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.

Absorption cooling sources atmospheric emissions decrease by implementation of simple algorithm for limiting temperature of cooling water

Science.gov (United States)

Wojdyga, Krzysztof; Malicki, Marcin

2017-11-01

Constant strive to improve the energy efficiency forces carrying out activities aimed at reduction of energy consumption hence decreasing amount of contamination emissions to atmosphere. Cooling demand, both for air-conditioning and process cooling, plays an increasingly important role in the balance of Polish electricity generation and distribution system in summer. During recent years' demand for electricity during summer months has been steadily and significantly increasing leading to deficits of energy availability during particularly hot periods. This causes growing importance and interest in trigeneration power generation sources and heat recovery systems producing chilled water. Key component of such system is thermally driven chiller, mostly absorption, based on lithium-bromide and water mixture. Absorption cooling systems also exist in Poland as stand-alone systems, supplied with heating from various sources, generated solely for them or recovered as waste or useless energy. The publication presents a simple algorithm, designed to reduce the amount of heat for the supply of absorption chillers producing chilled water for the purposes of air conditioning by reducing the temperature of the cooling water, and its impact on decreasing emissions of harmful substances into the atmosphere. Scale of environmental advantages has been rated for specific sources what enabled evaluation and estimation of simple algorithm implementation to sources existing nationally.

Techno-Economic Analysis of Solar Absorption Cooling for Commercial buildings in India

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Muthalagappan Narayanan

2017-11-01

Full Text Available Space cooling and heating always tends to be a major part of the primary energy usage. By using fossil fuel electricity for these purposes, the situation becomes even worse. One of the major electricity consumptions in India is air conditioning. There are a lot of different technologies and few researchers have come up with a debate between solar absorption cooling and PV electric cooling. In a previous paper, PV electric cooling was studied and now as a continuation, this paper focuses on solar thermal absorption cooling systems and their application in commercial/office buildings in India. A typical Indian commercial building is taken for the simulation in TRNSYS. Through this simulation, the feasibility and operational strategy of the system is analysed, after which parametric study and economic analysis of the system is done. When compared with the expenses for a traditional air conditioner unit, this solar absorption cooling will take 13.6 years to pay back and will take 15.5 years to payback the price of itself and there after all the extra money are savings or profit.  Although the place chosen for this study is one of the typical tropical place in India, this payback might vary with different places, climate and the cooling demand. Article History: Received May 12th 2017; Received in revised form August 15th 2017; Accepted 1st Sept 2017; Available online How to Cite This Article: Narayanan, M. (2017. Techno-Economic Analysis of Solar Absorption Cooling for Commercial Buildings in India.  International Journal of Renewable Energy Development, 6(3, 253-262. https://doi.org/10.14710/ijred.6.3.253-262

Use of process steam in vapor absorption refrigeration system for cooling and heating applications: An exergy analysis

Directory of Open Access Journals (Sweden)

S. Anand

2016-12-01

Full Text Available The exponential increase in cost of conventional fuels shifts the interest toward the use of alternative as well waste energy sources for the operation of refrigeration and air-conditioning units. The present study therefore analyzes the performance of a process steam-operated vapor absorption system for cooling and heating applications using ammonia and water as working fluids based on first and second laws of thermodynamics. A mathematical model has been developed based on exergy analysis to investigate the performance of the system. The different performance parameters such as coefficient of performance (COP and exergetic efficiency of absorption system for cooling and heating applications are also calculated under different operating conditions. The results obtained show that cooling and heating COP along with second law efficiency (exergy efficiency increases with the heat source temperature at constant evaporator, condenser, and absorber temperature. Also, COP as well as exergy efficiency increases with an increase in the evaporator temperature at constant generator, condenser, and absorber temperature. The effect of ambient temperature on the exergetic efficiency for cooling and heating applications is also studied. The results obtained from the simulation studies can be used to optimize different components of the system so that the performance can be improved significantly.

Testing and further development of a solar absorption cooling plant

Science.gov (United States)

Amannsberger, K.; Heckel, H.; Kreutmair, J.; Weber, K. H.

1984-12-01

Ammonia water absorption cooling units using the process heat of line-focusing solar collectors were developed and tested. Reduction of the evaporation temperature to minus 10 C; development of an air-cooled rectifying device for the refrigerant vapor; dry cooling of absorber and condenser by natural draft; refrigerating capacities of 14 to 10 kW which correspond to air temperatures of 25 to 40 C and 24 kW power consumption to heat the machine; auxiliary power requirement 450 W; full compatibility with changing heat input and air temperature, adaptation by automatic stabilization effects; and power optimization under changing boundary conditions by a simple regulating procedure independent of auxiliary power are achieved. The dynamic behavior of the directly linked collector-refrigeration machine system was determined. Operating conditions, market, and economic viability of solar cooling in third-world countries are described. Ice production procedures using absorption cooling units are demonstrated.

Energy and parametric analysis of solar absorption cooling systems in various Moroccan climates

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Y. Agrouaz

2017-03-01

Full Text Available The aim of this work is to investigate the energetic performance of a solar cooling system using absorption technology under Moroccan climate. The solar fraction and the coefficient of performance of the solar cooling system were evaluated for various climatic conditions. It is found that the system operating in Errachidia shows the best average annual solar fraction (of 30% and COP (of 0.33 owing to the high solar capabilities of this region. Solar fraction values in other regions varied between 19% and 23%. Moreover, the coefficient of performance values shows in the same regions a significant variation from 0.12 to 0.33 all over the year. A detailed parametric study was as well carried out to evidence the effect of the operating and design parameters on the solar air conditioner performance.

Exergoeconomic Assessment of Solar Absorption and Absorption–Compression Hybrid Refrigeration in Building Cooling

Directory of Open Access Journals (Sweden)

Yue Jing

2018-02-01

Full Text Available The paper mainly deals with the match of solar refrigeration, i.e., solar/natural gas-driven absorption chiller (SNGDAC, solar vapor compression–absorption integrated refrigeration system with parallel configuration (SVCAIRSPC, and solar absorption-subcooled compression hybrid cooling system (SASCHCS, and building cooling based on the exergoeconomics. Three types of building cooling are considered: Type 1 is the single-story building, type 2 includes the two-story and three-story buildings, and type 3 is the multi-story buildings. Besides this, two Chinese cities, Guangzhou and Turpan, are taken into account as well. The product cost flow rate is employed as the primary decision variable. The result exhibits that SNGDAC is considered as a suitable solution for type 1 buildings in Turpan, owing to its negligible natural gas consumption and lowest product cost flow rate. SVCAIRSPC is more applicable for type 2 buildings in Turpan because of its higher actual cooling capacity of absorption subsystem and lower fuel and product cost flow rate. Additionally, SASCHCS shows the most extensive cost-effectiveness, namely, its exergy destruction and product cost flow rate are both the lowest when used in all types of buildings in Guangzhou or type 3 buildings in Turpan. This paper is helpful to promote the application of solar cooling.

Open absorption system for cooling and air conditioning using membrane contactors - Final report

Energy Technology Data Exchange (ETDEWEB)

Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R.; Dorer, V. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland)

2008-07-01

Air conditioning systems based upon the open absorption principle, essentially an absorption device operating at atmospheric pressure, have been proposed and investigated at many instances in the past eighty years. Their potential for improving energy efficiency is clearly recognized in the earliest research reports. By the mid 1950ies, solar thermal energy was being applied to drive open absorption-based air conditioning systems. For several reasons, however, the open absorption technology was not mature enough to take place in the mainstream. In the past two decades, vigorous efforts have been undertaken to reverse this situation, but success continued to elude, despite the fact that the main problems, such as corrosion, aerosols in the supply air, etc., have been identified. This report details the work and the main results from the MemProDEC Project. In this project innovative solutions were proposed, and successfully investigated, for the corrosion problem and the improvement of efficiency of the absorption process, in particular a new method to cool a very compact absorber. The practically uniform flow distribution for all three streams in the absorber (air, water and desiccant) warrants the contact of the air to be dehumidified with the desiccant over the whole surface of exchange (across a porous membrane). This, together with the cooling with water in counter flow to the air, are the key factors for the excellent effectiveness of the absorber. As the results show, the dehydration effectiveness of the prototype absorber is up to 150 % higher than that previously obtained by others. The solutions developed for compactness and modularity represent an important step in the way to flexible manufacturing, i.e. using a single element size to assemble autonomous air handling units of various nominal capacities. And although the manufacturing methods of the individual elements require improvement, namely by avoiding adhesive bonding, the choice of materials and the

SIMULATION OF SOLAR LITHIUM BROMIDE–WATER ABSORPTION COOLING SYSTEM WITH DOUBLE GLAZED FLAT PLATE COLLECTOR FOR ADRAR

Directory of Open Access Journals (Sweden)

ML CHOUGUI

2014-12-01

Full Text Available Adrar is a city in the Sahara desert, in southern Algeria known for its hot and dry climate, where a huge amount of energy is used for air conditioning. The aim of this research is to simulate a single effect lithium bromide–water absorption chiller coupled to a double-glazed flat plate collector to supply the cooling loads for a house of 200m2 in Adrar. The thermal energy is stored in an insulated thermal storage tank. The system was designed to cover a cooling load of 10.39KW for design day of July. Thermodynamic model was established to simulate the absorption cycle. The results have shown that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 65.3 m2, which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy.

Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

International Nuclear Information System (INIS)

Kim, D.S.; Infante Ferreira, C.A.

2009-01-01

A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

Simulation of a combined heating, cooling and domestic hot water system based on ground source absorption heat pump

International Nuclear Information System (INIS)

Wu, Wei; You, Tian; Wang, Baolong; Shi, Wenxing; Li, Xianting

2014-01-01

Highlights: • A combined heating/cooling/DHW system based on GSAHP is proposed in cold regions. • The soil imbalance is effectively reduced and soil temperature can be kept stable. • 20% and 15% of condensation/absorption heat is recovered by GSAHP to produce DHW. • The combined system can improve the primary energy efficiency by 23.6% and 44.4%. - Abstract: The amount of energy used for heating and domestic hot water (DHW) is very high and will keep increasing. The conventional ground source electrical heat pump used in heating-dominated buildings has the problems of thermal imbalance, decrease of soil temperature, and deterioration of heating performance. Ground source absorption heat pump (GSAHP) is advantageous in both imbalance reduction and primary energy efficiency (PEE) improvement; however, the imbalance is still unacceptable in the warmer parts of cold regions. A combined heating/cooling/DHW (HCD) system based on GSAHP is proposed to overcome this problem. The GSAHPs using generator absorber heat exchange (GAX) and single-effect (SE) cycles are simulated to obtain the performance under various working conditions. Different HCD systems in Beijing and Shenyang are simulated comparatively in TRNSYS, based on which the thermal imbalance, soil temperature, heat recovery, and energy efficiency are analyzed. Results show that GSAHP–GAX–HCD is suitable for Beijing and GSAHP–SE–HCD is suitable for Shenyang. The imbalance ratio can be reduced to −14.8% in Beijing and to 6.0% in Shenyang with an annual soil temperature variation of only 0.5 °C and 0.1 °C. Furthermore, about 20% and 15% of the total condensation/absorption heat is recovered to produce DHW, and the PEE can reach 1.516 in Beijing and 1.163 in Shenyang. The combined HCD systems can achieve a PEE improvement of 23.6% and 44.4% compared with the normal heating/cooling systems

Energy and Exergy Based Optimization of Licl-Water Absorption Cooling System

Directory of Open Access Journals (Sweden)

Bhargav Pandya

2017-06-01

Full Text Available This study presents thermodynamic analysis and optimization of single effect LiCl-H2O absorption cooling system. Thermodynamic models are employed in engineering equation solver to compute the optimum performance parameters. In this study, cut off temperature to operate system has been obtained at various operating temperatures. Analysis depicts that on 3.59 % rise in evaporator temperature, the required cut-off temperature decreased by 12.51%. By realistic comparison between thermodynamic first and second law analysis, optimum generator temperature relative to energy and exergy based prospective has been evaluated. It is found that optimum generator temperature is strong function of evaporator and condenser temperature. Thus, it is feasible to find out optimum generator temperature for various combinations of evaporator and condenser temperatures. Contour plots of optimum generator temperature for several combinations of condenser and absorber temperatures have been also depicted.

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.

Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

International Nuclear Information System (INIS)

Gonzalez-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

2011-01-01

A new direct air-cooled single-effect LiBr-H 2 O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48 m 2 field of flat-plate collectors was used to test the single-effect operation mode of the prototype. Results from an experimental campaign carried out in Madrid during summer 2010 are shown and operation parameters corresponding to two typical summer days are detailed. The prototype worked efficiently, with COP values around 0.6. Cooling power varied from 2 kW to 3.8 kW, which represented about 85% of the prototype's nominal capacity. Chilled water temperatures mostly ranged between 14 o C and 16 o C, although the lowest measured value was of 12.8 o C. Condensation and absorption temperatures were under 50 o C and 46 o C, respectively, even with outdoor temperatures of 40 o C. Driving water temperature ranged between 85 o C and 110 o C. As a mean, the system was able to meet 65% of the cooling demand corresponding to a room of 40 m 2 . No signs of crystallization were observed during about a hundred hours of operation. - Highlights: → A novel direct air-cooled single-effect absorption prototype is described. → Feasibility of air-cooled technology for LiBr-H 2 O absorption cooling is proved. → An adiabatic absorber using flat-fan sheets avoids crystallization of the solution. → A field of flat-plate collectors powers the chiller at temperatures from 85 to 110 o C. → The prototype works with thermal COP about 0.6.

Cogen-absorption plants for refrigeration purposes and turbine air inlet cooling

Energy Technology Data Exchange (ETDEWEB)

Langreck, Juergen [Colibri bv (Netherlands)

2000-04-01

Most cogeneration systems produce power and heat but with absorption refrigeration plants (ARP) the products are power and 'cold'. An ARP driven by heat from a turbine exhaust can provide the cooling for the inlet air with very low consumption of electricity, consequently there is a significant increase in power output from the cogeneration unit. Two different ARP systems are currently available but the author describes only the ammonia-water system, which can achieve temperatures down to -60 degrees C. The article discusses the principle behind ARP, the capital cost and returns on investment, how the cogeneration plant is linked to the ARP, ARP for turbine inlet air cooling, and the potential applications of cogeneration-ARP.

Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

Energy Technology Data Exchange (ETDEWEB)

Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

2006-11-15

This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

Modeling and experimental validation of the solar loop for absorption solar cooling system using double-glazed collectors

International Nuclear Information System (INIS)

Marc, Olivier; Praene, Jean-Philippe; Bastide, Alain; Lucas, Franck

2011-01-01

Solar cooling applied to buildings is without a doubt an interesting alternative for reducing energy consumption in traditional mechanical steam compression air conditioning systems. The study of these systems should have a closely purely fundamental approach including the development of numerical models in order to predict the overall installation performance. The final objective is to estimate cooling capacity, power consumption, and overall installation performance with relation to outside factors (solar irradiation, outside temperature...). The first stage in this work consists of estimating the primary energy produced by the solar collector field. The estimation of this primary energy is crucial to ensure the evaluation of the cooling capacity and therefore the cooling distribution and thermal comfort in the building. Indeed, the absorption chiller performance is directly related to its heat source. This study presents dynamic models for double glazing solar collectors and compares the results of the simulation with experimental results taken from our test bench (two collectors). In the second part, we present an extensive collector field model (36 collectors) from our solar cooling installation at The University Institute of Technology in St Pierre, Reunion Island as well as our stratified tank storage model. A comparison of the simulation results with real scale solar experimental data taken from our installation enables validation of the double glazing solar collector and stratified tank dynamic models.

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

LiBr absorption systems integrated with high–efficiency IGSG plant

DEFF Research Database (Denmark)

Rokni, Masoud; Bellomare, Filippo

2015-01-01

vapor compression inverse cycles; waste heat from other systems can in fact be used as an efficient input instead of electrical energy. The opportunity to integrate Li-Br absorption systems with a high-efficiency energy plant was studied; rejected heat from a Municipal Solid Waste Gasification Plant......Over the last few years, the energy demand for cooling systems is increasing; different solutions in fact have been proposed in order to minimize the energetic and environmental impact of this trend. In this direction, absorption cooling systems are recognized as a valid alternative to traditional...

Exergetic and energetic comparison of LiCl-H_2O and LiBr-H_2O working pairs in a solar absorption cooling system

International Nuclear Information System (INIS)

Bellos, Evangelos; Tzivanidis, Christos; Antonopoulos, Kimon A.

2016-01-01

Highlights: • Two working pairs (LiCl-H_2O and LiBr-H_2O) are examined in a solar absorption chiller. • The examined single effect absorption chiller is driven by flat plate collectors. • The system is analyzed energetically and energetically for 3 ambient temperatures. • LiCl-H_2O performs better than LiBr-H_2O in all the examined cases. • The optimum operating temperature is lower for the case of pair LiCl-H_2O. - Abstract: The objective of this study is to investigate the use of an alternative working pair in a solar absorption cooling system. LiCl-H_2O is the new examined pair and it is compared energetically and exegetically with the conventional pair LiBr-H_2O, which is the most usual in air-conditioning applications. The simplest solar cooling system is analyzed in order to focus in the comparison between these working fluids. Specifically, flat plate collectors, coupled with a storage tank, feed the single effect absorption chiller which produces 250 kW cooling at 10 °C. The two pairs are examined parametrically for various heat source temperature levels and for three ambient temperature levels (25 °C, 30 °C and 35 °C). The minimization of the collecting area, which means maximum exergetic efficiency, is the optimization goal in every case. The final results show that LiCl-H_2O pair performs better in all cases by giving greater exergetic efficiency. More specifically, about 8% lower collecting area is required to cover the demanded cooling load with this working pair. Another interesting result is that the optimum heat source temperature for the LiCl-H_2O is roughly lower than the respective for the LiBr-H_2O. The system is analyzed in steady state with the commercial software Engineering Equator Solver (EES).

Experimental diagnosis of the influence of operational variables on the performance of a solar absorption cooling system

International Nuclear Information System (INIS)

Venegas, M.; Rodriguez-Hidalgo, M.C.; Salgado, R.; Lecuona, A.; Rodriguez, P.; Gutierrez, G.

2011-01-01

This paper presents the analysis of the performance of a solar cooling facility along one summer season using a commercial single-effect water-lithium bromide absorption chiller aiming at domestic applications. The facility works only with solar energy using flat plate collectors and it is located at Universidad Carlos III de Madrid, Spain. The statistical analysis performed with the gathered data shows the influence of five daily operational variables on the system performance. These variables are solar energy received along the day (H) and the average values, along the operating period of the solar cooling facility (from sunrise to the end of the cold-water production), of the ambient temperature (T -bar ), the wind velocity magnitude (V), the wind direction (θ) and the relative humidity (RH). First order correlation functions are given. The analysis of the data allows concluding that the most influential variables on the daily cooling energy produced and the daily averaged solar COP are H, V and θ. The period length of cold-water production is determined mainly by H and T -bar .

Experimental diagnosis of the influence of operational variables on the performance of a solar absorption cooling system

Energy Technology Data Exchange (ETDEWEB)

Venegas, M.; Rodriguez-Hidalgo, M.C.; Lecuona, A.; Rodriguez, P.; Gutierrez, G. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Salgado, R. [Dpto. Ingenieria Mecanica, Universidad Interamericana de Puerto Rico, Recinto de Bayamon, 500 Carretera Dr. John Will Harris Bayamon, PR 00957-6257 (United States)

2011-04-15

This paper presents the analysis of the performance of a solar cooling facility along one summer season using a commercial single-effect water-lithium bromide absorption chiller aiming at domestic applications. The facility works only with solar energy using flat plate collectors and it is located at Universidad Carlos III de Madrid, Spain. The statistical analysis performed with the gathered data shows the influence of five daily operational variables on the system performance. These variables are solar energy received along the day (H) and the average values, along the operating period of the solar cooling facility (from sunrise to the end of the cold-water production), of the ambient temperature (anti T), the wind velocity magnitude (V), the wind direction ({theta}) and the relative humidity (RH). First order correlation functions are given. The analysis of the data allows concluding that the most influential variables on the daily cooling energy produced and the daily averaged solar COP are H, V and {theta}. The period length of cold-water production is determined mainly by H and anti T. (author)

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.

Comparative analysis of thermally activated, environmentally friendly cooling systems

International Nuclear Information System (INIS)

Gupta, Y.; Metchop, L.; Frantzis, A.; Phelan, P.E.

2008-01-01

This paper compares the relative performances of three different thermally activated, environmentally friendly cooling systems, e.g. a silica-gel-water adsorption system, a LiBr-H 2 O absorption system and a desiccant air system. The adsorption and absorption systems in the current study employ water as the refrigerant, while the desiccant system cools atmospheric air directly. Each of these systems can be utilized at relatively low heat source temperatures such as achieved by flat plate solar collectors, but it is unclear which of these systems is best suited to what range of heat source temperature. Our study explores answers to this question by generating quantitative results comparing their relative thermal performance, i.e. COP and refrigeration capacity, and a qualitative comparison based on the size, maturity of technology, safe operation etc. In order to provide a fair comparison between the fundamentally different systems, a UA (overall heat transfer coefficient multiplied by the heat transfer area) value of 1.0 kW deg. C -1 is considered for the heat exchanger that transfers heat from the supplied hot water. Furthermore, to compare systems of similar size, the mass of silica-gel in the adsorption and desiccant systems and the mass of LiBr-H 2 O solution in the absorption system were specified such that each system provides the same amount of refrigeration (8.0 kW) at a source temperature of 90 deg. C. It is found that the absorption and adsorption cooling systems have a higher refrigeration capacity at heat source temperatures below 90 deg. C, while the desiccant air system outperforms the others at temperatures above 90 deg. C

Overview of Resources for Geothermal Absorption Cooling for Buildings

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gluesenkamp, Kyle R [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mehdizadeh Momen, Ayyoub [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-06-01

This report summarizes the results of a literature review in three areas: available low-temperature/coproduced geothermal resources in the United States, energy use for space conditioning in commercial buildings, and state of the art of geothermal absorption cooling.

Heat Driven Cooling in District Energy Systems; Vaermedriven Kyla

Energy Technology Data Exchange (ETDEWEB)

Rydstrand, Magnus; Martin, Viktoria; Westermark, Mats [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

2004-07-01

high costs. However heat sinks are unavoidable from a system perspective and there are potential cost savings since a low-pressure steam turbines will not be required if heat driven cooling is implemented. The fuel utilization for some technologies (not necessarily the best technology) was evaluated in two different scenarios: 1) with electricity production from coal; and 2) with electricity production from natural gas. It is shown in the scenarios that the heat driven cooling technologies give lower fuel consumption as compared producing electricity as an intermediate product before cooling is produced. Further it should be noted that electricity is produced, not consumed, if heat is used directly for the production of cooling. We claim that cost effective solutions for district heat driven chillers and/or combined production of electricity and district cooling can be found in all climates with high enough density of heating and cooling demands. It was found that district heat driven chillers can be very energy efficient in warm and humid climates since desiccant systems are an effective way of handling latent cooling loads. In dry climates, with low latent loads, water distributed cooling has a large potential and absorption cooling will give high fuel utilization seen from a system perspective. In climates where water shortage is a problem it is possible that the temperature lift of the conventional absorption chiller has to be increased in order to be able to use dry cooling towers. The temperature lift can be increased by changing the chiller design or by using a different working pair. Heat driven cooling can be integrated into an energy system in different ways. In USA and Japan, district heating is not well developed. Instead small, distributed combined heat and power (CHP) plants with high exhaust temperatures are widespread. Cooling is often produced, in these regions, through absorption cooling (using heat from CHP) or compression chillers depending on

The design of integrated cooling processes in district heating systems; Kylprocessers design i fjaerrvaermesystem

Energy Technology Data Exchange (ETDEWEB)

Martin, Viktoria [Royal Inst. of Technology, Stockholm (SE). Dept. of Chemical Engineering and Technology; Setterwall, Fredrik [Fredrik Setterwall Konsult AB, Sollentuna (Sweden); Andersson, Mikael [AB Berglunds Rostfria, Boden (Sweden)

2005-07-01

This report presents the results from an investigation regarding the design of integrated cooling processes in district heating systems. Increasing investment levels in district heating networks combined with expanding comfort cooling demand makes heat-driven cooling processes extremely interesting. This solution has a great potential tbe cost effective. At the same time, the problem with the environmentally harmful refrigerants used in conventional vapor compression chillers is avoided. In many cases it is beneficial for the district heating provider to lower the supply and/or return temperatures in the network, at least for part of the year. In combined heat and power generation (CHP) a lower supply temperature means that the electricity yield increases. In this context, it is important to consider that conventional absorption chillers are designed to run on 120 deg C heat. However,they can work on heat with temperature as low as 80 deg C if a chiller with a large enough generator area is used, although this has a negative impact on the dimensions of other components and leads ta lower coefficient of performance. For these reasons low temperature driven absorption chillers have been developed in recent years. Two concepts (from different manufacturers) are now available on the market. Factors that affect the choice of district heat-integrated cooling processes have been investigated in this study. Key system aspects that embody a holistic view on the production of heating, cooling and power are especially highlighted. Important tasks have been: To quantify the following effects on the design of an integrated cooling process: the temperatures in the district heating net, available cooling water temperature (to cool the absorber and condenser), electricity price, and the composition of the energy system (e.g. fuel and CHP or power-only mode of operation). To analyze the potential of the low temperature driven chiller concept with regards to energy and cost

Thermodynamic analysis of an absorption refrigeration system used to cool down the intake air in an Internal Combustion Engine

International Nuclear Information System (INIS)

Novella, R.; Dolz, V.; Martín, J.; Royo-Pascual, L.

2017-01-01

Highlights: • Enough power in the exhaust gases is available to operate the absorption cycle. • Three engine operating points are presented in the article. • Improvement potential up to 4% is possible in the engine indicated efficiency. • Engine indicated efficiency benefit was experimentally confirmed by direct testing. - Abstract: This paper deals with the thermodynamic analysis of an absorption refrigeration cycle used to cool down the temperature of the intake air in an Internal Combustion Engine using as a heat source the exhaust gas of the engine. The solution of ammonia-water has been selected due to the stability for a wide range of operating temperatures and pressures and the low freezing point. The effects of operating temperatures, pressures, concentrations of strong and weak solutions in the absorption refrigeration cycle were examined to achieve proper heat rejection to the ambient. Potential of increasing Internal Combustion Engine efficiency and reduce pollutant emissions was estimated by means of theoretical models and experimental tests. In order to provide boundary conditions for the absorption refrigeration cycle and to simulate its effect on engine performance, a 0D thermodynamic model was used to reproduce the engine performance when the intake air is cooled. Furthermore, a detailed experimental work was carried out to validate the results in real engine operation. Theoretical results show how the absorption refrigeration system decreases the intake air flow temperature down to a temperature around 5 °C and even lower by using the bottoming waste heat energy available in the exhaust gases in a wide range of engine operating conditions. In addition, the theoretical analysis estimates the potential of the strategy for increasing the engine indicated efficiency in levels up to 4% also at the operating conditions under evaluation. Finally, this predicted benefit in engine indicated efficiency has been experimentally confirmed by direct

Strandby Harbour on solar cooling. Demonstration of 8.000 m{sup 2} solar collectors combined with flue gas cooling with a absorption cooling system; Combined heat and power plant (CHP); Strandby havn paa solkoeling. Demonstration af 8.000 m{sup 2} solfangere kombineret med roeggaskoeling med absorptionskoeleanlaeg

Energy Technology Data Exchange (ETDEWEB)

Soerensen, Flemming (Strandby Varmevaerk, Strandby (Denmark)); Soerensen, Per Alex (PlanEnergi, Skoerping (Denmark)); Ulbjerg, F. (Ramboell, Odense (Denmark)); Sloth, H. (Houe and Olsen, Thisted (Denmark))

2010-04-15

The aim of the project was to demonstrate 1) high solar heating ratio (18% annually) at a decentralized natural gas combined heat and power plant; 2) increased efficiency (5% of the heat consumption) in a natural gas CHP by using an extra flue gas cooler and an absorption heat pump; 3) a double tank system where a new tank during winter is used for cooling/ heat storage for the absorption heat pump and during summer for solar heat storage in serial operation with the old tank. The concept of combining solar power, absorption cooling and natural gas-fired small-scale CHP in Strandby met expectations and could be replicated in other CHP plants. However, it is important to note that if major construction modifications in the flue gas condensation system in the boiler or engine are required, the operating hours must not be reduced significantly in the amortisation period for the conversion. (ln)

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.

MULTIFUNCTIONAL SOLAR SYSTEMS FOR HEATING AND COOLING

Directory of Open Access Journals (Sweden)

Doroshenko A.V.

2010-12-01

Full Text Available The basic circuits of multifunctional solar systems of air drainage, heating (hot water supply and heating, cooling and air conditioning are developed on the basis of open absorption cycle with a direct absorbent regeneration. Basic decisions for new generation of gas-liquid solar collectors are developed. Heat-mass-transfer apparatus included in evaporative cooling system, are based on film interaction of flows of gas and liquid and in them, for the creation of nozzle, multi-channel structures from polymeric materials and porous ceramics are used. Preliminary analysis of multifunctional systems possibilities is implemented.

Techno-Economic Analysis of Solar Absorption Cooling for Commercial buildings in India

OpenAIRE

Muthalagappan Narayanan

2017-01-01

Space cooling and heating always tends to be a major part of the primary energy usage. By using fossil fuel electricity for these purposes, the situation becomes even worse. One of the major electricity consumptions in India is air conditioning. There are a lot of different technologies and few researchers have come up with a debate between solar absorption cooling and PV electric cooling. In a previous paper, PV electric cooling was studied and now as a continuation, this paper focuses on so...

Turbine airfoil cooling system with cooling systems using high and low pressure cooling fluids

Science.gov (United States)

Marsh, Jan H.; Messmann, Stephen John; Scribner, Carmen Andrew

2017-10-25

A turbine airfoil cooling system including a low pressure cooling system and a high pressure cooling system for a turbine airfoil of a gas turbine engine is disclosed. In at least one embodiment, the low pressure cooling system may be an ambient air cooling system, and the high pressure cooling system may be a compressor bleed air cooling system. In at least one embodiment, the compressor bleed air cooling system in communication with a high pressure subsystem that may be a snubber cooling system positioned within a snubber. A delivery system including a movable air supply tube may be used to separate the low and high pressure cooling subsystems. The delivery system may enable high pressure cooling air to be passed to the snubber cooling system separate from low pressure cooling fluid supplied by the low pressure cooling system to other portions of the turbine airfoil cooling system.

Increasing utilisation of district heating through absorption cooling technology; Oekat fjaerrvaermeutnyttjande med hjaelp av absorptionstekniken

Energy Technology Data Exchange (ETDEWEB)

Bjurstroem, Henrik; Ingvarsson, Paul; Zinko, Heimo

2010-10-15

The purpose of the research project presented in this report was to find ways to return a lower temperature from the generator of the chillers in a supply/return connection. The initial target is 40 deg C. Ideally, the absorption chiller and possible ulterior uses of the remaining heat in the heat carrier (the water flowing through the generator) should be as close as possible to a pure heat load. The hot-water driven absorption chillers used today to produce cooling in DH networks are exclusively so-called single-effect (Sweden) chillers with water and lithium bromide as working pair. This study aims at raising as much as possible the upper bounds on the absorption chiller capacity that may be connected to a DH network, by lowering the temperature at the outlet. To this end, several approaches have been used: - A search for alternative designs of the absorption chiller, focusing on commercially available and tested technology, both those yielding a large temperature decrease over the generator and those that may be operated at lower temperatures than the conventional solutions; - An examination of the impact of further uses of the remaining heat on temperature in the return line. larger. Smaller units are considered only if they can be used to illustrate a principle. As a complement to this investigation, a few other issues have been treated: - What temperature levels should a system actually be designed for? - The LAVA method to calculate the impact of supply and return temperatures in the DH network on the economics of power production is presented; - Interesting technical solutions using desiccant-aided evaporative cooling are shortly described; - The modern developments in the field of working pairs (refrigerant and absorbent) are reviewed. Assumptions made here are that there is a significant demand for cooling, and that the demand is large enough to justify operating the cogeneration plant at a load level exceeding its lowest acceptable part load rather than

Norwegian contribution to the IEA Annex 24 - Absorption Machines for Heating and Cooling; IEA annex 24. Absorpsjonsmaskin for oppvarming og kjoeling

Energy Technology Data Exchange (ETDEWEB)

Grandum, Svein

2000-01-01

This report summarizes the Norwegian contribution to the IEA Annex 24 - Absorption Machines for Heating and Cooling in Future Energy Systems. Thermally operated heat pumps and coolers have not been widely used in Norway. They are not economically competitive compared to compression heat pumps because of Norway's cheap hydroelectric power. If the present trend in Norway's use of electricity persists, Norway will soon be dependent on imported electric power. This calls for measures to reduce the consumption of electricity, and the role of absorption heat pumps will be of increasing importance, especially for cooling purposes. For larger commercial buildings that require climate cooling, absorption coolers based on waste heat may have a good total economy. Industrial processes that have an excess of heat at a high temperature and which need cooling, may profit from the use of this type of cooler. Information dissemination is important for efficient use of this technology. The research work done at Institute of energy technology, Kjeller, Norway, is an important contribution to this end.

France uses the sun to cool its wine: the Banyuls winery solar cooling system

Energy Technology Data Exchange (ETDEWEB)

Anon.

2003-12-01

The engineering consultancy Tecsol was asked to design a cooling system for a winery that would limit the variations in temperature during the year. Tecsol proposed a solar system. The total investment cost amounted to nearly two million French Francs (300,000 euros), almost double the cost of a conventional air-conditioning system. However, because the solar system reduced the conventional energy needs of the warehouse by about 40%, the French Agency for Environment and Energy Management (ADEME) provided a 37% subsidy for its rational use of energy. The 'Solarclim' solar installation has three functions: it produces hot water via 693 vacuum tube collectors with a useful surface of 130 m{sup 2}. The collectors are fixed to the roof of the wine cellar, which has an angle of 15 deg. Heat from the collectors is transferred to a 1000-litre hot water storage tank; it produces chilled water using a lithium bromide absorption plant with a nominal cooling capacity of 52 kW. This is housed in the technical premises on the lowest level and is used in conjunction with a 180 kW open-circuit cooling tower on the north facade; and the third function combines air-conditioning and, when necessary, space heating. The installation has been operating for 12 years with no particular problems. The equipment is environmentally friendly. The solar heat source avoids CO{sub 2} emissions, the absorption machine does not use CFCs or HCFCs, and the system is totally silent. (UK)

Energetic and economic evaluation of solar thermal and photovoltaic cooling system in Cuban hotel

International Nuclear Information System (INIS)

Díaz Torres, Yamile; Valdivia Nodal, Yarelis; Castellanos Molina, Luis Miguel; Torres del Toro, Migdalia; Monteagudo Llanes, José

2015-01-01

The present paper discusses the energetic and economic feasibility of using two configurations of solar cooling in a Cuban Hotel. The air conditioning hybrid system schemes are: conventional system (Chiller) interconnected in parallel with a solar- powered absorption cooling system (SACS); and a photovoltaic cooling system (PCS). There were analyzed by methodologies and thermodynamic principles governing these technologies. The results show that their uses are alternatives for reducing energy consumption and environmental impact. (full text)

Review on absorption technology with emphasis on small capacity absorption machines

Directory of Open Access Journals (Sweden)

Labus Jerko M.

2013-01-01

Full Text Available The aim of this paper is to review the past achievements in the field of absorption systems, their potential and possible directions for future development. Various types of absorption systems and research on working fluids are discussed in detail. Among various applications, solar cooling and combined cooling, heating and power (CCHP are identified as two most promising applications for further development of absorption machines. Under the same framework, special attention is given to the small capacity absorption machines and their current status at the market. Although this technology looks promising, it is still in development and many issues are open. With respect to that fact, this paper covers all the relevant aspects for further development of small capacity absorption machines.

Designing the lithium bromide air conditioning absorption system for a bus

International Nuclear Information System (INIS)

Yusoff Ali; Kamaruzzaman Sopian; Hariadi

2006-01-01

A system of air-conditioning using Lithium Bromide absorption system is used as an alternative refrigerant that will not pollute the atmosphere. Lithium Bromide is a chemical salt soluble in water. There is a big difference between vapour compression system and LiBr 2 absorption system. The absorption air conditioning system is made of a generator, a condenser, an evaporator and an absorber with necessary pumps and piping. When LiBr 2 solution is heated under low pressure, water will evaporate first, while LiBr 2 will remain in the solution and will become more concentrated. The water is the refrigerant in this system. The generator, where the water is vapourised, is heated using an electric heater or solar energy. The LiBr 2 weak solution under low pressure in the generator is heated and the water evaporate into vapour. The vapour produced is then cooled in the condenser and then expanded into the evaporator. The refrigerant (water) in evaporator change phase from liquid to vapour by absorbing heat from cooling water, which flow in the coil in the evaporator. The chilled water obtained is then pumped into the fan coil, which will be used in conditioning the passenger area of the bus. The water vapour from the evaporator is absorbed into LiBr 2 solution in the absorber, forming a weak solution of LiBr 2 . the weak solution from the absorber is then pumped back to the generator to regenerate. The absorption system does not use compressor, but requires pumps that need lower input power compared to that of a compressor. The system is considered as a new application for the bus. This will have great potential and will be environmentally friendly. The model in this study will be used for calculation of the cooling load for the bus

Solar-powered single-and double-effect directly air-cooled LiBr–H2O absorption prototype built as a single unit

International Nuclear Information System (INIS)

Izquierdo, M.; González-Gil, A.; Palacios, E.

2014-01-01

Highlights: • This work presents a novel solar cooling air-cooled absorption prototype for buildings. • The solution (LiB r –H 2 O) and the refrigerant (H 2 O) are cooled directly by air. • The cooling is produced from solar energy when operates in single-effect mode. • If the demand is not met the prototype is able to operate in double-effect mode. - Abstract: This work describes an installation in Madrid, Spain, designed to test a new solar-powered air-cooled absorption refrigeration system. This installation essentially consists of a-48 m 2 field of flat-plate solar collectors, a 1500-L hot water storage tank and a single and-double effect air-cooled lithium bromide absorption prototype. Designed and built by our research group, this prototype is able to operate either as a single-effect unit (4.5 kW) or as a double-effect unit (7 kW). In operation as single-effect mode, the prototype is driven by solar energy, whereas in operation as a double effect mode, an external energy source may be used. The prototype’s evaporator is connected to a fan-coil placed inside an 80-m 2 laboratory that represent the average size of a Spanish housing unit. In August 2009, the cooling system was tested in the single-effect operation mode. The results show that the system is able to meet approximately 65% of the laboratory’s seasonal cooling demand, although 100% may be reached for a few days. The prototype can also operate in double-effect mode to meet the cooling demand. In that case, the prototype is fed by thermal oil, which is warmed until it reaches the process temperature in the high-temperature generator. The prototype can operate in either single-effect mode or in double-effect mode or can also operate simultaneously both modes using the components common to both modes, namely, the absorber, evaporator, condenser, solution pumps and control equipment. This paper reports the experimental results from the prototype operating separately in single-effect and

Solar absorption cooling

NARCIS (Netherlands)

Kim, D.S.

2007-01-01

As the world concerns more and more on global climate changes and depleting energy resources, solar cooling technology receives increasing interests from the public as an environment-friendly and sustainable alternative. However, making a competitive solar cooling machine for the market still

Design optimization and sensitivity analysis of a biomass-fired combined cooling, heating and power system with thermal energy storage systems

International Nuclear Information System (INIS)

Caliano, Martina; Bianco, Nicola; Graditi, Giorgio; Mongibello, Luigi

2017-01-01

Highlights: • A novel operation strategy for biomass-fired combined cooling, heating and power system is presented. • A design optimization of the system is conducted. • The effects of variation of the incentive for the electricity generation are evaluated. • The effects of the variation of the absorption chiller size and the thermal energy storage system one are evaluated. • The inclusion of a cold storage system into the combined cooling, heating and power system is also analyzed. - Abstract: In this work, an operation strategy for a biomass-fired combined cooling, heating and power system, composed of a cogeneration unit, an absorption chiller, and a thermal energy storage system, is formulated in order to satisfy time-varying energy demands of an Italian cluster of residential multi-apartment buildings. This operation strategy is adopted for performing the economical optimization of the design of two of the devices composing the combined cooling, heating and power system, namely the absorption chiller and the storage system. A sensitivity analysis is carried out in order to evaluate the impact of the incentive for the electricity generation on the optimized results, and also to evaluate, separately, the effects of the variation of the absorption chiller size, and the effects of the variation of the thermal energy storage system size on the system performance. In addition, the inclusion into the system of a cold thermal energy storage system is analyzed, as well, assuming different possible values for the cold storage system cost. The results of the sensitivity analysis indicate that the most influencing factors from the economical point of view are represented by the incentive for the electricity generation and the absorption chiller power. Results also show that the combined use of a thermal energy storage and of a cold thermal energy storage during the hot season could represent a viable solution from the economical point of view.

A parametric study of solar operated cooling system

International Nuclear Information System (INIS)

Zagalei, Abdullatif Salin

2006-01-01

Because of energy for air conditioning has been the fastest-growing segment of energy of consumption market in Libya and generally in north Africa, and with the realization depleting nature of fossil fuel, solar cooling of buildings which leads to the improvement of human comfort represents a potentially significant application of solar energy where the availability of solar radiation meets with the cooling load demand. This application has been shown to be technically feasible but the equipment needs further investigative research to improve its performance and feasibility. A solar operated absorption cooling system with energy storage is selected. A latent heat storage would be a space saver for such application for solar energy. A system modeling is an essential activity in order to go for system simulation. A complete solar cooling system to be modeled through the thermodynamic analysis of each system components. Resulting a package of equations used directly to the system simulation in order to predict the system performance to obtain the optimum working conditions for the selected cooling system. A computer code which is used to simulate a series of calculations was written in Fortran language according to the constructed information flow diagram and simulation program flow char. For a typical input data a set of results are reported and discussed and shows that the selected system promises to be a good choice for air conditioning application in Libya specially for large building as storehouses, shopping centers, public administrative.(Author)

Analysis of an electricity–cooling cogeneration system based on RC–ARS combined cycle aboard ship

International Nuclear Information System (INIS)

Liang, Youcai; Shu, Gequn; Tian, Hua; Liang, Xingyu; Wei, Haiqiao; Liu, Lina

2013-01-01

Highlights: • A novel electricity–cooling cogeneration system was used to recover waste heat aboard ships. • Performance of such RC–ARS system was investigated theoretically. • Optimal exergy output can be obtained when the vaporization pressure of RC is 300 kPa. • The exergy efficiency of cogeneration system is 5–12% higher than that of basic Rankine cycle only. - Abstract: In this paper, an electricity–cooling cogeneration system based on Rankine–absorption refrigeration combined cycle is proposed to recover the waste heat of the engine coolant and exhaust gas to generate electricity and cooling onboard ships. Water is selected as the working fluid of the Rankine cycle (RC), and a binary solution of ammonia–water is used as the working fluid of the absorption refrigeration cycle. The working fluid of RC is preheated by the engine coolant and then evaporated and superheated by the exhaust gas. The absorption cycle is powered by the heat of steam at the turbine outlet. Electricity output, cooling capacity, total exergy output, primary energy ratio (PER) and exergy efficiency are chosen as the objective functions. Results show that the amount of additional cooling output is up to 18 MW. Exergy output reaches the maximum 4.65 MW at the vaporization pressure of 300 kPa. The study reveals that the electricity–cooling cogeneration system has improved the exergy efficiency significantly: 5–12% increase compared with the basic Rankine cycle only. Primary energy ratio (PER) decreases as the vaporization pressure increases, varying from 0.47 to 0.40

Parallel LC circuit model for multi-band absorption and preliminary design of radiative cooling.

Science.gov (United States)

Feng, Rui; Qiu, Jun; Liu, Linhua; Ding, Weiqiang; Chen, Lixue

2014-12-15

We perform a comprehensive analysis of multi-band absorption by exciting magnetic polaritons in the infrared region. According to the independent properties of the magnetic polaritons, we propose a parallel inductance and capacitance(PLC) circuit model to explain and predict the multi-band resonant absorption peaks, which is fully validated by using the multi-sized structure with identical dielectric spacing layer and the multilayer structure with the same strip width. More importantly, we present the application of the PLC circuit model to preliminarily design a radiative cooling structure realized by merging several close peaks together. This omnidirectional and polarization insensitive structure is a good candidate for radiative cooling application.

An active cooling system for photovoltaic modules

International Nuclear Information System (INIS)

Teo, H.G.; Lee, P.S.; Hawlader, M.N.A.

2012-01-01

The electrical efficiency of photovoltaic (PV) cell is adversely affected by the significant increase of cell operating temperature during absorption of solar radiation. A hybrid photovoltaic/thermal (PV/T) solar system was designed, fabricated and experimentally investigated in this work. To actively cool the PV cells, a parallel array of ducts with inlet/outlet manifold designed for uniform airflow distribution was attached to the back of the PV panel. Experiments were performed with and without active cooling. A linear trend between the efficiency and temperature was found. Without active cooling, the temperature of the module was high and solar cells can only achieve an efficiency of 8–9%. However, when the module was operated under active cooling condition, the temperature dropped significantly leading to an increase in efficiency of solar cells to between 12% and 14%. A heat transfer simulation model was developed to compare to the actual temperature profile of PV module and good agreement between the simulation and experimental results is obtained.

Solar heating and cooling system installed at Leavenworth, Kansas

Science.gov (United States)

1980-01-01

A solar heating and cooling is described which is designed to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2,200 square feet. Five 3 ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3,000 gallon chilled water storage tank. Two 3,000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

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.

Device for recirculation cooling of cooling water by natural or forced chaft

Energy Technology Data Exchange (ETDEWEB)

Ruehl, H; Honekamp, H; Katzmann, A

1975-10-23

The invention is concerned with a device for recirculation cooling of cooling water by natural or forced draft. Through a cascading system mounted on supporting columns at a vertical distance to ground level, cooling air is flowing in cross- or counterflow to the cooling water freely falling from the cascading system. The cooling water collecting zone below the cascading system has an absorption floor arranged nearly horizontal and/or inclined, with a cam-type profile on its upperside, which is bounded on its circumference by at least one cooling water release channel provided below its level and/or which is divided in the sense of a surface subdivision. By these means, a reduction of the amount of material required for the supporting columns and an increase of the stability of the columns is to be achieved. Furthermore, the deposition of mud is to be avoided as for as possible, and noise generation during operation is to be reduced considerably. For this purpose, the absorption floor may be made of material sound insulating and/or may be coated with such a material.

Exergy analysis of single effect absorption refrigeration systems: The heat exchange aspect

International Nuclear Information System (INIS)

Joybari, Mahmood Mastani; Haghighat, Fariborz

2016-01-01

Highlights: • Exergy analysis of LiBr/H 2 O absorption systems with identical COP was carried out. • Exergy destruction rank: absorber followed by generator, condenser and evaporator. • Lower heat source and chilled water inlet temperature reduced exergy destruction. • Higher cooling water inlet temperature reduced exergy destruction. • Lower HTF mass flow rate increased exergy efficiency even for fixed system COP. - Abstract: The main limitation of conventional energy analysis for the thermal performance of energy systems is that this approach does not consider the quality of energy. On the other hand, exergy analysis not only provides information about the systems performance, but also it can specify the locations and magnitudes of losses. A number of studies investigated the effect of parameters such as the component temperature, and heat transfer fluid (HTF) temperature and mass flow rate on the exergetic performance of the same absorption refrigeration system; thus, reported different coefficient of performance (COP) values. However, in this study, the system COP was considered to remain constant during the investigation. This means comparing systems with different heat exchanger designs (based on HTF mass flow rate and temperature) having the same COP value. The effect of HTF mass flow rate and inlet temperature of the cooling water, chilled water and heat source on the outlet specific exergy and exergy destruction rate of each component was investigated. It was found that the lower HTF mass flow rate decreased exergy destruction of the corresponding component. Moreover, the lower temperature of heat source and chilled water inlet increased the system exergetic efficiency. That was also the case for the higher cooling water inlet temperature. Based on the analysis, since the absorber and condenser accounted for a large portion of the total exergy destruction, cooling tower modification with lower cooling water mass flow rate is recommended

Artificial neural network analysis of triple effect absorption refrigeration systems

Energy Technology Data Exchange (ETDEWEB)

Hajizadeh Aghdam, A. [Department of Mechanical Engineering, Islamic Azad University (Iran, Islamic Republic of)], email: a.hajizadeh@iaukashan.ac.ir; Nazmara, H.; Farzaneh, B. [Department of Mechanical Engineering, University of Tabriz (Iran, Islamic Republic of)], email: h.nazmara@nioec.org, email: b_farzaneh_ms@yahoo.com

2011-07-01

In this study, artificial neural networks are utilized to predict the performance of triple effect series and parallel flow absorption refrigeration systems, with lithium bromide/water as the working fluid. Important parameters such as high generator and evaporator temperatures were varied and their effects on the performance characteristics of the refrigeration unit were observed. Absorption refrigeration systems make energy savings possible because they can use heat energy to produce cooling, in place of the electricity used for conventional vapour compression chillers. In addition, non-conventional sources of energy (such as solar, waste heat, and geothermal) can be utilized as their primary energy input. Moreover, absorption units use environmentally friendly working fluid pairs instead of CFCs and HCFCs, which affect the ozone layer. Triple effect absorption cycles were analysed. Results apply for both series and parallel flow systems. A relative preference for parallel-flow over series-flow is also shown.

Absorption of water vapour in the falling film of water-(LiBr + LiI + LiNO{sub 3} + LiCl) in a vertical tube at air-cooling thermal conditions

Energy Technology Data Exchange (ETDEWEB)

Bourouis, Mahmoud; Valles, Manel; Medrano, Marc; Coronas, Alberto [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, CREVER, Universitat Rovira i Virgili, Autovia de Salou, s/n, 43006, Tarragona (Spain)

2005-05-01

In air-cooled water-LiBr absorption chillers the working conditions in the absorber and condenser are shifted to higher temperatures and concentrations, thereby increasing the risk of crystallisation. To develop this technology, two main problems are to be addressed: the availability of new salt mixtures with wider range of solubility than water-LiBr, and advanced absorber configurations that enable to carry out simultaneously an appropriate absorption process and an effective air-cooling. One way of improving the solubility of LiBr aqueous solutions is to add other salts to create multicomponent salt solutions. The aqueous solution of the quaternary salt system (LiBr + LiI + LiNO{sub 3} + LiCl) presents favourable properties required for air-cooled absorption systems: less corrosive and crystallisation temperature about 35 K lower than that of water-LiBr.This paper presents an experimental study on the absorption of water vapour over a wavy laminar falling film of an aqueous solution of (LiBr + LiI + LiNO{sub 3} + LiCl) on the inner wall of a water-cooled smooth vertical tube. Cooling water temperatures in the range 30-45 C were selected to simulate air-cooling thermal conditions. The results are compared with those obtained in the same experimental set-up with water-LiBr solutions.The control variables for the experimental study were: absorber pressure, solution Reynolds number, solution concentration and cooling water temperature. The parameters considered to assess the absorber performance were: absorber thermal load, mass absorption flux, degree of subcooling of the solution leaving the absorber, and the falling film heat transfer coefficient.The higher solubility of the multicomponent salt solution makes possible the operation of the absorber at higher salt concentration than with the conventional working fluid water-LiBr. The absorption fluxes achieved with water-(LiBr + LiI + LiNO{sub 3} + LiCl) at a concentration of 64.2 wt% are around 60 % higher than

A dynamic model of an innovative high-temperature solar heating and cooling system

Directory of Open Access Journals (Sweden)

Buonomano Annamaria

2016-01-01

Full Text Available In this paper a new simulation model of a novel solar heating and cooling system based on innovative high temperature flat plate evacuated solar thermal collector is presented. The system configuration includes: flat-plate evacuated solar collectors, a double-stage LiBr-H2O absorption chiller, gas-fired auxiliary heater, a closed loop cooling tower, pumps, heat exchangers, storage tanks, valves, mixers and controllers. The novelty of this study lies in the utilization of flat-plate stationary solar collectors, manufactured by TVP Solar, rather than concentrating ones (typically adopted for driving double-stage absorption chillers. Such devices show ultra-high thermal efficiencies, even at very high (about 200°C operating temperatures, thanks to the high vacuum insulation. Aim of the paper is to analyse the energy and economic feasibility of such novel technology, by including it in a prototypal solar heating and cooling system. For this purpose, the solar heating and cooling system design and performance were analysed by means of a purposely developed dynamic simulation model, implemented in TRNSYS. A suitable case study is also presented. Here, the simulated plant is conceived for the space heating and cooling and the domestic hot water production of a small building, whose energy needs are fulfilled through a real installation (settled also for experimental purposes built up close to Naples (South Italy. Simulation results show that the investigated system is able to reach high thermal efficiencies and very good energy performance. Finally, the economic analysis shows results comparable to those achieved through similar renewable energy systems.

Proceedings: Cooling tower and advanced cooling systems conference

International Nuclear Information System (INIS)

1995-02-01

This Cooling Tower and Advanced Cooling Systems Conference was held August 30 through September 1, 1994, in St. Petersburg, Florida. The conference was sponsored by the Electric Power Research Institute (EPRI) and hosted by Florida Power Corporation to bring together utility representatives, manufacturers, researchers, and consultants. Nineteen technical papers were presented in four sessions. These sessions were devoted to the following topics: cooling tower upgrades and retrofits, cooling tower performance, cooling tower fouling, and dry and hybrid systems. On the final day, panel discussions addressed current issues in cooling tower operation and maintenance as well as research and technology needs for power plant cooling. More than 100 people attended the conference. This report contains the technical papers presented at the conference. Of the 19 papers, five concern cooling tower upgrades and retrofits, five to cooling tower performance, four discuss cooling tower fouling, and five describe dry and hybrid cooling systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

The development of a solar residential heating and cooling system

Science.gov (United States)

1975-01-01

The MSFC solar heating and cooling facility was assembled to demonstrate the engineering feasibility of utilizing solar energy for heating and cooling buildings, to provide an engineering evaluation of the total system and the key subsystems, and to investigate areas of possible improvement in design and efficiency. The basic solar heating and cooling system utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating, and an absorption cycle air conditioner for space cooling. A complete description of all systems is given. Development activities for this test system included assembly, checkout, operation, modification, and data analysis, all of which are discussed. Selected data analyses for the first 15 weeks of testing are included, findings associated with energy storage and the energy storage system are outlined, and conclusions resulting from test findings are provided. An evaluation of the data for summer operation indicates that the current system is capable of supplying an average of 50 percent of the thermal energy required to drive the air conditioner. Preliminary evaluation of data collected for operation in the heating mode during the winter indicates that nearly 100 percent of the thermal energy required for heating can be supplied by the system.

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.

Variation and design criterion of heat load ratio of generator for air cooled lithium bromide–water double effect absorption chiller

International Nuclear Information System (INIS)

Li, Zeyu; Liu, Liming; Liu, Jinping

2016-01-01

Highlights: • Design criterion of heat load ratio of generator is vital to system performance. • Heat load ratio of generator changes with working condition. • Change of heat load ratio of generator for four systems was obtained and compared. • Design criterion of heat load ratio of generator was presented. - Abstract: The heat load ratio of generator (HLRG) is a special system parameter because it is not fixed at the design value but changes with the working condition. For the air cooled chiller, the deviation from the design working condition occurs easily due to the variation of the surrounding temperature. The system is likely to suffer from crystallization when the working condition is different from the designed one if the HLRG is designed improperly. Consequently, the design criterion of HLRG based on a broad range of working condition is essential and urgent to the development of air cooled lithium bromide–water double effect absorption chiller. This paper mainly deals with the variation of HLRG with the working condition as well as corresponding design criterion. Four types of double effect chillers named series, pre-parallel, rear parallel and reverse parallel flow system were considered. The parametric model was developed by the introduction of a new thermodynamic relationship of generator. The change of HLRG for different types of chillers with the working condition was analyzed and compared. The corresponding design criterion of HLRG was presented. This paper is helpful for further improvement of the performance and reliability of air cooled lithium bromide–water double effect absorption chiller.

A study of the cool gas in the Large Magellanic Cloud. I. Properties of the cool atomic phase - a third H i absorption survey

Science.gov (United States)

Marx-Zimmer, M.; Herbstmeier, U.; Dickey, J. M.; Zimmer, F.; Staveley-Smith, L.; Mebold, U.

2000-02-01

The cool atomic interstellar medium of the Large Magellanic Cloud (LMC) seems to be quite different from that in the Milky Way. In a series of three papers we study the properties of the cool atomic hydrogen in the LMC (Paper I), its relation to molecular clouds using SEST-CO-observations (Paper II) and the cooling mechanism of the atomic gas based on ISO-[\\CII]-investigations (Paper III). In this paper we present the results of a third 21 cm absorption line survey toward the LMC carried out with the Australia Telescope Compact Array (ATCA). 20 compact continuum sources, which are mainly in the direction of the supergiant shell LMC 4, toward the surroundings of 30 Doradus and toward the eastern steep \\HI\\ boundary, have been chosen from the 1.4 GHz snapshot continuum survey of Marx et al. We have identified 20 absorption features toward nine of the 20 sources. The properties of the cool \\HI\\ clouds are investigated and are compared for the different regions of the LMC taking the results of Dickey et al. (survey 2) into account. We find that the cool \\HI\\ gas in the LMC is either unusually abundant compared to the cool atomic phase of the Milky Way or the gas is clearly colder (\\Tc\\ ~ 30 K) than that in our Galaxy (\\Tc\\ ~ 60 K). The properties of atomic clouds toward 30 Doradus and LMC 4 suggest a higher cooling rate in these regions compared to other parts of the LMC, probably due to an enhanced pressure near the shock fronts of LMC 4 and 30 Doradus. The detected cool atomic gas toward the eastern steep \\HI\\ boundary might be the result of a high compression of gas at the leading edge. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

Carbon Dioxide Absorption Heat Pump

Science.gov (United States)

Jones, Jack A. (Inventor)

2002-01-01

A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

Maximum Exergetic Efficiency Operation of a Solar Powered H2O-LiBr Absorption Cooling System

Directory of Open Access Journals (Sweden)

Camelia Stanciu

2017-12-01

Full Text Available A solar driven cooling system consisting of a single effect H2O-LiBr absorbtion cooling module (ACS, a parabolic trough collector (PTC, and a storage tank (ST module is analyzed during one full day operation. The pressurized water is used to transfer heat from PTC to ST and to feed the ACS desorber. The system is constrained to operate at the maximum ACS exergetic efficiency, under a time dependent cooling load computed on 15 July for a one storey house located near Bucharest, Romania. To set up the solar assembly, two commercial PTCs were selected, namely PT1-IST and PTC 1800 Solitem, and a single unit ST was initially considered. The mathematical model, relying on the energy balance equations, was coded under Engineering Equation Solver (EES environment. The solar data were obtained from the Meteonorm database. The numerical simulations proved that the system cannot cover the imposed cooling load all day long, due to the large variation of water temperature inside the ST. By splitting the ST into two units, the results revealed that the PT1-IST collector only drives the ACS between 9 am and 4:30 pm, while the PTC 1800 one covers the entire cooling period (9 am–6 pm for optimum ST capacities of 90 kg/90 kg and 90 kg/140 kg, respectively.

Heating up the gas cooling market

International Nuclear Information System (INIS)

Watt, G.

2001-01-01

Gas cooling is an exciting technology with a potentially bright future. It comprises the production of cooling (and heating) in buildings and industry, by substituting environmentally-friendlier natural gas or LPG over predominantly coal-fired electricity in air conditioning equipment. There are currently four established technologies using gas to provide cooling energy or conditioned air. These are: absorption, both direct gas-fired and utilising hot water or steam; gas engine driven vapour compression (GED); cogeneration, with absorption cooling driven by recovered heat; and desiccant systems. The emergence of gas cooling technologies has been, and remains, one of evolution rather than revolution. However, further development of the technology has had a revolutionary effect on the performance, reliability and consumer acceptability of gas cooling products. Developments from world-renowned manufacturers such as York, Hitachi, Robur and Thermax have produced a range of absorption equipment variously offering: the use of 100 percent environmentally-friendly refrigerants, with zero global warming potential; the ideal utilisation of waste heat from cogeneration systems; a reduction in electrical distribution and stand-by generation capacity; long product life expectancy; far less noise and vibration; performance efficiency maintained down to about 20 percent of load capacity; and highly automated and low-cost maintenance. It is expected that hybrid systems, that is a mixture of gas and electric cooling technologies, will dominate the future market, reflecting the uncertainty in the electricity market and the prospects of stable future gas prices

Helium-cooled nuclear reactor

International Nuclear Information System (INIS)

Longton, P.B.; Cowen, H.C.

1975-01-01

In helium cooled HTR's there is a by-pass circuit for cleaning purposes in addition to the main cooling circuit. This is to remove such impurities as hydrogen, methane, carbon monoxide and water from the coolant. In this system, part of the coolant successively flows first through an oxidation bed of copper oxide and an absorption bed of silica gel, then through activated charcoal or a molecular sieve. The hydrogen and carbon monoxide impurities are absorbed and the dry gas is returned to the main cooling circuit. To lower the hydrogen/water ratio without increasing the hydrogen fraction in the main cooling circuit, some of the hydrogen fraction converted into water is added to the cooling circuit. This is done, inter alia, by bypassing the water produced in the oxidation bed before it enters the absorption bed. The rest of the by-pass circuit, however, also includes an absorption bed with a molecular sieve. This absorbs the oxidized carbon monoxide fraction. In this way, such side effects as the formation of additional methane, carburization of the materials of the by-pass circuit or loss of graphite are avoided. (DG/RF) [de

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.

Process fluid cooling system

International Nuclear Information System (INIS)

Farquhar, N.G.; Schwab, J.A.

1977-01-01

A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

Optimum hot water temperature for absorption solar cooling

Energy Technology Data Exchange (ETDEWEB)

Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

2009-10-15

The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

Solar heating and cooling system installed at Leavenworth, Kansas. Final report

Energy Technology Data Exchange (ETDEWEB)

Perkins, R. M.

1980-06-01

The solar heating and cooling system installed at the headquarters of Citizens Mutual Savings Association in Leavenworth, Kansas, is described in detail. The project is part of the U.S. Department of Energy's solar demonstration program and became operational in March, 1979. The designer was TEC, Inc. Consulting Engineers, Kansas City, Missouri and contractor was Norris Brothers, Inc., Lawrence, Kansas. The solar system is expected to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2200 square feet. Five, 3-ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3000 gallon chilled water storage tank. Two, 3000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

Cryogenic cooling system for HTS cable

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Shigeru [Taiyo Nippon Sanso, Tsukuba (Japan)

2017-06-15

Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

The Proposed Heating and Cooling System in the CH2 Building and Its Impact on Occupant Productivity

Directory of Open Access Journals (Sweden)

Lu Aye

2012-11-01

Full Text Available Melbourne's climatic conditions demand that its buildings require both heating and cooling systems. In a multi-storey office building , however, cooling requirements will dominate. How the internal space is cooled and ventilation air is delivered will significantly impact on occupant comfort. This paper discusses the heating and cooling systems proposed for the CH2building. The paper critiques the proposed systems against previous experience, both internationally and in Australia. While the heating system employs proven technologies, less established techniques are proposed for the cooling system. Air movement in the shower towers, for example, is to be naturally induced and this has not always been successful elsewhere. Phase change material for storage of "coolth" does not appear to have been demonstrated previously in a commercial building, so the effectiveness of the proposed system is uncertain. A conventional absorption chiller backs up the untried elements of the cooling system, so that ultimately occupant comfort should not be compromised .

A very cool cooling system

CERN Multimedia

Antonella Del Rosso

2015-01-01

The NA62 Gigatracker is a jewel of technology: its sensor, which delivers the time of the crossing particles with a precision of less than 200 picoseconds (better than similar LHC detectors), has a cooling system that might become the precursor to a completely new detector technique.   The 115 metre long vacuum tank of the NA62 experiment. The NA62 Gigatracker (GTK) is composed of a set of three innovative silicon pixel detectors, whose job is to measure the arrival time and the position of the incoming beam particles. Installed in the heart of the NA62 detector, the silicon sensors are cooled down (to about -20 degrees Celsius) by a microfluidic silicon device. “The cooling system is needed to remove the heat produced by the readout chips the silicon sensor is bonded to,” explains Alessandro Mapelli, microsystems engineer working in the Physics department. “For the NA62 Gigatracker we have designed a cooling plate on top of which both the silicon sensor and the...

Modelization of cooling system components

Energy Technology Data Exchange (ETDEWEB)

Copete, Monica; Ortega, Silvia; Vaquero, Jose Carlos; Cervantes, Eva [Westinghouse Electric (Spain)

2010-07-01

In the site evaluation study for licensing a new nuclear power facility, the criteria involved could be grouped in health and safety, environment, socio-economics, engineering and cost-related. These encompass different aspects such as geology, seismology, cooling system requirements, weather conditions, flooding, population, and so on. The selection of the cooling system is function of different parameters as the gross electrical output, energy consumption, available area for cooling system components, environmental conditions, water consumption, and others. Moreover, in recent years, extreme environmental conditions have been experienced and stringent water availability limits have affected water use permits. Therefore, modifications or alternatives of current cooling system designs and operation are required as well as analyses of the different possibilities of cooling systems to optimize energy production taking into account water consumption among other important variables. There are two basic cooling system configurations: - Once-through or Open-cycle; - Recirculating or Closed-cycle. In a once-through cooling system (or open-cycle), water from an external water sources passes through the steam cycle condenser and is then returned to the source at a higher temperature with some level of contaminants. To minimize the thermal impact to the water source, a cooling tower may be added in a once-through system to allow air cooling of the water (with associated losses on site due to evaporation) prior to returning the water to its source. This system has a high thermal efficiency, and its operating and capital costs are very low. So, from an economical point of view, the open-cycle is preferred to closed-cycle system, especially if there are no water limitations or environmental restrictions. In a recirculating system (or closed-cycle), cooling water exits the condenser, goes through a fixed heat sink, and is then returned to the condenser. This configuration

Optimization study of a single-effect water–lithium bromide absorption refrigeration system powered by flat-plate collector in hot regions

International Nuclear Information System (INIS)

Saleh, A.; Mosa, M.

2014-01-01

Highlights: • A comprehensive analysis for optimizing solar absorption system in hot region. • The most important parameter to be controlled is hot source temperature. • Ensuring appropriate choice of parameters, COP of absorption unit exceeds 0.8. • Results show that solar cooling systems are promising in hot regions. • The research aims to play a vital role to promote the use of renewable energy. - Abstract: This investigation has been carried out to present a comprehensive analysis for optimizing the operation of solar absorption system in hot regions. To optimize performance of the system, the hot source temperature should be controlled in function of incident solar radiation, chilled and cooling water temperatures. With an appropriate control, these external conditions can be monitored to detect and implement the actual optimization conditions. Adopting typical values encountered in hot regions, the overall system performance takes its optimal value at temperatures between 75 and 80 °C. It was found that in designing or selecting solar collector, selective coating type is necessary to produce hot water with potential around 80–90 °C needed to optimize operation of absorption unit. By ensuring an appropriate choice of components temperatures, COP of absorption unit can exceed the value 0.8. Cooling water temperature above 40 °C reduces significantly the performance of the unit which requires, under conditions of extremely high external temperatures, dimensioning and selection of condensers and absorbers that guarantee values less than this limit

Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey. Final report

Energy Technology Data Exchange (ETDEWEB)

None

1981-03-01

Solar heating and cooling of a 40,000 square foot manufacturing building, sales offices and the solar computer control center/display room are described. Information on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature and as-built drawings are provided also. The solar system is composed of 6000 square feet of Sunworks double glazed flat plate collectors, external above ground storage subsystem, controls, ARKLA absorption chiller, heat recovery and a cooling tower.

Feasibility evaluation of two solar cooling systems applied to a cuban hotel. Comparative analysis

International Nuclear Information System (INIS)

Díaz Torres, Yamile; Valdivia Nodal, Yarelis; Monteagudo Yanes, José Pedro; Miranda Torres, Yudit

2016-01-01

The article presents an analysis of technical and economic feasibility of using two configurations of solar cooling in a Cuban hotel. HVAC hybrid schemes are: a cooler of ice water vapor compression (chiller) interconnected in parallel with a smaller capacity chiller, first with a solar-powered absorption cooling system (SACS), and then with a photovoltaic cooling system(PSC). Both were simulated taking into account the weather conditions in the region, thermodynamic calculation methodologies and principles that govern these technologies. The results show that the use of these alternatives contributes to reducing energy consumption and the environmental impact of heating, ventilation and air conditioning systems (HVAC). Economic analysis highlights that PCS is more favorable than the SACS taking into account the cooling cost generation (CCG) but energy assessment indicates that SACS has higher thermal performance for the case study to which it is applied. (author)

Performance and economic enhancement of cogeneration gas turbines through compressor inlet air cooling

Science.gov (United States)

Delucia, M.; Bronconi, R.; Carnevale, E.

1994-04-01

Gas turbine air cooling systems serve to raise performance to peak power levels during the hot months when high atmospheric temperatures cause reductions in net power output. This work describes the technical and economic advantages of providing a compressor inlet air cooling system to increase the gas turbine's power rating and reduce its heat rate. The pros and cons of state-of-the-art cooling technologies, i.e., absorption and compression refrigeration, with and without thermal energy storage, were examined in order to select the most suitable cooling solution. Heavy-duty gas turbine cogeneration systems with and without absorption units were modeled, as well as various industrial sectors, i.e., paper and pulp, pharmaceuticals, food processing, textiles, tanning, and building materials. The ambient temperature variations were modeled so the effects of climate could be accounted for in the simulation. The results validated the advantages of gas turbine cogeneration with absorption air cooling as compared to other systems without air cooling.

Cooling system for auxiliary reactor component

International Nuclear Information System (INIS)

Fujihira, Tomoko.

1991-01-01

A cooling system for auxiliary reactor components comprises three systems, that is, two systems of reactor component cooling water systems (RCCW systems) and a high pressure component cooling water system (HPCCW system). Connecting pipelines having partition valves are intervened each in a cooling water supply pipeline to an emmergency component of each of the RCCW systems, a cooling water return pipeline from the emmergency component of each of the RCCW systems, a cooling water supply pipeline to each of the emmergency components of one of the RCCW system and the HPCCW system and a cooling water return pipeline from each of the emmergency components of one of the RCCW system and the HPCCW system. With such constitution, cooling water can be supplied also to the emmergency components in the stand-by system upon periodical inspection or ISI, thereby enabling to improve the backup performance of the emmergency cooling system. (I.N.)

Influence of vapor absorption cooling on humidification-dehumidification (HDH desalination

Directory of Open Access Journals (Sweden)

C. Chiranjeevi

2016-09-01

Full Text Available The desalination yield in humidification-dehumidification (HDH process is increased by proposing cooling plant integration with two stage operation. The current work is targeted on the investigation of vapor absorption refrigeration (VAR parameters on overall energy utilization factor (EUF. The dephlegmator heat is recovered internally in VAR instead of rejecting to environment. This work can be used to control the operational conditions of VAR to enhance the desalination and cooling together. The studied process parameters in VAR are strong solution concentration, separator or generator temperature, dephlegmator effectiveness, circulating water inlet temperature and evaporator temperature. Out of these five variables, lower limit of separator temperature, upper limit of dephlegmator effectiveness and lower limit of circulating water temperature are fixed in the specified range to attain the optimum strong solution concentration and optimum evaporator temperature. At the specified boundaries of three variables, the optimized strong solution concentration and evaporator temperature are 0.47 and 10 °C respectively. At this condition, the maximized cycle EUF is 0.358.

Theoretical and experimental evaluation of an indirect-fired GAX cycle cooling system

Energy Technology Data Exchange (ETDEWEB)

Gomez, V.H.; Vidal, A. [Posgrado en Ingenieria, Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco S/N, Apdo. Postal 34, 62580 Temixco Morelos (Mexico); Best, R.; Garcia-Valladares, O. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco S/N, Apdo. Postal 34, 62580 Temixco Morelos (Mexico); Velazquez, N. [Instituto de Ingenieria, Universidad Autonoma de Baja California, Calle de la Normal S/N, Insurgentes Este, 21280 Mexicali, BC (Mexico)

2008-06-15

A theoretical and experimental evaluation of an indirect-fired GAX-Prototype Cooling System (GAX-PCS), using ammonia-water as the working fluid, is presented. The GAX-PCS was designed for a cooling capacity of 10.6 kW (3 tons). A simulation model was developed, calibrated and validated with experimental values in order to predict the performance of the system outside the design parameters. Experimental results were obtained using thermal oil, at temperatures from 180 to 195 C, as heating source. An internal heat recovery in the system of {proportional_to}55% with respect to the total heat supplied in the generator was obtained. Also the performance of the GAX absorption system, integrated to a micro gas turbine (MGT) as a cogeneration system was simulated. Overall efficiencies for the cogeneration system from 29% to 49% were obtained for cooling loads from 5 kW to 20 kW, respectively. With the theoretical and experimental study of the proposed cycle, it is concluded that the GAX-PCS presents potential to compete technically in the Mexican air conditioning market. (author)

Core cooling system for reactor

International Nuclear Information System (INIS)

Kondo, Ryoichi; Amada, Tatsuo.

1976-01-01

Purpose: To improve the function of residual heat dissipation from the reactor core in case of emergency by providing a secondary cooling system flow channel, through which fluid having been subjected to heat exchange with the fluid flowing in a primary cooling system flow channel flows, with a core residual heat removal system in parallel with a main cooling system provided with a steam generator. Constitution: Heat generated in the core during normal reactor operation is transferred from a primary cooling system flow channel to a secondary cooling system flow channel through a main heat exchanger and then transferred through a steam generator to a water-steam system flow channel. In the event if removal of heat from the core by the main cooling system becomes impossible due to such cause as breakage of the duct line of the primary cooling system flow channel or a trouble in a primary cooling system pump, a flow control valve is opened, and steam generator inlet and outlet valves are closed, thus increasing the flow rate in the core residual heat removal system. Thereafter, a blower is started to cause dissipation of the core residual heat from the flow channel of a system for heat dissipation to atmosphere. (Seki, T.)

Cooling water distribution system

Science.gov (United States)

Orr, Richard

1994-01-01

A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

Techno-economic studies on hybrid energy based cooling system for milk preservation in isolated regions

International Nuclear Information System (INIS)

Edwin, M.; Joseph Sekhar, S.

2014-01-01

Highlights: • Performance studies on biomass and biogas based milk cooling systems in remote areas. • Economic analysis of milk cooling system operated with locally available renewable energy sources. • Payback period for replacing conventional milk cooling systems with renewable energy based cooling system. • Identification of the suitable combination of locally available renewable energy sources for milk cooling. • Hybrid energy based milk cooling system for regions that have rubber and paddy cultivation, in India. - Abstract: In developing countries like India, about 70% of the population is engaged in the production of milk, fruits and vegetables. Due to the lack of proper storage and transit facilities, the agricultural produce, in remote areas loses its value. This spoilage could be prevented at the local village level, by providing cooling units for short term preservation. In this paper, the possibility of a hybrid energy based thermally operated cold storage has been considered to meet the cooling needs of the villages in the southern parts of India, where biomass, biogas and gobar gas are available in abundance. A milk cooling system that uses various combinations of locally available renewable energy sources to operate an aqua ammonia vapour absorption cooling system has been analysed using the Matlab software. The impact of various combinations of renewable energy sources on the Coefficient of Performance (COP), Net Present Value (NPV) and payback period of the total cooling system has been studied. The analysis shows that the COP and payback period of the proposed hybrid renewable energy based milk cooling system are 0.16–0.23 and 4–6 years respectively

Radiant Floor Cooling Systems

DEFF Research Database (Denmark)

Olesen, Bjarne W.

2008-01-01

In many countries, hydronic radiant floor systems are widely used for heating all types of buildings such as residential, churches, gymnasiums, hospitals, hangars, storage buildings, industrial buildings, and smaller offices. However, few systems are used for cooling.This article describes a floor...... cooling system that includes such considerations as thermal comfort of the occupants, which design parameters will influence the cooling capacity and how the system should be controlled. Examples of applications are presented....

Experimental investigation of integrated refrigeration system (IRS) with gas engine, compression chiller and absorption chiller

International Nuclear Information System (INIS)

Sun, Z.G.

2008-01-01

An integrated refrigeration system (IRS) with a gas engine, a vapor-compression chiller and an absorption chiller is set up and tested. The vapor-compression refrigeration cycle is operated directly by the gas engine. The waste heat from the gas engine operates the absorption refrigeration cycle, which provides additional cooling. The performance of the IRS is described. The cooling capacity of the IRS is about 596 kW, and primary energy ratio (PER) reaches 1.84 at air-conditioning rated conditions. The refrigerating capacity of the prototype increased and PER of prototype decreased with the increase of the gas engine speed. The gas engine speed was preferably regulated at part load condition in order to operate the prototype at high-energy efficiency. The refrigerating capacity and PER of the prototype increased with the increase of the outlet temperature of chilled water or the decrease of the inlet temperature of cooling water. The integrated refrigeration chiller in this work saves running costs as compared to the conventional refrigeration system by using the waste heat

46 CFR 153.432 - Cooling systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Cooling systems. 153.432 Section 153.432 Shipping COAST... Control Systems § 153.432 Cooling systems. (a) Each cargo cooling system must have an equivalent standby... cooling system. (b) Each tankship that has a cargo tank with a required cooling system must have a manual...

Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

Science.gov (United States)

1980-01-01

The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

Analytical and experimental investigation of closed-cycle sorption cooling systems

Science.gov (United States)

Liu, Lianquan

1992-01-01

The first part of the present thesis concerns the Coefficient of Performance (COP) of two types of closed-cycle sorption cooling systems: the Single Effect Liquid (SEL) absorption system and the Regenerative Solid (RS) adsorption system. When specific cycle configurations are considered, the COP is always less than that allowed by the second law. The potential of the two systems to approach the second law limit is considered in this work. The analysis shows that COP of a SEL system using LiBr-H2O is not limited by one, as believed before, and that the COP of a RS cooling system using zeolite-water is considerably larger than that of the SEL system. This is due to recovery of the heat of adsorption which is made possible by capturing the thermal wave in the solid adsorbent. In the second part, a one dimensional model has been developed for a real RS cooling system featured by finite heat transfer coefficients. The problem is solved numerically to yield the temperature and uptake profiles, COP, and cooling capacity and cooling rates. The effects of various design and operating parameters on system performance have been investigated by using the model. The convective heat transfer coefficient at the inner wall of the fluid channel passing through the zeolite columns, the flow rate of the heat transfer fluid, the condenser and evaporator temperature are identified as the most significant factors. A new correlation of adsorption equilibrium has been derived in this thesis. The derivation is based on established thermodynamic relationships and is shown to be able to well represent the data of three adsorption pairs widely used in sorption cooling applications: zeolite-water, silica gel-water and activated carbon-methanol. Finally, in the experimental part of the present work a test set-up of a zeolite-water heat and mass regenerator was designed, instrumented and built. Temperature profiles at various operating conditions were measured. The data of a 'single blow' mode

Using waste heat of ship as energy source for an absorption refrigeration system

International Nuclear Information System (INIS)

Salmi, Waltteri; Vanttola, Juha; Elg, Mia; Kuosa, Maunu; Lahdelma, Risto

2017-01-01

Highlights: • A steady-state thermodynamic model is developed for absorption refrigeration in a ship. • Operation profile of B.Delta37 bulk carrier is used as an initial data. • Suitability of water-LiBr and ammonia-water working pairs were validated. • Coefficient of performance (COP) was studied in ISO and tropical conditions. • Estimated energy savings were 47 and 95 tons of fuel every year. - Abstract: This work presents a steady-state thermodynamic model for absorption refrigeration cycles with water-LiBr and ammonia-water working pairs for purpose of application on a ship. The coefficient of performance was studied with different generator and evaporator temperatures in ISO and tropical conditions. Absorption refrigeration systems were examined using exhaust gases, jacket water, and scavenge air as energy sources. Optimal generator temperatures for different refrigerant temperatures were found using different waste heat sources and for the absorption cycle itself. Critical temperature values (where the refrigeration power drops to zero) were defined. All of these values were used in order to evaluate the cooling power and energy production possibilities in a bulk carrier. The process data of exhaust gases and cooling water flows in two different climate conditions (ISO and tropical) and operation profiles of a B. Delta37 bulk carrier were used as initial data in the study. With the case ship data, a theoretical potential of saving of 70% of the electricity used in accommodation (AC use) compressor in ISO conditions and 61% in tropical conditions was recognized. Those estimates enable between 47 and 95 tons of annual fuel savings, respectively. Moreover, jacket water heat recovery with a water-LiBr system has the potential to provide 2.2–4.0 times more cooling power than required during sea-time operations in ISO conditions, depending on the main engine load.

Core cooling systems

International Nuclear Information System (INIS)

Hoeppner, G.

1980-01-01

The reactor cooling system transports the heat liberated in the reactor core to the component - heat exchanger, steam generator or turbine - where the energy is removed. This basic task can be performed with a variety of coolants circulating in appropriately designed cooling systems. The choice of any one system is governed by principles of economics and natural policies, the design is determined by the laws of nuclear physics, thermal-hydraulics and by the requirement of reliability and public safety. PWR- and BWR- reactors today generate the bulk of nuclear energy. Their primary cooling systems are discussed under the following aspects: 1. General design, nuclear physics constraints, energy transfer, hydraulics, thermodynamics. 2. Design and performance under conditions of steady state and mild transients; control systems. 3. Design and performance under conditions of severe transients and loss of coolant accidents; safety systems. (orig./RW)

Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

Science.gov (United States)

Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

2016-02-01

A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

Simulations of floor cooling system capacity

International Nuclear Information System (INIS)

Odyjas, Andrzej; Górka, Andrzej

2013-01-01

Floor cooling system capacity depends on its physical and operative parameters. Using numerical simulations, it appears that cooling capacity of the system largely depends on the type of cooling loads occurring in the room. In the case of convective cooling loads capacity of the system is small. However, when radiation flux falls directly on the floor the system significantly increases productivity. The article describes the results of numerical simulations which allow to determine system capacity in steady thermal conditions, depending on the type of physical parameters of the system and the type of cooling load occurring in the room. Moreover, the paper sets out the limits of system capacity while maintaining a minimum temperature of the floor surface equal to 20 °C. The results are helpful for designing system capacity in different type of cooling loads and show maximum system capacity in acceptable thermal comfort condition. -- Highlights: ► We have developed numerical model for simulation of floor cooling system. ► We have described floor system capacity depending on its physical parameters. ► We have described floor system capacity depending on type of cooling loads. ► The most important in the obtained cooling capacities is the type of cooling loads. ► The paper sets out the possible maximum cooling floor system capacity

Cooled Water Production System,

Science.gov (United States)

The invention refers to the field of air conditioning and regards an apparatus for obtaining cooled water . The purpose of the invention is to develop...such a system for obtaining cooled water which would permit the maximum use of the cooling effect of the water -cooling tower.

Exergy based parametric analysis of a combined reheat regenerative thermal power plant and water–LiBr vapor absorption refrigeration system

International Nuclear Information System (INIS)

Gogoi, T.K.; Talukdar, K.

2014-01-01

Highlights: • Exergy analysis of a combined power–absorption cooling system is provided. • Exergetic efficiency of the power cycle and absorption cooling system are calculated. • Irreversibility in each component and total system irreversibility are calculated. • Effect of operating parameters on exergetic performance and irreversibility is analyzed. • Optimum operating parameters are identified based on energy and exergy based results. - Abstract: In this paper, exergy analysis of a combined reheat regenerative steam turbine (ST) based power cycle and water–LiBr vapor absorption refrigeration system (VARS) is presented. Exergetic efficiency of the power cycle and VARS, energy utilization factor (EUF) of the combined system (CS) and irreversibility in each system component are calculated. The effect of fuel flow rate, boiler pressure, cooling capacity and VARS components’ temperature on performance, component and total system irreversibility is analyzed. The second law based results indicate optimum performance at 150 bar boiler pressure and VARS generator, condenser, evaporator and absorber temperature of 80 °C, 37.5 °C, 15 °C and 35 °C respectively. The present exergy based results conform well to the first law based results obtained in a previous analysis done on the same combined system. Irreversibility distribution among various power cycle components shows the highest irreversibility in the cooling tower. Irreversibility of the exhaust flue gas leaving the boiler and the boiler are the next major contributors. Among the VARS components, exergy destruction in the generator is the highest followed by irreversibility contribution of the absorber, condenser and the evaporator

Cooling performance and energy saving of a compression-absorption refrigeration system assisted by geothermal energy

International Nuclear Information System (INIS)

Kairouani, L.; Nehdi, E.

2006-01-01

The objectives of this paper are to develop a novel combined refrigeration system, and to discuss the thermodynamic analysis of the cycle and the feasibility of its practical development. The aim of this work was to study the possibility of using geothermal energy to supply vapour absorption system cascaded with conventional compression system. Three working fluids (R717, R22, and R134a) are selected for the conventional compression system and the ammonia-water pair for the absorption system. The geothermal temperature source in the range 343-349 K supplies a generator operating at 335 K. Results show that the COP of a combined system is significantly higher than that of a single stage refrigeration system. It is found that the COP can be improved by 37-54%, compared with the conventional cycle, under the same operating conditions, that is an evaporation temperature at 263 K and a condensation temperature of 308 K. For industrial refrigeration, the proposed system constitutes an alternative solution for reducing energy consumption and greenhouse gas emissions

Numerical and experimental analysis of a thin liquid film on a rotating disk related to development of a spacecraft absorption cooling system

Science.gov (United States)

Faghri, Amir; Swanson, Theodore D.

1989-01-01

The numerical and experimental analysis of a thin liquid film on a rotating and a stationary disk related to the development of an absorber unit for a high capacity spacecraft absorption cooling system, is described. The creation of artificial gravity by the use of a centrifugal field was focused upon in this report. Areas covered include: (1) One-dimensional computation of thin liquid film flows; (2) Experimental measurement of film height and visualization of flow; (3) Two-dimensional computation of the free surface flow of a thin liquid film using a pressure optimization method; (4) Computation of heat transfer in two-dimensional thin film flow; (5) Development of a new computational methodology for the free surface flows using a permeable wall; (6) Analysis of fluid flow and heat transfer in a thin film in the presence and absence of gravity; and (7) Comparison of theoretical prediction and experimental data. The basic phenomena related to fluid flow and heat transfer on rotating systems reported here can also be applied to other areas of space systems.

Alternatives for metal hydride storage bed heating and cooling

International Nuclear Information System (INIS)

Fisher, I.A.; Ramirez, F.B.; Koonce, J.E.; Ward, D.E.; Heung, L.K.; Weimer, M.; Berkebile, W.; French, S.T.

1991-01-01

The reaction of hydrogen isotopes with the storage bed hydride material is exothermic during absorption and endothermic during desorption. Therefore, storage bed operation requires a cooling system to remove heat during absorption, and a heating system to add the heat needed for desorption. Three storage bed designs and their associated methods of heating and cooling and accountability are presented within. The first design is the current RTF (Replacement Tritium Facility) nitrogen heating and cooling system. The second design uses natural convection cooling with ambient glove box nitrogen and electrical resistance for heating. This design is referred to as the Naturally Cooled/Electrically Heated (NCEH) design. The third design uses forced convection cooling with ambient glove box nitrogen and electrical resistance for heating. The design is referred to as the Forced Convection Cooled/Electrically Heated (FCCEH) design. In this report the operation, storage bed design, and equipment required for heating, cooling, and accountability of each design are described. The advantages and disadvantages of each design are listed and discussed. Based on the information presented within, it is recommended that the NCEH design be selected for further development

Reactor cooling system

International Nuclear Information System (INIS)

Kato, Etsuji.

1979-01-01

Purpose: To eliminate cleaning steps in the pipelines upon reactor shut-down by connecting a filtrating and desalting device to the cooling system to thereby always clean up the water in the pipelines. Constitution: A filtrating and desalting device is connected to the pipelines in the cooling system by way of drain valves and a check valve. Desalted water is taken out from the exit of the filtrating and desalting device and injected to one end of the cooling system pipelines by way of the drain valve and the check valve and then returned by way of another drain valve to the desalting device. Water in the pipelines is thus always desalted and the cleaning step in the pipelines is no more required in the shut-down. (Kawakami, Y.)

Performance characteristic of hybrid cooling system based on cooling pad and evaporator

Science.gov (United States)

Yoon, J. I.; Son, C. H.; Choi, K. H.; Kim, Y. B.; Sung, Y. H.; Roh, S. J.; Kim, Y. M.; Seol, S. H.

2018-01-01

In South Korea, most of domestic animals such as pigs and chickens might die due to thermal diseases if they are exposed to the high temperature consistently. In order to save them from the heat wave, numerous efforts have been carried out: installing a shade net, adjusting time of feeding, spraying mist and setting up a circulation fan. However, these methods have not shown significant improvements. Thus, this study proposes a hybrid cooling system combining evaporative cooler and air-conditioner in order to resolve the conventional problems caused by the high temperature in the livestock industry. The problem of cooling systems using evaporative cooling pads is that they are not effective for eliminating huge heat load due to their limited capacity. And, temperature of the supplied air cannot be low enough compared to conventional air-conditioning systems. On the other hand, conventional air-conditioning systems require relatively expensive installation cost, and high operating cost compared to evaporative cooling system. The hybrid cooling system makes up for the lack of cooling capacity of the evaporative cooler by employing the conventional air-conditioner. Additionally, temperature of supplied air can be lowered enough. In the hybrid cooling system, induced air by a fan is cooled by the evaporation of water in the cooling pad, and it is cooled again by an evaporator in the air-conditioner. Therefore, the more economical operation is possible due to additionally obtained cooling capacity from the cooling pads. Major results of experimental analysis of hybrid cooling system are as follows. The compressor power consumption of the hybrid cooling system is about 23% lower, and its COP is 17% higher than that of the conventional air-conditioners. Regarding the condition of changing ambient temperature, the total power consumption decreased by about 5% as the ambient temperature changed from 28.7°C to 31.7°C. Cooling capacity and COP also presented about 3% and 1

Performance of one and a half-effect absorption cooling cycle of H2O/LiBr system

International Nuclear Information System (INIS)

Wang Jianzhao; Zheng Danxing

2009-01-01

The performances of half-effect, single-effect and double-effect H 2 O/LiBr absorption cooling cycles were analyzed, and it was found that there is an obvious blank for generation temperature between the maximum generation temperature of the single-effect cycle and the minimum generation temperature of the double-effect cycle. It was proposed that the one and a half-effect (1.5-effect) cycle can fill up the blank perfectly. The state of the art in the 1.5-effect cycles was reviewed and analyzed, and two new configurations of 1.5-effect cycles were proposed. Three configurations of 1.5-effect cycles, which are suitable for H 2 O/LiBr as working fluids, were selected to be analyzed in detail. The 1.5-effect cycle shows the optimum performance at the foregoing blank of generation temperature. For example, under the conditions of evaporation temperature t E is 5 deg. C, and condensation temperature t C is 42 deg. C, and absorption temperature t A is 37 deg. C, the optimum range of generation temperature t G for the 1.5-effect cycle is from 110 deg. C to 140 deg. C. The coefficient of performance of the 1.5-effect cycle is about 1.0, which is more than 30% higher than that of the single-effect cycle at the same condition. The effects of the efficiency of solution heat exchanger, the generation temperature, the absorption temperature (or the condensation temperature) and the evaporation temperature on the performances of the three configurations of 1.5-effect cycle were analyzed. It was shown that the configuration II, which is composed with a high-temperature single-effect subcycle and a low-temperature half-effect subcycle, has the highest coefficient of performance and the best operational flexibility. Among the four parameters analyzed, the performances of 1.5-effect cycles are most sensitive to the change of absorption temperature (or condensation temperature), and then to the change of generation temperature.

ABSORPTIONS IN THE VISIBLE OF PROTONATED PYRENE COLLISIONALLY COOLED TO 15 K

Energy Technology Data Exchange (ETDEWEB)

Hardy, F.-X.; Gause, O.; Rice, C. A.; Maier, J. P., E-mail: j.p.maier@unibas.ch [Department of Chemistry, University of Basel, Klingelbergstr. 80, 4056-CH Basel (Switzerland)

2013-12-01

Protonated polycyclic hydrocarbons have been added to the list of suggested carriers of diffuse interstellar absorptions. To test this proposition requires laboratory spectra measured under interstellar conditions, in particular with the rotational and vibrational degrees of freedom equilibrated to low temperatures. This has been achieved for protonated pyrene with absorption bands in the visible, using an ion trap and collisional cooling to ≈15 K. A two-photon excitation-dissociation scheme was employed to record the (1) {sup 1} A' ← X {sup 1} A' electronic spectrum on around 10{sup 5} ions per duty cycle. The origin band of the absorption spectrum of this relatively large polycyclic aromatic species with 27 atoms is located at 4858.86 Å. Two further comparably intense spectral features are present at 4834.48 and 4809.32 Å. This is one of the largest protonated aromatics studied in the gas phase and compared to astronomical observations; however, it is not a carrier of known diffuse interstellar bands.

Experimental investigation on charging and discharging performance of absorption thermal energy storage system

International Nuclear Information System (INIS)

Zhang, Xiaoling; Li, Minzhi; Shi, Wenxing; Wang, Baolong; Li, Xianting

2014-01-01

Highlights: • A prototype of ATES using LiBr/H 2 O was designed and built. • Charging and discharging performances of ATES system were investigated. • ESE and ESD for cooling, domestic hot water and heating were obtained. - Abstract: Because of high thermal storage density and little heat loss, absorption thermal energy storage (ATES) is known as a potential thermal energy storage (TES) technology. To investigate the performance of the ATES system with LiBr–H 2 O, a prototype with 10 kW h cooling storage capacity was designed and built. The experiments demonstrated that charging and discharging processes are successful in producing 7 °C chilled water, 65 °C domestic hot water, or 43 °C heating water to meet the user’s requirements. Characteristics such as temperature, concentration and power variation of the ATES system during charging and discharging processes were investigated. The performance of the ATES system for supplying cooling, heating or domestic hot water was analyzed and compared. The results indicate that the energy storage efficiencies (ESE) for cooling, domestic hot water and heating are 0.51, 0.97, 1.03, respectively, and the energy storage densities (ESD) for cooling, domestic hot water and heating reach 42, 88, 110 kW h/m 3 , respectively. The performance is better than those of previous TES systems, which proves that the ATES system using LiBr–H 2 O may be a good option for thermal energy storage

Cooling Tower Overhaul of Secondary Cooling System in HANARO

Energy Technology Data Exchange (ETDEWEB)

Park, Young Chul; Lee, Young Sub; Jung, Hoan Sung; Lim, In Chul [KAERI, Daejeon (Korea, Republic of)

2007-07-01

HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 .deg. C in summer and the reactor is operated with the full power.

Turbine airfoil with ambient cooling system

Science.gov (United States)

Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

2016-06-07

A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

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

Two-dimensional atom localization via probe absorption in a four-level atomic system

International Nuclear Information System (INIS)

Wang Zhi-Ping; Ge Qiang; Ruan Yu-Hua; Yu Ben-Li

2013-01-01

We have investigated the two-dimensional (2D) atom localization via probe absorption in a coherently driven four-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of 2D atom localization can be significantly improved via adjusting the system parameters. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization

Monitoring Cray Cooling Systems

Energy Technology Data Exchange (ETDEWEB)

Maxwell, Don E [ORNL; Ezell, Matthew A [ORNL; Becklehimer, Jeff [Cray, Inc.; Donovan, Matthew J [ORNL; Layton, Christopher C [ORNL

2014-01-01

While sites generally have systems in place to monitor the health of Cray computers themselves, often the cooling systems are ignored until a computer failure requires investigation into the source of the failure. The Liebert XDP units used to cool the Cray XE/XK models as well as the Cray proprietary cooling system used for the Cray XC30 models provide data useful for health monitoring. Unfortunately, this valuable information is often available only to custom solutions not accessible by a center-wide monitoring system or is simply ignored entirely. In this paper, methods and tools used to harvest the monitoring data available are discussed, and the implementation needed to integrate the data into a center-wide monitoring system at the Oak Ridge National Laboratory is provided.

Analysis of a combined heating and cooling system model under different operating strategies

Science.gov (United States)

Dzierzgowski, Mieczysław; Zwierzchowski, Ryszard

2017-11-01

The paper presents an analysis of a combined heating and cooling system model under different operating strategies. Cooling demand for air conditioning purposes has grown steadily in Poland since the early 1990s. The main clients are large office buildings and shopping malls in downtown locations. Increased demand for heat in the summer would mitigate a number of problems regarding District Heating System (DHS) operation at minimum power, affecting the average annual price of heat (in summertime the share of costs related to transport losses is a strong cost factor). In the paper, computer simulations were performed for different supply network water temperature, assuming as input, real changes in the parameters of the DHS (heat demand, flow rates, etc.). On the basis of calculations and taking into account investment costs of the Absorption Refrigeration System (ARS) and the Thermal Energy Storage (TES) system, an optimal capacity of the TES system was proposed to ensure smooth and efficient operation of the District Heating Plant (DHP). Application of ARS with the TES system in the DHS in question increases net profit by 19.4%, reducing the cooling price for consumers by 40%.

Conceptual development of a building-integrated photovoltaic–radiative cooling system and preliminary performance analysis in Eastern China

International Nuclear Information System (INIS)

Zhao, Bin; Hu, Mingke; Ao, Xianze; Pei, Gang

2017-01-01

Highlights: •A specific spectral characteristic for both PV and RC was proposed. •The PV/RC hybrid system based on spectral characteristic is original. •A thermal model of the system was established and the performance was analyzed. •The performance comparison with the conventional PV system was conducted. •The system shows considerable performance for both PV and RC. -- Abstract: Building-integrated photovoltaic/thermal (BIPV/T) technology has been receiving considerable research attention because of its ability to generate electricity and thermal energy simultaneously. However, space cooling is crucial for buildings in hot regions where space heating is of little use. This study proposed a building-integrated photovoltaic–radiative cooling system (BIPV–RC) that can generate electricity via photovoltaic (PV) conversion during daytime and generate cooling energy via radiative cooling (RC) during nighttime to satisfy the demand in such areas. The selective plate, which is the main component of the BIPV–RC system, exhibits high spectral absorptivity (emissivity) in the PV conversion band of crystalline silicon solar cells and in the atmospheric window band (i.e., 0.3–1.1 μm and 8–13 μm), as well as low spectral absorptivity (emissivity) in other bands. A quasi-steady-state mathematical model was built, and its performance under realistic ambient conditions was analyzed. The electrical efficiencies of the BIPV–RC and conventional BIPV systems were then compared under different solar radiations. Comparison results show that the annual electricity production and cooling energy gain of the BIPV–RC system in Hefei reached 156.74 kW h m −2 (equivalent to 564.26 MJ m −2 ) and 579.91 MJ m −2 , respectively. The total electricity production and cooling energy gain of this system are 96.96% higher than those of the BIPV system. Parametric studies show that the precipitable water vapor amount has remarkable effects on the nocturnal RC performance

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

Thermodynamic analysis of a novel exhaust heat-driven non-adiabatic ejection-absorption refrigeration cycle using R290/oil mixture

International Nuclear Information System (INIS)

Li, Keqiao; Cai, Dehua; Liu, Yue; Jiang, Jingkai; Sun, Wei; He, Guogeng

2017-01-01

Graphical abstract: A novel air-cooled non-adiabatic ejection-absorption refrigeration cycle using R290/refrigeration oil has been thermodynamically analyzed. Influences of the ejector and the non-adiabatic absorber applications on the system performance and other system operation parameters have been investigated. The simulation results will be of great help to the miniaturization and practical application of the air-cooled absorption refrigeration system. - Highlights: • A novel air-cooled non-adiabatic ejection-absorption refrigeration cycle is proposed. • Influences of the ejector and the air-cooled non-adiabatic absorber applications on the system performance are investigated. • Variations of system performance and other system operation parameters are investigated. • R290/refrigeration oil mixture used as working pairs is analyzed. - Abstract: This paper thermodynamically analyzes a novel air-cooled non-adiabatic ejection-absorption refrigeration cycle with R290/oil mixture driven by exhaust heat. An ejector located at the upstream of the non-adiabatic absorber is employed to improve the cycle performance. Variations of COP, circulation ratio and component heat load of the system as a function of generating temperature, pressure ratio, absorption temperature, condensing temperature and evaporating temperature have been investigated in this work. The simulation results show that, compared with the conventional absorption refrigeration cycle, this non-adiabatic ejection-absorption refrigeration cycle has higher absorption efficiency, better performance, wider working condition range and lower total heat load and its COP can reach as high as 0.5297. The implementation of the ejector and the non-adiabatic absorber helps to realize the miniaturization and wider application of the absorption refrigeration system. In addition, R290/oil mixture is a kind of highly potential working pairs for absorption refrigeration.

Emergency core cooling system

International Nuclear Information System (INIS)

Ando, Masaki.

1987-01-01

Purpose: To actuate an automatic pressure down system (ADS) and a low pressure emergency core cooling system (ECCS) upon water level reduction of a nuclear reactor other than loss of coolant accidents (LOCA). Constitution: ADS in a BWR type reactor is disposed for reducing the pressure in a reactor container thereby enabling coolant injection from a low pressure ECCS upon LOCA. That is, ADS has been actuated by AND signal for a reactor water level low signal and a dry well pressure high signal. In the present invention, ADS can be actuated further also by AND signal of the reactor water level low signal, the high pressure ECCS and not-operation signal of reactor isolation cooling system. In such an emergency core cooling system thus constituted, ADS operates in the same manner as usual upon LOCA and, further, ADS is operated also upon loss of feedwater accident in the reactor pressure vessel in the case where there is a necessity for actuating the low pressure ECCS, although other high pressure ECCS and reactor isolation cooling system are not operated. Accordingly, it is possible to improve the reliability upon reactor core accident and mitigate the operator burden. (Horiuchi, T.)

Thermodynamic performance optimization of the absorption-generation process in an absorption refrigeration cycle

International Nuclear Information System (INIS)

Chen, Yi; Han, Wei; Jin, Hongguang

2016-01-01

Highlights: • This paper proposes a new thermal compressor model with boost pressure ratio. • The proposed model is an effective way to optimize the absorption-generation process. • Boost pressure ratio is a key parameter in the proposed thermal compressor model. • The optimum boost pressure ratios for two typical refrigeration systems are obtained. - Abstract: The absorption refrigeration cycle is a basic cycle that establishes the systems for utilizing mid-low temperature heat sources. A new thermal compressor model with a key parameter of boost pressure ratio is proposed to optimize the absorption-generation process. The ultimate generation pressure and boost pressure ratio are used to represent the potential and operating conditions of the thermal compressor, respectively. Using the proposed thermal compressor model, the operation mechanism and requirements of the absorption refrigeration system and absorption-compression refrigeration system are elucidated. Furthermore, the two typical heat conversion systems are optimized based on the thermal compressor model. The optimum boost pressure ratios of the absorption refrigeration system and the absorption-compression refrigeration system are 0.5 and 0.75, respectively. For the absorption refrigeration system, the optimum generation temperature is 125.31 °C at the cooling water temperature of 30 °C, which is obtained by simple thermodynamic calculation. The optimized thermodynamic performance of the absorption-compression refrigeration system is 16.7% higher than that of the conventional absorption refrigeration system when the generation temperature is 100 °C. The thermal compressor model proposed in this paper is an effective method for simplifying the optimization of the thermodynamic systems involving an absorption-generation process.

Cooling Performance Analysis of ThePrimary Cooling System ReactorTRIGA-2000Bandung

Science.gov (United States)

Irianto, I. D.; Dibyo, S.; Bakhri, S.; Sunaryo, G. R.

2018-02-01

The conversion of reactor fuel type will affect the heat transfer process resulting from the reactor core to the cooling system. This conversion resulted in changes to the cooling system performance and parameters of operation and design of key components of the reactor coolant system, especially the primary cooling system. The calculation of the operating parameters of the primary cooling system of the reactor TRIGA 2000 Bandung is done using ChemCad Package 6.1.4. The calculation of the operating parameters of the cooling system is based on mass and energy balance in each coolant flow path and unit components. Output calculation is the temperature, pressure and flow rate of the coolant used in the cooling process. The results of a simulation of the performance of the primary cooling system indicate that if the primary cooling system operates with a single pump or coolant mass flow rate of 60 kg/s, it will obtain the reactor inlet and outlet temperature respectively 32.2 °C and 40.2 °C. But if it operates with two pumps with a capacity of 75% or coolant mass flow rate of 90 kg/s, the obtained reactor inlet, and outlet temperature respectively 32.9 °C and 38.2 °C. Both models are qualified as a primary coolant for the primary coolant temperature is still below the permitted limit is 49.0 °C.

Dry and mixed air cooling systems

International Nuclear Information System (INIS)

Gutner, Gidali.

1975-01-01

The various dry air cooling systems now in use or being developed are classified. The main dimensioning parameters are specified and the main systems already built are given with their characteristics. The available data allow dry air cooling to be situated against the other cooling modes and so specify the aim of the research or currently developed works. Some systems at development stages are briefly described. The interest in mixed cooling (assisted draft) and the principal available systems is analyzed. A program of research is outlined [fr

Emergency core cooling system

International Nuclear Information System (INIS)

Abe, Nobuaki.

1993-01-01

A reactor comprises a static emergency reactor core cooling system having an automatic depressurization system and a gravitationally dropping type water injection system and a container cooling system by an isolation condenser. A depressurization pipeline of the automatic depressurization system connected to a reactor pressure vessel branches in the midway. The branched depressurizing pipelines are extended into an upper dry well and a lower dry well, in which depressurization valves are disposed at the top end portions of the pipelines respectively. If loss-of-coolant accidents should occur, the depressurization valve of the automatic depressurization system is actuated by lowering of water level in the pressure vessel. This causes nitrogen gases in the upper and the lower dry wells to transfer together with discharged steams effectively to a suppression pool passing through a bent tube. Accordingly, the gravitationally dropping type water injection system can be actuated faster. Further, subsequent cooling for the reactor vessel can be ensured sufficiently by the isolation condenser. (I.N.)

Steady state simulation of a double-effect steam absorption chiller

Energy Technology Data Exchange (ETDEWEB)

Ahmed, M.S.A.M.S.; Gilani, S.I.U.H. [Universiti Teknologi Petronas, Tronoh, Perak (Malaysia). Dept. of Mechanical Engineering

2011-07-01

Absorption cooling systems have become increasingly popular in recent years from the viewpoint of energy and environment. Despite a lower coefficient of performance (COP) as compared to the vapor compression, absorption refrigeration systems are attractive for using inexpensive waste heat, solar, geothermal or biomass energy sources for which the cost of supply is negligible in many cases. In addition absorption refrigeration uses natural substances which do not contribute towards ozone depletion and global warming. Owing to the serious environmental problems and the price of the traditional energy resources, the use of industrial waste heat or renewable energy as the driving force for vapor absorption cooling systems is continuously increasing. A steady-state model is developed to predict the performance of an absorption refrigeration system using LiBr-water as working pair. Each component of the cycle is modelled based on mass and energy balances. The design point parameters are determined. The refrigeration effect, coefficient of performance and load factor are analyzed for different heat input. Simulation is carried out and the results are compared with actual data and showed good agreement.

Smart Cooling Controlled System Exploiting Photovoltaic Renewable Energy Systems

Directory of Open Access Journals (Sweden)

Ahmad Atieh

2018-03-01

Full Text Available A smart cooling system to control the ambient temperature of a premise in Amman, Jordan, is investigated and implemented. The premise holds 650 people and has 14 air conditioners with the cooling capacity ranging from 3 to 5 ton refrigerant (TR each. The control of the cooling system includes implementing different electronics circuits that are used to sense the ambient temperature and humidity, count the number of people in the premise and then turn ON/OFF certain air conditioner(s. The data collected by different electronic circuits are fed wirelessly to a microcontroller, which decides which air conditioner will be turned ON/OFF, its location and its desired set cooling temperature. The cooling system is integrated with an on-grid solar photovoltaic energy system to minimize the operational cost of the overall cooling system.

Comparative analysis on operation strategies of CCHP system with cool thermal storage for a data center

International Nuclear Information System (INIS)

Song, Xu; Liu, Liuchen; Zhu, Tong; Zhang, Tao; Wu, Zhu

2016-01-01

Highlights: • Load characteristics of the data center make a good match with CCHP systems. • TRNSYS models was used to simulate the discussed CCHP system in a data center. • Comprehensive system performance under two operation strategies were evaluated. • Cool thermal storage was introduced to reuse the energy surplus by FEL system. • The suitable principle of equipment selection for a FEL system were proposed. - Abstract: Combined Cooling, Heating, and Power (CCHP) systems with cool thermal storage can provide an appropriate energy supply for data centers. In this work, we evaluate the CCHP system performance under two different operation strategies, i.e., following thermal load (FTL) and following electric load (FEL). The evaluation is performed through a case study by using TRNSYS software. In the FEL system, the amount of cool thermal energy generated by the absorption chillers is larger than the cooling load and it can be therefore stored and reused at the off-peak times. Results indicate that systems under both operation strategies have advantages in the fields of energy saving and environmental protection. The largest percentage of reduction of primary energy consumption, CO_2 emissions, and operation cost for the FEL system, are 18.5%, 37.4% and 46.5%, respectively. Besides, the system performance is closely dependent on the equipment selection. The relation between the amount of energy recovered through cool thermal storage and the primary energy consumption has also been taken into account. Moreover, the introduction of cool thermal storage can adjust the heat to power ratio on the energy supply side close to that on the consumer side and consequently promote system flexibility and energy efficiency.

Current fluctuations in quantum absorption refrigerators

Science.gov (United States)

Segal, Dvira

2018-05-01

Absorption refrigerators transfer thermal energy from a cold bath to a hot bath without input power by utilizing heat from an additional "work" reservoir. Particularly interesting is a three-level design for a quantum absorption refrigerator, which can be optimized to reach the maximal (Carnot) cooling efficiency. Previous studies of three-level chillers focused on the behavior of the averaged cooling current. Here, we go beyond that and study the full counting statistics of heat exchange in a three-level chiller model. We explain how to obtain the complete cumulant generating function of the refrigerator in a steady state, then derive a partial cumulant generating function, which yields closed-form expressions for both the averaged cooling current and its noise. Our analytical results and simulations are beneficial for the design of nanoscale engines and cooling systems far from equilibrium, with their performance optimized according to different criteria, efficiency, power, fluctuations, and dissipation.

Use of a temperature-initiated passive cooling system (TIPACS) for the modular high-temperature gas-cooled reactor cavity cooling system (RCCS)

International Nuclear Information System (INIS)

Forsberg, C.W.; Conklin, J.; Reich, W.J.

1994-04-01

A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS's heat-removal capabilities. Section 5 analyzes the operation of the temperature-control mechanism that determines under what conditions the TIPACS rejects heat to the environment. Section 6 addresses other design and operational issues. Section 7 identifies uncertainties, and Section 8 provides conclusions. The appendixes provide the detailed data and models used in the analysis

Use of a temperature-initiated passive cooling system (TIPACS) for the modular high-temperature gas-cooled reactor cavity cooling system (RCCS)

Energy Technology Data Exchange (ETDEWEB)

Forsberg, C.W.; Conklin, J.; Reich, W.J.

1994-04-01

A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS`s heat-removal capabilities. Section 5 analyzes the operation of the temperature-control mechanism that determines under what conditions the TIPACS rejects heat to the environment. Section 6 addresses other design and operational issues. Section 7 identifies uncertainties, and Section 8 provides conclusions. The appendixes provide the detailed data and models used in the analysis.

Energy analysis of a diffusion absorption cooling system using lithium nitrate, sodium thiocyanate and water as absorbent substances and ammonia as the refrigerant

International Nuclear Information System (INIS)

Acuña, A.; Velázquez, N.; Cerezo, J.

2013-01-01

A diffusion absorption cooling system is analyzed to determine the appropriate fluid for the unit, based on the coefficient of performance (COP) and operating conditions, by comparing lithium nitrate (LiNO 3 ), sodium thiocyanate (NaSCN) and water (H 2 O) as absorbent substances and by using ammonia (NH 3 ) as the refrigerant. The presence of crystallization in the system is analyzed as a function of the generator and absorber temperatures. Additionally, the effects on the efficiency of the system from adding the inert gas helium (He) or hydrogen (H 2 ) are studied. A mathematical model is developed and compared to experimental studies reported in the literature. At an evaporator temperature of −15 °C, a generator temperature of 120 °C and absorber and condenser temperatures of 40 °C, the results show that the best performance is achieved by the NH 3 –LiNO 3 –He mixture, with a COP of 0.48. This mixture performs 27–46% more efficient than the NH 3 –NaSCN mixture. The NH 3 –H 2 O mixture is 52–69% less efficient than the NH 3 –LiNO 3 mixture. However, when the evaporator runs at 7.5 °C, the NH 3 –H 2 O–He mixture achieves a more efficient COP than does the NH 3 –LiNO 3 –He mixture, and the NH 3 –NaSCN–He and NH 3 –LiNO 3 –He mixtures achieve the same COP when the evaporator is at 10 °C. At temperatures below 7.5 °C, the NH 3 –NaSCN–He mixture achieves a higher COP than does the NH 3 –H 2 O–He mixture. The NH 3 –LiNO 3 mixture shows crystallization at higher temperatures in the generator than does the NH 3 –NaSCN mixture. Moreover, at the same evaporator temperature, the NH 3 –LiNO 3 mixture works at activation temperatures lower than does the NH 3 –NaSCN mixture. -- Highlights: ► We studied a diffusion absorption cooling system with different working mixtures. ► The NH 3 –LiNO 3 mixture showed more efficiency than NH 3 –H 2 O mixture and NH 3 –NaSCN mixture. ► The generator and absorber temperature

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

Exergy and Exergoenvironmental Analysis of a CCHP System Based on a Parallel Flow Double-Effect Absorption Chiller

Directory of Open Access Journals (Sweden)

Ali Mousafarash

2016-01-01

Full Text Available A combined cooling, heating, and power (CCHP system which produces electricity, heating, and cooling is modeled and analyzed. This system is comprised of a gas turbine, a heat recovery steam generator, and a double-effect absorption chiller. Exergy analysis is conducted to address the magnitude and the location of irreversibilities. In order to enhance understanding, a comprehensive parametric study is performed to see the effect of some major design parameters on the system performance. These design parameters are compressor pressure ratio, gas turbine inlet temperature, gas turbine isentropic efficiency, compressor isentropic efficiency, and temperature of absorption chiller generator inlet. The results show that exergy efficiency of the CCHP system is higher than the power generation system and the cogeneration system. In addition, the results indicate that when waste heat is utilized in the heat recovery steam generator, the greenhouse gasses are reduced when the fixed power output is generated. According to the parametric study results, an increase in compressor pressure ratio shows that the network output first increases and then decreases. Furthermore, an increase in gas turbine inlet temperature increases the system exergy efficiency, decreasing the total exergy destruction rate consequently.

Appropriate heat load ratio of generator for different types of air cooled lithium bromide–water double effect absorption chiller

International Nuclear Information System (INIS)

Li, Zeyu; Liu, Jinping

2015-01-01

Highlights: • Effect of heat load ratio of generator on the performance was analyzed. • The performance is sensitive to heat load ratio of generator. • The appropriate heat load ratio of generator for four systems was obtained. • The change of appropriate heat load ratio of generator for four systems was studied. - Abstract: The lower coefficient of performance and higher risk of crystallization in the higher surrounding temperature is the primary disadvantage of air cooled lithium bromide–water double effect absorption chiller. Since the coefficient of performance and risk of crystallization strongly depend on the heat load ratio of generator, the appropriate heat load ratio of generator can improve the performance as the surrounding temperature is higher. The paper mainly deals with the appropriate heat load ratio of generator of air cooled lithium bromide–water double effect absorption chiller. Four type systems named series, pre-parallel, rear parallel and reverse parallel flow configuration were considered. The corresponding parametric model was developed to analyze the comprehensive effect of heat load ratio of generator on the coefficient of performance and risk of crystallization. It was found that the coefficient of performance goes up linearly with the decrease of heat load ratio of generator. Simultaneously, the risk of crystallization also rises slowly at first but increases fast finally. Consequently, the appropriate heat load ratio of generator for the series and pre-parallel flow type systems is suggested to be 0.02 greater than the minimum heat load ratio of generator and that for the rear parallel and reverse parallel flow chillers should be 0.01 higher than the minimum heat load ratio of generator. Besides, the changes of minimum heat load ratio of generator for different type systems with the working condition were analyzed and compared. It was found that the minimum heat load ratio of generator goes up with the increase of

Design of absorption system water-ammonia by using solar radiation as thermal source

Energy Technology Data Exchange (ETDEWEB)

Cavalcanti, Eduardo J. Cidade; Souza, Luiz Guilherme Meira [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Tecnlogia. Dept. de Engenharia Mecanica], E-mails: educanti@gmail.com, lguilherme@dem.ufrn.br

2010-07-01

An absorption refrigeration system with the single effect of par ammonia water with 1.758 kW (1 / 2 RT) cooling capacity was designed. The system was operating under conditions of 5 degree C evaporation and 45 degree C condensation temperature. The absorption system has a heat exchanger to improve performance. The heat source is the cylinder parabolic solar concentrator (CPC). The design of the concentrator was estimated based on experimental data of the pilot plant built in the Solar Energy Laboratory, Federal University of Rio Grande do Norte. The thermodynamic model with heat and mass transfer was made to the project areas of heat exchange (absorber) and consequent construction of the system. The rectifying column was modeling assuming that liquid is in equilibrium with the vapor state in all plate. The results should show the dimensions of the compact and allows a future assessment of the operational cost. (author)

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

Emergency cooling system for a gas-cooled nuclear reactor

International Nuclear Information System (INIS)

Cook, R.K.; Burylo, P.S.

1975-01-01

The site of the gas-cooled reactor with direct-circuit gas turbine is preferably the sea coast. An emergency cooling system with safety valve and emergency feed-water addition is designed which affects at least a part of the reactor core coolant after leaving the core. The emergency cooling system includes a water emergency cooling circuit with heat exchanger for the core coolant. The safety valve releases water or steam from the emergency coolant circuit when a certain temperature is exceeded; this is, however, replaced by the emergency feed-water. If the gas turbine exhibits a high and low pressure turbine stage, which are flowed through by coolant one behind another, a part of the coolant can be removed in front of each part turbine by two valves and be added to the haet exchanger. (RW/LH) [de

Investigations of combined used of cooling ponds with cooling towers or spraying systems

International Nuclear Information System (INIS)

Farforovsky, V.B.

1990-01-01

Based on a brief analysis of the methods of investigating cooling ponds, spraying systems and cooling towers, a conclusion is made that the direct modelling of the combined use of cooling systems listed cannot be realized. An approach to scale modelling of cooling ponds is proposed enabling all problems posed by the combined use of coolers to be solved. Emphasized is the importance of a proper choice of a scheme of including a cooler in a general water circulation system of thermal and nuclear power plants. A sequence of selecting a cooling tower of the type and spraying system of the size ensuring the specified temperature regime in a water circulation system is exemplified by the water system of the Ghorasal thermal power plant in Bangladesh

ITER cooling systems

International Nuclear Information System (INIS)

Natalizio, A.; Hollies, R.E.; Sochaski, R.O.; Stubley, P.H.

1992-06-01

The ITER reference system uses low-temperature water for heat removal and high-temperature helium for bake-out. As these systems share common equipment, bake-out cannot be performed until the cooling system is drained and dried, and the reactor cannot be started until the helium has been purged from the cooling system. This study examines the feasibility of using a single high-temperature fluid to perform both heat removal and bake-out. The high temperature required for bake-out would also be in the range for power production. The study examines cost, operational benefits, and impact on reactor safety of two options: a high-pressure water system, and a low-pressure organic system. It was concluded that the cost savings and operational benefits are significant; there are no significant adverse safety impacts from operating either the water system or the organic system; and the capital costs of both systems are comparable

The development of air cooled condensation systems

International Nuclear Information System (INIS)

Bodas, J.

1990-01-01

EGI - Contracting/Engineering has had experience with the development of air cooled condensing systems since the 1950's. There are two accepted types of dry cooling systems,the direct and the indirect ones. Due to the fact that the indirect system has several advantages over the direct one, EGI's purpose was to develop an economic, reliable and efficient type of indirect cooling system, both for industrial and power station applications. Apart from system development, the main components of dry cooling plant have been developed as well. These are: the water-to-air heat exchangers; the direct contact (DC, or jet) condenser; the cooling water circulating pumps and recovery turbines; and the peak cooling/preheating units. As a result of this broad development work which was connected with intensive market activity, EGI has supplied about 50% of the dry cooling plants employed for large power stations all over the world. This means that today the cumulated capacity of power units using Heller type dry cooling systems supplied and contracted by EGI is over 6000 MW

A Solar Heating and Cooling System in a Nearly Zero-Energy Building: A Case Study in China

Directory of Open Access Journals (Sweden)

Zhifeng Sun

2017-01-01

Full Text Available The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Therefore, a nearly zero-energy building, incorporating a solar heating and cooling system, was designed and built in Beijing, China. The system included a 35.17 kW cooling (10-RT absorption chiller, an evacuated tube solar collector with an aperture area of 320.6 m2, two hot-water storage tanks (with capacities of 10 m3 and 30 m3, respectively, two cold-water storage tanks (both with a capacity of 10 m3, and a 281 kW cooling tower. Heat pump systems were used as a backup. At a value of 25.2%, the obtained solar fraction associated with the cooling load was close to the design target of 30%. In addition, the daily solar collector efficiency and the chiller coefficient of performance (COP varied from 0.327 to 0.507 and 0.49 to 0.70, respectively.

Experimental analysis of a diffusion absorption refrigeration system used alternative energy sources

International Nuclear Information System (INIS)

Soezen, A.; Oezbas, E.

2009-01-01

The continuous-cycle absorption refrigeration device is widely used in domestic refrigerators, and recreational vehicles. It is also used in year-around air conditioning of both homes and larger buildings. The unit consists of four main parts the boiler, condenser, evaporator and the absorber. When the unit operates on kerosene or gas, the heat is supplied by a burner. This element is fitted underneath the central tube. When operating on electricity, the heat is supplied by an element inserted in the pocket. No moving parts are employed. The operation of the refrigerating mechanism is based on Dalton's law. In this study, experimental analysis was performed of a diffusion absorption refrigeration system (DARS) used alternative energy sources such as solar, liquid petroleum gas (LPG) sources. Two basic DAR cycles were set up and investigated: i) In the first cycle (DARS-1), the condensate is sub-cooled prior to the evaporator entrance by the coupled evaporator/gas heat exchanger similar with manufactured by Electrolux Sweden. ii) In the second cycle (DARS-2), the condensate is not sub-cooled prior to the evaporator entrance and gas heat exchanger is separated from the evaporator. (author)

Parametric analysis of an irreversible proton exchange membrane fuel cell/absorption refrigerator hybrid system

International Nuclear Information System (INIS)

Yang, Puqing; Zhang, Houcheng

2015-01-01

A hybrid system mainly consisting of a PEMFC (proton exchange membrane fuel cell) and an absorption refrigerator is proposed, where the PEMFC directly converts the chemical energy contained in the hydrogen into electrical and thermal energies, and the thermal energy is transferred to drive the bottoming absorption refrigerator for cooling purpose. By considering the existing irreversible losses in the hybrid system, the operating current density region of the PEMFC permits the absorption refrigerator to exert its function is determined and the analytical expressions for the equivalent power output and efficiency of the hybrid system under different operating conditions are specified. Numerical calculations show that the equivalent maximum power density and the corresponding efficiency of the hybrid system can be respectively increased by 5.3% and 6.8% compared to that of the stand-alone PEMFC. Comprehensive parametric analyses are conducted to reveal the effects of the internal irreversibility of the absorption refrigerator, operating current density, operating temperature and operating pressure of the PEMFC, and some integrated parameters related to the thermodynamic losses on the performance of the hybrid system. The model presented in the paper is more general than previous study, and the results for some special cases can be directly derived from this paper. - Highlights: • A CHP system composed of a PEMFC and an absorption refrigerator is proposed. • Current density region enables the absorption refrigerator to work is determined. • Multiple irreversible losses in the system are analytically characterized. • Maximum power density and corresponding efficiency can be increased by 5.3% and 6.8%. • Effects of some designing and operating parameters on the performance are discussed

Solar heating, cooling, and hot water systems installed at Richland, Washington

Science.gov (United States)

1979-01-01

The project described is part of the U. S. Department of Energy's solar demonstration program, and became operational in April 1978. The solar system uses 6,000 square feet of flat-plate liquid collectors in a closed loop to deliver solar energy through a liquid-liquid heat exchanger to the building heat-pump duct work or 9,000-gallon thermal energy storage tank. A 25-ton Arkla solar-driven absorption chiller provides the cooling, in conjunction with a 2,000 gallon chilled water storage tank and reflective ponds on three sides of the building surplus heat. A near-by building is essentially identical except for having conventional heat-pump heating and cooling, and can serve as an experimental control. An on-going public relations program was provided from the beginning of the program, and resulted in numerous visitors and tour groups.

Solar-assisted absorption air-conditioning systems in buildings: Control strategies and operational modes

International Nuclear Information System (INIS)

Shirazi, Ali; Pintaldi, Sergio; White, Stephen D.; Morrison, Graham L.; Rosengarten, Gary; Taylor, Robert A.

2016-01-01

Highlights: • A simulation model of a solar driven absorption chiller is developed in detail. • Three control strategies were proposed in the solar loop of the plant. • Series and parallel auxiliary heater arrangements were investigated. • The results showed the auxiliary-heater in parallel outperformed the series one. • Solar fraction can be increased by 20% by implementing the proposed configuration. - Abstract: Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems. Three control scenarios are proposed for the solar collector loop. The first uses a constant flow pump, while the second and third control schemes employ a variable speed pump, where the solar collector (SC) set-point temperature could be either fixed or adjusted to the required demand. Series and parallel arrangements, between the auxiliary heater and the storage tank, have been examined in detail from an energy efficiency perspective. A simulation model for different system layouts is developed in the transient system simulation environment (TRNSYS, Version 17). Simulation results revealed that the total solar fraction of the plant is increased by up to 11% when a variable speed solar loop pump is used to achieve a collector set-point temperature adjusted according to the building load demand. Another significant finding of this study is that a parallel configuration for the auxiliary heater out-performs a conventional series configuration. The yearly performance of an auxiliary heater in parallel with the storage

Annual DOE active solar heating and cooling contractors' review meeting. Premeeting proceedings and project summaries

Energy Technology Data Exchange (ETDEWEB)

None,

1981-09-01

Ninety-three project summaries are presented which discuss the following aspects of active solar heating and cooling: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology. (LEW)

Trigeneration System Based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

DEFF Research Database (Denmark)

Katsaros, Giannis; Nguyen, Tuong-Van; Rokni, Masoud

2016-01-01

of a specific building is also investigated and the system can fully meet the electricity and cooling demands, whereas the heat needs can be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period is 4.3 years and the net present value exceeds 5 MEUR.......The present work focuses on the design of a novel tri-generation system based on municipal solid wastes gasification, solid oxide fuel cell and an ammonia-water absorption chiller. Trigeneration systems can be implemented in buildings such as hospitals, where there is a continuous and large demand...

Performance assesment of solar heating and cooling systems

Energy Technology Data Exchange (ETDEWEB)

Shesho, Igor; Armenski, Slave [Faculty of Mechanical Engineering, ' Ss. Cyril and Methodius' University, Skopje (Macedonia, The Former Yugoslav Republic of); others, and

2014-07-01

Thermal performance of the solar thermal systems are estimated using numerical methods and software since the solar processes are transitient in nature been driven by time dependent forcing functions and loads. The system components are defined with mathematical relationships that describe how components function. They are based on the first principles (energy balances, mass balances, rate equations and equilibrium relationships) at one extreme or empirical curve fits to operating data from specific machines such as absorption chillers. The component models are programed, i.e. they represent written subroutines which are simultaneously solved with the executive program. In this paper for executive program is chosen TRNSYS containing library with solar thermal system component models. Validation of the TRNSYS components models is performed, i.e. the simulation results are compared with experimental measurements. Analysis is performed for solar assisted cooling system in order to determine the solar fractions and efficiencies for different collector types, areas and storage tanks. Specific indicators are derived in order to facilitate the techno-economic analysis and design of solar air-conditioning systems. (Author)

ITER cooling system

International Nuclear Information System (INIS)

Kveton, O.K.

1990-11-01

The present specification of the ITER cooling system does not permit its operation with water above 150 C. However, the first wall needs to be heated to higher temperatures during conditioning at 250 C and bake-out at 350 C. In order to use the cooling water for these operations the cooling system would have to operate during conditioning at 37 Bar and during bake-out at 164 Bar. This is undesirable from the safety analysis point of view, and alternative heating methods are to be found. This review suggests that superheated steam or gas heating can be used for both baking and conditioning. The blanket design must consider the use of dual heat transfer media, allowing for change from one to another in both directions. Transfer from water to gas or steam is the most intricate and risky part of the entire heating process. Superheated steam conditioning appears unfavorable. The use of inert gas is recommended, although alternative heating fluids such as organic coolant should be investigated

Theoretical thermodynamics analysis of cooling cycle bu advanced gas absorption using solar energy; Analisis teorico-experimental de un ciclo de refrigeracion por absorcion avanzado gax, operando con energia solar

Energy Technology Data Exchange (ETDEWEB)

Gomez, V. E.; Vidal, A. S.; Garcia, C. A.; Garcia-Valladares, O.; Best, R. B.; Hernandez, J. G.; Velazquez, N. L.

2004-07-01

In this article a solar system of refrigeration by absorption with heat exchange generator absorber (GAX) was analyzed. A theoretical thermodynamic analysis of the energetic behavior of the GAX absorption system was made. Experimental results were obtained with generation temperatures of 190 and 220 C, the evaporation temperature was set at 9 C and temperatures of cooling fluids (air and water) were set at 30 C and 28 C, respectively. It was possible to appreciate that the GAX effect decrease whether absorber, type falling film, is operated in option of parallel flow and it was increased when the absorber was operated in option of counterflow. (Author)

SNS Resonance Control Cooling Systems and Quadrupole Magnet Cooling Systems DIW Chemistry

Energy Technology Data Exchange (ETDEWEB)

Magda, Karoly [ORNL

2018-01-01

This report focuses on control of the water chemistry for the Spallation Neutron Source (SNS) Resonance Control Cooling System (RCCS)/Quadrupole Magnet Cooling System (QMCS) deionized water (DIW) cooling loops. Data collected from spring 2013 through spring 2016 are discussed, and an operations regime is recommended.It was found that the RCCS operates with an average pH of 7.24 for all lines (from 7.0 to 7.5, slightly alkaline), the average low dissolved oxygen is in the area of < 36 ppb, and the main loop average resistivity of is > 14 MΩ-cm. The QMCS was found to be operating in a similar regime, with a slightly alkaline pH of 7.5 , low dissolved oxygen in the area of < 45 ppb, and main loop resistivity of 10 to 15 MΩ-cm. During data reading, operational corrections were done on the polishing loops to improve the water chemistry regime. Therefore some trends changed over time.It is recommended that the cooling loops operate in a regime in which the water has a resistivity that is as high as achievable, a dissolved oxygen concentration that is as low as achievable, and a neutral or slightly alkaline pH.

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.

Huge opportunity for solar cooling

International Nuclear Information System (INIS)

Rowe, Daniel

2014-01-01

In Europe more than 400 solar cooling systems have been installed. By contrast, only a small number of solar cooling installations exist in Australia - primarily adsorption and absorption systems for commercial and hospitals - although these systems are growing. As with other renewable energy technologies, cost is a challenge. However solar cooling is currently competitive with other technologies, with some suggesting that system costs have been decreasing by about 20% per annum in recent times. Australia is also leading efforts in the development of residential solar desiccant technology, currently commercialising Australian-developed technology. Commercial and industrial enterprises are increasingly aware of the impact of demand charges, the potential to install technology as a hedge against future energy price rises and opportunities associated with increased on-site generation and reduced reliance on the grid, often necessitating on-site demand reduction and management. They are also driven by environmental and corporate social responsibility objectives as well as the opportunity for energy independence and uninterruptible operation. Interestingly, many of these interests are mirrdred at residential level, inspiring CSIRO's commercialisation of a domestic scale solar air conditioner with Australian manufacturer Brevis Climate Systems. Australia and other countries are increasingly aware of solar cooling as technology which can reduce or replace grid-powered cooling, particularly in applications where large building thermal energy requirements exist. In these applications, heating, cooling and hot water are generated and used in large amounts and the relative amounts of each can be varied dynamically, depending on building requirements. Recent demonstrations of solar cooling technology in Australia include Hunter TAFE's Solar Desiccant Cooling System - which provides heating, cooling and hot water to commercial training kitchens and classrooms - GPT

Solar radiation and cooling load calculation for radiant systems: Definition and evaluation of the Direct Solar Load

DEFF Research Database (Denmark)

Causone, Francesco; Corgnati, Stefano P.; Filippi, Marco

2010-01-01

The study of the influence of solar radiation on the built environment is a basic issue in building physics and currently it is extremely important because glazed envelopes are widely used in contemporary architecture. In the present study, the removal of solar heat gains by radiant cooling systems...... is investigated. Particular attention is given to the portion of solar radiation converted to cooling load, without taking part in thermal absorption phenomena due to the thermal mass of the room. This specific component of the cooling load is defined as the Direct Solar Load. A simplified procedure to correctly...... calculate the magnitude of the Direct Solar Load in cooling load calculations is proposed and it is implemented with the Heat Balance method and the Radiant Time Series method. The F ratio of the solar heat gains directly converted to cooling load, in the case of a low thermal mass radiant ceiling...

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.

Feasibility and Basic Design of Solar Integrated Absorption Refrigeration for an Industry

KAUST Repository

Akhtar, Saad

2015-08-28

This paper presents a review of existing solar cooling technologies and a feasibility study of a solar absorption cooling system for a packaging facility at Tetrapak Lahore, Pakistan. The review includes brief description of existing chiller technologies and solar collectors. The case study includes analysis of the solar potential and design of the cooling system at considered site. The design calculations upon which the feasibility analysis is carried out are solar collector area and type, cooling capacity, cooling area. A comparison is made between solar cooling potential of Pakistan and existing sites all across the globe. Finally an economic analysis is carried out to demonstrate the financial viability of the new cooling system.

Emergency reactor cooling systems for the experimental VHTR

International Nuclear Information System (INIS)

Mitake, Susumu; Suzuki, Katsuo; Miyamoto, Yoshiaki; Tamura, Kazuo; Ezaki, Masahiro.

1983-03-01

Performances and design of the panel cooling system which has been proposed to be equipped as an emergency reactor cooling system for the experimental multi purpose very high temperature gas-cooled reactor are explained. Effects of natural circulation flow which would develop in the core and temperature transients of the panel in starting have been precisely investigated. Conditions and procedures for settling accidents with the proposed panel cooling system have been also studied. Based on these studies, it has been shown that the panel cooling system is effective and useful for the emergency reactor cooling of the experimental VHTR. (author)

Maximization of primary energy savings of solar heating and cooling systems by transient simulations and computer design of experiments

International Nuclear Information System (INIS)

Calise, F.; Palombo, A.; Vanoli, L.

2010-01-01

In this paper, the simulation of the performance of solar-assisted heating and cooling systems is analyzed. Three different plant layouts are considered: (i) the first one consists of evacuated solar collectors and a single-stage LiBr-H 2 O absorption chiller; here in order to integrate the system in case of insufficient solar radiation, an electric water-cooled chiller is activated; (ii) configuration of the secondly considered system is similar to the first one, but the absorption chiller and the solar collector area are sized for balancing about 30% of the building cooling load only; (iii) the layout of the thirdly considered system differs from the first one since the auxiliary electric chiller is replaced by a gas-fired heater. Such system configurations also include: circulation pumps, storage tanks, feedback controllers, mixers, diverters and on/off hysteresis controllers. All such devices are modelled for maximizing the system energy efficiency. In order to simulate the systems' performance for dynamic heating/cooling loads, a single-lumped capacitance building is also modelled and implemented in the computer code. A cost model is also developed in order to calculate the systems' operating and capital costs. All the models and the relative simulations are carried out by TRNSYS. A design of experiment procedure is also included. By such tool the effects of the system operating parameters' variation on the relative energy efficiency are analyzed. In addition, the set of synthesis/design variables maximizing the system's energetic performance can be also identified. The annual primary energy saving is chosen as the optimization objective function, whereas collector slope, pump flows, set-point temperatures and tank volume are selected as optimizing system design variables. A case study was developed for an office building located in South Italy. Here, the energetic and the economic analysis for all the three considered system layouts are carried out. The

Cooling systems for waste heat. Cooling systems, review and selection criteria. Kuehlsysteme fuer Abwaerme. Kuehlsysteme, Ueberblick und Auswahlkriterien

Energy Technology Data Exchange (ETDEWEB)

Mueller, W. (Jaeggi, Wallisellen (Switzerland))

1990-05-01

In many areas of ventilation, air-conditioning and refrigeration engineering, chemical and process engineering and energy production waste heat occurs. If a reduction in energy losses or heat recovery is not possible waste heat has to be drawn off through cooling systems. For this the following systems can be used: dry cooling systems, dry cooler with spray system, open-cycle wet cooler, hybrid dry cooler, and closed-cycle wet cooler. Particularly hybrid cooling systems can give acceptable solutions when the results with other systems are only unsatisfactory. (BWI).

Modeling and simulation of a 100 kWe HT-PEMFC subsystem integrated with an absorption chiller subsystem

DEFF Research Database (Denmark)

Arsalis, Alexandros

2012-01-01

A 100 kWe liquid-cooled HT-PEMFC subsystem is integrated with an absorption chiller subsystem to provide electricity and cooling. The system is designed, modeled and simulated to investigate the potential of this technology for future novel energy system applications. Liquid-cooling can provide...

Thermoeconomic optimization of Solar Heating and Cooling systems

International Nuclear Information System (INIS)

Calise, F.; D'Accadia, M. Dentice; Vanoli, L.

2011-01-01

In the paper, the optimal thermoeconomic configuration of Solar Heating and Cooling systems (SHC) is investigated. In particular, a case study is presented, referred to an office building located in Naples (south Italy); for such building, three different SHC configurations were analyzed: the first one is based on the coupling of evacuated solar collectors with a single-stage LiBr-H 2 O absorption chiller equipped with a water-to-water electrical heat pump, to be used in case of insufficient solar radiation; in the second case, a similar layout is considered, but the capacities of the absorption chiller and the solar field are smaller, since they are requested to balance just a fraction of the total cooling load of the building selected for the case study; finally, in the third case, the electric heat pump is replaced by an auxiliary gas-fired heater. A zero-dimensional transient simulation model, developed in TRNSYS, was used to analyze each layout from both thermodynamic and economic points of view. In particular, a cost model was developed in order to assess the owning and operating costs for each plant layout. Furthermore, a mixed heuristic-deterministic optimization algorithm was implemented in order to determine the set of the synthesis/design variables able to maximize the overall thermo-economic performance of the systems under analysis. For this purpose, two different objective functions were selected: the Pay-Back Period and the overall annual cost. Possible public funding, in terms of Capital Cost Contributions and/or feed-in tariff, were also considered. The results are presented on monthly and weekly basis, paying special attention to the energy and monetary flows in the optimal configurations. In particular, the thermoeconomic analysis and optimization showed that a good funding policy for the promotion of such technologies should combine a feed-in tariff with a slight Capital Cost Contribution, allowing to achieve satisfactory Pay-Back Periods.

COOLING STAGES OF CRYOGENIC SYSTEMS

OpenAIRE

Троценко, А. В.

2011-01-01

The formalized definition for cooling stage of low temperature system is done. Based on existing information about the known cryogenic unit cycles the possible types of cooling stages are single out. From analyses of these stages their classification by various characteristics is suggested. The results of thermodynamic optimization of final throttle stage of cooling, which are used as working fluids helium, hydrogen and nitrogen, are shown.

Design, evaluation and recommedation effort relating to the modification of a residential 3-ton absorption cycle cooling unit for operation with solar energy

Science.gov (United States)

Merrick, R. H.; Anderson, P. P.

1973-01-01

The possible use of solar energy powered absorption units to provide cooling and heating of residential buildings is studied. Both, the ammonia-water and the water-lithium bromide cycles, are considered. It is shown that the air cooled ammonia water unit does not meet the criteria for COP and pump power on the cooling cycle and the heat obtained from it acting as a heat pump is at too low a temperature. If the ammonia machine is water cooled it will meet the design criteria for cooling but can not supply the heating needs. The water cooled lithium bromide unit meets the specified performance for cooling with appreciably lower generator temperatures and without a mechanical solution pump. It is recommeded that in the demonstration project a direct expansion lithium bromide unit be used for cooling and an auxiliary duct coil using the solar heated water be employed for heating.

TPX heating and cooling system

International Nuclear Information System (INIS)

Kungl, D.J.; Knutson, D.S.; Costello, J.; Stoenescu, S.; Yemin, L.

1995-01-01

TPX, while having primarily super-conducting coils that do not require water cooling, still has very significant water cooling requirements for the plasma heating systems, vacuum vessel, plasma facing components, diagnostics, and ancillary equipment. This is accentuated by the 1000-second pulse requirement. Two major design changes, which have significantly affected the TPX Heating and Cooling System, have been made since the conceptual design review in March of 1993. This paper will discuss these changes and review the current status of the conceptual design. The first change involves replacing the vacuum vessel neutron shielding configuration of lead/glass composite tile by a much simpler and more reliable borated water shield. The second change reduces the operating temperature of the vacuum vessel from 150 C to ≥50 C. With this temperature reduction, all in-vessel components and the vessel will be supplied by coolant at a common ≥50 C inlet temperature. In all, six different heating and cooling supply requirements (temperature, pressure, water quality) for the various TPX components must be met. This paper will detail these requirements and provide an overview of the Heating and Cooling System design while focusing on the ramifications of the TPX changes described above

Hot gas path component cooling system

Science.gov (United States)

Lacy, Benjamin Paul; Bunker, Ronald Scott; Itzel, Gary Michael

2014-02-18

A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

Development of Innovative Heating and Cooling Systems Using Renewable Energy Sources for Non-Residential Buildings

Directory of Open Access Journals (Sweden)

Cinzia Buratti

2013-10-01

Full Text Available Industrial and commercial areas are synonymous with high energy consumption, both for heating/cooling and electric power requirements, which are in general associated to a massive use of fossil fuels producing consequent greenhouse gas emissions. Two pilot systems, co-funded by the Italian Ministry for the Environment, have been created to upgrade the heating/cooling systems of two existing buildings on the largest industrial estate in Umbria, Italy. The upgrade was specifically designed to improve the system efficiency and to cover the overall energy which needs with renewable energy resources. In both cases a solar photovoltaic plant provides the required electric power. The first system features a geothermal heat pump with an innovative layout: a heat-storage water tank, buried just below ground level, allows a significant reduction of the geothermal unit size, hence requiring fewer and/or shorter boreholes (up to 60%–70%. In the other system a biomass boiler is coupled with an absorption chiller machine, controlling the indoor air temperature in both summer and winter. In this case, lower electricity consumption, if compared to an electric compression chiller, is obtained. The first results of the monitoring of summer cooling are presented and an evaluation of the performance of the two pilot systems is given.

Controlled cooling of an electronic system for reduced energy consumption

Science.gov (United States)

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

2016-08-09

Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.

Controlled cooling of an electronic system for reduced energy consumption

Energy Technology Data Exchange (ETDEWEB)

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

2018-01-30

Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.

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

Cooling water systems design using process integration

CSIR Research Space (South Africa)

Gololo, KV

2010-09-01

Full Text Available Cooling water systems are generally designed with a set of heat exchangers arranged in parallel. This arrangement results in higher cooling water flowrate and low cooling water return temperature thus reducing cooling tower efficiency. Previous...

Development of design program for small-sized gas absorption chiller/heaters

Energy Technology Data Exchange (ETDEWEB)

Yoon, J.I.; Kwon, O.K.; Moon, C.K. [Pukyong National University, Pusan (Korea); Yang, Y.M.; Kim, H.Y. [R and D Center, Korea Gas Corporation, Ansan (Korea)

1999-10-01

Analysis of basic data is performed for development of small size water-cooled household absorption chiller/heater using non CFC refrigerant, analytic simulation program of air cooling performance is developed that system has 1.5-10RT of air cooling performance, we perform cycle analysis and numerical simulation. We develope a performance analysis of simulation program to perform a basic design for 1.5-10RT apparatus of small size system of development model in gas driven double effect absorption chiller/heater. The system working condition and operation limit condition is decided from the existing data which is analyzed and the conference with KOGAS. After the basic input variable and regular condition is established for heat cycle analysis, the simulation algorithm is set up and performance simulation program is coded according to the organized algorithm. The basic design of optimum system is completed from parametric study using developed simulation program and establishing the design variable range of developing object model. 20 refs., 30 figs., 9 tabs.

Evaporative cooling enhanced cold storage system

Science.gov (United States)

Carr, P.

1991-10-15

The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream. 3 figures.

Experimental analysis and dynamic simulation of a novel high-temperature solar cooling system

International Nuclear Information System (INIS)

Buonomano, Annamaria; Calise, Francesco; D’Accadia, Massimo Dentice; Ferruzzi, Gabriele; Frascogna, Sabrina; Palombo, Adolfo; Russo, Roberto; Scarpellino, Marco

2016-01-01

Highlights: • The paper presents an innovative high temperature solar cooling system. • The system is based on novel flat-plate evacuated solar thermal collectors. • Results of an experimental campaign in Saudi Arabia are reported. • A dynamic simulation model and a detailed economic analyses are developed. • Results show that the collector and the system as a whole exhibit excellent performance. - Abstract: This paper presents experimental and numerical analyses of a novel high-temperature solar cooling system based on innovative flat-plate evacuated solar thermal collectors (SC). This is the first solar cooling system, including a double-effect absorption chiller, which is based on non-concentrating solar thermal collectors. The aim of the paper is prove the technical and economic feasibility of the system, also presenting a comparison with a conventional technology, based on concentrating solar thermal collectors. To this scope, an experimental setup has been installed in Saudi Arabia. Here, several measurement devices are installed in order to monitor and control all the thermodynamic parameters of the system. The paper presents some of the main results of this experimental campaign, showing temperatures, powers, energies and efficiencies for a selected period. Experimental results showed that collector peak efficiency is higher than 60%, whereas daily average efficiency is around 40%. This prototypal solar cooling system has been numerically analysed, developing a dynamic simulation model aiming at predicting system performance. For a representative operating period, numerical data were compared with the experimental one, showing an excellent accuracy of the model. A similar system, equipped with Parabolic Trough solar thermal collectors (PTC) was also simulated in order to compare the novel solar collectors with such reference technology. For both systems a detailed thermo-economic model has been implemented in order to perform such comparison also

Thermodynamic analysis of a combined gas turbine, ORC cycle and absorption refrigeration for a CCHP system

International Nuclear Information System (INIS)

Mohammadi, Amin; Kasaeian, Alibakhsh; Pourfayaz, Fathollah; Ahmadi, Mohammad Hossein

2017-01-01

Highlights: • Thermodynamic analysis of a hybrid CCHP system. • Sensitivity analysis is performed on the most important parameters of the system. • Pressure ratio and gas turbine inlet temperature are the most effective parameters. - Abstract: Hybrid power systems are gained more attention due to their better performance and higher efficiency. Widespread use of these systems improves environmental situation as they reduce the amount of fossil fuel consumption. In this paper a hybrid system composed of a gas turbine, an ORC cycle and an absorption refrigeration cycle is proposed as a combined cooling, heating and power system for residential usage. Thermodynamic analysis is applied on the system. Also a parametric analysis is carried out to investigate the effect of different parameters on the system performance and output cooling, heating and power. The results show that under design conditions, the proposed plant can produce 30 kW power, 8 kW cooling and almost 7.2 ton hot water with an efficiency of 67.6%. Moreover, parametric analysis shows that pressure ratio and gas turbine inlet temperature are the most important and influential parameters. After these two, ORC turbine inlet temperature is the most effective parameter as it can change both net output power and energy efficiency of the system.

Cooling system for the IFMIF-EVEDA radiofrequency system

International Nuclear Information System (INIS)

Perez Pichel, G. D.

2012-01-01

The IFMIF-EVEDA project consists on an accelerator prototype that will be installed at Rokkasho (Japan). Through CIEMAT, that is responsible of the development of many systems and components. Empresarios Agrupados get the responsibility of the detailed design of the cooling system for the radiofrequency system (RF system) that must feed the accelerator. the RF water cooling systems is the water primary circuit that provides the required water flow (with a certain temperature, pressure and water quality) and also dissipates the necessary thermal power of all the radiofrequency system equipment. (Author) 4 refs.

Fundamental research on the cooling characteristic of passive containment cooling system

International Nuclear Information System (INIS)

Kawakubo, M.; Kikura, H.; Aritomi, M.; Inaba, N.; Yamauchi, T.

2004-01-01

The objective of this experimental study is to clarify the heat transfer characteristics of the Passive Containment Cooling System (PCCS) with vertical heat transfer tubes for investigating the influence of non-condensable gas on condensation. Furthermore, hence we obtained new experimental correlation formula to calculate the transients in system temperature and pressure using the simulation program of the PCCS. The research was carried out using a forced circulation experimental loop, which simulates atmosphere inside PCCS with vertical heat transfer tubes if a loss of coolant accident (LOCA) occurs. The experimental facility consists of cooling water supply systems, an orifice flowmeter, and a tank equipped with the heat transfer pipe inside. Cooling water at a constant temperature is injected to the test part of heat transfer pipe vertically installed in the tank by forced circulation. At that time, the temperature of the cooling water between inlet and outlet of the pipe was measured to calculate the overall heat transfer coefficient between the cooling water and atmosphere in the tank. Thus, the heat transfer coefficient between heat transfer surface and the atmosphere in the tank considering the influence of the non-condensable gas was clarified. An important finding of this study is that the amount of condensation in the steamy atmosphere including non-condensable gas depends on the cooling water Reynolds number, especially the concentration of non-condensable gas that has great influence on the amount of condensation. (authors)

Fiscal 1974 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system (R and D on the system for new detached houses); 1994 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu. Shinchiku kojin jutakuyo system no kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-05-30

This report describes the fiscal 1974 result on the solar cooling/heating and hot water supply system. The report includes the system analysis result (collection of existing technical data, analysis of weather conditions, profitability assessment, concept design of the primary experimental house), and the research result on equipment and materials (view and evaluation of existing technologies, selective transparent and absorption materials, the primary prototype solar heat collector model, refrigerator). As the study result, the spheroidal experimental house was adopted. The solar heat utilization system is a central air-conditioning equipment composed of heating by hot water obtained from the solar heat collector, and cooling by absorption refrigerator. Heat collection efficiencies were measured for (1) stainless steel substrate collector, (2) copper substrate collector, and (3) glass pipe collector prepared as prototype collectors. (2) was higher in heat collection efficiency than (1). The efficiency of (3) hardly increased by rise in heat collection temperature due to vacuum structure and selective absorption membrane. Further measurement of such characteristics is necessary at higher temperatures. (NEDO)

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

Analysis of a solid desiccant cooling system with indirect evaporative cooling

DEFF Research Database (Denmark)

Bellemo, Lorenzo

investigates the performance of a solid desiccant cooling system implementing in-direct evaporative cooling processes. The aim is to quantify the system thermal and electrical performance for varying component dimensions and operating conditions, and to identify its range of applicability. This information...... evaporative cooler. Detailed steady state numerical models are developed and implemented in MATLAB. The models need to be accurate and require low computational effort, for analysing the internal heat and mass transfer processes, as well as carrying out repetitive design and optimization simulations......-to-air heat exchanger for enhancing cooling capacity and thermal performance. The system perfor-mance is investigated considering regeneration temperatures between 50 ºC and 90 ºC, which enable low temperature heat sources, such as solar energy or waste heat, to be used. The effects of several geometrical...

The stochastic-cooling system for COSY-Juelich

International Nuclear Information System (INIS)

Brittner, P.; Danzglock, R.; Hacker, H.U.; Maier, R.; Pfister, U.; Prasuhn, D.; Singer, H.; Spiess, W.; Stockhorst, H.

1991-01-01

The cooling in the Cooler Synchrotron COSY will work in the ranges: Band 1: 1 to 1.8 GHz, Band 2: 1.8 to 3 GHz. The system allows cooling in the energy range of 0.8 to 2.5 GeV. The stochastic-cooling system is under development. Cooling characteristics have been calculated. The tanks are similar to those of the CERN-AC. But the COSY parameters have required changes of the tank design. Active RF components have been developed for COSY. Measured results are presented

Interotex-innovative gas equipment for heating and cooling

Energy Technology Data Exchange (ETDEWEB)

Winnington, T.L. [Interotex Ltd. (United Kingdom); Moore, N. [British Gas plc (United Kingdom); Valle, F.; Sanz, J. I. [Gas Natural SDG S.A. (Spain); Chavarri, J.M. [Fagor Electrodomesticos S. Coop. (Spain); Uselton, R. [Lennox Industries Inc. (United States)

1997-10-01

Conventionally, cooling technology for the residential market is provided by electrically driven vapour re-compression systems. But lately, due to the Montreal Protocol - restricting the utilisation of ozone depleting substances - and to the high peak demand in electricity, created by electrical air conditioning systems, there is a commercial opportunity for gas fired air conditioning appliances. This paper describes the development programme for a radical new absorption technology, from the theoretical studies, through the experimental programme, to the building, commissioning and installation of demonstration machines. It also includes an analysis of the world-wide residential cooling market and the opportunities available to manufacturers and gas utilities to introduce new gas heating and cooling technology, capable of competing effectively with electrical systems. (au)

Conceptual design study on simplified and safer cooling systems for sodium cooled FBRs

International Nuclear Information System (INIS)

Hayafune, Hiroki; Shimakawa, Yoshio; Ishikawa, Hiroyasu; Kubota, Kenichi; Kobayashi, Jun; Kasai, Shigeo

2000-06-01

The objective of this study is to create the FBR plant concepts increasing economy and safety for the Phase-I 'Feasibility Studies on Commercialized Fast Reactor System'. In this study, various concepts of simplified 2ry cooling system for sodium cooled FBRs are considered and evaluated from the view points of technological feasibility, economy, and safety. The concepts in the study are considered on the basis of the following points of view. 1. To simplify 2ry cooling system by moderating and localizing the sodium-water reaction in the steam generator of the FBRs. 2. To simplify 2ry cooling system by eliminating the sodium-water reaction using integrated IHX-SG unit. 3. To simplify 2ry cooling system by eliminating the sodium-water reaction using a power generating system other than the steam generator. As the result of the study, 12 concepts and 3 innovative concepts are proposed. The evaluation study for those concepts shows the following technical prospects. 1. 2 concepts of integrated IHX-SG unit can eliminate the sodium-water reaction. Separated IHX and SG tubes unit using Lead-Bismuth as the heat transfer medium. Integrated IHX-SG unit using copper as the heat transfer medium. 2. Cost reduction effect by simplified 2ry cooling system using integrated IHX-SG unit is estimated 0 to 5%. 3. All of the integrated IHX-SG unit concepts have more weight and larger size than conventional steam generator unit. The weight of the unit during transporting and lifting would limit capacity of heat transfer system. These evaluation results will be compared with the results in JFY 2000 and used for the Phase-II study. (author)

Performance comparison between a solar driven rotary desiccant cooling system and conventional vapor compression system (performance study of desiccant cooling)

International Nuclear Information System (INIS)

Ge, T.S.; Ziegler, F.; Wang, R.Z.; Wang, H.

2010-01-01

Solar driven rotary desiccant cooling systems have been widely recognized as alternatives to conventional vapor compression systems for their merits of energy-saving and being eco-friendly. In the previous paper, the basic performance features of desiccant wheel have been discussed. In this paper, a solar driven two-stage rotary desiccant cooling system and a vapor compression system are simulated to provide cooling for one floor in a commercial office building in two cities with different climates: Berlin and Shanghai. The model developed in the previous paper is adopted to predict the performance of the desiccant wheel. The objectives of this paper are to evaluate and compare the thermodynamic and economic performance of the two systems and to obtain useful data for practical application. Results show that the desiccant cooling system is able to meet the cooling demand and provide comfortable supply air in both of the two regions. The required regeneration temperatures are 55 deg. C in Berlin and 85 deg. C in Shanghai. As compared to the vapor compression system, the desiccant cooling system has better supply air quality and consumes less electricity. The results of the economic analysis demonstrate that the dynamic investment payback periods are 4.7 years in Berlin and 7.2 years in Shanghai.

Absorption-heat-pump system

Science.gov (United States)

Grossman, G.; Perez-Blanco, H.

1983-06-16

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Experiments on novel solar heating and cooling system

International Nuclear Information System (INIS)

Wang Yiping; Cui Yong; Zhu Li; Han Lijun

2008-01-01

Solar heating and nocturnal radiant cooling techniques are united to produce a novel solar heating and cooling system. The radiant panel with both heating and cooling functions can be used as structural materials for the building envelope, which realizes true building integrated utilization of solar energy. Based on the natural circulation principle, the operation status can be changed automatically between the heating cycle and the cooling cycle. System performances under different climate conditions using different covers on the radiant panel are studied. The results show that the novel solar heating and cooling system has good performance of heating and cooling. For the no cover system, the daily average heat collecting efficiency is 52% with the maximum efficiency of 73%, while at night, the cooling capacity is about 47 W/m 2 on a sunny day. On a cloudy day, the daily average heat collecting efficiency is 47% with the maximum of 84%, while the cooling capacity is about 33 W/m 2 . As a polycarbonate (PC) panel or polyethylene film are used as covers, the maximum heat collecting efficiencies are 75% and 72% and the daily average heat collecting efficiencies are 61% and 58%, while the cooling capacities are 50 W/m 2 and 36 W/m 2 , respectively

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

KAUST Repository

Huang, B.J.

2011-11-01

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 load to reduce the energy consumption of the air conditioner installed as the base-load cooler. A standard SACH-2 system for cooling load 3.5. kW (1. RT) and daily cooling time 10 h is used for case study. The cooling performance is assumed only in summer seasons from May to October. In winter season from November to April, only heat is supplied. Two installation locations (Taipei and Tainan) were examined.It was found from the cooling performance simulation that in order to save 50% energy of the air conditioner, the required solar collector area is 40m2 in Taipei and 31m2 in Tainan, for COPj=0.2. If the solar collector area is designed as 20m2, the solar ejector cooling system will supply about 17-26% cooling load in Taipei in summer season and about 21-27% cooling load in Tainan. Simulation for long-term performance including cooling in summer (May-October) and hot water supply in winter (November-April) was carried out to determine the monthly-average energy savings. The corresponding daily hot water supply (with 40°C temperature rise of water) for 20m2 solar collector area is 616-858L/day in Tainan and 304-533L/day in Taipei.The economic analysis shows that the payback time of SACH-2 decreases with increasing cooling capacity. The payback time is 4.8. years in Tainan and 6.2. years in Taipei when the cooling capacity >10. RT. If the ECS is treated as an additional device used as a protective equipment to avoid overheating of solar collectors and to convert the excess solar heat in summer into cooling to reduce the energy consumption of air conditioner, the payback time is less than 3 years for cooling capacity larger than 3. RT. © 2011 Elsevier Ltd.

Qubit absorption refrigerator at strong coupling

Science.gov (United States)

Mu, Anqi; Agarwalla, Bijay Kumar; Schaller, Gernot; Segal, Dvira

2017-12-01

We demonstrate that a quantum absorption refrigerator (QAR) can be realized from the smallest quantum system, a qubit, by coupling it in a non-additive (strong) manner to three heat baths. This function is un-attainable for the qubit model under the weak system-bath coupling limit, when the dissipation is additive. In an optimal design, the reservoirs are engineered and characterized by a single frequency component. We then obtain closed expressions for the cooling window and refrigeration efficiency, as well as bounds for the maximal cooling efficiency and the efficiency at maximal power. Our results agree with macroscopic designs and with three-level models for QARs, which are based on the weak system-bath coupling assumption. Beyond the optimal limit, we show with analytical calculations and numerical simulations that the cooling efficiency varies in a non-universal manner with model parameters. Our work demonstrates that strongly-coupled quantum machines can exhibit function that is un-attainable under the weak system-bath coupling assumption.

Tri-generation System based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

Directory of Open Access Journals (Sweden)

Giannis Katsaros

2018-03-01

Full Text Available The present work focuses on the design of a novel tri-generation system based on gasification of municipal solid wastes, a solid oxide fuel cell and an ammonia-water absorption chiller. Tri-generation systems can be implemented in buildings such as hospitals and hotels, where there is a continuous and large demand for electricity, heating and cooling. The system is modelled in Aspen Plus and the influence of different operating parameters on the system performance was studied. The findings suggest that low air equivalent ratios and high gasification temperatures enhance the overall system performance. Syngas cleaning with metal sorbents zinc oxide and sodium bicarbonate for the removal of hydrogen sulfide and hydrogen chloride concentrations proved to be very effective, reducing the concentration of contaminants to < 1 ppm (part per million levels. The possibility of covering the demand profiles of a specific building was also investigated: the system could fully meet the electricity and cooling demands, whereas the heat requirements could be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period was 4.5 years and the net present value exceeded 5 million euros.

Forced draft wet cooling systems

International Nuclear Information System (INIS)

Daubert, A.; Caudron, L.; Viollet, P.L.

1975-01-01

The disposal of the heat released from a 1000MW power plant needs a natural draft tower of about 130m of diameter at the base, and 170m height, or a cooling system with a draft forced by about forty vans, a hundred meters in diameter, and thirty meters height. The plumes from atmospheric cooling systems form, in terms of fluid mechanics, hot jets in a cross current. They consist in complex flows that must be finely investigated with experimental and computer means. The study, currently being performed at the National Hydraulics Laboratory, shows that as far as the length and height of visible plumes are concerned, the comparison is favorable to some types of forced draft cooling system, for low and medium velocities, (below 5 or 6m/s at 10m height. Beyond these velocities, the forced draft sends the plume up to smaller heights, but the plume is generally more dilute [fr

Evaluation of heat exchange performance for the auxiliary component cooling water system cooling tower in HTTR

International Nuclear Information System (INIS)

Tochio, Daisuke; Kameyama, Yasuhiko; Shimizu, Atsushi; Inoi, Hiroyuki; Yamazaki, Kazunori; Shimizu, Yasunori; Aragaki, Etsushi; Ota, Yukimaru; Fujimoto, Nozomu

2006-09-01

The auxiliary component cooling water system (ACCWS) is one of the cooling system in High Temperature Engineering Test Reactor (HTTR). The ACCWS has main two features, many facilities cooling, and heat sink of the vessel cooling system which is one of the engineering safety features. Therefore, the ACCWS is required to satisfy the design criteria of heat removal performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the ACCWS cooling tower was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that ACCWS cooling tower has the required heat exchange performance in the design. (author)

Controlled cooling of an electronic system based on projected conditions

Science.gov (United States)

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

2015-08-18

Energy efficient control of a cooling system cooling an electronic system is provided based, in part, on projected conditions. The control includes automatically determining an adjusted control setting(s) for an adjustable cooling component(s) of the cooling system. The automatically determining is based, at least in part, on projected power consumed by the electronic system at a future time and projected temperature at the future time of a heat sink to which heat extracted is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on an experimentally obtained model(s) relating the targeted temperature and power consumption of the adjustable cooling component(s) of the cooling system.

On synthesis and optimization of cooling water systems with multiple cooling towers

CSIR Research Space (South Africa)

Gololo, KV

2011-01-01

Full Text Available -1 On Synthesis and Optimization of Cooling Water Systems with Multiple Cooling Towers Khunedi Vincent Gololo?? and Thokozani Majozi*? ? Department of Chemical Engineering, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa ? Modelling...

Development of an Ionic-Liquid Absorption Heat Pump

Energy Technology Data Exchange (ETDEWEB)

Holcomb, Don

2011-03-29

Solar Fueled Products (SFP) is developing an innovative ionic-liquid absorption heat pump (ILAHP). The development of an ILAHP is extremely significant, as it could result in annual savings of more than 190 billion kW h of electrical energy and $19 billion. This absorption cooler uses about 75 percent less electricity than conventional cooling and heating units. The ILAHP also has significant environmental sustainability benefits, due to reduced CO2 emissions. Phase I established the feasibility and showed the economic viability of an ILAHP with these key accomplishments: • Used the breakthrough capabilities provided by ionic liquids which overcome the key difficulties of the common absorption coolers. • Showed that the theoretical thermodynamic performance of an ILAHP is similar to existing absorption-cooling systems. • Established that the half-effect absorption cycle reduces the peak generator temperature, improving collector efficiency and reducing collector area. • Component testing demonstrated that the most critical components, absorber and generator, operate well with conventional heat exchangers. • Showed the economic viability of an ILAHP. The significant energy savings, sustainability benefits, and economic viability are compelling reasons to continue the ILAHP development.

PEP cooling water systems and underground piped utilities design criteria report

International Nuclear Information System (INIS)

Hall, F.; Robbins, D.

1975-10-01

This paper discusses the cooling systems required by the PEP Storage Ring. Particular topics discussed are: Cooling tower systems, RF cavity and vacuum chamber LCW cooling systems, klystron and ring magnet LLW cooling systems, Injection magnet LCW Cooling Systems; PEP interaction area detector LCW Cooling Systems; and underground piped utilities. 1 ref., 20 figs

Economical and environmental assessment of an optimized solar cooling system for a medium-sized benchmark office building in Los Angeles, California

Energy Technology Data Exchange (ETDEWEB)

Hang, Yin; Qu, Ming [School of Civil Engineering, Purdue University, CIVL G243, 550 Stadium Mall Drive, West Lafayette, IN 47907 (United States); Zhao, Fu [School of Mechanical Engineering, Purdue University (United States)

2011-02-15

This paper presents a systematic energetic, economical, and environmental assessment on a solar cooling system for a medium-sized office building in Los Angeles, California by means of system modeling. The studied solar cooling system primarily consists of evacuated tube solar collectors, a hot water storage tank, a single-effect LiBr-H{sub 2}O absorption chiller, and a gas-fired auxiliary heater. System performance optimization and sensitivity analysis were conducted by varying two major parameters (i.e. storage tank volume and collector area). The results suggest that a trade-off exists between economic performance indicated by the equivalent uniform annual cost (EUAC) and the energetic/environmental performance indicated by the solar fraction and CO{sub 2} reduction percentage, respectively. The cost of carbon footprint reduction was defined and served as an indicator for the overall system performance. Based on this indicator, the optimal system design could be found for a solar cooling system. The approach adapted in this study can be applied to other buildings located in different climate zones to reveal the cost and benefits of solar cooling technologies and facilitate decision-making. (author)

Solar-Heated and Cooled Office Building--Columbus, Ohio

Science.gov (United States)

1982-01-01

Final report documents solar-energy system installed in office building to provide space heating, space cooling and domestic hot water. Collectors mounted on roof track Sun and concentrate rays on fluid-circulating tubes. Collected energy is distributed to hot-water-fired absorption chiller and space-heating and domestic-hot-water preheating systems.

Conduction cooling systems for linear accelerator cavities

Science.gov (United States)

Kephart, Robert

2017-05-02

A conduction cooling system for linear accelerator cavities. The system conducts heat from the cavities to a refrigeration unit using at least one cavity cooler interconnected with a cooling connector. The cavity cooler and cooling connector are both made from solid material having a very high thermal conductivity of approximately 1.times.10.sup.4 W m.sup.-1 K.sup.-1 at temperatures of approximately 4 degrees K. This allows for very simple and effective conduction of waste heat from the linear accelerator cavities to the cavity cooler, along the cooling connector, and thence to the refrigeration unit.

Method of injecting cooling water in emergency core cooling system (ECCS) of PWR type reactor

International Nuclear Information System (INIS)

Sobajima, Makoto; Adachi, Michihiro; Tasaka, Kanji; Suzuki, Mitsuhiro.

1979-01-01

Purpose: To provide a cooling water injection method in an ECCS, which can perform effective cooling of the reactor core. Method: In a method of injecting cooling water in an ECCS as a countermeasure against a rupture accident of a pwr type reactor, cooling water in the first pressure storage injection system is injected into the upper plenum of the reactor pressure vessel at a set pressure of from 50 to 90 atg. and a set temperature of from 80 to 200 0 C, cooling water in the second pressure storage injection system is injected into the lower plenum of the reactor pressure vessel at a pressure of from 25 to 60 atg. which is lower than the set pressure and a temperature less than 60 0 C, and further in combination with these procedures, cooling water of less than 60 0 C is injected into a high-temperature side piping, in the high-pressure injection system of upstroke of 100 atg. by means of a pump and the low-pressure injection system of upstroke of 20 atg. also by means of a pump, thereby cooling the reactor core. (Aizawa, K.)

ELECTRONIC CIRCUIT BOARDS NON-UNIFORM COOLING SYSTEM MODEL

Directory of Open Access Journals (Sweden)

D. V. Yevdulov

2016-01-01

Full Text Available Abstract. The paper considers a mathematical model of non-uniform cooling of electronic circuit boards. The block diagram of the system implementing this approach, the method of calculation of the electronic board temperature field, as well as the principle of its thermal performance optimizing are presented. In the considered scheme the main heat elimination from electronic board is produced by the radiator system, and additional cooling of the most temperature-sensitive components is produced by thermoelectric batteries. Are given the two-dimensional temperature fields of the electronic board during its uniform and non-uniform cooling, is carried out their comparison. As follows from the calculations results, when using a uniform overall cooling of electronic unit there is a waste of energy for the cooling 0f electronic board parts which temperature is within acceptable temperature range without the cooling system. This approach leads to the increase in the cooling capacity of used thermoelectric batteries in comparison with the desired values. This largely reduces the efficiency of heat elimination system. The use for electronic boards cooling of non-uniform local heat elimination removes this disadvantage. The obtained dependences show that in this case, the energy required to create a given temperature is smaller than when using a common uniform cooling. In this approach the temperature field of the electronic board is more uniform and the cooling is more efficient. 

Modelling and analysis of a desiccant cooling system using the regenerative indirect evaporative cooling process

DEFF Research Database (Denmark)

Bellemo, Lorenzo; Elmegaard, Brian; Reinholdt, Lars O.

2013-01-01

This paper focuses on the numerical modeling and analysis of a Desiccant Cooling (DEC) system with regenerative indirect evaporative cooling, termed Desiccant Dewpoint Cooling (DDC) system. The DDC system includes a Desiccant Wheel (DW), Dew Point Coolers (DPCs), a heat recovery unit and a heat...... in different climates: temperate in Copenhagen and Mediterranean in Venice. Cheap and clean heat sources (e.g. solar energy) strongly increase the attractiveness of the DDC system. For the Mediterranean climate the DDC system represents a convenient alternative to chiller-based systems in terms of energy costs...... and CO2 emissions. The electricity consumption for auxiliaries in the DDC system is higher than in the chiller-based systems. The number of commercial-size DPC units required to cover the cooling load during the whole period is high: 8 in Copenhagen and 12 in Venice....

Core test reactor shield cooling system analysis

International Nuclear Information System (INIS)

Larson, E.M.; Elliott, R.D.

1971-01-01

System requirements for cooling the shield within the vacuum vessel for the core test reactor are analyzed. The total heat to be removed by the coolant system is less than 22,700 Btu/hr, with an additional 4600 Btu/hr to be removed by the 2-inch thick steel plate below the shield. The maximum temperature of the concrete in the shield can be kept below 200 0 F if the shield plug walls are kept below 160 0 F. The walls of the two ''donut'' shaped shield segments, which are cooled by the water from the shield and vessel cooling system, should operate below 95 0 F. The walls of the center plug, which are cooled with nitrogen, should operate below 100 0 F. (U.S.)

Assessment of off-design performance of a small-scale combined cooling and power system using an alternative operating strategy for gas turbine

International Nuclear Information System (INIS)

Han, Wei; Chen, Qiang; Lin, Ru-mou; Jin, Hong-guang

2015-01-01

Highlights: • We develop an off-design model for a CCP system driven by gas turbine. • An alternative operating strategy is proposed to improve the system performance. • Off-design performance of the combined cooling and power system (CCP) is enhanced. • Effects of both the different operating strategy are analyzed and compared. • Performance enhancement mechanism of the proposed operating strategy is presented. - Abstract: A small-scale combined cooling and power (CCP) system usually serves district air conditioning apart from power generation purposes. The typical system consists of a gas turbine and an exhaust gas-fired absorption refrigerator. The surplus heat of the gas turbine is recovered to generate cooling energy. In this way, the CCP system has a high overall efficiency at the design point. However, the CCP system usually runs under off-design conditions because the users’ demand varies frequently. The operating strategy of the gas turbine will affect the thermodynamic performance of itself and the entire CCP system. The operating strategies for gas turbines include the reducing turbine inlet temperature (TIT) and the compressor inlet air throttling (IAT). A CCP system, consisting of an OPRA gas turbine and a double effects absorption refrigerator, is investigated to identify the effects of different operating strategies. The CCP system is simulated based on the partial-load model of gas turbine and absorption refrigerator. The off-design performance of the CCP system is compared under different operating strategies. The results show that the IAT strategy is the better one. At 50% rated power output of the gas turbine, the IAT operating strategy can increase overall system efficiency by 10% compared with the TIT strategy. In general, the IAT operating strategy is suited for other gas turbines. However, the benefits of IAT should be investigated in the future, when different gas turbine is adopted. This study may provide a new operating

Thermal cooling using low-temperature waste heat. A cost-effective way for industrial companies to improve energy efficiency?

Energy Technology Data Exchange (ETDEWEB)

Schall, D.; Hirzel, S. [Fraunhofer Institute for Systems and Innovation Research ISI, Breslauer Strasse 48, 76139 Karlsruhe (Germany)

2012-11-15

As a typical cross-cutting technology, cooling and refrigeration equipment is used for a variety of industrial applications. While cooling is often provided by electric compression cooling systems, thermal cooling systems powered by low-temperature waste heat could improve energy efficiency and promise a technical saving potential corresponding to 0.5 % of the total electricity demand in the German industry. In this paper, we investigate the current and future cost-effectiveness of thermal cooling systems for industrial companies. Our focus is on single-stage, closed absorption and adsorption cooling systems with cooling powers between 40 and 100 kW, which use low-temperature waste heat at temperature levels between 70C and 85C. We analyse the current and future cost-effectiveness of these alternative cooling systems using annual cooling costs (annuities) and payback times. For a forecast until 2015, we apply the concept of experience curves, identifying learning rates of 14 % (absorption machines) and 17 % (adsorption machines) by an expert survey of the German market. The results indicate that thermal cooling systems are currently only cost-effective under optimistic assumptions (full-time operation, high electricity prices) when compared to electric compression cooling systems. Nevertheless, the cost and efficiency improvements expected for this still young technology mean that thermal cooling systems could be more cost-effective in the future. However, depending on future electricity prices, a high number of operating hours is still crucial to achieve payback times substantially below 4 years which are usually required for energy efficiency measures to be widely adopted in the industry.

Initial operation of a solar heating and cooling system in a full-scale solar building test facility

Science.gov (United States)

Knoll, R. H.; Miao, D.; Hamlet, I. L.; Jensen, R. N.

1976-01-01

The Solar Building Test Facility (SBTF) located at Hampton, Virginia became operational in early summer of 1976. This facility is a joint effort by NASA-Lewis and NASA-Langley to advance the technology for heating and cooling of office buildings with solar energy. Its purposes are to (1) test system components which include high-performing collectors, (2) test performance of complete solar heating and cooling system, (3) investigate component interactions and (4) investigate durability, maintenance and reliability of components. The SBTF consists of a 50,000 square foot office building modified to accept solar heated water for operation of an absorption air conditioner and for the baseboard heating system. A 12,666 square foot solar collector field with a 30,000 gallon storage tank provides the solar heated water. A description of the system and the collectors selected is given here, along with the objectives, test approach, expected system performance and some preliminary results.

System technology improves the chances of solar cooling

International Nuclear Information System (INIS)

Schmid, W.

2008-01-01

This article takes a look at the increasing range of products on offer in the solar cooling area. Such an increase applies in particular to products in the low and medium power ranges under 30 kilowatts. Several hindrances to the expansion of the solar air-conditioning (SAC) market are named, both in the technological as well as in the operational area. The author states that a considerable amount of optimisation work is still to be done. Market offerings using absorption and adsorption techniques are examined, as are silica gel-based systems. Companies in the German-speaking parts of Europe active in the area are listed and their work is reviewed. The opinions of various experts that were presented at a congress on the subject are noted. Planning tools made available by the International Energy Agency's Task 38 'Solar air-conditioning and refrigeration' are mentioned.

Lamination cooling system

Science.gov (United States)

Rippel, Wally E.; Kobayashi, Daryl M.

2005-10-11

An electric motor, transformer or inductor having a lamination cooling system including a stack of laminations, each defining a plurality of apertures at least partially coincident with apertures of adjacent laminations. The apertures define a plurality of cooling-fluid passageways through the lamination stack, and gaps between the adjacent laminations are sealed to prevent a liquid cooling fluid in the passageways from escaping between the laminations. The gaps are sealed by injecting a heat-cured sealant into the passageways, expelling excess sealant, and heat-curing the lamination stack. The apertures of each lamination can be coincident with the same-sized apertures of adjacent laminations to form straight passageways, or they can vary in size, shape and/or position to form non-axial passageways, angled passageways, bidirectional passageways, and manifold sections of passageways that connect a plurality of different passageway sections. Manifold members adjoin opposite ends of the lamination stack, and each is configured with one or more cavities to act as a manifold to adjacent passageway ends. Complex manifold arrangements can create bidirectional flow in a variety of patterns.

Mathematical Model of a Lithium-Bromide/Water Absorption Refrigeration System Equipped with an Adiabatic Absorber

Directory of Open Access Journals (Sweden)

Salem M. Osta-Omar

2016-11-01

Full Text Available The objective of this paper is to develop a mathematical model for thermodynamic analysis of an absorption refrigeration system equipped with an adiabatic absorber using a lithium-bromide/water (LiBr/water pair as the working fluid. The working temperature of the generator, adiabatic absorber, condenser, evaporator, the cooling capacity of the system, and the ratio of the solution mass flow rate at the circulation pump to that at the solution pump are used as input data. The model evaluates the thermodynamic properties of all state points, the heat transfer in each component, the various mass flow rates, and the coefficient of performance (COP of the cycle. The results are used to investigate the effect of key parameters on the overall performance of the system. For instance, increasing the generator temperatures and decreasing the adiabatic absorber temperatures can increase the COP of the cycle. The results of this mathematical model can be used for designing and sizing new LiBr/water absorption refrigeration systems equipped with an adiabatic absorber or for optimizing existing aforementioned systems.

Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

International Nuclear Information System (INIS)

Bharathan, D.; Nix, G.

2001-01-01

Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures

Augmented cooling vest system subassembly: Design and analysis

International Nuclear Information System (INIS)

D’Angelo, Maurissa; D’Angelo, Joseph; Almajali, Mohammad; Lafdi, Khalid; Delort, Antoine; Elmansori, Mohamed

2014-01-01

Highlights: • Thermoelectric cooler (TEC) was employed to provide cooling air to cooling vest. • Aluminum cooling fins were used to exchange heat for hot and cold sides of TEC. • Performance of the system was determined and the experimental technique was described. • Heat sink is capable to remove additional heat and heat exchanger provides cooling air. • Future work is proposed to optimize the efficiency of the system. - Abstract: A prototype cooling engine consisting of thermoelectric coolers (TECs) was developed and designed. In this prototype, aluminum cooling fins were employed as the heat exchange method for both the hot and cold sides of the TEC. Aluminum fins were used to cool the ambient air through a heat exchanger and dissipate heat build up from the heat sink. This system was modeled and performance capabilities were determined. The experimental technique used to monitor parameters affecting the efficiency of the designed system was described. These parameters include the temperatures of the inlets and outlets of both heat exchanger and heat sink and the flow rate of the cooled air. The experiment was run under three input DC powers; 15 V, 18 V, and 21 V. As the power increased, both the flow rate and the temperature difference between the hot and cold side of thermoelectric cooler increased, demonstrating the heat sink capability to remove the additional heat. However, the temperature difference between the inlet and outlet of the heat exchanger decreases as the power increase. The findings demonstrated the effectiveness of this cooling system and future work is proposed to optimize the heat

Preoperational test report, recirculation condenser cooling systems

Energy Technology Data Exchange (ETDEWEB)

Clifton, F.T.

1997-11-04

This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

Preoperational test report, recirculation condenser cooling systems

International Nuclear Information System (INIS)

Clifton, F.T.

1997-01-01

This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

Turbine airfoil with laterally extending snubber having internal cooling system

Science.gov (United States)

Scribner, Carmen Andrew; Messmann, Stephen John; Marsh, Jan H.

2016-09-06

A turbine airfoil usable in a turbine engine and having at least one snubber with a snubber cooling system positioned therein and in communication with an airfoil cooling system is disclosed. The snubber may extend from the outer housing of the airfoil toward an adjacent turbine airfoil positioned within a row of airfoils. The snubber cooling system may include an inner cooling channel separated from an outer cooling channel by an inner wall. The inner wall may include a plurality of impingement cooling orifices that direct impingement fluid against an outer wall defining the outer cooling channel. In one embodiment, the cooling fluids may be exhausted from the snubber, and in another embodiment, the cooling fluids may be returned to the airfoil cooling system. Flow guides may be positioned in the outer cooling channel, which may reduce cross-flow by the impingement orifices, thereby increasing effectiveness.

A combined capillary cooling system for cooling fuel cells

Energy Technology Data Exchange (ETDEWEB)

Silva, Ana Paula; Pelizza, Pablo Rodrigo; Galante, Renan Manozzo; Bazzo, Edson [Universidade Federal de Santa Catarina (LabCET/UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], Emails: ana@labcet.ufsc.br, pablo@labcet.ufsc.br, renan@labcet.ufsc.br, ebazzo@emc.ufsc.br

2010-07-01

The operation temperature control has an important influence over the PEMFC (Proton Exchange Membrane Fuel Cell) performance. A two-phase heat transfer system is proposed as an alternative for cooling and thermal control of PEMFC. The proposed system consists of a CPL (Capillary Pumped Loop) connected to a set of constant conductance heat pipes. In this work ceramic wick and stainless mesh wicks have been used as capillary structure of the CPL and heat pipes, respectively. Acetone has been used as the working fluid for CPL and deionized water for the heat pipes. Experimental results of three 1/4 inch stainless steel outlet diameter heats pipes and one CPL have been carried out and presented in this paper. Further experiments are planned coupling the proposed cooling system to a module which simulates the fuel cell. (author)

Dry cooling systems with plastic surfaces

International Nuclear Information System (INIS)

Roma, Carlo; Leonelli, Vincenzo

1975-01-01

Research and experiments made on dry cooling systems with plastic surfaces are described. The demonstration program planned in Italy for a 100Gcal/h dry cooling system is exposed, and an installation intended for a large 1300Mwe nuclear power station is described with reference to the assembly (exploitation and maintenance included). The performance and economic data relating to this installation are also exposed [fr

Solar cooling between thermal and photovoltaic: An energy and economic comparative study in the Mediterranean conditions

International Nuclear Information System (INIS)

Noro, M.; Lazzarin, R.M.

2014-01-01

This paper considers different cooling systems and investigates the most promising alternatives when solar energy is to be used to supply the cooling demand. All the systems are evaluated during a summer cooling season by the energetic and economic point of view by dynamic simulation for two different climates. For Milan (Cfb climate) the highest OSE (overall system efficiency) is reached by LiBr (lithium-bromide) double effect absorption chiller driven by parabolic through collector (0.53). In terms of the collecting surface area, the best systems for Milan feature 0.08 m 2  MJ −1 per day both for electric system (mono-crystalline photovoltaic coupled to water cooled chiller) and thermal system (PTC (parabolic trough collectors) coupled to double effect water-LiBr absorption chiller). Southern latitudes like Trapani (Csa climate) allow a quite better performance for thermal solar cooling solutions. The NPV (net present worths) of electric solar cooling solutions are favorable with respect to the traditional solution and the DPV (discounted payback periods) are all lower than the period of economic analysis above all for water cooled chillers. Finally a sensitivity analysis of the specific investment cost (€ MJ −1 per day) is carried out regarding the investment cost of collectors, the solar ratio and the interest rate. - Highlights: • Solar cooling is obtained with solar thermal or PV (photovoltaic) with easy available equipment. • In the past PV driven systems for solar cooling were not considered as too expensive. • An energy/economic comparison is carried out for the various solar cooling systems. • Sensitivity analyses are carried out varying different parameters

Post-accident cooling capacity analysis of the AP1000 passive spent fuel pool cooling system

International Nuclear Information System (INIS)

Su Xia

2013-01-01

The passive design is used in AP1000 spent fuel pool cooling system. The decay heat of the spent fuel is removed by heating-boiling method, and makeup water is provided passively and continuously to ensure the safety of the spent fuel. Based on the analysis of the post-accident cooling capacity of the spent fuel cooling system, it is found that post-accident first 72-hour cooling under normal refueling condition and emergency full-core offload condition can be maintained by passive makeup from safety water source; 56 hours have to be waited under full core refueling condition to ensure the safety of the core and the spent fuel pool. Long-term cooling could be conducted through reserved safety interface. Makeup measure is available after accident and limited operation is needed. Makeup under control could maintain the spent fuel at sub-critical condition. Compared with traditional spent fuel pool cooling system design, the AP1000 design respond more effectively to LOCA accidents. (authors)

Preoperational test report, primary ventilation condenser cooling system

Energy Technology Data Exchange (ETDEWEB)

Clifton, F.T.

1997-10-29

This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

Preoperational test report, primary ventilation condenser cooling system

International Nuclear Information System (INIS)

Clifton, F.T.

1997-01-01

This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

CAREM 25: Suppression pool cooling and purification system

International Nuclear Information System (INIS)

Carlevaris, Rodolfo; Patrignani, Alberto; Vindrola, Carlos; Palmerio, Hector D.; Quiroz, Horacio; Ramilo, Lucia B.

2000-01-01

The suppression pool cooling and purification system has the following main functions: purify and cool water from the suppression pool, cool and send water to the residual heat extraction system, and transfer water to the fuel element transference channel. In case of Loss of Coolant Accident (LOCA), the system sends water from the suppression pool to the spray network, thus cooling and reducing pressure in the primary containment. The system has been designed in accordance with the requirements of the following standards: ANSI/ANS 52.1; ANSI/ANS 57.2; ANSI/ANS 56.2; ANSI/ANS 59.1; ANSI/ANS 58.3; ANSI/ANS 58.9; and ANSI/ANS 56.5. The design of the system fulfils all the assigned functions. (author)

Exergetic analysis of a double stage LiBr-H2O thermal compressor cooled by air/water and driven by low grade heat

International Nuclear Information System (INIS)

Izquierdo, M.; Venegas, M.; Garcia, N.; Palacios, E.

2005-01-01

In the present paper, an exergetic analysis of a double stage thermal compressor using the lithium bromide-water solution is performed. The double stage system considered allows obtaining evaporation temperatures equal to 5 deg. C using solar heat coming from flat plate collectors and other low grade thermal sources. In this study, ambient air and water are alternatively used as cooling fluids without crystallization problems up to condensation-absorption temperatures equal to 50 deg. C. The results obtained give the entropy generated, the exergy destroyed and the exergetic efficiency of the double stage thermal compressor as a function of the absorption temperature. The conclusions obtained show that the irreversibilities generated by the double stage thermal compressor will tend to increase with the absorption temperature up to 45 deg. C. The maximum value corresponds to 1.35 kJ kg -1 K -1 . The entropy generated and the exergy destroyed by the air cooled system are higher than those by the water cooled one. The difference between the values increases when the absorption temperature increases. For an absorption temperature equal to 50 deg. C, the air cooled mode generates 14% more entropy and destroys 14% more exergy than the water cooled one. Also, the results are compared with those of previous studies for single and double effect air cooled and water cooled thermal compressors. The conclusions show that the double stage system has about 22% less exergetic efficiency than the single effect one and 32% less exergetic efficiency than the double effect one

The importance of the ammonia purification process in ammonia-water absorption systems

International Nuclear Information System (INIS)

Fernandez-Seara, Jose; Sieres, Jaime

2006-01-01

Practical experience in working with ammonia-water absorption systems shows that the ammonia purification process is a crucial issue in order to obtain an efficient and reliable system. In this paper, the detrimental effects of the residual water content in the vapour refrigerant are described and quantified based on the system design variables that determine the effectiveness of the purification process. The study has been performed considering a single stage system with a distillation column with complete condensation. The ammonia purification effectiveness of the column is analysed in terms of the efficiencies in the stripping and rectifying sections and the reflux ratio. By varying the efficiencies from 0 to 1, systems with neither the rectifying nor stripping section, with either the rectifying or stripping section, or with both sections can be considered. The impact of the ammonia purification process on the absorption system performance is studied based on the column efficiencies and reflux ratio; and its effects on refrigerant concentration, system COP, system pressures and main system mass flow rates and concentrations are analysed. When the highest efficiency rectifying sections are used a combination of generation temperature and reflux ratio which leads to optimum COP values is found. The analysis covers different operating conditions with air and water cooled systems from refrigeration to air conditioning applications by changing the evaporation temperature. The importance of rectification in each kind of application is evaluated

Understanding aging in containment cooling systems

International Nuclear Information System (INIS)

Lofaro, R.J.

1993-01-01

A study has been performed to assess the effects of aging in nuclear power plant containment cooling systems. Failure records from national databases, as well as plant specific data were reviewed and analyzed to identify aging characteristics for this system. The predominant aging mechanisms were determined, along with the most frequently failed components and their associated failure modes. This paper discusses the aging mechanisms present in the containment spray system and the containment fan cooler system, which are two systems used to provide the containment cooling function. The failure modes, along with the relative frequency of each is also discussed

New Protective Measures for Cooling Systems

International Nuclear Information System (INIS)

Carter, D. Anthony; Nonohue, Jonh M.

1974-01-01

Cooling water treatments have been updated and improved during the last few years. Particularly important are the nontoxic programs which conform plant cooling water effluents to local water quality standards without expenditures for capital equipment. The relationship between scaling and corrosion in natural waters has been recognized for many years. This relationship is the basis for the Langelier Saturation Index control method which was once widely applied to reduce corrosion in cooling water systems. It used solubility characteristics to maintain a very thin deposit on metal surfaces for preventing corrosion. This technique was rarely successful. That is, the solubility of calcium carbonate and most other inorganic salts depends on temperature. If good control exists on cold surfaces, excessive deposition results on the heat transfer tubes. Also, because water characteristic normally vary in a typical cooling system, precise control of scaling at both hot and cold surfaces is virtually impossible

Operation method and operation control device for emergency core cooling system

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Shoichiro; Takahashi, Toshiyuki; Fujii, Tadashi [Hitachi Ltd., Tokyo (Japan); Mizutani, Akira

1996-05-07

The present invention provides a method of reducing continuous load capacity of an emergency cooling system of a BWR type reactor and a device reducing a rated capacity of an emergency power source facility. Namely, the emergency core cooling system comprises a first cooling system having a plurality of power source systems based on a plurality of emergency power sources and a second cooling system having a remaining heat removing function. In this case, when the first cooling system is operated the manual starting under a predetermined condition that an external power source loss event should occur, a power source division different from the first cooling system shares the operation to operate the secondary cooling system simultaneously. Further, the first cooling system is constituted as a high pressure reactor core water injection system and the second cooling system is constituted as a remaining heat removing system. With such a constitution, a high pressure reactor core water injection system for manual starting and a remaining heat removing system of different power source division can be operated simultaneously before automatic operation of the emergency core cooling system upon loss of external power source of a nuclear power plant. (I.S.)

Development of the interactive model between Component Cooling Water System and Containment Cooling System using GOTHIC

International Nuclear Information System (INIS)

Byun, Choong Sup; Song, Dong Soo; Jun, Hwang Yong

2006-01-01

In a design point of view, component cooling water (CCW) system is not full-interactively designed with its heat loads. Heat loads are calculated from the CCW design flow and temperature condition which is determined with conservatism. Then the CCW heat exchanger is sized by using total maximized heat loads from above calculation. This approach does not give the optimized performance results and the exact trends of CCW system and the loads during transient. Therefore a combined model for performance analysis of containment and the component cooling water(CCW) system is developed by using GOTHIC software code. The model is verified by using the design parameters of component cooling water heat exchanger and the heat loads during the recirculation mode of loss of coolant accident scenario. This model may be used for calculating the realistic containment response and CCW performance, and increasing the ultimate heat sink temperature limits

The ATLAS IBL CO2 Cooling System

CERN Document Server

Verlaat, Bartholomeus; The ATLAS collaboration

2016-01-01

The Atlas Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

Simulation of absorption refrigeration system for automobile application

Directory of Open Access Journals (Sweden)

Ramanathan Anand

2008-01-01

Full Text Available An automotive air-conditioning system based on absorption refrigeration cycle has been simulated. This waste heat driven vapor absorption refrigeration system is one alternate to the currently used vapour compression refrigeration system for automotive air-conditioning. Performance analysis of vapor absorption refrigeration system has been done by developing a steady-state simulation model to find the limitation of the proposed system. The water-lithium bromide pair is used as a working mixture for its favorable thermodynamic and transport properties compared to the conventional refrigerants utilized in vapor compression refrigeration applications. The pump power required for the proposed vapor absorption refrigeration system was found lesser than the power required to operate the compressor used in the conventional vapor compression refrigeration system. A possible arrangement of the absorption system for automobile application is proposed.

Computational Fluid Dynamics Analysis of an Evaporative Cooling System

Directory of Open Access Journals (Sweden)

Kapilan N.

2016-11-01

Full Text Available The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.

RAMI analysis for DEMO HCPB blanket concept cooling system

Energy Technology Data Exchange (ETDEWEB)

Dongiovanni, Danilo N., E-mail: danilo.dongiovanni@enea.it [ENEA, Unità Tecnica Fusione, ENEA C. R. Frascati (Italy); Pinna, Tonio [ENEA, Unità Tecnica Fusione, ENEA C. R. Frascati (Italy); Carloni, Dario [KIT, Institute of Neutron Physics and Reactor Technology (INR) – KIT (Germany)

2015-10-15

Highlights: • RAMI (reliability, availability, maintainability and inspectability) preliminary assessment for HCPB blanket concept cooling system. • Reliability block diagram (RBD) modeling and analysis for HCPB primary heat transfer system (PHTS), coolant purification system (CPS), pressure control system (PCS), and secondary cooling system. • Sensitivity analysis on system availability performance. • Failure models and repair models estimated on the base of data from the ENEA fusion component failure rate database (FCFRDB). - Abstract: A preliminary RAMI (reliability, availability, maintainability and inspectability) assessment for the HCPB (helium cooled pebble bed) blanket cooling system based on currently available design for DEMO fusion power plant is presented. The following sub-systems were considered in the analysis: blanket modules, primary cooling loop including pipework and steam generators lines, pressure control system (PCS), coolant purification system (CPS) and secondary cooling system. For PCS and CPS systems an extrapolation from ITER Test Blanket Module corresponding systems was used as reference design in the analysis. Helium cooled pebble bed (HCPB) system reliability block diagrams (RBD) models were implemented taking into account: system reliability-wise configuration, operating schedule currently foreseen for DEMO, maintenance schedule and plant evolution schedule as well as failure and corrective maintenance models. A simulation of plant activity was then performed on implemented RBDs to estimate plant availability performance on a mission time of 30 calendar years. The resulting availability performance was finally compared to availability goals previously proposed for DEMO plant by a panel of experts. The study suggests that inherent availability goals proposed for DEMO PHTS system and Tokamak auxiliaries are potentially achievable for the primary loop of the HCPB concept cooling system, but not for the secondary loop. A

Thermodynamic analysis of an absorption refrigeration system with ionic-liquid/refrigerant mixture as a working fluid

International Nuclear Information System (INIS)

Kim, Yoon Jo; Kim, Sarah; Joshi, Yogendra K.; Fedorov, Andrei G.; Kohl, Paul A.

2012-01-01

Thermodynamics of an ionic-liquid (IL) based absorption refrigeration system has been numerically analyzed. It provides an alternative to the normally toxic working fluids, such as the ammonia in conventional absorption systems. The use of ILs also eliminates crystallization and metal-compatibility problems of the water/LiBr system. Mixtures of refrigerants and imidazolium-based ILs are theoretically explored as the working fluid pairs in a miniature absorption refrigeration system, so as to utilize waste-heat to power a refrigeration/heat pump system for electronics cooling. A non-random two-liquid (NRTL) model was built and used to predict the solubility of the mixtures. Saturation temperatures at the evaporator and condenser were set at 25 °C and 50 °C, respectively, with the power dissipation of 100 W. Water in combination with [emim][BF 4 ] (1-ethyl-3-methylimidazolium tetrafluoroborate) gave the highest coefficient of performance (COP) around 0.9. The refrigerant/IL compatibility indicated by the circulation ratio, alkyl chain length of the IL, and thermodynamic properties of the refrigerants, such as latent heat of evaporation were proven to be important factors in determining the performance of the absorption system. The negative effect of high viscosity was mitigated by dilution of the IL with the refrigerant and the use of slightly larger microfluidic channel heat exchangers. -- Highlights: ► Mixtures of refrigerant/ionic-liquid are studied for absorption system. ► We carry out comprehensive theoretical thermodynamic analysis. ► The essential factors of refrigerant/IL affecting the performance are identified. ► Water/[emim][BF 4 ] showed the best performance of COP. ► The effects of high viscosity ILs on the system performance are not significant.

CAREM-25. Suppression Pool Cooling and Purification System

International Nuclear Information System (INIS)

Carlevaris, Rodolfo; Palmerio, D.; Patrignani, A.; Quiroz, H.; Ramilo, L.; Vindrola, C.

2000-01-01

The Suppression Pool Cooling and Purification System has the following main functions: purify and cool water from the Suppression Pool, cool and send water to the Residual Heat Extraction System, and transfer water to the Fuel Element Transference Channel. In case of Loss of Coolant Accident (LOCA), the system sends water from the Suppression Pool to the spray network, thus cooling and reducing pressure in the primary containment.The system has been designed in accordance with the requirements of the following standards ANSI/ANS 52.1 [1], ANSI/ANS 57.2 [2], ANSI/ANS 56.2 [3], ANSI/ANS 59.1 [4] ANSI/ANS 58.3 [5], ANSI/ANS 58.9 [6], and ANSI/ANS 56.5 [7]. The design of the system fulfils all the assigned functions

Exergy analysis of a gas-hydrate cool storage system

International Nuclear Information System (INIS)

Bi, Yuehong; Liu, Xiao; Jiang, Minghe

2014-01-01

Based on exergy analysis of charging and discharging processes in a gas-hydrate cool storage system, the formulas for exergy efficiency at the sensible heat transfer stage and the phase change stage corresponding to gas-hydrate charging and discharging processes are obtained. Furthermore, the overall exergy efficiency expressions of charging, discharging processes and the thermodynamic cycle of the gas-hydrate cool storage system are obtained. By using the above expressions, the effects of number of transfer units, the inlet temperatures of the cooling medium and the heating medium on exergy efficiencies of the gas-hydrate cool storage system are emphatically analyzed. The research results can be directly used to evaluate the performance of gas-hydrate cool storage systems and design more efficient energy systems by reducing the sources of inefficiency in gas-hydrate cool storage systems. - Highlights: • Formulas for exergy efficiency at four stages are obtained. • Exergy efficiency expressions of two processes and one cycle are obtained. • Three mainly influencing factors on exergy efficiencies are analyzed. • With increasing the inlet temperature of cooling medium, exergy efficiency increases. • With decreasing the inlet temperature of heating medium, exergy efficiency increases

Wet bar detection by using water absorption detector

International Nuclear Information System (INIS)

Kim, Hee Soo; Bae, Yong Chae; Kee, Chang Doo

2008-01-01

Water leaks in water-cooled generator stator windings can generate serious accidents such as insulation breakdown and result in unexpected sudden outages. Thus, it is important to diagnose their water absorption for effective operation of the power plant. Especially, since the capacitance values that are measured for diagnosis are very small so special diagnosis methods like stochastic theory are needed. KEPRI developed a more advanced water absorption detector and diagnosis technology for it. They were applied to a real system and the results of the water absorption test for stator windings agree with the water leak test

Integrated cooling system for the Mirror Fusion Test Facility

International Nuclear Information System (INIS)

Johnson, B.; Chang, Y.

1979-01-01

The MFTF components that require water cooling include the neutral beam dumps, ion dumps, plasma dumps, baffle plates, magnet liners, gas boxes, streaming guns, and the neutral beam injectors. A total heat load of nearly 500 MW for 0.5 s dissipates over 4-min intervals. A steady-flow, closed-loop system is utilized. The design of the cooling system assumes that all components require cooling simultaneously. The cooling system contains process instrumentation for loop control. Alarms and safety interlocks are incorporated for the safe operation of the system

Exergetic analysis of a double stage LiBr-H{sub 2}O thermal compressor cooled by air/water and driven by low grade heat

Energy Technology Data Exchange (ETDEWEB)

Izquierdo, M. [Instituto C.C. Eduardo Torroja (CSIC), Edificacion y Habitabilidad, Madrid (Spain); Venegas, M.; Garcia, N. [Universidad Carlos III de Madrid (Spain). Departamento de Ingenieria Termica y Fluidos; Palacios, E. [Universidad Politecnica de Madrid (Spain). Departamento de Mecanica Industrial

2005-05-01

In the present paper, an exergetic analysis of a double stage thermal compressor using the lithium bromide-water solution is performed. The double stage system considered allows obtaining evaporation temperatures equal to 5{sup o} C using solar heat coming from flat plate collectors and other low grade thermal sources. In this study, ambient air and water are alternatively used as cooling fluids without crystallization problems up to condensation-absorption temperatures equal to 50 {sup o}C. The results obtained give the entropy generated, the exergy destroyed and the exergetic efficiency of the double stage thermal compressor as a function of the absorption temperature. The conclusions obtained show that the irreversibilities generated by the double stage thermal compressor will tend to increase with the absorption temperature up to 45 {sup o}C. The maximum value corresponds to 1.35 kJ kg{sup -}1{sup K-1}. The entropy generated and the exergy destroyed by the air cooled system are higher than those by the water cooled one. The difference between the values increases when the absorption temperature increases. For an absorption temperature equal to 50 {sup o}C, the air cooled mode generates 14% more entropy and destroys 14% more exergy than the water cooled one. Also, the results are compared with those of previous studies for single and double effect air cooled and water cooled thermal compressors. The conclusions show that the double stage system has about 22% less exergetic efficiency than the single effect one and 32% less exergetic efficiency than the double effect one. (author)

Absorption heat pump system

Science.gov (United States)

Grossman, G.

1982-06-16

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Atmospheric impacts of evaporative cooling systems

International Nuclear Information System (INIS)

Carson, J.E.

1976-10-01

The report summarizes available information on the effects of various power plant cooling systems on the atmosphere. While evaporative cooling systems sharply reduce the biological impacts of thermal discharges in water bodies, they create (at least, for heat-release rates comparable to those of two-unit nuclear generating stations) atmospheric changes. For an isolated site such as required for a nuclear power plant, these changes are rather small and local, and usually environmentally acceptable. However, one cannot say with certainty that these effects will remain small as the number of reactors on a given site increases. There must exist a critical heat load for a specific site which, if exceeded, can create its own weather patterns, and thus create inadvertent weather changes such as rain and snow, severe thunderstorms, and tornadoes. Because proven mathematical models are not available, it is not now possible to forecast precisely the extent and frequency of the atmospheric effects of a particular heat-dissipation system at a particular site. Field research on many aspects of cooling system operation is needed in order to document and quantify the actual atmospheric changes caused by a given cooling system and to provide the data needed to develop and verify mathematical and physical models. The more important topics requiring field study are plume rise, fogging and icing (from certain systems), drift emission and deposition rates, chemical interactions, cloud and precipitation formation and critical heat-release rates

Solar thermally driven cooling systems: Some investigation results and perspectives

International Nuclear Information System (INIS)

Ajib, Salman; Günther, Wolfgang

2013-01-01

Highlights: ► Two types of solar thermally driven absorption refrigeration machines (ARMs) have been investigated. ► We investigated the influence of the operating conditions on the effectiveness of the ARMs. ► The influence of the flow rate of the work solution on the effectiveness of the ARMs has been tested. ► Two laboratory test plants have been built and tested under different operating conditions. - Abstract: A big increase in the number of solar thermal cooling installations and research efforts could be seen over the last years worldwide. Especially the producers of solar thermal collectors and systems have been looking for thermal chillers in the small capacity range to provide air conditioning for one or two family houses. Furthermore, many developments aim to increase the efficiency of the system and to decrease the specific costs of the produced refrigeration capacity. The growth in the use of solar thermal cooling systems amounted about 860% from 52 units in 2004 to 450 units in 2009 [1]. This tendency is expected to be continuously in the next years. The practical examinations on solar thermally driven absorption machines with refrigeration capacity of 15, 10 and 5 kW have shown that this technology has a good chance to be standardized and to replace partly the conventional one. These systems can save more primary energy at high fraction of solar thermally driving by suitable control and regulation of the system. The investing costs still higher as the conventional one, however, the operating costs are less than the conventional one. The Coefficient of Performance (COP) depends on the kind of the system, work temperatures and conditions as well as the refrigeration capacity of the systems. It lies between 0.4 and 1.2. In the framework of the research on this field, we built, tested and measured two prototypes. After measuring the first prototype, the chillers were redesigned to reduce internal heat losses and make the heat and mass transfer

Load calculations of radiant cooling systems for sizing the plant

DEFF Research Database (Denmark)

Bourdakis, Eleftherios; Kazanci, Ongun Berk; Olesen, Bjarne W.

2015-01-01

The aim of this study was, by using a building simulation software, to prove that a radiant cooling system should not be sized based on the maximum cooling load but at a lower value. For that reason six radiant cooling models were simulated with two control principles using 100%, 70% and 50......% of the maximum cooling load. It was concluded that all tested systems were able to provide an acceptable thermal environment even when the 50% of the maximum cooling load was used. From all the simulated systems the one that performed the best under both control principles was the ESCS ceiling system. Finally...... it was proved that ventilation systems should be sized based on the maximum cooling load....

An experimental study of water absorption characteristics for generator stator winding insulation

International Nuclear Information System (INIS)

Lee, D. S.; Bae, Y. C.; Kim, H. S.; Kim, Y. H.; Lee, H.

2004-01-01

Leaking water coolant into stator electrical insulation is a growing concern for the aging water-cooled generator since leaks in the generator water-cooled stator winding can affect machine availability and insulation life. But a domestic techniques of such field are insufficient and depend wholly on GE or TOSHIBA technique. Therefore this paper introduces measuring principle and developed measuring system, which has been used to detecting wet absorption. We accomplished the experiment with a stator promotion of virtue which is used in actual power plant. Also, experimental method of generator stator winding, which is investigated into wet absorption test

Absorption technology for solar and waste heat utilization

International Nuclear Information System (INIS)

Grossman, G.

1993-01-01

Absorption heat pumps, first developed in the 19th century, have received renewed and growing attention in the past two decades. With the increasing cost of oil and electricity, the particular features of this heat-powered cycle have made it attractive for both residential and industrial applications. Solar-powered air conditioning, gas-fired domestic cooling and waste-heat-powered temperature boosters are some of the applications on which intensive research and development has been conducted. This paper describes the operation of absorption systems and discusses several practical applications. It surveys recent advances in absorption technology, including the selection of working fluids, cycle improvements and multi-staging, and fundamentals of the combined heat and mass transfer in absorption processes. (author)

Low pressure cooling seal system for a gas turbine engine

Science.gov (United States)

Marra, John J

2014-04-01

A low pressure cooling system for a turbine engine for directing cooling fluids at low pressure, such as at ambient pressure, through at least one cooling fluid supply channel and into a cooling fluid mixing chamber positioned immediately downstream from a row of turbine blades extending radially outward from a rotor assembly to prevent ingestion of hot gases into internal aspects of the rotor assembly. The low pressure cooling system may also include at least one bleed channel that may extend through the rotor assembly and exhaust cooling fluids into the cooling fluid mixing chamber to seal a gap between rotational turbine blades and a downstream, stationary turbine component. Use of ambient pressure cooling fluids by the low pressure cooling system results in tremendous efficiencies by eliminating the need for pressurized cooling fluids for sealing this gap.

Evaluation of Active Cooling Systems for Non-Residential Buildings

Directory of Open Access Journals (Sweden)

M.A. Othuman Mydin

2014-05-01

Full Text Available Cooling systems are an essential element in many facets of modern society including cars, computers and buildings. Cooling systems are usually divided into two types: passive and active. Passive cooling transfers heat without using any additional energy while active cooling is a type of heat transfer that uses powered devices such as fans or pumps. This paper will focus on one particular type of passive cooling: air-conditioning systems. An air-conditioning system is defined as controlled air movement, temperature, humidity and cleanliness of a building area. Air conditioning consists of cooling and heating. Therefore, the air-conditioning system should be able to add and remove heat from the area. An air-conditioning system is defined as a control or treatment of air in a confined space. The process that occurs is the air-conditioning system absorbs heat and dust while, at the same time, cleaning the air breathed into a closed space. The purpose of air-conditioning is to maintain a comfortable atmosphere for human life and to meet user requirements. In this paper, air-conditioning systems for non-residential buildings will be presented and discussed.

System for Cooling of Electronic Components

Science.gov (United States)

Vasil'ev, L. L.; Grakovich, L. P.; Dragun, L. A.; Zhuravlev, A. S.; Olekhnovich, V. A.; Rabetskii, M. I.

2017-01-01

Results of computational and experimental investigations of heat pipes having a predetermined thermal resistance and a system based on these pipes for air cooling of electronic components and diode assemblies of lasers are presented. An efficient compact cooling system comprising heat pipes with an evaporator having a capillary coating of a caked copper powder and a condenser having a developed outer finning, has been deviced. This system makes it possible to remove, to the ambient air, a heat flow of power more than 300 W at a temperature of 40-50°C.

Study of a cogeneration system (power and cooling) operating with two distinct prime-movers; Estudo de um sistema de cogeracao (potencia eletrica e refrigeracao) operando com dois motores termicos distintos

Energy Technology Data Exchange (ETDEWEB)

Benito, Yipsy Roque; Parise, Jose Alberto Reis [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Mecanica], e-mail: gipsyrb@mec.puc-rio.br, e-mail: parise@mec.puc-rio.br; Vargas, Jose Viriato Coelho [Universidade Federal do Parana (DEM/UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica], e-mail: jvargas@demec.ufpr.br

2006-07-01

When dealing with complex thermal systems generating different energy products from a single fuel source (for example, as in the present work, electric and refrigeration power, with two gas-powered prime movers), one has to find the most energy efficient production scheme. To that end, each load demand (power and cooling), the efficiencies of each component, the cooling to power load ratio and the power distribution among the prime-movers, all have to be considered. This work presents the main equations for the energy balance of a cogeneration system with two primemovers (a gas turbine and an internal combustion engine), a waste heat driven absorption chiller and an auxiliary vapor compression chiller. The energy conservation equation was applied for each control volume comprising the system. Three possible cases were defined according to how cooling power demand and cooling power produced by the waste heat driven absorption cycle compared. As a result, characteristic performance curves were obtained for a typical application, allowing for the determination of maximum global efficiency values (represented by an energy conversion ratio) as a function of: the electric power to cooling power demand ratio, of the power generation distribution ratio among the two prime-movers, and of the part-load ratio operation of each prime mover. The resulting system of equations was solved by the software EES (Engineering Equation Solver{sup R}). (author)

Connecting the Interstellar Gas and Dust Properties in Distant Galaxies Using Quasar Absorption Systems

Science.gov (United States)

Aller, Monique C.; Dwek, Eliahu; Kulkarni, Varsha P.; York, Donald G.; Welty, Daniel E.; Vladilo, Giovanni; Som, Debopam; Lackey, Kyle; Dwek, Eli; Beiranvand, Nassim;

Transient Performance of Air-cooled Condensing Heat Exchanger in Long-term Passive Cooling System during Decay Heat Load

Energy Technology Data Exchange (ETDEWEB)

Kim, Myoung Jun; Lee, Hee Joon [Kookmin University, Seoul (Korea, Republic of); Moon, Joo Hyung; Bae, Youngmin; Kim, Young-In [KAERI, Daejeon (Korea, Republic of)

2015-05-15

In the event of a 'loss of coolant accident'(LOCA) and a non-LOCA, the secondary passive cooling system would be activated to cool the steam in a condensing heat exchanger that is immersed in an emergency cooldown tank (ECT). Currently, the capacities of these ECTs are designed to be sufficient to remove the sensible and residual heat from the reactor coolant system for 72 hours after the occurrence of an accident. After the operation of a conventional passive cooling system for an extended period, however, the water level falls as a result of the evaporation from the ECT, as steam is emitted from the open top of the tank. Therefore, the tank should be refilled regularly from an auxiliary water supply system when the system is used for more than 72 hours. Otherwise, the system would fail to dissipate heat from the condensing heat exchanger due to the loss of the cooling water. Ultimately, the functionality of the passive cooling system would be seriously compromised. As a passive means of overcoming the water depletion in the tank, Kim et al. applied for a Korean patent covering the concept of a long-term passive cooling system for an ECT even after 72 hours. This study presents transient performance of ECT with installing air-cooled condensing heat exchanger under decay heat load. The cooling capacity of an air-cooled condensing heat exchanger was evaluated to determine its practicality.

The low-ion QSO absorption-line systems

International Nuclear Information System (INIS)

Lanzetta, K.M.

1988-01-01

Various techniques are used to investigate the class of QSO absorption-line systems that exhibit low-ion absorption lines. Four separate investigations are conducted as follows: Spectroscopy of 32 QSOs at red wavelengths is presented and used to investigate intermediate-redshift MgII absorption. A total of 22 Mg II doublets are detected, from which properties of the Mg II absorbers are derived. Marginal evidence for intrinsic evolution of the number density of the Mg II absorbers with redshift is found. The data are combined with previous observations of C IV and C II seen in the same QSOs at blue wavelengths, and the properties of Mg II- and C IV-selected systems are compared. A sample is constructed of 129 QSOs for which are available published data suitable for detecting absorption-line systems that are optically thick to Lyman continuum radiation. A total of 53 such Lyman-limit systems are found, from which properties of the Lyman-limit systems are derived. It is found that the rate of incidence of the systems does not strongly evolved with redshift. This result is contrasted with the evolution found previously for systems selected on the basis of Mg II absorption. Spectroscopy at red wavelengths of eight QSOs with known damped Lyα absorption systems is presented. Spectroscopic and spectrophotometric observations aimed at detecting molecular hydrogen and dust in the z = 2.796 damped Lyα absorber toward Q1337 + 113 are presented

Intervening O vi Quasar Absorption Systems at Low Redshift: A Significant Baryon Reservoir.

Science.gov (United States)

Tripp; Savage; Jenkins

2000-05-01

Far-UV echelle spectroscopy of the radio-quiet QSO H1821+643 (zem=0.297), obtained with the Space Telescope Imaging Spectrograph (STIS) at approximately 7 km s-1 resolution, reveals four definite O vi absorption-line systems and one probable O vi absorber at 0.15quasar in redshift; these are likely intervening systems unrelated to the background QSO. In the case of the strong O vi system at zabs=0.22497, multiple components are detected in Si iii and O vi as well as H i Lyman series lines, and the differing component velocity centroids and b-values firmly establish that this is a multiphase absorption system. A weak O vi absorber is detected at zabs=0.22637, i.e., offset by approximately 340 km s-1 from the zabs=0.22497 system. Lyalpha absorption is detected at zabs=0.22613, but no Lyalpha absorption is significantly detected at 0.22637. Other weak O vi absorbers at zabs=0.24531 and 0.26659 and the probable O vi system at 0.21326 have widely diverse O vi/H i column density ratios with N(O vi)/N(H i) ranging from systems is Omegab(Ovi&parr0; greater, similar0.0008 h-175. With an assumed metallicity of 1/10 solar and a conservative assumption that the fraction of oxygen in the O vi ionization stage is 0.2, we obtain Omegab(Ovi&parr0; greater, similar0.004 h-175. This is comparable to the combined cosmological mass density of stars and cool gas in galaxies and X-ray-emitting gas in galaxy clusters at low redshift.

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

Misting-cooling systems for microclimatic control in public space

OpenAIRE

Nunes, Joao; Zoilo, Inaki; Jacinto, Nuno; Nunes, Ana; Torres-Campos, Tiago; Pacheco, Manuel; Fonseca, David

2011-01-01

Misting-cooling systems have been used in outdoor spaces mainly for aesthetic purposes, and punctual cooling achievement. However, they can be highly effective in outdoor spaces’ bioclimatic comfort, in terms of microclimatic control, as an evaporative cooling system. Recent concerns in increasing bioclimatic standards in public outdoor spaces, along with more sustainable practices, gave origin to reasoning where plastic principles are combined with the study of cooling efficacy, in order to ...

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

Analysis and simulation of mobile air conditioning system coupled with engine cooling system

International Nuclear Information System (INIS)

Qi, Zhao-gang; Chen, Jiang-ping; Chen, Zhi-jiu

2007-01-01

Many components of the mobile air conditioning system and engine cooling system are closely interrelated and make up the vehicle climate control system. In the present paper, a vehicle climate control system model including air conditioning system and engine cooling system has been proposed under different operational conditions. All the components have been modeled on the basis of experimental data. Based on the commercial software, a computer simulation procedure of the vehicle climate control system has been developed. The performance of the vehicle climate control system is simulated, and the calculational data have good agreement with experimental data. Furthermore, the vehicle climate control simulation results have been compared with an individual air conditioning system and engine cooling system. The influences between the mobile air conditioning system and the engine cooling system are discussed

Containment atmosphere cooling system for experimental fast reactor 'JOYO'

International Nuclear Information System (INIS)

Sasaki, Mikio; Hoshi, Akio; Sato, Morihiko; Takeuchi, Kaoru

1979-01-01

The experimental fast reactor ''JOYO'', the first sodium-cooled fast reactor in Japan, achieved the initially licensed full power operation (50 MW) in July 1978 and is now under steady operation. Toshiba has participated in the construction of this reactor as a leading manufacturer and supplied various systems. This article outlines the design philosophy, system concepts and the operating experience of the containment atmosphere cooling system which has many design interfaces throughout the whole plant and requires especially high reliability. The successful performance of this system during the reactor full-power operation owes to the spot cooling design philosophy and to the preoperational adjustment of heat load during the preheating period of reactor cooling system peculiar to FBR. (author)

Passive cooling system for nuclear reactor containment structure

Science.gov (United States)

Gou, Perng-Fei; Wade, Gentry E.

1989-01-01

A passive cooling system for the contaminant structure of a nuclear reactor plant providing protection against overpressure within the containment attributable to inadvertent leakage or rupture of the system components. The cooling system utilizes natural convection for transferring heat imbalances and enables the discharge of irradiation free thermal energy to the atmosphere for heat disposal from the system.

Study on the simulation of heat pump heating and cooling systems to hospital building

International Nuclear Information System (INIS)

Choi, Young Don; Han, Seong Ho; Cho, Sung Hwan; Kim, Du Sung; Um, Chul Jun

2008-01-01

In Korea, air source heat pump system is less efficient than conventional heat source facilities, because the air temperature in winter season is so low that COP of air source heat pump system drops below 3.0. Therefore, the study on the application of heat pump heating and cooling systems is crucial for the efficient popularization of heat pump. In this work, we present the dynamic analysis of energy consumption for the large hospital building by heat resistance-capacitance method. The system simulation of water storage air source heat pump is additionally performed by changing sizes and locations of the hospital building. The computed results show that energy cost of water storage air source heat pump is low, so it is more economical than absorption chiller and heater

Percutaneous radiofrequency ablation of osteoid osteoma using cool-tip electrodes without the cooling system

International Nuclear Information System (INIS)

Miyazaki, Masaya; Miyazaki, Akiko; Nakajima, Takahito; Koyama, Yoshinori; Shinozaki, Tetsuya; Endo, Keigo; Aoki, Jun

2011-01-01

The aim of this study was to evaluate the efficacy of percutaneous radiofrequency ablation (RFA) for osteoid osteoma (OO) using cool-tip electrodes without the cooling system. A total of 17 patients (13 males, 4 females; mean age 19.1 years; range 7-49 years) with OO (tibia, n=7; femur, n=5; acetabulum, n=2; radius, n=1; talus, n=1; lumbar spine, n=1) underwent RFA. Using a cool-tip electrode without the cooling system, the lesion was heated to 90degC for 4 or 5 min. Procedures were considered technically successful if the electrode was placed into the nidus and the target temperature was reached and maintained for at least 4 min. Clinical success of the treatment was defined as complete or partial pain relief after RFA. All procedures were considered technically successful, although two patients encountered complications (pes equinus contracture, skin burn). Altogether, 16 of the 17 patients (94.1%) achieved complete or partial pain relief after primary RFA. Two patients had pain recurrence, with one of them treated successfully with a second RFA. The overall clinical success rate was 88.2%. Histological findings confirmed the presence of OO in 13 patients (76.5%). Percutaneous RFA of OO using cool-tip electrodes without the cooling system is a safe, effective procedure. (author)

Design Requirements of an Advanced HANARO Reactor Core Cooling System

International Nuclear Information System (INIS)

Park, Yong Chul; Ryu, Jeong Soo

2007-12-01

An advanced HANARO Reactor (AHR) is an open-tank-type and generates thermal power of 20 MW and is under conceptual design phase for developing it. The thermal power is including a core fission heat, a temporary stored fuel heat in the pool, a pump heat and a neutron reflecting heat in the reflector vessel of the reactor. In order to remove the heat load, the reactor core cooling system is composed of a primary cooling system, a primary cooling water purification system and a reflector cooling system. The primary cooling system must remove the heat load including the core fission heat, the temporary stored fuel heat in the pool and the pump heat. The purification system must maintain the quality of the primary cooling water. And the reflector cooling system must remove the neutron reflecting heat in the reflector vessel of the reactor and maintain the quality of the reflector. In this study, the design requirement of each system has been carried out using a design methodology of the HANARO within a permissible range of safety. And those requirements are written by english intend to use design data for exporting the research reactor

Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

Directory of Open Access Journals (Sweden)

Zeng Wei

2018-03-01

Full Text Available For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

Science.gov (United States)

Zeng, Wei; Deng, Li; Chen, Aixi

2018-03-01

For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D) atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

Cooling System Design Options for a Fusion Reactor

Science.gov (United States)

Natalizio, Antonio; Collén, Jan; Vieider, Gottfried

1997-06-01

The objective of a fusion power reactor is to produce electricity safely and reliably. Accordingly, the design, objective of the heat transport system is to optimize power production, safety, and reliability. Such an optimization process, however, is constrained by many factors, including, among others: public safety, worker safety, steam cycle efficiency, reliability, and cost. As these factors impose conflicting requirements, there is a need to find an optimum design solution, i.e., one that satisfies all requirements, but not necessarily each requirement optimally. The SEAFP reactor study developed helium-cooled and water-cooled models for assessment purposes. Among other things, the current study demonstrates that neither model offers an optimum solution. Helium cooling offers a high steam cycle efficiency but poor reliability for the cooling of high heat flux components (divertor and first wall). Alternatively, water cooling offers a low steam cycle efficiency, but reasonable reliability for the cooling of such components. It is concluded that an optimum solution includes helium cooling of low heat flux components and water cooling of high heat flux components. Relative to the SEAFP helium model, this hybrid system enhances safety and reliability, while retaining the high steam cycle efficiency of that model.

PERFORMANCE EVALUATION OF CEILING RADIANT COOLING SYSTEM IN COMPOSITE CLIMATE

Energy Technology Data Exchange (ETDEWEB)

Sharma, Anuj [Malaviya National Institute of Technology (MNIT), Jaipur, India; Mathur, Jyotirmay [Malaviya National Institute of Technology (MNIT), Jaipur, India; Bhandari, Mahabir S [ORNL

2015-01-01

Radiant cooling systems are proving to be an energy efficient solution due to higher thermal capacity of cooling fluid especially for the buildings that require individual zone controls and where the latent loads are moderate. The Conventional air conditioners work at very low temperature i.e.5-8 c (refrigerant evaporator inlet) while the radiant cooling systems, also referred as high temperature cooling system, work at high temperatures i.e. 14-18 c. The radiant cooling systems can maintain lower MRT (Mean Radiant Temperature) as ceiling panels maintain uniform temperature gradient inside room and provide higher human comfort. The radiant cooling systems are relatively new systems and their operation and energy savings potential are not quantified for a large number of buildings and operational parameters. Moreover, there are only limited numbers of whole building simulation studies have been carried out for these systems to have a full confidence in the capability of modelling tools to simulate these systems and predict the impact of various operating parameters. Theoretically, savings achieve due to higher temperature set point of chilled water, which reduces chiller-running time. However, conventional air conditioner runs continuously to maintain requisite temperature. In this paper, experimental study for performance evaluation of radiant cooling system carried out on system installed at Malaviya National Institute of Technology Jaipur. This paper quantifies the energy savings opportunities and effective temperature by radiant cooling system at different chilled water flow rates and temperature range. The data collected/ analysed through experimental study will used for calibration and validation of system model of building prepared in building performance simulation software. This validated model used for exploring optimized combinations of key parameters for composite climate. These optimized combinations will used in formulation of radiant cooling system

Cooling system for superconducting magnet

Science.gov (United States)

Gamble, Bruce B.; Sidi-Yekhlef, Ahmed

1998-01-01

A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir.

A geothermal recycling system for cooling and heating in deep mines

International Nuclear Information System (INIS)

Guo, Pingye; He, Manchao; Zheng, Liange; Zhang, Na

2017-01-01

Highlights: • A geothermal recycling system for cooling and heating was presented in coal mines. • The COP of this cooling subsystem is 30% higher than that of others. • The COP is 20% higher with the parallel running of cooling and heating systems. - Abstract: In the operation of deep coal mines, cooling systems must be built (in most cases) because of the high-temperature working environment within such mines. Once the coal is mined, it is often used to supply heat for buildings and domestic hot water. In either instance, the energy consumed can create environmental pollution. As a potential solution to this problem, we present a geothermal recycling system for mines (GRSM) for parallel mine cooling and surface heating. The performance of this system is investigated based on the observed data. Compared with traditional cooling systems, the most obvious feature of this system is the removal of a cooling tower, which contributes to a 30% increase in performance. Moreover, the parallel running of cooling and heating systems can effectively recover waste heat, improving energy efficiency by 20%.

CoolPack – Simulation tools for refrigeration systems

DEFF Research Database (Denmark)

Jakobsen, Arne; Rasmussen, Bjarne D.; Andersen, Simon Engedal

1999-01-01

CoolPack is a collection of programs used for energy analysis and optimisation of refrigeration systems. CoolPack is developed at the Department of Energy Engineering at the Technical University of Denmark. The Danish Energy Agency finances the project. CoolPack is freeware and can be downloaded...

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)

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

Operational cost minimization in cooling water systems

Directory of Open Access Journals (Sweden)

Castro M.M.

2000-01-01

Full Text Available In this work, an optimization model that considers thermal and hydraulic interactions is developed for a cooling water system. It is a closed loop consisting of a cooling tower unit, circulation pump, blower and heat exchanger-pipe network. Aside from process disturbances, climatic fluctuations are considered. Model constraints include relations concerning tower performance, air flowrate requirement, make-up flowrate, circulating pump performance, heat load in each cooler, pressure drop constraints and climatic conditions. The objective function is operating cost minimization. Optimization variables are air flowrate, forced water withdrawal upstream the tower, and valve adjustment in each branch. It is found that the most significant operating cost is related to electricity. However, for cooled water temperatures lower than a specific target, there must be a forced withdrawal of circulating water and further makeup to enhance the cooling tower capacity. Additionally, the system is optimized along the months. The results corroborate the fact that the most important variable on cooling tower performance is not the air temperature itself, but its humidity.

Cooling Grapple System for FMEF hot cell

International Nuclear Information System (INIS)

Semmens, L.S.; Frandsen, G.B.; Tome, R.

1983-01-01

A Cooling Grapple System was designed and built to handle fuel assemblies within the FMEF hot cell. The variety of functions for which it is designed makes it unique from grapples presently in use. The Cooling Grapple can positively grip and transport assemblies vertically, retrieve assemblies from molten sodium where six inches of grapple tip is submerged, cool 7 kw assemblies in argon, and service an in-cell area of 372 m 2 (4000 ft 2 ). Novel and improved operating and maintenance features were incorporated in the design including a shear pin and mechanical catcher system to prevent overloading the grapple while allowing additional reaction time for crane shutdown

System design package for the solar heating and cooling central data processing system

Science.gov (United States)

1978-01-01

The central data processing system provides the resources required to assess the performance of solar heating and cooling systems installed at remote sites. These sites consist of residential, commercial, government, and educational types of buildings, and the solar heating and cooling systems can be hot-water, space heating, cooling, and combinations of these. The instrumentation data associated with these systems will vary according to the application and must be collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. Overall software system requirements were established for use in the central integration facility which transforms raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems.

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

Potential Evaluation of Solar Heat Assisted Desiccant Hybrid Air Conditioning System

Science.gov (United States)

Tran, Thien Nha; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

The solar thermal driven desiccant dehumidification-absorption cooling hybrid system has superior advantage in hot-humid climate regions. The reasonable air processing of desiccant hybrid air conditioning system and the utility of clean and free energy make the system environment friendly and energy efficient. The study investigates the performance of the desiccant dehumidification air conditioning systems with solar thermal assistant. The investigation is performed for three cases which are combinations of solar thermal and absorption cooling systems with different heat supply temperature levels. Two solar thermal systems are used in the study: the flat plate collector (FPC) and the vacuum tube with compound parabolic concentrator (CPC). The single-effect and high energy efficient double-, triple-effect LiBr-water absorption cooling cycles are considered for cooling systems. COP of desiccant hybrid air conditioning systems are determined. The evaluation of these systems is subsequently performed. The single effect absorption cooling cycle combined with the flat plate collector solar system is found to be the most energy efficient air conditioning system.

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.

Overpower transient in the first wall cooling system of NET/ITER

International Nuclear Information System (INIS)

Komen, E.M.J.; Koning, H.

1993-09-01

The overpower transient from a plasma power excursion. The overpower transient considered in this report results from a postulated linear increase of the plasma power from the nominal generated power to four times this nominal power in 30 s. The Next European Torus (NET) design or the International Thermonuclear Experimental Reactor (ITER) design will be cooled by a number of separate cooling systems. The most important cooling systems are: The first wall cooling system, the blanket cooling system, the divertor cooling system, and the shield cooling system. In this report, the thermal-hydraulic analysis of the above-mentioned overpower transient will be presented for the first wall cooling system of NET/ITER. During overpower transients, the fusion power will increase to less than four times the nominal power. For this reason, the overpower transient considered in this report is the worst case scenario. The analysis of the thermal-hydraulic system behaviour during the considered overpower transient has been performed for a coolant temperature of 333 K (60 C) in the first wall inlet manifolds and 433 K (160 C) in the first wall outlet manifolds. The analysis has been performed using the thermal-hydraulic system analysis code RELAP5/MOD3. In the analysis, special attention has been paid to the transient thermal-hydraulic behaviour of the cooling system and the temperature development in the first wall. (orig.)

Control of Non-linear Marine Cooling System

DEFF Research Database (Denmark)

Hansen, Michael; Stoustrup, Jakob; Bendtsen, Jan Dimon

2011-01-01

We consider the problem of designing control laws for a marine cooling system used for cooling the main engine and auxiliary components aboard several classes of container vessels. We focus on achieving simple set point control for the system and do not consider compensation of the non-linearitie......-linearities, closed circuit flow dynamics or transport delays that are present in the system. Control laws are therefore designed using classical control theory and the performance of the design is illustrated through two simulation examples....

MHD/gas turbine systems designed for low cooling water requirements

International Nuclear Information System (INIS)

Annen, K.D.; Eustis, R.H.

1983-01-01

The MHD/gas turbine combined-cycle system has been designed specifically for applications where the availability of cooling water is very limited. The base case systems which were studied consist of a coal-fired MHD plant with an air turbine bottoming plant and require no cooling water. In addition to the base case systems, systems were considered which included the addition of a vapor cycle bottoming plant to improve the thermal efficiency. These systems require a small amount of cooling water. The results show that the MHD/gas turbine systems have very good thermal and economic performances. The base case I MHD/gas turbine system (782 MW /SUB e/ ) requires no cooling water, has a heat rate which is 13% higher, and a cost of electricity which is only 7% higher than a comparable MHD/steam system (878 MW /SUB e/ ) having a cooling tower heat load of 720 MW. The case I vapor cycle bottomed systems have thermal and economic performances which approach and even exceed those of the MHD/steam system, while having substantially lower cooling water requirements. Performances of a second-generation MHD/gas turbine system and an oxygen-enriched, early commercial system are also evaluated. An analysis of nitric oxide emissions shows compliance with emission standards

Instrumentation for NBI SST-1 cooling water system

International Nuclear Information System (INIS)

Qureshi, Karishma; Patel, Paresh; Jana, M.R.

2015-01-01

Neutral Beam Injector (NBI) System is one of the heating systems for Steady state Superconducting Tokamak (SST-1). It is capable of generating a neutral hydrogen beam of power 0.5 MW at 30 kV. NBI system consists of following sub-systems: Ion source, Neutralizer, Deflection Magnet and Magnet Liner (ML), Ion Dump (ID), V-Target (VT), Pre Duct Scraper (PDS), Beam Transmission Duct (BTD) and Shine Through (ST). For better heat removal management purpose all the above sub-systems shall be equipped with Heat Transfer Elements (THE). During beam operation these sub-systems gets heated due to the received heat load which requires to be removed by efficient supplying water. The cooling water system along with the other systems (External Vacuum System, Gas Feed System, Cryogenics System, etc.) will be controlled by NBI Programmable Logic Control (PLC). In this paper instrumentation and its related design for cooling water system is discussed. The work involves flow control valves, transmitters (pressure, temperature and water flow), pH and conductivity meter signals and its interface with the NBI PLC. All the analog input, analog output, digital input and digital output signals from the cooling water system will be isolated and then fed to the NBI PLC. Graphical Users Interface (GUI) needed in the Wonderware SCADA for the cooling water system shall also be discussed. (author)

Uniform semiclassical approximation for absorptive scattering systems

International Nuclear Information System (INIS)

Hussein, M.S.; Pato, M.P.

1987-07-01

The uniform semiclassical approximation of the elastic scattering amplitude is generalized to absorptive systems. An integral equation is derived which connects the absorption modified amplitude to the absorption free one. Division of the amplitude into a diffractive and refractive components is then made possible. (Author) [pt

Thermodynamic performance analysis of a vapor compression–absorption cascaded refrigeration system

International Nuclear Information System (INIS)

Jain, Vaibhav; Kachhwaha, S.S.; Sachdeva, Gulshan

2013-01-01

Highlights: • Study includes first and second law analysis with alternatives refrigerants. • Power consumption in cascaded system is 61% less than vapor compression system. • COP of compression system is improved by 155% with cascaded absorption system. • Condenser is more sensitive to external fluid temperature as compare to evaporator. - Abstract: In the present study, a thermodynamic model for cascaded vapor compression–absorption system (CVCAS) has been developed which consists of a vapor compression refrigeration system (VCRS) coupled with single effect vapor absorption refrigeration system (VARS). Based on first and second laws, a comparative performance analysis of CVCAS and an independent VCRS has been carried out for a design capacity of 66.67 kW. The results show that the electric power consumption in CVCAS is reduced by 61% and COP of compression section is improved by 155% with respect to the corresponding values pertaining to a conventional VCRS. However there is a trade-off between these parameters and the rational efficiency which is found to decrease to half of that for a VCRS. The effect of various operating parameters, i.e., superheating, subcooling, cooling capacity, inlet temperature and the product of effectiveness and heat capacitance of external fluids are extensively studied on the COP, total irreversibility and rational efficiency of the CVCAS. Besides, the performance of environment friendly refrigerants such as R410A, R407C and R134A is found to be almost at par with that of R22. Hence, all the alternative refrigerants selected herein can serve as potential substitutes for R22. Furthermore, it has been found that reducing the irreversibility rate of the condenser by one unit due to decrease in condenser temperature depicted approximately 3.8 times greater reduction in the total irreversibility rate of the CVCAS, whereas unit reduction in the evaporator’s irreversibility rate due to increase in evaporator temperature reduced

Solar heating and cooling of mobile homes, Phase II. Final report

Energy Technology Data Exchange (ETDEWEB)

Jacobsen, A.A.

1976-12-01

The specific objectives of the Phase II program were: (1) through system testing, confirm the feasibility of a solar heated and cooled mobile home; (2) update system performance analysis and provide solar heating and cooling computer model verification; (3) evaluate the performance of both an absorption and a Rankine air conditioning system; (4) perform a consumer demand analysis through field survey to ascertain the acceptance of solar energy into the mobile home market; and (5) while at field locations to conduct the consumer demand analysis, gather test data from various U.S. climatic zones. Results are presented and discussed. (WHK)

Simulation of the compressor-assisted triple-effect H{sub 2}O/LiBr absorption cooling cycles

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Soo; Ziegler, F. [Bavarian Center for Applied Energy Research, Garching (Germany); Lee, Huen [Korea Advanced Inst. of Science and Technology, Taejon (Korea). Dept. of Chemical Engineering

2002-03-01

The construction of a triple-effect absorption cooling machine using the lithium bromide-based working fluid is strongly limited by the corrosion problem caused by the high generator temperature. In this study four compressor-assisted H{sub 2}O/LiBr cooling cycles were suggested to solve the problem by lowering the generator temperature of the basic theoretical triple-effect cycle. Each cycle includes one compressor at a different state point to elevate the pressure of the refrigerant vapor up to a useful condensation temperature. Cycle simulations were carried out to investigate both a basic triple-effect cycle and four compressor-assisted cycles. All types of compressor-assisted cycles were found to be operable with a significantly lowered generator temperature. The temperature decrements increase with elevated compression ratios. This means that, if a part of energy input is changed from heat to mechanical energy, the machine can be operated in a favorable region of generator temperature not to cause corrosion problems. In order to obtain 40 K of generator temperature decrement (from 475.95 K) for all cycles, 3-5% of cooling capacity equivalent mechanical energies were required for operating the compressor. A great advantage of the investigated triple-effect cycles is that the conventionally used H{sub 2}O/LiBr solution can be used as a working fluid without the danger of corrosion or without integrating multiple solution circuits.(author)

Application of fuzzy control in cooling systems save energy design

Energy Technology Data Exchange (ETDEWEB)

Chen, M.L.; Liang, H.Y. [Chienkuo Technology Univ., Changhua, Taiwan (China). Dept. of Electrical Engineering

2005-07-01

A fuzzy logic programmable logic controller (PLC) was used to control the cooling systems of frigorific equipment. Frigorific equipment is used to move unwanted heat outside of building in order to control indoor temperatures. The aim of the fuzzy logic PLC was to improve the energy efficiency of the cooling system. Control of the cooling pump and cooling tower in the system was based on the water temperature of the condenser during frigorific system operation. A human computer design for the cooling system control was used to set speeds and to automate and adjust the motor according to the fuzzy logic controller. It was concluded that if fuzzy logic controllers are used with all components of frigorific equipment, energy efficiency will be significantly increased. 5 refs., 3 tabs., 9 figs.

Reports on 1979 result of Sunshine Project. R and D on solar cooling/heating and hot-water supply system (R and D on system for large-sized building); 1979 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Ogata kenchikubutsuyo system no kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-03-01

Equipment was developed constituting a solar cooling/heating and hot-water supply system, as was the system using such equipment as well as being safe and easy to carry out inspection and maintenance, with the purpose of putting into practice an innovative system capable of cooling/heating and hot-water supply for a large-sized building economically by means of solar energy. An analysis was conducted on the test result in an experimental system having a practical size, with the effect confirmed of the improvement work of fiscal 1978. An inspection was made for the cause of piping corrosion, as were the examination and proposal for anti-corrosion measures. Heat and weather resistance tests were carried out on selective absorption films and a convection preventive structure. A selective absorption film processing was performed on a heat collecting plate for a large heat-collecting device, with a durability test conducted for the device by assembling the film in it. A test equipment was designed and manufactured for a latent heat type heat-collecting system of a practical size, performing various experiments and an automatically controlled operation. Displayed in the test by the practical size experiment system (in the Oita University laboratory) were the cooling/heating operation mode, summary of a whole day operation, daily fluctuation of electrical power and kerosene consumption, and a graph of accumulating totals. A long-term/short-term instrumentation analysis were also performed. (NEDO)

Energy saving potential of an indirect evaporative cooler as a pre-cooling unit for mechanical cooling systems in Iran

Energy Technology Data Exchange (ETDEWEB)

Delfani, Shahram; Esmaeelian, Jafar; Karami, Maryam [Department of Installation, Building and Housing Research Center (BHRC), PO Box 13145-1696, Tehran (Iran, Islamic Republic of); Pasdarshahri, Hadi [Department of Mechanical Engineering, Tarbiat Modares University, PO Box 14115-143, Tehran (Iran, Islamic Republic of)

2010-11-15

The performance of indirect evaporative cooling system (IEC) to pre-cool air for a conventional mechanical cooling system has been investigated for four cities of Iran. For this purpose, a combined experimental setup consisting of an IEC unit followed by a packaged unit air conditioner (PUA) was designed, constructed and tested. Two air simulators were designed and used to simulate indoor heating load and outdoor design conditions. Using of experimental data and an appropriate analytical method, the performance and energy reduction capability of combined system has been evaluated through the cooling season. The results indicate IEC can reduce cooling load up to 75% during cooling seasons. Also, 55% reduction in electrical energy consumption of PUA can be obtained. (author)

Open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water

International Nuclear Information System (INIS)

Hou Shaobo; Li Huacong; Zhang Hefei

2007-01-01

This paper presents an open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water and proves its feasibility through performance simulation. Pinch technology is used in analysis of heat exchange in the surface heat exchanger, and the temperature difference at the pinch point is selected as 6 o C. Its refrigeration depends mainly on both air and vapor, more efficient than a conventional air cycle, and the use of turbo-machinery makes this possible. This system could use the cool in the cool water, which could not be used to cool air directly. Also, the heat rejected from this system could be used to heat cool water to 33-40 o C. The sensitivity analysis of COP to η c and η t and the simulated results T 4 , T 7 , T 8 , q 1 , q 2 and W m of the cycle are given. The simulations show that the COP of this system depends mainly on T 7 , η c and η t and varies with T 3 or T wet and that this cycle is feasible in some regions, although the COP is sensitive to the efficiencies of the axial compressor and turbine. The optimum pressure ratio in this system could be lower, and this results in a fewer number of stages of the axial compressor. Adjusting the rotation speed of the axial compressor can easily control the pressure ratio, mass flow rate and the refrigerating capacity. The adoption of this cycle will make the air conditioned room more comfortable and reduce the initial investment cost because of the obtained very low temperature air. Humid air is a perfect working fluid for central air conditioning and no cost to the user. The system is more efficient because of using cool water to cool the air before the turbine. In addition, pinch technology is a good method to analyze the wet air heat exchange with water

The ATLAS IBL CO2 Cooling System

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00237783; The ATLAS collaboration; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

2017-01-01

The ATLAS Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity.

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

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.

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.

Configuration optimization of series flow double-effect water-lithium bromide absorption refrigeration systems by cost minimization

DEFF Research Database (Denmark)

Mussati, Sergio F.; Cignitti, Stefano; Mansouri, Seyed Soheil

2018-01-01

An optimal process configuration for double-effect water-lithium bromide absorption refrigeration systems with series flow – where the solution is first passed through the high-temperature generator – is obtained by minimization of the total annual cost for a required cooling capacity. To this end......) takes place entirely at the high-temperature zone, and the sizes and operating conditions of the other process units change accordingly in order to meet the problem specification with the minimal total annual cost. This new configuration was obtained for wide ranges of the cooling capacity (150–450 k.......9%, respectively. Most importantly, the obtained optimal solution eliminates the low-temperature solution heat exchanger from the conventional configuration, rendering a new process configuration. The energy integration between the weak and strong lithium bromide solutions (cold and hot streams, respectively...

Cooling system with automated seasonal freeze protection

Science.gov (United States)

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth, Jr., Michael J.; Iyengar, Madhusudan K.; Simons, Robert E.; Singh, Prabjit; Zhang, Jing

2016-05-24

An automated multi-fluid cooling system and method are provided for cooling an electronic component(s). The cooling system includes a coolant loop, a coolant tank, multiple valves, and a controller. The coolant loop is at least partially exposed to outdoor ambient air temperature(s) during normal operation, and the coolant tank includes first and second reservoirs containing first and second fluids, respectively. The first fluid freezes at a lower temperature than the second, the second fluid has superior cooling properties compared with the first, and the two fluids are soluble. The multiple valves are controllable to selectively couple the first or second fluid into the coolant in the coolant loop, wherein the coolant includes at least the second fluid. The controller automatically controls the valves to vary first fluid concentration level in the coolant loop based on historical, current, or anticipated outdoor air ambient temperature(s) for a time of year.

Thermal analysis of the conduction cooling system for HTS SMES system of 600 kJ class

International Nuclear Information System (INIS)

Hong, Yong Ju; Yeom, Han Kil; Park, Seong Je; Kim, Hyo Bong; Koh, Deuk Yong

2007-01-01

SMES systems need cryogenic cooling systems. Conduction cooling system has more effective, compact structure than cryogen. In general, 2 stage GM cryocoolers are used for conduction cooling of HTS SMES system. 1st stages of cryocoolers are used for the cooling of current leads and radiation shields, and 2nd stages of cryocoolers for HTS coil. For the effective conduction cooling of the HTS SMES system, the temperature difference between the cryocooler and HTS coil should be minimized. In this paper, a cryogenic conduction cooling system for HTS SMES is analyzed to evaluate the performance of the cooling system. The analysis is carried out for the steady state with the heat generation of the HTS coil and effects of the thermal contact resistance. The results show the effects of the heat generation and thermal contact resistance on the temperature distribution

System and method for pre-cooling of buildings

Science.gov (United States)

Springer, David A.; Rainer, Leo I.

2011-08-09

A method for nighttime pre-cooling of a building comprising inputting one or more user settings, lowering the indoor temperature reading of the building during nighttime by operating an outside air ventilation system followed, if necessary, by a vapor compression cooling system. The method provides for nighttime pre-cooling of a building that maintains indoor temperatures within a comfort range based on the user input settings, calculated operational settings, and predictions of indoor and outdoor temperature trends for a future period of time such as the next day.

Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

Energy Technology Data Exchange (ETDEWEB)

Pilatowsky, I.; Gamboa, S.A.; Rivera, W. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas - UAEM, Cuernavaca, Morelos (Mexico); Isaza, C.A. [Universidad Pontificia Bolivariana, Medellin (Colombia). Instituto de Energia y Termodinamica; Sebastian, P.J. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Moreira, J. [Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico)

2007-10-15

In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine-water solutions (MMA-WS), with low vapor generation temperatures (up to 80 C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system. (author)

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

Active cooling system for Tokamak in-vessel operation manipulator

Energy Technology Data Exchange (ETDEWEB)

Yuan, Jianjun, E-mail: yuanjj@sjtu.edu.cn; Chen, Tan; Li, Fashe; Zhang, Weijun; Du, Liang

2015-10-15

Highlights: • We summarized most of the challenges of fusion devices to robot systems. • Propose an active cooling system to protect all of the necessary components. • Trial design test and theoretical analysis were conducted. • Overall implementation of the active cooling system was demonstrated. - Abstract: In-vessel operation/inspection is an indispensable task for Tokamak experimental reactor, for a robot/manipulator is more capable in doing this than human being with more precise motion and less risk of damaging the ambient equipment. Considering the demanding conditions of Tokamak, the manipulator should be adaptable to rapid response in the extreme conditions such as high temperature, vacuum and so on. In this paper, we propose an active cooling system embedded into such manipulator. Cameras, motors, gearboxes, sensors, and other mechanical/electrical components could then be designed under ordinary conditions. The cooling system cannot only be a thermal shield since the components are also heat sources in dynamics. We carry out a trial test to verify our proposal, and analyze the active cooling system theoretically, which gives a direction on the optimization by varying design parameters, components and distribution. And based on thermal sensors monitoring and water flow adjusting a closed-loop feedback control of temperature is added to the system. With the preliminary results, we believe that the proposal gives a way to robust and inexpensive design in extreme environment. Further work will concentrate on overall implementation and evaluation of this cooling system with the whole inspection manipulator.

Numerical study of a novel dew point evaporative cooling system

Energy Technology Data Exchange (ETDEWEB)

Riangvilaikul, B.; Kumar, S. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120 (Thailand)

2010-11-15

Dew point evaporative cooling system is an alternative to vapor compression air conditioning system for sensible cooling of ventilation air. This paper presents the theoretical performance of a novel dew point evaporative cooling system operating under various inlet air conditions (covering dry, moderate and humid climate) and influence of major operating parameters (namely, velocity, system dimension and the ratio of working air to intake air). A model of the dew point evaporative cooling system has been developed to simulate the heat and mass transfer processes. The outlet air conditions and system effectiveness predicted by the model using numerical method for known inlet parameters have been validated with experimental findings and with recent literature. The model was used to optimize the system parameters and to investigate the system effectiveness operating under various inlet air conditions. (author)

Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

Science.gov (United States)

Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

2012-02-01

Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality.

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.

Hybrid radiator cooling system

Science.gov (United States)

France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

2016-03-15

A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

Cooling with solar energy - Tests in practice passed

International Nuclear Information System (INIS)

Lainsecq de, M.

2004-01-01

This article discusses the use of solar energy to provide summer cooling. Starting with centuries-old methods of adiabatic cooling used in the southern valleys of the Grisons in Switzerland, various methods of using solar energy to generate cold are examined. The article mentions the increasing load being placed on electricity supplies by conventional cooling systems and describes two real-life installations that use solar energy to generate cold. The first installation described uses evacuated tube collectors to provide around 45,000 kilowatt-hours of energy for an office complex, of which one third is used in summer to generate cold. The second installation features flat-plate collectors and two absorption refrigeration machines. Financial and environmental balances are presented and discussed

Potential of district cooling in hot and humid climates

DEFF Research Database (Denmark)

Dominkovic, Dominik Franjo; Rashid, K. A. Bin Abdul; Romagnoli, A.

2017-01-01

Efficiently utilizing energy that is currently being wasted can significantly increase energy efficiency of the system, as well as reduce the carbon footprint. In hot climates with large cooling demands, excess waste heat can be utilized via absorption chillers to generate cold. Moreover, cold from...... liquefied natural gas gasification process can further provide energy source for meeting the cold demand. In order to connect the large sources of waste heat and cold energy with customers demanding the cold, a significant investment in district cooling grid is a necessity. In order to deal...

High temperature solar heating and cooling systems for different Mediterranean climates: Dynamic simulation and economic assessment

International Nuclear Information System (INIS)

Calise, Francesco

2012-01-01

The paper presents a dynamic model of an innovative solar heating and cooling system (SHC) based on the coupling of Parabolic Trough Collectors (PTC) with a double-stage LiBr-H 2 O absorption chiller; auxiliary energy for both heating and cooling is supplied by a biomass-fired heater. The system layout also includes a number of additional components such as: cooling tower, pumps, heat exchangers, etc. The consumption of non-renewable energy resources is only due to the small amount of electrical energy consumed by some auxiliary device. A case study is presented, in which the SHC provides space heating and cooling and domestic hot water for a small university hall, all year long. Both the SHC system and the building were dynamically simulated in TRNSYS. In order to evaluate the performance of the investigated system in various climatic conditions, the analyses were performed for seven Mediterranean cities in Italy, Spain, Egypt, France, Greece and Turkey. The analysis was also performed for a similar SHC in which the biomass heater was replaced by a gas-fired heater, in order to evaluate the influence of biomass to the overall system economic and energetic performance. In addition, a parametric analysis was performed in order to evaluate the sensitivity of the results, when varying some of the main design and operating parameters, such as: collector field area, tank volume and set-point temperatures. The results showed that the SHC system layout investigated can be competitive for the majority of the locations analysed, although the economic profitability is higher for the hottest climates. - Highlights: → In the high temperature SHC system the auxiliary heat is provided by biomass. → The energetic performance of the system is excellent during the summer. → In the winter the system suffers of the low beam radiation incident on the PTC. → The Simple Pay Back Period is encouraging, particularly in case of public funding. → An increase of the solar field

Thermal Hydraulic Analysis of RPV Support Cooling System for HTGR

International Nuclear Information System (INIS)

Min Qi; Wu Xinxin; Li Xiaowei; Zhang Li; He Shuyan

2014-01-01

Passive safety is now of great interest for future generation reactors because of its reduction of human interaction and avoidance of failures of active components. reactor pressure vessel (RPV) support cooling system (SCS) for high temperature gas-cooled reactor (HTGR) is a passive safety system and is used to cool the concrete seats for the four RPV supports at its bottom. The SCS should have enough cooling capacity to ensure the temperature of the concrete seats for the supports not exceeding the limit temperature. The SCS system is composed of a natural circulation water loop and an air cooling tower. In the water loop, there is a heat exchanger embedded in the concrete seat, heat is transferred by thermal conduction and convection to the cooling water. Then the water is cooled by the air cooler mounted in the air cooling tower. The driving forces for water and air are offered by the density differences caused by the temperature differences. In this paper, the thermal hydraulic analysis for this system was presented. Methods for decoupling the natural circulation and heat transfer between the water loop and air flow were introduced. The operating parameters for different working conditions and environment temperatures were calculated. (author)

The performance of a temperature cascaded cogeneration system producing steam, cooling and dehumidification

KAUST Repository

Myat, Aung

2013-02-01

This paper discusses the performance of a temperature-cascaded cogeneration plant (TCCP), equipped with an efficient waste heat recovery system. The TCCP, also called a cogeneration system, produces four types of useful energy-namely, (i) electricity, (ii) steam, (iii) cooling and (iv) dehumidification-by utilizing single fuel source. The TCCP comprises a Capstone C-30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste-heat-activated devices, namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption chiller and (iv) a multi-bed desiccant dehumidifier. The performance analysis was conducted under different operation conditions such as different exhaust gas temperatures. It was observed that energy utilization factor could be as high as 70% while fuel energy saving ratio was found to be 28%. © 2013 Desalination Publications.

Replacement inhibitors for tank farm cooling coil systems

International Nuclear Information System (INIS)

Hsu, T.C.

1995-01-01

Sodium chromate has been an effective corrosion inhibitor for the cooling coil systems in Savannah River Site (SRS) waste tanks for over 40 years. Due to their age and operating history, cooling coils occasionally fail allowing chromate water to leak into the environment. When the leaks spill 10 lbs. or more of sodium chromate over a 24-hr period, the leak incidents are classified as Unusual Occurrences (UO) per CERCLA (Comprehensive Environmental Response, Compensation and Liability Act). The cost of reporting and cleaning up chromate spills prompted High Level Waste Engineering (HLWE) to initiate a study to investigate alternative tank cooling water inhibitor systems and the associated cost of replacement. Several inhibitor systems were investigated as potential alternatives to sodium chromate. All would have a lesser regulatory impact, if a spill occurred. However, the conversion cost is estimated to be $8.5 million over a period of 8 to 12 months to convert all 5 cooling systems. Although each of the alternative inhibitors examined is effective in preventing corrosion, there is no inhibitor identified that is as effective as chromate. Assuming 3 major leaks a year (the average over the past several years), the cost of maintaining the existing inhibitor was estimated at $0.5 million per year. Since there is no economic or regulatory incentive to replace the sodium chromate with an alternate inhibitor, HLWE recommends that sodium chromate continue to be used as the inhibitor for the waste tank cooling systems

Turbine airfoil with an internal cooling system having vortex forming turbulators

Science.gov (United States)

Lee, Ching-Pang

2014-12-30

A turbine airfoil usable in a turbine engine and having at least one cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels having a plurality of turbulators protruding from an inner surface and positioned generally nonorthogonal and nonparallel to a longitudinal axis of the airfoil cooling channel. The configuration of turbulators may create a higher internal convective cooling potential for the blade cooling passage, thereby generating a high rate of internal convective heat transfer and attendant improvement in overall cooling performance. This translates into a reduction in cooling fluid demand and better turbine performance.

Lamination cooling system formation method

Science.gov (United States)

Rippel, Wally E [Altadena, CA; Kobayashi, Daryl M [Monrovia, CA

2009-05-12

An electric motor, transformer or inductor having a cooling system. A stack of laminations have apertures at least partially coincident with apertures of adjacent laminations. The apertures define straight or angled cooling-fluid passageways through the lamination stack. Gaps between the adjacent laminations are sealed by injecting a heat-cured sealant into the passageways, expelling excess sealant, and heat-curing the lamination stack. Manifold members adjoin opposite ends of the lamination stack, and each is configured with one or more cavities to act as a manifold to adjacent passageway ends. Complex manifold arrangements can create bidirectional flow in a variety of patterns.

Liquid Cooling System for CPU by Electroconjugate Fluid

Directory of Open Access Journals (Sweden)

Yasuo Sakurai

2014-06-01

Full Text Available The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less.

Exergy analysis of a combined vapor power cycle and boiler flue gas driven double effect water–LiBr absorption refrigeration system

International Nuclear Information System (INIS)

Talukdar, K.; Gogoi, T.K.

2016-01-01

Highlights: • A combined vapor power and double effect water–LiBr absorption refrigeration system is proposed. • The flue gas of the power cycle boiler is the heat source for the double effect refrigeration system. • Energy and exergy analyses are performed to evaluate performance of the combined system. • Effect of high pressure generator temperature on combined system performance is highlighted. • Comparison is provided with a single effect absorption system integrated combined system. - Abstract: A combined vapor power cycle (PC) and double effect water–LiBr absorption refrigeration system (ARS) is proposed in this study. The boiler leaving flue gas of the PC is the heat source for the high pressure generator (HPG) of the double effect ARS. Exergy analysis of the proposed system is performed to show the performance variation of both the topping PC and the bottoming ARS with changing HPG temperature from 120 °C to 150 °C. Further the performance of double effect ARS integrated combined power and cooling system is compared with a similar system integrated with a single effect ARS. HPG temperature of the double effect ARS and generator temperature of the single effect ARS are considered as 120 °C and 80 °C respectively. Results show that the power and efficiency of the topping PC decreases with HPG temperature due to reduction in steam generation rate in the boiler. COP and exergy efficiency of the double effect ARS also reduces with increasing HPG temperature. The irreversible losses in the PC components decrease while the total irreversibility of the combined power and cooling system increases with HPG temperature due to increase in exergy loss with the HPG leaving flue gas and irreversibility of the ARS components. PC performance does not vary much due to replacement of the double effect ARS with the single effect ARS, however higher COP and exergy efficiency of the double effect system are achieved with much lower irreversible losses in the

Description and cost analysis of a deluge dry/wet cooling system.

Energy Technology Data Exchange (ETDEWEB)

Wiles, L.E.; Bamberger, J.A.; Braun, D.J.; Braun, D.J.; Faletti, D.W.; Willingham, C.E.

1978-06-01

The use of combined dry/wet cooling systems for large base-load power plants offers the potential for significant water savings as compared to evaporatively cooled power plants and significant cost savings in comparison to dry cooled power plants. The results of a detailed engineering and cost study of one type of dry/wet cooling system are described. In the ''deluge'' dry/wet cooling method, a finned-tube heat exchanger is designed to operate in the dry mode up to a given ambient temperature. To avoid the degradation of performance for higher ambient temperatures, water (the delugeate) is distributed over a portion of the heat exchanger surface to enhance the cooling process by evaporation. The deluge system used in this study is termed the HOETERV system. The HOETERV deluge system uses a horizontal-tube, vertical-plate-finned heat exchanger. The delugeate is distributed at the top of the heat exchanger and is allowed to fall by gravity in a thin film on the face of the plate fin. Ammonia is used as the indirect heat transfer medium between the turbine exhaust steam and the ambient air. Steam is condensed by boiling ammonia in a condenser/reboiler. The ammonia is condensed in the heat exchanger by inducing airflow over the plate fins. Various design parameters of the cooling system have been studied to evaluate their impact on the optimum cooling system design and the power-plant/utility-system interface. Annual water availability was the most significant design parameter. Others included site meteorology, heat exchanger configuration and air flow, number and size of towers, fan system design, and turbine operation. It was concluded from this study that the HOETERV deluge system of dry/wet cooling, using ammonia as an intermediate heat transfer medium, offers the potential for significant cost savings compared with all-dry cooling, while achieving substantially reduced water consumption as compared to an evaporatively cooled power plant. (LCL)

Cooling the intact loop of primary heat transport system using shut down cooling system after events such as LOCA

International Nuclear Information System (INIS)

Icleanu, D.L.

2015-01-01

The purpose of this paper is to model the Shutdown Cooling System operation for CANDU 6 NPP in case of LOCA accident, using Flowmaster calculation code by delimiting models and setting calculation assumptions and input data for hydraulic analysis, and and assumptions for the calculation and input data for calculating thermal performance check heat exchangers that are part of this system. The Flowmaster V7.8 code provides system engineers with a powerful tool to investigate pressure surge, pressure drop, flow rate, temperature and system response times - removing the uncertainty from fluid flow systems. Flowmaster is a one-dimensional thermal-hydraulic calculation code for dimensioning, analyzing and verifying the pipeline systems operation. Each component of Flowmaster is a mathematical model for an equipment that is included in a facility. Selected components are connected via nodes in order to form a network, which constitutes a computerized model of the system. Analyzing the parameters of the cooling system for all cooling processes considered it was found that the values obtained for thermal-hydraulic parameters, as well as the duration up to reaching specified limits fall within the design values of the system. This document is made up of an abstract and the slides of the presentation

The optimal operation of cooling tower systems with variable-frequency control

Science.gov (United States)

Cao, Yong; Huang, Liqing; Cui, Zhiguo; Liu, Jing

2018-02-01

This study investigates the energy performance of chiller and cooling tower systems integrated with variable-frequency control for cooling tower fans and condenser water pumps. With regard to an example chiller system serving an office building, Chiller and cooling towers models were developed to assess how different variable-frequency control methods of cooling towers fans and condenser water pumps influence the trade-off between the chiller power, pump power and fan power under various operating conditions. The matching relationship between the cooling tower fans frequency and condenser water pumps frequency at optimal energy consumption of the system is introduced to achieve optimum system performance.

Improvement of Cooling Performance of a Compact Thermoelectric Air Conditioner Using a Direct Evaporative Cooling System

Science.gov (United States)

Tipsaenporm, W.; Lertsatitthanakorn, C.; Bubphachot, B.; Rungsiyopas, M.; Soponronnarit, S.

2012-06-01

This paper presents the results of tests carried out to investigate the potential application of a direct evaporative cooling (DEC) system for improving the performance of a compact thermoelectric (TE) air conditioner. The compact TE air conditioner is composed of three TE modules. The cold and hot sides of the TE modules were fixed to rectangular fin heat sinks. The DEC system produced cooling air that was used to assist the release of heat from the heat sinks at the hot side of the TE modules. The results showed that the cooling air dry bulb temperature from the DEC system achieved drops of about 5.9°C in parallel with about a 33.4% rise in relative humidity. The cooling efficiency of the DEC system varies between 72.1% and 81.5%. It increases the cooling capacity of the compact TE air conditioner from 53.0 W to 74.5 W. The 21.5 W (40.6%) increase represents the difference between the compact air conditioner operating with ambient air flowing through the TE module's heat sinks, and the compact air conditioner operating with the cooler air from the DEC system flowing through the TE module's heat sinks. In both scenarios, electric current of 4.5 A was supplied to the TE modules. It also has been experimentally proven that the coefficient of performance (COP) of the compact TE air conditioner can be improved by up to 20.9% by incorporating the DEC system.

A systemic approach for optimal cooling tower operation

International Nuclear Information System (INIS)

Cortinovis, Giorgia F.; Paiva, Jose L.; Song, Tah W.; Pinto, Jose M.

2009-01-01

The thermal performance of a cooling tower and its cooling water system is critical for industrial plants, and small deviations from the design conditions may cause severe instability in the operation and economics of the process. External disturbances such as variation in the thermal demand of the process or oscillations in atmospheric conditions may be suppressed in multiple ways. Nevertheless, such alternatives are hardly ever implemented in the industrial operation due to the poor coordination between the utility and process sectors. The complexity of the operation increases because of the strong interaction among the process variables. In the present work, an integrated model for the minimization of the operating costs of a cooling water system is developed. The system is composed of a cooling tower as well as a network of heat exchangers. After the model is verified, several cases are studied with the objective of determining the optimal operation. It is observed that the most important operational resources to mitigate disturbances in the thermal demand of the process are, in this order: the increase in recycle water flow rate, the increase in air flow rate and finally the forced removal of a portion of the water flow rate that enters the cooling tower with the corresponding make-up flow rate.

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

Simulation of an active cooling system for photovoltaic modules

International Nuclear Information System (INIS)

Abdelhakim, Lotfi

2016-01-01

Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

Simulation of an active cooling system for photovoltaic modules

Energy Technology Data Exchange (ETDEWEB)

Abdelhakim, Lotfi [Széchenyi István University of Applied Sciences, Department of Mathematics, P.O.Box 701, H-9007 Győr (Hungary)

2016-06-08

Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

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.

Study on performance prediction and energy saving of indirect evaporative cooling system

Energy Technology Data Exchange (ETDEWEB)

Yoo, Seong Yeon; Kim, Tae Ho; Kim, Myung Ho [Dept. of Mechanical Design Engineering, Chungnam National University, Daejeon (Korea, Republic of)

2015-09-15

The purpose of this study is to predict the performance of an indirect evaporative cooling system, and to evaluate its energy saving effect when applied to the exhaust heat recovery system of an air-handling unit. We derive the performance correlation of the indirect evaporative cooling system using a plastic heat exchanger based on experimental data obtained in various conditions. We predict the variations in the performance of the system for various return and outdoor air conditioning systems using the obtained correlation. We also analyze the energy saving of the system realized by the exhaust heat recovery using the typical meteorological data for several cities in Korea. The average utilization rate of the sensible cooling system for the exhaust heat recovery is 44.3% during summer, while that of the evaporative cooling system is 96.7%. The energy saving of the evaporative cooling system is much higher compared to the sensible cooling system, and was about 3.89 times the value obtained in Seoul.

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)

Shock and vibration protection of submerged jet impingement cooling systems: Theory and experiment

International Nuclear Information System (INIS)

Haji Hosseinloo, Ashkan; Tan, Siow Pin; Yap, Fook Fah; Toh, Kok Chuan

2014-01-01

In the recent years, advances in high power density electronics and computing systems have pushed towards more advanced thermal management technologies and higher-capacity cooling systems. Among different types of cooling systems, jet impingement technology has gained attention and been widely used in different industries for its adaptability, cooling uniformity, large heat capacity, and ease of its localization. However, these cooling systems may not function properly in dynamically harsh environment inherent in many applications such as land, sea and air transportation. In this research article, a novel double-chamber jet impingement cooling system is fabricated and its performance is studied in harsh environment. Using the authors' previous studies, isolators with optimum properties are selected to ruggedize the chassis containing the cooling chamber against shock and random vibration. Experiments are conducted on both hard-mounted and isolated chassis and the cooling performance of the system is assessed using the inlet, and impingement surface temperatures of the cooling chamber. The experimental results show the isolation system prevents any failure that otherwise would occur, and also does not compromise the thermal performance of the system. - Highlights: • A novel double-chamber jet impingement cooling system was designed and fabricated. • Comprehensive set of random vibration and shock tests are conducted. • The isolation system proved to protect the cooling system properly against mechanical failure. • Cooling system performance was not significantly affected by the input random vibration and shock

Adsorption Cooling System Using Metal-Impregnated Zeolite-4A

Directory of Open Access Journals (Sweden)

Somsuk Trisupakitti

2016-01-01

Full Text Available The adsorption cooling systems have been developed to replace vapor compression due to their benefits of being environmentally friendly and energy saving. We prepared zeolite-4A and experimental cooling performance test of zeolite-water adsorption system. The adsorption cooling test-rig includes adsorber, evaporator, and condenser which perform in vacuum atmosphere. The maximum and minimum water adsorption capacity of different zeolites and COP were used to assess the performance of the adsorption cooling system. We found that loading zeolite-4A with higher levels of silver and copper increased COP. The Cu6%/zeolite-4A had the highest COP at 0.56 while COP of zeolite-4A alone was 0.38. Calculating the acceleration rate of zeolite-4A when adding 6% of copper would accelerate the COP at 46%.

Systemic Absorption of Nanomaterials by Oral Exposure

DEFF Research Database (Denmark)

Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister

This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

Energy and water management in evaporative cooling systems in Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Kassem, Abdel-wahab S. (Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Hassa (Saudi Arabia))

1994-11-01

A mathematical model was developed to estimate water evaporation rate, airflow rate and cooling effect in an evaporative cooling system for farm structures. The model was only applied to evaporative cooling systems for greenhouses. The effect of ambient air temperature, solar radiation and system efficiency on water evaporation rate, airflow rate and the resulting cooling effect were studied. Generally, water flow rate and air flow rate are adjusted based on daily maximum temperature. However, a substantial saving in energy and water consumption in the cooling system would be achieved by regulating water flow rate and air flow rate to follow the diurnal variation on temperature. Improving the cooling efficiency and covering the roof of the greenhouse with an external shading would save an appreciable amount of energy and water consumption. The model could also be applied to other farm structures such as animal shelters

A second law analysis and entropy generation minimization of an absorption chiller

KAUST Repository

Myat, Aung; Thu, Kyaw; Kim, Youngdeuk; Chakraborty, Anutosh; Chun, Wongee; Ng, K. C.

2011-01-01

This paper presents performance analysis of absorption refrigeration system (ARS) using an entropy generation analysis. A numerical model predicts the performance of absorption cycle operating under transient conditions along with the entropy generation computation at assorted heat source temperatures, and it captures also the dynamic changes of lithium bromide solution properties such as concentration, density, vapor pressure and overall heat transfer coefficients. An optimization tool, namely the genetic algorithm (GA), is used as to locate the system minima for all defined domain of heat source and cooling water temperatures. The analysis shows that minimization of entropy generation the in absorption cycle leads to the maximization of the COP. © 2011 Elsevier Ltd. All rights reserved.