Multi-Split AC Mode Switching With Differential Pressure Relief
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Solution Overview
Problem
Multi-split air conditioning systems face issues with pipe cracking and noise due to large differential pressures during mode switching, affecting system reliability and noise quality.
Innovation Solution
A method and system that control the switching between operating modes by reducing differential pressure across valves using a shunt device with throttling components and a bypass valve, and utilizing a switching flag bit to manage the four-way valve and control valves, thereby minimizing refrigerant impact and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the refrigeration control valve (heating control valve) is opened quickly during mode switching, then the switching speed is improved, but the differential pressure across the valve causes large pipeline vibration and pipe cracking risks
Solution Approach 1:
The patent applies preliminary action by controlling the four-way valve to switch before controlling the refrigeration/heating control valves to open. This sequence reduces the differential pressure across the control valves during switching, preventing pipeline vibration and cracking while maintaining efficient mode transition. The four-way valve switching prepares the system in advance to minimize harmful pressure differentials.
2Ease of operation
If the four-way valve and refrigeration control valve are switched independently (switching twice), then the mode switching control is simplified, but the pipe system experiences large impact twice causing serious reliability issues and noise
Solution Approach 1:
The patent merges the switching operations by coordinating the four-way valve and refrigeration/heating control valve switching to occur in a integrated sequence rather than independently. The control method ensures the four-way valve switches first, then the refrigeration/heating control valves follow, combining what would be two separate switching events into a coordinated single switching process that eliminates repeated impacts on the pipe system.
3Loss of time
If the refrigeration control valve (heating control valve) is opened quickly during mode switching, then the response time is reduced, but refrigerant impact noise is generated affecting product noise quality
Solution Approach 1:
By switching the four-way valve before the refrigeration/heating control valves, the system prepares the refrigerant flow path in advance. This preliminary action ensures that when the control valves open, the differential pressure is already reduced, minimizing refrigerant impact noise while maintaining acceptable switching response time.
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 solution effectively reduces the risk of pipe cracking and noise, enhancing the reliability and noise quality of the multi-split air conditioning system by optimizing the switching process.
Implementation Method 1
a first throttling component arranged between an outlet of a first heat exchange flow path of the first heat exchange component and an inlet of a first heat exchange flow path of the second heat exchange component, a second throttling component arranged between an outlet of a first heat exchange flow path of the second heat exchange component and an inlet of a second heat exchange flow path of the second heat exchange component
Implementation Method 2
releasing a pressure by controlling the second throttling component, the first control valve and the bypass valve to reduce a differential pressure across the refrigeration control valve or the heating control valve
Implementation Method 3
The outdoor unit includes a compressor and a four-way valve
Implementation Method 4
a first heat exchange component, a second heat exchange component
Data Source
Figure 1
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AI summary
A multi-split air conditioning system and a switching control method for an operating mode of indoor units thereof. The method comprises the following steps: when any indoor unit (21, 22, 23, 24) in multiple indoor units (21, 22, 23, 24) receives a mode switching instruction, the indoor unit (21, 22, 23, 24) sends the mode switching instruction to a shunt device (30) (S1); the shunt device (30) performs switching control on a heating control valve or a refrigeration control valve corresponding to the indoor unit (21, 22, 23, 24) according to the received mode switching instruction, releases pressure by controlling a second throttling assembly (34), a first control valve, and a bypass valve in order to reduce a differential pressure across the refrigeration control valve or the heating control valve corresponding to the indoor unit (21, 22, 23, 24), obtains a switching flag bit of a four-way valve, and controls the refrigeration control valve or the heating control valve corresponding to the indoor unit (21, 22, 23, 24) and the four-way valve according to the switching flag bit of the four-way valve (S2).