TANDEM COMPRESSOR DISCHARGE PRESSURE AND TEMPERATURE CONTROL LOGIC

• US 20150338133A1
• Filed: 05/22/2015
• Published: 11/26/2015
• Est. Priority Date: 05/23/2014
• Status: Active Grant

• Current Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Original Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Inventors: Havard, Harold Gene Jr., Leal, Rosa Maria, Hadzidedic, Darko, Sundararajan, Anuradha, Hung, Der-Kai, Curry, Jimmie Lee, Toombs, William Clay Jr.
• Granted Patent: US 10,197,304 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/32 Responding to malfunctions or emergencies
• CPC Class Codes: F24F 11/38 Failure diagnosis
• CPC Class Codes: F24F 11/85 using variable-flow pumps
• CPC Class Codes: F24F 2110/00 Control inputs relating to air properties
• CPC Class Codes: F25B 2400/075 with parallel compressors
• CPC Class Codes: F25B 2600/024 by controlling the electric parameters, e.g. current or voltage
• CPC Class Codes: F25B 2600/0251 with on-off operation
• CPC Class Codes: F25B 2700/151 of the compressor motor
• CPC Class Codes: F25B 2700/1931 Discharge pressures
• CPC Class Codes: F25B 2700/21152 at the discharge side of the compressor
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 49/022 Compressor control arrangements
• CPC Class Codes: F25B 7/00 Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit F25B9/00 takes precedence

Abstract

An HVAC system, comprising a plurality of sensors, a tandem compressor comprising a first compressor and a second compressor, and a controller communicatively coupled to the plurality of sensors and the tandem compressor. The controller may determine a first interruption of power to the tandem compressor and identify a sensor corresponding to the first interruption of power. The controller is further operable to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding a tolerance condition. The controller may also reconfigure the tandem compressor, wherein on or off settings of the first compressor and the second compressor are determined based on a required load operation of the tandem compressor and the determination that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

Claims

1. A heating, ventilation, and air-conditioning (HVAC) system, comprising:

a plurality of sensors;

a tandem compressor comprising a first compressor and a second compressor;

a controller communicatively coupled to the plurality of sensors and the tandem compressor, the controller operable to;

determine a first interruption of power to the tandem compressor;

identify a sensor corresponding to the first interruption of power to the tandem compressor, the sensor being one of the plurality of sensors;

determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding a tolerance condition; and

reconfigure the tandem compressor, wherein on or off settings of the first compressor and the second compressor are determined based on a required load operation of the tandem compressor and the determination that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

2. The system of claim 1, wherein to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition, the controller is further operable to:

power on the first compressor while the second compressor is powered off; and

determine a second interruption of power to the tandem compressor in response to powering on the first compressor while the second compressor is powered off.

3. The system of claim 1, wherein to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition, the controller is further operable to:

power on the second compressor while the first compressor is powered off; and

determine that there is no interruption of power to the tandem compressor in response to powering on the second compressor while the first compressor is powered off.

4. The system of claim 1, wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a temperature above a set point temperature.

5. The system of claim 1, wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a pressure above a set point pressure.

6. The system of claim 1, wherein the sensor corresponding to the first interruption comprises a switch configured to change to a position that prevents power from being delivered to the tandem compressor in response to determining that the refrigerant associated with the first compressor exceeds the tolerance condition.

7. The system of claim 1, further comprising:

a first pipe leg coupled to the first compressor, the first pipe leg configured to be in fluid communication with a common pipe;

a second pipe leg coupled to the second compressor, the second pipe leg configured to be in fluid communication with the common pipe;

wherein at least one of the plurality of sensors comprises a switch, the switch coupled to the common pipe and configured to change to a first position that prevents power from being delivered to the tandem compressor and a second position that allows power to be delivered to the tandem compressor; and

the controller is further operable to;

in response to determining the first interruption of power to the tandem compressor, determine that the switch is in the first position;

in response to determining that the switch is in the first position;

powering on the first compressor;

determining a second interruption of power to the tandem compressor;

powering off the first compressor;

powering on the second compressor;

determining that there is no interruption of power to the tandem compressor;

in response to determining that there is the second interruption of power to the tandem compressor after powering on the first compressor and that there is no interruption of power to the tandem compressor after powering on the second compressor, determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

8. A controller for operating a heating, ventilation, and air-conditioning (HVAC) system, comprising:

a memory; and

a processor communicatively coupled to the memory, the processor operable to;

determine a first interruption of power to a tandem compressor, the tandem compressor comprising a first compressor and a second compressor;

determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding a tolerance condition; and

reconfigure the tandem compressor, wherein on or off settings of the first compressor and the second compressor are determined based on a required load operation of the tandem compressor and the determination that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

9. The controller of claim 8, wherein to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition, the processor is further operable to:

power on the first compressor while the second compressor is powered off; and

determine a second interruption of power to the tandem compressor in response to powering on the first compressor while the second compressor is powered off.

10. The controller of claim 8, wherein to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition, the processor is further operable to:

power on the second compressor while the first compressor is powered off; and

determine that there is no interruption of power to the tandem compressor in response to powering on the second compressor while the first compressor is powered off.

11. The controller of claim 8, wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a temperature above a set point temperature.

12. The controller of claim 8, wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a pressure above a set point pressure.

13. The controller of claim 8, wherein the processor is operable to determine that the first interruption of power occurred based on the position of a switch in a sensor that monitors the refrigerant associated with the first compressor, wherein the position of the switch prevents power from being delivered to the tandem compressor.

14. The controller of claim 8, wherein

the processor is further configured to:

in response to determining the first interruption of power to the tandem compressor, determine that a switch of a sensor is in a first position, the switch coupled to a common pipe, the common pipe in fluid communication with a first pipe leg coupled to the first compressor and a second pipe leg coupled to the second compressor;

in response to determining that the switch is in the first position;

powering on the first compressor;

determining a second interruption of power to the tandem compressor;

powering off the first compressor;

powering on the second compressor;

determining that there is no interruption of power to the tandem compressor;

in response to determining that there is the second interruption of power to the tandem compressor after powering on the first compressor and that there is no interruption of power to the tandem compressor after powering on the second compressor, determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

15. A non-transitory computer readable storage medium comprising instructions, the instructions, when executed by a processor, executable to:

determine a first interruption of power to a tandem compressor, the tandem compressor comprising a first compressor and a second compressor;

determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding a tolerance condition; and

reconfigure the tandem compressor, wherein on or off settings of the first compressor and the second compressor are determined based on a required load operation of the tandem compressor and the determination that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

16. The non-transitory computer readable storage medium of claim 15, wherein to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition, the instructions are further executable to:

power on the first compressor while the second compressor is powered off; and

determine a second interruption of power to the tandem compressor in response to powering on the first compressor while the second compressor is powered off.

17. The non-transitory computer readable storage medium of claim 15, wherein to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition, the instructions are further executable to:

power on the second compressor while the first compressor is powered off; and

determine that there is no interruption of power to the tandem compressor in response to powering on the second compressor while the first compressor is powered off.

18. The non-transitory computer readable storage medium of claim 15, wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a temperature above a set point temperature.

19. The non-transitory computer readable storage medium of claim 15, wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a pressure above a set point pressure.

20. The non-transitory computer readable storage medium of claim 15, wherein the instructions are executable to determine that the first interruption of power occurred based on the position of a switch in a sensor that monitors the refrigerant associated with the first compressor, wherein the position of the switch prevents power from being delivered to the tandem compressor.