Applied research of reaction coefficient method for unsteady heat transfer in the wall

According to a buildingʹs characteristics, a wall may be divided into three categories (heavy, middle and light) from the aspect of heat transmission. Using theory on unsteady heat transmission of the wall and simulated calculation by computer, the influences on reaction coefficients (yn) exerted by a series of roots (αi) from the transcendental equation B(s)=0 and on heat transmission calculation exerted by the items (n) of reaction coefficients are analyzed. In this paper, when heat transfer reaction coefficients y0 and y1 are calculated, αi 100 and when yn are calculated, αi 30. The definite values for the items of reaction coefficients for different wall types are introduced, that is, n=96 for heavy wall, n=72 for middle wall and n=48 for light wall. The work of calculation may be greatly simplified and the accuracy of reaction coefficients is guaranteed. The calculation method of heat transfer reaction coefficient was further perfected and the condition to use this method was improved.