## Software modules for pipe network planning

### PSS®SINCAL

## Calculations for different pressure levels

PSS®SINCAL Gas calculates the flow conditions in meshed networks with different pressure levels. It is possible to perform steady-state as well as dynamic calculations. The effects of time events or time series on network performance can be displayed as a function of location in various graphs.

With the aid of dynamic simulation, it is possible to observe different states and changes of state in the network at certain times. In this way, it is also possible on the basis of predetermined time series (for consumers, supply, control, etc.) and time events (valve position, consumer shut-off etc.) to calculate values for quantities, flows and pressures in the network.

## Hydraulic calculations

The program can handle all steady-state pressure, volume and temperature distribution in meshed networks.

## Features

The program works according to the Hardy-Cross Method and the second rule of Kirchhoff.

For lambda calculations there is a choice between Nikuradse’s or Prantl-Colebrook’s or Unger Prantl-Colebrock’s formula.

Undersupply

If the differential pressure is below the minimum pressure although all valves are open, the consumption of the customers will decrease. If required, this effect can be modeled in PSS®SINCAL.Re-dispatch of supply

It monitors the limits of the supplies and re-distributes the energy between the different sources.Locking of pipes

Locking of pipes (or other elements) on one or both sides is possible without deleting the elements.Definition of characteristic curves for pumps and valves

Checking of the operating points and limits of pumps, valves and network groups

Weak point analysis and color-coded identification of the weak points in the network

Graphical identification of elements which are affected by pipe failures

Definition of specific groups of network elements, e.g. consumer groups with identical behavior

Pumps and valves in every network situation, e.g. in loops

## Network Elements

Nodes

Geodetic altitudes will be taken into consideration. Coordinates can be entered in the Gauss-Krueger-System.Leakage node

Only in dynamic calculation. The user can enter starting and ending time of the leakage, output surface (mm^{2}), pressure and leakage with/without resistance.Generators

The following infeed types are available:

- Flow supply: The input flow at the supply remains constant and does not depend on the pressure at the source. Constant supply can be given in Nm^{3}/h, m^{3}/h or MW. Initial starting values can be considered for dynamic simulations.

- Pressure supply: Surplus pressure will be constant at the supply point. It is independent of the load distribution in the network. The pressure supply compensates the difference between the total input at supply points and the total output at the distribution points.Pipes

Pressure losses are calculated for pipe elements. A data base with appropriate inside diameters of pipes can be defined. The roughness of the pipes, the additional factor for the pipe bend, Zeta, annual roughness increase and annual diameter reduction and leakage will be taken into account during the calculation. Pipe data can be entered for each pipe individually or by reference to a standard type.Locking fittings − sliding valves

Pipes with a valve for which the diameter of the valve can be regulated. Additionally, the Zeta value can be entered as a function of the valve position. This behavior can be defined in a table/diagram.Check valve

Pipe with uni-directional flow (from pipe start to end). The diameter is a function of flow velocity. The pressure loss of the check valve is a function of the opening angle which is a function of velocity.Pressure regulator

This network element regulates the pressure so that the pressure set point will be maintained at a specified node. It can result in a pressure increase or decrease.The set point can be a fixed value or can be dependent of a governor value, the circulation volume.Pressure guards and pressure limitations will be checked.Constant pressure decrease

A pressure decrease between a start and end point can be defined. The pressure decrease is independent of the output flow.Compressor

A pressure increase between the start point and the end point can be defined. Any node pressure can be regulated by this element.Line with constant flow

The flow in the line remains constant and is independent of the load distribution within the network and the pressure.Differential pressure regulator

This network element maintains a given pressure difference between reference nodes. The point of regulation can be on both sides of the pipe.Pressure buffer

This element simulates a gas reservoir with overflow. There will be a flow in or out of the pressure buffer. If the pressure is below a defined threshold there will be no consumption. If the pressure exceeds the threshold value the consumption will be calculated in such a way that the pressure equals the defined pressure. In the dynamic calculation the starting pressure will be taken from the steady-state calculation.Consumer

Consumers create gas flows in pipes which are equivalent to the specified consumption and independent of the pressure. Consumer types with different characteristics can be defined and these types can be assigned to groups of consumers.

**Tables and reports**

The user can define the content of reports in selection lists.

General network data

All element data

Node reports with pressures (absolute, working, air), altitude and flow (Nm

^{3}/h) and all connected elements with flow, flow speed and pressure differencePipe elements with flow, pressure, pressure decrease, flow speed, length and diameter etc.

Results summaries with minimal and maximum pressure and maximum velocity

**Diagrams
**Longitudinal section.

The user can define free routes through the network showing the values for

Pressure

Air pressure

along automatically generated paths.

**Network Diagram
**Graphical output of following values:

Nodes: altitude, consumption, pressure absolute, relative

Pipes: flow, pressure absolute, pressure decrease, length, diameter, flow speed

Color-coded filter functions for pressure, flow, speed, consumption, etc.

## Load profiles

**Time Series
**The Load Profile simulation is a special form of flow calculation that allows the simulation of varying consumption or infeed conditions based on chronological profiles, e.g. daily profiles in 15-min time steps.

For this task, in addition to their nominal data the consumer and infeed models include an assigned load/infeed profile which can be defined in absolute or relative values.

Based on the specified nominal data and time series the gas flows in the network are calculated. The time series analysis also allows modeling consumption taking into account the effect of simultaneity depending on the number of consumers of identical type. This can be achieved by defining and assigning consumer types.

The outcome of the time series simulation is:

The results of flow calculations of all time steps are available, including the analysis of maximum or minimum values (e.g. pressure, etc.).

Diagrams showing daily profiles of result data observed at selected nodes and branches in the network.

## Contingency analysis

The purpose of the Contingency Analysis module is to assess the performance of the network during outage of network components. The outcome of the contingency analysis is the determination of weak points or conditions that may lead supply interruptions.

Contingency Analysis comprises a series of flow calculations. One or more elements are considered on outage in each individual load flow calculation. PSS®SINCAL can simulate the outage of a single network component or a group of components. Conditional and unconditional outages as well as base and resulting outages can be modeled.

All relevant results (minimum and maximum values, unsupplied consumers, etc.) are recorded and summarized in a clearly arranged results dialog window.

## Dynamic simulation

This method calculates the gas transportation time and flow path:

Calculation of transportation time and flow path for freely defined consumers.

Results can be displayed graphically.

Flow paths through the network are determined automatically, even in meshed networks.

## Steady-state, dynamic and water tower filling calculation

In the water supply field, PSS®SINCAL calculates the steady-state and dynamic flow conditions in any meshed network with different pressure levels for Newtonian liquids in filled pipes. The Hardy-Cross method is applied for this purpose.

Steady-state calculation provides results such as pressure, rate of flow and flow velocity, as well as the operating points of control devices. In addition, pressure characteristic graphs are also available.

With the aid of dynamic simulation, it is possible to observe different states and changes of state in the network at certain times. In this way, it is also possible on the basis of predetermined time series (for consumers, supply, regulators, etc.) and time events (valve position, consumer shut-off etc.) to calculate values for quantities, flows and pressures in the network.

Using the Water Tower Filling model, it is possible to perform calculations for the water network on a quasi-dynamic basis. Here, the changes in pressure in the network caused by in- and outflows in the water towers are taken into account. The effects of changes in the loading of the network and in the position of control elements are simulated by time events or time series.

Water Tower Filling makes it possible to plan the optimum layout of new tanks and capacity utilization of existing tanks. The results can be visualized as graphs for pressure, filling level, filling volume or in- and outflow at the water towers as a function of time.

## Hydraulic calculations

The program can handle all steady-state pressure, volume and temperature distribution in meshed networks.

## Features

The program works according to the Hardy-Cross Method and the second rule of Kirchhoff.

For lambda calculations there is a choice between Nikuradse’s or Prantl-Colebrook’s or Unger Prantl-Colebrock’s formula.

Undersupply

If the differential pressure is below the minimum pressure although all valves are open, the consumption of the customers will decrease. This effect can be taken into account, if required.Re-dispatch of supply

It monitors the limits of the supplies and re-distributes the energy between the different sources.Locking of pipes

Locking of pipes (or other elements) on one or both ends is possible without deleting the elements.Definition of characteristic curves for pumps and valves

Checking of the operating points and limits of pumps, valves and network groups

Weak point analysis and color-coded identification of the weak points in the network

Graphical identification of elements which are affected by pipe failures

Definition of specific groups of network elements, e.g. consumer groups with identical behavior

Pumps and valves in every network situation, e.g. in loops

## Network Elements

Nodes

Geodetic altitudes will be taken into consideration. Coordinates can be entered in the Gauss-Krueger-System.Generators

The following infeed types are available:

Water tower: The pressure in the water tower will be kept constant independently of the consumption in the network. The water level is set by the user. The water tower compensates the difference between the total input at supply points and the total output at the distribution points.

- Reciprocating pump: This element supplies water to the network at a constant output flow. The water comes from a water reservoir, which is assumed to be unlimited or an upstream supply network. The output flow is independent from the pressure at the source node.

- Centrifugal pump: The centrifugal pump supplies water in accordance to a given infeed characteristic assuming an unlimited water reservoir or upstream supply network as source. The predicted output is used as the initial starting value for the simulation. The pump’s operating point is determined by interpolation between the nearest set points of the pump characteristic.Pipes

Pressure losses are calculated for this element. A data base with appropriate inside diameters of pipes can be defined. The roughness of the pipes, the additional factor for the pipe bend, Zeta, annual roughness increase and annual diameter reduction and leakage will be taken into account during the calculation. Types of pipes with special values can be defined and used for groups of pipes.Locking fittings − sliding valves

Pipe with a valve for which the diameter of the valve can be regulated. As a special function the Zeta value can be given as a function of the valve position. This function can be defined in a table/diagram.Check valve

Pipe with uni-directional flow. Cross section is a function of flow speed. Pressure losses through the check valve are a function of opening angle, which is a function of speed.Pressure regulator

Network element which regulates the pressure in a way that the set point of the pressure on a defined node will be maintained. This could be a pressure increase or a pressure decrease element. The position of the valve will be calculated out of the Zeta value. The set point can be a fixed value or can be dependent of a governor value, the circulation volume. Pressure guards and pressure limitations will be checked.Constant pressure decrease

A pressure decrease between the start and end point can be defined. The pressure decrease is independent of the output flow.Differential pressure regulator

The given value for regulation is the difference of pressure between two reference nodes. The point of regulation can be both sides of the pipe. The set point can be a fixed value or can be dependent of a governor value, the circulation volume.Pumps

Pumps can have different operation types:

- Fixed output: reciprocating pump

- Fixed speed: centrifugal pump

- Fixed output height: pressure regulation

- Fixed pressure: pressure regulation

For other details see specific regulators.Pressure buffer

This element simulates a water reservoir with overflow. If the pressure is below a defined value there will be no consumption. If the pressure exceeds the defined pressure threshold, the consumption will be calculated in such a way that the pressure equals the defined pressure. In the dynamic calculation the starting pressure will be taken from the steady state calculation. With this value the filling of the tower will be calculated according to the pressure buffer characteristic. There will be a flow in or out of the pressure buffer.Consumer

Consumers create water flows in the network that are equivalent to their consumption in the outlet pipes. The flow is independent of the consumer’s water pressure. Types of consumers with special values can be defined and assigned to groups of consumers.

**Tables and reports**

The user can define the content of reports in selection lists.

General network data

All element data

Node reports with pressure and altitude and all connected elements with flow, flow speed and pressure difference

Pipe elements with flow, pressure, pressure decrease, flow speed, length and diameter

Results summaries with minimal and maximum pressure and maximum velocity

**Diagrams **Longitudinal section.

The user can define free routes through the network showing the values for

Pressure

Altitude

along automatically generated paths.

**Network Diagram **Graphical output of following values:

Nodes: altitude, consumption, absolute and relative pressure

Pipes: flow, absolute pressure, pressure drop, length, diameter, flow speed, type of pipe

Color-coded filter functions for pressure, flow, speed, consumption, etc.

## Load profiles

**Time Series **The load profile calculation is a special form of flow calculation that allows the simulation of varying consumption or infeed conditions based on chronological profiles, e.g. daily profiles in 15-min time steps.

For this task, the consumer and infeed models, additionally to their nominal data, include an assigned consumption/infeed profile which can be defined in absolute or relative values.

Based on the specified nominal data and time series the water flows are calculated. The time series analysis also allows modeling consumption taking into account the effect of simultaneity depending on the number of consumers of identical type. This can be achieved by defining and assigning consumer types.

The following results are available:

All flow calculations of all time steps are available, including the analysis of maximum or minimum values (e.g. pressure flows, etc.);

Diagrams showing daily profiles of the result data observed at selected nodes and branches in the network.

## Water tower filling

In interaction with the network, in- and outflowing water results in changing geodetic heights of the water level in water towers.

PSS®SINCAL’s Water Tower Filling method is used to calculate the required water tower filling for the next day.

The water level inside the tower indirectly indicates the pressure at the water tower node.

The stored water volume is defined by the water tower shape and the height of the water level. The water tower shape can be entered by the user.

Calculation time and time steps can be chosen freely. The result diagrams of the Water Tower Filling module show height, pressure, volume and flow as functions of time.

## Contingency analysis

The purpose of the Contingency Analysis module is to assess the performance of the network during outage of network components. The outcome of the contingency analysis is the determination of weak points or conditions that may lead to supply interruptions.

Contingency Analysis comprises a series of flow calculations. One or more elements are considered on outage in each individual load flow calculation. PSS®SINCAL can simulate the outage of a single network component or a group of components. Conditional and unconditional outages as well as base and resulting outages can be modeled.

All relevant results (minimum and maximum values, unsupplied consumers, etc.) are recorded and summarized in a clearly arranged results dialog window.

## Dynamic simulation

Calculation of water transportation time and flow path:

Calculation of transportation time and flow path for freely defined consumers.

Results can be displayed graphically.

Flow paths through the network are determined automatically, even in meshed networks.

## Calculation of flow and return flow

PSS®SINCAL District Heating and Cooling can provide the answer to whether in any meshed network steady-state or dynamic flow calculations are required. In addition to pressure, rates of flow and flow velocities, the pressure difference between flow and return flow, the operating points of the pumps, along with temperature and heat output, are all shown. Pressure graphs are also available.

Individual elements can optionally be taken into account in flow and/or return flow. For simulation of consumption and pressure profiles, valve positions and faults, definitions of time series and time events are available.

## Hydraulic calculations

The program can handle any steady-state pressure, volume and temperature distribution in meshed networks. Networks can be built symmetrically and asymmetrically with different dimensions in flow and return flow.

## Features

Symmetrical and asymmetrical networks

4 conductor (or more) networks (2 flow pipes and 2 return pipes). Flow pipes can be connected via bypasses.Simulation of primary and secondary networks

Calculation can simulate more than one independent network at the same time. Networks with locking and primary and secondary networks connected by heat exchangers can be simulated together.Undersupply

If the differential pressure is below the minimum pressure although all valves are open, the consumption of the customers will decrease. This effect can be modeled, if required.Re-dispatch of supply

It monitors the limits of the supplies and re-distributes the energy between the different sources.Locking of pipes

Locking of pipes (or other elements) on one or both sides is possible without deleting the elements. This can even be done in asymmetrical networks.Definition of characteristic curves for pumps and valves

Checking of the operating points and limits of pumps, valves and network groups

Weak point analysis and color-coded identification of the weak points in the network

Graphical identification of elements which are affected by pipe failures

Definition of specific groups of network elements, e.g. consumer groups with specific behavior

Consideration of different cool-down temperatures of consumers.

Pumps and valves in every network situation, e.g. in loops

Calculation of temperature regulated admixtures for the flow pipe into the return pipe

Heat/Cooling generators with different flow temperatures

Closed-loop calculation between flow and return

## Network Elements

Nodes

Geodetic altitudes will be taken into consideration. Coordinates can be entered in the Gauss-Krueger-System.Generators

The following infeed types are available:

- Pressure infeed: Pressure will be constant when the temperature is given. This element can be in the flow and return pipe. The pressure can be fixed by entering flow or return temperature or differential temperature.

- Power infeed: The infeed power or/and infeed volume will be fixed at a given temperature or difference in temperature. Can be entered into the flow or return path.

- Pump infeed: Centrifugal pump with output according to the characteristic curve of the pump. Can be entered into the flow or return path.Pipes

Pressure losses and heat losses are calculated for pipe elements. A data base with appropriate inside diameters of pipes can be defined. The roughness of the pipes, the additional factor for the pipe bend, Zeta, profile factor, heat conduction factor and leakage will be taken into account during the calculation. Types of pipes with special values can be defined and used for groups of pipes.Bypasses

Element with pipe characteristic between flow pipe 1 and flow pipe 2.Locking fittings

Pipe with a valve where the diameter of the valve can be regulated. As a special function the Zeta value can be given as a function of the valve position. This function can be defined in a table/diagram. This element can be entered in the flow pipe.Check valve

Pipe with uni-directional flow. Cross section is a function of flow speed. Pressure losses through the check valve are a function of opening degree, which is a function of speed. This element can be entered into the flow pipe.Pressure regulator

Network element which regulates the pressure in a way that the set point of the pressure on a defined node will be maintained. This could be a pressure increase or a pressure decrease element. The position of the valve will be calculated from the Zeta value. The set point can be a fixed value or can be dependent of a governor value, the circulation volume. Pressure guards and pressure limitations will be checked.Differential pressure regulator

The given value for regulation is the difference of pressure between two reference nodes. The point of regulation can be in the flow or return pipe. The set point can be a fixed value or can be dependent of a governor value, the circulation volume.Pumps

Pumps can have different operation types:

- Fixed output: piston pump

- Fixed speed: circulation pump

- Fixed output height: pressure regulation

- Fixed pressure: pressure regulation

For other details see specific regulators.Flow temperature regulator

This network element simulates a valve that regulates a flow temperature at a reference node by infeeding water of the return flow. This element can be used in flow und return pipes.Heat exchanger

This element is used for hydraulic decoupling of primary and secondary networks. The flow temperature at a reference node in the secondary network will be fixed by transmitting heat from the primary to the secondary network. This is achieved by means of a generated consumer at the element’s start point and an infeed with pressure regulation at the end point. The set point can be a fixed value or can be dependent of a governor value, in this case the outside temperature.Pressure buffer

This element simulates a water reservoir with overflow. If the pressure is below a defined value there will be no consumption. If the pressure exceeds the defined pressure threshold, the consumption will be calculated in such a way that the pressure equals the defined pressure. In the dynamic calculation the starting pressure will be taken from the steady-state calculation. With this value the filling of the tower will be calculated according to the pressure buffer characteristic. There will be a flow in or out of the pressure buffer.Consumer

Consumers create flows in the network that are equivalent to their consumption. This flow is independent of the consumer’s water pressure.

The consumer can have a constant consumption power or/and constant consumption volume. The user can choose between fixed temperature or fixed difference of temperature between flow and return pipe. Types of consumers with special values can be defined and assigned to groups of consumers.

**Tables and reports**

The user can define the content of reports in selection lists.

General network data

All element data

Node reports with pressure, altitude and temperature and all connected elements with flow, flow speed and pressure difference

Pipe elements with flow, pressure, pressure decrease, flow speed, length, diameter and temperature difference

Results summaries with minimum and maximum pressure, maximum speed and losses in flow and return and the total losses

**Diagrams
**Longitudinal section

The user can define free routes through the network showing the values for

Pressure flow and return (absolute and relative)

Steam pressure (absolute and relative)

Altitude

Temperature

along automatically generated paths.

**Network Diagram
**Graphical output of following values:

Nodes: altitude, consumption, absolute, relative and specific pressure, temperature

Pipes: flow, absolute, relative and specific pressure, temperature difference, length, diameter, flow speed, losses

Color-coded filter functions for pressure (all types), temperatures, flow, speed, consumption, etc.

## Load profiles

**Time Series
**The Load Profile calculation is a special form of flow calculation that allows the simulation of varying consumption or infeed conditions based on chronological profiles, e.g. daily profiles in 15-min time steps.

Pipe elements with flow, pressure, pressure decrease, flow speed, length, diameter and temperature difference

Results summaries with minimum and maximum pressure, maximum speed and losses in flow and return and the total losses

For this task, the consumer and infeeder model, additionally to their nominal data, include an assigned consumption / infeed profile which can be defined in absolute or relative values.

Based on the specified nominal data and time series the flows in the network are calculated. The time series analysis also allows modeling consumption taking into account the effect of simultaneity depending on the number of consumers of identical type. This can be achieved by defining and assigning consumer types.

The following results are available:

All flow calculations of all time steps are available including the analysis of maximum or minimum values (e.g. pressure flows, etc.);

Diagrams showing daily profiles of result data observed at selected nodes and branches in the network.

## Contingency analysis

The purpose of the Contingency Analysis module is to assess the performance of the network during outage of network components. The outcome of the contingency analysis is the determination of weak points or conditions that may lead to supply interruptions.

Contingency Analysis comprises a series of flow calculations. One or more elements are considered on outage in each individual load flow calculation. PSS®SINCAL can simulate the outage of a single network component or a group of components. Conditional and unconditional outages as well as base and resulting outages can be modeled.

All relevant results (minimum and maximum values, unsupplied consumers, etc.) are recorded and summarized in a clearly arranged results dialog window.

## Dynamic simulation

Calculation of transportation time and flow path.

Calculation of transportation time and flow path for freely defined consumers.

Results can be displayed graphically.

Flow paths through the network are determined automatically even in meshed networks.

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