共查询到19条相似文献,搜索用时 312 毫秒
1.
2.
3.
贯流式水轮机是开发低水头水能资源和潮汐能的最佳机型,文章结合我国南方某贯流式水电站的建设,介绍了大型贯流式水轮机组结构特点和安装技术,用3Ds max实现了贯流式水轮机组安装工艺的可视化,对同类机组的安装有指导意义。 相似文献
4.
超低水头轴流式水轮机CFD优化及流动特性研究 总被引:1,自引:0,他引:1
结合某水电站改造要求,研发了一种设计水头为2.75 m的超低水头轴流式水轮机并对其性能进行优化,以达到有效利用低水头水力资源的目的。基于不可压缩连续方程及雷诺时均Navier-Stokes方程,采用Spalart-Allmaras湍流模型和SIMPLEC算法对轴流式水轮机进行三维全流场数值模拟,分别分析了轴流式转轮叶片翼型、轮毂比、导叶开度及安放角对水轮机性能的影响,并对最优模型进行实测验证。结果表明,在满足设计水头为2.75 m的情况下,选用配置叶片B、轮毂比为0.30、叶片相对安放角为-2°的水轮机,当导叶相对开度为0°时,装置水力损失最小,最高效率达83.7%,且数值模拟计算所得出力与实测结果误差小于099%,表明基于CFD的数值模拟对超低水头轴流式水轮机的性能预测精度较高。 相似文献
5.
6.
《水电能源科学》2021,39(7):154-158,98
基于STAR CCM+软件,对贯流式水轮机全流道进行三维非定常数值模拟,研究不同水头工况下贯流式水轮机的内部流动特性及压力脉动特性。结果表明,贯流式水轮机内部压力脉动主要受到叶片通过频率(10Hz)和低频压力脉动的影响,在转轮进口和无叶区处,水轮机压力脉动主要由转轮旋转引起,在尾水管进口处,压力脉动既有低频压力脉动也有高频压力脉动,在尾水管中间,压力脉动受低频压力脉动影响;随着水头的变化,转轮中心截面上的压力和速度变化呈周期性分布;尾水管管壁流速随着水头的增加逐渐减小,尾水管中低频压力脉动频率较高,截面上的漩涡较大,当水头达8.6m时,尾水管进口处的漩涡逐渐减小,流态较好。 相似文献
7.
水轮机的选型设计在水电站设计中至关重要。依据国内近十年来投产的大中型混流式水轮机设计资料,采用非线性回归统计方法统计分析了混流式水轮机比转速与额定水头之间的关系,得到了不同水头段、不同单机容量时比转速与额定水头间的统计公式,并绘制了置信区间和预测区间。所得结果对混流式水轮机的选型设计具有一定参考价值。 相似文献
8.
9.
为探究低水头混流式水轮机尾水管扩散段底板抬起角对其性能的影响,结合西南某水电站增效扩容项目,在保证尾水管扩散段上下面角度不变的前提下,拟定了两套扩散段底板抬起角方案,利用相关软件建立了高效区内导叶开度为35°时水轮机的水体模型,并对其进行了流场数值模拟。结果表明,尾水管扩散段底板抬起角对水轮机效率影响不大,对水轮机出力和尾水管回能系数影响较大;随着底板抬起角的增加,相同水头下水轮机出力逐渐减小;在低水头(小流量)时,有适当的底板抬起角比没有时更有利。 相似文献
10.
11.
通过数值模拟等手段开发了一种双级贯流式超低比转速水轮机,利用循环冷却水出口的富余能量推动水轮机转动带动风扇旋转制冷,以达到节能目的。以富余流量0.823 m3/s的水轮机为例,以Fluent软件为平台进行计算分析,对双级贯流式超低比转速水轮机的叶片、导叶形式及其安放位置进行了优化,并采用Navier-Stokes方程、SIMPLEC算法对水轮机进行全三维湍流数值模拟,获得了水轮机内部流动细节,预估了水轮机的性能。计算结果表明,优化后的叶片及导叶表现出较高的效率。 相似文献
12.
13.
Bi-directional turbines combined with rotary motors may be a feasible option for developing high power thermoacoustic generators with low cost. A general expression for the acoustic characteristics of the bi-directional turbine was proposed based on theoretical derivation, which was validated by computational fluid dynamics modeling of an impulse turbine with fixed guide vanes. The structure of the turbine was optimized primarily using steady flow with an efficiency of near 70% (the shaft power divided by the total energy consumed by the turbine). The turbine in the oscillating flow was treated in a lumped-parameter model to extract the acoustic impedance characteristics from the simulation results. The key acoustic impedance characteristic of the turbine was the resistance and inertance due to complex flow condition in the turbine, whereas the capacitance was treated as an adiabatic case because of the large-scale flow channel relative to the heat penetration depth. Correlations for the impedance were obtained from both theoretical predictions and numerical fittings. The good fit of the correlations shows that these characteristics are valid for describing the bi-directional turbine, providing the basis for optimization of the coupling between the thermoacoustic engine and the turbine using quasi-one-dimensional theory in the frequency domain. 相似文献
14.
15.
Paolo Gobbato Massimo MasiAndrea Toffolo Andrea Lazzaretto 《International Journal of Hydrogen Energy》2011,36(13):7993-8002
The interest for hydrogen-fuelled combustors is recently growing thanks to the development of gas turbines fed by high content hydrogen syngas. The diffusion flame combustion is a well-known and consolidated technology in the field of industrial gas turbine applications. However, few CFD analyses on commercial medium size heavy duty gas turbine fuelled with pure hydrogen are available in the literature. This paper presents a CFD simulation of the air-hydrogen reacting flow inside a diffusion flame combustor of a single shaft gas turbine. The 3D geometrical model extends from the compressor discharge to the gas turbine inlet (both liner and air plenum are included). A coarse grid and a very simplified reaction scheme are adopted to evaluate the capability of a rather basic model to predict the temperature field inside the combustor. The interest is focused on the liner wall temperatures and the turbine inlet temperature profile since they could affect the reliability of components designed for natural gas operation. Data of a full-scale experimental test are employed to validate the numerical results. The calculated thermal field is useful to explain the non-uniform distribution of the temperature measured at the turbine inlet. 相似文献
16.
17.
This paper describes the numerical simulation of three-dimensional viscous flows in fir-cooled turbine blade rows with the effects of coolant ejection. A TVD Navier-Stokes flow solver incorporated with Baldwin-Lomax turbulence model and multi-grid convergence acceleration algorithm are used for the simulation. The influences of coolant ejection on the main flow are accounted by volumetric coolant source terms. Numerical results for a four-stage turbine are presented and discussed. 相似文献
18.
汽轮机直齿与斜齿汽封内部流场的数值计算与结构优化 总被引:1,自引:0,他引:1
利用数值计算软件对汽轮机光轴直齿与斜齿两种结构的迷宫式汽封内部流场进行了数值研究,给出了汽封内部流动特性和漏汽量随相对齿间距和齿倾斜角度变化的规律.在汽封段轴向长度一定和相同的流动条件下,存在最佳齿数范围和倾角范围,它可使迷宫式汽封的漏汽量最小. 相似文献