灯泡贯流式水轮机协联关系及性能研究

发布时间：2018-06-18 08:38

本文选题：灯泡贯流式水轮机 + 协联关系　；参考：《兰州理工大学》2014年博士论文

【摘要】：小水电约占我国水电装机及发电量的30%,其中灯泡贯流式水轮机占一定份额。在设计阶段考虑到少弃水的因素,使灯泡贯流式水轮机的临界弃水点向低水头侧移动,导致运行偏离最优工况。另外其桨叶与导叶在运行中的均可调性,以及其低水头、大流量的特点,常常使真机协联不能最优,从而使得水轮机效率低、稳定性差。一直以来,灯泡贯流水轮机协联关系的科研是从设计角度出发、基于水轮机模型试验的研究,而从实际运行角度出发,基于真机协联关系的研究,在理论上一直没有得到很好的解决,而且在真机协联关系发生变化的过程中,水轮机内部流场的运动特性、动力特性、内部漩涡变化机理,以及与灯泡贯流水轮机协联关系外特性性能的内在规律,很少有人做过深入研究,实际上这些问题时刻影响着水轮机效率及稳定性,故研究灯泡贯流式水轮机的协联关系及性能对于提高机组效率及稳定性具有非常重要的意义。本文以灯泡贯流机组为研究对象,进行了7-9m水头区间的水轮机协联关系及其性能研究。本文主要研究工作：首先,在原水轮机模型试验成果的基础上,进行了协联工况的计算策略研究,得到计算真机协联关系。然后,对协联工况的水轮机内部流场的运动特性、动力特性、内部漩涡变化机理进行研究,针对流场不稳定流动进行水轮机流固耦合计算。最后,通过真机协联试验,对计算与分析结论进行验证,并在此基础上对水轮机协联工况及优化运行进行预测及应用。通过研究得到求取灯泡贯流式水轮机真机协联关系的理论研究方法,解决了设计协联失真的缺陷；得到7-9m水头灯泡贯流式水轮机协联关系、出力、效率、流量等特性曲线；通过对协联工况的动力特性研究发现：在定常流场下,叶片根部流动分离的程度、全流道流场速度、以及其叶片正背面压差均随协联外特性参数按规律变化,非定常流场下,得到前流道、转轮、尾水管内流向涡涡核Hn随协联工况的变化规律,其规律也是外特性参数变化的内部机理；通过协联工况的运动特性研究发现：非定常流场下全流道不同部位流向涡演变周期不同,导致了水轮机各部位的不同振型,此为水轮机协联工况振动的内部变化机理；依据以上研究成果准确预测了灯泡贯流水轮机7-9m水头的全协联工况,设计了灯泡贯流式水轮机基于协联工况的机组优化运行方案,试验验证此优化设计正确、可行。
[Abstract]:Small hydropower accounts for about 30 percent of the installed and generated electricity in China, among which bulb tubular turbine accounts for a certain share. In the design stage, the critical water disposal point of the bulb tubular turbine is moved to the low head side, which leads to the deviation from the optimal operating condition. In addition, its blade and guide blade can be adjustable in operation, as well as the characteristics of low head and large flow rate, which often lead to the failure of the real coalitions, which makes the turbine low efficiency and poor stability. For a long time, the research on the relationship between bulb turbine and turbine is based on the model test of the turbine from the design point of view, and the research on the relationship between the real turbine and the turbine from the point of view of actual operation. In theory, it has not been solved well, and in the course of the change of the relationship between the real engine and the joint, the motion characteristics, the dynamic characteristics, the internal whirlpool change mechanism of the turbine internal flow field, As well as the inherent law of the external characteristics of the relationship between the bulb turbine and the bulb turbine, few people have done in-depth research. In fact, these problems affect the efficiency and stability of the turbine at all times. Therefore, it is very important to study the coconnection and performance of bulb tubular turbine to improve the efficiency and stability of unit. In this paper, the relationship and performance of turbine coconnection between 7 and 9 m water head are studied with bulb tubular unit as the research object. The main research work of this paper is as follows: firstly, based on the model test results of the original turbine, the calculation strategy of the coworking condition is studied, and the true cocoupling relationship is obtained. Then, the kinematic characteristics, dynamic characteristics and internal vortex variation mechanism of the turbine are studied, and the fluid-solid coupling calculation is carried out for the unstable flow field of the turbine. At last, the results of calculation and analysis are verified by the test of the real machine, and the prediction and application of the coworking condition and the optimal operation of the turbine are carried out on this basis. Through the research, the theoretical research method of calculating the true cocoupling relation of bulb tubular turbine is obtained, and the defect of design cocoupling distortion is solved, and the characteristic curves of 7-9m bulb tubular turbine, such as output force, efficiency, flow rate and so on, are obtained. It is found that the degree of flow separation at the root of the blade, the velocity of the flow field in the whole channel and the pressure difference between the blade and the back of the blade vary according to the law of the parameters of the external characteristics of the cocoupling under the steady flow field, and under the unsteady flow field, the dynamic characteristics of the cocoupling are studied. The variation law of vortex core H _ n in front runner, runner and draft tube with coworking condition is obtained, which is also the internal mechanism of the change of external characteristic parameters. It is found that the different flow direction vortex evolution cycles of different parts of the flow channel under unsteady flow field lead to different modes of vibration of each part of the turbine, which is the internal variation mechanism of the vibration of the turbine under the combined working condition. Based on the above research results, the full coconnecting condition of the 7-9m head of the bulb tubular turbine is accurately predicted, and the optimal operation scheme of the bulb tubular turbine is designed based on the co-connected working condition. The experimental results show that the optimization design is correct and feasible.
【学位授予单位】：兰州理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TK730

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