Comparação das eficiências de um sistema gaseificador/grupo gerador utilizando motores alternativos de combustão interna de quatro e seis cilindros

Abstract

This undergraduate work aims to present a comparison of efficiencies of a gasifier/generator set system, changing, in its configuration, the generator set used. The system consists of a biomass gasifier, fixed bed type, open top, downdraft, with a thermal capacity of 80 kWt, using wood residues, and equipped with a gas washing system. The comparative analysis is based on the tests performed by Bezerra (2016), using a four-cylinder MWM D229-4 engine and a 36 kVA generator, and on the tests performed by Luna (2018), using a MWM D229-6 engine and a 150 kVA generator; the two engines, originally Diesel cycle, were converted to poor gas operation at the Innovation Laboratory of the Federal University of Paraíba. Following an exploratory and explanatory experimental methodology, a literature review was provided on biomass gasification, on the operation of internal combustion engines, and on the conversion of Diesel engines to Otto cycle besides exposing and comparing the experimental procedures followed by the authors, in which were used, in the engines, ignition advance angles of 22°, 16°, 9° and 7°. Then, for a common set of generated powers, the gasifier and generator set efficiencies were compared in isolation, as well as the overall efficiency of the gasifier/generator set system. Through this comparison, were finally identified average reduction of 9.68 percentage points, in the gasifier efficiency, of 11.10 percentage points, in the generator set efficiency, and of 11.37 percentage points in the overall system efficiency, when using the six-cylinder engine.