mprovement of ecological and economic indicators of a diesel engine at increase of supercharging pressure

Abstract

At the present stage of internal combustion engine development, the application of supercharging allows to meet the requirements to the tractive characteristics of vehicles, to reduce or keep the weight and dimensions of the engine, to improve the economic performance, to reduce the emissions of carbon dioxide and toxic substances. For high boosting of internal combustion engines having the value of average effective pressure of 2.5 MPa, it is necessary to provide the degree of pressure increase πk = 4.5. The most rational way to achieve such πk is to use two-stage supercharging with intercooling. The advantage of such a system is the use of standard turbochargers in both stages. Together with two-stage supercharging the Miller cycle is used, which reduces the temperature of fresh charge due to early closing of the intake valve for 40...60 degrees of crankshaft rotation up to BDC.