Conference Papers
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Item Analytical computation of gwp, odp, rf number and tewi analysis of various r134a/r1270/r290 blends as r22 alternatives(CRC Press/Balkema, 2018) Vali, S.S.; Ashok Babu, T.P.The principal objective of the present work is to compute the GWP, ODP, RF number and TEWI analysis of various ternary R134a/R1270/R290 blends as alternatives to R22. In this study thirteen refrigerant blends consists of R134a, R1270 and R290 at different compositions are taken. GWP and ODP of refrigerant blends are computed by using various simple correlations. The estimation of emission of greenhouse gases and flammability study of refrigerants are done by using TEWI and RF analysis respectively. Analytical results revealed that all the thirteen studied fluids are ozone friendly in nature. The GWP of refrigerant M6 (651) is lower than that of GWP of R22 (1760). RF analysis exhibited that all the thirteen refrigerant blends are categorized as ASHRAE A2 flammability category. Thermodynamic analysis revealed that COP of M6 (3.608) is higher that of COP of R22 (3.534). TEWI of M6 is lower among the R22 and thirteen studied fluids. Hence refrigerant M6 (R134a/R1270/R290 50/5/45 by mass%) is an alternative to R22. © 2018 Taylor & Francis Group, London.Item Analytical computation of thermodynamic performance parameters of actual vapour compression refrigeration system with R22, R32, R134a, R152a, R290 and R1270(EDP Sciences edps@edpsciences.com, 2018) Vali, S.S.; Setty, T.P.; Babu, A.The present work focuses on analytical computation of thermodynamic performance of actual vapour compression refrigeration system by using six pure refrigerants. The refrigerants are namely R22, R32, R134a, R152a, R290 and R1270 respectively. A MATLAB code is developed to compute the thermodynamic performance parameters of actual vapour compression system such as refrigeration effect, compressor work, COP, power per ton of refrigeration, compressor discharge temperature and volumetric refrigeration capacity at condensing and evaporating temperatures of 54.4oC and 7.2oC respectively. Analytical results exhibited that COP of both R32 and R134a are 15.95% and 11.71% higher among the six investigated refrigerants. However R32 and R134a cannot be replaced directly into R22 system. This is due to their higher compressor discharge temperature and poor volumetric capacity respectively. The discharge temperature of both R1270 and R290 are lower than R22 by 20-26oC. Volumetric refrigeration capacity of R1270 (3197 kJ/m3) is very close to that of volumetric capacity of R22 (3251 kJ/m3). Both R1270 and R290 shows good miscibility with R22 mineral oil. Overall R1270 would be a suitable ecofriendly refrigerant to replace R22 from the stand point of ODP, GWP, volumetric capacity, discharge temperature and miscibility with mineral oil although its COP is lower. © The Authors, published by EDP Sciences, 2018.Item Performance computation of window air conditioner with very low GWP near azeotropic refrigerant mixtures as a drop in Substitutes to R22(EDP Sciences edps@edpsciences.com, 2018) Vali, S.S.; Setty, T.P.; Babu, A.The principal objective of the present study is to compute the thermodynamic performance of window air conditioner based on standard vapour compression refrigeration cycle using R22, R407C and nineteen refrigerant mixtures. In this work nineteen R290/R1270 blends at different compositions are developed. A MATLAB code is developed to compute the thermodynamic performance parameters of all the studied refrigerants at condensing and evaporating temperatures of 54.4°C and 7.2°C respectively. The performance parameters are cooling effect, compressor work, COP, compressor discharge temperature, power per ton of refrigeration and volumetric cooling capacity respectively. Analytical results revealed that COP of new binary mixture R290/R1270 (90/10 by mass %) is 2.82% higher among R22, R407C and nineteen studied refrigerants. Energy required by the compressor per ton of refrigeration for R290/R1270 (90/10 by mass %) is 2.73% lower among R22, R407C and nineteen studied fluids. The discharge temperature of the compressor for all the nineteen investigated blends are reduced by 6.0-8.9oC compared to R22. Overall thermodynamic performance of window air conditioner with R290/R1270 (90/10 by mass %) is better than R22 with significant savings in energy consumption and hence it is an energy efficient ecofriendly refrigerant mixture as a drop in substitute to R22. © The Authors, published by EDP Sciences, 2018.Item Automotive air-conditioning system technology: A review(Inderscience Publishers editor@inderscience.com 29, route de Pre-Bois Case Postale 856, CH-1215 Geneva 15 CH-1215, 2020) Vali, S.S.; Saboor, S.; Prithivi Rajan, S.; Ashok Babu, T.P.A.Air conditioning in the automobile has become an important area of research. The performance of an air conditioning system in an automobile depends upon three basic important factors such as compressor speed, evaporator load, and condensing temperature. How these factors when varied affects the COP of the system have been detailed in this review paper. Several performance studies on various refrigerants (R134a, R152a, CO2 and R1234yf) used in the automotive air conditioning system operating with various conditions revealed the better COP for R152a in comparison with R134a, whereas COP of R1234yf and CO2 was observed to be slightly lower than R134a. However, safety measures must be followed while using R152a due to its slightly flammable nature (ASHRAE A2 group). In this work, various alternative air conditioning systems used for automobiles have been presented in detail. © © 2020 Inderscience Enterprises Ltd.