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EN
The manuscript presents a comparative analysis of the performance and emission characteristics of a compression ignition engine equipped with a Common Rail injection system. The engine is fueled with diesel-biodiesel mixtures containing 25% and 50% share (by volume) of renewable components. Conventional diesel is used as a reference. Turkey lard and rapeseed oil are used as raw materials and subjected to the single-stage transesterification process to obtain methyl esters. The experiments are performed on a medium-duty, turbocharged, inter-cooled, Common Rail Direct Injection (CRDI) diesel engine. This study concentrates on one engine speed of 1500 rpm, typical for gen-set applications, and mid-load range from 100 Nm to 200 Nm. The scope of measurements covers the analysis of exhaust gasses concentration and engine efficiency parameters. In addition, the in-cylinder pressure measurements are performed in order to provide insight into the differences in combustion characteristics between examined fuel mixtures. The study reveals that the addition of the renewable component to fuel mixture positively affects a number of examined performance parameters as well as de-creases the concentration of the examined toxic exhaust components, in the majority of cases.
EN
Combustion analysis was carried out using Telops MS-IR MW camera which allows multispectral imaging at a high frame rate. A motorized filter wheel allowing synchronized acquisitions on eight (8) different channels was used to provide time-resolved multispectral imaging of combustion products of a candle in which black powder has been burnt to create a burst (carbon dioxide and water). It was then possible to estimate the temperature of the candle’s plume by modeling spectral profile derived from information obtained with the different spectral filters. Comparison with temperatures obtained using conventional broadband imaging illustrates the benefits of time-resolved multispectral imaging for the characterization of combustion processes.
EN
Optimization procedure of the si engines feeding systems requires the application of newer and more sophisticated tools, as an addition to well known but expensive experimental methods. Numerical methods can be considered nowadays as once playing the most important role in the combustion process analysis. Paper describes the application of the dual zone model, allowing the analysis of the combustion process in an SI engine with the possibility of estimating 10 different exhaust gases i.e.: CO2, CO, H2O O2, NO, N2, H2, H, O and OH. The research has been carried on a 1.6 litr es four cylinder SI engine, fed with petrol and alternatively with LPG and CNG. In-cylinder pressure for the 4th cylinder of the tested engine has been acąuired for several engine speeds. registered in-cylinder pressure traces p=p((fi), together with the volume variation nii=nii((fi) infunction ofcrank angle, were used in the combustion process simulating calculations. Obtained results made it possible to compare selected parameters describing the combustion process. Obtained results do also prove recognized fact related to the higher temperature necessary to initiate gaseous fuel combustion.
EN
The influence of hydrogen-methane blends application in SI engines on their CO2 emission is the main goal of this paper. The 1.6 litre engine alternatively fed with either petrol, CNG and with methane-hydrogen blends has been tested in the research program. The possibility of passenger car engine operation on H2-CH4 mixtures has been demonstrated in the paper, with the underlining of the potential of those mixtures in the increasing of the engine efficiency. Necessary changes in strategy of engine regulation, especially in air/fuel ratio, ignition advance and EGR rate, were noticed and prepared. The methane-hydrogen blends, which were used in the research programme featured ratios as follows: 5%, 10% and 15% of hydrogen. For selected engine operating points, following data has been acquired: in cylinder pressure variation, crank angle, manifold pressure and finally mass fuel consumption. On the basis of registered data for all fuels - burned temperature in cylinder has been estimated, as well as the charge combustion ratio, and the heat release rate. With help of mathematical model describing the exhaust gases formation it has been possible to estimate the NO, CO and CO2 emission level. Obtained results made it possible to compare the combustion process for all tested fuels and pointed on the significant influence of hydrogen percentage for the methane-hydrogen blends, on the CO2 emission reduction up to 20%. Negative aspects of chosen blends application have been also describe in the paper, especially of increasing engine thermal load.
EN
A significant reduction of CO2 emission in the road transport is a major challenge for next years. In the combination with efficient powertrain technologies, the potential of natural gas is excellent for comparably light and cost effective reduction of CO2 and toxic emission in the future [1-2]. As the CNG fuelling stations in Poland are not so far widespread enough to make a dedicated natural gas vehicle practical, it results necessary to start with proposing alternatively CNG powered engines. Such a bi-fuel automotive engines are necessary to bridge the gap between petrol and natural gas. As a sample of modern engine design an Opel 1.6 litre 4-cylinder engine has been selected as a base of powertrain for development of bi-fuelpassenger car engine. The influence of ignition timing on CNG combustion process has been presented in this paper. A 1.6 litre SI engine has been tested in the special program. For selected engine operating conditions, following data were acquired: in cylinder pressure, crank angle, fuel mass consumption and exhaust gases temperatures. For the settings of 6, 9, 12 and 15 deg crank angle timing advance correction, the internal temperature of combustion chamber has been estimated, as well as the charge combustion ratio and ratio of heat release were tested. With the help of the mathematical model, emissions of NO, CO and CO2 were additionally estimated. Obtained results made it possible to compare the influence of ignition timing advance on natural gas combustion in SI engine.
EN
The paper presents the chromatographic determination of nitrogen in organic nitrogen compounds and food stuff products by means of an analytical assembly consisting of a gas chro-matograph equipped with a thermal conductivity detector and a pyrolysis unit of own construction. The principle of determination relys on a prior combustion/degradation of analyzed samples into nitrogen oxides, their subsequent reduction into molecular nitrogen and its final gas chromatographic (GC-TCD) determination. The analytical procedure, with exception of the manual weighing of samples, is fully automatized. The mass of samples analyzed ranged from 0.5 to 4 mg; time of determination was approximately 3 min.
PL
Przedstawiono oznaczanie azotu w związkach organicznych, żywności i paszach wykorzystując zestaw analityczny złożony z chromatografu gazowego z detektorem termokondukto-metrycznym i przystawki pirolitycznej własnej konstrukcji. Zasada oznaczania polega na wstępnej spaleniowej degradacji azotu organicznego do tlenków azotu za pomocą stałego utleniacza (Co3O4), które po dalszej redukcji do azotu cząsteczkowego, oznaczano dalej chromatograficznie (OC-TCD). Postępowanie analityczne poza odważaniem próbki jest zautomatyzowane. Masa badanej substancji potrzebna do jednej analizy wynosi od 0.5 do 4 mg, a czas oznaczania azotu wynosi około 3 minut.
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