Passive Modification of a Heat Exchanger using Spherical Turbulators

Karan Hiranandani, Aditya Manjeshwar

Heat exchangers can be enhanced by different kinds of methods, namely Active, Passive, and Compound methods. Active Methods involve supply of external power to increase the rate of heat transfer. While constructing such heat exchangers leads to a rather complex design, external power is not easy to provide in certain scenarios.

Passive Methods do not need any external power supply and improve the efficiency of the heat transfer through structural alterations. This, however, leads to utilization of energy from the available energy in the heat exchanger, thereby leading to an increased pressure drop. It has been the aim of all the scientists to obtain greater thermal contact i.e., increased heat transfer coefficient and lower pumping power.

The Passive Technique being discussed below involves the use of surface extensions. The surface extensions are further referred to as turbulators, and because of their spherical cross-section, they are conveniently termed as spherical turbulators. These Spherical Turbulators cause blockages in the flow passage. This leads to enhanced secondary flow and due to the increased surface area as well, there is an improvement in the overall heat transfer coefficient—which is manifested by an increase in the outlet temperature of the fluid to be heated and the Nusselt Number.

https://doi.org/10.31871/IJNTR.4.10.33