Method for controlling vehicle air-conditioning system, and vehicle air-conditioning system
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle air-conditioning systems cannot effectively manage faults in electronic expansion valves, leading to potential damage when the valves stall or fail to operate, as they lack adequate countermeasures to maintain system performance.
Innovation Solution
A control method that determines the fault state of the electronic expansion valve based on its opening degree, actual superheat degree, and preset superheat degree, and outputs a control signal to adjust the system's parameters, such as compressor speed or evaporator fan rotation, to maintain normal or degraded performance and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If an electronic expansion valve is used to control superheat degree, then the refrigeration system efficiency is improved and energy conservation is achieved, but the system becomes vulnerable to damage when the valve faults or stalls
Solution Approach 1:
The control system implements beforehand cushioning by detecting fault conditions of the electronic expansion valve in advance and activating compensatory control measures. When the valve opens to a maximum degree or fails to adjust properly, the system detects these conditions and compensates by adjusting compressor speed or evaporator fan speed to maintain safe operating parameters, preventing system damage before it occurs.
Solution Approach 2:
The system employs feedback control by continuously monitoring the opening degree of the electronic expansion valve and comparing it with expected values. When the valve malfunctions and cannot adjust to the required opening degree, the feedback mechanism detects this deviation and triggers compensatory actions through the executive control mechanism, adjusting other system parameters to maintain proper refrigeration cycle operation.
2Productivity
If the electronic expansion valve is regulated according to various parameters, then the refrigeration system efficiency is improved, but the system cannot take countermeasures when the valve generates a stalling fault
Solution Approach 1:
The system implements self-service by automatically detecting faults in the electronic expansion valve and executing compensatory control actions without external intervention. The control system monitors the valve's operation, identifies stalling or malfunction conditions, and automatically adjusts compressor speed or evaporator fan speed to maintain system performance, enabling the system to service itself during fault conditions.
Solution Approach 2:
The control system prepares for potential faults by establishing safety thresholds and compensatory control strategies in advance. When the electronic expansion valve stalls or fails to open to the required degree, the pre-programmed response mechanisms are activated to adjust other system parameters, cushioning against the impact of the fault and maintaining system reliability.
3Reliability
If the electronic expansion valve cannot be opened to a certain interval due to fault, then the system lacks countermeasures to maintain performance, but adding fault detection and compensatory control increases system complexity
Solution Approach 1:
The control system achieves universality by using a multi-functional executive control mechanism that can perform both normal refrigeration control and fault compensatory control. The same control unit adjusts compressor speed, evaporator fan speed, and monitors valve operation, eliminating the need for separate dedicated fault protection systems and reducing overall system complexity while maintaining reliability.
Solution Approach 2:
The system uses feedback control to monitor the opening degree of the electronic expansion valve and compare it with target values. When the valve fails to open to the required interval, the feedback mechanism detects this deviation and automatically triggers compensatory actions. This intelligent feedback approach enables reliable fault response without requiring complex additional hardware, as the control system adapts its behavior based on real-time sensor data.
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
Enables the vehicle air-conditioning system to continue operating safely by adjusting parameters in response to electronic expansion valve faults, thereby preventing damage and ensuring continued refrigeration performance.
Implementation Method 1
The liquid refrigerant is throttled and depressurized by the throttling element and then enters into the evaporator to exchange heat in the evaporator, with air outside the evaporator
Implementation Method 2
A gaseous refrigerant with high temperature and high pressure discharged from the compressor changes into a liquid refrigerant after being condensed by the condenser
Data Source
AI summary
A method for controlling a vehicle air-conditioning system and a vehicle air-conditioning system, the method includes acquiring an actual degree of superheat, a preset degree of superheat and a degree of opening of an electronic expansion valve; determining, according to the actual degree of superheat, the preset degree of superheat and the degree of opening of the electronic expansion valve and whether the electronic expansion valve is in a fault state; and outputting a control signal to an executive control mechanism to adjust a parameter of a device in a vehicle air-conditioning system, which influences the variation of the actual degree of superheat, so as to adjust the degree of superheat of the vehicle air-conditioning system.