Screw compressor, refrigeration system, and method for controlling refrigeration system

A screw compressor, comprising:

• a screw compressor housing;
• a discharge cavity, the discharge cavity being defined by at least one part of the screw compressor housing, the at least one part of the screw compressor housing defining the discharge cavity forming a wall of the discharge cavity, and a hole is provided in the wall of the discharge cavity;
• an adjustment box, the adjustment box being arranged on an outer side of the screw compressor housing and defining an adjustment cavity, and the adjustment cavity and the hole forming a continuous channel;
• an adjustment piston configured to be inserted into the continuous channel and move therein;
• and
• a silencing channel, the silencing channel being formed by the hole, the adjustment piston and the adjustment box, and the silencing channel being in fluid communication with the discharge cavity,
• wherein a position of the adjustment piston in the hole and the adjustment cavity determines a silencing length of the silencing channel.

A screw compressor, comprising:

• a screw compressor housing;
• a discharge cavity, the discharge cavity being defined by at least one part of the screw compressor housing, the at least one part of the screw compressor housing defining the discharge cavity forming a wall of the discharge cavity, and at least two holes being provided in the wall of the discharge cavity;
• at least two adjustment pistons each configured to be inserted into a respective hole of the at least two holes and to move therein;
• and
• at least two silencing channels, the at least two silencing channels being formed by the at least two holes and the at least two adjustment pistons, and the at least two silencing channels being in fluid communication with the discharge cavity,
• wherein a respective position of each of the at least two adjustment pistons in the at least two holes determines a silencing length of a respective silencing channel of the at least two silencing channels;
• and
• wherein the at least two adjustment pistons can do reciprocating movement relative to the screw compressor housing independently of each other, thereby changing the silencing length of each of the at least two silencing channels.

A screw compressor, comprising:

• a screw compressor housing;
• a discharge cavity, the discharge cavity being defined by at least one part of the screw compressor housing, the at least one part of the screw compressor housing defining the discharge cavity forming a wall of the discharge cavity, and at least one hole being provided in the wall of the discharge cavity;
• at least one adjustment piston configured to be inserted into the at least one hole and move therein;
• and
• at least one silencing channel, the at least one silencing channel being formed by the at least one hole and the at least one adjustment piston, and the at least one silencing channel being in fluid communication with the discharge cavity,
• wherein a position of the at least one adjustment piston in the at least one hole determines a silencing length of the at least one silencing channel;
• wherein the at least one hole is provided with an inlet end and a distal end opposite to the inlet end, and the at least one adjustment piston is configured to be inserted into the at least one hole from the distal end;
• and
• wherein the at least one adjustment piston is provided with a recess extending from an end surface of one end of the at least one adjustment piston to another end, and a distance between a bottom of the recess of the at least one adjustment piston and the inlet end is the silencing length.