PERFORMANCE ANALYSIS OF POSITIVE DISPLACEMENT REFRIGERATING COMPRESSORS

The strong need for improved performance compressors stimulated sufficient interest to look into the basic philosophy of compressor performance evaluation. The present study is a result of an effort in this direction. The three most important objectives of this research are: (1) To develop a generalized performance criterion for the compressor, that can be used as a basis for evaluating various new and existing design concepts analytically; (2) to use the approach thus developed to analyze three existing compressor design concepts; and (3) to give a comparative performance evaluation of the three existing design concepts. The three designs chosen for the study are rotary vane, rolling piston, and reciprocating compressors. A generalized approach to analyze compressor performance based on energy and mass flow loss relationships is developed. A new concept of efficiency of performance ((eta)(,p)) is developed that takes into consideration every factor that can affect the performance of a compressor substantially. Various energy and mass flow loss mechanisms are identified and simplified expressions for the losses inherent to all compressor designs are developed. The three compressor types chosen for the study are analyzed in detail. Formulas for the various losses are developed. The essential differences between the three design concepts are discussed and the potential advantages and disadvantages of one design over the other are highlighted