Heat Exchanger Fault Diagnostic

Abstract

A fault diagnostic method for a heat exchanger in which ambient air temperature and heat exchanger temperature are measured. Also disclosed is the use of a single temperature sensor, in combination with a microprocessor, to measure temperature emitted from a heat exchanger and ambient air temperature surrounding the heat exchanger.

1 . A fault diagnostic method for a heat exchanger in which ambient air temperature and heat exchanger temperature are measured, the method comprising:
 measuring the temperature of the heat exchanger when the heat exchanger is in operation,   measuring the temperature of ambient air around the heat exchanger when the heat exchanger is not in operation,   comparing the two temperatures, and   when the difference between the two temperatures is greater than a selected temperature difference, sounding an alarm, alerting an engineer and/or disabling operation of the heat exchanger.   
     
     
         2 . The method according to  claim 1  further comprising steps preceding steps a) to d), wherein:
 i) a maximum operating temperature for the heat exchanger is set; and 
 ii) a temperature difference between the heat exchanger temperature and ambient air temperature is set for an efficiently operating heat exchange system. 
 
     
     
         3 . The method according to  claim 2 , wherein the maximum operating temperature for the heat exchanger is set within a range of about 50 to 125 degrees Celsius. 
     
     
         4 . The method according to  claim 1 , wherein the temperature difference is about 30 degrees Celsius. 
     
     
         5 . The method according to  claim 1 , wherein operation of the heat exchanger is informed by the operation of a compressor or pump associated with the heat exchanger. 
     
     
         6 . The method according to  claim 1 , wherein the temperature measurements are stored in a microprocessor. 
     
     
         7 . The method according to  claim 6 , wherein the microprocessor senses or detects whether or not the pump or compressor is in operation. 
     
     
         8 . The method according to  claim 6 , wherein the temperature readings are saved by the microprocessor into separate files as ‘heat exchanger temperature’ and ‘ambient air temperature’. 
     
     
         9 . The method according to  claim 8 , wherein the microprocessor subtracts ambient air temperature from heat exchanger temperature to ascertain whether or not the heat exchanger is functioning efficiently. 
     
     
         10 . The method according to  claim 1 , wherein measurement of ambient air temperature is made after a time period that is sufficient to enable the heat exchanger to cool to, or near to, ambient temperature. 
     
     
         11 . The method according to  claim 10 , wherein the time period is between about 2 and 5 minutes after the heat exchanger has ceased to operate. 
     
     
         12 . The method according to  claim 1 , wherein the temperatures are measured by two temperature sensors. 
     
     
         13 . The method according to  claim 1 , wherein the temperatures are measured by a single temperature sensor. 
     
     
         14 . The method according to  claim 13 , wherein the single temperature sensor is located on or close to the heat exchanger. 
     
     
         15 . Use of a single temperature sensor, in combination with a microprocessor, to measure temperature emitted from a heat exchanger and ambient air temperature surrounding the heat exchanger. 
     
     
         16 . Use according to  claim 15 , wherein the temperature sensor a) measures the temperature emitted from the heat exchanger when the heat exchanger is in operation and b) measures the temperature of ambient air around the heat exchanger when the heat exchanger is not in operation. 
     
     
         17 . Use according to  claim 15 , wherein ambient air temperature is subtracted from the temperature emitted from the heat exchanger and, when the difference between the two temperatures is greater than about 30 degrees Celsius, the microprocessor issues a fault alert. 
     
     
         18 . Use according to  claim 15 , wherein operation of the heat exchanger is informed by the operation of a pump or compressor associated with the heat exchanger. 
     
     
         19 . Use according to  claim 18 , wherein the microprocessor senses or detects whether or not the pump or compressor is in operation. 
     
     
         20 . Use according to  claim 15 , wherein the microprocessor saves the temperature readings. 
     
     
         21 . Use according to  claim 20 , wherein the temperature readings are saved by the microprocessor into separate files as ‘heat exchanger temperature’ and ‘ambient air temperature’. 
     
     
         22 . Use according to  claim 21 , wherein the microprocessor subtracts ambient air temperature from heat exchanger temperature to ascertain whether or not the heat exchanger is functioning efficiently. 
     
     
         23 . Use according to  claim 15 , wherein measurement of ambient air temperature is made after a time period that is sufficient to enable the heat exchanger to cool to, or near to, ambient temperature. 
     
     
         24 . Use according to  claim 23 , wherein the time period between about 2 and 5 minutes after the heat exchanger has ceased to operate. 
     
     
         25 . Use according to  claim 15 , wherein the temperature sensor is located on or close to the heat exchanger. 
     
     
         26 . Use according to  claim 15  to diagnose a fault in a heat exchanger.