Analysis of rod reversal in reciprocating compressor with capacity regulating system

In reciprocating compressors, partial unloading stepless capacity regulation causes the power consumption to reduce in proportion to the decrease in capacity. To enable the widespread application of this method, it is necessary to analyse the changes in the mechanical status of a reciprocating compressor while its capacity is being regulated. This study focused on the rod reversal in a reciprocating compressor and evaluated the influence of capacity regulation. Based on a thermodynamic cycle model, the reversal angles for different capacities were calculated and compared for an M-type reciprocating compressor. The calculated results show that, for a compressor for which the designed reversal angles are sufficiently large to ensure good lubrication for pin and bushing assemblies, stepless capacity regulation can guarantee its safe operation.