Multi-Evaporator Refrigerator Defrost Control by Valve Opening Time
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Solution Overview
Problem
Conventional refrigerator defrost control methods are inadequate for refrigerators with multiple evaporators, leading to unnecessary defrosting of unfrosted evaporators and inefficient temperature management, especially when cooling both freezing and refrigerating chambers independently.
Innovation Solution
A method of controlling refrigerators with multiple evaporators using a refrigerant control valve to determine the exact defrosting time based on the opening integration time of the valve, with separate defrost settings and sensors for each evaporator, and ambient temperature adjustments to prevent excessive heating and improve cooling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional defrost control based on compressor operation time is applied to refrigerators with multiple evaporators, then the control system remains simple, but unnecessary defrosting occurs on evaporators that have not been frosted
Solution Approach 1:
The patent segments the refrigerant control system by introducing separate refrigerant control valves for each evaporator (freezing chamber evaporator and refrigerating chamber evaporator). This allows independent control and monitoring of refrigerant flow to each evaporator, enabling accurate determination of which evaporator actually requires defrosting based on individual usage patterns rather than applying a blanket defrost control to all evaporators.
Solution Approach 2:
The patent implements feedback control by monitoring the opening integration time of refrigerant control valves for each evaporator and using this information to determine defrost timing. The controller continuously tracks refrigerant flow patterns and triggers defrost operations only when the accumulated valve opening time exceeds a predetermined threshold, ensuring defrosting occurs only when actually needed based on real-time operational data.
2Ease of operation
If defrost operation is performed on all evaporators regardless of actual frosting condition, then defrost control is simplified, but temperature stability within storage chambers deteriorates
Solution Approach 1:
The patent employs dynamic defrost control by continuously monitoring the opening integration time of refrigerant control valves and adjusting defrost timing based on actual evaporator usage conditions. Rather than using fixed time-based defrost schedules, the system dynamically determines when each evaporator requires defrosting based on accumulated refrigerant flow data, allowing flexible adaptation to varying operational patterns while maintaining temperature stability.
Solution Approach 2:
The patent changes the control parameter from fixed compressor operation time to variable refrigerant valve opening integration time for each evaporator. This parameter change enables more precise control over defrost timing by directly measuring actual evaporator activity through valve operation data, triggering defrost only when the integrated valve opening time exceeds a threshold, thereby preventing unnecessary defrost operations that would disrupt temperature stability.
3Productivity
If unnecessary defrosting operations are performed on unfrosted evaporators, then the defrost control system operates frequently, but energy consumption and cooling efficiency deteriorate
Solution Approach 1:
The patent applies partial action by performing defrost operations only on evaporators that actually require it, rather than defrosting all evaporators uniformly. By monitoring individual refrigerant valve opening times and triggering defrost only when specific thresholds are exceeded, the system performs defrost actions partially and selectively, avoiding excessive defrost operations on evaporators that remain unfrosted, thereby reducing unnecessary heater energy consumption.
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 ensures precise defrosting of each evaporator at the required time, minimizes temperature fluctuations, and enhances cooling efficiency by preventing unnecessary heater operation and optimizing defrost end times based on ambient temperatures.
Implementation Method 1
a refrigerant control valve for controlling refrigerant introduced into the plurality of evaporators
Implementation Method 2
a plurality of evaporators installed to independently cool the plurality of storage chambers, respectively
Implementation Method 3
an evaporator for evaporating and gasifying liquefied refrigerant fed from the pressure reducing means
Implementation Method 4
a heater installed in the main body, heating and defrosting the evaporator
Implementation Method 5
heating and defrosting the evaporator
Data Source
AI summary
The present invention provides a method of controlling a refrigerator, including a main body having a plurality of storage chambers; a plurality of evaporators installed to independently cool the plurality of storage chambers, respectively; and a refrigerant control valve for controlling refrigerant introduced into the plurality of evaporators, the method includes a refrigerant control valve opening step of opening the refrigerant control valve so that the refrigerant can be introduced into at least one of the plurality of evaporators; an evaporator defrost step of, when an opening integration time of the refrigerant control valve is higher than a defrost setting time of the evaporator, at which the refrigerant is introduced by the refrigerant control valve, operating the refrigerator in a defrost mode of the evaporator in which the refrigerant is introduced; and an evaporator defrost end step of, when temperatures sensed by defrost sensors of the evaporators that are being defrosted are higher than return setting temperatures after the evaporator defrost step begins, ending the defrost mode of the refrigerator. Accordingly, the present invention is advantageous in that it can defrost each evaporator efficiently at an exact point of time at which defrosting is required.