常压塔技术改造——塔顶循环回流取热

<正> 一、前言 辽阳石油化纤公司炼油厂常减压蒸馏装置的设计加工原油为150万吨/年。装置主体设备常压塔的能耗较高,塔顶低温位热量全部由冷却器冷却,热量不仅未能利用,还增加了冷却负荷。为了降低能耗,在常压塔增设了塔顶循环回流,由此回收塔顶部分低温位热能,取得了良好的效果:每年可回收低温位热量折合燃料油960吨,节电18.4×10~4度,总经济效益49.5万元(人民币)/年。现将常压塔顶循环回流技术改造情况介绍如下。     

常减压蒸馏装置的常压系统流程模拟

常减压蒸馏装置是石油炼制过程的龙头装置,常减压蒸馏的操作条件以及产品的馏出率不仅影响下游的生产过程,而且对炼油厂的能耗有很大影响。针对我国某常减压蒸馏装置由于加工的原料由国内原油变为国外原油,原有的操作条件使得常减压蒸馏装置的馏出率低且能耗高的特点,对常减压蒸馏装置进行常压系统的流程模拟,模拟结果对实际生产过程的优化改造起到指导作用。     

常减压蒸馏装置常压塔区配管设计要点

当前时期下,我国炼油厂中大量地使用常减压整流装置,该装置为炼油厂的高效运行起到了十分重要的作用,因此常减压蒸馏装置工艺设计的好坏,会直接影响到炼油厂的炼油效率。本文就是攫取了常减压蒸馏装置常压塔区配管设计进行着重阐述。     

5.5Mt/a常减压蒸馏装置常压塔塔顶冷凝系统防腐技措

通过对兰州石化公司5.5 Mt/a常减压蒸馏装置原油蒸馏过程中酸值和硫含量的评价分析,制定相应的设备防腐和工艺防腐措施,有效控制了常压塔顶冷凝系统的腐蚀.     

常压塔压降增高影响因素分析及调整措施

由于常减压装置原料携带杂质较多,沉积在电脱盐或携带至后续工序,加之长期低负荷运行,常压塔上部塔盘因油泥沉积导致浮阀堵塞,甚至无法正常开启,塔内压降增大,影响正常的汽液相交换,汽柴油分离精度下降、馏程重叠严重。在上一生产周期末期表现明显,本周期开工后,对此问题展开长周期攻关,通过一系列调整措施和对关键点常压塔第4层至第15层塔盘压降监控,有效控制压降增长,保证常减压装置的长周期运行。     

丙烯腈流化床反应系统取热流程的改进

本文对丙烯腈流化床反应系统取热流程进行了分析，并对原流程进行了改进，该改进方案既可降低操作费用，又可节省设备投资。     

常压塔侧线外观异常的原因及建议

某石化公司常压装置原油加工能力为150万吨/年,采用“初馏+常压塔”工艺技术。在装置实际生产过程中,因装置加工原油偏离设计,且长期掺炼性质偏重、塔顶油收率偏低的原油,给塔顶低温腐蚀带来较大压力。通过装置的一次生产波动,重点对引起装置低温部位换热器腐蚀的直接原因和根本原因进行分析,针对分析的原因采取针对性措施并实施后,塔顶低温防腐取得较好的效果。     

常压塔装置的优化改造

常压塔装置是石油炼制中重要的处理工序,介绍了我国在提高常减压蒸馏技术水平方面采取的措施,如装置大型化技术、节能降耗技术、提高拔出率技术等;同时对这些技术进步进行了分析并提出了今后发展的方向。     

原油常减压蒸馏塔的流程模拟

常减压蒸馏装置是炼油加工的第一道工序,它的运行状况对后续装置乃至全厂都有着重要影响。针对初馏塔、常压蒸馏塔和减压蒸馏塔的稳态流程模拟,选取适合的蒸馏塔中段循环设定变量和减压塔模拟方法,最终流程模拟结果与实际工艺参数相似度极高,说明常减压蒸馏塔的流程模拟能够如实体现实际工艺状态,可以作为指导工艺生产、操作优化的有效方法。     

E3 Analysis for Crude and Vacuum Distillation System

Crude oil blending is a very common practice in petroleum refineries, where the main focus is to minimize the total purchase cost of crude oils under specified blending oil properties. Crude oil blending actually has significant impacts on energy consumption from heating furnaces during crude oil processing. Conceivably, furnace energy consumption from burning fuels such as natural gas, fuel oil, or propane causes huge amounts of CO₂ emissions. In this paper, a methodology framework for crude oil blending and processing with simultaneous consideration of energy, emission, and economic profit (E3) is developed. It includes four stages of work: steady‐state modeling, heating energy consumption calculation, emission model development, and economic evaluation. With Aspen HYSYS simulation, the developed methodology provides a quantitative support for refinery to identify an optimal E3 operating strategy. A case study is implemented to demonstrate the efficacy of this methodology.     

乙烯装置初分馏系统模拟计算和系统分析

对乙烯装置初分馏系统作了全面的模拟和分析，讨论了各参数对热量回收的影响。     

An Energy‐Efficient Crude Distillation Unit with a Prefractionator

An energy‐efficient crude distillation unit (CDU) was proposed, and its performance was evaluated and compared with that of a conventional CDU. The problem of the large energy demand associated with the single‐column operation of a conventional CDU was solved with a two‐column operation – a prefactionator and a main column – in the proposed CDU. The two‐column operation reduces feed‐tray mixing, and thus raises the thermodynamic efficiency of the CDU. The proposed unit has reduced heating and cooling duty compared with that of the conventional unit. The proposed unit also has fewer investment and utility costs. Vapor and liquid flow connections between the two columns are readily available by adjusting the difference in column operating pressure.     

负压粗苯蒸馏工艺介绍

介绍了负压粗苯蒸馏技术的主要特点。原料不经管式炉加热直接进粗苯塔,粗苯塔与再生塔共用1台加热炉,粗苯塔采用高效抗堵塔盘,装置操作灵活可靠。与常压直接蒸汽蒸馏工艺相比,具有节能、环保、操作稳定等优点。     

新型规整填料及塔内件在润滑油减压塔中的应用

列举了常减压蒸馏装置润滑油型减压塔的实际操作、标定及原始设计等方面的详实数据,并通过工业时间进行了较为系统、科学地对比分析和深层次研究。同时,重点介绍了新型规整填料及塔内件在大型润滑油减压塔中的实际应用。     

一种全新的精馏塔回流罐液位控制系统

针对某厂丁烯-1精馏装置运行中存在的问题,设计了一套全新的回流罐液位控制器结构.该方案采用回流量作为控制量,实现对精馏塔回流罐液位的稳定控制,同时使采出量随回流量成比例变化,提高了精馏塔回流比的易调节性.通过DCS上组态与参数整定,实现了设计的控制系统,取得了良好的控制效果,为后续的优化工作做好了准备.     

常减压蒸馏换热网络节能优化

利用夹点技术对常减压蒸馏换热网络进行分析,优化该常减压蒸馏装置换热网络结构,最大限度的回收热量,节能效果显著。     

粗苯蒸馏系统的技术改造

介绍了粗苯蒸馏系统的改造和生产调整情况．通过改造，取得了良好的效果，经济技术指标达到了历史最好水平。     

Energy Saving in Crude Oil Atmospheric Distillation Columns by Modifying the Vapor Feed Inlet Tray

Optimization of a typical crude oil atmospheric distillation unit and reduction of energy conservation were carried out through modifying the implementation and change in the flash zone of the tower. A conventional procedure in such units involves the combination of liquid and vapor product of the prefractionation train surge drum upon introduction to the tower. However, it is theoretically illustrated and represented by simulation means that introducing the vapor feed into the upper stages of the distillation column separately can lead to an energy saving of 12.6 % in the condenser duty, an increased liquid‐to‐gas flow (L/G) at certain points of the column, and hence to a reduction in diameter and investment costs of new tower designs of approximately US$ 0.7 million a^–1. The proposal can be put into practice without the need of additional equipments or additional cost of difficult rerouting the streams. An industrial case study of a steady‐state crude oil distillation unit is given by simulation provision of AspenHysys™.