Numerical Investigation of Heat Transfer in 4-Pass Fire-Tube Boiler

Abstract

In this paper, the heat transfer in 4-pass 500HP fire-tube steam boiler is numerically investigated. A calculation program is carried out in order to simulate the heat transfer characteristics between the hot gases and the boiler tube internal walls. Especially, the heat flux densities and the corresponding wall temperatures for different operating conditions. On these surfaces, an energy balance is established taking into account the radiation and the convection heat transfer. The model validation consists in comparing the predicted outlet gas temperature with the operating data of the PFTA 500HP fire-tube boiler for several steady-state conditions. The comparison shows that the calculation results are in good agreement with the boiler operating data. Furthermore, a sensitivity study has been carried out to investigate the operating pressure effect on the boiler thermal performances.