Maciej Mikulski

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...

On the adaptation of CAN BUS network for use in the ship electronic systems

On the adaptation of CAN BUS network for use in the ship electronic systems This paper presents an analysis of application of the CAN - based marine electronics standard NMEA 2000, recently developed one, on board sea-going vessels, especially in the context of small, recreational, sailing and motor craft. The idea and development of the system has been briefly presented. The properties of the CAN network has been described and the use of its functions by the NMEA system, discussed. The discussion has been performed for all layers of the communication protocol, according to the Open Systems Interconnection Reference Model worked out by ISO. All the features have been summarized and analyzed in the context of their possible use in various shipboard systems.

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.

THE IMPACT OF THE SHARE OF CNG ON THE COMBUSTION PROCESS IN A DUAL-FUEL COMPRESSION-IGNITION ENGINE WITH THE COMMON RAIL SYSTEM

The struggle against global warming necessitates the search for new sources of energy, which limit the emission of carbon dioxide into the atmosphere. Among various fuels used to supply energy nowadays, the importance of natural gas is constantly growing. This is caused by the fact that this fuel is characterised by the lowest share of coal among all fossil fuels. Because of its properties, natural gas can be used directly to power spark-ignition engines. The use of this fuel for compression-ignition engines on the other hand is limited due to the high autoignition temperature of methane. Currently, research is being conducted in numerous centres on the possibility of using fuel gases to power CI engines operating in a dual-fuel system. The present article discusses the impact of the share of CNG in the supply dose on the operation of a CI engine. An engine with the Common Rail injection system programmed for mono-fuel operation was used in the research. Based on the conducted tests it has been proved that supplying this type of engine with fuel gas considerably changes the course of the combustion process, which is caused by the fact that the gas and air mixture present in the combustion chamber starts burning now of the autoignition of the first portion of liquid fuel. The obtained test results confirm the necessity to change the injection parameters of the pilot dose of diesel fuel (the timing angle of injection and the pressure of fuel) in cases when this type of engine operates in a dual-fuel system.

THE IMPACT OF THE SHARE OF BIOGAS IN A SUPPLY DOSE ON LOAD PARAMETERS IN THE COMBUSTION CHAMBER OF A DUAL-FUEL COMPRESSION-IGNITION ENGINE

The need to increase the share of renewable fuels in the general energy balance necessitates the search for new possibilities of their use. One such fuel is biogas, which is generated both as a result of natural processes occurring, e.g. in landfills, and can also be obtained from various biological materials in biogas plants. Because of its properties, biogas may be used to power spark-ignition engines. At the same time, in numerous scientific centres attempts are underway at using biogas to power compression-ignition engines. Due to the relatively high autoignition temperature of methane, which is the main component of biogas, it is necessary to use dual-fuel supply systems in CI engines. Providing fuel gas to such an engine in the form of biogas, which can have a varying chemical composition, considerably changes the conditions of combustion in the engine compartment, which affects both the performance of the engine as well as the emission of toxic compounds into the atmosphere. The present paper discusses the impact of supplying an engine with fuel gas, as well as of the composition of biogas, on the ratios describing the load in the combustion chamber of a dual-fuel compression-ignition engine. The calculations were conducted for a four-cylinder forced induction engine, assuming that the volume of the drawn gas and air mixture equals the volume of the drawn air during mono-fuel operation.

Effect of fuel pilot dose parameters on efficiency of dual-fuel compression ignition engines fuelled with biogas

Increasing the share of renewable electrical energy in the overall energy balance is one of the major challenges of humanity. It is primarily connected with global warming and increasing environmental pollution. One of the ways to counteract this problem is to promote the importance of renewable fuels, including gaseous fuels which are relatively low in carbon.This paper presents the effects of selected parameters of a pilot dose of diesel fuel on the efficiency of a dual-fuel compression ignition engine. The dose of gaseous fuel powering the engine was a mixture of methane and carbon dioxide in varying proportions.

A Proposal Of Simulation Model Of A Wind-Steering System For Sailing Yachts, Based On Single-Stage Servo-Pendulum Coupled With Main Rudder

Abstract The aim of this study was to investigate possible application of fast design prototyping methods for wind-steering systems used in offshore sailing yachts. The development of such methods would help to speed up the construction work and reduce the scope of necessary experimental research, prior to implementation of the system. In the present work, based on an analysis of existing designs of windvane systems, a preliminary selection of the system configuration has been undertaken, in terms of a compromise between efficiency, performance, and design complexity. Construction design of a single-stage, servo – pendulum system, has been developed by using the Autodesk Inventor design package. Next, based on the design data, a simulation model of the system, has been produced by using Matlab - Simulink software and SimMechanics library. The model was further verified in terms of kinematics mapping with the use of Matlab visualization tools.

Effect of pilot charge size and biogas composition on the operating efficiency of a dual-fuel compression-ignition engine

Reduction of greenhouse gases emissions into the atmosphere, as well as increasing the share of renewables in the overall energy balance, forces the search for new, alternative energy sources. One of the fuels, which presents high potential for combustion engines are biomethane or biogas, with methane as the main flammable component. Biogas can be obtained from different products and using a variety of technologies which results in its wide availability and relatively easy manufacture. The largest sources of biogas can be animal farms or sewage treatment plants and waste dumps in which significant quantities of biogas are obtained as a result of naturally occurring processes. Biogas can also be obtained from processing of energy crops or waste processing in agricultural, food and meat processing plants. In this article, the possibility of using biogas as a fuel for CI engines has been examined. In such engine, combustion of biogas (methane) requires the use of dual fuel supply system, in which in addition to methane, liquid fuel is injected into the combustion chamber, in order to initiate the self-ignition of gaseous fuel. The paper presents exemplary results of the impact of the proportion of different fuels and biogas composition on the efficiency of the engine work cycle.