Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
COMPARISON OF THE THERMAL EFFICIENCY OF A GAS TURBINE WORKING WITH COMBUSTION AND DETONATION CHAMBERS
Submission Author:
Ramiro Veronese de Vargas , RS
Co-Authors:
Ramiro Veronese de Vargas, Rodrigo Savi Justi, CESAR ALEJANDRO QUISPE GONZALES, Andrés Armando Mendiburu Zevallos
Presenter: Ramiro Veronese de Vargas
doi://10.26678/ABCM.COBEM2021.COB2021-0929
Abstract
The objective of the present study is to perform a comparison in terms of the thermal efficiency and by varying the main parameters of the power generation by thermodynamical processes involving gas turbines where the combustion products are obtained in two different processes: by constant-pressure combustion inside a conventional combustion chamber and by a detonation process inside a detonation chamber. To achieve this goal, firstly a study of combustion reactions in the context of thermodynamics was performed; then, a computational model was developed in order to study the aforementioned processes.The thermodynamic model allows to study the influence of the compression ratio, fuel composition and equivalence ratio on the thermal efficiency and net-work generation. Initially, the constant-pressure combustion and detonation processes are compared for different equivalence ratios and air temperatures. For the combustion process, the flame temperature and products composition were determined by applying the Gibbs-minimization method together with mass and energy conservation equations. On the other hand, the detonation temperature and the products composition after the detonation process were determined by applying the Chapman-Jouguet theory together with Gibbs-minimization, mass conservation and energy conservation equations. Both thermodynamical models include a dilution process right after the combustion process due to high temperatures of the combustion products (in the order of 2000-2600 K) that a real-life turbine could not handle without failure. Typical values of isentropic efficiencies of compressors and turbines were considered, as well as the compression ratio. So far, the results obtained show that the detonation-chamber-based turbine wields a higher thermal efficiency than the combustion-chamber-based turbine in all comparisons made utilizing equal initial parameters; however, the pressure and temperatures of the chemical products in the detonation chamber are significantly higher, which, although theoretically beneficial, showcase practical limitations that imply the need of adaptations in the form of modifying the pre-and-post-combustion parameters and process in the thermodynamicenergy generation process.
Keywords
Detonation engine, combustion reaction, Gas Turbine, Thermodynamic Cycle
