Indoor Radiant Heat Distribution On The Walls Of Concentrated Heat Source Building

There is usually a concentrated heat source in the building interior.The heat source dissipates heat to the room through the effects of heat convection and heat radiation.As the temperature of the heat source increases,the proportion of radiant heat radiation increases.Radiant heat affects the heat transfer of the building envelope and the indoor thermal environment through the radiative heat transfer between the heat source and the inner wall surface.In order to accurately calculate the indoor thermal environment,this paper studies the distribution of indoor radiant heat on the walls of concentrated heat source buildings.First,the indoor radiant heat distribution model of the centralized heat source building is established,and the numerical calculation program of radiant heat transfer between closed space area sources is compiled by MATLAB.The effects of inner wall temperature,angle coefficient and emissivity on the static distribution of radiant heat are studied.It was found that the temperature of each inner wall surface of the high-temperature industrial building had a negligible effect on the heat radiation of each indoor wall surface.The net radiation heat intensity of the wall surface and the net radiant heat distribution ratio were respectively the angle coefficient of the wall facing the heat source surface and the angle of the heat source facing the wall surface The coefficient is proportional;the intensity of the net radiant heat gain on the wall is proportional to the heat source emissivity,and the net radiant heat gain distribution ratio is independent of the heat source emissivity.Secondly,the mathematical model of indoor dynamic radiation heat transfer of the centralized heat source building was established,and the corresponding calculation program was compiled by MATLAB,and compared with the experimental results to verify.Taking Xi’an as an example,a simulation study on the dynamic distribution ofradiant heat in buildings was carried out.It is found that the change law of the net radiant heat gain intensity is opposite to the fluctuation of outdoor environmental parameters.The temperature of the inner wall surface peaks from 16:00 to 18:00,while the net radiant heat gain intensity is the smallest in a day at this time When the temperature on the inner wall surface is low,the net radiation intensity is higher.Under different heat source temperatures and heat source area ratios,the fluctuation of the net radiant heat intensity on the wall is different.In order to measure the fluctuation of net radiant heat intensity during the day,the coefficient of variation was introduced as a measurement index,and the effects of heat source temperature,area ratio,heat source emissivity,and outdoor climate on the coefficient of variation were studied.The room has a closed space with a centralized heat source.The coefficient of variation of the net radiation heat intensity of each wall gradually decreases with the increase of the temperature of the heat source,and tends to be stable.The larger the indoor heat source area ratio,the greater the coefficient of variation at the same heat source temperature.When the heat source temperature is low(less than 673K),the influence of the heat source temperature on the coefficient of variation dominates,and when the heat source reaches a certain temperature(more than673K),the influence of the heat source area ratio on the coefficient of variation dominates.When the heat source temperature is less than 873 K,the coefficient of variation decreases with the increase of the heat source emissivity;when the heat source temperature is greater than 873 K,the influence of the heat source emissivity on the coefficient of variation can be basically ignored.The research results provide theoretical guidance for accurately predicting the indoor thermal environment of buildings.