Control sytem for bottom freezer refrigerator with ice maker in upper door

Abstract

A refrigerator includes a main body defining a compartment, the compartment having an access opening and a first wall, a door supported by the main body for selectively closing at least part of the access opening, a sub-compartment on the door, the sub-compartment including a second wall having an opening, a heat exchanger supported by the first wall and positioned so that when the door is closed the heat exchanger is exposed to an interior of the sub-compartment through the opening. The heat exchanger includes a heat exchanging plate. A sealed refrigeration system contains a working medium for cooling the heat exchanger and has one or more segments attached to the heat exchanging plate. A fan is configured to force air over the heat exchanging plate and into the interior of the sub-compartment. A thermistor is coupled to the heat exchanging plate for monitoring a temperature of the heat exchanging plate. A controller is configured to adjust a speed of the fan in dependence of the temperature of the heat-exchanging plate detected by the thermistor.

1 . A refrigerator comprising:
 a main body defining a compartment, the compartment having an access opening and a first wall;   a door supported by the main body for selectively closing at least part of the access opening;   a sub-compartment on the door, the sub-compartment comprising a second wall having an opening;   a heat exchanger supported by the first wall and positioned so that when the door is closed the heat exchanger is exposed to an interior of the sub-compartment through the opening, the heat exchanger comprising a heat exchanging plate;   a sealed refrigeration system containing a working medium for cooling the heat exchanger and comprising one or more segments attached to the heat exchanging plate;   a fan configured to force air over the heat exchanging plate and into the interior of the sub-compartment;   a thermistor coupled to the heat exchanging plate for monitoring a temperature of the heat exchanging plate; and   a controller configured to adjust a speed of the fan in dependence of the temperature of the heat-exchanging plate detected by the thermistor.   
     
     
         2 . The refrigerator of  claim 1 , wherein the controller is configured to adjust the speed of the fan to a low speed when the detected temperature is below a pre-determined temperature setpoint, and to a high speed when the detected temperature is above the pre-determined temperature setpoint. 
     
     
         3 . The refrigerator of  claim 2 , further comprising activating a cooling cycle of the refrigeration system when the speed of the fan is set to the high speed. 
     
     
         4 . The refrigerator of  claim 3 , further comprising a wherein the activation of the cooling cycle of the refrigeration system is independent of a cooling requirement for the compartment of the main body. 
     
     
         5 . The refrigerator of  claim 1 , wherein the controller is configured to detect an initiation of an ice formation cycle and set a speed of the fan to high. 
     
     
         6 . The refrigerator of  claim 5 , wherein the controller is configured to activate the refrigeration system to cool the heat exchanger when the speed of the fan is set to high. 
     
     
         7 . The refrigerator of  claim 5 , wherein the controller is configured measure an elapsed time from the initiation of the ice formation cycle and set the speed of the fan to a low speed cycle and the refrigeration system to a normal cooling cycle if the elapsed time exceeds a pre-determined time period. 
     
     
         8 . The refrigerator of  claim 1 , wherein the controller is configured to detect that the refrigeration system is in a cooling cycle, determine the temperature of the heat-exchanging plate and adjust the speed of the fan to cool the interior of the sub-compartment. 
     
     
         9 . The refrigerator of  claim 1 , wherein the controller is further configured to terminate a defrost cycle of the refrigerator in dependence of the temperature detected by the thermistor. 
     
     
         10 . A method comprising:
 detecting a temperature of a heat exchanging plate in a bottom freezer refrigerator having an ice sub-compartment on the door of a top mounted fresh food compartment; and   activating a fan for moving air across the heat exchanging plate and into the ice sub-compartment in dependence of the detected temperature.   
     
     
         11 . The method of  claim 10 , further comprising adjusting a speed of the fan to a low speed when the detected temperature is below a predetermined temperature setpoint and adjusting the speed of the fan to a higher speed when the detected temperature is above the predetermined temperature setpoint. 
     
     
         12 . The method of  claim 11 , further comprising detecting that the detected temperature is above a second predetermined temperature setpoint, setting the speed of the fan to a high speed and activating a refrigeration system of the refrigerator. 
     
     
         13 . The method of  claim 12 , further comprising that the activation of the refrigeration system occurs independently of a temperature requirement for a fresh food or freezer compartment of the refrigerator. 
     
     
         14 . The method of  claim 10 , further comprising activating the fan only when a refrigeration system for the refrigerator is in a cooling mode. 
     
     
         15 . The method of  claim 10 , further comprising:
 detecting that a state of an ice maker in the ice sub-compartment is in an ice formation cycle;   setting a speed of the fan to a high speed; and   activating a refrigeration system for the refrigeration to a cooling mode.   
     
     
         16 . The method of  claim 15 , further comprising:
 determining a pre-determined time period from a start of the ice formation cycle; and   setting the speed of the fan in dependence of the detected temperature.   
     
     
         17 . The method of  claim 10 , further comprising using a single thermistor coupled to the heat exchanging plate to detect the temperature of the heat exchanging plate. 
     
     
         18 . The method of  claim 10 , further comprising:
 detecting a defrost mode of the heat-exchanging plate; and   deactivating the defrost mode when the temperature of the heat-exchanging plate reaches a pre-determined defrost temperature setpoint.