Sublimation Defrosting Method for Continuous Cooling Operation
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Solution Overview
Problem
Conventional defrosting methods for cooling devices require stopping operations, consume high thermal energy, and have low efficiency, with sublimation methods being costly and inefficient due to the need for dehumidification and large heat input.
Innovation Solution
A sublimation defrosting method that heats the root-side region of the frost layer with a heat source located on the adhesion side, creating a temperature gradient to facilitate sublimation without stopping the cooling process, reducing the need for melting water removal and minimizing heat input by targeting the root-side region for sublimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the frost layer is heated and melted with a heater, then the frost layer can be removed, but the operation of the cooler needs to be stopped and it takes time to remove the melt water
Solution Approach 1:
The invention utilizes sublimation phase transition to remove frost directly from solid to vapor without passing through the liquid phase. By controlling the temperature to be below the melting point while providing sufficient heat, the frost layer sublimes directly, eliminating the need to stop cooling operations and avoiding melt water removal issues.
Solution Approach 2:
The invention changes the temperature parameter control strategy by maintaining the cooling surface temperature below the melting point of ice while providing heat to the frost layer. This parameter control enables sublimation without melting, resolving the contradiction between frost removal and continuous cooling operation.
2Reliability
If a dehumidifier is used to maintain unsaturated water vapor pressure for sublimation defrosting, then sublimation can occur, but the system becomes costly and complex
Solution Approach 1:
The invention extracts and removes the dehumidification subsystem from the defrosting system. By demonstrating that natural sublimation can occur without active dehumidification when the cooling surface temperature is controlled below the melting point, the complex and costly dehumidifier component is eliminated while maintaining defrosting effectiveness.
Solution Approach 2:
The invention enables the system to use its own cooling operation to create the necessary conditions for sublimation. The cooling surface naturally maintains the temperature gradient and unsaturated vapor pressure needed for sublimation without requiring an external dehumidification system, making the system self-sufficient.
3Reliability
If a large amount of heat is provided to sublimate the whole frost layer, then complete defrosting can be achieved, but the defrosting efficiency is low due to high energy consumption
Solution Approach 1:
The invention applies heat locally to the frost layer rather than uniformly heating the entire system. By concentrating thermal energy directly at the frost-cooling surface interface while maintaining the cooling surface temperature below melting point, sublimation is promoted efficiently with minimal energy input, avoiding the need to heat large volumes of air or water.
Solution Approach 2:
The invention uses partial action by providing just enough heat to initiate and sustain sublimation at the frost layer interface without excessive heating. The controlled heat input below the melting point threshold is sufficient to achieve complete frost removal through cumulative sublimation, reducing overall energy consumption compared to high-temperature melting methods.
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
Enables efficient defrosting without stopping the cooling operation, reduces heat consumption, and prevents frost clogging by focusing on the root-side region, thus improving defrosting efficiency and maintaining device compactness.
Implementation Method 1
a sublimation defrosting method for removing a frost layer adhering to a cooling surface for cooling a to-be-cooled gas
Implementation Method 2
form a temperature gradient in which a temperature of the frost layer gradually decreases from a root-side region to a tip-side region
Implementation Method 3
the cooling step includes keeping the tip-side region of the frost layer at a lower temperature than the adhesion portion
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
There is provided a sublimation defrosting method for removing a frost layer adhering to a cooling surface for cooling a to-be-cooled gas, including a heating/temperature-rising step of heating an adhesion portion of the cooling surface, to which the frost layer adheres, to rise a temperature of the adhesion portion by a heat source located on an adhesion portion side with respect to the frost layer, under a temperature condition below a melting point of the frost layer.