System for refrigerant charge verification

• US 10,488,090 B2
• Filed: 03/13/2014
• Issued: 11/26/2019
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Inventors: Pham, Hung M.
• Primary Examiner(s): Jules, Frantz
• Assistant Examiner(s): Tadesse, Martha
• Application Number:
  US14/208,636
• Publication Number:
  US 20140260390A1
• Time in Patent Office: 2,084 Days
• Field of Search: 62127
• CPC Class Codes: F25B 2345/003 Control issues for charging or collecting refrigerant to or from a cycle
• CPC Class Codes: F25B 2500/23 High amount of refrigerant in the system
• CPC Class Codes: F25B 2500/24 Low amount of refrigerant in the system
• CPC Class Codes: F25B 2600/19 Refrigerant outlet condenser temperature
• CPC Class Codes: F25B 2700/04 Refrigerant level
• CPC Class Codes: F25B 2700/2106 of fresh outdoor air
• CPC Class Codes: F25B 2700/21162 of the refrigerant at the inlet of the condenser
• CPC Class Codes: F25B 2700/21163 of the refrigerant at the outlet of the condenser
• CPC Class Codes: F25B 40/02 Subcoolers
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence

Abstract

A diagnostic system for a refrigeration system including a condenser is provided. The diagnostic system may include a controller determining a subcooling temperature of the refrigeration system, an approach temperature of the condenser, and a condenser temperature difference of the condenser. The controller may determine at least one of a fault condition of the refrigeration system and a charge of the refrigeration system based on the subcooling temperature, the approach temperature, and the condenser temperature difference.

Claims

1. A diagnostic system for a refrigeration system including a compressor and a condenser having an inlet, an outlet, and a coil circuit tube extending between the inlet and the outlet, the compressor and the condenser being connected in a circuit, the diagnostic system comprising:

a first coil temperature sensor located on said coil circuit tube a first distance from said inlet, wherein said first coil temperature sensor provides a signal indicative of a first coil temperature;

a second temperature sensor located on said coil circuit tube a second distance from said inlet, wherein said second temperature sensor provides a signal indicative of a second coil temperature;

a liquid line temperature sensor located on said circuit downstream of said outlet of said condenser having said first coil temperature sensor and said second coil temperature sensor and providing a signal indicative of a liquid line temperature of a liquid circulating within said circuit;

an outdoor ambient temperature sensor providing a signal indicative of an ambient temperature;

a controller receiving said first coil temperature, said second coil temperature, said liquid line temperature, and said ambient temperature from said first coil temperature sensor, said second coil temperature sensor, said liquid line temperature sensor, and said outdoor ambient temperature sensor, respectively;

said controller calculates a subcooling temperature of said refrigeration system, an approach temperature of said condenser, and a condenser temperature difference of said condenser from said first coil temperature, said second coil temperature, said liquid line temperature, and said ambient temperature,

wherein said controller determines at least one of a fault condition of said refrigeration system and a charge of said refrigeration system based on said subcooling temperature, said approach temperature, and said condenser temperature difference, and

wherein said controller determines an undercharge condition when said condenser temperature difference is less than a first threshold and a ratio of said approach temperature and said condenser temperature difference is greater than a second threshold different than said first threshold.

2. The system of claim 1, wherein said controller determines said subcooling temperature of the refrigeration system based on at least one of said first coil temperature and said second coil temperature.

3. The system of claim 1, wherein said controller determines a saturated condensing temperature based on one of said first coil temperature and said second coil temperature, said one of said first coil temperature and said second coil temperature being closer to an actual saturated condensing temperature of the condenser than the other of said first coil temperature and said second coil temperature.

4. The system of claim 3, wherein said ambient temperature sensor senses an ambient temperature of air proximate to said controller.

5. The system of claim 4, wherein said controller determines said condenser temperature difference by subtracting said ambient temperature from said saturated condensing temperature.

6. The system of claim 1, wherein said controller determines said approach temperature by subtracting said ambient temperature from said liquid temperature.

7. The system of claim 1, wherein said controller determines said fault condition based on a percent split or ratio of said subcooling temperature and said approach temperature.

8. The system of claim 1, wherein said controller determines an overcharge condition based on at least a ratio of said subcooling temperature and said condenser temperature difference.

9. The system of claim 1, wherein said controller determines said undercharge condition when said condenser temperature difference is less than approximately fifteen degrees Fahrenheit (15°

F.) and said ratio of said approach temperature and said condenser temperature difference is greater than approximately ninety percent (90%).

10. The system of claim 8, wherein said controller determines said overcharge condition when said condenser temperature difference is greater than approximately thirty five degrees Fahrenheit (35°

F.) and said ratio of said subcooling temperature and said condenser temperature difference is greater than approximately ninety percent (90%).

11. A controller determining at least one of a fault condition of a refrigeration system and a charge condition of the refrigeration system based on a subcooling temperature of the refrigeration system, an approach temperature of a condenser, and a condenser temperature difference of the condenser, wherein said controller determines an undercharge condition when said condenser temperature difference is less than a first threshold and a ratio of said approach temperature and said condenser temperature difference is greater than a second threshold different than said first threshold.

12. The controller of claim 11, wherein the controller determines said subcooling temperature of the refrigeration system based on at least one of a first temperature of the condenser and a second temperature of the condenser.

13. The controller of claim 12, wherein said controller determines a saturated condensing temperature based on one of said first temperature of said condenser and said second temperature of said condenser, said one of said first temperature of said condenser and said second temperature of said condenser being closer to an actual saturated condensing temperature of said condenser than said other of said first temperature of said condenser and said second temperature of said condenser.

14. The controller of claim 13, wherein said controller determines said condenser temperature difference by subtracting an ambient temperature of air proximate to the condenser from said saturated condensing temperature.

15. The controller of claim 14, wherein said controller determines said approach temperature by subtracting said ambient temperature from a liquid temperature of a liquid circulating in the refrigeration system.

16. The controller of claim 11, wherein the controller determines said fault condition based on a percent split or ratio of said subcooling temperature and said approach temperature.

17. The controller of claim 11, wherein said controller determines an overcharge condition based on at least a ratio of said subcooling temperature and said condenser temperature difference.

18. The controller of claim 11, wherein said controller determines said undercharge condition when said condenser temperature difference is less than approximately fifteen degrees Fahrenheit (15°

F.) and said ratio of said approach temperature and said condenser temperature difference is greater than approximately ninety percent (90%).

19. The controller of claim 17, wherein said controller determines said overcharge condition when said condenser temperature difference is greater than approximately thirty five degrees Fahrenheit (35°

F.) and said ratio of said subcooling temperature and said condenser temperature difference is greater than approximately ninety percent (90%).

20. Said refrigeration system incorporating the controller of claim 11, said refrigeration system including a condenser.

21. The refrigeration system of claim 20, further comprising a compressor.