Single evaporator refrigerator/freezer unit with interdependent temperature control

Abstract

A combination refrigerator/freezer unit with an insulated cabinet defining a refrigerator section, a freezer section and at least one air passage between the freezer section and refrigerator section. A single evaporator is disposed in the freezer section. A controller controls operation of the refrigeration system. The controller receives input signals from freezer and refrigerator sensors and controls the refrigeration system to pass refrigerant to the evaporator in the freezer section according to at least one temperature parameter of the refrigerator section sensed by the refrigerator sensor.

1 . A combination refrigerator/freezer unit, comprising:
 an insulated cabinet defining a refrigerator section, a freezer section and at least one air passage between the freezer section and refrigerator section;   a freezer sensor disposed in the freezer section that senses a freezer section temperature;   a refrigerator sensor disposed in the refrigerator section that senses a refrigerator section temperature;   a refrigeration system having a single evaporator disposed in the freezer section; and   a controller for controlling operation of the refrigeration system and receiving input signals from the freezer and refrigerator sensors, the controller configured to control the refrigeration system to pass refrigerant to the evaporator in the freezer section according to at least one temperature parameter of the refrigerator section sensed by the refrigerator sensor.   
   
   
       2 . The combination refrigerator/freezer unit of  claim 2 , wherein one temperature parameter is a refrigerator section minimum temperature and the controller is configured to prevent the refrigerator section temperature from dropping below the refrigerator section minimum temperature. 
   
   
       3 . The combination refrigerator/freezer unit of  claim 2 , wherein the controller is programmed with a freezer section set point and wherein the controller is configured to energize the refrigeration system when the freezer section temperature is above the freezer section set point. 
   
   
       4 . The combination refrigerator/freezer unit of  claim 3 , wherein another temperature parameter is a refrigerator section set point, and wherein the controller is configured to energize the refrigeration system when the refrigerator section temperature is above the refrigerator section set point. 
   
   
       5 . The combination refrigerator/freezer unit of  claim 4 , wherein the controller is configured to run the refrigeration system until the freezer section temperature is below the freezer section set point and the refrigerator section temperature is below the refrigerator section set point. 
   
   
       6 . The cooling unit of  claim 5 , wherein the controller is programmed with a freezer section set point offset, and wherein the controller is configured to shut off the refrigeration system when the freezer section temperature reaches the freezer section set point minus the freezer section set point offset and the refrigerator section temperature is below the refrigerator section set point. 
   
   
       7 . The cooling unit of  claim 5 , wherein another temperature parameter is a refrigerator section set point offset, wherein the controller is programmed with a freezer section set point offset, and wherein the controller is configured to shut off the refrigeration system when the refrigerator section temperature reaches the refrigerator section set point minus the refrigerator section set point offset after the controller has detected an event when the refrigerator section temperature was not below the refrigerator section set point when the freezer section temperature reached the freezer section set point minus the freezer section set point offset. 
   
   
       8 . The cooling unit of  claim 7 , further comprising a user input connected to the controller, wherein the temperature parameters can be set by the user input. 
   
   
       9 . The cooling unit of  claim 8 , wherein the freezer section set point equals the refrigerator section set point minus a temperature set point difference. 
   
   
       10 . The cooling unit of  claim 1 , wherein the freezer and refrigerator sensors are thermistors. 
   
   
       11 . A combination refrigerator/freezer unit, comprising:
 an insulated cabinet defining a refrigerator section, a freezer section and at least one air passage between the freezer section and refrigerator section;   a freezer thermistor disposed in the freezer section that senses a freezer section temperature;   a refrigerator thermistor disposed in the refrigerator section that senses a refrigerator section temperature;   a refrigeration system having a single evaporator disposed in the freezer section; and   a controller for controlling operation of the refrigeration system and receiving input signals from the freezer and refrigerator sensors, the controller programmed with a refrigerator section minimum temperature and a refrigerator section set point;   wherein the controller is configured to control the refrigeration system to energize the refrigeration system when the refrigerator section temperature is above the refrigerator section set point;   wherein the controller is configured to disable the refrigeration system when the refrigerator section temperature is less than the refrigerator section minimum temperature.   
   
   
       12 . The combination refrigerator/freezer unit of  claim 11 , wherein the controller is programmed with a freezer section set point and the controller is configured to energize the refrigeration system when the refrigerator section temperature is above the refrigerator section set point. 
   
   
       13 . The combination refrigerator/freezer unit of  claim 12 , wherein the controller is configured to energize the refrigeration system until the refrigerator section temperature reaches the refrigerator section set point. 
   
   
       14 . A method of controlling a combination refrigerator/freezer unit with an insulated cabinet defining a refrigerator section, a freezer section, at least one air passage between the freezer section and refrigerator section, and a refrigeration system having a single evaporator disposed in the freezer section, the method comprising:
 sensing a freezer section temperature with a refrigerator sensor;   sensing a refrigerator section temperature with a freezer sensor; and   controlling the refrigeration system to pass refrigerant to the evaporator in the freezer section according to at least one temperature parameter of the refrigerator section sensed by the refrigerator sensor.   
   
   
       15 . The method of  claim 14 , wherein one temperature parameter is a refrigerator section minimum temperature, and wherein the refrigerator section temperature is prevented from dropping below the refrigerator section minimum temperature. 
   
   
       16 . The method of  claim 15 , wherein the refrigeration system is energized when the freezer section temperature is above a freezer section set point. 
   
   
       17 . The method of  claim 16 , wherein another temperature parameter is a refrigerator section set point, and wherein the refrigeration system is energized when the refrigerator section temperature is below the refrigerator section set point. 
   
   
       18 . The method of  claim 17 , wherein the refrigeration system is energized until the freezer section temperature is above the freezer section set point and the refrigerator section temperature is above the refrigerator section set point. 
   
   
       19 . The method of  claim 15 , wherein another temperature parameter is a refrigerator section set point offset and wherein the refrigeration system is energized when the freezer section temperature reaches the freezer section set point plus a freezer section set point offset, wherein the refrigeration system is energized when the refrigerator section temperature reaches the refrigerator section set point plus the refrigerator section set point offset, wherein the refrigeration system is energized until the freezer section temperature reaches the freezer section set point minus the freezer section set point offset and wherein the refrigeration system is energized until the refrigerator section temperature reaches the refrigerator section set point. 
   
   
       20 . The method of  claim 19 , wherein the refrigeration system is energized until the refrigerator section set point reaches the refrigerator section set point minus the refrigerator section set point offset after an event when the freezer section temperature had reached the freezer section set point minus the freezer section set point offset and the refrigerator section temperature had not reached the refrigerator section set point.