共查询到17条相似文献,搜索用时 125 毫秒
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马健峰 刘长胜 孙玉莹 Hu Yong Li Zhenhua Huang Yingfu Zhang Wanyue Zhao Qiang Ma Feng Yang Zhiyong 《风机技术》2015,(3)
针对某组装式压缩机用半开式小流量系数叶轮,设计了两种不同型式的叶片扩压器,并对半开式叶轮和叶片扩压器组成的模型级的内部流动进行数值模拟,以及对两种扩压器的流场分布和性能进行了分析。试验结果表明:采用机翼形扩压器相比楔形扩压器,气动性能得到明显提高。 相似文献
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对某离心式压缩机小流量级的内部流动情况采用了三维粘性流场进行数值模拟。通过对其整级,特别是无叶扩压器和回流器内部流场进行了分析探讨,提出了无叶扩压器、弯道和回流器的改造方案,使其优化后的级多变效率在各个工况下均有所提高。 相似文献
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对由半开式叶轮和叶片扩压器组成的离心压缩机模型级内部的流动进行了数值模拟,分析了叶轮与叶片扩压器内部的流动情况及相互影响。结果表明,用半开式叶轮代替模拟级中的闭式三元叶轮后,流动情况严重恶化,级出口静压系数降低;与无叶扩压器相比,叶片扩压器使级出口压力系数升高。在相同叶轮出口速度下,叶片扩压器比无叶扩压器中气流速度下降迅速,叶轮出口处平均流场趋于均匀。 相似文献
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叶片扩压器内跨盘—盖流场的实验研究 总被引:1,自引:1,他引:1
采用三孔探针沿叶片扩压器轴向测量了跨盘-盖流场,获得了叶片扩压器内速度场和压力场跨盘-盖的分布特性,并分析了中、小流量时扩压器内流动的变化趋势。实验结果表明:叶片扩压器内流动是一个既扩压又均匀化的过程,随着流动向扩压器出口的发展,沿叶片吸力面侧低速流体区不断扩大,在小流量工况时靠近扩压器盘盖侧出现倒流,此时最容易引起离心压缩机工作性能失稳。 相似文献
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用数值模拟方法研究了某高压比斜流压气机级,并对最大效率工况点的扩压器内部流场进行了初步分析。结果表明,斜向扩压器的最大静压恢复系数为0.525,轴向扩压器为0.502;斜向扩压器叶片压力面附面层大面积分离,造成严重的气动损失,使得其总压恢复系数较低;轴向扩压器只在叶片吸力面出现部分附面层分离,总压恢复系数相对较高;经过一排斜向叶片扩压器和一排轴向叶片扩压器,气流流动方向与子午面的夹角总共扭转了大约50°,扭转角度过大因而附面层分离严重,是造成扩压器性能下降的主要原因。 相似文献
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针对通风机扩散器的导叶安装位置,利用COSMOS/FLOWORKS软件对扩散器内部流场进行模拟和数值分析,得到相应工况下扩散器的静压力系数C_p曲线、大气压力系数C_(pa)和效率η.分析得出导叶安装位置对扩散器性能影响的规律,为通风机扩散器的设计提供理论依据. 相似文献
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在级环境下采用遗传算法和人工神经网络对高压比离心压气机叶片扩压器叶片几何型线进行了多点气动优化设计。根据优化前后的计算结果,对优化前后叶片扩压器内部的流动特征进行了对比分析。优化结果表明,采用多点优化设计可以有效提高离心压气机的气动性能。 相似文献
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Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam turbine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal design of its structure without consideration of the wet steam condensing flow and the exhaust hood coupled with the front and rear parts. To better understand the aerodynamic performance influenced by the tilt angle of flow guide inside a diffuser, taking a 600 MW steam turbine as an example, a numerical simulator CFX is adopted to solve compressible three-dimensional(3D) Reynolds time-averaged N-S equations and standard k-e turbulence model.And the exhaust hood flow field influenced by different tilt angles of flow guide is investigated with consideration of the wet steam condensing flow and the exhaust hood coupled with the last stage blades and the condenser throat.The result shows that the total pressure loss coefficient and the static pressure recovery coefficient of exhaust hood change regularly and monotonously with the gradual increase of tilt angle of flow guide. When the tilt angle of flow guide is within the range of 30° to 40°, the static pressure recovery coefficient is in the range of 15.27% to 17.03% and the total pressure loss coefficient drops to approximately 51%, the aerodynamic performance of exhaust hood is significantly improved. And the effectiveenthalpy drop in steam turbine increases by 0.228% to 0.274%. It is feasible to obtain a reasonable title angle of flow guide by the method of coupling the last stage and the condenser throat to exhaust hood in combination of the wet steam model, which provides a practical guidance to flow guide transformation and optimal design in exhaust hood. 相似文献