REFRIGERATOR APPLIANCE AND METHOD OF OPERATING A REFRIGERATOR APPLIANCE
The present invention provides a refrigerator appliance and for operation of a refrigerator appliance. The refrigerator appliance and method of operating a refrigerator appliance include features for regulating the time between evaporator defrost cycles to efficiently defrost the evaporator. Features are also included for increasing the temperature of refrigerant circulating through a refrigeration system of the refrigerator appliance to prevent condensation on outer surfaces of the refrigerator.
1 . A method for operating a refrigerator appliance, the refrigerator appliance comprising a refrigeration system for cycling a refrigerant therethrough that includes a compressor, a condenser, and an evaporator, the method comprising the steps of:
activating a defrost heater configured to melt ice built up on the evaporator;
counting a time t defrost ;
determining if evaporator is defrosted and, if so, then
deactivating the defrost heater;
determining whether to increase the refrigerant temperature to prevent condensation on the external surfaces of the refrigerator appliance.
2 . The method of claim 1 , further comprising the step of decreasing the condenser fan speed if the refrigerant temperature is determined to be increased.
3 . The method of claim 1 , further comprising the step of increasing the compressor speed if the refrigerant temperature is determined to be increased.
4 . The method of claim 1 , wherein the step of determining whether to increase the refrigerant temperature comprises determining the relative magnitude of the time t defrost .
5 . The method of claim 1 , wherein the step of determining if the evaporator is defrosted comprises monitoring a defrost termination thermostat.
6 . The method of claim 1 , further comprising the steps of:
waiting a time interval t ice if the defrost heater is deactivated; and then reactivating the defrost heater.
7 . The method of claim 1 , further comprising the step of establishing a time interval t ice during the step of deactivating the defrost heater.
8 . The method of claim 7 , wherein time interval t ice is based at least in part on time t defrost .
9 . A method for operating a refrigerator appliance, the refrigerator appliance comprising a refrigeration system for cycling a refrigerant therethrough that includes a compressor, a condenser, and an evaporator, the method comprising the steps of:
activating a defrost heater configured to melt ice built up on the evaporator;
counting a time t defrost ;
determining if evaporator is defrosted and, if so, then
deactivating the defrost heater,
waiting a time interval t ice , and
reactivating the defrost heater;
determining whether to increase the refrigerant temperature to prevent condensation on the external surfaces of the refrigerator appliance.
10 . The method of claim 9 , further comprising the step of decreasing the condenser fan speed if the refrigerant temperature is determined to be increased.
11 . The method of claim 9 , further comprising the step of decreasing a condenser fan speed if the refrigerant temperature is determined to be increased.
12 . The method of claim 9 , wherein the step of determining whether to increase the refrigerant temperature comprises determining the relative magnitude of the time t defrost .
13 . The method of claim 9 , wherein the step of determining if the evaporator is defrosted comprises monitoring a defrost termination thermostat.
14 . The method of claim 9 , further comprising the step of establishing the time interval t ice during the step of deactivating the defrost heater.
15 . The method of claim 9 , wherein time t ice is based at least in part on time t defrost .
16 . A refrigerator appliance, comprising:
at least one compartment for storing food items;
a refrigeration system for cycling a refrigerant therethrough, the refrigeration system comprising
a compressor;
a condenser;
a condenser fan;
an evaporator; and
a defrost heater configured to melt ice accumulated on the evaporator;
a controller in operative communication with the compressor and the condenser fan, the controller configured for
activating a defrost heater configured to melt ice built up on the evaporator;
counting a time t defrost ;
determining if evaporator is defrosted and, if so, then
deactivating the defrost heater;
determining whether to increase the refrigerant temperature to prevent condensation on the external surfaces of the refrigerator appliance.
17 . The refrigerator appliance of claim 16 , wherein the controller is further configured for decreasing the condenser fan speed if the controller determines to increase the refrigerant temperature.
18 . The refrigerator appliance of claim 16 , wherein the controller is further configured for increasing the compressor speed if the controller determines to increase the refrigerant temperature.
19 . The refrigerator appliance of claim 16 , wherein the controller is further configured for
establishing a time interval t ice during the step of deactivating the defrost heater;
waiting time interval t ice ; and
reactivating the defrost heater,
wherein time interval t ice is based at least in part on time t defrost.