Network Report

Overview

The network report brings the network description, the diversity, the bill of materials, the steady-state calculation and the dynamic simulation of the active network together into one continuous document — with title page, table of contents, project data and page footer. It is written as PDF, Word (ODT), HTML or AsciiDoc.

In the chapter Steady state calculation, the report contains the pressure profile between every energy center and the index point and checks it against two pressure limits: the nominal pressure rating of the pipes on the path and the minimum operating pressure. Each limit receives a spelled-out verdict with a color swatch. This makes the network report the place where that check is recorded ready for documentation; while you are working, the same check is available as a status line in the path profile of the steady-state calculation.

Opening

Menu Reports > Network report…

The menu entry is only visible in the Districts perspective and stays disabled as long as no network is active. The report always covers the active network; its name is shown at the top left of the dialog next to Network:.

The Network Report dialog is split in two: the configuration on the left, with one collapsible page per chapter, and the page preview on the right. The preview does not follow your changes by itself — building the document renders every network image again and takes correspondingly long. Trigger it with Update preview once you are done configuring. Use the format selection and Export… to write the document to a file. With no network active, the right-hand side shows the note No network is active. The report covers the active network, so there is nothing to preview. instead of the preview.

Choosing the Chapters

Every page of the configuration carries a check box Print this chapter in its header. It switches the chapter off entirely without losing its settings — the page stays visible and is only greyed out.

Chapter	Content	Settings
Network description	Network extent, consumers and transfer stations, energy centers, plants inside the pipe network, boundary conditions of the heat exchange, fluid properties	Consumer table: Summary / Individual list, Plant and heating curve description, Pipe sizing assumptions
Diversity	Diversity reached in the network	none
Bill of materials	Pipe types with installed lengths, fittings, fluid content	Pipe type plan, Table type: Summary / Individual list, Fitting details, Show partitions separately with a selection list
Steady state calculation	Key figures per operating point, pressure profiles, pipe utilization, pump sizing, false-color maps	see Settings of the Steady-State Chapter
Dynamic simulation	Annual evaluation of the simulation with time-series charts	Evaluate from: / Evaluate until:, Result plots:, Evaluation of pump operation
Appendix: about the software	Description of the calculation methods used	none

Title page and Table of contents cannot be switched off — they are always printed and therefore have no page of their own in the configuration. Always present as well is the page General Settings above the chapters: report date, project information, the two document colors and the option Automatically turn network plans to fit the page.

The button Reset to default settings puts all options back in one step; the network being reported on is not affected.

Settings of the Steady-State Chapter

Field	Default	Meaning
Index point:	auto	Transfer station reported in the key figures table and used as the target of the pressure profiles. Left empty, it is determined automatically from the lowest — or, with decentral pumps, highest — pressure difference of every operating point. Auto resets a selection.
Detailed pipe network information	on	Prints the sections Pipe network and Height differences per operating point: heat losses, the hydraulic extremes together with the pipe that carries them, and the geodetic heights. Energy centers and index point are printed either way.
Pressure profile(s)	on	Prints the pressure profile from every energy center to the index point — the prerequisite for the check of the pressure limits.
Pipe utilization	on	Histogram that splits the route length over the utilization of the pipes, with the matching network plan.
Pump sizing	on	Table of the installed pumps and, per pump, a diagram of its operating area together with the plant curves of all printed operating points.
Operating points:	the one selected in the steady-state calculation	Selection list of the calculated operating points. Points without results carry the addition (no results) and cannot be selected.
False color maps:	–	Maps printed as a full-page plan for each printed operating point: Operating pressure in supply pipes, Supply pressure without the geodetic component, Operating pressure in return pipes, Return pressure without the geodetic component, Flow velocity, Pressure gradient, Supply temperature, Heat loss per pipe length

All fields of this page stay locked as long as no steady-state results are available; the note No steady state results are available. Run the steady state calculation first. is then shown above them.

Every setting of the dialog is stored in the project and can be undone individually (undo action Network report configuration modified). The settings only change how the report is presented and invalidate neither simulation nor calculation results.

Minimum Pressure Margin

The margin that forms the checked minimum operating pressure together with the vapour pressure is not a report setting but a property of the network. You will find it under menu Network > General settings …, in the group General settings:

Field	Default	Range	Meaning
Minimum pressure margin	1.5 bar	0 to 100 bar	Margin added to the vapour pressure at the hottest point of a pressure profile; the two together form the minimum operating pressure the profile is checked against

The default of 1.5 bar is made up of 0.5 bar against evaporation and cavitation — on which there is broad professional consensus — plus around 1.0 bar for the control tolerance of the pressure maintenance and for transients; the second part is a planning recommendation and not a standard. The value applies to the whole network and takes effect equally in the report and in the path profile of the steady-state calculation. It is stored with the project; the change is available as the undo action Modified default network settings.

The Pressure Profile Section

In the chapter Steady state calculation, every printed operating point receives its own block Results at <operating point>. Inside it, each energy center contributes a section Pressure profile between <energy center> and the index point. Two generation sites therefore produce two sections per operating point — the profile of one says nothing about the other.

The path checked and drawn is always the same: from the energy center through the supply pipes to the index point and back through the return pipes. If the index point is tapped into the supply pipe and is fed and drained through the same stub, the return curve ends where that stub meets the network; the report notes this below the section description.

Three diagrams over the Route length [m]:

Diagram	Unit	What it says
Operating pressure	bar	The pressure that actually stands in the pipes: the gauge pressure including the geodetic component. This is what the pressure limits are checked against.
Pressure loss line	bar	The same path without the geodetic component, that is the pressure lost along the way. The steepness of the curves shows in which sections much pressure is lost.
Geodetic height	m	The height profile of the route, lifted by the z-height of the project origin so that it shows the same absolute heights as the table Height differences

The two pressure diagrams carry four curves: the energy center, Supply pipe, the transfer station named as the index point and Return pipe. Below the diagrams stands a table with the pressure balance of the loop — Pressure loss of the supply pipe and Pressure loss of the return pipe, and, where decentral plants sit inline in a line, additionally the Pressure head of the decentral plants in the supply and in the return pipe — and below that, in the same table, the checked limits.

The Checked Limits

The table has the columns Quantity, Value, Limit and Result. For the rows of the pressure balance the two rear columns stay empty — which says that a pressure loss is not checked against anything. These two rows are checked:

Quantity	Limit	Result
Highest operating pressure	≤ lowest nominal pressure rating of the pipes on the path, reported as PN n	complied with or exceeded by X bar
Lowest operating pressure	≥ min. operating pressure: vapour pressure at the hottest point of the path plus the Minimum pressure margin, less the ambient pressure	complied with or undercut by X bar

The verdict is written out as text with a colored swatch in front of it — green for a limit that holds, red for one that is missed. Below the table, a note in small print states where the limits come from: with mixed nominal pressure ratings the sentence The path runs over pipes of PN a to b and is checked against the lowest of them., and for the lower limit The minimum operating pressure is the vapour pressure of … at …, the hottest point of the path, plus a margin of … covering evaporation, the control tolerance of the pressure maintenance and transients the steady state does not resolve, less the ambient pressure of … at … above sea level - the pressures of the profile are gauge pressures. The ambient pressure named there follows from the altitude of the project origin, see Pressure Calculation in the Network.

Why a minimum pressure above the vapour pressure is needed at all, which magnitudes are common in technical connection requirements and how the margin is derived is covered in detail under meeting operating pressure limits in heat networks.

Limits of the Check

The check is no substitute for sizing the pressure maintenance. What it does and what it does not do:

• One path is checked, not the network. Only the stretch from the energy center to the index point and back is considered. A high point or a branch away from that path does not enter the result.
• Only pipes carry a nominal pressure rating. Valves, fittings and plant components have no PN in the databases; they are left out of the upper limit. If the pipes on the path carry no nominal pressure rating at all, the row Highest operating pressure is omitted entirely — a check is then missing rather than failing.
• The vapour pressure holds above 100 °C as well. It is determined over the entire temperature range from the hottest fluid temperature of the path, following the industrial formulation IAPWS-IF97; supply temperatures above 100 °C are therefore assessed correctly. For cross-checking, a vapour pressure table is given in the knowledge article meeting operating pressure limits in heat networks. If the operating point supplies no fluid temperatures for the path, the row Lowest operating pressure is omitted.
• The standstill case is not checked. What is assessed is the calculated operating point with the pumps running. The state with the circulation at rest, which governs the sizing of the pressure maintenance, is not covered by the check.
• The minimum operating pressure is only checked in the steady state. The evaporation check depends on the ambient pressure and on the safety margin and is performed exclusively at the steady-state operating points. The dynamic simulation says nothing about it; it reports only the Pressure exceedance of the permissible pipe pressure.
• The differential pressure at the index point gets no verdict. The key figures table of the operating point reports Required differential pressure and Actual differential pressure side by side; you have to draw the comparison yourself.

Notes

• Missing, outdated or non-converged results are not printed into the document but shown as messages above the button row of the dialog. They do not prevent the export.
• Without steady-state results, the dialog reports No steady state results are available for this network, so the steady state chapter reports nothing. Run the steady state calculation.; if they are older than the network, The steady state results are older than the current network. Run the calculation again to report the current state. appears.
• If no path leads from an energy center to the index point, the dialog reports No path could be found from energy center ’…’ to the index point, so its pressure profile is not printed. In place of the section, the document then carries the sentence No path could be found from this energy center to the consumer.
• If the assigned network fluid has no density, the geodetic component cannot be determined. No pressure profile is printed at all — the dialog reports The network fluid has no density, so no pressure profile is printed., the section itself The pressure profile needs an energy center, a consumer and a network fluid with a density; at least one of them is missing.
• For operating points with anomalies, the dialog reports Operating point ’…’: … — with no results, not checked or … % of the outputs did not converge.
• If a stored index point refers to a node that no longer exists in the network as a transfer station, the report silently falls back to the automatic determination.

Related Topics

• Results of the Steady-State Calculation
• Performing the Calculation
• Elevation query
• Network settings and fluid
• Evaluation and export
• Meeting operating pressure limits in heat networks