Screw compressor and control method therefor

Abstract

A screw compressor (), comprising a screw rotor () and a spool valve (). The screw rotor () comprises a suction head end () and an exhaust tail end (). Gas is sucked in from the suction head end () and compressed gas is discharged from the exhaust tail end (). The spool valve () comprises a working side () for sealing a compression chamber of the screw rotor (). The working side () comprises a spool valve head end () and a spool valve tail end () and can do a reciprocating motion along the axis direction of the screw rotor (). When the spool valve () moves to a suction capacity adjusting position (), the spool valve head end () is located at the inner side of the suction head end () of the screw rotor (), and a suction capacity adjusting distance (D) is formed between the spool valve head end () and the suction head end () so that the suction capacity of the screw compressor is adjusted. The suction capacity of the screw compressor () can be adjusted by means of the spool valve (), so that the problem of motor temperature and exhaust gas temperature limits of conventional variable frequency screw sets is effectively solved and the operational range and the load regulation ability of the screw compressor are expanded.