Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Mathematical Modeling and Experimental Validation of Heat Exchangers Operating as a Boiler Using Volume Elements Method
Submission Author:
Diego de Lima Sousa , RN
Co-Authors:
Diego de Lima Sousa, Wellington Balmant, Flávio Júnior Santiago Silva, Iago Gomes Costa, Anne Defranceschi Oliveira, Heloísa da Silva, JOSÉ VIRIATO COELHO VARGAS
Presenter: Diego de Lima Sousa
doi://10.26678/ABCM.COBEM2023.COB2023-1170
Abstract
This work presents a mathematical modeling using volume elements (VEM) with experimental validation of a set of heat exchangers operating as a boiler. The heat energy used to heat water comes from the burning of solid urban waste in the incinerator. The first heat exchanger functions as an economizer, whereby the liquid water comes into indirect contact with the combustion gases of the waste and heats up to temperatures near the phase change temperature. The second heat exchanger is a phase change device, where the preheated water raises its temperature to the phase change temperature at a given pressure. The third is a superheater that allows only superheated steam to be produced. The objective is to analyze the system's performance and compare the results obtained with the experimental data. The mathematical modeling is performed considering the set in mixed regime, where the phase change step is treated in quasi-steady state, while the other phases (subcooled fluid and superheated vapor) operate in transient regime. The mathematical model is explained by a system of ordinary differential equations integrated with time, with precision and low computational time. Empirical correlations are used to quantify heat transfer coefficients for both the phase change and monophasic processes. The mathematical model was developed considering the heat transfer between the fluids circulating in the heat exchangers. Experimental validation was performed on a set of heat exchangers operating as a boiler. Experimental data were collected for different operating conditions, including mass flow rate and fluid temperature. The numerical simulation results were compared with the experimental data and showed good agreement. The VEM mathematical model presented good accuracy in predicting the system's performance. The results suggest that the VEM mathematical modeling can be a useful tool in analyzing and designing heat exchanger systems in boilers. The experimental validation confirmed that the set of heat exchangers operating as a boiler can present good thermal performance and that the VEM mathematical modeling can be an effective tool for the design and analysis of these systems.
Keywords
Mathematical Modeling., Experimental validation., Heat exchanger., volume element model, Volume Element Model (VEM)
