Simulation and optimisation of the waste water flow in urban sewer network

摘要

The irregular loading of waste water treatment systems is determined by the non-uniformity of dwelling and industrial sewers. Only industrial sewers can be controlled to regulate the total amount of waste waters received in the treatment system. To carry out such regulation it is necessary to take into account the enterprises' locations, pipe parameters and sewer system configurations. The computer model of the uniaxial liquid flow is based on a system of non-linear equations in partial derivatives with corresponding initial and boundary conditions. To solve this problem the finite - difference method is applied here. Two approaches are compared: the linearized system of the nonlinear equations and Newton's method. Areas of stability and convergence of both numerical solutions are estimated. The problem of modelling the dynamics of a liquid flow in a system of pipelines is also formulated. The objective function is determined as the remainder between the highest and lowest wastewater levels, i.e. non-uniformity of the loading of waste water treatment systems. The defined optimum solution shows that the non-uniformity of the fluid inflow in the cleaning structures can be reduced by one half.