Heat pump system reversing valve fault detection

Abstract

A method of operating a heat pump system includes performing two or more status checks of a reversing valve. Each status check includes comparing a respective set of measurements. The method further includes determining whether the reversing valve is in a fault condition based on at least one of the plurality of status checks.

What is claimed is: 
     
         1 . A method of operating a heat pump system, the heat pump system comprising an outdoor portion, an indoor portion, and a sealed system coupled between the outdoor portion and the indoor portion to circulate refrigerant through an indoor heat exchanger of the indoor portion and an outdoor heat exchanger of the outdoor portion, the sealed system comprising a reversing valve to selectively reverse flow direction of the refrigerant, the method comprising:
 performing a first status check of the reversing valve by comparing a first set of sensor measurements;   performing a second status check of the reversing valve by comparing a second set of sensor measurements; and   determining whether the reversing valve is in a fault condition based on at least one of the first status check and the second status check.   
     
     
         2 . The method of  claim 1 , wherein determining whether the reversing valve is in the fault condition comprises determining the reversing valve is in the fault condition based on both of the first status check and the second status check. 
     
     
         3 . The method of  claim 1 , wherein the first set of sensor measurements is obtained from a first temperature sensor and a second temperature sensor, and wherein the second set of sensor measurements is obtained from the first temperature sensor and a third temperature sensor. 
     
     
         4 . The method of  claim 1 , wherein the first set of sensor measurements is obtained from a first temperature sensor and a second temperature sensor, and wherein the second set of sensor measurements is obtained from a third temperature sensor and a fourth temperature sensor. 
     
     
         5 . The method of  claim 1 , wherein the first set of temperature measurements and the second set of temperature measurements are obtained from a plurality of sensors, further comprising performing a validation check for each sensor of the plurality of sensors by validating at least one measurement value from each sensor of the plurality of sensors, wherein each sensor measurement of the first set of sensor measurements and the second set of sensor measurements is obtained from a sensor which passed the validation check. 
     
     
         6 . The method of  claim 1 , further comprising performing a validation check for each sensor measurement of the first set of sensor measurements and the second set of sensor measurements, wherein the fault condition of the reversing valve is determined based on only the first status check when each sensor measurement of the first set of sensor measurements passes the validation check and at least one sensor measurement of the second set of sensor measurements does not pass the validation check, and wherein the fault condition of the reversing valve is determined based on only the second status check when each sensor measurement of the second set of sensor measurements passes the validation check and at least one sensor measurement of the first set of sensor measurements does not pass the validation check. 
     
     
         7 . The method of  claim 1 , wherein the first status check returns a fault status and the second status check returns a normal status, further comprising performing a third status check by comparing a third set of sensor measurements, wherein the third status check returns a fault status, and wherein determining whether the reversing valve is in the fault condition comprises determining the reversing valve is in the fault condition based on the first status check and the third status check. 
     
     
         8 . The method of  claim 1 , wherein the first status check returns a fault status and the second status check returns a normal status, further comprising performing a third status check by comparing a third set of sensor measurements, wherein the third status check returns a normal status, and wherein determining whether the reversing valve is in the fault condition comprises determining the reversing valve is not in the fault condition based on the second status check and the third status check. 
     
     
         9 . The method of  claim 1 , further comprising waiting for the heat pump system to stabilize at a steady state of operation prior to performing the first status check and performing the second status check. 
     
     
         10 . The method of  claim 1 , wherein the first set of sensor measurements comprises a first one and the second set of sensor measurements comprises a second one of the following sets:
 indoor air outlet temperature and indoor air inlet temperature;   indoor coil temperature and indoor air inlet temperature;   outdoor coil temperature and outdoor air inlet temperature;   indoor coil refrigerant pressure and indoor air inlet temperature;   outdoor coil refrigerant pressure and outdoor air inlet temperature;   indoor coil temperature and outdoor coil temperature; and   indoor coil refrigerant pressure and outdoor coil refrigerant pressure.   
     
     
         11 . A method of operating a heat pump system, the heat pump system comprising an outdoor portion, an indoor portion, and a sealed system coupled between the outdoor portion and the indoor portion to circulate refrigerant through an indoor heat exchanger of the indoor portion and an outdoor heat exchanger of the outdoor portion, the sealed system comprising a reversing valve to selectively reverse flow direction of the refrigerant, the method comprising:
 obtaining a plurality of measurements from a plurality of sensors in the heat pump system;   performing a plurality of status checks, wherein each status check comprises comparing a respective set of measurements from the plurality of measurements; and   determining whether the reversing valve is in a fault condition based on the plurality of status checks.   
     
     
         12 . The method of  claim 11 , further comprising performing a validation check on each measurement of the plurality of measurements prior to performing the plurality of status checks, wherein each set of measurements consists of only measurements that passed the validation check. 
     
     
         13 . The method of  claim 11 , wherein obtaining the plurality of measurements comprises obtaining a first measurement from a first sensor, a second measurement from a second sensor, and a third measurement from a third sensor. 
     
     
         14 . The method of  claim 11 , wherein the plurality of status checks comprises a first status check comparing a first set of measurements, a second status check comparing a second set of measurements, and a third status check comparing a third set of measurements. 
     
     
         15 . The method of  claim 14 , wherein determining whether the reversing valve is in the fault condition based on the plurality of status checks comprises determining whether the reversing valve is in the fault condition based on a majority of the plurality of status checks. 
     
     
         16 . The method of  claim 11 , further comprising waiting for the heat pump system to stabilize at a steady state of operation prior to obtaining the plurality of measurements. 
     
     
         17 . The method of  claim 11 , wherein each status check of the plurality of status checks comprises comparing one of the following sets of measurements:
 indoor air outlet temperature and indoor air inlet temperature;   indoor coil temperature and indoor air inlet temperature;   outdoor coil temperature and outdoor air inlet temperature;   indoor coil refrigerant pressure and indoor air inlet temperature;   outdoor coil refrigerant pressure and outdoor air inlet temperature;   indoor coil temperature and outdoor coil temperature; or   indoor coil refrigerant pressure and outdoor coil refrigerant pressure.