%A Pluta, Zbysław %A Wnuk, Ryszard %D 2011 %T NUMERIC MODELS OF HEAT-FLOW PROCESSES RELATING TO DOUBLE MEDIUM HEAT STORAGE TANKS %K %X The mathematical model and numeric simulation of transient heat conduction with simultaneous phase change in heterogeneous structures are presented. The working of a Solar Domestic Hot Water System was considered. The heat storage tanks the main element of this system, is filled with water and regularly placed balls or tubes enclosed in PCM material. The equations describing the overall heat transfer in the storage tank are presented. An original finite difference scheme for solving energy equation for PCM material in spherical and cylindrical coordinates was developed. The scheme is based on the control volume method and the Dufort-Frankel method. The results of the numeric simulation were experimentally verified. %U https://papers.itc.pw.edu.pl/index.php/JPT/article/view/208 %J Journal of Power Technologies %0 Journal Article %P 49-69%V 86 %@ 2083-4195