不同侧壁高度油池火实验分析与模型建立  

Experimental analyses and modeling of pool fires with different ullage heights

作　　者：朱华诚 胡振启 赵至善 陈诚 赵金龙[1] 杨锐[2] ZHU Huacheng;HU Zhenqi;ZHAO Zhishan;CHEN Cheng;ZHAO Jinlong;YANG Rui(School of Emergency Management and Safety Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国矿业大学(北京)应急管理与安全工程学院,北京100083 [2]清华大学工程物理系,北京100084

出　　处：《清华大学学报（自然科学版）》2023年第10期1512-1519,共8页Journal of Tsinghua University(Science and Technology)

基　　金：应急管理部消防救援局重点研发项目(2022XFZD04);中央高校基本科研业务费项目(2020QN05)。

摘　　要：近年来中国兴建了很多浮顶油品储罐。当浮顶储罐内部液位较低时,罐体内部易积聚蒸气,火灾风险增大。一旦发生火灾易形成侧壁约束下的油池火,给油品储运安全造成严重威胁。该文采用石英玻璃材质的油盘,开展了不同侧壁高度(油盘侧壁上边缘到油品表面的垂直距离,h=3~50 cm)的正庚烷油池火实验,研究了侧壁高度对灾变过程和关键火灾参数(燃烧速率、火焰高度)的影响。实验结果表明:侧壁高度对整个燃烧过程影响明显,尤其是对初始阶段和稳定阶段。对于初始阶段,低侧壁油池火燃烧速率快速增加,但高侧壁油池火燃烧速率呈现先快速增加随后逐渐减小的趋势,这主要是由于火焰根部不断抬升进而远离油品表面造成的。对于稳定阶段,随侧壁高度的增加,燃烧速率呈现先减小后增大随后再减小的趋势。其中的先减小后增大趋势是由于火焰根部逐渐从油盘外进入油盘内造成的,而随后的再减小趋势主要是由于火焰根部不断抬升造成的。基于高侧壁稳定阶段的火焰形态,可将火焰划分为外部火焰和内部火焰。随侧壁高度的增加,外部火焰高度逐渐降低,内部火焰高度逐渐增加。基于量纲归一化分析,考虑侧壁高度和空气卷吸因素,引入油盘特征直径,建立了不同侧壁高度下的无量纲内部火焰高度模型。该研究结果可增强对不同侧壁高度油池火火焰行为的理解,为储罐区浮顶储罐火灾的定量风险评估提供参考。[Objective]In recent years,floating-roof tanks have been widely used for liquid fuel storage in China.However,these tanks suffer from a considerable fire risk owing to the accumulation of highly flammable fuel vapors when the liquid fuel level is low.The risk of pool fires,confined by ullage heights,seriously threatens fuel storage and transportation.Furthermore,the flame characteristics,including burning rates and flame heights,are notably affected by ullage heights.However,the research on pool fires with different ullage heights is few.Hence,this study aims to experimentally study the pool fires for different ullage heights and analyze the key parameters(burning rate and flame height).Additionally,a correlation based on dimensionless analysis is proposed to predict the down-reaching flame height.[Methods]This study investigates the effect of ullage heights on pool fires.A series of pool fire experiments were conducted using a transparent quartz glass tray and heptane fuel.Different ullage heights(ranging from 3 cm to 50 cm,measured as the vertical distance from the tank top to the liquid fuel surface)were considered.The burning rate was measured using a Sartorius balance and video cameras were installed to record the burning process and flame heights.Flame heights were calculated by converting the flame videos into binary images.Subsequently,the key parameters were analyzed.[Results]The experimental results reveal the following:(1)The ullage height considerably affects the burning process,particularly at the initial and steady stages.At the initial stage,the burning rate sharply increases for cases with a low ullage height,while a burning rate decrease trend is observed after the rapid increase for cases with a large ullage height.This is mainly caused by the continuous uplift of the flame base,moving away from the fuel surface.(2)At the steady stage,the burning rate first decreases and then increases,followed by a final decrease with the increase of the ullage height.The increase in the distance between the fl

关 键 词：油池火 侧壁高度 燃烧速率 火焰高度 空气卷吸 

分 类 号：P624.8[天文地球—地质矿产勘探] TK16[天文地球—地质学]