Operation mode of valves in water conveyance system of North Ship Lock of Binhai hub
The North Ship Lock of Binhai hub is a permanent structure for navigation between Huaihe River and Tongyu River with the ship lock level of grade Ⅱ.The design of normal water level difference requires the water conveyance time to be 6~8 min.The design of high water level difference(5.99 m and 7.19 m head difference)requires the water conveyance time to be 9~12 min.The ship lock is subjected to two-way head action with the maximum forward water level difference of 7.19 m,and the maximum reverse water level difference of 1.91 m.To construct the ship lock the operation safety and water conveyance efficiency of the ship lock are the key technical problems to be solved.In order to ensure the safe and efficient operation along with providing technical references for the safe and reliable operation of the ship lock,the physical model test was used to study the hydraulic characteristics of the centralized water conveyance system of the North Ship Lock of the Binhai hub.According to the provisions and requirements of the"Design Code for filling and Emptying Systems of Shiplocks(JTJ 306-2001)"and the"Technical Code of Modelling Test for Port and Waterway Engineering(JTS/T 231-2021)",the weight and force scale of the original model was 27000,the flow velocity and time scale was 5.48,and the flow scale was 4 929.5.The overall physical model of the ship lock with a scale of 1∶30 was established.The side wall of the lock chamber,the water conveyance corridor and the inlet and outlet sections of the upper and lower lock heads were all made of polyethylene plastic plates.Reservoirs were set up in both upstream and downstream,and 2.3 m×2.5 m horizontal grooves were arranged in the reservoir to stabilize the upstream and downstream water levels.The hydraulic characteristics of the water conveyance process of the lock,the flow pattern in the lock chamber,the pressure change characteristics at the top of the water conveyance corridor and bollard force for ships moored in lock chambers under different valve opening time were analyzed by experiments,and the rationality of the overall layout design of the water conveyance system was verified.When the operating head was not greater than 5.99 m,the continuous opening time of the double-sided uniform speed of the filling valve is 7 min.When the operating head was greater than 5.99 m,the continuous opening time of the double-sided uniform speed of the filling valve is 9 min.In each operating water level combination,the continuous opening time of the double-sided uniform speed of the discharge valve is 7 min.When the upper lock head valve was continuously opened bilaterally for water filling for 6 to 9 min,the minimum instantaneous pressure at the top of the upper lock head water conveyance corridor was 2.57 mH2O.When the lower lock head valve was continuously opened bilaterally for water discharge for 6 to 9 min,the minimum instantaneous pressure at the top of the lower lock head water conveyance corridor was-0.26 mH2O.Under different water head conditions,the water level of the lock chamber rose and fell smoothly,the surface was calm,and there was no unfavorable flow pattern such as vortex and bubble vortex in the lock chamber,and as a whole flow pattern of the lock chamber was better.Under the recommended valve operation mode,the hydraulic characteristics of the lock,the pressure characteristics of the water conveyance corridor and bollard force for ships moored in lock chambers meet the specifications and design requirements.
North Ship Lockwater conveyance systemhydraulic characteristicsinstantaneous pressuremodel test