Study on refrigeration regulation and control optimization for multi-system integrated vehicle thermal management system

With the diversification and complexity of vehicle thermal management requirements, the integration and control of different subsystems for specific utilizations require effective architectures and methods. This paper proposes a hierarchical control architecture that defines the control logic for multi-system through framework design. Based on this, the study focuses on a multi-system integrated vehicle thermal management system including battery, air conditioner and vehicle refrigerator characterized by low refrigeration temperature and high integration complexity. Through the refrigeration regulation method based on the Variable Openings Valve (VOV) and proposed Compressor-Valve Synergistic Enhancement (CVSE) method, cooling assurance for multi-system is achieved while ensuring the thermal safety of the battery and the comfort of the cabin. Subsequently, by analyzing the operational mode and operational process, the study explored their impact on the temperature system control performance and energy efficiency, thus optimizing the operation of the CVSE method. Furthermore, implement the operation optimization, a multi-criteria fusion control strategy is designed for complex actual loaded operating condition, introducing vehicle speed, ambient conditions, and subsystems temperature as input parameters. The results indicated that compared to conventional strategy that does not utilize operation optimization, the proposed strategy achieved approximately 10.8% improvement in COP while maintaining effective temperature control under harsh operating conditions, achieving a balance between temperature control effectiveness and energy economy.