Study On The Characteristics Of Non-uniform Thermal Environment And Human Thermal State In Local Radiant Heating

Compared with the traditional convective heating terminal,radiant heating has the advantages of high efficiency and energy saving,high thermal comfort,quiet and health.For large-space office Spaces,the full-space heating mode does not consider station system rotation and local heating demand,resulting in heating energy waste and other problems.On-demand local space directional heating can effectively improve the utilization rate of heating energy and realize the purpose of fine and efficient heating.In this paper,a large office space with significant station layout requirements is selected as the research object,and the typical study and analysis of indoor thermal environment in different areas under local radiant heating mode are carried out,and the distribution characteristics of indoor non-uniform thermal environment under different local radiant heating conditions are obtained.Firstly,this paper selects the evaluation indexes of indoor non-uniform thermal environment,such as air temperature,average radiation temperature,asymmetric radiation temperature,etc.The variation law of the Angle coefficient of local radiation surface in different areas is studied.The results show that the influence of local radiation on people under ground conditions is greater than that under roof conditions.The Angle coefficient can be effectively improved by reducing the distance between people and local radiation sources under ground conditions.It is more effective to increase the local radiation area in the roof condition.Secondly,by changing the temperature,area,laying method(roof laying/floor radiation),laying position and other factors and parameters of local radiation sources,the indoor thermal environment distribution under the influence of local radiant heating modules in large space offices was analyzed,and the differential distribution characteristics of local radiation space in different working conditions were obtained.The analysis results show that,compared with local roof radiant heating,the difference of indoor thermal environment in different areas under local ground radiant heating mode is greater.When the local radiant area is 16.7% of the ground area,the average radiant temperature difference between the radiant area and the non-radiant area is more than 3℃,which has a significant effect on local environment construction.The asymmetric radiation temperature difference between local radiant heating area and non-radiant area is significant.Furthermore,experiments on indoor thermal environment of local radiant heating were carried out to verify and compare the numerical simulation model.The overall error was less than 5%,which verified that the model was accurate and reliable.The experimental test of human thermal state in local ground radiant heating room was carried out,and the vertical temperature distribution law of indoor thermal environment under different working conditions was obtained.Under local ground radiant heating condition,the vertical indoor air temperature fluctuated greatly within 0.1～0.6m,and the temperature distribution was similar in each area above 1.7m.Through the human thermal comfort experiment of local radiant heating,the distribution of local and overall thermal comfort/thermal sensation and the fluctuation of human skin temperature under different temperature and area of local radiant heating were obtained.