Discharge pressure calculation from torque in an HVAC system

Patent metadata

Field	Value
Publication number	US-9885508-B2
Application number	US-201214368941-A
Country	US
Kind code	B2
Filing date	Dec 21, 2012
Priority date	Dec 28, 2011
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

A method for determining discharge pressure for a compressor operatively connected to a condenser, an expansion device, and an evaporator in a serial relationship, includes receiving information indicative of a compressor torque or compressor current; and determining a discharge pressure in response to the receiving of the information.

First claim

The invention claimed is:

1. A method for determining discharge pressure for a compressor operatively connected to a condenser, an expansion device, and an evaporator in a serial relationship, comprising:
receiving information indicative of a compressor torque or compressor current;
receiving a compressor signal corresponding to a compressor speed of the compressor; and
receiving a sensor signal corresponding to a suction pressure of the compressor;
and
determining the discharge pressure as a function of each of (i) the compressor torque or compressor current, (ii) the compressor speed, and (iii) the suction pressure.

2. The method of claim 1 , wherein the received information comprises electric power data including data regarding at least one of a voltage differential, a current, and a phase-angle differential of a motor coupled to the compressor.

3. The method of claim 1 , wherein the determining of the discharge pressure further comprises mapping each of the compressor torque, compressor speed, and the suction pressure to the discharge pressure.

4. The method of claim 1 , further comprising modulating electric power delivered to a variable speed motor coupled to the compressor.

5. The method of claim 2 , wherein the receiving of the information further comprises receiving the electric power data from the motor.

6. The method of claim 1 , further comprising receiving a second sensor signal corresponding to a liquid temperature of a refrigerant.

7. The method of claim 1 , further comprising mapping the discharge pressure to a saturated discharge temperature.

8. The method of claim 7 , further comprising determining a degree of system subcooling from the saturated discharge temperature.

9. A discharge pressure determination system for a compressor, comprising:
a vapor compression system including a compressor, a condenser, an expansion device and an evaporator operatively connected in a serial relationship in a refrigerant flow circuit; and
a control unit configured for receiving information indicative of a compressor torque or compressor current;
a pressure sensor generating a signal corresponding to a suction pressure of the compressor;
the control unit receiving a signal corresponding to a compressor speed of the compressor; and
determining the discharge pressure as a function of each of (i) the compressor torque or compressor current, (ii) the compressor speed, and (iii) the suction pressure.

10. The system of claim 9 , wherein the received information comprises electric power data including data regarding at least one of a voltage differential, a current, and a phase-angle differential of a motor coupled to the compressor.

11. The system of claim 10 , wherein the control unit is configured for receiving the electric power data from the motor.

12. The system of claim 9 , wherein the control unit is configured for receiving the information from an inverter drive coupled to a variable speed motor.

13. The system of claim 12 , wherein the inverter drive is configured to modulate electric power delivered to the variable speed motor coupled to the compressor.

14. The system of claim 9 , wherein the control unit is configured for mapping each of the compressor torque, compressor speed, and the suction pressure to the discharge pressure.

15. The system of claim 9 , further comprising a temperature sensor for receiving a liquid temperature of a refrigerant in the refrigerant flow circuit.

16. The system of claim 9 , wherein the control unit is configured for mapping the discharge pressure to a saturated discharge temperature.

17. The system of claim 16 , wherein the control unit is configured for determining a degree of system subcooling from the saturated discharge temperature.

Assignees

• Carrier Corp

Inventors

• Schuster Don A
• Adepetu Adeyemi A
• Shah Rajendra K

Classifications

• F25B2700/21163

  of the refrigerant at the outlet of the condenser · CPC title

• F25B2700/1933

  Suction pressures · CPC title

• F25B2700/171

  of the compressor · CPC title

• F25B2700/15

  Power, e.g. by voltage or current · CPC title

• F25B2500/19

  Calculation of parameters · CPC title