Initial power up or power outage refrigerant purge

Abstract

A method for diluting a leaked refrigerant in a refrigeration system according to an example of the present disclosure includes operating the refrigeration system in a purge mode based on at least one purge condition prior to initiating a compressor of the refrigeration system. A refrigeration system according to an example of the present disclosure includes a compressor configured to compress refrigerant in a refrigerant line, a heat exchanger configured to exchange heat with the refrigerant line in a heat exchange mode, a fan configured to pass air through the heat exchanger to an indoor space, and a controller configured to operate the refrigeration system in a purge mode based on at least one purge condition prior to initiating the compressor.

What is claimed is: 
     
         1 . A method for diluting a leaked refrigerant in a refrigeration system, comprising:
 operating the refrigeration system in a purge mode based on at least one purge condition prior to initiating a compressor of the refrigeration system.   
     
     
         2 . The method of  claim 1 , operating the refrigeration system in the purge mode comprises operating a fan to pass air through a heat exchanger of the refrigeration system. 
     
     
         3 . The method of  claim 2 , wherein the at least one purge condition comprises a detected power outage to the compressor. 
     
     
         4 . The method of  claim 2 , wherein the at least one purge condition comprises the compressor and fan being off for at least a predefined time period. 
     
     
         5 . The method of  claim 2 , wherein said operating the fan comprises operating the fan for a predefined time period sufficient to dissipate refrigerant leaked from the heat exchanger into an air duct and a building, and reduce a concentration of the leaked refrigerant below a predefined level. 
     
     
         6 . The method of  claim 5 , comprising:
 performing a calibration adjustment of a refrigerant sensor associated with the heat exchanger prior to initiating the compressor and after the fan has operated for the predefined time period during the purge mode, wherein the calibration adjustment comprises determining a new sensor reading to utilize as a baseline for non-detection of leaked refrigerant in the refrigeration system.   
     
     
         7 . The method of  claim 6 , wherein said performing the calibration adjustment comprises:
 determining a previous sensor reading utilized as a baseline for non-detection of leaked refrigerant in the refrigeration system; and   triggering an alarm if a magnitude of a difference between the new and previous sensor readings exceeds a predefined alert threshold.   
     
     
         8 . The method of  claim 6 , wherein the refrigerant sensor is disposed within the heat exchanger. 
     
     
         9 . The method of  claim 1 , comprising:
 during a heat exchange mode, operating at least one of the compressor and an auxiliary heating device that heats air exiting or entering the heat exchanger; and   during the purge mode, maintaining the compressor and auxiliary heating device in an off state;   wherein the auxiliary heating device comprises an electric or gas heater.   
     
     
         10 . The method of  claim 1 , comprising:
 during a heat exchange mode, operating the compressor and also operating an air cleansing device to cleanse air exiting or entering the heat exchanger; and   during the purge mode, maintaining the compressor and air cleansing device in an off state;   wherein the air cleansing device comprises an electrostatic air cleaner or a short-wavelength ultraviolet (UVC) light.   
     
     
         11 . A refrigeration system comprising:
 a compressor configured to compress refrigerant in a refrigerant line;   a heat exchanger configured to exchange heat with the refrigerant line in a heat exchange mode;   a fan configured to pass air through the heat exchanger to an indoor space; and   a controller configured to operate the refrigeration system in a purge mode based on at least one purge condition prior to initiating the compressor.   
     
     
         12 . The refrigeration system of  claim 11 , wherein to operate the refrigeration system in the purge mode, the controller is configured to operate the fan to pass air through the heat exchanger. 
     
     
         13 . The refrigeration system of  claim 12 , wherein the at least one purge condition comprises a detected power outage to the compressor. 
     
     
         14 . The refrigeration system of  claim 12 , wherein the at least one purge condition comprises the compressor and fan being off for at least a predefined time period. 
     
     
         15 . The refrigeration system of  claim 12 , wherein the controller is configured to operate the fan during the purge mode for a predefined time period sufficient to dissipate refrigerant leaked from the heat exchanger into an air duct and a building, and reduce a concentration of the leaked refrigerant below a predefined level. 
     
     
         16 . The refrigeration system of  claim 15 , comprising:
 a refrigerant sensor configured to detect leaked refrigerant in the heat exchanger;   wherein the controller is configured to perform a calibration adjustment of the refrigerant sensor prior to initiating the compressor and after the fan has operated for the predefined time period during the purge mode, wherein as part of the calibration adjustment, the controller is configured to determine a new sensor reading to utilize as a baseline for non-detection of leaked refrigerant in the heat exchanger.   
     
     
         17 . The refrigeration system of  claim 16 , wherein as part of the calibration adjustment, the controller is configured to:
 determine a previous sensor reading utilized as a baseline for non-detection of leaked refrigerant in the heat exchanger; and   trigger an alarm if a magnitude of a difference between the new and previous sensor readings exceeds a predefined alert threshold.   
     
     
         18 . The refrigeration system of  claim 16 , wherein the refrigerant sensor is disposed within the heat exchanger. 
     
     
         19 . The refrigeration system of  claim 11 , comprising:
 an auxiliary heating device configured to heat air exiting the heat exchanger, wherein the auxiliary heating device comprises an electric heater or a gas heater;   wherein the controller is configured to:
 during a heat exchange mode, operate at least one of the compressor and the auxiliary heating device; and 
 during the purge mode, maintain the compressor and auxiliary heating device in an off state. 
   
     
     
         20 . The refrigeration system of  claim 11 , comprising:
 an air cleansing device configured to cleanse air exiting the heat exchanger, wherein the air cleansing device comprises an electrostatic air cleaner or a short-wavelength ultraviolet (UVC) light; and   wherein the controller is configured to:
 during a heat exchange mode, operate the compressor and also operate the air cleansing device; and 
 during the purge mode, maintain the compressor and air cleansing device in an off state.