Refrigeration system including a flexible sensor

Abstract

A refrigeration system including a compressor configured to compress a refrigerant, a condenser in fluid communication with the compressor and configured to remove heat from the refrigerant, and an expansion valve in fluid communication with the condenser and configured to decrease a pressure of the refrigerant. The refrigeration system also includes an evaporator in fluid communication with the expansion valve and configured to facilitate heat exchange between the refrigerant and another fluid, and a sensor configured to bend to measure a property of the refrigeration system. The sensor including a flexible substrate and a conductive material applied to the flexible substrate and having a resistance that changes in response to bending of the flexible substrate to generate a signal indicative of the property.

1 . A refrigeration system comprising:
 a compressor configured to compress a refrigerant;   a condenser in fluid communication with the compressor and configured to remove heat from the refrigerant;   an expansion valve in fluid communication with the condenser and configured to decrease a pressure of the refrigerant;   an evaporator in fluid communication with the expansion valve and configured to facilitate heat exchange between the refrigerant and another fluid; and   a sensor configured to bend to measure a property of the refrigeration system, the sensor including
 a flexible substrate, and 
 a conductive material applied to the flexible substrate and having a resistance that changes in response to bending of the flexible substrate to generate a signal indicative of the property. 
   
   
   
       2 . The refrigeration system of  claim 1 , wherein the sensor includes a sleeve positioned around at least a portion of the flexible substrate. 
   
   
       3 . The refrigeration system of  claim 1 , wherein the property is a liquid flow within at least one component of the refrigeration system. 
   
   
       4 . The refrigeration system of  claim 3 , wherein the liquid flow is a refrigerant flow. 
   
   
       5 . The refrigeration system of  claim 3 , wherein the liquid flow is an oil flow. 
   
   
       6 . The refrigeration system of  claim 3 , wherein failure of the expansion valve is determined by measuring the liquid flow with the sensor. 
   
   
       7 . The refrigeration system of  claim 3 , wherein a position of the expansion valve is determined by measuring the liquid flow with the sensor. 
   
   
       8 . The refrigeration system of  claim 3 , wherein a run time of the compressor is determined by measuring the liquid flow with the sensor. 
   
   
       9 . The refrigeration system of  claim 1 , wherein the property is an air flow. 
   
   
       10 . The refrigeration system of  claim 9 , wherein a demand defrost is triggered by measuring the air flow with the sensor. 
   
   
       11 . The refrigeration system of  claim 9 , wherein at least one of the condenser and the evaporator includes a fan, and wherein failure of the fan is determined by measuring the air flow with the sensor. 
   
   
       12 . The refrigeration system of  claim 9 , further comprising a display case including an air return grille, wherein blockage of the air return grille is determined by measuring the air flow with the sensor. 
   
   
       13 . The refrigeration system of  claim 9 , wherein blockage of the condenser is determined by measuring the air flow with the sensor. 
   
   
       14 . The refrigeration system of  claim 1 , wherein the property is a fluid level within at least one component of the refrigeration system. 
   
   
       15 . The refrigeration system of  claim 14 , further comprising a receiver configured to hold a portion of the refrigerant, wherein the fluid level is a refrigerant level within the receiver. 
   
   
       16 . The refrigeration system of  claim 14 , wherein the fluid level is an oil level within the compressor. 
   
   
       17 . The refrigeration system of  claim 14 , further comprising a display case including a drain, wherein blockage of the drain is determined by measuring the fluid level within the display case with the sensor. 
   
   
       18 . The refrigeration system of  claim 1 , further comprising a display case including a door, wherein the property is a position of the door. 
   
   
       19 . The refrigeration system of  claim 1 , further comprising a display case including a shelf, wherein the property is a load condition of the shelf. 
   
   
       20 . The refrigeration system of  claim 1 , further comprising a circuit breaker, wherein the property is a status of the circuit breaker. 
   
   
       21 . The refrigeration system of  claim 1 , further comprising a contactor configured to transmit power to at least one component of the refrigeration system, wherein the property is a status of the contactor. 
   
   
       22 . The refrigeration system of  claim 1 , further comprising a second refrigeration unit configured to circulate a second refrigerant that exchanges heat with the first-mentioned refrigerant, wherein the property is a fluid flow within the second refrigeration unit. 
   
   
       23 . A method of measuring a property of a refrigeration system, the refrigeration system including a compressor, a condenser in fluid communication with the compressor, an expansion valve in fluid communication with the condenser, and an evaporator in fluid communication with the expansion valve, the method comprising:
 providing a sensor including a flexible substrate and a conductive material applied to the flexible substrate, the conductive material having a resistance that changes in response to bending of the flexible substrate;   compressing a refrigerant with the compressor;   removing heat from the refrigerant with the condenser;   decreasing a pressure of the refrigerant with the expansion valve;   exchanging heat between the refrigerant and another fluid with the evaporator; and   bending the sensor to generate a signal indicative of a property of the refrigeration system.   
   
   
       24 . The method of  claim 23 , wherein bending the sensor includes bending the sensor to measure a liquid flow within at least one component of the refrigeration system. 
   
   
       25 . The method of  claim 24 , wherein the liquid flow is a refrigerant flow. 
   
   
       26 . The method of  claim 24 , wherein the liquid flow is an oil flow. 
   
   
       27 . The method of  claim 24 , wherein bending the sensor to measure a liquid flow includes bending the sensor to determine a failure of the expansion valve. 
   
   
       28 . The method of  claim 24 , wherein bending the sensor to measure a liquid flow includes bending the sensor to determine a position of the expansion valve. 
   
   
       29 . The method of  claim 24 , wherein bending the sensor to measure a liquid flow includes bending the sensor to determine a run time of the compressor. 
   
   
       30 . The method of  claim 23 , wherein bending the sensor includes bending the sensor to measure an air flow within at least one component of the refrigeration system. 
   
   
       31 . The method of  claim 30 , wherein bending the sensor to measure an air flow includes bending the sensor to trigger a demand defrost. 
   
   
       32 . The method of  claim 30 , wherein at least one of the condenser and the evaporator includes a fan, and wherein bending the sensor to measure an air flow includes bending the sensor to determine a fan failure. 
   
   
       33 . The method of  claim 30 , wherein the refrigeration system further includes a display case having an air return grille, and wherein bending the sensor to measure an air flow includes bending the sensor to determine blockage of the air return grille. 
   
   
       34 . The method of  claim 30 , wherein bending the sensor to measure an air flow includes bending the sensor to determine blockage of the condenser. 
   
   
       35 . The method of  claim 23 , wherein bending the sensor includes bending the sensor to measure a fluid level within at least one component of the refrigeration system. 
   
   
       36 . The method of  claim 35 , wherein the refrigerant system further includes a receiver configured to hold a portion of the refrigerant, and wherein bending the sensor to measure a fluid level includes bending the sensor to measure a refrigerant level within the receiver. 
   
   
       37 . The method of  claim 35 , wherein bending the sensor to measure a fluid level includes bending the sensor to measure an oil level within the compressor. 
   
   
       38 . The method of  claim 35 , wherein the refrigeration system further includes a display case having a drain, and wherein bending the sensor to measure a fluid level includes bending the sensor to determine blockage of the drain. 
   
   
       39 . The method of  claim 23 , wherein the refrigeration system further includes a display case having a door, and wherein bending the sensor includes bending the sensor to determine a position of the door. 
   
   
       40 . The method of  claim 23 , wherein the refrigeration system further includes a display case having a shelf, and wherein bending the sensor includes bending the sensor to determine a load condition of the shelf. 
   
   
       41 . The method of  claim 23 , wherein the refrigeration system further includes a circuit breaker, and wherein bending the sensor includes bending the sensor to determine a status of the circuit breaker. 
   
   
       42 . The method of  claim 23 , wherein the refrigeration system further includes a contactor configured to transmit power to at least one component of the refrigeration system, and wherein bending the sensor includes bending the sensor to determine a status of the contactor. 
   
   
       43 . The method of  claim 23 , wherein the refrigeration system further includes a second refrigeration unit configured to circulate a second refrigerant that exchanges heat with the first-mentioned refrigerant, and wherein bending the sensor includes bending the sensor to measure a fluid flow within the second refrigeration unit. 
   
   
       44 . An evaporative cooler comprising:
 a housing having at least one vent and configured to contain water;   a blower positioned within the housing and configured to draw air through the at least one vent;   an evaporator pad positioned adjacent to the at least one vent;   a pump configured to spray at least a portion of the evaporator pad with the water; and   a sensor configured to bend to measure a property of the evaporative cooler, the sensor including
 a flexible substrate, and 
 a conductive material applied to the flexible substrate and having a resistance that changes in response to bending of the flexible substrate to generate a signal indicative of the property. 
   
   
   
       45 . The evaporative cooler of  claim 44 , wherein the property is a water level within the housing. 
   
   
       46 . The evaporative cooler of  claim 44 , wherein the property is a spray flow from the pump.