Motor temperature control

• US 6,324,858 B1
• Filed: 11/27/1998
• Issued: 12/04/2001
• Est. Priority Date: 11/27/1998
• Status: Expired due to Term

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Holden, Steven J.
• Primary Examiner(s): WAYNER, WILLIAM E
• Application Number:
  US09/200,816
• Time in Patent Office: 1,103 Days
• Field of Search: 622/30, 622/11, 625/05, 417/423.8, 310/16, 310/53, 318/473
• US Class Current: 62/211
• CPC Class Codes: F04D 25/06 the pump being electrically driven F04D25/08 takes precedence
• CPC Class Codes: F04D 27/00 Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
• CPC Class Codes: F04D 29/5806 Cooling the drive system
• CPC Class Codes: F05D 2270/335 Output power or torque
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 2400/23 Separators
• CPC Class Codes: F25B 31/008 by injecting a liquid

Abstract

The motor power consumption and motor winding temperature are monitored and, responsive thereto, the flow of refrigerant to the motor is controlled so as to control the temperature of the motor. The motor power consumption in the primary control input because it anticipates cooling requirements whereas the motor temperature indicates current cooling requirements. The cooling flow may be provided in an on-off manner or there may be a constant flow portion with an on-off parallel cooling flow path.

Claims

1. In a closed refrigeration system serially including a compressor driven by a motor, a condenser, an expansion device, and an evaporator, with a liquid refrigerant line connecting said condenser and said expansion device, means for controlling the temperature of said motor driving said compressor comprising:

means for sensing a parameter indicative of electrical power supplied to said motor for driving said compressor;

means for sensing a parameter indicative of the temperature of said motor;

a first fluid path connecting said liquid refrigerant line and said motor;

means for controlling flow in said first fluid path responsive to said parameter indicative of electrical power supplied and responsive to said parameter indicative of the temperature of said motor whereby the temperature of said motor is controlled.

2. In a closed refrigeration system serially including a compressor driven by a motor, a condenser, an expansion device, an evaporator, with a liquid refrigerant line connecting said condenser and said expansion device, means for controlling the temperature of said motor driving said compressor comprising:

means for sensing a parameter indicative of electrical power supplied to said motor for driving said compressor;

means for sensing a parameter indicative of electrical power supplied to said motor for driving said compressor;

a first fluid path connecting said liquid refrigerant line and said motor;

a second fluid path connected to said motor at least partially in parallel with said first fluid path and providing a constant flow of refrigerant to said motor for cooling;

means for controlling flow in said first fluid path responsive to said parameter indicative of the temperature of said motor whereby the temperature of said motor is controlled.

3. The means for controlling the temperature of said motor of claim 2 wherein said means for controlling flow in said first fluid path is responsive to a duty cycle limited to a range of zero corresponding to no flow and one corresponding to full flow where:

4. The means for controlling the temperature of said motor of claim 3 wherein said second flow path includes an economizer.

5. The means for controlling the temperature of said motor of claim 3 wherein said second flow path connects said liquid refrigerant line and said motor.

6. In a close refrigeration system serially including a compressor driven by a motor, a condenser, an expansion device, an evaporator, with a liquid refrigerant line connecting said condenser and said expansion device, means for controlling the temperature of said motor driving said compressor comprising:

means for sensing a parameter indicative of electrical power supplied to said motor for driving said compressor;

means for sensing a parameter indicative of electrical power supplied to said motor for driving said compressor;

a first fluid path connecting said liquid refrigerant line and said motor;

means for controlling flow in said first fluid path responsive to said parameter indicative of the temperature of said motor whereby the temperature of said motor is controlled, wherein said means for controlling flow in said first fluid path is responsive to a duty cycle limited to a range of zero corresponding to no flow and one corresponding to full flow where;