Refrigerator Evaporator Defrost Control Using Valve Opening Time
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Solution Overview
Problem
Conventional refrigerator defrost control methods are inadequate for refrigerators with independently installed freezing and refrigerating chamber evaporators, leading to unnecessary defrosting of unfrosted evaporators and excessive temperature rises due to improper defrost timing.
Innovation Solution
A method of controlling refrigerant flow through a refrigerant control valve to independently manage defrosting of each evaporator based on its specific opening integration time and ambient temperature settings, ensuring precise defrosting and minimizing temperature fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional defrost control based on compressor operation integration time is applied to a refrigerator with independently installed freezing chamber evaporator and refrigerating chamber evaporator, then the defrost operation can be performed at regular intervals, but unnecessary defrosting of unfrosted evaporators occurs and both evaporators may be defrosted even when only one requires defrosting
Solution Approach 1:
The patent segments the defrost control for each evaporator independently by introducing separate refrigerant control valves (freezing chamber refrigerant control valve and refrigerating chamber refrigerant control valve) for each evaporator. This allows the defrost operation to be controlled separately for each evaporator based on its own frosting condition, preventing unnecessary defrosting of unfrosted evaporators.
Solution Approach 2:
The patent changes the control parameter from compressor operation integration time to refrigerant control valve opening integration time. By measuring the opening integration time of each evaporator's refrigerant control valve, the system can accurately determine when each evaporator actually requires defrosting, thereby improving defrost control accuracy and avoiding unnecessary heater operations.
2Reliability
If defrost operation is performed frequently to ensure evaporators are always defrosted, then evaporator performance is maintained, but temperature within the refrigerator rises excessively due to excessive heater operation
Solution Approach 1:
The patent changes the control parameter from fixed time-based defrost scheduling to dynamic valve opening integration time measurement. This allows the system to perform defrost operations only when actually needed, maintaining evaporator performance while avoiding excessive heater operation that would cause temperature rises in the refrigerator.
Solution Approach 2:
The system uses feedback from the refrigerant control valve opening integration time measurement to determine when defrosting is actually required. This feedback mechanism ensures defrost operations are performed based on actual evaporator conditions rather than fixed schedules, preventing unnecessary heater operations and maintaining temperature stability.
3Device complexity
If a single evaporator is used to cool both freezing chamber and refrigerating chamber, then device complexity is reduced, but independent cooling control of each chamber is compromised
Solution Approach 1:
The patent segments the refrigerant distribution system by introducing a refrigerant control valve for each evaporator (freezing chamber refrigerant control valve and refrigerating chamber refrigerant control valve). This segmentation enables independent control of refrigerant flow to each evaporator, allowing independent cooling control of each chamber while maintaining the benefit of multiple evaporators for simultaneous cooling.
Solution Approach 2:
The patent employs a multi-functional refrigerant control valve system where each valve can independently control refrigerant flow to its corresponding evaporator. This universal control mechanism allows the system to adapt to different cooling requirements of each chamber independently, enhancing versatility while managing device complexity through standardized valve components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for accurate defrosting of each evaporator at the required time, preventing unnecessary heater operation and improving cooling performance by setting distinct return temperatures based on ambient conditions.
Implementation Method 1
operating the refrigerator in a defrost mode of the evaporator in which the refrigerant is introduced
Data Source
AI summary
A method of controlling a refrigerator is provided. The refrigerator may include a main body having a plurality of storage chambers, a plurality of evaporators to independently cool the plurality of storage chambers, and a refrigerant control valve that controls refrigerant flow into the plurality of evaporators. The method may include opening the control valve and allowing refrigerant to flow into at least one of the plurality of evaporators, when an opening integration time of the control valve is greater than a defrost setting time of the evaporator, operating the refrigerator in a defrost mode, and, when a temperature sensed by a defrost sensor of an evaporator being defrosted is greater than return setting temperatures, terminating operation in the defrost mode. In this manner, each evaporator may be defrosted efficiently, and at a point in time at which defrosting is required.