Simulation Analysis And Influence Factors Of VOCs Concentration And Distribution In Vehicle

With the rapid development of automobile industry,it also brings us a series of safety problems.Especially in the car formaldehyde,toluene and xylene and other volatile organic pollutants(VOCs)harm,seriously affect the health of people and driving safety.At present,researches on vehicle VOCs concentration and influencing factors mostly focus on experimental testing methods,and domestic testing standards are mostly static testing of vehicle detection point VOCs concentration.So the research on VOCs concentration and dynamic distribution urgently needs to be carried out.As a result,this paper established a numerical simulation model of analyzing VOCs concentration and its distribution by using Fluent software based on CFD theory,and in-depth studied the influence of temperature,ventilation rate,ventilation mode and the materials of parts on VOCs concentration and its dynamic distribution at the breathing positions of driver and passengers,as well as some typical sampling lines.The main research contents are as follows:(1)The concentration and distribution of VOCs in vehicles at different temperatures were investigated.It was found that the temperature has a significant effect on VOCs concentration in the vehicle.This is mainly due to the high temperature accelerate the emission of VOCs in the car.The concentration of formaldehyde and toluene in the car at65℃ tends to expand.The concentration of formaldehyde and toluene in the breathing position of drivers and passengers is most affected by temperature,so it is necessary to focus on controlling the temperature in the car to prevent the occurrence of high temperature in the car,so as to avoid the pollution of formaldehyde and toluene in the driver and passenger’s breathing position and reduce the health risk of human.(2)Study the influence of ventilation system on the dynamic distribution of VOCs in the vehicle,and analyze : By analyzing the influence of ventilation system(ventilation rate,ventilation mode)on the distribution of VOCs in the vehicle,it can be seen from the VOCs concentration data in the simulation cloud diagram and typical sampling locations that: under different ventilation rates,the concentration of VOCs in the vehicle presents different distribution characteristics of "hyperbolic" and "hump" due to vortex flow field.VOCs concentration in the front row is lower than that in the rear row.The formaldehyde and toluene concentration in the rear row is low in the middle and high in the edge.Therefore,it is necessary to strengthen ventilation in the rear row,especially near the rear door,and increase air supply volume of the air conditioner,which will help reduce formaldehyde and toluene pollution in the breathing position of the rear occupant and ensure the health of the occupant.When the ventilation rate is less than 1.6m/s,VOCs concentration is greatly affected by ventilation rate.But when the ventilation rate is larger than 1.6m/s,VOCs concentration does not change significantly with the increase of ventilation rate.Adding the rear ventilation in pillar B can reduce the pollution of formaldehyde and toluene in the breathing position of the rear passenger.(3)Orthogonal test method was adopted to comprehensively consider the synergistic effects of temperature,ventilation rate and ventilation mode,and the optimal parameter combination was studied and determined when the breathing position of driver and passenger and the VOCs concentration at the vehicle detection point was the lowest: temperature 25℃,ventilation rate 0.5m/s,ventilation mode 2.(4)From the perspective of car parts,the influence of different materials of parts on the concentration and distribution of VOCs in the car was explored.The simulation results show that: improving the materials of parts is an effective way to improve the air quality in the car.The concentration of VOCs in the car is lower by using PET carpet,leather seat and hard ceiling.In addition,carpet has the greatest influence on VOCs concentration in the front row space,while seat and ceiling have the greatest influence on VOCs concentration in the rear row space.This research can provide new technical methods and effective solutions for the prediction and evaluation of in-car air quality,and provide technical support for the future green design and manufacturing of vehicle.