Análise de eficiência, gases de exaustão e consumo de combustível de um gerador acoplado com motor de ignição por compressão trabalhado a diesel comum

Abstract

In many regions of Brazil, especially localities not integrated into the National Interconnected System (SIN), the electricity supply depends predominantly on diesel-powered generator sets. These systems are essential to guarantee access to energy, but their operation is associated with high fuel costs and the emission of atmospheric pollutants. In this context, the evaluation of the energy and environmental performance of diesel engines becomes important for optimizing power generation and reducing environmental impacts, in addition to providing a basis of comparison for similar studies conducted with fuels, such as biodiesel, that can be produced from vegetable crops present in these remote locations, even touching on the promotion of the local economy from this exploitation. This study aims to analyze the behavior of a two-cylinder diesel engine operating with commercial mineral diesel under different load conditions, simulating situations typical of demand in power generation systems. The tests were conducted on an instrumented experimental test bench for monitoring the engine's main operating parameters. Three load points were evaluated, corresponding to 9,5%, 18,9%, and 28,4% of the equipment's available power. During the tests, the specific fuel consumption, fuel mass flow rate, effective thermal efficiency, exhaust gas temperature, and emissions of the pollutants methane (CH4) and carbon dioxide (CO2) at the exhaust outlet were determined. The exhaust gas temperatures proved to be relatively stable given the 180-second pre-heating time of the engine, increasing with the rise in load. An increase in the diesel consumption rate was noted as the power required by the electrical load generated by the resistors increased. On the other hand, the specific fuel consumption decreased, accompanied by an increase in effective thermal efficiency. Nevertheless, there was an increase in (CO2) emissions as the load increased, while the behavior of the studied unburned hydrocarbon (CH4), indicated a possible influence of local combustion conditions, which do not always occur ideally on a global scale.