【作者】 李辉；

【导师】 赵春雨； 姚红良；

【作者基本信息】 东北大学 ， 机械设计及理论， 2012， 硕士

【摘要】 空气分离是生产高纯度氧气、氮气、氩气和其它工业气体的重要工业生产过程。空分装置是钢铁、化工等行业的重要设备。随着我国经济的飞速发展,空分设备的设计制造逐渐向大型化、低能耗化方向发展。然而,由于当前相关理论研究不足,使得我国空分设备中关键设备不得不依赖于国外进口,如大型压缩机、大型膨胀机等。空分设备的工作环境总是在不断变化的,其中一些变化甚至是周期性或者是近似周期性的规律变化,环境参数的变化必然会对压缩机等关键设备的工作部件载荷情况造成影响。而在压缩机、增压机和膨胀机的设计计算中,往往只采用一组热力学参数(入口压力、入口温度和出口压力),这与它们在实际工作中所处的工况是不符的。因此,研究空气分离过程中工艺参数随环境条件的变化规律,对确定各空分设备的关键零部件的负荷变动极限情况,保证其稳定安全运行具有重要的理论意义和实际应用价值。本文以某40000m3/h等级空分成套设备为例,探索了原料空压机、增压机和增压透平膨胀机在系统运行时各自状态参数随环境工况的变化规律,主要完成以下研究内容。(1)针对某40000m3/h等级空分成套设备,具体分析了空分工艺流程,并建立了该空分设备流程中各模块的数学模型。在建模过程中对气体状态方程做出了必要的修正,以使其更加适应实际计算的需要。(2)应用化工流程软件Aspen HYSYS对系统进行了数值分析,讨论了环境参数、级间冷却水流量变化对原料压缩机排气参数的影响,以及低压空气、高压空气和膨胀空气三股气流参数对整个工艺流程的影响。结果表明：环境参数、级间冷却效果的变化对压缩空气进入冷却塔时的热力学参数带来较大影响,进而影响到低压空气、高压空气和膨胀空气参数,改变整套设备的运行工况。(3)利用MATLAB,开发出由原料空压机、增压机和增压透平膨胀机组成的多机组同步运行的动态仿真软件。分析了空压机入口压力、温度和湿度的变化对原料空压机、增压机各级以及增压透平膨胀机增压端、膨胀端热力学状态参数的影响。结果表明：压缩机的压缩比将受到入口状态参数的影响,其后同步运行的各机组状态参数也会因而发生改变。更多还原

【Abstract】 Air separation is important productive process in industry to produce high-purity oxygen, nitrogen, argon and other industrial gases. The air separation plant is key equipment of many industries, such as iron&steel industries, chemical industries and so on. With the rapid economic development, the design and manufacturing of air separation equipment is tended to the direction of large-scale, low-energy consumption gradually. However, the air separation industries in our country have to depend on the products of foreign companies in the key equipment, such as large compressors, expanders, etc.It’s frequent to use only one set of thermal performance parameters (the inlet pressure and temperature, and the outlet pressure) in the calculations of design for the compressor or expander used in the air separation plant. This differs from the conditions of the practical work. In fact, the environment in which the air separation plant works is always variable. Some of the changes are regular changes with Periodicity or proximate Periodicity. The change of the environmental parameters will lead to the variation of the load of the working parts for the compressor or other critical equipment inevitably. Therefore, it is necessary to investigate the changing rule of multi-units synchronous running state parameters to provide the reliable load data for the design of the critical parts in the system when the air separation plant works in changing environment. This papetr explores the change laws of the thermal performance parameters for the air compressor, booster and booster braked expander when they work in changing environment. The main works and contributions are decribed as follows:(1) Taking one of40000m3/h air separation plants as an exsample, the paper analyzes the air separation process and esatablishes the mathematic model of the plant, in which the equation of state for gases is amended.(2) A software simulation model of the air separation whole process is built by uising Aspen HYSYS and numerical analysis is conducted. Then, the paper discusseses the influence of the environmental parameter and inter-stage cooling water flow on the outlet thermodynamic parameters of the compressor, as well as the effect of the changes of the low pressure air, high pressure air and the expanded air on the whole process. The results show that the changes of the environmental parameters and inter-stage cooling water flow make a profound impact on the outlet thermodynamic parameters of the compressor. This impaction can change the parameters of low pressure air, high pressure air and the expanded air.(3) A dynamic model of multi-unit synchronous running system is established, which is composed of an air compressor, a booster and a booster braked expander. Analysis is conducted to explore the change laws of the parameters of every stage in the air compressor, the booster, the booster/expander of the booster braked expander when the pressure, temperature or humidity in the inlet of the air compressor change. The results show that the compression ratio of the compressor varies with the inlet parameters, which results in the change of tbe thermodynamic parameters for all the units after the air compressor.更多还原