No abstract

The foregoing explains the experimentally established fact that in a heat-insulated diesel engine, diffusion combustion is of great importance - both in terms of the share of heat release and the duration of combustion. To compensate for the decrease in the efficiency of a thermally insulated diesel engine due to an increase in the duration of combustion, the injection advance is increased. The economic effect achieved in this way by increasing the maximum cylinder pressure cannot be considered due to thermal insulation. For typical compression end temperatures in a thermally insulated diesel engine, diffusion combustion, especially in the near-wall layers, is limited by transfer processes. This fact, in addition to the need to eliminate re-enriched zones in the near-wall layers, urgently requires additional turbulization of the working fluid during mixture formation and combustion in thermally insulated engines. The difficulty in solving this problem lies in the fact that one of the most important turbulence generators is the intake process, and one of the most effective solutions is special intake channels. However, the averaged motion and turbulence in the combustor decay significantly during compression. This process is enhanced in a thermally insulated diesel engine due to an increase in the molecular viscosity of the air. The same applies to the generation of turbulence at the end of compression-beginning of expansion. Thus, turbulization of the charge in the combustion chamber of a thermally insulated diesel engine is an urgent problem.

In article, the solution of problem of the combined use of fuel in operation is considered. It is shown that during the operation of the gasoline automobile engine the requirement to octane number of fuel changes depending on engine operation mode: at increase in rotary speed the required octane number of fuel decreases, and at increase in loading increase in octane number of fuel is necessary. The combined use of low-bracket gasoline with high-octane liquefied gas is given. The condition supporting necessary octane number of fuel on various modes for ensuring without detonation work and optimization of combustion procedure is defined. At all engine operating modes in operation on combined fuel, only a high-octane component should be supplied. To control the change in the ratio of the supplied components of the combined power system, it is necessary and sufficient to use any combination of the following parameters: – vacuum in the intake manifold; – is the engine speed; – is the degree of opening of the throttle valve of the carburetor, or others, which are functionally dependent on the above. As a result, the feasibility of choosing one or another option is determined by the design features of the fuel combination implementation system