Compressor Having Oil-Level Sensing System

Patent metadata

Field	Value
Publication number	US-2017089340-A1
Application number	US-201615376742-A
Country	US
Kind code	A1
Filing date	Dec 13, 2016
Priority date	Apr 29, 2015
Publication date	Mar 30, 2017
Grant date	—

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 of a lubricant at a first position; a second temperature sensor at least partially disposed within said lubricant sump and configured to measure a second temperature of said lubricant at a second position that is vertically higher than said first position; and a control module in communication with said first and second temperature sensors, said control module configured to determine a first difference between the first temperature and the second temperature, said control module configured to determine whether a liquid level of said lubricant in said lubricant sump is below a predetermined level based on said first difference.

2 . The compressor of claim 1 , wherein a vertical height of said second 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 , further comprising a third temperature sensor at least partially disposed within said shell and configured to measure a temperature of working fluid at a third position that is vertically higher than said first and second positions, wherein said control module is configured to determine a second difference between the second temperature of said lubricant and the temperature of said working fluid at said third temperature sensor, said control module configured to determine whether a vertical height of said lubricant is below said second position based on said second difference.

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

6 . The compressor of claim 1 , further comprising a pressure sensor disposed at least partially within said shell vertically above said predetermined level, wherein said control module determines whether said liquid level is below said predetermined level based on data from said pressure sensor.

7 . The compressor of claim 1 , further comprising a pressure sensor disposed at least partially within said shell, wherein said control module determines whether said liquid level is below said predetermined level based on whether data from said pressure sensor indicates a presence of liquid working fluid in said shell.

8 . 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.

9 . 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.

10 . 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,

11 . The compressor of claim 10 , wherein said first temperature sensor is disposed within said fluid path adjacent said first end.

12 . The compressor of claim 11 , wherein said fluid path is at least partially defined by said shell and a baffle disposed within said shell.

13 . A method comprising:
determining a first temperature from a first temperature sensor at a first location within a compressor; determining a second temperature from a second temperature sensor at a second location within said compressor; determining a first difference between said first and second temperatures; determining a third temperature from a third temperature sensor at a third location within said compressor; determining a second difference between said second and third temperatures; and determining whether a liquid level in a lubricant sump within said compressor is below a predetermined level based on at least one of said first difference and said second difference.

14 . The method of claim 13 , wherein said second location within said compressor is vertically higher than said first location within said compressor.

15 . The method of claim 13 , further comprising determining a first standard deviation of measurements from one of said first and second temperature sensors, wherein determining whether said liquid level is below said predetermined level is based on said first standard deviation.

16 . The method of claim 13 , 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.

17 . The method of claim 16 , wherein said first temperature sensor is disposed within said fluid path adjacent said first end.

18 . The method of claim 17 , wherein said fluid path is defined by a shell of said compressor and a baffle disposed within said shell.

19 . The method of claim 13 , further comprising determining a pressure from a pressure sensor disposed at least partially within a shell of said compressor at a fourth location vertically above said predetermined level; and determining whether said liquid level in said lubricant sump is below said predetermined level based on said pressure.

20 . The method of claim 13 , 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.

Assignees

• Emerson Climate Technologies

Inventors

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

Classifications

• F04C18/34

  having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members · CPC title

• F04B49/10

  Other safety measures · CPC title

• F04C18/0215

  where only one member is moving · CPC title

• F25B2700/03

  Oil level · CPC title

• F04B39/0207

  with lubrication control systems · CPC title