Numerical Simulation Of Air Contamination In Office Buildings

With the development of computer technology and computational fluid dynamics,CFD (Computational Fluid Dynamics) has become one of the main methods researchingbuilding indoor environment. Currently, the indoor pollutant dispersion modelingsoftware is few, and mature CFD softwares are all developed by foreign institutions.It isdifficult for ordinary users because it is not only expensive, but also requiresprofessional knowledge. Therefore, there is a high scientific value to develop a low-cost,easy to promote and fast CFD visualization simulation software. Targeted indoorenvironment simulation software was developed to improve the software IndoorThermal Environment Simulation (ITES1.0) with Compaq Visual FORTRAN6.6andVB.NET mixed programming.Firstly, fluid flow and heat transfer was researched from the diffusion model andthe key parameters of indoor pollutants, and the common control equation of the corecalculation program was established.Then solving region was meshed with internalnode methodand common control differential equationswere discreted by the finitevolume method.Finallythe discrete equationswere solved by TDMA iterativemethod.And it will provide theoretical basis for the software-improvement.A visualization and easy user interfacewas developed to achieve operations such asmulti-dimensional model rotation, multi-level undo of settings panelby VB.NET,and thecore calculation program was improved on Compaq Visual Fortran6.6platformto makethe simulation results of the different pollutants more in line with the actual situation;and the numerical results were programmed outputted in a certain data structure, thenthe results were analyzedby softawre Tecplot360, therebyit was achieved to optimizetheindoor thermal environment simulation software ITES2.0.Indoor environmental conditions of office building in Jiulongpo district wereinvestigatedby questionnaire and field testing. It was indicated the unacceptable rateofindoor air quality was14.2%, so there wasa "good indoor air quality" status. Otherwisetemperature, relative humidity, air velocity, HCHO and CO2field tested all met nationalstandards.Finally, the feasibility of ITES2.0was verified from both subjectiveness andobjectiveness, namely compare the measured and simulated values of temperature,relative humidity, air velocity, HCHO, CO2, the studies showed thatthe simulated values trended the same as the measured values,and the feasibility of ITES2.0was confirmedby experimental data results.On the other hand indoor air quality level was evaluated bygrey correlation analysis, and comparing the level with questionnaire results, theconsistency of the numerical simulation and questionnaire results was verifiedindirectly.