Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
THERMODYNAMIC MODELLING OF A POWER GENERATION STEAM ENGINE
Submission Author:
André Aronis , RS , Brazil
Co-Authors:
André Aronis, Macklini Dalla Nora, Maria Fernanda Possebon Mazer, Leonardo Sonego Hatschbach, Mario Martins
Presenter: Mario Martins
doi://10.26678/ABCM.ENCIT2018.CIT18-0347
Abstract
During the industrial revolution steam engines were the main responsible for the increase in production capacity and were used in the most diverse applications. When it comes to power generation, its efficiency for small power plants (between 75 kW and 5 MW) may exceed that of other renewable energy sources such as hydric, solar and wind. Considering that the raw material used in the boiler can be biomass or industrial waste such as rice husk, its operational cost also becomes competitive. In this context, the use of steam engines is a viable alternative in remote areas. Steam engines work by expanding the superheated fluid in the working chamber, which have their intake and exhaust through windows. Thus, its evaluation to optimize the opening and closing points of the windows and ideal operation conditions are necessary. In this sense, a computational model was developed for thermodynamic analysis to determine the ideal operation points and steam cut-off. A steam engine with a displacement of 15.6 L and fed by 1400 kg/h of superheated steam at 498 K and 1.50 MPa of pressure was modeled. The target power considering the capacity of the generator was approximately 75 kW, which was achieved with the steam cut-off occurring at 43.5° crank angle after top dead center. It was possible to increase this power by changing the cut-off points, but at the expense of thermal efficiency. The thermodynamic efficiency of the real engine based on the second law was found at 8.59%. The simulated parameters were found at 8.37%, 75.75 kW and 1392 kg/h for thermal efficiency, engine brake power and steam mass flow rate, respectively.
Keywords
Steam engine, Renewable source, Microgeneration, Thermodynamic system, computational model
