CIESC Journal ›› 2021, Vol. 72 ›› Issue (5): 2896-2904.DOI: 10.11949/0438-1157.20201574

• Process safety • Previous Articles    

Flame behavior of jet fire confined by the tank wall

WU Yueqiong(),ZHOU Kuibin(),HUANG Mengyuan,ZHOU Mengya   

  1. College of Safety Science Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
  • Received:2020-11-03 Revised:2020-12-13 Online:2021-05-05 Published:2021-05-05
  • Contact: ZHOU Kuibin

储罐壁面限制条件下喷射火火焰行为

吴月琼(),周魁斌(),黄梦源,周梦雅   

  1. 南京工业大学安全科学与工程学院,江苏 南京 211816
  • 通讯作者: 周魁斌
  • 作者简介:吴月琼(1994—),女,硕士研究生, 2983317140@qq.com
  • 基金资助:
    国家自然科学基金项目(51876088);江苏省第十六批“六大人才高峰”高层次人才项目(XNYQC-005);江苏省研究生实践创新计划项目(SJCX20_0387)

Abstract:

Leakage of high-pressure gas storage tanks is very easy to induce jet fire. By building a jet fire experiment device with different jet angles under the restriction of the tank wall, the jet fire with restricted flow field near the nozzle was systematically studied, and the test repeatability of the device was verified. Experimental results show that the lift-off height of confined jet fire is less than that of the free jet. Numerical simulation confirms the effect of tank wall on the air entrainment that dominates the lift-off. The flame length of vertical free jet is less than that of vertical confined jet, but the flame length decreases with the increase of the inclined angle for both free and confined jet fires. The critical Froude number to distinguish the buoyancy and momentum-dominated jet fire, is constant despite the jet angle and the restriction condition of space. The study also found that the blocking effect of tank wall will reduce the liftoff velocity and increase the blowout velocity of the jet flame, as compared to the free jet.

Key words: jet angle, jet flame, lift-off height, flame length, tank wall, safety, instability, fluid mechanics

摘要:

高压燃气储罐泄漏极易诱发喷射火。通过搭建储罐壁面限制条件下不同喷射角度的喷射火实验装置,对近喷口流场受限的喷射火进行了系统研究,并验证了装置测试的可重复性。实验结果表明,储罐壁面限制条件下推举高度小于自由射流的推举高度,并通过数值模拟分析了两种空间条件下空气卷吸流场的差异性,从而物理解释了储罐壁面限制条件对推举高度的影响。两种空间条件下火焰长度都随喷射角度的增加而减小,但自由垂直射流的火焰长度小于储罐壁面限制条件下的火焰长度。火焰行为由浮力控制转为动量控制的临界Froude数与喷射角度和空间限制条件无关。研究还发现,与自由射流相比,储罐壁面的阻塞效应会降低火焰的推举速度,提高火焰的吹熄速度。

关键词: 喷射角度, 喷射火, 推举高度, 火焰长度, 储罐壁面, 安全, 不稳定性, 流体力学

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