【作者】 马宗宁；

【导师】 叶启亮；

【作者基本信息】 华东理工大学 ， 化学工程， 2011， 硕士

【摘要】 原油是极其复杂的混合物,必须经过一系列的加工处理才能得到多种有用的产品。原油蒸馏是根据产品以及下游工艺装置对原料的要求,通过加热、分馏和冷却等方法把原油分割成为不同沸点范围的馏分,一般包括原油的预处理、常压蒸馏和减压蒸馏。本文根据原油蒸馏原理,通过Visual Basic编程辅助完成了某炼油企业500万吨/年常减压蒸馏装置中常压塔的设计计算,并根据Visual Basic得到的石油馏分的流量和中段循环回流的取热量用Aspen Plus对常减压装置中的初馏塔和常压塔进行模拟,最后根据减压塔的设计原则用Visual Basic调用Aspen Plus得到减压塔中段循环回流取热量,从而完成减压塔的模拟。具体研究工作包括：(1)根据精馏原理建立了原油蒸馏装置的MESH模型；(2)根据原油的累积质量收率、累积体积收率曲线和切割方案,得到各石油馏分的质量收率和体积收率,并计算三条蒸馏曲线；(3)根据原油的密度曲线得到各石油馏分的密度,进而计算出15.6℃时的相对密度；(4)根据各石油馏分的ASTM曲线得到平均沸点、分子量、特性因数、真假临界常数、焦点压力、焦点温度以及偏心因子等基本物性参数；(5)根据焓值计算公式得到各石油馏分在一定压力、温度下的焓值；(6)根据经验选定各塔段塔板数,并根据物料衡算和能量衡算得到各主要塔板温度和汽液负荷。在求取塔顶、一线、二线和三线温度时,采用四重循环迭代,而且每改变一次温度重新进行一次全塔能量分配,使计算的结果比手工计算更加准确；(7)根据Visual Basic计算得到的石油馏分的流量和常压塔中段循环回流取热量,用Aspen Plus软件对初馏塔和常压塔进行模拟；(8)对于减压塔的设计,根据减压馏分的切割范围得到减压塔塔顶和侧线馏分的流量,并根据经验选定各塔段的塔板数。通过编程迭代计算顶循和中段循环回流的取热量,最后将其作为Aspen Plus必要的输入数据,由Aspen Plus得到全塔的温度和汽液负荷分布。总之,在进行原油蒸馏工艺设计时,首先用Visual Basic编程模拟,得到各石油馏分的产量、汽化段温度、加热炉温度以及各中段循环回流的取热量,然后将其作为Aspen Plus必要的输入数据,用Aspen Plus模拟得到各个塔板的温度和汽液负荷。更多还原

【Abstract】 Crude oil is an extremely complex mixture. Consequently, it must be processed so that many useful products can be obtained. Crude oil distillation is a process in which heating, fraction, and cooling methods are used to divide petroleum into different distillate fractions on the basis of the requirements of raw materials and downstream processing equipments. Generally, preprocessing, atmospheric distillation and vacuum distillation are included in the process.The crude oil distillation device whose processing capacity is 5 million tons per year was investigated and the design of atmospheric column was accomplished with Visual Basic according to the principles of crude oil distillation. And then, the primary and atmospheric columns were simulated by Aspen Plus simulation software according to the flow rates of petroleum fractions and the heat duties of pumparounds obtained by Visual Basic. Finally, the heat duties of pumparounds were calculated by calling Aspen Plus with Visual Basic on the basis of the principles of vacuum column design. Vacuum column was simulated in accordance with the data. The researches done in the paper are as following:ⅰ. MESH model was established according to the principles of distillation.ⅱ. Based on cumulative weight yield, volume yield and cutting scheme, three distillation curves of petroleum fractions were obtained.ⅲ. Densities of petroleum fractions were got on the basis of the density curve, and relative densities at 15.6℃were also calculated.iv. Average boiling points, molecular weights, characterization factors, true and pseudo critical constants, focus pressures, focus temperatures and acentric factors were computed from ASTM curves of each petroleum fraction.ⅴ. Enthalpies of petroleum fractions at certain pressure and temperature were obtained by enthalpy formulas.ⅵ. The number of stages in every section was selected according to the experience, and the temperatures, liquid and vapor flow rates were calculated through material balance and energy balance. Four-variable iteration was applied to calculate the temperatures at the top of column, in No.1, No.2 and No.3 side lines simultaneously. Once each temperature was changed, the residual energy would be recalculated and the energy in the column would be redistributed. Consequently, the results obtained by Visual Basic are more accurate than hand calculation. ⅶ. Based on the flow rates of petroleum fractions and the heat duties of pumpaounds in atmospheric column calculated by Visual Basic, primary and atmospheric columns were simulated by Aspen Plus simulation software.ⅷ. As to the design of vacuum column, the flow rates of the petroleum fractions at the top of column and in the side lines were obtained according to the cutting range. And then, the numbers of stages at each column section were selected on the basis of experience. After that, the heat duties at the top cycle and of the pumparouds were calculated by programming which were considered as the critical input data and were input into Aspen Plus. Finally, the distribution of temperature, liquid and vapor flow rates on each stage were obtained by Aspen Plus simulation software.In brief, when designing the process of crude oil distillation, accomplish the simulation by programming with Visual Basic firstly to obtain the critical process parameters, such as the flow rates of petroleum fractions, the temperature at vaporization section, the temperature in the heating furnace, heat duties of pumparounds, and so on. And then input the data into Aspen Plus, and run the simulation to get the temperatures, liquid and vapor flow rates on each stage.更多还原