Experimental investigation of R290/R600a mixture as an alternative to R134a in a domestic refrigerator

Department of Mechanical Engineering, National Institute of Technology Calicut, Calicut 673601, India
International Journal of Thermal Sciences (Impact Factor: 2.56). 05/2009; 48(5):1036-1042. DOI: 10.1016/j.ijthermalsci.2008.08.001

ABSTRACT R134a is the most widely used refrigerant in domestic refrigerators. It must be phased out soon according to Kyoto protocol due to its high global warming potential (GWP) of 1300. In the present work, an experimental investigation has been made with hydrocarbon refrigerant mixture (composed of R290 and R600a in the ratio of 45.2:54.8 by weight) as an alternative to R134a in a 200 l single evaporator domestic refrigerator. Continuous running tests were performed under different ambient temperatures (24, 28, 32, 38 and 43 °C), while cycling running (ON/OFF) tests were carried out only at 32 °C ambient temperature. The results showed that the hydrocarbon mixture has lower values of energy consumption; pull down time and ON time ratio by about 11.1%, 11.6% and 13.2%, respectively, with 3.25–3.6% higher coefficient of performance (COP). The discharge temperature of hydrocarbon mixture was found to be 8.5 to 13.4 K lower than that of R134a. The overall performance has proved that the above hydrocarbon refrigerant mixture could be the best long term alternative to phase out R134a.

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Available from: M. Mohanraj, Feb 04, 2015
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    • "Thermodynamic properties of R134a are good but the global warming potential (GWP) is 1430 which is quite high considering the human health and environmental norms. Keeping in view the GWP of R134a, it is an urgent need to find the alternative refrigerants [1] [2]. As per latest European norms, the refrigerants which are having GWP more than 150 cannot be used in the automobile air conditioning systems [3]. "
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    • "Since the latent heat of hydrocarbons is much higher than that of R134a, the amount of refrigerant charge can be reduced. An experimental investigation was conducted by Mohanraj et al. [12] using a hydrocarbon mixture consisting of propane and isobutane with a ratio of 45.2:54.8 by weight as a replacement for R134a in a domestic refrigerator. The results showed that this hydrocarbon mixture leads to a reduction in the compressor energy consumption, pull down time, 1 and ON time ratio 2 by 11.1%, 11.6% and 13.2%, respectively. "
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    ABSTRACT: This paper is devoted to feasibility study of substitution of two hydrocarbon refrigerants instead of R134a in a domestic refrigerator. Experiments are designed on a refrigerator manufactured for 105 g R134a charge. The effect of parameters including refrigerant type, refrigerant charge and compressor type are investigated. This research is conducted using R436A (mixture of 46% iso-butane and 54% propane) and R600a (pure iso-butane) as hydrocarbon refrigerants, HFC type compressor (designed for R134a) and HC type compressor (designed for R600a). The results show that for HFC type compressor, the optimum refrigerant charges are 60 g and 55 g for R436A and R600a, respectively. Moreover, for this type of compressor, the energy consumption of R436A and R600a at the optimum charges is reduced about 14% and 7%, respectively in comparison to R134a. On the other hand, when using HC type compressor, the optimum refrigerant charges for R436A and R600a are both 50 g, and the energy consumption of R436A and R600a at the optimum charges are reduced about 14.6% and 18.7%, respectively. Furthermore, when the refrigerator is equipped with HC type compressor, working under optimum charges of R436A and R600a have a total equivalent warming impact about 16% and 21% lower than base refrigerator, respectively. Total exergy destruction of the domestic refrigerator with HFC type compressor for R134a, R600a and R436A are 0.0389, 0.0301, 0.0471, respectively and for R600a and R436A with HC type compressor are 0.0292, 0.0472, respectively.
    International Journal of Thermal Sciences 12/2013; 74:86-94. DOI:10.1016/j.ijthermalsci.2013.07.009
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    • "In further work, the same ternary HC refrigerant mixture was tested experimentally in a 280 liter domestic refrigerator (Fatouh and Kafafy, 2006b). In another work, Mohanraj et al. (2009b) tested with binary HC mixture composed of R290 and 600a (in ratio of 45.2:54.8, by mass) as substitute to R134a in a domestic refrigerator working with an inner volume of 200 l at wide range of ambient temperatures between 24 and 43 °C. Similarly, Jwo et al. (2009) compared the performance of a 400 liter refrigerator working with R134a and binary HC refrigerant mixture composed of R290 and R600a (in the ratio of 50:50, by mass) and reported with 4.4% lower energy consumption compared to R134a. "
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    ABSTRACT: In this work, the energy performance of a domestic refrigerator has been assessed theoretically with R134a and R430A as alternative refrigerant. The performance has been assessed for three different condensing temperatures, specifically, 40, 50 and 60 °C with a wide range of evaporator temperatures between − 30 and 0 °C. The performance of the domestic refrigerator was compared in terms of volumetric cooling capacity, coefficient of performance, compressor power consumption and compressor discharge temperature. Total equivalent global warming impact of the refrigerator was assessed for a 15-year life time. The results showed that volumetric cooling capacities of R430A and R134a are similar, so that R134a compressor can be used for R430A without modifications. The coefficient of performance of R430A was found to be higher than that of R134a by about 2.6–7.5% with 1–9% lower compressor power consumption at all operating temperatures. The compressor discharge temperature of R430A was observed to be 3–10 °C higher than that of R134a. Total equivalent global warming impact of R430A was found to be lower than that of R134a by about 7% due to its higher energy efficiency. The results confirmed that R430A is an energy efficient and environment-friendly alternative to R134a in domestic refrigerators.
    Energy for Sustainable Development 10/2013; 17(5):471–476. DOI:10.1016/j.esd.2013.05.005
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