Tag Archives: combustion

981–998 M. Gailis, and V. Pirs
Experimental analysis of combustion process in SI Engine using ethanol and ethanol-gasoline blend
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Experimental analysis of combustion process in SI Engine using ethanol and ethanol-gasoline blend

M. Gailis¹,²* and V. Pirs²

¹ Riga Technical University, Faculty of Mechanical Engineering, Transport and Aeronautics, Department of Automotive Engineering, Viskalu 36A, LV 1006 Riga, Latvia
² Latvia University of Agriculture, Faculty of Engineering, Motor Vehicle Institute, Liela street 2, LV 3001 Jelgava, Latvia
*Correspondence: maris.gailis@rtu.lv

Abstract:

Effect of fuel composition and ignition timing on combustion parameters of spark ignition (SI) port fuel injection (PFI) engine had been studied experimentally. The engine was fuelled with an ethanol and ethanol-gasoline blend E85. The engine was operated at steady speed at 1,500 min-1 and four load points have been used. Minimal ignition timing advance for maximal brake torque (MBT) at stoichiometric air/ fuel ratio for the tested fuels were found. The fuels were tested at their respective MBT timing and gasoline MBT timing. MBT timing was retarded by 8–11% for ethanol and 5–10% for E85 fuel, comparing to gasoline MBT timing. Indicated mean effective pressure (IMEP) was not affected by ignition timing in tested conditions. Maximal cylinder pressure was increased and flame development phase was extended, when gasoline MBT was used with fuels with high ethanol content at tested conditions.

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725–732 D. Černý, J. Malaťák and J. Bradna
Influence of biofuel moisture content on combustion and emission characteristics of stove
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Influence of biofuel moisture content on combustion and emission characteristics of stove

D. Černý*, J. Malaťák and J. Bradna

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague, Czech Republic
*Correspondence: david.cerny@dotacenazeleno.cz

Abstract:

 The research aim was to study the effect of moisture in solid fuel on combustion in a stove and its emissions. Analysed samples were from spruce woodchips. Four samples were prepared with different moisture contents and furthermore spruce wood was used as a reference sample. Combustion device used was a stove with a fixed fire grate. Studied parameters were ambient temperature, temperature of flue gases, coefficient of excess air, and contents of oxygen and carbon monoxide in flue gases. Laboratory measurement was performed on an analyser of flue gases whose function is based on electro-chemical converters. Measured values were first converted to a referential oxygen content in flue gases. Evaluation of these values was then made by regression analyses. The course of combustion process and its quality can be seen well in functional dependence of carbon monoxide on excess air coefficient. The area of combustion was the smallest with the least moist sample (3.2%) and increases with increasing moisture. A sample with high moisture (31.1%) was already causing the fire to gradually extinguish. Because flue gas temperature is in the same range for all samples, the overall efficiency of the stove decreases sharply with fuel moisture due to specific heat of flue gases. It has been thus confirmed that fuel moisture content has a substantial influence on combustion, especially in the chosen combustion device, which has been verified by comparison with the reference fuel.

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611-622 V. Suzdalenko, M. Gedrovics and V. Vitolins
Experimental pilot device for thermal analysis of biomass co-firing
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Experimental pilot device for thermal analysis of biomass co-firing

V. Suzdalenko*, M. Gedrovics and V. Vitolins

Institute of Energy Systems and Environment, Riga Technical University, Kronvalda boulevard 1, LV-1010 Riga, Latvia; *Correspondence: Vera.Suzdalenko@rtu.lv

Abstract:

The share of biomass in the transformation sector of Latvia accounts for only 15%, at the same time natural gas share in transformation sector is about 80%. Nonetheless, an ongoing natural gas price growth stimulates its full replacement with biomass. The goal of the research was to construct an experimental pilot device, where could be possible to combust biomass with gaseous fossil fuel. The pilot device was equipped with the following measurement instruments: thermocouples for local temperature measurements and gas analyzer for measurements of flue gas composition, temperature, and combustion efficiency.

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157-166 V. Mikita, J. Roots and J. Olt
Simulation model of the combustion processes of a diesel engine
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Simulation model of the combustion processes of a diesel engine

V. Mikita¹, J. Roots² and J. Olt¹

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56,
EE51014, Tartu, Estonia; e-mail: villu.mikita@emu.ee,
²Institute of Economics and Social Sciences, Estonian University of Life Sciences,
Kreutzwaldi 56, EE51014 Tartu, Estonia

Abstract:

It is foreseen that in the near future in Estonia there will be growth in the consumption of alternative liquid fuels in internal combustion engines. The main share of it will be formed by the local raw material based diesel fuel and ethanol. In connection with this, the choice of fuels and the variety of their qualitative characteristics in filling stations will grow. This kind of situation will give rise to the necessity of creating new quality assessment methods which should be reliable, efficient and economical. There may be several assessment methods for taking fuel samples. Drivers consider the fuel quality assessment express methods especially valuable. Working out a new method like that is at present also supported by the electronic control system of the engine and the use of digital diagnostic devices. Creating and implementing the fuel quality assessment express method requires a considerable amount of effort. It includes the evaluation and prognosis of the fuels physical and chemical parameters, designing the simulation models of the engine combustion process pressure and temperature and carrying out the control testing.

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