METHODS FOR EVALUATING THE EFFICIENCY OF TURBOCHARGING SYSTEM OF PISTON ENGINE WITH POWER TURBINE

Author(s):  
A. N. Berdnik

The analysis of existing methods for assessing the loss of gases performance in the flow part of turbocharging system of piston engine is presented. It is shown that the exergy method provides a complete picture about of local energy transformations in the intake and exhaust systems of a piston engine, which makes it possible to use it to evaluate the efficiency of turbocharging system of piston engine with power turbine when forcing a piston engine by on the average effective pressure.

Author(s):  
A.N. Berdnik ◽  
D.V. Timoshenko ◽  
A.V. Passar

В статье представлены результаты исследования импульсной и изобарной систем выпуска поршневого двигателя в зависимости от среднего эффективного давления. Целью данной работы является выявление эффективного использования импульсной или изобарной системы выпуска с точки зрения потерь работоспособности газов при движении энергетического потока от цилиндров до турбины при форсировании поршневого двигателя по среднему эффективному давлению. Существующие системы газотурбинного наддува не имеют чёткой области использования в зависимости от среднего эффективного давления. До сих пор на практике в процессе создания более форсированных дизельных двигателей конструкторы вынуждены подбирать многие элементы выпускных систем на основе ранее приобретенного опыта эксплуатации предыдущих конструкций. Причина кроется в отсутствии понимания физической сущности процессов локальных потерь работоспособности рабочего тела, например, при движении газов от цилиндров двигателя к турбине. В работе получены новые результаты расчётов импульсной и изобарной систем выпуска двигателя Caterpillar 3508С в зависимости от уровня форсирования по среднему эффективному давлению с использованием метода характеристик, квазистационарного метода и эксергетического метода. Разработан комплексный подход к решению проблемы выбора оптимальной системы выпуска при форсировании по среднему эффективному давлению поршневого двигателя. Для решения поставленной цели исследования в работе применился современный подход к оценке эффективности различных систем газотурбинного наддува эксергетический метод. Полученные результаты подтверждают возможность использования эксергетического метода для оценки эффективности систем выпуска с точки зрения потерь работоспособности газов. Выбрана оптимальная система выпуска двигателя Caterpillar 3508С с точки зрения потерь работоспособности выпускных газов в зависимости от среднего эффективного давления.The article presents the results of the study of pulse and Isobaric exhaust systems of a piston engine depending on the average effective pressure. The purpose of this work is to identify the effective use of a pulsed or isobaric exhaust system from the point of view of the loss of working capacity of exhaust gases during the movement of the energy flow from cylinders to the turbine when forcing the piston engine according to the average effective pressure. Existing supercharging systems do not have a clear area of use depending on the average effective pressure. Until now, in practice, in the process of creating more forced diesel engines, designers are forced to select many elements of exhaust systems on the basis of previously acquired experience in the operation of previous designs. The reason lies in the lack of understanding of the physical essence of the processes of local losses of the working capacity working fluid, for example, during the movement of gases from the engine cylinders to the turbine. In the work are obtained new results of calculations of impulse and isobaric exhaust systems of Caterpillar 3508C engine depending on the level of forcing on the average effective pressure with the use of the characteristics method, the quasi-stationary method and the exergy method are obtained. A comprehensive approach to solving the problem of choosing the optimal exhaust system when forcing the piston engine according to the average effective pressure is developed. To solve the goal of the study, a modern approach to assessing the efficiency of various supercharging systems exergy method was applied. The obtained results confirm the possibility of using the exergy method to assess the efficiency of exhaust systems from the point of view of the losses of working capacity of exhaust gases. The selected optimum system of exhaust system of the Caterpillar 3508C engine in terms of the losses of working capacity of exhaust gases depending on the average effective pressure.


2020 ◽  
Vol 178 ◽  
pp. 01038
Author(s):  
George Marin ◽  
Dmitrii Mendeleev ◽  
Boris Osipov ◽  
Azat Akhmetshin

Modern energy development strategies of advanced countries are based on the construction of gas turbine units which is associated with sufficiently high values of thermal efficiency and a relatively short term for putting them into operation. In this paper, the NK-8 engine is considered. It is modernized with a mixing chamber and a power turbine for the purpose of its ground application. A study was conducted of the injection of an additional working fluid into the flow part of a dual-circuit gas turbine engine. Steam is used as an injectable substance. For research a mathematical model was created in the AS «GRET» software package. The studies were carried out under constant load, the maximum load during injection was determined. An additional worker can be supplied with summer power limitations when it is necessary to increase the power of a gas turbine installation. Studies have shown that the maximum power that can be obtained by supplying steam to the flow part is 32.2 MW.


1989 ◽  
Vol 111 (3) ◽  
pp. 560-569 ◽  
Author(s):  
E. Meier ◽  
J. Czerwinski

The turbocharging systems of highly boosted four-stroke diesel engines (BMEP 25 bar/363 psi) have to cope with two basic problems: lack of air and compressor surge at reduced engine speed. In the case of medium speed engines for ship propulsion and stationary applications, the following three control interventions have proved to be successful solutions: (1) waste gating air or exhaust gas at full load and speed, (2) using a compounded or independent exhaust gas driven power turbine that can be shut off at part load and speed, and (3) blowing air from the compressor outlet to the turbine inlet through a controlled bypass. The effect of these control interventions on engine performance is shown by examples and analyzed by means of characteristic quantities for the efficiency of the turbocharging system and the engine. The definitions and meanings of these quantities are explained in the first part of the paper.


Author(s):  
A. N. Berdnik ◽  
V. O. Remeslovskiy

A method for calculating the non-stationary gas flow in the exhaust pipeline of a piston engine by the method of solitary waves of finite amplitude is presented. The comparison of experimental data and calculation results by the method of characteristics and obtained when considering the process of propagation of solitary waves through the exhaust pipeline of a piston engine equipped with a pulsed turbocharging system is shown.


Author(s):  
Mihail Zver'kov

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.


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