| 摘要 |
A multistage centrifugal compressor, comprising a casing having an inlet portion and a compression portion. The inlet portion has an inlet opening gaseously coupled to an evaporator so as to receive a gaseous refrigerant. The inlet and compression portions each have a plurality of gas passages therethrough. The compression portion has an outlet opening that is located at the end of the casing which is opposite the end of the casing having the inlet opening. An electric motor assembly is positioned within the inlet portion of the casing so as to provide a transfer of heat dissipated by the motor assembly to the gaseous refrigerant entering through the inlet opening. The gaseous refrigerant flowing in the inlet opening passes through and about the motor assembly so as to cool the motor assembly. The gaseous refrigerant is heated by the heat dissipated by the motor assembly so as to evaporate any liquid molecules within the gaseous refrigerant thereby permitting the evaporator to operate at a zero superheat level. A shaft is disposed within and is coaxial with the axis of the casing. The shaft is rotatably engaged with the motor assembly. A first rotor is disposed within the compression portion and attached to the shaft so as to provide a first centrifugal compression stage. The first compression stage is gaseously coupled to the gas passages of the inlet portion. A second rotor is disposed within the compression portion and attached to the shaft so as to provide a second centrifugal compression stage. The second centrifugal compression stage is gaseously coupled to first centrifugal compression stage. The second centrifugal stage is intermediate the first compression stage and the outlet opening. The second centrifugal compression stage being gaseously coupled to said outlet opening. |
