Study On Indoor Pollutant Diffusion Simulation In Office Buildings Under Different Ventilation Modes

As the quality of people's lives improves,people's working places are increasingly moving indoors.People work indoors for a long time every day,so the requirements for indoor environment and comfort are constantly improving.The indoor pollution is becoming more and more serious,how to use the reasonable air conditioning way to effectively discharge the indoor pollutants is the current concern.Different air distribution has certain influence on indoor air quality and comfort.Office buildings generally adopt natural ventilation,upper air supply,displacement ventilation and other ways to maintain indoor comfort and air quality.By studying the influence of different ventilation modes on the diffusion of pollutants,the air conditioning mode of effectively discharging pollutants and maintaining good indoor comfort can be obtained,which provides a theoretical basis for the design and equipment selection of indoor air conditioning system of office buildings in the future.In this paper,CFD technology and Fluent software are mainly used to analyze the diffusion of pollutants in office buildings under different indoor relative humidity and different ventilation modes.The standard k-? model and the component transport model were selected through the comparison of previous studies.Firstly,the diffusion of pollutants under different indoor relative humidity was analyzed,and then the temperature distribution and velocity distribution obtained from the combination of pollutant concentration distribution under five different ventilation modes were analyzed.Finally,the conclusion is as follows:(1)According to the flow diagram of simulation,the simulation results are basically consistent with the streamline characteristics of air distribution of the five ventilation modes.The accuracy of the selected model is proved.(2)The concentration of pollutants increases with the increase of indoor relative humidity.At the same time,considering the indoor comfort,the optimal relative humidity for working indoors is 40%-50%.(3)According to the simulation results,the average indoor temperature of displacement ventilation and upper and lower ventilation cannot meet the requirements,and other ventilation can meet the requirements of comfort.At the same time,the average wind speed of the indoor working area of the five ventilation modes meets the comfort requirements of the workers and will not produce cold feeling.Therefore,it is proved that the design parameters of air supply conform to the requirements.(4)Pollutants cannot be discharged effectively and smoothly under the condition of low wind speed of natural ventilation,and people with high wind speed will feel cold.Only in the area with the direction of air supply is the concentration of the upper loop and the upper loop and the lower loop.The wind speed of displacement ventilation is low and the air supply from the lower part makes the air flow out from the upper exhaust outlet along the wall.There is little air flow in the indoor working area,and the overall pollutant concentration is high.Side air supply makes the indoor overall pollutant concentration is low,and indoor comfort is high.