Theoretical Development of Thermodynamic Properties of Environmental Friendly Refrigerant RE170 by Using Martin Hou Equation of State

This paper deals with the theoretical development of thermodynamic properties of an environmental friendly refrigerant dimethylether (RE170). Since hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are going to be phase out and phase down as per Montreal and Kyoto protocol respectively. Refrigerant RE170 has zero ozone depletion potential (ODP) and very low global warming potential (GWP) which is less than two. Hence RE170 is considered as a viable option to replace for the refrigerants with high global warming potential (GWP) like HCFCs and HFCs. RE170 can be used as blend component with other ecofriendly refrigerant. The main objective of the present study is to compute the thermodynamic properties of RE170 by using Martin Hou equation of state. Thermodynamic properties are useful to do the thermodynamic analysis of vapour compression refrigeration cycle. The properties computed are saturation vapour pressure, liquid density, specific volume, enthalpy and entropy (both in the saturated liquid and vapour state). In the present study a MATLAB code is developed to compute the above considered thermodynamic properties from the temperature about 133K-363K and pressure up to 27.2 bar. The computed properties of dimethylether is compared with NIST REFPROP database. Since thermodynamic properties of RE170 is not available in ASHRAE hand book and also in literature. Therefore NIST REFRPROP can be considered as reliable source as that of ASHRAE. The results shows that deviation of liquid and vapour phase enthalpy from that of NIST is -0.058 to 2.55%. Similarly deviation of liquid and vapour phase entropy from that of NIST is -0.037 to 1.88%. Deviation of specific volume and liquid density from that NIST is 0.10 to -2.54% and -0.42 to 0.008% respectively. Variation of saturation pressure is less than -0.65%. Overall the computed thermodynamic properties of RE170 by using Martin-Hou equation of state shows good agreement with NIST for the temperature range (133K-363K) and pressure up to 27.2 bar

Thermodynamic Analysis of Vapour Compression Refrigeration System with Sustainable Refrigerant Blends as Alternatives to Replace R22

The phase out schedule of a hydrochlorofluorocarbon refrigerant R22 demands the development of ecofriendly refrigerants. Since R22 has adverse ecological effects like high ODP and high GWP. Hence the present paper emphasis on the thermodynamic analysis of vapour compression refrigeration system with various ozone friendly refrigerant blends as an alternatives to R22. In this work eight refrigerant mixtures composed of R290, R134a, R152a, R125 and R32 at various compositions are developed. All the developed refrigerants possess zero ODP and low GWP compared to R22. The main objective of the present work is to compute the thermodynamic performance parameters of R22 and its alternatives based on actual vapour compression refrigeration cycle. The performance parameters of all the eight investigated refrigerants are computed at evaporating and condensing temperature of 7.2oC and 54.4oC respectively by using a MATLAB code. The results showed that COP of a refrigerant mixture RM40 (3.541) is higher among eight studied refrigerants and it is 0.2 % higher than the COP of R22 (3.534). GWP of RM40 (10) is lowest among the R22 and eight studied refrigerants. The compressor discharge temperature of RM40 is lower among the eight studied refrigerants and it is reduced by 6.6oC when compared to R22. Power spent per ton of refrigeration of RM40 (0.992 kW/TR) is lower among the eight studied blends and it is marginally lower than that of R22 (0.994 kW/TR). Volumetric refrigeration of capacity of RM40 (2837 kJ/m3) is higher among the eight investigated refrigerant blends and it is closer to that of volumetric capacity of R22 (3086 kJ/m3). Overall the thermodynamic performance of new binary blend RM40 (R290/R152a 95/5 by mass %) is very close to R22 and hence it is a sustainable alternative refrigerant to replace R22

Performance computation of window air conditioner with very low GWP near azeotropic refrigerant mixtures as a drop in Substitutes to R22

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

Analytical computation of thermodynamic performance parameters of actual vapour compression refrigeration system with R22, R32, R134a, R152a, R290 and R1270

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

Performance computation of window air conditioner with very low GWP near azeotropic refrigerant mixtures as a drop in Substitutes to R22

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

Analytical computation of thermodynamic performance parameters of actual vapour compression refrigeration system with R22, R32, R134a, R152a, R290 and R1270

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

sj-docx-1-pie-10.1177_09544089221134447 - Supplemental material for Experimental study on effectiveness in segmental baffled shell tube and heat exchanger using Al₂O₃ nanofluid at variable concentrations

Supplemental material, sj-docx-1-pie-10.1177_09544089221134447 for Experimental study on effectiveness in segmental baffled shell tube and heat exchanger using Al2O3 nanofluid at variable concentrations by Syed Sameer, SB Prakash, Sharmas Vali Shaik and Narayana Swamy G in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p

Thermal Analysis of Building Roofs with Latent Heat Storage for Reduction in Energy Consumption and CO2 Emissions: An Experimental and Numerical Research

In green energy buildings, air conditioning charges can be lowered through careful planning of the building’s envelope. This article investigates several strategically designed phase change material (PCM) roof envelopes for savings on air conditioning prices, CO2 emission abatement, and payback timeframes in hot–arid and warm-temperate climates, taking into account unsteady heat transfer characteristics, cooling, and heating degree–hours. This is accomplished by using six different PCMs–RCC (reinforced cement concrete) roof envelope cases (RCC roof with PCM layer on the outer side, RCC roof with PCM layer on the center (middle), RCC roof with PCM layer on the inside, RCC roof with PCM layers placed on the outside and center, RCC roof with PCM layers placed on the center and inside, and RCC roof with PCM layers placed on the outer side and inside) with three PCMs (FS29 (form stable mixture), HS29 (hydrated salt), and OM29 (organic mixture)). PCM thermophysical characteristics are experimentally measured. The analytical results are experimentally validated. In hot–arid and warm-temperate regions, the layer of PCM installed on the outside of the RCC with HS29 saved the most on air conditioning expenses, at 6.29 and 6.61 $/m2, respectively. They also reported the greatest carbon mitigation of 300.55 kg of CO2/year and 281.58 kg of CO2/year with the faster payback periods. PCM roof envelopes are the most energy-efficient option for green buildings

Thermal Analysis of Building Roofs with Latent Heat Storage for Reduction in Energy Consumption and CO2 Emissions: An Experimental and Numerical Research

In green energy buildings, air conditioning charges can be lowered through careful planning of the building’s envelope. This article investigates several strategically designed phase change material (PCM) roof envelopes for savings on air conditioning prices, CO2 emission abatement, and payback timeframes in hot–arid and warm-temperate climates, taking into account unsteady heat transfer characteristics, cooling, and heating degree–hours. This is accomplished by using six different PCMs–RCC (reinforced cement concrete) roof envelope cases (RCC roof with PCM layer on the outer side, RCC roof with PCM layer on the center (middle), RCC roof with PCM layer on the inside, RCC roof with PCM layers placed on the outside and center, RCC roof with PCM layers placed on the center and inside, and RCC roof with PCM layers placed on the outer side and inside) with three PCMs (FS29 (form stable mixture), HS29 (hydrated salt), and OM29 (organic mixture)). PCM thermophysical characteristics are experimentally measured. The analytical results are experimentally validated. In hot–arid and warm-temperate regions, the layer of PCM installed on the outside of the RCC with HS29 saved the most on air conditioning expenses, at 6.29 and 6.61 $/m2, respectively. They also reported the greatest carbon mitigation of 300.55 kg of CO2/year and 281.58 kg of CO2/year with the faster payback periods. PCM roof envelopes are the most energy-efficient option for green buildings