小尺度油罐火燃烧特性与火焰图像特征参量变化规律

发布时间：2018-02-06 03:16

本文关键词： 风速油罐火开口因子燃烧速率火焰辐射火焰图像　出处：《中国科学技术大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着经济的飞速发展,国家对各种油品的需求日益增加,各个国家都加快石油的储备,我国各个地区成品油库数量也迅速上升。增加石油储备的同时如何保障储油罐区的安全问题亟需解决和研究。石油本身有易燃、易爆等特性,因此储油罐区一旦发生火灾将难以扑灭,不仅会造成重大国家经济损失,还会对人员生命安全、环境安全造成严重威胁。由于储油罐区一般在室外建造,实际发生火灾时,自然环境风速将会对火灾产生影响,火焰发生倾斜,相邻油罐辐射、热蒸汽的流动都将有所变化,火焰与周围环境的卷吸强度加强,加速火灾的蔓延。目前对油罐火的研究主要集中在无风条件下,因此急需对有风条件下油罐火燃烧特性进行研究,为实际油罐火灾的扑救、防治提供理论依据。根据实际储油罐区火灾事故调研发现,伴随着火灾的进行,油罐罐顶会发生破裂,其中顶部被完全掀开的约占实际油罐火灾总案例的40%,还存在顶部被部分掀开等情况,因此本文对有风条件下不同开口模式的油罐火灾燃烧特性进行实验研究,通过小尺寸实验模拟实际油罐发生火灾的不同工况,研究油罐火的燃烧特性及图像参数,实验设定各种工况下如：两种液位、不同开口因子下、不同的风速对燃烧参量如燃烧速率、辐射分数、火焰温度、以及图像参量(火焰倾角、火焰长度、火焰高度)的影响规律进行了研究及分析。实验设定油罐高10cm,直径为15cm。为了更好模拟实际油罐发生火灾时顶部不同掀开情况,本文设计了5种罐顶开口因子,分别为1、3/4开口因子、1/2开口因子、1/4开口因子和1/8开口因子(开口因子指开口面积与全开口面积之比)。并且为了模拟不同储油条件下油罐火燃烧特性,实验设计两种液位(6cm和8cm)。而围绕外界风对油罐火燃烧参数及图像特征的影响研究,本文设定多种风速情况(0m/s、0.5m/s、1.0m/s、1.5m/s、2.0m/s、2.5m/s),实验在中国科学技术大学火灾国家重点实验室风洞平台进行,采用电子天平实时采集燃料质量变化数据,温度数据使用铠装热电偶采集,利用辐射热流计测得火焰上风处和下风处辐射通量,火焰图像数据使用DV摄像机进行采集,并进行处理分析。不同开口大小影响油罐火的发展过程,为了定性研究开口因子对油罐火燃烧特性的影响,建立无量纲参数开口因子,对实验数据进行处理分析,建立开口因子和油罐火燃烧速率之间的关系式,及开口因子与无量纲火焰高度及火焰长度之间的拟合关系,得到开口因子对油罐火燃烧特性和图像参数的影响规律。对两种液位下油罐火燃烧特性和图像参数进行对比分析,得到液位与燃烧过程中各种参数之间的变化规律。有风条件下火焰发生倾斜,火焰与液面之间的热量交换、与周围环境之间的卷吸及火焰图像都发生变化,对采集到的实验数据进行处理分析,得到风速与火焰倾角、无量纲火焰高度之间的拟合关系,发现风速对火焰的燃烧特性及图像特征参数的影响规律。
[Abstract]:With the rapid development of economy, the national demand for oil is increasing, all countries speed up oil reserves, China's various regions of oil products quantity is also increasing rapidly. How to increase oil reserves and security problems should be solved and studied. The tank itself has oil storage of flammable, explosive and other characteristics, so the oil tank area once the fire will not be extinguished, not only will cause great economic losses to the country, but also the safety of personnel, causing a serious threat to environmental safety. Because the oil storage tank area in general outdoor construction, the actual fire occurs, the natural environment will affect the speed of fire, the flame tilt of adjacent tank radiation, steam flow will be change the flame and the surrounding environment to strengthen the strength of the entrainment, accelerating the spread of fire. The current research on the oil tank fire mainly in no wind condition, therefore It is urgent to study the combustion characteristics of the oil tank under the condition of wind, and provide the theoretical basis for the actual oil tank fire fighting and the prevention and control.
According to the actual storage tank fire accident investigation, accompanied by fire, oil tank can rupture, the top is fully opened about 40% of the total actual tank fire case, there is the top part opened etc., so the wind conditions are not the same opening mode of tank fire combustion characteristics experiments were carried out under different conditions, the actual tank fire simulation through small scale experiments, combustion characteristics and image parameters of oil tank fire, the experiment set under various conditions such as: two level, different opening factor under different wind velocity on combustion parameters such as burning rate, radiation fraction, flame temperature, and image parameters (flame angle, flame length and flame height) effects were studied and analyzed.
The experimental setting tank height 10cm, diameter of 15cm. in order to better simulate the actual tank fire at the top of the lift, this paper designed 5 kinds of roof opening factor, respectively 1,3/4 opening factor, 1/2 opening factor, 1/4 factor and 1/8 factor (opening opening opening factor refers to the opening area and open area ratio). And in order to simulate the different storage conditions of oil tank fire combustion, experimental design of two level (6cm and 8cm). And Research on the influence of wind on the tank fire parameters and image features, this paper set a variety of wind conditions (0m/s, 0.5m/s, 1.0m/s, 1.5m/s, 2.0m/s, 2.5m/s). The experiment was performed at the State Key Laboratory University of Science & Technology China wind tunnel fire platform, the real-time data acquisition of electronic balance fuel quality change, temperature data using armored thermocouple acquisition, using the radiometer measured upwind and downwind of the flame The radiant flux, the flame image data are collected by the DV camera and processed and analyzed.
Different opening size affect the development process of oil tank fire, in order to investigate the opening factor effect on the combustion characteristics of oil tank fire, a dimensionless parameter opening factor, analyzing the experimental data, to establish the relationship between opening factor and tank fire burning rate, fitting and the relationship between the opening factor and the dimensionless flame height and flame length the influence of factors on the combustion characteristics and regularity of the opening image parameter storage tank fire. A comparative analysis of the two kinds of liquid level of tank fire combustion characteristics and image parameters variation between various parameters and liquid level in the combustion process. Under the condition of flame tilt and surface heat exchange between the flame and the surrounding. The environment between the entrainment and flame image changes, analyzing the experimental data collected, wind speed and flame angle, dimensionless flame The fitting relationship between the height and the influence of wind speed on the combustion characteristics of the flame and the characteristic parameters of the image is found.

【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE88;TQ038

【参考文献】