Studies On The Effect Of Indoor Thermal Environment And Energy Consumption Of Non-radiation Inner Surface Emission Rate Under Floor Radiant System

This paper mainly studies the effect of the inner surface emission rate of the enclosure structure on indoor thermal environment and energy consumption under the floor radiation system.At present,because the radiation cooling heating system is both comfortable and energy-saving advantages,the application in the Yangtze River basin increased year by year.For the radiation system,its characteristic son is that radiation heat exchange accounts for more than half of the total heat exchange,and building materials and indoor objects will store a part of the heat,so the radiation heat transfer between the inner surface of the enclosure structure is one of the important factors affecting the indoor thermal environment and energy consumption.The radiation heat transfer is closely related to the performance of building materials,and one of the important parameters is the surface emission rate.At present,the surface emission rate of commonly used building materials is usually between 0.85～0.95,the absorption capacity of heat radiation is very strong,which means that in winter heating part of the heat is absorbed by the containment structure,and then transmitted to the outdoor or storage,heating after the heating off becomes invalid heat dissipation,and the cold in summer cooling is also the same,the radiation system is more obvious.When the inner surface of the enclosure structure uses low emission material,the low emission rate surface can reflect part of the energy back into the room,reducing the absorption of the radiation source energy,thereby reducing the indoor and outdoor heat exchange,affecting the indoor thermal environment and energy consumption.This study uses theoretical analysis,experimental analysis and simulation analysis methods,first of all,theoretical analysis of the heat transfer characteristics of floor radiation heating system and the accuracy of the average radiation temperature under low emission conditions,second,through experimental analysis of the interior surface of the enclosure structure with low emission rate materials in the building indoor thermal environment,and with high emission rate materials,and finally,the use of numerical simulation of the inner surface emission rate of the enclosure structure on indoor thermal environment and system energy consumption of the comprehensive analysis.The results show that for the calculation of mean radiant temperature,the indoor surface emission rate should be changed by definition calculation or simulation simplification method,and the traditional simplification method is no longer applicable.With the reduction of the inner wall emission rate,the other surface temperature except the floor increases when the heat is cooled in summer,and in winter heating is reduced,which is conducive to reducing wall heat transfer.Summer cooling experiments show that when the inner surface of the enclosure structure has a emission rate of 0.05 aluminum foil,the indoor average radiation temperature can be reduced by about 4℃ compared to commonly used building materials.Numerical simulation results show that in winter floor radiation heating,with the reduction of the internal surface emission rate of the enclosure structure,the average radiation temperature in the room increased,the average air temperature decreased,in general,the operating temperature increased,the summer floor radiation cooling is the opposite.When the emission rate is reduced from 0.9 to 0.1,the average temperature of indoor radiation during heating is increased by about 3.53℃,the response time is significantly shortened,the operating temperature is increased by about1.06℃,and the average temperature of indoor radiation in the heating is reduced by about2.65℃,and the operating temperature is reduced by about 0.72℃.Therefore,the use of low emission material on the inner surface of the enclosure structure is beneficial to improve human comfort.In terms of energy consumption,controlling operative temperature is 26℃ in summer,18℃ in winter,the transmission rate of the non-radiation inner surface of the enclosure structure is reduced from 0.9 to 0.1,the rated power can be reduced by about15.8%,energy saving is about 14.4%,and energy saving can be about 16.7% under the outer insulation form.During the season heating in the form of internal insulation can reduce the rated power of heating equipment about 16.1%,energy saving of about 15.1%,in the form of external insulation can save energy of about 26.2%,the emission rate of external insulation form of energy consumption impact is greater.