WD095微型燃机离心压气机扩压器及整机性能研究

发布时间：2018-03-07 04:12

本文选题：离心压气机　切入点：扩压器　出处：《大连理工大学》2011年硕士论文　论文类型：学位论文

【摘要】：微型燃机以其高效、灵活、可靠、体积小等优点,除了广泛应用于分布式发电外,还可用于备用电站、热电联产、并网发电、尖峰负荷发电等,无论对中心城市还是远郊农村甚至边远地区均能适用。此外,微型燃气轮机在民用交通运输(混合动力汽车)以及军车以及陆海边防方面均具有优势。作为微型燃机的重要组成部件之一的离心压气机,其性能的好坏直接关系到微型燃机的效率高低。为进一步提高WD095型微型燃机离心压气机的性能,本文对不同结构形式的扩压器内部流动进行了全面和深入的数值研究,以期通过研究探索与叶轮和蜗壳更为匹配的扩压器结构。本文利用商用透平机械CFD软件NUMECA,首先对单列叶栅扩压器子午流道的渐缩程度进行了系统研究,通过对比发现,对本文研究的微型离心压气机而言,扩压器出口与进口宽度的宽度比为0.5-0.7时,叶轮与扩压器连算结构内部的流动效果相对最好,性能相对最优。其次,本文针对扩压器串列叶栅第1列叶片出口角的大小对性能的影响进行了深入研究。研究发现：当第1列叶片出口角为31.5。时,由于第1列叶片出口与第2列叶片进口径向连接区域形成渐缩型通道,因此扩压器的扩压速度比最小,多变效率、压比和总压恢复系数都达到最高。最后,在上述研究基础上,本文对带等宽子午流道扩压器的离心压气机在设计转速下的全工况特性进行了数值研究,获得了全工况特性曲线,反映出该离心压气机在设计转速下具有较为平稳的特性,但高效区不够宽。在设计工况下计算对比了带等宽子午流道与带渐缩子午流道扩压器的整机性能,发现带渐缩流道扩压器的离心压气机整机性能明显优于带等宽流道扩压器的离心压气机,其多变效率相对提高了2.9%,总压比也相对提高了1.85%。通过对设计工况下带串列叶栅扩压器的整机性能的研究发现,当第1列叶片偏向第2列叶片吸力面时,离心压气机性能更优,且出口角为31.5。时,流动效果较其他结构最好。
[Abstract]:Because of its advantages of high efficiency, flexibility, reliability and small size, micro gas turbine can be widely used in distributed power generation, as well as in standby power stations, cogeneration of heat and power, grid-connected power generation, peak load generation, etc. In addition, micro gas turbines have advantages in civil transportation (hybrid electric vehicles), military vehicles and land and sea border defense. As one of the important components of micro gas turbine, the performance of centrifugal compressor is directly related to the efficiency of micro gas turbine. In this paper, the internal flow of diffuser with different structure forms is studied comprehensively and deeply in order to explore the diffuser structure which is more suitable to the impeller and volute. In this paper, the commercial turbine machinery CFD software NUMECA is used to systematically study the degree of meridional channel shrinkage of a single-row cascade diffuser. Through comparison, it is found that, for the miniature centrifugal compressor studied in this paper, When the width ratio of outlet to inlet width of diffuser is 0.5-0.7, the flow effect of impeller and diffuser is the best and the performance is the best. Secondly, the effect of the outlet angle of the first row blade in the cascade cascade of diffuser on the performance is studied in depth. It is found that when the outlet angle of the first row blade is 31.5. Since the radial connection between the outlet of the first row and the inlet of the second row of blades forms a tapered channel, the diffuser has the highest diffuser speed ratio, variable efficiency, pressure ratio and total pressure recovery coefficient. Finally, on the basis of the above research, the full working condition characteristic of centrifugal compressor with equal width meridional passage diffuser under the design speed is studied numerically, and the whole working condition characteristic curve is obtained. The results show that the centrifugal compressor has stable characteristics at the design speed, but the high efficiency zone is not wide enough. The performance of the diffuser with equal width meridian passage and with tapered meridian passage is calculated and compared under the design conditions. It is found that the whole performance of centrifugal compressor with tapered diffuser is obviously superior to that of centrifugal compressor with equal width diffuser. The variable efficiency is improved by 2.9 and the total pressure ratio by 1.85. By studying the performance of the whole machine with cascade diffuser in the design condition, it is found that the centrifugal compressor performance is better when the first row blade is inclined to the second row blade suction surface. When the outlet angle is 31.5, the flow effect is better than that of other structures.
【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】：TH452

【引证文献】