Multi-Split Air Conditioner Valve Control for Refrigerant Balancing
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Solution Overview
Problem
In multi-split air conditioner systems, uneven refrigerant distribution among outdoor units due to installation location, spacing, and drop height leads to abnormal operating conditions, such as backflow, high exhaust temperatures, and potential damage to compressors.
Innovation Solution
A method for controlling the multi-split air conditioner system by detecting the degree of superheat and average exhaust temperature of each outdoor unit, adjusting the electronic expansion valve to equalize these parameters across the system, and determining the optimal degree of opening based on preset values to ensure even refrigerant distribution and normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If outdoor units are connected in parallel with the same pipe diameter and valve body control, then the device complexity is reduced and installation is simplified, but uneven refrigerant distribution occurs leading to abnormal operation and reduced reliability
Solution Approach 1:
The patent applies local quality by introducing individual electronic expansion valves for each outdoor unit, allowing each unit to have customized refrigerant flow control despite using standard pipe diameters. This enables differentiated refrigerant distribution to each unit based on its specific operating conditions, resolving the contradiction between simplified installation and reliable operation.
Solution Approach 2:
The patent changes the control parameter from fixed valve body configuration to dynamically adjustable electronic expansion valves. By controlling the degree of opening of each electronic expansion valve based on exhaust temperature differences, the system achieves balanced refrigerant distribution across parallel-connected outdoor units, maintaining both simplicity and reliability.
2Reliability
If electronic expansion valve is adjusted to equalize exhaust temperature across outdoor units, then refrigerant distribution becomes even and reliability improves, but the control complexity and measurement precision requirements increase
Solution Approach 1:
The patent implements feedback control by continuously monitoring the exhaust temperature of each outdoor unit and adjusting the electronic expansion valve opening degrees accordingly. The control system compares actual exhaust temperatures with target values and dynamically adjusts refrigerant flow to eliminate temperature differences, ensuring balanced refrigerant distribution and system reliability.
Solution Approach 2:
The patent replaces traditional mechanical valve body control with electronic expansion valves that can be precisely controlled through electrical signals. This substitution enables more accurate and flexible adjustment of refrigerant flow, allowing the system to achieve balanced operation across parallel outdoor units with better control precision and adaptability.
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 method effectively controls the exhaust temperature and ensures even refrigerant distribution, preventing damage and improving the reliability of the refrigeration system by adjusting the electronic expansion valve's opening to match the average exhaust temperature across all units.
Implementation Method 1
controlling an electronic expansion valve to operate according to a result of comparing the average exhaust temperature of each outdoor unit with the average exhaust temperature of the outdoor unit system
Implementation Method 2
detecting whether a degree of superheat of each outdoor unit meets a target requirement
Data Source
AI summary
A method for controlling a multi-split air conditioner. The method includes detecting whether the degree of superheat of each outdoor unit meets a target requirement, if yes, determining whether a difference between an average exhaust temperature of each outdoor unit and an average exhaust temperature of an outdoor unit system reaches a preset value, if yes, comparing the size of the average exhaust temperature of each outdoor unit with the size of the average exhaust temperature of the outdoor unit system, according to the result between the size of the average exhaust temperature of each outdoor unit and the size of the average exhaust temperature of the outdoor unit system, controlling an electronic expansion valve to actuate to make the average exhaust temperature of each outdoor unit to approximate to the average exhaust temperature of the outdoor unit system.