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COBEM 2021
26th International Congress of Mechanical Engineering
MATHEMATICAL MODELING OF RECUPERATIVE HEAT EXCHANGER
Submission Author:
Diego de Lima Sousa , RN
Co-Authors:
Diego de Lima Sousa, JOSÉ VIRIATO COELHO VARGAS, Wellington Balmant
Presenter: Diego de Lima Sousa
doi://10.26678/ABCM.COBEM2021.COB2021-1024
Abstract
It is well known that one of the great challenges that exists today, is to be able to increase energy production efficiently, preserving the environment. In this way, the development of equipment such as heat exchangers that can use energy with minimal waste, becomes something substantial, thus allowing the improvement of industrial processes and contributing to the reduction of pollutant gas calls. Reclaiming heat exchangers are equipment widely used in the most diverse areas of society, covering from domestic applications, such as air conditioning, to industrial ones, such as in boilers for the generation of superheated steam. Thus, the development of new and efficient devices becomes a great option to reduce energy consumption. One of the most effective ways to contribute to this is through the design of mathematical models that are possible to predict the physical behavior of this equipment. In this way, this project aims to develop the modeling and simulation of heat exchanger with phase change. The system consists of three devices that operate like a boiler, in order to heat water from the liquid phase, as a subcooled fluid, to overheated steam. The mathematical modeling is done considering that the set works in a mixed way, that is, the stage where the phase change occurs is treated in a quasi-permanent regime, where deviations from equilibrium are considered negligible. The other phases (subcooled fluid and superheated steam) will be operating in a transient regime. The model is based on the volume element method that combines the principles of thermodynamics and heat transfer, applying them to the components of the system assuming thermodynamic control volumes for each component. The mathematical model is explained by a system of ordinary differential equations integrated with time, with precision and low computational time. Empirical correlations were used to quantify the coefficients of heat transfer for both the phase change process and the single-phase process. The model was implemented in MATLAB® and is capable of satisfactorily predicting numerical responses providing a basis for the behavior of heat exchangers.
Keywords
mathematical modeling, Volume Element Method (VEM), Heat exchanger
