engleski

Numerical Modelling in Wastewater Collection Systems Optimization

Planning, analysis and design of the sewage systems is almost inconceivable without the implementation of numerical modelling. Sophisticated models developed for that purpose are capable of simulating the generation and transport processes of wastewater flows inside the channel network comprising all of the system peculiarities. Flexible set of hydraulic modelling capabilities within numerical models discards the need for conventional methods in calculation and design of the sewage systems. Conventional concept is usually unable to describe the certain hydraulic conditions. Due to the simplicity of conventional calculation processes, the acceptance of overvalued security factors is often required resulting with over-dimensioning the whole system. Likewise, conventional concept including steady flow analyses is replaced with numerical model's capabilities to simulate dynamic conditions inside the system. Specific site conditions such as terrain configuration with slight slopes might require a need for large number of pumping stations just to lift wastewater to higher elevations inside the system or for pressurized segments with long pipelines. Thereby, identifying all dynamic processes in the model is of special concern, as well as, precise definition of time-varying input parameters (inflows, rainfall, control rules to simulate the operation of pumps, etc.). Retention capacity in storage units (pump stations) and pipelines by means of system capability to storage a certain amounts of wastewater in short periods of time must also be taken into consideration while optimizing the whole system. This paper analyses hypothetical example with layout and input values that describe real state conditions. The EPA Storm Water Management Model (SWMM) was chosen as competent tool for simulation processes. Detailed analysis of specific cases and its comparison with the results obtained by conventional methods has shown the importance of numerical modelling implementation in wastewater management optimization.

sewage systems; numerical modelling; SWMM; optimization

nije evidentirano