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Compression Refrigeration System (compression + refrigeration_system)
Selected AbstractsPerformance and exergetic analysis of vapor compression refrigeration system with an internal heat exchanger using a hydrocarbon, isobutane (R600a)INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2008Ahmet Kabul Abstract Hydrocarbons (HCs) are excellent refrigerants in many ways such as energy efficiency, critical point, solubility, transport and heat transfer properties, but they are also flammable, which causes the need for changes in standards, production and product. There are increasing number of scientists and engineers who believe that an alternative solution, which has been overlooked, may be provided by using HCs. The main objective of this study is to perform energy and exergy analyses for a vapor compression refrigeration system with an internal heat exchanger using a HC, isobutene (R600a). For a refrigeration capacity of 1 kW and cold chamber temperature of 0°C, energy and exergy balances are taken into account to determine the performance of the refrigeration system. Energy and exergy fluxes are determined, and irreversibility rates are calculated for every component of the system. It is seen that the compressor has the highest irreversibility rate, and the heat exchanger has the lowest. Also from the result of the analysis, it is found that condenser and evaporator temperatures have strong effects on energetic and exergetic performances of the system such as coefficient of performance (COP), efficiency ratio (,), exergetic efficiency (,) and irreversibility rate. Copyright © 2008 John Wiley & Sons, Ltd. [source] Photovoltaic-powered cold store and its performanceINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2001J. Nagaraju Abstract A photovoltaic-powered cold store plant, the first of its kind, has been developed to store 10 tons of frozen fish at ,15°C. It consists of a photovoltaic array (4 kW peak), a battery bank (96 V DC, 180 A H), a vapour compression refrigeration system (1 ton), electronic controls for automatic operation of plant and an insulated cold chamber. Experiments were conducted on the system to evaluate its performance with no heat load (frozen fish at ,15°C) and with different heat loads. It is observed that the system can be operated with a maximum heat load of 2350 W to maintain the walk-in-cooler temperature below the freezing point of fish (,2°C). The performance studies conducted on these subsystems viz., photovoltaic array and battery bank showed that their output has deteriorated in 5 years. Copyright © 2001 John Wiley & Sons, Ltd. [source] Simulation of compression refrigeration systemsCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 3 2006Jaime Sieres Abstract This study presents the main features of a software for simulating vapor compression refrigeration systems that are self designed by the user. A library of 10 different components is available: compressor, expansion device, condenser, evaporator, heat exchanger, flash tank, direct intercooler flash tank, indirect intercooler flash tank, mixer, and splitter. With these components and a library of different refrigerants many different refrigeration systems may be solved. By a user-friendly interface, the user can draw the system scheme by adding different components, connecting them and entering different input data. Results are presented in the form of tables and the cycle diagram of the system is drawn on the logP,h and T,s thermodynamic charts. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 188,197, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20075 [source] Thermodynamic analysis of subcooling and superheating effects of alternative refrigerants for vapour compression refrigeration cyclesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2006encan Abstract This paper presents a computer-based first law and exergy analysis applied to vapour compression refrigeration systems for determining subcooling and superheating effects of environmentally safe new refrigerants. Three refrigerants are considered: R134a, R407c and R410a. It is found that subcooling and superheating temperatures directly influence the system performance as both condenser and evaporator temperatures are affected. The thermodynamic properties of the refrigerants are formulated using artificial neural network (ANN) methodology. Six ANNs were trained to predict various properties of the three refrigerants. The training and validation of the ANNs were performed with good accuracy. The correlation coefficient obtained when unknown data were used to the networks were found to be equal or very near to 1 which is very satisfactory. Additionally, the present methodology proved to be much better than the linear multiple regression analysis. From the analysis of the results it is found that condenser and evaporator temperatures have strong effects on coefficient of performance (COP) and system irreversibility. Also both subcooling and superheating affect the system performance. This effect is similar for R134a and R407c, and different for R410a. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||