Conference Papers
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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 Theoretical Evaluation of Energy Performance of a Vapour Compression Refrigeration System Using Sustainable Refrigerants(Springer, 2020) Vali, S.V.; Ashok Babu, T.P.The chief goal of this present investigation is to evaluate performance parameters of various sustainable refrigerants as R22 alternatives. In this investigation apart from R290, R134a and R22, twelve mixture refrigerants were developed at various composition. Results showed that energy efficiency ratio (EER) of mixture refrigerant MR40 (R290/R134a 95/5 in mass%) (4.546) stood greatest among twelve investigated alternatives and it was closer to the EER of R22 (4.602). Compressor discharge temperature of MR40 was lower than R22 by 16.020C. Volumetric refrigeration capacity of MR40 (3424 kJ/m3) was relatively lesser than R22 (3801 kJ/m3). Power spent per ton of refrigeration (PPTR) of MR40 (0.773 kW/TR) stood lowest among twelve investigated alternatives and it was fairly greater than R22 (0.764 kW/TR). Global warming potential (GWP100) of MR40 (68) was very low compared to R22 (1760). Overall, performance of MR40 was closer to R22, when compared with all the twelve investigated alternatives, and hence, it might be treated as a suitable replacement to refrigerant R22. © 2020, Springer Nature Singapore Pte Ltd.Item Analytical computation of thermodynamic performance of various new eco-friendly alternative refrigerants applicable for air conditioners(Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2021) Vali, S.V.; Ashok Babu, T.P.; Mahapatra, D.; Saboor, S.; Gorantla, K.K.; Sai Siva Subramanyam, V.The objective of the present investigation is to do the theoretical thermodynamic analysis of various new eco-friendly R22 substitutes used in vapour compression refrigeration (VCR) cycle. In this work, nine mixture refrigerants were considered at different compositions. Thermodynamic properties of all the considered refrigerants were developed and the same properties were used in the performance analysis of alternative refrigerants. Standard VCR cycle was considered for the thermodynamic assessment of alternative refrigerants. The working conditions considered are expressed as Te = 7.2 °C, Tk = 54.4 °C, ΔTsup = 11.1 °C and ΔTsub = 8.3 °C, respectively. Results revealed that the COP of mixture refrigerant MR20 (R600a/R134a/R1270 5/47.5/47.5 in mass%) was 2.02% higher than the COP of R22 and other nine investigated refrigerants. Discharge temperature of compressor obtained for MR20 was 11.79 °C lower compared to that of R22. Compressor power obtained for MR20 was 1.96% lower than that of R22. Volumetric refrigeration capacity obtained for MR20 was relatively closer to that of R22. GWP100 of MR20 (619) was lower compared to the GWP100 of R22 (1760). Overall, the performance of mixture refrigerant MR20 was better compared to all the considered R22 alternatives, and therefore it might be an appropriate candidate to replace R22 used in air conditioners. © Springer Nature Singapore Pte Ltd 2021.