Mohammad Jafari - Assistant Professor, Mechanical Engineering Department, Lorestan University, Iran

The effects of a number of longitudinal chains soldered on the inner tube of a double pipe heat exchanger on its thermal performance are investigated experimentally. The chains have been made of a copper wire with ۱mm diameter. Each circle of the chain has ۳ mm internal diameter. The heat exchanger has an inner copper tube with ۱۶ mm outer diameter and ۱mm thickness when the outer pipe has ۴۰ mm inner diameter. 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 ۳۰۰۰ to ۶۰۰۰. The results showed that the usage of the longitudinal chains leads to a noticeable growth in the overall heat transfer of the heat exchanger from ۱۰ to ۴۰ %. On other side, the results also represented an increase of the pressure loss in the outer tube, resulting an increase in the friction factor from ۸ to ۳۵ % based on the Reynolds number and number of the used chains.

Double Pipe Heat Exchanger, Longitudinal Chain, Thermal Performance