Refrigerant cooled variable frequency drive and method for using same

• US 6,874,329 B2
• Filed: 05/30/2003
• Issued: 04/05/2005
• Est. Priority Date: 05/30/2003
• Status: Expired due to Fees

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Stark, Michael Alan, Holmes, Cornelius
• Primary Examiner(s): Jiang, Chen Wen
• Application Number:
  US10/448,861
• Publication Number:
  US 20040237554A1
• Time in Patent Office: 676 Days
• Field of Search: 622/30, 622/26, 621/13, 622/22, 622/284, 622/592
• US Class Current: 62/230
• CPC Class Codes: F25B 2600/021 Inverters therefor
• CPC Class Codes: F25B 2600/2501 Bypass valves
• CPC Class Codes: F25B 31/006 Cooling of compressor or motor
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A method for operating a vapor compression system having a compressor driven by a variable frequency drive, wherein the compressor feeds a refrigerant loop, wherein the refrigerant loop includes a cooling circuit for the variable frequency drive, and wherein a flow control member is positioned for controlling flow of refrigerant from the refrigerant loop to the cooling circuit including the steps of: sensing an operating temperature of the variable frequency drive; and controlling the flow control member based upon the operating temperature.

Claims

1. A method for operating a vapor compression system having a compressor driven by a variable frequency drive, wherein said compressor feeds a refrigerant loop, wherein said refrigerant loop includes a cooling circuit for said variable frequency drive, and wherein a flow control member is positioned for controlling flow of refrigerant from said refrigerant loop to said cooling circuit, comprising the steps of:

sensing an operating temperature of said variable frequency drive; and

controlling said flow control member based upon said operating temperature, further comprising selecting a set point temperature for said variable frequency drive, and controlling said flow control member to increase refrigerant flow to said cooling circuit when said operating temperature exceeds said set point temperature, wherein said flow control member has a maximum setting corresponding to a maximum flow of refrigerant to said cooling circuit, and further comprising reducing a power rating of said variable frequency drive when said operating temperature exceeds said set point temperature and said flow control member is at said maximum setting.

2. The method of claim 1, wherein said flow control member is an electronically controllable expansion valve.

3. A vapor compression system, comprising:

a compressor driven by a variable frequency drive, said compressor being communicated with a refrigerant loop, said loop including a cooling circuit for said variable frequency drive and a flow control member for controlling flow of refrigerant from said refrigerant loop to said cooling circuit; and

a control member adapted to sense an operating temperature of said variable frequency drive, and to control said flow control member based upon said operating temperature,

wherein said control member has a stored set point temperature, and is further adapted to control said flow control member to increase refrigerant flow to said cooling circuit when said operating temperature exceeds said set point temperature,

wherein said flow control member has a maximum setting corresponding to a maximum flow of refrigerant to said cooling circuit, and

wherein the control member is further adapted to reduce a power rating of said variable frequency drive when said operating temperature exceeds said set point temperature and said flow control member is at said maximum setting.

4. The system of claim 3, wherein said flow control member is an electronically controllable expansion valve.