The Research Of Combination Relationship And Performance Of Bulb Tubular Turbine

Small hydropower accounts for about30%of installed and power generation capacity of China’s hydropower. Among them, the share of the bulb tubular turbine is considerable. Considering of less abandoned water in the design,it prefer to move the critical abandoned water point of bulb turbine to the low head side, which leads to the deviation from optimal conditions. In addition, the blades and guide vanes are adjustable in operation, and the characteristics of the low water head and large flow, which often make the real machines combination is not optimal, so as to the turbine’s low efficiency and poor stability. For a long time, the study of the combination relationship of bulb turbine is based on the design and the research of turbine model test. While from the practical operation, the research of the association relationship of real machine research has not been solved very well in theory. And there has no in-depth research in the change process of association relationship of real machine, the internal flow field movement characteristics, the dynamic characteristics and internal vortex change mechanism of the turbine, as well as the Inherent law of the external characteristics of the association relationship of bulb turbine. In fact, these problems affects the turbine’s efficiency and stability, therefore, it is significant to study the association relationship of bulb tubular turbine and its performance to enhance the efficiency and stability. This paper researches the bulb tubular turbine combination relationship and its performance at the head of7-9m.The main research work of this paper: At first, it on the basis of the original water turbine model’s test results, researches the Computing strategy of the combination conditions, and got the association relationship of real machine. Then, it studies the internal flow field movement characteristics, dynamic characteristics and the internal vortex change mechanism. And it calculates turbine’s coupled fluid-structure in unstable flow. At last, it verifies this calculation and analysis of the results which associated with real machine test, and forecasts the turbine combination conditions and its optimizing operation and then applies it.This paper gets the research methods of the relationship of bulb tubular turbine, and solves the universal defect of the combination design. And it also obtained the bulb tubular turbine combination relationship, output, efficiency, flow characteristic curves at the head of7-9m.Through the study of dynamic characteristics it has found the flow separation in blade root, full port flow velocity, and the differential pressure of the blade were changed with external characteristic parameters of combination in the steady flow. And in the unsteady flow, the internal mechanism of the change of combination conditions in the front runners, runner and flow vortex Hn of draft tube has got. Besides, through the research on motion characteristics, it has been found that the evolution cycle of flow vortex is different at different positions of the full port in unsteady flow field, which leads to the different modes of vibration in different parts, this is the internal change mechanism of turbine vibration in combination conditions. Moreover, the water turbine full combination condition of7-9m head has predicted successfully based on the above research results, and optimizing operation scheme of combination conditions has got,as well as great benefit.