefficient. Different power outputs are employed in order to evaluate its effect to the required enrichment for criticality, breeding capability, void reactivity and fissile inventory accumulation. The obtained value of the conversion ratios is evaluated by using the equilibrium atom composition. The conversion ratio is employed based on the

  11. Reduction of circulation power for helium-cooled fusion reactor blanket using additive CO{sub 2} gas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yeon-Gun [Department of Nuclear Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Department of Nuclear and Energy Engineering, Jeju National University, 102 Jejudaehakno, Jeju-si 690-756, Jeju (Korea, Republic of); Park, Il-Woong [Department of Nuclear Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Lee, Dong Won [Nuclear Fusion Engineering Development Center, Korea Atomic Energy Research Institute, Daedeokdaero 989 beon-gil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Eung-Soo, E-mail: kes7741@snu.ac.kr [Department of Nuclear Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2015-11-15

    Helium (He) cooling requires large circulation power to remove high heat from plasma side and nuclear heating by high energy neutron in fusion reactors due to its low density. Based on the recent findings that the heat transfer capability of the light gas can be enhanced by mixing another heavier gas, this study adds CO{sub 2} to a reference helium coolant and evaluates the cooling performance of the binary mixture for various compositions. To assess the cooling performance, computational fluid dynamic (CFD) analyses on the KO HCML (Korea Helium Cooled Molten Lithium) TBM are conducted. As a result, it is revealed that the binary mixing of helium, which has favorable thermophysical properties but the density, with a heavier noble gas or an unreactive gas significantly reduces the required circulation power by an order of magnitude with meeting the thermal design requirements. This is attributed to the fact that the density can be highly increased with small amount of a heavier gas while other gas properties are kept relatively comparable. The optimal CO{sub 2} mole fraction is estimated to be 0.4 and the circulation power, in this case, can be reduced to 13% of that of pure helium. This implies that the thermal efficiency of a He-cooled blanket system can be fairly enhanced by means of the proposed binary mixing.

  12. Occupational radiation exposure at light water cooled power reactors. Annual report, 1977

    International Nuclear Information System (INIS)

    Peck, L.J.

    1979-04-01

    This report presents an updated compilation of occupational radiation exposures at commercial light water cooled nuclear power reactors (LWRs) for the years 1969 through 1977. The information contained in this document was derived from reports submitted to the United States Nuclear Regulatory Commission in accordance with requirements of individual plant Technical Specifications, and in accordance with Part 20.407 of Title 10, Chapter 1, Code of Federal Regulations (10 CFR Part 20.407). An additional 4 LWRs completed a full calendar year of commercial operation for the first time in 1977. This report now encompasses data from 57 commercially operating U.S. nuclear power plants. The number of personnel monitored at LWRs increased approximately 10% in 1977, and the average collective dose to personnel (man-rems per reactor-year) increased 14% over the 1976 average. The average number of personnel receiving measurable exposure per reactor increased 11%, and the average exposure per individual in 1977 was 0.8 rem per person

  13. Evaluation of post-LOCA long term cooling performance in Korean standard nuclear power plants

    International Nuclear Information System (INIS)

    Bang, Young Seok; Jung, Jae Won; Seul, Kwang Won; Kim, Hho Jung

    2001-01-01

    The post-LOCA long term cooling (LTC) performance of the Korean Standard Nuclear Power Plant (KSNPP) is analyzed for both small break loss-of-coolant accidents (LOCA) and large break LOCA at cold leg. The RELAP5/MOD3.2.2 beta code is used to calculate the LTC sequences based on the LTC plan of the Korean Standard Nuclear Power Plants (KSNPP). A standard input model is developed such that LOCA and the followed LTC sequence can be calculated in a single run for both small break LOCA and large break LOCA. A spectrum of small break LOCA ranging from 0.02 to 0.5 ft 2 of break area and a double-ended guillotine break are analyzed. Through the code calculations, the thermal-hydraulic behavior and the boron behavior are evaluated and the effect of the important action including the safety injection tank (SIT) isolation and the simultaneous injection in LTC procedure is investigated. As a result, it is found that the sufficient margin is available in avoiding the boron precipitation in the core. It is also found that a further specific condition for the SIT isolation action need to be setup and it is recommended that the early initiation of the simultaneous injection be taken for larger break LTC sequences. (author)

  14. Analysis of the accident in the second power-generating unit of the Chernobyl nuclear power plant caused by inadequate makeup of the reactor cooling loop

    International Nuclear Information System (INIS)

    Vasil'chenko, V.N.; Kramerov, A.Ya.; Mikhailov, D.A.

    1995-01-01

    The accident in the second power-generating unit of the Chernobyl nuclear power plant on October 11, 1991 was the result of unauthorized connection of the TG-4 turbogenerator, which was shut down for repairs, into the grid (in the off-design asynchronous engine mode), and this resulted in a serious fire in the machine room and subsequent failure of systems which are important for safety and which ensure the design mode of reactor cooling: These were primarily failures of the feed and emergency feed pumps and failure of the BRU-B control valve, which regulates steam release during cooling

  15. Rehabilitation of two natural draught cooling towers at Grohnde 1300 MW nuclear power station, taking into account a completely new concept

    International Nuclear Information System (INIS)

    Schwickert, M.; Meyer, V.

    1992-01-01

    The natural draught cooling towers for Grohnde Nuclear Power Station were completed in 1983. During the operating period from 1984 to 1990, partial areas of these cooling tower structures collapsed. A combination of high performance cooling installations with so-called spray screens were offered for the necessary rehabilitation. Since rehabilitation of both cooling towers had to be carried out during the operation of the power station, parts of the surfaces of the cooling towers were closed off in order to be able to carry out the difficult installation of the structures. Acceptance measurements have confirmed the thermodynamic calculations. (orig.) [de

  16. Validation of the kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems

    International Nuclear Information System (INIS)

    Lietzke, M.H.

    1977-01-01

    The purpose of this report is to present a validation of a previously described kinetic model which was developed to predict the composition of chlorinated fresh water discharged from power plant cooling systems. The model was programmed in two versions: as a stand-alone program and as a part of a unified transport model developed from consistent mathematical models to simulate the dispersion of heated water and radioisotopic and chemical effluents from power plant discharges. The results of testing the model using analytical data taken during operation of the once-through cooling system of the Quad Cities Nuclear Station are described. Calculations are also presented on the Three Mile Island Nuclear Station which uses cooling towers

  17. Thermal-hydraulic analysis of the OSURR pool for power upgrade with natural convection core cooling

    International Nuclear Information System (INIS)

    Ha, J.J.; Aldemir, T.

    1988-01-01

    Natural convection mode core cooling will be maintained in the LEU conversion/power upgrade of The Ohio State University Research Reactor (OSURR) to 250-500 kW. The pool water will be cooled by a water-glycol-air and a water-water heat exchanger. A plume disperser will be installed in the pool to minimize evaporation from the pool top and to maintain the dose rate due to N-16 activity within allowable levels. The minimization of the pool heat removal system operation costs necessitates maximizing the inlet temperature to the water-glycol-air heat exchanger. For the maximization process, the change in the pool temperature and velocity fields have to be investigated as a function of: location and orientation of the heat removal system components and the plume disperser in the pool; mass flow rate through the plume disperser. The velocity and temperature fields in the pool are determined using COMMIX-1A. The computational system model accounts for the presence of all the pool components (i.e. core, thermal column, beam ports, ion chamber, guide tubes, rabbit, neutron source etc.). The results show that: (1) Both the heat removal system inlet point and the plume disperser have to be located close to the top of the core. (2) Using a disperser system consisting of several pipes may be more feasible than a single unit. (3) For high disperser flow, the disperser jet has to be almost parallel to the top of the core to prevent flow reversal in coolant channels. (4) More than one disperser system may be necessary to create an inversion layer in the pool

  18. Aquatic ecology of the Kadra reservoir, the source of cooling water for Kaiga nuclear power plant

    International Nuclear Information System (INIS)

    Ghosh, T.K.; Zargar, S.; Dhopte, R.; Kulkarni, A.; Kaul, S.N.

    2002-01-01

    The study is being conducted since July 2000 to evaluate impact of cooling water discharges from Kaiga Nuclear Power Plant on physicochemical and biological characteristics of Kadra reservoir. Besides marginal decrease of DO, sulfate, nitrate and potassium near discharge point at surface water, abiotic features of the water samples collected from three layers, viz. surface, 3-m depth and bottom at nine locations of the reservoir, did not show remarkable differences with reference to pH, phosphate, conductivity, suspended solids, sodium, hardness, chloride, alkalinity and heavy metals (Cu, Fe, Ni, Zn, Pb, Cd, Cr and Mn). The DT varied between 5 and 8.5 degC at surface water during the study. The abiotic characteristics of the reservoir water meet the specification of drinking water standard of Bureau of Indian Standards. While the counts of phytoplankton and zooplankton were reduced near discharge point, their population at 500 m off the discharge point was comparable to those near dam site at about 11 km down stream from plant site. Plamer's index (0-15) and Shannon's diversity index values (1.39-2.44) of the plankton at different sampling points indicate oligotrophic and semi productive nature of the water body. The total coliform (TC), staphylococcus and heterotrophic counts were, in general, less near discharge point. Based on TC count, the reservoir water, during most of the period, is categorized as 'B' following CPCB classification of surface waters. Generation of data needs to be continued till 2-3 years for statistical interpretation and drawing conclusions pertaining to extent of impact of cooling water discharges on Kadra reservoir ecology. (author)

  19. Thermodynamic evaluation of chemical looping combustion for combined cooling heating and power production driven by coal

    International Nuclear Information System (INIS)

    Fan, Junming; Hong, Hui; Zhu, Lin; Wang, Zefeng; Jin, Hongguang

    2017-01-01

    Highlights: • An ex-situ coal gasification chemical looping combustion integrated with CCHP process has been presented. • This novel process maintains a maximum energy efficiency of 60.34%. • The fossil energy saving ratio of this process is optimize to be 27.20%. - Abstract: This study carries out an investigation concerning on the benefits of ex-situ coal gasification chemical looping combustion integrated with combined cooling, heating and power generation (CCHP-CLC) by means of thermodynamic evaluation. The coal gasification syngas is introduced into chemical looping combustion for inherent separation of CO_2 without extra energy consumed. The combustion flue gases from both air reactor and fuel reactor are sequentially fed into gas turbines for electricity production, a heat recovery vapor generator unit for further electricity generation with driving a LiBr-H_2O absorption chiller for cooling production in summer and finally a heat exchanger for daily heat water production. A preliminary parameter analysis helps to obtain the optimum operating condition, as steam-to-coal ratio (S/C) of 0.05, oxygen-to-coal ratio (O/C) of 0.75, and operating pressure of chemical looping combustion process of 5 bar. The overall energy efficiency of the CCHP-CLC process is calculated equal to 58.20% in summer compared with that of 60.34% in winter. Importantly, by utilization of such process, the reduction potential of fossil fuel (coal) consumption has been demonstrated to be 23.36% in summer and 27.20% in winter.

  20. Indian experience with radionuclide transport, deposition and decontamination in water-cooled nuclear power reactors

    International Nuclear Information System (INIS)

    Narasimhan, S.V.; Das, P.C.; Lawrence, D.A.; Mathur, P.K.; Venkateswarlu, K.S.

    1983-01-01

    The present generation of water-cooled nuclear reactors uses construction materials chosen with utmost care so that minimum corrosion occurs during the life of the reactor. As interaction between the primary coolant and the construction materials is unavoidable, the coolant is chemically treated to achieve maximum compatibility. First measurements of the chemical and radiochemical composition of the crud present on the in-core and out-of-core primary heat transport system surfaces of a pressurized heavy-water-moderated and cooled reactor (PHWR) are given; then experience in India in the development of a low temperature, one-stage decontaminating formulation for chemical decontamination of the radioactive deposits formed on stainless steel surfaces under BWR conditions is discussed. The effect of the magnitude of the transients in parameters such as reactor power, system temperature, dissolved oxygen content in the coolant, etc. on the nature and migration behaviour of primary heat transport system crud in a PHWR is described. Contributions to radioactive sources and insoluble crud from different primary heat transport system materials are identified and correlated with reactor operations in a PHWR. Man-rem problems faced by nuclear reactors, especially during off-line maintenance, stress the need for reducing the deposited radioactive sources from system surfaces which would otherwise be accessible. Laboratory and on-site experimentation was carried out to effect chemical decontamination on the radioactive deposits formed on the stainless steel surfaces under BWR conditions. Both the reducing and oxidizing formulations were subsequently used in a small-scale, in-plant trial in the clean-up system of a BWR. More than 85% of the deposited 60 Co activity was found to have been removed by the oxidizing formulation. Efforts to develop a decontaminating mixture containing a reducing agent with the help of a circulating loop are in progress in the laboratory. (author)

  1. Performance characteristics of a methanol ejector refrigeration unit

    International Nuclear Information System (INIS)

    Alexis, G.K.; Katsanis, J.S.

    2004-01-01

    This paper discusses the behavior of methanol through an ejector operating in a refrigeration system with a medium temperature thermal source. For detailed calculation of the proposed system, a method has been developed, which employs analytical functions describing the thermodynamic properties of methanol. The proposed cycle has been compared with a Carnot cycle working at the same temperature levels. The influences of three major parameters, generator, condenser and evaporator temperatures, on ejector efficiency and coefficient of performance are discussed. Also, the maximum value of COP was estimated by correlation of the above three temperatures for constant superheated temperature 150 deg. C, and it was 0.139-0.467. The design conditions were generator temperature 117.7-132.5 deg. C, condenser temperature 42-50 deg. C and evaporator temperature -10-5 deg. C

  2. Water, Air Emissions, and Cost Impacts of Air-Cooled Microturbines for Combined Cooling, Heating, and Power Systems: A Case Study in the Atlanta Region

    Directory of Open Access Journals (Sweden)

    Jean-Ann James

    2016-12-01

    Full Text Available The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide (CO2 and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal (heating and cooling demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamily residential buildings.

  3. Method of 16N generation for test of radiation controlled channels at nuclear power stations with water-cooled reactors

    International Nuclear Information System (INIS)

    Khryachkov, V.A.; Bondarenko, I.P.; Dvornikov, P.A.; Zhuravlev, B.V.; Kovtun, S.N.; Khromyleva, T.A.; Pavlov, A.V.; Roshchin, N.G.

    2012-01-01

    The preferences of nuclear reaction use for radiation control channels test in water-cooled power reactors have been analyzed in the paper. The new measurements for more accurate determination of reaction cross section energy dependence have been carried out. A set of new methods for background reducing and improvement of events determination reliability has also been developed [ru

  4. MoXy fiber with active cooling cap for bovine prostate vaporization with high power 200W 532 nm laser

    Science.gov (United States)

    Peng, Steven Y.; Kang, Hyun Wook; Pirzadeh, Homa; Stinson, Douglas

    2011-03-01

    A novel MoXyTM fiber delivery device with Active Cooling Cap (ACCTM) is designed to transmit up to 180W of 532 nm laser light to treat benign prostatic hyperplasia (BPH). Under such high power tissue ablation, effective cooling is key to maintaining fiber power transmission and ensuring the reliability of the fiber delivery device To handle high power and reduce fiber degradation, the MoXy fiber features a larger core size (750 micrometer) and an internal fluid channel to ensure better cooling of the fiber tip to prevent the cap from burning, detaching, or shattering during the BPH treatment. The internal cooling channel was created with a metal cap and tubing that surrounds the optical fiber. In this study MoXy fibers were used to investigate the effect of power levels of 120 and 200 W on in-vitro bovine prostate ablation using a 532 nm XPSTM laser system. For procedures requiring more than 100 kJ, the MoXy fiber at 200W removed tissue at twice the rate of the current HPS fiber at 120W. The fiber maintained a constant tissue vaporization rate during the entire tissue ablation process. The coagulation at 200W was about 20% thicker than at 120W. In conclusion, the new fibers at 200W doubled the tissue removal rate, maintained vaporization efficiency throughout delivery of 400kJ energy, and induced similar coagulation to the existing HPS fiber at 120W.

  5. Ejector-Enhanced, Pulsed, Pressure-Gain Combustor

    Science.gov (United States)

    Paxson, Daniel E.; Dougherty, Kevin T.

    2009-01-01

    An experimental combination of an off-the-shelf valved pulsejet combustor and an aerodynamically optimized ejector has shown promise as a prototype of improved combustors for gas turbine engines. Despite their name, the constant pressure combustors heretofore used in gas turbine engines exhibit typical pressure losses ranging from 4 to 8 percent of the total pressures delivered by upstream compressors. In contrast, the present ejector-enhanced pulsejet combustor exhibits a pressure rise of about 3.5 percent at overall enthalpy and temperature ratios compatible with those of modern turbomachines. The modest pressure rise translates to a comparable increase in overall engine efficiency and, consequently, a comparable decrease in specific fuel consumption. The ejector-enhanced pulsejet combustor may also offer potential for reducing the emission of harmful exhaust compounds by making it practical to employ a low-loss rich-burn/quench/lean-burn sequence. Like all prior concepts for pressure-gain combustion, the present concept involves an approximation of constant-volume combustion, which is inherently unsteady (in this case, more specifically, cyclic). The consequent unsteadiness in combustor exit flow is generally regarded as detrimental to the performance of downstream turbomachinery. Among other adverse effects, this unsteadiness tends to detract from the thermodynamic benefits of pressure gain. Therefore, it is desirable in any intermittent combustion process to minimize unsteadiness in the exhaust path.

  6. Spray cooling

    International Nuclear Information System (INIS)

    Rollin, Philippe.

    1975-01-01

    Spray cooling - using water spraying in air - is surveyed as a possible system for make-up (peak clipping in open circuit) or major cooling (in closed circuit) of the cooling water of the condensers in thermal power plants. Indications are given on the experiments made in France and the systems recently developed in USA, questions relating to performance, cost and environmental effects of spray devices are then dealt with [fr

  7. Exergetic Analysis of a Novel Solar Cooling System for Combined Cycle Power Plants

    Directory of Open Access Journals (Sweden)

    Francesco Calise

    2016-09-01

    Full Text Available This paper presents a detailed exergetic analysis of a novel high-temperature Solar Assisted Combined Cycle (SACC power plant. The system includes a solar field consisting of innovative high-temperature flat plate evacuated solar thermal collectors, a double stage LiBr-H2O absorption chiller, pumps, heat exchangers, storage tanks, mixers, diverters, controllers and a simple single-pressure Combined Cycle (CC power plant. Here, a high temperature solar cooling system is coupled with a conventional combined cycle, in order to pre-cool gas turbine inlet air in order to enhance system efficiency and electrical capacity. In this paper, the system is analyzed from an exergetic point of view, on the basis of an energy-economic model presented in a recent work, where the obtained main results show that SACC exhibits a higher electrical production and efficiency with respect to the conventional CC. The system performance is evaluated by a dynamic simulation, where detailed simulation models are implemented for all the components included in the system. In addition, for all the components and for the system as whole, energy and exergy balances are implemented in order to calculate the magnitude of the irreversibilities within the system. In fact, exergy analysis is used in order to assess: exergy destructions and exergetic efficiencies. Such parameters are used in order to evaluate the magnitude of the irreversibilities in the system and to identify the sources of such irreversibilities. Exergetic efficiencies and exergy destructions are dynamically calculated for the 1-year operation of the system. Similarly, exergetic results are also integrated on weekly and yearly bases in order to evaluate the corresponding irreversibilities. The results showed that the components of the Joule cycle (combustor, turbine and compressor are the major sources of irreversibilities. System overall exergetic efficiency was around 48%. Average weekly solar collector

  8. High power beam dump project for the accelerator prototype LIPAc: cooling design and analysis

    International Nuclear Information System (INIS)

    Parro Albeniz, M.

    2015-01-01

    In the nuclear fusion field running in parallel to ITER (International Thermonuclear Experimental Reactor) as one of the complementary activities headed towards solving the technological barriers, IFMIF (International Fusion Material Irradiation Facility) project aims to provide an irradiation facility to qualify advanced materials resistant to extreme conditions like the ones expected in future fusion reactors like DEMO (DEMOnstration Power Plant). IFMIF consists of two constant wave deuteron accelerators delivering a 125 mA and 40 MeV beam each that will collide on a lithium target producing an intense neutron fluence (1017 neutrons/s) with a similar spectra to that of fusion neutrons [1], [2]. This neutron flux is employed to irradiate the different material candidates to be employed in the future fusion reactors, and the samples examined after irradiation at the so called post-irradiative facilities. As a first step in such an ambitious project, an engineering validation and engineering design activity phase called IFMIF-EVEDA (Engineering Validation and Engineering Design Activities) is presently going on. One of the activities consists on the construction and operation of an accelerator prototype named LIPAc (Linear IFMIF Prototype Accelerator). It is a high intensity deuteron accelerator identical to the low energy part of the IFMIF accelerators. The LIPAc components, which will be installed in Japan, are delivered by different european countries. The accelerator supplies a 9 MeV constant wave beam of deuterons with a power of 1.125 MW, which after being characterized by different instruments has to be stopped safely. For such task a beam dump to absorb the beam energy and take it to a heat sink is needed. Spain has the compromise of delivering such device and CIEMAT (Centro de Investigaciones Energéticas Medioambientales y Tecnológicas) is responsible for such task. The central piece of the beam dump, where the ion beam is stopped, is a copper cone with

  9. Numerical study of the thermo-flow performances of novel finned tubes for air-cooled condensers in power plant

    Science.gov (United States)

    Guo, Yonghong; Du, Xiaoze; Yang, Lijun

    2018-02-01

    Air-cooled condenser is the main equipment of the direct dry cooling system in a power plant, which rejects heat of the exhaust steam with the finned tube bundles. Therefore, the thermo-flow performances of the finned tubes have an important effect on the optimal operation of the direct dry cooling system. In this paper, the flow and heat transfer characteristics of the single row finned tubes with the conventional flat fins and novel jagged fins are investigated by numerical method. The flow and temperature fields of cooling air for the finned tubes are obtained. Moreover, the variations of the flow resistance and average convection heat transfer coefficient under different frontal velocity of air and jag number are presented. Finally, the correlating equations of the friction factor and Nusselt number versus the Reynolds number are fitted. The results show that with increasing the frontal velocity of air, the heat transfer performances of the finned tubes are enhanced but the pressure drop will increase accordingly, resulting in the average convection heat transfer coefficient and friction factor increasing. Meanwhile, with increasing the number of fin jag, the heat transfer performance is intensified. The present studies provide a reference in optimal designing for the air-cooled condenser of direct air cooling system.

  10. Technical analysis of a river basin-based model of advanced power plant cooling technologies for mitigating water management challenges

    International Nuclear Information System (INIS)

    Stillwell, Ashlynn S; Clayton, Mary E; Webber, Michael E

    2011-01-01

    Thermoelectric power plants require large volumes of water for cooling, which can introduce drought vulnerability and compete with other water needs. Alternative cooling technologies, such as cooling towers and hybrid wet-dry or dry cooling, present opportunities to reduce water diversions. This case study uses a custom, geographically resolved river basin-based model for eleven river basins in the state of Texas (the Brazos and San Jacinto-Brazos, Colorado and Colorado-Brazos, Cypress, Neches, Nueces, Red, Sabine, San Jacinto, and Trinity River basins), focusing on the Brazos River basin, to analyze water availability during drought. We utilized two existing water availability models for our analysis: (1) the full execution of water rights-a scenario where each water rights holder diverts the full permitted volume with zero return flow, and (2) current conditions-a scenario reflecting actual diversions with associated return flows. Our model results show that switching the cooling technologies at power plants in the eleven analyzed river basins to less water-intensive alternative designs can potentially reduce annual water diversions by 247-703 million m 3 -enough water for 1.3-3.6 million people annually. We consider these results in a geographic context using geographic information system tools and then analyze volume reliability, which is a policymaker's metric that indicates the percentage of total demand actually supplied over a given period. This geographic and volume reliability analysis serves as a measure of drought susceptibility in response to changes in thermoelectric cooling technologies. While these water diversion savings do not alleviate all reliability concerns, the additional streamflow from the use of dry cooling alleviates drought concerns for some municipal water rights holders and might also be sufficient to uphold instream flow requirements for important bays and estuaries on the Texas Gulf coast.

  11. Thermodynamic assessment of power requirements and impact of different gas-turbine inlet air cooling techniques at two different locations in Oman

    International Nuclear Information System (INIS)

    Dawoud, B.; Zurigat, Y.H.; Bortmany, J.

    2005-01-01

    Gas-turbine inlet air cooling has been considered for boosting the power output during hot seasons. In this paper, the power requirements of several inlet air cooling techniques for gas-turbine power plants in two locations; namely, Marmul and Fahud, in Oman have been evaluated using typical meteorological year (TMY) data. The considered techniques are evaporative cooling, fogging cooling, absorption cooling using both LiBr-H 2 O and aqua-ammonia, and vapour-compression cooling systems. For evaporative cooling, an 88% approach to the wet-bulb temperature has been considered, compared with a 98% approach for fogging cooling. A design compressor inlet air temperature of 14 deg C has been assigned to LiBr-water chilling systems. For both aqua-ammonia absorption and vapour-compression refrigerating systems, a design compressor inlet air temperature of 8 deg C has been selected to avoid the formation of ice fragments as the air is drawn into the mouth of the compressor. These technologies have been compared with respect to their effectiveness in power boosting of small-size gas-turbine power plants used in two oil fields at Marmul and Fahud in the Sultanate of Oman. Fogging cooling is accompanied with 11.4% more electrical energy in comparison with evaporative cooling in both locations. The LiBr-H 2 O cooling offers 40% and 55% more energy than fogging cooling at Fahud and Marmul, respectively. Applying aqua-ammonia-water and vapour-compression cooling, a further annual energy production enhancement of 39% and 46% is expected in comparison with LiBr-H 2 O cooling at Fahud and Marmul, respectively

  12. Cooling of high-density and power electronics by means of heat pipes

    International Nuclear Information System (INIS)

    Hubbeling, L.

    1980-06-01

    This report describes how heat pipes can be used for cooling modern electronic equipment, with numerous advantages over air-cooled systems. A brief review of heat-pipe properties is given, with a detailed description of a functioning prototype. This is a single-width CAMAC unit containing high-density electronic circuits cooled by three heat pipes, and allowing a dissipation of over 120 W instead of the normal maximum of 20 W. (orig.)

  13. Improving activity transport models for water-cooled nuclear power reactors

    Energy Technology Data Exchange (ETDEWEB)

    Burrill, K.A

    2001-08-01

    Eight current models for describing radioactivity transport and radiation field growth around water-cooled nuclear power reactors have been reviewed and assessed. A frequent failing of the models is the arbitrary nature of the determination of the important processes. Nearly all modelers agree that the kinetics of deposition and release of both dissolved and particulate material must be described. Plant data must be used to guide the selection and development of suitable improved models, with a minimum of empirically-based rate constraints being used. Limiting case modelling based on experimental data is suggested as a way to simplify current models and remove their subjectivity. Improved models must consider the recent change to 'coordinated water chemistry' that appears to produce normal solubility behaviour for dissolved iron throughout the fuel cycle in PWRs, but retrograde solubility remains for dissolved nickel. Profiles are suggested for dissolved iron and nickel concentrations around the heat transport system in CANDU reactors, which operate nominally at constant chemistry, i.e., pH{sub T} constant with time, and which use carbon steel isothermal piping. These diagrams are modified for a CANDU reactor with stainless steel piping, in order to show the changes expected. The significance of these profiles for transport in PWRs is discussed for further model improvement. (author)

  14. Onsite nondestructive examination techniques for irradiated water-cooled power reactor fuel

    International Nuclear Information System (INIS)

    1981-03-01

    The International Atomic Energy Agency, in response to the recommendations from several Member States, has prepared this Guidebook on Onsite Non-Destructive Techniques for Irradiated Water-Cooled Power Reactor Fuel with the assistance of a number of experts and organizations in this field. During the preparation of this report it became evident that a comparison between different techniques is a most difficult task and depends on a number of factors related to fuel design, plant characteristics and operating conditions. Consequently the emphasis of the report is on the survey of different techniques presently available. It is also to be noted that because the degree of development for any given technique varies significantly among organizations, it is understood that the report should not be used as consensus standard of the minimum capabilities for each class of techniques, nor does it give recommendations in the regulatory sense. Furthermore, the inclusion of some commercial pieces of equipment, services and other products are for illustrative purposes only and neither implies any preference by the Agency nor can the Agency be liable for any material presented in the report

  15. Magnetocaloric properties and critical behavior of high relative cooling power FeNiB nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, V. [Interdisciplinary Graduate School, Nanyang Technological University, Singapore 639798 (Singapore); Energy Research Institute @NTU, Nanyang Technological University, Singapore 637553 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Maheswar Repaka, D. V.; Chaturvedi, A.; Ramanujan, R. V., E-mail: ramanujan@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Sridhar, I. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2014-10-28

    Low cost magnetocaloric nanomaterials have attracted considerable attention for energy efficient applications. We report a very high relative cooling power (RCP) in a study of the magnetocaloric effect in quenched FeNiB nanoparticles. RCP increases from 89.8 to 640 J kg{sup −1} for a field change of 1 and 5 T, respectively, these values are the largest for rare earth free iron based magnetocaloric nanomaterials. To investigate the magnetocaloric behavior around the Curie temperature (T{sub C}), the critical behavior of these quenched nanoparticles was studied. Detailed analysis of the magnetic phase transition using the modified Arrott plot, Kouvel-Fisher method, and critical isotherm plots yields critical exponents of β = 0.364, γ = 1.319, δ = 4.623, and α = −0.055, which are close to the theoretical exponents obtained from the 3D-Heisenberg model. Our results indicate that these FeNiB nanoparticles are potential candidates for magnetocaloric fluid based heat pumps and low grade waste heat recovery.

  16. Cooling water intake and discharge facilities for Ikata Nuclear Power Station

    International Nuclear Information System (INIS)

    Ishihara, Hisashi; Iwabe, Masakazu

    1977-01-01

    Igata Nuclear Power Station is located at the root of Sadamisaki peninsula in the western part of Ehime Prefecture, Japan, and faces the Iyonada sea area in Seto Inland Sea. The most part of the shoreline forms the cliffs, and the bottom of the sea is rather steep, reaching 60 m depth at 300 m offshore. Considering warm water discharge measures in addition to the natural conditions of tide and current, temperature of sea water, water quality and wave data, it was decided that the deep layer intake system using bottom laid intake pipes and the submerged discharge system with caisson penetrable dike would be adopted for cooling water. The latter was first employed in Japan, and the submerged discharge system with caisson penetrable dike had been developed. The intake was designed to take sea water of about 38 m 3 per sec for each condenser unit at the depth of approximately 17 m with 4.8 m diameter and 116 m length pipes and its calculation details and construction are described. The discharge system was designed to provide a horseshoe-shaped discharge pond with inner diameter of approximately 50 m, surrounded by 17 concrete caissons, and to spout warm water discharge from eight openings of 1.58 m diameter, at the location of approximately 300 m eastward of the intake. Its hydraulic studies and model experiments and its construction are reported. (Wakatsuki, Y.)

  17. Power combiners/dividers for loop pickup and kicker arrays for FNAL stochastic cooling rings

    International Nuclear Information System (INIS)

    Johnson, J.K.; Nemetz, R.

    1985-05-01

    The anti-proton accumulator and debuncher at FNAL will use stochastic methods to ''cool'' the beam. Pairs of quarter-wavelength directional-coupler loops are used to detect and kick the beam. The loops are copper plates which are flush with the upper and lower wall of a rectangular beam pipe. The plates, when surrounded by a properly sized pocket, form a 100-ohm transmission-line directional coupler. As the beam passes, a signal which gives position and time information, is induced in the plates. But, because the signal levels are low (<.5 picowatts per pair), a power combiner (usually several primary combiners feeding a secondary combiner) is used to combine the outputs of many loops. Subsequently, the combined signal is amplified, filtered and then fed into a divider, (that is, a combiner operating in reverse). The divider distributes the signal into a different set of loops which modify (kick) the beam's position. Since the loop couplers are arranged linearly, in arrays of various lengths, combiners also provide a convenient method of reducing the number of vacuum feedthroughs and preamplifiers and their related costs in performance and dollars. In this note we describe various stripline combiner systems that add the outputs of 4, 8, 16 or 32 loops

  18. Hydrogen behaviour and mitigation in water-cooled nuclear power reactors

    International Nuclear Information System (INIS)

    Della Loggia, E.

    1992-01-01

    The Commission of the European Communities (CEC) and the International Atomic Energy Agency (IAEA), within the framework of their safety research activities, initiated and arranged a series of specialist meetings and research contracts on hydrogen behaviour and control. The result of this work is summarized in a report jointly prepared by the two international organizations entitled 'Hydrogen in water-cooled nuclear power reactors'. Independently, the Kurchatov Atomic Energy Institute organized a workshop on the hydrogen issue in Sukhumi, USSR, with CEC and IAEA cooperation. Commonly expressed views have emerged and recommendations were formulated to organize the subsequent seminar/workshop concentrating mainly on the most recent research and analytical projects and findings related to the hydrogen behaviour, and-most importantly-on the practical approaches and engineering solutions to the hydrogen control and mitigation. The seminar/workshop, therefore, addressed the 'theory and practice' aspects of the hydrogen issue. The workshop was structured in the following sessions: combustible gas production; hydrogen distribution; combustion phenomena; combustion effects and threats; and detection and migration

  19. Reducing Pumping Power in Hydronic Heating and Cooling Systems with Microencapsulated Phase Change Material Slurries

    Science.gov (United States)

    Karas, Kristoffer Jason

    Phase change materials (PCMs) are being used increasingly in a variety of thermal transfer and thermal storage applications. This thesis presents the results of a laboratory study into the feasibility of improving the performance of hydronic heating and cooling systems by adding microcapsules filled with a PCM to the water used as heat transport media in these systems. Microencapsulated PCMs (MPCMs) increase the heat carrying capacity of heat transport liquids by absorbing or releasing heat at a constant temperature through a change of phase. Three sequences of tests and their results are presented: 1) Thermal cycling tests conducted to determine the melting temperatures and extent of supercooling associated with the MPCMs tested. 2) Hydronic performance tests in which MPCM slurries were pumped through a fin-and-tube, air-to-liquid heat exchanger and their thermal transfer performance compared against that of ordinary water. 3) Mechanical stability tests in which MPCM slurries were pumped in a continuous loop in order to gauge the extent of rupture due to pumping. It is shown that slurries consisting of water and MPCMs ˜ 14-24 mum in diameter improve thermal performance and offer the potential for power savings in the form of reduced pumping requirements. In addition, it is shown that while slurries of MPCMs 2-5 mum in diameter appear to exhibit better mechanical stability than slurries of larger diameter MPCMs, the smaller MPCMs appear to reduce the thermal performance of air-to-liquid heat exchangers.

  20. Micro Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center, Mississippi State University

    Energy Technology Data Exchange (ETDEWEB)

    Louay Chamra

    2008-09-26

    specifications is observed. Case study data for various micro-CHP system configurations have been discussed and compared. Comparisons are made of the different prime mover/fuel combinations. Also, micro- CHP monthly energy cost results are compared for each system configuration to conventional monthly utility costs for equivalent monthly building power, heating, and cooling requirements.

  1. The decommissioning of commercial magnox gas cooled reactor power stations in the United Kingdom

    International Nuclear Information System (INIS)

    Holt, G.

    1998-01-01

    There are nine commercial Magnox gas-cooled reactor power stations in the United Kingdom. Three of these stations have been shutdown and are being decommissioning, and plans have also been prepared for the eventual decommissioning of the remaining operational stations. The preferred strategy for the decommissioning of the Magnox power stations has been identified as 'Safestore' in which the decommissioning activities are carried out in a number of steps separated by quiescent periods of care and maintenance. The final clearance of the site could be deferred for up to 135 years following station shutdown so as to obtain maximum benefit from radioactive decay. The first step in the decommissioning strategy is to defuel the reactors and transport all spent and new fuel off the site. This work has been completed at all three shutdown stations. Decommissioning work is continuing on the three sites and has involved activities such as dismantling, decontamination, recycling and disposal of some plant and structures, and the preparation of others for retention on the site for a period of care and maintenance. Significant experience has been gained in the practical application of decommissioning, with successful technologies and processes being identified for a wide range of activities. For example, large and small metallic and concrete structures, some with complex geometries, have been successfully decontaminated. Also, the reactors have been prepared for a long period of care and maintenance, with instrumentation and sampling systems having been installed to monitor their continuing integrity. All of this work has been done under careful safety, technical, and financial control. (author)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  3. Cycle improvement for nuclear steam power plant

    International Nuclear Information System (INIS)

    Silvestri, G.J. Jr.

    1976-01-01

    A pressure-increasig ejector element is disposed in an extraction line intermediate to a high pressure turbine element and a feedwater heater. The ejector utilizes high pressure fluid from a reheater drain as the motive fluid to increase the pressure at which the extraction steam is introduced into the feedwater heater. The increase in pressure of the extraction steam entering the feedwater heater due to the steam passage through the ejector increases the heat exchange capability of the extraction steam thus increasing the overall steam power plant efficiency

  4. Evaluation on Cooling Performance of Containment Fan Cooler during Design Basis Accident with Loss of Offsite Power for Kori 3 and 4 Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Bok; Lee, Sang Won [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of); Park, Young Chan [Atomic Creative Technology Co., LTD., Daejeon (Korea, Republic of)

    2007-10-15

    The purpose of this study is to evaluate cooling performance of containment fan cooler units and to review a technical background related to Generic Letter 96-06. In case that design basis accident (DBA) and loss of offsite power (LOOP) occurs, component cooling water (CCW) pumps cannot provide the cooling water source to fan cooler units while fan coolers coast down. Fan cooler units and CCW pumps are restarted by emergency diesel generator (EDG) operation and it takes about 30 seconds. In this scenario, before the EDG restarts and CCW flowrate is restored, heated air in the containment passes through coil of fan cooler units without cooling water source. In this situation, the boiling of water in the fan cooler units may occur. Restarting of CCW pumps may bring about condensation by injected cooling water and water hammer may occur. This thermal-hydraulic effect is sensitive to system configuration, i.e system pressure, containment pressure/temperature, EDG restarting time, etc. In this study, the evaluation of containment fan cooler units was performed for Kori 3 and 4 nuclear power plant.

  5. An Integrated Lumped Parameter-CFD approach for off-design ejector performance evaluation

    International Nuclear Information System (INIS)

    Besagni, Giorgio; Mereu, Riccardo; Chiesa, Paolo; Inzoli, Fabio

    2015-01-01

    Highlights: • We validate a CFD approach for a convergent nozzle ejector using global and local measurement. • We evaluate seven RANS turbulence models for convergent nozzle ejector. • We introduce a lumped parameter model for on-design and off-design ejector performance evaluation. • We analyze the relationship between local flow behavior and lumped parameters of the model. • We discuss how to improve predicting capabilities of the model by variable parameters calibrated on CFD simulations. - Abstract: This paper presents an Integrated Lumped Parameter Model-Computational Fluid-Dynamics approach for off-design ejector performance evaluation. The purpose of this approach is to evaluate the entrainment ratio, for a fixed geometry, in both on-design and off-design operating conditions. The proposed model is based on a Lumped Parameter Model (LPM) with variable ejector component efficiencies provided by CFD simulations. The CFD results are used for developing maps for ejector component efficiencies in a broad range of operating conditions. The ejector component efficiency maps couple the CFD and the LPM techniques for building an Integrated LPM-CFD approach. The proposed approach is demonstrated for a convergent nozzle ejector and the paper is structured in four parts. At first, the CFD approach is validated by global and local data and seven Reynolds Averaged Navier Stokes (RANS) turbulence models are compared: the k–ω SST showed good performance and was selected for the rest of the analysis. At second, a Lumped Parameter Model (LPM) for subsonic ejector is developed and the ejector component efficiencies have been defined. At third, the CFD approach is used to investigate the flow field, to analyze its influence on ejector component efficiencies and to propose efficiency correlations and maps linking ejector component efficiencies and local flow quantities. In the last part, the efficiency maps are embedded into the lumped parameter model, thus creating

  6. Improved thermal/MHD design of self-cooled blankets for high-power-density fusion reactors

    International Nuclear Information System (INIS)

    Sedehi, S.; Lund, K.O.

    1986-01-01

    In this work, an improved self-cooled blanket design is conceived that seeks to minimize the induced current and pressure loss, while maintaining effective cooling and power output. Standard solutions for fully developed MHD flows in rectangular ducts are utilized to describe the magnetic pressure drop in rectangular ducts in terms of the duct aspects ratio. A newly available analytical result for developing and fully developed temperatures is utilized in determining the maximum wall temperature and outlet temperature. Based on results from rectangular ducts, improved annular-type duct designs are proposed and evaluated. The results from the rectangular duct analysis indicate reduced pressure drop and increased thermal performance for large aspect ratio (ratio of duct width in the toroidal B-field direction to width normal to B-field). An infinite aspect ratio occurs for the annular duct design and it is shown that this configuration has superior characteristics as a self-cooled blanket design concept

  7. Research on CO2 ejector component efficiencies by experiment measurement and distributed-parameter modeling

    International Nuclear Information System (INIS)

    Zheng, Lixing; Deng, Jianqiang

    2017-01-01

    Highlights: • The ejector distributed-parameter model is developed to study ejector efficiencies. • Feasible component and total efficiency correlations of ejector are established. • New efficiency correlations are applied to obtain dynamic characteristics of EERC. • More suitable fixed efficiency value can be determined by the proposed correlations. - Abstract: In this study we combine the experimental measurement data and the theoretical model of ejector to determine CO 2 ejector component efficiencies including the motive nozzle, suction chamber, mixing section, diffuser as well as the total ejector efficiency. The ejector is modeled utilizing the distributed-parameter method, and the flow passage is divided into a number of elements and the governing equations are formulated based on the differential equation of mass, momentum and energy conservation. The efficiencies of ejector are investigated under different ejector geometric parameters and operational conditions, and the corresponding empirical correlations are established. Moreover, the correlations are incorporated into a transient model of transcritical CO 2 ejector expansion refrigeration cycle (EERC) and the dynamic simulations is performed based on variable component efficiencies and fixed values. The motive nozzle, suction chamber, mixing section and diffuser efficiencies vary from 0.74 to 0.89, 0.86 to 0.96, 0.73 to 0.9 and 0.75 to 0.95 under the studied conditions, respectively. The response diversities of suction flow pressure and discharge pressure are obvious between the variable efficiencies and fixed efficiencies referring to the previous studies, while when the fixed value is determined by the presented correlations, their response differences are basically the same.

  8. Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

    2009-06-30

    This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well as feasibility of managing cooling water quality with traditional chemical management schemes. Options for chemical treatment to prevent corrosion, scaling, and biofouling were identified through review of current practices, and were tested at bench and pilot-scale. Secondary treated wastewater is the most widely available impaired water that can serve as a reliable source of cooling water makeup. There are no federal regulations specifically related to impaired water reuse but a number of states have introduced regulations with primary focus on water aerosol 'drift' emitted from cooling towers, which has the potential to contain elevated concentrations of chemicals and microorganisms and may pose health risk to the public. It was determined that corrosion, scaling, and biofouling can be controlled adequately in cooling systems using secondary treated municipal wastewater at 4-6 cycles of concentration. The high concentration of dissolved solids in treated AMD rendered difficulties in scaling inhibition and requires more comprehensive pretreatment and scaling controls. Addition of appropriate chemicals can adequately control corrosion, scaling and biological growth in ash transport water, which typically has the best water quality among the three waters evaluated in this study. The high TDS in the blowdown from pilot-scale testing units with both passively treated mine drainage and secondary treated municipal wastewater and the high sulfate concentration in the mine drainage blowdown water were identified as the main challenges for blowdown

  9. POWER CYCLE AND STRESS ANALYSES FOR HIGH TEMPERATURE GAS-COOLED REACTOR

    International Nuclear Information System (INIS)

    Oh, Chang H; Davis, Cliff; Hawkes, Brian D; Sherman, Steven R

    2007-01-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold (1) efficient low cost energy generation and (2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with three turbines and four compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with three stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and a 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to

  10. Exergy analysis of an integrated solid oxide fuel cell and organic Rankine cycle for cooling, heating and power production

    Science.gov (United States)

    Al-Sulaiman, Fahad A.; Dincer, Ibrahim; Hamdullahpur, Feridun

    The study examines a novel system that combined a solid oxide fuel cell (SOFC) and an organic Rankine cycle (ORC) for cooling, heating and power production (trigeneration) through exergy analysis. The system consists of an SOFC, an ORC, a heat exchanger and a single-effect absorption chiller. The system is modeled to produce a net electricity of around 500 kW. The study reveals that there is 3-25% gain on exergy efficiency when trigeneration is used compared with the power cycle only. Also, the study shows that as the current density of the SOFC increases, the exergy efficiencies of power cycle, cooling cogeneration, heating cogeneration and trigeneration decreases. In addition, it was shown that the effect of changing the turbine inlet pressure and ORC pump inlet temperature are insignificant on the exergy efficiencies of the power cycle, cooling cogeneration, heating cogeneration and trigeneration. Also, the study reveals that the significant sources of exergy destruction are the ORC evaporator, air heat exchanger at the SOFC inlet and heating process heat exchanger.

  11. Assessment on the Reactor Containment Cooling Capability of Kori Unit 1 Under LOCA Conditions with Loss of Offsite Power

    International Nuclear Information System (INIS)

    Lee, Jin Yong; Park, Jong Woon; Kim, Hyeong Taek

    2006-01-01

    The fan cooler system is designed to remove heat from containment under postulated accident conditions. During a postulated LOCA concurrent with a Loss of Offsite Power (LOOP), the Component Cooling Water (CCW) pumps that supply cooling water to the fan cooler and the fan that supplies containment air to the fan cooler will temporarily lose power. Then, the high temperature steam in the containment atmosphere will pass over the fan cooler tubing without forced cooling water flow. In that case, boiling may occur in the fan cooler tubes causing steam bubbles to form and pass into the attached CCW piping creating steam voids. Prior to the CCW pumps restart, the presence of steam and subcooled water can induce the potential for water hammer. As the CCW pumps restart, the accumulated steam condenses and the pumped water can produce a water hammer when the void closes. The hydrodynamic loads caused by such a water hammer event could challenge the integrity and the function of the fan cooler and associated CCW system. With respect to this phenomena, the United States Nuclear Regulatory Commission (USNRC) issued the Generic Letter (GL) 96-06, which requests an assessment of the possibility of boiling and water hammer in the cooling water system. The objectives of this study are to develop a analysis method for predicting the thermal hydraulic status of containment fan cooler and then to assess the containment fan cooler of Kori Unit 1 using the developed model under a LOCA with LOOP

  12. Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues.

    Energy Technology Data Exchange (ETDEWEB)

    Kimmell, T. A.; Veil, J. A.; Environmental Science Division

    2009-04-03

    This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on water uses, particularly during drought conditions, this report focuses solely on impacts to the U.S. steam electric power plant fleet. Included are both fossil-fuel and nuclear power plants. One plant examined also uses biomass as a fuel. The purpose of this project is to estimate the impact on generation capacity of a drop in water level at U.S. steam electric power plants due to climatic or other conditions. While, as indicated above, the temperature of the water can impact decisions to halt or curtail power plant operations, this report specifically examines impacts as a result of a drop in water levels below power plant submerged cooling water intakes. Impacts due to the combined effects of excessive temperatures of the returned cooling water and elevated temperatures of receiving waters (due to high ambient temperatures associated with drought) may be examined in a subsequent study. For this study, the sources of cooling water used by the U.S. steam electric power plant fleet were examined. This effort entailed development of a database of power plants and cooling water intake locations and depths for those plants that use surface water as a source of cooling water. Development of the database and its general characteristics are described in Chapter 2 of this report. Examination of the database gives an indication of how low water levels can drop before cooling water intakes cease to function. Water level drops are evaluated against a number of different power plant characteristics, such as the nature of the water source (river vs. lake or reservoir

  13. Leakage investigation in an underground cooling water pipeline at a thermal power station using radiotracer technique

    International Nuclear Information System (INIS)

    Khan, I.H.; Din, U.G.; Gul, S.; Farooq, M.; Qureshi, R.M.

    2004-05-01

    The objective of this study was to locate the leakage point(s) in an underground cooling water pipeline of a Thermal Power Station for pre-shutdown planning purposes. The internal diameter of the pipeline was 2240 mm with 12 mm with 12 (mild steel) wall thickness and it was buried under 1.0 meter reinforced concrete and 0.5-1.0 meter soil/sand cover. The volume flow rate of the pipeline was 29043 m/sup 3/hour at 2kg/cm/sup 2/ pressure. The linear speed of water flowing inside the pipeline was around 2 m/sec. This gave rise to a very high volume fast moving system. Radiotracer technique was used to investigate the problem under investigation. About 50 mCi of /sup 131/I radiotracer, in the form of NaI solution, was injected into the system and radiotracer evolution near suspected leakage point(s) was monitored using radiation detectors (NaI, 2 x 2 inch crystal size). Seven detectors were installed around three teeing off pipes (leakage area) inside the plant building and one at the injection point near the pump outlet. On line data acquisition system was used to acquire the radiotracer data. The leakage water was exiting from the floor just along the pipes carrying main flow of water. The time lag between the arrival, at detectors, of radiotracer flowing inside the pipeline and that present in the leakage water (outside the pipeline) was exploited to identify the position of leakage. The tracer test revealed that there was leakage at two points. The leakage at one point was small as compared at the other points. (author)

  14. PH adjustment of power plant cooling water with flue gas/fly ash

    Science.gov (United States)

    Brady, Patrick V.; Krumhansl, James L.

    2015-09-22

    A system including a vessel including a heat source and a flue; a turbine; a condenser; a fluid conduit circuit disposed between the vessel, the turbine and the condenser; and a diverter coupled to the flue to direct a portion of an exhaust from the flue to contact with a cooling medium for the condenser water. A method including diverting a portion of exhaust from a flue of a vessel; modifying the pH of a cooling medium for a condenser with the portion of exhaust; and condensing heated fluid from the vessel with the pH modified cooling medium.

  15. District heating and cooling systems for communities through power plant retrofit and distribution network. Final report. Volume I. Text

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-15

    An analysis was performed investigating the potential of retrofitting Detroit Edison's Conners Creek power plant to supply district heating and cooling to an area surrounding the plant and within the City of Detroit. A detailed analysis was made of the types and ages of the buildings in the service area as a basis for establishing loads. The analysis of the power plant established possible modifications to the turbines to serve the load in the area. Based upon the service area data and plant retrofit schemes, a distribution system was developed incrementally over a 20-y period. An economic analysis of the system was performed to provide cash flows and payback periods for a variety of energy costs, system costs, and escalation rates to determine the economic viability of the system analyzed. The legal and regulatory requirements required of the district heating and cooling system owner in Michigan were also analyzed to determine what conditions must be met to own and operate the system.

  16. RETRAN-02 analysis of upper head cooling during controlled natural circulation cooldown of Yankee Nuclear Power Station

    International Nuclear Information System (INIS)

    Fujita, N.; Helrich, R.E.; Bergeron, P.A.

    1982-01-01

    RETRAN-02 is particularly well-suited for investigating the fluid conditions in the upper head during a natural circulation cooldown. The RETRAN input model was developed with four basic objectives: (1) accurate description of the upper head cooling mechanisms; (2) proper simulation of natural circulation; (3) respresentations of operator actions required to proceed from full-power to shutdown-cooling-system conditions using both automatic and manual controls; and (4) reduction of the computer cost of simulating this evolution of approximately 10-hour duration. The response of the upper head fluid temperature calculated by RETRAN was in close agreement with measured data obtained from a natural circulation cooldown experiment performed for the Connecticut Yankee Plant, whose design is very similar to the Yankee Nuclear Power Station

  17. A preliminary definition of the parameters of an experimental natural - uranium, graphite - moderated, helium - cooled power reactor

    International Nuclear Information System (INIS)

    Baltazar, O.

    1978-01-01

    A preliminary study of the technical characteristic of an experiment at 32 MWe power with a natural uconium, graphite-moderated, helium cooled reactor is described. The national participation and the use of reactor as an instrument for the technological development of future high temperature gas cooled reactor is considered in the choice of the reactor type. Considerations about nuclear power plants components based in extensive bibliography about similar english GCR reactor is presented. The main thermal, neutronic an static characteristic and in core management of the nuclear fuel is stablished. A simplified scheme of the secondary system and its thermodynamic performance is determined. A scheme of parameters calculation of the reactor type is defined based in the present capacity of calculation developed by Coordenadoria de Engenharia Nuclear and Centro de Processamento de Dados, IEA, Brazil [pt

  18. Design Study of Modular Nuclear Power Plant with Small Long Life Gas Cooled Fast Reactors Utilizing MOX Fuel

    Science.gov (United States)

    Ilham, Muhammad; Su'ud, Zaki

    2017-01-01

    Growing energy needed due to increasing of the world’s population encourages development of technology and science of nuclear power plant in its safety and security. In this research, it will be explained about design study of modular fast reactor with helium gas cooling (GCFR) small long life reactor, which can be operated over 20 years. It had been conducted about neutronic design GCFR with Mixed Oxide (UO2-PuO2) fuel in range of 100-200 MWth NPPs of power and 50-60% of fuel fraction variation with cylindrical pin cell and cylindrical balance of reactor core geometry. Calculation method used SRAC-CITATION code. The obtained results are the effective multiplication factor and density value of core reactor power (with geometry optimalization) to obtain optimum design core reactor power, whereas the obtained of optimum core reactor power is 200 MWth with 55% of fuel fraction and 9-13% of percentages.

  19. Special power supply and control system for the gas-cooled fast reactor-core flow test loop

    International Nuclear Information System (INIS)

    Hudson, T.L.

    1981-09-01

    The test bundle in the Gas-Cooled Fast Reactor-Core Flow Test Loop (GCFR-CFTL) requires a source of electrical power that can be controlled accurately and reliably over a wide range of steady-state and transient power levels and skewed power distributions to simulate GCFR operating conditions. Both ac and dc power systems were studied, and only those employing silicon-controlled rectifiers (SCRs) could meet the requirements. This report summarizes the studies, tests, evaluations, and development work leading to the selection. it also presents the design, procurement, testing, and evaluation of the first 500-kVa LMPL supply. The results show that the LMPL can control 60-Hz sine wave power from 200 W to 500 kVA

  20. A 3D TCAD simulation of a thermoelectric module configured for thermoelectric power generation, cooling and heating

    Science.gov (United States)

    Gould, C. A.; Shammas, N. Y. A.; Grainger, S.; Taylor, I.; Simpson, K.

    2012-06-01

    This paper documents the 3D modeling and simulation of a three couple thermoelectric module using the Synopsys Technology Computer Aided Design (TCAD) semiconductor simulation software. Simulation results are presented for thermoelectric power generation, cooling and heating, and successfully demonstrate the basic thermoelectric principles. The 3D TCAD simulation model of a three couple thermoelectric module can be used in the future to evaluate different thermoelectric materials, device structures, and improve the efficiency and performance of thermoelectric modules.

  1. District heating and cooling systems for communities through power plant retrofit and distribution network, city of Piqua, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The feasibility analysis and evaluation of the Piqua, Ohio District Heating and Cooling Demonstration program is being conducted by the Piqua Municipal Power Co., the Piqua Law Dept., the Public Works Dept., a firm of economic analysts, and the Georgia Tech Engineering Dept. This volume contains information on the organization and composition of the demonstration team; characterization of the Piqua community; and the technical, environmental, institutional; financial, and economic assessments of the project. (LCL)

  2. Consideration of inflation in comparing cooling systems for a nuclear power station

    International Nuclear Information System (INIS)

    Sullivan, W.G.; Fell, H.A.

    1976-01-01

    Based only on the initial capital outlay for each cooling system, natural-draft cooling towers were $7.828 x 10 6 less expensive than once-through cooling. This margin favoring natural-draft cooling dropped to only $2.24 x 10 6 when the present-worth of after-tax cash flow was evaluated in terms of constant-worth dollars. Annual estimates of after-tax cash flow took into account various costs that were either responsive or non-responsive to inflation, the method of loan repayment, and local and federal taxes. It is believed that the tabular procedure presented in the article has widespread applicability to other economic analyses involving the presence of inflation. Its simplicity and ease of understanding should be appealing to decision makers

  3. Effect of water treatment on the comparative costs of evaporative and dry cooled power plants

    International Nuclear Information System (INIS)

    Gold, H.; Goldstein, D.J.; Yung, D.

    1976-07-01

    The report presents the results of a study on the relative cost of energy from a nominal 1000 Mwe nuclear steam electric generating plant using either dry or evaporative cooling at four sites in the United States: Rochester, New York; Sheridan, Wyoming; Gallup, New Mexico and Dallas, Texas. Previous studies have shown that because of lower efficiencies the total annual evaluated costs for dry cooling systems exceeds the total annual evaluated costs of evaporative cooling systems, not including the cost of water. The cost of water comprises the cost of supplying the makeup water, the cost of treatment of the makeup and/or the circulating water in the tower, and the cost of treatment and disposal of the blowdown in an environmentally acceptable manner. The purpose of the study is to show the effect of water costs on the comparative costs of dry and evaporative cooled towers

  4. User's manual for the BNW-II optimization code for dry/wet-cooled power plants

    International Nuclear Information System (INIS)

    Braun, D.J.; Bamberger, J.A.; Braun, D.J.; Faletti, D.W.; Wiles, L.E.

    1978-05-01

    The User's Manual describes how to operate BNW-II, a computer code developed by the Pacific Northwest Laboratory (PNL) as a part of its activities under the Department of Energy (DOE) Dry Cooling Enhancement Program. The computer program offers a comprehensive method of evaluating the cost savings potential of dry/wet-cooled heat rejection systems. Going beyond simple ''figure-of-merit'' cooling tower optimization, this method includes such items as the cost of annual replacement capacity, and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence the BNW-II code is a useful tool for determining potential cost savings of new dry/wet surfaces, new piping, or other components as part of an optimized system for a dry/wet-cooled plant

  5. Cryo-cooled high-power window for high-frequency plasma heating

    International Nuclear Information System (INIS)

    Norajitra, P.; Bojarsky, E.; Reiser, H.; Haefner, H.E.

    1991-09-01

    Within the framework of gyrotron window development, IMF pursues the concept of a single-disk window with edge cooling. Compared to a double-disk window with surface cooling, this concept offers a number of advantages in terms of safety, reliability, and ease of design and fabrication. The coolants which can be used for this purpose are liquid nitrogen and helium at very low temperature. (orig.) [de

  6. A licence to discharge cooling waters in tidal rivers, examplified by the 'Nuclear Power Station Unterweser'

    International Nuclear Information System (INIS)

    Kunz, H.

    1976-01-01

    Illustrated by the example of the lower Weser, aspects for automatic control, supervision measurements, and measurements for the securing of evidence, all in connection with cooling water discharges, are presented. The particularities of tidal rivers and the conditions for measuring systems resulting therefrom are explained. The cooling water discharge of the Kernkraftwerk Unterweser has been assigned an extensive measurement system for the automatic compilation of hydrologic data. The measurement systems design, the measurement stations, and the central station are described. (orig.) [de

  7. Thermal and stability considerations for a supercritical water-cooled fast reactor during power-raising phase of plant startup

    International Nuclear Information System (INIS)

    Cai, Jiejin; Ishiwatari, Yuki; Oka, Yoshiaki; Ikejiri, Satoshi

    2009-01-01

    This paper describes thermal analyses and linear stability analyses of the Supercritical Water-cooled Fast Reactor with 'two-path' flow scheme during the power-raising phase of plant startup. For thermal consideration, the same criterion of the maximum cladding surface temperature (MCST) as applied to the normal operating condition is used. For thermal-hydraulic stability consideration, the decay ratio of 0.5 is applied, which is taken from BWRs. Firstly, we calculated the flow rate distribution among the parallel flow paths from the reactor vessel inlet nozzles to the mixing plenum below the core using a system analysis code. The parallel flow paths consist of the seed fuel assemblies cooled by downward flow, the blanket fuel assemblies cooled by downward flow and the downcomer. Then, the MCSTs are estimated for various reactor powers and feedwater flow rates with system analyses. The decay ratios are estimated with linear stability analyses. The available range of the reactor power and feedwater flow rate to satisfy the thermal and stability criteria is obtained. (author)

  8. CFD investigations on supersonic ejectors for refrigeration applications

    International Nuclear Information System (INIS)

    Bartosiewicz, Y.; Aidoun, Z.; Mercadier, Y.

    2004-01-01

    This paper presents numerical results of a supersonic ejector for refrigeration applications. One of the interesting features is that the current model is based on the NIST properties for the R142b refrigerant: to the authors knowledge, it is the first paper dealing with a local CFD model which takes into account shock-boundary layer interactions in a real refrigerant. The numerical results put demonstrate the crucial role of the secondary nozzle for the mixing rate performance. In addition, these results point out the need of an extensive validation of the turbulence model, especially in the modeling of the off-design mode. (author)

  9. Site dependent factors affecting the economic feasibility of solar powered absorption cooling

    Science.gov (United States)

    Bartlett, J. C.

    1978-01-01

    A procedure was developed to evaluate the cost effectiveness of combining an absorption cycle chiller with a solar energy system. A basic assumption of the procedure is that a solar energy system exists for meeting the heating load of the building, and that the building must be cooled. The decision to be made is to either cool the building with a conventional vapor compression cycle chiller or to use the existing solar energy system to provide a heat input to the absorption chiller. Two methods of meeting the cooling load not supplied by solar energy were considered. In the first method, heat is supplied to the absorption chiller by a boiler using fossil fuel. In the second method, the load not met by solar energy is net by a conventional vapor compression chiller. In addition, the procedure can consider waste heat as another form of auxiliary energy. Commercial applications of solar cooling with an absorption chiller were found to be more cost effective than the residential applications. In general, it was found that the larger the chiller, the more economically feasible it would be. Also, it was found that a conventional vapor compression chiller is a viable alternative for the auxiliary cooling source, especially for the larger chillers. The results of the analysis gives a relative rating of the sites considered as to their economic feasibility of solar cooling.

  10. An investigation on the supersonic ejectors working with mixture of air and steam

    Energy Technology Data Exchange (ETDEWEB)

    Shafaee, Maziar; Tavakol, Mohsen; Riazi, Rouzbeh [University of Tehran, Tehran (Iran, Islamic Republic of); Sharifi, Navid [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2015-11-15

    This study evaluated the performance of an ejector using two streams of fluids as suction flow. Three motive flow pressures were considered when investigating ejector performance; the suction flow pressure was assumed to be constant. The suction flow consisted of a mixture of air and steam and the mass fraction of air in this mixture varied from 0 to 1. The ejector performance curves were analyzed for different mass fractions of air. The results indicate that variation of the mass fraction of air in the suction flow mixture had a significant effect on ejector performance. At all motive flow pressures, the ejector entertainment ratio increased as the mass fraction of air in the suction flow increased. The results also show that the sensitivity of ejector performance to variation in the mass fraction of air in the suction flow decreases at higher motive flow pressures. An increase in motive flow pressure caused the transition from supersonic to subsonic flow to occur at higher ejector discharge pressures.

  11. An investigation on the supersonic ejectors working with mixture of air and steam

    International Nuclear Information System (INIS)

    Shafaee, Maziar; Tavakol, Mohsen; Riazi, Rouzbeh; Sharifi, Navid

    2015-01-01

    This study evaluated the performance of an ejector using two streams of fluids as suction flow. Three motive flow pressures were considered when investigating ejector performance; the suction flow pressure was assumed to be constant. The suction flow consisted of a mixture of air and steam and the mass fraction of air in this mixture varied from 0 to 1. The ejector performance curves were analyzed for different mass fractions of air. The results indicate that variation of the mass fraction of air in the suction flow mixture had a significant effect on ejector performance. At all motive flow pressures, the ejector entertainment ratio increased as the mass fraction of air in the suction flow increased. The results also show that the sensitivity of ejector performance to variation in the mass fraction of air in the suction flow decreases at higher motive flow pressures. An increase in motive flow pressure caused the transition from supersonic to subsonic flow to occur at higher ejector discharge pressures

  12. Safety actuator of the Cabri reactor as a function of its power and cooling fluid flow rate

    International Nuclear Information System (INIS)

    Bertrand, Jean; Da Costa Vieira, David; Tattegrain, Alain

    1969-04-01

    This report present a device which is to provide a stop command to the Cabri reactor when the rate of its power to the cooling fluid rate reaches a value determined with respect to water temperature in the circuit. The stop command is delivered by an actuator which opens a relay contact when the power reaches a specific value. The authors present the device, its characteristics, and principle. They also present the different amplifier circuits, the input and output circuits (flow rate input, temperature input, and output circuit), the energy supply, and the various adjustments

  13. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    International Nuclear Information System (INIS)

    Sant, T; Buhagiar, D; Farrugia, R N

    2014-01-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units

  14. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    Science.gov (United States)

    Sant, T.; Buhagiar, D.; Farrugia, R. N.

    2014-06-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

  15. Possible efficiency improvement by application of various operating regimes for the cooling water pump station at thermal power plant - Bitola

    Directory of Open Access Journals (Sweden)

    Mijakovski Vladimir

    2012-01-01

    Full Text Available Thermal power plant (TPP - Bitola is the largest electricity producer in the Republic of Macedonia with installed capacity of 691 MW. It is a lignite fired power plant, in operation since 1982. Most of the installed equipment is of Russian origin. Power plant's cold end comprised of a condenser, pump station and cooling tower is depicted in the article. Possible way to raise the efficiency of the cold end by changing the operating characteristics of the pumps is presented in the article. Diagramic and tabular presentation of the working characteristics of the pumps (two pumps working in paralel for one block with the pipeline, as well as engaged power for their operation are also presented in this article.

  16. Eye-flukes in fish, living in cooling water from nuclear power plants

    International Nuclear Information System (INIS)

    Hoeglund, J.; Thulin, J.

    1988-01-01

    We report here on the effects of raised water temperature on the prevalence, mean infrapopulation density and consequences of eye-flukes in fish. The study was mainly performed in the Biotest basin situated 120 km north of Stockholm, Sweden. This 1 km 2 basin is an enclosed brackish water (5 permillage) area receiving heated (about 8 degree C) cooling water (90 m 3 /s) from Forsmark nuclear power station. Both morphological and experimental studies of the parasite larvae of sampled fish indicate that we are dealing with four strains of Diplostomum, two of which occur in perch and the other two in roach. Since taxonomic revisions are under hand elsewhere we prefer to name these strains Diplostomum sp1-4. Metacercariae of D.sp 1 were found between the retina and sclera in the eye of perch while that of D.sp 4 were found in the eye-lens of roach in over 90 % of fish examined. Metacercariae of the other two D.-species and of Tylodelphys clavata and Cotylurus sp were found at lower frequencies. Cercariae of Diplostomum spp were found to develop from sporocysts in snails of the genus Lymnaea. The period of cercarial shedding starts about one month earlier and is also prolonged in the Biotest basin compared to the reference locality. The infection procedure, however, is the same in both areas. During experimental infections with cercariae on yearlings of bleak we found a distinct correlation between an increased fry mortality and an increased cercariae density, a connection which was strengthened at increased water temperature. Furthermore, the results indicate that the defence mechanisms of the fish respond slower towards infections with Diplostomum spp than that is known to be the case with bacterial infections. The speed with which the metacercariae accumulate in the eye of the fish is higher in the Biotest basin than in the reference locality. In spite of this, the mean infrapopulation density of metacercariae in older fish is not higher here than in the reference

  17. Nuclear reactor, its cooling facility, nuclear power plant, and method of operating the same

    International Nuclear Information System (INIS)

    Tate, Hitoshi; Tominaga, Kenji; Fujii, Tadashi.

    1993-01-01

    The upper surface of inner structural materials in a container is partitioned by concrete structural walls to form an upper space portion. A pressure relief plate is disposed on the concrete structural walls. If an accident occurs, the pressure relief plate is operated to form a circulation path for a gas to return to the upper space portion again from the upper space portion. The temperature of cooling water in a pressure suppression chamber, that is, a wet well liquid phase portion is elevated by after heat of a reactor core. Evaporated steams transfer from the wet well gas phase portion to the upper space portion passing through pipelines and are mixed with N 2 gas present in the upper space portion. The mixed gas is cooled by a container inner wall cooled by air passing through an air cooling duct, flows downward by way of the pressure relief plate and reaches the wet well gas phase portion again. Since the gases in the upper space circulate by a driving force caused by the after heat, reliability of cooling performance can be improved upon occurrence of an accident without using an active driving force. (I.N.)

  18. Water and Climate Impacts on Power System Operations: The Importance of Cooling Systems and Demand Response Measures

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Connell, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miara, Ariel [City College of New York, NY (United States); Ibanez, Eduardo [GE Energy Connections, Atlanta, GA (United States); Hummon, Marissa [Tendril, Denver, CO (United States)

    2016-12-01

    The U.S. electricity sector is highly dependent upon water resources; changes in water temperatures and water availability can affect operational costs and the reliability of power systems. Despite the importance of water for power system operations, the effects of changes in water characteristics on multiple generators in a system are generally not modeled. Moreover, demand response measures, which can change the magnitude and timing of loads and can have beneficial impacts on power system operations, have not yet been evaluated in the context of water-related power vulnerabilities. This effort provides a first comprehensive vulnerability and cost analysis of water-related impacts on a modeled power system and the potential for demand response measures to address vulnerability and cost concerns. This study uniquely combines outputs and inputs of a water and power plant system model, production cost, model, and relative capacity value model to look at variations in cooling systems, policy-related thermal curtailments, and demand response measures to characterize costs and vulnerability for a test system. Twenty-five scenarios over the course of one year are considered: a baseline scenario as well as a suite of scenarios to evaluate six cooling system combinations, the inclusion or exclusion of policy-related thermal curtailments, and the inclusion or exclusion of demand response measures. A water and power plant system model is utilized to identify changes in power plant efficiencies resulting from ambient conditions, a production cost model operating at an hourly scale is used to calculate generation technology dispatch and costs, and a relative capacity value model is used to evaluate expected loss of carrying capacity for the test system.

  19. A Techno-Economic Assessment of Hybrid Cooling Systems for Coal- and Natural-Gas-Fired Power Plants with and without Carbon Capture and Storage.

    Science.gov (United States)

    Zhai, Haibo; Rubin, Edward S

    2016-04-05

    Advanced cooling systems can be deployed to enhance the resilience of thermoelectric power generation systems. This study developed and applied a new power plant modeling option for a hybrid cooling system at coal- or natural-gas-fired power plants with and without amine-based carbon capture and storage (CCS) systems. The results of the plant-level analyses show that the performance and cost of hybrid cooling systems are affected by a range of environmental, technical, and economic parameters. In general, when hot periods last the entire summer, the wet unit of a hybrid cooling system needs to share about 30% of the total plant cooling load in order to minimize the overall system cost. CCS deployment can lead to a significant increase in the water use of hybrid cooling systems, depending on the level of CO2 capture. Compared to wet cooling systems, widespread applications of hybrid cooling systems can substantially reduce water use in the electric power sector with only a moderate increase in the plant-level cost of electricity generation.

  20. Energetic analysis of a novel vehicle power and cooling/heating cogeneration energy system using cascade cycles

    International Nuclear Information System (INIS)

    Yue, Chen; Han, Dong; Pu, Wenhao; He, Weifeng

    2015-01-01

    This study proposes and investigates a novel VCES (Vehicle power and cooling/heating Cogeneration Energy System), including a topping vehicle engine subsystem, and a bottoming waste-heat recovery subsystem which uses the zeotropic working fluid. The various grade exhaust and coolant waste-heat of the topping subsystem are cascade recovered by the bottoming subsystem, and slide-temperature thermal match in waste heat recovery heat exchangers and the condenser is considered also, obtaining power output and cooling/heating capacity. Based on the experimental data from an actual vehicle's energy demands and its waste-heat characteristics, the proposed VCES (vehicle cogeneration energy system) model is built and verified. Using ammonia-water as working fluid of the bottoming subsystem, integrated thermodynamic performances of the VCES are discussed through introducing three variables: an ambient temperature, the vehicle's velocity and the number of seated occupants. The influence of above three variables on the proposed VCES′ overall thermodynamic performance is analyzed by comparing it to a conventional VCES, and suitable operation conditions are recommended under cooling and heating conditions. - Highlights: • A novel vehicle cogeneration energy system is proposed. • Slide-temperature thermal match at two levels are considered. • Integration of the topping vehicle engine and bottoming waste heat recovery cycle is designed. • The cogeneration system model is built and verified based on experimental data. • Energy-saving potential of the proposed system is investigated

  1. Advanced chip designs and novel cooling techniques for brightness scaling of industrial, high power diode laser bars

    Science.gov (United States)

    Heinemann, S.; McDougall, S. D.; Ryu, G.; Zhao, L.; Liu, X.; Holy, C.; Jiang, C.-L.; Modak, P.; Xiong, Y.; Vethake, T.; Strohmaier, S. G.; Schmidt, B.; Zimer, H.

    2018-02-01

    The advance of high power semiconductor diode laser technology is driven by the rapidly growing industrial laser market, with such high power solid state laser systems requiring ever more reliable diode sources with higher brightness and efficiency at lower cost. In this paper we report simulation and experimental data demonstrating most recent progress in high brightness semiconductor laser bars for industrial applications. The advancements are in three principle areas: vertical laser chip epitaxy design, lateral laser chip current injection control, and chip cooling technology. With such improvements, we demonstrate disk laser pump laser bars with output power over 250W with 60% efficiency at the operating current. Ion implantation was investigated for improved current confinement. Initial lifetime tests show excellent reliability. For direct diode applications 96% polarization are additional requirements. Double sided cooling deploying hard solder and optimized laser design enable single emitter performance also for high fill factor bars and allow further power scaling to more than 350W with 65% peak efficiency with less than 8 degrees slow axis divergence and high polarization.

  2. Theoretical assessment of evaporation rate of isolated water drop under the conditions of cooling tower of thermal power plant

    Directory of Open Access Journals (Sweden)

    Shevelev Sergey

    2017-01-01

    Full Text Available The purpose of the work is numerical modelling of heat and mass transfer at evaporation of water drops under the conditions which are typical for a modern chimney-type cooling tower of a thermal power plant. The dual task of heat and mass transfer with movable boundary at convective cooling and evaporation for a ‘drop–humid air’ system in a spherical coordinate system has been solved. It has been shown that there is a rapid decline of water evaporation rate at the initial stage of the process according to temperature decrease of its surface. It has been stated that the effect of evaporation rate decrease appears greatly in the area of small radiuses.

  3. Economic analysis of wind-powered refrigeration cooling/water-heating systems in food processing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.; Welch, M.

    1980-03-01

    Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in refrigeration cooling and water heating systems in food processing plants. Types of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture.

  4. Prediction of hottest spot temperature in power transformer windings with non-directed and directed oil-forced cooling

    Energy Technology Data Exchange (ETDEWEB)

    Taghikhani, M.A.; Gholami, A. [Electrical Engineering Department, Iran University of Science and Technology (IUST), Narmak, 16846 Tehran (Iran)

    2009-09-15

    Power transformer outages have a considerable economic impact on the operation of an electrical network. One of the most important parameters governing transformer's life expectancy is the hottest spot temperature (HST) value. The classical approach has been to consider the hottest spot temperature as the sum of the ambient temperature, the top-oil temperature rise, and the hottest spot to top-oil temperature gradient. The authors proposed a numerical method based on heat transfer theory using the finite element method and they only needed to solve heat conduction equation. The transformer selected for simulation was a 32 MVA transformer with non-directed oil-forced (NDOF) cooling and directed oil-forced (DOF) cooling. A comparison of the authors results with those obtained from finite integral transform and experimental test confirms the validity and accuracy of the proposed method. (author)

  5. Conceptual design of power conversion system for a fusion power reactor with self-cooled LiPb-blanket. EFDA Task TW2-TRP-PPCS12 - Deliverable 4

    International Nuclear Information System (INIS)

    Vieider, Gottfried

    2002-05-01

    For FPRs with self-cooled LiPb-blanket and He-cooled first wall and divertor a conceptual design of the power conversion system is developed with emphasis on component feasibility, safety, reliability and thermal efficiency. The resulting power conversion system with a steam turbine is based on proven technology for Na- and He-cooled fission reactors and is assessed to yield an overall net thermal plant efficiency of ∼40 % provided the high primary coolant temperatures of ∼700 deg C can be achieved. The required complexity of the five linked cooling systems can be expected to influence plant cost and reliability

  6. Bottoming organic Rankine cycle configurations to increase Internal Combustion Engines power output from cooling water waste heat recovery

    International Nuclear Information System (INIS)

    Peris, Bernardo; Navarro-Esbrí, Joaquín; Molés, Francisco

    2013-01-01

    This work is focused on waste heat recovery of jacket cooling water from Internal Combustion Engines (ICEs). Cooling water heat does not always find use due to its low temperature, typically around 90 °C, and usually is rejected to the ambient despite its high thermal power. An efficient way to take benefit from the ICE cooling water waste heat can be to increase the power output through suitable bottoming Organic Rankine Cycles (ORCs). Thereby, this work simulates six configurations using ten non flammable working fluids and evaluates their performances in efficiency, safety, cost and environmental terms. Results show that the Double Regenerative ORC using SES36 gets the maximum net efficiency of 7.15%, incrementing the ICE electrical efficiency up to 5.3%, although requires duplicating the number of main components and high turbine size. A more rigorous analysis, based on the system feasibility, shows that small improvements in the basic cycle provide similar gains compared to the most complex schemes proposed. So, the single Regenerative ORC using R236fa and the Reheat Regenerative ORC using R134a seem suitable cycles which provide a net efficiency of 6.55%, incrementing the ICE electrical efficiency up to 4.9%. -- Highlights: • Suitable bottoming cycles for ICE cooling water waste heat recovery are studied. • Non flammable working fluids and various ORC configurations are evaluated. • Double regenerative cycle using SES36 is the most efficient configuration. • Regenerative and reheat regenerative ORCs seem feasible cycles. • Electrical efficiency of the ICE can be improved up to 5.3%

  7. Materials and manufacturing for sodium cooled breeder and fusion power reactor

    International Nuclear Information System (INIS)

    Baldev Raj

    2013-01-01

    The paper narrates definitions of challenges relating to materials and manufacturing for sodium cooled fast reactors thermonuclear fusion reactors. Science and technology developed indigenously but in the context of bench marks in the world is described through examples. Solutions to challenges requires synergy among theoretical physicists, computational chemists, material scientists, metallurgists and engineers with their domains of expertise along with foresight effective management

  8. Water-Cooled Data Center Packs More Power Per Rack | Poster

    Science.gov (United States)

    By Frank Blanchard and Ken Michaels, Staff Writers Behind each tall, black computer rack in the data center at the Advanced Technology Research Facility (ATRF) is something both strangely familiar and oddly out of place: It looks like a radiator. The back door of each cabinet is gridded with the coils of the Liebert cooling system, which circulates chilled water to remove heat

  9. Historical records of the electric power and cooling water systems for the experimental facilities in the I.P.P. (1964-1983)

    International Nuclear Information System (INIS)

    Kitajima, Miyoshi.

    1984-01-01

    Twenty years have passed, since experimental studies began in the IPP. This is a status report on the electric power and cooling water systems in this Institute. Historical records on consumption of the electric power and cooling water for experimental facilities are summarized, also. Valuable stories obtained through operation, control and periodic inspection of these systems are described, which will be helpful for construction of new systems in future. Finally problems on safety, reliability, and economy are commented. (author)

  10. Investigation of Absorption Cooling Application Powered by Solar Energy in the South Coast Region of Turkey

    Directory of Open Access Journals (Sweden)

    Ozgoren M.

    2013-04-01

    Full Text Available In this study, an absorption system using ammonia-water (NH3-H2O solution has been theoretically examined in order to meet the cooling need of a detached building having 150 m2 floor area for Antalya, Mersin and Mugla provinces in Turkey. Hourly dynamic cooling load capacities of the building were determined by using Radiant Time Series (RTS method in the chosen cities. For the analysis, hourly average meteorological data such as atmospheric air temperature and solar radiation belonging to the years 1998-2008 are used for performance prediction of the proposed system. Thermodynamic relations for each component of absorption cooling system is explained and coefficients of performance of the system are calculated. The maximum daily total radiation data were calculated as 7173 W/m2day on July 15, 7277 W/m2 day on July 19 and 7231 W/m2day on July 19 for Mersin, Antalya and Mugla, respectively on the 23° toward to south oriented panels from horizontal surface. The generator operating temperatures are considered between 90-130°C and the best result for 110°C is found the optimum degree for maximum coefficient of performance (COP values at the highest solar radiation occurred time during the considered days for each province. The COP values varies between 0.521 and 0.530 for the provinces. In addition, absorber and condenser capacities and thermal efficiency for the absorption cooling system were calculated. The necessary evacuated tube collector area for the different provinces were found in the range of 45 m2 to 47 m2. It is shown that although the initial investment cost is higher for the proposed absorption cooling system, it is economically feasible because of its lower annual operation costs and can successfully be operated for the considered provinces.

  11. Thermodynamic and economic studies of two new high efficient power-cooling cogeneration systems based on Kalina and absorption refrigeration cycles

    International Nuclear Information System (INIS)

    Rashidi, Jouan; Ifaei, Pouya; Esfahani, Iman Janghorban; Ataei, Abtin; Yoo, Chang Kyoo

    2016-01-01

    Highlights: • Proposing two new power and cooling cogeneration systems based on absorption chillers and Kalina cycles. • Model-based comparison through thermodynamic and economic standpoints. • Investigating sensitivity of system performance and costs to the key parameters. • Reducing total annual costs of the base system up to 8% by cogeneration. • Increasing thermal efficiency up to 4.9% despite of cooling generation. - Abstract: Two new power and cooling cogeneration systems based on Kalina cycle (KC) and absorption refrigeration cycle (AC) are proposed and studied from thermodynamic and economic viewpoints. The first proposed system, Kalina power-cooling cycle (KPCC), combines the refrigerant loop of the water-ammonia absorption chiller, consisting of an evaporator and two throttling valves with the KC. A portion of the KC mass flow enters the evaporator to generate cooling after being condensed in the KPCC system. KPCC is a flexible system adapting power and cooling cogeneration to the demand. The second proposed system, Kalina lithium bromide absorption chiller cycle (KLACC), consists of the KC and a single effect lithium bromide-water absorption chiller (AC_L_i_B_r_-_w_a_t_e_r). The KC subsystem discharges heat to the AC_L_i_B_r_-_w_a_t_e_r desorber before condensing in the condenser. The performance and economic aspects of both proposed systems are analyzed and compared with the stand alone KC. A parametric analysis is conducted to evaluate the sensitivity of efficiencies and the generated power and cooling quantities to the key operating variables. The results showed that, thermal efficiency and total annual costs decreased by 5.6% and 8% for KPCC system but increased 4.9% and 58% for KLACC system, respectively. Since the power-cooling efficiency of KLACC is 42% higher than KPCC it can be applied where the aim is cooling generation without considering economic aspects.

  12. IMPROVEMENT OF SYSTEMS OF TECHNICAL WATER SUPPLY WITH COOLING TOWERS FOR HEAT POWER PLANTS TECHNICAL AND ECONOMIC INDICATORS PERFECTION. Part 2

    Directory of Open Access Journals (Sweden)

    Yu. A. Zenovich-Leshkevich-Olpinskiy

    2016-01-01

    Full Text Available The method of calculation of economic efficiency that can be universal and is suitable for feasibility study of modernization of irrigation and water distribution system of cooling towers has been developed. The method takes into account the effect of lower pressure exhaust steam in the condenser by lowering the temperature of the cooling water outlet of a cooling tower that aims at improvement of technical and economic indicators of heat power plants. The practical results of the modernization of irrigation and water distribution system of a cooling tower are presented. As a result, the application of new irrigation and water distribution systems of cooling towers will make it possible to increase the cooling efficiency by more than 4 оС and, therefore, to obtain the fuel savings by improving the vacuum in the turbine condensers. In addition, the available capacity of CHP in the summer period is increased. The results of the work, the experience of modernization of irrigation and water distribution systems of the Gomel CHP-2 cooling towers system, as well as the and methods of calculating of its efficiency can be disseminated for upgrading similar facilities at the power plants of the Belarusian energy system. Some measures are prosed to improve recycling systems, cooling towers and their structures; such measures might significantly improve the reliability and efficiency of technical water supply systems of heat power plants.

  13. Safety assessment for electricity generation failure accident of gas cooled nuclear power plant using system dynamics (SD) method

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

    2013-04-15

    The power production failure happens in the loss of coolant of the nuclear power plants (NPPs). The air ingress is a serious accident in gas cooled NPPs. The quantification of the study performed by the system dynamics (SD) method which is processed by the feedback algorithms. The Vensim software package is used for the simulation, which is performed by the Monte-Carlo method. Two kinds of considerations as the economic and safety properties are important in NPPs. The result shows the stability of the operation when the power can be decided. The maximum value of risk is the 11.77 in 43rd and the minimum value is 0.0 in several years. So, the success of the circulation of coolant is simulated by the dynamical values. (orig.)

  14. Control oriented modeling of ejector in anode gas recirculation solid oxygen fuel cell systems

    International Nuclear Information System (INIS)

    Zhu Yinhai; Li Yanzhong; Cai Wenjian

    2011-01-01

    A one-equation model is proposed for fuel ejector in anode gas recirculation solid oxide fuel cell (SOFC) system. Firstly, the fundamental governing equations are established by employing the thermodynamic, fluid dynamic principles and chemical constraints inside the ejector; secondly, the one-equation model is derived by using the parameter analysis and lumped-parameter method. Finally, the computational fluid dynamics (CFD) technique is employed to obtain the source data for determining the model parameters. The effectiveness of the model is studied under a wide range of operation conditions. The effect of ejector performance on the anode gas recirculation SOFC system is also discussed. The presented model, which only contains four constant parameters, is useful in real-time control and optimization of fuel ejector in the anode gas recirculation SOFC system.

  15. Output feedback dissipation control for the power-level of modular high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Dong, Z.

    2011-01-01

    Because of its strong inherent safety features and the high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR) is the chosen technology for a new generation of nuclear power plants. Such power plants are being considered for industrial applications with a wide range of power levels, thus power-level regulation is very important for their efficient and stable operation. Exploiting the large scale asymptotic closed-loop stability provided by nonlinear controllers, a nonlinear power-level regulator is presented in this paper that is based upon both the techniques of feedback dissipation and well-established backstepping. The virtue of this control strategy, i.e., the ability of globally asymptotic stabilization, is that it takes advantage of the inherent zero-state detectability property of the MHTGR dynamics. Moreover, this newly built power-level regulator is also robust towards modeling uncertainty in the control rod dynamics. If modeling uncertainty of the control rod dynamics is small enough to be omitted, then this control law can be simplified to a classical proportional feedback controller. The comparison of the control performance between the newly-built power controller and the simplified controller is also given through numerical study and theoretical analysis. (author)

  16. Output Feedback Dissipation Control for the Power-Level of Modular High-Temperature Gas-Cooled Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2011-11-01

    Full Text Available Because of its strong inherent safety features and the high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR is the chosen technology for a new generation of nuclear power plants. Such power plants are being considered for industrial applications with a wide range of power levels, thus power-level regulation is very important for their efficient and stable operation. Exploiting the large scale asymptotic closed-loop stability provided by nonlinear controllers, a nonlinear power-level regulator is presented in this paper that is based upon both the techniques of feedback dissipation and well-established backstepping. The virtue of this control strategy, i.e., the ability of globally asymptotic stabilization, is that it takes advantage of the inherent zero-state detectability property of the MHTGR dynamics. Moreover, this newly built power-level regulator is also robust towards modeling uncertainty in the control rod dynamics. If modeling uncertainty of the control rod dynamics is small enough to be omitted, then this control law can be simplified to a classical proportional feedback controller. The comparison of the control performance between the newly-built power controller and the simplified controller is also given through numerical study and theoretical analysis.

  17. Acidity of vapor plume from cooling tower mixed with flue gases emitted from coal-fired power plant.

    Science.gov (United States)

    Hlawiczka, Stanislaw; Korszun, Katarzyna; Fudala, Janina

    2016-06-01

    Acidity of products resulting from the reaction of flue gas components emitted from a coal-fired power plant with water contained in a vapor plume from a wet cooling tower was analyzed in a close vicinity of a power plant (710 m from the stack and 315 m from the cooling tower). Samples of this mixture were collected using a precipitation funnel where components of the mixed plumes were discharged from the atmosphere with the rainfall. To identify situations when the precipitation occurred at the same time as the wind directed the mixed vapor and flue gas plumes above the precipitation funnel, an ultrasound anemometer designed for 3D measurements of the wind field located near the funnel was used. Precipitation samples of extremely high acidity were identified - about 5% of samples collected during 12 months showed the acidity below pH=3 and the lowest recorded pH was 1.4. During the measurement period the value of pH characterizing the background acidity of the precipitation was about 6. The main outcome of this study was to demonstrate a very high, and so far completely underestimated, potential of occurrence of episodes of extremely acid depositions in the immediate vicinity of a coal-fired power plant. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Effect of cycle coupling-configuration on energy cascade utilization for a new power and cooling cogeneration cycle

    International Nuclear Information System (INIS)

    Jing, Xuye; Zheng, Danxing

    2014-01-01

    Highlights: • A new power and cooling cogeneration cycle was proposed. • The thermophysical properties and the performance of the new cycle were calculated. • Different cycle coupling-configurations were analyzed. • The energy efficiency boosting mechanism of the new cycle was elucidated. - Abstract: To recover mid-low grade heat, a new power/cooling cogeneration cycle was proposed by combining the Kalina cycle and the double-effect ammonia–water absorption refrigeration (DAAR) cycle together, and the equivalent heat-to-power and exergy efficiencies of the cogeneration cycle reached 41.18% and 58.00%, respectively. To determine the effect of cycle coupling-configuration on energy cascade utilization for the new cycle, the cycle coupling-configuration of the Kalina and DAAR cycles were first analyzed, after which the cycle coupling-configuration of the new cycle was analyzed. Analysis results showed that the cycle coupling-configuration of the new cycle enhanced the energy cascade utilization. Furthermore, the energy efficiency boosting mechanism of the new cycle was elucidated

  19. Power deposition distribution in liquid lead cooled fission reactors and effects on the reactor thermal behaviour

    International Nuclear Information System (INIS)

    Cevolani, S.; Nava, E.; Burn, K. W.

    2001-01-01

    In the framework of an ADS study (Accelerator Driven System, a reactor cooled by a lead bismuth alloy) the distribution of the deposited energy between the fuel, coolant and structural materials was evaluated by means of Monte Carlo calculations. The energy deposition in the coolant turned out to be about four percent of the total deposited energy. In order to study this effect, further calculations were performed on water and sodium cooled reactors. Such an analysis showed, for both coolant materials, a much lower heat deposition, about one percent. Based on such results, a thermohydraulic analysis was performed in order to verify the effect of this phenomenon on the fuel assembly temperature distribution. The main effect of a significant fraction of energy deposition in the coolant is concerned with the decrease of the fuel pellet temperature. As a consequence, taking into account this effect allows to increase the possibilities of optimization at the disposal of the designer [it

  20. Plugging inaccessible leaks in cooling water pipework in nuclear power plants

    International Nuclear Information System (INIS)

    Powell, A.B.; May, R.; Down, M.G.

    1988-01-01

    The manifestation of initially small leaks in ancilliary reactor cooling water systems is not an unusual event. Often these leaks are in virtually inaccessible locations - for example, buried in thick concrete shielding or situated in cramped and highly radioactive vaults. Such leaks may ultimately prejudice the availability of the entire nuclear system. Continued operation without repair can result in the leak becoming larger, and the leaking water can cause further corrosion problems and interfere with instrumentation. In addition, the water may increase the volume of radwaste. In short, initially trivial leaks may cause significant operating problems. This paper describes the sealing of such leaks in the biological shield cooling system of Ontario Hydro's Pickering nuclear generating station CANDU reactors