Patent attributes
A motor coolant method and system is used to cool a compressor motor (36) in a refrigeration system having a multi-stage compressor (38). The compressor includes a first compressor stage (42) and a second compressor stage (44), the first compressor stage providing compressed refrigerant to an input of the second compressor stage. The motor coolant system has a first connection with the refrigerant loop to receive refrigerant into the motor cavity for cooling, the received refrigerant provided from a system component having a high pressure, and a second connection with the refrigerant loop to return refrigerant to an intermediate pressure greater than an evaporator operating pressure. The pressure inside the motor cavity may be approximately the pressure within the first stage discharge and second stage suction to minimized seal leakage between the motor cavity and the internal pressures of the first and second stage compressors.
