NESEI

NESEI is a software package comprising several partial programs used for the hydraulic simulation and analysis of water supply networks.

AutoCAD® by Autodesk® or BricsCAD® by Bricsys® can be used for plan-oriented, interactive graphical processing of the data and for creation and further processing of the simulation model. The data are managed in a Microsoft® SQL database. Simulation is done in the hydraulic program SUPERNET.

The simulation results are depicted graphically with the programs SURFER® by Golden Software and TIMWIN.

Furthermore, the simulation results can also be depicted in the form of hydraulic longitudinal sections.

The supply network data are managed in multiple generations which can be independently processed and modified. Working from the model of the existing network, copies can be edited and extended in order to optimize different variants and to keep the network at the latest state.

NESEI can be used to derive and verify network improvements from steady-state and dynamic simulations. There are multiple simulation modes available for this:

  • Steady-state simulation: Steady-state simulation is employed to simulate an instantaneous network state (e.g. medium, minimum or maximum load case)
  • Auto-dimensioning of the pipe diameters: Working from a deliberately undersized hydraulic model, an automated series of simulations can be run to determine adequate pipe diameters in order to ensure a specific maximum flow rate cannot be exceeded.
  • Time-step simulation: Every time-dependent load can be approximately replaced by a series of individual steady-state simulations (time steps). New initial conditions, load factors and valve parameters can be specified at the beginning of each individual steady-state simulation.
  • Propagation simulation: Starting from a result file from the steady-state simulation and several source nodes with defined initial concentrations and starting times, the combined propagation concentrations for inert materials (concentration does not diminish over time) and combined propagation times (transport times) can be calculated for the entire pipe network.

Applications of NESEI

NESEI is used for simulating water and gas networks.

Simulations:

  • Estimating pressure, throughput, inflow and outflow based on DVGW rules GW 303, G 464 and W 302; also derived parameters such as flow rate, pressure loss and pressure gradients
  • Simulation of dynamic conditions in flow networks. Based on given time series (e.g. for consumers, infeed) and certain operating cases (e.g. slider positions, fire outbreak, pipe burst), the time series for volumetric flows, network pressures, tank hydrographs (e.g. with initial water levels) and pump operation can be calculated from several subnetworks separated by controllers (pumps, sliders, flaps, check valves, shut-off valves, flow governors, pressure control valves or pressure reducers).
  • Network capacity analysis functions
  • Automatic calculation of extinguishing water quantities at hydrants
  • Light-load simulation
  • Comparison of flow direction between multiple simulation cases
  • Automatic calculation of superimposed networks (e.g. high/medium/low pressure)
  • Calculation of consumption distributions over the annual consumption calculation
  • Computer-aided estimation of feed requirements at consumer nodes based on mean daily consumption

Technical characteristics:

  • Provision of input data to create a network via a graphical user interface in a graphical information system (GIS) without simplification or network reduction
  • Changes within the network diagram are automatically adopted into the network database and vice-versa. GUI for reading information and making changes
  • Data transfer capability to and from other computing systems
  • Simulation of arbitrarily meshed networks
  • Presentation and calculation of building service lines
  • Automatic allocation of ha meters and buildings to network nodes
  • Network simulation with predefined elements (sliders, controllers, pumps, elevated tanks, heat exchangers, feeding plants etc.)
  • Interactive switching of sliders, controllers and pumps in the database and diagram, changing the outcome of the simulation
  • Object-related steering with defined attributes to produce various results
  • Arbitrary drawing of contour lines relating to node values (e.g. elevation lines, pressure lines etc.)
  • Calculation of inner pipe diameter from separately managed pipe type library
  • Saving of different simulation cases for a given network
  • Filing of extension and planning scenarios
  • Dynamic simulation of successive load cases with storage in tanks/pipelines/nodes and results presented in time diagrams

Database functions:

  • Consistent graphic and object-related data retention
  • Report generator for output of freely configurable lists
  • Numerical operations such as average, maximum, minimum and sum of numerical values (diameters, lengths, throughputs etc.)
  • Swap any data values
  • Content search (e.g.: names, or with conditions such as rate < limit, or general search conditions such as equal to, not equal to, less than or equal to, greater than or equal to, greater than, including, excluding etc.)
  • Delete objects
  • Rename node names
  • Sort by any value
  • Simultaneously filter by several linked fields with additional marking and sorting
  • Special functions, e.g.:
    • Filter
    • Sort
    • Global replace
  • Creation of groups, e.g. number of pipes of a certain rated diameter
  • Import variant data into inventory data