Wyniki wyszukiwania - BazTech

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Laminar burning velocity predictions of single-fuel mixtures of C1-C7 normal hydrocarbon and air

Jach A., Żbikowski M., Teodorczyk A.

Journal of KONES

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2018

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Vol. 25, No. 3

227--235

EN

The numerical modelling of combustion phenomena is an important task due to safety issues and development and optimization of engines. Laminar burning velocity (LBV) is one of the most important physical properties of a flammable mixture. Knowing its exact value if crucial for assessment of flame stabilization, turbulent flame structure. It influences strongly safety, probability of knocking combustion and it is one of parameters used for assessment and development of detailed chemical kinetic mechanisms. Hence, the goal of this work is to develop models by means of Machine Learning algorithms for predicting laminar burning velocities of single-fuel C1-C7 normal hydrocarbon and air mixtures. Development of the models is based on a large experimental data set collected from literature. In total more than 1000, LBVs were accumulated for hydrocarbons from methane up to n-heptane. The models are developed in MATLAB 2018a with use of Machine Learning toolbox. Algorithms taken into account are multivariate regression, support vector machine, and artificial neural network. Performance of the models is compared with most widely used detailed chemical kinetics mechanisms’ predictions obtained with use of LOFEsoft. These kind of models might be efficiently used in CFD combustion models based on flamelet approach. The main advantage in comparison to chemical kinetics calculation is much shorter computational time needed for computations of a single value and comparable performance in terms of R2 (coefficient of determination), RMSE (root-mean-square error) and MAE (mean absolute error).

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Ocena możliwości wykorzystania gazu ze zgazowania osadów ściekowych

Werle S.

Proceedings of ECOpole

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2016

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Vol. 10, No. 1

341--348

PL

W pracy zaprezentowano wyniki badań eksperymentalnych wyznaczania normalnej prędkości spalania gazu ze zgazowania osadów ściekowych. Wykorzystano metodę palnika Bunsena. Jednocześnie wyznaczono rozkład temperatury w płomieniu. Wyniki pokazują, że istnieją optymalne warunki prowadzenia procesu spalania gazu ze zgazowania osadów ściekowych, przy których możliwe jest stabilne prowadzenie tego procesu z jednoczesnym efektywnym wywiązywaniem się ciepła. Wyniki wskazują, że niskokaloryczne gazy z termicznego przetwarzania biomasy odpadowej mogą stanowić źródło paliwa na potrzeby produkcji finalnych postaci energii.

EN

The paper presents the results of experimental investigation of the laminar flame speed of the sewage sludge gasification gas. Bunsen burner method was used. Additionally, the temperature distribution in the flame was determined. The results show that there are optimum conditions for conducting combustion of the sewage sludge gasification gas, with which it is possible to carry out the stable process with effective heat release. The results indicate that low calorific gas from the thermal processing of waste biomass can be a source of fuel for the production of final forms of energy.

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Evaluation of the possibility of the sewage sludge gasification gas use as a fuel

Werle S., Dudziak M.

Ecological Chemistry and Engineering. S

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2016

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Vol. 23, nr 2

229--236

EN

Biomass is one of the major sources of energy that is estimated to contribute between 10% and 14% of the world’s energy supply. Over the past several years, many societies have established policy targets to increase their production of renewable energy from biomass. The thermo-chemical utilization of biomass includes 4 technologies: the most popular combustion and co-firing, and unconventional: pyrolysis and gasification. Gasification is considered to be the perspective technology because has many advantages in comparison to traditional process of combustion: (1) limited emission of the SO2, NOx, oxides of the heavy metals and no risk of the dioxins and furans emission due to reducing atmosphere in the gasification reactor, (2) volume of the gasification gas is smaller in comparison to flue gases from combustion due to the reducing atmosphere, (3) gasification process produce gas which is potential gaseous fuel in power engineering (engines, gas turbines and boilers) and chemistry. Unfortunately, composition of the gasification gas is always described as a variable. Moreover, it depends on the conditions of the process and quality of the base fuel. For this reason, the use of gasification gas can’t be very easy. For this reason, the knowledge of the basic properties of the gas is very important. Laminar burning velocity is assumed as an important quantity for in the process of the design equipment for the gas utilization. The numerical and experimental results of the laminar burning velocity of sewage sludge gasification gases were presented. Experimental Bunsen burner method was used. Cosilab 3© software for numerical analysis was used. GRI-Mech 3.0 mechanism of gas oxidation was implemented. As a result of the work, the set of the parameters where the sewage sludge gasification gas combustion process is stable with effective heat release, were presented.

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Ocena możliwości i zagrożeń stosowania amoniaku jako potencjalnego paliwa

Grzesiak D., Popławski D., Kędzior R., Hałat A., Falewicz P.

Proceedings of ECOpole

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2015

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Vol. 9, No. 1

223--229

PL

W dobie malejących zasobów surowców energetycznych oraz negatywnego wpływu produktów ich spalania na środowisko naturalne poszukuje się nowych, niekonwencjonalnych paliw. W ostatnich latach rozważa się amoniak jako potencjalne paliwo wolne od emisji CO2, umożliwiające pracę silników pneumatycznych z zapłonem iskrowym oraz ogniw paliwowych. Wzrost zainteresowania niekonwencjonalnymi paliwami w energetyce i transporcie stwarza potrzebę lepszego zrozumienia ich procesu spalania, a także zagrożeń związanych z obrotem oraz wykorzystaniem. W literaturze niezwykle trudno znaleźć eksperymentalne dane dla amoniaku, dotyczące jego palności oraz skłonności do wybuchu w warunkach zwiększonego ciśnienia i temperatury. Przykładem takich szczególnych danych są wyniki prac przeprowadzonych w ramach europejskiego projektu SAFEKINEX No. EVG1-CT-2002-00072. W projekcie przedstawiono wartości stężeniowych granic palności, maksymalnej szybkości narostu ciśnienia podczas wybuchu, maksymalnego ciśnienia wybuchu oraz indeksu deflagracji dla różnego rodzaju mieszanin gazowych. Wyniki pozwalają również na oszacowanie jednej z najważniejszych wielkości dla procesu spalania, jaką jest prędkość spalania. W pracy dokonano oceny amoniaku jako potencjalnego paliwa w odniesieniu do paliw konwencjonalnych. Wykorzystując dane z projektu SAFEKINEX, oszacowano także wartości prędkości spalania laminarnego amoniaku dla warunków podwyższonej temperatury 20, 100, 200, 250ºC przy ciśnieniu 1 i 5 bar.

EN

In an era of dwindling energy resources and the negative impact their combustion products on the environment are being looked for the new unconventional fuels. In the last years ammonia has been considered as the potential CO2 emission-free fuel, which is able to working with spark-ignition engines and fuel cells. The increased interest in unconventional fuels in the energy sector and transport creates the need for a better understanding of the combustion process as well as the risks connected with the turnover and application. In the literature it is extremely difficult to find experimental data for ammonia concerning flammability and prone to explosion at the elevated pressure and temperature. An example of such specific data are the results of the work carried out within the European project SAFEKINEX No. EVG1-CT-2002-00072. The project presented flammability limits, maximum pressure rise during explosion, maximum pressure of explosion and deflagration index for different kind of mixtures of gases. The results also allow for the estimation one of the most important value for combustion process - flame speed. In this work were made the evaluation of ammonia as potential fuel in comparison with the conventional fuels. Using the data from SAFEKINEX project were estimated values of laminar burning velocity ammonia at elevated temperature 20, 100, 200, 250ºC and pressure 1 and 5 bar.

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Ammonia as a sustainable fuel

Grzesiak D., Kędzior R., Popławski D., Hałat A., Falewicz P.

Ecological Chemistry and Engineering. A

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2015

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Vol. 22, nr 3

393--401

EN

An ammonia evaluation as a potential sustainable fuel in comparison with other fuels was made. Values of laminar burning velocity ammonia at ambient and elevated temperatures 20, 100, 200, 250 oC and pressure 100 and 500 kPa using the data from SAFEKINEX project were estimated.

PL

W pracy dokonano oceny przydatności amoniaku jako potencjalnego paliwa w odniesieniu do paliw konwencjonalnych. Wykorzystując dane z projektu SAFEKINEX, oszacowano także wartości prędkości spalania laminarnego amoniaku w temperaturze 20, 100, 200, 250 oC przy ciśnieniu 100 i 500 kPa.