To reduce the emission of nitrogen oxides (NOx) during the co-disposal of sludge in a TTF-type precalciner, an optimized co-disposal process of a TTF-type precalciner has been implemented in a cement plant in Hebei. The model was built using ANSYS FLUENT software. The effects of three single-factor perspectives (sludge input ratio, gas flow rate, and tertiary air temperature on NO concentration) were investigated. The response surface method of Box–Behnken design was used. When the sludge ratio increased from 0 to 25%, the NO concentration at the outlet was 122–297 mg/m3. Meanwhile, it increased from 192 mg/ m3 to 241 mg/ m3 since the airflow increased from 95 m3/s to 122 m3/s. The maximum NO concentration was 192 mg/ m3 when the tertiary air temperature was 1170 K. The inter-action between airflow and sludge ratio was more significant than any other interaction between other conditions (P < 0.05). Finally, the optimum conditions were a sludge ratio of 5%, airflow 109 m3/s, and tertiary air temperature 1280 K. NO concentration was 166.9 mg/m3 under this condition.
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Brak możliwości przeprowadzenia rzeczywistych badań rozwoju pożaru w projektowanym obiekcie powoduje, że symulacje numeryczne pozostają jedyną drogą, która pozwala na określenie skali zagrożenia dla życia i zdrowia osób. Zatem wykorzystanie programów realizujących numeryczną mechanikę płynów w zagadnieniach bezpieczeństwa pożarowego stało się konieczne. Stosuje sieje do analizowania sposobu rozprzestrzeniania się dymu i ciepła w czasie rozwoju pożaru co pozwala równocześnie ocenić warunki panujące na drogach ewakuacyjnych. Programy numeryczne dają również możliwość badania działania poszczególnych urządzeń ochrony przeciwpożarowej takich jak tryskacze czy wentylatory oddymiające lub osiowe. W pracy pokazano rozwój pożaru w realnym obiekcie infrastruktury transportowej - w podziemnym garażu. Analizy numeryczne zostały wykonane za pomocą pakietu ANSYS FLUENT. Oprogramowanie to umożliwia budowę bardzo dokładnego modelu badanego zjawiska ze szczegółowym uwzględnieniem zachodzących w trakcie pożaru procesów.
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Inability to perform actual tests of fire development in the designed facility makes the numerical simulations to be the only way which allows to determine the scale of the threat to life and health of people. Therefore, the use of programs implementing numerical fluid mechanics in issues of fire safety has become necessary. They are used to analyze the spreading of smoke and heat during the development of a fire, thus allow to assess conditions on escape routes. Numerical programs provide also the opportunity to study the effect of various fire protection devices, such as sprinklers or smoke exhaust fans or axial fans. The work shows the development of a fire in a facility of transport infrastructure - in an underground garage. Numerical analyses were performed using ANSYS FLUENT package. This software allows to build a very accurate model of the studied phenomenon with particular focus on occurring during a fire processes.
In this paper, a study of the effect of winglet sweep angle and winglet tip chord of the aircraft wing on the aerodynamics performances and how to improve it are carried out, assuming Cant angle 60°, winglet height = 3.5 m, Toe angle = -5°, and Twist angle = +5°. Different sweep angles tested (-25°, -15°, 0°, +15°, +25°, +35°, and +45°) and winglet tip chord (0.25, 0.375, and 0.5 m). Four Angle of attack is presented (0°, 3°, 6°, and 9°). The aerodynamics properties of the wing were measured in terms of calculated lift to drag ratio to decide which wing has a high value of lift and lower drag. All models of a wing (eighty-four models) are drawn for 3D using the SOLIDWORKS program. Boeing 737-800 wing dimensions were used. All models of a wing were analyzed using ANSYS FLUENT. The results showed that sweep angle and winglet tip chord of the winglet by changing their configuration can improve aerodynamic performance for various attack angles. The maximum value of the lift to drag ratio was obtained with a sweep angle -15°, winglet tip chord 0.375m, and angle of attack 3°.
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