| The Yellow River Diversion Project in Shanxi Province is an important project in the construction of the "Twelfth Five-Year Plan" in Shanxi Province,mainly to solve the unbalanced development of water resources imbalance in Shanxi Province.Engineering from the upper reaches of the Yellow River Bridge water,through the pumping station water,the water resources to open channels,tunnels,inverted siphon,dark culvert and other forms to the water supply area.The water supply project includes the water supply tunnel of the bridge after the water supply and the water pump project after the tunnel.The water supply project is an open water supply system,which the need for open channel and pressure pipe combined with the form of open channel in the unsteady flow is mostly due to the gate opening and closing and other human factors,in order to meet the needs of the actual water supply,the need for water The process of the transition process to determine the system when the non-constant flow water level,flow,velocity,water depth and other hydraulic elements along the process and the law of change over time.In the long-distance water operational control mechanics numerical simulation of unsteady flow simulation,analysis of hydraulic characteristics of the process of transition elements,for water system and equipment selection and maintenance are of great significance.This paper mainly studies the hydraulic transition process of the pumping station in the central Yellow River Diversion Project and the transition process of water level and flow in the open channel.The concrete study is as follows:(1)The study of water intake project,focusing on the pump station accident shutdown is the pump after the first end of the valve and the inlet pressure is too large problem,the use of characteristic line method,the establishment of the pumping station water hammer transition process calculation model.At the same time,combined with the project general situation,established the setting model of two stage pumping station outlet valve,in order to reduce the model after the pump valve head and inlet pressure as the objective function,to close the angle valve two stage and slow closing time for setting variables,constraint conditions and corresponding to the setting of the two stage valve,determine the minimum value of the objective function,and then reduce the tuning step further tuning.The results show that when the 6s setting fast turn 72 degrees,18 degrees 17s slow closing valve after the pump,the head pressure is 345.33m,inlet pressure is 88.0m,the maximum speed is 1.04 times of reverse pump rated speed,the best tuning results.(2)To study the water conveyance project1)We first study the transition process of the single-dimensional open channel,from the mechanism of the solution of the unsteady flow of the channel Saint-Venus partial differential equation,the preparation of the program to get the boundary conditions caused by changes in flow and water level changes in the data,The data into the system identification toolbox,identify the transfer function can be used as a canal model;at the same time the channel object modeling,the use of identification of the channel transfer function to build a channel model control chart,adjust the control parameters to be corresponding water level change value.2)Secondly,we study the multidimensional open channel,and use the San Weinan equation from the mechanism to form the mathematical model of the channel operation control,and then convert the mathematical model into the state space model.A single MPC controller performs the overall control to obtain the corresponding simulation results.But for a large matrix with a single controller to control will have a greater error,is not conducive to adjust the controller opening degree of the shortcomings of the use of decentralized predictive control for large matrix channels in accordance with the number of controllers to disperse,the use of(DMPC)theory and centralized(CMPC)dispersion theory,the relative good results are obtained. |
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