WorldWideScience

Sample records for absorption refrigeration systems

  1. Compression-absorption cascade refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Sieres, Jaime; Vazquez, Manuel [Area de Maquinas y Motores Termicos, Escuela Tecnica Superior de Ingenieros Industriales, Universidade de Vigo, Campus Lagoas-Marcosende, 9, 36200 Vigo (Spain)

    2006-04-01

    This paper describes the study carried out to analyse a refrigeration system in cascade with a compression system at the low temperature stage and an absorption system at the high temperature stage to generate cooling at low temperatures, as well as the possibility of powering it by means of a cogeneration system. CO{sub 2} and NH{sub 3} have been considered as refrigerants in the compression stage and the pair NH{sub 3}-H{sub 2}O in the absorption stage. The analysis has been realized by means of a mathematical model of the refrigeration system implemented in a computer program and taking into account the characteristic operating conditions of a cogeneration system with gas engines. The paper presents the results obtained regarding the performance of the refrigeration system and the adaptability between the power requirements of the refrigeration system and the power supplied by the cogeneration system taking into account the present Spanish Regulations about the use of cogeneration systems. [Author].

  2. COMPARISON OF ENERGY AND EXERGY EFFICIENCIES OF ABSORPTION REFRIGERATION SYSTEM WITH MECHANICAL COMPRESSION REFRIGERATION SYSTEM

    OpenAIRE

    YAKAR, Gülay; KARABACAK, Rasim; Burçin DEDA ALTAN

    2005-01-01

    In this study, energy and exergy analysis of absorption refrigeration system using LiBr- water and mechanical compression refrigeration system using R134-a were performed at different evaporation temperatures. The results are presented in tables and figures.

  3. COMPARISON OF ENERGY AND EXERGY EFFICIENCIES OF ABSORPTION REFRIGERATION SYSTEM WITH MECHANICAL COMPRESSION REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Gülay YAKAR

    2005-02-01

    Full Text Available In this study, energy and exergy analysis of absorption refrigeration system using LiBr- water and mechanical compression refrigeration system using R134-a were performed at different evaporation temperatures. The results are presented in tables and figures.

  4. Analysis of crystallization risk in double effect absorption refrigeration systems

    International Nuclear Information System (INIS)

    Absorption refrigeration systems are an alternative to vapor compression ones in cooling and refrigeration applications. In comparison with single effect absorption units, double effect systems have improved performance. Also, they are more available commercially than the other multi effect absorption cycles. An important challenge in the operation of such systems is the possibility of crystallization within them. This is especially true in developing air-cooled absorption systems, which are attractive because cooling tower and associated installation and maintenance issues can be avoided. Therefore, distinguishing the working conditions that may cause crystallization can be useful in the design and control of these systems. In this paper a computational model has been developed to study and compare the effects of operating parameters on crystallization phenomena in three classes of double effect lithium bromide-water absorption refrigeration systems (series, parallel and reverse parallel) with identical refrigeration capacities. It is shown that the range of operating conditions without crystallization risks in the parallel and the reverse parallel configurations is wider than those of the series flow system. - Highlights: → We study crystallization of double effect absorption refrigeration systems. → We consider series, parallel and reverse parallel cycles. → We study the effect of operating conditions on crystallization. → We choose optimum distribution ratio for parallel and reverse parallel systems. → Crystallization possibility is low in parallel and reverse parallel cycles.

  5. 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.

  6. Absorber-evaporator unit for an absorption-refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Hallatt, R.J.; Rorschach, R.L.

    1965-01-26

    This low temperature absorption-refrigeration system uses an absorber-evaporator. A conduit is connected between the upper portion of the absorber and the lower portion of the evaporator to conduct inert gas from the absorber to the evaporator. A second conduit connects the upper portion of the evaporator to the lower portion of the absorber and a blower in this conduit circulates the inert gas through the closed system. By placing the blower between the evaporator ad the absorber, the pressure in the evaporator is maintained at a minimum so that the working temperature is as low as possible. The medium to be cooled by the refrigerant is circulated through a heat exchanger located within the evaporator, whereby the latent heat of vaporization of the liquid refrigerant is employed to cool the outside medium. (2 claims)

  7. Energy and exergy analyses of the diffusion absorption refrigeration system

    International Nuclear Information System (INIS)

    This paper describes the thermodynamic analyses of a DAR (diffusion absorption refrigeration) cycle. The experimental apparatus is set up to an ammonia–water DAR cycle with helium as the auxiliary inert gas. A thermodynamic model including mass, energy and exergy balance equations are presented for each component of the DAR cycle and this model is then validated by comparison with experimental data. In the thermodynamic analyses, energy and exergy losses for each component of the system are quantified and illustrated. The systems' energy and exergy losses and efficiencies are investigated. The highest energy and exergy losses occur in the solution heat exchanger. The highest energy losses in the experimental and theoretical analyses are found 25.7090 W and 25.4788 W respectively, whereas those losses as to exergy are calculated 13.7933 W and 13.9976 W. Although the values of energy efficiencies obtained from both the model and experimental studies are calculated as 0.1858, those values, in terms of exergy efficiencies are found 0.0260 and 0.0356. - Highlights: • The diffusion absorption refrigerator system is designed manufactured and tested. • The energy and exergy analyses of the system are presented theoretically and experimentally. • The energy and exergy losses are investigated for each component of the system. • The highest energy and exergy losses occur in the solution heat exchanger. • The energy and the exergy performances are also calculated

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

    International Nuclear Information System (INIS)

    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][BF4] (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][BF4] showed the best performance of COP. ► The effects of high viscosity ILs on the system performance are not significant.

  9. Automotive exhaust gas flow control for an ammonia–water absorption refrigeration system

    International Nuclear Information System (INIS)

    A considerable part of the energy generated by an automotive internal combustion engine is wasted as heat in the exhaust system. This wasted heat could be recovered and applied to power auxiliary systems in a vehicle, contributing to its overall energy efficiency. In the present work, the experimental analysis of an absorption refrigeration system was performed. The exhaust system of an automotive internal combustion engine was connected to the generator element of an absorption refrigeration system. The performance of the absorption refrigerator was evaluated as a function of the supplied heat. The use of a control strategy for the engine exhaust gas mass flow rate was implemented to optimize the system. Exhaust gas flow was controlled by step-motor actuated valves commanded by a microcontroller in which a proportional-integral control scheme was implemented. Information such as engine torque, speed, key temperatures in the absorption cycle, as well as internal temperatures of the refrigerator was measured in a transient regime. The results indicated that the refrigeration system exhibited better performance when the amount of input heat is controlled based on the temperature of the absorption cycle generator. It was possible to conclude that, by dynamically controlling the amount of input heat, the utilisation range of the absorption refrigeration system powered by exhaust gas heat could be expanded in order to incorporate high engine speed operating conditions. - Highlights: •An absorption refrigerator was driven by automotive exhaust gas heat. •A system for controlling the refrigeration system heat input was developed. •Excessive exhaust gas heat leads to ineffective operation of the refrigerator. •Control of refrigerator's generator temperature led to better performance. •The use of exhaust gas was possible for high engine speeds

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

    International Nuclear Information System (INIS)

    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

  11. Theoretical Study of New Combined Absorption-Ejector Refrigeration System

    Science.gov (United States)

    Abed, A. M.; Sopian, K.; Alghoul, M. A.; Al-Shamani, A. N.; Ruslan, M. H.; Mat, S.

    2015-09-01

    An improved system of the new combined single stage absorption cycle operated with NH3/H2O as working fluid was performed. In order to enhance performance the cycle a new configuration of absorption system was utilized. The performances of two configurations of the combined absorption cycle were compared; a) with common solution heat exchanger and b) divided the streamline of solution heat exchanger to recover the internal heat. Based on the analysis, it has been shown that the second configuration a significant reduction of the required generator and absorber loads by about 20% and 17% respectively, with increased coefficient of performance (COP) about 12% compared to the first configuration. This improvement in the overall COP is found due to improve energy utilization efficiency significantly.

  12. Thermodynamic analysis and comparison of combined ejector–absorption and single effect absorption refrigeration systems

    International Nuclear Information System (INIS)

    Highlights: • Ammonia/LiNO3 and ammonia/NaSCN combined ejector–absorption refrigeration cycles are analyzed. • The performance of combined cycles is compared to that of single effect cycles. • Ejector is used to facilitate pressure recovery of the absorber and improve mixing. • For low generator temperatures combined cycles have better performance. • Influence of various operating parameters on performance of cycles is investigated. - Abstract: Alternatives to ammonia/water absorption refrigeration cycles that have no need for purification include ammonia/LiNO3 and ammonia/NaSCN cycles. Similar to the other absorption refrigeration cycles they have low coefficients of performance and exergy efficiencies at low generator temperatures. Combined single effect cycles can reduce this problem. In these cycles the solution expansion valve is replaced with an ejector to allow for pressure recovery from the absorber and to enhance mixing of the weak solution and refrigerant vapor from the evaporator. Simulations are used to examine the influence of various operating parameters on performance and the possibility of crystallization in these cycles, and to compare their performances with single effect cycles. It is shown that the combined cycles have better performance than single effect ones at low generator temperatures

  13. Materials and systems developments on solid absorption refrigeration with CaCl2·xNH3

    International Nuclear Information System (INIS)

    The paper presents some developments on the stabilization of CaCl2 for use as a solid absorption material in refrigerators, the development of a refrigerator using the stabilized salt, and computer modelling of the refrigerator system. (author). 8 refs, 19 figs

  14. Modeling And Experimental Analysis Of Generator In Vapour Absorption Refrigeration System

    Directory of Open Access Journals (Sweden)

    Christy V Vazhappilly

    2013-09-01

    Full Text Available A breadboard prototype of an absorption system for refrigeration using heat from the exhaust-gases is to be designed, built and tested. In the commercial vapour absorption refrigeration system a heating coil generator system has been employed to vaporize the ammonia efrigerant. In the present work, the heating coil generator system has been replaced by the frame plate type heat exchanger. The exhaust gases from the IC engine have been utilized to vaporize the ammonia refrigerant. The available heat in the exhaust gases has to be estimated based on actual I.C-Engine driving cycles. The frame plate type heat exchanger has to be modeled and flow analysis inside the heat exchanger has to be analyzed. In addition, the recoverable energy of the exhaust gases is to be analyzed for representative Internal Combustion Engine.

  15. Application of waste heat powered absorption refrigeration system to the LNG recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Kalinowski, Paul; Hwang, Yunho; Radermacher, Reinhard [Center for Environmental Energy Engineering, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742 (United States); Al Hashimi, Saleh; Rodgers, Peter [The Petroleum Institute, Abu Dhabi (United Arab Emirates)

    2009-06-15

    The recovery process of the liquefied natural gas requires low temperature cooling, which is typically provided by the vapor compression refrigeration systems. The usage of an absorption refrigeration system powered by waste heat from the electric power generating gas turbine could provide the necessary cooling at reduced overall energy consumption. In this study, a potential replacement of propane chillers with absorption refrigeration systems was theoretically analyzed. From the analysis, it was found that recovering waste heat from a 9 megawatts (MW) electricity generation process could provide 5.2 MW waste heat produced additional cooling to the LNG plant and save 1.9 MW of electricity consumption. Application of the integrated cooling, heating, and power is an excellent energy saving option for the oil and gas industry. (author)

  16. Second law comparison of single effect and double effect vapour absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Gomri, Rabah [Engineering Faculty, Department of Genie Climatique, Constantine University, 25000 Constantine (Algeria)

    2009-05-15

    In this paper a comparative study between single effect and double effect absorption refrigeration systems with identical cold output is carried out. Simulation results were used to study the influence of the various operating parameters on the performance coefficient, the thermal loads of the components, exergetic efficiency (rational efficiency) and the total change in exergy of the two systems. It is concluded that the COP of double effect system is approximately twice the COP of single effect system but the exergetic efficiency of double effect system increase slightly compared to the exergetic efficiency of single effect system. It is found that for each condenser and evaporator temperature, there is an optimum generator temperature where the total change in exergy of the single effect and double effect absorption refrigeration systems is minimum. At this point the COP and exergetic efficiency of the systems become maximum. In this study and when the evaporation temperature is varied from 4 C to 10 C, condenser and absorber temperatures are varied from 33 C to 39 C and generator (HPG) temperature is varied from 60 C to 190 C the maximum COP values of the single effect refrigeration systems are in the range of 0.73-0.79 and for double effect refrigeration systems are in the range of 1.22-1.42. The maximum exergetic efficiency values of the single effect refrigeration systems are in the range of 12.5-23.2% and for double effect refrigeration systems are in the range of 14.3-25.1%. (author)

  17. Quantum-enhanced absorption refrigerators.

    Science.gov (United States)

    Correa, Luis A; Palao, José P; Alonso, Daniel; Adesso, Gerardo

    2014-01-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

  18. Solar Absorption Refrigeration System for Air-Conditioning of a Classroom Building in Northern India

    Science.gov (United States)

    Agrawal, Tanmay; Varun; Kumar, Anoop

    2015-10-01

    Air-conditioning is a basic tool to provide human thermal comfort in a building space. The primary aim of the present work is to design an air-conditioning system based on vapour absorption cycle that utilizes a renewable energy source for its operation. The building under consideration is a classroom of dimensions 18.5 m × 13 m × 4.5 m located in Hamirpur district of Himachal Pradesh in India. For this purpose, cooling load of the building was calculated first by using cooling load temperature difference method to estimate cooling capacity of the air-conditioning system. Coefficient of performance of the refrigeration system was computed for various values of strong and weak solution concentration. In this work, a solar collector is also designed to provide required amount of heat energy by the absorption system. This heat energy is taken from solar energy which makes this system eco-friendly and sustainable. A computer program was written in MATLAB to calculate the design parameters. Results were obtained for various values of solution concentrations throughout the year. Cost analysis has also been carried out to compare absorption refrigeration system with conventional vapour compression cycle based air-conditioners.

  19. Seven-effect absorption refrigeration

    Science.gov (United States)

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  20. NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • It addresses the size and cost estimation of cascaded refrigeration system. • Cascaded system is a promising decarburizing and energy efficient technology. • Second law analysis is carried out with modified Gouy-Stodola equation. • The total annual cost of plant operation is optimized in present work. - Abstract: This paper addresses the size and cost estimation of vapor compression–absorption cascaded refrigeration system (VCACRS) for water chilling application taking R410a and water–LiBr as refrigerants in compression and absorption section respectively which can help the design engineers in manufacturing and experimenting on such kind of systems. The main limitation in the practical implementation of VCACRS is its size and cost which are optimized in the present work by implementing Direct Search Method in non-linear programming (NLP) mathematical model of VCACRS. The main objective of optimization is to minimize the total annual cost of system which comprises of costs of exergy input and capital costs in monetary units. The appropriate set of decision variables (temperature of evaporator, condenser, generator, absorber, cascade condenser, degree of overlap and effectiveness of solution heat exchanger) minimizes the total annual cost of VCACRS by 11.9% with 22.4% reduction in investment cost at the base case whereas the same is reduced by 7.5% with 11.7% reduction in investment cost with reduced rate of interest and increased life span and period of operation. Optimization results show that the more investment cost in later case is well compensated through the performance and operational cost of the system. In the present analysis, optimum cascade condensing temperature is a strong function of period of operation and capital recovery factor. The cascading of compression and absorption systems becomes attractive for lower rate of interest and increase life span and operational period

  1. Optimization of operation of energy supply systems with co-generation and absorption refrigeration

    Directory of Open Access Journals (Sweden)

    Stojiljković Mirko M.

    2012-01-01

    Full Text Available Co-generation systems, together with absorption refrigeration and thermal storage, can result in substantial benefits from the economic, energy and environmental point of view. Optimization of operation of such systems is important as a component of the entire optimization process in pre-construction phases, but also for short-term energy production planning and system control. This paper proposes an approach for operational optimization of energy supply systems with small or medium scale co-generation, additional boilers and heat pumps, absorption and compression refrigeration, thermal energy storage and interconnection to the electric utility grid. In this case, the objective is to minimize annual costs related to the plant operation. The optimization problem is defined as mixed integer nonlinear and solved combining modern stochastic techniques: genetic algorithms and simulated annealing with linear programming using the object oriented “ESO-MS” software solution for simulation and optimization of energy supply systems, developed as a part of this research. This approach is applied to optimize a hypothetical plant that might be used to supply a real residential settlement in Niš, Serbia. Results are compared to the ones obtained after transforming the problem to mixed 0-1 linear and applying the branch and bound method.

  2. The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

    Directory of Open Access Journals (Sweden)

    Sun Lunan

    2016-01-01

    Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

  3. A Cooling System for an Automobile Based on Vapour Absorption Refrigeration Cycle Using Waste Heat of an Engine.

    Directory of Open Access Journals (Sweden)

    Satish K. Maurya

    2014-03-01

    Full Text Available Now a days the air conditioning system of cars is mainly uses “Vapour Compression Refrigerant System” (VCRS which absorbs and removes heat from the interior of the car that is the space to be cooled and rejects the heat to atmosphere. In vapour compression refrigerant system, the system utilizes power from engine shaft as the input power to drive the compressor of the refrigeration system, hence the engine has to produce extra work to run the compressor of the refrigerating system utilizing extra amount of fuel. This loss of power of the vehicle for refrigeration can be neglected by utilizing another refrigeration system i.e. a “Vapour Absorption Refrigerant System”. As well known thing about VAS that these machines required low grade energy for operation. Hence in such types of system, a physicochemical process replaces the mechanical process of the Vapour Compression Refrigerant System by using energy in the form of heat rather than mechanical work. This heat obtained from the exhaust of high power internal combustion engines.

  4. Thermodynamic Analysis of an Absorption/Compression Refrigeration System Using Geothermal Energy

    Directory of Open Access Journals (Sweden)

    L. Kairouani

    2005-01-01

    Full Text Available This article presents the potential use and exploration of geothermal energy for cooling applications using a combined absorption/compression system. The considered system uses R134a for the compression part and the cool water-ammonia for the absorption part of the installation. The geothermal temperature source is in the range 343-349K, the condensation temperature is 308 K, and in order to produce ice, the R134a evaporation temperature is 263 K. The COP is about 5.4. Therefore, based on the typical geothermal energy sources in Tunisia which present a refrigeration potential power of 9.1 MW, the quantity of ice that could be produced is about 82 tons per hour. The greenhouse gas emissions should thus be reduced by about 5884 tons of CO2 per year, which represents (59%.

  5. Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

    International Nuclear Information System (INIS)

    Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

  6. Modelling and data validation for the energy analysis of absorption refrigeration systems

    OpenAIRE

    Martínez Maradiaga, David Estéfano

    2013-01-01

    Data validation and reconciliation techniques have been extensively used in the process industry to improve the data accuracy. These techniques exploit the redundancy in the measurements in order to obtain a set of adjusted measurements that satisfy the plant model. Nevertheless, not many applications deal with closed cycles with complex connectivity and recycle loops, as in absorption refrigeration cycles. This thesis proposes a methodology for the steady-state data validation of absorption ...

  7. Thermodynamic Investigation of Two-Stage Absorption Refrigeration System Connected by a Compressor

    Directory of Open Access Journals (Sweden)

    L. Kairouani

    2005-01-01

    Full Text Available The present work is to analyze a two-stage cycle based on the ammonia-water absorption system, with intermediate compression. The two generators of the system are heated by geothermal energy at low temperature. The study shows that this system makes it possible at lower generator temperature, under the limits permitted by the systems suggested up to now. For Tg = 335 K, Tc = Ta = 308 K and Te = 263 K, based on the electric consumption, the system efficiency is 8.2. The comparative study of the hybrid system and vapor compression systems shows the superiority of the proposed system. Supplied by the geothermal sources of the Tunisian south, the system makes it possible to obtain for a pilot geothermal station, a production of 75 tons of ice per day. The greenhouse gas emissions should thus be reduced by about 2.38 tons of CO2 per day. Therefore, based on the typical geothermal energy sources in Tunisia which present a global refrigeration potential of 4.4 MW, the daily quantity of ice that could be produced is about 865 tons. The greenhouse gas emissions should thus be reduced by about 10,000 tons of CO2 per year.

  8. Solar hybrid cooling system for high-tech offices in subtropical climate - Radiant cooling by absorption refrigeration and desiccant dehumidification

    Energy Technology Data Exchange (ETDEWEB)

    Fong, K.F., E-mail: bssquare@cityu.edu.hk [Building Energy and Environmental Technology Research Unit, School of Energy and Environment and Division of Building Science and Technology, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong (China); Chow, T.T.; Lee, C.K.; Lin, Z.; Chan, L.S. [Building Energy and Environmental Technology Research Unit, School of Energy and Environment and Division of Building Science and Technology, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong (China)

    2011-08-15

    Highlights: {yields} A solar hybrid cooling system is proposed for high-tech offices in subtropical climate. {yields} An integration of radiant cooling, absorption refrigeration and desiccant dehumidification. {yields} Year-round cooling and energy performances were evaluated through dynamic simulation. {yields} Its annual primary energy consumption was lower than conventional system up to 36.5%. {yields} The passive chilled beams were more energy-efficient than the active chilled beams. - Abstract: A solar hybrid cooling design is proposed for high cooling load demand in hot and humid climate. For the typical building cooling load, the system can handle the zone cooling load (mainly sensible) by radiant cooling with the chilled water from absorption refrigeration, while the ventilation load (largely latent) by desiccant dehumidification. This hybrid system utilizes solar energy for driving the absorption chiller and regenerating the desiccant wheel. Since a high chilled water temperature generated from the absorption chiller is not effective to handle the required latent load, desiccant dehumidification is therefore involved. It is an integration of radiant cooling, absorption refrigeration and desiccant dehumidification, which are powered up by solar energy. In this study, the application potential of the solar hybrid cooling system was evaluated for the high-tech offices in the subtropical climate through dynamic simulation. The high-tech offices are featured with relatively high internal sensible heat gains due to the intensive office electric equipment. The key performance indicators included the solar fraction and the primary energy consumption. Comparative study was also carried out for the solar hybrid cooling system using two common types of chilled ceilings, the passive chilled beams and active chilled beams. It was found that the solar hybrid cooling system was technically feasible for the applications of relatively higher cooling load demand. The annual

  9. A Cooling System for an Automobile Based on Vapour Absorption Refrigeration Cycle Using Waste Heat of an Engine.

    OpenAIRE

    Satish K. Maurya; Saurabh Awasthi

    2014-01-01

    Now a days the air conditioning system of cars is mainly uses “Vapour Compression Refrigerant System” (VCRS) which absorbs and removes heat from the interior of the car that is the space to be cooled and rejects the heat to atmosphere. In vapour compression refrigerant system, the system utilizes power from engine shaft as the input power to drive the compressor of the refrigeration system, hence the engine has to produce extra work to run the compressor of the refrigerating s...

  10. A comparative study on the GAX based absorption refrigeration systems: SGAX, GAXH and GAX-E

    International Nuclear Information System (INIS)

    In this paper, two GAX-ejector absorption refrigeration cycles are proposed and investigated thermodynamically. In the first cycle (GAX-E Model A), the ejector draws vapor from the evaporator and raises the absorber pressure. In the second combined cycle (GAX-E Model B), the ejector is used to raise the condenser pressure. The performances of these two cycles are compared with those of the standard GAX (SGAX) cycle and two different arrangements of the hybrid GAX (GAXH Model A and GAXH Model B) cycles at the same working conditions. The comparison is performed through parametric studies in which the effects of generator and evaporator temperatures as well as the degassing range on the first and second law efficiencies are investigated. It is found that the COP of GAX-E Model B cycle is higher than that of the SGAX cycle by up to 16.7%. The maximum second law efficiency for the GAX-E Model B cycle is only slightly lower than the highest efficiency value which is obtained for the GAXH Model B cycle. As there is no compressor in the GAX-E Model B cycle, this cycle can be recommended for refrigeration purposes from the viewpoint of thermo-economics. - Highlights: ► Five different configurations of GAX based cycles are compared thermodynamically. ► For all the GAX cycles the highest exergy destructions occur in the absorber–desorber. ► The COP of standard GAX cycle is enhanced by 16.7% when an ejector is employed.

  11. Thermoeconomic Analysis of a Single and Double-Effect LiBr/H2O Absorption Refrigeration System

    Directory of Open Access Journals (Sweden)

    Silvia Azucena Nebra

    2009-06-01

    Full Text Available

    The aim of this work is to carry out a thermoeconomic analysis of a single and double-effect LiBr/H2O absorption refrigeration system. The methodology of functional analysis with negentropy is used. The exergetic cost of the main product, the cooling cost, was calculated as a function of the exergy of the heat source. Two cases were analyzed for each system: the first considers a direct-fired system while the second considers a hot-water driven system for the single-effect system and a steam-driven system for the double effect system as part of a cogeneration system. As expected, the resultant exergetic cost of the main product was higher for the direct-fired system.

    • This paper is an updated version of a paper published in the ECOS'08 proceedings. 

  12. Thermodynamic Investigation of Two-Stage Absorption Refrigeration System Connected by a Compressor

    OpenAIRE

    L. Kairouani; E. Nehdi; R. B. Iffa

    2005-01-01

    The present work is to analyze a two-stage cycle based on the ammonia-water absorption system, with intermediate compression. The two generators of the system are heated by geothermal energy at low temperature. The study shows that this system makes it possible at lower generator temperature, under the limits permitted by the systems suggested up to now. For Tg = 335 K, Tc = Ta = 308 K and Te = 263 K, based on the electric consumption, the system efficiency is 8.2. The comparative study of th...

  13. Simultaneous heat and mass transfer of a packed distillation column for ammonia-water absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Sieres, Jaime; Vazquez, Manuel [Area de Maquinas y Motores Termicos, Escuela Tecnica Superior de Ingenieros Industriales de Vigo, Universidad de Vigo, Campus Lagoas-Marcosende, N circle 9, 36200, Vigo (Spain)

    2002-10-01

    This paper presents a study on the NH{sub 3}-H{sub 2}O distillation process using a packed column with liquid reflux from the condenser in an absorption refrigeration system. A differential mathematical model has been developed on the basis of mass and energy balances and the heat and mass transfer equations. A net molar flux between the liquid and vapour phases has been considered in the mass transfer equation, which obviates the need to assume equimolar counter-diffusion. The model equations have been solved using the finite-difference method. Results obtained for a specific application are shown, including parameter distributions along the column length. The influence of rectifying and stripping lengths, mass and heat transfer coefficients and volumetric heat rejection from the column, on the distillate ammonia concentration has been analysed. (authors)

  14. The Absorption Refrigerator as a Thermal Transformer

    Science.gov (United States)

    Herrmann, F.

    2009-01-01

    The absorption refrigerator can be considered a thermal transformer, that is, a device that is analogous to the electric transformer. The analogy is based on the correspondence between the extensive quantities, entropy and electric charge and the intensive variables, temperature and electric potential. (Contains 1 footnote and 6 figures.)

  15. 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.

  16. Solar heating and cooling with absorption refrigeration

    OpenAIRE

    Montlló Casabayó, Gerard

    2010-01-01

    This project is focused on solar heating and cooling installations that use solar thermal energy to produce heat for domestic hot water or space heating, and cooling for air conditioning through absorption refrigeration cycle. The first part of the project is a literature review of said technology. The main components of such installations are described and results and conclusions from existing installations are reviewed. The second part is focused on designing, modelling and simula...

  17. Application of a solar refrigeration system by absorption for the air conditioning of buildings

    Energy Technology Data Exchange (ETDEWEB)

    Machielsen, Cees H. M [Delft University of Technology, Mekelweg (Netherlands); Hagendijk, Andre E [Consultancy and Research (Netherlands)

    2000-07-01

    This paper describes the Sofri project, a cooperation between Ceeran Ltd and The Delft University of Technology. The main objective of this project is to develop the necessary knowledge and experience to commercialize solar-assisted air conditioning and dehumidification systems in the Dutch Caribbean. The project is motivated by the present needs of the Dutch Caribbean for renewable energy sources and the fact that the Caribbean has a high and uniform insolation throughout the year. Furthermore, hotels and offices in this area use more than 40% of their energy for air-conditioning purposes. Therefore solar-assisted air conditioning systems are a logic approach in reducing the energy demand and to lower the peak electricity reducing the energy demands for the local power station. Ceeran Ltd has the objective to reach full commercialization of the proposed technologies in the Dutch Caribbean. The research is concentrated on liquid absorption machines and solar collection systems such as flat plates with selective surfaces, heat pipe evacuated tubes flat plate collectors, and Compound Parabolic Concentrators. The first demonstration unit is planned to be installed in an office building in Curacao. The installation consists of a 35 kW LiBr/H{sub 2}O absorption machine driven by 100 m{sup 2} flat pate collectors with a gas backup system. The system will provide comfort air-conditioning for this these type of office buildings during daytime. [Spanish] Este documento describe el proyecto SOFRI, una cooperacion entre Ceeran, Ltd, y la Universidad Tecnologica del Delft. El principal objetivo de este proyecto es el de desarrollar el conocimiento necesario y la experiencia para comercializar los sistemas de aire acondicionado y deshumidificacion ayudados por la energia solar en el Caribe Holandes. Este proyecto ha sido motivado por las actuales necesidades del Caribe Holandes de fuentes de energia renovable y por el hecho de que el Caribe tiene una alta y uniforme insolacion

  18. Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells

    Directory of Open Access Journals (Sweden)

    Zi-Jie Chien

    2013-01-01

    Full Text Available This experiment is to study an absorption refrigerator driven by solar cells. Hand-held or carried in vehicle can be powered by solar energy in places without power. In the evenings or rainy days, it is powered by storage battery, and it can be directly powered by alternating current (AC power supply if available, and the storage battery can be charged full as a backup supply. The proposed system was tested by the alternation of solar irradiance 550 to 700 W/m2 as solar energy and 500ml ambient temperature water as cooling load. After 160 minutes, the proposal refrigerator can maintain the temperature at 5–8°C, and the coefficient of performance (COP of NH3-H2O absorption refrigeration system is about 0.25. Therefore, this system can be expected to be used in remote areas for refrigeration of food and beverages in outdoor activities in remote and desert areas or long-distance road transportation of food or low temperature refrigeration of vaccine to avoid the deterioration of the food or the vaccines.

  19. 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)

  20. Refrigeration systems and applications

    CERN Document Server

    Dincer, Ibrahim

    2010-01-01

    Refrigeration Systems and Applications, 2nd edition offers a comprehensive treatise that addresses real-life technical and operational problems, enabling the reader to gain an understanding of the fundamental principles and the practical applications of refrigeration technology. New and unique analysis techniques (including exergy as a potential tool), models, correlations, procedures and applications are covered, and recent developments in the field are included - many of which are taken from the author's own research activities in this area. The book also includes so

  1. An Exergy Analysis of LiBr-Water Absorption Refrigerators

    Science.gov (United States)

    Asano, Hitoshi; Fujii, Terushige; Wang, Xiao; Origane, Takafumi; Katayama, Masatoshi; Inoue, Umeo

    Absorption refrigerators are very efficient as a heat recovery unit in a co-generation system.In order to design an absorption refrigerator for an arbitrary heat source properly, it is important to consider not only quantity but also quality of heat flow. The evaluation of exergy loss in each component is also effective for the improvement of system. This paper deals with the exergy analysis on a LiBr-water absorption refrigerator consisted of a single-and a double-effect cycle driven by the exhaust gas of the micro gas turbine with the output power of about 30 kW. Moreover, exergy loss in absorption process was eva1uated. As a result, it was shown that 80% of the exergy loss in an absorber was caused in absorption process, and the exergy loss decreased with decreasing the change in solution concentration in absorber. In these calculated results,the maximum cooling load of 77.8 kW was obtained from the exhaust gas with the temperature of 2900°C by utilizing both a single-and a double-effect cycles in combination. The energy and exergy efficiency of the system was 88.0% and 25.6%, respectively.

  2. Performance comparison between a conventional vapor compression and compression-absorption single-stage and double-stage systems used for refrigeration

    International Nuclear Information System (INIS)

    This study reports a comparison from the first and second law of thermodynamics of a conventional vapor compression cooling system, a compression-absorption single-stage (CASS) system, and a compression-absorption double-stage (CADS) system operating with CO2 and R134a in the compression cycle and H2O/LiBr in the absorption cycles. The CADS system is being by the first time proposed in the literature. The performance of the systems were analyzed as function of diverse operating parameters. It was found that the electrical energy consumption in the refrigeration cycles was about 45% lower than in the classical compression refrigeration cycles using CO2 and R134a as refrigerants under the same operating conditions. The results showed that the COP for the CADS could be 50% higher than those obtained with the CASS system. The systems operating with R134a always achieved higher COP than those obtained using CO2. From the exergy analysis it was clear that the highest irreversibilities occurs in the absorber and the evaporator for both mixtures. It was also found that the irreversibilities of the proposed system using R134a in the compression cycle were 17% lower than those obtained with the system using CO2 - Highlights: • A compression-absorption double-stage (CADS) system is by the first time proposed. • The compression power in cascade cycles was 45% lower than in compression cycles. • The COP for proposed system was up to 45.2% higher than those with other systems. • The systems operating with R134a achieved higher COP than those obtained using CO2. • The irreversibilities for the CADS using R134a were 17% lower than using CO2

  3. Refrigerant ammonia, used by absorption refrigeration engineering. Das Kaeltemittel Ammoniak in der Absorptionstechnik

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, H. (Ingenieurbuero H. Foerster, Magdeburg (Germany))

    1992-01-01

    The development of fossile oil prices and demands of evironmental protection are new arguments for application of absorption refrigeration engineering. Besides the environmental - friendly refrigerant ammonia the atmospheric CO{sub 2}-output was decreased proportional. Further conditions for application of absorption refrigeration engineering are described, the ways to an energetic optimal rating, respectively to a rating by criteria of lowest investment costs are represented and possibilities for minimizing of cooling water consumption are pointed out. (orig.).

  4. Study and control of the optimal generation temperature in NH{sub 3}-H{sub 2}O absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Vazquez, Manuel [Escuela Tecnica Superior de Ingenieros Industriales, Area de Maquinas y Motores Termicos, Vigo (Spain)

    2001-02-01

    This paper presents the results of a study on the optimal generator temperature (OGT) in single stage NH{sub 3}-H{sub 2}O Absorption Refrigeration Systems (AARS). It is well known that the generation temperature affects the AARS's Coefficient of Performance (COP) and that there is a temperature value, called optimal generation temperature, for which the COP is maximum. Therefore, to develop new control strategies designed to maintain the optimal temperature in the system generator, it is necessary to study the dependency of this temperature on thermal operating conditions and system design parameters. One such type of study has been carried out here by means of a parametric analysis, using a simple model implemented in a computer program. Based on the results obtained a novel control system that works on two separated control-loops has been designed. The proposed control system maintains a constant temperature in the space to refrigerate as well as the optimal temperature in the system generator. (Author)

  5. Extending the market for cogeneration with absorption refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Langreck, J. [Colibri, Vaals (Netherlands); Pruiksma, E. [Stork Thermeq, Hengelo (Netherlands)

    1999-07-01

    The use of heat generated by cogeneration plants for absorption refrigeration plants (ARPs) is discussed in this article, and the advantages of the combination of cogeneration and ARPs are reported. Details are given of the two different types of ARPs, its operation, the importance of the food industry and industries that need cooling as a market for ARP, and recent cogeneration-ARP systems such as that installed in a margarine production plant in Rotterdam. The use of the fluegases from cogeneration plants and heat flows from chemical plants to drive ARPs are considered. (UK)

  6. Heat recovery system to power an onboard NH{sub 3}-H{sub 2}O absorption refrigeration plant in trawler chiller fishing vessels

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, J.; Vales, A.; Vazquez, M. [Escuela Tecnica Superior de Ingenieros Industriales, Vigo (Spain). Area de Maquinas y Motores Termikcos

    1998-12-01

    This paper is concerned with the design, modelling and parametric analysis of a gas-to-thermal fluid heat recovery system from engine exhausts in a trawler chiller fishing vessel to power an NH{sub 3}-H{sub 2}O absorption refrigeration plant for onboard cooling production. Synthetic oil was used as heat transfer fluid and recirculated. The major components of the system are fluid-to-solution and gas-to-fluid heat exchangers. Both heat exchangers and the complete system have been modelled. Models are implemented in several computer programs. These models have been used to study the influence of geometric design parameters and thermal operating conditions on heat exchangers and system thermal performance. The analysis of the results allowed us to find the optimum thermal operating conditions that minimise total heat transfer area. Optimal design based on real data was performed and the operating function of exhaust gases by-pass control was obtained and is presented. (author)

  7. Energy Efficiency of Refrigeration Systems

    OpenAIRE

    Arnemann, Michael

    2012-01-01

    Energy efficiency plays an important role in the development and operation of refrigeration systems. The method of the VDMA 24247-2 2 “Energy efficiency of refrigeration systems – Requirements for the system design and the components” were recently published. The method will be described within this paper, with the focus on the graphical interpretation.

  8. Performance Analysis of Vapour Compression Refrigeration System Utilizing Different Refrigerant

    OpenAIRE

    Ashish Patidar 1; Amitesh Paul

    2014-01-01

    The performance of heat transfer is one of the most important research areas in the field of thermal engineering. There are a large number of refrigerants, which are used to transfer heat from low temperature reservoir to high temperature reservoir by using vapour compression refrigeration system. This paper presents a performance analysis of vapour compression refrigeration system with using refrigerants like R-134a & Blend of R-290(propane) (50%) and R-600a (50% Isobutane). ...

  9. The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J.J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

    1995-12-31

    Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

  10. Hourly performance prediction of ammonia–water solar absorption refrigeration

    International Nuclear Information System (INIS)

    This paper deals with the hourly performance investigation of solar absorption refrigeration (SAR) system with evacuated tube collector and ammonia–water (NH3–H2O) solution. The SAR system is presented to simulate the system characteristic variations using hourly atmospheric air temperature and solar radiation data for Adana province in Turkey. The evaluation is performed for the maximum temperature occurrence day on July 29. First, the variations of various parameters, such as absorption refrigeration machine efficiency, condenser capacity and heat transfer rate in the generator and absorber during the day, are calculated for different cooling capacities and generator temperatures. Later, the minimum evacuated tube collector surface area is determined. According to the obtained results, the SAR system is considerably suitable for home/office-cooling purposes between the hours 09:00 and 16:00 in the southern region of Turkey such as Adana province. The most suitable performance of the absorption cooling system is calculated for the generator temperature values equal to or higher than 110 °C. The performance coefficient of the cooling (COPcooling) varies in the range of 0.243–0.454 while that of the heating (COPheating) changes from 1.243 to 1.454 during the day. Evacuated tube collector area for a 3.5 kW cooling load capacity is found to be 35.95 m2 for the region at 16:00 whereas it is 19.85 m2 at 12:00. - Highlights: ► Hourly performance investigation of solar absorption NH3–H2O refrigeration system is performed. ► Hourly atmospheric temperature and solar radiation on July 29 for Adana province in Turkey were used in the analysis. ► Optimum generator temperature for evacuated tube collector type was determined as higher than 110 °C. ► COPcooling was calculated in the range of 0.243–0.454 between hours 09:00 and 16:00.

  11. Industrial ammonia absorption refrigeration plants in combination with gas engines; Groupes de refrigeration industriels a absorption d'ammoniac combines avec des moteurs a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Bassols, J. [Colibri bv (Netherlands); Sahu, J. [Gas Natural SDG, S.A. (Spain)

    2000-07-01

    In many industrial sectors, co-generation systems with gas turbines or engines and ammonia absorption refrigeration plants are being introduced for the simultaneous production of electricity and refrigeration in order to meet the energy requirements inherent to each process and to reduce the operating costs. The different possibilities to link the absorption refrigeration plant to the cogeneration system and to the consumers are described. Different examples of realised projects are used to illustrate the different systems. Despite the fact that, compared to compression refrigeration machines, ARP's have lower COP (coefficient of performance) and higher investment costs, the advantage of using thermal energy as a driving energy instead of electricity makes the combination cogeneration-ARP very attractive. The plants can easily be integrated into an existing refrigeration installation. The full automatic control systems provide a trouble-free operation. Because most of the components of an ARP are heat exchangers, the plants only need little maintenance and are not susceptible to trouble. For their maintenance, no special knowledge is necessary. Plants working with NH{sub 3}-H{sub 2}O use ammonia as a refrigerant, which is a natural and environment-friendly fluid. (authors)

  12. Modeling of Artificial Neural Network for Predicting Specific Heat capacity of working fluid LiBr-H2O used in Vapor Absorption Refrigeration System

    Directory of Open Access Journals (Sweden)

    Dheerendra Vikram Singh

    2011-05-01

    Full Text Available The objective of this work is to model an artificial neural network (ANN to predict the value of specific heat capacity of working fluid LiBr-H2O used in vapour absorption refrigeration systems. A feed forward back propagation algorithm is used for the network, which is most popular for ANN. The consistence between experimental and ANN’s approach result was achieved by a mean relative error -0.00573, sum of the squares due to error0.00321, coefficient of multiple determination R-square 0.99961and root mean square error 0.01573 for test data. These results had been achieved in Matlab environment and the use of derived equations in any programmable language for deriving the specific heat capacity of LiBr-H2O solution.

  13. Thermodynamic Analysis of the Irreversibilities in Solar Absorption Refrigerators

    Directory of Open Access Journals (Sweden)

    Emma Berrich Betouche

    2016-03-01

    Full Text Available A thermodynamic analysis of the irreversibility on solar absorption refrigerators is presented. Under the hierarchical decomposition and the hypothesis of an endoreversible model, many functional and practical domains are defined. The effect of external heat source temperature on the entropy rate and on the inverse specific cooling load (ISCL multiplied by the total area of the refrigerator A/Qe are studied. This may help a constructor to well dimension the solar machine under an optimal technico-economical criterion A/Qe and with reasonable irreversibility on the refrigerator. The solar concentrator temperature effect on the total exchanged area, on the technico-economical ratio A/Qe, and on the internal entropy rate are illustrated and discussed. The originality of these results is that they allow a conceptual study of a solar absorption refrigeration cycle.

  14. Energy and Exergy Analysis of Vapour Absorption Refrigeration Cycle—A Review

    Science.gov (United States)

    Kanabar, Bhaveshkumar Kantilal; Ramani, Bharatkumar Maganbhai

    2016-07-01

    In recent years, an energy crisis and the energy consumption have become global problems which restrict the sustainable growth. In these scenarios the scientific energy recovery and the utilization of various kinds of waste heat become very important. The waste heat can be utilized in many ways and one of the best practices is to use it for vapour absorption refrigeration system. To ensure efficient working of absorption cycle and utilization of optimum heat, exergy is the best tool for analysis. This paper provides the comprehensive picture of research and development of absorption refrigeration technology, practical and theoretical analysis with different arrangements of the cycle.

  15. Comparison of the Performances of NH3-H20 and Libr-H2O Vapour Absorption Refrigeration Cycles

    Directory of Open Access Journals (Sweden)

    Prof. Nilesh B. Totla

    2016-04-01

    Full Text Available Developments in absorption cooling technology present an opportunity to achieve significant improvements on micro-scale to buildings, cooling, heating and power systems for residential and light commercial buildings. Their resultant effects are effective, energy efficient and economical. This study therefore contributes an important knowledge and method in the development, fabrication and application of an absorption refrigerator as a better alternative to the commonly used compressor refrigerators. Two fluid gas absorption refrigerators use electric based heater installed generator and no moving parts, such as pumps and compressors, and operate at a single system pressure. In this paper the performances analysis of the NH3-H2O and possible alternative cycles as lithium bromide-water are compared in respect of the (COP and different operating conditioning. The highest COP was found as a function of the absorber, generator, condenser, and evaporating temperature. This paper compares the performance of vapour absorption refrigeration cycles that are used for refrigeration temperatures below 0°C. Since the most common vapour absorption refrigeration systems use ammonia-water solution with ammonia as the refrigerant and water as the absorbent, research has been devoted to improvement of the performance of ammonia-water absorption refrigeration systems in recent years.

  16. Refrigeration Playbook: Natural Refrigerants; Selecting and Designing Energy-Efficient Commercial Refrigeration Systems That Use Low Global Warming Potential Refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Caleb [CTA Architects Engineers, Boise, ID (United States); Reis, Chuck [CTA Architects Engineers, Boise, ID (United States); Nelson, Eric [CTA Architects Engineers, Boise, ID (United States); Armer, James [CTA Architects Engineers, Boise, ID (United States); Arthur, Rob [CTA Architects Engineers, Boise, ID (United States); Heath, Richard [CTA Architects Engineers, Boise, ID (United States); Rono, James [CTA Architects Engineers, Boise, ID (United States); Hirsch, Adam [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Doebber, Ian [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-03-01

    This report provides guidance for selecting and designing energy efficient commercial refrigeration systems using low global warming potential refrigerants. Refrigeration systems are generally the largest energy end use in a supermarket type building, often accounting for more than half of a building's energy consumption.

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

    International Nuclear Information System (INIS)

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

  18. Determination of a Vapor Compression Refrigeration System Refrigerant Charge

    Institute of Scientific and Technical Information of China (English)

    YangChun-Xin; DangChao-Bin

    1995-01-01

    A physical model is established in this paper to describe the heat transfer and two phase flow of a refrigerant in the evaporator and condenser of a vapor compression refrigeration system.The model in then used to determine the refrigerant charge in vapor compression units.The model is used for a sensitivity analysis to determine the effect that varing design parameters on the refrigerant charge,The model is also used to evaluate the effect of refrigerant charge and the thermal physical properties on the refrigeration cycle,The predicted value of the refigerant charge and experimental data agree well The model and the method presented in this paper could be used to design vapour compression units such as domestic refrigeratirs and air conditioners.

  19. Investigation of ejector re-compression absorption refrigeration cycle

    OpenAIRE

    Wu, Shenyi

    1999-01-01

    This thesis describes a theoretical and experimental investigation of the ejector re-compression lithium bromide absorption refrigeration cycle. In this novel cycle, a steam ejector is used to enhance the concentration process by compressing the vapour to a state that it can be used to re-heat the solution from where it was evolved. Since this cycle recovers the heat otherwise wasted in a conventional absorption cycle, the energy performance of the cycle is improved. The theoretical study sho...

  20. REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

    Science.gov (United States)

    Large refrigeration systems are found in several applications including supermarkets, cold storage warehouses, and industrial processes. The sizes of these systems are a contributing factor to their problems of high refrigerant leak rates because of the thousands of connections, ...

  1. 溴化锂吸收式制冷机模拟实验教学系统设计%Design of simulating experimental teaching system for LiBr absorption-type refrigerating machines

    Institute of Scientific and Technical Information of China (English)

    王美霞; 邵莉; 韩吉田

    2011-01-01

    A simulation experimental system for absorption-type refrigerating machines was designed based on the ACAD and Visual Basic software. The use of the system can not only complete structure model of absorption-type refrigerating machine and thermal calculation for the absorption-type refrigerating cycle, but also simulate the PID control system and realize intelligent controls. The experimental system has the friendly man-machine interface beneficial to the students' operating and understanding, thereby decreasing the students' difficulties in learning and improving the experiment teaching effect.%利用ACAD和Visual Basic软件对溴化锂吸收式制冷机组进行实验教学仿真系统设计,可以完成机组结构剖析、循环热力计算和控制回路模拟等演示实验.实验系统采用友好的人机交互界面,便于操作和理解,既降低了学习难度,又提高了实验教学的效果.

  2. Optimization of a solar driven absorption refrigerator in the transient regime

    International Nuclear Information System (INIS)

    Highlights: ► Dynamic behavior of a solar absorption refrigerator endoreversible model. ► Using the principles of classical thermodynamics, mass and heat transfers. ► Minimizing heat exchange time to reach maximum performances. ► Major influence of the collector temperature on the model’s characteristics. ► Analogous effects of both the thermal load and the thermal conductance. -- Abstract: This contribution deals with the theoretical study in dynamic mode of an absorption refrigerator endoreversible model. The system is a cold generating station driven by solar energy. The main elements of the cycle are a refrigerated space, an absorption refrigerator and a solar collector form. A mathematical model is developed. It combines the classical thermodynamics and mass and heat transfers principles. The numerical simulation is made for different operating and conceptual conditions. A global minimizing time optimization is performed in view to reach maximum performances. Appropriate dimensionless groups are defined. The results are presented in normalized charts for general applications. The collector temperature presents major influence on the conceptual and functional characteristics compared to the stagnation temperature influence. On the other hand the thermal load in the refrigerated space and the thermal conductance of the walls has analogous effects, therefore important to be considered in actual design. As a result, the model is expected to be a useful tool for simulation, design, and optimization of solar collector based energy systems.

  3. A small quantum absorption refrigerator with reversed couplings

    OpenAIRE

    Silva, Ralph; Skrzypczyk, Paul; Brunner, Nicolas

    2015-01-01

    Small quantum absorption refrigerators have recently attracted renewed attention. Here we present a missing design of a two-qubit fridge, the main feature of which is that one of the two machine qubits is itself maintained at a temperature colder than the cold bath. This is achieved by 'reversing' the couplings to the baths compared to previous designs, where only a transition is maintained cold. We characterize the working regime and the efficiency of the fridge. We demonstrate the soundness...

  4. High Efficiency, Low Emission Refrigeration System

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center; Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center

    2016-08-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

  5. Refrigeration system having dual suction port compressor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Guolian

    2016-01-05

    A cooling system for appliances, air conditioners, and other spaces includes a compressor, and a condenser that receives refrigerant from the compressor. The system also includes an evaporator that receives refrigerant from the condenser. Refrigerant received from the condenser flows through an upstream portion of the evaporator. A first portion of the refrigerant flows to the compressor without passing through a downstream portion of the evaporator, and a second portion of the refrigerant from the upstream portion of the condenser flows through the downstream portion of the evaporator after passing through the upstream portion of the evaporator. The second portion of the refrigerant flows to the compressor after passing through the downstream portion of the evaporator. The refrigeration system may be configured to cool an appliance such as a refrigerator and/or freezer, or it may be utilized in air conditioners for buildings, motor vehicles, or other such spaces.

  6. Thermo-economic analysis of steady state waste heat recovery in data centers using absorption refrigeration

    International Nuclear Information System (INIS)

    Highlights: • Absorption refrigeration is powered by data center waste heat. • Waste heat from 3 to 5 server racks produces cooling for an additional rack. • An economic analysis shows the payback period can be as short as 4–5 months. - Abstract: This paper addresses the technical and economic issues associated with waste heat recovery in data centers through the use of absorption cooling machines. The theoretical possibility of utilizing the heat dissipated by a server, or a number of servers, to power an absorption system, which in turn produces cooling for other servers in the data center, is investigated. For this purpose, a steady-state thermodynamic model is developed to perform energy balance and exergy analyses for a novel configuration of an on-chip two-phase cooling system and an absorption refrigeration system. This combination is created by replacing the condenser in the on-chip cooling circuit with the generator of an absorption refrigeration cycle. The performance of the developed model in simulating both LiBr–water and water–ammonia absorption cooling systems is examined through verification of the model results against the reference data available in the literature. The verification indicates the superiority of LiBr–water absorption system for data center/server operating conditions. Therefore, a LiBr–water absorption refrigeration system is modeled in the novel combined heat recovery system. For these systems it is shown that the traditional definition for the coefficient of performance (COP) is not appropriate to evaluate the performance and, in its place, introduce a new figure of merit. Through a sensitivity analysis, the effects of server waste heat quality, server coolant type, solution peak concentration, solution heat exchanger effectiveness, evaporator temperature, and operating pressures on the performance of the novel system are investigated. Finally, using the thermodynamic model and cost information provided by the

  7. Geothermal absorption refrigeration for food processing industries. Final report, December 13, 1976--November 13, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Harris, R.L.; Olson, G.K.; Mah, C.S.; Bujalski, J.H.

    1977-11-01

    The first step in the economic analysis of the integration of geothermally powered absorption refrigeration into a food processing plant was an evaluation of the potential geothermal sites in the Western United States. The evaluation covered availability of raw materials, transportation, adequate geothermal source, labor, and other requirements for food processing plants. Several attractive geothermal sites were identified--Raft River, Idaho; Sespe Hot Springs, California; Vale Hot Springs, Oregon; Weisler-Crane Creek, Idaho; Cosco Hot Springs, California; and the Imperial Valley, California. The most economically attractive food processing industry was then matched to the site based on its particular energy, raw material, and transportation requirements. The more promising food processors identified were for frozen potato or vegetable products, freeze-dried products, and meat processing. For the refrigeration temperature range of +32/sup 0/F to -40/sup 0/F and geothermal temperature range of 212/sup 0/F to 300/sup 0/F, an absorption refrigeration system had to be identified, designed, and evaluated. Both the conventional ammonia/water and an organic absorption refrigeration system using monochlorodifluoromethane (R-22) as the refrigerant and dimethyl formamide (DMF) as the absorbent were studied. In general, only a 60/sup 0/F to 100/sup 0/F temperature drop would be effectively used for refrigeration leaving the remainder of the allowable temperature drop available for other use. The economic evaluation of the geothermal system installed in a food processing plant required the comparison of several principal alternatives. These alternatives were evaluated for three different food processing plants located at their optimum geothermal site: a forzen potato product processing plant located at Raft River, Idaho; a freeze-dried product plant located at Sespe Hot Springs, California; a beef slaughter operation located in the Imperial Valley of California. (JGB)

  8. Modelling of a refrigerating system coupled with a refrigerated room

    Science.gov (United States)

    Wang, Hongwei

    1991-08-01

    The development of a set of comprehensive computer models to simulate and analyze both steady state and non steady state behavior of a refrigerating system coupled with a refrigerated room is described. The refrigerating system is a single stage vapor compression system consisting of four basic elements: a reciprocating piston compressor, a dry expansion evaporator (or cooler), a shell and tube watercooled condensor and a thermostatic expansion valve. To validate the computer models, a test plant on which steady state and dynamic measurements were carried out, was set up. Experiments to determine several empirical constants encountered in the models were done, and the simulation results were compared with a series of measurements within a wide range of operation conditions. The validated models were applied to the prediction of the air distributions in a cold store and the study of a system with different capacity control systems, proving the capability and reliability of the models.

  9. Thermodynamic analysis of a novel air-cooled non-adiabatic absorption refrigeration cycle driven by low grade energy

    International Nuclear Information System (INIS)

    Graphical abstract: To improve the performance of the air-cooled type absorption refrigeration, a novel non-adiabatic absorber has been applied in the cycle. Simulation results show that low grade energy is applicable for NH3/NaSCN and NH3/LiNO3 absorption refrigeration system under air cooling condition and relatively high system performance can be obtained. - Highlights: • We analyze an absorption refrigeration cycle driven by low grade energy. • Working fluids thermophysical property correlations are corrected. • Influence of non-adiabatic absorber on system performance is investigated. • We propose system operation parameters under air-cooled condition. - Abstract: An air-cooled type absorption refrigeration cycle using ammonia–lithium nitrate and ammonia–sodium thiocyanate solutions as working fluids are thermodynamically studied in this paper. In the case of many occasions especially small cooling capacity occasion where water cooling is restricted or inconvenient, application of conventional adiabatic absorbers in air-cooled type absorption refrigeration system has been studied by many investigators. Comparing to the adiabatic absorber, a novel air-cooled non-adiabatic absorber is applied to the absorption refrigeration system in this study to improve system performance. It is shown that, system performance has a significant improvement when temperatures of rich ammonia solution at the outlet of absorber decrease under the effect of the heat dissipation capacity of the non-adiabatic absorber. Another advantage is that heat load of the system heat exchangers including generator, solution heat exchanger and air-cooler, decreases with the solution temperature decrease at the outlet of the absorber under the same system cooling capacity condition, which brings benefits to the system cost reduction. Variation of system performance and other system operation parameters with generator temperature, absorption temperature and absorption efficiency has

  10. Industrial refrigeration by absorption/compression; Refrigeracion industrial por absorcion/compresion

    Energy Technology Data Exchange (ETDEWEB)

    Ayala Delgado, Ramon; Heard, Christopher Lionel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The use of the absorption/compression refrigeration in the industrial area is analyzed. It is estimated than in Mexico 50% of the food is wasted for lack of refrigeration in the producing centers and by the inefficient distribution system, as well as for the hot climate. The functioning of the absorption refrigeration and the hybrid system absorption/compression which can operate with the two thermodynamic cycles in variable proportions, depending on the specific application, looking for operational advantages and energy efficiency is described. This type of technology could be applied in Mexico due to the lack of industrial refrigeration and to the need of substituting compressors in some companies which have up to 20 years of use [Espanol] Se analiza el uso de la refrigeracion por absorcion/compresion en el area industrial. En Mexico se estima que se desperdicia el 50% de los alimentos por falta de refrigeracion en los centros productores y por el deficiente sistema de distribucion, asi como por el clima calido. Se describe el funcionamiento de la refrigeracion por absorcion y la refrigeracion por absorcion/compresion o sistema hibrido, el cual puede funcionar con los dos tipos de ciclos termodinamicos, en proporciones variables, dependiendo de la aplicacion especifica, buscando ventajas de operacion y eficiencia energetica. Este tipo de tecnologia podria aplicarse en Mexico debido a la falta de refrigeracion industrial y a la necesidad de sustituir compresores en algunas empresas los cuales tienen hasta 20 anos de uso

  11. Research on performance of mixed absorption refrigeration for solar air-conditioning

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel lithium bromide/water mixed absorption refrigeration cycle that is suitable for the utilization of solar air-conditioning and can overcome the drawbacks of low system overall efficiency of traditional solar absorption refrigeration air-condition systems is presented.The accessorial high pressure generator was added in the cycle.The lithium bromide solution flowing out from the high pressure generator was mixed with the solution from the low pressure absorber to increase lithium bromide solution concentration and decrease pressure in the high pressure absorber.The performance of a mixed absorption refrigeration cycle was analyzed.The theoretical analysis shows that the highest COP is 0.61,while the highest available temperature difference of heat resource is 33.2℃.The whole coefficient of performance of the solar air-conditioning using mixed absorption cycle is 94.5% higher than that of two-stage absorption.The advantages of solar air-conditioning can be markedly made use of by the cycle.

  12. Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Donald C, Energy Concepts Co.; Lauber, Eric, Western Refining Co.

    2008-06-20

    An emerging DOE-sponsored technology has been deployed. The technology recovers light ends from a catalytic reformer plant using waste heat powered ammonia absorption refrigeration. It is deployed at the 17,000 bpd Bloomfield, New Mexico refinery of Western Refining Company. The technology recovers approximately 50,000 barrels per year of liquefied petroleum gas that was formerly being flared. The elimination of the flare also reduces CO2 emissions by 17,000 tons per year, plus tons per year reductions in NOx, CO, and VOCs. The waste heat is supplied directly to the absorption unit from the Unifiner effluent. The added cooling of that stream relieves a bottleneck formerly present due to restricted availability of cooling water. The 350oF Unifiner effluent is cooled to 260oF. The catalytic reformer vent gas is directly chilled to minus 25oF, and the FCC column overhead reflux is chilled by 25oF glycol. Notwithstanding a substantial cost overrun and schedule slippage, this project can now be considered a success: it is both profitable and highly beneficial to the environment. The capabilities of directly-integrated waste-heat powered ammonia absorption refrigeration and their benefits to the refining industry have been demonstrated.

  13. Intermittent Solar Ammonia Absorption Cycle (ISAAC) refrigeration for lesser developed countries

    Science.gov (United States)

    Erickson, Donald C.

    1990-02-01

    The Intermittent Solar Ammonia Absorption Cycle (ISAAC) refrigerator is a solar thermal technology which provides low cost, efficient, reliable ice-making to areas without ready access to electricity. An ISAAC refrigeration system consists of a compound parabolic solar collector, two pressure vessels, a condenser, a cold box or refrigerated space, and simple connective piping -- no moving parts or electrical components. Most parts are simple construction or plumbing grade materials, locally available in many remote areas. This technology has numerous potential benefits in lesser developed countries both by providing a cheap, reliable source of ice, and, since manufacture requires only semi-skilled labor, a source of employment to the local economy. Applications include vaccine storage for health care clinics; fish, meat, and dairy product storage; and personal consumption. Importantly, this technology increases the quality of life for people in lesser developed countries without depleting fossil fuel resources or increasing the release of greenhouse gases such as CO2 and chlorofluorocarbons.

  14. Design and Simulation of an Absorption Diffusion Solar Refrigeration Unit

    Directory of Open Access Journals (Sweden)

    B. Chaouachi

    2007-01-01

    Full Text Available The purpose of this study was the design and the simulation of an absorption diffusion refrigerator using solar as source of energy, for domestic use. The design holds account about the climatic conditions and the unit cost due to technical constraints imposed by the technology of the various components of the installation such as the solar generator, the condenser, the absorber and the evaporator. Mass and energy conservation equations were developed for each component of the cycle and solved numerically. The obtained results showed, that the new designed mono pressure absorption cycle of ammonia was suitable well for the cold production by means of the solar energy and that with a simple plate collector we can reach a power, of the order of 900 watts sufficient for domestic use.

  15. DESIGN AND OPTIMIZATION OF A REFRIGERATION SYSTEM

    Science.gov (United States)

    The paper discusses the design and optimization of a refrigeration system, using a mathematical model of a refrigeration system modified to allow its use with the optimization program. he model was developed using only algebraic equations so that it could be used with the optimiz...

  16. ESO2 Optimization of Supermarket Refrigeration Systems

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Madsen, Henrik; Heerup, Christian

    Supermarket refrigeration systems consists of a number of display cases, cooling cabinets and cold rooms connected to a central compressor pack. This configuration saves energy compared to placing a compressor at each cooling site. The classical control setup of a supermarket refrigeration system...

  17. Exergo-economic analysis of a solar driven hybrid storage absorption refrigeration cycle

    International Nuclear Information System (INIS)

    Highlights: • Exergo-economic analysis for solar-powered hybrid storage absorption system is done. • Pump, SHX and generator have higher exergetic efficiencies than other components. • Initial cost of evaporator and generator should be reduced even at the expense of irreversibilities. • Irreversibilities cost in SHX should be reduced even at the expense of its initial cost. - Abstract: This paper presents the exergo-economic analysis of a 5 kW refrigeration cycle with hybrid storage system. The novel hybrid storage comprises a cold (ice) storage tank, an ammonia storage tank, a weak solution tank and a strong solution tank to suffice the nighttime cooling load. The exergo-economic analysis is performed to compare the components of the refrigeration cycle based on the costs of initial capital investment and the costs of irreversibilities. The components of the refrigeration cycle are evaluated and compared using exergo-economic variables such as the relative cost difference, exergy destruction cost rate and exergo-economic factor. The effect of generator temperature, condenser temperature and evaporator temperature on the exergetic efficiency of the system is also studied. The paper also presents a quasi-steady exergy and exergo-economic analysis for a representative summer day of Dhahran region. This study can be further used in the optimization of design variables of the studied refrigeration cycle

  18. 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)

    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

  19. Two-phase flow in refrigeration systems

    CERN Document Server

    Gu, Junjie; Gan, Zhongxue

    2013-01-01

    Two-Phase Flow in Refrigeration Systems presents recent developments from the authors' extensive research programs on two-phase flow in refrigeration systems. This book covers advanced mass and heat transfer and vapor compression refrigeration systems and shows how the performance of an automotive air-conditioning system is affected through results obtained experimentally and theoretically, specifically with consideration of two-phase flow and oil concentration. The book is ideal for university postgraduate students as a textbook, researchers and professors as an academic reference book, and b

  20. Model Based Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth

    Today refrigeration control systems consist of a number of self-contained distributed control loops that during the past years has been optimized obtaining a high performance of the individual subsystems, thus disregarding cross-couplings as well dynamically as statically. The supervisory control...... for automation of these procedures, that is to incorporate some "intelligence" in the control system, this project was started up. The main emphasis of this work has been on model based methods for system optimizing control in supermarket refrigeration systems. The idea of implementing a system optimizing......-couplings resulting in large disturbances. In supermarkets refrigeration systems the temperature control in the refrigerated display cases are maintained by hysteresis controllers. Based on a model predictive hybrid framework a novel approach for desynchronization is presented. The approach is applied...

  1. Mathematical Modeling of Magnetic Regenerator Refrigeration Systems

    OpenAIRE

    Salarvand, Navid

    2009-01-01

    ABSTRACT: Active magnetic regenerative refrigeration (AMRR) systems are designed based on magnetocaloric effect of some special solid materials, such as Gadolinium-Silicon-Germanium, Ferrum-Rhodium, etc. During the last three decades, a variety of cooling systems have been proposed using magnetic materials at room temperature. In this thesis, an AMRR system using FeRh as refrigerant is studied. For the simulation, a one-dimensional, time-varying mathematical model is developed. This model co...

  2. Simulation of the Energy Saver refrigeration system

    International Nuclear Information System (INIS)

    The helium refrigeration for the Energy Saver is supplied by a Central Helium Liquefier and 24 Satellite Refrigerators installed over a 1-1/4 square mile area. An interactive, software simulator has been developed to calculate the refrigeration available from the cryogenic system over a wide range of operating conditions. The refrigeration system simulator incorporates models of the components which have been developed to quantitatively describe changes in system performance. The simulator output is presented in a real-time display which has been used to search for the optimal operating conditions of the Satellite-Central system, to examine the effect of an extended range of operating parameters and to identify equipment modifications which would improve the system performance

  3. 46 CFR 151.40-11 - Refrigeration systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required...

  4. Study of the ship's refrigeration system "Glacier"

    OpenAIRE

    Subirats Pages, Enric

    2012-01-01

    The main objective of this project is to make the whole process of calculation and design of the refrigeration system of a reefer. The refrigeration system must be designed and calculated to cool, store the products of each chamber at determinate temperatures. It will contain two parts. The theoretical part will provide the knowledge needed to develop calculation section. It requires the demonstration of each component calculated and the selection. We should make an economic study of the s...

  5. Refrigeration system having standing wave compressor

    Science.gov (United States)

    Lucas, Timothy S.

    1992-01-01

    A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

  6. Design, Fabrication and Performance Evaluation of a Micro-Absorption Refrigerator

    Directory of Open Access Journals (Sweden)

    Hyginus .U. Ugwu

    2012-11-01

    Full Text Available Developments in absorption cooling technology present an opportunity to achieve significant improvements on micro-scale to buildings, cooling, heating and power systems for residential and light commercial buildings. Their resultant effects are effective, energy efficient and economical. This study therefore contributes an important knowledge and method in the development, fabrication and application of an absorption refrigerator as a better alternative to the commonly used compressor refrigerators. In its embodiment, the work focuses on the design and fabrication of the absorption chiller system with low or no vibration since there are virtually no moving parts. Also, it dovetailed into the selection of a suitable refrigerant that is economically friendly in order to reduce or eliminate its ozone depleting effect. Consequently, the design was fabricated using adapted locally sourced materials. This is to encourage local ingenuity and to reduce cost of production comparable to already made custom-imported ones. It is designed to be simple, handy and readily available to be used by anyone in case of malfunctioning and for easy relocation. Though, the main limitation of the system fabricated is the long time it uses to achieve cooling, the performance of the machine generally is very efficient as its calculated coefficient of performance ( C.O.P is 1.21, which compared favourably well with the literature value of 1.00-2.00. Also, the total cost including an over-head of 30% of the machine was estimated at forty-one thousand, two hundred and fifty-nine (N41,259.40 naira, forty kobo only based on current price structure compared to an equivalent custom-made-imported type estimated at between sixty to seventy thousand (N60,000.00 to N70,000.00 naira. Hence, the machine is affordable to all, and is highly recommended for local entrepreneurs for mass production because of its cost effectiveness, simplicity and availability of spare parts.

  7. Thermodynamic and thermo-economic analysis and optimization of performance of irreversible four-temperature-level absorption refrigeration

    International Nuclear Information System (INIS)

    Highlights: • The feasibility of performance of four-heat-source irreversible refrigerators is investigated. • The latter is achieved using NSGA algorithm and thermodynamic analysis. • Three well known decision makers are accomplished to indicate optimum outputs obtained with optimization process. - Abstract: This paper presents a developed ecological function for absorption refrigerators with four-temperature-level. Moreover, aforementioned absorption refrigerator is optimized by implementing ecological function. With the aim of the first and second laws of thermodynamics, an equivalent system is initially determined. To reach the addressed goal of this research, three objective functions that the coefficient of performance (COP), the ecological function (E) and thermoeconomic criterion (F) have been involved in optimization process simultaneously. Three objective functions are maximized at the same time. Developed multi objective evolutionary approaches (MOEAs) on the basis of NSGA-II method is implemented throughout this work

  8. Analysis of ammonia/water and ammonia/salt mixture absorption cycles for refrigeration purposes in fishing ships

    International Nuclear Information System (INIS)

    In this work, the use of waste heat energy of jacket water in diesel engines of fishing ships was analysed for use as a heat source for absorption refrigeration systems. The thermodynamic simulation of an absorption refrigeration cycle with three different working fluid mixtures that use ammonia as a refrigerant was carried out. This analysis was assessed in terms of the cooling demand and cycle performance as a function of the evaporator, condenser and generator temperatures. Moreover, the need for rectifying the vapour stream leaving the generator was analysed together with the drag of the fraction of non-evaporated liquid to the absorber. The results show that the NH3/(LiNO3 + H2O) and NH3/LiNO3 fluid mixtures have higher values of COP as compared to NH3/H2O fluid mixture, the differences being more pronounced at low generation temperatures. If the activation temperature is set to 85 °C, the minimum evaporation temperatures that can be achieved are −18.8 °C for the cycle with NH3/LiNO3, −17.5 °C for the cycle with NH3/(LiNO3 + H2O) cycle and −13.7 °C for the NH3/H2O cycle at a condensing temperature of 25 °C. Also, for the NH3/(LiNO3 + H2O) fluid mixture, it has been demonstrated that the absorption refrigeration cycle can be operated without a distillation column and in this case the water content in the refrigerant stream entering the evaporator is less than 1.5% in weight at the operating conditions selected. - Highlights: •Ammonia absorption systems can provide refrigeration necessities for fishing ships. •Absorption refrigeration systems reduce the energy consumption of fishing ships. •The NH3/(LiNO3 + H2O) mixture is recommended for absorption refrigeration cycles

  9. Data-Driven Control of Refrigeration System

    OpenAIRE

    Vinther, Kasper

    2014-01-01

    Refrigeration is used in a wide range of applications, e.g., for storage of food at low temperatures to prolong shelf life and in air conditioning for occupancy comfort. The main focus of this thesis is control of supermarket refrigeration systems. This market is very competitive and it is important to keep the variable costs at a minimum and, if possible, offer products which have higher robustness, performance, and functionality than similar products from competitors. However, the multitude...

  10. Thermodynamic evaluation of new absorbent mixtures of lithium bromide and organic salts for absorption refrigeration machines

    Energy Technology Data Exchange (ETDEWEB)

    Donate, Marina; Rodriguez, Luis; Lucas, Antonio De; Rodriguez, Juan F. [Department of Chemical Engineering, University of Castilla-La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain)

    2006-01-01

    Mixtures of lithium bromide and organic salts of sodium and potassium (formate, acetate and lactate) have been evaluated as alternative absorbents for absorption refrigeration machines. The main objective is to overpass the limitations of lithium bromide and improve the characteristics and the efficiency of the refrigeration cycle. In order to select the mixture that presents better properties for its employment in absorption refrigeration cycles, a thermodynamic analysis have been done. Density, viscosity, enthalpies of dilution, solubility and vapour pressure data of the proposed mixtures have been measured. A simulation program has been developed to evaluate temperatures, heats exchanged in the different sections and the efficiency of the cycle. (author)

  11. Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

    Institute of Scientific and Technical Information of China (English)

    Maogang HE; Xinzhou SONG; Ying ZHANG; Jiantao ZHANG

    2008-01-01

    A new tandem double-capillary tube refri-geration system for refrigerator-freezers is proposed. A capillary tube was added between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of state was adopted to calculate the thermodynamic properties of the refrigerants, and the available energy analysis of the vapor compression refrigeration cycle was programmed to calculate the thermodynamic perfor-mances of the new and the conventional refrigeration cycle of the refrigerator-freezer. The calculation results show that the available energy efficiency of the conven-tional refrigeration cycle of the refrigerator-freezer is 21.20% and 20.57%, respectively when the refrigerant is R12 and R134a, while that of the double-capillary tube refrigeration cycle of the refrigerator-freezer is 23.97% and 23.44%, respectively. By comparison, the available energy efficiency of the new refrigeration system increases by 13.07% and 13.95%, respectively.

  12. Defrost Temperature Termination in Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

    2011-11-01

    The objective of this project was to determine the potential energy savings associated with implementing demand defrost strategies to defrost supermarket refrigerated display case evaporators, as compared to the widely accepted current practice of controlling display case defrost cycles with a preset timer. The defrost heater energy use of several representative display case types was evaluated. In addition, demand defrost strategies for refrigerated display cases as well as those used in residential refrigerator/freezers were evaluated. Furthermore, it is anticipated that future work will include identifying a preferred defrost strategy, with input from Retail Energy Alliance members. Based on this strategy, a demand defrost system will be designed which is suitable for supermarket refrigerated display cases. Limited field testing of the preferred defrost strategy will be performed in a supermarket environment.

  13. Heat-power station and refrigeration machine in a combined system. The combination of power-heat-refrigeration and their use in building engineering. BHKW und Kaeltemaschine im Verbundsystem. Die Kraft-Waerme-Kaeltekopplung und ihre Anwendung in der Gebaeudetechnik

    Energy Technology Data Exchange (ETDEWEB)

    Engelhorn, H.R.

    1991-10-01

    A combination of power-heat-refrigeration consists of combining a heat-power station with an absorption refrigeration machine. For buildings with a specific requirement profile of power, heat and refrigeration this provides especially economical use of the primary energy utilized. The article deals with plant systems as well as with the energy and economic relationships of this technology. (orig.).

  14. The Design and Performance Analysis of Refrigeration System Using R12 & R134a Refrigerants

    OpenAIRE

    K. Nagalakshmi; G. Marurhiprasad Yadav

    2014-01-01

    The design and performance analysis of refrigeration system using R12 & R134a refrigerants are presented in this report. The design calculations of the suitable and necessary refrigerator equipment and their results are also reported here. CFC-12 is the most widely used refrigerant. It serves both in residential and commercial applications, from small window units to large water chillers, and everything in between. Its particular combination of efficiency, capacity and pressur...

  15. Development of a novel refrigeration system for refrigerated trucks incorporating phase change material

    International Nuclear Information System (INIS)

    Highlights: ► A refrigeration system having low energy cost and producing no local greenhouse gas emission. ► A PCM is experimentally developed which is able to maintain the refrigerated truck at −18 °C. ► A TRNSYS model is developed to simulate the proposed refrigeration system. -- Abstract: An innovative refrigeration system incorporating phase change material (PCM) is proposed to maintain refrigerated trucks at the desired thermal conditions. The advantage of using PCM to maintain low temperatures is that a conventional refrigeration system does not have to be located on-board the vehicle. In addition, the system consumes less energy and produces much lower local greenhouse gas (GHG) emissions. The phase change thermal storage unit (PCTSU) is charged by a refrigeration unit located off the vehicle when stationary. The PCM is discharged and provides cooling when in service. A new PCM with a lower cost than currently available PCMs was developed, suitable for maintaining the refrigerated truck at a temperature of −18 °C. The PCM has a melting temperature of −26.7 °C and a latent heat of 154.4 kJ kg−1. A prototype system was constructed and test results proved that the proposed refrigeration system is feasible for mobile transport. An analysis shows that delivery of refrigerated products can be made with a PCM system having a weight comparable to that of an on board conventional refrigeration system with less than half of the energy cost.

  16. Absorption refrigeration using waste heat; Refrigeracion por absorcion utilizando calor de desecho

    Energy Technology Data Exchange (ETDEWEB)

    Heard, Christopher; Ayala, Ramon; Best, Roberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1994-07-01

    In this article a detailed analysis is made of the absorption refrigeration system that uses waste heat and because of being of low temperature, can make the processes more efficient being at the same time an important factor in the country`s energy resources saving, since the system permits to increase the availability of electricity and fuel`s energy. The Instituto de Investigaciones Electricas (IIE) and the Universidad Nacional Autonoma de Mexico (UNAM) absorption refrigeration experience is described and the economic aspects related with this system are analyzed. [Espanol] En este articulo se presenta un analisis detallado del sistema de refrigeracion por absorcion que utiliza calor de desecho y que, siendo de baja temperatura, puede hacer mas eficientes los procesos y ser a la vez un factor importante en el ahorro de los recursos energeticos del pais, pues el sistema permite aumentar la disponibilidad energetica de electricidad y combustibles. Se describe la experiencia del Instituto de Investigaciones Electricas (IIE) en refrigeracion por absorcion y la de la Universidad Nacional Autonoma de Mexico (UNAM), y se analizan los aspectos economicos relacionados con este sistema.

  17. Systematic modelling and simulation of refrigeration systems

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.; Jakobsen, Arne

    1998-01-01

    The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose of the s......The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose...... of the simulation, to select appropriate component models and to set up the equations in a well-arranged way. In this paper the outline of such a method is proposed and examples showing the use of this method for simulation of refrigeration systems are given....

  18. Compression-absorption (resorption) refrigerating machinery. Modeling of reactors; Machine frigorifique a compression-absorption (resorption). Modelisation des reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Lottin, O.; Feidt, M.; Benelmir, R. [LEMTA-UHP Nancy-1, 54 - Vandoeuvre-les-Nancy (France)

    1997-12-31

    This paper is a series of transparencies presenting a comparative study of the thermal performances of different types of refrigerating machineries: di-thermal with vapor compression, tri-thermal with moto-compressor, with ejector, with free piston, adsorption-type, resorption-type, absorption-type, compression-absorption-type. A prototype of ammonia-water compression-absorption heat pump is presented and modeled. (J.S.)

  19. Reduction of chlorofluorocarbon emissions from refrigeration systems

    International Nuclear Information System (INIS)

    Recently enacted State and Federal legislation, (The Clean Air Act and Colorado Senate Bill 77), and the implementation of regulations for each, forbid the intentional release of ozone depleting chlorofluorocarbons(CFCs) from refrigeration and air conditioning systems to the atmosphere. In addition, an international agreement (The Montreal Protocol), calls for CFC manufacturing reductions, which began in 1991, and eventual discontinuation. The declining supply and resultant escalating costs of CFCs are additional driving forces toward conservation and reuse of present refrigerant resources. Rocky Flats Plant (RFP) currently has an estimated 42,000 pounds of CFCs in refrigeration and air conditioning systems. The purpose of this paper is to discuss steps being taken at RFP toward the abatement of CFC releases. The main thrust of our efforts is the use of a refrigerant management system, used to recover and recycle our current CFC stock. Additional methods of further reducing CFC emissions will also be discussed. These include the installation of state-of-the-art oil filtration systems on major chiller units, installation of spring-loaded pressure relief valves and the retrofitting of major chiller units to accept less harmful, alternative refrigerants

  20. Toward High Performance in Industrial Refrigeration Systems

    OpenAIRE

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industrial refrigeration systems.

  1. Functional Nanomaterials Useful for Magnetic Refrigeration Systems

    Science.gov (United States)

    Aslani, Amir

    Magnetic refrigeration is an emerging energy efficient and environmentally friendly refrigeration technology. The principle of magnetic refrigeration is based on the effect of varying a magnetic field on the temperature change of a magnetocaloric material (refrigerant). By applying a magnetic field, the magnetic moments of a magnetic material tend to align parallel to it, and the thermal energy released in this process heats the material. Reversibly, the magnetic moments become randomly oriented when the magnetic field is removed, and the material cools down. The heating and the cooling of a refrigerant in response to a changing magnetic field is similar to the heating and the cooling of a gaseous medium in response to an adiabatic compression and expansion in a conventional refrigeration system. One requirement to make a practical magnetic refrigerator is to have a large temperature change per unit of applied magnetic field, with sufficiently wide operating temperature. So far, no commercially viable magnetic refrigerator has been built primarily due to the low temperature change of bulk refrigerants, the added burden of hysteresis, and the system's low cooling capacity. The purpose of this dissertation is to explore magnetic refrigeration system. First, the Active Magnetic Regenerator (AMR) system built by Shir et al at the GWU's Institute for Magnetics Research (IMR) is optimized by tuning the heat transfer medium parameters and system's operating conditions. Next, by reviewing literature and works done so far on refrigerants, a number of materials that may be suitable to be used in magnetic refrigeration technology were identified. Theoretical work by Bennett et al showed an enhancement in magnetocaloric effect of magnetic nanoparticles. Research was performed on functional magnetic nanoparticles and their use in magnetic refrigeration technology. Different aspects such as the size, shape, chemical composition, structure and interaction of the nanoparticle with

  2. Energy analysis of a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Jensen, Jakob Munch; Jakobsen, Arne; Rasmussen, Bjarne D.;

    1999-01-01

    From 1995 to 1998, an energy test method for supermarket refrigeration systems was developed in a project financed by the Danish Energy Agency. The purpose of the energy test method is to provide the means for evaluating the energy efficiency of these systems. The test method requires measurement...

  3. Energy performance of supermarket refrigeration and air conditioning integrated systems working with natural refrigerants

    International Nuclear Information System (INIS)

    The current trends in commercial refrigeration aim at reducing the synthetic refrigerant charge, either by minimising the internal volume of the circuit or by utilising natural refrigerants, and at energy saving. The energy efficiency of supermarkets can be improved by optimising components design, recovering thermal and refrigerating energy, adopting innovative technology solutions, integrating the HVAC system with medium temperature and low temperature refrigeration plants and, finally, reducing thermal loads on refrigerated cases. This study aims at investigating the performance of different lay-out and technological solutions where only natural refrigerants are used and at finding the potential for improving energy efficiency over the traditional systems in different climates. In the analysis, chillers and heat pumps working with ammonia or propane, medium temperature systems working with ammonia or propane and carbon dioxide as heat transfer fluid or with carbon dioxide as the refrigerant and low temperature systems working with carbon dioxide are considered and benchmarked with a state-of-the-art HFCs based plant. The most efficient investigated solution enables an annual energy saving higher than 15% with respect to the baseline solution for all the considered climates. - Highlights: ► Different natural refrigerants supermarket HVAC and R integrated systems are analysed. ► Some of the proposed solutions offer a significant benefit over the baseline one. Up to 18.7% energy saving is achieved in the considered climates. ► The refrigeration unit condensation by the AC chiller offers the poorest results.

  4. Waste Heat Recapture from Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL

    2011-11-01

    The objective of this project was to determine the potential energy savings associated with improved utilization of waste heat from supermarket refrigeration systems. Existing and advanced strategies for waste heat recovery in supermarkets were analyzed, including options from advanced sources such as combined heat and power (CHP), micro-turbines and fuel cells.

  5. Synchronization Analysis of the Supermarket Refrigeration System

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Chen, Liang; Larsen, Lars Finn Sloth

    2009-01-01

    The supermarket refrigeration system typically has a distributed control structure, which neglects interactions between its subsystems. These interactions from time to time lead to a synchronization operation of the display-cases which causes an inferior control performance and increased energy...

  6. INJECTING ABSORPTION REFRIGERATION CYCLE%引射吸收式制冷循环

    Institute of Scientific and Technical Information of China (English)

    苏芬仙; 敖越; 等

    2001-01-01

    提出了引射吸收式制冷循环。它可以强化吸收,而且可以扩大吸收式制冷的应用领域。分析了引射吸收式制冷循环,提出了参数选择方法,分析了影响引射式吸收制冷循环中吸收过程的因素并与喷淋吸收过程进行了比较。%A new injecting absorption refrigeration cycle is put forward.The new refrigeration cycle can consolidate absorption of the absorption process and at the same time,the absorption refrigeration cycle can be used in more areas.The new refrigeration cycle is analyzed.A method of choosing the parameters is given.The factors are decribed which affect the absorption process.A comparison with the traditional absorption process is also made.

  7. New refrigeration system using CO2 vapor-solid as refrigerant

    Institute of Scientific and Technical Information of China (English)

    Dongping HUANG; Guoliang DING; Hans QUACK

    2008-01-01

    A refrigerant must be in the vapor-liquid phase in a vapor-compression refrigeration system, therefore, CO2 cannot be used as a refrigerant for temperatures lower than -56℃ because solid CO2 will form under the triple point temperature of -56℃. A refrigeration system with CO2 vapor-solid particles as refrigerant is put forward, by which a temperature lower than the triple point is achieved. An adjustable nozzle, a sublimator, a high-pressure regulating valve and a low-pressure regulat-ing valve are used to replace the conventional evaporator. Theoretical cycle analysis of the refrigeration system shows that its COP can be 50% higher than that of the conventional one.

  8. Thermo-economic optimization of an endoreversible four-heat-reservoir absorption-refrigerator

    International Nuclear Information System (INIS)

    Based on an endoreversible four-heat-reservoir absorption-refrigeration-cycle model, the optimal thermo-economic performance of an absorption-refrigerator is analyzed and optimized assuming a linear (Newtonian) heat-transfer law applies. The optimal relation between the thermo-economic criterion and the coefficient of performance (COP), the maximum thermo-economic criterion, and the COP and specific cooling load for the maximum thermo-economic criterion of the cycle are derived using finite-time thermodynamics. Moreover, the effects of the cycle parameters on the thermo-economic performance of the cycle are studied by numerical examples

  9. CONTROL OF HYDROCARBON EMISSIONS FROM GASOLINE LOADING BY REFRIGERATION SYSTEMS

    Science.gov (United States)

    The report gives results of a study of the capabilities of refrigeration systems, operated at three temperatures, to control volatile organic compound (VOC) emissions from truck loading at bulk gasoline terminals. Achievable VOC emission rates were calculated for refrigeration sy...

  10. Variation of Performance of Refrigeration System at different Temperature

    OpenAIRE

    Ankit Tiwari,; Prof. S.S Pawar,; Prof. Sachin Baraskar

    2014-01-01

    In this paper, the performances of four ozone-friendly Hydrofluorocarbon (HFC) refrigerants (R125, R134a, R143a and R152a) selected to replace R12 in a vapour compression refrigeration system were investigated experimentally and compared. The performance in term of coefficient of performance (COP), refrigerating capacity (RC), and compressor work (We) were evaluated for the investigated refrigerants at various evaporating and condensing temperatures. The system performance inc...

  11. Absorption cycle commercial refrigerator using wood burning cook stove; Geladeira de absorcao acionada por fogao a lenha

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Jose Tomaz Vieira; Martins, Gilberto [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia

    1990-12-31

    The current utilization of wood burning cook stoves in Brazil and the socio-economical profile of their users were surveyed. A traditional heavy-mass wood-burning cook stove was studied as a thermal equipment. Simple changes in the geometry of the combustion chamber were suggested to improve the cooking efficiency. A closed two-phase thermosyphon using water as working fluid was designed, built and connected between the combustion chamber of the cook stove and a depressurized absorption refrigeration system to determine the heat flux and the temperature level. A commercial refrigerator unit, using the absorption cycle, was coupled with the wood stove through the thermosyphon. The overall results of the coupling point to successful country-side applications. (author) 12 refs., 9 figs., 4 tabs.

  12. Development and proof-testing of advanced absorption refrigeration cycle concepts

    Energy Technology Data Exchange (ETDEWEB)

    Modahl, R.J.; Hayes, F.C. (Trane Co., La Crosse, WI (United States). Applied Unitary/Refrigeration Systems Div.)

    1992-03-01

    The overall objectives of this project are to evaluate, develop, and proof-test advanced absorption refrigeration cycles that are applicable to residential and commercial heat pumps for space conditioning. The heat pump system is to be direct-fired with natural gas and is to use absorption working fluids whose properties are known. Target coefficients of performance (COPs) are 1.6 at 47{degrees}F and 1.2 at 17{degrees} in the heating mode, and 0.7 at 95{degree}F in the cooling mode, including the effect of flue losses. The project is divided into three phases. Phase I entailed the analytical evaluation of advanced cycles and included the selection of preferred concepts for further development. Phase II involves the development and testing of critical components and of a complete laboratory breadboard version of the selected system. Phase III calls for the development of a prototype unit and is contingent on the successful completion of Phase II. This report covers Phase I work on the project. In Phase 1, 24 advanced absorption cycle/fluid combinations were evaluated, and computer models were developed to predict system performance. COP, theoretical pump power, and internal heat exchange were calculated for each system, and these calculations were used as indicators of operating and installed costs in order to rank the relative promise of each system. The highest ranking systems involve the cycle concept of absorber/generator heat exchange, generator heat exchanger/absorber heat exchange, regeneration, and resorption/desorption, in combination with the NH{sub 3}/H{sub 2}O/LiBr ternary absorption fluid mixture or with the NH{sub 3}/H{sub 2}O binary solution. Based upon these conclusions, the recommendation was made to proceed to Phase II, the laboratory breadboard proof-of- concept.

  13. Simulation studies of the behaviour of a heat pipe-assisted solar absorption refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hindi, R.R.; Khalifa, A.M.A.; Akyurt, M.

    1988-01-01

    Simulation work on an intermittent-duty, heat pipe-assisted, solar-operated aqua-ammonia absorption refrigerator is reported. The low-thermal mass collector is the integral evaporator of an acetone-copper heat pipe which delivers the collected energy isothermally to a distant generator. The shell-and-tube type generator receives the energy by vapour condensation. The condenser is air cooled. A separate R-22/steel heat-pipe system serves to cool the absorber tanks via a radiation/convection panel. Heat and mass balances are outlined on several units. The resulting equations are solved for day and night operation. It is concluded that both the initial solution (absorbent) concentration and the absorber temperature must be kept low for adequate ice production.

  14. Data-Driven Control of Refrigeration System

    DEFF Research Database (Denmark)

    Vinther, Kasper

    traditionally are a pressure and a temperature sensor. In this thesis, a novel maximum slope-seeking (MSS) control method is developed. This has resulted in a control implementation, which successfully has been able to control the evaporator superheat in four widely different refrigeration system test...... conditions make optimal tuning of controllers a difficult and time consuming task. These are also some of the challenges which make advanced model-based control difficult, and a model-based controller will often be tailored to a specific system. The focus in this thesis is therefore instead on development...... of data-driven control strategies with a higher plug and play potential. One of the main control challenges in refrigeration systems is proper control of superheat for efficient and safe operation of the system. This task can be performed by an electronic expansion valve and requires two sensors, which...

  15. Hybrid control of the distributed refrigeration system

    DEFF Research Database (Denmark)

    Chen, L.; Wisniewski, R.

    2010-01-01

    The supermarket refrigeration system typically has a distributed control structure, which neglects interactions between its subsystems. These interactions from time to time lead to a synchronization operation of the display-cases which causes an inferior control performance and increased energy...... Lyapunov exponent and a de-synchronization controller by chaotifying the system using the time-delayed impulsive method, essentially a kind of hybrid control. © 2010 IEEE....

  16. Performance Characteristics of the R404A Indirect Refrigeration System Using CO2 as a Secondary Refrigerant

    OpenAIRE

    Jung-In Yoon*; Kwang-Hwan Choi; Chang-Hyo Son

    2014-01-01

    In this study, to investigate the performance characteristics of the R404A indirect refrigeration system using CO2 as a secondary refrigerant, the R404A refrigeration system was analyzed experimentally. Under given experimental conditions, the lower the difference between the R404A condensing temperature and the CO2 cooling temperature was, the greater the coefficient of performance (COP) of the total indirect refrigeration system was, including the R404A refrigeration and CO2...

  17. Refrigeration system for W7-X

    International Nuclear Information System (INIS)

    The refrigeration system for the W7-X superconducting magnet and the divertor cryo-vacuum pumps is presented. In total, five main helium cooling circuits have to be supplied by the refrigerator-four for the magnet including auxiliary equipment like support structure, thermal shield and current leads, and one for the cryo-pumps. For the shields of the latter, an additional LN2-cooling circuit is required. The lowest operating temperature is 3.3 K. It will be provided by evacuating a sub-cooler bath using a cold or warm compressor. Three of the helium cooling circuits use altogether four identical cold circulators. Apart from the current leads which are supplied with the coolant from a LHe storage tank, the peak reserve power required is equal to 7 kW at 4.5 K entropy equivalent. However, this potential maximal demand occurs continuously for periods of only a few hours at most, and altogether for less than 1% of annual time. The refrigerator thus will be designed for 5 kW continuous power at 4.5 Kequiv. corresponding to 1.5 MW compressor connected rating. The reserve peak power will be covered, if necessary, by using the latent heat and vapour enthalpy of LHe from a storage tank. This supporting LHe stream is added to the phase separator and fed subsequently to the low pressure return stream at the cold end of the cold box. LN2-pre-cooling equipment of the cold box - which is installed for W7-X cool-down anyway - can also be used to increase refrigeration power. The LHe required for maintaining reserve refrigeration power as well as for running the current leads is generally produced overnight when W7-X is in idle current mode. (author)

  18. Model based control of refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Sloth Larsen, L.F.

    2005-11-15

    The subject for this Ph.D. thesis is model based control of refrigeration systems. Model based control covers a variety of different types of controls, that incorporates mathematical models. In this thesis the main subject therefore has been restricted to deal with system optimizing control. The optimizing control is divided into two layers, where the system oriented top layers deals with set-point optimizing control and the lower layer deals with dynamical optimizing control in the subsystems. The thesis has two main contributions, i.e. a novel approach for set-point optimization and a novel approach for desynchronization based on dynamical optimization. The focus in the development of the proposed set-point optimizing control has been on deriving a simple and general method, that with ease can be applied on various compositions of the same class of systems, such as refrigeration systems. The method is based on a set of parameter depended static equations describing the considered process. By adapting the parameters to the given process, predict the steady state and computing a steady state gradient of the cost function, the process can be driven continuously towards zero gradient, i.e. the optimum (if the cost function is convex). The method furthermore deals with system constrains by introducing barrier functions, hereby the best possible performance taking the given constrains in to account can be obtained, e.g. under extreme operational conditions. The proposed method has been applied on a test refrigeration system, placed at Aalborg University, for minimization of the energy consumption. Here it was proved that by using general static parameter depended system equations it was possible drive the set-points close to the optimum and thus reduce the power consumption with up to 20%. In the dynamical optimizing layer the idea is to optimize the operation of the subsystem or the groupings of subsystems, that limits the obtainable system performance. In systems

  19. Performance Assessment and Active System Monitoring for Refrigeration Systems

    DEFF Research Database (Denmark)

    Green, Torben

    The refrigeration system in a supermarket is an important part of the business for the supermarkets, both in terms of the possibility it provides and because of the associated cost of operating the system. It provides the possibility of selling chilled and frozen food but on the other hand...... the operation of the refrigeration system is associated with a signicant cost. Cost ecient operation of the refrigeration system is therefore very important for the supermarkets. To ensure that the systems are operated cost efficient a performance assessment scheme is required. In addition, there exists a need...... for algorithms that ensures or improves the performance of the system. A supermarket refrigeration system is usually a complex and distributed control system, and it can therefore be difficult to assess the performance without a formal method. The main interest for a supermarket, with respect...

  20. IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAN

    2003-05-19

    With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system types investigated include the following: distributed compressor systems--small parallel compressor racks are located in close proximity to the food display cases they serve thus significantly shortening the connecting refrigerant line lengths; secondary loop systems--one or more central chillers are used to refrigerate a secondary coolant (e.g. brine, ice slurry, or CO2) that is pumped to the food display cases on the sales floor; self-contained display cases--each food display case

  1. Toward High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  2. Towards High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  3. Industrial refrigeration with high efficiency absorption; Refrigeracion industrial por absorcion de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Ayala Delgado, R.; Heard, C. L. [Instituto de Investigaciones Electricas, Cuernavaca, (Mexico); Pardubicki, J. [LAJ International, Mexico D. F. (Mexico)

    1995-12-31

    The absorption refrigeration ammonia-lithium nitrate offers great advantages compared with the mechanical compression refrigeration with ammonia as well as with the absorption ammonia-water refrigeration. With heat temperatures of 1000 to 1400 Celsius degrees, for instance low pressure steam the generation of cold at low temperatures (-100 to -200 Celsius degrees) is possible. The system has less components and is much less expensive than the ammonia-water equipment with a price very similar to the ammonia mechanical compression equipment. The equipment consists of five main heat exchangers and a solution pump, resulting in a high reliability of its operation, requiring a minimum maintenance. The operation cost depends directly of the cost of the energy source. In case of using residual heat the operation cost is only the maintenance cost. Nowadays the cost of the electric energy is below the production cost, which can be a short term situation. In time terms of the comparable useful life time of an absorption refrigeration system (in excess of 20 years), it is reasonable to think that the operation costs will be less than the operation costs of an equipment with mechanical compression. To this day it is available a demonstration unit to exhibit the system in industrial plants with different energy sources. [Espanol] La refrigeracion por absorcion amoniaco/nitrato de litio ofrece grandes ventajas comparada tanto con la refrigeracion por compresion mecanica con amoniaco como con la refrigeracion por absorcion amoniaco/agua. Este sistema es mas eficiente y sencillo que el sistema de amoniaco/agua. Con calor de temperatura (100 a 140 grados centigrados por ejemplo vapor de baja presion, se permite la generacion de frio a temperaturas bajas (-10 a -20 grados centigrados). El sistema tiene menos componentes y es mucho mas barato que equipo de amoniaco/agua con un precio muy similar a sistemas por compresion mecanica de amoniaco. El sistema consiste en cinco

  4. 扩散吸收式制冷系统中板式换热器综合传热性能分析%Heat Transfer Performances of Plate Heat Exchangers Used in Diffusion-Absorption Refrigeration System

    Institute of Scientific and Technical Information of China (English)

    王寒栋

    2012-01-01

    在一种太阳能驱动、采用喷雾吸收器并以板式换热器作为主要换热部件的LiNO3-NH3-He三工质扩散吸收式制冷系统中,根据试验测得的运行参数,以溶液的p-t-x西方程及物性方程、传热基础理论等为依据,提出了计算溶液换热器中溶液流量的方法,并利用综合传热系数k、传热单元数N_TU与换热器效率s研究了板式换热器作为LiN03-NH3-He扩散吸收式制冷系统发生器、冷凝器、溶液热交换器、溶液冷却器时的换热性能.试验与分析表明,板式换热器的换热面积及其内部流道中的流量(流速)对其综合传热性能具有较大影响;在介质流量一定时,板式换热器不宜考虑过大的面积预留量;板式溶液换热器内部流道宜采用多流程布置形式以强化传热、提高换热效率.%A LiNO3-NH3-He diffusion-absorption refrigeration system driven by solar energy is introduced, in which a spray absorber is used to enhance the heat and mass transfer, and plate heat exchangers (PHEs) used as generator, condenser, solution heat exchanger (SHE) and solution cooler, respectively. Besides, solution flow rates in the system are evaluated based on p-t-x and physical property equations of LiNO3-NH3 solution, principles of heat transfer, and parameters such as pressure, temperatures and flow rates. Heat transfer performances are also investigated according to the overall heat transfer coefficient k, number of heat transfer units NTU and heat exchanger efficiency ε. Experiments and analysis show that, in LiNO3-NH3-He diffusion-absorption refrigeration system, heat transfer area and solution flow rates of PHEs affect the overall heat transfer performance of the PHEs. Therefore, extra size on PHE is not recommended if the solution flow rate is kept constant, and inner passageways of PHEs should adopt multi-pass to enhance heat transfer.

  5. Exergy analysis of a novel air-cooled non-adiabatic absorption refrigeration cycle with NH3–NaSCN and NH3–LiNO3 refrigerant solutions

    International Nuclear Information System (INIS)

    Graphical abstract: A methodology based on the second law of thermodynamic has been carried out in the analysis of an air-cooled type ammonia/salt absorption refrigeration system. Simulation results show that Low grade energy is applicable for NH3/NaSCN and NH3/LiNO3 absorption refrigeration system under air cooling condition and relatively high exergetic efficiency can be obtained. - Highlights: • We analyze an absorption refrigeration cycle driven by low grade energy. • Modified Methodology in entropy calculation is presented. • New exergy calculation method of ammonia/salt solution is presented. • Exergy analysis under air-cooled condition is carried out. • Influence of non-adiabatic absorber to exergetic efficiency is analyzed. - Abstract: This paper presents a methodology of exergy analysis for ammonia-lithium nitrate and ammonia-sodium thiocyanate absorption refrigeration cycle which applies a novel air-cooled type non-adiabatic absorber to improve both the coefficient of performance and exegetic efficiency of the system under air cooling condition. A modified entropy calculation method for NH3/NaSCN and NH3/LiNO3 solutions is presented in this literature and different results are obtained comparing to previous research. In addition to the variation of solution temperature and pressure from specific working state to the reference state, the variation of solution concentration, which was always neglected by previous researchers in ammonia/salt solution exergy calculation, has been taken into account while analyzing the least potential of ammonia/salt solution for doing useful work, and a corresponding approach for specific exergy calculation is presented. The effects of generator temperature, absorber outlet temperature, absorber efficiency and other system parameters on system exergetic efficiency have been discussed in this study. Analysis results indicate that relatively high system performance can be obtained by air-cooled type ammonia

  6. Two stage sorption type cryogenic refrigerator including heat regeneration system

    Science.gov (United States)

    Jones, Jack A.; Wen, Liang-Chi; Bard, Steven

    1989-01-01

    A lower stage chemisorption refrigeration system physically and functionally coupled to an upper stage physical adsorption refrigeration system is disclosed. Waste heat generated by the lower stage cycle is regenerated to fuel the upper stage cycle thereby greatly improving the energy efficiency of a two-stage sorption refrigerator. The two stages are joined by disposing a first pressurization chamber providing a high pressure flow of a first refrigerant for the lower stage refrigeration cycle within a second pressurization chamber providing a high pressure flow of a second refrigerant for the upper stage refrigeration cycle. The first pressurization chamber is separated from the second pressurization chamber by a gas-gap thermal switch which at times is filled with a thermoconductive fluid to allow conduction of heat from the first pressurization chamber to the second pressurization chamber.

  7. Advanced Supermarket Refrigeration/ Heat Recovery Systems - Workshop Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, P.

    2001-06-15

    This CD ROM brings together proceedings of the Annex 26 Workshop 'Advanced Supermarket Refrigeration/ Heat Recovery Systems' held in Sweden, 2-3 October 2000. Sessions at the workshop were: Session 1: The supermarket as a system, Session 2: Analysis and modeling, Session 3: Field experiences, Session 4: Energy-efficient equipment. Annex 26 investigates candidate advanced system design approaches to determine their potential to reduce refrigerant usage and energy consumption for both refrigeration and heating/ air conditioning in supermarkets. Advanced supermarket refrigeration system concepts to be considered include, but are not limited to secondary loop systems, distributed compressors systems, and self-contained display cases.

  8. Analysis of a solar powered absorption system

    International Nuclear Information System (INIS)

    Highlights: • Conventional absorption system modified to increase COP. • Results indicated increase of 10% in COP due to dephlegmator heat recovery. • Results indicated increase of 8% in COP due to refrigerant storage unit. • Results indicated increase of 18% in COP due to combined effect of modifications. • Simulation results indicated a very good agreement with the measured results. - Abstract: Today, fossil fuel is the primary extensively used source of energy. However, its negative impact on the environment have forced the energy research continuity to seriously consider renewable sources of energy. Solar energy, in particular, has been the main focus in this regard because it is a source of clean energy and naturally available. This study presents the design and analysis of a solar powered absorption refrigeration system modified to increase its coefficient of performance (COP). The modifications include recovering of waste heat from a dephlegmator and utilization of a refrigerant storage unit. The simulation results indicate an increase of 10% in the COP of the conventional design using dephlegmator heat recovery and an increase of 8% in the COP of the conventional design due to the use of a refrigerant storage. The analysis for the combined effect of modifications indicates an increase of 18% in the COP compared to conventional design. Calculated values of coefficient of performance indicate a very good agreement with the ones obtained based on measurement

  9. Performance improvement clarification for refrigeration system using active system monitoring

    DEFF Research Database (Denmark)

    Green, Torben; Niemann, Hans Henrik; Izadi-Zamanabadi, Roozbeh

    2011-01-01

    This paper addresses the problem of determining whether a refrigeration plant has the possibility of delivering a better performance of the operation. The controllers are wellknown but detailed knowledge about the underlying dynamics of the refrigeration plant is not available. Thus, the question...... is if it is possible to achieve a better performance by changing the controller parameter. An approach to active system monitoring, based on active fault diagnosis techniques, is employed in order to evaluate changes in the system performance under operation....

  10. NLP modeling for the optimization of LiBr-H2O absorption refrigeration systems with exergy loss rate, heat transfer area, and cost as single objective functions

    DEFF Research Database (Denmark)

    Mussati, Sergio F.; Gernaey, Krist; Morosuk, Tatiana;

    2016-01-01

    and all stream temperatures, while the optimal solution obtained by minimization of the total heat transfer area provides the lower bounds for these model variables, to solve a cost optimization problem. The minimization of the total exergy loss rate by varying parametrically the available total heat...... to the theoretical value. The optimal solutions corresponding to the theoretical and the practical upper bound values for the total heat transfer area (100 m2 and 61 m2, respectively) as well as the optimal solution obtained by minimization of the total annual cost are discussed for a case study considering...... exergy loss rate, the total heat transfer area, and the total annual cost of the system. It was found that the optimal solution obtained by minimization of the total exergy loss rate provides “theoretical” upper bounds not only for the total heat transfer area of the system but also for each process unit...

  11. Refrigerator oils for mobile refrigeration systems; Kaeltemaschinenoele fuer die Anwendung in der mobilen Kaeltetechnik

    Energy Technology Data Exchange (ETDEWEB)

    Bock, W. [Fuchs Petrolub AG, Mannheim (Germany); Fahl, J. [Fuchs-Dea Schmierstoff GmbH und Co. KG, Mannheim (Germany)

    1999-08-01

    Synthetic polyglycol based refrigerator oils (PAG) for vehicle air conditioning systems which use R134a are compared with synthetic refrigerator oils based on special polyol esters (POE) in bus applications with R134a. Current development products and trends for the natural CO{sub 2} refrigerant are discussed. (orig.) [Deutsch] Es wird ein Ueberblick ueber die derzeitige und zukuenftige Situation der Schmierstoff-Kaeltemittel-Kombinationen in der mobilen Kaeltetechnik gegeben. Dabei werden die in Pkw-Klimaanlagen eingesetzten Polyglykol-R134a-Systeme mit Polyolester-R134a-Gemischen fuer Busklimaanlagen verglichen. Ausserdem werden aktuelle Schmierstoffentwicklungen fuer das Kaeltemittel CO{sub 2} vorgestellt. (orig.)

  12. Modeling and calculation of open carbon dioxide refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • A model of open refrigeration system is developed. • The state of CO2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO2 has little relation to the state of CO2. • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration

  13. Commercial Refrigeration: Heat Transfer Optimization and Energy Reduction, Measurement and Verification of a Liquid Refrigerant Pump System Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gaul, Chris [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheppy, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-22

    This study describes the test results of a Refrigerant Pump System integrated into a commercial supermarket direct expansion (DX) vapor compression refrigeration system. The Liquid Refrigerant Pump System retrofit (patent-pending; application number 13/964,198) was introduced to NREL in August 2014 by CTA Architects Engineers.

  14. Optimal Cooling Load and COP Relationship of a Four-Heat-Reservoir Endoreversible Absorption Refrigeration Cycle

    Directory of Open Access Journals (Sweden)

    Chih Wu

    2004-06-01

    Full Text Available Abstract: On the basis of a four-heat-reservoir endoreversible absorption refrigeration cycle model, another linear heat transfer law [i.e., the heat-flux] is adopted, the fundamental optimal relation between the coefficient of performance (COP and the cooling load, as well as the maximum cooling load and the corresponding COP of the cycle coupled to constant-temperature heat reservoirs are derived by using finite-time thermodynamics or thermodynamic optimization. The optimal distribution of the heat-transfer surface areas is also obtained. Moreover, the effects of the cycle parameters on the COP and the cooling load of the cycle are studied by detailed numerical examples. The results obtained herein are of importance to the optimal design and performance improvement of an absorption refrigeration cycle.

  15. Generalized Performance Characteristics of Refrigeration and Heat Pump Systems

    OpenAIRE

    Mahmoud Huleihil; Bjarne Andresen

    2010-01-01

    A finite-time generic model to describe the behavior of real refrigeration systems is discussed. The model accounts for finite heat transfer rates, heat leaks, and friction as different sources of dissipation. The performance characteristics are cast in terms of cooling rate (r) versus coefficient of performance (w). For comparison purposes, various types of refrigeration/heat pump systems are considered: the thermoelectric refrigerator, the reverse Brayton cycle, and the reverse Rankine ...

  16. Development of Low Global Warming Potential Refrigerant Solutions for Commercial Refrigeration Systems using a Life Cycle Climate Performance Design Tool

    OpenAIRE

    Abdelaziz, Omar; Fricke, Brian; Vineyard, Edward A.

    2012-01-01

    Commercial refrigeration systems are known to be prone to high leak rates and to consume large amounts of electricity. As such, both the direct emissions related to refrigerant leakage and the indirect emissions resulting from primary energy consumption contribute greatly to their Life Cycle Climate Performance (LCCP). In this paper, an LCCP design tool is used to evaluate the performance of a typical commercial refrigeration system with alternative refrigerants and minor system modifications...

  17. Performance Analysis of Multipurpose Refrigeration System (MRS on Fishing Vessel

    Directory of Open Access Journals (Sweden)

    Ust Y.

    2016-04-01

    Full Text Available The use of efficient refrigerator/freezers helps considerably to reduce the amount of the emitted greenhouse gas. A two-circuit refrigerator-freezer cycle (RF reveals a higher energy saving potential than a conventional cycle with a single loop of serial evaporators, owing to pressure drop in each evaporator during refrigeration operation and low compression ratio. Therefore, several industrial applications and fish storage systems have been utilized by using multipurpose refrigeration cycle. That is why a theoretical performance analysis based on the exergetic performance coefficient, coefficient of performance (COP, exergy efficiency and exergy destruction ratio criteria, has been carried out for a multipurpose refrigeration system by using different refrigerants in serial and parallel operation conditions. The exergetic performance coefficient criterion is defined as the ratio of exergy output to the total exergy destruction rate (or loss rate of availability. According to the results of the study, the refrigerant R32 shows the best performance in terms of exergetic performance coefficient, COP, exergy efficiency, and exergy destruction ratio from among the other refrigerants (R1234yf, R1234ze, R404A, R407C, R410A, R143A and R502. The effects of the condenser, freezer-evaporator and refrigerator-evaporator temperatures on the exergetic performance coefficient, COP, exergy efficiency and exergy destruction ratios have been fully analyzed for the refrigerant R32.

  18. Exergoeconomic Analysis of A Two-stage Absorption Refrigeration System Using the Waste Geothermal Water%地热水双级吸收式制冷系统的火用经济分析

    Institute of Scientific and Technical Information of China (English)

    王永真; 罗向龙; 陈颖; 胡嘉灏; 龚宇烈

    2015-01-01

    With a concern of the vast geothermal waste water during the operation of flash geothermal power plant in Fengshun and the residents′need for cooling load, this paper proposes an integrated sys-tem which synthesizes a TSARS to the original flash power generation cycle, improving the utilization effi-ciency of the geothermal water by taking the advantage of two-stage LiBr-H2 O absorption refrigeration sys-tem( TSARS) in the utilization of low grade heat.First, with the field research made to establish the ex-ergoeconomic model, analysis of this geothermal water integrated system was addressed.Then, Compa-ring the ways of the geothermal water entering the TSARS, it was found that the parallel way is better than the cascade on the exergoeconomic performance.In addition, exergoeconomic analysis of each equipment of the paralleled TSARS was made.All above provide a certain reference to the further actual engineering application.%针对我国丰顺地热电站大量地热尾水直接排弃的问题和当地居民对制冷负荷的需求,基于双级溴化锂吸收式制冷循环( TSARS)在低品位热能利用方面的优势,提出将双级溴化锂吸收式制冷循环应用于地热电站尾水余热的回收,形成地热梯级综合利用系统,以进一步提高地热水的利用率。采用火用经济学分析方法,通过对电站的实地调研,建立地热水TSARS火用经济模型,进而对地热水级联到TSARS的两种可能模式(串联和并联)进行对比分析。结果发现地热水以并联方式供入TSARS具有较好的火用经济性能,同时对设计工况下的地热水并联TSARS的各设备进行了火用经济分析评价,为后期实际工程做参考。

  19. Coherence-assisted single-shot cooling by quantum absorption refrigerators

    OpenAIRE

    Mitchison, Mark T.; Woods, Mischa P.; Prior, Javier; Huber, Marcus

    2015-01-01

    The extension of thermodynamics into the quantum regime has received much attention in recent years. A primary objective of current research is to find thermodynamic tasks which can be enhanced by quantum mechanical effects. With this goal in mind, we explore the finite-time dynamics of absorption refrigerators composed of three qubits. The aim of this finite-time cooling is to reach low temperatures as fast as possible and subsequently extract the cold particle to exploit it for information ...

  20. Optimal Cooling Load and COP Relationship of a Four-Heat-Reservoir Endoreversible Absorption Refrigeration Cycle

    OpenAIRE

    Chih Wu; Fengrui Sun; Tong Zheng; Lingen Chen

    2004-01-01

    Abstract: On the basis of a four-heat-reservoir endoreversible absorption refrigeration cycle model, another linear heat transfer law [i.e., the heat-flux] is adopted, the fundamental optimal relation between the coefficient of performance (COP) and the cooling load, as well as the maximum cooling load and the corresponding COP of the cycle coupled to constant-temperature heat reservoirs are derived by using finite-time thermodynamics or thermodynamic optimization. The optimal distribution of...

  1. Control systems in refrigeration engineering; Regelung in der Kaeltetechnik

    Energy Technology Data Exchange (ETDEWEB)

    Hegglin, A.

    1996-09-01

    The article describes the various types of control systems in refrigeration engineering: Hermetic sealing of the refrigeration circuit; Control systems for better performance; Overheat control (electronic); Control systems for capacity adaptation; Electronic injection. (HW) [Deutsch] Der Artikel beschreibt die verschiedenen Arten der Regelsysteme in der Kaeltetechnik: - Hermetisierung des Kaeltekreislaufes - Regelverfahren zur Verbesserung des Wirkungsgrades - Ueberhitzungsregelung (elektronisch) - Regelverfahren zur Leistungsanpassung - elektronische Einspritzung. (HW)

  2. Refrigerating and air conditioning systems: dilemmas in the future development

    International Nuclear Information System (INIS)

    harmful influence of CFC fluids, depletion on the ozone layer and global warming of Earth. Survey on the most applied refrigerants and their potentials for harmful influence on the ozone layer and global warming. Montreal protocol and additional regulations (amendments). Measures for a phase-out of CFCs in Republic of Macedonia, projects, forming of training centers, training courses for good maintenance and servicing of refrigerating and air conditioning systems, equipment for recovery and recycling of refrigerants. The newest alternative refrigerants and their properties. Specifics in application of the new HFC fluids. Natural refrigerants: ammonia, carbon-hydrogen's, carbon-dioxide, water, air. Failing (toxicity and flammability) and advantages in their appliance. New concepts of refrigerating and air conditioning systems. Cross way in the future development of refrigerating and air conditioning systems. Crossing of opposite views and interest on the international level. Missing of strategy in Republic of Macedonia in the field of refrigeration and air conditioning. paradox in R. Macedonia: ammonia refrigerating systems go out of use. (Author)

  3. The Research on Optimal Control of Hvac Refrigeration System

    OpenAIRE

    He Bingqiang; Liao Chunling

    2012-01-01

    This paper gives a kind of optimal control method for HVAC refrigeration system. Controlling the frequency of compressor based on the suction pressure as control variable. Calculating the optimal suction pressure of various loads on principle of BP neural network model, so that make the refrigeration system obtain optimal state.

  4. 46 CFR 128.410 - Ship's service refrigeration systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ship's service refrigeration systems. 128.410 Section 128.410 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS... service refrigeration systems. No self-contained unit either for air-conditioning or for...

  5. Active Sensor Configuration Validation for Refrigeration Systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Blanke, Mogens; Niemann, Hans Henrik;

    2010-01-01

    Major faults in the commissioning phase of refrigeration systems are caused by defects related to sensors. With a number of similar sensors available that do not differ by type but only by spatial location in the plant, interchange of sensors is a common defect. With sensors being used quite...... differently by the control system, fault-finding is difficult in practice and defects are regularly causing commissioning delays at considerable expense. Validation and handling of faults in the sensor configuration are therefore essential to cut costs during commissioning. With passive fault......-diagnosis methods falling short on this problem, this paper suggests an active diagnosis procedure to isolate sensor faults at the commissioning stage, before normal operation has started. Using statistical methods, residuals are evaluated versus multiple hypothesis models in a minimization process to uniquely...

  6. A new generation of absorption refrigeration units; Neue Generation von Absorptionskaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, Hans [IFM - Ingenieurbuero Dr.-Ing. H. Foerster, Magdeburg (Germany)

    2012-07-01

    The conditions for the absorption refrigeration are now more opportune than it has been in a long time. The achieved and published progress as well as the utilization of a so-called medium pressure stage result in a deeper cooling of the heat carrier and an enhanced cooling efficiency of heat offerings. Medium pressure desorbers enable a cooling of heat sources up to a temperature of 70 Celsius. For the moment, cooling capacities of 40 kW and 250 kW with evaporation temperatures between - 3 and - 30 Celsius are available. The series production is being prepared. Larger cooling capacities are included in the product range in foreseeable future. Due to the shown alternatives for adsorption refrigeration plants with a medium-pressure part, the heat generated by the engine cooling in the summer can be used in the winter partially or fully as space heating for buildings and technological heat loads. There are good prospects that the absorption refrigeration technology becomes part of the energy revolution.

  7. Supermarket Refrigeration System - Benchmark for Hybrid System Control

    DEFF Research Database (Denmark)

    Sloth, Lars Finn; Izadi-Zamanabadi, Roozbeh; Wisniewski, Rafal

    2007-01-01

    This paper presents a supermarket refrigeration system as a benchmark for development of new ideas and a comparison of methods for hybrid systems' modeling and control. The benchmark features switch dynamics and discrete valued input making it a hybrid system, furthermore the outputs are subjected...

  8. The Design and Performance Analysis of Refrigeration System Using R12 & R134a Refrigerants

    Directory of Open Access Journals (Sweden)

    K. Nagalakshmi

    2014-02-01

    Full Text Available The design and performance analysis of refrigeration system using R12 & R134a refrigerants are presented in this report. The design calculations of the suitable and necessary refrigerator equipment and their results are also reported here. CFC-12 is the most widely used refrigerant. It serves both in residential and commercial applications, from small window units to large water chillers, and everything in between. Its particular combination of efficiency, capacity and pressure has made it a popular choice for equipment designers. Nevertheless, it does have some ODP, so international law set forth in the Montreal Protocol has put CFC-12 on a phase out schedule.HFC-134a has been established as a drop-in alternative for CFC-12 in the industry due to their zero Ozone Depletion Potential (ODP and similarities in thermodynamic properties and performance. However, when a system is charged with a HFC-134a compressor oil has to be changed.Not enough research has been done to cover all aspects of alternative refrigerants applications in the systems. This project intended to explore behavior of this alternative refrigerants compare to CFC-12 and challenges the industry is facing in design, operation services and maintenance of these equipments.The purpose of this project is to investigate behavior of R134a refrigerant. This includes performance and efficiency variations when it replaces R12 in an existing system as well as changes involved in maintaining the system charged with R134a. This project is intended to address challenges faced in the real world and some practical issues. Theoretical and experimental approaches used as a methodology in this work.

  9. The estimation of energy efficiency for hybrid refrigeration system

    International Nuclear Information System (INIS)

    Highlights: ► We present the experimental setup and the model of the hybrid cooling system. ► We examine impact of the operating parameters of the hybrid cooling system on the energy efficiency indicators. ► A comparison of the final and the primary energy use for a combination of the cooling systems is carried out. ► We explain the relationship between the COP and PER values for the analysed cooling systems. -- Abstract: The concept of the air blast-cryogenic freezing method (ABCF) is based on an innovative hybrid refrigeration system with one common cooling space. The hybrid cooling system consists of a vapor compression refrigeration system and a cryogenic refrigeration system. The prototype experimental setup for this method on the laboratory scale is discussed. The application of the results of experimental investigations and the theoretical–empirical model makes it possible to calculate the cooling capacity as well as the final and primary energy use in the hybrid system. The energetic analysis has been carried out for the operating modes of the refrigerating systems for the required temperatures inside the cooling chamber of −5 °C, −10 °C and −15 °C. For the estimation of the energy efficiency the coefficient of performance COP and the primary energy ratio PER for the hybrid refrigeration system are proposed. A comparison of these coefficients for the vapor compression refrigeration and the cryogenic refrigeration system has also been presented.

  10. Mixed refrigerant composition shift due to throttle valves opening in auto cascade refrigeration system

    Institute of Scientific and Technical Information of China (English)

    Xiongwen Xu; Jinping Liu; Le Cao

    2015-01-01

    Auto cascade refrigeration (ACR) cycle with phase separators is widely used in the cryogenic system. The compo-sition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of infinite volume of phase separator, ACR system with one phase separator is simulated in this paper. The variation of refrigerant composition under different valves opening is obtained. A related experimental system is set up to verify the variation. The result shows that when the valve opening connected to the evaporator increases or the valve opening under the phase separator decreases, the low-boiling component concentration of the working mixture passing through the compressor and condenser increases, while the high-boiling component concentra-tion decreases. Furthermore, the variations of condensation pressure and evaporation pressure under different valves opening are also observed. This paper is helpful to deepen the understanding of ACR system.

  11. The Refrigeration System; Appliance Repair--Advanced: 9027.01.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This course outline provides students with an understanding of the observation of basic refrigeration system components, the techniques used in working with copper tubing, and practice demonstrations to show what they have learned. Course content includes specific block objectives, orientation, refrigeration components (evaporator, compressor,…

  12. Modeling Supermarket Refrigeration Systems with EnergyPlus

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, Therese K [ORNL; Baxter, Van D [ORNL

    2010-01-01

    Supermarket refrigeration capabilities were first added to EnergyPlus in 2004. At that time, it was possible to model a direct expansion (DX) rack system with multiple refrigerated cases. The basic simulation software handles all the building energy uses, typically on a 5 to 10 minute time step throughout the period of interest. The original refrigeration module included the ability to model the sensible and latent interactions between the refrigerated cases and the building HVAC system, along with some basic heat recovery capabilities. Over the last few years, the refrigeration module has been expanded to handle more complex systems, such as secondary loops, shared condensers, cascade condensers, subcoolers, and walk-in coolers exchanging energy with multiple conditioned zones.

  13. Energy Efficiency and Environmental Impact Analyses of Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL; Bansal, Pradeep [ORNL; Zha, Shitong [Hillphoenix

    2013-01-01

    This paper presents energy and life cycle climate performance (LCCP) analyses of a variety of supermarket refrigeration systems to identify designs that exhibit low environmental impact and high energy efficiency. EnergyPlus was used to model refrigeration systems in a variety of climate zones across the United States. The refrigeration systems that were modeled include the traditional multiplex DX system, cascade systems with secondary loops and the transcritical CO2 system. Furthermore, a variety of refrigerants were investigated, including R-32, R-134a, R-404A, R-1234yf, R-717, and R-744. LCCP analysis was used to determine the direct and indirect carbon dioxide emissions resulting from the operation of the various refrigeration systems over their lifetimes. Our analysis revealed that high-efficiency supermarket refrigeration systems may result in up to 44% less energy consumption and 78% reduced carbon dioxide emissions compared to the baseline multiplex DX system. This is an encouraging result for legislators, policy makers and supermarket owners to select low emission, high-efficiency commercial refrigeration system designs for future retrofit and new projects.

  14. Helium refrigeration systems for super-conducting accelerators

    International Nuclear Information System (INIS)

    Many of the present day accelerators are based on superconducting technology which requires 4.5-K or 2-K helium refrigeration systems. These systems utilize superconducting radio frequency (SRF) cavities and/or superconducting magnets which are packaged into vacuum vessels known as cryo-modules (CM’s). Many of the present day accelerators are optimized to operate primarily at around 2-K, requiring specialized helium refrigeration systems which are cost intensive to produce and to operate. Some of the cryogenic refrigeration system design considerations for these challenging applications are discussed

  15. Helium refrigeration systems for super-conducting accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ganni, V. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606, USA Email: ganni@jlab.org (United States)

    2015-12-04

    Many of the present day accelerators are based on superconducting technology which requires 4.5-K or 2-K helium refrigeration systems. These systems utilize superconducting radio frequency (SRF) cavities and/or superconducting magnets which are packaged into vacuum vessels known as cryo-modules (CM’s). Many of the present day accelerators are optimized to operate primarily at around 2-K, requiring specialized helium refrigeration systems which are cost intensive to produce and to operate. Some of the cryogenic refrigeration system design considerations for these challenging applications are discussed.

  16. Trends and perspectives for supermarket refrigeration systems; Trends und Perspektiven fuer Supermarkt-Kaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Kauffeld, M. [Hochschule Karlsruhe - Technik und Wirtschaft (Germany). Inst. fuer Kaelte-, Klima- und Umwelttechnik

    2008-04-15

    This paper describes the latest trends and perspectives in supermarket refrigeration. Focus is on improving energy efficiency, reducing refrigerant charge and using natural refrigerants. Several alternative systems such as indirect, distributed, cascade and two-stage are described. (orig.)

  17. De-synchronization of the Distributed Refrigeration System

    DEFF Research Database (Denmark)

    Chen, Liang; Wisniewski, Rafal

    2010-01-01

    The supermarket refrigeration system typically has a distributed control structure, which simple and flexible, however, neglects interactions between its subsystems. Practice shows that these interactions lead to a synchronous operation of the display cases. It causes excessive wear on the compre......The supermarket refrigeration system typically has a distributed control structure, which simple and flexible, however, neglects interactions between its subsystems. Practice shows that these interactions lead to a synchronous operation of the display cases. It causes excessive wear...... on the compressors and increased energy consumption. The paper focuses on the synchronization analysis and de-synchronization control. The supermarket refrigeration system is modeled as a piecewise-affine switched system. The system behavior is decomposed such that synchronization analysis can be completed by using...... performance and can deal with the large scale refrigeration system with different system parameters in the display cases....

  18. Control Methods Utilizing Energy Optimizing Schemes in Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, L.S; Thybo, C.; Stoustrup, Jakob;

    2003-01-01

    The potential energy savings in refrigeration systems using energy optimal control has been proved to be substantial. This however requires an intelligent control that drives the refrigeration systems towards the energy optimal state. This paper proposes an approach for a control, which drives...... the condenser pressure towards an optimal state. The objective of this is to present a feasible method that can be used for energy optimizing control. A simulation model of a simple refrigeration system will be used as basis for testing the control method....

  19. Development of 18 K helium refrigeration system for CERN

    CERN Document Server

    CERN. Geneva

    2004-01-01

    The Conseil Europeen pour Ia Recherche Nucleaire (CERN) placed an order for a 1.8 K helium refrigeration system with IHI for the Large Hadron Collider project in 1999. IHI formed a consortium with Linde Kryotechnik AG (Switzerland), which has long experience with helium refrigeration systems. IHI designed and manufactured cold compressors based on leading technologies and expertise for turbo machinery. The cold compressor has the highest efficiency in the world. This paper describes the 1.8 K helium refrigeration system and performance test results at CERN. (5 refs).

  20. 一个新的吸收-喷射复合制冷循环%A NOVEL COMBINED EJECTOR-ABSORPTION REFRIGERATION CYCLE

    Institute of Scientific and Technical Information of China (English)

    洪大良; 唐黎明; 邹云霞; 何一坚; 陈光明

    2011-01-01

    提出了一个新的吸收-喷射复合制冷循环.在新循环中,部分冷凝器出口的饱和液态制冷剂被冷剂泵加压到制冷剂在发生温度下对应的饱和压力,这股高压制冷剂液体在一个沸腾器里被加热成饱和高压蒸气后将预热器出口的过热制冷剂蒸气引射到冷凝压力.由于在新循环中发生压力可以比冷凝压力低,因此该系统可以利用较低品位的热量制取低温下的冷量.研究结果表明:新循环可以利用比传统两级吸收式制冷循环温度更低的热源,制取同一温度下的冷量.此外,在蒸发温度或发生温度较低时,新循环的COP比单效循环高得多;当发生温度或蒸发温度较高时,新循环和传统单效循环的COP相同.%To make refrigeration at low temperature with low-grade heat source, a novel combined ejector-absorption refrigeration cycle was proposed in this paper. In the new cycle, part of saturated liquid refrigerant from the condenser was pumped to saturated pressure of the refrigerant at generation temperature. This stream was heated into saturated vapor in a boiler and injected the superheating refrigerant vapor from a preheater to condenser pressure. Since the generation pressure is lower than condenser pressure in the new cycle, the system can make refrigeration at low temperature with low-grade heat source. The research results show that the generation temperature of the new cycle is even lower than that of the conventional two-stage absorption refrigeration cycle to make refrigeration at the same low temperature. In addition, the COP of the new cycle is much higher than that of single-effect cycle at the low refrigeration temperature and generation temperature. If the refrigeration temperature or the temperature of heat source is high enough, the COP of the new cycle is the same as that of the conventional single-effect cycle.

  1. Experimental study on neon refrigeration system using commercial helium compressor

    Science.gov (United States)

    Ko, Junseok; Kim, Hyobong; Hong, Yong-Ju; Yeom, Hankil; Koh, Deuk-Yong; Park, Seong-Je

    2012-06-01

    In this study, we developed neon refrigeration system using commercial helium compressor which was originally designed for GM cryocooler. We performed this research as precedent study before developing neon refrigeration system for small-scale hydrogen liquefaction system. The developed system is based on precooled Linde-Hampson system with liquid nitrogen as precoolant. Design parameters of heat exchangers are determined from thermodynamic cycle analysis with operating pressure of 2 MPa and 0.4 MPa. Heat exchangers have concentric-tube heat exchanger configuration and orifice is used as Joule- Thomson expansion device. In experiments, pressure, temperature, mass flow rate and compressor input power are measured as charging pressure. With experimental results, the characteristics of heat exchanger, Joule-Thomson expansion and refrigeration effect are discussed. The developed neon refrigeration system shows the lowest temperature of 43.9 K.

  2. Materials Compatibility of HVACR System Materials with Low GWP Refrigerants

    OpenAIRE

    Majurin, Julie A.; Gilles, William; Staats, Steven J.

    2014-01-01

    When assessing the suitability of next generation refrigerants for use with current HVACR system materials, two areas of concern need to be thoroughly investigated and understood: 1) chemical stability of the fluids when exposed to system materials under the anticipated conditions of use, and 2) compatibility of the system materials when in contact with the fluids. This paper will summarize materials compatibility evaluations of unsaturated hydrofluorocarbon (HFO) refrigerants, and HFO refrig...

  3. Optimization of refrigeration system with gas-injected scroll compressor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Baolong; Shi, Wenxing; Han, Linjun; Li, Xianting [Department of Building Science, Tsinghua University, Beijing 100084 (China)

    2009-11-15

    Gas refrigerant injection has been proven as an effective method to improve the performance of the scroll compressor and its refrigeration system under high compression ratio working conditions. Much research on the injected scroll compressor and its system has been conducted, but the universal control and design method is still lacking. A model of the refrigeration system with a gas-injected scroll compressor is developed in this paper. With this model, the effects of gas injection on the system and component parameters are investigated. Based on the identified evaporator characteristics and thermodynamic analysis, a set of general principles for the design and operation of the refrigeration or heat pump system with a gas-injected scroll compressor is proposed. (author)

  4. Performance evaluation of integrated trigeneration and CO2 refrigeration systems

    International Nuclear Information System (INIS)

    Food retailing is one of the most energy intensive sectors of the food cold chain. Its environmental impacts are significant not only because of the indirect effect from CO2 emissions at the power stations but also due to the direct effect arising from refrigerant leakage to the atmosphere. The overall energy efficiency of supermarkets can be increased by integrating the operation of CO2 refrigeration and trigeneration systems. This paper compares three alternative schemes in a medium size supermarket. Experimental results and simulation studies have shown that the best scheme for energy and GHG emissions savings is the one where the cooling produced by the trigeneration system is used to condense the CO2 fluid in the refrigeration system to ensure subcritical operation throughout the year. It is shown that this system can produce 30% energy savings and over 40% greenhouse gas emissions savings over conventional refrigeration and indoor environment control systems in supermarkets.

  5. Re-engineering of refrigeration system of Heavy Water Plant Tuticorin

    International Nuclear Information System (INIS)

    Refrigeration system - a typical vapour compression system - normally an energy intensive process provides a good scope for energy conservation. After a detailed study of our refrigeration system, we have re-engineered our entire refrigeration system which has resulted in a tremendous power saving of 10300 units per day. This paper deals with the modifications implemented in HWP, Tuticorin in the refrigeration network. (author)

  6. A novel absorption refrigeration cycle for heat sources with large temperature change

    International Nuclear Information System (INIS)

    To increase the use efficiency of available thermal energy in the waste gas/water, a novel high-efficient absorption refrigeration cycle regarded as an improved single-effect/double-lift configuration is proposed. The improved cycle using an evaporator/absorber (E/A) promotes the coefficient of performance and reduces the irreversible loss. Water–lithium bromide is used as the working pair and a simulation study under the steady working conditions is conducted. The results show that the temperature of waste gas discharged is about 20 °C lower than that of the conventional single-effect cycle and the novel cycle we proposed can achieve more cooling capacity per unit mass of waste gas/water at the simulated working conditions. -- Graphical abstract: Pressure – temperature diagram for water – lithium bromide. Highlights: ► A novel waste heat-driven absorption refrigeration cycle is presented. ► The novel cycle can reject heat at much lower temperature. ► The available temperature range of heat source of the proposed cycle is wider. ► Multiple heat sources with different temperatures can be used in the novel cycle

  7. Aspects on modeled and the design of a system of refrigeration by absorption attended with solar energy; Aspectos sobre el modelado y diseno de un sistema de refrigeracion por absorcion asistido con energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Cascales, J. R.; Vera Garcia, F.; Cano Izquierdo, J. M.; Delgado Marin, J. P.; Martinez Sanchez, R.

    2008-07-01

    In this paper, we study the global modelling of an absorption system working with Br Li-H{sub 2}O. It satisfies the air-conditioning necessities of a classroom in an educational centre in Puerto Lumbreras. Murcia. This system utilises a set of solar collector to satisfy the thermal necessities of the vapour generator in the absorption system. For the dynamical simulation of the system we have used the TRNSYS software. The air-conditioned place has been modelled by using a TRNSYS module called PREBID. In this work, special attention is paid to the absorption equipment model developed by using neural networks which has been implemented in TRNSYS. The paper is closed drawing some conclusions. (Author)

  8. Advanced Supermarket Refrigeration / Heat Recovery Systems. Annex 26

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    This CD-ROM contains the proceedings (16 papers) of a workshop (held in Stockholm, Sweden, 2-3 October 2000) on Advanced Supermarket Refrigeration/ Heat Recovery Systems. Sessions at the workshop discussed: The supermarket as a system, Analysis and modelling, Field experiences and Energy-efficient equipment. The 16 papers presented at the workshop provide a useful information source for all involved in supermarket refrigeration.

  9. Overview of Deployment of Magnetic Refrigeration in Heat Pump Systems

    OpenAIRE

    Kawanami, Tsuyoshi; Vuarnoz, Didier

    2015-01-01

    The majority of cooling systems are based upon vapor-compression refrigeration technology. Its principle has been unchanged for more than a century. Miniaturization and competitiveness have been gained, but there’s still a need of alternative technologies, which can operate with better efficiency, lower energy consumption and better environmental safety. One of the most promising alternatives to a conventional vapor compression system is magnetic refrigeration. In this article, an overview of...

  10. The design and control of mine refrigeration systems

    OpenAIRE

    Howes, Michael

    1992-01-01

    The research is directed towards modelling the chiller set, the heat rejection and the load subsystems of a complete mine refrigeration system and simulating the performance in order that the design can be optimised and the most cost effective control system determined. The refrigeration load profile for a mechanised mine is complex and primarily a function of surface climatic variations, the strongly cyclic sources of heat resulting from the operation of diesel powered mining equipment and t...

  11. Heat driven refrigeration cycle at low temperatures

    Institute of Scientific and Technical Information of China (English)

    HE Yijian; HONG Ronghua; CHEN Guangming

    2005-01-01

    Absorption refrigeration cycle can be driven by low-grade thermal energy, such as solar energy, geothermal energy and waste heat. It is beneficial to save energy and protect environment. However, the applications of traditional absorption refrigeration cycle are greatly restricted because they cannot achieve low refrigeration temperature. A new absorption refrigeration cycle is investigated in this paper, which is driven by low-grade energy and can get deep low refrigeration temperature. The mixture refrigerant R23+R134a and an absorbent DMF are used as its working fluid. The theoretical results indicate that the new cycle can achieve -62℃ refrigeration temperature when the generation temperature is only 160℃. This refrigeration temperature is much lower than that obtained by traditional absorption refrigeration cycle. Refrigeration temperature of -47.3℃ has been successfully achieved by experiment for this new cycle at the generation temperature of 157℃, which is the lowest temperature obtained by absorption refrigeration system reported in the literature up to now. The theoretical and experimental results prove that new cycle can achieve rather low refrigeration temperature.

  12. Energy Efficiency Improvements in Household Refrigeration Cooling Systems

    OpenAIRE

    Björk, Erik

    2012-01-01

    This thesis is based on eight articles all related to the characteristics of the cooling system and plate evaporator of a household refrigerator. Through these articles, knowledge is provided that can be used to increase the operational efficiency in household refrigeration. Papers A, B and C focus on heat transfer and pressure drop in a commonly used free convection evaporator – the plate evaporator. Applicable correlations are suggested on how to estimate the air side heat transfer, the ref...

  13. An alternative method to estimate refrigeration system inventory

    International Nuclear Information System (INIS)

    Refrigeration system performance is directly related to the refrigerant mass charge in the equipment. This means that there is an optimum fluid amount that requires less power usage and contributes indirectly to a reduction in greenhouse gas output. Another important factor in fluid charge optimization is that it protects against compressor failure. The best approach for predicting refrigeration system inventory is to find the distribution of refrigerant mass in the evaporator and condenser. This work presents an alternative method for estimation of the refrigeration system inventory based on the first law of thermodynamics and the void fraction correlation of Hughmark. The average error of this alternative method was 5.1% and 7.2% for the first and second experimental validations, respectively, whereas the classical method of Otaki produced an error of 10%. Additionally, a convergence study and a sensitivity test were carried out. This alternative method is especially relevant for unusual heat exchanger geometries, when the external heat transfer coefficient is difficult to obtain from the literature. -- Highlights: ► We create an alternative method to determine the refrigerant charge inventory. ► We carried out experimental validations of this new method. ► We performed a convergence test and sensitivity test to verify the accuracy of the method. ► The results show that the new method generates excellent results. ► The new method has a relevant application in cases of uncommon external geometry

  14. Development and proof-testing of advanced absorption refrigeration cycle concepts. Report on Phases 1 and 1A

    Energy Technology Data Exchange (ETDEWEB)

    Modahl, R.J.; Hayes, F.C. [Trane Co., La Crosse, WI (United States). Applied Unitary/Refrigeration Systems Div.

    1992-03-01

    The overall objectives of this project are to evaluate, develop, and proof-test advanced absorption refrigeration cycles that are applicable to residential and commercial heat pumps for space conditioning. The heat pump system is to be direct-fired with natural gas and is to use absorption working fluids whose properties are known. Target coefficients of performance (COPs) are 1.6 at 47{degrees}F and 1.2 at 17{degrees} in the heating mode, and 0.7 at 95{degree}F in the cooling mode, including the effect of flue losses. The project is divided into three phases. Phase I entailed the analytical evaluation of advanced cycles and included the selection of preferred concepts for further development. Phase II involves the development and testing of critical components and of a complete laboratory breadboard version of the selected system. Phase III calls for the development of a prototype unit and is contingent on the successful completion of Phase II. This report covers Phase I work on the project. In Phase 1, 24 advanced absorption cycle/fluid combinations were evaluated, and computer models were developed to predict system performance. COP, theoretical pump power, and internal heat exchange were calculated for each system, and these calculations were used as indicators of operating and installed costs in order to rank the relative promise of each system. The highest ranking systems involve the cycle concept of absorber/generator heat exchange, generator heat exchanger/absorber heat exchange, regeneration, and resorption/desorption, in combination with the NH{sub 3}/H{sub 2}O/LiBr ternary absorption fluid mixture or with the NH{sub 3}/H{sub 2}O binary solution. Based upon these conclusions, the recommendation was made to proceed to Phase II, the laboratory breadboard proof-of- concept.

  15. Experimental study on the performance of the thermoacoustic refrigerating system

    International Nuclear Information System (INIS)

    This study is on the performance of the thermoacoustic refrigerating system with respect to some critical operating parameters. Experiments were performed on the system under various operating conditions. The experimental setup consists of the thermoacoustic refrigerating system with appropriate valves for the desired controls, instrumentation and the electronic data acquisition system. The resonator was constructed from aluminum tubing but it had plastic tube lining on the inside to reduce heat loss by conduction. Significant factors that influence the performance of the system were identified. The cooling produced increases with the temperature difference between the two ends of the stack. High pressure in the system does not necessarily result in a higher cooling load. There exists an optimum pressure and an optimum frequency for which the system should be operated in order to obtain maximum cooling load. Consequently, for the thermoacoustic refrigeration system, there should be a related compromise between cooling load, pressure and frequency for best performance.

  16. Ejector Performance of a Pump-less Ejector Refrigeration System Driven by Solar Thermal Energy

    OpenAIRE

    Dai, Zhengshu; He, Yijian; Huang, Yunzhou; Tang, Liming; Chen, Guangming

    2012-01-01

    Ejector refrigeration is considered as one of the three main ways of refrigeration and air-conditioning to utilize lowgrade energy. Use of pump-less technology to eliminate the mechanical circulating pump of the working fluid from condenser to generator in ejector refrigeration systems can meet the minimal maintenance requirement and increase operation lifetime of the system. In this study, a pump-less ejector refrigeration system driven by solar thermal energy, using R134a as refrigerant is ...

  17. Modeling and Control of a Double-effect Absorption Refrigerating Machine

    Science.gov (United States)

    Hihara, Eiji; Yamamoto, Yuuji; Saito, Takamoto; Nagaoka, Yoshikazu; Nishiyama, Noriyuki

    For the purpose of impoving the response to cooling load variations and the part load characteristics, the optimal operation of a double-effect absorption refrigerating machine was investigated. The test machine was designed to be able to control energy input and weak solution flow rate continuously. It is composed of a gas-fired high-temperature generator, a separator, a low-temperature generator, an absorber, a condenser, an evaporator, and high- and low-temperature heat exchangers. The working fluid is Lithium Bromide and water solution. The standard output is 80 kW. Based on the experimental data, a simulation model of the static characteristics was developed. The experiments and simulation analysis indicate that there is an optimal weak solution flow rate which maximizes the coefficient of performance under any given cooling load condition. The optimal condition is closely related to the refrigerant steam flow rate flowing from the separator to the high temperature heat exchanger with the medium solution. The heat transfer performance of heat exchangers in the components influences the COP. The change in the overall heat transfer coefficient of absorber has much effect on the COP compared to other components.

  18. Installation of a small central thermoelectric using biomass and cogeneration with absorption refrigeration system: alternative for small rural isolated communities; Instalacao de uma pequena central termeletrica a biomassa e cogeracao com sistema de refrigeracao por absorcao: alternativa para pequenas comunidades agricolas isoladas

    Energy Technology Data Exchange (ETDEWEB)

    Zukowski Junior, Joel Carlos; Marcon, Rogerio Olavo; Reys, Marcos Alves dos [Centro Universitario Luterano de Palmas (CEULP), TO (Brazil); Cortez, Luis Augusto Barbosa [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE)

    2004-07-01

    The lack of electrical energy in several localities of Brazil results in a slow perspective of in terms of economic growth and scientific and technological development. In order to minimize these problems it is proposed the use of co-generation systems with small thermoelectric plants burning rice rusk (an abundant biomass in certain regions of Brazil, as for example the Tocantins State) as a heat source and to utilize the discharged steam from the turbine to generate cold through an absorption refrigeration system. The work intends to show a possible solution to the problems originated from the absence of electric power in small and isolated rural villages, also problems of processing storage of agricultural residues and to generate cold for several applications. (author)

  19. Coherence-assisted single-shot cooling by quantum absorption refrigerators

    Science.gov (United States)

    Mitchison, Mark T.; Woods, Mischa P.; Prior, Javier; Huber, Marcus

    2015-11-01

    The extension of thermodynamics into the quantum regime has received much attention in recent years. A primary objective of current research is to find thermodynamic tasks which can be enhanced by quantum mechanical effects. With this goal in mind, we explore the finite-time dynamics of absorption refrigerators composed of three quantum bits (qubits). The aim of this finite-time cooling is to reach low temperatures as fast as possible and subsequently extract the cold particle to exploit it for information processing purposes. We show that the coherent oscillations inherent to quantum dynamics can be harnessed to reach temperatures that are colder than the steady state in orders of magnitude less time, thereby providing a fast source of low-entropy qubits. This effect demonstrates that quantum thermal machines can surpass classical ones, reminiscent of quantum advantages in other fields, and is applicable to a broad range of technologically important scenarios.

  20. An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01

    Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCP of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.

  1. TEWI Evaluation for Household Refrigeration and Air-Conditioning Systems

    Science.gov (United States)

    Sobue, Atsushi; Watanabe, Koichi

    In the present study, we have quantitatively evaluated the global warming impact by household refrigerator and air-conditioning systems on the basis of reliable TEWI information. In TEWI evaluation of household refrigerators, the percentage of the impact by refrigerant released to the atmosphere (direct effect) is less than 18.6% in TEWI. In case of room air-conditioners, however, the percentage of direct effect is less than 5.4% in TEWI. Therefore, it was confirmed that impact by CO2 released as a result of the energy consumed to drive the refrigeration or air-conditioning systems throughout their lifetime (indirect effect) is far larger than direct effect by the entire system. A reduction of indirect effect by energy saving is the most effective measure in reducing the global warming impact by refrigeration and air-conditioning systems, For a realization of the energy saving, not only the advanced improvement in energy efficiency by household appliance manufacturers but also the improvement of consumer's mind in selecting the systems and a way of using are concluded important.

  2. A global optimization method for regenerative air refrigeration systems

    International Nuclear Information System (INIS)

    The air refrigeration systems always involve such physical processes as heat transfer processes in heat exchangers, compression processes in compressors and expansion processes in expanders. This contribution proposes a theoretical global optimization method for regenerative air refrigeration systems and introduces the entransy theory to analyze the heat transfer processes in the hot-end heat exchanger, the cold-end heat exchanger and the regenerator. Integration of the heat transfer analyses and the thermodynamic analyses for the compression and expansion processes yields a mathematical model to describe the physical relation between the design requirements and the unknown design parameters, i.e. the heat transfer area of each heat exchanger and the heat capacity rate and the intermediate temperature of the air. Based on this model, the optimization can be converted into a conditional extremum problem. That is, solving the problem via the Lagrange multiplier method offers an optimization equation group, which directly leads to the optimal values of all the unknown parameters. Finally, this optimization method is validated through an optimization case to minimize the total thermal conductance of all the heat exchangers in a typical regenerative air refrigeration system. - Highlights: •An optimization method is proposed for regenerative air refrigeration systems. •Heat transfer processes in heat exchangers is analyzed by the entransy theory. •A mathematical relation between design parameters and requirements is derived. •This optimization method is validated by analyzing a typical refrigeration system

  3. Advanced Supermarket Refrigeration/Heat Recovery Systems. Country Report, Denmark

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard; Christensen, K. G.

    conclusions as far energy conservation and TEWI reduction is concerned. The conclusion justify that advanced supermarket systems with heat recovery should receive great attention and support. And there is still further research needed in several areas. The Annex also included a thorough system analyses...... provide valuable information for practitioners (designers, installers) and manufactures of supermarket refrigeration systems....

  4. Modular Modelling and Simulation Approach - Applied to Refrigeration Systems

    DEFF Research Database (Denmark)

    Sørensen, Kresten Kjær; Stoustrup, Jakob

    2008-01-01

    is divided into components where the inputs and outputs are described by a set of XML files that can be combined into a composite system model that may be loaded into MATLABtrade. A set of tools that allows the user to easily load the model and run a simulation are provided. The results show a simulation......This paper presents an approach to modelling and simulation of the thermal dynamics of a refrigeration system, specifically a reefer container. A modular approach is used and the objective is to increase the speed and flexibility of the developed simulation environment. The refrigeration system...

  5. Non-linear and adaptive control of a refrigeration system

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Larsen, Lars F. S.

    2011-01-01

    are capable of adapting to variety of systems. This paper proposes a novel method for superheat and capacity control of refrigeration systems; namely by controlling the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed...... and used in a backstepping design of a nonlinear adaptive controller. The stability of the proposed method is validated theoretically by Lyapunov analysis and experimental results show the performance of the system for a wide range of operating points. The method is compared to a conventional method based...

  6. A fault tolerant superheat control strategy for supermarket refrigeration systems

    DEFF Research Database (Denmark)

    Vinther, Kasper; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik;

    2013-01-01

    In this paper, a fault tolerant control (FTC) strategy is proposed for evaporator superheat control in supermarket refrigeration systems. Conventional control uses a pressure and temperature sensor for this purpose, however, the pressure sensor can fail to function. A contingency control strategy......, based on a maximum slope-seeking control method and only a single temperature sensor, is developed to drive the evaporator outlet temperature to a level that gives a suitable superheat of the refrigerant. The FTC strategy requires no a priori system knowledge or additional hardware and functions...... system....

  7. Potential Energy Savings in Refrigeration Systems Using Optimal Setpoints

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Slot; Thybo, Claus

    2004-01-01

    Energy efficiency of refrigeration systems has gradually been improved with help of control schemes utilizing the more flexible components. This paper proposes an approach in line with this trend, where a suboptimal condenser pressure is found in order to minimize the energy consumption. The obje......Energy efficiency of refrigeration systems has gradually been improved with help of control schemes utilizing the more flexible components. This paper proposes an approach in line with this trend, where a suboptimal condenser pressure is found in order to minimize the energy consumption....... The objective is to give an idea of how this optimization scheme works as well as to show what amount of energy it is possible to save. A steady state model of a simple refrigeration system will be used as a basis for the optimization....

  8. Preliminary Study on the Performance of the Diffusion Absorption Refrigerator Operating With the Mixed Refrigerant%混合工质扩散吸收制冷系统初步实验研究

    Institute of Scientific and Technical Information of China (English)

    王勤; 郝楠; 孙腾飞; 龚磊; 韩晓红; 陈光明

    2012-01-01

    This paper investigated the performance of a diffusion absorption refrigerator operating with R23/R32/R134a as the mixed refrigerant,DMF(N,N-dimethylformamide) as the absorbent, helium as the auxiliary inert gas and a solution pump.The experimental results show that the high pressure mixed refrigerant can be further cooled and liquefied in the refrigerant recuperator by the low pressure mixed refrigerant,and diffuse into helium at low refrigerating temperature,then the system can reach much low refrigerating temperature,which is also benefitted from the introduce of the component R32.The feasibility of horizontal serpentine tube-in-tube recuperator in the system has been verified in experiment,but the structure of the recuperator needs to be improved as well as the processing technique and installation accuracy of the recuperator in future.%本文研究了一种混合工质扩散吸收制冷循环,在带溶液泵的循环实验装置上,以R23/R32/R134a为混合制冷剂,He为扩散气体,DMF(二甲基甲酰胺)为吸收剂,进行了实验研究。结果表明,高压侧混合制冷剂在回热器中进一步被低压侧混合制冷剂冷却,使其在更低的温度下液化并与He扩散蒸发,可以实现较低的蒸发温度。中间沸点组分R32可以改善系统的制冷性能,有利于较低蒸发温度的实现。本文提出的水平蛇形套管换热器用作扩散吸收系统回热器是可行的,但还需进一步改进回热器的结构,提高加工工艺和安装精度。

  9. Corrosion inhibitor for aqueous ammonia absorption system

    Science.gov (United States)

    Phillips, Benjamin A.; Whitlow, Eugene P.

    1998-09-22

    A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

  10. Influence of mass-flow injection ratio on an economised indirect multi-temperature transport refrigeration system

    OpenAIRE

    Smyth, Shane; Brophy, Barry; Finn, Donal

    2011-01-01

    Refrigerant leakage associated with multi-temperature direct expansion (DX) systems in transport refrigeration applications has lead to increased interest in alternative refrigeration concepts. One alternative design approach aimed at reducing refrigerant charge and simplifying system control, involves the use of an indirect (IDX) refrigeration circuit. Recent investigations, concerned with the deployment of indirect systems for supermarket applications have shown that penalties in cooling...

  11. Compounds produced by motor burnouts of refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Koester, C.; Hawley-Fedder, R.; Foiles, L.

    1995-05-24

    The phase-out of chlorofluorocarbons has necessitated the introduction of alternate refrigerants. R22 (CF{sub 2}ClH), R134a (CF{sub 3}CH{sub 2}F), and R507 (50/50 CHF{sub 2}CF{sub 3}/CF{sub 3}CH{sub 3}) are newer fluids which are used in cooling systems. Recently, concern over the possible formation of toxic compounds during electrical arcing through these fluids has prompted us to identify their electrical breakdown products by electron ionization GC/MS. For example, it is known that perfluoroisobutylene (PFIB), which have an threshold limit value of 10 ppb (set by the American Conference of Government Industrial Hygienists), is produced from the thermal and electrical breakdown of some refrigerants. We have used specially designed test cells, equipped with electrodes, to simulate the electrical breakdown of R22, R134a, and R507 in refrigeration systems.

  12. Conference on Refrigeration for Cryogenic Sensors and Electronic Systems

    CERN Document Server

    Sullivan, D B; McCarthy, S E; Cryogenic Refrigeration Conference; International Cryocooler Conference; Cryocoolers 1

    1981-01-01

    This proceedings documents the output of a meeting of refrigeration specialists held at the National Bureau of Standards, Boulder, CO, on October 6 and 7, 1980. Building on an earlier invitation-only meeting in 1977, the purpose of this first open meeting was to discuss progress in the development of refrigeration systems to cool cryogenic sensors and electronic systems in the temperature range below 20 K and with required cooling capacities below 10 W. The meeting was jointly sponsored by the International Institute of Refrigeration - Commission A1/2, the Office of Naval Research, the Naval Research Laboratory, the Cryogenic Engineering Conference, and the National Bureau of Standards. This first open cryocooler conference consisted of 23 papers presented by representatives of industry, government, and academia. The conference proceedings reproduced here was published by the National Bureau of Standards in Boulder, Colorado as NBS Special Publication #607. Subsequent meetings would become known as the Intern...

  13. Optimising Performance in Steady State for a Supermarket Refrigeration System

    DEFF Research Database (Denmark)

    Green, Torben; Kinnaert, Michel; Razavi-Far, Roozbeh;

    2012-01-01

    Using a supermarket refrigeration system as an illustrative example, the paper postulates that by appropriately utilising knowledge of plant operation, the plant wide performance can be optimised based on a small set of variables. Focusing on steady state operations, the total system performance...

  14. Optimising performance in steady state for a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Green, Torben; Kinnaert, Michel; Razavi-Far, Roozbeh;

    2012-01-01

    Using a supermarket refrigeration system as an illustrative example, the paper postulates that by appropriately utilising knowledge of plant operation, the plant wide performance can be optimised based on a small set of variables. Focusing on steady state operations, the total system performance...

  15. Performance Evaluation of an Economised Indirect Multi-Temperature Transport Refrigeration System

    OpenAIRE

    Smyth, Shane; Brophy, Barry; Finn, Donal

    2010-01-01

    Direct expansion (DX) refrigeration technology is almost exclusively used in multi-temperature transport refrigeration systems. Multi-temperature systems use up to three evaporators, requiring large refrigerant charges and system pressure control to operate over a wide range of set-point conditions. Despite incremental design improvements over the past decade, environmental and control issues continue to arise with DX systems. Deployment of indirect refrigeration systems (IDX) offers an alte...

  16. Plant-wide performance optimisation – The refrigeration system case

    DEFF Research Database (Denmark)

    Green, Torben; Razavi-Far, Roozbeh; Izadi-Zamanabadi, Roozbeh;

    2012-01-01

    This paper investigates the problem of plant-wide performance optimisation seen from an industrial perspective. The refrigeration system is used as a case study, because it has a distributed control architecture and operates in steady state conditions, which is common for many industrial applicat...

  17. 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 ...

  18. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  19. Photovoltaic-Powered Vaccine Refrigerator: Freezer Systems Field Test Results

    Science.gov (United States)

    Ratajczak, A. F.

    1985-01-01

    A project to develop and field test photovoltaic-powered refrigerator/freezers suitable for vaccine storage was undertaken. Three refrigerator/freezers were qualified; one by Solar Power Corp. and two by Solvolt. Follow-on contracts were awarded for 19 field test systems and for 10 field test systems. A total of 29 systems were installed in 24 countries between October 1981 and October 1984. The project, systems descriptions, installation experiences, performance data for the 22 systems for which field test data was reported, an operational reliability summary, and recommendations relative to system designs and future use of such systems are explained. Performance data indicate that the systems are highly reliable and are capable of maintaining proper vaccine storage temperatures in a wide range of climatological and user environments.

  20. Load management for refrigeration systems: Potentials and barriers

    Energy Technology Data Exchange (ETDEWEB)

    Grein, Arne, E-mail: a.grein@tu-berlin.de [University of Technology Berlin, Institute for Energy Technology, Department of Energy Systems, Einsteinufer 25 (TA8), 10587 Berlin (Germany); Pehnt, Martin [Institute for Energy and Environmental Research Heidelberg (ifeu), Wilckensstr. 3, 69120 Heidelberg (Germany)

    2011-09-15

    As a strategy to deal with the increasing intermittent input of renewable energy sources in Germany, the adaptation of power consumption is complementary to power-plant regulation, grid expansion and physical energy storage. One demand sector that promises strong returns for load management efforts is cooling and refrigeration. In these processes, thermal inertia provides a temporal buffer for shifting and adjusting the power consumption of cooling systems. We have conducted an empirical investigation to obtain a detailed and time-resolved bottom-up analysis of load management for refrigeration systems in the city of Mannheim, Germany. We have extrapolated our results to general conditions in Germany. Several barriers inhibit the rapid adoption of load management strategies for cooling systems, including informational barriers, strict compliance with legal cooling requirements, liability issues, lack of technical experience, an inadequate rate of return and organizational barriers. Small commercial applications of refrigeration in the food-retailing and cold storage in hotels and restaurants are particularly promising starting points for intelligent load management. When our results are applied to Germany, suitable sectors for load management have theoretical and achievable potential values of 4.2 and 2.8 GW, respectively, amounting to about 4-6% of the maximum power demand in Germany. - Highlights: > Potential and barriers for implementation of load shifting for refrigeration. > Empirical investigation for time-resolved bottom-up analysis in Mannheim, Germany. > Suitable sectors and further recommendations for introducing load management.> Extrapolation of results from local to national level.

  1. Generalized Performance Characteristics of Refrigeration and Heat Pump Systems

    Directory of Open Access Journals (Sweden)

    Mahmoud Huleihil

    2010-01-01

    Full Text Available A finite-time generic model to describe the behavior of real refrigeration systems is discussed. The model accounts for finite heat transfer rates, heat leaks, and friction as different sources of dissipation. The performance characteristics are cast in terms of cooling rate (r versus coefficient of performance (w. For comparison purposes, various types of refrigeration/heat pump systems are considered: the thermoelectric refrigerator, the reverse Brayton cycle, and the reverse Rankine cycle. Although the dissipation mechanisms are different (e.g., heat leak and Joule heating in the thermoelectric refrigerator, isentropic losses in the reverse Brayton cycle, and limits arising from the equation of state in the reverse Rankine cycle, the r−w characteristic curves have a general loop shape. There are four limiting types of operation: open circuit in which both r and w vanish in the limit of slow operation; short circuit in which again r and w vanish but in the limit of fast operation; maximum r; maximum w. The behavior of the considered systems is explained by means of the proposed model. The derived formulae could be used for a quick estimation of w and the temperatures of the working fluid at the hot and cold sides.

  2. Two-dimensional Numerical Analysis on Ejector of Vapour Jet Refrigeration System

    OpenAIRE

    Kodamkayath Mani, Arun; Tiwari, Shaligram; Annamalai, Mani

    2014-01-01

    A vapour jet refrigeration system (VJRS) is an alternative to the conventional mechanically driven vapor-compression refrigeration system. The VJRS utilizes a supersonic ejector as a thermal compressor and has the potential to reduce energy consumption in refrigeration systems [1]. In the present study, the performance characteristics of VJRS ejectors with R134a as refrigerant have been investigated numerically using ANSYS Fluent. VJRS works on the principle that the high-pressure vapour from...

  3. 78 FR 57139 - Decision and Order Granting a Waiver to Panasonic Appliances Refrigeration Systems Corporation of...

    Science.gov (United States)

    2013-09-17

    ... storage, suggesting that this temperature is presumed to be representative of expected consumer use. 77 FR... Appliances Refrigeration Systems Corporation of America Corporation (PAPRSA) From the Department of Energy... Refrigeration Systems Corporation of America (PAPRSA) a waiver from the DOE electric refrigerator...

  4. 49 CFR 173.5b - Portable and mobile refrigeration systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Portable and mobile refrigeration systems. 173.5b...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS General § 173.5b Portable and mobile refrigeration... refrigeration systems, which may or may not be permanently mounted to a transport vehicle, used for...

  5. OPTIMAL SYSNTHESIS PROCESSES OF LOW-TEMPERATURE CONDENSATION ASSOCIATED OIL GAS PLANT REFRIGERATION SYSTEM

    OpenAIRE

    O. Ostapenko; O. Yakovleva; M. Khmelniuk; Zimin, A.

    2015-01-01

    Design of modern high-efficient systems is a key priority for the Energy Sector of Ukraine. The cooling technological streams of gas and oil refineries, including air coolers, water cooling and refrigeration systems for specific refrigerants are the objectives of the present study. Improvement of the refrigeration unit with refrigerant separation into fractions is mandatory in order to increase cooling capacity, lowering the boiling point of coolant and increasing the coefficient of target hy...

  6. Absorption refrigeration cycle applied to offshore platforms; Refrigeracao por absorcao aplicada a plataformas de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Maximino Joaquim Pina [KROMAV Engenharia, Rio de Janeiro, RJ (Brazil); Pinto, Luiz Antonio Vaz; Belchior, Carlos Rodrigues Pereira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

    2004-07-01

    To produce cold from the heat seems a task unlikely or even impossible. However, absorption systems produce cooling from heat sources and it exist since the century XIX. In industrial places is very important to improve the energy use, even more in places where the activities involve great costs and incomes. Traditionally the alternatives conflict in the aspects of initial and operational costs. This paper describes the absorption systems operation and its main advantages and disadvantages, when compared to the traditional systems with compressor. The known fact that a vapor compressor system presents larger efficiency is not enough to validate it for all of the applications. In this sense, the initial and operational analysis of the costs of the absorption systems becomes interesting. In spite of, double effect absorption systems are demonstrating the evolution of the absorption cycle in order to obtain better performance. Turbo-generators and Turbo-compressors of the offshore platforms are thermal machines that reject great amount of heat in the exhaust gases. This heat is used for heating of water used in the Process Plant. The processes of separation of the mixture water-oil-gas from the well, for instance, use that heat. Even after the passage of the water in the Plant of Process, the residual heat is still enough for the use in absorption systems. A simulation is done using real data of an offshore platform. Two possible alternatives are compared under technical and economical aspects. Sensibility analysis is also performed in order to verify possible impacts of variations of electric power cost. (author)

  7. OPTIMAL SYSNTHESIS PROCESSES OF LOW-TEMPERATURE CONDENSATION ASSOCIATED OIL GAS PLANT REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    O. Ostapenko

    2015-10-01

    Full Text Available Design of modern high-efficient systems is a key priority for the Energy Sector of Ukraine. The cooling technological streams of gas and oil refineries, including air coolers, water cooling and refrigeration systems for specific refrigerants are the objectives of the present study. Improvement of the refrigeration unit with refrigerant separation into fractions is mandatory in order to increase cooling capacity, lowering the boiling point of coolant and increasing the coefficient of target hydrocarbons extraction from the associated gas flow. In this paper it is shown that cooling temperature plays significant role in low-temperature condensation process. Two operation modes for refrigeration unit were proposed: permanent, in which the concentration of the refrigerant mixture does not change and dynamic, in which the concentration of refrigerant mixtures depends on the ambient temperature. Based on the analysis of exergy losses the optimal concentration of refrigerant mixtures propane/ethane for both modes of operation of the refrigeration unit has been determined. On the basis of the conducted pinch-analysis the modification of refrigeration unit with refrigerant separation into fractions was developed. Additional recuperative heat exchangers for utilization heat were added to the scheme. Several important measures to increase the mass flow rate of refrigerant through the second section of the refrigeration centrifugal compressor from 22.5 to 25 kg/s without violating the agreed operational mode of the compressor sections were implemented.

  8. Modeling Supermarket Refrigeration Systems for Supervisory Control in Smart Grid

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Rasmussen, Henrik; Stoustrup, Jakob

    2013-01-01

    A modular modeling approach of supermarket refrigeration systems (SRS) which is appropriate for smart grid control purposes is presented in this paper. Modeling and identification are performed by just knowing the system configuration and measured data disregarding the physical details. So...... regarding their power/energy consumptions in the future smart grids. Moreover, the developed model is validated by real data collected from a supermarket in Denmark. The utilization of the produced model is also illustrated by a simple simulation example....

  9. Performance Prediction of Solar Adsorption Refrigeration System by Ann

    OpenAIRE

    Baiju, V.; C. Muraleedharan

    2012-01-01

    This paper proposes a new approach for the performance analysis of a single-stage solar adsorption refrigeration system with activated carbon-R134a as working pair. Use of artificial neural network has been proposed to determine the performance parameters of the system, namely, coefficient of performance, specific cooling power, adsorbent bed (thermal compressor) discharge temperature, and solar cooling coefficient of performance. The ANN used in the performance prediction was made in MATLAB ...

  10. Status of not-in-kind refrigeration technologies for household space conditioning, water heating and food refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Pradeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Vineyard, Edward Allan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2012-07-19

    This paper presents a review of the next generation not-in-kind technologies to replace conventional vapor compression refrigeration technology for household applications. Such technologies are sought to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration for domestic use. These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption refrigeration, adsorption refrigeration, and compressor driven metal hydride heat pumps. Furthermore, heat pump water heating and integrated heat pump systems are also discussed due to their significant energy saving potential for water heating and space conditioning in households. The paper provides a snapshot of the future R&D needs for each of the technologies along with the associated barriers. Both thermoelectric and magnetic technologies look relatively attractive due to recent developments in the materials and prototypes being manufactured.

  11. Analysis of synchronization in a supermarket refrigeration system

    Institute of Scientific and Technical Information of China (English)

    Rafael WISNIEWSKI; John LETH; Jakob G. RASMUSSEN

    2014-01-01

    In a supermarket refrigeration, the temperature in a display case, surprisingly, influences the temperature in other display cases. This leads to a synchronous operation of all display cases, in which the expansion valves in the display cases turn on and off at exactly the same time. This behavior increases both the energy consumption and the wear of components. Besides this practical importance, from the theoretical point of view, synchronization, likewise stability, Zeno phenomenon, and chaos, is an interesting dynamical phenomenon. The study of synchronization in the supermarket refrigeration systems is the subject matter of this work. For this purpose, we model it as a hybrid system, for which synchronization corresponds to a periodic trajectory. To examine whether it is stable, we transform the hybrid system to a single dynamical system defined on a torus. Consequently, we apply a Poincar ´e map to determine whether this periodic trajectory is asymptotically stable. To illustrate, this procedure is applied for a refrigeration system with two display-cases.

  12. Experimental research on LiBr refrigeration - Heat pump system applied in CCHP system

    International Nuclear Information System (INIS)

    A new heat recovery technique for a LiBr refrigeration-heat pump system applied in CCHP(Combined Cooling, Heating and Power system) system is proposed in this paper. The system can recover the heat of the LiBr refrigeration cooling water to heat the demineralized water of the boiler. Experimental research on the operating characteristics of the compound system is carried out and the obtained conclusions are as follows: The LiBr refrigeration-heat pump system is able to perform stably and flexibly. The heat pump system has a relative large coefficient of performance (COPP) which can be as high as 6.13. When the outlet temperature of the demineralized water is 67.8 oC, the CCHP system brings 26.6% decrease in primary energy rate consumption compared with the combined heat and power production system (CHP) plus electricity-driven refrigeration. It is suggested that heat pumps should be used in CCHP system to heat the demineralized water of the boiler by recovering the exhaust heat of the LiBr refrigeration system. - Highlights: → LiBr refrigeration-heat pump system applied in CCHP system is proposed. → This system can recover the heat of the LiBr refrigeration cooling water to heat the demineralized water of the boiler. → Using heat pump to recover exhaust heat can increase the energy efficiency of the whole CCHP.

  13. Control Methods for Energy Management of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan

    In this study, a high fidelity model for supermarket refrigeration systems is developed. The problem of energy management is investigated under two different demand-side management schemes: indirect and direct load control. The former is based on the electricity price incentive, and in the latter...... the consumption is directly managed by a third party based on a contract. For the indirect load control, we propose two different supervisory control approaches using model predictive control (MPC) technique to address the problem of electricity cost minimization. For the direct load control, three different...... control methods are proposed. The first method is the least complex one including decentralized proportional-integral control loops that can be applied to a general class of supermarket refrigeration systems. In the second method, an MPC is formulated for which a high fidelity model specific for each...

  14. Experimental Results of Integrated Refrigeration and Storage System Testing

    Science.gov (United States)

    Notardonato, W. U.; Johnson, W. L.; Jumper, K.

    2009-01-01

    Launch operations engineers at the Kennedy Space Center have identified an Integrated Refrigeration and Storage system as a promising technology to reduce launch costs and enable advanced cryogenic operations. This system uses a close cycle Brayton refrigerator to remove energy from the stored cryogenic propellant. This allows for the potential of a zero loss storage and transfer system, as well and control of the state of the propellant through densification or re-liquefaction. However, the behavior of the fluid in this type of system is different than typical cryogenic behavior, and there will be a learning curve associated with its use. A 400 liter research cryostat has been designed, fabricated and delivered to KSC to test the thermo fluid behavior of liquid oxygen as energy is removed from the cryogen by a simulated DC cycle cryocooler. Results of the initial testing phase focusing on heat exchanger characterization and zero loss storage operations using liquid oxygen are presented in this paper. Future plans for testing of oxygen densification tests and oxygen liquefaction tests will also be discussed. KEYWORDS: Liquid Oxygen, Refrigeration, Storage

  15. A Review on Diffusion Absorption Refrigeration Technology%扩散吸收式制冷技术进展

    Institute of Scientific and Technical Information of China (English)

    曹园树; 李华山; 龙臻; 卜宪标; 马伟斌

    2014-01-01

    The diffusion absorption refrigeration (DAR) that could use low-grade thermal sources such as solar energy and waste heat, etc, is an environmental-friendly and energy-efficient technology and thus has a very promising prospect. By reviewing the latest researches around the world, this paper introduces the main findings for the DAR technology from three aspects including working fluid selection, cycle thermodynamic analysis as well as system improvement and optimization. Also, the development trends and future research directions of the DAR technology are presented. Some research works done by our team are also summarized.%扩散吸收式制冷(Diffusion Absorption Refrigeration,DAR)能够利用低品位能源如太阳能和余热等,是一种有利于环保和能源高效利用的技术,具有十分广阔的应用前景。结合国内外的最新研究动态,本文从工质选择、循环热力学分析、系统改进与优化研究三个方面介绍扩散吸收式制冷技术的主要研究成果,并对扩散吸收式制冷技术的发展趋势以及未来研究方向进行展望。同时,对本课题组关于扩散吸收式制冷所做的工作也进行了总结。

  16. Plant-wide performance optimisation – The refrigeration system case

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh; Green, Torben; Razavi-Far, Roozbeh;

    2012-01-01

    This paper investigates the problem of plant-wide performance optimisation seen from an industrial perspective. The refrigeration system is used as a case study, because it has a distributed control architecture and operates in steady state conditions, which is common for many industrial....... Furthermore, invasive weed optimisation is used to find the optimal parameters for local controllers based on the plant wide performance measure....

  17. Large-scale helium refrigeration system for KEKB/TRISTAN superconducting cavities. Operation experience for 27 years and next operation

    International Nuclear Information System (INIS)

    This article describes the configuration and heat loads of the large-scale helium refrigeration system for the superconducting cavities utilized for the TRISTAN and KEKB Factory accelerators. The control system of the refrigeration system is also introduced. The fatal failures of the refrigeration system during the past long-term operation are summarized to entice discussions on future stable operation of the refrigeration system, since the refrigeration system will also be used for the SuperKEKB superconducting cavities. (author)

  18. Load management for refrigeration systems: Potentials and barriers

    International Nuclear Information System (INIS)

    As a strategy to deal with the increasing intermittent input of renewable energy sources in Germany, the adaptation of power consumption is complementary to power-plant regulation, grid expansion and physical energy storage. One demand sector that promises strong returns for load management efforts is cooling and refrigeration. In these processes, thermal inertia provides a temporal buffer for shifting and adjusting the power consumption of cooling systems. We have conducted an empirical investigation to obtain a detailed and time-resolved bottom-up analysis of load management for refrigeration systems in the city of Mannheim, Germany. We have extrapolated our results to general conditions in Germany. Several barriers inhibit the rapid adoption of load management strategies for cooling systems, including informational barriers, strict compliance with legal cooling requirements, liability issues, lack of technical experience, an inadequate rate of return and organizational barriers. Small commercial applications of refrigeration in the food-retailing and cold storage in hotels and restaurants are particularly promising starting points for intelligent load management. When our results are applied to Germany, suitable sectors for load management have theoretical and achievable potential values of 4.2 and 2.8 GW, respectively, amounting to about 4-6% of the maximum power demand in Germany. - Highlights: → Potential and barriers for implementation of load shifting for refrigeration. → Empirical investigation for time-resolved bottom-up analysis in Mannheim, Germany. → Suitable sectors and further recommendations for introducing load management.→ Extrapolation of results from local to national level.

  19. Application of Absorption Refrigeration in the Coal Mine & Fluent Simulation%吸收式制冷在深部矿井高温热害处理中的应用与FLUENT模拟计算

    Institute of Scientific and Technical Information of China (English)

    杨前明; 杜雪

    2015-01-01

    For mine deep heat damage problem, effective use of low-grade waste heat of the Swallet, as the driving heat absorption refrigeration constructed absorption refrigeration, resolve deep coal thermal damage circulatory system through the use of deep water source heat pump heated gushing, so lithium bromide absorption chiller cooling at the same time on the working surface, as the heat absorption refrigeration cycle using design using auxiliary heating source heat pump to drive the refrigeration unit Swallet system. Fluent use of numerical simulation of the text, comparative analysis of the effect of coal mine deep under the best air cooling conditions, to provide a theoretical basis for the absorption refrigeration technology in actual use in deep.%针对煤矿深部热害问题,提出了利用矿井涌水中的低品位废热,作为吸收式制冷的驱动热源,构建了吸收式制冷循环系统解决煤矿深部开采工作面热害问题。依据煤矿深井开采工作面热舒适度要求,对制冷降温系统热参数进行估算;运用Fluent数值模拟,对比分析出最佳送风条件下的煤矿深井制冷效果。理论分析与数值模拟结果表明了采用吸收式制冷循环解决煤矿深井开采工作面热害问题可行性。

  20. Evaluation of a system of refrigeration with absorption cycle using the direct burning of natural gas for tropical fruits storage; Avaliacao de um sistema de refrigeracao com ciclo de absorcao utilizando a queima direta de gas natural para armazenamento de frutas tropicais

    Energy Technology Data Exchange (ETDEWEB)

    Bartolomeu, Lair S.; Torres, Ednildo A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Lab. de Energia e Gas; Silva, Gabriel F. [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil); Martins, Ronaldo M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Materiais. CQDM; Campos, Michel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Gerencia de Tecnologia do Gas Natural. Rede GasEnergia

    2004-07-01

    This work has the purpose to analyze an alternative method in the conservation of tropical fruits in chamber cooled through the technology of use of the natural gas as energy source. The study it was carried through in chiller of absorption, Robur model, of 5TR, which meets in the campus of the Federal University of Sergipe (UFS/LEG). The energy analysis had as objective to study the process involving the cycle and its components. Of the analysis of first law was gotten a power of refrigeration of 8,8 kW and a COP=0,32 and the analysis of second law {beta}=0,29. The exergetic analysis had for intention to evaluate the amount and the quality of the energy in the system. The heat generator was the component that presented the biggest irreversibility, whose relation with the total irreversibility was about 70%. In the absorber the lesser exergetic efficiency was verified. Project is supported by the GasEnergia/PETROBRAS. (author)

  1. Two-statge sorption type cryogenic refrigerator including heat regeneration system

    Science.gov (United States)

    Jones, Jack A. (Inventor); Wen, Liang-Chi (Inventor); Bard, Steven (Inventor)

    1989-01-01

    A lower stage chemisorption refrigeration system physically and functionally coupled to an upper stage physical adsorption refrigeration system. Waste heat generated by the lower stage cycle is regenerated to fuel the upper stage cycle thereby greatly improving the energy efficiency of a two-stage sorption refrigerator. The two stages are joined by disposing a first pressurization chamber providing a high pressure flow of a first refrigerant for the lower stage refrigeration cycle within a second pressurization chamber providing a high pressure flow of a second refrigerant for the upper stage refrigeration cycle. The first pressurization chamber is separated from the second pressurization chamber by a gas-gap thermal switch which at times is filled with a thermoconductive fluid to allow conduction of heat from the first pressurization chamber to the second pressurization chamber.

  2. Modeling Supermarket Refrigeration Systems for Demand-Side Management

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Rasmussen, Henrik; Stoustrup, Jakob

    2013-01-01

    Modeling of supermarket refrigeration systems for supervisory control in the smart grid is presented in this paper. A modular modeling approach is proposed in which each module is modeled and identified separately. The focus of the work is on estimating the power consumption of the system while...... estimating the cold reservoir temperatures as well. The models developed for each module as well as for the overall integrated system are validated by real data collected from a supermarket in Denmark. The results show that the model is able to estimate the actual electrical power consumption with a high...

  3. Analysis of Synchronization of Supermarket Refrigeration System

    DEFF Research Database (Denmark)

    Zheng, Li; Larsen, Lars Finn Sloth; Izadi-Zamanabadi, Roozbeh;

    2016-01-01

    Hybrid control has in the recent years drawn considerable attention in academia as it poses a large number of theoretical and computational challenges. The interested scientific community has proposed various methods to address some of the problems related to modeling and control of hybrid systems...... for the development of new ideas and a comparison of methods. Based on the model of this coupled hybrid system, we analyze the synchronization of the controllers in terms of the theories about topological space and Section Mapping....

  4. 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.

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

    International Nuclear Information System (INIS)

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

  6. On subcooler design for integrated two-temperature supermarket refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Chun-Lu [College of Mechanical Engineering, Tongji University, No. 4800, Cao An Highway, Shanghai 201804 (China)

    2011-01-15

    The energy saving opportunity of supermarket refrigeration systems using subcooler between the medium-temperature (MT) refrigeration system and the low-temperature (LT) refrigeration system has been identified in the previous work. This paper presents a model-based comprehensive analysis on the subcooler design. The optimal subcooling control is discussed as well. With optimal subcooler size and subcooling control, the maximum energy savings of integrated two-temperature supermarket refrigeration system using R404A or R134a as working fluid can achieve 27% or 20%, respectively. The load ratio of MT to LT system and the operating conditions have considerable impact on the energy savings. (author)

  7. Data Mining Approcah for Performance Analysis of Variable Speed Refrigeration System

    OpenAIRE

    KIZILKAN, Önder; KÜÇÜKSİLLE, Ecir Uğur; Ahmet KABUL

    2015-01-01

    The aim of this study is to carry out performance modeling of an experimental refrigeration system driven by variable speed compressor using Data Mining techniques with small data sets. In order to vary the capacity of the refrigeration systems, one of the best methods is controlling the rotational speed of the compressor motor with a frequency inverter. For this aim, an experimental refrigeration system is setup with a frequency inverter for controlling the speed of compressor electric motor...

  8. OPTIONS FOR REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

    Science.gov (United States)

    The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characteriz...

  9. Design study of 1.8 K 200 W helium refrigeration system

    International Nuclear Information System (INIS)

    The superconducting RF cavities of the superconducting proton linac will be cooled by superfluid helium below 2.0 K. The cooling test of the superconducting RF cavities will be required about 200 W of cooling power at 1.8 K. Refrigeration using superfluid helium is required a helium refrigeration system cooling down to 1.8 K. A cold compressor is a key component for the system. IHI carried out 1.8 K 200 W helium refrigeration system design for cooling test of the superconducting RF cavities. The preliminary design study of the 1.8 K 200 W helium refrigeration system is presented. (author)

  10. Performance test of a helium refrigerator for the cryogenic hydrogen system in J-PARC

    CERN Document Server

    Tatsumoto, H; Kato, T; Ohtsu, K; Hasegawa, S; Maekawa, F; Futakawa, M

    2009-01-01

    In J-PARC, a cryogenic hydrogen system, which plays a role in providing supercritical hydrogen with a pressure of 1.5 MPa and a temperature of 20 K to three moderators, has been designed. The performance test of the helium refrigeration system that is a part of the cryogenic hydrogen system was conducted independently. The helium refrigeration system was cooled down to 18 K within 4.5 hours, and the refrigerator power of 6.45 kW at 15.6 K was confirmed. The performance test results verified that the helium refrigerator satisfied the performance requirements.

  11. Power Consumption in Refrigeration Systems - Modeling for Optimization

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Skovrup, Morten Juel;

    2011-01-01

    there is a possibility for optimizing the power consumption by utilizing load shifting strategies. This paper describes the dynamics and the modeling of a vapor compression refrigeration system needed for sufficiently realistic estimation of the power consumption and its minimization. This leads to a non-convex function...... with possibly multiple extrema. Such a function can not directly be optimized by standard methods and a qualitative analysis of the system’s constraints is presented. The description of power consumption contains nonlinear terms which are approximated by linear functions in the control variables and the error...

  12. Simulation study of a combined adsorption refrigeration system

    International Nuclear Information System (INIS)

    In this study, we have divided combined ADRS into four types based on different arrangements of two working pairs, Zeolite 13x/CaCl2-water and Silica gel (RD type)–water, to analyze the performance of combined ADRS. After validating mathematical models with available experimental data, ADRS is simulated by using Simulink–Matlab software to achieve optimum times for various processes. The results of simulation show that the cooling capacity of the system with Zeolite 13x/CaCl2-water is more than the other types. The results have shown that the arrangement of adsorbents affects cooling capacity of combined ADRS significantly. In Type A, Zeolite 13x/CaCl2-water has been used as an adsorbent for both top and bottom cycles. This type not only has more cooling capacity than the other types, but also the effect of hot water temperature on cooling capacity of this type is less than the others. Furthermore, a sensitivity analysis has been done to determine the importance of each parameter on ADRS system because the cooling capacity and the COP are influenced by many constant parameters. - Highlights: • Development of a thermodynamic model for a combined adsorption refrigeration system. • Zeolite 13X/CaCl2 is considered as a new adsorbent in a combined adsorption refrigeration system. • Zeolite 13X/CaCl2-water are more advantageous than the other working pairs

  13. Control of Refrigeration Systems for Trade-off between Energy Consumption and Food Quality Loss

    OpenAIRE

    Cai, Junping

    2008-01-01

    In supermarkets, control strategies determine both the energy consumption of refrigeration systems and the quality loss of refrigerated foodstuffs. The question is, what can be done to optimize the balance between quality loss and energy consumption? This thesis tries to answer this question by applying two main optimization strategies to traditional refrigeration systems. The first strategy is a new defrost-on-demand scheme, which based on an objective function between quality loss and energ...

  14. Simulation of a new combined absorption-compression refrigeration cycle%一种新型吸收-压缩复合制冷循环模拟

    Institute of Scientific and Technical Information of China (English)

    唐鹏武; 陈光明; 唐黎明; 刘利华

    2011-01-01

    A program compiled by Visual Basic language was used to simulate a new combined absorption-compression refrigeration cycle for performance research, including the effect of generation temperature , evaporation temperature, condensation temperature, heat flux and refrigeration capacity on system performance which was compared with a conventional vapour compression refrigeration cycle. Simulation results show that when generation temperature increases, the coefficient of performance ( COP) of new cycle increases first and then decreases. When evaporation temperature or heat flux increases, the COP of new cycle increases. When condensation temperature or refrigeration capacity increases, the COP of new cycle decreases. Under most simulation conditions, the COP of new cycle can be 10% higher than that of conventional vapour compression refrigeration cycle. The new cycle can not only reduce air conditioning load greatly, but also provide the possibility of efficient utilization of low grade energy such as solar energy.%为了对一种新型吸收-压缩复合制冷循环的性能进行模拟,使用Visual Basic语言自行编制了一个程序.该程序模拟了发生温度、蒸发温度、冷凝温度、加热量、制冷量对系统性能的影响,并将其性能与传统蒸气压缩式制冷循环作了对比.模拟结果表明:当发生温度升高时,新循环的制冷系数先增大后减小;当蒸发温度升高或加热量增大时,新循环的制冷系数增大;当冷凝温度升高或制冷量增大时,新循环的制冷系数减小.在大部分假定工况下,新循环的制冷系数比传统蒸气压缩式循环的高10%以上.新循环的提出不仅能够大幅度减少空调电力负荷,还为太阳能等低品位能源的高效利用提供了可能.

  15. Progress and status of cryogenic refrigeration system for project Hydra

    Science.gov (United States)

    Yuan, J.; Catseman, F.; Tilleman, H.; Henderson, N.

    2015-12-01

    In the last two decades, HTS cables have been successfully demonstrated around the world, preparing HTS power cables for a full commercial introduction. Among the demonstration projects, circulating subcooled liquid nitrogen to maintain the HTS cable at operating temperature is a widely adopted approach. In this approach, the cooling systems are absolutely critical to the successful operation of the HTS cables. This paper describes the progress and status of the cryogenic refrigeration system designed and manufactured for project Hydra, which is a project jointly funded by the U.S. Department of Homeland Security Science and Technology Directorate, American Superconductor and Consolidated Edison Company of New York, Inc. American Superconductor is leading the team supported by Con Edison, Ultera, Altran Solutions, and DH Industries. The cable is an inherently fault current limiting HTS cable, approximately 200 m long and designed to carry 96 MVA at a distribution level voltage of 13.8 kV. The cable will be installed and energized near New York City. The refrigeration system was designed and manufactured by DH Industries. This paper provides details on the successful factory acceptance testing completed in November 2014.

  16. Graphical expression of thermodynamic characteristics of absorption process in ammonia-water system

    Directory of Open Access Journals (Sweden)

    Fortelný Zdeněk

    2012-04-01

    Full Text Available The adiabatic sorption is very interesting phenomenon that occurs when vapor of refrigerant is in contact with unsaturated liquid absorbent-refrigerant mixture and exchange of heat is forbid between the system and an environment. This contribution introduces new auxiliary lines that enable correct position determination of the adiabatic sorption process in the p-T-x diagram of ammoniawater system. The presented auxiliary lines were obtained from common functions for fast calculation of water-ammonia system properties. Absorption cycles designers often utilize p-t-x diagrams of working mixtures for first suggestion of new absorption cycles. The p-t-x diagrams enable fast correct determination of saturate states of liquid (and gaseous mixtures of refrigerants and absorbents. The working mixture isn’t only at saturated state during a real working cycle. If we know pressure and temperature of an unsaturated mixture, exact position determination is possible in the p-t-x diagrams too.

  17. Field measurements of supermarket refrigeration systems. Part I: Analysis of CO2 trans-critical refrigeration systems

    International Nuclear Information System (INIS)

    This study investigates the refrigeration performance of three CO2 trans-critical solutions based on field measurements. The measurements are carried out in five supermarkets in Sweden. Using the field measurements, low and medium temperature level cooling capacities and COP's are calculated for ten-minute intervals, filtered and averaged to monthly values. The results indicate that the systems using trans-critical booster system with gas removal from the intermediate vessel have relatively the highest total COP. The reasons are higher evaporation temperatures, lower internal and external superheat and higher total efficiency of booster compressors. Another important factor is gas removal from the intermediate vessel which leads to higher COP of low temperature level. Comparing the older and newer installed systems, a trend in energy efficiency improvement has been seen. The study shows this improvement originates from both changes in the system design (e.g. two stage expansion) and components efficiency improvement (e.g. higher total efficiency of compressors - lower internal superheat and higher evaporation temperatures of cabinets). - Highlights: • Five Swedish supermarkets using three CO2 refrigeration solutions are analyzed. • A trend of improvement in energy efficiency has been observed. • Parallel CO2 system with indirect heat rejection offers the lowest energy efficiency. • CO2 trans-critical booster with gas removal achieves up to 35% COP improvement

  18. A Comparative Study on the Environmental Impact of CO2 Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01

    Supermarket refrigeration systems have high environmental impact due to their large refrigerant charge and high leak rates. Accordingly, the interest in using natural refrigerants, such as carbon dioxide (CO2), and new refrigerant blends with low GWP in such systems is increasing. In this paper, an open-source Life Cycle Climate Performance (LCCP) framework is presented and used to compare the environmental impact of three supermarket refrigeration systems. These systems include a transcritical CO2 booster system, a cascade CO2/N-40 system, and a baseline R-404A multiplex direct expansion system. The study is performed for cities representing different climates within the USA using EnergyPlus to simulate the systems' hourly performance. Finally, a parametric analysis is performed to study the impact of annual leak rate on the systems' LCCP.

  19. 太阳能驱动吸收式与吸附式制冷技术的比较分析研究%Comparison and Analytical Investigation of Solar Powered Absorption Refrigeration and Adsorption Refrigeration

    Institute of Scientific and Technical Information of China (English)

    朱斌祥; 孙李; 喻志强; 徐军; 牛晓文

    2016-01-01

    介绍了太阳能吸收式制冷技术与吸附式制冷技术,并对这2种技术的原理特性、应用领域、工质对、系统结构、效率损失等问题进行了比较分析研究。研究表明:吸收式技术制冷系数高,但吸附式制冷对驱动热源的温度要求低;2种制冷技术的制冷性能与集热器、发生器、吸收器、吸附床和工质对等的特性密切相关。本文为提高太阳能制冷的效率和应用领域、促进太阳能制冷技术的发展提供了一定的技术方向和理论参考。%The current technology of solar absorption refrigeration and adsorption refrigeration were introduced and compared in aspects of principle and properties,application area,working medium pairs,systematic structure and efficiency.It was shown that refrigeration coefficient of absorption refrigeration is higher,however adsorption refrigeration has lower requirement for driving heat source.Furthermore performance of these two refrigeration technology was highly related to collector,generator,absorber,adsorbent bed,working medium pairs and etc.This paper offers technical direction and theoretical reference for efficiency improvement, broaden of application and technology development of solar powered refrigeration.

  20. Control optimizations for heat recovery from CO2 refrigeration systems in supermarket

    International Nuclear Information System (INIS)

    Highlights: • Application of supermarket energy control system model. • Heat recovery from CO2 refrigeration system in supermarket space conditioning. • Effect of pressure controls of CO2 refrigeration system on heat recovery potentials. • Control optimization of CO2 refrigeration system for heat recovery in supermarket. - Abstract: A modern supermarket energy control system has a concurrent need for electricity, food refrigeration and space heating or cooling. Approximately 10% of this energy is for conventional gas-powered heating. In recent years, the use of CO2 as a refrigerant in supermarket systems has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. CO2 refrigeration systems also offer more compact component designs over a conventional HFC system and heat recovery potential from compressor discharge. In this paper, the heat recovery potential of an all-CO2 cascade refrigeration system in a supermarket has been investigated using the supermarket simulation model “SuperSim” developed by the authors. It has been shown that at UK weather conditions, the heat recovery potential of CO2 refrigeration systems can be increased by increasing the condenser/gas cooler pressure to the point where all the heat requirements are satisfied. However, the optimum level of heat recovery will vary during the year and the control system should be able to continuously optimize this level based on the relative cost of energy, i.e., gas and electricity

  1. PERFORMANCE STUDY OF A TWO STAGE SOLAR ADSORPTION REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    BAIJU. V

    2011-07-01

    Full Text Available The present study deals with the performance of a two stage solar adsorption refrigeration system with activated carbon-methanol pair investigated experimentally. Such a system was fabricated and tested under the conditions of National Institute of Technology Calicut, Kerala, India. The system consists of a parabolic solar concentrator,two water tanks, two adsorbent beds, condenser, expansion device, evaporator and accumulator. In this particular system the second water tank is act as a sensible heat storage device so that the system can be used during night time also. The system has been designed for heating 50 litres of water from 25oC to 90oC as well ascooling 10 litres of water from 30oC to 10oC within one hour. The performance parameters such as specific cooling power (SCP, coefficient of performance, solar COP and exergetic efficiency are studied. The dependency between the exergetic efficiency and cycle COP with the driving heat source temperature is also studied. The optimum heat source temperature for this system is determined as 72.4oC. The results show that the system has better performance during night time as compared to the day time. The system has a mean cycle COP of 0.196 during day time and 0.335 for night time. The mean SCP values during day time and night time are 47.83 and 68.2, respectively. The experimental results also demonstrate that the refrigerator has cooling capacity of 47 to 78 W during day time and 57.6 W to 104.4W during night time.

  2. Orthogonal Design for Thermosyphon Operated in Absorption Refrigeration Cycles%小型吸收式制冷热虹吸泵的正交试验设计

    Institute of Scientific and Technical Information of China (English)

    王欣; 杨洪海; 张总辉; 杨丰畅; 叶志秦

    2015-01-01

    Thermosyphon was the core component of mini-type solar absorption refrigerator.Its efficiency decided the perform-ance of mini-type solar absorption refrigerator,and mostly depended on the capability of lift pipe.In this paper,according to the design requirements of lithium bromide absorption refrigeration cycle,thermosyphon theoretical model and performance simulation results,we has designed the experiment device and parts of thermosyphon visualization,successfully build and debug experiment device.Using orthogonal test method research factors such as heat,system pressure and immerson ratio influence on thermal si-phon pump performance,the analysis indicates that for the thermal siphon performance,the most important influencing factor is heat,the secondary factor is system pressure and the immerson ratio has minimal impat.%热虹吸泵是小型无泵溴化锂吸收式制冷机的核心部件,对制冷机的运行及工作性能起关键影响。本文根据溴化锂吸收式制冷循环的设计要求,以热虹吸泵理论模型和性能模拟结果为指导,进行了热虹吸泵沿程加热可视化试验装置的方案设计和部件设计,搭建并调试成功试验装置。采用正交试验法研究加热量、系统压力和沉浸比等因素对热虹吸泵提升性能的影响,分析得知,对于热虹吸泵提升性能影响最大的因素是加热量,次要影响因素是系统压力,沉浸比对其影响最小。

  3. Refrigerant Control Strategies for Residential Air-Conditioning and Heat-Pump System

    Institute of Scientific and Technical Information of China (English)

    SU Shun-yu; ZHANG Chun-zhi; CHEN Jian

    2009-01-01

    This paper simulated the optimal refrigerant charge inventory of a refrigeration system in air-con-ditioning operation and heat-pump operation respectively,and studied the refrigerant control strategies in this system.The void fraction in two-phase fluid region was calculated by Harms model.And based on distributed parameter model and Harms model,the refrigerant charge inventory in condenser and evaporator were calculated and analyzed in air-conditioning conditions and heat-pump conditions,respectively.The calculating results of dif-ferent refrigerant mass between refrigeration and heating conditions indicate that the optimal refrigerant charge inventory in heat-pump conditions is lower than that in air-eonditioning conditions.To avoid the decrease of COP due to the surplus refrigerant in heating conditions,we introduced the liquid reservoir control method and associate capillary control method.Both of them could increase the heating capacity of the air-source heat pump-The difference of optimal refrigerant charge inventory in air-conditioning and heat-pump system can be controlled by the liquid reservoir or the associate capillary.

  4. Modelling of a chemisorption refrigeration and power cogeneration system

    International Nuclear Information System (INIS)

    Highlights: • An adsorption cogeneration was proposed and simulated for cooling and electricity. • A dynamic model was built and studied to demonstrate the variability of the system. • A dynamic model included the complex coupling of thermodynamic and chemical kinetic. • Mutual constrains between main components and optimisation methods were discussed. • The highest theoretical COP and exergy efficiency of cogeneration is 0.57 and 0.62. - Abstract: The present work for the first time explores the possibility of a small-scale cogeneration unit by combining solid–gas chemisorption refrigeration cycle and a scroll expander. The innovation in this work is the capability of producing refrigeration and electricity continuously and simultaneously without aggravating the energy scarcity and environmental impact. Individual modelling for each component, which has been validated by experimental data, was firstly investigated in order to identify the proper operation condition for the cogeneration mode achieving 1000 W power output. Subsequently, with the integrated modelling of two components the cogeneration performance was studied to demonstrate the viability of this concept. However, because of the mutual constraint between the chemisorption and the expansion when they link in series, the power output of the cogeneration mode was only around one third of the original expectation under the same condition identified in the individual modelling. Methods of improving the global performance including the selection of reactive mediums were also discussed and would be of referable value for the future practical investigation

  5. The maintenance record of the KSTAR helium refrigeration system

    International Nuclear Information System (INIS)

    Korea Superconducting Tokamak Advanced Research (KSTAR) has a helium refrigeration system (HRS) with the cooling capacity of 9 kW at 4.5 K. Main cold components are composed of 300 tons of superconducting (SC) magnets, main cryostat thermal shields, and SC current feeder system. The HRS comprises six gas storage tanks, a liquid nitrogen tank, the room temperature compression sector, the cold box (C/B), the 1st stage helium distribution box (DB no.1), the PLC base local control system interconnected to central control tower and so on. Between HRS and cold components, there is another distribution box (DB#2) nearby the KSTAR device. The entire KSTAR device was constructed in 2007 and has been operated since 2008. This paper will present the maintenance result of the KSTAR HRS during the campaign and discuss the operation record and maintenance history of the KSTAR HRS.

  6. Modeling Supermarket Refrigeration Systems for Demand-Side Management

    Directory of Open Access Journals (Sweden)

    Jakob Stoustrup

    2013-02-01

    Full Text Available Modeling of supermarket refrigeration systems for supervisory control in the smart grid is presented in this paper. A modular modeling approach is proposed in which each module is modeled and identified separately. The focus of the work is on estimating the power consumption of the system while estimating the cold reservoir temperatures as well. The models developed for each module as well as for the overall integrated system are validated by real data collected from a supermarket in Denmark. The results show that the model is able to estimate the actual electrical power consumption with a high fidelity. Moreover a simulation benchmark is introduced based on the produced model for demand-side management in smart grid. Finally, a potential application of the proposed benchmark in direct control of the power/energy consumption is presented by a simple simulation example.

  7. The LSST Camera 500 watt -130 degC Mixed Refrigerant Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, Gordon B.; Langton, Brian J.; /SLAC; Little, William A.; /MMR-Technologies, Mountain View, CA; Powers, Jacob R; Schindler, Rafe H.; /SLAC; Spektor, Sam; /MMR-Technologies, Mountain View, CA

    2014-05-28

    The LSST Camera has a higher cryogenic heat load than previous CCD telescope cameras due to its large size (634 mm diameter focal plane, 3.2 Giga pixels) and its close coupled front-end electronics operating at low temperature inside the cryostat. Various refrigeration technologies are considered for this telescope/camera environment. MMR-Technology’s Mixed Refrigerant technology was chosen. A collaboration with that company was started in 2009. The system, based on a cluster of Joule-Thomson refrigerators running a special blend of mixed refrigerants is described. Both the advantages and problems of applying this technology to telescope camera refrigeration are discussed. Test results from a prototype refrigerator running in a realistic telescope configuration are reported. Current and future stages of the development program are described. (auth)

  8. The LSST camera 500-watt -130°C mixed refrigerant cooling system

    Science.gov (United States)

    Bowden, Gordon B.; Langton, Brian J.; Little, William A.; Powers, Jacob R.; Schindler, Rafe H.; Spektor, Sam

    2014-07-01

    The LSST Camera has a higher cryogenic heat load than previous CCD telescope cameras due to its large size (634 mm diameter focal plane, 3.2 Giga pixels) and its close coupled front-end electronics operating at low temperature inside the cryostat. Various refrigeration technologies are considered for this telescope/camera environment. MMR-Technology's Mixed Refrigerant technology was chosen. A collaboration with that company was started in 2009. The system, based on a cluster of Joule-Thomson refrigerators running a special blend of mixed refrigerants is described. Both the advantages and problems of applying this technology to telescope camera refrigeration are discussed. Test results from a prototype refrigerator running in a realistic telescope configuration are reported. Current and future stages of the development program are described.

  9. The LSST Camera 500 watt -130 degC Mixed Refrigerant Cooling System

    International Nuclear Information System (INIS)

    The LSST Camera has a higher cryogenic heat load than previous CCD telescope cameras due to its large size (634 mm diameter focal plane, 3.2 Giga pixels) and its close coupled front-end electronics operating at low temperature inside the cryostat. Various refrigeration technologies are considered for this telescope/camera environment. MMR-Technology's Mixed Refrigerant technology was chosen. A collaboration with that company was started in 2009. The system, based on a cluster of Joule-Thomson refrigerators running a special blend of mixed refrigerants is described. Both the advantages and problems of applying this technology to telescope camera refrigeration are discussed. Test results from a prototype refrigerator running in a realistic telescope configuration are reported. Current and future stages of the development program are described. (auth)

  10. Model-Based Predictive Control Scheme for Cost Optimization and Balancing Services for Supermarket Refrigeration Systems

    DEFF Research Database (Denmark)

    Weerts, Hermanus H. M.; Shafiei, Seyed Ehsan; Stoustrup, Jakob;

    2014-01-01

    A new formulation of model predictive control for supermarket refrigeration systems is proposed to facilitate the regulatory power services as well as energy cost optimization of such systems in the smart grid. Nonlinear dynamics existed in large-scale refrigeration plants challenges the predictive...

  11. A decentralized control method for direct smart grid control of refrigeration systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik;

    2013-01-01

    A decentralized control method is proposed to govern the electrical power consumption of supermarket refrigeration systems (SRS) for demand-side management in the smart grid. The control structure is designed in a supervisory level to provide desired set-points for distributed level controllers...... simulates the CO2 booster system of a supermarket refrigeration....

  12. Drop-in Performance of Low GWP Refrigerants in a Heat Pump System for Residential Applications

    OpenAIRE

    Barve, Atharva; Cremaschi, Lorenzo

    2012-01-01

    R410A is one of the main refrigerants used for air conditioning and heat pump systems in residential applications. It has zero ozone depletion potential but its global warming potential is about 2,000. In China and Japan, refrigerant R32 (GWP = 675, zero ODP) has been proposed, as possible replacement for R410A but this refrigerant is slightly flammable. HFO-1234yf is a refrigerant with low GWP (GWP = 4, zero ODP) that is currently being used in European car market as a possible replacement f...

  13. Computer simulation with TRNSYS for a mobile refrigeration system incorporating a phase change thermal storage unit

    International Nuclear Information System (INIS)

    Highlights: • A mobile refrigeration system incorporating phase change thermal storage was simulated using TRNSYS. • A TRNSYS component of a phase change thermal storage unit was created and linked to other components from TRNSYS library. • The temperature in the refrigerated space can be predicted using this TRNSYS model under various conditions. • A mobile refrigeration system incorporating PCM and an off-peak electric driven refrigeration unit is feasible. • The phase change material with the lowest melting temperature should be selected. - Abstract: This paper presents a new TRNSYS model of a refrigeration system incorporating phase change material (PCM) for mobile transport. The PCTSU is charged by an off-vehicle refrigeration unit and the PCM provides cooling when discharging and the cooling released is utilized to cool down the refrigerated space. The advantage of this refrigeration system compared to a conventional system is that it consumes less energy and produces significantly lower greenhouse gas emissions. A refrigeration system for a typical refrigerated van is modelled and simulations are performed with climatic data from four different locations. The main components of the TRNSYS model are Type 88 (cooling load estimation) and Type 300 (new PCTSU component), accompanied by other additional components. The results show that in order to maintain the temperature of the products at −18 °C for 10 h, a total of 250 kg and 390 kg of PCM are required for no door opening and 20 door openings during the transportation, respectively. In addition, a parametric study is carried out to evaluate the effects of location, size of the refrigerated space, number of door openings and melting temperature of the PCM on the thermal performance

  14. Data-Driven Predictive Direct Load Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Knudsen, Torben; Wisniewski, Rafal;

    2015-01-01

    is proposed to fulfil two important objectives: to secure high coefficient of performance and to participate in power consumption management. Moreover, a new method for design of input signals for system identification is put forward. The control method is fully data driven without an explicit use of model......A predictive control using subspace identification is applied for the smart grid integration of refrigeration systems under a direct load control scheme. A realistic demand response scenario based on regulation of the electrical power consumption is considered. A receding horizon optimal control...... in the control implementation. As an important practical consideration, the control design relies on a cheap solution with available measurements than using the expensive mass flow meters. The results show successful implementation of the method on a large-scale non-linear simulation tool which is validated...

  15. Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU

    International Nuclear Information System (INIS)

    The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system

  16. PERFORMANCE ANALYSIS OF VCR SYSTEM WITH VARYING THE DIAMETERS OF HELICAL CONDENSER COIL BY USING R-134A REFRIGERANT

    OpenAIRE

    R.Hussain Vali; P.Yagnasri; S.Naresh Kumar Reddy

    2016-01-01

    Vapor compression machine is a refrigerator in which the heat removed from the cold by evaporation of the refrigerant is given a thermal potential so that it can gravitate to a natural sink by compressing the vapor produced. Majority of the refrigerators works on the Vapor compression refrigeration system. The system consists of components like compressor, condenser, expansion valve and evaporator. The performance of the system depends on the performance of all the components of the system. ...

  17. Climate-friendly refrigerators for supermarkets. Comparative assessment of supermarket refrigeration systems; Klimafreundlich Kuehlen im Supermarkt. Vergleichende Bewertung von Supermarktkaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2008-10-15

    On 5 September 2008, a meeting was held at the Federal Environmental Office (Umweltbundesamt, UBA) at Dessau where the results of the research project ''Comparative evaluation of the climate relevance of refrigeration plants and systems for supermarkets'' were presented and discussed among more than 50 experts. Towards the end of the meeting, the discussions became more heated as the underlying data base became the subject of attention. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Mohammed Khennich

    2016-03-01

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

  19. Control of Refrigeration Systems for Trade-off between Energy Consumption and Food Quality Loss

    DEFF Research Database (Denmark)

    Cai, Junping

    In supermarkets, control strategies determine both the energy consumption of refrigeration systems and the quality loss of refrigerated foodstuffs. The question is, what can be done to optimize the balance between quality loss and energy consumption? This thesis tries to answer this question by a...

  20. Grey-box Modeling for System Identification of Household Refrigerators: a Step Toward Smart Appliances

    DEFF Research Database (Denmark)

    Costanzo, Giuseppe Tommaso; Sossan, Fabrizio; Marinelli, Mattia;

    2013-01-01

    This paper presents the grey-box modeling of a vapor-compression refrigeration system for residential applications based on maximum likelihood estimation of parameters in stochastic differential equations. Models obtained are useful in the view of controlling refrigerators as flexible consumption...

  1. Potential energy savings using dynamically optimizing control in refrigeration systems under daily variations in ambient temperature

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth; Thybo, Claus; Wisniewski, Rafal;

    2007-01-01

    The objective of this study is to investigate the energy saving potential for refrigeration systems by refrigeration more at the colder night time than at the warmer day time. The potential is evaluated using an optimal control policy and illustrated on a simulation example. The results show...

  2. 太阳能单效溴化锂吸收式制冷空调技术研究现状%Research Status of Solar Single-effect Lithium Bromide Absorption Refrigeration and Air Conditioning Technology

    Institute of Scientific and Technical Information of China (English)

    周兴法; 谢应明; 谢振兴

    2014-01-01

    In view of the solar single-effect lithium bromide absorption refrigeration and air conditioning technology , which is used mostly in solar refrigeration technology at present , the solar collectors that are available for solar refrigeration are introduced in detail,large amounts of the cases of experimental study and simulation analysis are enumerated ,and finally a novel solar refrige-ration system with bubble pump is presented .Because of its several advantages such as quiet , small volume, energy conserva-tion,and cooling heat recovery ,it is an important development direction of solar absorption refrigeration system in terms of minia-turization.%针对目前太阳能制冷技术中应用最多的太阳能单效溴化锂吸收式制冷空调技术,介绍各种可用于太阳能制冷空调的集热器,列举大量的太阳能单效溴化锂吸收式制冷空调系统的试验研究和模拟分析的案例,最后提出一个新型太阳能无泵溴化锂吸收式制冷空调系统。该系统具有运行安静、体积小、节能、可回收冷却热等优点,是太阳能吸收式制冷系统小型化的一个重要发展方向。

  3. Combined Refrigeration Cycle for Thermal Power Plant Using Low Grade Waste Steam

    Directory of Open Access Journals (Sweden)

    Satish Maurya*,

    2014-02-01

    Full Text Available Now a days, In most of the thermal power plant, where low-pressure steam is being exhausted to the atmosphere as a waste steam. This waste heat could be use to operate many small preheating or cooling equipments or small scale plants. There are many refrigeration systems present for refrigeration and air condition purpose. Such as air refrigeration, vapour compression, vapour absorption etc. In this paper we have presented the concept of combined vapour absorption and vapour compression refrigeration system. We present about the idea discuss here that how a vapour absorption and vapour compression can be used together as one complete working refrigeration plant. By using such concept of refrigeration we can improve the co-efficient of performance of whole plant by minimizing the input. We can also named the system as waste heat recovery refrigeration system.

  4. 'TEWI' concept for estimation of the global warming from the refrigerating and air conditioning systems

    International Nuclear Information System (INIS)

    The most applied CFC refrigerants and their HFC alternatives. values of ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) of the most used refrigerants. natural working fluids and their properties. Montreal Protocol and Kyoto Protocol, illogical relations between them concerning to the HFC fluids. Confusion and polemics on the international level about the appliance of HFCs which, by the Kyoto Protocol, are liable to reduction. Introduction of the TEWI concept as a method for estimating the overall influence of refrigerating and air conditioning systems on the greenhouse effect: the direct emission (refrigerant leakage in the atmosphere) and indirect emission as a result of the electrical energy consumption. A demonstration of the TEWI concept on the concrete example in several variants. A discussion about the appliance of the TEWI concept. Meaning of the energy efficiency of the refrigerating systems (indirect CO2 emission). One of the main measures: prevention of refrigerant leakage (direct CO2 emission). A need of permanent education and training courses of the people who work on refrigerating and air conditioning systems. A necessity for constitution of an expert body in the country, preparation of a strategy to lay obligations on the new changes of the Kyoto Protocol and news on the world market. Introduction of country regulations, certification of the companies and people involved in refrigeration and air conditioning. (Author)

  5. Absorption and adsorption chillers applied to air conditioning systems

    Science.gov (United States)

    Kuczyńska, Agnieszka; Szaflik, Władysław

    2010-07-01

    This work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperature Tdes = 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling water Tc = 25 °C and temperature in evaporator Tevap = 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.

  6. CO2 Supermarket Refrigeration Systems for Southeast Asia and the USA

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Vishaldeep [ORNL; Fricke, Brian A [ORNL; Bansal, Pradeep [ORNL

    2014-01-01

    This paper presents a comparative analysis of the annual energy consumption of these refrigeration systems in eighty eight cities from all climate zones in Southeast Asia. Also, the performance of the CO2 refrigeration systems is compared to the baseline R404A multiplex direct expansion (DX) system. Finally, the overall performance of the CO2 refrigeration systems in various climatic conditions in Southeast Asia is compared to that in the United States. For the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) performs better or equivalent to the R404A multiplex DX system in the northern regions of Southeast Asia (China and Japan). In the southern regions of Southeast Asia (India, Bangladesh, Burma), the R404A multiplex DX system and the Combined Secondary Cascade (CSC) system performs better than the TBS-BC.

  7. Plant-wide dynamic and static optimisation of supermarket refrigeration systems

    DEFF Research Database (Denmark)

    Green, Torben; Izadi-Zamanabadi, Roozbeh; Razavi-Far, Roozbeh;

    2013-01-01

    Optimising the operation of a supermarket refrigeration system under dynamic as well as steadystate conditions is addressedin thispaper. For thispurpose anappropriateperformance function that encompasses food quality, system efficiency, and also component reliability is established. The choice...

  8. Progress of helium refrigeration system for Wendelstein 7-X

    International Nuclear Information System (INIS)

    The helium refrigerator for the fusion experiment Wendelstein 7-X is required for cooling the superconducting coils, casings, supports and divertor cryo-vacuum pumps at 3.4 K in peak power and 3.9 K in standard operating modes. The refrigerator supplied by Linde Kryotechnik AG has an equivalent refrigeration power of 7 kW at 4.5 K. In the meantime the corresponding hardwares are installed and the commissioning is approaching towards completion. The preparations for the acceptance tests have begun. (author)

  9. Cooling load and COP optimization of an irreversible Carnot refrigerator with spin-1/2 systems

    Directory of Open Access Journals (Sweden)

    Xiaowei Liu, Lingen Chen, Feng Wu, Fengrui Sun

    2011-09-01

    Full Text Available A model of an irreversible quantum refrigerator with working medium consisting of many non-interacting spin-1/2 systems is established in this paper. The quantum refrigeration cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot refrigeration cycle. Expressions of some important performance parameters, such as cycle period, cooling load and coefficient of performance (COP for the irreversible spin quantum Carnot refrigerator are derived, and detailed numerical examples are provided. The optimal performance of the quantum refrigerator at high temperature limit is analyzed with numerical examples. Effects of internal irreversibility and heat leakage on the performance are discussed in detail. The endoreversible case, frictionless case and the case without heat leakage are discussed in brief.

  10. Optimization of solar adsorption refrigeration system using experimental and statistical techniques

    International Nuclear Information System (INIS)

    This paper presents the design of new prototype of a solar adsorption refrigeration unit with certain specifications and requirements to be used as an air conditioning and refrigeration unit suitable to be used in remote areas. The new device uses activated carbon (used as adsorbents) with methanol (as adsorbate) forming an adsorbent-adsorbate pairs. Experimental data with statistical technique are used in this paper to get the optimum design parameters of the solar adsorption refrigeration system with an acceptable result of COP (coefficient of performance) and cooling production. The minimum temperature obtained for the refrigerator was 9 deg. C while the ambient temperature was 26 deg. C. The effective refrigeration started at 21:10 and the temperature decreased gradually until it reached 9 deg. C at 01:30 next day then it increased above the minimum temperature. The gross cycle coefficient of performance, COPa = 0.688 from the thermodynamic calculations.

  11. Alternative Refrigerants: A Review

    OpenAIRE

    S.K. Kalla*; , J.A. Usmani

    2014-01-01

    During the last decade, substantial research activities have been undertaken regarding refrigeration cycles and systems with particular emphasis on the replacement of refrigerants like R134a by refrigerants like hydrocarbons which have negligible GWP (Global Warming Potential).Besides using eco-friendly refrigerants, thrust has been given upon devising methods to increase the efficiency of the refrigeration cycle/system, which will also contribute to reducing emission of GHG(G...

  12. Non-linear and adaptive control of a refrigeration system

    OpenAIRE

    Rasmussen, Henrik,; Larsen, Lars F. S.

    2011-01-01

    In a refrigeration process heat is absorbed in an evaporator by evaporating a flow of liquid refrigerant at low pressure and temperature. Controlling the evaporator inlet valve and the compressor in such a way that a high degree of liquid filling in the evaporator is obtained at all compressor capacities ensures a high energy efficiency. The level of liquid filling is indirectly measured by the superheat. Introduction of variable speed compressors and electronic expansion valves enables the u...

  13. Performance Comparison of Single-Stage and Cascade Refrigeration Systems Using R134a as the Working Fluid

    OpenAIRE

    HOŞÖZ, Murat

    2005-01-01

    This study presents an experimental comparison of single-stage and cascade vapour-compression refrigeration systems using R134a as the refrigerant. The experimental plants employ a vapour-compression refrigeration cycle serving as a base unit, a cooling tower and another vapour-compression refrigeration cycle serving as a higher-temperature unit in the cascade operation. In the single-stage operation the condenser of the base unit was connected to the cooling tower, whereas in the ca...

  14. Refrigerating and air conditioning systems in the Republic of Macedonia regarding to the use of CFC fluids

    International Nuclear Information System (INIS)

    Classification of refrigerating systems and their condition in the Republic of Macedonia, by the capacity and application. Review of the subjects involved in refrigeration in the Republic of Macedonia: manufactures of refrigerating systems, distributors of refrigerating equipment, distributors of (CFC) refrigerants, maintenance and servicing of refrigerating systems regarding to the quality and the weak points. Measures and projects in the Republic of Macedonia in the field of the protection of the ozone layer. Regulations by the Montreal protocol. Regulations in the Republic of macedonia concerning refrigerating systems and CFC fluids in them. Country programme of the Republic of Macedonia and institutional activities. Projects in 'Frinko; and 'Sileks' where the manufacturing technologies are changed. Project 'Refrigerant management plan' in which are included: forming of training centers, training of service technicians and engineers involved in refrigeration and air conditioning, equipping of services and companies with on equipment for good practice in refrigeration and refrigerant's recovery, forming of recycling centers for purification of used refrigerants, training of custom officers. (Author)

  15. Three-dimensional Numerical Investigations on Ejector of Vapour Jet Refrigeration System

    OpenAIRE

    Jiautheen, Parveen Banu; Tiwari, Shaligram; Annamalai, Mani

    2014-01-01

    Vapour Jet Refrigeration System (VJRS) is preferred among various heat operated refrigeration systems because it has potential of utilizing low temperature heat source, consumes less electrical energy causing less atmospheric pollution and requires less maintenance cost due to absence of moving parts [1]. Ejector, a thermal compressor, is one of the crucial components of VJRS. Performance of the whole system is based on the satisfactory operation of the ejector. Hence, it has to be designed c...

  16. Design and dynamic behaviour of a cold storage system combined with a solar powered thermoacoustic refrigerator

    International Nuclear Information System (INIS)

    A heat powered thermoacoustic refrigerator consists in a thermoacoustic engine that produces acoustic work utilizing heat, coupled to a thermoacoustic cooler that converts this acoustic energy into cooling effect. These machines have already proved their capability in laboratory or in space refrigeration. Previous studies have also demonstrated the possibility of using concentrated solar energy as thermal energy sources for low power heat driven thermoacoustic refrigerators. As other solar refrigeration systems, even if the cooling demand generally increases with the intensity of the solar radiation, one of the major difficulties is to insure a frigorific power supply when there is no, or low, solar radiation. The aim of this work is to study a kW scale solar thermoacoustic refrigerator capable to reach temperatures of the industrial refrigeration domain. This refrigerator is combined with a latent cold storage in order to guarantee a sufficient cooling capacity to face to refrigeration loads in spite of the production fluctuations. A description of the studied prototype is done and the model developed to describe the transient behaviour of the main components of this machine is introduced. The results obtained with a simulation of one week with real solar radiations are presented and the behaviour and the energetic performances of the entire system are analysed. Finally the impact of the sizing of the cold storage system is discussed. With the best storage design, the system is capable to supply a cooling power of 400 W at a temperature equal or lower than −20 °C with an average Coefficient Of Performance of the solar thermoacoustic refrigerator equal to 21%

  17. EVALUATION OF A MULTIFUNCTIONAL VALVE ASSEMBLY IN A DIRECT EXPANSION REFRIGERATION SYSTEM REPORT

    Science.gov (United States)

    The report describes the performance, including energy consumption, of a refrigeration system incorporating a multifunctional valve (MXV assembly). The MXV assembly (consisting of additional liquid line, an XTC valve, and a larger thermostatic expansion valve) was installed on al...

  18. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1996-07-01

    The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

  19. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

    1999-01-01

    The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilities access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

  20. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1996-11-15

    The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

  1. Interconnected refrigeration compressors. A promising systems engineering solution. Kaelteverdichter im Verbund schalten. Anlagetechnik mit Zukunft

    Energy Technology Data Exchange (ETDEWEB)

    Pielke, R.

    1989-10-01

    The interconnected operation of several refrigeration compressors in one system requires no more but an appropriate design, installation, and connection of tubes in the sense of fluid mechanics and flow characteristics. Designs such as these insure that refrigerant/oil transports and oil/gas compensation are within the tubing, and that compressors are sufficiently being supplied with oil. Several examples facilitate access to basic planning elements. Reference is made to systems and solutions available on the market. (BWI).

  2. DSM opportunities in underground refrigeration systems / E.L. Strydom-Bouwer.

    OpenAIRE

    Strydom-Bouwer, Emile Liché

    2008-01-01

    This study will focus on the feasibility of demand side electricity management on underground refrigeration systems. It will include a relevant literature study, the investigation process, a simulation model, expected simulated results, implementation of DSM on an underground refrigeration system, actual results, recommendations of further study, and a conclusion. Eskom is presently struggling to adhere to the electricity demand in South Africa, specifically in the peak cons...

  3. Solar-driven refrigeration systems with focus on the ejector cycle

    OpenAIRE

    Pridasawas, Wimolsiri

    2006-01-01

    Interest in utilizing solar-driven refrigeration systems for air-conditioning or refrigeration purposes has grown continuously. Solar cooling is com-prised of many attractive features and is one path towards a more sus-tainable energy system. Compared to solar heating, the cooling load, par-ticularly for air-conditioning applications, is generally in phase with solar radiation. The objective of this thesis is to establish a fundamental basis for further research and development within the fie...

  4. Advanced Supermarket Refrigeration/Heat Recovery Systems Vol 1 - Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-15

    Annex 26 is the first international project under the IEA Heat Pump Programme that links refrigeration and heat pump technology. Recovering heat from advanced supermarket refrigeration systems for space and water heating purposes seems obvious and is beneficial for owners and operators. Because there are world-wide a great number of supermarkets that offer frozen and chilled food under further growth of this sector may be expected, the amount of energy used for refrigeration is enormous and will likely increase substantially in the near future. This volume of the IEA Annex 26 final report contains a detailed summary of the Annex activities including principal conclusions from each participant.

  5. Energetic, Exergetic and Exergoeconomic Analysis of CO2 Refrigeration Systems Operating in Hot Climates

    DEFF Research Database (Denmark)

    Gullo, Paride; Elmegaard, Brian; Cortella, Giovanni

    2015-01-01

    Carbon dioxide is one of the most interesting refrigerants in terms of both environmental impact and efficiency at low outdoor temperatures. Its use in warm climates still needs for some improvements as well as some economic evaluations in order to analyse its real potential in such weather...... conditions. CO2 refrigeration system with parallel compression represents one of the solutions which have been proposed in the last few years in order to enhance the performance of a single-stage refrigeration system. The main target of this study is to compare the thermodynamic efficiency and the final cost...... of the product of a R744 refrigeration solution with auxiliary compressor with those of a R744 conventional system, both of them operating in transcritical conditions. The results pointed out that the adoption of an auxiliary compressor resulted in an increase of the COP by approximately 18.7% over...

  6. Energetic and exergetic analyses of carbon dioxide transcritical refrigeration systems for hot climates

    Directory of Open Access Journals (Sweden)

    Fazelpour Farivar

    2015-01-01

    Full Text Available In the last two decades many scientific papers and reports have been published in the field of the application of the carbon dioxide as a refrigerant for refrigeration systems and heat pumps. Special attention has been paid to the transcritical cycle. However, almost no papers discussed such cycles for hot climates, i.e., when the temperature of the environment is higher than 40ºС during a long period of time. This paper deals with the energetic and exergetic evaluation of a CO2 refrigeration system operating in a transcritical cycle under hot climatic conditions. The performance and exergy efficiency of the CO2 refrigeration system depend on the operation conditions. The effect of varying these conditions is also investigated as well as the limitations associated with these conditions.

  7. ZnO nanorefrigerant in R152a refrigeration system for energy conservation and green environment

    Science.gov (United States)

    Sendil Kumar, D.; Elansezhian, R.

    2014-03-01

    In this paper the reliability and performance of a vapour compression refrigeration system with ZnO nanoparticles in the working fluid was investigated experimentally. Nanorefrigerant was synthesized on the basis of the concept of the nanofluids, which was prepared by mixing ZnO nanoparticles with R152a refrigerant. The conventional refrigerant R134a has a global warming potential (GWP) of 1300 whereas R152a has a significant reduced value of GWP of 140 only. An experimental test rig is designed and fabricated indigenously in the laboratory to carry out the investigations. ZnO nanoparticles with refrigerant mixture were used in HFC R152a refrigeration system. The system performance with nanoparticles was then investigated. The concentration of nano ZnO ranges in the order of 0.1% v, 0.3% v and 0.5%v with particle size of 50 nm and 150 g of R152a was charged and tests were conducted. The compressor suction pressure, discharge pressure and evaporator temperature were measured. The results indicated that ZnO nanorefrigerant works normally and safely in the system. The ZnO nanoparticle concentration is an important factor considered for heat transfer enhancement in the refrigeration system. The performance of the system was significantly improved with 21% less energy consumption when 0.5%v ZnO-R152a refrigerant. Both the suction pressure and discharge pressure were lowered by 10.5% when nanorefrigerant was used. The evaporator temperature was reduced by 6% with the use of nanorefrigerant. Hence ZnO nanoparticles could be used in refrigeration system to considerably reduce energy consumption. The usage of R152a with zero ozone depleting potential (ODP) and very less GWP and thus provides a green and clean environment. The complete experimental results and their analysis are reported in the main paper.

  8. Thermodynamical comparison and analysis of electric compression refrigeration cycle and absorption refrigeration cycle%电压缩式制冷循环与吸收式制冷循环的热力学比较分析

    Institute of Scientific and Technical Information of China (English)

    冯丽洁; 付林; 张世钢; 江亿

    2012-01-01

    Applying the exergy efficiency and exergy loss analysis method, calculates and compares the exergy efficiency between the electric compression refrigeration cycle and the single-effect absorption refrigeration cycle and the exergy losses of each part of the two cycles under the typical condition. The results show that the exergy efficiency of the two cycles is basically the same when the generator temperature and the heat source temperature are appropriately selected; most part of exercy losses of the electric compression refrigeration cycle occur in the compressor, and most part of exercy losses of the single-effect absorption refrigeration cycle occur in the absorber and generator. Discusses the improving methods for the two cycles.%采用(火用)效率与炯损失分析方法,计算比较了电压缩式制冷循环与单效吸收式制冷循环的(火用)效率及两种制冷循环在典型工况下各环节的(火用)损失.结果表明,当采用合适的发生器温度和热源温度时,两种制冷循环的(火用)效率基本相同;电压缩式制冷循环的主要(火用)损失发生在压缩机环节,吸收式制冷循环的主要(火用)损失发生在吸收器和发生器.讨论了两种制冷循环的改进途径.

  9. Analysis of synchronization in a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Leth, John-Josef; Rasmussen, Jakob Gulddahl

    2014-01-01

    In a supermarket refrigeration, the temperature in a display case, surprisingly, influences the temperature in other display cases. This leads to a synchronous operation of all display cases, in which the expansion valves in the display cases turn on and off at exactly the same time. This behavior...... increases both the energy consumption and the wear of components. Besides this practical importance, from the theoretical point of view, synchronization, likewise stability, Zeno phenomenon, and chaos, is an interesting dynamical phenomenon. The study of synchronization in the supermarket refrigeration...

  10. Combined Refrigeration Cycle for Thermal Power Plant Using Low Grade Waste Steam

    OpenAIRE

    Satish Maurya*,; Dharmendra Patel

    2014-01-01

    Now a days, In most of the thermal power plant, where low-pressure steam is being exhausted to the atmosphere as a waste steam. This waste heat could be use to operate many small preheating or cooling equipments or small scale plants. There are many refrigeration systems present for refrigeration and air condition purpose. Such as air refrigeration, vapour compression, vapour absorption etc. In this paper we have presented the concept of combined vapour absorption and vapour compression refri...

  11. INVESTIGATIONS ON THE PERFORMANCE OF VAPOUR COMPRESSION SYSTEM RETROFITTED WITH ZEOTROPIC REFRIGERANT R404A

    OpenAIRE

    A. Lovelin Jerald; D. SenthilKumaran

    2014-01-01

    The environmental impacts like global warming and ozone depletion has become a challenge to the refrigeration and air conditioning industry. Chloro Fluoro Carbons (CFCs) and Hydro Flouro Carbons (HCFCs) are referred to as an Ozone Depleting Substances (ODS) because once these gases are released into the environment and reach the stratosphere, depletes the ozone layer. This research paper aims to study the performance characteristics of an R12 (CFC) vapour compression refrigeration system retr...

  12. Optimization of active magnetic regenerative refrigeration systems using Design of Experiments

    OpenAIRE

    Roudaut, Julien; Bouchekara, Houssem; Kedous-Lebouc, Afef; Coulomb, Jean-Louis

    2009-01-01

    International audience This paper attends to demonstrate the usefulness of Design of Experiments (DOE) method in magnetic refrigeration (MR) understanding and optimization. A numerical DOE is applied to a simple 1D finite difference model describing an Active Magnetic Regenerative Refrigeration (AMRR) system. The heat transfer fluid is water, the regenerator consists of stacked gadolinium plates and the model is based on the assumption of an equivalent single plate. A two-level 27-3 fracti...

  13. Energetic and exergetic analyses of carbon dioxide transcritical refrigeration systems for hot climates

    OpenAIRE

    Fazelpour Farivar

    2015-01-01

    In the last two decades many scientific papers and reports have been published in the field of the application of the carbon dioxide as a refrigerant for refrigeration systems and heat pumps. Special attention has been paid to the transcritical cycle. However, almost no papers discussed such cycles for hot climates, i.e., when the temperature of the environment is higher than 40ºС during a long period of time. This paper deals with the energetic and exerget...

  14. SIMULATING THE REFRIGERATION OF BATCH DAIRY PRODUCTS IN A MULTIZONE COLD SUPPLY SYSTEM

    OpenAIRE

    BUAYNOVA I.V.

    2014-01-01

    Methods that simulate the fast refrigeration of foods on the basis of a model of adjustable heat sink according to the principle of programmed freezing are considered. In this case, a fast freezer is seen as a system of modules, each of which can independently ensure the necessary heat-sink conditions for the fast refrigeration process. The focus is made on the analysis of physicochemical processes that form the water crystallization front at the first freezing stage, taking into account the ...

  15. Space Station thermal storage/refrigeration system research and development

    Science.gov (United States)

    Dean, W. G.; Karu, Z. S.

    1993-01-01

    single centralized radiator system. As per the scope of work of this task, the applicability of refrigeration system tailored to meet the specialized requirements of storage of food and biological samples was investigated. The issues addressed were the anticipated power consumption and feasible designs and cycles for meeting specific storage requirements. Further, development issues were assessed related to the operation of vapor compression systems in micro-gravity addressing separation of vapor and liquid phases (via capillary systems).

  16. Air conditioning and refrigeration engineering

    Energy Technology Data Exchange (ETDEWEB)

    Kreith, F. [ed.] [Univ. of Colorado, Boulder, CO (US)

    1999-12-01

    This book supplies the basics of design, from selecting the optimum system and equipment to preparing the drawings and specifications. It discusses the four phases of preparing a project: gathering information, developing alternatives, evaluating alternatives, and selling the best solution. In addition, the author breaks down the responsibilities of the engineer design documents, computer aided design, and government codes and standards. It provides you with an easy reference to all aspects of the topic. This resource addresses the most current areas of interest, such as computer aided design and drafting, desiccant air conditioning and energy conservation. It is a thorough and convenient guide to air conditioning and refrigeration engineering. Contents include: introduction; psychrometrics; air-conditioning processes and cycles; refrigerants and refrigeration cycles; outdoor design conditions and indoor design criteria; load calculations; air handling units and packaged units; refrigeration components and evaporative coolers; water systems; heating systems; refrigeration systems; thermal storage system; air system basics; absorption systems; air-conditioning systems and selection; and desiccant dehumidification and air-conditioning.

  17. The Performance Evaluation of Vapor Compression Heat Pump System Using HFC Alternative Refrigerant Mixtures

    Science.gov (United States)

    Taira, Shigeharu; Yazima, Ryuzaburo; Tarutani, Isamu; Koyama, Shigeru

    This paper deals with an experimental study on the performance evaluation of heat pump systems using HFC alternative refrigerants. The tested heat pump systems are modified from the R22 use to alternative refrigerants. Refrigerant mixtures of R410A, R407C. R32/125 and R32/134a are tested. where R410A and R407C launched into global market recently. Pure refrigerants of R22, R32, R125 and R134a are also tested. The experimental results of alternative refrigerants are evaluated in comparison with the result of R22, and the following are confirmed : (1) the performance of R32 is the highest. (2) adding R125 to R32 and R32/134a results into the deterioration of the performance, (3) the use of counter flow-like heat exchangers for a zeotropic refrigerant mixtures are effective, and (4) in case of R410A. the modification of the compressor to fit operating pressure heightens the performance. The effects of the performance of components on the COP are also analyzed based on the measured thermodynamic states at both ends of components in the system. Then, it is clarified that the most effective factor is irreversibility of compressors and the following is the pressure drop in low pressure side including the evaporator and the suction pipe.

  18. INVESTIGATIONS ON THE PERFORMANCE OF VAPOUR COMPRESSION SYSTEM RETROFITTED WITH ZEOTROPIC REFRIGERANT R404A

    Directory of Open Access Journals (Sweden)

    A. Lovelin Jerald

    2014-01-01

    Full Text Available The environmental impacts like global warming and ozone depletion has become a challenge to the refrigeration and air conditioning industry. Chloro Fluoro Carbons (CFCs and Hydro Flouro Carbons (HCFCs are referred to as an Ozone Depleting Substances (ODS because once these gases are released into the environment and reach the stratosphere, depletes the ozone layer. This research paper aims to study the performance characteristics of an R12 (CFC vapour compression refrigeration system retrofitted with zeotrope blend of refrigerant R404a, used for cooling liquids with five different configuration of capillaries of diameters 0.033”, 0.036”, 0.044”, 0.050” and 0.30” (2 Way. The refrigerant R404a is an alternate refrigerant to CFCs and HCFCs as they are ozone friendly and have less Global Warming Potential (GWP than R12 and R134a. The parameters employed in analysis of the performance characteristics are the Evaporator load (Qe, Coefficient of Performance (COP, Work done by the compressor (Wc and Refrigeration Effect (RE. A detailed experimentation was carried out to compare the performance and effectiveness of the system using five different capillaries. The result obtained from the observation will help to identify the optimum diameter of capillary which could be used in the system to give the best performance.

  19. Evaluation of non-azeotropic mixtures containing HFOs as potential refrigerants in refrigeration and high-temperature heat pump systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With the increasing environmental concern on global warming, hydrofluoro-olefin (HFOs), possessing low GWP, has attracted great attention of many researchers recently. In this study, non-azeotropic mixtures composed of HFOs (HFO-1234yf, HFO-1234ze(z), HFO-1234ze(e) and HFO-1234zf) are developed to substitute for HFC-134a and CFC-114 in air-conditioning and high-temperature heat pump systems, respectively. The cycle performances were evaluated by an improved theoretical cy-cle evaluation methodology. The results showed that all the mixtures proposed herein were favorable refrigerants with excel-lent thermodynamic cycle performances. M1A presented lower discharge temperature and pressure ratio and higher COPc than that of HFC-134a. The volumetric cooling capacity was similar to HFC-134a. It can be served as a good environmentally friendly alternative to replace HFC-134a. M3H delivered similar discharge temperature as CFC-114 did. And the COPh was 3% higher. It exhibits excellent cycle performance in high-temperature heat pump and is a promising refrigerant to substitute for CFC-114. And the gliding temperature differences enable them to exhibit better coefficient of performance by matching the sink/source temperature in practice. Because the toxicity, flammability and other properties are not investigated in detail, ex-tensive toxicity and flammability testing needs to be conducted before they are used in a particular application.

  20. Refrigerating machine oil

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, K.

    1981-03-17

    Refrigerating machine oil to be filled in a sealed motorcompressor unit constituting a refrigerating cycle system including an electric refrigerator, an electric cold-storage box, a small-scaled electric refrigerating show-case, a small-scaled electric cold-storage show-case and the like, is arranged to have a specifically enhanced property, in which smaller initial driving power consumption of the sealed motor-compressor and easier supply of the predetermined amount of the refrigerating machine oil to the refrigerating system are both guaranteed even in a rather low environmental temperature condition.

  1. Evaluation of a seasonal storage system of solar energy for house heating using different absorption couples

    International Nuclear Information System (INIS)

    Research highlights: → An absorption system for long-term energy storage for house heating is presented. → The storage capacity and efficiency of seven absorption couples are studied. → The influence of temperature of absorption, evaporation and storage is evaluated. → The appearance of crystals in the storage tank increases the storage capacity. -- Abstract: In this paper, an innovative concept is presented for a long-term energy storage system for house heating, using the absorption process. The solar energy is stored during summer through desorption and the heat is released during winter through absorption. The originality of this concept is to allow the solution to reach the crystallization point, which is usually avoided in the absorption refrigeration machines. The storage capacity and efficiency of seven absorption couples, CaCl2/H2O, Glycerin/H2O, KOH/H2O, LiBr/H2O, LiCl/H2O, NaOH/H2O and H2O/NH3, as a function of the temperature of absorption, temperature of evaporation, temperature of the solution before absorption and the presence of crystals in the storage tank have been studied in this paper. The appearance of crystals increases the storage capacity. The storage capacity increases with the temperature of evaporation and the temperature of the solution before absorption but decreases with the temperature of absorption.

  2. Overview of Air Liquide refrigeration systems between 1.8 K and 200 K

    Science.gov (United States)

    Gondrand, C.; Durand, F.; Delcayre, F.; Crispel, S.; Baguer, G. M. Gistau

    2014-01-01

    Cryogenic refrigeration systems are necessary for numerous applications. Gas purification and distillation require temperatures between 15 K and 200 K depending on the application, space simulation chambers down to 15 K, superconductivity between 1.8 K and up to 75 K (magnets, cavities or HTS devices like cables, FCL, SMES, etc), Cold Neutron Sources between 15 and 20 K, etc. Air Liquide Advanced Technologies is designing and manufacturing refrigerators since 60 years to satisfy those needs. The step by step developments achieved have led to machines with higher efficiency and reliability. In 1965, reciprocating compressors and Joule Thomson expansion valves were used. In 1969, centripetal expanders began to be used. In 1980, oil lubricated screw compressors took the place of reciprocating compressors and a standard range of Claude cycle refrigerators was developed: the HELIAL series. 1980 was also the time for cryogenic centrifugal compressor development. In 2011, driven by the need for lower operational cost (high efficiency and low maintenance), cycle oil free centrifugal compressors on magnetic bearings were introduced instead of screw compressors. The power extracted by centripetal expanders was recovered. Based on this technology, a range of Turbo-Brayton refrigerators has been designed for temperatures between 40 K and 150 K. On-going development will enable widening the range of Turbo-Brayton refrigerators to cryogenic temperatures down to 15 K.. Cryogenic centrifugal circulators have been developed in order to answer to an increasing demand of 4 K refrigerators able to distribute cold power.

  3. Overview of Air Liquide refrigeration systems between 1.8 K and 200 K

    Energy Technology Data Exchange (ETDEWEB)

    Gondrand, C.; Durand, F.; Delcayre, F.; Crispel, S. [AL-AT, 2 rue de Clémencières, 38360 Sassenage (France); Baguer, G. M. Gistau [CRYOGUY, 44, chemin de la Buisse, 38330 Biviers (France)

    2014-01-29

    Cryogenic refrigeration systems are necessary for numerous applications. Gas purification and distillation require temperatures between 15 K and 200 K depending on the application, space simulation chambers down to 15 K, superconductivity between 1.8 K and up to 75 K (magnets, cavities or HTS devices like cables, FCL, SMES, etc), Cold Neutron Sources between 15 and 20 K, etc. Air Liquide Advanced Technologies is designing and manufacturing refrigerators since 60 years to satisfy those needs. The step by step developments achieved have led to machines with higher efficiency and reliability. In 1965, reciprocating compressors and Joule Thomson expansion valves were used. In 1969, centripetal expanders began to be used. In 1980, oil lubricated screw compressors took the place of reciprocating compressors and a standard range of Claude cycle refrigerators was developed: the HELIAL series. 1980 was also the time for cryogenic centrifugal compressor development. In 2011, driven by the need for lower operational cost (high efficiency and low maintenance), cycle oil free centrifugal compressors on magnetic bearings were introduced instead of screw compressors. The power extracted by centripetal expanders was recovered. Based on this technology, a range of Turbo-Brayton refrigerators has been designed for temperatures between 40 K and 150 K. On-going development will enable widening the range of Turbo-Brayton refrigerators to cryogenic temperatures down to 15 K.. Cryogenic centrifugal circulators have been developed in order to answer to an increasing demand of 4 K refrigerators able to distribute cold power.

  4. Refrigerator Based on Chemisorption

    Science.gov (United States)

    Jones, Jack A.

    1987-01-01

    Reversible chemical reaction generates pressurized oxygen for cooling. Concept for cryogenic refrigerator based on chemical absorption of oxygen by praseodymium/cerium oxide (PCO) compound. Refrigerator produces cryogenic liquid for cooling infrared sensors. Also used for liquefying air and separating oxygen from nitrogen in air. In chemisorption refrigerator, PCO alternately absorbs and desorbs oxygen depending on whether cooled or heated. One pair of compressors accepts oxygen while others releases it. Compressed oxygen liquefied when precooked and expanded.

  5. Data Mining Approcah for Performance Analysis of Variable Speed Refrigeration System

    Directory of Open Access Journals (Sweden)

    Önder KIZILKAN

    2015-02-01

    Full Text Available The aim of this study is to carry out performance modeling of an experimental refrigeration system driven by variable speed compressor using Data Mining techniques with small data sets. In order to vary the capacity of the refrigeration systems, one of the best methods is controlling the rotational speed of the compressor motor with a frequency inverter. For this aim, an experimental refrigeration system is setup with a frequency inverter for controlling the speed of compressor electric motor. The experiments are made for 35 Hz to 50 Hz electric motor frequencies. Data mining technique is applied to determine the system performance parameters using actual data obtained from the measurements. From the results, it is observed that data mining procedure is suitable for forecasting the system characteristics for different compressor frequencies and cooling loads instead of making several experiments

  6. Nonlinear FOPDT Model Identification for the Superheat Dynamic in a Refrigeration System

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Sun, Zhen; Andersen, Casper

    2011-01-01

    An on-line nonlinear FOPDT system identification method is proposed and applied to model the superheat dynamic in a supermarket refrigeration system. The considered nonlinear FOPDT model is an extension of the standard FOPDT model by means that its parameters are time dependent. After the conside......An on-line nonlinear FOPDT system identification method is proposed and applied to model the superheat dynamic in a supermarket refrigeration system. The considered nonlinear FOPDT model is an extension of the standard FOPDT model by means that its parameters are time dependent. After......-dependent parameters. The proposed method is firstly tested through a number of numerical examples, and then applied to model the superheat dynamic in a supermarket refrigeration system based on experimental data. As shown in these studies, the proposed method is quite promising in terms of reasonable accuracy, large...

  7. Thermodynamic analysis of transcritical CO{sub 2} booster refrigeration systems in supermarket

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y.T., E-mail: yunting.ge@brunel.ac.u [Mechanical Engineering, School of Engineering and Design, Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom); Tassou, S.A. [Mechanical Engineering, School of Engineering and Design, Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom)

    2011-04-15

    Research highlights: {yields} The CO{sub 2} booster systems are widely applied in supermarket refrigeration. {yields} Control optimisation can improve the performance of the CO{sub 2} refrigeration systems. {yields} The effects of some important parameters on the system performance are examined. {yields} The optimal high-side pressure in the transcritical cycles is established and derived. -- Abstract: Due to less environmental impact, the CO{sub 2} booster refrigeration system has been widely applied in the modern supermarket as a substitute for the conventional R404A multiplex system. However, the performance efficiency of the CO{sub 2} system still requires further improvement in order to save energy; thus, one of the most efficient techniques would be to investigate and employ the optimal controls for refrigerant high side pressures at various operating states. In this paper, the possible parameters affecting system efficiency of the CO{sub 2} system in the transcritical cycle at a higher ambient air temperature are identified through thermodynamic analysis, but cannot be quantified mathematically because of the high non-linearity involved. Instead, sensitive analysis of the system by means of the thermodynamic model is used to examine the effects of parameters including high side refrigerant pressure, ambient air temperature, refrigerant intermediate pressure, and medium and low evaporating temperatures, superheating, effectiveness of suction line heat exchanger, and compressor efficiency on system performance. Consequently, the optimal high side pressure in the transcritical cycle is established and derived as a function of three important parameters consisting of ambient air temperature, the effectiveness of suction line heat exchanger and compressor efficiency. In addition, optimal operating parameters such as the intermediate pressure are also proposed to improve the system performance.

  8. Advanced Supermarket Refrigeration - Heat Recovery Systems. Annex 26. Final report. Volume 2. Country reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-04-01

    Annex 26 has produced three deliverables: (1) Workshop (October 2000) proceedings Stockholm, Sweden, on CD-ROM (HPP-AN26-1); (2) Final report, Volume 1, Executive Summary, as report (HPP-AN26-2); and (3) Final report, Volume 2, Country reports (described in this record). Each of these reports, available from the HPC, provide valuable information for practitioners (designers, installers) and manufacturers of supermarket refrigeration systems. Annex 26 is the first international project under the IEA Heat Pump Programme that links refrigeration and heat pump technology. Recovering heat from advanced supermarket refrigeration systems for space and water heating purposes seems obvious and is beneficial for owners and operators. Because there are world-wide a great number of supermarkets that offer frozen and chilled food and further growth of this sector may be expected, the amount of energy used for refrigeration is enormous and will likely increase substantially in the near future. Annex 26 analysed several advanced supermarket refrigeration systems and came to remarkable conclusions as far as energy conservation and TEWI reduction is concerned. The conclusions justify that advanced supermarket systems with heat recovery should receive great attention and support. And there is still further research needed in several areas. The Annex also included a thorough system cost analyses and proposals for cost reductions are given.

  9. Advanced Supermarket Refrigeration - Heat Recovery Systems. Annex 26. Final report. Volume 1. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D. (ed.) [Oak Ridge National Laboratory ORNL, Oak Ridge, TN (United States)

    2003-04-01

    Annex 26 has produced three deliverables: (1) Workshop (October 2000) proceedings Stockholm, Sweden, on CD-ROM (HPP-AN26-1); (2) Final report, described in this record; and (3) Final report, Volume 2, Country reports, on CD-ROM (HPP-AN26-3). Each of these reports, available from the HPC, provide valuable information for practitioners (designers, installers) and manufacturers of supermarket refrigeration systems. Annex 26 is the first international project under the IEA Heat Pump Programme that links refrigeration and heat pump technology. Recovering heat from advanced supermarket refrigeration systems for space and water heating purposes seems obvious and is beneficial for owners and operators. Because there are world-wide a great number of supermarkets that offer frozen and chilled food and further growth of this sector may be expected, the amount of energy used for refrigeration is enormous and will likely increase substantially in the near future. Annex 26 analysed several advanced supermarket refrigeration systems and came to remarkable conclusions as far as energy conservation and TEWI reduction is concerned. The conclusions justify that advanced supermarket systems with heat recovery should receive great attention and support. And there is still further research needed in several areas. The Annex also included a thorough system cost analyses and proposals for cost reductions are given.

  10. Sub-cooled liquid nitrogen cryogenic system with neon turbo-refrigerator for HTS power equipment

    Science.gov (United States)

    Yoshida, S.; Hirai, H.; Nara, N.; Ozaki, S.; Hirokawa, M.; Eguchi, T.; Hayashi, H.; Iwakuma, M.; Shiohara, Y.

    2014-01-01

    We developed a prototype sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The system consists of a neon turbo-Brayton refrigerator with a LN sub-cooler and LN circulation pump unit. The neon refrigerator has more than 2 kW cooling power at 65 K. The LN sub-cooler is a plate-fin type heat exchanger and is installed in a refrigerator cold box. In order to carry out the system performance tests, a dummy cryostat having an electric heater was set instead of a HTS power equipment. Sub-cooled LN is delivered into the sub-cooler by the LN circulation pump and cooled within it. After the sub-cooler, sub-cooled LN goes out from the cold box to the dummy cryostat, and comes back to the pump unit. The system can control an outlet sub-cooled LN temperature by adjusting refrigerator cooling power. The refrigerator cooling power is automatically controlled by the turbo-compressor rotational speed. In the performance tests, we increased an electric heater power from 200 W to 1300 W abruptly. We confirmed the temperature fluctuation was about ±1 K. We show the cryogenic system details and performance test results in this paper.

  11. Theoretical Study on CO2 Transcritical Cycle Combined Ejector Cycle Refrigeration System

    Institute of Scientific and Technical Information of China (English)

    卢苇; 马一太; 李敏霞; 查世彤

    2003-01-01

    Chlorofluorocarbons(CFCs) or hydrochlorofluorocarbons(HCFCs) are as main refrigerants used in traditional refrigeration systems driven by electricity from burning fossil fuels, which is regarded as one of the major reasons for ozone depletion (man-made refrigerants emission) and global warming (CO2 emission). So people pay more and more attention to natural refrigerants and energy saving technologies. An innovative system combining CO2 transcritical cycle with ejector cycle is proposed in this paper. The CO2 compression sub-cycle is powered by electricity with the characteristics of relatively high temperature in the gas cooler (defined as an intercooler by the proposed system). In order to recover the waste heat, an ejector sub-cycle operating with the natural refrigerants (NH3, H2O) is employed. The two sub-cycles are connected by an intercooler. This combined cycle joins the advantages of the two cycles together and eliminates the disadvantages. The influences of the evaporation temperature in CO2 compression sub-cycle, the evaporation temperature in the ejector sub-cycle, the temperature in the intercooler and the condensation temperature in the proposed system performance are discussed theoretically in this study. In addition, some unique features of the system are presented.

  12. State-space modelling for the ejector-based refrigeration system driven by low grade energy

    International Nuclear Information System (INIS)

    This paper presents a novel global state-space model to describe the ejector-based refrigeration system, which includes the dynamics of the two heat exchangers and the static properties of ejector, compressor and expansion valve. Different from the existing methods, the proposed method introduces some intermediate variables into the dynamic modelling in developing reduced order models of the heat exchangers (evaporator and condenser) based on the Number of Transfer Units (NTU) method. This global model with fewer dimensions is much simpler and can be more convenient for the real-time control system design, compared with other dynamic models. Finally, the proposed state-space model has been validated by dynamic response experiments on the ejector-based refrigeration cycle with refrigerant R134a.The experimental results indicate that the proposed model can predict well the dynamics of the ejector-based refrigeration system. - Highlights: • A low-order state-space model of ejector-based refrigeration system is presented. • Reduced-order models of heat exchangers are developed based on NTU method. • The variations of mass flow rates are introduced in multiple fluid phase regions. • Experimental results show the proposed model has a good performance

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

    Directory of Open Access Journals (Sweden)

    İbrahim ÜÇGÜL

    2009-02-01

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

  14. Numerical model for thermoeconomic diagnosis in commercial transcritical/subcritical booster refrigeration systems

    DEFF Research Database (Denmark)

    Ommen, Torben; Elmegaard, Brian

    2012-01-01

    Transcritical/subcritical booster refrigeration systems are increasingly installed and used in Danish supermarkets. The systems operate in both transcritical and subcritical conditions dependent on the heat rejection performance and the ambient conditions. The plant consists of one refrigerant...... cycle supplying refrigerant for evaporators in both chilled and frozen display cases. In the paper, thermoeconomic theory is used to establish the cost of cooling at each individual temperature level based on operating costs.With a high amount of operating systems, faulty operation becomes an economic......, and environmental, interest. A general solution for evaluation of these systems is considered, with the objective to reduce cost and power consumption of malfunctioning equipment in operation. An analysis of the use of thermoeconomic diagnosis methods is required, as these methods may prove applicable...

  15. Installation and Commissioning of the Helium Refrigeration System for the HANARO-CNS

    International Nuclear Information System (INIS)

    The cold neutron source (CNS), which will be installed in the vertical CN hole of the reflector tank at HANARO, makes thermal neutrons to moderate into the cold neutrons with the ranges of 0.1 ∼ 10 meV passing through a moderator at about 22K. A moderator to produce cold neutrons is liquid hydrogen, which liquefies by the heat transfer with cryogenic helium flowing from the helium refrigeration system. For the maintenance of liquid hydrogen in the IPA, the CNS system is mainly consisted of the hydrogen system to supply the hydrogen to the IPA, the vacuum system to keep the cryogenic liquid hydrogen in the IPA, and the helium refrigeration system to liquefy the hydrogen gas. The helium refrigeration system can be divided into two sections: one is the helium compression part from the low pressure gas to the high pressure gas and the other is the helium expansion part from the high temperature gas and pressure to low temperature and pressure gas by the expansion turbine. The helium refrigeration system except the warm helium pipe and the helium buffer tank has been manufactured by Linde Kryotechnik, AG in Switzerland and installed in the research reactor hall, HANARO. Other components have been manufactured in the domestic company. This technical report deals with the issues, its solutions, and other particular points while the helium refrigeration system was installed at site, verified its performance, and conducted its commissioning along the reactor operation. Furthermore, the operation procedure of the helium refrigeration system is included in here for the normal operation of the CNS

  16. Fault Detection and Isolation for a Supermarket Refrigeration System - Part Two

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Rasmussen, Karsten B.; Kieu, Anh T.;

    2011-01-01

    The Fault Detection and Isolation (FDI) using the Unknown Input Observer (UIO) for a supermarket refrigeration system is investigated. The original system's state $T_{goods}$ (temp. of the goods) is regarded as a system unknown input in this study, so that the FDI decision is not disturbed...

  17. Risks in the physical recovery system of waste refrigerator cabinets and the controlling measure.

    Science.gov (United States)

    Ruan, Jujun; Xue, Mianqiang; Xu, Zhenming

    2012-12-18

    Environmental information in physical recovery system of waste refrigerator cabinets was provided in this paper. The system included closed shearing, activated carbon adsorption (ACA), air current separation, magnetic separation, and eddy current separation. Exposures of CFC-11, heavy metals, and noise emitted from the system were assessed. Abundant CFC-11 (>510 mg/m³) was detected in crusher cavity. However, due to the employment of ACA, little CFC-11 (refrigerator cabinets on environmental protection. Meanwhile, it contributed to the knowledge of environmental information of physical technology for recovering e-waste.

  18. Potential of the tractor-trailer and container segments as entry markets for a proposed refrigeration technology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.A.; Davis, L.J.; Garrett, B.A.

    1987-05-01

    The refrigerated trailer and container segments of the transportation industry are evaluated as potential entry markets for a proposed absorption refrigeration technology. To perform this analysis the existing transportation refrigeration industry is characterized; this includes a description of the current refrigeration technology, rating systems, equipment manufacturers, maintenance requirements, and sales trends. This information indicates that the current transportation refrigeration industry is composed of two major competitors, Thermo King and Carrier. In addition, it has low profit potential, some barriers to entry and low growth potential. Data are also presented that characterize the transportation refrigeration consumers, specifically, major groups, market segmentation, consumer decision process, and buying criteria. This consumer information indicates that the majority of refrigerated trailer consumers are private carriers, and that the majority of refrigerated container consumers are shipping companies. Also, these consumers are primarily interested in buying reliable equipment at a low price, and are quite satisfied with existing refrigeration equipment.

  19. Thermodynamic Analysis of Actual Vapour Compression System with R12 and Its Eco-Friendly Alternatives Refrigerants

    OpenAIRE

    Vijay Singh Bisht; A.K.Pratihar

    2014-01-01

    This paper presents a theoretical performance study of a vapour compression refrigeration system with refrigerants R-12, R134a and R1234yf. A computational model based on energy first law analysis is presented for the investigation of the effects of evaporating temperatures, degree of subcooling, dead state temperatures and effectiveness of the liquid vapour heat exchanger on the relative capacity change index, coefficient of performance of the vapour compression refrigeration cycle. RCI (rel...

  20. 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....

  1. The Effect of the Capillary Tube Coil Number on the Refrigeration System Performance

    OpenAIRE

    Thamir K. Salim

    2012-01-01

    The capillary tube performance for (R134a) is experimentally investigated. The experimental setup is a real vapor compression refrigeration system. All properties of the refrigeration system are measured for various mass flow rate from (13 – 23 kg/hr) and capillary tube coil number (0-4) with fixed length (150 cm) and capillary diameter(2.5mm).The results showed that the theoretical compression power increases by (65.8 %) as the condenser temperature increases by (2.71%), also the theoretical...

  2. Quantum refrigeration cycles using spin-1/2 systems as the working substance.

    Science.gov (United States)

    He, Jizhou; Chen, Jincan; Hua, Ben

    2002-03-01

    The cycle model of a quantum refrigerator composed of two isothermal and two isomagnetic field processes is established. The working substance in the cycle consists of many noninteracting spin-1/2 systems. The performance of the cycle is investigated, based on the quantum master equation and semigroup approach. The general expressions of several important performance parameters, such as the coefficient of performance, cooling rate, and power input, are given. Especially, the case at high temperatures is analyzed in detail. The results obtained are further generalized and discussed, so that they may be directly used to describe the performance of the quantum refrigerator using spin-J systems as the working substance. Finally, the optimum characteristics of the quantum Carnot refrigerator are derived simply. PMID:11909203

  3. Adapting CHP Software to suit the modelling of heat pump and refrigeration systems

    NARCIS (Netherlands)

    Verschoor, M.J.E.

    1998-01-01

    The role of heat pumps and refrigeration machines as integrated parts of energy supply systems is increasing as a result of the search for systems which supply the desired amounts and types of energy in an energy-efficient manner. Tools to support engineers in designing, analysing and optimising suc

  4. Performance Monitoring in Supermarket Refrigeration Systems - Synchronisation of Refrigerated Display Cases

    DEFF Research Database (Denmark)

    Chen, Liang; Green, Torben; Sloth Larsen, Lars Finn;

    2009-01-01

    Hybrid control has in the recent years drawn considerable attention in academia as it poses a large number of theoretical and computational challenges. The interested scientific community has proposed various methods to address some of the problems related to modeling and control of hybrid system...

  5. STUDY ON SYNTHETIC REFRIGERATION OIL FOR REFRIGERATION SYSTEM USING R134a/R22 REFRIGERANT%用于R134a和R22制冷系统的合成冷冻机油研究

    Institute of Scientific and Technical Information of China (English)

    陈美名; 宗明

    2011-01-01

    Based on the requirements of refrigeration system to refrigeration oil .the characteristics of refrigeration oil and adopting technical indexes from the commercial norm A-A-50634 of US Navy as reference,a specification for synthetic refrigeration oil was proposed. Using modified polyether as base oil,the synthetic refrigeration oil meeting said specification was prepared. A series of tests for the obtained refrigeration oil was carried out, such as physical-chemical properties analysis, miscibility with R134a/R22 refrigerant, chemical stability (sealed glass tube test) , stability (Philips test) , insulation and lubricity tests. Finally,it was applied in a compressor of R134a car air conditioner. The results of evaluation and application showed that this synthesized refrigeration oil well met the requirements of the proposed specification,and it could be used in the R134a/R22 refrigeration system.%根据制冷系统对冷冻机油性能的要求、合成冷冻机油性能特点,参照美国海军商业规范A-A-50634提出研制合成冷冻机油的主要技术指标,制备出了一种以改性聚醚作基础油的合成冷冻机油.对研制油的理化性质、与制冷剂R134a和R22的互溶性、化学稳定性(密封管试验)、稳定性(菲利浦试验)、电绝缘性、润滑性等进行评价,并在斜盘式汽车空调压缩机上与R134a配套使用.评价和应用结果表明,研制的合成冷冻机油满足制定的技术指标要求,并可用于R134a和R22制冷系统.

  6. Artificial neural network analysis of a refrigeration system with an evaporative condenser

    Energy Technology Data Exchange (ETDEWEB)

    Ertunc, H.M. [Department of Mechatronics Engineering, Kocaeli University, 41040 Kocaeli (Turkey); Hosoz, M. [Department of Mechanical Education, Kocaeli University, 41380 Kocaeli (Turkey)

    2006-04-01

    This paper describes an application of artificial neural networks (ANNs) to predict the performance of a refrigeration system with an evaporative condenser. In order to gather data for training and testing the proposed ANN, an experimental refrigeration system with an evaporative condenser was set up. Then, steady-state test runs were conducted varying the evaporator load, air and water flow rates passing through the condenser and both dry and wet bulb temperatures of the air stream entering the condenser. Utilizing some of the experimental data, an ANN model for the system based on standard backpropagation algorithm was developed. The ANN was used for predicting various performance parameters of the system, namely the condenser heat rejection rate, refrigerant mass flow rate, compressor power, electric power input to the compressor motor and the coefficient of performance. The ANN predictions usually agree well with the experimental values with correlation coefficients in the range of 0.933-1.000, mean relative errors in the range of 1.90-4.18% and very low root mean square errors. Results show that refrigeration systems, even complex ones involving concurrent heat and mass transfer such as systems with an evaporative condenser, can alternatively be modelled using ANNs within a high degree of accuracy. [Author].

  7. Thermodynamic analysis of a novel energy-efficient refrigeration system subcooled by liquid desiccant dehumidification and evaporation

    International Nuclear Information System (INIS)

    Highlights: • An energy-efficient refrigeration system with a novel subcooling method is proposed. • Thermodynamic analysis is conducted to discuss the effects of operation parameters. • Two different utilization ways of condensation heat are compared. • The system achieves much higher COP, even higher than reverse Carnot cycle. • Suggested mass concentration for LiCl–H2O is around 32% at a typical case. - Abstract: A new energy-efficient refrigeration system subcooled by liquid desiccant dehumidification and evaporation was proposed in this paper. In the system, liquid desiccant system could produce very dry air for an indirect evaporative cooler, which would subcool the vapor compression refrigeration system to get higher COP than conventional refrigeration system. The desiccant cooling system can use the condensation heat for the desiccant regeneration. Thermodynamic analysis is made to discuss the effects of operation parameters (condensing temperature, liquid desiccant concentration, ambient air temperature and relative humidity) on the system performance. Results show that the proposed hybrid vapor compression refrigeration system achieves significantly higher COP than conventional vapor compression refrigeration system, and even higher than the reverse Carnot cycle at the same operation conditions. The maximum COPs of the hybrid systems using hot air and ambient air are 18.8% and 16.3% higher than that of the conventional vapor compression refrigeration system under varied conditions, respectively

  8. Molecular hydrogen absorption systems in SDSS

    CERN Document Server

    Balashev, S A; Ivanchik, A V; Varshalovich, D A; Petitjean, P; Noterdaeme, P

    2014-01-01

    We present a systematic search for molecular hydrogen absorption systems at high redshift in quasar spectra from the Sloan Digital Sky Survey (SDSS) II Data Release 7 and SDSS-III Data Release 9. We have selected candidates using a modified profile fitting technique taking into account that the Ly$\\alpha$ forest can effectively mimic H$_2$ absorption systems at the resolution of SDSS data. To estimate the confidence level of the detections, we use two methods: a Monte-Carlo sampling and an analysis of control samples. The analysis of control samples allows us to define regions of the spectral quality parameter space where H$_2$ absorption systems can be confidently identified. We find that H$_2$ absorption systems with column densities $\\log {\\rm N_{H_2}} > 19$ can be detected in only less than 3% of SDSS quasar spectra. We estimate the upper limit on the detection rate of saturated H$_2$ absorption systems ($\\log {\\rm N_{H_2}} > 19$) in Damped Ly-$\\alpha$ (DLA) systems to be about 7%. We provide a sample of ...

  9. Fault Detection and Isolation for a Supermarket Refrigeration System - Part One

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Rasmussen, Karsten B.; Kieu, Anh T.;

    2011-01-01

    Fault Detection and Isolation (FDI) using the Kalman Filter (KF) technique for a supermarket refrigeration system is explored. Four types of sensor fault scenarios, namely drift, offset, freeze and hard-over, are considered for two temperature sensors, and one type of parametric fault scenario...

  10. EXERGOECONOMIC COMPARISON OF ABSORPTION REFRIGERATION SYSTEMS INCLUDING A HIBRID ABSORPTION-EJECTO COMPRESSION CHILLER

    Directory of Open Access Journals (Sweden)

    JUAN CARLOS BURBANO JARAMILLO

    2011-01-01

    Full Text Available El estudio de los sistemas de refrigeración por absorción ha tomado una importancia creciente en los últimos años, ya que la energía primaria que es usada en un sistema de absorción puede ser calor disponible de una fuente residual o de una renovable. Por lo tanto, estos sistemas no sólo usan energía que sería rechazada al ambiente sino también, evitan el consumo de energías fósiles o eléctricas costosas. El costo de producción de trabajo mecánico necesario para obtener un kW de refrigeración para el ciclo de compresión mecánico es, normalmente, más alto que el costo para recuperar el calor necesario para obtener el mismo kW en un ciclo de absorción. También, el uso de estos sistemas reduce el impacto ambiental disminuyendo la emisión de CO2. Este artículo pretende mostrar el desempeño de un chiller híbrido de absorción-eyecto compresión comparado con sistemas de absorción convencionales de agua/bromuro de litio de simple y doble efecto, por medio de un análisis exergético y exergoeconómico de estas configuraciones a fin de calcular el costo con base exergética del producto final. Fue incluido un sistema de refrigeración por compresión de vapor en los resultados, como comparación del desempeño con los sistemas de refrigeración por absorción analizados.

  11. Exergoeconomic comparison of absorption refrigeration systems including a hibrid absorption-ejecto compression chiller

    OpenAIRE

    JUAN CARLOS BURBANO JARAMILLO; LUIZ FELIPE PELLEGRINI; SILVIO DE OLIVEIRA JR.

    2011-01-01

    El estudio de los sistemas de refrigeración por absorción ha tomado una importancia creciente en los últimos años, ya que la energía primaria que es usada en un sistema de absorción puede ser calor disponible de una fuente residual o de una renovable. Por lo tanto, estos sistemas no sólo usan energía que sería rechazada al ambiente sino también, evitan el consumo de energías fósiles o eléctricas costosas. El costo de producción de trabajo mecánico necesario para obtener un kW de refrigeración...

  12. Analysis on energy saving potential of integrated supermarket HVAC and refrigeration systems using multiple subcoolers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); China R and D Center, Carrier Corporation, No. 3239 Shen Jiang Road, Shanghai 201206 (China); Zhang, Chun-Lu [China R and D Center, Carrier Corporation, No. 3239 Shen Jiang Road, Shanghai 201206 (China)

    2010-02-15

    The paper presents a model-based analysis on the energy saving potential of supermarket HVAC (heating, ventilating, and air-conditioning) and refrigeration systems using multiple subcoolers among the high-temperature HVAC system, the medium-temperature refrigeration system, and the low-temperature refrigeration system. The principle of energy reduction is to have the higher COP (coefficient of performance) system generate more cooling capacity to increase the cooling capacity or reduce the power consumption of the lower COP system. The subcooler could be placed between the medium-temperature and low-temperature systems, between the high-temperature and medium-temperature systems, and between the high-temperature and low-temperature systems. All integration scenarios of adding one, two and three subcoolers have been investigated. The energy saving potential varies with the load ratio between high-, medium- and low-temperature systems, COP of three systems, and the ''on-off'' duty time of HVAC system. The optimal sequence of adding subcoolers is also proposed. (author)

  13. Utilization of process energy from supermarket refrigeration systems. Coupling of cooling and heating; Prozessenergienutzung von Supermarktkaelteanlagen. Kaelte-Waerme-Kopplung

    Energy Technology Data Exchange (ETDEWEB)

    Wirsching, Alexander [TEKO Gesellschaft fuer Kaeltetechnik mbH, Altenstadt (Germany). Technologie und Kommunikation

    2010-03-15

    The efficiency is defined as the relation between utility and expenditure. Thus, it is obvious for the specialist of refrigeration to tackle with the expenditure (energy consumption) since the utilization conventionally is defined as the produced/need cooling performance of a refrigeration plant. If refrigeration plants are regarded according to their function (withdrawal of heat from a refrigeration chamber and delivery to the environment), the heating system is the producer of the requirement for cooling in 'the winter' (heating season). Thus, the refrigeration plant perhaps already has a marvellous efficiency, and the separate heating system too - however in interaction. The broad view moves into the focus. The possible approaches and effects are described in the contribution under consideration using the example of a Discount supermarket with a sales area of 800 square meters and a requirement of cooling of more than 30 kW.

  14. 2012 International Conference on Medical Physics and Biomedical Engineering Thermal Economic Analysis on LiBr Refrigeration -Heat Pump System Applied in CCHP System

    Science.gov (United States)

    Zhang, CuiZhen; Yang, Mo; Lu, Mei; Zhu, Jiaxian; Xu, Wendong

    LiBr refrigeration cooling water contains a lot of low-temperature heat source, can use this part of the heat source heat boiler feed water. This paper introduced LiBr refrigeration - heat pump system which recovery heat of the LiBr refrigeration cooling water by heat pump system to heat the feed water of boiler. Hot economic analysis on the system has been performed based on the experimental data. Results show that LiBr refrigeration-heat pump system brings 26.6 percent decrease in primary energy rate consumption comparing with the combined heat and power production system(CHP) and separate generation of cold;

  15. Performance of Active Wave Absorption Systems

    DEFF Research Database (Denmark)

    Hald, Tue; Frigaard, Peter

    A comparison of wave gauge based on velocity meter based active absorption systems is presented discussing advantages and disadvantages of the systems. In detail one system based on two surface elevations, one system based on a surface elevation and a horisontal velocity and one system based...... on a horisontal and vertical velocity are treated. All three systems are based on digital FIR-filters. For numerical comparison a performance function combining the frequency response of the set of filters for each system is derived enabling discussion on optimal filter design and system setup. Irregular wave...

  16. Refrigerant and Lubricant Mass Distribution in a Convertible Split System Residential Air-Conditioner

    OpenAIRE

    Wujek, Scott S.; Bowers, Chad D.; Powell, Joshua W.; Urrego, Roberto A.; Hessell, Edward T.; Benanti, Travis L.

    2014-01-01

    Lubricants are utilized in air-conditioning systems for the purpose of decreasing friction and wear within the compressor. While ideally the lubricant remains in the compressor, some lubricant is entrained and transported by the refrigerant to the other system components. During operational transients, the lubricant is redistributed throughout the various system components. The equilibrium distribution of lubricant depends among other things on fluid properties, phase change processes, flow r...

  17. 三元制冷系统分析%Exergy analysis of a ternary refrigeration system

    Institute of Scientific and Technical Information of China (English)

    张小锋; 冯霄

    2016-01-01

    The separation process of an ethylene plant should be operated at low temperature. Therefore,a compression refrigeration system is needed to provide refrigerant. A ternary refrigeration system can provide a continuous cooling curve matching very well with the process stream cooling curve,and has higher thermodynamic efficiency,lower energy consumption than a cascaded refrigerant system. In order to analyze the energy saving potential of a ternary refrigeration system,in this paper, the ternary refrigerant system in a certain ethylene plant was analyzed by exergy analysis. From the exergy grand composite curve(EGCC),it could be found that the refrigerant configuration of the ternary refrigeration system was reasonable and the total exergy loss was small. The system is classified into four sub-systems:heat exchanger,compressor,throttle valve and flash drum sub-systems. The results of exergy losses show that the total exergy loss of the ternary refrigeration system is 24238.1kW,about 90% of which concentrates on the heat exchanger and compressor sub-systems. Furthermore,the exergy losses are divided into avoidable and inevitable exergy losses,in which the total inevitable exergy loss is 13539.9kW,and the total avoidable exergy loss is 10698.2kW. The work for energy conservation should focus on reducing the avoidable exergy loss.%乙烯装置产品分离过程需要在低温下进行,为此需配置压缩制冷系统为深冷分离提供冷量。三元压缩制冷由于能提供温位连续的制冷曲线,与工艺物流降温曲线更好地匹配,相比传统的复叠制冷具有热力学效率高、制冷能耗低的特点。为了分析三元压缩制冷的节能潜力,本文对某乙烯装置的三元制冷系统进行了㶲分析。从㶲总复合曲线(EGCC)图的分析可以得出该系统三元冷剂配置是比较合理的,㶲损失较小。将该制冷系统划分为换热器、压缩机、节流阀、闪蒸罐等子系统,并分别计算了

  18. Solar Multi-stage Refrigeration Systems on the Basis of Absorber with the Internal Evaporative Cooling

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-08-01

    Full Text Available In the article, the developed schematics are presented for the alternative refrigeration systems and air-conditioning systems, based on the use of absorbing cycle and solar energy for the regeneration of absorbent solution. Multi-stage principle of construction of drying and cool contours of solar systems is used with growth of concentration of absorbent on the stages of cooler. An absorber with internal evaporative cooling, allowing to remove the separate evaporated cooler, usually included after the absorber of the proper stage, is developed. Heat-mass-transfer apparatus of film-type, entering in the complement of drying and cool contours compatible and executed on the basis of multichannel compositions from polymeric materials. The preliminary comparative analysis of possibilities of the solar refrigeration systems and air-conditioning systems is executed.

  19. Heat transfer design in adsorption refrigeration systems for efficient use of low-grade thermal energy

    International Nuclear Information System (INIS)

    Adsorption refrigeration and heat pump systems have been considered as important means for the efficient use of low-grade thermal energy of 60-150 oC. Sorption systems are merely thermodynamic systems based on heat exchangers, and therefore a good design to optimize heat and mass transfer with reaction or sorption processes is very important, for which the notable technique is the use of expanded graphite to improve both heat and mass transfer in the chemisorption beds. Studies have also shown the need to enhance the heat transfer in adsorption bed by matching with the efficient heat transfer of thermal fluids. Heat pipes and good thermal loop design coupled with adsorption beds could yield higher thermal performance of a sorption system. A novel design with passive evaporation, known as rising film evaporation coupled with a gravity heat pipe was introduced for high cooling output. It has also been shown that the performance of traditional heat and mass recovery in the sorption systems is limited, and novel arrangement of thermal fluid and refrigerant may improve the performance of sorption systems. Based upon the above researches, various sorption systems have been developed, and high performances have been reached. -- Highlights: →Heat transfer design in adsorption refrigeration systems is researched. →Solidified adsorbent is an effective way to improve the heat transfer. →Heat pipe and rising film evaporation could generate high cooling output. With efficient design two adsorption systems are developed. →Double way and double effect cycle is introduced.

  20. 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.

  1. Self operating absorption cooling system using solar energy: Small power experimental plant

    Science.gov (United States)

    Velluet, P.; Dehausse, R.

    This study deals with a solar system for refrigeration specially designed for remote areas conditions. So, it must be very simple and reliable, and in addition it must be also mechanically self-operating. The thermodynamic cycle used is an ammonia-water absorption one. It consumes only thermal energy, which is easily and cheaply converted directly from solar radiation. In order to make a self-operating system, an engine is located between the boiler (at high pressure) and the absorber (at low pressure). It expands ammonia vapor and produces mechanical energy to run the solution pump.

  2. Commissioning of a 20 K Helium Refrigeration System for NASA-JSC Chamber A

    Science.gov (United States)

    Homan, J.; Redman, R.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Norton, R.; Lauterbach, J.; Linza, R.; Vargas, G.

    2013-01-01

    A new 20 K helium refrigerator installed at NASA Johnson Space Center s Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope (JWST). The chamber previously and currently still has helium cryo-pumping panels (CPP) and liquid nitrogen shrouds used to create low earth orbit environments. Now with the new refrigerator and new helium shrouds the chamber can create a deep space environment. The process design, system analysis, specification development, and commissioning oversight were performed by the cryogenics department at Jefferson Lab, while the contracts and system installation was performed by the ESC group at JSC. Commissioning data indicate an inverse coefficient of performance better than 70 W/W for a 18 kW load at 20 K (accounting for liquid nitrogen pre-cooling power) that remains essentially constant down to one third of this load. Even at 10 percent of the maximum capacity, the performance is better than 150 W/W at 20 K. The refrigerator exceeded all design goals and demonstrated the ability to support a wide load range from 10 kW at 15 K to 100 kW at 100 K. The refrigerator is capable of operating at any load temperature from 15 K to ambient with tight temperature stability. The new shroud (36 tons of aluminum) can be cooled from room temperature to 20 K in 24 hours. This paper will outline the process design and commissioning results.

  3. 20 K Helium Refrigeration System for NASA-JSC Chamber-A

    Science.gov (United States)

    Homan, J.; Redman, R.; Ganni, V.; Sidi-Yekhelef, A.; Knudsen, P.; Norton, R.; Lauterbach, J.; Linza, R.; Vargas, G.

    2013-01-01

    A new 20 K helium refrigerator installed at NASA Johnson Space Center's Space Environment Simulation Laboratory (SESL) was successfully commissioned and tested in 2012. The refrigerator is used to create a deep space environment within SESL s Chamber A to perform ground testing of the James Webb Space Telescope. The chamber previously and currently still has helium cryopumping panels (CPP) and LN2 shrouds used to create Low Earth Orbit environments. Now with the new refrigerator and new helium shrouds (45 x 65 ) the chamber can create a deep space environment. The process design, system analysis, specification development, and commissioning oversight were performed by the cryogenics department at Jefferson Labs, while the contracts and system installation was performed by the ESC group at JSC. Commissioning data indicate a inverse coefficient of performance better than 70 W/W for a 18 KW load at 20 K (accounting for liquid nitrogen precooling power) that remains essentially constant down to 1/3 of this load. Even at 10 percent of the maximum capacity, the performance is better than 140 W/W at 20K. The refrigerator exceeded all design goals and demonstrated the ability to support a wide load range from 10kW at 15 K to 100 kW at 100K. The refrigerator is capable of operating at any load temperature from 15K to ambient with tight temperature stability. The new shroud (36 tons of aluminum) can be cooled from room temperature to 20 K in 24 hours. This paper will outline the process design and commissioning results.

  4. Potassium emission absorption system. Topical report 12

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, L.E.

    1995-04-01

    The Potassium Emission Absorption System is one of the advanced optical diagnostics developed at Mississippi State University to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the upstream of an MHD flow, the system directly measures gas temperature and neutral potassium atom number density through spectroscopic emission absorption techniques. From these measurements the electron density can be inferred from a statistical equilibrium calculation and the electron conductivity in the MHD channel found by use of an electron mobility model. The instrument has been utilized for field test measurements on MHD facilities for almost a decade and has been proven to provide useful measurements as designed for MHD nozzle, channel, and diffuser test sections. The theory of the measurements, a system description, its capabilities, and field test measurement results are reported here. During the development and application of the instrument several technical issues arose which when addressed advanced the state of the art in emission absorption measurement. Studies of these issues are also reported here and include: two-wavelength measurements for particle-laden flows, potassium D-line far wing absorption coefficient, bias in emission absorption measurements arising from dirty windows and misalignments, non-coincident multiwavelength emission absorption sampling errors, and lineshape fitting for boundary layer flow profile information. Although developed for NLHD application, the instrument could be applied to any high temperature flow with a resonance line in the 300 to 800 nm range, for instance other types of flames, rocket plumes or low temperature plasmas.

  5. An experimental and numerical study on dynamic characteristic of linear compressor in refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun; Roh, Chul-gi; Kim, Jong-kwon; Shin, Jong-min [Digital Appliance Company Laboratory, LG Electronics 391-2, Ga Eum Jeong-Dong, Changwon Gyeong Nam 641-711 (Korea); Hwang, Yujin; Lee, Jae-keun [School of Mechanical Engineering, Pusan National University, San 30, Changjeon-Dong, Keumjeong-Ku, Pusan 609-735 (Korea)

    2009-11-15

    This paper presents experimental and numerical results of the dynamic characteristic and COP of a linear compressor in a refrigeration system using R600 refrigerant. The numerical analysis consists of a model and a simulation that includes the linear compressor. In this study, the dynamic characteristic of the natural frequency of the linear compressor is validated by comparing the simulation results with the experimental results. To investigate the effect of system resonance on the performance of linear compressor, COP is evaluated under evaporator pressure in the range of 48.3-63.2 kPa abs, and condenser pressure in the range of 439.0-573.3 kPa abs. Based on the results, the system resonance at the TDC was varied within a range of 3% under the test conditions. COP and its sensitivity were found to vary within 3% according to the operating frequency of the system ranging from 48.5 to 51.5 Hz. (author)

  6. Model Identification for Control of Display Units in Supermarket Refrigeration Systems

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Madsen, Henrik; Andersen, Philip Hvidthøft Delff;

    In this paper we propose a method for identifying and validating a model of the heat dynamics of a supermarket refrigeration display case for the purpose of advanced control. The model is established to facilitate the development of novel model-based control techniques for individual display units...... in a supermarket refrigeration system. The grey-box modelling approach is adopted, using stochastic differential equations to define the dynamics of the model, combining prior knowledge of the physical system with data-driven modelling. Model identification is performed using the forward selection method......, and the performance of candidate models is evaluated through cross-validation.The model developed in this work uses operational data from a small Danish supermarket. A three-state model is determined to be most appropriate for describing the dynamics of this system. Advanced local control employing the identified...

  7. Study on the Irreversible Thermodynamics of a Marine Engine Exhaust-powered Adsorption Refrigerating System

    Institute of Scientific and Technical Information of China (English)

    XIE Yingchun; MEI Ning; XU Zhen

    2006-01-01

    This study investigates the heat and mass transfer mechanism of a marine engine exhaust-powered adsorption refrigerating system by using irreversible thermodynamics. The equations of entropy-production rate and the linear phenomenological equations of thermodynamic flux and force are established. The conventional experimental facilities of unit tube are developed and the phenomenological coefficients are obtained by fitting the experimental data. It is concluded that the thermodynamic process in the adsorbent bed is determined by the coupling effect of the heat and mass transfer; furthermore, the mass transfer is determined by the heat transfer. Taking some measures to increase heat transfer can improve the performance of the adsorption refrigerating system. The conclusions presented in this paper may be of value to the engineering applications of the system.

  8. Performance study of unglazed cylindrical solar collector for adsorption refrigeration system

    Science.gov (United States)

    Mahesh, A.; Kaushik, S. C.; Kumaraguru, A. K.

    2013-12-01

    In the present communication, the unglazed cylindrical solar adsorber module is suggested for refrigeration and theoretical models for the heat and mass transfer in the cylindrical adsorber with heat balance equations in the collector components have been developed. It has been found that, both the SCP and COPsolar raises with increasing the evaporation temperature and drop off with the increase of the condensation temperature. The COPsolar increased from 0.15 to 0.52 with the increase of the total solar energy absorbed by the collector while the COPcycle varied in the range of 0.57-0.73. The efficiency of unglazed solar collector varied from 36 to 44 %. The cost of current unglazed adsorption refrigeration system is compared with the glazed system, and it is 33 to 50 % less than the cost of glazed system.

  9. Study on the irreversible thermodynamics of a marine engine exhaust-powered adsorption refrigerating system

    Science.gov (United States)

    Xie, Yingchun; Mei, Ning; Xu, Zhen

    2006-04-01

    This study investigates the heat and mass transfer mechanism of a marine engine exhaust-powered adsorption refrigerating system by using irreversible thermodynamics. The equations of entropy-production rate and the linear phenomenological equations of thermodynamic flux and force are established. The conventional experimental facilities of unit tube are developed and the phenomenological coefficients are obtained by fitting the experimental data. It is concluded that the thermodynamic process in the adsorbent bed is determined by the coupling effect of the heat and mass transfer; furthermore, the mass transfer is determined by the heat transfer. Taking some measures to increase heat transfer can improve the performance of the adsorption refrigerating system. The conclusions presented in this paper may be of value to the engineering applications of the system.

  10. Investigation of flushing and clean-out methods for refrigeration equipment to ensure system compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, J.J.; Shows, M.; Abel, M.W. [Integral Sciences Inc., Columbus, OH (United States)

    1996-04-24

    SECTION 608 of the Clean Air Act Amendments has altered much of the refrigeration service contracting industry. MCLR Project Number 660-52502 was established to examine two areas where the Amendments are influencing contractors to determine if more cost-effective service procedures might be developed. One area where existing service procedures are being revisited involves the removal of contaminants from a refrigeration system after a motor burnout. At one time, a Class 1 substance such as CFC-11 or CFC-113 was used as a flushing agent for cleaning a system after a burnout. On large systems, the compressor was disassembled, and the parts were cleaned using 1,1,1-trichloroethane (TCA) or a TCA-containing mixture. Such alternatives are seldom possible today, as the manufacture of Class 1 substances was banned on January 1, 1996. This report describes processes for mineral oil removal, process alternatives for servicing burnouts, solvents, and laboratory retrofit tests.

  11. About Solar Refrigeration

    Directory of Open Access Journals (Sweden)

    Laura Coroiu

    2008-05-01

    Full Text Available This paper has the purpose to unfold the results of all researches which proved before that the solar energy constitutes itself as an ideal resource for heating application that necessitate lower temperature,e.g. the heating of a certain space or the preparation ofthe domestic hot water. The refrigeration systems, which are based on the nontoxic refrigerants for the environment, offer a sustained advantage when compared to the other types of the refrigerants. But, whichever might be the case, the use of the energy associated to the operation of the refrigeration system and with the impact that it has upon the environment, as well as the association with its production and distribution, have often a bigger importance than the selection of the refrigerant. In order to minimize the impact which the operation of the refrigeration systems exerts upon the environment, it is recommended that there should be checked all thepossibilities of using a pure source of energy.

  12. The Experimental Research on Refrigerant Mixtures of a Linde-Hampson Refrigeration System%混合工质Linde-Hampson制冷系统的实验研究

    Institute of Scientific and Technical Information of China (English)

    朱军韬; 张华

    2012-01-01

    搭建了混合工质Linde-Hampson制冷系统,将4种工质R245fa/R600a/R508b/R14按照不同比例混合后进行实验研究.通过优化制冷剂组分得到不同配比下的最低运行温度,分析了最优配比下环境温度对系统运行性能的影响.结果表明:将4种工质按照不同配比进行混合,系统的最低运行温度范围在-45℃~-85℃之间.在环境温度35℃时,混合工质按比例R245 fa∶R600a∶R508b∶R 14=0.45∶0.3∶0.18∶0.07充注时,系统运行温度可达到-85℃,在此条件下,将环境温度从35℃降低到5℃,系统运行温度则从-85.5℃降低到-89.3℃.%The performance of quaternionic refrigerant mixtures, R345fa/R600a/R508b/R14, in Linde-Hampson refrigeration cycle was experimentally investigated. To get the lowest operation temperature, the components of refrigerant mixtures were optimized. The influence of ambient temperature on system operational performance was analyzed. It is shown that the lowest system operation temperature could reach from -4S'C to -85°C when mixing the four refrigerant components at different species ratio,. If the proportion of the refrigerant mixtures charged is R245fa:R600a:R508b:R14=0.45:0.3:0.18:0.07, the operating temperature of the system can reach -85℃ when the ambient temperature is 35°C. With the same refrigerant mixtures, the system temperature can reach -89.3℃ if the ambient temperature decreases from 35℃to5℃.

  13. Cooling performance and evaluation of automotive refrigeration system for a passenger car

    Science.gov (United States)

    Prajitno, Deendarlianto, Majid, Akmal Irfan; Mardani, Mahardeka Dhias; Wicaksono, Wendi; Kamal, Samsul; Purwanto, Teguh Pudji; Fauzun

    2016-06-01

    A new design of automotive refrigeration system for a passenger car was proposed. To ensure less energy consumption and optimal thermal comfort, the performance of the system were evaluated. This current research was aimed to evaluate the refrigeration characteristics of the system for several types of cooling load. In this present study, a four-passenger wagon car with 1500 cc gasoline engine that equipped by a belt driven compressor (BDC) was used as the tested vehicle. To represent the tropical condition, a set of lamps and wind sources are installed around the vehicle. The blower capacity inside a car is varied from 0.015 m/s to 0.027 m/s and the compressor speed is varied at variable 820, 1400, and 2100 rpm at a set temperature of 22°C. A set of thermocouples that combined by data logger were used to measure the temperature distribution. The system uses R-134a as the refrigerant. In order to determine the cooling capacity of the vehicle, two conditions were presented: without passengers and full load conditions. As the results, cooling capacity from any possible heating sources and transient characteristics of temperature in both systems for the cabin, engine, compressor, and condenser are presented in this work. As the load increases, the outlet temperature of evaporator also increases due to the increase of condensed air. This phenomenon also causes the increase of compressor work and compression ratio which associated to the addition of specific volume in compressor inlet.

  14. Modeling and investigation of refrigeration system performance with two-phase fluid injection in a scroll compressor

    Science.gov (United States)

    Gu, Rui

    Vapor compression cycles are widely used in heating, refrigerating and air-conditioning. A slight performance improvement in the components of a vapor compression cycle, such as the compressor, can play a significant role in saving energy use. However, the complexity and cost of these improvements can block their application in the market. Modifying the conventional cycle configuration can offer a less complex and less costly alternative approach. Economizing is a common modification for improving the performance of the refrigeration cycle, resulting in decreasing the work required to compress the gas per unit mass. Traditionally, economizing requires multi-stage compressors, the cost of which has restrained the scope for practical implementation. Compressors with injection ports, which can be used to inject economized refrigerant during the compression process, introduce new possibilities for economization with less cost. This work focuses on computationally investigating a refrigeration system performance with two-phase fluid injection, developing a better understanding of the impact of injected refrigerant quality on refrigeration system performance as well as evaluating the potential COP improvement that injection provides based on refrigeration system performance provided by Copeland.

  15. Thermodynamic design of a cascade refrigeration system of liquefied natural gas by applying mixed integer non-linear programming

    Institute of Scientific and Technical Information of China (English)

    Meysam Kamalinejad; Majid Amidpour; S.M. Mousavi Naeynian

    2015-01-01

    Liquefied natural gas (LNG) is the most economical way of transporting natural gas (NG) over long distances. Liq-uefaction of NG using vapor compression refrigeration system requires high operating and capital cost. Due to lack of systematic design methods for multistage refrigeration cycles, conventional approaches to determine op-timal cycle are largely trial-and-error. In this paper a novel mixed integer non-linear programming (MINLP) model is introduced to select optimal synthesis of refrigeration systems to reduce both operating and capital costs of an LNG plant. Better conceptual understanding of design improvement is illustrated on composite curve (CC) and exergetic grand composite curve (EGCC) of pinch analysis diagrams. In this method a superstruc-ture representation of complex refrigeration system is developed to select and optimize key decision variables in refrigeration cycles (i.e. partition temperature, compression configuration, refrigeration features, refrigerant flow rate and economic trade-off). Based on this method a program (LNG-Pro) is developed which integrates VBA, Refprop and Excel MINLP Solver to automate the methodology. Design procedure is applied on a sample LNG plant to illustrate advantages of using this method which shows a 3.3% reduction in total shaft work consumption.

  16. 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)

  17. Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Cartlidge; Hans Schellhase

    2003-07-31

    This report summarizes a literature review to assess the acidity characteristics of the older mineral oil and newer polyolester (POE) refrigeration systems as well as to evaluate acid measuring techniques used in other non-aqueous systems which may be applicable for refrigeration systems. Failure in the older chlorofluorocarbon/hydrochlorofluorocarbon (CFC/HCFC) / mineral oil systems was primarily due to thermal degradation of the refrigerant which resulted in the formation of hydrochloric and hydrofluoric acids. These are strong mineral acids, which can, over time, severely corrode the system metals and lead to the formation of copper plating on iron surfaces. The oil lubricants used in the older systems were relatively stable and were not prone to hydrolytic degradation due to the low solubility of water in oil. The refrigerants in the newer hydrofluorocarbon (HFC)/POE systems are much more thermally stable than the older CFC/HCFC refrigerants and mineral acid formation is negligible. However, acidity is produced in the new systems by hydrolytic decomposition of the POE lubricants with water to produce the parent organic acids and alcohols used to prepare the POE. The individual acids can therefore vary but they are generally C5 to C9 carboxylic acids. Organic acids are much weaker and far less corrosive to metals than the mineral acids from the older systems but they can, over long time periods, react with metals to form carboxylic metal salts. The salts tend to accumulate in narrow areas such as capillary tubes, particularly if residual hydrocarbon processing chemicals are present in the system, which can lead to plugging. The rate of acid production from POEs varies on a number of factors including chemical structure, moisture levels, temperature, acid concentration and metals. The hydrolysis rate of reaction can be reduced by using driers to reduce the free water concentration and by using scavenging chemicals which react with the system acids. Total acid

  18. Thermodynamic Analysis of a Cascade Refrigeration System Based On Carbon Dioxide and Ammonia

    Directory of Open Access Journals (Sweden)

    Satyananda Tripathy

    2014-07-01

    Full Text Available Thermodynamic analysis of a cascade refrigeration system that uses carbon dioxide-ammonia (R744-R717 as refrigerant is presented in this paper to determine the optimum condensing temperature of the cascade condenser at given design parameters, to maximize the COP of the system. The design and operating parameters considered in this study include (1 condensing, sub cooling, evaporating and super heating temperatures in the ammonia (R717 high-temperature circuit, (2 temperature difference in the cascade heat exchanger, and (3 evaporating, superheating, condensing and sub cooling in the carbon dioxide (R744 low-temperature circuit. A multilinear regression analysis was employed in order to develop two useful correlations for maximum COP, and optimum condensing temperature.

  19. New report reveals eco-efficiency of supermarket refrigeration systems. Refrigerant choice; Rapport onthult eco-effiency van supermarktkoelsystemen. Koudemiddelkeuze

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-11-15

    Ever since the EU has committed to cut greenhouse gas emissions by 20%, food retailers have been under enormous pressure to reduce their carbon footprint. Refrigeration is part of the solution, as it accounts for some 50% of the energy consumption in a typical store. A new report by the British environmental consultants SKM Enviros evaluates different refrigeration solutions. [Dutch] Sinds de EU heeft besloten de uitstoot van broeikasgassen met twintig procent terug te brengen, staan foodretailers onder enorme druk om hun ecologische 'footprint' te verminderen. Koeling is een onderdeel van de oplossing, omdat het circa vijftig procent van het energiegebruik in een gemiddelde winkel voor zijn rekening neemt. Een nieuw rapport van de Britse milieuconsultants SKM Enviros evalueert verschillende koeloplossingen.

  20. Using Vibration Analysis to Determine Refrigerant Levels In an Automotive Air Conditioning System

    OpenAIRE

    Stasiunas, Eric Carl

    2002-01-01

    Presently, auto manufacturers do not have do not have efficient or accurate methods to determine the amount of refrigerant (R-134a) in an air conditioning system of an automobile. In the research presented, vibration analysis is examined as a possible method to determine this R-134a amount. Initial laboratory tests were completed and experimental modal analysis methods were investigated. This approach is based on the hypothesis that the natural frequency of the accumulator bott...

  1. Demand-side energy management of a cascade mine surface refrigeration system / A.J. Schutte

    OpenAIRE

    Schutte, Abraham Jacobus

    2007-01-01

    The investigations focus on load shifting, load clipping and energy efficiency through control strategies. Load shifting is achieved by increasing the amount of work done in the Eskom non-peak period. This then results in a decrease in the Eskom peak time work load. The mine refrigeration system is modelled and verified with the data. A simulation is made from the model and the simulation is used to develop the new control strategy and new operational parameters. Predicted results are ver...

  2. Performance analysis of absorption heat transformer cycles using ionic liquids based on imidazolium cation as absorbents with 2,2,2-trifluoroethanol as refrigerant

    International Nuclear Information System (INIS)

    Highlights: • TFE + [emim][BF4] (or [bmim][BF4]) absorption heat transformer cycles are studied. • Influence of various operating conditions on cycle’s performance is investigated. • Performance comparisons with H2O + LiBr and TFE + TEGDME cycles are done. • Enthalpy data for TFE + [emim][BF4] (or [bmim][BF4]) liquid mixtures are calculated. • TFE + [emim][BF4] (or [bmim][BF4]) cycles have higher gross temperature lift (GTL). - Abstract: A detailed thermodynamic performance analysis of a single-stage absorption heat transformer and double absorption heat transformer cycles using new working pairs composed of ionic liquids (1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4])) as absorbent and 2,2,2-trifluoroethanol (TFE) as refrigerant has been studied. Several performance indicators were used to evaluate and compare the performance of the cycles using the TFE + [emim][BF4] and TFE + [bmim][BF4] working pairs with the conventional H2O + LiBr and organic TFE + TEGDME working pairs. The obtained results show that the ionic liquid based working pairs are suitable candidates to replace the conventional H2O + LiBr working pairs in order to avoid the disadvantages associated with it mainly crystallization and corrosion and also they perform better (higher gross temperature lift) than TFE + TEGDME working pair at several operating conditions considered in this work

  3. An Investigation of Refrigerant Oil Retention in an Air Conditioning System with Two Inverter Compressors in Parallel

    OpenAIRE

    Kuo, Cheng-Shu; Cheng, Wei-Yueh; Hsieh, Wen-Der; Liu, Yangguang

    2012-01-01

    A VRF (variable refrigerant flow) air conditioning, having a number of air handling units connected to an external condensing unit, commonly uses two or more compressors in the system. The complicated piping system of the VRF air conditioning causes difficulties for refrigerant oils to return back to each compressor, especially for compressors operating in different frequencies. Compressors need lubrication in operation process, otherwise the compressor will burn out because of wearing and ov...

  4. A real time control strategy for optimisation of an economised indirect multi-temperature transport refrigeration system

    OpenAIRE

    Smyth, Shane; Brophy, Barry; Finn, Donal

    2011-01-01

    This paper describes an approach for control of an economiser cycle based on the use of economiser pressure as theprimary control parameter. In the study, the economiser cycle was used to optimise a multi-temperature indirect (IDX) transport refrigeration system, where hydronic secondary loops were utilised. In transport refrigeration applications, IDX systemscan offer the potential to address a number of important environmental and control issues associated with direct expansion (DX) systems...

  5. User evaluation of photovoltaic-powered vaccine refrigerator/freezer systems

    Science.gov (United States)

    Ratajczak, Anthony F.

    1987-01-01

    The NASA Lewis Research Center has concluded a project to develop and field test photovoltaic-powered refrigerator/freezers for vaccine storage in remote areas of developing countries. As a conclusion to this project, questionnaires were sent to the in-country administrators for each test site probing user acceptance of the systems and attitudes regarding procurement of additional systems. Responses indicate that the systems had a positive effect on the local communities, that they made a positive impression on the local health authorities, and that system cost and scarcity of funds are the major barriers to procurements of additional systems.

  6. High-efficiency absorption-type heat pumps and refrigerators. From topology to the pilot plant; Hocheffiziente Absorptionsmaschinen zur Versorgung mit Kaelte und Waerme. Von der Topologie zur Pilotanlage

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, F.; Demmel, S.; Lamp, P. [Bayerisches Zentrum fuer Angewandte Energieforschung e.V. (ZAE Bayern), Wuerzburg (Germany); Kahn, R. [Technische Univ. Muenchen (Germany). Physik Dept. E19; Alefeld, G.

    1998-12-31

    Absorption-type heat pumps or refrigerators are systems operated with heat. They have been known for a long time and are frequently used especially in airconditioning in the USA and south-east Asia. However, the conventional technique used is subject to many physical limitations, restricting their broader use. The paper demonstrates ways of overcoming these restrictions, for instance by multi-stage design. The exploitation of topological principles much facilitates the synthesis of novel circuits. The technical relevance of such developments is demonstrated by means of selected examples of executed laboratory and pilot plants. Modern absorption technology saves resources and prevents environmental pollution by consuming less fossil energy compared with the conventional technique, for instance by harnessing the thermal potential of solar energy or utilizing waste heat and residual heat, and, not least, thanks to the use of natural refrigerants. (orig.) [Deutsch] Absorptionswaermepumpen oder -kaeltemaschinen sind durch Waerme angetriebene Anlagen, die seit langem bekannt sind und besonders in der Klimatechnik in den USA und im suedostasiatischen Raum haeufig eingesetzt werden. Die dabei verwendete konventionelle Technik unterliegt allerdings vielfaeltigen physikalischen Einschraenkungen, die ihre noch breitere Anwendung verhindern. Es wird gezeigt, wie diese Einschraenkungen beispielsweise durch Mehrstufigkeit ueberwunden werden koennen. Durch die Verwendung topologischer Grundsaetze wird die Synthese neuartiger Kreislaeufe stark vereinfacht. Die technische Bedeutung solcher Entwicklungen wird an ausgewaehlten Beispielen ausgefuehrter Labor- und Pilotanlagen gezeigt. Durch den im Vergleich zu konventioneller Technik geringeren Verbrauch an fossiler Energie, beispielsweise durch die thermische Nutzung von Sonnenenergie oder durch die Nutzung von Ab- oder Restwaerme und nicht zuletzt durch die Verwendung natuerlicher Kaeltemittel werden bei Einsatz moderner

  7. Insertable system for fast turnaround time microwave experiments in a dilution refrigerator.

    Science.gov (United States)

    Ong, Florian R; Orgiazzi, Jean-Luc; de Waard, Arlette; Frossati, Giorgio; Lupascu, Adrian

    2012-09-01

    Microwave experiments in dilution refrigerators are a central tool in the field of superconducting quantum circuits and other research areas. This type of experiments relied so far on attaching a device to the mixing chamber of a dilution refrigerator. The minimum turnaround time in this case is a few days as required by cooling down and warming up the entire refrigerator. We developed a new approach, in which a suitable sample holder is attached to a cold-insertable probe and brought in contact with transmission lines permanently mounted inside the cryostat. The total turnaround time is 8 h if the target temperature is 80 mK. The lowest attainable temperature is 30 mK. Our system can accommodate up to six transmission lines, with a measurement bandwidth tested from zero frequency to 12 GHz. This bandwidth is limited by low-pass components in the setup; we expect the intrinsic bandwidth to be at least 18 GHz. We present our setup, discuss the experimental procedure, and give examples of experiments enabled by this system. This new measurement method will have a major impact on systematic ultra-low temperature studies using microwave signals, including those requiring quantum coherence. PMID:23020391

  8. The Effect of the Capillary Tube Coil Number on the Refrigeration System Performance

    Directory of Open Access Journals (Sweden)

    Thamir K. Salim

    2012-06-01

    Full Text Available The capillary tube performance for (R134a is experimentally investigated. The experimental setup is a real vapor compression refrigeration system. All properties of the refrigeration system are measured for various mass flow rate from (13 – 23 kg/hr and capillary tube coil number (0-4 with fixed length (150 cm and capillary diameter(2.5mm.The results showed that the theoretical compression power increases by (65.8 % as the condenser temperature increases by (2.71%, also the theoretical compression power decreases by (10.3 % as the capillary tube coil number increases.The study shows also that the cooling capacity increases by (65.3% as the evaporator temperature increases by (8.4 %, and the cooling capacity increases by (1.6%as the capillary tube coil number increases in the range (0-4.The coefficient of performance decreases by (43.4 %, as the mass flow rateincreases by (76.9%, also the coefficient of performance increases by (13.51 % as thecapillary tube coil number increases in the range (0-4.Through this study, it was found that the best coil number in refrigeration cycle at the lowest mass flow rate (31 Kg/hr and at high mass flow rate (23 Kg/hr is (coil number = 4, this will give the highest performance, cooling capacity and lowest theoretical compression power.

  9. PROCESSES OF HEAT-MASS-TRANSFER IN APPARATUS OF SOLAR ABSORBING REFRIGERATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2014-12-01

    Full Text Available Ideology of development of the solar refrigeration systems and systems of air-conditioning, based on the use of absorbing cycle and solar energy for the regeneration of absorbent solution, is presented in the article. The processes of joint heat-mass-transfer are considered in the direct and indirect types of evaporated coolers taking into account the phenomenon of re-condensation of aquatic steams at the low temperature evaporated cooling of environments. The pre-liminary analysis of possibilities of the solar systems is executed as it applies in relation to the tasks of cooling of envi-ronments and air-conditioning systems.

  10. Effect of operating conditions on the performance of the bubble pump of absorption-diffusion refrigeration cycles

    Directory of Open Access Journals (Sweden)

    Benhmidene Ali

    2011-01-01

    Full Text Available The mathematical model will be able to predict the operated condition (required tube diameters, heat input and submergence ratio….. That will result in a successful bubble pump design and hence a refrigeration unit. In the present work a one-dimensional two-fluid model of boiling mixing ammonia-water under constant heat flux is developed. The present model is used to predict the outlet liquid and vapor velocities and pumping ratio for different heat flux input to pump. The influence of operated conditions such as: ammonia fraction in inlet solution and tube diameter on the functioning of the bubble pump is presented and discussed. It was found that, the liquid velocity and pumping ratio increase with increasing heat flux, and then it decreases. Optimal heat flux depends namely on tube diameter variations. Vapour velocity increases linearly with increasing heat flux under designed conditions.

  11. Extra-low-noise refrigerator with active noise control system, GR-W40NVI. Nodo seigyo choseiongata reizoko GR-W40NVI

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, Y.; Nakanishi, K.; Saruta, S. (Toshiba Corp., Tokyo (Japan))

    1991-04-20

    Aiming at lowering the noise down to a domestic background noise level, development was made of GR-W40NVI, extra-low-noise refrigerator with an active noise control system. The active control for lowering the noise is methodically to artificially generate sound, reverse in phase against the noise to be generated, silence it by acoustic wave interference, and theoretically reduce the acoustic pressure to zero. Such a technology was applied to the refrigerator morphologically as follows: In order to silence the noise, generated by the compressor and three-dimensionally diffused, by a simple structure, duct structure is applied for the noise to be diffused in one direction only, by acoustically insulating and confining the compressor with exception of its thermal exhaust opening. In order to lower the noise, generated by the compressor and amplified in zonal region, the active control is applied against the low frequency noise, while the conventional acoustic insulation/absorption technology is done against the high frequency noise. In order to quickly and accurately prepare sound, reverse in phase against the noise under fluctuation, signal processing is made by using digital signal processor (DSP), hardware exclusively for it. As a result, the noise was lowered by about 7dB (1/5) for the basic type of refrigerator. 12 figs.

  12. Experimental study on activated carbon-nitrogen pair in a prototype pressure swing adsorption refrigeration system

    Science.gov (United States)

    Anupam, Kumar; Palodkar, Avinash V.; Halder, G. N.

    2016-04-01

    Pressure swing adsorption of nitrogen onto granular activated carbon in the single-bed adsorber-desorber chamber has been studied at six different pressures 6-18 kgf/cm2 to evaluate their performance as an alternative refrigeration technique. Refrigerating effect showed a linear rise with an increase in the operating pressure. However, the heat of adsorption and COP exhibited initial rise with the increasing operating pressure but decreased later after reaching a maximum value. The COP initially increases with operating pressures however, with the further rise of operating pressure it steadily decreased. The highest average refrigeration, maximum heat of adsorption and optimum coefficient of performance was evaluated to be 415.38 W at 18 kgf/cm2, 92756.35 J at 15 kgf/cm2 and 1.32 at 12 kgf/cm2, respectively. The system successfully produced chilled water at 1.7 °C from ambient water at 28.2 °C.

  13. Improving Energy Efficiency of a Refrigeration System with a Rankine Cycle and an Expander

    OpenAIRE

    Subiantoro, Alison

    2015-01-01

    A method to increase energy efficiency of a vapor compression refrigeration system by using a Rankine cycle and an expander is studied. The systems studied include the R134a and the transcritical CO2 cycles with a 5 kW capacity. The working fluids of the Rankine cycle are R134a, propane and R123. The available heat input power is 1-5 kW. The results show that in the R134a and CO2 systems, 18-40% and 30-67% improvements of Coefficient of Performance (COP), respectively, can be achieved. The me...

  14. Modeling the dynamic response of pressures in a distributed helium refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, J.C.

    1997-12-01

    A mathematical model is created of the dynamic response of pressures caused by flow inputs to an existing distributed helium refrigeration system. The dynamic system studied consists of the suction and discharge pressure headers and compressor portions of the refrigeration system used to cool the superconducting magnets of the Tevatron accelerator at the Fermi National Accelerator Laboratory. The modeling method involves identifying the system from data recorded during a series of controlled tests, with effort made to detect locational differences in pressure response around the four mile accelerator circumference. A review of the fluid mechanics associated with the system indicates linear time invariant models are suitable for the identification, particularly since the governing equations of one dimensional fluid flow are approximated by linear differential equations. An outline of the experimental design and the data acquisition system are given, followed by a detailed description of the modeling, which utilized the Matlab programming language and associated System Identification Toolbox. Two representations of the system are presented. One, a black box model, provides a multi-input, multi-output description assembled from the results of single input step function testing. This description indicates definite variation in pressure response with distance from the flow input location, and also suggests subtle differences in response with the input location itself. A second system representation is proposed which details the relation between continuous flow changes and pressure response, and provides explanation of a previously unappreciated pressure feedback internal to the system.

  15. Thermodynamic Analysis of Actual Vapour Compression System with R12 and Its Eco-Friendly Alternatives Refrigerants

    Directory of Open Access Journals (Sweden)

    Vijay Singh Bisht

    2014-04-01

    Full Text Available This paper presents a theoretical performance study of a vapour compression refrigeration system with refrigerants R-12, R134a and R1234yf. A computational model based on energy first law analysis is presented for the investigation of the effects of evaporating temperatures, degree of subcooling, dead state temperatures and effectiveness of the liquid vapour heat exchanger on the relative capacity change index, coefficient of performance of the vapour compression refrigeration cycle. RCI (relative capacity change index of the system is highest for R1234yf and with increase in degree of subcooling; R1234yf has the highest percentage increase in COP. The total compressor work requirement for system is highest with R134a. R1234yf is the only refrigerants of all the refrigerants used in present work that satisfy MAC directive (2006/40/EG because of GWP value less than 150. From these results, it is indicated that R1234yf is the refrigerant for future.

  16. Measured impacts of supermarket humidity level on defrost performance and refrigerating system energy use

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, H.I.; Khattar, M.

    1999-07-01

    This paper presents field-monitor data from two supermarkets where the impact of space humidity on refrigerating system energy use was evaluated. Direct digital control (DDC) systems were used at both stores to collect 15-minute monitored data. At Store A in Minneapolis, the DDC system was used to monitor system performance as well as to implement temperature-terminated control in place of time-terminated control on 16 refrigerated zones using hot gas defrost. At Store B in Indianapolis, the DDC system was used to quantify the performance trends for the single compressor rack system with electric defrost. The results at Store B showed that refrigerating system energy use decreases by nearly 10 kWh/day for each 1% drop in space relative humidity, or about 0.4% of average annual system energy use. This value includes the impact of reduced latent loads, the reduction in direct energy use and imposed load from reduced electric defrost heater operation, and the smaller imposed load from reduced anti-sweat heater energy use. The measured reductions agree well with the impact predicted using the calculation methods developed by Howell (1933b) in ASHRAE Research Project 596. At Store A, the measured data show that implementing temperature-terminated defrost reduced refrigerating system energy use by nearly 70 kWh/day over the winter period when the average space humidity was 22% RH. The savings from temperature-terminated defrost increase by 4 kWh/day per each 1% drop in relative humidity. At both stores, the same type of mechanical controls were used to duty cycle the anti-sweat heaters based on store dew point. Anti-sweat heater electricity use was observed to decrease by 4.6 kWh/day at Store B and 3.4 kWh/day at Store A for each 1% drop in relative humidity. At Store A, a more aggressive control scheme was implemented with the DDC system that reduced anti-sweat heater energy use by 7.8 kWh/day per % RH. The more aggressive control approach was reported to properly

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

    Directory of Open Access Journals (Sweden)

    Cüneyt Ezgi

    2015-12-01

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

  18. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

    1998-08-01

    The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufactures and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on many refrigerants including propane, ammonia, water, carbon dioxide, propylene, ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates.

  19. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1997-02-01

    The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alterative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on various refrigerants. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates.

  20. Research and implementation of a load reduction system for a mine refrigeration system / Jan-Johan Calitz

    OpenAIRE

    Calitz, Jan-Johan

    2006-01-01

    In this study, a system was developed to shift electrical load out of Eskom's peak period to the OR-peak periods. This system was designed, based on research done for load shift philosophies of a refrigeration system of a mine. The investigation focussed on the mining industry, for it consumes a large percentage of the electrical energy generated in South Africa. The research results ensured a successful implementation of a Demand Side Management (DSM) program on the ventilatio...

  1. Conclusions on 8 Years Operation of the LEP 4.5 K Refrigeration System at CERN

    CERN Document Server

    Bangert, N; Gayet, P; Sanmartí, M

    2002-01-01

    After 11 years of operation the Large Electron/Positron collider (LEP) was stopped in November 2000. Since 1993 a cryogenic system has been used to supply up to 72 superconducting (SC) cavity modules, using four large liquid-helium refrigerators at 4.5 K. We review eight years of operation of one of the world's largest helium cryogenic systems, its evolution and cooling capacity availability correlated to the LEP increasing energy program. Failure statistics, availability, recovery time after breakdowns and reliability are analyzed, and the most relevant problems encountered during the operation and their cure exposed. The operational organization is also briefly described.

  2. A supervisory control approach in economic MPC design for refrigeration systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Stoustrup, Jakob; Rasmussen, Henrik

    2013-01-01

    A model predictive control at the supervisory level is proposed for refrigeration systems using price and temperature predictions. The control objective is to minimize the overall energy cost within the prediction horizon. The method is mainly developed for demand-side management in the future...... to rearrange the problem to facilitate convex programming. A nonlinear continuous time model validated by real data is employed to simulate system operation. The results show a considerable economic saving as well as a trade-off between the saving level and design complexity....

  3. Model predictive control technologies for efficient and flexible power consumption in refrigeration systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Edlund, Kristian;

    2012-01-01

    explicitly address advantages from daily variations in outdoor temperature and electricity prices. Secondly, we formulate a new cost function that enables the refrigeration system to contribute with ancillary services to the balancing power market. This involvement can be economically beneficial...... for the system itself, while crucial services can be delivered to a future flexible and intelligent power grid (Smart Grid). Furthermore, we discuss a novel incorporation of probabilistic constraints and Second Order Cone Programming (SOCP) with economic MPC. A Finite Impulse Response (FIR) formulation...

  4. Investigation of the potential of application of single effect and multiple effect absorption cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Gomri, Rabah [Laboratory of ' ' Genie Climatique' ' , Faculty of Engineering - Department of ' ' Genie Climatique' ' , University of Constantine, 25000 Constantine (Algeria)

    2010-08-15

    Owing to the serious environmental problems and the price of the traditional energy resources the use of industrial waste heat or the renewable energy, especially the solar energy, as the driving force for vapour absorption cooling systems is continuously increasing. A particular attention was given to single effect cycle. The main objective of higher effect cycle is to increase system performance when high temperature heat source is available. The purpose of the present study was to investigate the potential for the application of single effect double effect and triple effect absorption cooling cycles for production chilled water. For the three systems identical cold output of 300 kW is used. Simulation results were used to study the influence of the various operating parameters on the performance coefficient, exergetic efficiency and the ratio of mass flow rate of refrigerant generated to the heat supplied of the three systems. It is concluded that the COP of double effect system is approximately twice the COP of single effect system and that the COP of triple effect system is slightly less than thrice the COP of single effect system. The exergetic efficiency of double effect system and triple effect system increase slightly compared to the exergetic efficiency of single effect system. It is found that for each condenser and evaporator temperature, there is an optimum generator temperature. At this point the COP and exergetic efficiency of the systems become maximum. Triple effect system generates more vapour refrigerant per unit heat supplied as compared with single effect and double effect systems. (author)

  5. Satellite refrigerator compressors with the oil and moisture removal systems

    International Nuclear Information System (INIS)

    There are twenty-eight compressors installed around the Main Accelerator Ring in seven locations. Drawing 9140-ME-129720 shows the piping and the components schematic for four Mycom compressor skids per building with each having an independent oil and moisture removal system. The Mycom skids each consist of an oil injected screw compressor of 750 SCFM capacity with a 350 hp motor, oil pump, oil cooler, and oil separator. Helium gas returning from the heat exchanger train is compressed from 1 atm to 20 atm in the compressor. The compressed gas is then passed through the three coalescer de-mister where oil mist is separated from the helium gas. The helium gas then flows through the charcoal adsorber and molecular sieve where any residual oil vapor and water vapor are removed. The final stage of purification is the final filter which removes any remaining particulates from the compressed helium gas. The end product of this system is compressed and purified helium gas ready to be cooled down to cryogenic temperatures

  6. R&D on The Cooling Systems Using Natural Refrigerants

    Science.gov (United States)

    Yanagi, Hideharu

    The use of waste heat of low temperatures is an important problem from the environmental considerations. Notice that adsorption cycles have a distinct advantage over other systems of their ability to produce cooling by using low waste heat as 60 to 80°C and also being absolutely benign for the environment. However the present available adsorption chillers are still heavier and larger in size. Hence their compactness and cost reduction as well as higher efficiency are urgent tasks for wider use. This review discusses recent development on adsorption heat pumps as well as forthcoming applications. The sources are mainly papers and discussions at the IEA Annex 24 Workshop in Turin, Italy (1999), FOA6 (Fundamental of Adsorption) Conference in Presquile de Giens, France (1998) and ISHPC (International Sorption Heat Pump Conference) in Munich, Germany (1999).

  7. Energetic and exergetic comparison of basic and ejector expander refrigeration systems operating under the same external conditions and cooling capacities

    International Nuclear Information System (INIS)

    Highlights: • An ejector was used as an expander for reducing throttling losses. • Experiments were made under the same external conditions and cooling capacities. • Work recovery in the ejector was achieved about 39–42%. • The exergy efficiency of the R134a cycle was improved by 6.6–11.24%. - Abstract: An experimental study was conducted on vapor compression refrigerators using R134a refrigerant for the purpose of achieving energy recovery and decreasing the effects of irreversibility. An ejector was used as an expander instead of an expansion valve. The coefficient of performance of the ejector refrigeration system and the amount of irreversibility and efficiency of each of its components were determined and compared with those of a basic vapor compression refrigeration system of the same cooling capacity under the same external conditions. It was found that the ejector expander system exhibited a lower total irreversibility in comparison with the basic system. When the ejector was used as the expander in the refrigeration system, the coefficient of performance was higher than in the basic system by 7.34–12.87%, while the exergy efficiency values were 6.6–11.24% higher than in the basic system

  8. THE RELATIVISTIC HEAVY ION COLLIDER (RHIC) REFRIGERATOR SYSTEM AT BROOKHAVEN NATIONAL LABORATORY: SYSTEM PERFORMANCE AND OPERATIONS UPGRADES FOR 2003

    International Nuclear Information System (INIS)

    The main function of the RHIC cryogenic system is to maintain the superconducting magnets in the two rings of the new collider-accelerator at Brookhaven National Laboratory at or below 4.5K. The main feature in the RHIC cryogenic system is the helium refrigerator. A new process control philosophy was implemented that allows this system to track the actual load from the accelerator rings and lets it respond accordingly. The refrigerator capacity decreases as the load decreases and increases as the load increases. This has resulted in the following improvements in the operation of the system: (1) Higher reliability because the rotating equipment does not have to run at full load continuously. (2) Greater stability because the system tracks the load continuously and responds quickly to any transients such as a quench. (3) Reduced power consumption because the discharge pressure of the system is adjusted continuously to match the load; therefore, the compressors draw less power when the load fi-om the accelerator rings decreases. This paper also addresses other modifications introduced that added to the efficiency, stability, and reliability of the system. As a result of this upgrade the Carnot efficiency of the refrigerator system has increased to 15% from around 10%

  9. Structure optimization and performance experiments of a solar-powered finned-tube adsorption refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • New-structure finned-tube adsorption bed for enhancing heat and mass transfer. • Temperatures on different parts of the adsorption tubes differ little. • Maximum COP of 0.122 and maximum daily ice-making of 6.5 kg are achieved by experiments. • Cooling efficiency of system with valve control higher than that without valve control. - Abstract: A large-diameter aluminum-alloy finned-tube absorbent bed collector was designed and optimized by enhancing the heat and mass transfer in the collector. The collection efficiency of the adsorbent bed collector was between 31.64% and 42.7%, and the temperature distribution in the absorbent bed was relatively uniform, beneficial to adsorption/desorption of the adsorbate in the absorbent bed. A solar-powered solid adsorption refrigeration system with the finned-tube absorbent bed collector was built. Some experiments corresponding to the adsorption/desorption process with and without a valve control were conducted in four typical weather conditions: sunny with clear sky, sunny with partly cloudy sky, cloudy sky and overcast sky. Activated carbon–methanol was utilized as the working pair for adsorption refrigeration in the experiments. The experiments achieved the maximum COP of 0.122 and the maximum daily ice-making of 6.5 kg. Under the weather conditions of sunny with clear sky, sunny with partly cloudy sky, and cloudy sky, ice-making phenomenon were observed. Even in the overcast-sky weather condition, the cooling efficiency of the system still reached 0.039 when the total solar radiation was 11.51 MJ. The cooling efficiency of the solar-powered adsorption refrigeration system with a valve control in the adsorption/desorption process was significantly higher than that without a valve control

  10. Climate influence on the operation of refrigeration system using the effective radiation into space

    International Nuclear Information System (INIS)

    Theoretically possible cooling capacity of an ideal refrigeration system using the effective radiation into space was calculated by two methods. The calculations were performed for the cities located from 43° to 59° north latitude: Almaty, Vladivostok, Ust Kamenogorsk, Petropavlovsk, Omsk, Kazan, Moscow and St. Petersburg. The graphs of the total amount of cold for the year and for some months depending on the temperature of the radiating surface are shown. It is found that the greatest amount of cold for the year can be produced in the climatic conditions of the city of Omsk, and the smallest in Almaty. A method for estimating the amount of heat withdrawn from the radiator due to convective heat transfer through the cooling degree hours is developed. The results of the calculation of the cooling degree hours for the year for all of the above cities are presented. Also graphs in the article are showing how many hours per year the temperature in each of the cities is below given temperature. With the help of these graphs it is expected to make an assessment of the working time of the refrigeration system during the year. In the summer period due to effective radiation the coolant temperature can become not lower than 15...20 °C. In the winter, it is impossible to use the effective radiation for stable cooling to a temperature below –10 °C in all reviewed cities. The data obtained can be used in the design of cooling systems of the considered type, as well as in the standard refrigeration systems that use natural cooling (Free cooling)

  11. Performance Evaluation of a Solar Adsorption Refrigeration System with a Wing Type Compound Parabolic Concentrator

    Directory of Open Access Journals (Sweden)

    Muhammad Umair

    2014-03-01

    Full Text Available Simulation study of a solar adsorption refrigeration system using a wing type compound parabolic concentrator (CPC is presented. The system consists of the wing type collector set at optimum angles, adsorption bed, a condenser and a refrigerator. The wing type collector captures the solar energy efficiently in the morning and afternoon and provides the effective temperature for a longer period of time compared to that achieved by a linear collector. The objectives of the study were to evaluate the system behavior, the effect of wing length, and to compare the performance of the systems with wing type and linear CPCs. A detailed dynamic simulation model was developed based on mass and energy balance equations. The simulation results show that the system performance with wing type CPC increases by up to 6% in the summer and up to 2% in the winter, compared to the performance with a linear CPC having same collector length. The ice production also increases up to 13% in the summer with the wing type CPC. This shows that the wing type CPC is helpful to increase the performance of the system compared to the linear CPC with the same collector length and without the need for tracking.

  12. Magnetic refrigerator for hydrogen liquefaction

    OpenAIRE

    Matsumoto, Koichi; Kondo, T.; Yoshioka, S; Kamiya, K.; Numazawa, T.

    2009-01-01

    Magnetic refrigeration which is based on the magnetocaloric effect of solids has the potential to achieve high thermal efficiency for hydrogen liquefaction. We have been developing a magnetic refrigerator for hydrogen liquefaction which cools down hydrogen gas from liquid natural gas temperature and liquefies at 20 K. The magnetic liquefaction system consists of two magnetic refrigerators: Carnot magnetic refrigerator (CMR) and active magnetic regenerator (AMR) device. CMR with Carnot cycle s...

  13. 46 CFR 154.1720 - Indirect refrigeration.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression....

  14. Effect of Condenser Fouling on Performance of Vapor Compression Refrigeration System

    OpenAIRE

    Naveen Solanki; Akhilesh Arora; S. C. Kaushik

    2015-01-01

    Effect of condenser fouling is evaluated on the performance of a vapour compression system with refrigerants HFO1234yf and HFO1234ze as an alternative to HFC134a. The condenser coolant temperature has been varied between 35 and 40°C to evaluate the effect of fouling at different condenser temperatures. A simulation model is developed in EES for computing the results. The results have been computed by varying condenser conductance. The same has been validated with literature available before c...

  15. Effect of refrigerant mal-distribution in fin-and-tube evaporators on system performance

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Larsen, Lars Finn Sloth

    2009-01-01

    Refrigerant mal-distribution in fin-and-tube evaporators for residential air-conditioning (RAC) is investigated numerically in this paper. A model of the system is developed in the object-oriented modeling language Modelica. Themodels of the compressor and expansion valve are static, whereas...... the condenser is a dynamic moving boundary model. The evaporator model is a dynamic distributed one-dimensional homogeneous equilibrium model, in order to capture the distribution phenomena. Fin-and-tube heat exchangers usually have a complex circuitry, however the evaporator will be simplified to be two...

  16. Reliability analysis of air recirculation and-refrigeration systems of Angra-1 reactor containment

    International Nuclear Information System (INIS)

    A reliability analysis of the air refrigeration and recirculation containment systems (ARRCS) of Angra-1 nuclear power plants, were done. The fault tree analysis was used. The failure primary data were taken out of Wash-1400 and IEEE. These data were processed by these following computer codes : Prep-Kitt, Sample, Trebil, Cressex and Streusl for the two stages of ARRCS operation. The design bases accident studied was a LOCA (loss of coolant). The component that more contribution give to the non-availability of ARRCS is the motor of the ARRCS. (E.G.)

  17. Research on a New Type of Solar-driven Air-cooled NH3H2O Absorption Refrigeration Cycle%新型太阳能风冷氨水吸收式制冷循环的研究

    Institute of Scientific and Technical Information of China (English)

    任秀宏; 王林

    2012-01-01

    A new type of solar-driven air-cooled NH3H2O absorption refrigeration cycle was proposed. It have rectification e-quipment for purifying ammonia steam and recovers heat from rectifier and absorber. By these realizing small size, air - cooled and the effective use of solar energy. So the coefficient of performance (COP) is increased compared with traditional models. Based on energy conservation, solution mass conservation and ammonia components mass conservation,the thermodynamic math-ematic model of each component is established. Then cycle performance is calculated by writing programs. The effect of main operation parameters(heat source temperature, evaporating temperature,condensing temperature)on the coefficient of performance ( COP) was studied, laying the foundation for optimization design and operation of refrigeration system.%提出一种新型太阳能风冷氨水吸收式制冷循环系统,该系统设置精馏器提纯氨蒸汽,并有效回收精馏器精馏热及中温吸收器吸收热,实现对太阳能的有效利用以及机组风冷化和小型化,与传统系统相比其系统性能系数(COP)显著提高.基于能量守恒、溶液质量守恒和氨组分质量守恒建立系统各部件热力学数学模型,在此基础上编写程序对系统循环特性进行理论计算,分析热源温度、蒸发温度、冷凝温度等参数对系统COP的影响,为系统优化设计及建立最优运行方案提供理论支持.

  18. Suitability of commercially available laboratory cryogenic refrigerators to support shipboard electro-optical systems in the 10 - 77 Kelvin region

    Science.gov (United States)

    Hansen, R. G.; Byrd, E. A.

    1983-01-01

    The primary development of cryogenically cooled infrared systems was accomplished by FLIR systems designed for airborne, passive night vision. Essential to the development of these FLIR systems was a family of closed cycle refrigerators which had to meet a limited envelope requirement, utilize a nonlubricated compressor module, and be light in weight. Closed cycle refrigerators accomplished the same cooling function, they use modified oil lubricated reciprocating compressors which are limited in their axis of orientation to an angle of approximately 15-20 degrees maximum from horizon.

  19. Modeling solar-driven ejector refrigeration system offering air conditioning for office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Guo, J.; Shen, H.G. [School of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620 (China)

    2009-02-15

    A lumped method combined with dynamic model is proposed for use in investigating the performance and solar fraction of a solar-driven ejector refrigeration system (SERS) using R134a, for office air conditioning application for buildings in Shanghai, China. Classical hourly outdoor temperature and solar radiation model were used to provide basic data for accurate analysis of the system performance. Results indicate that during the office working-time, i.e., from 9:00 to 17:00, the average COP and the average solar fraction of the system were 0.48 and 0.82 respectively when the operating conditions were: generator temperature (85 C), evaporator temperature (8 C) and condenser temperature varying with ambient temperature. Compared with traditional compressor based air conditioner, the system can save upto 80% electric energy when providing the same cooling capacity for office buildings. Hence, the system offers a good energy conservation method for office buildings. (author)

  20. Field Testing and Modeling of Supermarket Refrigeration Systems as a Demand Response Resource

    Energy Technology Data Exchange (ETDEWEB)

    Deru, Michael; Hirsch, Adam; Clark, Jordan; Anthony, Jamie

    2016-08-26

    Supermarkets offer a substantial demand response (DR) resource because of their high energy intensity and use patterns; however, refrigeration as the largest load has been challenging to access. Previous work has analyzed supermarket DR using heating, ventilating, and air conditioning; lighting; and anti-sweat heaters. This project evaluated and quantified the DR potential inherent in supermarket refrigeration systems in the Bonneville Power Administration service territory. DR events were carried out and results measured in an operational 45,590-ft2 supermarket located in Hillsboro, Oregon. Key results from the project include the rate of temperature increase in freezer reach-in cases and walk-ins when refrigeration is suspended, the load shed amount for DR tests, and the development of calibrated models to quantify available DR resources. Simulations showed that demand savings of 15 to 20 kilowatts (kW) are available for 1.5 hours for a typical store without precooling and for about 2.5 hours with precooling using only the low-temperature, non-ice cream cases. This represents an aggregated potential of 20 megawatts within BPA's service territory. Inability to shed loads for medium-temperature (MT) products because of the tighter temperature requirements is a significant barrier to realizing larger DR for supermarkets. Store owners are reluctant to allow MT case set point changes, and laboratory tests of MT case DR strategies are needed so that owners become comfortable testing, and implementing, MT case DR. The next-largest barrier is the lack of proper controls in most supermarket displays over ancillary equipment, such as anti-sweat heaters, lights, and fans.

  1. Numerical investigation of an R744 liquid ejector for supermarket refrigeration systems

    Directory of Open Access Journals (Sweden)

    Haida Michal

    2016-01-01

    Full Text Available This paper presents a numerical investigation of an R744 liquid ejector applied to a supermarket refrigeration system. The use of the liquid ejector enables the operation of the evaporator in a flooded mode and recirculates the R744 liquid phase, which improves the energy efficiency of the refrigeration system. The investigation was performed using two ejectors of different sizes installed in a multi-ejector block. The numerical model was formulated based on the homogenous equilibrium model and validated with the experimental results. The influence of the pre-mixer, mixer and diffuser dimensions on the ejector performance measured using the mass entrainment ratio is presented. The results show that the best liquid ejector performance was obtained for the short lengths of the pre-mixer and mixer compared to the broadly investigated two-phase ejectors connected to the evaporator port. In addition, wide diffuser angles improved the mass entrainment ratio of both liquid ejectors, which may lead to a reduction in the diffuser length.

  2. Noise Source Identification of Small Fan-BLDC Motor System for Refrigerators

    Directory of Open Access Journals (Sweden)

    Yong-Han Kim

    2006-01-01

    Full Text Available Noise levels in household appliances are increasingly attracting attention from manufacturers and customers. Legislation is becoming more severe on acceptable noise levels and low noise is a major marketing point for many products. The latest trend in the refrigerator manufacturing industry is to use brushless DC (BLDC motors instead of induction motors in order to reduce energy consumption and noise radiation. However, cogging torque from BLDC motor is an undesirable effect that prevents the smooth rotation of the rotor and results in noise. This paper presents a practical approach for identifying the source of excessive noise in the small fan-motor system for household refrigerators. The source is presumed to a mechanical resonance excited by torque ripple of the BLDC motor. By using finite element analysis, natural frequencies and mode shapes of the rotating part of the system are obtained and they are compared with experimental mode shapes obtained by electronic torsional excitation test which uses BLDC motor itself as an exciter. Two experimental validations are carried out to confirm the reduction of excessive noise.

  3. Prospects for utilisation of solar driven ejector-absorption cooling system in Turkey

    International Nuclear Information System (INIS)

    Solar assisted refrigeration appears to be a promising alternative to the conventional electrical driven units. The main advantages of solar assisted refrigeration systems concern the reduction of peak loads for electricity utilities, the use of zero ozone depletion impact refrigerants, the decreased primary energy consumption and decreased global warming impact. The main focus of this study is to investigate usage possibility of ejector-absorption cooling system (EACS) in Turkey. This study determines whether or not required heat for generator of EACS can be obtained from solar energy in Turkey. There are two important reasons for the utilisation of EACSs in Turkey. One of them is that the production and use of the CFCs and HCFCs will be phased out in a few years according to Montreal Protocol, adopted in 1987. The other is that Turkey has high solar energy potential because of its location in the northern hemisphere with latitudes 36-42 deg. N and longitudes 26-45 deg. E and the yearly average solar radiation is 3.6 kW h/m2 day, and the total yearly radiation period is ∼2610 h. For analysis, 17 cities were selected in different regions of Turkey in which the radiation data and sunshine duration information have been collected since 2000. By using the meteorological data, it was aimed that required optimum collector surface area for maximum coefficient of performance (COPmax) conditions of EACSs operated with aqua-ammonia was defined. In addition, required minimum energy for auxiliary heater was calculated so that the system can be used throughout the year. It was found that the heat gain factor (HGF) varies in the range from 0.5 to 2.68 for the all the seasons in the selected cities. The maximum HGF of about 2.68 was obtained for Van in July. This study shows that there is a great potential for utilisation of solar cooling system for domestic heating/cooling applications in Turkey

  4. Thermodynamic analysis and theoretical study of a continuous operation solar-powered adsorption refrigeration system

    International Nuclear Information System (INIS)

    Due to the intermittent nature of the solar radiation, the day-long continuous production of cold is a challenge for solar-driven adsorption cooling systems. In the present study, a developed solar-powered adsorption cooling system is introduced. The proposed system is able to produce cold continuously along the 24-h of the day. The theoretical thermodynamic operating cycle of the system is based on adsorption at constant temperature. Both the cooling system operating procedure as well as the theoretical thermodynamic cycle are described and explained. Moreover, a steady state differential thermodynamic analysis is performed for all components and processes of the introduced system. The analysis is based on the energy conservation principle and the equilibrium dynamics of the adsorption and desorption processes. The Dubinin–Astakhov adsorption equilibrium equation is used in this analysis. Furthermore, the thermodynamic properties of the refrigerant are calculated from its equation of state. The case studied represents a water chiller which uses activated carbon–methanol as the working pair. The chiller is found to produce a daily mass of 2.63 kg cold water at 0 °C from water at 25 °C per kg of adsorbent. Moreover, the proposed system attains a cooling coefficient of performance of 0.66. - Highlights: • A new continuous operation solar-driven adsorption refrigeration system is introduced. • The theoretical thermodynamic cycle is presented and explained. • A complete thermodynamic analysis is performed for all components and processes of the system. • Activated carbon–methanol is used as the working pair in the case study

  5. Mountain Plains Learning Experience Guide: Heating, Refrigeration, & Air Conditioning.

    Science.gov (United States)

    Carey, John

    This Heating, Refrigeration, and Air Conditioning course is comprised of eleven individualized units: (1) Refrigeration Tools, Materials, and Refrigerant; (2) Basic Heating and Air Conditioning; (3) Sealed System Repairs; (4) Basic Refrigeration Systems; (5) Compression Systems and Compressors; (6) Refrigeration Controls; (7) Electric Circuit…

  6. Exergy and energy analysis of three stage auto refrigerating cascade system using Zeotropic mixture for sustainable development

    International Nuclear Information System (INIS)

    Highlights: • Zeotropic mixture of R290/R23/R14 works with 22.6% increased exergic efficiency. • Zeotropic mixture of mass fraction 0.218:0.346:0.436 offers COP of 0.253. • Since emphasis on COP, evaporating temperature 0.253 COP became the only alternate. • This is the only alternate refrigerant mixture for three stage ARC system at −97 °C. - Abstract: The Zeotropic mixture of environment friendly refrigerants (HC’s and HFC’s) being the only alternatives for working fluid in low temperature refrigeration system and hence three stage auto refrigerating cascade (ARC) system was studied for the existence using two combinations of (R290/R23/R14, R1270/R170/R14) three component Zeotropic mixture of five different refrigerants. The exergy analysis confirmed the existence of three stage ARC system. The performances of the system like Coefficient of Performance (COP), exergy lost, exergic efficiency, efficiency defect and the evaporating temperature achieved were investigated for different mass fractions in order to verify the effect of mass fraction on them. In accordance with the environmental issues and the process of sustainable development, the three component Zeotropic mixture of R290/R23/R14 with the mass fraction of 0.218:0.346:0.436 was performing better and hence can be suggested as an alternative refrigerant for three stage ARC system operating at very low evaporating temperature in the range of 176 K (−97 °C) at COP of 0.253 with 58.5% exergic efficiency (comparatively 22.6% increased value)

  7. Performance Evaluation of a Lithium-Chloride Absorption Refrigeration and an Assessment of Its Suitability for Biomass Waste Heat

    Directory of Open Access Journals (Sweden)

    Sacha Oberweis

    2012-10-01

    Full Text Available This paper presents a computer model that will evaluate the performance of a thermo-chemical accumulator. The model is based on operational data such as temperatures and flow rates. The ultimate goal for this model is to estimate the coefficient of performance (COP of this unit when run on hot water from biomass combustion as the heat source. The outputs of the model are verified by comparing the simulation of the actual machine with published experimental data. The computed results for cooling COP are within 10% of the measured data. The simulations are all run for heat load temperatures varying between 80 °C and 110 °C. As expected, simulation results showed an increase in COP with increased heat source temperatures. The results demonstrate that the potential of combined solar and biomass combustion as a heat source for absorption cooling/heating in climates with low solar radiation can be coupled with biomass waste.

  8. 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.

  9. 新型太阳能增压吸收式制冷循环%A New Solar-Supercharge Absorption Refrigerator Circle

    Institute of Scientific and Technical Information of China (English)

    刘辉; 李长胜

    2011-01-01

    提出了一个以NH3-LiNO3为工质对、压缩蒸发器出口冷剂蒸气、利用太阳能进行制冷的新循环,采用数值计算的方法对新循环的性能指数、(火用)效率、电热比和冷却水量进行了研究,计算结果表明补偿相当于0.7%~10.68%太阳能能量的电能可使热源进口温度自95℃降低16℃~22℃,新循环的性能指数在0.495~1.201之间,(火用)效率在0.245~0.122之间,冷却水流量随驱动热源进口温度的降低基本呈线性从7.24kg/s减少至3.74kg/s.克服了传统循环受限于太阳能波动的不足,具有很好的节能效益和实践价值.%A new absorption refrigeration circle is proposed, which takes NH3-LiNO3 as the working fluids, compresses the refrigerant vapor out of evaporator and is driven by solar energy. The COP, exergy efficiency, the ratio of the electricity to heat and the flow rate of the cooling water in the proposed circle is numerically studied. The results reveals that: taking electricity about 0.7 to 10.68 percent of the solar energy can reduce 16 to 22 °C of input temperature of the driven water from 95 ℃; the COP is between 0.495 and 1.201 while the exergy efficiency is between 0.245 and 0.122; the flow rate of cooling water will be decreased linearly from 7.24kg/s to 3.74kg/s with the decrease of the temperature of driven water. This circle overcomes the shortage that the traditional solar cycle is subjected to the fluctuation of solar, so it has good energy efficiency and practical value.

  10. Modelling and Assessment of the Capabilities of a Supermarket Refrigeration System for the Provision of Regulating Power

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Madsen, Henrik; Pinson, Pierre;

    This report presents an analysis of the demand response capabilities of a supermarket refrigeration system, with a particular focus on the suitability of this resource for participation in the regulating power market. An ARMAX model of the system is identified from experimental data, and the model...

  11. Evaluation of a solar intermittent refrigeration system for ice production operating with ammonia/lithium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, W.; Moreno-Quintanar, G.; Best, R. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, A.P. 34, 62580 Temixco, Mor. (Mexico); Rivera, C.O.; Martinez, F. [Facultad de Ingenieria Campus Coatzacoalcos, Universidad Veracruzana, Av. Universidad Km 7.5, 96530 Coatzacoalcos, Ver. (Mexico)

    2011-01-15

    A novel solar intermittent refrigeration system for ice production developed in the Centro de Investigacion en Energia of the Universidad Nacional Autonoma de Mexico is presented. The system operates with the ammonia/lithium nitrate mixture. The system developed has a nominal capacity of 8 kg of ice/day. It consists of a cylindrical parabolic collector acting as generator-absorber. Evaporator temperatures as low as -11 C were obtained for several hours with solar coefficients of performance up to 0.08. It was found that the coefficient of performance increases with the increment of solar radiation and the solution concentration. A dependency of the coefficient of performance was not founded against the cooling water temperature. Also it was found that the maximum operating pressure increases meanwhile the generation temperature decreases with an increase of the solution concentration. (author)

  12. Absorption refrigeration cycle driven by waste heat using R124-DMAC as working fluids%基于R124-DMAC为工质对的余热吸收式制冷

    Institute of Scientific and Technical Information of China (English)

    李星; 徐士鸣; 李见波

    2015-01-01

    Energy saving and emission reduction technologies for vehicles have been paid more attention in recent years, and it is necessary to investigate how to efficiently recover and utilize the waste heat from vehicle engines to drive automotive air conditioning system. Based on that, a full air-cooled bubble absorption refrigeration test system with 3 kW cooling capacity driven by waste heat, using R124-DMAC as working fluids was designed and built. In the system, engine exhaust gas was simulated by heated air. Operating parameters were tested through changing heat source temperature, chilled water temperature and pump flow rate. The maximum COP of the system could reach 0.54 under the condition of generator temperature 100℃ and evaporating temperature−4℃. Heat source and chilled water temperatures had an important effect on cooling capacity and COP, and this system had good stability. However when evaporating temperature was below 5℃, a rectification unit should be considered in order to improve cooling effects. Additionally, this experiment proved that the air-cooled bubble absorber worked well, providing theoretical support for the refrigeration system driven by waste heat in vehicle air conditioning.%设计并搭建了制冷量为3 kW、以R124-DMAC为工质、采用电热高温空气模拟发动机排气废热的空冷鼓泡吸收制冷实验系统,通过改变热空气进口温度、冷冻水温度和浓溶泵流率测试系统工作参数的变化趋势。实验结果表明,当发生器稀溶液出口温度约为100℃时,蒸发温度为−4℃,系统COP值最大可达到约0.54,而且实验系统稳定性较好;影响系统制冷量和COP值的主要参数是热空气进口温度和冷冻水温度;当蒸发温度低于5℃时,为了提高制冷效果需考虑设置精馏装置。

  13. Numerical optimization of a transcritical CO2/propylene cascaded refrigeration-heat pump system with economizer in HT cycle

    Indian Academy of Sciences (India)

    Alok Manas Dubey; Suresh Kumar; Ghanshyam Das Agrawal

    2015-04-01

    Use of organic refrigerants such as Hydrochlorofluorocarbons and Chlorofluorocarbons have been criticized for their adverse impact on the Earth's protective ozone layer and for their significant global warming potential (GWP). CO2 has been receiving great concern as an alternative refrigerant. Cascade refrigeration systems employing CO2 are used for low temperature applications. Being a low critical temperature fluid CO2 transcritical cascade systems offer low COP for a given application. Parallel compression economization is one of the promising cycle modifications to improve the COP of transcritical CO2 cascaded systems. In this paper, transcritical CO2/propylene cascade system with parallel compression economization in the HT cycle has been analysed for cooling/heating applications. An enhancement in COP of 9% has been predicted. Thermodynamic analysis on R744-R1270 cascade refrigeration system has been performed to determine the optimal value of the various design parameters of the system. The design parameters included are: gas cooler outlet temperature and intermediate temperature in the high temperature circuit and evaporator temperature and temperature difference in the cascade condenser in the low temperature circuit.

  14. 5-year operation experience with the 1.8 K refrigeration units of the LHC cryogenic system

    Science.gov (United States)

    Ferlin, G.; Tavian, L.; Claudet, S.; Pezzetti, M.

    2015-12-01

    Since 2009, the Large Hadron Collider (LHC) is in operation at CERN. The LHC superconducting magnets distributed over eight sectors of 3.3-km long are cooled at 1.9 K in pressurized superfluid helium. The nominal operating temperature of 1.9 K is produced by eight 1.8-K refrigeration units based on centrifugal cold compressors (3 or 4 stages depending to the vendor) combined with warm volumetric screw compressors with sub-atmospheric suction. After about 5 years of continuous operation, we will present the results concerning the availability for the final user of these refrigeration units and the impact of the design choice on the recovery time after a system trip. We will also present the individual results for each rotating machinery in terms of failure origin and of Mean Time between Failure (MTBF), as well as the consolidations and upgrades applied to these refrigeration units.

  15. 5-year operation experience with the 1.8 K refrigeration units of the LHC cryogenic system

    CERN Document Server

    Ferlin, G; Claudet, S; Pezzetti, M

    2015-01-01

    Since 2009, the Large Hadron Collider (LHC) is in operation at CERN. The LHC superconducting magnets distributed over eight sectors of 3.3-km long are cooled at 1.9 K in pressurized superfluid helium. The nominal operating temperature of 1.9 K is produced by eight 1.8-K refrigeration units based on centrifugal cold compressors (3 or 4 stages depending to the vendor) combined with warm volumetric screw compressors with sub-atmospheric suction. After about 5 years of continuous operation, we will present the results concerning the availability for the final user of these refrigeration units and the impact of the design choice on the recovery time after a system trip. We will also present the individual results for each rotating machinery in terms of failure origin and of Mean Time between Failure (MTBF), as well as the consolidations and upgrades applied to these refrigeration units.

  16. Solar-driven ejector-absorption cooling system

    International Nuclear Information System (INIS)

    The usage possibility of ejector-absorption cooling systems (EACSs) in Turkey using meteorological data has been investigated. This study also determines whether or not the required heat for the generator of an EACS can be obtained from solar energy in Turkey. There are two important reasons for the usage of EACSs in Turkey. One of them is that the production and use of the CFCs and HCFCs will be phased out a few years according to the Montreal Protocol, signed in 1987. The other is that Turkey is located between 36 deg. and 42 deg. N latitudes and has a typical Mediterranean climate. Therefore, Turkey has a high solar-energy potential, and the yearly average solar-radiation and the total yearly radiation period are 3.6 kW h/m2 day and ∼2610 h, respectively. Sixteen cities (Ordu, Tekirdag, Sakarya, Corum, Erzincan, Bursa, Balikesir, Afyon, Bingoel, Burdur, Konya, Nigde, Adiyaman, Hakkari, Anamur, Finike) were selected in Turkey for which the radiation data and sunshine-duration information have been collected since 2000. The required optimum collector-surface area was identified by using the meteorological data for maximum coefficient-of-performance (COPmax) conditions of the EACS operated with aqua-ammonia. In addition, the required minimum energy for the auxiliary heater was also calculated so that the system can be used throughout the year. It is shown that the heat-gain factor (HGF) varies in the range from 1.34 to 2.85 for all the seasons in the selected cities. The maximum HGF is 2.85 for Finike. According to the results obtained in this study, for 8 → 9 months (March-October), it is sufficient to have a collector surface-area of 4 m2 with high-performance refrigeration all over of Turkey. This study will provide guidance for the efficient utilisation of renewable energy sources in Turkey, which is heavily dependent upon imported energy sources, i.e. natural gas

  17. Stirling Refrigerator

    Science.gov (United States)

    Kagawa, Noboru

    A Stirling cooler (refrigerator) was proposed in 1862 and the first Stirling cooler was put on market in 1955. Since then, many Stirling coolers have been developed and marketed as cryocoolers. Recently, Stirling cycle machines for heating and cooling at near-ambient temperatures between 173 and 400K, are recognized as promising candidates for alternative system which are more compatible with people and the Earth. The ideal cycles of Stirling cycle machine offer the highest thermal efficiencies and the working fluids do not cause serious environmental problems of ozone depletion and global warming. In this review, the basic thermodynamics of Stirling cycle are briefly described to quantify the attractive cycle performance. The fundamentals to realize actual Stirling coolers and heat pumps are introduced in detail. The current status of the Stirling cycle machine technologies is reviewed. Some machines have almost achieved the target performance. Also, duplex-Stirling-cycle and Vuilleumier-cycle machines and their performance are introduced.

  18. Prediction and analysis of the seasonal performance of tri-generation and CO2 refrigeration systems in supermarkets

    International Nuclear Information System (INIS)

    Highlights: ► Integration model of a trigeneration with CO2 refrigeration systems in supermarket. ► Validation of the developed integration model with site and laboratory measurement. ► Application of the trigeneration system in power generation and space conditioning. ► Performance analysis and comparison of the integrated system in supermarket. - Abstract: A modern supermarket energy control system has a concurrent need for electricity, space heating or cooling, and food refrigeration. The power supply to the supermarket is primarily from the national grid, where losses in efficiency are due to the processes of energy conversion and transmission. Combined heat and power (CHP) offers the potential to locally produce electrical power and heating which could save energy and reduce CO2 emissions in the long run. During the summer months, as the space heating requirement in a supermarket is relatively small, the energy efficiency of a CHP installation can be improved by using excess thermal energy to drive a sorption refrigeration system to provide space cooling or refrigeration. This process is also known as tri-generation. In recent years, the use of CO2 as a refrigerant in supermarkets has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. Consequently, the application of a tri-generation system in a supermarket with CO2 refrigeration merits further investigation. In this paper, to evaluate the performance of a tri-generation system in the supermarket, a previously tested 80 kWe microturbine device was applied into an operational supermarket to generate power and provide space heating and cooling through exhaust heat. The performance evaluation and comparison for this tri-generation application is based on the prediction from an integrated model of supermarket energy control, cascade CO2 refrigeration and tri-generation systems. The results from

  19. Cloud Absorption Radiometer Autonomous Navigation System - CANS

    Science.gov (United States)

    Kahle, Duncan; Gatebe, Charles; McCune, Bill; Hellwig, Dustan

    2013-01-01

    CAR (cloud absorption radiometer) acquires spatial reference data from host aircraft navigation systems. This poses various problems during CAR data reduction, including navigation data format, accuracy of position data, accuracy of airframe inertial data, and navigation data rate. Incorporating its own navigation system, which included GPS (Global Positioning System), roll axis inertia and rates, and three axis acceleration, CANS expedites data reduction and increases the accuracy of the CAR end data product. CANS provides a self-contained navigation system for the CAR, using inertial reference and GPS positional information. The intent of the software application was to correct the sensor with respect to aircraft roll in real time based upon inputs from a precision navigation sensor. In addition, the navigation information (including GPS position), attitude data, and sensor position details are all streamed to a remote system for recording and later analysis. CANS comprises a commercially available inertial navigation system with integral GPS capability (Attitude Heading Reference System AHRS) integrated into the CAR support structure and data system. The unit is attached to the bottom of the tripod support structure. The related GPS antenna is located on the P-3 radome immediately above the CAR. The AHRS unit provides a RS-232 data stream containing global position and inertial attitude and velocity data to the CAR, which is recorded concurrently with the CAR data. This independence from aircraft navigation input provides for position and inertial state data that accounts for very small changes in aircraft attitude and position, sensed at the CAR location as opposed to aircraft state sensors typically installed close to the aircraft center of gravity. More accurate positional data enables quicker CAR data reduction with better resolution. The CANS software operates in two modes: initialization/calibration and operational. In the initialization/calibration mode

  20. On-line Auto-Tuning of PI Control of the Superheat for a Supermarket Refrigeration System

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Andersen, Casper; Izadi-Zamanabadi, Roozbeh

    2011-01-01

    An online PI auto-tuning method is proposed for superheat control for a type of supermarket refrigeration systems. The proposed procedure consists of three serial steps: Step-One uses one of the two proposed empirical methods, namely multi-step method and relay method, for modeling initialization...

  1. 2nd Biennial Conference on Refrigeration for Cryogenic Sensors and Electronic Systems

    CERN Document Server

    1983-01-01

    This proceedings documents the output of the Second Biennial Conference on Refrigeration for Cryogenic Sensors and Electronic Systems held at the National Aeronautics and Space Administration's Goddard Space Flight Center, Greenbelt, Maryland, on December 7-8, 1982. Building on the first open meeting hosted by the National Bureau of Standards in 1980, the focus of this second meeting was again on low-temperature, closed-cycle cooler technology. However, higher temperature coolers (77 K), with technology applicable to the low temperature coolers, were considered to be within the scope of this meeting. This second conference consisted of 30 papers presented by representatives of industry, government, and academia. The conference proceedings reproduced here was published by the NASA Goddard Space Flight Center in Greenbelt Maryland as NASA Conference Publication 2287.

  2. Model Predictive Control of Hybrid Thermal Energy Systems in Transport Refrigeration

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Alleyne, Andrew

    2015-01-01

    and future estimate of the vehicle driving state and load prediction. This assumes vehicle communications are aware of the traffic state along the prescribed delivery route. For the test case under consideration, this paper first shows that a 17% savings in energy use is achieved for charging the TES......A predictive control scheme is designed to control a transport refrigeration system, such as a delivery truck, that includes a vapor compression cycle configured in parallel with a thermal energy storage (TES) unit. A novel approach to TES utilization is introduced and is based on the current...... by simply shifting the charging to the time when vehicle is moving above a threshold speed. Subsequently, a cascade control structure is proposed consisting of (i) an outer loop controller that schedules the TES charging profile using a receding horizon optimization, and (ii) an inner loop model predictive...

  3. Advanced exergy analysis of a R744 booster refrigeration system with parallel compression

    DEFF Research Database (Denmark)

    Gullo, Paride; Elmegaard, Brian; Cortella, Giovanni

    2016-01-01

    In this paper, the advanced exergy analysis was applied to a R744 booster refrigeration system with parallel compression taking into account the design external temperatures of 25 degrees C and 35 degrees C, as well as the operating conditions of a conventional European supermarket. The global...... efficiencies of all the chosen compressors were extrapolated from some manufactures' data and appropriated optimization procedures of the performance of the investigated solution were implemented.According to the results associated with the conventional exergy evaluation, the gas cooler/condenser, the HS (high...... stage) compressor and the MT (medium temperature) display cabinet exhibited the highest enhancement potential. The further splitting of their corresponding exergy destruction rates into their different parts and the following assessment of the interactions among the components allowed figuring out...

  4. Thermodynamic optimization of mixed refrigerant Joule- Thomson systems constrained by heat transfer considerations

    Science.gov (United States)

    Hinze, J. F.; Klein, S. A.; Nellis, G. F.

    2015-12-01

    Mixed refrigerant (MR) working fluids can significantly increase the cooling capacity of a Joule-Thomson (JT) cycle. The optimization of MRJT systems has been the subject of substantial research. However, most optimization techniques do not model the recuperator in sufficient detail. For example, the recuperator is usually assumed to have a heat transfer coefficient that does not vary with the mixture. Ongoing work at the University of Wisconsin-Madison has shown that the heat transfer coefficients for two-phase flow are approximately three times greater than for a single phase mixture when the mixture quality is between 15% and 85%. As a result, a system that optimizes a MR without also requiring that the flow be in this quality range may require an extremely large recuperator or not achieve the performance predicted by the model. To ensure optimal performance of the JT cycle, the MR should be selected such that it is entirely two-phase within the recuperator. To determine the optimal MR composition, a parametric study was conducted assuming a thermodynamically ideal cycle. The results of the parametric study are graphically presented on a contour plot in the parameter space consisting of the extremes of the qualities that exist within the recuperator. The contours show constant values of the normalized refrigeration power. This ‘map’ shows the effect of MR composition on the cycle performance and it can be used to select the MR that provides a high cooling load while also constraining the recuperator to be two phase. The predicted best MR composition can be used as a starting point for experimentally determining the best MR.

  5. Cogeneration in breweries analysis and simulation of systems for simultaneous generation of power, heat and refrigeration using natural gas; Sistemas de refrigeracao a partir da cogeracao: analise e simulacao de propostas para o caso de cervejarias utilizando gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, Antonio Garrido

    1998-07-01

    The present work analyses some proposals of cogeneration systems for the simultaneous generation of power, heat and refrigeration in a brewery. The requirements of steam, refrigeration and electricity, as well as the production of beer in a plant of the Antarctica Company, located in Jaguariuna - SP were collected monthly for the year of 1997. Three conceptions of systems using two gas turbines with heat recovery steam generator were then proposed to meet the surveyed demand. The proposals differ in the refrigeration system: the first one uses a traditional ammonia compression system while the second uses an ammonia absorption system, the third proposal is a combination of the compression and absorption systems. These proposals are compared to the present configuration which purchases electricity from the Public Utility for power and refrigeration (using an ammonia compression)system, and fuel oil to generate steam for process heat. The technical, economical and environmental feasibility of the proposals, as well as of the present configuration are discussed on the basis of mass balances, energy balances (first law of Thermodynamics), exergy fluxes (second law analysis), operational and capital cost, based on simulation of the performance of each configuration proposed to meet the monthly electricity, steam and refrigeration requirements for the referred plant. The turbines were chosen so as to meet the peek energy demand of the plant and two cases were simulated for each proposal: turbine operational meets only the demand of the plant and turbine operates at full load, selling electricity for the Public utility. Results obtained show that the current operational costs are higher than any of the proposals presented. The high capital costs of the proposals, though,make them less interesting financially. The simulation of the case of excess electricity to the Public Utility is very attractive, considering the cost of natural gas 3,38 U$/M btu and the fare of 40 U

  6. Refrigerated display cabinets; Butikskyla

    Energy Technology Data Exchange (ETDEWEB)

    Fahlen, Per

    2000-07-01

    This report summarizes experience from SP research and assignments regarding refrigerated transport and storage of food, mainly in the retail sector. It presents the fundamentals of heat and mass transfer in display cabinets with special focus on indirect systems and secondary refrigerants. Moreover, the report includes a brief account of basic food hygiene and the related regulations. The material has been compiled for educational purposes in the Masters program at Chalmers Technical University.

  7. Development of GM cryocooler separate type liquid-helium-free 3He-4He dilution refrigerator system

    Science.gov (United States)

    Yamanaka, Y.; Ito, T.; Umeno, T.; Suzuki, Y.; Yoshida, S.; Kamioka, Y.; Maehata, K.

    2009-02-01

    We developed the new liquid-helium-free dilution refrigerator system, in which the Gifford-McMahon (GM) cycle cryocooler and dilution refrigerator (DR) unit are separated. We obtained the base temperature below 50 mK in this DR system. In usual liquid-helium-free DR systems, the DR unit directly couples with GM-cryocooler in the same vacuum chamber. Therefore the mechanical vibration of GM-cryocooler is hardly removed from DR unit. In order to eliminate the vibration problem, the separated vacuum chamber contacting the GM-cryocooler is connected with the DR unit chamber by the flexible hose with length of about 1 meter. Thin flexible tubes used for circulation of the refrigerant gas and radiation shield are installed in the connection hose. The 4He gas, cooled in the GM-cryocooler unit, transfers to the DR unit throw the thin flexible tubes. After cooling the DR unit, the gas returns to GM-cryocooler unit with cooling of the radiation shield. We expect that our separate-type dilution refrigerator becomes a useful piece of apparatus for the low temperature experiments.

  8. Development of GM cryocooler separate type liquid-helium-free {sup 3}He-{sup 4}He dilution refrigerator system

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Y; Ito, T; Umeno, T; Suzuki, Y; Yoshida, S; Kamioka, Y [Taiyo Nippon Sanso Corporation, 10 Okubo, Tsukuba-shi, 300-2611 (Japan); Maehata, K [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka-shi, 819-0395 (Japan)], E-mail: Yoshihiro.Yamanaka@tn-sanso.co.jp

    2009-02-01

    We developed the new liquid-helium-free dilution refrigerator system, in which the Gifford-McMahon (GM) cycle cryocooler and dilution refrigerator (DR) unit are separated. We obtained the base temperature below 50 mK in this DR system. In usual liquid-helium-free DR systems, the DR unit directly couples with GM-cryocooler in the same vacuum chamber. Therefore the mechanical vibration of GM-cryocooler is hardly removed from DR unit. In order to eliminate the vibration problem, the separated vacuum chamber contacting the GM-cryocooler is connected with the DR unit chamber by the flexible hose with length of about 1 meter. Thin flexible tubes used for circulation of the refrigerant gas and radiation shield are installed in the connection hose. The {sup 4}He gas, cooled in the GM-cryocooler unit, transfers to the DR unit throw the thin flexible tubes. After cooling the DR unit, the gas returns to GM-cryocooler unit with cooling of the radiation shield. We expect that our separate-type dilution refrigerator becomes a useful piece of apparatus for the low temperature experiments.

  9. Energy-smart calculation of thermal loads in mobile and stationary heating, ventilation, air conditioning, and refrigeration systems

    OpenAIRE

    Fayazbakhsh, Mohammad Ali

    2015-01-01

    The energy consumption by heating, ventilation, air conditioning, and refrigeration systems forms a large portion of the total energy usage in buildings. Vehicle fuel consumption and emissions are also significantly affected by air conditioning. Air conditioning is also a critical system for hybrid electric vehicles and electric vehicles as the second most energy consuming system after the electric motor. Proper design and efficient operation of air conditioning systems require accurate calcu...

  10. NH3/CO2 Supermarket Refrigeration System with CO2 in the Cooling and Freezing Section. Technical, Energetic and Economical Issues

    Energy Technology Data Exchange (ETDEWEB)

    Van Riessen, G. J.

    2004-08-01

    The application of the natural refrigerant CO2 in combination with NH3 has shown a large increase in industrial refrigeration over the last few years. Until April 2004, all supermarkets in the Netherlands were still working with systems using the environmentally harmful HFCs (greenhouse gases) or even HCFCs (ozone depleting substances). The advantages of a CO2 supermarket system seem to be overshadowed by fear of owners of supermarkets and installers for an unfamiliar system with higher installation costs. The natural refrigerants NH3 and CO2 are now introduced in the Dutch commercial refrigeration. The first supermarket refrigeration system in the Netherlands with only natural refrigerants has become operational in March 2004 and is located in Bunschoten. The NH3/CO2 cascade system has NH3 as primary refrigerant evaporating at -16C in two parallel cascade heat exchangers, where CO2 is condensing at -12C. One CO2 circuit is used for the cooling, which is an innovation for supermarket refrigeration. From the cascade heat exchanger, CO2 is pumped into the cooling section. In the other CO2 circuit, direct expansion and a CO2 compressor provides the freezing section with CO2 of -30C. The most experiments with CO2 in supermarkets in Europe have been restricted to the application of CO2 in the freezing section. Therefore, the application of CO2 as a phase changing secondary refrigerant in the cooling section is an interesting innovation. The technical, energetic and economical aspects of the installation are considered. The technical operation of the cascade refrigeration system in a supermarket is discussed. The energy savings are calculated and the installation and running costs evaluated. Experiences and problems during the installation and control of the installation will be discussed.

  11. Regulating Power from Supermarket Refrigeration

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Madsen, Henrik; Pinson, Pierre;

    2014-01-01

    This paper presents an analysis of the demand response capabilities of a supermarket refrigeration system, with a particular focus on the suitability for participation in the regulating power market. An ARMAX model of a supermarket refrigeration system is identified using experimental data from...... nature of demand response from refrigeration is identified as the key consideration when considering participation in the regulating power market. It is demonstrated that by restricting the operating regions of the supermarket refrigeration system, a simple relationship can be found between the available...

  12. Energy optimisation of domestic refrigerators

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.

    1998-01-01

    This paper describes the main results of a research project with the objective of reducing the energy consumption of domestic refrigerators by increasing the efficiency of the refrigeration system. The improvement of the system efficiency was to be obtained by:1) Introducing continuous operation...... by using a variable speed compressor for controlling the capacity of the refrigeration system.2) Introducing a variable speed fan for enhancing the heat transfer in the evaporator.It was the aim of the project to reduce the energy consumption of a standard refrigerator, available on the market today, by 50 %....

  13. Mathematical modelling of supermarket refrigeration systems for design, energy prediction and control

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y.T.; Tassou, S.A. [Brunel Univ., Dept. of Mechanical Engineering, Uxbridge (United Kingdom)

    2000-04-01

    This paper describes a mathematical model developed to simulate the performance of supermarket refrigeration systems. Such a model can be used for the comparison of different systems and control strategies in terms of their energy and total equivalent warming impact. The model is based on a larger number of component models which have been linked together within the TRNSYS environment. Major component models include the compressor, air-cooled condenser, thermostatic expansion valve, display cabinet and control. The overall system model has been validated against monitored data obtained from both a laboratory-based system and a full-scale system in a supermarket in Scotland. The value of the model is illustrated by determining and comparing the effectiveness of head pressure and variable-speed control against fixed head pressure and constant speed control. It is shown that even at summer ambient conditions the system can be operated without problems at much lower head pressures than is done in practice under fixed-pressure control strategies. The use of variable-speed control on one of the compressors can also provide better control of the suction pressure and a substantial (up to 23 per cent) energy savings compared to on-off control. (Author)

  14. Theoretical study of heat pump system using CO2/dimethylether as refrigerant

    Directory of Open Access Journals (Sweden)

    Fan Xiao-Wei

    2013-01-01

    Full Text Available Nowadays, HCFC22 is widely used in heat pump systems in China, which should be phased out in the future. Thus, eco-friendly mixture CO2/dimethylether is proposed to replace HCFC22. Compared with pure CO2 and pure dimethylether, the mixture can reduce the heat rejection pressure, and suppress the flammability and explosivity of pure dimethylether. According to the Chinese National Standards on heat pump water heater and space heating system, performances of the subcritical heat pump system are discussed and compared with those of the HCFC22 system. It can be concluded that CO2 /dimethylether mixture works efficiently as a refrigerant for heat pumps with a large heat-sink temperature rise. When mass fraction of dimethylether is increased, the heat rejection pressure is reduced. Under the nominal working condition, there is an optimal mixture mass fraction of 28/72 of CO2/dimethylether for water heater application under conventional condensation pressure, 3/97 for space heating application. For water heater application, both the heating coefficient of performance and volumetric heating capacity increase by 17.90% and 2.74%, respectively, compared with those of HCFC22 systems. For space heating application, the heating coefficient of performance increases by 8.44% while volumetric heating capacity decreases by 34.76%, compared with those of HCFC22 systems. As the superheat degree increases, both the heating coefficient of performance and volumetric heating capacity tend to decrease.

  15. Solid state magnetic refrigerator

    International Nuclear Information System (INIS)

    Highlights: ► One proposes a magnetic refrigerator not requiring the use of fluids. ► Materials whose thermal conductivities depend on an applied magnetic field are used. ► Numerical simulations show that the coefficient of performance attained reaches 1.5. ► The device can be triggered from cooler to heat source by varying the frequency. - Abstract: The viability and operation of a fully solid state magnetic refrigeration system with envisaged applications on chip, sensor and device cooling is here tested using numerical simulations. The proposed system relies on the combined use of materials displaying the magnetocaloric effect and of materials whose thermal conductivities are controlled by an external magnetic field. This allows the switching of the heat flow direction in sync with the temperature variation of the magnetocaloric material, removing the necessity to use fluids which has for long hindered the implementation of magnetic refrigeration. We have found the optimum operating conditions of the proposed refrigerator, for which a cooling power density of ∼2.75 W cm−2 was obtained for an operating temperature of ∼296 K, using Gadolinium as the magnetocaloric material and an applied magnetic field of 1 T. The coefficient of performance (COP) achieved by this refrigerator was found to be COP ∼1.5, making it a viable alternative to thermoelectric refrigeration.

  16. Theoretical studies on new refrigerant in refrigeration system for freeze and cold storage%用于冷冻冷藏制冷系统的新型制冷剂的理论研究

    Institute of Scientific and Technical Information of China (English)

    高赞军; 徐英杰; 仇宇; 李鹏; 韩晓红; 陈光明

    2012-01-01

    综述在冷冻冷藏系统中制冷剂替代研究的现状.在此基础上,提出一种新的混合制冷剂(HFG-161/HFC-125/HFC-143a,15/45/40)用于替代HFC-404A,该新型制冷剂的ODP为零,GWP比HFC-404A和R507A要小,其基本热力学性能与HFC-404A相近.对新型混合制冷剂和HFC-404A的循环性能进行理论分析与比较.结果表明,新型混合制冷剂的性能要比HFC-404A优越,环境性能更好,是HFC-404A潜有力的替代制冷剂.%The research status on refrigerant substitute for the freeze and cold storage system is reviewed. Based on this,a new ternary non-azeotropic mixture of HFC-161/HFC-125/HFC-143a( 15/45/40) as a promising mixed refrigerant to HFO404A is presented. The ODP of the new refrigerant is zero and its basic thermodynamic properties are similar to those of HFC-404A,and its GWP is much smaller than that of R507A or HFC-404A. The cycle performance between the new mixture refrigerant and HFC-404A is theoretically analyzed and compared. The results show that the cycle performance and environmental performance of the new mixture refrigerant are better than those of HFC-404A. The new mixture refrigerant may be a promising alternative refrigerant for HFC-404A.

  17. Insertable system for fast turnaround time microwave experiments in a dilution refrigerator

    OpenAIRE

    Ong, Florian R.; Orgiazzi, Jean-Luc; de Waard, Arlette; Frossati, Giorgio; Lupascu, Adrian

    2012-01-01

    Microwave experiments in dilution refrigerators are a central tool in the field of superconducting quantum circuits and other research areas. This type of experiments relied so far on attaching a device to the mixing chamber of a dilution refrigerator. The minimum turnaround time in this case is a few days as required by cooling down and warming up the entire refrigerator. We developed a new approach, in which a suitable sample holder is attached to a cold-insertable probe and brought in cont...

  18. Long Term Viability of HFO-1234yf in Stationary Refrigeration Systems – Multi-Year Evaluation of Refrigerant, Lubricant, and Compressor Performance in a Domestic Freezer

    OpenAIRE

    Allgood, Charles C.; Hydutsky, Bianca; Leck, Thomas J.; Hughes, Joshua

    2014-01-01

    In recent years, HFO-1234yf has been introduced as a low global warming potential (GWP) replacement for HFC-134a in a variety of refrigeration and air conditioning applications both as a pure fluid (mildly flammable) and in refrigerant blends (both mildly flammable and non-flammable). A large and growing body of work on HFO-1234yf exists for mobile air conditioning, however recently interest in the use of R-1234yf in stationary refrigeration applications is growing. This paper will report the...

  19. Energy simulation of solar assisted absorption system and examination of clearness index effects on auxiliary heating

    International Nuclear Information System (INIS)

    The smog and pollutants in the atmospheric air of heavily populated urban areas are anticipated to have substantial adverse effects on the collection of solar energy and the performance of solar energy systems. The objectives of this study are (a) to develop a simulation model for analyzing the performance of a water-LiBr solar assisted absorption system with an auxiliary heating source and (b) to examine the effects of clearness index on the auxiliary heating requirements. To achieve the objectives, a numerical model for a water-LiBr solar assisted absorption system is developed, and the influence of a reduction in the clearness index, based on actual recorded data, is investigated for constant and time varying cooling loads. Under the condition of peak solar gain on July 21, when a 1000 m2 solar collector is designed to provide 70% of the heating energy required for a constant cooling load of 1265 MJ/h (=100 refrigeration tons), as the system coefficient of performance decreases due to higher ambient temperatures, it is found that a reduction in the clearness index from 0.63 to 0.52 results in a 67% increase in auxiliary heating required of the boiler. It is concluded that accounting for clearness index data is necessary for accurate prediction of solar energy collection

  20. Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

    International Nuclear Information System (INIS)

    Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

  1. Energy Simulation of Integrated Multiple-Zone Variable Refrigerant Flow System

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

    2013-01-01

    We developed a detailed steady-state system model, to simulate the performance of an integrated five-zone variable refrigerant flow (VRF)heat pump system. The system is multi-functional, capable of space cooling, space heating, combined space cooling and water heating, and dedicated water heating. Methods were developed to map the VRF performance in each mode, based on the abundant data produced by the equipment system model. The performance maps were used in TRNSYS annual energy simulations. Using TRNSYS, we have successfully setup and run cases for a multiple-split, VRF heat pump and dehumidifier combination in 5-zone houses in 5 climates that control indoor dry-bulb temperature and relative humidity. We compared the calculated energy consumptions for the VRF heat pump against that of a baseline central air source heat pump, coupled with electric water heating and the standalone dehumidifiers. In addition, we investigated multiple control scenarios for the VRF heat pump, i.e. on/off control, variable indoor air flow rate, and using different zone temperature setting schedules, etc. The energy savings for the multiple scenarios were assessed.

  2. Experimental and computational studies on a steam jet refrigeration system with constant area and variable area ejectors

    International Nuclear Information System (INIS)

    Graphical abstract: The work aimed at studying the performance of a steam jet refrigeration system with (i) a constant area ejector and (ii) a variable area ejector under different operating conditions both experimentally and computationally. The boiler temperature was varied from 90 °C to 120 °C, the evaporator temperature was varied from 5 °C to 15 °C and the entertainment ratio, variation of Mach number along the ejector and the Coefficient of Performance were obtained. With proper design, the shock phenomenon in the variable area ejector was eliminated as shown in the left figure, which resulted in a better performance of the variable area ejector over a range of evaporator temperatures. The study also confirmed that the system can operate steadily at a boiler temperature of 90 °C which can be obtained from waste heat. - Highlights: • Experimental and computational studies on steam jet refrigeration system carried out. • Constant area and variable area ejectors were designed for low heat input. • Evaporator temperature was varied from 5 °C to 15 °C and the boiler temperature from 90 °C to 120 °C. • At the lower boiler temperature, no shock formed in the variable area ejector resulting in better performance. • A steam jet refrigeration system can operate steadily at boiler temperature of 90 °C. - Abstract: This paper first presents the results from an experimental study of a conventional steam jet ejector refrigeration system and compares the performance with the computational fluid dynamics (CFD) results of the same. Secondly, it describes a method of developing a variable area supersonic ejector and presents experimental results of the operating performance of the variable area ejector over the same operating conditions. The two ejectors were experimentally tested for boiler temperatures below 120 °C and an evaporator temperature below 15 °C. It was found that the steam jet refrigeration system can operate with stability at low boiler

  3. The Role of Absorption Cooling for Reaching Sustainable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lindmark, Susanne

    2005-07-01

    This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO{sub 2} emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield. The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO{sub 2} emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO{sub 2} emissions can be lowered to 45 CO{sub 2}/MWh{sub c} by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study. Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand.

  4. Improvement of xenon purification system using a combination of a pulse tube refrigerator and a coaxial heat exchanger

    CERN Document Server

    Chen, Wan-Ting; Cussonneau, J -P; Donnard, J; Duval, S; Lemaire, O; Calloch, M Le; Ray, P Le; Mohamad-Hadi, A -F; Morteau, E; Oger, T; Scotto-Lavina, L; Stutzmann, J -S; Thers, D; Briend, P; Haruyama, T; Mihara, S; Tauchi, T

    2012-01-01

    We have developed a compact cryogenic system with a pulse tube refrigerator and a coaxial heat exchanger. This liquefaction-purification system not only saves the cooling power used to reach high gaseous recirculation rate, but also reduces the impurity level with high speed. The heat exchanger operates with an efficiency of 99%, which indicates the possibility for fast xenon gas recirculation in a highpressurized large-scale xenon storage with much less thermal losses.

  5. 复合制冷循环间冷系统制冷剂/工质的选择论证%A Selection Demonstration of Refrigerant/Medium for Compound Refrigerating Cycle of Indirect Air Cooling System

    Institute of Scientific and Technical Information of China (English)

    杨善让; 雷扬; 赵波; 盛杰; 陈立军

    2012-01-01

    该文旨在从目前80余种制冷剂(包括替代工质)中筛选出能满足复合制冷循环间冷系统f以下简称复间冷)要求的中间传热介质(制冷剂/工质)。筛选步骤如下:1)按制冷剂的臭氧损耗潜势和全球变暖潜势挑选出满足环保要求的“环保型制冷剂”;2)根据环保型制冷剂的物性对复间冷要求的满足程度,挑出合适度比较高的若干种;3)从前两轮筛选出的制冷剂/工质挑出做功能力最大者。最终氨成为3轮筛选唯一胜出的自然物质。考虑到氨的气味对人的呼吸道有刺激性,条件具备时可燃可爆,故再次仔细分析了其安全性,指出其燃爆可防、易防,拟定了相应防范措施,并列举了应用实例。全文结论为:氨物性对复间冷的合适度最高,环境最友好,安全可靠,性价比高。作为复间冷的制冷剂/工质,氨虽非最佳,但目前尚无更佳的替代物。%This paper aims at sieving out the intermediate heat transfer medium (namely refrigerant/medium) for the compound refrigerating cycle from more than 80 refrigerants, which are capable of meeting the compound refrigerating cycle's demands. The sieve course are comprised of 3-steps: 1)According to the values of ozone depletion potential (ODP) and global warming potential (GWP) of refrigerants sifted the so called "environment protection type refrigerant" which meet the environment protection requirements; 2) Based on property parameters of the environment protection type refrigerants/ mediums select those refrigerants which are in accord with requirements of compound refrigerating cycle of indirect air cooling system; 3)The third criterion is that the power capability of medium in inverse refrigerating cycle is the maximum of all the mediums selected by the first and second round of the sifting. At last, the ammonia became the only natural materials which satisfy all

  6. Properties of the Carrol system and a machine design for solar-powered, air cooled, absorption space cooling

    Science.gov (United States)

    1981-05-01

    The name Carrol was selected as a convenient shorthand designation for a prime candidate chemical system comprising ethylene glycol-lithium bromide as an absorbent mixture with water as a refrigerant. The instrumentation, methods of handling data and numerical results from a systematic determination of Carrol property data required to design an air cooled absorption machine based on this chemical system are described. These data include saturation temperature, relative enthalpy, density, specific heat capacity, thermal conductivity, viscosity and absorber film heat transfer coefficient as functions of solution temperature and Carrol concentration over applicable ranges. For each of the major components of the absorption chiller, i.e., generator, chiller, absorber, condenser, heat exchanger, purge and controls, the report contains an assembly drawing and the principal operating characteristics of that component.

  7. Performance evaluation of heat pump system using R744/R161 mixture refrigerant

    Directory of Open Access Journals (Sweden)

    Zhang Xian-Ping

    2014-01-01

    Full Text Available As an efficient and energy conservation technology, heat pumps working with R22, which are scheduled to be phased out by Montreal Protocol, are widely used in China at present. The global deteriorating ecology environment would accelerate the phase-out time of R22 in developing countries. Therefore, as a matter of urgency, an eco-friendly substitute should be investigated in order to replace R22. Under this context, and with a consideration of the environmental protection, R744/R161 mixture refrigerant is proposed. R744/R161 mixture refrigerant’s condensation pressure is reduced and its flammability and explosivity are suppressed. A thermodynamic model is developed, and under the given working conditions, the performances of subcritical heat pump system using R744/R161 mixture of variable mass fraction are discussed and compared with those of the R22 system. The optimal mass fraction of R744/R161 is given, which corresponds to a maximal heating coefficient of performance. The simulation results show that R744/R161 mixture can work as a competitive alternative to R22 in heat pump system.

  8. Analyse des interactions energetiques entre un arena et son systeme de refrigeration

    Science.gov (United States)

    Seghouani, Lotfi

    La presente these s'inscrit dans le cadre d'un projet strategique sur les arenas finance par le CRSNG (Conseil de Recherche en Sciences Naturelles et en Genie du Canada) qui a pour but principal le developpement d'un outil numerique capable d'estimer et d'optimiser la consommation d'energie dans les arenas et curlings. Notre travail s'inscrit comme une suite a un travail deja realise par DAOUD et coll. (2006, 2007) qui a developpe un modele 3D (AIM) en regime transitoire de l'arena Camilien Houde a Montreal et qui calcule les flux de chaleur a travers l'enveloppe du batiment ainsi que les distributions de temperatures et d'humidite durant une annee meteorologique typique. En particulier, il calcule les flux de chaleur a travers la couche de glace dus a la convection, la radiation et la condensation. Dans un premier temps nous avons developpe un modele de la structure sous la glace (BIM) qui tient compte de sa geometrie 3D, des differentes couches, de l'effet transitoire, des gains de chaleur du sol en dessous et autour de l'arena etudie ainsi que de la temperature d'entree de la saumure dans la dalle de beton. Par la suite le BIM a ete couple le AIM. Dans la deuxieme etape, nous avons developpe un modele du systeme de refrigeration (REFSYS) en regime quasi-permanent pour l'arena etudie sur la base d'une combinaison de relations thermodynamiques, de correlations de transfert de chaleur et de relations elaborees a partir de donnees disponibles dans le catalogue du manufacturier. Enfin le couplage final entre l'AIM +BIM et le REFSYS a ete effectue sous l'interface du logiciel TRNSYS. Plusieurs etudes parametriques on ete entreprises pour evaluer les effets du climat, de la temperature de la saumure, de l'epaisseur de la glace, etc. sur la consommation energetique de l'arena. Aussi, quelques strategies pour diminuer cette consommation ont ete etudiees. Le considerable potentiel de recuperation de chaleur au niveau des condenseurs qui peut reduire l'energie requise par

  9. Simulation of air-supply systems efficiency in refrigerated vehicles to prevent food spoilage

    OpenAIRE

    Pitarma, R. A.; Ramos, J. E.; Lima, Nelson; Carvalho, M. G.

    2005-01-01

    An improper air distribution within refrigerated truck chambers is the major cause of inadequate road transport of perishable products under controlled temperature. Inadequate temperature control permits microbial and/or enzymatic deterioration. Experimental results in refrigerated long road vehicles show temperatures differences in the cargo of as much as 12ºC. This paper presents a computational model to predict, and visualize, the temperature conditions (e.g. velocity, temperat...

  10. Optimal Energy Consumption in Refrigeration Systems - Modelling and Non-Convex Optimisation

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Skovrup, Morten J.;

    2012-01-01

    Supermarket refrigeration consumes substantial amounts of energy. However, due to the thermal capacity of the refrigerated goods, parts of the cooling capacity delivered can be shifted in time without deteriorating the food quality. In this study, we develop a realistic model for the energy...... for the same conceptual example. The tailored approach is somewhat faster than the general optimisation method and the solutions obtained are almost identical....

  11. A review on thermodynamic optimization of irreversible refrigerator and verification with transcritical CO2 system

    OpenAIRE

    Sarkar, Jahar

    2014-01-01

    The transcritical vapor compression refrigeration cycle consists of isothermal heat addition process and isobaric non-isothermal heat rejection process with highly variable heat capacity unlike to the subcritical cycle. Hence, it is quite interesting whether the analysis and optimization results of irreversible Carnot-like refrigerator are applicable for this case. The present study consists of two parts: the detailed review on theoretical analysis and analytical optimizations of irreversible...

  12. Influence of power source type on energy effectiveness and environmental impact of cooling system with adsorption refrigerator

    International Nuclear Information System (INIS)

    Highlights: • Sustainability development in industrial energy systems was studied. • Solar energy and waste heat for feeding of adsorption refrigerator were used. • Primary energy savings for cooling systems were examined. • Greenhouse gasses savings with renewable and non-renewable sources were estimated. - Abstract: In the paper the method for energy and ecological evaluation of refrigeration system based on the adsorption machine is presented. The energy effectiveness is calculated on the level of the primary energy consumption. The method for ecological evaluation is also discussed. In the ecological evaluation the influence on greenhouse gasses (GHG) is taken into account and the ecological effects are expressed as equivalent CO2 emission. The authors compare the effectiveness of a refrigerator existing in an example Polish food factory supplied with heat from a boiler house fired with natural gas, a cogeneration system and solar collectors. In the last case the climatic conditions and detailed solar radiation data for Poland have been used. The authors demonstrated that the application of cogeneration or renewable energy sources (RES) for the cooling system can lead to energy savings and ecological benefits. To measure the energy effects the authors introduced the following indices: (PES) – Primary Energy Savings and (GHGS) – Greenhouse Gasses Savings. The results of the mentioned indices for different configuration of heating systems are calculated and presented in the paper

  13. Nonlinear Absorption and Refraction in Multilevel Organic Molecular System

    Institute of Scientific and Technical Information of China (English)

    LI Chun-Fei; DENG Xiao-Xu; WANG Yu-Xiao

    2000-01-01

    The nonlinear absorption and refraction in a multilevel organic molecular system is described by using the density matrix theory. The total absorptive coefficient of the system in the low-density case is equal to a linear sum of contributions from each energy level. Similarly, the total refractive index is equal to a linear sum of contributions from each energy level plus the refractive index of the vacuum. The absorption coefficient or refractive index due to each level is proportional to the population of that level, where the constant of proportionality is called the absorption cross-section or the refraction volume, respectively. The relation between the absorption cross-section and the refraction volume for each level is also given.

  14. Thermodynamic analysis of an absorption system using [bmim]Zn2Cl5/NH3 as the working pair

    International Nuclear Information System (INIS)

    Highlights: • Thermodynamic analysis of [bmim]Zn2Cl5/NH3 absorption system was conducted. • Performance of [bmim]Zn2Cl5/NH3 system was compared with NaSCN/NH3 system. • COP and ηex are higher than NaSCN/NH3 system when TG is high and TG and TG are low. • [bmim]Zn2Cl5/NH3 system can be well used in both cooling and heating applications. - Abstract: The thermodynamic performance of an absorption system using [bmim]Zn2Cl5/NH3 as working pair for cooling and heating applications was numerically analyzed. Changes in the coefficient of performance (COP) and exergetic efficiency for [bmim]Zn2Cl5/NH3 absorption refrigeration with varying generation temperature, absorption temperature and condensation temperature were simulated and compared with that of the NaSCN/NH3 system. It was observed that the COP and exergetic efficiency of the [bmim]Zn2Cl5/NH3 system are slightly higher than that of the NaSCN/NH3 system when the generation temperature is high and the condensing temperature and absorption temperature are low. The effects of the generation temperature on the COP and the circulation ratio for cooling were investigated and analyzed. The results indicate that the [bmim]Zn2Cl5/NH3 system is suitable for use in cooling applications. The effects of the generation temperature on the COP, exergy efficiency and circulation ratio for heating were evaluated and discussed. The findings indicate that the [bmim]Zn2Cl5/NH3 absorption system exhibits good thermal performance for heating applications

  15. Optimal analysis of gas cooler and intercooler for two-stage CO2 trans-critical refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • Simplified model for tube-fin gas cooler for CO2 refrigeration system was presented and validated. • Several parameters were investigated using 1st law and 2nd law in component and system level. • Practical guidelines of optimum for tube-fin gas cooler and intercooler were proposed. - Abstract: Energy-based 1st law and exergy-based 2nd law are both employed in the paper to assess the optimal design of gas cooler and intercooler for two-stage CO2 refrigeration system. A simplified mathematical model of the air-cooled coil is presented and validated against experimental data with good accuracy. The optimum circuit length under the influence of frontal air velocity and deep rows is investigated first. Thereafter, designed coil with optimum circuit length is further evaluated within the two-stage refrigeration system. It is found out the optimum point using 1st law does not coincide with the point using 2nd law in isolated component and the simulation results from isolated component by 2nd law are closer to system analysis. Results show optimum circuit length is much bigger for gas cooler than intercooler and the influence on the length from variation of frontal air velocity and deep rows may be neglected. There does exist optimum frontal air velocity which will decrease with more number of deep rows

  16. A resorption cycle for the cogeneration of electricity and refrigeration

    International Nuclear Information System (INIS)

    Graphical abstract: A novel resorption cycle driven by low grade heat for cogeneration of electricity and refrigeration is studied. The cycle features in high exergy efficiency, very little or no ammonia liquid inside and simple structure. Highlights: ► A resorption cogeneration cycle for electricity and refrigeration is proposed. ► The cycle improved refrigeration COP by 10 times compared with Goswami cycle. ► The highest exergy efficiency of the cogeneration cycle is as high as 0.9. ► The cycle also features in safety and simple structure. - Abstract: This paper describes a novel resorption cycle driven by the low grade heat for the cogeneration of electricity and refrigeration, which is based on ammonia adsorption refrigeration technology. The presented cycle features a variable endothermic process which stands for higher adaptability if compared with the traditional Rankine cycle, very little or no ammonia liquid in the system which is a safety feature, solid adsorbents inside the beds, and simple structure for the fact of no rectifying equipment and circulation pumps required by the working fluids. This cycle can be utilised for the heat source with the temperature higher than 100 °C, and it has an electricity generation exergy efficiency of up to 0.69 and a refrigeration coefficient of performance (COP) of up to 0.77. If compared with the Goswami cycle, which is established based on the absorption Kalina cycle for the cogeneration of electricity and refrigeration, the novel resorption cycle kept the merit of the high exergy efficiency for electricity generation, meanwhile, it overcame the limitation of the low refrigeration coefficient of performance (COP) of Goswami cycle, and improved the COP by 10 times. The optimum overall exergy efficiency is as high as 0.9, which is 40–60% improved compared with the Goswami cycle under the same working conditions

  17. Dynamic Simulation of Household Refrigerators: Numerical Model and Experimental Comparison

    OpenAIRE

    Ablanque, Nicolas; Oliet, Carles; Rigola, Joaquim; Lehmkuhl, Oriol; Oliva, Assensi

    2014-01-01

    This work presents a dynamic model to simulate a whole household refrigeration unit taking into account both the refrigeration cycle itself and the refrigerated compartments network. The methodology implemented to achieve the transient simulation of the whole system combines a steady-state approach for the refrigerating cycle loop with a transient approach for the refrigerated compartments loop. Both loops are solved at each time step (the linking boundary conditions for the refrigerating cyc...

  18. Recent Refrigeration Cycle Technologies for Household Refrigerators

    Science.gov (United States)

    Nagatomo, Shigemi

    The household refrigerator is one of the most important and the biggest energy-consuming home appliances. This paper summarize recent refrigeration cycle developments in the field of domestic household refrigerators based on a survey of publications.

  19. Sorption Refrigeration / Heat Pump Cycles

    Science.gov (United States)

    Saha, Bidyut Baran; Alam, K. C. Amanul; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    Over the past few decades there have been considerable efforts to use adsorption (solid/vapor) for cooling and heat pump applications, but intensified efforts were initiated only since the imposition of international restrictions on the production and use of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). Up to now, only the desiccant evaporative cooling system of the open type has achieved commercial use, predominantly in the United States. Closed-type adsorption refrigeration and heat pump systems are rarely seen in the market, or are still in the laboratory testing stage. Promising recent development have been made in Japan for the use of porous metal hydrides and composite adsorbents. In this paper, a short description of adsorption theories along with an overview of present status and future development trends of thermally powered adsorption refrigeration cycles are outlined putting emphasis on experimental achievements. This paper also addressed some advanced absorption cycles having relatively higher COP, and also summarizes fundamental concepts of GAX cycles and various GAX cycles developed for heat pump applications.

  20. Experimental studies on heat and mass transfer performance of a coiled tube absorber for R134a-DMAC based absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Mohideen, S.T. [Institute of Road and Transport Technology, Erode, Tamil Nadu (India); Renganarayanan, S. [Institute for Energy Studies, Anna University, Chennai, Tamil Nadu (India)

    2008-11-15

    Absorber is an important component in vapor absorption refrigeration system and its performance has greater influence in overall efficiency of absorption machines. Falling film heat and mass transfer in an absorber is greatly influenced by fluid properties, geometry of heat exchanger and its operating parameters. This paper presents on the results of experimental studies on the heat and mass transfer characteristics of a coiled tube falling film absorber, using 1,1,1,2-Tetrafluroethane(R-134a) and N-N Dimethyl Acetamide (DMAC) as working fluids. The effects of film Reynolds number, inlet solution temperature and cooling water temperature on absorber heat load, over all heat transfer coefficient and mass of refrigerant absorbed are presented and discussed. Normalized solution and coolant temperature profiles and refrigerant mass absorbed along the height of absorber are also observed from the experimental results. The optimum over all heat transfer coefficient for R-134a-DMAC solution found to be 726 W/m{sup 2}K for a film Reynolds number of 350. The R-134a vapour absorption rate is maximum in the normalized coil height of 0.6 to 1. (orig.)

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

    OpenAIRE

    Cüneyt Ezgi; Ibrahim Girgin

    2015-01-01

    Naval surface ships should use thermally driven heating and cooling technologies to continue the Navy’s leadership role in protecting the marine environment. Steam ejector refrigeration (SER) or steam ejector heat pump (SEHP) systems are thermally driven heating and cooling technologies and seem to be a promising technology to reduce emissions for heating and cooling on board naval surface ships. In this study, design and thermodynamic analysis of a seawater cooled SER and SEHP as an HVAC sys...

  2. ANALYSIS OF LOW GLOBAL WARMING POTENTIAL FLUORIDE WORKING FLUIDS IN VAPOUR COMPRESSION SYSTEMS. EXPERIMENTAL EVALUATION OF COMMERCIAL REFRIGERATION ALTERNATIVES.

    OpenAIRE

    Mota Babiloni, Adrián

    2016-01-01

    [EN] Climate change is one of the short term threats for the humanity because it can affect seriously to the environment and, consequently, to vegetal and animal life. If it is not stopped in next years, maybe this effect will be irreversible. Climate change is produced by anthropogenic emissions of Greenhouse Gas to Earth's atmosphere. Vapour compression systems are one of the main contributors to this phenomenon. Among them, commercial refrigeration applications, through HFC usage, can be h...

  3. Refrigerant charge management in a heat pump water heater

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jie; Hampton, Justin W.

    2016-07-05

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, and methods of managing refrigerant charge. Various embodiments remove idle refrigerant from a heat exchanger that is not needed for transferring heat by opening a refrigerant recovery valve and delivering the idle refrigerant from the heat exchanger to an inlet port on the compressor. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled by controlling how much refrigerant is drawn from the heat exchanger, by letting some refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and various components can be interconnected with refrigerant conduit. Some embodiments deliver refrigerant gas to the heat exchanger and drive liquid refrigerant out prior to isolating the heat exchanger.

  4. Effect of Condenser Fouling on Performance of Vapor Compression Refrigeration System

    Directory of Open Access Journals (Sweden)

    Naveen Solanki

    2015-01-01

    Full Text Available Effect of condenser fouling is evaluated on the performance of a vapour compression system with refrigerants HFO1234yf and HFO1234ze as an alternative to HFC134a. The condenser coolant temperature has been varied between 35 and 40°C to evaluate the effect of fouling at different condenser temperatures. A simulation model is developed in EES for computing the results. The results have been computed by varying condenser conductance. The same has been validated with literature available before calculating the results. It is observed that the condenser fouling has larger effect on compressor power (Wcp% as it increases up to 9.12 for R1234yf and 7.41 for R1234ze, whereas for R134a its value increases up to 7.38. The cooling capacity (Qevap% decreases up to 13.25 for R1234yf and 8.62 for R1234ze, whereas for R134a its value decreases up to 8.76. The maximum percentage of decrease in value of COP is up to 19.29 for R1234yf and 14.47 for R1234ze, whereas for R134a its value decreases up to 14.49. The second-law efficiency is also observed to decrease with decrease in the condenser conductance. The performance of HFO1234ze is found to be better under fouled conditions in comparison to R134a and R1234yf.

  5. Performance optimization for a variable throat ejector in a solar refrigeration system

    KAUST Repository

    Yen, R.H.

    2013-08-01

    In a solar vapor ejector refrigeration system, the solar heat supply may vary because of variations in solar irradiation intensity, making it difficult to maintain a steady generator temperature. To improve ejector performance, this study proposes a variable throat ejector (VTEJ) and analyzes its performance using CFD simulations. The following conclusions can be drawn. An ejector with a greater throat area and larger solar collector allows a wider operating range of generator temperatures, but may be overdesigned and expensive. Conversely, decreasing the throat area limits the operating range of generator temperatures. Thus the ejector with a fixed throat area may be unsuitable to use solar energy as a heat source. For a VTEJ, this study derives a curve-fitting relationship between the optimum throat area ratio and the operating temperatures. Using this relationship to adjust the throat area ratio, the ejector can consistently achieve optimal and stable performances under a varying solar heat supply. © 2013 Elsevier Ltd and IIR. All rights reserved.

  6. Electromagnetically induced absorption in a three-resonator metasurface system.

    Science.gov (United States)

    Zhang, Xueqian; Xu, Ningning; Qu, Kenan; Tian, Zhen; Singh, Ranjan; Han, Jiaguang; Agarwal, Girish S; Zhang, Weili

    2015-01-01

    Mimicking the quantum phenomena in metamaterials through coupled classical resonators has attracted enormous interest. Metamaterial analogs of electromagnetically induced transparency (EIT) enable promising applications in telecommunications, light storage, slow light and sensing. Although the EIT effect has been studied extensively in coupled metamaterial systems, excitation of electromagnetically induced absorption (EIA) through near-field coupling in these systems has only been sparsely explored. Here we present the observation of the EIA analog due to constructive interference in a vertically coupled three-resonator metamaterial system that consists of two bright and one dark resonator. The absorption resonance is one of the collective modes of the tripartite unit cell. Theoretical analysis shows that the absorption arises from a magnetic resonance induced by the near-field coupling of the three resonators within the unit cell. A classical analog of EIA opens up opportunities for designing novel photonic devices for narrow-band filtering, absorptive switching, optical modulation, and absorber applications. PMID:26023061

  7. Refrigerator-freezer energy testing with alternative refrigerants

    Science.gov (United States)

    Vineyard, E. A.; Sand, J. R.; Miller, W. A.

    1989-07-01

    As a result of the Montreal Protocol that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must be resolved. Among these are energy impacts, system compatibility, cost, and availability. In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers. The results are presented for an 18 cubic foot (0.51 cubic meter), top-mount refrigerator-freezer with a static condenser using the following refrigerants: R12, R500, R12/Dimethyl-ether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12 /DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants indicating a higher capacity. While the R134a and R22/R142b results were less promising, changes to the refrigeration system, such as a different capillary tube or compressor, may improve performance.

  8. Refrigeration Showcases

    Science.gov (United States)

    1997-01-01

    Through the Technology Affiliates Program at the Jet Propulsion Laboratory (JPL), valuable modifications were made to refrigerator displays built by Displaymor Manufacturing Company, Inc. By working with JPL, Displaymor could address stiffer requirements that ensure the freshness of foods. The application of the space technology meant that the small business would be able to continue to market its cases without incurring expenses that could threaten the viability of the business, and the future of several dozen jobs. Research and development improvements in air flow distribution and refrigeration coil technology contributed greatly to certifying Displaymor's showcases given the new federal regulations. These modifications resulted in a refrigerator case that will keep foods cooler, longer. Such changes maintained the openness of the display, critical to customer visibility and accessibility, impulse buying, and cross-merchandising.

  9. OPTIMISATION D’UN SYSTEME DE REFRIGERATION SOLAIRE A ABSORPTION A USAGE DOMESTIQUE

    OpenAIRE

    CHERIFI, Karima

    2015-01-01

    a réfrigération solaire permet d’économiser une quantité appréciable de la consommation d’énergie primaire, Cela réduit la production de dioxyde de carbone et les pics de consommation d’électricité en été, ce qui est un avantage important pour l’environnement et l’économie nationale. Une présentation détaillée de la réfrigération solaire et des différentes technologies ont été utilisées dans ce domaine. Nous avons donné aussi une comparaison détaillée dans laquelle nous avons résumé les tr...

  10. Steam Driven Triple Effect Absorption Solar Cooling System

    OpenAIRE

    Yabase, Hajime; Makita, Kazuyuki

    2012-01-01

    The authors propose a solar cooling system employing a steam-driven triple effect absorption chiller as a new technique for saving CO2 emission in the air conditioning field. The absorption chiller is a cooling machine using thermal energy as a drive source, and it is ideal for utilizing solar heat. In addition, by employing a triple effect absorption chiller of high efficiency, a high energy saving effect and a significant CO2 saving effect can be expected. As a result of studies, it has bee...

  11. Quantum Stirling heat engine and refrigerator with single and coupled spin systems

    Science.gov (United States)

    Huang, Xiao-Li; Niu, Xin-Ya; Xiu, Xiao-Ming; Yi, Xue-Xi

    2014-02-01

    We study the reversible quantum Stirling cycle with a single spin or two coupled spins as the working substance. With the single spin as the working substance, we find that under certain conditions the reversed cycle of a heat engine is NOT a refrigerator, this feature holds true for a Stirling heat engine with an ion trapped in a shallow potential as its working substance. The efficiency of quantum Stirling heat engine can be higher than the efficiency of the Carnot engine, but the performance coefficient of the quantum Stirling refrigerator is always lower than its classical counterpart. With two coupled spins as the working substance, we find that a heat engine can turn to a refrigerator due to the increasing of the coupling constant, this can be explained by the properties of the isothermal line in the magnetic field-entropy plane.

  12. Internal heat exchange in an ejector-compression solar refrigeration system with R142b

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Joge I; Estrada, Claudio A; Best, Roberto [Centro de Investigacion en Energia, UNAM, Temixco, Morelos (Mexico); Dorantes Ruben, J [Departamento de Energia, UNAM Azcapotzalco, Mexico, D.F. (Mexico)

    2000-07-01

    One way to use more efficiently the actual energy transfer in the ejector-compression system, is the use of heat exchangers between some of the components. The inclusion of two heat exchangers, preheater and precooler, is considered in a basic ejector-compression refrigeration system with refrigerant 142b. This study accounts for the energy and exergy efficiencies. COP and {epsilon}, according to parameter variations such as ejector efficiency, generation temperature with different superheating, condensation temperature and heat exchangers effectiveness. As known, the most important parameters in ejector-compression system analysis are the entrain-ment ratio U and system efficiencies COP and {epsilon}. The highest system COP and {epsilon}, as the entrainment ratio U, correspond to the highest exchangers effectiveness, highest superheating generator temperatures, highest ejector efficiency and lowest condenser temperature. For the COP and {epsilon} ratios, their maxima correspond to the same independent variables aforementioned for one of the higher superheating generator temperatures. In this case, this result indicates that the exergy efficiency {epsilon} does not contradict the information given by energy efficiency COP. So, to select correctly and optimum design condition, is enough to employ the COP ratio, which maximum value for the data shown corresponds to a superheating generator temperature of about 110 Celsius degrees, that can only be reached by evacuated tubular collectors or CPC solar concentrators. [Spanish] Una forma de usar mas eficientemente la transferencia real de energia en el sistema eyector-compresion es el uso de intercambiadores de calor entre algunos de los componentes. La inclusion de dos intercambiadores de calor precalentador y pre-enfriador se considera en un sistema de refrigeracion eyector-compresion con refrigerante 142b. Este estudio toma en cuenta las eficiencias de energia y exergia, COP y {epsilon}, de acuerdo con las variaciones

  13. 高低温试验箱制冷系统最佳制冷剂充注量研究%Research on Best Refrigerant Charges in Refrigeration System of High and Low Temperature Test Chamber

    Institute of Scientific and Technical Information of China (English)

    李佳; 张华

    2015-01-01

    高低温试验箱适用于工业产品高、低温的可靠性试验.本文以一高低温试验箱为对象,在完成制冷系统设计,包括制冷剂选择、制冷系统部件选型等工作的基础上,对高低温试验箱进行制冷剂充注量实验,得到试验箱在最佳运行状态下的最佳充注量.%High and low temperature test chamber is suitable for the reliability test at high and low temperatures for industrial products. The research object is a high and low temperature test chamber. After completing the design of the refrigeration system, including the choose of refrigerant and the selection of the system components, the refrigerant charge experiments were processed and the optimal refrigerant charge for the chamber at the best operation state was obtained.

  14. Numerical modelling and analysis of a room temperature magnetic refrigeration system

    DEFF Research Database (Denmark)

    Petersen, Thomas Frank

    transient and steady-state phenomena. The AMR performance can be evaluated in terms of the no-load temperature span as well as the refrigeration capacity and the COP. The AMR model was verified extensively and it was concluded that the model has energy conservation and that the solution is independent....... The AMR performs a cyclic process, and to simulate the AMR refrigeration cycle the model starts from an initial temperature distribution in the regenerator and fluid channel and takes time steps forward in time until the cyclical steady-state is obtained. The model can therefore be used to study both...

  15. Simple uniaxial pressure device for ac-susceptibility measurements suitable for closed cycle refrigerator system.

    Science.gov (United States)

    Arumugam, S; Manivannan, N; Murugeswari, A

    2007-06-01

    A simple design of the uniaxial pressure device for the measurement of ac-susceptibility at low temperatures using closed cycle refrigerator system is presented for the first time. This device consists of disc micrometer, spring holder attachment, uniaxial pressure cell, and the ac-susceptibility coil wound on stycast bobbin. It can work under pressure till 0.5 GPa and at the temperature range of 30-300 K. The performance of the system at ambient pressure is tested and calibrated with standard paramagnetic salts [Gd(2)O(3), Er(2)O(3), and Fe(NH(4)SO(4))(2)6H(2)O], Fe(3)O(4), Gd metal, Dy metal, superconductor (YBa(2)Cu(3)O(7)), manganite (La(1.85)Ba(0.15)MnO(3)), and spin glass material (Pr(0.8)Sr(0.2)MnO(3)). The performance of the uniaxial pressure device is demonstrated by investigating the uniaxial pressure dependence of La(1.85)Ba(0.15)MnO(3) single crystal with P||c axis. The Curie temperature (T(c)) decreases as a function of pressure with P||c axis (dT(c)dP(||c axis)=-11.65 KGPa) up to 46 MPa. The design is simple, is user friendly, and does not require pressure calibration. Measurement can even be made on thin and small size oriented crystals. The failure of the coil is remote under uniaxial pressure. The present setup can be used as a multipurpose uniaxial pressure device for the measurement of Hall effect and thermoelectric power with a small modification in the pressure cell. PMID:17614625

  16. Experimental evaluation of desuperheating and oil cooling process through liquid injection in two-staged ammonia refrigeration systems with screw compressors

    International Nuclear Information System (INIS)

    This paper examines the problem of achieving desuperheating through liquid injection in two-staged refrigeration systems based on screw compressors. The oil cooling process by refrigerant injection is also included. The basic thermodynamic principles of desuperheating and compressor cooling as well as short comparison with traditional method with a thermosyphon system have also been presented. Finally, the collected data referring to a big refrigeration plant are analyzed in the paper. Specific ammonia system concept applied in this refrigeration plant has demonstrated its advantages and disadvantages. - Highlights: ► An experiment was setup during a frozen food factory refrigeration system reconstruction and adaptation. ► Desuperheating and low-stage compressors oil cooling process were investigated. ► Efficiency of compression process and high-stage compressors functioning were examined. ► Evaporation temperature reduction has great influence on the need for injected liquid refrigerant. ► Several cases in which desuperheating and oil cooling process application are justified were determined.

  17. Refrigeration Servicing.

    Science.gov (United States)

    Hamilton, Donald L.; And Others

    This self-study course is designed to familiarize Marine enlisted personnel with the services required to be performed on refrigeration equipment. The course contains four study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work…

  18. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures

    Science.gov (United States)

    Ellis, P. F., II; Ferguson, A. F.

    1995-04-01

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPM's) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  19. Application of exergetic sustainable index to the quantum irreversible Diesel refrigerator cycles for 1D box system

    Science.gov (United States)

    Açıkkalp, Emin; Caner, Necmettin

    2015-04-01

    In this paper, an irreversible quantum Diesel refrigerator for a 1D-box system is described and analyzed. The exergetic sustainability index that is the rate of the exergy output from the system to the total exergetic losses including exergy destruction and exergy loss from the system is applied for the first time to an irreversible quantum engine. Other thermodynamic parameters including work input, cooling load, exergy destruction, COP and exergy efficiency are investigated according to the cycle temperatures and numerical results are presented.

  20. Energy analysis of a solar advanced refrigeration system; Analisis energetico de un sistema de refrigeracion solar avanzado

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Limon, Nicolas [Universidad Autonoma de Baja California (Mexico); Best y Brown, Roberto [Universidad Nacional Autonoma de Mexico, Temixco, Morelos (Mexico)

    2000-07-01

    In this article is presented a solar refrigeration system that integrates the more recent and important technological advances of the training solar systems (SCS) and of the advanced absorption units. An analysis and evaluation is made of the energy behavior of the absorption system with heat exchanger absorber-generator (GAX), air cooled and assisted by a hybrid power plant natural gas-solar. Given the characteristic of high not-linearity of the resulting system of occupations, the proposed methodology contemplates a calculation sequence for the external currents and an iterative procedure for the internal currents. The unit was designed with a capacity of 10.6 kw (3 tons.) of cooling and uses ammonia-water as working fluid. Giving priority to internal energy integration, an arrangement of the GAX cycle is proposed, that allows 19% of solar contribution at full load, being able to be greater at partial loads. In spite of using as cooling means air at 40 Celsius degrees with a relative humidity of 24%, a COP of 0.86 in the cooling mode was obtained and 1.86 in the heating mode, with an internal energy integration of 1013 kJ/min, 37% more of the energy that is supplied in the generator. The massic flow rates of the GAX cycle were compared with those of a basic cycle, resulting 73% and 62% lower for the circulation rate and for the flow rate, respectively. [Spanish] En este articulo se presenta un sistema de refrigeracion solar que integra los avances tecnologicos mas recientes e importantes de los sistemas de capacitacion solar (SCS) y de las unidades de absorcion avanzadas. Se realiza un analisis y evaluacion del comportamiento energetico del sistema de absorcion con intercambio de calor absorbedor-generador (GAX), enfriado por aire y asistido por una fuente de energia hibrida gas natural-solar. Dada la caracteristica de alta no-linealidad del sistema de ocupaciones resultante, la metodologia propuesta contempla una secuencia de calculo para las corrientes externas

  1. Effect of heat transfer on the performance of thermoelectric generator-driven thermoelectric refrigerator system

    Science.gov (United States)

    Chen, Lingen; Meng, Fankai; Sun, Fengrui

    2012-01-01

    A model of thermoelectric generator-driven thermoelectric refrigerator with external heat transfer is proposed. The performance of the combined thermoelectric refrigerator device obeying Newton's heat transfer law is analyzed using the combination of finite time thermodynamics and non-equilibrium thermodynamics. Two analytical formulae for cooling load vs. working electrical current, and the coefficient of performance (COP) vs. working electrical current, are derived. For a fixed total heat transfer surface area of four heat exchangers, the allocations of the heat transfer surface area among the four heat exchangers are optimized for maximizing the cooling load and the coefficient of performance (COP) of the combined thermoelectric refrigerator device. For a fixed total number of thermoelectric elements, the ratio of number of thermoelectric elements of the generator to the total number of thermoelectric elements is also optimized for maximizing both the cooling load and the COP of the combined thermoelectric refrigerator device. The influences of thermoelectric element allocation and heat transfer area allocation are analyzed by detailed numerical examples. Optimum working electrical current for maximum cooling load and COP at different total number of thermoelectric elements and different total heat transfer area are obtained, respectively.

  2. A diagnostic methodology for refrigerating systems; Methodologie de diagnostic des installations frigorifiques

    Energy Technology Data Exchange (ETDEWEB)

    Vrinat, G. [Association Francaise du Froid (AFF), 75 - Paris (France)

    1997-12-31

    A diagnostic methodology for refrigerating machines, equipment and plants has been defined and evaluated for EDF, the French national power utility and ADEME, the French Agency for Energy Conservation, in the framework of energy conservation objectives: the diagnostic method should enable to identify malfunctions, assess the cost efficiency of the equipment, identify limiting factors, and consider corrective measures

  3. The Modification of the Valves of a Refrigeration Piston Compressor due to the Refrigerant Change

    OpenAIRE

    Li Liansheng; Zhao Yuanyang; Guo Bei; Shu Pengcheng

    2003-01-01

    Compressor and refrigerant play key roles in a refrigeration system. Owing to the de-mands of environment protection, the CFCs and HCFCs refrigerants will be phased out in a short time, and new refrigerants such as R600, R134a and R407C will be used. As the new refrigerant is selected, the motion regularity of the valves will be changed. The motion regularity of the ring valves of a 2-stage refrigerating piston compressor is simulated, and the calculations are done respectively with refrigera...

  4. Electromagnetically induced absorption in a three-resonator metasurface system

    OpenAIRE

    Zhang, Xueqian; Xu, Ningning; Qu, Kenan; Tian, Zhen; Singh, Ranjan; Han, Jiaguang; Agarwal, Girish S.; Zhang, Weili

    2015-01-01

    Mimicking the quantum phenomena in metamaterials through coupled classical resonators has attracted enormous interest. Metamaterial analogs of electromagnetically induced transparency (EIT) enable promising applications in telecommunications, light storage, slow light and sensing. Although the EIT effect has been studied extensively in coupled metamaterial systems, excitation of electromagnetically induced absorption (EIA) through near-field coupling in these systems has only been sparsely ex...

  5. Gas absorption in an agitated gas-liquid-liquid system

    NARCIS (Netherlands)

    Cents, A.H.G.; Brilman, D.W.F.; Versteeg, G.F.

    2001-01-01

    Gas-liquid-liquid systems have gained interest in the past decade and are encountered in several important industrial applications. In these systems an immiscible liquid phase may affect the gas absorption rate significantly. This phenomenon, however, is not completely understood and underlying mech

  6. Kinematic Interpretation of the Centaurus A Absorption-Line System

    NARCIS (Netherlands)

    Eckart, A.; Wild, W.; Ageorges, N.

    1999-01-01

    The location of the gas responsible for the absorption-line system toward the nucleus of Centaurus A is a puzzle. It is generally accepted that the line features close to the systemic velocity originate in the disk. The redshifted line features in particular, however, are usually thought to be due t

  7. The Modification of the Valves of a Refrigeration Piston Compressor due to the Refrigerant Change

    Directory of Open Access Journals (Sweden)

    Li Liansheng

    2003-03-01

    Full Text Available Compressor and refrigerant play key roles in a refrigeration system. Owing to the de-mands of environment protection, the CFCs and HCFCs refrigerants will be phased out in a short time, and new refrigerants such as R600, R134a and R407C will be used. As the new refrigerant is selected, the motion regularity of the valves will be changed. The motion regularity of the ring valves of a 2-stage refrigerating piston compressor is simulated, and the calculations are done respectively with refrigerants R717 (ammonia, R22 and R134a. The results show that refrigerants and working conditions of a compressor have a direct effect on the motion of the ring valves. Comparing the original design parameters of the ring valves with the modified ones, the former are effective for the HCFC refrigerants, the latter have perfect motion of the valves for the new refrigerants, and the refrigeration system performance parameters, such as input power, the refrigerating quantity and the COP value, are also better. Service life test of the compressor system using the ring valves has been done for R717. The compressor using the modified ring valves has a life exceeding 8000 hours. Hence, the valve design should consider the influences of the refrigerant.

  8. Keeping Cool With Solar-Powered Refrigeration

    Science.gov (United States)

    2003-01-01

    In the midst of developing battery-free, solar-powered refrigeration and air conditioning systems for habitats in space, David Bergeron, the team leader for NASA's Advanced Refrigerator Technology Team at Johnson Space Center, acknowledged the need for a comparable solar refrigerator that could operate in conjunction with the simple lighting systems already in place on Earth. Bergeron, a 20-year veteran in the aerospace industry, founded the company Solus Refrigeration, Inc., in 1999 to take the patented advanced refrigeration technology he co-developed with his teammate, Johnson engineer Michael Ewert, to commercial markets. Now known as SunDanzer Refrigeration, Inc., Bergeron's company is producing battery-free, photovoltaic (PV) refrigeration systems under license to NASA, and selling them globally.

  9. Energy Efficient Commercial Refrigeration with Carbon Dioxide Refrigerant and Scroll Expanders

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, John [TIAX LLC, Lexington, MA (United States)

    2013-04-04

    Current supermarket refrigeration systems are built around conventional fluorocarbon refrigerants – HFC-134a and the HFC blends R-507 and R404A, which replaced the CFC refrigerants, R-12 and R-502, respectively, used prior to the Montreal Protocol phase out of ozone depleting substances. While the HFC refrigerants are non-ozone depleting, they are strong greenhouse gases, so there has been continued interest in replacing them, particularly in applications with above average refrigerant leakage. Large supermarket refrigeration systems have proven to be particularly difficult to maintain in a leak-tight condition. Refrigerant charge losses of 15% of total charge per year are the norm, making the global warming impact of refrigerant emissions comparable to that associated with the energy consumption of these systems.

  10. 46 CFR 58.20-15 - Installation of refrigerating machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Installation of refrigerating machinery. 58.20-15... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of refrigerating machinery. (a) Where refrigerating machines are installed in which anhydrous ammonia is used as...

  11. Fluorescent refrigeration

    Science.gov (United States)

    Epstein, Richard I.; Edwards, Bradley C.; Buchwald, Melvin I.; Gosnell, Timothy R.

    1995-01-01

    Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement.

  12. 自动复叠式制冷系统中制冷剂的组分分离研究%Automatic Cascade Refrigeration System of Refrigerant Components Separation Research

    Institute of Scientific and Technical Information of China (English)

    郑大宇; 陈秋燕

    2015-01-01

    With a single agent for refrigerant single-stage vapor compression refrigeration system was limited due to condensing pressure and compression ratio determined by the environment temperature, normally only applied in the temperature range of more than 200 k.And use a single refrigerant will be limited due to low evaporation pressure on the poles of the cycle, or refrigerant solidification.Multiple nonazeotropic mixed working medium automatic cascade can achieve in temperature range of 100 k, but as a result of working medium, the separation of gas and liquid two is not completely, make the system energy efficiency is low, the capacity is small, so that its application has great limitations.So study the phase change law of refrigeration technology and refrigeration equipment, improve the sepa-ration effect of the system, has important theory value and application significance.%以单一工质为制冷剂的单级蒸汽压缩制冷系统因受外界环境温度所决定的冷凝压力及压缩比的制约,一般只能应用于200K以上的温区。而采用单一制冷剂的两极循环将受到蒸发压力过低,或制冷剂凝固的限制。多元非共沸混合工质自动复叠可达到-100K以下的温区,但由于工质气液两相分离不完全,使系统能效较低,制冷量小,从而使其应用有较大局限。因此研究该制冷工艺的相变规律,制冷装置,提高该系统的分离效果,具有重要的理论价值和应用意义。

  13. Investigation into the Possible Benefits of a Refrigeration Based Intercooling System

    OpenAIRE

    Kierans, Ronan; McGovern, Jim

    2010-01-01

    This paper describes findings from analysis and simulation in relation to the possible benefits of applying refrigeration based intercooling to the engine of a modern passenger car or haulage vehicle. Initial theoretical analysis showed that, depending on the engine specifications and the boost pressure level of the turbo/supercharger, the power improvement could range from 15–30% and there would be a similar improvement in torque. This meant a smaller engine could be used to do the work of a...

  14. Definition of a reference dataset for life cycle consideration of refrigeration systems

    OpenAIRE

    Mas Méndez, Roger

    2013-01-01

    In recent decades society has increased its concern about environmental protection, in order to achieve the goal of sustainable development. However, there are several economic sectors like refrigeration industry, which still are cause for a wide number of environmental impacts and, therefore, require improvement in their processes. The purpose of this final work is to establish the current state of the art regarding Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), particularized to ...

  15. Noise Source Identification of Small Fan-BLDC Motor System for Refrigerators

    OpenAIRE

    Chang-Joon Kim; Bo-Suk Yang; Yong-Han Kim

    2006-01-01

    Noise levels in household appliances are increasingly attracting attention from manufacturers and customers. Legislation is becoming more severe on acceptable noise levels and low noise is a major marketing point for many products. The latest trend in the refrigerator manufacturing industry is to use brushless DC (BLDC) motors instead of induction motors in order to reduce energy consumption and noise radiation. However, cogging torque from BLDC motor is an undesirable effect that prevent...

  16. Theoretical study of ejector refrigeration system with working fluid R410a

    OpenAIRE

    Sandeep Kashyap; Gupta, R. C.

    2011-01-01

    In this paper, simulation program is developed on based of one dimensional mathematical modal to analysis the performance ejector refrigeration cycle with working fluid R410a and also compared with performance of R134a. A performance comparison is made on various operating condition and ejector geometry. The result shows that performance of R134a is better than R410a for area ratio 5.64 and 7.84.

  17. Theoretical study of ejector refrigeration system with working fluid R410a

    Directory of Open Access Journals (Sweden)

    Sandeep Kashyap

    2011-08-01

    Full Text Available In this paper, simulation program is developed on based of one dimensional mathematical modal to analysis the performance ejector refrigeration cycle with working fluid R410a and also compared with performance of R134a. A performance comparison is made on various operating condition and ejector geometry. The result shows that performance of R134a is better than R410a for area ratio 5.64 and 7.84.

  18. Waste heat usage in commercial refrigeration systems - Energy analysis of two retail outlets; Abwaermenutzung in der gewerblichen Kaelte. Energetische Analyse von zwei Verkaufsstellen - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Erb, M.; Gutzwiller, S.

    2009-09-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of an analysis made on the use of waste heat produced by the refrigeration systems in two retail stores. The results of field measurements made in two installations in Migros and Coop supermarkets are presented. The efficiencies of heat recovery determined for the refrigeration systems are presented and discussed. The electro-thermal amplification factors (ETV) of the systems determined for the two installations are discussed. Basically, the authors are of the opinion that the ETV noted are very good. In both installations, heat recovery is energetically and ecologically very efficient. The factors leading to a high ETV are discussed and recommendations for the planning of such heat-recovery systems are made. An appendix includes schematics of the refrigeration systems in the two stores.

  19. Active Absorption Wave Maker System for Irregular Waves

    Institute of Scientific and Technical Information of China (English)

    柳淑学; 王先涛; 李木国; 郭美谊

    2003-01-01

    The key problem in physical model tests with highly reflective structures is to prevent the multiple reflections between the reflective structures and the wave maker. An active absorption wave maker system is described and the representative frequency method for irregular waves is proposed in this paper. Physical model tests are conducted to verify the effectiveness of the proposed method.

  20. Experimental study on an innovative multifunction heat pipe type heat recovery two-stage sorption refrigeration system

    International Nuclear Information System (INIS)

    An innovative multifunction heat pipe type sorption refrigeration system is designed, in which a two-stage sorption thermodynamic cycle based on two heat recovery processes was employed to reduce the driving heat source temperature, and the composite sorbent of CaCl2 and activated carbon was used to improve the mass and heat transfer performances. For this test unit, the heating, cooling and heat recovery processes between two reactive beds are performed by multifunction heat pipes. The aim of this paper is to investigate the cycled characteristics of two-stage sorption refrigeration system with heat recovery processes. The two sub-cycles of a two-stage cycle have different sorption platforms though the adsorption and desorption temperatures are equivalent. The experimental results showed that the pressure evolutions of two beds are nearly equivalent during the first stage, and desorption pressure during the second stage is large higher than that in the first stage while the desorption temperatures are same during the two operation stages. In comparison with conventional two-stage cycle, the two-stage cycle with heat recovery processes can reduce the heating load for desorber and cooling load for adsorber, the coefficient of performance (COP) has been improved more than 23% when both cycles have the same regeneration temperature of 103 deg. C and the cooling water temperature of 30 deg. C. The advanced two-stage cycle provides an effective method for application of sorption refrigeration technology under the condition of low-grade temperature heat source or utilization of renewable energy