导流锥式超音速旋流器流场特性与实验研究

发布时间：2018-05-11 02:20

本文选题：气液分离 + 超音速冷凝旋流分离器　；参考：《大连理工大学》2015年硕士论文

【摘要】：天然气作为一种清洁能源已经走进千家万户并广泛应用,天然气开采后的脱水过程却十分复杂。超音速分离装置(简称SGS)引起了足够关注,它集合了膨胀过程、分离过程与压缩过程于一体,整个过程仅利用了天然气本身的压力降,无需任何外力做功。因此,该项技术具有良好的应用前景与商业价值。本文建立数值模型,通过模拟得到的最佳尺寸设计并制造了一种导流锥式超音速冷凝旋流分离器,建立实验平台研究操作参数与结构参数对分离效果的影响并根据理论公式,分别研究面积比与压比对喷管内部流场分布的影响,本文主要结论为：(1)本文建立的湍流模型与湿蒸气自发凝结模型可以反映实际流场与凝结状态,并建立新型轴流式旋流器三维几何模型,结果显示,轴流式旋流发生器较传统切向入口的旋流器相比拥有压力损失小与离心加速度大的特点,具有106g量级的离心力,保证了液滴在短时间内可以甩到喷管内壁面上。(2)设计了一种导流锥式SGS设备,建立三维模型预测喷管内部流场,改变结构参数实现最优结构,结果表明：压比为1.5时,最佳面积比为1.27,采取平齐式排液口结构,喷管内达到最大马赫数为1.19,最低温度可达234K。通过自发凝结流动Eulerian模型预测喷管内凝结状态,过饱和度S在喷管内的值始终大于1,在喉部形成大量形成凝结核心。(3)根据一维变截面等熵流的理论针对流场参数分布进行研究,结果表明：在相同压比情况下,面积比越小,越容易实现全喷管内的超音速流动,便于湿蒸气的冷凝。最佳面积比是在保证全超音速流的面积比中的最大面积比,此时不仅保证全喷管的超音速流,而且使得整个喷管内的温度最低,分离效率也最高。(4)建立实验平台,根据实验研究表明：固定面积比下,乙醇脱除率与露点降都随压比的增高先增大后减小,最佳压比为1.3,当面积比为1.27时,乙醇脱除率δETH为47.4%,露点降△Td为7.0K。在压比固定情况下,分离效果随面积比增大而减小,新型导流锥式SGS设备较内锥芯式SGS设备在乙醇脱除率上有所提高,在压比为1.3,面积比为1.27时,乙醇脱除率δETH提高了1.9倍。
[Abstract]:As a kind of clean energy, natural gas has been widely used, but the dehydration process is very complicated. Supersonic separation device (SGS) has attracted enough attention. It integrates the expansion process, the separation process and the compression process. The whole process only uses the pressure drop of natural gas itself without any external force to do work. Therefore, this technology has good application prospect and commercial value. In this paper, a numerical model is established, and a supersonic condensing cyclone separator is designed and manufactured by simulation. The experimental platform is established to study the influence of operating parameters and structural parameters on the separation effect. The effect of area ratio and pressure ratio on the flow field distribution in nozzle is studied. The main conclusion is: 1) the turbulent model and the wet vapor spontaneous condensation model established in this paper can reflect the actual flow field and condensation state. The 3D geometric model of the new axial flow cyclone is established. The results show that the axial flow generator has less pressure loss and greater centrifugal acceleration than the traditional tangential inlet cyclone, and has a centrifugal force of 106 g. A flow guide cone SGS device is designed to predict the flow field in the nozzle and change the structure parameters to realize the optimal structure. The results show that the pressure ratio is 1.5. The optimum area ratio is 1.27, and the structure of horizontal outlet is adopted. The maximum Mach number in nozzle is 1.19, and the lowest temperature is 234K. The Eulerian model of spontaneous condensation flow is used to predict the condensation state in the nozzle. The value of supersaturation S in the nozzle is always greater than 1, and a large number of condensation cores are formed in the throat.) according to the theory of one-dimensional isentropic flow with variable cross section, the distribution of flow field parameters is studied. The results show that under the same pressure ratio, the smaller the area ratio, the easier it is to realize supersonic flow in the nozzle, which is convenient for the condensation of wet vapor. The optimum area ratio is the maximum area ratio in ensuring the area ratio of the total supersonic flow. In this case, not only the supersonic flow of the whole nozzle is guaranteed, but also the temperature in the whole nozzle is the lowest, and the separation efficiency is the highest. The experimental results show that the ethanol removal rate and dew-point drop increase first and then decrease with the increase of the pressure ratio, and the optimum pressure ratio is 1.3. When the area ratio is 1.27, the ethanol removal rate 未 ETH is 47.4 and the dew point drop TD is 7.0 K. When the pressure ratio is fixed, the separation efficiency decreases with the increase of the area ratio, and the ethanol removal rate 未 ETH is increased by 1.9 times when the pressure ratio is 1.3 and the area ratio is 1.27, and the new type of diversion cone type SGS equipment is better than the inner cone core type SGS equipment in the removal rate of ethanol, and when the pressure ratio is 1.3 and the area ratio is 1.27, the ethanol removal efficiency is 1.9 times higher than that of the inner cone type SGS equipment.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE96

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