Sławomir Wierzbicki

The concept of an integrated laboratory control system for a dual - fuel diesel engine

The need to limit greenhouse gases emissions and to increase the share of renewable fuels in the general energy balance forces people to look for new alternative energy sources. Methane or biogas, in which methane is the main combustible component, is one of such fuels, which is believed to be a promising diesel engine fuel. It is worth emphasizing that biogas might be believed to be one of the cleanest fuels due to the fact that it can be produced from waste, which in normal conditions decomposes releasing methane into the atmosphere. Methane (biogas) combustion in diesel engines requires a dual-fuel feed system, in which the liquid fuel initiating auto-ignition will be injected into the combustion chamber. It comes as a consequence of a relatively high spontaneous combustion temperature of methane, which is not able to self-ignite in the chamber without an external source of ignition. This article presents a concept of constructing an integrated laboratory control system, which will provide optimal feed control of complex composition gaseous fuel and of the injection of an appropriate pilot dose of a liquid fuel into the combustion chamber. The solution proposed to control a dual-fuel diesel engine, which was mounted on the test bed, enables performing comprehensive diesel engine research, ensuring not only stable working conditions for the engine, but also granting an opportunity to smoothly regulate the composition of the artificial biogas which feeds the engine and to control basic parameters of the liquid fuel pilot dose.

Visualization of the Parameters and Changes of Signals Controlling the Operation of Common Rail Injectors

The electromagnetic injector in the Common Rail system is the actuator directly responsible for fuel injection. Its proper operation is enabled by ensuring appropriately shaped changes of the electric signal worked out by the output stage of the controller. This paper determines the repeatability of the control signal and the possibility of using this signal for the diagnostics of the electrical part of the injector.

Effect of CNG in a fuel dose on the combustion process of a Compression-Ignition engine

AbstractCurrently, one of the major trends in the research of contemporary combustion engines involves the potential use of alternative fuels. Considerable attention has been devoted to methane, which is the main component of Natural Gas (NG) and can also be obtained by purification of biogas. In compression-ignition engines fired with methane or Compressed Natural Gas (CNG), it is necessary to apply a dual-fuel feeding system. This paper presents the effect of the proportion of CNG in a fuel dose on the process of combustion. The recorded time series of pressure in a combustion chamber was used to determine the repeatability of the combustion process and the change of fuel compression-ignition delay in the combustion chamber. It has been showed that NG does not burn completely in a dual-fuel engine. The best conditions for combustion are ensured with higher concentrations of gaseous fuel. NG ignition does not take place simultaneously with diesel oil ignition. Moreover, if a divided dose of diesel is inj...

Biogas as a fuel for diesel engines

The pursuit of reduced greenhouse gas emissions, as well as the increased share of renewable fuels in the overall energy balance has led to a search for alternative energy sources. One of the fuels on which great hopes are set as fuel for engines is biomethane or biogas, whose main component is methane. Biogas can be obtained from different products by using different technologies, so that it has potential as a widelyavailable fuel, which is quite easy to produce. The percentage of methane in biogas depends on the technology for obtaining biogas and ranges from 35% to around 75%. The largest biogas sources can be animal farms, where it is obtained from animal excrement. Another source is sewage treatment plants and rubbish dumps, where substantial quantities of biogas are obtained as a result of natural processes occurring in waste dumping sites or sewage. Biogas can also be acquired from waste obtained from fruit and vegetable processing as well as waste from meat plants. This paper examines the possibility of using biogas as a fuel for diesel engines. In these engines, the combustion of biogas (methane) requires the application of a dual-fuel supply system in which liquid fuel initiating gas fuel selfignition will be injected into the combustion chamber along with methane. The paper also contains example results showing the effect of the methane dose on the course of the combustion process in diesel engines.

Laboratory Control and Measurement System of a Dual-Fuel Compression Ignition Combustion Engine Operating in a Cogeneration System

Electrical energy production from renewable energy sources is currently one of the key directions of conducted research. This paper describes a developed laboratory control system for the operation of a dual-fuel compression ignition engine in which the main fuel charge is fed in the form of biogas with variable composition, it also describes a system enabling the measurement of waste heat from this engine.

The effect of diesel-biodiesel blends on the performance and exhaust emissions of a direct injection off-road diesel engine

AbstractThis paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 mi...

THE CONCEPT AND CONSTRUCTION OF THE ENGINE TEST BED FOR EXPERIMENTS WITH A MULTI-FUEL CI ENGINE FED WITH CNG AND LIQUID FUEL AS AN IGNITION DOSE

The experiments described in the article aimed at adjusting the engine test bed, its equipment and software to perform comprehensive tests on a dual-fuel spontaneous combustion engine with the main gas dose (methane or biogas) and a liquid fuel ignition dose. The steps undertook during the tests included installing a new engine on the engine test bed, installing its equipment and preparing a dual-fuel feed system. The toxic emissions analysis system was also modified, thanks to which a thorough research based on current test methods was possible. All measurement devices were integrated and are governed by one system of data acquisition and controlling, which ensures repeatable testing conditions. In order to exercise better control over the oil pilot dose injection, the previously used engine was replaced with a Common Rail one, which facilitates better control over the pilot dose injection and ensures controlling the system through an external driver. Providing the engine with a set of measurement systems makes it possible to test it not only with reference to its power and toxic emissions into the atmosphere, but also to the heat absorbed by the cooling system, which enables testing engines for cogeneration units.

Verification of a 2–Phase, Zero-Dimensional Model of a Multifuel Compression-Ignition Engine in Single Fuel Operation

Improving the efficiency or work and reducing the emissions of toxic substances into the atmosphere are the two key directions of development of modern combustion engines. Improvement of engine efficiency is feasible only by increasing the precision of control thereof, which necessitates long-term operating tests. Regrettably, due to complexity of processes taking place during the combustion of fuel, these phenomena can only be tested on simulation models, based on a mathematical description of the phenomena.This paper presents the results of verification tests of the developed fuel combustion model in a multifuel compression-ignition engine for an engine running only on diesel fuel.

INFLUENCE OF CONTRIBUTION OF BIOFUELS DERIVED FROM RENEWABLE MATERIALS IN THE FUEL ON THE COMBUSTION PROCESS AND TOXIC COMPOUNDS EMISSION OF COMPRESSION IGNITION ENGINE

The use of liquid fuels as an energy source for internal combustion engines is unavoidable nowadays, further consumption increases with the development of industry and economic growth of the country. The abundance of the world in fossil fuels is a highly controversial issue; however, irrespective of forecasts concerning deposits of mineral fuels, undisputable fact is that these are resources, which will deplete. Economic, environmental and legislative issues also impose a limitation of use of fossil fuels. Under the problems associated with fossil fuels, an interesting alternative may be fuel derived from renewable sources. Biodiesel understood as a renewable energy source, used to feed compression ignition engines seem to be the ideal solution to meet energy needs, facing so called economic circulation era. Many research results confirm that combustion of pure biofuels in the currently highly advanced injection systems causes many problems. Different biofuel properties from diesel, such as viscosity or density directly influences on combustion process and emission of toxic components in the exhaust gases. Therefore, biodiesel blends with diesel fuel in all proportions; the combustion of such mixtures carries a number of benefits, from consumption reduction of non-renewable resources to reduction of harmful components in the exhaust gases. In this paper, the effect of doping methyl esters on the process of combustion and exhaust gases emissions in a compression ignition engine feed with mixtures of esters and diesel was examined. Tests were performed on four-cylinder, CI Andoria ACDR engine equipped with Common Rail fuel injection system. In order to investigate the combustion process, cylinder pressure and toxic components in exhaust gases steady state measurements were performed.

Possibility of Automation of a Mobile Biodiesel Production Plant

This paper presents a method of production and properties of ethyl esters as well as the differences between them and methyl esters. It discusses the technology of esterification and the benefits brought by the use of rapeseed ethyl esters as renewable fuel. It also presents elements of structure, actuators and control mechanisms of a mobile biodiesel production plant, owned by the Department of Mechatronics, University of Warmia and Mazury. An algorithm of a transesterification process is presented along with algorithms of a flow-through process control and the possibilities of their automation. The benefits of applying such a solution are also discussed.