Hydrocarbons as Alternate Refrigerants to Replace R134a in Domestic Refrigerators Parashurama Siddegowda 1* , Govindegowda Mundur Sannappagowda 2 , Vaibhav Jain 3 , Satheesh Javare Gowda 4 1 Mechanical Engineering Department, JSSATE, Bengaluru 560 060, India 2 Principal, Vivekananda college of Engineering and Technology, Puttur 574203, D.K, India 3 Mechanical& Automation Engineering Department, MAIT, New Delhi 110086, India 4 Department of Mechanical Engineering, SJBIT, Bengaluru 560 060, India Corresponding Author Email: parashurams@rediffmail.com https://doi.org/10.18280/rcma.290204 ABSTRACT Received: 15 January 2019 Accepted: 26 March 2019 The thermodynamic properties of hydrocarbons namely Propane, Cyclopropane, Propene, Methyl acetylene, Propadiene and Dimethyether as alternatives to replace R134a have been predicted using SRK EOS. The values of vapour pressure, liquid specific volume, vapour specific volume, liquid enthalpy, vapour enthalpy, liquid entropy, vapour entropy have been estimated over the temperature range from -250 ℃ to +550 ℃. Simulation of 89W domestic refrigerator is carried out using ten state point vapour compression cycle. The theoretical performances of the hydrocarbons have been comparatively assessed using standard refrigeration parameters. According to our results, Propane, Propene are appropriate and recommended as alternatives of R134a with lower displacement compressor and Cyclopropane as direct substitute. Also implications with respect to material and lubricant oil compatibility, heat transfer characteristics are discussed. Keywords: COP, compressor work input, discharge temperature, displacement volume, volumetric efficiency 1. INTRODUCTION Refrigeration technology plays a significant role in safety and health of people especially the preservation of food and lifesaving drugs. Refrigeration technology is also applied to provide comfort through air conditioning systems and for industrial processes. Knowing the CFC hazard and regulations from Montreal and Kyoto protocols one has to consider Generation-3 refrigerants -HCs & Natural refrigerants. When applied to the Refrigerator sector CFC-12 is outdated and has been substituted by the intermediate refrigerant HFC-134a (Generation-2). However, by 2020 the Generation-2 refrigerants must also be phased out; in this context, prospects of Generation-3 refrigerants need to be analysed and the existing HFC-134a refrigerator inventories need to be retrofit or replaced. Many works have been done in order to develop alternative refrigerants to R12 in accordance with Montreal and Kyoto protocols. R152a [1-2] is an excellent alternative and compatible with mineral oils. Its pressure level discourages its use as a substitute of R12.Ammonia [3-4] is one of the refrigerants in the field of refrigeration especially for very low temperatures but it is toxic. Interaction coefficients for binary mixtures R12/R152a, R134a/R134 and R22/F152a have been calculated by J.R Sand et al. [5] Propane is [6] an attractive alternative regarding its COP, its compatibility with mineral oil, its low cost, availability and its negligible GWP. Concerning the research of new fluids, the majority of previous results [1, 7-12] show that R134a is the best possible substitute of R12.It has zero ODP but it is global warming gas, not miscible with mineral oil, its energy efficiency is slightly lower and poor heat transfer at low temperatures. Jung et al. [13] performed a computer simulation of domestic refrigerator charged with many pure and mixture as possible alternatives of R12 and studied experimentally R290/ R600a (60/40) and obtained 2.45 % increase in energy efficiency compared to R12. The predicted properties are not reliable as only NBP and structural details are used in the development of properties. Somchai Wongwises et al. [14] have determined the performance of vapour compression system with Propane, HC, HFC mixtures and recommended R290/R600a/R14a (40/30/30) as alternative from energy point of view. Tashtoush et al. [15] investigated experimentally ternary mixture of butane /propane/ R134a (43.91/33.31/22.78) and the obtained performance was higher than that of R12. Sekhar et al. [16] suggested R134a/R600a/R290 as a retrofit mixture for R12 systems and obtained 4.1-7.6 % energy savings compared to R12. Kuijipers et al. [17] have investigated experimentally HFC 152a, DME, HC270 and HC290/R600a (21/79) and concluded that the performance of R152a, R270 and R290/R600a (21/79) was found to be slightly higher than that of DME. Eric Granryd [18] analysed Hydrocarbons theoretically and concluded that Hydrocarbons are the better substitutes of R12. Saleh et al. [19] developed properties of candidate refrigerants as alternatives to R12 using Back one equation of state, did thermodynamic analysis and concluded that RE170, R152a and RC270 are promising refrigerants to replace R12. The problem in case of mixtures is that there is uncertainty of their thermodynamic and thermo physical properties and also in case of leakage it becomes very critical that the performance of the refrigeration system changes. Hydrocarbon refrigerants have zero ODP, negligible GWP and are compatible with commonly used mineral oil. The main drawback of these refrigerants is that they are highly flammable. Hydrocarbons, in comparison to R12 have high latent heat of vaporization and low value of density make these Revue des Composites et des Matériaux Avancés Vol. 29, No. 2, April, 2019, pp. 95-99 Journal homepage: http://iieta.org/journals/rcma 95