超音速分离器内流动及其应用基础研究

发布时间：2018-06-05 11:40

本文选题：混合气体分离 + 超音速　；参考：《大连理工大学》2011年硕士论文

【摘要】：超音速分离技术(Super Sonic Separator,缩写为3S),是一种将气体超音速低温凝结效应和旋流分离技术相结合而实现多组分气体冷凝分离的混合气体分离技术。与传统的分离技术相比,具有等熵效率高,结构简单,占地面积小,投资费用低等优点。但是,目前国内外关于该项技术的研究报道很少,距离该技术的成熟应用尚需一段时间。本文将对超音速分离器内部流动行为进行研究,并在此基础上对装置结构和操作参数影响装置性能的规律进行分析和总结,以便为该技术的实际应用提供理论依据和设计基础。建立可描述气体超音速流动的二维数值模型,为超音速分离器的研究提供理论基础；分析结构参数和操作参数影响超音速分离装置性能的规律,为超音速分离器实际运行提供指导；建立超音速分离工艺流程,分析该工艺的优缺点,验证超音速分离技术的有效性。本文的主要研究工作及所形成的结果与结论如下： ①建立了可以模拟超音速分离器的二维和三维数值模型,通过对两种模型的结构进行对比表明,二维模型能够清晰表达超音速分离器内部流动状况,与三维模型的结果差别不大,可以满足对超音速分离器分析的需要。 ②通过分析喷管出口与喉部面积比、排液口当量面积比、排液器内倾角、锥芯等结构参数对超音速喷管流动的影响,得出以下结论：随着喷管出口与喉部面积比的增加,喷管中温降增大,Ma数平均值增加。面积比过小,气流不能保持超音速状态；面积比过大,喷管渐扩段内将产生激波,均不利于装置运行。一定压比和面积比的情况下,过小的排液口当量面积比将使得喷管渐扩段内产生激波,排液口前温度骤升,不利于超音速分离器低温冷凝。排液器内倾角存在最佳值,增大排液器内倾角,喷管工作段内的气流平均马赫数减小,平均温度增加；减小排液器倾角,虽然气流温度和马赫数变化不大,但是流动紊乱程度加剧,损失提高,两者均不利于装置形成低温。通过对比有无锥芯的超音速分离器内流场发现,锥芯式超音速分离器结构设计时需校核锥芯的粗细,否则将出现不利于装置低温冷凝的现象。 ③通过分析装置进出口压比、出口压力以及旋流强度等操作参数对装置内流动的影响,得出以下结论：其他参数一定,压比减小,装置模型内气流的马赫数平均值减小,平均温度增加,不利于装置低温冷凝,装置对气流操作条件也更加敏感,因此实际条件允许的情况下,应提高进出口的压比以保障装置稳定运行。一定面积比的情况下,适当增加出口压力能有效改善装置内气流的流动性能。通过改变旋流器的高度,可以实现超音速分离器装置旋转速度的增加和减小,是控制超音速分离性能的一种有效途径。
[Abstract]:Super Sonic Separator (abbreviated as 3SN) is a mixed gas separation technology, which combines the low temperature condensation effect of supersonic gas with the swirl separation technology to realize the condensing separation of multi-component gases. Compared with the traditional separation technology, it has the advantages of high Isentropic efficiency, simple structure, small area and low investment cost. However, there are few reports on this technology at home and abroad, and it is still some time before its mature application. In this paper, the internal flow behavior of supersonic separator is studied, and on this basis, the influence of device structure and operating parameters on the performance of the device is analyzed and summarized in order to provide the theoretical basis and design basis for the practical application of the technology. A two-dimensional numerical model for describing supersonic gas flow is established, which provides a theoretical basis for the study of supersonic separators, and analyzes the effects of structural and operational parameters on the performance of supersonic separators. It provides guidance for the practical operation of supersonic separator, establishes supersonic separation process, analyzes its advantages and disadvantages, and verifies the effectiveness of supersonic separation technology. The main research work and the results and conclusions are as follows: 1 A two-dimensional and three-dimensional numerical model is established to simulate supersonic separators. The comparison of the structures of the two models shows that the two models can be used to simulate supersonic separators. The two-dimensional model can clearly express the internal flow situation of supersonic separator, which is not different from the result of three-dimensional model, and can meet the needs of supersonic separator analysis. 2 by analyzing the ratio of nozzle outlet to throat area, The effect of the equivalent area ratio of the outlet, the inclination angle of the drain and the cone core on the flow of the supersonic nozzle is discussed. The following conclusions are drawn: with the increase of the area ratio of the nozzle outlet to the throat, the average value of Ma number increases with the increase of the temperature drop in the nozzle. If the area ratio is too small, the airflow can not be kept supersonic, and if the area ratio is too large, shock waves will be produced in the expanding section of the nozzle, which is not conducive to the operation of the device. Under the condition of certain pressure ratio and area ratio, a small equivalent area ratio of the outlet will cause shock waves in the expanding section of the nozzle, and the temperature before the outlet will rise suddenly, which is not conducive to the cryogenic condensation of the supersonic separator. There is an optimum value of dip angle in the effluents. When the inclination angle increases, the average Mach number and mean temperature in the nozzle working section decrease, and the inclination angle decreases, although the air flow temperature and Mach number do not change much. However, the degree of flow disorder and loss are increased, both of which are not conducive to the formation of low temperature. By comparing the flow field of supersonic separator with or without cone core, it is found that the thickness of cone core should be checked in the structural design of supersonic separator with cone core, otherwise, the phenomenon of low temperature condensation will appear. 3 by analyzing the inlet and outlet pressure ratio of the device, The influence of operating parameters such as outlet pressure and swirl intensity on the flow in the device is obtained. The following conclusions are drawn: the other parameters are constant, the pressure ratio decreases, the Mach number average of the air flow in the device model decreases, and the average temperature increases. It is unfavorable to the low temperature condensation of the device and more sensitive to the air flow operating conditions, so the pressure ratio of the inlet and outlet should be increased to ensure the stable operation of the device if the actual conditions permit. Under the condition of a certain area ratio, properly increasing the outlet pressure can effectively improve the flow performance of the airflow in the device. By changing the height of the cyclone, the rotation speed of the supersonic separator can be increased and decreased, which is an effective way to control the supersonic separation performance.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH237.5

【引证文献】