Study On The Distribution Law Of Indoor Humidity Of Typical Moisture Sources

The distribution of indoor humidity is very important for creating a healthy and suitable indoor environment,and it has received widespread attention in many places such as civil buildings,industrial buildings,schools,and office buildings.Generally speaking,the diffusion of humidity in indoor space is a complex physical process,but the diffusion and mixing of humidity from some specific sources of humidity in the room have relatively simple forms.The understanding of the indoor humidity distribution under the action of a typical humidity source,that is,the understanding of the humidity diffusion mode of the humidity source,can recognize the most typical indoor humidity distribution characteristics.At the same time,it is also helpful to start with the analysis of typical models,which is further helpful for indoor moisture diffusing and effective control under the actual combined humidity source condition.Based on the moisture diffusion theory,component diffusion equation,convective mass transfer equation,and numerical simulation,aimed at the moisture transfer of saturated planar moisture source and body moisture source in closed and ventilated rooms,this paper studies the indoor humidity distribution is studied under the steady state.The influence of factors such as temperature,location,aspect ratio,area size,initial relative humidity and area size of the plane moisture source in the confined room on the law of indoor humidity distribution is studied.For the ventilated room,this paper proposes the ventilation humidity efficiency index.In addition,this paper explores the influence of factors such as the temperature of saturated planar moisture source,the moisture diffusing intensity of body moisture source,source location,air supply method,air exchange frequency,air supply state parameters and other factors on indoor speed,humidity distribution and ventilation humidity efficiency.The research results show that in a confined space,the surface temperature of the moisture source has a significant influence on the indoor humidity distribution.When the temperature difference between the moisture source and the air is different,the indoor humidity distribution law is also different.In addition,the higher the initial indoor relative humidity,the smaller the influence of the humidity source on the relative humidity of the indoor air.When the initial relative humidity reaches 90%,the relative humidity change in the room is less than 0.5%.In terms of the physical factors of the moisture source and the room,the influence of the height of the moisture source on the indoor humidity distribution is related to the surface temperature of the moisture source.When the humidity source is approximately square or approximately linear,the variation law of indoor relative humidity along the height direction is different.The smaller the area of the room or the larger the area of the source of humidity,the larger the range of moist air that spreads downwards after it rises to the top of the room,the greater the average relative humidity of the horizontal surface of each height in the room,and the greater the influence of the source of humidity on the top of the room.When the moisture source area is 0.5times the indoor area,the maximum change in indoor relative humidity is about 8.5%.In the ventilated room,when the temperature of the moisture source is lower than the air temperature,the ventilation humidity efficiency is higher when the upper air supply and lower return air is used;when the moisture source temperature is not lower than the indoor air temperature,the ventilation humidity efficiency is higher when the lower supply air is used.As the number of air changes increases,the relative humidity changes gradually along the height direction,and the humidity becomes more uniform.When the humidity source temperature is different,the number of air changes and air supply parameters used for the maximum ventilation humidity efficiency obtained are also different.Regarding the humidity distribution of the body moisture source in the ventilated room,as the increase of the intensity and height of the moisture source,the indoor ventilation humidity efficiency gradually increases.As the number of air changes increases,the indoor wind speed gradually increases,the influence of the supply air flow on the indoor humidity diffusion gradually increases,and the indoor relative humidity distribution gradually becomes uniform.When the number of air changes is 2h^-1,the indoor ventilation humidity efficiency is the highest.