DOUBLE-LAYER SPLIT COMBUSTION SYSTEM OF DIRECT-INJECTION DIESEL ENGINE

摘要

A double-layer split combustion system of a direct-injection diesel engine. A fuel injection nozzle injects atomized high-pressure fuel in the form of fuel sprays into a combustion chamber (4) formed of a cylinder head (1), a cylinder liner (2), and a piston (3). The combustion chamber (4) is divided into an upper layer and a lower layer; the diameter D1 of a combustion chamber upper layer (8) is greater than the diameter D2 of a combustion chamber lower layer (9); a spray impingement platform (7) is arranged at the joint of the combustion chamber upper layer (8) and the combustion chamber lower layer (9); an atomized fuel spray (6) squirted at a primary fuel injection stage of the fuel injection nozzle (5) is injected to the spray impingement platform (7); a profile suitable for the flow of the spray is provided on the spray impingement platform (7); a part of the atomized fuel spray (6) rebounds, and another part of the atomized fuel spray (6) quickly spreads along a guide surface of the spray impingement platform (7) to arrive above and below the impingement platform, thereby implementing double-layer splitting. Through the guided splitting, accumulation of the spray at and near the landing point is reduced; the diffusion is fast, and the air entrainment volume is increased. Therefore, uniform mixed gas is formed quickly, so that the combustion is fast and complete.