The invention discloses a Francis turbine with long and short blades, which comprises a spiral case, a guide vane area, a runner and a draft tube connected sequentially across the river basin, in which the runner blade is composed of several long blades and short blade spacing, the elliptical section length ratio of the spiral case is golden section ratio, the guide vane profile is a crescent shape with negative curvature, and the runner blade is composed of long and short blades, and the short blade is the same. The diameter difference ratio between the inlet and outlet of the blade and the long blade is 0.859. A rectifier plate is arranged in the conical draft tube. The invention aims at realizing the efficient utilization of water flow energy, improving the working efficiency of hydraulic turbines and improving the operation stability of units, has broad application prospects and popularization value, and is of great significance to the transformation of small hydropower stations and the improvement of operation stability of units in various power stations in China.
【技术实现步骤摘要】
一种混流式长短叶片水轮机
本专利技术属于水力机械
,特别是涉及一种混流式长短叶片水轮机。
技术介绍
环境是人类社会生存和发展的基本前提,随着人类环保意识的增强及可持续发展战略的实施,火力发电逐渐受到制约,另一方面新能源技术不成熟阻碍了诸如风力、太阳能及核电的发展。相对而言,技术成熟的水力发电备受青睐,且水资源是可再生绿色能源。水利发电的关键在于机组性能,主要指标包括对水流能的利用效率,关系到机组安全运行及寿命的稳定性能和空化性能,归根结底影响上述指标的原因在于水轮机内部流场特性。具有良好运行性能的水轮机不仅能够满足当下小水电改造的需求,亦是国内外各水电站发展的必然趋势。现有混流式水轮机转轮多为长度一致的叶片,叶片个数较多致使转轮出口叶间距较窄容易产生空化现象,而叶片偏少导致转轮进口叶间距过大,极易产生涡旋引起流场不稳定。水轮机中长短叶片的设置,使得叶片总数量增多,从而单叶片应力负荷减小,增强了转轮的整体强度性能。中国专利申请201710822929.6公开了一种长短叶片的双击式水轮机转轮,其叶片结构简单、运行维护方便,但存在明显的结构设计不合理问题,诸如水流作用面积小,作功能力弱等。中国专利申请201310704054.1公开了一种混流式水泵水轮机,其采用了三种不同长度的叶片减小了二次流损失,但该方式叶片组成结构复杂,加工安装成本高,且过窄的叶间距影响转轮过流能力,会进一步影响出力效果。综上所述,为提高混流式水轮机运行效率、稳定性及空化性能,改良机组转轮特性是时下国内外学者研究的热点方向,如何克服现有技术的不足,进一步改善或者消除流道内不稳定流态及其 ...
【技术保护点】
1.一种混流式长短叶片水轮机,其特征在于,该水轮机的过流域包括依次连接的蜗壳(1)、导叶域(2)、转轮(4)和尾水管(7);其中,转轮叶片由若干长叶片(6)和短叶片(5)间隔组成,转轮叶片为空间三维扭曲曲面,在转轮(4)的长叶片(6)高度方向位置上均分截取四个叶型曲面,该四个叶型曲面八条曲线拟合后方程如下:曲面Ⅰ:A:z=4597+81.21x+145.7y+0.3266x2+0.3919xy‑0.2027y2+3.783e‑04x3‑1.517e‑05x2y+4.088e‑04xy2‑1.088e‑03y3B:z=5736+103.5x+162.4y+0.4433x2+0.4431xy‑0.4343y2‑5.514e‑04x3‑6.234e‑05x2y+4.228e‑05xy2‑9.456e‑04y3曲面Ⅱ:C:z=‑4661‑41.54x‑41.52y‑0.1215x2‑0.1008xy‑0.0368y2‑1.162e‑04x3+6.523e‑07x2y‑2.538e‑04xy2+2.794e‑04y3D:z=47360+492.7x+377.6y+1.633x2+0.8231xy ...
【技术特征摘要】
1.一种混流式长短叶片水轮机,其特征在于,该水轮机的过流域包括依次连接的蜗壳(1)、导叶域(2)、转轮(4)和尾水管(7);其中,转轮叶片由若干长叶片(6)和短叶片(5)间隔组成,转轮叶片为空间三维扭曲曲面,在转轮(4)的长叶片(6)高度方向位置上均分截取四个叶型曲面,该四个叶型曲面八条曲线拟合后方程如下:曲面Ⅰ:A:z=4597+81.21x+145.7y+0.3266x2+0.3919xy-0.2027y2+3.783e-04x3-1.517e-05x2y+4.088e-04xy2-1.088e-03y3B:z=5736+103.5x+162.4y+0.4433x2+0.4431xy-0.4343y2-5.514e-04x3-6.234e-05x2y+4.228e-05xy2-9.456e-04y3曲面Ⅱ:C:z=-4661-41.54x-41.52y-0.1215x2-0.1008xy-0.0368y2-1.162e-04x3+6.523e-07x2y-2.538e-04xy2+2.794e-04y3D:z=47360+492.7x+377.6y+1.633x2+0.8231xy-0.2759y2-1.75e-03x3-5.929e-04x2y+1.862e-03xy2-2.808e-03y3曲面Ⅲ:E:z=-28730-222.2x-141y-0.585x2-0.354xy-0.0439y2-5.212e-04x3+1.347e-05x2y-8.291e-04xy2+1.099e-03y3F:z=7320+71.38x+9.083y+0.2279x2-0.02838xy-0.1483y2+2.428e-04x3-2.11e-04x2y+3.844e-05xy2-3.038e-04y3曲面Ⅳ:G:z=-71920-506.7x-167.6y-1.224x2-0...
【专利技术属性】
技术研发人员:毛秀丽,陈帝伊,李全武,毛高强,
申请(专利权)人:西北农林科技大学,
类型:发明
国别省市:陕西,61
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