Simplified transient thermal model for integrated structures of solar collector with building envelope

Abstract

Building integrated solar thermal (BIST) systems have attracted more and more attention in researches and applications. The transient thermal performance of BIST components is different from separate solar collectors and building envelopes (walls or roofs). This paper proposed a simplified transient thermal model for integrated structure of flat plate solar collector with building envelope. The simplified model takes the absorber plate as the interface, the integrated structure is divided into top part and back part by the interface, the absorber plate temperature is calculated without consideration heat capacitance of the wall and taken as the input to calculate heat transfer through the wall by response factor method. The calculated results by the simplified model agreed well with the state space model under various conditions, suggesting the simplified model is valid. The analysis of heat transfer through the top part is further simplified and influence of simplification is discussed.