Refrigeration Cycle Blower Control to Reduce Defrost Time
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Solution Overview
Problem
Conventional refrigeration cycle apparatuses require a longer time for defrosting operations due to the large amount of liquid refrigerant in the evaporator, which prolongs the interruption of normal operation and affects user comfort.
Innovation Solution
Increasing the air flow rate by the indoor fan during the defrosting operation to enhance heat exchange efficiency, reduce the amount of liquid refrigerant, and promote vaporization, thereby shortening the defrosting time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the defrosting operation is performed with a large amount of liquid refrigerant in the evaporator, then the heat exchange efficiency is maintained, but the length of time required for defrosting operation increases
Solution Approach 1:
The system performs preliminary action by increasing the air flow rate before the defrosting operation starts. The control unit increases the rotation speed of the blower motor to increase air flow through the evaporator, which promotes vaporization of liquid refrigerant and reduces the amount of liquid refrigerant before defrosting begins. This preliminary reduction of liquid refrigerant amount ensures that when defrosting starts, less heat is consumed for vaporization and more heat is available for melting frost, thereby shortening the defrosting time while maintaining heat exchange efficiency.
2Temperature
If the amount of liquid refrigerant in the evaporator is large at the start of defrosting, then the heat exchange efficiency is improved, but the amount of heat available for melting frost is reduced
Solution Approach 1:
The control unit increases the rotation speed of the blower motor before the defrosting operation starts, which increases the air flow rate through the evaporator. This enhanced air flow promotes vaporization of the liquid refrigerant, reducing the amount of liquid refrigerant present when defrosting begins. Consequently, when the defrosting operation commences, less heat energy is consumed for vaporizing liquid refrigerant, and more heat energy is available for melting frost on the evaporator surface, thereby resolving the contradiction between maintaining heat exchange efficiency and ensuring sufficient heat for frost removal.
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
The increased air flow rate reduces the time required for defrosting, minimizing the interruption of normal operation and enhancing user comfort by efficiently melting frost.
Implementation Method 1
a refrigeration cycle apparatus according to the present invention is characterized in that an amount of air blown by a first blower per unit time after a start condition for a defrosting operation is satisfied is larger than an amount of air blown by the first blower per unit time before the start condition is satisfied
Implementation Method 2
the heat exchange efficiency of an evaporator after the start condition for the defrosting operation is satisfied is increased and vaporization of liquid refrigerant is promoted
Implementation Method 3
vaporization of liquid refrigerant is promoted
Implementation Method 4
an amount of heat used to vaporize the liquid refrigerant, of an amount of heat generated to melt frost
Data Source
Figure 1
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Figure 3
AI summary
A refrigeration cycle apparatus (1) according to the present invention circulates refrigerant in order of a first heat exchanger (101), a compressor (102), a second heat exchanger (103), and an expansion valve (104). The refrigeration cycle apparatus (1) performs defrosting operation when a start condition for the defrosting operation is satisfied. The refrigeration cycle apparatus (1) includes a first blower (111) and a controller (31). The first blower (111) blows air into the first heat exchanger (101). The controller (31) controls an amount of air blown by the first blower (111). The controller (31) increases the amount of air blown by the first blower (111) per unit time, when the start condition for the defrosting operation is satisfied.