| Yizhuang regulating pool is one of supporting projects of South-to-North Water Diversion Projec in Beijing,and is water control pivot that connects the East Canal project and South Canal project.Its main function consists of water diversion,water storage,and as a forebay of Yizhuang pumping station.Yizhuang regulating pool project is located in southeastern of Beijing,east of Daxing District Nanhaizi country park and San Hai Zi Dong Lu,and north of Huang Yi Lu.Major constructions of the projects include Yizhuang regulation pool,Yizhuang pumping station,Yizhuang waterworks intakes,Yongle waterworks intake,connectivity of gates,regulating pond inlet pipe,regulation pool return water,life management and police base etc..In order to ensure the stable operation and safety of water supply,the difference influences casued by different design conditions for Yizhuang regulating reservoir must be fully analyzed.The flow characteristics of Yizhuang Regulating reservoir is comprehensively investigated by physical model,including the normal operation conditions of regulation reservoir,accident conditions of South-to-North Water Diversion Project and loop pipeline.According to each operation condition,the variation of flow pattern,flow rate and water level of regulation reservoir for both water inlet and water intake pump station,both Yongle waterworks intakes and Yizhuang waterworks intakes are analyzed.The operation management of both pump station intakes and waterworks intakes are also analyzed and suggested;the energy loss at both trashrack of pump station intake and waterworks intakes are observed and analyzed as well.Throughout the physical model study,the following main conclusions can be drawn:(1)There is no adverse water flow pattern near the water intakes,and no adverse impact occurs on water efficiency of pump and buildings;(2)The maximum flow velocity at intakes appears at the edge of the pool,which ia about less than 1m/s.The velocity distribution at the water intake section is relatively uniform,and no adverse effect on the water intake of the pumping station.(3)The water level near the intakes is very stable,no disadvantage factors exist.(4)When the pumping water intakes operate in the low water level of regulation pool,it is recommended to open the pump as even as possible in order to keep the pump station forebay good flow pattern.As for the recent flow rate,it is recommend that the pump of Yizhuang waterworks intakes and Yongle waterworks intakes be operated either centralized or decentralized.(5)Trash racks inherent energy loss is relatively small.During the operation,it should pay more attention to clean up trash rack in time in order to ensure trash rack at good working conditions. |
