Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
THERMODYNAMIC MODELING OF A HYBRID PLANT CONSIDERING SOLAR THERMAL ENERGY AND COMBINED POWER CYCLE
Submission Author:
Bernardo Bergantini Botamede , SP
Co-Authors:
Bernardo Bergantini Botamede, Leandro Salviano
Presenter: Bernardo Bergantini Botamede
doi://10.26678/ABCM.COBEM2021.COB2021-2113
Abstract
Solar Thermal Energy is currently used for power generation as a reliable carbon-free source in many countries. Unfortunately, there is no such commercial project under operation in Brazil, although great solar potential is verified. In this context, a transition strategy is to develop a hybrid solar plant which can be applied on current thermoelectric power plants. Therefore, the present work investigate some layout alternatives for coupling solar thermal plant with an operational plant base on combined cycle (Brayton and Rankine cycle) located in Brazil. A parabolic trough collector was selected for this study, as the most consolidated concentrated solar power (CSP) technology, considering two types of working fluid for solar plant: oil and molten salt. The thermodynamic modeling and additional mathematical models were developed on the open source software OpenModelica. The thermodynamic modeling of the current power plant model was validated through real operating data, and a typical concentrate solar plant with thermal storage was modeled and validated through reference software called by System Advisor Model (SAM) from National Renewable Energy Laboratory (NREL) in EUA. One dimensional (1-D) dynamic mathematical model was used for modeling the trough collector receiver and internal flow on each section of Heat Recovery Steam Generator (HRSG). Conduction, convection and radiation heat transfer was modeled on receiver tube, cover and brackets. Constant isentropic efficiency was adopted for pumps, gas and steam turbines, and the heat exchangers in the solar plant were modeled by means of Number of Transfer Units method (NTU). A thermal energy storage (TES) system was modeled as two tank system with both direct or indirect storage, and a TES dispatch strategy was developed. A proposed solar plant with thermal storage is integrated to Heat Recovery Steam Generator (HRSG) considering several layout for different strategies either to supply heated water, saturated or superheated steam. A typical meteorological year (TMY) hourly data was used as input, and simulation was performed on selected days to represent different climatic conditions. The average net power generated by power plant and global efficiency is used to evaluate and compare the performance of each layout.
Keywords
thermodynamic modeling, solar thermal energy, parabolic trough collector, Hybrid Power Plant
