What is the cycle of a diesel engine?
Diesel suggested compressing not the air-fuel mixture in the cylinder, but air. At the end of the compression stroke, fuel was supplied in a mixture with air, from the high temperature and pressure at the end of the compression stroke, fuel self-ignition occurred. Compression (ac in the diagram) was also carried out along the adiabat. Heat is supplied isobarically (c-z in the diagram). This was followed by adiabatic expansion (z-b in the diagram), followed by isochoric heat removal (b-a in the diagram). A significant advantage of this cycle is the possibility of using high compression ratios (over 20, Diesel himself wanted about 100, but its further increase is impractical due to the high mechanical and thermal stress of engine parts). Heat is supplied isobaric and removed isochoric (isochoric). Fuel injection took place at the end of the compression stroke. A special feature of the Diesel cycle, in its original form, was compressor pneumatic atomization of fuel. The refusal from this cycle was due to the fact that the compressor drive (and the “real” diesel had compressor injection of the fuel-air mixture) accounted for 10-15% of the engine’s operation, and therefore the fuel consumption of such diesels was not entirely acceptable, because .e. the effective indicators were lower than those of the Sabate-Trinkler cycle, but at the same time the indicator indicators and environmental indicators were higher than those of the engines operating on the Sabate-Trinkler cycle (they will be discussed below). This was due to a better mixture base – a fuel-air mixture was supplied, and non-fuel in the liquid phase, like in modern diesel engines. The widespread transition from pneumatic to mechanical atomization of fuel and, accordingly, from the Diesel cycle to the Sabate – Trinkler cycle began in the 30s of the last century. Almost now, engines operating on the Diesel cycle are not produced (with the exception of experimental samples).
