Patent ID: 11946674
Assignee: CARRIER CORPORATION
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  H | IPC F  H

Claim 2:
3. A cooling method for a drive motor of an air conditioning system for use in the air conditioning system including:
a main circuit having a multi-stage compressor, a condenser, a throttling element and an evaporator connected by pipelines;
a cooling branch, the inlet of which is connected to the main circuit between the condenser and the throttling element, and the outlet of which is connected to at least one of the first-stage suction port and the intermediate-stage suction port of the multi-stage compressor, wherein the cooling branch flows through the drive motor of the multi-stage compressor, and a regulating valve for controlling the cooling branch is provided on the cooling branch; and
a control module that controls the opening of the regulating valve on the cooling branch based on the temperature of the outlet downstream of the drive motor on the cooling branch and the intermediate suction pressure of the intermediate-stage suction port of the multi-stage compressor;
the method comprising:
detecting the temperature of the outlet downstream of the drive motor on the cooling branch and the intermediate suction pressure of the intermediate-stage suction port of the multi-stage compressor;
when the difference between the temperature of the outlet and the saturation temperature corresponding to the intermediate suction pressure is greater than the preset superheat temperature, increasing the opening of the regulating valve; or, when the difference between the temperature of the outlet and the saturation temperature corresponding to the intermediate suction pressure is smaller than the preset superheat temperature, decreasing the opening of the regulating valve.