EFFECT OF PITCH ON HEAT TRANSFER CHARACTERISTICS OF HELICAL COILS TO BE USED FOR BIOGAS PRODUCTION

Dawit . G. Gunjo, P. K. Mahanta, P. S. Robi

Abstract: Maintaining temperature and eliminating loss from anaerobic reactor highly improve the production of biogas .To achieve the required temperature inside the reactor supplying hot fluid externally using helical coil heat exchanger is required. Helical coil heat exchangers are widely used in industrial applications because they are more efficient as compared to straight tube type heat exchangers. This paper deals with the effect of pitch variation on the heat transfer characteristics (convective heat transfer coefficient, Nusselt number dean number heat removal rate etc.) of helical coil heat exchangers that can be used for supplying hot fluid to maintain the temperature of the reactor to achieve high biogas production. ANSYS 14.5 was used for the numerical investigation and the present study is done for three different coils of two turns having the same cross section and coil diameter but each coil having a different pitch. Modeling of the study was carried out based on the principles of thermodynamics, fluid mechanics, heat transfer and implementing the necessary boundary conditions. The results indicate that the heat transfer enhances with increasing pitch of the helical coil but with an increased pressure drop.

Keywords: Biogas, Helical coil heat exchanger, Pitch, Heat transfer characteristic

DOI: https://doi.org/10.15623/ijret.2015.0407057