Optimization Design of Actuator Parameters in Multistage Reciprocating Compressor Stepless Capacity Control System Based on NSGA-II

Table 1

Description of unloader and suction valve movement process.

Angle	Yes or no	Description
	New process
	No	Capacity regulation condition or normal condition, suction valve opening process
	No	Capacity regulation condition or normal condition, suction process
	No	Normal condition, suction valve closing process
	No	Reversal point of piston, i.e., crank angle is 180°
	Yes	Capacity regulation condition, suction valve is pressed off, backflow process
	No	When , suction valve closing process
	Yes	When , suction valve closing process
	No	To avoid the impact between unloader and valve plate, unloader is pressed off after suction valve opening process