Performance analysis of a two stage vapor compression refrigeration cycle offering two cold temperatures

2014 ◽  
Author(s):  
Mbarek Wafa Halfaoui ◽  
Khir Tahar ◽  
Ben Brahim Ammar
Keyword(s):  
Performance Analysis ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Two Stage ◽  
Cold Temperatures ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

Optimum Refrigerating Efficiency and Exergy Index of a Two-Stage Refrigeration Cycle

Volume 1 ◽  
2004 ◽  
Author(s):  
J. S. Tiedeman ◽  
S. A. Sherif
Keyword(s):  
Performance Optimization ◽  
Geometric Mean ◽  
Maximum Error ◽  
Second Law ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Two Stage ◽  
Optimization Study ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

This paper presents results of an optimization study for a two-stage vapor compression refrigeration cycle based on the refrigerating efficiency and exergy index. Traditional two-stage refrigeration cycle studies have focused on the first law performance, while those studies dealing with the second law have primarily been limited to performance analysis as opposed to performance optimization. Results of this study indicate that the use of the common approximation of the geometric mean to find the optimum interstage pressure leads to nearly optimum results for the refrigerating efficiency, with maximum error in the neighborhood of 5%. However, the error associated with using this approximation to find the optimum exergy index is too large, approaching 15%. Second law optimization revealed that the optimum data curves themselves have maxima for each set of conditions tested. There are a series of conditions that lead to the conclusion that, for a given system, there is an optimum set of conditions that lead to the lowest amount of exergy destruction for that system. Polynomial equations have been fitted to the resultant optimum data for the refrigerating efficiency and exergy index. These equations allow for the reproduction of optimum points based on high- and low-pressure compressor efficiencies and condenser and evaporator pressures.

scholarly journals Parametric analysis of a combined ejector-vapor compression refrigeration cycle

2020 ◽  
Vol 15 (3) ◽  
pp. 398-408
Author(s):  
I Ouelhazi ◽  
Y Ezzaalouni ◽  
L Kairouani
Keyword(s):  
Current Model ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Constant Area ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

Abstract From the last few years, the use of efficient ejector in refrigeration systems has been paid a lot of attention. In this article a description of a refrigeration system that combines a basic vapor compression refrigeration cycle with an ejector cooling cycle is presented. A one-dimensional mathematical model is developed using the flow governing thermodynamic equations based on a constant area ejector flow model. The model includes effects of friction at the constant-area mixing chamber. The current model is based on the NIST-REFPROP database for refrigerant property calculations. The model has basically been used to determine the effect of the ejector geometry and operating conditions on the performance of the whole refrigeration system. The results show that the proposed model predicts ejector performance, entrainment ratio and the coefficient of performance of the system and their sensitivity to evaporating and generating temperature of the cascade refrigeration cycle. The simulated performance has been then compared with the available experimental data from the literature for validation.

Molecular-level computer simulation of a vapor-compression refrigeration cycle

2007 ◽  
Vol 259 (2) ◽  
pp. 195-200 ◽  
Author(s):  
S. Figueroa-Gerstenmaier ◽  
M. Francova ◽  
M. Kowalski ◽  
M. Lisal ◽  
I. Nezbeda ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Molecular Level ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

scholarly journals THEORETICAL AND EXPERIMENTAL ANALYSIS OF A VAPOR-COMPRESSION REFRIGERATION CYCLE WITH A HEAT EXCHANGER BETWEEN THE SUCTION AND LIQUID LINES

2019 ◽  
Vol 18 (2) ◽  
pp. 19
Author(s):  
L. S. Santana ◽  
J. Castro ◽  
L. M. Pereira
Keyword(s):  
Heat Exchanger ◽  
Experimental Analysis ◽  
Thermodynamic Cycle ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration ◽  
Liquid Heat

Vapor-compression refrigeration systems require a significant amount of electrical energy. Therefore, there is a need for finding efficient ways of operating this equipment, reducing their energy consumption. The use of heat exchangers between the suction line and the liquid line can produce a better performance of the thermodynamic cycle, as well as reduce it. The present work aims at an experimental analysis of the suction/liquid heat exchanger present in a freezer running with refrigerant fluid R-134a. Three different scenarios were used in order to evaluate the thermal performance of the refrigeration cycle. The first scenario was the conventional freezer set up to collect the required data for further comparison. Moreover, the second and third scenarios were introduced with a 20 cm and 40 cm suction/liquid heat exchanger, respectively, into the system. From the experiments, it was observed that the heat exchange does not significantly affect the coefficient of performance (COP) of the freezer. It was concluded from this work that the best scenario analyzed was the 20 cm suction/liquid heat exchanger where most of the thermodynamic properties were improved, one of them being the isentropic efficiency.

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