Steady state modeling of a fire tube boiler

Abstract

Manufacturers increasingly strive to customize fire tube boiler designs to specific needs. A comprehensive thermal design model is therefore necessary. In this article a steady state thermal model based on the plug flow furnace model and the ε- NTU method is presented. The model includes the turn boxes which other authors neglect. The steady state model furthermore allows optimizing the boiler designs. It is used to analyze the gas temperature along the flow length. Secondly, the article compares a plug flow furnace model, the ε- NTU method with and without radiation. The ε- NTU with radiation allows decreasing the number of control volumes while retaining accuracy. Additionally the effect of the turn boxes is investigated.