Energy-saving-oriented dynamic co-regulation of vehicle cabin thermal comfort via fuzzy PID: Coupling temperature and air velocity control

Most existing studies on vehicle air-conditioning control take cabin temperature as the single controlled variable. However, thermal comfort depends on multiple environmental factors including air temperature, velocity, and humidity, and thus cannot be sufficiently guaranteed by temperature-only control. To address this issue, this study simplifies the Fanger PMV model and derives the optimal relationship between air temperature and velocity for thermal comfort. A coupled framework is established combining a 3D CFD cabin thermal-flow model and a 1D air-conditioning thermodynamic model. A fuzzy PID control strategy is then proposed to dynamically regulate outlet air temperature and velocity for real-time cabin thermal comfort management. Compared with conventional PID control under tested thermal conditions, the proposed method improves thermal comfort stability with PMV rapidly converging to the comfortable range [−0.5, 0.5]. Meanwhile, it reduces compressor energy consumption by 5.3%, PTC heating energy consumption by 8.8%, and blower energy consumption by 48%. The proposed strategy achieves better thermal comfort and significant energy-saving performance simultaneously, making it suitable for real-world vehicle air-conditioning applications.