Study on the combustion process in a modern diesel engine controlled by pre-injection strategy

[摘要] The paper aims to study the combustion process in a modern diesel engine over the engine operating map. In order to study the rate of heat release (ROHR), an automotive diesel engine was experimentally tested using the injection parameters factory defined. The experimental test was conducted over the engine operating map as the engine speed was limited to 2400 rpm. Then, an engine simulation model was developed in AVL Boost. By means of that model the ROHR was estimated and approximated by means of double Vibe function. In all engine operating points we found two peaks at the ROHR. The first is a result of the pilot injection as the second corresponds to the main injection. There was not found an overlap between both peaks. It was found that the first peak of ROHR occurs closely before top dead center (BTDC) at partial load than full load. The ROHR peak as a result of main injection begins from 4°BTDC to 18°ATDC. It starts earlier with increasing engine speed and load. The combustion duration varies from 30 °CA to 70 °CA. In order to verify the results pressure curve was estimated by means of defined Vibe function parameters and combustion duration. As a result, we observed small deviation between measured and simulated pressure curves.

[发布机构] Technical University of Sofia, Department of Internal Combustion Engines, Automobiles and Transport, Kl. Ohridski blvd. 8, Sofia; 1756, Bulgaria^1;Conservatoire National des Arts et Métiers, CMGPCE, 292 rue Saint Martin, Paris; 75003, France^2

[效力级别] 运输工程 [学科分类] 工业工程学

[关键词] Combustion duration;Combustion pro-cess;Engine simulation models;Experimental test;Function parameters;Injection parameters;Operating points;Rate of heat release