化工生产过程中误操作的原因及防范措施

通过对近年来某公司在生产过程中发生的由于人员误操作而导致的事故进行总结分析,找出发生误操作事故的原因,从而制定防范措施,达到减少生产安全事故事件发生的目的。     

1,2,3-三硝基氮杂环丁烷溶析结晶动力学研究

基于分级法[1]求解了TNAZ间歇溶析结晶过程的粒数衡算方程,通过激光粒度分布测量仪测量了结晶过程中粒度分布随不同温度、搅拌强度、溶析剂滴加速率的变化规律。利用已建立的TNAZ间歇溶析结晶过程的粒数衡算方程求解模型得到了生长动力学参数,最后用最小二乘法模拟出了成核速率和生长速率方程[2]。成核速率和生长速率是结晶模拟过程中最核心的控制条件。     

石化行业开停车操作过程误操作分析

本文系统地分析了在石油化工连续稳定操作条件下,导致误操作出现的原因,设计了一个对开停车过程中潜在误操作的原因进行层次分析的方法。首先对石化生产过程的开停车过程中的影响操作人员操作效果的各层次因素进行了总结和分析,然后以BP炼油厂事故为例展示了如何根据工厂实际情况对误操作原因进行层次性分析。在石化装置开停车前对潜在的操作问题进行系统的分析,并积极采取措施,有助于避免误操作的出现,进而能够有效避免事故的发生。     

石化装置特殊管理手阀辨识及管理分级方法

在国内外石化行业发展历程中,因员工误操作阀门引发过程安全事故的案例时有发生。通过分析可知,石化装置内有部分不属于主流程范围、而在正常生产中也无需操作调整的手阀被误操作的概率较大,此类阀门一旦被误操作可能会引发非常严重的事故后果。通过归纳总结石化装置中需要执行特殊管理手阀的几种类型,指导设计单位和运行单位辨识装置中需要特殊管理的手阀,再基于风险的概念,通过阀门被误操作的后果严重程度和被误操作的可能性,综合评估其所需的管理级别,指导企业合理选择防止手阀被误操作的管理模式。     

甲醇储罐区火灾后果危险性评价

石油化工企业存在的最严重的事故后果主要为储罐泄漏导致发生的火灾爆炸的事故。由于装储工艺流程简单、装置设备少、事故类型少的特性,往往容易使操作人员形成侥幸心理,容易造成误操作及违规操作。运用池火灾模型对某公司的甲醇储罐区泄漏进行模拟分析,得出了当甲醇储罐泄露发生池火灾时,距离液池中心不同范围内,设备的损失情况与停留在该区域内人员伤亡情况,划分危险区域范围。     

基于ALOHA软件对苯乙烯储罐泄露事故的后果分析

苯乙烯是一种危险的合成高分子材料的重要原料,其储罐发生泄漏会导致火灾、爆炸和人员中毒事故,采用ALOHA软件对储罐泄露后果进行模拟,定量得出了苯乙烯储罐泄露导致火灾、爆炸、中毒事故后果的危害范围。根据对储罐工艺过程风险分析的结果从预防事故发生的可能性及控制事故后果的严重程度两个方面,提出工艺过程风险控制措施。     

“全回流”间歇精馏塔顶贮槽内液体流动时的混合

引　言2 0世纪 80年代末 ,余国琮、杨志才等[1] 参照连续精馏开工过程的操作方法提出并实验证明了一种新的间歇精馏操作方法———塔顶累积全回流法(本文简称“全回流”) .采用此法 ,笔者[2 ] 最近推导出在理想操作条件下间歇精馏二元理想混合物精馏过程中塔顶贮槽内液体流动为完全混合时最小汽化总量计算法 .由于采用此法 ,塔顶贮槽内存液量可能很大 ,往往必须考虑塔顶贮槽内液体流动时的混合程度 .本文以多级串联混合模型的级数表示采用此操作方法塔顶贮槽内液体流动时的混合程度 ,以在理想操作条件下间歇精馏二元理想混合物为例 ,通过举…     

氯铝酸盐离子液体催化苯与十二烯烷基化反应

针对酸性氯铝酸盐室温离子液体[BMIM][AlCl4]催化苯与1-十二烯烷基化合成十二烷基苯反应体系的物理化学特性,设计了一套可以分别进行间歇和连续操作的连续流动搅拌反应装置。间歇操作的反应结果表明．[BMIM][AlCl4]催化剂体系的总体结果优于传统催化剂无水AlCl3和氢氟酸,催化剂的用量和反应温度可以大大降低,2-苯基异构体的选择性较高。在连续操作条件下,一定的流量范围内实现了离子液体催化剂和反应料液的原位分离,催化剂被有效地局限在反应区域,并因在运转过程中始终未暴露从而得到了比间歇操作更加稳定和高效的反应结果。     

间歇精馏塔启动过程的模型化

引　言在以往的研究中 ,间歇精馏塔的模型大部分建立在平衡模型的基础上[1] ,系统初值的选取基于伪热初始状态 ,即每层塔板上有足够的积液量 ,塔板温度在泡点温度以上的汽液平衡状态 .多数间歇精馏过程的仿真模拟软件中使用伪热状态作为初始状态[2 ] ,例如 ,ＨＹＳＹＳ Ｒ○ (Ｈｙｐｒｏｔｅｃｈ )、ＢＡＴＣＨＦＲＡＣＴＭ (Ａｓｐｅｎｔｅｃｈ )和ＣＣ -ＢＡＴＣＨ Ｒ○(ＣＨＥＭＣＡＤ) .它们都是通过稳态和平衡计算为微分代数方程组提供了满足一致性要求的初始值 .间歇精馏过程的一个特点就是精馏塔频繁地从冷状态启动 ,初始状态会因再…     

基于图模型的间歇过程误操作风险辨识

提出了一套基于图模型的建模方法,该模型以Petri网和符号有向图（SDG）为基础将模型分为上部和下部,加入操作点、控制库所、判断模块等模型元素,并结合间歇过程的特点,提出了关联变量、目标变量检查表、操作点检查表和关联变量检查表等概念。根据误开误关、过早过晚、步骤添加删除等误操作,对模型进行验证。验证结果表明,该模型解决了先前方法难以描述具体操作的缺陷,并且模型结构简单,具有整体性。不仅能够方便地描述3种不同类型的误操作,还能有效地对误操作进行风险辨识,具有一定的适用性。     

A combined batch process simulation in a production support environment

Productive and safety production of high quality products is required in batch processes, and the importance of generating control recipes, which defines operations of each batch, is increasing. The control recipe is generated through the evolutionary cycle: initiate operations, evaluate performance and modify operations, and combined batch process simulator plays an important role for evaluating the performance. This paper describes the development of production support environment to generate control recipe, and embedding combined discrete/continuous batch process simulator. Based on the activity model of batch production, a framework of the support environment is proposed, and to date development of embedding combined batch process simulator is explained.     

Consequence Identification for Maloperation in Batch Process

Batch processes are important in chemical industry, in which operators usually play a major role and hazards may arise by their inadvertent acts. In this paper, based on hazard and operability study and concept of qualitative simulation, an automatic method for adverse consequence identification for potential maloperation is proposed. The qualitative model for production process is expressed by a novel directed graph. Possible operation deviations from normal operating procedure are identified systematically by using a group of guidewords. The proposed algorithm is used for qualitative simulation of batch processes to identify the effects of maloperations. The method is illustrated with a simple batch process and a batch reaction process. The results show that batch processes can be simulated qualitatively and hazards can be identified for operating procedures including maloperations. After analysis for possible plant maloperations, some measures can be taken to avoid maloperations or reduce losses resulted from maloperations.     

多效干燥过程的排产调度优化

针对干燥过程是一个高能耗的间歇单元操作,对多效干燥过程进行了排产调度研究。根据干燥速率曲线,将各效干燥过程设计为等操作时间,建立了多效干燥过程排产调度的优化模型。以效数和干燥器干燥时间为决策变量,以年费用最小为目标表达为一个混合整数非线性规划（MINLP）的数学模型,利用GAMS进行求解。以淤泥1～5效干燥为算例进行了优化调度分析,结果表明：在4效时年费用最小;与1效干燥相比,在最优条件下年生产费用可节约26%。同时获得了最优排产调度的Gantt图,从而可以得出干燥设备的最小操作周期,据此对多效干燥过程进行排产,使间歇多效干燥过程可以实现连续化生产,对多效干燥的工业化具有一定的意义。     

基于线性规划的单杂质间歇过程用水最小化

对间歇化工过程的单杂质用水网络提出了以新鲜水量最小为目标的优化设计方法。该方法对间歇过程的每个操作假定为一个操作接一个储罐,对所有操作按出口浓度从小到大排序,避免了高浓度水回用到低浓度水的操作中,去掉了用水网络中多余的连接,构造了用水网络超结构。该超结构可以表述为一个线性规划模型。通过GAMS求解该模型得出每个操作周期的最小新鲜水量,并通过证明得出该最小用水量随操作周期增加最终不再变化。该方法可以用作有、无中间储罐间歇过程用水网络综合,实例计算结果表明该方法是可行的,与其他方法相比更简单。     

Development of hidden semi-Markov models for diagnosis of multiphase batch operation

This paper deals with automatic on-line detection and diagnosis of fault patterns in multiphase batch processes. A novel and flexible approach based on the combination of hidden segmental semi-Markov models (HSMM) and multiway principal component analysis (MPCA) is proposed. In all batch operations, process variables may have correlations with each other, and MPCA is used to handle cross-correlation among process variables. In multiphase batch processes, the effect of external factors on process variables is phase-specific and the duration of each phase varies from batch to batch. HSMM is used to model the multiphase batch operation by representing each phase with a macro-state whose duration is determined by a phase-specific probability distribution of a number of micro-states. The output of each micro-state corresponds to the values of the monitored variables at a specific point in time. Given this structure, MPCA-HSMM parameters are trained by the batch operation data and recursive Viterbi algorithm is used to find out the optimum state sequence from each batch. Probability values of the optimum state sequence are collected to construct the probabilistic model which is used to compute the corresponding control limit for the specified operating condition. One MPCA-HSMM model is to be built for each type of previously known operating condition—normal and fault events. The power and advantages of the proposed method are successfully demonstrated in a simulated fed-batch penicillin cultivation process. MPCA-HSMM correctly identifies the type of fault from the batch operation data.     

基于核Fisher包络分析的间歇过程故障诊断

随着间歇过程越来越受重视,其过程监控和故障诊断技术也成为研究热点。以核Fisher判别分析为基础,提出了基于核Fisher的正常工况与故障包络面模型,给出了基于该模型的在线故障诊断流程。此方法利用了Fisher判别分析对类别的划分特点,分别针对正常工况数据和各故障类型数据建立包络曲面模型。与多向Fisher判别分析相比,该方法按批次方向将数据展开,能够解决生产周期不一致问题,在线故障诊断时也不需要预报完整的生产轨迹,并且加入核函数来处理复杂的非线性。最后在青霉素发酵过程的仿真平台上对该方法进行测试,与改进多向Fisher判别分析方法进行对比,该方法获得了满意的诊断效果：能够及早诊断出故障的发生,并在有效识别已有故障的同时还具有对新故障的自学习能力。     

间歇过程的故障分析和互锁控制器综合的集成

Integration amongst various decision-making processes, such as planning, design, and operation is necessary to dynamic and flexible batch production. To achieve a batch production integration, utilization of common models used for various decision-making processes is an effective approach. From this point of view, a batch system common model as described by a Petri net is proposed. In this article, a fault diagnosis technique for batch processes is presented using information about fault propagation and the possibilities of integration of fault analysis and controller synthesis are discussed on the basis of the Petri net based common models.     

Modelling batch bioreactions with continuous process simulators

Process models are increasingly becoming necessary for process understanding and optimizing. However, in the field of bioprocessing, modelling using a generic process simulator suffers from shortcomings given that many simulators cannot model batch mode bioreactors with varying reaction rates based on microbial metabolism. Bioprocesses, mostly batch, are difficult to model because most of the available unit operations in process simulators operate continuously. Our aim is to provide a general simulation platform to model these batch bioprocesses in commercial process simulators and explain how to transform batch processes with varying reaction rate into continuous unit operations for simulation purposes. Two typical fermentation processes, lactose fermentation and glucose/xylose co-fermentation, were simulated in steady state as case studies. The results are discussed as examples using the proposed approach. The potential of how to extend the simulation platform is also explained in detail.     

单杂质间歇过程用水网络优化

对间歇化工过程用水网络优化提出了基于非线性规划的优化设计方法。该方法采用一个中间贮罐用来接收各单元操作的排水,增加各单元操作之间的水再利用机会。对所有单元操作按照排水时间从早到晚进行排序,只有排在前面的操作才提供给后面的操作用水,结合其他的简化规则,构造了用水网络超结构。该超结构的数学模型为一组非线性方程,利用GAMS软件进行求解,得到各个周期的最小新鲜水量和最优的用水网络结构。实例计算结果表明,该方法可行。     

Batch-to-batch optimal control of a batch polymerisation process based on stacked neural network models

A neural network based batch-to-batch optimal control strategy is proposed in this paper. In order to overcome the difficulty in developing mechanistic models for batch processes, stacked neural network models are developed from process operational data. Stacked neural networks have enhanced model generalisation capability and can also provide model prediction confidence bounds. However, the optimal control policy calculated based on a neural network model may not be optimal when applied to the true process due to model plant mismatches and the presence of unknown disturbances. Due to the repetitive nature of batch processes, it is possible to improve the operation of the next batch using the information of the current and previous batch runs. A batch-to-batch optimal control strategy based on the linearisation of stacked neural network model is proposed in this paper. Applications to a simulated batch polymerisation reactor demonstrate that the proposed method can improve process performance from batch to batch in the presence of model plant mismatches and unknown disturbances.