High capacity chiller compressor
A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. A cooling system provides direct, two-phase cooling of the rotor by combining gas refrigerant from the evaporator section with liquid refrigerant from the condenser section to affect a liquid/vapor refrigerant mixture. Cooling of the stator with liquid refrigerant may be provided by a similar technique. A noise suppression system is provided by injecting liquid refrigerant spray at points between the impeller and the condenser section. The liquid refrigerant may be sourced from high pressure liquid refrigerant from the condenser section.
1. A chiller system comprising: a compressor assembly including a motor and an aerodynamic section, said motor including a rotor assembly operatively coupled with a motor shaft and a stator assembly to produce rotation of said motor shaft, said motor shaft and said aerodynamic section being arranged for direct drive of said aerodynamic section; a condenser section and an evaporator section, each operatively coupled with said aerodynamic section, said condenser section having a higher operating pressure than said evaporator section; a liquid bypass circuit that cools said stator assembly and said rotor assembly with a liquid refrigerant, said liquid refrigerant being supplied by said condenser section and returned to said evaporator section, said liquid refrigerant being motivated through said liquid bypass circuit by said higher operating pressure of said condenser section relative to said evaporator section; a gas bypass circuit that cools said rotor assembly with a gas refrigerant, said gas refrigerant being drawn from said evaporator section and returned to said evaporator section by pressure differences caused by said rotation of said motor shaft, and
wherein said gas refrigerant from said evaporator section is mixed with said liquid refrigerant from said condenser section before entering said motor.
2. The chiller system of claim 1 , wherein a flow restriction device is disposed between said condenser section and said aerodynamic section.
3. The chiller system of claim 1 , further including structure defining a passageway located around the stator assembly for liquid cooling.
4. The chiller system of claim 1 , wherein a central longitudinal passage is defined within the motor shaft for cooling said rotor assembly.
5. The chiller system of claim 1 , wherein the temperature of said gas refrigerant in said gas bypass circuit is monitored by a feedback element.
6. The chiller system of claim 1 wherein said motor is a permanent magnet motor, said permanent magnet motor adapted to provide power exceeding approximately 140 KW of power, speeds in excess of 11,000 revolutions per minute, and at least a 200-ton refrigeration capacity at standard industry rating conditions.
7. The chiller system of claim 6 wherein said compressor assembly further comprises a discharge housing and an inlet housing, wherein the assembly of said motor housing, said discharge housing and said inlet housing fits within dimensions of 45 inches length by 25 inches width by 25 inches height.
8. The chiller system of claim 6 wherein said compressor assembly weighs less than 2500 pounds.
9. The chiller system of claim 1 wherein said motor shaft is supported by magnetic bearings.
10. The chiller system of claim 1 , wherein the motor housing is made of aluminum alloy components.