Effects of the chain-rings on performance of a double pipe heat exchanger

The effects of eight numbers of copper chain rings on thermal performance of a double pipe heat exchanger (DPHE) are experimentally investigated. The used chain for the rings is made of a copper wire. The rings are soldered around the inner tube of DPHX with equal interwall (۵ cm). The heat exchanger is made of a copper inner tube and a plastic outer tube. The study was carried out when the Reynolds number of the hot fluid flow passing in the inner tube was ۴۰۰۰ when the Reynolds number of cold fluid passing through the annulus area were changed from ۴۰۰۰ to ۶۰۰۰. The results showed that the usage of the chain rings has a significant potential for a noticeable growth in the performance of the heat exchanger when the recorded increase in the pressure drop in the outer tube is quite acceptable. The results indicate up to ۲۵ precents increase in the overall heat transfer rate when change in the pressure drop is about ۲۰ % in the outer tube. The results emphasize that the efficiency of chain rings on the thermal performance of the test heat exchanger is highly related to the Reynolds number of the flow field in the anulus area of the heat exchanger.

Keywords:

Heat Exchanger , DPHX , Chain-Rings , Thermal Efficiency , Turbulent Flow.