Create and size the network

Cold district heating, part 1: create a cold district heating network in VICUS Districts and define the pipe dimensions

Overview ▶ 0:10

Project view with OpenStreetMap section and development plan for the cold district heating network — Starting point: project with imported OpenStreetMap section and development plan for a new-build area

This tutorial shows how a cold district heating network is created in VICUS Districts. In the first step, the consumers and the network are drawn, and then the pipe sizing is performed.

As a starting point, we use a project in which an OpenStreetMap section and a development plan for a new-build area have already been imported.

Preparing the development plan ▶ 0:46

Development plan with reduced saturation for better overview — Development plan with reduced saturation for a clearer display during network planning

To improve clarity during planning, the imported development plan can be adjusted:

Double-click the DXF drawing in the navigation tree.
Turn the saturation all the way down for a better overview.

Drawing consumers ▶ 1:05

Consumers are placed on the development plan with heating power and COP entry — Placing consumers with entry of energy standard, heating power, and COP at design conditions

The consumers (buildings) are placed at the positions where the heat pumps are to be connected.

Click on Consumer and set the building positions on the plan.
Select an energy standard (e.g. GEG reference house).
Assign the heating power (e.g. 12 kW for single-family houses).
As a name, you can enter “Single-family house”, for example.
The connected to a heat pump checkbox is already set, as is a COP at design conditions.

COP at design conditions

The COP is used only for the steady-state calculation (i.e. the pipe sizing). It serves to distinguish between the building’s heating power and the heat pump’s evaporator power on the cold side. The evaporator power is the decisive quantity for network sizing.

Adding further consumers ▶ 2:21

Additional consumers such as row houses are placed on the plan — Adding further consumers (e.g. row houses with 7 kW heating power) at the planned positions

Additional consumers (e.g. row houses with 7 kW heating power) can be drawn in the same way. The remaining settings stay identical.

Drawing the network ▶ 2:53

Pipe network is drawn along the planned route — Drawing the pipe network along the planned route with automatic snapping to existing edges

Start at a suitable location and draw the network along the planned route.
Confirm with Enter — once to close the polyline and again to create the network line.
Draw additional lines. The software automatically snaps to existing edges.
Overhanging lines can be trimmed afterwards.

Drawing the energy plant ▶ 3:48

Energy plant is placed at the location of the probe field — Placing the energy plant (e.g. geothermal probe field) at the desired position

Position the energy plant at the desired location (e.g. for a probe field).
Assign a name (e.g. “Geothermal”).
Click Create energy plant.

Connecting consumers and energy plant ▶ 4:10

Network mode with automatic connection of consumers and energy plant — Automatic connection of consumers and energy plant in network mode

Switch to network mode.
Click Connect consumers — both the consumers and the energy plant are automatically connected to the network.
Select Remove open ends to obtain a valid network topology.

Note on the fluid ▶ 4:33

Fluid settings with preset glycol-based fluid for frost protection — Preset glycol-based fluid with frost protection and higher viscosity at low temperatures

When the project is created as a cold district heating network, a glycol-based fluid is already preset. It provides frost protection and accounts for the higher viscosity at low temperatures, which is relevant for pressure-loss calculation.

Checking the connection load ▶ 5:08

Connection load of the consumers with evaporator power on the cold side — Display of the connection load (evaporator power) of the consumers on the cold side of the heat pump

On the next tab, the connection load is displayed. This does not correspond to the building’s heating power but to the evaporator power on the cold side of the heat pump.

When clicking a consumer, a dynamic profile together with all values for heating power and heating energy demand are already stored. These can be changed flexibly at any time.

Performing the pipe sizing ▶ 5:50

Pipe sizing dialog with supply temperature, spread, and pipe selection — Pipe sizing with entry of supply temperature (0 °C), temperature spread (3 K), and selection of uninsulated pipes

Switch to the Pipes tab.
Click Size pipes.
Set the supply temperature (e.g. 0 °C — a rather safe value, since the fluid becomes more viscous at lower temperatures).
Set the temperature spread to 3 Kelvin.
Select the available pipes. For a cold district heating network, uninsulated pipes are used in order to take advantage of heat gains from the ground. Holding the Shift key lets you select several entries at once.
Enable the simultaneity factor for the sizing.
Perform the sizing (e.g. at 100 Pa/m pressure loss).

Displaying results ▶ 7:25

Sizing results with pipe dimensions on the network plan and bill of materials — Pipe sizing results: visualization in the network plan and bill of materials for all pipes

Once the sizing is complete, the results can be visualized:

The pipe dimensions are shown in the network plan.
Via Results > Bill of materials, you obtain a listing of all pipes and pipe fittings.