Reciprocating CompressorsIn a recip

Reciprocating CompressorsIn a reciprocating compressor, as shown in Figure 9.8.1(a), a crankshaft connected to the motor shaftdrives 2, 3, 4, or 6 single-acting pistons moving reciprocally in the cylinders via a connecting rod.The refrigeration capacity of a reciprocating compressor is a fraction of a ton to about 200 tons.Refrigerants R-22 and R-134a are widely used in comfort and processing systems and sometimes R717 in industrial applications. The maximum compression ratio Rcom for a single-stage reciprocatingcompressor is about 7. Volumetric efficiency ηv drops from 0.92 to 0.65 when Rcom is raised from 1 to6. Capacity control of reciprocating compressor including: on-off and cylinder unloader in whichdischarge gas is in short cut and return to the suction chamber.Although reciprocating compressors are still widely used today in small and medium-sized refrigeration systems, they have little room for significant improvement and will be gradually replaced by scrolland screw compressors.