Influence of external environment on thermal environment of cabin and optimization of air supply strategy of air conditioner

Abstract

This paper employs CFD software to establish a mathematical model of a full-vehicle environmental wind tunnel, and couples it with the Berkeley thermal comfort evaluation model to assess human thermal comfort. The study investigates the impact of varying solar radiation intensities, outdoor temperatures, and vehicle speeds on the total load of the air conditioning system and human thermal comfort. It is found that solar radiation intensity has a significant effect on thermal comfort, while vehicle speed has a relatively minor impact on thermal comfort but a substantial influence on thermal load. Subsequently, by taking the supply air velocity as the independent variable and combining it with different external environmental conditions, the overall thermal comfort index of the occupants is considered as the research object. A regression equation is fitted to describe the relationship between them, and recommended supply air velocity ranges are solved, leading to an optimization scheme. The optimization results for nine different environmental conditions are as follows: the driver's overall thermal comfort has improved by an average of 0.9, and the load on the air conditioning system has decreased by an average of 8.3 %, achieving the goal of collaborative optimization of thermal comfort and energy consumption.

Keywords

• Passenger cabin
• Thermal comfort
• Thermal load
• External environment
• Optimization