OIL MANAGEMENT SYSTEM FOR A COMPRESSOR

• US 20130115063A1
• Filed: 10/31/2012
• Published: 05/09/2013
• Est. Priority Date: 11/04/2011
• Status: Active Grant

• Current Assignee: Copeland Europe GmbH
• Original Assignee: Emerson Climate Technologies GmbH (Emerson Electric Company)
• Inventors: Waller, Barry Granville
• Granted Patent: US 9,551,357 B2
• Time in Patent Office: Days
• US Class Current: 415/177
• CPC Class Codes: F04B 39/0207 with lubrication control systems
• CPC Class Codes: F04D 29/582 specially adapted for elastic fluid pumps
• CPC Class Codes: F25B 2400/01 Heaters
• CPC Class Codes: F25B 2500/31 Low ambient temperatures
• CPC Class Codes: F25B 31/002 Lubrication

Abstract

The invention relates to an oil management system for a compressor in a refrigeration system comprising: an oil temperature sensor; a heater arranged to heat oil in a crank case of the compressor; and a controller operatively associated with the temperature sensor and the heater, the controller arranged to control operation of the heater on the basis of ambient air temperature and oil temperature to maintain the oil temperature within a range Tmax≧R≧Tmin where Tmax>Tmin.

Claims

1. An oil management system for a compressor in a refrigeration system comprising:

an oil temperature sensor;

a heater arranged to heat oil in a crank case of the compressor; and

,

a controller operatively associated with the temperature sensor and the heater, the controller arranged to control operation of the heater on the basis of ambient air temperature and oil temperature to maintain the oil temperature within a range Tmax≧

R≧

Tmin where Tmax>

Tmin.

2. The oil management system according to claim 1 comprising an ambient air temperature sensor for measuring ambient temperature (Tamb) and wherein the controller is operatively associated with the air temperature sensor and arranged to calculate Tmin using Tamb.

3. The oil management system according to claim 1 wherein the controller is arranged to determine Tmin on the basis of:

saturation temperature (Tsat) of refrigerant used in the refrigeration system.

4. The oil management system according to claim 3 comprising a pressure sensor which measures crank case pressure of the compressor and is operatively associated with the controller, and wherein the controller is further arranged to calculate the saturation temperature (Tsat) from the measured crank case pressure.

5. The oil management system according to claim 1 wherein the controller is arranged to enable a user to input Tmin and Tmax under the constraint that Tmax>

Tmin.

6. The oil management system according to claim 1 wherein the controller is arranged to control the heater only when the compressor is in an OFF state.

7. The oil management system according to claim 6 comprising a compressor state sensor operatively associated with the controller, the compressor state sensor arranged to sense an operational state of the compressor and deliver to the controller:

an OFF state signal when the compressor is sensed as being in an OFF state, and an ON state signal when the compressor is sensed as being in the ON state.

8. The oil management system according to claim 7 wherein the compressor state sensor comprises a vibration transducer mechanically coupled to the crank case.

9. The oil management system according to claim 7 wherein the compressor state sensor comprises a refrigerant temperature sensing device to sense temperature of refrigerant at a discharge side of the compressor.