An Experimental Investigation of A Modified Heat Exchanger for A Solar Domestic Hot Water System Part (2)

Abstract

The current paper is an extension of a previously published paper, where in this paper the first immersion heat exchanger (Immhx 1) was developed to the second heat exchanger (Immhx 2). The (Immhx 2) was inserted horizontally to avoid the elbow problem and to save space for heat transfer. Helical fins of 4.76 mm were added to (Immhx2) in order to improve the heat transfer rate. The results showed, that the immersion shell-and-coil (ImmS&Chx ) delivers higher energy compared with immersion heat exchanger (Immhx 2 ), and the heat exchanger (Immhx 2 ) achieved better behavior compared with submerged heat exchanger (Immhx 1). Also, it was obtained that the collector surface achieved the highest accumulated heat. Concerning the thermal stratification, the heat exchanger (Immhx 2) achieved lower temperature difference in the tank compared with heat exchanger shell-and-coil (ImmS&Chx)