Research On Performance Parameter Optimization Of Industrial Building Envelope Based On Sensitivity Analysis

At present,the research on the optimization design of the envelope structure is mainly concentrated in the civil construction and industrial buildings with heating and air-conditioning,and its optimization goal is to reduce the energy consumption of heating and air conditioning.For natural ventilation industrial buildings,the objective and strategy of optimal design of envelope structure is different from that of civil buildings.In this paper,the performance parameters of the envelope structure are optimized based on the sensitivity analysis for the natural ventilation industrial building.Firstly,The typical natural ventilation industrial building model was established via investigation.Three indexes including high temperature hours that indoor air temperature over 30?,low temperature hours indoor air temperature under 14?,total hours that indoor air temperature over 30?or under 14?were introduced as indoor thermal environment indicators under different indoor heat gain are calculated by EnergyPlus.Influence on indoor thermal environment of eight envelope design parameters including external wall heat transfer coefficient,roof heat transfer coefficient,window heat transfer coefficient,window solar heat gain coefficient,surface absorptivity of external wall,surface absorptivity of roof,window to wall ratio and the skylights to roof ratio is analysed and compared using local sensitivity analysis methods.The results show that when the air change times are constant,when the indoor heat gain is 1~5W/m~3,the most important parameters affecting the high temperature hours in summer are the skylights to roof ratio and the surface absorptivity of roof;the most important parameters affecting the low temperature hours are the roof heat transfer coefficient and the skylights to roof ratio.The most important parameters affecting the total hours in the whole year are the skylights to roof ratio,the roof heat transfer coefficient and the external wall heat transfer coefficient.And according to the characteristics of industrial buildings,the optimization strategy of corresponding parameters is formulated.According to the results of the sensitivity analysis,the ratio of the transparent area to roof is selected as the optimization variable,and the lighting calculation model is established with other parameters kept consistent with the base model.Using Ecotect's method of calling Radiance,the CIE Overcast sky model is selected to simulate the hourly average illumination of the winter solstice day.In order to meet the illuminance requirements of the working face at 9:00-16:00 on the winter solstice date,the optimal values for the skylights to roof ratio of the industrial building are obtained under different window to wall ratio.According to the baseline model and the results of lighting optimization,window to wall ratio and the ratio of the transparent area to roof are selected as the fixed values.According to the results of the sensitivity analysis,the external wall heat transfer coefficient,the roof heat transfer coefficient and surface absorptivity of roof are selected as optimization variables and scenarios are formulated with different values of the parameters.Aiming at the indoor thermal environment and taking into account the total hours of low temperature and high temperature,Using the EnergyPlus parallel computing program developed by the author and the Pareto multi-objective optimization method,this paper gives the optimal values of the performance parameters of the envelope structure under different indoor heat gain.For other design parameters that have less impact on the indoor thermal environment,suggestions of design values are given.This research results provide the basis for the reconstruction and optimization design of the natural ventilation industrial building envelope in WuHan.