Electronic Expansion Valve Speed Control for Stable Vehicle AC
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Solution Overview
Problem
Conventional air conditioning systems, especially those in vehicles, face challenges in maintaining operation stability due to varying environmental conditions, as they require more intelligent and flexible control of electronic expansion valves to adjust refrigerant flow according to different operation states.
Innovation Solution
An air conditioning system with an electronic expansion valve and an electronic control component that receives and processes input signals from vehicle systems or sensors to send control signals for varying motion speeds, enabling the valve to perform initialization, pre-adjustment, negative feedback, and quick turning-off procedures, ensuring stable operation by adjusting refrigerant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electronic expansion valve operates at a constant preset speed, then the control is simple and reliable, but the system cannot respond flexibly to varying environmental conditions in moving air conditioning systems
Solution Approach 1:
The patent applies the dynamics principle by transitioning from a static constant-speed control mode to a dynamic variable-speed control mode. The electronic expansion valve is equipped with a step motor that can adjust its rotation speed based on real-time system conditions (such as superheat degree, refrigerant flow rate, and environmental parameters). This allows the valve to adapt its opening speed to different operating scenarios, improving system responsiveness while maintaining controllable complexity through automated control algorithms.
Solution Approach 2:
The patent implements parameter changes by modifying the rotational speed parameter of the step motor driving the electronic expansion valve. Instead of maintaining a fixed preset speed, the system dynamically adjusts the motor speed parameter based on feedback from sensors monitoring system conditions. This enables the valve to operate at optimal speeds for different situations (e.g., faster adjustment when rapid response is needed, slower adjustment for fine-tuning), thereby improving adaptability without requiring complete redesign of the control mechanism.
2Speed
If the electronic expansion valve adjusts refrigerant flow rapidly, then the system responds quickly to environmental changes, but the operation stability deteriorates under great disturbance
Solution Approach 1:
The patent applies periodic action through a multi-stage adjustment strategy. Instead of a single rapid adjustment, the system performs valve opening/closing in controlled stages: an initial rapid adjustment phase to quickly respond to environmental changes, followed by a fine-tuning phase with slower, smaller adjustments to stabilize the system. This periodic, phased approach allows the valve to achieve both quick response and operational stability by alternating between fast and slow adjustment modes based on real-time feedback.
Solution Approach 2:
The patent implements feedback control by continuously monitoring system parameters (such as evaporator outlet temperature, refrigerant pressure, and superheat degree) and using this information to adjust the valve opening speed dynamically. When the system detects large deviations or disturbances, the feedback mechanism reduces the adjustment speed to prevent overshooting and oscillations. When conditions are stable, the system can afford faster adjustments. This closed-loop feedback ensures that rapid response and operational stability are balanced according to actual system needs.
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 system effectively stabilizes the air conditioning performance by allowing the electronic expansion valve to move at different speeds based on changing conditions, improving the system's responsiveness and stability in varying environments.
Implementation Method 1
a controller periodically sends a sequence of voltage pulses to coils of a step-motor for an electronic expansion valve, to energize and de-energize the coils of phases of the step-motor periodically. Thus, the change in the magnetism of rotors of the stator can be controlled periodically to control the rotation of the rotator
Data Source
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AI summary
Disclosed is an air conditioning system(100), applied to a vehicle, comprising an air conditioning controller (1) and an electronic expansion valve (2). The air conditioning controller (1), according to a preset control program for the electronic expansion valve (2) and collected triggering input information, sends different actuation speed control signals to the electronic expansion valve (2) such that the electronic expansion valve (2) carries out actuations at different actuation speeds; in this way, not only the operational stability but also a quick response of the air conditioning system can be ensured. Further disclosed is an air conditioning control method.