Air conditioner and defrosting operation method therefor
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Solution Overview
Problem
Existing air conditioner defrosting methods, such as hot gas bypass and reverse cycle defrosting, face challenges in balancing defrosting time and heating capacity, with hot gas bypass reducing heating capacity during large frosting events and reverse cycle defrosting prolonging room temperature recovery after defrosting.
Innovation Solution
An air conditioner system that dynamically selects between hot gas bypass and reverse cycle defrosting operations based on the frosting amount on the outdoor heat exchanger, using a control device to open a hot gas bypass circuit or switch the four-way valve to optimize defrosting time and heating capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hot gas bypass defrosting operation is performed, then heating operation can be maintained during defrosting, but heating capacity decreases due to energy used for defrosting
Solution Approach 1:
The system dynamically switches between hot gas bypass defrosting and reverse cycle defrosting based on real-time detection of frosting amount. When frosting is light, hot gas bypass is used to maintain heating capacity; when frosting is heavy, reverse cycle is used to ensure effective defrosting. This dynamic adaptation resolves the contradiction by optimizing the balance between heating capacity and defrosting effectiveness.
2Loss of time
If reverse cycle defrosting operation is performed, then defrosting capacity is high and defrosting time is short, but heating operation is suspended and room temperature drops
Solution Approach 1:
The control device dynamically selects the defrosting method based on frosting amount detection. For light frosting, hot gas bypass defrosting is used which maintains heating operation continuity. For heavy frosting, reverse cycle defrosting is used which provides high defrosting capacity. This dynamic selection resolves the contradiction between defrosting speed and heating continuity.
Solution Approach 2:
The system changes the operating parameters by switching between two distinct defrosting modes (hot gas bypass and reverse cycle) based on the detected frosting conditions. This parameter change allows the system to adapt to different frosting scenarios, resolving the contradiction between maintaining heating operation and achieving effective defrosting.
3Speed
If hot gas bypass defrosting operation is performed, then room temperature rises quickly after defrosting, but defrosting operation time is long when frosting amount is large
Solution Approach 1:
The system dynamically adjusts the defrosting method based on real-time frosting detection. When frosting is light, hot gas bypass is used which enables quick room temperature recovery. When frosting is heavy, reverse cycle is used which completes defrosting faster. This dynamic adaptation resolves the contradiction between room temperature recovery speed and defrosting duration.
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 reduces the total time required for defrosting and heating operation startup, thereby minimizing the decrease in heating capacity during air conditioner operation by selecting the most appropriate defrosting method based on frosting severity.
Implementation Method 1
feeding a part of a compressor discharge gas refrigerant to an outdoor heat exchanger to remove the frost
Implementation Method 2
switching a four-way valve to a cooling operation side to remove the frost
Implementation Method 3
a compressor, a four-way valve, a use side heat exchanger, an expansion valve, and a heat source side heat exchanger are connected to configure a freezing cycle
Data Source
AI summary
A hot gas bypass circuit that connects a discharge side of the compressor and a portion between the heat source side heat exchanger and the expansion valve, an on-off valve that opens and closes a channel of the hot gas bypass circuit, and a control device performing control to select one of hot gas bypass defrosting and reverse cycle defrosting according to a frosting amount on the heat source side heat exchanger and perform defrosting. The control device controls to open the on-off valve of the hot gas bypass circuit such that a part of a refrigerant discharged from the compressor is supplied to the heat source side heat exchanger via the hot gas bypass circuit and, the control device switches switch the four-way valve such that the refrigerant discharged from the compressor is supplied to the heat source side heat exchanger after passing through the four-way valve.