Analysis Of Thermal Comfort And Marginal Utility On Energy Saving In Vehicle’s Cabin

According to the statistics of the National Bureau of Statistics,at the end of 2017,China’s civil vehicles ownership exceeded 200 million for the first time,reaching 209.0 million vehicles,an increase of 12.6% over 2016.In order to enhance the competitiveness of the products,the automobile factories have been improving the thermal comfort and energy saving of the passenger compartment.Based on this background,how to achieve a relatively ideal balance between thermal comfort and energy consumption cost in the passenger compartment,there is no clear answer in the literature at present.Therefore,this paper tries to study the influence of different supply air parameters and environmental parameters on thermal comfort and energy consumption cost of passenger compartment,and proposes a new evaluation method,which links thermal comfort and energy consumption cost,and establishes a theoretical system to achieve an ideal balance between thermal comfort and energy consumption cost of passenger compartment.In order to solve these problems,the main contents and achievements of this paper are as follows:First,according to the characteristics of thermal comfort evaluation index of passenger compartment,the research progress at home and abroad is divided into four stages: single parameter model stage,empirical statistical model stage,uniform thermal environment model stage and non-uniform thermal environment model stage.The advantages and disadvantages of thermal comfort evaluation methods in each stage are summarized and compared,and the application of thermal comfort index in China is described.2.Create AEQT field function and MAA field function in Star CCM+.Then the load model in the cabin is calibrated by steady heat balance method.Finally,a new evaluation method,Marginal Utility of Thermal Comfort and Energy Saving,is proposed to indicate the unit number of overall thermal comfort index deviation increase for every additional 1KW unit of cabin load.It is used to characterize the sensitivity of thermal comfort of passenger compartment to the change of unit load.3.The thermal comfort analysis software of the passenger compartment is compiled,which greatly improves the efficiency of thermal comfort simulation analysis of the passenger compartment.Then the thermal comfort model of passenger compartment is calibrated by the vehicle cooling performance test.The accuracy of the simulation model is verified by comparing the simulated and experimental values of supply air volume and temperature and occupant breathing point temperature.4.The thermal comfort and load of passenger compartment are analyzed from the air supply parameters and environmental parameters,and the Marginal Utility of Thermal Comfort and Energy Saving of passenger compartment is further analyzed.Then the recommended thermal comfort interval where thermal comfort and energy consumption cost can be balanced under different air supply environment parameters is calculated.And three basic principles for analyzing thermal comfort zone are determined to establish a theoretical system for achieving an ideal balance between thermal comfort and energy consumption cost of passenger compartment.