具有体积分数梯度的连通装置甲烷-空气爆炸特性数值模拟

许晓元; 孙金华; 刘晅亚

doi:10.11883/bzycj-2020-0086

具有体积分数梯度的连通装置甲烷-空气爆炸特性数值模拟

doi: 10.11883/bzycj-2020-0086

许晓元^{1, 2,},
孙金华¹,
刘晅亚²

1.
中国科学技术大学，安徽合肥 230026
2.
应急管理部天津消防研究所，天津 300381

基金项目: 国家重点研发计划（2017YFC0806600）

详细信息

作者简介:
许晓元（1986－　），女，博士，助理研究员，xuxiaoyuan@tfri.com.cn

中图分类号: O381
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- 被引次数: 0
出版历程
- 收稿日期: 2020-03-26
- 修回日期: 2020-10-10
- 网络出版日期: 2021-03-05
- 刊出日期: 2021-04-14

Numerical simulation of methane-air explosion in a connected device with volume fraction gradient

1.
University of Science and Technology of China, Hefei 230026, Anhui, China
2.
Tianjin Fire Research Institute of MEM, Tianjin 300381, China

摘要

摘要: 为了研究具有体积分数梯度的连通装置内甲烷-空气爆炸特性，以60 L圆柱体容器和20 L圆柱体容器通过3 m长，截面为0.035 m×0.035 m的方形管道而连接形成的容器管道连通装置作为研究对象，利用Fluidyn软件对均一体积分数的连通装置以及具有体积分数梯度的连通装置中甲烷-空气爆炸的特性进行了数值模拟。结果表明：连通装置中甲烷的均一体积分数为6.517%～8.067%时，并由大容器中心点火工况时，最大爆炸压力、最大爆炸压力上升速率、最高温度和最大速度，以及这些爆炸参数达到最大值时的时刻值随体积分数的变化约呈线性关系；连通装置大容器甲烷体积分数6.0%体积分数梯度为2.0%～8.0%且大容器中心点火时，最大爆炸压力、最大爆炸压力上升速率、最高温度和最大速度随体积分数梯度总体上呈现先增大后减小趋势；大容器中心点火时，最大爆炸压力位于小容器，最大压力上升速率位于管道1或管道2，最大速度位于管道3，速度值可达400～600m/s。本研究可为连通装置内可燃气体爆炸事故防控提供理论指导。
- 连通装置 /
- 体积分数梯度 /
- 甲烷爆炸 /
- 压力上升速率
Abstract: A connected vessel is a common typical chemical plant, and its explosion hazard is much higher than that of an independent vessel. In an actual explosion accident, the combustible gas volume fraction in the connected device presents a non-uniform state, and there is a volume fraction gradient. A connected device was chosen as the research object. The device was formed by connecting two cylindrical vessels with the volumes of 60 litres and 20 litres, respectively, through a square pipe as long as 3 meters, with a cross section of 35 mm×35 mm. To explore the methane-air explosion characteristics in the connected device with combustible gas volume fraction gradient, the Fluidyn software was applied to numerically simulate the methane-air explosions in the connected devices with uniform and non-uniform combustible gas volume fractions, respectively. The results show as follows. When the volume fraction of the methane in the connected device is uniform and ranges from 6.517% to 8.067% and the ignition is located in the center of the large vessel, the maximum explosion pressure, the maximum explosion pressure rise rate, the maximum temperature and the maximum velocity as well as their arrival times change linearily with the volume fraction of the methane. When the volume fraction of the methane in the large vessel of the connected device is 6.0%, the volume fraction gradient of the methane is 2.0% to 8.0%, and the ignition is located in the center of the large vessel, the maximum values of the parameters, including explosion pressure, explosion pressure rise rate, flame temperature and velocity, increase firstly and then decrease with increasing volume fraction gradient. When the ignition is located in the center of the large vessel, the maximum explosion pressure is in the small vessel, the maximum pressure rising rate is in the pipe connected to the large vessel, and the maximum flame velocity is in the pipe connected to the small vessel, and the flame velocity can reach 400-600 m/s. The research results can provide a theoretical guidance for preventing and controling combustible gas explosion accident in connected devices.
- connected device /
- volume fraction gradient /
- methane explosion /
- pressure rise rate

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图 1 体积分数梯度分类

Figure 1. Volume fraction gradient classification

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图 2 管道容器连通装置

Figure 2. A connection device with pipes and vessels

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图 3 网格划分

Figure 3. Model mesh generation

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图 4 实验装置和物理模型的比较

Figure 4. Comparison between the experimental apparatus and the physical model

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图 5 不同工况条件下最大爆炸压力随体积分数和体积分数梯度变化曲线

Figure 5. Changes of the maximum explosion pressure with volume fraction and volume fraction gradient under different working conditions

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图 6 不同工况条件下最大爆炸压力时刻值随体积分数和体积分数梯度变化曲线

Figure 6. Changes of the arrival time of the maximum explosion pressure with volume fraction and volume fraction gradientunder different working conditions

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图 7 不同工况下最大压力上升速率随体积分数和体积分数梯度的变化

Figure 7. Changes of the maximum pressure rise rate with volume fraction and volume fraction gradient under different working conditions

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图 8 不同工况下最大压力上升速率时刻随体积分数和体积分数梯度的变化

Figure 8. Changes of the arrival time of the maximum pressure rise rate with volume fraction and volume fraction gradient under different working conditions

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图 9 不同工况下最高温度随体积分数和体积分数梯度的变化

Figure 9. Changes of the maximum temperature with volume fraction and volume fraction gradient under different working conditions

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图 10 不同工况下最高温度时刻值随体积分数和体积分数梯度的变化

Figure 10. Changes of the arrival time of the maximum temperature with volume fraction and volume fraction gradient under different working conditions

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表 1 模拟工况

Table 1. Simulated working conditions

工况	体积分数梯度/%	体积分数分布/%
工况	体积分数梯度/%	区域1	区域2	区域3	区域4	区域5
1	0			6.517
2	2	6	6.5	7	7.5	8
3	0			7.034
4	4	6	7	8	9	10
5	0			7.551
6	6	6	7.5	9	10.5	12
7	0			7.697
8	6.5	6	7.625	9.25	10.875	12.5
9	0			7.827
10	7	6	7.75	9.5	11.25	13
11	0			7.958
12	7.5	6	7.875	9.75	11.625	13.5
13	0			8.067
14	8	6	8	10	12	14

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表 2 连通装置不同体积分数时最大爆炸压力相关参数

Table 2. Related parameters of the maximum explosion pressures for different volume fractions of connected devices

工况	体积分数/%	最大爆炸压力
工况	体积分数/%	位置	时刻/s	数值/MPa
1	6.517	区域5	0.157	0.716
3	7.034	区域5	0.147	0.758
5	7.551	区域5	0.139	0.797
7	7.696	区域5	0.137	0.810
9	7.827	区域5	0.135	0.820
11	7.958	区域5	0.133	0.829
13	8.067	区域5	0.132	0.834

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表 3 连通装置不同体积分数梯度时最大爆炸压力相关参数

Table 3. Related parameters of the maximum explosion pressures for different volume fraction gradients of connected devices

工况	体积分数梯度/%	最大爆炸压力
工况	体积分数梯度/%	位置	时刻/s	数值/MPa
2	2.0	区域5	0.154	0.754
4	4.0	区域5	0.147	0.820
6	6.0	区域5	0.151	0.814
8	6.5	区域5	0.154	0.817
10	7.0	区域5	0.156	0.821
12	7.5	区域5	0.158	0.821
14	8.0	区域5	0.160	0.791

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表 4 连通装置不同体积分数时最大压力上升速率相关参数

Table 4. Related parameters of the maximum pressure rise rates for different volume fractions of connected devices

工况	体积分数/%	最大压力上升速率
工况	体积分数/%	位置	时刻/s	数值/（GPa·s⁻¹）
1	6.517	区域2	0.150	0.194
3	7.034	区域3	0.138	0.220
5	7.551	区域2	0.132	0.247
7	7.697	区域2	0.130	0.255
9	7.830	区域2	0.129	0.260
11	7.958	区域2	0.127	0.265
13	8.067	区域3	0.123	0.267

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表 5 连通装置不同体积分数梯度时最大压力上升速率相关参数

Table 5. Parameters related to the maximum pressure rise rates in the connected devices with different volume fraction gradients

工况	体积分数梯度/%	最大压力上升速率
工况	体积分数梯度/%	位置	时刻/s	数值/（GPa·s⁻¹）
2	2.0	区域3	0.144	0.220
4	4.0	区域2	0.141	0.263
6	6.0	区域2	0.144	0.240
8	6.5	区域2	0.146	0.231
10	7.0	区域2	0.148	0.234
12	7.5	区域2	0.151	0.250
14	8.0	区域2	0.153	0.247

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表 6 连通装置不同均一体积分数下最高温度相关参数

Table 6. Related parameters of the maximum temperatures in connected devices with different volume fractions

工况	体积分数/%	最高温度
工况	体积分数/%	位置	时刻/s	数值/℃
1	6.517	区域1	0.189	1 917.58
3	7.034	区域1	0.182	2 023.45
5	7.551	区域1	0.179	2 121.45
7	7.697	区域1	0.176	2 156.08
9	7.827	区域1	0.175	2 181.71
11	7.958	区域1	0.173	2 209.39
13	8.067	区域1	0.172	2 223.58

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表 7 连通装置不同体积分数梯度时最高温度相关参数

Table 7. Rrelated parameters of the maximum temperatures in connected devices with different volume fraction gradients

工况	体积分数梯度/%	最高温度
工况	体积分数梯度/%	位置	时刻/s	数值/℃
2	2.0	区域5	0.208	1 946.72
4	4.0	区域5	0.201	2 250.03
6	6.0	区域5	0.205	2 248.07
8	6.5	区域5	0.207	2 247.44
10	7.0	区域5	0.208	2 291.28
12	7.5	区域5	0.217	2 302.43
14	8.0	区域5	0.242	2 251.81

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表 8 连通装置不同体积分数时最大速度相关参数

Table 8. Related parameters of the maximum velocities in connected devices with different volume fractions

工况	体积分数/%	最大速度
工况	体积分数/%	位置	时刻/s	数值/（m·s⁻¹）
1	6.517	区域4	0.141	450.01
3	7.034	区域4	0.133	486.93
5	7.551	区域4	0.125	517.60
7	7.696	区域4	0.122	527.40
9	7.827	区域4	0.121	533.92
11	7.957	区域4	0.119	540.47
13	8.067	区域4	0.118	543.77

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表 9 连通装置存在不同体积分数梯度时最大速度相关参数

Table 9. Related parameters of the maximum velocities in connected devices with different volume fraction gradients

工况	体积分数梯度/%	最大速度
工况	体积分数梯度/%	位置	时刻/s	数值/（m·s⁻¹）
2	2.0	区域4	0.138	445.20
4	4.0	区域4	0.133	456.60
6	6.0	区域4	0.136	448.40
8	6.5	区域4	0.138	443.01
10	7.0	区域4	0.141	437.55
12	7.5	区域4	0.143	431.70
14	8.0	区域4	0.145	427.08

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