مطالعه ساختار شعله گاز سنتزتحت شرایط سوخت-هوا، اکسیژن غنی و سوخت-اکسیژن بدون شعله: بررسی اثر ترکیب سوخت، دمای پیش‌گرمایش و کسر مولی اکسیژن اکسنده

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشگاه کاشان

2 عضو هیات علمی دانشکده مهندسی مکانیک - دانشگاه کاشان

3 دانشگاه تفرش

10.22034/jfnc.2023.387218.1339

چکیده

در مطالعه حاضر تأثیر دمای پیش‌گرمایش اکسنده و کسر جرمی اکسیژن موجود در آن به‌عنوان پارامترهای اصلی و موثر بر احتراق بدون شعله گاز سنتز تحت شرایط سوخت- هوا، اکسیژن غنی و سوخت- اکسیژن بررسی شده است. شبیه‌سازی‌ها‌ به‌وسیله حلگر شعله نفوذی جریان متقابل با استفاده از سینتیک شیمیایی GRI3.0 انجام شده است. به‎منظور تفکیک اثرات فیزیکی و شیمیایی جایگزینی CO2 با N2، از گونه مجازی VCO2 با خواص فیزیکی کاملاً مشابه با CO2 بدون حضور در زنجیره واکنش‌ها استفاده شده است. مطابق با نتایج به‌دست آمده اثرات فیزیکی در دماهای اکسنده پایین‌تر و اثرات شیمیایی در دماهای اکسنده بالاتر غالب هستند. بررسی تأخیرتأخیر در اشتعال نشان‌دهنده آن است که تحت شرایط سوخت-اکسیژن، افزایش نسبت هیدروژن به مونوکسید کربن سوخت از 25/0 به یک و از یک به چهار به ترتیب منجر به کاهش فاصله محوری اشتعال از 4/0 به 39/0 و از 39/0 به 375/0 می‌شود. مقایسه میان کسر مولی اکسیژن اکسنده و دمای پیش‌گرمایش ورودی نشان می‌دهد که دمای پیش‌گرمایش تأثیر بیشتری بر پارامترهای ساختار جریان واکنشی نظیر تأخیر در اشتعال و حرارت آزاد شده دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical simulation of the syngas flame structure under air-fuel, oxygen enriched, and oxy-fuel regimes with flameless combustion: the impacts of fuel composition, preheating temperature, and oxygen mole fraction

نویسندگان [English]

  • Ahmad Shaker 1
  • اسماعیل Ebrahimi Fordoei 3
1 Kashan University
2
3 Tarbiat Modares University
چکیده [English]

In the present study, the influence of the oxidizer preheating temperature and oxygen mass fraction as the effective parameters on the flameless combustion under oxy-syngas, air-syngas, and oxygen-enriched conditions have been investigated. The simulations have been carried out with applying the counter-flow diffusion flame solver using GRI3.0 chemical kinetics. In order to separate the physical and chemical impacts of substituting CO2 with N2, a virtual species (VCO2) has been used with physical properties similar to CO2 without being present in the reactions chain. According to the obtained results, physical and chemical impacts are dominant for lower preheating temperatures and higher preheating temperatures, respectively. The investigation of ignition delay time shows that under oxy-syngas conditions, increasing the H2/CO ratio from 0.25 to 1 and from 1 to 4 leads to a decrease in the axial distance of ignition from 0.4 cm to 0.39 cm and it changes from 0.39 cm to 0.375 cm, respectively. The comparison between the oxygen mole fraction and the inlet preheating temperature indicates that the preheating temperature has a greater effect on the reactive flow structure parameters such as ignition delay and released heat.
.

کلیدواژه‌ها [English]

  • Syngas fuel
  • Flameless combustion
  • Numerical study
  • Chemical and physical impacts
  • Chemical kinetic
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