Sa. Tassou et Tq. Qureshi, COMPARATIVE PERFORMANCE EVALUATION OF POSITIVE DISPLACEMENT COMPRESSORS IN VARIABLE-SPEED REFRIGERATION APPLICATIONS, International journal of refrigeration, 21(1), 1998, pp. 29-41
This paper presents the results of investigations into the performance
of positive-displacement refrigeration compressors for variable-speed
capacity control applications. Compressors tested include an open-typ
e reciprocating, a semi-hermetic reciprocating and an open-type rotary
vane. All three compressors were tested under constant and variable h
ead-pressure operating conditions. The results indicate that all three
compressors were designed for maximum efficiency at nominal speed. At
constant head-pressure only the open-type compressor exhibited an imp
rovement in the COP at reduced speeds. With variable head pressure-con
trol all three compressors showed an increase in the COP with a reduct
ion in speed. The results of an energy analysis carried out based on t
he experimental results and weather conditions for two locations repre
senting temperate and warm weather conditions showed that all three co
mpressors when operated at variable speed offer energy savings compare
d to their fixed-speed counterparts. The analysis has shown the open-t
ype reciprocating compressor to be the most efficient system offering
12% savings when operating in a temperate climate and 24% savings when
operating in a warm climate. (C) 1998 Elsevier Science Ltd and IIR. A
ll rights reserved.