Cooling system

Patent metadata

Field	Value
Publication number	US-10746447-B2
Application number	US-201715825197-A
Country	US
Kind code	B2
Filing date	Nov 29, 2017
Priority date	Nov 29, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

An apparatus includes a microchannel heat exchanger, a load, a compressor, and a controller. The microchannel heat exchanger removes heat from a refrigerant. The load uses the refrigerant to remove heat from a space proximate the load. The compressor compresses the refrigerant from the load. The controller determines a discharge temperature of the refrigerant at the compressor and predicts a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger. The controller also determines a discharge superheat by subtracting the saturation temperature from the discharge temperature and triggers an alarm if the discharge superheat is below a threshold temperature.

First claim

What is claimed is:

1. An apparatus comprising: a microchannel heat exchanger configured to remove heat from a refrigerant;
a load;
a compressor configured to compress the refrigerant from the load; and
a controller configured to:
determine a discharge temperature of the refrigerant at the compressor;
predict a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger;
determine a discharge superheat by subtracting the saturation temperature from the discharge temperature; and
trigger an alarm if the discharge superheat is below a threshold temperature, and if the discharge superheat is above the threshold temperature and below a second threshold temperature for multiple cycles.

2. The apparatus of claim 1 , wherein the microchannel heat exchanger comprises a channel through which the refrigerant flows, the channel having a diameter less than or equal to 2 millimeters.

3. The apparatus of claim 1 , wherein the controller predicts the saturation temperature by:
determining an outdoor temperature; and
adding a constant to the outdoor temperature to produce the predicted saturation temperature.

4. The apparatus of claim 3 , wherein the constant is 20 degrees Fahrenheit.

5. An apparatus comprising:
a microchannel heat exchanger configured to remove heat from a refrigerant;
a load;
a compressor configured to compress the refrigerant from the load; and
a controller configured to:
determine a discharge temperature of the refrigerant at the compressor;
predict a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger;
determine a discharge superheat by subtracting the saturation temperature from the discharge temperature; and
trigger an alarm if the discharge superheat is below a threshold temperature, and if the discharge temperature is below an outdoor temperature plus a constant.

6. The apparatus of claim 5 , wherein the constant is 40 degrees Fahrenheit.

7. The apparatus of claim 5 , wherein the controller is further configured to trigger the alarm if the discharge temperature is above the outdoor temperature plus a second constant and below the outdoor temperature plus a third constant.

8. The apparatus of claim 7 , wherein the second constant is 40 degrees Fahrenheit and the third constant is 50 degrees Fahrenheit.

9. A method comprising:
removing heat from a refrigerant using a microchannel heat exchanger;
using the refrigerant to remove heat from a space proximate a load;
compressing the refrigerant from the load using a compressor;
determining a discharge temperature of the refrigerant at the compressor;
predicting a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger;
determining a discharge superheat by subtracting the saturation temperature from the discharge temperature; and
triggering an alarm if the discharge superheat is below a threshold temperature, and if the discharge superheat is above the threshold temperature and below a second threshold temperature for multiple cycles.

10. The method of claim 9 , wherein the microchannel heat exchanger comprises a channel through which the refrigerant flows, the channel having a diameter less than or equal to 2 millimeters.

11. The method of claim 9 , wherein predicting the saturation temperature comprises:
determining an outdoor temperature; and
adding a constant to the outdoor temperature to produce the predicted saturation temperature.

12. The method of claim 11 , wherein the constant is 20 degrees Fahrenheit.

13. A method comprising:
removing heat from a refrigerant using a microchannel heat exchanger;
using the refrigerant to remove heat from a space proximate a load;
compressing the refrigerant from the load using a compressor;
determining a discharge temperature of the refrigerant at the compressor;
predicting a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger;
determining a discharge superheat by subtracting the saturation temperature from the discharge temperature; and
triggering an alarm if the discharge superheat is below a threshold temperature, and if the discharge temperature is below an outdoor temperature plus a constant.

14. The method of claim 13 , wherein the constant is 40 degrees Fahrenheit.

15. The method of claim 13 , further comprising triggering the alarm if the discharge temperature is above the outdoor temperature plus a second constant and below the outdoor temperature plus a third constant.

16. The method of claim 15 , wherein the second constant is 40 degrees Fahrenheit and the third constant is 50 degrees Fahrenheit.

17. A system comprising:
a microchannel heat exchanger configured to remove heat from a refrigerant;
a compressor configured to compress the refrigerant; and
a controller configured to:
determine a discharge temperature of the refrigerant at the compressor;
predict a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger;
determine a discharge superheat by subtracting the saturation temperature from the discharge temperature; and
trigger an alarm if the discharge superheat is below a threshold temperature, and if the discharge superheat is above the threshold temperature and below a second threshold temperature for multiple cycles.

18. The system of claim 17 , wherein the microchannel heat exchanger comprises a channel through which the refrigerant flows, the channel having a diameter less than or equal to 2 millimeters.

19. The system of claim 17 , wherein the controller predicts the saturation temperature by:
determining an outdoor temperature; and
adding a constant to the outdoor temperature to produce the predicted saturation temperature.

20. The system of claim 19 , wherein the constant is 20 degrees Fahrenheit.

21. A system comprising:
a microchannel heat exchanger configured to remove heat from a refrigerant;
a compressor configured to compress the refrigerant; and
a controller configured to:
determine a discharge temperature of the refrigerant at the compressor;
predict a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger;
determine a discharge superheat by subtracting the saturation temperature from the discharge temperature; and
trigger an alarm if the discharge superheat is below a threshold temperature, and if the discharge temperature is below an outdoor temperature plus a constant.

22. The system of claim 21 , wherein the constant is 40 degrees Fahrenheit.

23. The system of claim 21 , wherein the controller is further configured to trigger the alarm if the discharge temperature is above the outdoor temperature plus a second constant and below the outdoor temperature plus a third constant.

24. The system of claim 23 , wherein the second constant is 40 degrees Fahrenheit and the third constant is 50 degrees Fahrenheit.

Assignees

• Lennox Ind Inc

Inventors

• Goel Rakesh
• Giles Eric
• Rajan Siddarth

Classifications

• F25B39/04

  Condensers · CPC title

• F25B49/005

  of safety devices (F25B49/02 and F25B49/04 take precedence) · CPC title

• F25B49/02 Primary

  for compression type machines, plants or systems · CPC title

• F25B2700/2106

  of fresh outdoor air · CPC title

• F25B2700/21152

  at the discharge side of the compressor · CPC title