Studied is a kind of NH3/CO2 two-stage low temperature refrigeration system, in which NH3 is used as the refrigerant in the high-temperature stage and CO2 is used as the refrigerant in the low-temperature stage. The performance of the system is simulated and analyzed by changing the mean temperature of the evaporator-condenser and the temperature of the condenser. The mean temperatures of the e...

Capacity and efficiency of any refrigerating system diminish rapidly as the difference between the evaporating and condensing temperature is increased by reduction in the evaporator temperature. The single stage vapour compression refrigeration system is limited to an evaporator temperature of -40 C. Below temperature of -40 C the either cascade refrigeration system or multi stage vapour compre...

Capacity and efficiency of any refrigerating system diminish rapidly as the difference between the evaporating and condensing temperature is increased by a reduction in the evaporator temperature. The single stage vapour compression refrigeration system using various refrigerants are limited to an evaporator temperature of -40 0C. Below temperature of -40 0C the either cascade refrigeration sys...

Refrigerator is one of the home appliance utilizing mechanical vapour compression cycle in it process. Performance of the system becomes main issue and many researches are still ongoing to evaluate and improve efficiency of the system. Therefore, this paper presents the development process of refrigerator test rig and performance analysis of a domestic refrigerator. The experiment platform whic...

This paper describes thermal modeling of Vapor Compression Refrigeration System using R134a in primary circuit and AL2O3-Water based nanofluids in secondary circuit. The model uses information of the secondary fluids input conditions geometric characteristics of the system, size of nanoparticles and the compressor speed to predict the secondary fluids output temperatures, the operating pressure...

This paper presents the analysis results of R429A, R430A, R431A and R435A as drop in substitute for R152a at various evaporating temperature with condenser temperature 30°C, 40°C and 50°C. A theoretical study of thermodynamic properties such as pressure, density, and specific volume, latent heat of vaporization compression index, and critical values are done. The theoretical performance of vapo...

The effect of the internal heat exchanger (IHE) on the performance of the transcritical carbon dioxide refrigeration cycle with an expander is analyzed theoretically on the basis of the first and second laws of thermodynamics. The possible parameters affecting system efficiency such as heat rejection pressure, gas cooler outlet temperature, evaporating temperature, expander isentropic efficienc...