Improvement of compressor efficiency using the alternative refrigerant is demanded strongly to reduce CO2 emission, which causes the global warming. Especially the compressor using in frozen temperature level has long lifetime, and the correspondence to above-mentioned is one of the most important subjects. The scroll compressor is the promising structure to solve this problem. A technical poin...

New lubricant which can dissolve with ammonia refrigerant was developed. PAG based oil was found to be dissolved with ammonia and to have fine stability. It contributes to realize maintenancefree refrigerating system because oil returning are possible. It also helps to reduce refrigerant amount because of improvement of thermal conductivity. Ammonia refrigerant will be focused more as an altern...

Air-cooled cross flow heat exchangers are very popular in the refrigeration and air conditioning industry. The fin type, tube arrangement, flow circuitry, and many geometry parameters, are to be designed and optimized. In this paper, a generic simulation and optimization tool for the design of air-cooled condensers/evaporators is introduced. It is featured with a user-friendly interface, freedo...

Title of Document: INVESTIGATION OF REFRIGERANT DISTRIBUTION IN A HOUSEHOLD REFRIGERATOR WITH A FOCUS ON THE ROLE OF THE ACCUMULATOR Cara Sanderson Martin, M.S. Mechanical Engineering, 2007 Directed By: Professor Reinhard Radermacher, Ph.D. Department of Mechanical Engineering In order to maximize household refrigerator performance, it is important to understand the basic relationship between e...

For the environmentally aware, natural refrigerant such as CO2 is recommended and pursued by researchers for refrigerators. In this paper, a transcritical CO2 heat pump system was set up to investigate the influence of refrigerant charge on the performance of a small-sized heat pump water heater. The transcritical CO2 heat pump system was composed of a rotary compressor, a tube-in-tube evaporat...

During the process of refrigerant alternative, R290 (propane), as a nature refrigerant used in Room Air Condition (RAC) system, is thought as a long-team substance and has attracted great attention. This paper simply introduced the characteristics and standard demands of R290 application, then, based on a 1HP R290 DC INV. RAC system at first, then finished the comparison test when a one-cylinde...

Modern lifestyle, industrialization and economy thrive on energy which is getting expensive overtime. Thermosyphon based systems are getting attraction for their promising heat transfer efficiency and zero energy utilization. Refrigerants having ozone depletion potential (ODP) and high Global Warming Potential (GWP) have been banned or under time bared permission under Montreal (1987) and Kyoto...

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...

We have developed a new CO2 heat pump water heater compressor with a single rotary mechanism in practical use for the first time in the world. CO2 refrigerant doesn't destroy the ozone layer, and the global warming potential (GWP) is less than 1/1000 in comparison to hydro-fluorocarbon refrigerants. However the operating pressure of CO2 refrigerant is approximately three times as high as that o...