Freezer Defrost Circuit Using Hot Refrigerant Bypass
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Solution Overview
Problem
Conventional refrigeration appliances face inefficiencies in defrosting the freezer evaporator, as existing methods either require significant electric power or cause temperature fluctuations, and there is a need for an accelerated defrost system specifically for the freezer compartment.
Innovation Solution
A refrigeration appliance with a switching valve that allows direct communication between the compressor, the freezing coil, and a defrost circuit line, enabling the transfer of hot refrigerant directly to the freezing coil, thereby facilitating an accelerated defrost operation by bypassing the condenser coil and using separate lines for the cooling, defrost, and freezing circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a defrost heater is employed to thaw ice on the evaporator, then the ice is removed, but electric power is consumed and temperature fluctuations occur reducing efficiency
Solution Approach 1:
The invention converts the harmful hot refrigerant gas that would otherwise be wasted into a useful defrosting agent. By diverting this hot gas through the defrost circuit line to the freezing coil, the system uses what would be thermal waste to melt ice accumulation, thereby eliminating the need for electric defrost heaters and reducing power consumption.
Solution Approach 2:
The switching valve acts as an intermediary device that directs refrigerant flow to different circuits based on operational needs. During defrost mode, it routes hot refrigerant gas through the defrost circuit line to the freezing coil, enabling controlled defrosting without direct electric heating and maintaining system efficiency.
2Object-affected harmful factors
If hot refrigerant is directed to the evaporator to defrost ice, then ice is melted, but the defrost operation is not accelerated sufficiently for the freezer compartment
Solution Approach 1:
The refrigeration system is segmented into separate functional circuits: a cooling circuit, a freezing circuit, and a defrost circuit. The defrost circuit includes dedicated components (defrost expansion element, defrost circuit line) that allow independent and accelerated defrosting of the freezing coil without interfering with the cooling function, thereby improving defrost productivity.
Solution Approach 2:
The defrosting process is localized to the freezing coil through the dedicated defrost circuit line, allowing concentrated thermal energy delivery precisely where needed. This localized approach accelerates ice removal from the freezing coil surface without requiring system-wide defrosting, improving overall defrost speed and efficiency.
3Object-affected harmful factors
If a conventional defrost system is used, then ice is removed, but thermal energy transfer efficiency is reduced due to temperature fluctuations
Solution Approach 1:
The system implements periodic defrosting cycles where the switching valve directs hot refrigerant gas to the freezing coil at scheduled intervals. This periodic action prevents excessive ice accumulation while maintaining efficient thermal transfer during cooling periods, balancing ice removal needs with energy transfer efficiency by defrosting only when necessary.
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 configuration efficiently and rapidly thaws ice on the freezer cooling coil surface, maintaining thermal energy transfer efficiency and reducing electric power expenditure by directly routing hot refrigerant to the freezing coil, thus addressing the inefficiencies of prior methods.
Implementation Method 1
a compressor (2) for compressing a refrigerant to a high temperature and a high pressure
Implementation Method 2
transfer of hot refrigerant directly to the freezing coil (8), thereby facilitating an accelerated defrost operation
Implementation Method 3
The refrigerant changes to liquid-vapor phase in the refrigerant expansion element while the pressure thereof is being reduced
Data Source
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AI summary
The present invention relates to a refrigeration appliance having at least one fresh food refrigeration compartment and at least one freezer compartment, the refrigeration appliance having a refrigeration and defrost circuit (1) comprising a compressor (2) for compressing a refrigerant to a high temperature and a high pressure, a condenser coil (3) in connection with the compressor (2) and in which the refrigerant is condensable into liquid, a cooling coil (5) in connection with the condenser coil (3) through a first refrigerant expansion element (6) and a freezing coil (8) in connection with the condenser coil (3) through a second refrigerant expansion element (7).