Control system for a refrigerated merchandiser

Abstract

A method of controlling a refrigerated merchandiser. The method includes refrigerating a product display area of the merchandiser using a refrigerant, detecting a presence of an air-refrigerant mixture in the refrigerated merchandiser, activating a fan in response to detecting the presence of an air-refrigerant mixture, and at least partially evacuating an interior of the merchandiser in response to fan activation.

1 . A method of controlling a refrigerated merchandiser, the method comprising:
 refrigerating a product display area of the merchandiser using a refrigerant;   detecting a presence of an air-refrigerant mixture in the refrigerated merchandiser;   activating a fan in response to detecting the presence of an air-refrigerant mixture; and   at least partially evacuating an interior of the merchandiser in response to fan activation.   
     
     
         2 . The method of  claim 1 , further comprising
 de-energizing electrical components of the merchandiser in response to detecting the presence of an air-refrigerant mixture.   
     
     
         3 . The method of  claim 2 , further comprising activating the fan and de-energizing the electrical components in response to the detected air-refrigerant mixture reaching a predetermined threshold. 
     
     
         4 . The method of  claim 1 , further comprising activating an alarm in response to detecting the air-refrigerant mixture. 
     
     
         5 . The method of  claim 3 , wherein the refrigerant is a hydrocarbon refrigerant, and wherein the predetermined threshold is approximately 25% of a lower flammability limit of the hydrocarbon refrigerant. 
     
     
         6 . The method of  claim 1 , wherein at least partially evacuating the interior includes blowing air into the interior from outside the merchandiser. 
     
     
         7 . The method of  claim 1 , further comprising determining a presence of an ignition source prior to activating the fan. 
     
     
         8 . A method of controlling a refrigerated merchandiser, the method comprising:
 refrigerating a product display area of the merchandiser using a refrigerant;   detecting a presence of an air-refrigerant mixture in the refrigerated merchandiser;   initiating an action in response to the detected air-refrigerant mixture reaching a predetermined threshold relative to a lower flammability limit of the refrigerant.   
       at least one of activating a fan and de-energizing one or more electrical components of the merchandiser in response to the detected air-refrigerant mixture reaching a predetermined threshold relative to a lower flammability limit of the refrigerant 
     
     
         9 . The method of  claim 8 , wherein initiating an action includes at least one of activating a fan, de-energizing one or more electrical components of the merchandiser, and activating an alarm. 
     
     
         10 . The method of  claim 9 , further comprising
 de-energizing the one or more components;   activating the fan after the one or more components are de-energized; and   at least partially evacuating an interior of the merchandiser of the detected air-refrigerant mixture in response to fan activation.   
     
     
         11 . The method of  claim 8 , further comprising determining a presence of an ignition source prior to initiating the action. 
     
     
         12 . The method of  claim 11 , further comprising activating a fan to clear an interior of the merchandiser of the detected air-refrigerant mixture regardless of whether an ignition source is detected. 
     
     
         13 . The method of  claim 8 , further comprising determining whether a predetermined time has elapsed after detecting the presence of the air-refrigerant mixture reaching the predetermined threshold before initiating the action. 
     
     
         14 . A refrigerated merchandiser comprising:
 a case defining a product display area;   a refrigeration system including an evaporator coupled to the case and through which a hydrocarbon refrigerant is circulated to condition the product display area;   a sensor coupled to the case and configured to detect an air-refrigerant mixture within the merchandiser and to generate a signal indicative of the detected air-refrigerant mixture; and   a controller programmed to initiate an action in response to the signal indicative of the air-refrigerant mixture reaching a predetermined threshold relative to a lower flammability limit of the refrigerant.   
     
     
         15 . The refrigerated merchandiser of  claim 14 , wherein the controller is in communication with at least one of 1) a fan to clear an interior of the merchandiser of the detected air-refrigerant mixture, 2) one or more electrical components of the merchandiser to selectively de-energize the components, and 3) an alarm indicator to signal the presence of an air-refrigerant mixture in the merchandiser. 
     
     
         16 . The refrigerated merchandiser of  claim 15 , wherein the controller is programmed to activate the fan after the one or more electrical components are de-energized. 
     
     
         17 . The refrigerated merchandiser of  claim 14 , wherein the controller is programmed to initiate the action after a predetermined time has elapsed. 
     
     
         18 . The refrigerated merchandiser of  claim 14 , wherein the predetermined threshold is approximately 25% of the lower flammability limit. 
     
     
         19 . The refrigerated merchandiser of  claim 14 , wherein the controller is further programmed to determine the presence of an ignition source prior to initiation of the action. 
     
     
         20 . The refrigerated merchandiser of  claim 19 , wherein the controller is programmed to activate a fan to clear an interior of the merchandiser of the detected air-refrigerant mixture regardless of whether the presence of an ignition source is detected.