化学反应失控紧急泄放研究

【作者】 周建东；

【导师】 李志义；

【作者基本信息】 大连理工大学 ， 化工过程机械， 2000， 硕士

【摘要】 化学反应失控的紧急泄放是化工设计中的一个重要的安全问题，由于失控过程的复杂性，该问题仍未得到很好的解决。西方国家特别是美国在这方面的研究处于领先的地位，许多权威的组织（如美国石油协会，美国紧急泄放协会等）和跨国化学公司都针对此问题提出了各自的解决方案。 本文首先对六十年代以来该领域的研究状况进行了综述，着重从研究方法、设计模型和实验方法等方面，对现有的成果进行了介绍和评述。 对化学反应失控紧急泄放的研究的最终目的是，给出准确且安全的泄放尺寸。本文从能量和质量平衡方程出发，经过一定的假设和推导，对不同的泄放模型（两相流泄放、蒸气泄放和液体泄放）分别给出确定泄放尺寸的方程。 对容易出现反应失控的聚合反应进行了简要的介绍，并从化学反应动力学出发，导出了自由基聚合反应的反应速率方程。在此方程的基础上，对自由基聚合反应的失控过程进行了数值模拟，得到了温度、压力随时间的变化关系，并与一些文献的模拟结果进行了比较。 能模拟出失控化学反应的实验室级的装置要求有很高的绝热性，且需要一套实时的动态调节温度、压力的自控系统，比较复杂。本文首先用苯乙烯作为反应介质进行了温度分布、最高失控压力实验，从而对实验装置的搅拌问题、设计压力等问题有了确定的依据。并在此基础上设计了一套实验系统，在其上进行了多次聚合反应试验，对失控反应发生的条件有了进一步的认识。此外，对于试验过程中压力、温度信号的自动采集，采用VB6.0编制了数据采集及处理软件，用调用动态连接库的方法采集数据，实现了温度、压力信号的实时显示，并可在采集结束后对数据进行处理，计算泄放尺寸。更多还原

【Abstract】 Emergency venting of runaway reactions is an important safety issue in chemical engineering design~ and is also an active area concerned consistently by researchers. Yet an unitive and exact scheme still has not been worked out due to the complicated runaway process. West countries, especially the United States, set the pace in this field. Many authoritative organizations such as API (American Petroleum institute) and AIChE’S Design institute for Emergency Relief Systems (D1ERS) have presented integrated approach respectively. This paper summarizes the research status of this area since I 960s.The emphasis is laid on the research strategies, design models and experimental methods, and some comments are made on these respects. The purpose of the study in this area is to gain the accurate and safety size of relief devices. Governing equations for relief vent rate requirement can be obtained from the macroscopic energy and mass balance by making some hypothesis’s and derivation, which can be used to yield the relief vent requirement for homogeneous venting, all-vapor venting and all-liquid venting. Polymeric reaction, the typical extroexothermic reaction that tends to runaway is introduced briefly. Starting off from the chemical reaction kinetics equation, the reaction velocity equation is obtained. Temperature and pressure histories for free-radix polymeric reaction are obtained by detailed computer simulation based on the equation. Bench scale apparatus that can simulate the nmaway reaction requires high adiabaticity, and automatic control system for temperature and pressure adjustment is needed. In this thesis, by using styrene as reactant, temperature distribution experiments and II maximum runaway pressure experiments are carried out, which help to consider churn-dasher and design pressure of the ultimate equipment container. Based on these experiments, an equipment system is designed and some polymeric reaction experiments are carried out. Besides, data collection program is applied to gather the signals of temperature and pressure. The codes are wrote with Visual Basic 6.0, which is the famous product of Microsoft Corporation. The program calls DLL (li)ynamic Link Library) to gather the signals, the mn-time temperature and pressure histories curves are plotted simultaneously. After the data collection, data is processed and the relief vent size is calculated finally.更多还原