• STUDYING THE CHARACTERISTICS OF OPERATIONAL PROCESS OF DIESEL ENGINE AND GAS DIESEL ENGINE CYCLES

    Machines. Technologies. Materials., Vol. 10 (2016), Issue 3, pg(s) 29-31

    Energy efficient improvement and bringing to conformity with long-term environmental safety requirements are considered as an important stage to improve ship engines. The values of the mentioned characteristics are mostly determined by the type of consumed fuel and organization of operational process that in turn conditions the intensity of the process of combustion and heat release in the cylinder. And these parameters are the determined factors in the view of improving the technical and economic performance of diesel engines. From this point of view, at this stage conversion some types from the ship diesel engine cycle into the gas diesel engine cycle.

    The paper aims to determine the heat release characteristics on the basis of theoretical and experimental analysis of ship engine performance when implementing the operational process of both diesel engine and gas diesel engine cycles. The given paper dwells on comparative characteristic and efficiency analysis of diesel engine and gas diesel engine cycles, on the basis of experimental modeling.

  • ANALYSIS AND ASSESSMENT OF GAZ-DIESEL CYCLE EFFICIENCY

    Machines. Technologies. Materials., Vol. 9 (2015), Issue 9, pg(s) 26-27

    The paper dwells on peculiarities of operation of engine running on gaseous fuel that envisages the influence of the period of impeding spontaneous combustion on the operation of engine with the dependence on dosing of fuse. Simultaneously, there is considered the influence of changeability of the air-excess coefficient on the engine load when using the different gaseous fuels, as well as its influence on the efficient operation of engine, improvement of ecological and economic parameters, with account for improving geometrical parameters of engine. There are given the analysis and comparison of the efficient characteristics of the ideal cycle of diesel engine when running on liquid and gaseous fuel.

  • DIESEL ENGINE’S COMBINED CARBURETION PROCESS

    Machines. Technologies. Materials., Vol. 8 (2014), Issue 8, pg(s) 3-4

    The carburation process in modern diesel engines practically begins with the moment of fuel injection in into the cylinder, and ends at the same time as the combustion process. The improvement and development of the carburation process depend on the injection parameters, particularly on: the motion of charge in the combustion chamber; fuel properties; combustion chamber sizes; a surface temperature; interdependent motion of charge and fuel. With a view to carburation in diesel engines, we obtain a nonhomogeneous mixture in diesel engines. First of all, the internal carburation process cannot ensure uniform distribution of the injected fuel’s steam and air. Besides, the improvement of carburation process is impeded by fact that as a result of the combustion process development there occur the fuel injection and carburation that increases that amount of fuel, which is burnt in the expansion line. All this causes increasing thermal heat losses and growing amount of toxic substances in exhaust emissions. Also, the improvement and efficiency largely depends on the length of self-ignition impeding period that directly defines the engine’s dynamic magnification factor. The paper dwells also on the possibilities of partial eradication of negative phenomena and increasing the engine’s efficiency, as well as reducing toxicity. In the engine’s intake system, the electric injector is inserted, by means of which, at the beginning of the intake process, there is carried out the injection of a certain amount of fuel in front of the inlet valve, and together with the air coming into the cylinder it creates the mixture, which occurs during the filling and compression process, and at the end of the compression process, the main amount of fuel is atomized by means of basic injector.

    By the end of the compression process, until the fuel is atomized from the basic injector, we have the depleted, but almost homogenous mixture, and therefore, this mixture is uniformly distributed in the combustion chamber. At the same time, the primary oxides, to a certain extent, are created for starting combustion. Immediately after the fuel atomizing from the basic injector, we will obtain the mixture required for combustion, and the combustion process begins earlier than during the process of the creation of a standard mixture, and this means that the length of self-ignition impeding period reduces, and consequently the efficiency goes up, and the amount of soot in exhaust emissions is reduced.