A study of the Convection Heat Transfer Coefficient for the Interior Walls of Building

利用墙体表面附近空气温度测量装置，研究了内墙体对流换热系数的测量方法和误差。用表面空气温度梯度乘以空气导热系数来估算对流换热的量，用每平方米每小时流出墙体表面的对流换热除以距墙面10 cm的空气温差来计算墙体的对流换热系数。因此，该装置的设计是这样的：热边界层的空气温度是通过安装CA热电偶的直径0.05 mm来测量的，以接近或远离表面并将其保持在任意预定距离(例如，距表面0.25 mm，0.5 mm，1，2，3，4 mm)。2.墙体局部对流换热系数的最大值和最小值分别出现在距地面50 cm和25 cm附近。3、墙体中心与墙角的对流换热系数比较，墙角处的对流换热系数小于墙角处的对流换热系数。

A Study of the measuring method and error of coefficient of heat transfer by convection for the interior walls have been studied using the appratus for measuring the air temperature near the surface of a wall.Quantity of heat flow by convection are assessed from multipling the air temperature gradient at the surfce by thermal conductivity of air.Values of the coefficient of heat transfer by convection for a wall are obtained by dividing the convection heat leaving the wall surface per square meter per hour by the temperature difference between the surface and the air 10cm away from the surface. The apparatus is therefore designed so that the air temperature of the thermal boundary layer is measured by a 0.05mm diameter,CA thermocouple mounted,to move near or away from the surface and holding it at any predetermined distance.(e.g.0.25,0.5,1,2,3,4mm from surface) The following can be deduced from experimental results;1.Comparing with the other methods this method takes a shorter time and dose not disturb the surface condition.2.The maxmum and minimum value of the local heat transfer coefficient by convection for a wall is found at the distances approximately 50cm and 25cm consecutivity from the floor.3 Comparing the convection heat transfer coefficient along the wall at the center,with heat transfer coefficient at the corner of the wall,the value obtained at the corner is smaller than the value at the center.