热作用下固态二氧化碳BLEVE过程的理论与实验研究

发布时间：2018-01-20 17:41

本文关键词： 二氧化碳沸腾液体扩展蒸气爆炸过热液体过热极限理论突变理论　出处：《北京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：在碳捕集与贮存（Carbon Capture and Storage，CCS）及其提高油田采收率技术（Carbon Capture and Storage-Enhanced Oil Recovery，CCS-EOR）技术中，需要将高压下的液态或超临界CO2通过油管注入到井下，实现原油驱替。在这一生产流程中，存在发生严重的CO2沸腾液体扩展蒸气爆炸（Boiling Liquid Expanding VaporExplosion，BLEVE）事故的风险。目前国内外对于BLEVE的研究主要是针对液化石油气、液化天然气和过热水等物质，但对于CO2-BLEVE的机理、过程、效应的研究很少。为此，论文从理论和实验两方面对CO2-BLEVE过程进行了探索性的研究。过热极限温度是BLEVE现象的一个重要指标，根据过热极限理论，它决定了BLEVE是否发生以及蒸气爆炸剧烈程度。论文以范德华方程为基础，利用突变理论的分析方法，，建立了热作用下CO2蒸气爆炸的尖点突变模型，提出了基于突变理论的CO2过热极限温度的计算方法。指出由于势的变化导致气液两相系统状态的改变，通过尖点突变的拐点集计算得到CO2在不同压力下的过热极限温度。借助“CO2可视两相流动及爆炸实验装置”对固态CO2在热作用下发生蒸气爆炸过程进行了实验研究，发现容器内的CO2从上至下按过热气相、饱和气液两相、过冷液相分层存在，且温度从上部到底部逐步降低，热分层导致相同容器压力下液相的能量降低，影响了沸腾响应和压力恢复过程，泄放后压力下降幅度和下降速率越大，压力回升幅度及回升达到的最大压力也越大，大致呈线性关系。实验结果和论文所建立的理论模型进行了对比，发现过热极限理论所提出的过热极限温度不是CO2-BLEVE发生的必要条件，但是相对升压量与相对降压量之间存在着很强的正相关性，即过热度越大，CO2发生蒸气爆炸强度越剧烈，压力反弹越大。
[Abstract]:Carbon Capture and Storage in carbon capture and storage. CCS) and its enhanced oil recovery technology carbon Capture and Storage-Enhanced Oil Recovery. In CCS-EOR technology, it is necessary to inject the liquid or supercritical CO2 under high pressure into the well through the tubing to realize the displacement of crude oil. There is a serious CO2 boiling liquid spreading vapor explosion that causes Liquid Expanding VaporExplosion. At present, domestic and foreign research on BLEVE is mainly focused on liquefied petroleum gas, liquefied natural gas and superhot water and other substances, but for the mechanism of CO2-BLEVE, the process. There are few studies on the effects. Therefore, the CO2-BLEVE process is studied theoretically and experimentally. Superheated limit temperature is an important index of BLEVE phenomenon. According to the superheating limit theory, it determines whether BLEVE occurs and the intensity of vapor explosion. The paper is based on van der Waals equation. The cusp catastrophe model of CO2 vapor explosion under thermal action is established by using the analysis method of catastrophe theory. A method for calculating the superheated limit temperature of CO2 based on catastrophe theory is proposed. It is pointed out that the state of gas-liquid two-phase system is changed due to the change of potential. The superheated limit temperature of CO2 at different pressures is obtained by calculating the inflection point set of the cusp mutation. The vapor explosion process of solid CO2 under thermal action was studied by means of "CO2 visible two-phase flow and explosion experimental device". It was found that the CO2 in the container was superheated gas phase from top to bottom. Saturated gas-liquid two-phase supercooled liquid delamination exists and the temperature gradually decreases from upper to bottom. Thermal stratification results in the decrease of liquid energy at the same pressure which affects the boiling response and pressure recovery process. The larger the pressure drop and the decrease rate after release, the greater the pressure rise range and the maximum pressure reached, which is approximately linear. The experimental results are compared with the theoretical model established in this paper. It is found that the superheating limit temperature proposed by the superheating limit theory is not a necessary condition for the occurrence of CO2-BLEVE, but there is a strong positive correlation between the relative pressure rise and the relative pressure reduction, that is, the greater the superheat is. The more intense the CO2 vapor explosion, the greater the pressure rebound.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.45

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