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This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the evaluation. The TOPSIS method was used to evaluate the best generation technology.

The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation are CO₂ emissions, NOX emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost.

The results drawn from the analysis in technology wise are as follows: natural gas fuelled solid oxide fuel cells>natural gas combined cycle>natural gas fuelled phosphoric acid fuel cells>natural gas internal combustion engine>hydrogen fuelled solid oxide fuel cells>hydrogen internal combustion engines>hydrogen combustion turbines>hydrogen fuelled phosphoric acid fuel cells> and natural gas turbine. It shows that the natural gas fuelled solid oxide fuel cells are the best technology available among all the available technology considering the seven criteria such as service life, electricity cost, O&M costs, capital cost, NOX emissions, CO₂ emissions and efficiency of the plant.

The most dominant electricity generation technology proved to be the natural gas fuelled solid oxide fuel cells which ranked in the first place among nine alternatives. The research is helpful to evaluate the different alternatives.

The research is helpful to evaluate the different alternatives and can be extended in all the spares of technologies.

The research was the original one. Nine energy generation options were evaluated with regard to seven criteria. The energy generation options were the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation were efficiency, CO₂ emissions, NOX emissions, capital cost, O&M costs, electricity cost and service life.

The internal combustion engine operated on gaseous fuels shows great potential in terms of integration of the renewable and traditional sources for an effective solution for clean energy production challenge. Different fuel mixtures that can be used to power the engine are characterized by various combustion properties, which can affect its overall efficiency. The purpose of this paper is to provide reasonable answer, how the operation condition can change due to different fuel, without enormous cost of prototyping processes using physical models a digital model can be seen as promising technique.

Presented work discusses the application, and extensive description of two commercial codes Ansys Fluent and Forte for modeling stationary engine fueled by compressed natural gas (CNG) and biogas. To check the model accuracy, all carried out numerical results were compared against experimental data collected at in-house test rig of single cylinder four stroke engine. The impacts of tested gaseous fuel on the engine working conditions and emission levels were investigated.

Carried out simulations showed good agreement with experimental data for investigated cases. Application on numerical models give possibility to visualize flame front propagation and pollutant formation for tested fuels. The biogas fuel has shown the impaired early flame phase, which led to longer combustion, lower efficiency, power output, repeatability and in some cases higher HC and carbon monoxide (CO) emissions as a result of combustion during the exhaust stroke. Looking at the CO formation it was observed that it instantly accrue with flame front propagation as a result of methane oxidation, while for NOx formation revers effect was seen.

The application of new approach for modeling combustion process in stationary engines fueled by CNG and alternative biogas fuel has been discussed. The cons and pros of the Forte code in terms of its application for engine prototaping process has been discussed.

This paper aims to use the crankshaft-bearing system of a four-cylinder internal combustion engine as the studying object, and develop a multi-objective optimization design of the crankshaft-bearing. In the current optimization design of engine crankshaft-bearing, only the crankshaft-bearing was considered as the studying object. However, the corresponding relations of major structure dimensions exist between the crankshaft and the crankshaft-bearing in internal combustion engine, and there are the interaction effects between the crankshaft and the crankshaft-bearing during the operation of internal combustion engine.

The crankshaft mass and the total frictional power loss of crankshaft-bearing s are selected as the objective functions in the optimization design of crankshaft-bearing. The Particle Swarm Optimization algorithm based on the idea of decreasing strategy of inertia weight with the exponential type is used in the optimization calculation.

The total frictional power loss of crankshaft-bearing and the crankshaft mass are decreased, respectively, by 26.2 and 5.3 per cent by the multi-objective optimization design of crankshaft-bearing, which are more reasonable than the ones of single-objective optimization design in which only the crankshaft-bearing is considered as the studying object.

The crankshaft-bearing system of a four-cylinder internal combustion engine is taken as the studying object, and the multi-objective optimization design of crankshaft-bearing based on the crankshaft-bearing system is developed. The results of this paper are helpful to the design of the crankshaft-bearing for engine. There is universal significance to research the multi-objective optimization design of crankshaft-bearing based on the crankshaft-bearing system. The research method of the multi-objective optimization design of crankshaft-bearing based on the crankshaft-bearing system can be used to the optimization design of the bearing in the shaft-bearing system of ordinary machinery.

The lack of integrity of the piston machine combustion chamber manifests itself in leakages of the working fluid between the piston and the cylinder liner, at valves mounted in the cylinder head and between the head and the liner. An untight combustion chamber leads to decreased power output or efficiency of the engine, while leaks of a fluid may cause damage to many components of the chamber. The actual value of working chamber leak is a desired and essential piece of information for planning operations of a given machine.

This research paper describes causes and mechanisms of leakage from the working chamber of internal combustion engines. Besides, the paper outlines presently used methods and means of leak identification and states that their further development and improvements are needed. New methods and their applicability are presented.

The methods of leak identification have been divided into diagnostic and non-working machine leak identification methods. The need has been justified for the identification of leakage from the combustion chamber of a non-working machine and for using the leakage measure as the value of the cross-sectional area of the equivalent leak, defined as the sum of cross-section areas of all leaking paths. The analysis of possible developments of tightness assessment methods referring to the combustion chamber of a non-working machine consisted in modelling subsequent combustion chamber leaks as gas-filled tank leak, leak from another element of gas-filled tank and as a regulator of gas flow through a nozzle.

A measurement system was built allowing the measurement of pressure drop in a tank with the connected engine combustion chamber, which indicated the usefulness of the system for leakage measurement in units as defined in applicable standards. A pneumatic sensor was built for measuring the cross-sectional area of the equivalent leak of the combustion chamber connected to the sensor where the chamber functioned as a regulator of gas flow through the sensor nozzle. It has been shown that the sensor can be calibrated by means of reference leaks implemented as nozzles of specific diameters and lengths. The schematic diagram of a system for measuring the combustion chamber leakage and a diagram of a sensor for measuring the cross-sectional area of the equivalent leak of the combustion chamber leakage are presented. The results are given of tightness tests of a small one-cylinder combustion engine conducted by means of the set up measurement system and a pre-prototype pneumatic sensor. The two solutions proved to be practically useful.

THERE is probably no one among those listening to me this evening who does not know, or who has not realised through personal experience, the importance of the problem of detonation in internal combustion engine technique. Indeed, since petrol engines have been working on the Beau do Rochas cycle, the phenomenon of “knocking” has been an obstacle—which has gradually been driven into the background, it is true, but which is really insurmountable—to the increase in compression which is recommended by thermodynamics and which experience has shown to produce an increase in output equal to, and even slightly in excess of, the calculated theoretical value.

The development of a theoretical model for predicting the combustion, performance and emission characteristics of a cylinder head porous medium engine becomes necessary due to imposed requirements from the viewpoint of power, efficiency and toxic gases in the exhaust. The cylinder head porous medium engine was found to have superior combustion, performance and emission characteristics when compared to a conventional diesel engine. The paper aims to discuss these issues.

Due to heterogeneous and transient operation of diesel engine under conventional and porous medium mode, the combustion process becomes complex, and achieving a pure analytical solution to the problem was difficult. Although, closer accuracy of correlation between the computer models and the experimental results is improbable, the computer model will give an opportunity to quantify the combustion and heat transfer processes and thus the performance and emission characteristics of an engine.

In this research work, a theoretical model was developed to predict the combustion, performance and emission characteristics of a cylinder head porous medium engine through two-zone combustion modeling technique, and the results were validated through experimentation.

The two-zone model developed by using programming language C for the purpose of predicting combustion, performance and emission characteristics of a porous medium engine is the first of its kind.

A BRIEF discussion of combustion research, which has been in progress for over three hundred years, must be limited to a specific subdivision of the field. For presentation before the Society of Automotive Engineers, it is logical that this report should be confined, in a general way, to that phase of combustion research which is concerned with explosions in gases, and particularly with explosions from which, through the medium of the internal combustion engine, usable power may be derived.

We present results of a mathematical model for the gas flow in an internal combustion engine consisting of a single cylinder with an inlet and outlet pipe. In order to achieve optimal performance of the engine the dependence of the gas flow on physical parameters such as pipe dimensions and valve geometry need to be understood. A system of ordinary differential equations (in time t) with discontinuous right‐hand side describes the gas properties in the cylinder, whereas the gas flow in each pipe is modelled by the Euler equations, a system of hyperbolic partial differential equations. The explicit method of Euler and a TVD scheme are used for solving these equations. However, since the coupling of the pipe equations with the o.d.e. system in the cylinder on one side and atmospheric gas properties on the other appeared to be a main problem, we concentrate on appropriate coupling conditions. The numerical techniques involve discretization in space and time, and we present different methods of discrete coupling. As a main result we show that the various coupling methods lead to quite different numerical solutions. Therefore, a careful treatment of the coupling conditions is crucial.