Compressor having oil-level sensing system

Patent metadata

Field	Value
Publication number	US-10180139-B2
Application number	US-201615376742-A
Country	US
Kind code	B2
Filing date	Dec 13, 2016
Priority date	Apr 29, 2015
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

A compressor may include a shell containing a motor, a compression mechanism and a lubricant sump. The compressor may also include first and second temperature sensors, and a control module. The first temperature sensor may be at least partially disposed within the lubricant sump and may measure a first temperature of a lubricant at a first position. The second temperature sensor may be at least partially disposed within the lubricant sump and may measure a second temperature of the lubricant at a second position that is vertically higher than the first position. The control module is in communication with the first and second temperature sensors. The control module may determine a first difference between the first temperature and the second temperature. The control module may determine whether a liquid level of the lubricant in the lubricant sump is below a predetermined level based on the first difference.

First claim

What is claimed is:

1. A compressor comprising:
a shell including a motor, a compression mechanism and a lubricant sump;
a first temperature sensor at least partially disposed within said lubricant sump and configured to measure a first temperature at a first position;
a second temperature sensor at least partially disposed within said lubricant sump and configured to measure a second temperature at a second position that is vertically higher than said first position;
a third temperature sensor at least partially disposed within said shell and configured to measure a third temperature at a third position that is vertically lower than said first and second positions;
a pressure sensor disposed at least partially within said shell vertically above said first and third positions; and
a control module in communication with said first, second and third temperature sensors and said pressure sensor,
wherein said control module is configured to determine a first difference between the third temperature and the second temperature,
wherein said control module is configured to determine a second difference between the first temperature and the second temperature, and
wherein, if the second difference is less than a predetermined value, said control module determines whether a liquid level of lubricant in said lubricant sump is below a predetermined level based on data from said pressure sensor.

2. The compressor of claim 1 , wherein a vertical height of said third position is equal to a vertical height of said predetermined level.

3. The compressor of claim 1 , wherein said predetermined level equals a minimum acceptable vertical height of said lubricant.

4. The compressor of claim 1 , wherein said shell defines a suction chamber containing working fluid that is drawn into said compression mechanism for compression therein during operation of the compressor, and wherein said first temperature sensor is disposed within said suction chamber.

5. The compressor of claim 1 , wherein said control module determines whether said liquid level is below said predetermined level based on whether the compressor is on or off.

6. The compressor of claim 1 , further comprising a heating element configured to heat liquid within said lubricant sump, and wherein said control module determines whether said liquid level is below said predetermined level based on whether said heating element is functioning.

7. The compressor of claim 1 , further comprising a fluid path for delivering suction gas, the fluid path having a first end proximate said lubricant sump and a second end proximate a suction inlet extending through said shell.

8. The compressor of claim 7 , wherein said first temperature sensor is disposed within said fluid path adjacent said first end.

9. The compressor of claim 8 , wherein said fluid path is at least partially defined by said shell and a baffle disposed within said shell.

10. The compressor of claim 1 , wherein, if the second difference is greater than a predetermined value, said control module determines whether said liquid level is below said predetermined level based on a third difference between said first temperature and said third temperature.

11. A method comprising:
determining a first temperature at a first location from a first temperature sensor disposed within a lubricant sump of a compressor;
determining a second temperature from a second temperature sensor at a second location within said compressor, wherein the second location is vertically higher than the first location;
determining a third temperature at a third location from a third temperature sensor disposed within the lubricant sump of said compressor, wherein said third temperature sensor is disposed vertically lower than said first temperature sensor;
determining a pressure from a pressure sensor disposed at least partially within a shell of said compressor at a fourth location vertically above said first and third locations; and
determining whether a liquid level in said lubricant sump is below a predetermined level based on said pressure and said first, second and third temperatures.

12. The method of claim 11 , further comprising directing suction gas along a fluid path having a first end proximate said lubricant sump and a second end proximate a suction inlet of said compressor.

13. The method of claim 12 , wherein said first temperature sensor is disposed within said fluid path adjacent said first end.

14. The method of claim 13 , wherein said fluid path is defined by a shell of said compressor and a baffle disposed within said shell.

15. The method of claim 11 , further comprising determining whether a heating element for said lubricant sump is functioning; and determining whether said liquid level in said lubricant sump is below said predetermined level based on whether said heating element is functioning.

16. The method of claim 11 , further comprising:
determining a first difference between the third temperature and the second temperature;
determining a second difference between the first temperature and the second temperature; and
if the second difference is less than a predetermined value, determining whether said liquid level in said lubricant sump is below said predetermined level based on data from said pressure sensor.

17. The method of claim 16 , further comprising: if the second difference is greater than a predetermined value, determining whether said liquid level in said lubricant sump is below said predetermined level based on a third difference between said first temperature and said third temperature.

Assignees

• Emerson Climate Technologies

Inventors

• BROSTROM Troy Richard
• JORWEKAR Pavankumar Pralhad
• JAGDALE Prashant Ramesh
• Juge Vinayak Madanrao
• Ahire Pankaj

Classifications

• F25B2700/03

  Oil level · CPC title

• F04B2205/10

  Inlet temperature · CPC title

• F04C2240/81

  Sensor, e.g. electronic sensor for control or monitoring · CPC title

• F04C2270/19

  Temperature · CPC title

• F25B31/002

  Lubrication · CPC title