Papers by Dr. Suneel Kumar Kalla
Journal of Thermal Engineering, 2017
The aim of this paper is to evaluate the performance of refrigerants R22, R407C, R432A, R438A and... more The aim of this paper is to evaluate the performance of refrigerants R22, R407C, R432A, R438A and NM1 (R32/R125/R600a) in order to find a suitable alternative refrigerant for HCFC 22. For this purpose energy as well as exergy analysis has been performed using NIST CycleD program for vapour compression refrigeration cycle design and TEWI (total equivalent warming impact) has also been computed for these refrigerants. From the analysis it is found that the values of COP were nearer to those of R-22, e.g. at 25, 45 and 55 °C condensing temperature, COP of R432a is lower than that of R22 by about 5.5%, 4% and 4.38% respectively. The results show that by considering the energetic efficiency, exergetic efficiency, TEWI and flammability simultaneously, R438A proves to be a better option to replace R22.
Journal of Thermal Engineering, 2018
The aim of this paper is to determine the best available alternative which could replace existing... more The aim of this paper is to determine the best available alternative which could replace existing refrigerant R22, with minimum or no changes in the air conditioning system. For this purpose, both the theoretical as well as experimental studies done in this area of research have been reviewed. The most popular HFC, R410A is having lower critical temperature, which restricts its usage in compression based systems working at higher condensing temperatures whereas for R407C, a change to synthetic lubricant is required and HC-290 is flammable. It is suggested that until the safety issue of use of hydrocarbon refrigerants in quantities exceeding 500gm is resolved, we should go for those mixtures of HFCs and HCs for which TEWI index is the lowest.
International Journal of Engineering Research and, 2015
In this study, the energy performance of R438A and M1 (R32/R125/R600A) mixture has been assessed ... more In this study, the energy performance of R438A and M1 (R32/R125/R600A) mixture has been assessed theoretically in a residential air conditioner. The performance has been assessed for five different condensing temperatures, i.e. 35, 40, 45, 50 and 55 °C with an evaporator temperature of-10 °C. The volumetric cooling capacity, coefficient of performance, compressor power consumption and compressor discharge temperature were used as the parameters for comparing the performance of the residential air conditioner. Total equivalent warming impact of the air conditioner was assessed for a 15year life time. The results indicated that volumetric cooling capacities of M1 and R22 are similar, so that R22 compressor can be used for M1 without modifications, but R438A has slightly lower volumetric cooling capacity. The coefficient of performance of R438A was found to be higher than that of M1 by at least 17 % with 26 % lower compressor power consumption at all condenser temperatures. The compressor discharge temperature of R438A was observed to be at least 10°C lower than that of M1. Total equivalent warming impact of R438Awas found to be lower than that of M1 by about 13% due to its higher energy efficiency. The results showed that R438A is a more energy efficient and environment-friendly alternative to R22 than M1 in residential air conditioners.
Uploads
Papers by Dr. Suneel Kumar Kalla