Research On Optimization Design Of Rainwater Storage Tank Based On Sponge City

In recent years,with the increasing urbanization rate in our country,the original rainwater drainage pipe network in the city has been overloaded,and serious water logging problems have occurred in many cities.At the same time,our country has been increased the attention of controlling water environmental pollution.In the municipal rainwater pipe canal,a certain scale rainwater storage tank is set in municipal rainwater pipes can effectively control non-point source pollution and reduce peak flow.Therefore,it is necessary to study the optimal design of rainwater storage tank and reasonably determine the design scheme of rainwater storage tank.The thesis have expounded that the optimal design basis of runoff pollution control and peak flow reduction in the city comprehensively,including the pollutant scouring law of rainfall runoff,the calculation method of initial rainfall amount,and the inference formula method of pipe design flow.Then,the thesis has introduced that the classification,function,layout and design position of conventional rainwater storage tanks,and the calculation formula for controlling non-point source pollution and reducing the volume of rainwater storage tanks are summarized,which provides theoretical basis and guidance for the follow-up research.For the rainwater storage tank of controlling non-point source pollution.A nonlinear integer programming model is established,which takes the minimum cost of storage tank as the objective and the reduction rate of non-point source pollution as the constraint,the particle swarm optimization algorithm is used to solve the problem.The process of particle swarm optimization is realized by programming with MATLAB.It is concluded that the effect of different non-point source pollution reduction rate on the setting mode and scale of rainwater storage tank is not alike.When the non-point source pollution reduction rate is less than 60%,the centralized rainwater storage tanks should be adopted.When the reduction rate of non-point source pollution is more than or equal to 60%,it is advisable to adopt dispersed rainwater storage tanks.For the rainwater storage tank of reducing the peak flow,a nonlinear integer programming model is established,which takes the minimum cost of stormwater system as the objective and the design parameters of storm sewer as the constraints,and solved by particle swarm optimization algorithm.The calculation results of an example show that the optimal design of rainwater storage tank with reduced peak flow can effectively reduce the stormwater system cost,and its setting mode and quantity have great impact on the total cost of rainwater system.The total cost of scheme with three storage tanks set up can be saved by 16.96% compared with that of no storage tank.It is proved that these models can determine the design scheme of rainwater storage tank to control runoff pollution and reduce peak discharge reasonably.