Control method, control device and air conditioning system
Solution Overview
Problem
The use of low GWP refrigerants like R32 and R454B in air conditioning systems poses safety risks due to their flammability, particularly in the event of refrigerant leakage, which can lead to fires or explosions.
Innovation Solution
A control method and system that includes an actuator, which performs a routine protection operation upon detecting refrigerant leakage, and a backup protection operation if the routine operation is ineffective, thereby providing dual countermeasures to reduce safety risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If low GWP refrigerants (R32, R454B) are used in air conditioning systems, then environmental performance is improved, but safety risks worsen due to flammability
Solution Approach 1:
The patent implements a dual protection mechanism that prepares emergency backup measures in advance. When refrigerant leakage is detected, the system first executes routine protection operations (closing valves, stopping compression). If these fail to stop the leakage, a backup protection operation is automatically triggered to close additional valves and isolate the leakage source. This pre-prepared backup scheme ensures that even if the primary protection fails, safety is maintained, thus cushioning against the inherent flammability risks of low GWP refrigerants.
2Device complexity
If a single routine protection operation is implemented for refrigerant leakage, then device complexity is reduced, but reliability worsens due to potential protection failure
Solution Approach 1:
The system performs preliminary monitoring of refrigerant leakage and prepares multiple protection schemes in advance. When leakage is detected, the routine protection operation is executed first. The system monitors the effectiveness of this operation, and if leakage continues, the backup protection operation is automatically activated. This preliminary preparation of multiple protection layers ensures high reliability without requiring complex real-time decision-making during the emergency.
Solution Approach 2:
The patent implements a feedback mechanism that continuously monitors whether the routine protection operation successfully stops the refrigerant leakage. Based on this feedback, the system automatically determines whether to activate the backup protection operation. If the leakage rate exceeds the threshold after routine protection, the backup scheme is triggered; otherwise, the system returns to normal operation. This feedback-based control achieves reliable dual protection without excessive complexity.
3Reliability
If dual protection operations are implemented for refrigerant leakage, then safety reliability is improved, but device complexity increases
Solution Approach 1:
The dual protection system is designed to be dynamic rather than statically complex. The backup protection operation remains dormant during normal operation and only activates when the routine protection fails to stop the leakage. The system dynamically adjusts its protection level based on the actual leakage situation, using simple on/off control logic rather than complex continuous regulation. This dynamic design achieves high reliability while maintaining relatively simple device structure.
Data Source
AI summary
A control method includes determining that refrigerant leakage occurs in an air conditioning system and controlling an actuator to perform a routine protection operation. The control method further includes controlling the actuator to perform a backup protection operation in response to determining that an abnormality occurs in the routine protection operation.