Study On Long-Term Predicting Method Of Indoor VOC Concentration

Volatile organic compounds?VOC?is one of the main causes of indoor air pollution.Long term prediction of indoor VOC concentration can provide guidance for people to choose building materials rationally,and provide help for promoting green standardization of China's building materials market.In the long term prediction,the attenuation of the VOC content of the panel can not be ignored,and the current mathematical model and related research can not describe the decay process well.At the same time,for long-term prediction,it is necessary for the wood-based panel VOC to distribute the database to provide the emission characteristic parameters of wood-based panels under different environmental parameters.This paper aims at the above problems,and the main results are as follows:?1?Put forward a new parameter attenuation coefficient theta to describe the attenuation ratio of total VOC content of wood-based panels.By using the principle of similarity,the numerical value of attenuation coefficient theta under different season conditions is designed and tested.The comparison conditions are added before and after the typical seasonal working conditions,and the attenuation coefficient theta is determined by the ratio of the concentration to the time point of the contrast conditions.?2?The influence of temperature,relative humidity,air change times and other environmental parameters on the formaldehyde emission rate of the wood-based panel is designed.The higher the temperature and relative humidity,the faster the VOC emission rate,the higher the temperature,and the increase of the air change times will reduce the time of the VOC concentration in the environment to the peak value.?3?To test the distribution characteristics of the wood-based panel under the typical hot and wet conditions of the season,create the VOC distribution database of the woodbased panel,and determine the test conditions by using the heat and humidity parameters of each season in Chongqing.The data types include the basic parameters of the building materials,the distribution characteristic parameters and the testing conditions,and the emission characteristic parameters include attenuation coefficient theta and emission characteristic curve.The key parameters of the line and mass transfer model C₀,D and K.?4?A long-term prediction method of indoor VOC concentration is proposed: using the attenuation coefficient theta to modify the VOC content of the artificial board under each seasonal condition,and take the corrected parameters into the selected mathematical model to find out the distribution curves of each season,the simultaneous emission curve and the VOC mass balance equation can be used to solve the indoor VOC concentration curve.?5?An integral algorithm of exposure dose is proposed.This algorithm has the following advantages: Based on the principle of dose reaction of formaldehyde,the integration algorithm can describe the exposure dose more accurately.The application range is wide.According to the different range of integration,we can calculate health risk assessment value in different long and short time periods.