Refrigeration apparatus demand defrost control system and method
AssigneeGeneral Electric Company
InventorRobert B. Brooks
Life of this patent
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Abstract
A demand defrost control system which responds to whether a predetermined evaporator temperature is reached during a defrosting operation. If the predetermined temperature is not reached, then a relatively shorter interval before the next defrosting operation is established. If the predetermined temperature is reached, then a relatively longer interval before the next defrosting operation is established.
Claims11
An automatically-defrosting refrigeration apparatus including a refrigerant evaporator, a heater for defrosting said evaporator, and a demand defrost control system, said demand defrost control system comprising:
- a defrost control including means for establishing either a relatively shorter or a relatively longer interval between successive defrosting operations, said defrost control further including means for establishing the duration of a defrosting operation;
- means for de-energizing said evaporator and energizing said heater upon initiation of a defrosting operation and for de-energizing said heater by at least the end of a defrosting operation;
- a thermal sensor responsive to a predetermined evaporator temperature being reached during a defrosting operation;
- and
- means responsive to said thermal sensor for selecting the interval before the next defrosting operation, the relatively shorter interval being selected if the predetermined temperature is not reached during a defrosting operation, and the relatively longer interval being selected if the predetermined temperature is reached during a defrosting operation.
The method of controlling the interval between successive evaporator defrosting operations in a refrigeration apparatus, which method comprises:
- establishing the duration of a defrost operation;
- energizing a heater upon initiation of a defrosting operation and de-energizing the heater at least by the end of the defrosting operation;
- sensing the temperature of the evaporator during a defrosting operation;
- selecting a relatively shorter interval before the next defrosting operation if a predetermined sensed temperature is not reached during a defrosting operation, and selecting a relatively longer interval before the next defrosting operation if the predetermined sensed temperature is reached during a defrosting operation.
Dependencies are inferred from the claim text.