The structure of large-scale shaft tubular pumping station is complex, the structure and size of each pouring block are different, and the temperature control index is also different. Especially in summer construction, it is very difficult to control temperature and prevent cracks. For different structural parts, refined peak clipping strength index should be adopted. In this paper, the equivalent cooling algorithm was used to simulate the peak-cutting intensity of cuboid pouring block under different water pipe layout, water temperature and water flow rate with different hydration heat inhibitor dosage and without hydration heat inhibitor. Then a series of quantitative formulas were put forward. According to the dosage of hydration heat inhibitor and peak-cutting intensity index, the layout density and water flow rate of cooling water pipes with corresponding water temperature can be calculated with these formulas. The results can provide quantitative reference for the establishment of temperature control measures for similar pumping stations constructed in high temperature season.

In order to study the temporal and spatial evolution characteristics of internal dynamic response and energy transfer of fresh concrete under the action of surface vibration load, a laboratory vibratory plate compaction test of fresh concrete was carried out. Real-time dynamic response characteristic parameters were obtained by acceleration sensors at different buried depths in the compaction process of vibrated concrete. The vibration signal was denoised by wavelet threshold denoising method. The temporal and spatial evolution law of internal motion energy of fresh concrete was analyzed by measuring point acceleration response. The results show that the aggregate particles near the surface vibration source mainly move vertically, and the surface of fresh concrete is obviously settled on the macro scale. With the increase of burial depth, the internal particles at the far end cannot get enough vibration energy, so it is difficult to overcome the extrusion force between particles and the friction resistance in the medium and maintain the initial equilibrium state, which is less affected by vibration. The vertical acceleration of internal particles is greater than the lateral acceleration during the vibration compaction of fresh concrete. With the increase of the compaction degree of fresh concrete, the vertical acceleration amplitude first decreases and then basically remains unchanged, while the lateral acceleration amplitude first decreases and then slightly increases. The vibration energy attenuation of concrete near the vibration source is the largest, but it is not significant with the increase of buried depth. The work in this paper can provide reference for the theoretical construction and in-depth study of vibration compaction of fresh concrete.

Dynamic strength is an important parameter for dam stability and safety analysis, which is of great significance to engineering design. Variable amplitude cyclic loading and unloading test was carried out to explore the effect of different confining pressure and cement content on the dynamic stress-strain relationship of cemented sand gravel (CSG) material by large dynamic triaxial instrument. Based on the Mohr Coulomb strength criterion, the evolution law of dynamic strength parameters of CSG materials during plastic deformation was studied by taking the dynamic strain as the plastic internal variable. The results show that the dynamic cohesion and dynamic internal friction angle increase with the increase of cement content. As the dynamic strain increases, the dynamic cohesion decreases rapidly, the dynamic internal friction angle increases, and the friction force generated by the shear slip between the aggregates dominates. When the peak dynamic stress is reached, the effective stress surface between aggregates decreases obviously, the dynamic cohesion decreases gently, the dynamic internal friction angle decreases with a certain hysteresis. The law of dynamic cohesion with dynamic strain conforms to the power function relationship. The law of dynamic internal friction angle and dynamic strain change conforms to the quadratic function relationship. The research results can provide a theoretical reference for the optimization of seismic design of CSG dam.

Taking a reconstruction canal section in Zuncun Irrigation District as the research object, this paper studied the sediment transport characteristics and scouring and silting change law of the canal. The causes of channel siltation were analyzed by sampling suspended matter, bed sand and measured velocity. The results show that the most serious siltation occurs at the head of the canal, and the siltation during the water shut-down period is an important factor causing the siltation of the canal. The flow rate of sediment carrying under each water conveyance condition is given, which provides the basis for the reduction of siltation and the efficient operation of the irrigation area in the future.

In order to solve the problem of benefit sharing amount, a quantitative model was established, and a case study was conducted on the application of the model and the corresponding benefit distribution ideas. The results indicate that the stakeholders of hydropower development projects mainly include the central government, local governments, hydropower enterprises and reservoir immigrants, and the net present value method can be used to construct the benefit sharing model, in which the stakeholders take the product of the sum of the present value of net cash flows of hydropower projects and their input shares as the sharing amount. The grey prediction method was used to solve the model. The case of Xiluodu Hydropower Station proves its rationality. It is suggested to establish a development fund for immigrants and safeguard the interests of other parties to open up a new situation of co-construction and win-win of hydropower development.

Taking the mixed-flow pump turbine as the research object, a fully elliptical volute was designed, which could meet the working conditions of the turbine and the pump. The ratio of the length and short half axis of the elliptical section of the volute was guaranteed to be fixed. The worm shell was designed by its outlet circumferential velocity and the circumferential velocity moment of each section, and the relationship between the size and flow rate of each section of the volute was given. Through CFD numerical simulation, the variation law of the circumferential velocity of the volute outlet and the circumferential velocity moment of each section was obtained. The distribution law of the velocity and pressure inside the volute was summarized, and the simulation results meet the design requirements, which has high practical application value.

The flow channel model and the shafting model of the turbine unit were established, and the fluid-solid coupling method was used to analyze the dynamic characteristics of the shafting system vibration of turbine unit induced by hydraulic factors under the steady-state conditions with different loads. The measured data were compared to verify the feasibility of the method. And then the correlation mechanism between the vibration characteristics and the internal flow characteristics under typical steady-state conditions was studied. The results show that the vibration characteristics of the guide bearing obtained by this method are basically consistent with the experimental values, and the trend of vibration changes with the change of load is consistent. Due to the positional relationship, the vibration characteristics of the water guide bearing and the upper guide bearing have a certain amplitude difference. The horizontal vibration amplitude of the unit is the largest due to the obvious vortex belt in the draft tube when running at 75% load condition. The research results can provide a scientific reference for the stable operation of hydropower turbine units under different loads.

A turbine runner of a certain power station often produces cracks due to excessive blade stress, which threat to the safe operation of the unit seriously. To solve the problem of the turbine runner blade stress, based on RNGk- ε turbulence model, the modeling and mesh of turbine components were carried out for a bulb tubular turbine. Through the runner blade thickening and angle optimization, CFD technology was used to optimize runner hydraulic performance and strength comparative analysis. The results show that the stress and deformation of the optimized runner blade are greatly improved, which meets the actual engineering needs and can effectively avoid the generation of runner cracks.

In view of the serious cavitation erosion and local cracks of water turbine runner after the capacity expansion and transformation of four runners in Shangyoujiang hydropower station in 1998, JF3057 turbine runner with excellent hydraulic performance was developed through numerical analysis and optimization design in 2017 for the innovation of unit ^#2 of the power station. The measured results of the prototype turbine after innovation show that the new runner has greater output and higher efficiency, and the vibration and the shaft runout are normal, but strong noise and metal roar within a certain load range exist in the turbine. In 2018, the strong noise and metal roar were basically eliminated after the blade outlet edge modification. After 5-year operation test and periodic inspections of the runner, the cavitation phenomenon of the new runner has been greatly improved, and the transformation of No. 2 turbine has been successful.

In order to solve the current situation that hydraulic turbine fault diagnosis relies excessively on expert experience and has low efficiency, the historical data of hydraulic turbine fault and relevant expert experience were used to establish the fault tree model for seeking the mapping between risk hidden danger and fault diagnosis. Through the conversion of fault tree model and Bayesian network model, the probability importance and sensitivity of root node were deeply studied by using the reverse diagnosis technology of Bayesian network. Hydraulic turbine components and fault causes were inferred to realize the fault diagnosis.