Erosion Analysis Of Y-type Diversion Bifurcated Pipe Of Hydropower Station Based On DPM

At present,many medium and high water head diversion hydropower stations use the mode of "one pipe and several machines".As an important part of the diversion system,bifurcated pipe is of great importance to its structure and safety.Erosion wear,as one of the main destructive factors of pipelines,should be paid special attention to.In view of water and soil losses in most rivers of China during flood season,the water flow and sediment content in the diversion system of power plant is large,which results in erosion and wear of complex bifurcated pipes to varying degrees.At present,the research on erosion and wear of pipeline is mainly focused on Petrochemical field,but there is little research on water conveyance pipeline,especially on steel bifurcated pipe of large-diameter hydropower station.Taking an asymmetric Y-shaped bifurcated pipe in the diversion system of a "one pipe,two machines" diversion power plant in the middle and lower reaches of Lancang River as the actual research object,this paper carries out three-dimensional modeling of the bifurcated pipe and uses DPM(Discrete Phase Model)Multiphase flow discrete phase model,which calculates the opening state combinations of different units under design conditions,analyses the velocity distribution,pressure distribution and erosion characteristics in pipes.The influence of flow rate,sediment mass flow rate and rib width ratio of crescent rib in bifurcated pipe on erosion is also discussed.The trend of average erosion rate with each influencing factor is obtained by calculating the average erosion rate.The results show that the main erosion area of Y-shaped bifurcated pipe is around the rib of the bifurcated section;the average erosion rate of the pipe wall increases with the increase of flow rate and sediment mass flow rate;the average erosion rate and maximum erosion rate are both the highest when the rib width ratio is 0.40 in the calculation range,and the erosion wear of the pipe wall is the most serious.The results of this study can provide a reference for pipe design and maintenance,engineering application and further study on erosion and wear of subsequent bifurcates.