CIESC Journal ›› 2019, Vol. 70 ›› Issue (10): 4089-4098.DOI: 10.11949/j.issn.0438-1157.20190617

• Process safety • Previous Articles    

Study on mechanism and law of liquid overheating and explosive boiling caused by leakage

Shicheng SHI1(),Supan WANG1,2,3,Xuhai PAN1,2,3(),Yuheng MA1,Juncheng JIANG1,2,3   

  1. 1. College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
    2. Institute of Fire Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
    3. Jiangsu Key Laboratory of Hazardous Chemicals Safety and Control, Nanjing 211816, Jiangsu, China
  • Received:2019-06-02 Revised:2019-08-07 Online:2019-10-05 Published:2019-10-05
  • Contact: Xuhai PAN

泄漏引发液体过热爆沸机理及规律研究

时事成1(),王苏盼1,2,3,潘旭海1,2,3(),马煜衡1,蒋军成1,2,3   

  1. 1. 南京工业大学安全科学与工程学院,江苏 南京 211816
    2. 南京工业大学火灾与消防研究所,江苏 南京 211816
    3. 江苏省危险化学品本质安全与控制技术重点实验室,江苏 南京 211816
  • 通讯作者: 潘旭海
  • 作者简介:时事成(1995—),男,硕士研究生,997445542@qq.com
  • 基金资助:
    国家重点研发计划项目(2017YFC0804700)

Abstract:

To explore the mechanism and law of liquid superheating and boiling caused by tank leakage, a small device was established to study the bubble evolution, pressure and medium superheat response during the bumping process. Upon the typical features of medium superheat degree, overheat time was further introduced to characterize the delay degree of boiling. The results show that a large number of bubbles were generated and grew rapidly in the medium after the vessel rupture. Bubble-growth process could be divided into a relatively stable stage and an accelerated stage, and the obvious pressure recovery was attributed to the accelerated growth of bubbles. According to the response of temperature sensors in the medium, the boiling occurred and spread from top to bottom and from the inner wall to the inside of the medium. And the medium underwent a cycle of supercoiling—saturation—superheat—saturation—supercooling during boiling. In addition, it was found that the increase of initial pressure and the decrease of initial liquid level could both improve the maximum superheat degree of medium, especially a maximum superheat of 9. 4℃ with the initial liquid level of 50%. What’s more, the ascent of the initial pressure or the initial liquid level also hold a significant lower overheat time. And the rise of the initial liquid level would contribute to a more serious rebound phenomena of pressure. On the basis of the overheat time obtained by experiments, the mathematical model of the overheat time was also verified. The results showed that the calculation of the mathematical model was basically consistent with the experimental data.

Key words: explosive boiling, vaporization, two-phase flow, superheat degree, overheat time, model

摘要:

为探究储罐泄漏引发液体过热爆沸的机理及规律,实验建立了小型装置,对爆沸过程中的气泡演化、压力及介质过热度响应进行研究。根据介质过热度的变化特征,提出表征沸腾延时程度的参数——过热时间,并建立相应描述过热时间的数学模型。实验结果表明,容器破裂后,大量气泡于介质内部产生并迅速成长,其成长可分为相对稳定阶段与加速成长阶段,而后引起明显的压力反弹。整个沸腾自上而下、自内壁向介质内部进行,且介质经历过冷—饱和—过热—饱和—过冷的循环过程。此外,实验发现初始压力的升高或初始液位的降低,都会使介质达到的最大过热度提高,尤其是50%初始液位时其介质最大过热度高达9.4℃。而随着初始压力或初始液位的升高,过热时间呈明显降低趋势,且初始液位升高时还会引起更明显的压力反弹。基于实验数据,对过热时间数学模型进行验证,结果表明数学模型计算结果和实验数据基本吻合。

关键词: 爆沸, 气化, 两相流, 过热度, 过热时间, 模型

CLC Number: