Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
DEVELOPMENT OF OFF-DESIGN MODELLINGS FOR DISTINCT HEAT EXCHANGERS COUPLED TO AN INTERNAL COMBUSTION ENGINE
Submission Author:
Bruno Muniz de Freitas Miotto , ES
Co-Authors:
Diogo Alencar Zimerer, André Lucas Pereira, Andre Chun, Bruno Muniz de Freitas Miotto, Vitor Buson de Paula, Carla César Martins Cunha, João L M Donatelli, José Joaquim Conceição Soares Santos
Presenter: Bruno Muniz de Freitas Miotto
doi://10.26678/ABCM.COBEM2021.COB2021-1925
Abstract
In order to maintain and guarantee a safe and secure electrical energy grid in Brazil, several thermal power plants were built driven by stationary internal combustion engines in the last decades. Nevertheless, as the main objective was to supply only the necessary energy demand, these power plants were designed without engaging high efficiency issues and not recovering waste heat from these facilities. The present work is part of a Research and Development project (ANEEL PD-06483-0318/2018) called Chiller as Recovery Alternative Technology for Optimization of Systems (CRATOS) whose objective is to increase the net power production of a Wärtsilä 20V34SG engine by cooling and dehumidifying the intake air, expecting an increase of the air density and, consequently, the amount of air in the combustion process. In order to accomplish this goal, a cooling coil on the compressor’s upstream is proposed, thereby, delivering cooled air with less moisture to the engine. Moreover, a plate heat exchanger is proposed to cool the engine cooling water before it goes to charge air coolers. These intercoolers of the engine may present condensation process if the dry bulb temperature decreases below the dew point temperature, therefore, the off-design modelling will allow to observe whether condensed water is formed or not. This work presents several simulations of off-design modellings for distinct heat exchangers, based on heat and mass transfers fundamentals, in an effort to analyze the performance of the entire integrated thermal system. The off-design modellings are developed in regard to the cooling coil, plate heat exchanger, charge air cooler and WHR heat exchanger. The turbocharged engine is modelled and simulated in the GT-Power software and the resulting data is used as curve fitting equations as input parameters to the other off-design modellings. The results are expressed in terms of effectivity, heat exchanged, global heat transfer coefficient and the output temperatures with variation of mass flow and temperatures of the fluids. It will be presented results of each heat exchanger in order to predict the possible operating limitations of the thermal system with the internal combustion engine in terms of different air conditions according to the ambient variation of the region that the power plant is located.
Keywords
off-design, condensation, Heat and mass transfer, Simulation, Engineering Equation Solver
