To provide pregiven quality ratings of control processes of maximal speed deviation and transient process duration is an important task for diesel generators. Calculation study of methods intended for improving transient process quality is carried out using mathematical dynamic model of diesel engine and control system. Dynamic operation modes of turbocharged engine differ considerably from static ones. Experimental study of one-cylinder diesel engine was conducted with transient condition simulation to validate approaches to the development of engine dynamic model. Based on the study results, mathematical model and computer program to calculate transient processes were developed. Calculation study of methods intended for improving diesel-generator control processes was performed using the computer program.

Обоснование эффективности отключения цилиндров как метода управления дизельным двигателем на частичных режимах часто проводят по характеристикам, соответствующим его работе без отключения цилиндров. При этом теоретические и практические результаты значительно различаются, так как рабочие процессы в отключенных и работающих цилиндрах протекают по-разному. Методом моделирования проведен анализ рабочего процесса дизельного двигателя при отключении цилиндров. С помощью компьютерной модели выполнены расчеты рабочих процессов в отключенных и работающих цилиндрах. Дана оценка потерь энергии, определяющих топливную экономичность двигателя. Установлено, что значительное влияние на удельный эффективный расход топлива оказывает работа системы газораспределения в отключенных цилиндрах. Рассмотрена работа двигателя на частичных по частоте вращения и крутящему моменту режимах при отключении различного числа цилиндров. Полученные результаты показывают особенности рабочего процесса дизельного двигателя при отключении цилиндров и позволяют более точно оценивать эффективность такого метода управления двигателями.Ключевые слова: дизельный двигатель, рабочий процесс, отключение цилиндров, система газораспределения, топливная экономичность, баланс энергии топливаThe effect of cylinder deactivation as a method of controlling a diesel engine working in partial load modes is usually justified based on the characteristics corresponding to the engine performance without cylinder deactivation. However, the results obtained through theoretical analysis and in practice have significant differences, since the working processes of activated and deactivated cylinders run in different ways. In this paper, a simulation method is used to analyze the working process of the diesel engine under cylinder deactivation. The working processes in activated and deactivated cylinders are calculated using a computer model, and energy losses determining engine fuel efficiency are estimated. It is shown that the valve system in deactivated cylinders has a significant effect on the specific fuel consumption. The engine performance in partial load modes at different rotational speeds and torques and with a varying number of deactivated cylinders is investigated. The results obtained demonstrate the characteristics of the engine working

The potential benefit of cylinder deactivation (CDA) on power and emission performances has been numerically investigated on a locomotive 16-cylinder diesel engine. A 1D model combined with a predictive friction model and a 3D combustion model based and validated on experimental data have been developed to simulate engine working processes by deactivating half of the cylinders by cutting off the fuel supply and maintaining/cutting off valve motions. The results demonstrate that CDA with the valves closed decreases the BSFC by 11% at 450 rpm and by 14% at 556 rpm with a load of 1000 N∙m, due to increased indicated efficiency and reduced mechanical losses. After deactivating cylinders, frictional losses of piston rings increase in the active cylinders because of the raised gas pressure and the lubricating oil temperature decrease. Friction losses of the main bearings and big-end connecting rod bearings decrease due to the overall load drop. In comparison with the normal operation, CDA with the valves closed decreases the BSCO emission by 75.26% and the BSsoot emission by 62.9%. As the EGR rate is 30%, CDA with the valves closed effectively reduces the BSNOx emission to 4.2 g/(kW·h) at the cost of a 0.8% increase in the BSFC and without the rise in the BSCO emission.

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The introduction of modern diesel fuel supply systems and the use of electronic components in control systems provide new possibilities for shaping engine characteristics targeted at specific energy consumers. Under these conditions, the type of engine characteristics is determined by the operation of the air supply system. This work examines the formation of static characteristics for a promising D500 diesel engine for train and ship power plants. Modeling of the diesel operation modes is carried out on computer models in the MATLAB/Simulink and Diesel-RK software packages. Variants of the full-load curves of the diesel engine are presented for different ways of turbocharger control: using a turbine of variable geometry and with sequential turbocharging. The fuel supply is limited according to the air-fuel ratio and the maximum pressure in the engine cylinders. For a variable geometry turbine, a matrix of the positions of the guide vane blades is obtained from the condition of optimizing diesel modes for fuel efficiency. Possibilities to obtain the efficiency characteristic that would provide the minimal fuel consumption for train and ship power plants are shown.