Indoor Heat Exchanger Freezing Control for Self-Cleaning Air Conditioners
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Solution Overview
Problem
Existing air conditioner technologies face challenges in ensuring adequate water adhesion to the indoor heat exchanger for effective cleaning, which can lead to incomplete cleansing of the indoor heat exchanger.
Innovation Solution
The air conditioner incorporates a refrigerant circuit and control unit that causes the indoor heat exchanger to function as an evaporator and the blower fan to rotate backward during freezing, promoting frost formation and subsequent ice buildup for effective cleansing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If normal air cooling operation is performed after air heating operation to provide water adhesion, then water is provided to the indoor heat exchanger, but the amount of water adhering is insufficient for effective cleansing
Solution Approach 1:
The invention changes the operational parameters by switching the indoor heat exchanger to evaporator mode with refrigerant circulation, achieving much higher water adhesion amounts compared to normal air cooling operation. The refrigerant evaporation process actively condenses and adheres water vapor to the heat exchanger surface, providing sufficient moisture for effective dust and grit removal during subsequent thawing.
Solution Approach 2:
The invention utilizes phase transitions of the refrigerant (evaporation from liquid to gas) to drive water vapor condensation and adhesion to the indoor heat exchanger. This phase change process actively pulls moisture from the air and deposits it on the heat exchanger surface, ensuring adequate water coverage for cleansing without relying on insufficient passive cooling condensation.
2Quantity of substance
If the blower fan rotates in forward direction during freezing processing, then normal air circulation is maintained, but frost formation on the indoor heat exchanger is insufficient for effective cleaning
Solution Approach 1:
The invention reverses the blower fan rotation direction from forward to backward during freezing processing. This inversion changes the air flow pattern to actively promote frost formation on the indoor heat exchanger by directing air flow in a manner that enhances moisture deposition. The backward rotation, while unusual, effectively increases frost coverage for better cleaning performance.
3Quantity of substance
If the indoor heat exchanger is used as condenser during air heating operation, then heating function is provided, but the heat exchanger surface remains dry and cannot be cleansed
Solution Approach 1:
The invention makes the indoor heat exchanger multi-functional by enabling it to operate as both condenser (during air heating for heating function) and evaporator (during freezing processing for moisture adhesion and cleansing). This versatility allows the same component to serve different purposes at different times, achieving both heating performance and self-cleaning capability without requiring separate dedicated 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 configuration ensures proper cleansing of the indoor heat exchanger by ensuring sufficient moisture adhesion and frost formation, effectively removing dust and grit, and subsequent drying to maintain a clean state.
Implementation Method 1
refrigerant sequentially circulates in a refrigeration cycle through a compressor, a condenser, an expansion valve, and an evaporator
Implementation Method 2
refrigerant sequentially circulates in a refrigeration cycle through a compressor, a condenser, an expansion valve, and an evaporator
Implementation Method 3
causing ice to adhere to the indoor heat exchanger
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An air conditioner (100) includes a refrigerant circuit (Q) configured such that refrigerant sequentially circulates in a refrigeration cycle through a compressor (31), a condenser, an outdoor expansion valve (34), and an evaporator, and a control unit configured to control at least the compressor (31) and the outdoor expansion valve (34). One of the condenser or the evaporator is an outdoor heat exchanger (32), and the other one of the condenser or the evaporator is an indoor heat exchanger (12). The control unit causes the indoor heat exchanger (12) to function as the evaporator, and an indoor fan (14) to rotate backward during the freezing processing of freezing the indoor heat exchanger (12).