Air-to-refrigerant heat exchangers are a key component in all air-conditioning, heat pump and refrigeration systems. The most common of types of air-to-refrigerant heat exchangers are tube-fin and microchannel heat exchangers. There has always been a great emphasis on understating the underlying physics and improving the performance of these heat exchangers. More recently, researchers have been...

Tests were run with both R-12 and R-l34a in a water calorimeter. Refrigerant 12 was run with mineral oil as the lubricant. Evaporating and condensing heat transfer coefficients were calculated over a range of temperatures. To evaluate the impact of the lubricant on the heat transfer coefficients, a oil separator was added. Tests were then run with the oil separator over the same temperature ran...

Vapor compression systems continuously leak a small fraction of their refrigerant charge to the environment, whether during operation or servicing. As a result of the slow leak rate occurring during operation, the refrigerant charge decreases until the system is serviced and recharged. This charge degradation, after a certain limit, begins to have a detrimental effect on system capacity, energy...

In this paper analytical study has been made to investigate a hybrid refrigerant consists of different refrigerants with mixing ratios and find out its effects on the performance cycle specify best that gives least environmental pollution. Firstly vapor compression refrigeration system analyzed several pure refrigerants( R11, R12, R13,R22,R23, R32, R41, R115, R116, R124, R125, R134a, R142a, R14...

Refrigerant mass flow rate is an important measurement for monitoring equipment performance and enabling fault detection and diagnostics. However, a traditional mass flow meter is expensive to purchase and install. A virtual refrigerant mass flow sensor (VRMF) uses a mathematical model to estimate flow rate using low-cost measurements and can potentially be implemented at low cost. This study e...

This paper presents the results of the analysis of an ejector refrigeration system operating with Freons as the working substance. Such a system is suitable for operating at subzero evaporator temperatures. The mass of motive refrigerant vaoour per hour per ton and the coefficient of performance are calculated for various assumed operating parameters such as boiler temperature, evaporator temoe...