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| 基于转轮进口水流角的贯流水轮机最优工况应用 | |
| 引用本文： | 李正贵,魏显著,李凤臣,邓飞,张毅鹏.基于转轮进口水流角的贯流水轮机最优工况应用[J].农业工程学报,2015,31(14):83-89. |
| 作者姓名： | 李正贵 魏显著 李凤臣 邓飞 张毅鹏 |
| 作者单位： | 1. 哈尔滨大电机研究所水力发电设备国家重点实验室,哈尔滨 150040;南昌工程学院机电工程学院,南昌 330099 2. 哈尔滨大电机研究所水力发电设备国家重点实验室,哈尔滨,150040 3. 哈尔滨工业大学能源科学与工程学院,哈尔滨,150001 4. 南昌工程学院机电工程学院,南昌,330099 |
| 基金项目： | 江西省科技计划项目（20132BDH80022） |
| 摘 要： | 贯流式水轮机是农村小水电电网中的重要组成部分,其低水头、大流量的特点,易导致电站机组效率低下、出力降低。而贯流式水轮机运行中的最优运行问题很少引起学者关注,目前最优工况的研究仅仅局限于某点或线。该文从转轮水力损失的角度,理论上分析了影响贯流式水轮机效率的翼型阻力损失、端部损失与撞击损失,依据现场实际导叶与桨叶翼型,在定水头、定桨叶方式下,通过改变转轮进口水流角,对转轮进、出口速度三角形进行计算,从能量角度,进行工况优化,得到转轮10°工况下导叶在53.9°~58.8°的最优特性区域,效率可提高约3%~8%。利用数值仿真技术,对其工况做相应的数值仿真,并进行流场分析,在此基础上,进行真机试验,结果与理论分析相符,与数值仿真计算的误差小于2%,采用此方法对电站机组的全工况进行了计算,全工况范围内进行区域工况优化,得到转轮在7°~42°,导叶在0~78°的最优特性曲线,通过一段时间运行,数据显示机组的能量特性与稳定性效果比较理想。 |
| 关 键 词： | 贯流水轮机 流场 效率 数值仿真 转轮进口水流角 最优运行区域 应用 |
| 收稿时间： | 2015/3/26 0:00:00 |
| 修稿时间： | 5/4/2015 12:00:00 AM |
Based on turbine inlet flow angle of tubular turbine optimal working conditions research and apply |
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| Li Zhenggui,Wei Xianzhu,Li Fengchen,Deng Fei and Zhang Yipeng.Based on turbine inlet flow angle of tubular turbine optimal working conditions research and apply[J].Transactions of the Chinese Society of Agricultural Engineering,2015,31(14):83-89. | |
| Authors: | Li Zhenggui Wei Xianzhu Li Fengchen Deng Fei and Zhang Yipeng |
| Institution: | 1. State Key laboratory of Hydropower Equipment, Harbin Research Institute of Large Electrical Machinery, Harbin 150040, China; 2. Mechanical and Electronic School, Nanchang Institute of Technology, Nanchang 330099, China,1. State Key laboratory of Hydropower Equipment, Harbin Research Institute of Large Electrical Machinery, Harbin 150040, China,3. Energy Science and Engineering School ,Harbin Industry University, Harbin 150001, China,2. Mechanical and Electronic School, Nanchang Institute of Technology, Nanchang 330099, China and 2. Mechanical and Electronic School, Nanchang Institute of Technology, Nanchang 330099, China |
| Abstract: | Abstract: Tubular turbine is an important part of the rural small hydropower electrical net. Owing to the low water head and large flow quantity of tubular turbine, the efficiency of power station units as well as the output value is low. The actual operation efficiency of similar units varying from 3 to 5 blades from home and abroad is between 84% and 88%, which is far from meeting the corresponding design requirements. In addition, the current studies of optimal working condition of tubular turbines are limited to a certain operating point or curve. From the perspective of runner hydraulic power loss, the typical tubular turbines on the Yellow River are chosen as study objects in this paper. In the meantime, we have done theoretical analysis on the factors influencing the efficiency of tubular turbines, such as aerofoil loss of resistance, ends loss of resistance and impact loss of resistance. According to the actual shapes of blade and vane, with the water head of 8 m and the chosen blade angle of 10°, by changing the turbine inlet flow angle from 39.2 to 58.8°, the velocity triangles of the inlet and outlet positions are calculated. Based on this theoretical analysis, it turns out that the most stable operating range for tubular turbines is between 56.6 and 58.8°, and the non-optimal range is between 39.2 and 51.1°. The optimal range is also the area showing the highest efficiency. In order to verify the correctness of this analysis, CFX technology has been applied to carry out numerical simulation of the working condition of tubular turbines. During the process, we have taken the isometric model calculation and analysed the flow field. It is found that vortex and secondary flow appear in low efficiency and non-optimal range, which is very unstable and will generate great loss. The flow regime in the high efficiency range is relatively stable. This result on optimal operation range fits the outcome of theoretical analysis. Based on this, real machine experiments have been carried out, using the index method of relative efficiency test. By measuring the runner pressure difference, index flow has been calculated to substitute actual flow. Finally the relative efficiency and the output value of the turbine are calculated to pinpoint optimal efficiency. The result of real machine experiments accords with theoretical analysis. The error between simulation and real machine experiments is smaller than 2%. At last, by calculating the whole working condition of the targeted station units using this method, we have proposed the optimal operating area within overall working condition range and improved the actual efficiency by 6%. The pressure fluctuations have been significantly reduced. The effect is distinct after long-time operation. By expanding from point and line to area, the research method provides evidence for the design proposals of optimal working conditions of real machine experiment. This has rendered effective solutions for the safe and highly efficient operation of tubular turbines. |
| Keywords: | tubular turbines flow fields efficiency numerical simulation runner inlet flow angle optimal area of operating condition application |
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