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1

Numerical investigation on the effects of fueling the Turbulent Jet Ignition gas engine with methane and hydrogen

Pielecha Ireneusz, Szwajca Filip, Skobiej Kinga

Pojazdy Szynowe

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2023

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Nr 1-2

46--57

EN

The modern solution of two-stage combustion, namely the Turbulent Jet Ignition (TJI), enables the combustion of ultra-lean mixtures. Thanks to this solution, it became possible to reduce fuel consumption and, at the same time, to increase the combustion process indicators (including the overall combustion system efficiency). The article presents the results of numerical tests of a heavy-duty engine equipped with the TJI system running on gas fuels. The AVL BOOST software was used to analyze the effects of different fuel injection rates into the pre-chamber and various ignition timing angles, while maintaining a constant global excess air ratio. Increasing the proportion of hydrogen in the prechamber resulted in its reduction in the main chamber (the fuel dose was kept constant with different excess air coefficients in each of the chambers). The maximum combustion pressure values in both chambers were investigated. Changes in the amount of heat released and its release rate were determined. As a result of the simulations, different ignition and combustion conditions were presented for the tested fuels. Based on this, maps of fuel dose to prechamber vs. ignition advance angle were drawn up, showing selected thermodynamic indicators of the combustion process.

2

Sonically modified zeolites with MFI and USY type structure as catalysts for methane combustion. Preparation and physicochemical characterisation

Kuterasiński Łukasz, Dymek Klaudia, Jodłowski Przemysław Jakub

Science, Technology and Innovation

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2019

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Vol. 6, no. 3

11--18

EN

The objectives of our study were to prepare of ZSM-5 and USY-based catalysts by hydrothermal method, containing metallic active phase, deposited by both conventional ionic-exchange or ultrasonic irradiation. Prepared materials were characterized by various physicochemical methods, such as XRD, BET, SEM, UV-VIS and the sorption of ammonia monitored by FT- -IR spectroscopy. The XRD data confirmed pure MFI or USY type structure zeolite. BET and ammonia sorption results have shown that the presented method leads to preparation of highly porous and acidic systems. Metallic active phase was found as cations and oxides with hexagonal and octahedral coordination.

3

Application of Model-Based Tests for Analysing the Consequences of Mine Fires

Tutak M.

Multidisciplinary Aspects of Production Engineering

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2018

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Vol. 1, Iss. 1

767--774

EN

One of the most common and most dangerous hazards in underground coal mines is fire hazard. Mine fires can be exogenous or endogenous in nature. In the case of the former, a particular hazard is posed by methane fires that occur in dog headings and longwalls. Endogenous and exogenous fires are large hazard for working crew in mining headings and cause economics losses for mining plants. Mine fires result in emission of harmful chemical products and have a crucial impact on the physical parameters of the airflow. The subject of the article concerns the analysis of the consequences of methane fires in dog headings. These consequences were identified by means of model-based tests. For this purpose, a model was developed and boundary conditions were adopted to reflect the actual layout of the headings and the condition of the atmosphere in the area under analysis. The objective of the test was to determine the effects of methane fires on the chemical composition of the atmosphere and the physical parameters of the gas mixture generated in the process. The results obtained clearly indicate that fires have a significant impact on the above-mentioned values. The paper presents the distributions for the physical parameters of the resulting gas mixture and the concentration of fire gases. Moreover, it shows the distributions of temperature and oxygen concentration levels in the headings under analysis. The methodology developed for the application of model-based tests to analyse fire events in mine headings represents a new approach to the problem of investigating the consequences of such fires. It is also suitable for variant analyses of the processes related to the ventilation of underground mine workings as well as for analyses of emergency states. Model-based tests should support the assessment of the methane hazard levels and, subsequently, lead to an improvement of work safety in mines.

4

Ocena możliwości utylizacji energii spalania metanu z powietrza wentylacyjnego kopalń węgla kamiennego do odsalania ścieków

Gosiewski K.

Prace Naukowe Instytutu Inżynierii Chemicznej Polskiej Akademii Nauk

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2016

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nr 20

91--115

PL

Spalanie nisko stężonego metanu zawaltego w powietrzu wentylacyjnym kopalń węgla kamiennego rodzi problem racjonalnego wykorzystania uzyskiwanej energii. Dokonano analizy zapotrzebowania energii różnych metod odsalania. Artykuł zawiera studium możliwości wykorzystania energii spalania metanu wentylacyjnego do odsalania ścieków kopalnianych w układzie kogeneracyjnym, w którym w pełni wykorzystuje się uzyskiwaną energię cieplną i elektryczną.

EN

Combustion of Jean metbane contained in the hard coal mines ventilation air raises a problem of rational use of the obtained energy. An analysis of energy demand for various desalination methods was done. The paper presents a study of possibilities to utilize energy of the ventilation air methane for desalination of mine sewage in the cogeneration system, which fully expJoits the produced heat and electrical energy.

5

Study of influence of tremors on combined hazards. Longwall mining operations in co-occurrence of natural hazards. A case study

Trenczek S.

Journal of Sustainable Mining

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2016

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Vol. 15, iss. 1

36--47

EN

Combined hazards occurring in areas of hard coal mines were characterised. A possible course of processes leading to a mining catastrophe, associated with occurrence of combined hazards, was discussed. An example of a cause and effect chain is presented, where rockburst hazard initiates – with co-occurring climatic hazard – an increase in the level of spontaneous fire hazard, methane explosion hazard and coal dust explosion hazard. Possibility of improving detection of spontaneous fire hazard in presence of co-occurring combined hazards was analysed.

6

Uproszczony opis kinetyki spalania metanu w powietrzu w pobliżu punktu stechiometrycznego w odniesieniu do strumienia molowego

Kędzior R., Grzesiak D., Popławski D., Hałat A., Głowiński J.

Przemysł Chemiczny

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2015

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T. 94, nr 6

948-951

PL

Przedstawiono uproszczony opis kinetyczny spalania metanu w powietrzu w pobliżu punktu stechiometrycznego po stronie mieszanek ubogich w paliwo. Bazując na wynikach symulacji spalania metanu, wyznaczono parametry proponowanych równań kinetycznych.

EN

The model of Warnatz mechanismus of the reaction and a com. computer program were used to simulate the combustion of MeH-air mixts. (MeH content 9.14–9.50% by vol.) to est. the parameters of the reaction kinetic equations.

7

The effect of the method of active phase preparation on the catalytic activity of LaCoO3 perovskite-based monoliths in combustion of methane

Kucharczyk B.

Polish Journal of Applied Chemistry

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2003

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Vol. 47, nr 4

263-273

EN

LaCoO3 perovskite-based monolithic catalysts supported on heat resisting foils were investigated for the effect of the preparation method on their activity during methane combustion. A mixture of lanthanum and cobalt nitrates used as the precursor of the LaCoO3 perovskite gave the catalyst with a slightly higher activity in methane combustion than when a mixture of appropriate carbonates or hydroxides was used as the precursor. The decrease in the calcination temperature of the LaCoO3 perovskite-type oxides from 1200oC to 750oC brought about an increase in their BET surface area and in the activity of the monolithic catalyst during methane combustion. Catalysts incorporating 11.7 wt.% or 22.7 wt.% LaCoO3 active phase calcined at 750oC displayed similar activities. In the presence of catalysts resting on an Al2O3-La2O3-TiO2 washcoated support, the extent of methane conversion was found to increase owing to the increased specific surface area of the support. However, the presence of the washcoat lowered the resistance of the catalyst to thermal shocks.

PL

Przeprowadzono badania wpływu sposobu preparatyki fazy aktywnej monolitycznego katalizatora perowskitowego LaCoO3 na jego aktywność w spalaniu metanu. Zastosowanie jako prekursora perowskitu LaCoO3 mieszaniny azotanów lantanu i kobaltu zapewnia nieco wyższą aktywność katalizatora, niż przy zastosowaniu odpowiednich mieszanin węglanów lub wodorotlenków. Obniżenie temperatury kalcynacji tlenków typu perowskitu LaCoO3 z 1200oC do 750oC podwyższa ich powierzchnię BET i aktywność katalizatora. Katalizatory monolityczne zawierające 11,7% i 22,7% fazy aktywnej LaCoO3, kalcynowanej w temperaturze 750oC, wykazują jednakową aktywność. Stwierdzono, że naniesienie na nośnik warstwy pośredniej o składzie Al2O3-La2O3-TiO2 podwyższa stopień przereagowania metanu ze względu na wzrost powierzchni właściwej nośnika. Obecność warstwy pośredniej obniża jednak odporność katalizatora na szoki termiczne.