Wyniki wyszukiwania - Biblioteka Nauki

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Spalanie gazów ziemnych niskokalorycznych w turbinach gazowych

100%

Ślefarski R. , Dobski T. , Grzymisławski P. , Gołębiewski M.

Rynek Energii

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2014

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tom Nr 2

54--60

PL

Artykuł przedstawia wyniki badań spalania gazów ziemnych niskokalorycznych LCNG - Low Calorific Natural Gases - w warunkach jakie panują w turbinach gazowych, za wyjątkiem ciśnienia, gdyż większość badań została wykonana dla ciśnienia otoczenia. Gazy LCNG mają podobne właściwości do gazów niekonwencjonalnych: uwięzionych i łupkowych. Stwierdzono, że spalanie gazów LCNG, zawierających nawet 50% azotu jest możliwe z puntu widzenia głównych parametrów pracy turbin: sprawności termodynamicznej, stabilności płomienia oraz emisji związków toksycznych NOx i CO. Parametry pracy są nawet lepsze niż turbin zasilanych gazami ziemnymi wysokometanowymi typu E, pod warunkiem dobrego zaprojektowania palników gazowych. Zasadniczo spalanie gazów LCNG powinno przebiegać w przepływie z silnym zawirowaniem, jednak stopień zawirowania, określony liczbą wirową S powinien być optymalnie dobrany do udziału molowego azotu w gazie. Wyniki badań i obliczeń zostały uzupełnione badaniami i oceną danych z elektrociepłowni wyposażonych w turbiny gazowe zasilane gazami ziemnymi niskokalorycznymi.

EN

Paper presents results of investigation combustion of natural gases- LCNG - Low Calorific Natural Gases - in the conditions as those used in a gas turbine, with the exception of the pressure, since most studies has been done for ambient pressure. LCNG gases have similar properties to the unconventional tight and shale gases. It has been found that the combustion LCNG gas containing 50% nitrogen as possible from the point of view of the main parameters of the gas turbine thermodynamic efficiency, flame stability and emission of pollutants: NOx and CO. Parameters are even better than the gas-powered turbines with H-Gas, on condition a good design of the gas burners. Essentially combustion gases LCNG should proceed in the flow with strong swirl, however, the degree of turbulence – particularly the swirl number S defined to be optimally selected for the mole fraction of nitrogen in the gas. Test results and calculations have been completed research and evaluation of data from power plants equipped with gas turbines powered by gas low-calorific natural gases.

2

Combustion Gases in Highly Preheated Air (HiTAC) Technology

100%

Dobski T. , Ślefarski R. , Jankowski R.

Archivum Combustionis

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2008

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tom Vol. 28 nr 3-4

173-185

EN

The paper deals with combustion of typical industrial gases in configurations characterized by the separation of the jets of gas and air flowing into the combustion chamber. The experiments involved three types of fuel gases: LPG, high methane natural gas and low calorific natural gases. The low calorific gases were composed as mixture of the natural gas (containing about 97% methane, less than 1 per cent of highest hydrocarbons and nitrogen) and nitrogen as inert gas. The experiment involved fuels as poor as containing only 50% of combustible gases (LHV lower than 18 MJ/Nm3). The results of investigation of combustion a gases in regenerative burner are presented in the paper. The paper presents also data from the burning of the above gases in a Semi Industrial Gas Burner (SIGB). Such a burner consists of a pipe carrying highly preheated air and at least two nozzles providing the gas. The data include the geometry of SIGB, the level of air preheating and the density of heat release. Generally, the investigation shows that for the temperature of preheated air over 650oC (a typical temperature for central recuperators in industrial gas furnaces) and temperature of furnace 1250oC it is possible to lower the emission of pollutant NOx over 3.5 times. The paper also presents some data on combustion of LPG at an industrial furnace equipped with the set of SIGB gas burner. The furnace was built for heat treatment of steel to process 80 t/h at over 1200oC. There were 17 sets of gas burners on the furnace.

3

The tests of natural gas and propane : combustion in a HiTAC regenerative gas burner

100%

Ślefarski R. , Dobski T. , Jankowska R.

Systems : journal of transdisciplinary systems science

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2008

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tom Vol. 13, spec. iss. 1/2

81--88

EN

The paper presents the results of the tests performed on a semi industrial scale regenerative gas burner. The tests were performed on a gas burner fitted with four regenerative beds built into the burner. The beds generated the exhaust-to-air energy transfer intensity sufficient to obtain the efficiency of the furnace charge preheating process of at least 70%. The paper presents the influence of various operating parameters of the burner on the combustion process (particularly the emission of nitric oxides) such as air excess coefficient λ , operating time of the regenerators and combustion chamber operating temperature. liven in the least advantageous conditions when the air is preheated to reach the temperature above 1000°C - less than 100 K lower than the temperature of the combustion chamber- the NOx emission did not exceed 100 ppm.

4

Combustion of mixtures of biogases and syngases with high molar fraction of methane in strong swirl flow

100%

Ślefarski R. , Sacha J. , Grzymisławski P.

Archivum Combustionis

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2014

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tom Vol. 34 nr 2

117--128

EN

The paper presents results of experimental studies on combustion of mixtures of methane and biogas and syngas in the swirl burner. The swirl of the stream of mixture of air and gases in the burner was generated by a swirler with helical blades. The study was focused on the influence of molar fraction of carbon dioxide (for biogas) and hydrogen (for syngas) on flame stability and emissions of nitric oxide compounds during combustion. The results, both experimental and numerical, show that a low content of carbon dioxide in methane- air mixture leads to better flame stability through an increase of the volume of the recirculation zone. It also leads to the lowering of emission of nitric oxides caused in the first order by the lowering of the temperature of flame. Co-combustion of natural gas with syngas containing hydrogen results in a considerable increase in flame stability due to a strong increase in velocity of flame propagation in laminar flow. It also causes increasing turbulent velocity of flame propagation. However, when a limit of molar fraction of hydrogen is passed, it leads to flashback.

5

Analysis of combustion process in industrial gas engines powered with high methane and nitrified low-calorific gases

100%

Rojewski J. , Ślefarski R. , Wawrzyniak J.

Silniki Spalinowe

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2013

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tom R. 52, nr 1

42-50

EN

The paper presents the results of an investigation of gas engines used in the Polish system of natural gas transmission. The investigation concerned both four-stroke and two-stroke engines. The engines were fed with two kinds of gas fuel - low-calorific natural gas containing 54.5 % of methane, and with high-methane (up to 95 %) natural gas. Combustion in both types of engines with different methods of mixture supply into the cylinder was analysed for different parameters. The paper also presents numerical computations of basic physical values characterizing combustion of gas fuels in engines. The computations were made with Cantera numerical code based on the mechanism of elementary reactions occurring while burning methane GRI 3.0 for various molar fractions of methane in the gas fuel.

PL

W artykule przedstawiono rezultaty badań silników gazowych wykorzystywanych w polskim systemie przesyłowym gazu ziemnego. Badania te wykonano na silnikach cztero- i dwusuwowych. Jednostki te były zasilane dwoma rodzajami paliw gazowych: niskokalorycznym gazem ziemnym o zawartości metanu wynoszącej 54,5 % oraz wysokometanowym gazem ziemnym zawierającym do 95 % metanu. Analizie poddano proces spalania w wyżej wymienionych silnikach dla różnych parametrów eksploatacyjnych oraz różnych metod doprowadzenia mieszanki do cylindra. Przedstawiono również obliczenia numeryczne podstawowych wielkości fizycznych charakteryzujących proces spalania paliw gazowych w silnikach. Obliczenia przeprowadzono przy użyciu kodu numerycznego Cantera, bazującego na mechanizmie reakcji elementarnych zachodzących przy spalaniu metanu GRI 3.0 dla różnych udziałów molowych metanu w gazie paliwowym.