Research on external flow and heat transfer characteristics of H-type fin tube based on longitudinal vortex

An H-type fin tube based on longitudinal vortex for boiler economizer is put forward in this paper, in order to solve the problem of too high temperature for denitration catalyst reaction for flue gas leaving the econonmizer. CFD method is adopted to study the external flow and heat transfer characteristics of the H-type fin tube based on longitudinal vortex, obtaining the flow field and temperature field distribution in the near wall region outside the fin tube. The results show that vortex flow in different degrees occurs in the rear flow field of the H-type fin tube based on longitudinal vortex, which introduces velocity component normal to main stream direction to the fluid of main flow zone, improves the synergy of temperature gradient field with velocity field and significantly enhances heat transfer performance of the fin tube. Within the parameter range studied in this paper, the 30 degrees attack angle makes the best PEC value and correspondingly best comprehensive heat transfer performance.