Development of a simulator for teaching thermal processes in a four-pass firetube boiler

Abstract

Recent studies show how the use of interactive platforms and simulators favor the learning process of engineering students. This work is part of the teaching of subjects in the area of thermal processes and focuses on the development of a simulator that emulates the operation of a 4-pass fire-tube boiler that generates steam. The simulator includes models for the combustion process, giving the option to select different types of fuels, the heat transfer processes in the hearth tube, as well as the heat transfer in the three remaining steps. In this way, the temperatures of the smoke circuit, the thermal performance of the boiler and the gaseous emissions generated are obtained, for different conditions of excess air regulation. Among the most innovative aspects, the simulator includes the parameterization of the emissivity of the flame based on the volumetric fractions of soot of the different fuels, based on emissivity ratios vs. the C/H ratio. The model is validated through the analysis of experimental results obtained from previous works, with the boiler operating with diesel. The correlations of different thermophysical properties and semi-empirical correlations were obtained through the simulation in the EES platform, to later implement them in the simulator models