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Title
Fluent-based numerical simulation and temperature control in coal tar slurry bed hydrogenation reactor
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作者
黄鑫高云鹤郭莉王丹军牛鸿权付鑫付峰
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Author
HUANG Xin;GAO Yunhe;GUO Li;WANG Danjun;NIU Hongquan;FU Xin;FU Feng
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单位
延安大学化学与化工学院陕煤集团榆林化学有限责任公司兖矿榆林精细化工有限公司
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Organization
College of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering
Shaanxi Coal Group Yulin Chemical Limited Liability Company
Yankuang Yulin Fine Chemical Company Limited
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摘要
作为煤焦油悬浮床加氢技术的核心设备———煤焦油悬浮床加氢反应器,其中上部温度骤升问题已经成为制约该技术实际应用的技术瓶颈之一。为了解决温度骤升问题,采用计算流体力学方法,基于Fluent软件,对加氢反应器内温度变化进行了数值模拟,并对温度控制措施展开了研究。结果表明,煤焦油悬浮床加氢反应器在3.0m高度处出现温度骤升,在温度骤升处增设冷氢管,冷氢的通入不仅可有效控制反应器中上部温度,解决温度骤升问题,还使得反应器内温度的轴向和径向分布趋于均匀,且冷氢的适宜温度为41℃~43℃,最佳温度为43℃。在此基础上,研究了冷氢通入前后加氢反应器内流场的变化。根据流速分布模拟结果,结合温度分布云图,可推测出无冷氢通入时,反应器在3.5m左右高度处出现局部结焦现象,当高度达到5.0m时,反应器内开始出现因结焦而导致的局部堵塞,当高度到达5.5m左右时,反应器内出现因结焦而导致的严重堵塞。43℃冷氢的通入不仅解决了加氢反应器温度骤升问题,还抑制了加氢反应器内的轴向流,促进了反应物料的径向流动及混合,使得流速以及气含率(气相体积占气液混合物体积的百分比)的分布更加均匀,有利于加氢反应器内传质及煤焦油加氢反应的进行。
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Abstract
The coal tar slurry bed hydrogenation reactor is the core equipment of coal tar slurry bed hydrogenation technology. However, a significant challenge in its practical application lies in the temperature surge observed in the upper and middle sections of the reactor. To address this issue, computational fluid dynamics and Fluent software were used to simulating tempera-ture variations within the hydrogenation reactor and investigates various temperature control strategies. The results show that the temperature within the coal tar slurry bed hydrogenation re-actor rapidly increases at a height of 3.0 m. After the implementation of a cold hydrogen tube at the specific location where the temperature surge occurs, the introduction of cold hydrogen not only effectively regulates the temperature in the upper part of the reactor, resolving the tempera-ture surge issue, but also led to a more uniform distribution of temperature both axially and ra-dially throughout the reactor. The suitable temperature range of cold hydrogen is 41 ℃-43 ℃, while the optimum temperature is 43 ℃. Furthermore, the alterations of the flow field within the reactor, both prior to and subsequent to the introduction of cold hydrogen were studied. Based on the simulation results of flow velocity patterns and the nephograms of temperature distribution, it can be inferred that without the introduction of cold hydrogen, local coking phenomenon occurs at the height of 3.5 m within the reactor. When the height reaches 5.0 m, local blockage caused by coking starts to appear in the reactor, and at a height of 5.5 m, serious blockages occur due to extensive coking. The introduction of 43 ℃ cold hydrogen not only resolves the temperature surge issues, but also inhibites the axial flow within the reactor, thereby promoting the radial flow and mixing of the reaction materials. This results in a more uniform distribution of velocity and gas holdup, which is beneficial to the mass transfer and coal tar hydrogenation within the re-actor.
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关键词
煤焦油悬浮床加氢数值模拟温度分布流速分布气含率
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KeyWords
coal tar slurry bed hydrogenation, numerical simulation, temperature distri-bution, flow velocity distribution, gas content
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基金项目(Foundation)
国家自然科学基金项目(22168040)和陕西省自然科学基础研究计划项目(S2022-JC-YB-1350).
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DOI
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引用格式
黄 鑫,高云鹤,郭 莉,等.基于 Fluent的煤焦油悬浮床加氢反应器数值模拟与温度控制研究[J].煤炭转化,2024,47(1):38-48
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Citation
HUANG Xin,GAO Yunhe,GUO Li,et al.Fluent-based numerical simulation and temperature control in coal tar slurry bed hydrogenation reactor[J].Coal Conversion,2024,47(1):38-48