Dynamic Thermal Environment Simulation Of Industrial Buildings Based On Zone Model

Industrial buildings usually have local high temperature heat sources,and the indoor heat distribution is extremely uneven.The lumped parameter method used in the existing indoor dynamic thermal environment simulation software for civil buildings cannot accurately reflect the thermal conditions in the working areas of industrial buildings.Therefore,this paper proposes a dynamic thermal environment simulation method for industrial buildings based on the regional model,aiming at the characteristics of local high temperature heat source and tall space,so as to form a general calculation program.This paper analyzes the influence process of external disturbance,internal disturbance and ventilation on the thermal environment of industrial building,establishes the physical model and mathematical model for the simulation of the thermal environment of industrial building,and gives the solution method of the thermal process.The indoor heat distribution under the centralized heat source mode is analyzed,the generating process of the hot jet above the heat source is described,and the influencing factors of the centralized heat source on the temperature distribution are summarized.The indoor distribution of heat emitted by local hot heat source is the key to establish a regional model for dynamic simulation of thermal environment.Two calculation methods of heat distribution coefficient,thermometer algorithm and coefficient calculation method,are given.MATLAB programming tools will calculate the coefficient method for data fitting,get an accurate formula,and the fitting function expression results in the form of code to express,generate a graphical user interface.The efficient calculation of heat distribution coefficient and heat dissipation from heat source in working area is realized.Considering the influence of the distribution of heat source in the horizontal direction on the thermal distribution coefficient,the dispersion coefficient m4 was proposed,which was added into the calculation program of the thermal distribution coefficient before,and the calculation result of the thermal distribution coefficient was modified,which improved the accuracy of the calculation program of the thermal distribution coefficient.The finite volume method is used to derive the discrete equation of heat transfer in the envelope structure.In terms of time,the backward difference method is used to deduce the air thermal balance equation,and the matrix solution form of envelope node temperature is listed.On this basis,the dynamic simulation program of indoor thermal environment of single-node model is established,and the dynamic simulation calculation tool of thermal environment is established with the help of MATLAB programming tools.Based on the actual workshop,SketchUp software was used to build the model,and EnergyPlus software was used to simulate the calculation.The results were compared and analyzed with the results of dynamic simulation program for thermal environment of single-node model.The accuracy of the program was verified,which laid a theoretical foundation for the calculation program of regional model.On the basis of the single-node model thermal environment dynamic simulation program,the discrete equation of heat transfer in the enclosure structure of the regional model and the heat balance equation of indoor air are derived discretely,and a dynamic simulation calculation tool for the thermal environment of industrial buildings is established with the help of MATLAB programming language.Based on the actual workshop,the regional model dynamic simulation program was used to solve the indoor thermal environment,and the results were compared with those of the single-node program.The difference and influence between the zoning calculation and the lumped calculation in solving the indoor thermal environment of industrial buildings were analyzed.Selected the area A cold weather,cold area A,hot summer and cold winter,hot summer and warm winter four climate zones on behalf of the city,by writing this study area model thermal environment dynamic computing program to solve the regional temperature,temperature and the comparison of the work and non-work area regional temperature differences between different climate zones,the relatively reliable change rule,this procedure was validated by multiple sets of conditions calculation accuracy.The research shows that the temperature in the working area is lower than that calculated by lumped parameter method because a lot of heat in the industrial building is concentrated in the upper space.Therefore,the thermal performance of the building envelope should be optimized in different areas in the design of energy saving.