| 摘要: |
| 目的 天然气掺氢后燃烧特性会发生改变，因此，有必要对掺氢天然气热放空过程进行研究，以确定掺氢输送条件下原有高架火炬适用的工况条件，从而确保天然气管输系统在掺氢输送时的安全。方法 结合掺氢燃烧实验和CFD数值模拟，研究掺氢（摩尔分数 0 ~ 20%）天然气进行扩散燃烧时燃烧特性及热辐射半径变化情况，揭示掺氢对燃烧热辐射半径的影响机理，明确API STD 521—2014《泄压和减压系统》中热辐射半径解析模型可用于掺氢天然气的计算。结果 在等体积流量下，掺氢减小了热释放量从而减短了火焰长度，而在侧风作用下的火焰倾斜角几乎不变，因此缩小了热辐射半径；在等质量流量下，掺氢增加了热释放量从而增长了火焰长度，而火焰倾斜角变大，使得热辐射半径变化极小。同时，风速增大会导致热辐射半径扩大。结论 在安全热辐射半径不变的前提下，按体积流量计算，掺氢条件下最多可提高19% ~ 23%体积流量的放空量，火炬系统的排放效率有所提高；按质量流量计算，掺氢条件下高架火炬的质量流量放空量与掺氢前相比几乎保持不变。 |
| 关键词: 高架火炬 掺氢 天然气 热辐射 CFD 火焰倾斜角 |
| DOI：10.3969/j.issn.1007-3426.2024.05.006 |
| 分类号: |
| 基金项目:北京燃气集团科研项目“掺氢对中低压燃气管网设施抢修作业影响及应对措施研究”（HX20220447） |
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| Thermal radiation simulation study of hydrogen-blended elevated flare combustion |
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Heng SUN1, Xiaoyu GAO2, Churu LIU3, Jinliang GENG4
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1.National Engineering Research Center of Oil and Gas Pipeline Transportation Safety, China University of Petroleum, Beijing, China;2.Sinopec Ningbo Engineering Co., Ltd., Ningbo, Zhejiang, China;3.PetroChina Southwest Oil & Gasfield Company Gas Company, Chengdu, Sichuan, China;4.PipeChina Oil & Gas Control Center, Beijing, China
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| Abstract: |
| Objective Adding hydrogen to natural gas alters its combustion characteristics, prompting this study to investigate the thermal venting process of hydrogen-blended natural gas. The aim is to ascertain the appropriate operating conditions for existing elevated flare systems under hydrogen transportation scenarios, ensuring the safety of the natural gas pipeline system during hydrogen blending. Methods By integrating hydrogen blending combustion experiments and numerical simulations of CFD, in this study, the combustion characteristics and changes of thermal radiation radius changes during the diffusion combustion of natural gas blended with 0 to 20 mol% hydrogen are explored, the mechanisms by which hydrogen blending influences the thermal radiation radius is revealed, and it is defined establishes that the thermal radiation radius analysis model in API-521 is suitable for calculating hydrogen-blended natural gas. Results At equal volume flow rates, hydrogen blending has been observed to reduce the heat release, thus shortening the flame length. In the presence of side winds, the flame tilt angle remains almost the same, reducing the radius of the heat radiation. At equal mass flow rates, hydrogen blending has been observed to increase the heat release, thus increasing the flame length. Concurrently, the flame tilt angle becomes larger, which results in a tiny change in the radius of the heat radiation. Additionally, the higher wind speed leads to a bigger radius of heat radiation. Conclusions Under the condition that the safety thermal radiation radius is constant, the volumetric flow rates when the hydrogen is added can be increased by approximately 19% to 23% at most when the hydrogen is added, thereby enhancing the emission efficiency of the flare system. The mass flow rates of flares when hydrogen is added are almost the same. |
| Key words: elevated flare hydrogen-blending natural gas thermal radiation CFD flame tilt angle |
