Hvac compressor prognostics

Patent metadata

Field	Value
Publication number	US-2016290671-A1
Application number	US-201615088334-A
Country	US
Kind code	A1
Filing date	Apr 1, 2016
Priority date	Apr 1, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

Systems and methods for determining the health of a compressor are disclosed. In one embodiment, a prognostic-diagnostic unit (PDU) compares expected compressor power consumption, based on current operating conditions of the HVAC system, to actual compressor power consumption. If the actual power consumption is within a predefined range of the expected power consumption under current operational conditions, the HVAC system is determined to be operating properly. If the actual power consumption deviates from the expected power consumption, a fault is indicated. An appropriate action is taken, such as displaying a fault alert, transmitting a fault message to another device, and storing information relating to the fault for later retrieval to assist troubleshooting.

First claim

What is claimed is:

1 . A method for determining an operational condition of a compressor operatively coupled to an electric motor, comprising:
receiving information indicative of an actual input power of the electric motor; receiving information indicative of a compressor speed, a compressor saturated suction temperature, and a compressor saturated discharge temperature; determining a mapped input power from the received compressor speed, the compressor saturated suction temperature, and the compressor saturated discharge temperature; and determining the operational condition of the compressor from the actual input power and the mapped input power.

2 . The method in accordance with claim 1 , wherein receiving information indicative of an actual input power includes receiving the information from an inverter drive coupled to the electric motor.

3 . The method in accordance with claim 1 , wherein receiving information indicative of a compressor speed includes receiving the information from an inverter drive coupled to the electric motor.

4 . The method in accordance with claim 1 , further comprising:
receiving a sensor signal corresponding to a compressor saturated discharge pressure; and mapping the compressor saturated discharge pressure to the compressor saturated discharge temperature.

5 . The method in accordance with claim 1 , further comprising:
receiving a sensor signal corresponding to a compressor saturated suction pressure; and mapping the compressor saturated suction pressure to the compressor saturated suction temperature.

6 . The method in accordance with claim 1 , wherein determining the operational condition of the compressor includes determining if the ratio between the actual input power and the mapped input power exceeds a predetermined ratio.

7 . The method in accordance with claim 6 , further comprising issuing an alert in response to the exceeding.

8 . The method in accordance with claim 6 , wherein the predetermined ratio is selected from the group consisting of about 1.1:1 and about 1.3:1.

9 . The method in accordance with claim 1 , wherein determining the operational condition of the compressor includes determining if the ratio between the actual input power and the mapped input power is less than a predetermined ratio.

10 . The method in accordance with claim 9 , further comprising issuing an alert in response to a determination that the mapped input power is less than a predetermined ratio.

11 . The method in accordance with claim 9 , wherein the predetermined ratio is selected from the group consisting of about 0.7:1 and about 0.85:1.

12 . The method in accordance with claim 1 , further comprising storing historical information including at least one of a timestamp, information indicative of the actual input power of the electric motor, information indicative of the compressor speed, information indicative of the compressor saturated discharge temperature, and/or information indicative of the compressor saturated suction temperature in a memory device.

13 . The method in accordance with claim 12 , further comprising retrieving, from the memory device, the historical information.

14 . The method in accordance with claim 1 , wherein determining a mapped input power includes calculating the mapped input power in accordance with the equation:
P mapped =a+b*T css +c*T csd +d*T css 2 +e*T css *T csd +f*T csd 2 +g*T css 3 +h*T csd *T css 2 +i*T css *T csd 2 +j*T csd 3

15 . An HVAC compressor prognostics system, comprising:
a compressor; an electric motor configured to drive the compressor; and a prognostic-diagnostic unit configured for receiving information indicative of motor input power, compressor speed, compressor saturated discharge temperature, and compressor saturated suction temperature, the prognostic-diagnostic unit further configured to determine an operational condition of the compressor from the received information.

16 . The HVAC compressor prognostics system in accordance with claim 15 , wherein the prognostic-diagnostic unit is further configured to receive a signal indicative of motor input power from an inverter drive coupled to the electric motor.

17 . The HVAC compressor prognostics system in accordance with claim 15 , wherein the prognostic-diagnostic unit is further configured to receive a signal indicative of compressor speed from an inverter drive coupled to the electric motor.

18 . The HVAC compressor prognostics system in accordance with claim 15 , wherein the prognostic-diagnostic unit is configured for receiving a signal indicative of compressor saturated discharge pressure, and wherein the prognostic-diagnostic unit is further configured to map the compressor saturated discharge pressure to compressor saturated discharge temperature.

19 . The HVAC compressor prognostics system in accordance with claim 15 , wherein the prognostic-diagnostic unit is configured for receiving a signal indicative of compressor saturated suction pressure, and wherein the prognostic-diagnostic unit is further configured to map the compressor saturated suction pressure to compressor saturated suction temperature.

20 . The HVAC compressor prognostics system in accordance with claim 15 , wherein the prognostic-diagnostic unit is further configured for receiving signals indicative of the input current of the electric motor and of the input voltage of the electric motor, and wherein the prognostic-diagnostic unit is further configured to calculate the input power of the electric motor from the signals.

21 . The HVAC compressor prognostics system in accordance with claim 15 , wherein the prognostic-diagnostic unit is further configured to determine a mapped input power from the received compressor speed, the compressor saturated discharge temperature, and the compressor saturated suction temperature.

22 . The HVAC compressor prognostics system in accordance with claim 21 , wherein the prognostic-diagnostic unit is further configured for calculating the mapped input power in accordance with the equation:
P mapped =a+b*T css +c*T csd +d*T css 2 +e*T css *T csd +f*T csd 2 +g*T css 3 +h*T csd *T css 2 +i*T css *T csd 2 +j*T csd 3 .

23 . The HVAC compressor prognostics system in accordance with claim 21 , wherein the prognostic-diagnostic unit is further configured for determining a ratio between motor input power and mapped input power.

24 . The HVAC compressor prognostics system in accordance with claim 23 , wherein the prognostic-diagnostic unit is further configured to transmit a fault signal if the ratio between the motor input power and the mapped input power exceeds a predetermined ratio.

25 . The HVAC compressor prognostics system in accordance with claim 24 , wherein the prognostic-diagnostic unit is further configured to transmit a second fault signal if the ratio between the motor input power and the mapped input power exceeds a second predetermined ratio.

26 . The HVAC compressor prognostics system in accordance with claim 23 , the prognostic-diagnostic unit further comprising a memory device, wherein the prognostic-diagnostic unit is further configured to store historical information including at least one of a timestamp, information indicative of the actual input power of the e

Assignees

• Trane Int Inc

Inventors

• Schuster Don A
• Reed Thomas
• Yan Chuan

Classifications

• F25B2700/21152

  at the discharge side of the compressor · CPC title

• F24F2011/0091

  Mechanical Engineering · mapped topic

• F04C18/0215

  where only one member is moving · CPC title

• F04C29/0085 Primary

  Prime movers · CPC title

• F25B2700/21151

  at the suction side of the compressor · CPC title