Study On Structure And Performance Of Automobile Interior Thermal Insulation Material

With the maturity of automobile technology,the automobile competitiveness gradually transfers from the vehicle dynamic performance,safety performance and economic performance to comfort.The comfort of vehicle passenger compartment,especially the thermal comfort,can be directly perceived by the human body.Auto thermal comfort as another index of modern automobile which is more and more favored by consumers,The information that consumers touch and feel in the shortest time comes from the vehicle interior,the roof as an important part of the vehicle interior,plays an indispensable role in improving the competitiveness of automobile,Its functions are also changing,not only to improve the interior decoration of automobiles,but also to have excellent thermal insulation effects and reduce the noise inside the car.However,the internal and external environment of vehicle passenger compartment is extremely complex,There are too many factors affecting the temperature field and air flow,including the operation of the air conditioning in the car,whether the car is equipped with skylight,the status of its windows,the heat from the peaple and the changeable solar radiation and so on,the domestic and foreign researchs about the car insulation pay more attention to the passenger compartment structure design and optimization of the flow field of automotive air conditioning and reduce air conditioning load,few people discuss and optimize the design of the related heat insulation material and heat insulation layer from the material of the roof of the car.The index of thermal insulation that affects the insulation is the comprehensive heat transfer coefficient,which is closely related to the radiation of the sun,the heat conduction between the layers of materials,and the convection between the material and the air.The thermal conductivity is the key factor that affects the thermal insulation performance of the material itself,and the smaller the thermal conductivity of the material is,the better the thermal insulation performance of the material.Therefore,the research content of this paper is to select the thermal insulation material based on the small thermal conductivity and strong reflection heat wave radiation function as the car roof insulation base material,then the composite thermal insulation material with strong thermal insulation ability is selected,and then the following experiments and simulation are carried out on a certain domestic vehicle as the main line: the thermal insulation performance simulation test of the closed and semi-closed vehicle cabin model are carried out according to the GB/T12546-2007 "test method of automobile thermal insulation and ventilation",according to the heat insulation performance test of the Original Equipment Manufacturers(OEMs),the heat insulation test of the whole vehicle is carried out in the third party Laboratory,finally the test results are analyzed and compared with the results of the numerical calculation software Fluent,and the reliability of the numerical simulation is verified.The research shows that under the premise of meeting the necessary functional requirements,the composite insulation material of multilayer structure is a reasonable choice.Multilayer composite thermal insulation material should meet the heat conduction,convection and heat radiation heat transfer modes at the same time,that is to say,thermal wave radiation material should be wrapped by those with small thermal conductivity and loose structure materials and finally compound them together.The thermal insulation performance of selected composite thermal insulation materials improved significantly,adopting the optimized composite insulation layer with excellent thermal insulation performance is about 1-2 ℃ lower than the original car roof material,the numerical simulation results are in good agreement with the experimental results.The test proved that windows have obvious influence on the thermal insulation of the vehicle,we are looking forward to the improvement of vehicle’s thermal insulation performance depends on the windows’ thermal insulation performance.