Investigation and Experimental Evaluation of Vapor Compression Refrigeration System by Means of Alternative Refrigerants
22 Mar 2019-pp 10-26
TL;DR: In this paper, a theoretical investigation is considered to discover possible alternatives on behalf of R134a, R12 and R22 for traditional vapor compression refrigeration system for the same two azeotrope blends, R404A and R407C are nominated.
Abstract: A theoretical investigation is considered to discover possible alternatives on behalf of R134a, R12 and R22 for traditional vapor compression refrigeration system. For the same two azeotrope blends, R404A and R407C are nominated. The theoretical analysis is conceded for the refrigerating system at a continual condensation temperature of 50 ℃ and −10 ℃ to 10 ℃ evaporating temperature. Results to investigate alternative refrigerant have slightly lower performance coefficient than HFC134a, CFC22 and CFC12 respectively. Further, it is noticed the average performance coefficient of alternative refrigerants is 7.26% for R404A and 1.41% for R407C enhanced for the degree of superheating and sub cooling. The experimental setup is developed for R404A and R407C to observed different parameters such as pull down time for evaporator temperature, discharge pressure, power consumption, performance coefficient and energy efficiency ratio and compared with R134a. Smaller pull down time, lesser power consumption and isentropic work done improves the performance coefficient of the system, similar or maybe higher behavior like R134a proved that the nominated refrigerants used as an alternative to R12 and R22.
Citations
More filters
01 Oct 2007
TL;DR: In this paper, the ternary non-azeotropic mixture of R-32/R-125/ R-161 and R-407C was proposed as an alternative refrigerant to R-481C.
Abstract: This paper presents the new ternary non-azeotropic mixture of R-32/R-125/R-161 as an alternative refrigerant to R-407C. The physical properties of the ternary mixture are similar to those of R-407C, and it is environmental friendly, that is, it has zero ozone-depletion potentials (ODP) and lower global warming potentials (GWP) than R-407C. Theoretical cycle performances of R-32/R-125/R-161 and R-407C are calculated and analyzed firstly. Based on the theoretical study, experimental tests are performed on a vapour-compression refrigeration system with a rotor compressor which was originally designed for R-407C (without any modifications to system components for R-407C). Experimental results under different working conditions indicate that the pressure ratio and power consumption of the new refrigerant are lower than those of R-407C, and its refrigerating capacity and COP are superior to those of R-407C, respectively, and its discharge temperature is slightly higher than that of R407C. Therefore, the new refrigerant R-32/R-125/R-161 could be considered as a promising refrigerant to R-407C. [Reprinted with permission from Elsevier. Copyright, 2007].
4 citations
References
More filters
TL;DR: In this article, a theoretical performance study on a traditional vapour-compression refrigeration system with refrigerant mixtures based on HFC134a, HFC152a, HC32, HC290, HC1270, HC600, and HC600a was done for various ratios and their results are compared with CFC12, CFC22, and HFC 134a as possible alternative replacements.
160 citations
TL;DR: In this paper, the ternary non-azeotropic mixture of R32/R125/R161 and R407C was proposed as an alternative refrigerant to R407c.
80 citations
TL;DR: In this paper, the authors explored the thermodynamic performance limits of the vapor compression cycle and developed Pareto fronts for the objective functions COP and volumetric capacity to evaluate the performance of refrigerants.
Abstract: This paper explores the thermodynamic performance limits of the vapor compression cycle. We have applied evolutionary algorithms to explore the performance of hypothetical refrigerants defined by the thermodynamic parameters used by the extended corresponding states model for fluid properties. We identified optimal values of these parameters required to reach the performance limits. The study confirmed the fundamental trade-off between the coefficient of performance (COP) and volumetric capacity, and indicated refrigerant critical temperature as the dominant parameter influencing the tradeoff. Thermodynamic performance limits depend on the operating conditions and the cycle design. These limits are represented by Pareto fronts developed for the objective functions COP and volumetric capacity. As expected, the performance of current refrigerants falls below the Pareto front limits. We demonstrate that for practical cycles the developed methodology and resulting Pareto fronts are more realistic benchmarks for the performance potentials of refrigerants than is COP alone, which is an efficiency only metric.
67 citations
TL;DR: In this article, the two-phase heat transfer coefficient characteristics of R404A condensing under forced flow conditions inside smooth, microfin and cross-hatched horizontal tubes are experimentally investigated.
Abstract: Two-phase heat transfer coefficient characteristics of R404A condensing under forced flow conditions inside smooth, microfin and cross-hatched horizontal tubes are experimentally investigated. Experimental parameters include a lubricating polyol ester oil concentration varied from 0 to 4%. The test runs were done at average inlet saturated condensing temperatures of 40 °C. The inlet vapor was kept at saturation (quality=1.0). The mass fluxes were between 200 and 600 kg/m 2 s, and the heat fluxes were selected to obtain a quality of 0.0 at the outlet of the test section, varying from 5 to 45 kW/m 2 . The heat transfer enhancement factor varied between 1.8 and 2.4 for both microfin and cross-hatched tubes. The larger values applied for larger mass fluxes for the cross-hatched tube and smaller mass fluxes for the microfin tube. Enhancement factors increased as oil concentration increased up to oil concentrations of 2%. For higher oil concentrations the enhancement decreased especially at high mass fluxes, the cross-hatched tube being less sensitive to oil contamination. Pressure drop in the test section increased by approximately 25% as the oil concentration increased from 0 to 4%. The results from the experiments are compared with those calculated from correlations reported in the literature. Moreover, modified correlations for the condensation heat transfer coefficient are proposed for practical applications.
33 citations
TL;DR: In this paper, a window air conditioner of 3.5 kW capacity was fitted with Electronic Expansion Valve (EEV) instead of capillary tube as an expansion device, w as tested for its performance with the selected eco friendly refrigerants R407C and R290 as an alterna tive to R22 under fixed indoor and outdoor chamber temperatures in the experimental set up and varying the EEV opening.
Abstract: Problem statement: There are two types of global warming contribution s through refrigeration and air conditioning systems. The fir st one is the Direct Global Warming Potential (DGWP) due to the emission of refrigerants and thei r interaction with heat radiation. The second one i s the Indirect Global Warming Potential (IDGWP) due to the emission of Carbon Dioxide (CO 2) by consuming the energy that is generated through the combustion of fossil fuels. Most of refrigerants us ed in vapor Compression system were Chlorofluorocarbon (CFCs) and Hydro Chlorofluorocarbon (HCFCs) which contains chlorine and if any leakage in the s ystem, these gases will go up and reach stratospher e. The chlorine atoms in the gases will act as a catalyst to destroy ozone layer and cause ozone depletion which causes health hazards, global warming, melting of p olar ice caps and drought. Hence, it is necessary t o minimize the Global warming and Ozone depletion. The refrigerant R22 widely used in the air- conditioners is a major Contributor of Chlorofluoro carbons (CFCs) which cause irreparable loss to the ozone layer and has to be replaced. Approach: To conserve the energy and minimize the global warming, the systems should be designed as more energy efficient and also to minimize Ozone depletion, the eco friendly refrigerants are to be selected and tested as alternative refrigerants to R22. Hence, a window air conditioner of 3.5 kW capacity fitted with Electronic Expansion Valve (EEV)) instead of capillary tube as an expansion device, w as tested for its performance with the selected eco friendly refrigerants R407C and R290 as an alterna tive to R22 under fixed indoor and outdoor chamber temperatures in the experimental set up and varying the EEV opening. Results: It has been observed from the experimental studies that when the smaller capacity R22 window air conditioner with EEV is retrofitted with R407C and R290, compared to the performance given by R22, the Coefficient Of Performance (COP) given by R407C and R290 is improved in the range of 4.8-7.1 and 8.0-12.3% respectively and the Energy Efficiency Ratio (EER) is increased by 4.2-6.9% for R407C and 6.4-10.8% for R290. Conclusion: The performance of Electronic Expansion Valve (EEV) with eco friendly refrigerant R290 in the given air conditioner shows a positive effect in terms of COP and energy efficiency and enables the industry to favorably di splace the R22 and other types of expansion devices .
12 citations