Tandem compressor discharge pressure and temperature control logic

Patent metadata

Field	Value
Publication number	US-10197304-B2
Application number	US-201514720049-A
Country	US
Kind code	B2
Filing date	May 22, 2015
Priority date	May 23, 2014
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

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.

First claim

The invention claimed is:

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, the tandem compressor operable to compress a refrigerant, the tandem compressor associated with the plurality of sensors;
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 at a first time, the first interruption of power resulting in the first compressor and the second compressing being off;
in response to determining a first interruption of power to the tandem compressor, turn on the first compressor of the tandem compressor at a second time, keeping the second compressor off the second time being after the first time;
monitor whether power to the tandem compressor is interrupted;
determine a second interruption of power at a third time, the third time being after the second time;
in response to determining the second interruption of power at the third time, 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;
turn off the first compressor of the tandem compressor at a fourth time, the fourth time being after the third time;
based on a temperature demand, determine that the second compressor of the tandem compressor be turned on; and
turn on the second compressor of the tandem compressor.

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 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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 at a first time, the first interruption of power resulting in the first compressor and the second compressing being off, the tandem compressor comprising a first compressor and a second compressor, the tandem compressor operable to compress a refrigerant, the tandem compressor associated with a plurality of sensors;
in response to determining a first interruption of power to the tandem compressor, turn on the first compressor of the tandem compressor at a second time, keeping the second compressor off, the second time being after the first time;
monitor whether power to the tandem compressor is interrupted;
determine a second interruption of power at a third time, the third time being after the second time;
in response to determining the second interruption of power at the third time 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;
turn off the first compressor of the tandem compressor at a fourth time, the fourth time being after the third time;
based on a temperature demand, determine that the second compressor of the tandem compressor be turned on; and
turn on the second compressor of the tandem compressor.

8. The controller of claim 7 , 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.

9. The controller of claim 7 , wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a temperature above a set point temperature.

10. The controller of claim 7 , wherein the refrigerant associated with the first compressor exceeding the tolerance condition comprises the refrigerant being at a pressure above a set point pressure.

11. The controller of claim 7 , 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.

12. The controller of claim 7 , 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 compr

Assignees

• Lennox Ind Inc

Inventors

• Havard Jr Harold Gene
• Leal Rosa Maria
• Hadzidedic Darko
• Curry Jimmie Lee
• Sundararajan Anuradha
• Hung Der-Kai
• Toombs Jr William Clay

Classifications

• F25B49/005 Primary

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

• F24F11/85

  using variable-flow pumps · CPC title

• F25B7/00 Primary

  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) · CPC title

• F24F11/001

  Mechanical Engineering · mapped topic

• F24F2011/0052

  Mechanical Engineering · mapped topic