Calculating method for diameter of rotating wheel of reversible pump turbine

Abstract

The invention discloses a calculating method for the diameter of a rotating wheel of a reversible pump turbine. The calculating method can be used for calculating the diameter of a high-pressure side of the rotating wheel and the diameter of a low-pressure side of the rotating wheel, a simple calculating statistic formula for calculating the diameter of the rotating wheel of the reversible pump turbine is provided according to detailed research and analysis about correlations of diameters of rotating wheels of a plurality of pump turbines and parameters such as minimum head, minimum head flow, specific speed, rated output power of shafts of power generation motors, and the like. The calculating statistic formula for calculating the diameter of the rotating wheel of the reversible pump turbine provides the scientific and reasonable calculating method for the diameter of the rotating wheel of the reversible pump turbine, so that a designer can calculate and select the proper diameter of the rotating wheel without the aid of hydraulic model tests, labor and materials are saved, and efficiency is improved.

Description

technical field [0001] The invention relates to a calculation method for the diameter of a water pump turbine runner, in particular to a calculation method for the diameter of a reversible water pump turbine runner. Background technique [0002] In the prior art, the calculation of the diameter of the runner of the reversible water pump turbine mainly depends on the model test of the unit or the estimation of the unit flow rate according to the operating conditions of the turbine. [0003] (1) Determined by model test: According to the comprehensive model characteristic curve of the pump turbine unit in the same water head / lift section, after comprehensively considering the performance of the pump and the turbine, select the appropriate unit flow Q of the rated water head of the turbine 11 , and then calculate the diameter of the pump turbine runner according to the following formula: [0004] D 1 = [ ...

AI Technical Summary

Problems solved by technology

[0010] 1) Due to the limitation of the construction conditions of the energy storage power station, it is basically impossible to find the comprehensive model characteristic curve of the pump-turbine unit with the same head / lift. It is necessary to draw a new model comprehensive curve after repairing and testing the pump-turbine model based on the similar head / lift , so that the investment is greatly increased, and it takes nearly half a year of model testing time

This method is only suitable for the actual hydraulic design of the power station after the manufacturer bids or wins the bid, but in the engineering feasibility study design, there are many alternatives, so it is impossible to use this method

[0011] 2) This method can only calculate the diameter of the high-pressure side of the runner, but cannot calculate the diameter of the low-pressure side of the runner

[0018] 1) This calculation method selects the specific speed under the rated water head of the turbine working condition based on the statistical specific speed coefficient curves of different water head sections. On the one hand, the same statistical curve is used for the rated water head within a certain range, and there is a large error. On the other hand, The actual situation shows that for pump turbines with the same capacity and the same rated water head, if the minimum head is different, the diameter of the runner will be greatly different, but the calculation results according to the above method will be the same, and there will be a large error. accurate, impractical

[0019] 2) This method is purely to calculate the diameter of the runner according to the working condition of the turbine, but the working condition of the pump in the pumped storage power station is more complicated than that of the hydraulic turbine, and it is generally designed according to the working condition of the pump, that is, the performance of the pump is given priority. Generally, it is difficult to guarantee the working condition performance of the pump, and the calculated diameter cannot well meet the requirements of the working condition of the pump.

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