主管：中华人民共和国应急管理部
主办：应急管理部天津消防研究所
ISSN 1009-0029  CN 12-1311/TU
消防科学与技术

消防科学与技术 ›› 2023, Vol. 42 ›› Issue (11): 1555-1561.

• • 上一篇    下一篇

不同弯管角度和入口速度下管道内压缩空气泡沫流动研究

谭甜甜1, 张佳庆1, 吴革新2, 李博2   

  1. （1. 国网安徽省电力有限公司电力科学研究院 电力火灾与安全防护安徽省重点实验室(国家电网公司输变电设施火灾防护实验室)，安徽 合肥230601；2. 中国地质大学（武汉） 工程学院，湖北 武汉430074）
  • 出版日期:2023-11-15 发布日期:2023-11-15
  • 作者简介:谭甜甜（1994- ），女，安徽阜阳人，国网安徽省电力有限公司电力科学研究院博士后，主要从事固定式压缩空气泡沫灭火技术及综合管廊电力舱火灾防护方面的研究，安徽省合肥市蜀山区紫云路299号，230601。
  • 基金资助:
    国家电网有限公司科学技术项目（521205220009）

Numerical study on the flow behavior of compressed air foam in pipes with different bending angles and inlet velocities

Tan Tiantian1, Zhang Jiaqing1, Wu Gexin2, Li Bo2   

  1. (1. State Grid Anhui Electric Power Research Institute, Anhui Province Key Laboratory of Electric Fire and Safety Protection (State Grid Laboratory of Fire Protection for Transmission and Distribution Facilities), Anhui Hefei 230601, China; 2. Faculty of Engineering, China University of Geosciences(Wuhan), Hubei Wuhan 430074, China)
  • Online:2023-11-15 Published:2023-11-15

摘要： 理解和预测管道内压缩空气泡沫流体的流动规律，有利于消防工作者根据火灾类型和规模铺设合适的管路以及选用合理的泡沫流体。本文采用CFD仿真模拟分析了不同弯管角度和泡沫流体入口速度对管道内压缩空气泡沫流动行为的影响。研究发现,随着弯管角度的增加，出口段的内壁流速呈现3种变化现象：涡旋和回流现象、回流现象、近似直管流动现象。随着弯管角度增大，弯头转折点的泡沫流体平均速度逐渐增大。由于离心作用，更多的泡沫流体被挤压加速，导致泡沫流体在弯头处的平均速度均大于入口流速，并且在弯管角度θ≥120°时，由于低速区的消失，2种泡沫入口流速下均出现平均速度增长率相对更大的现象。发现泡沫流经弯管时，动力黏度呈现非单调演化趋势。当泡沫流经弯头时，由于弯头的阻碍作用，使流速降低，出现低黏度区间，导致局部黏度下降至2 kg/（m·s）以内（约为稳定段黏度的1/3）。

关键词: 压缩空气泡沫, 消防灭火, Fluent数值模拟, 弯管角度, 入口速度, 黏度

Abstract: Understanding and predicting the flow law of compressed air foam fluid in the pipeline is helpful for fire fighters to lay appropriate pipelines and select reasonable foam fluid according to the fire type and scale. In this paper, CFD simulation is used to analyze the influence of different bending angles and foam fluid inlet velocity on the flow behavior of compressed air foam in the pipeline. Research has found that as the angle of the bend increases, the inner wall velocity of the outlet section exhibits three changes: vortex and reflux phenomenon, reflux phenomenon, and approximate straight pipe flow phenomenon. With the increase of bending angle, the average velocity of foam fluid at elbow turning point increases gradually. At the same time, due to centrifugal effect, more foam fluid is squeezed and accelerated, resulting in the average velocity of foam fluid at the elbow is greater than the inlet velocity. Due to the disappearance of the low-speed zone, the average speed growth rate is relatively higher under the condition of elbow angle θ≥120°. On the other hand, it is found that when foam flows through the bend, the dynamic viscosity presents a non monotonic evolution trend. When foam flows through the elbow, due to the obstruction of the elbow, the flow rate decreases, resulting in the local viscosity falling to within 2 kg/(m·s)(about 1/3 of the viscosity of the stable section), and a low viscosity range.

Key words: compressed air foam, fire extinguishing, Fluent simulation, bending angle, entrance speed, viscosity