In this paper the results of both modeling and testing a representative 3-ton air-to-air heat pump running with the baseline refrigerant (HCFC-22) and zero ODP alternative refrigerants will be presented. Alternative refrigerant simulation runs are made with two pure fluids (HFC-134a and HFC-152a) and an azeotropicmixture (60/40wt%) ofHFC-32 and HFC125 (Allied-Signal Inc. U.S. Patent 4,978,467)....

This paper presents how the refrigerant dissolved in oil affects on Journal bearings reliability. The bearing model test is performed using the hermetic test apparatus. The oil film pressure is measured under several types of bearing grooves, L/D ratios and mixing ratios of refrigerant to oil. As a result, the means by which the refrigerant dissolved in oil causes damage to journal bearings is ...

Water-cooled chiller systems have typically been designed around entering condenser water temperatures of 85°F with a Optimization of Water Cooled Chiller – Cooling Tower Combinations The warm water leaving the chilled water coils is pumped to the evaporator of the chiller, where the unwanted heat from the building is transferred by the latent heat of vaporization of the refrigerant. The compre...

The working fluids most widely used for small and mid-sized air conditioning systems globally are R-410A and R22. While these fluids have many positive attributes for cooling and heating, they are the subject of valid criticisms regarding their high direct global warming potential (GWP) and, in the case of R-22, ozone depletion potential (ODP) also. In the interest of improved environmental sus...

f liquid g gas ABSTRACT The experimental apparatus was build according to the national standards of India.. The performance of the refrigeration system depends upon the heat transfer capacity of the refrigerant. Normally R12, R22, R600, R600a and 134a are used as a refrigerant. This refrigerant heat transfer capacity is not so good and increase power consumption. Due to these limitation nanoflu...

Refrigerant mass migration and redistribution are regarded as key factors affecting the cycling perfor­ mance of air conditioning and refrigeration systems. A dynamic model of an R134a automotive air conditioning system is presented as an example in this paper to capture the refrigerant migration during compressor shut-down and start-up operations. Model validation against experimental data dem...

Air conditioning refrigerant R134a has value of global warming potential (GWP) 1300, which is much higher than MAC Directive (GWP below 150) passed in July 2006. This prompted a search for alternative refrigerant with GWP value less than 150. R1234yf is a new refrigerant which has lower GWP value of 4. Effect of blower speed has been compared and flammability issue of R1234yf has been addre...

In order to improve the application possibility of CO 2 /R41 azeotropy mixture in refrigeration industry, optimum mass ratio composition is defined and determined according thermodynamic properties safety. On basis first second laws thermodynamics, a model proposed evaluate performance single-stage transcritical cycle (CO cycle) which throttling valve integrated refrigerant adopted. The at then...

Multi-evaporator vapor compression systems (ME-VCS) provide cooling to multiple zones. The thermodynamic conditions in these zones are independent: the heat loads often differ, and the occupants of these spaces often have different desired room temperatures. Therefore, in order to regulate each zone to its desired setpoint temperature, the amount of thermal energy removed by each evaporator mus...

Due to worldwide demand for energy saving, many new technologies have been developed in the air conditioning field. Packaged indoor unit and outdoor unit vapor compression refrigerating heat pump system using the change of refrigerant’s condition between liquid and gas is a recently developed air conditioning system. The cooling cycle is composed of an evaporator, a condenser, a compressor, an ...