Steady-state calculation & pump sizing

District heating network, part 2: perform the steady-state calculation and size the pump

Overview ▶ 0:10

District heating network ready for steady-state calculation and pump sizing — Starting point: the network created in the first tutorial for system configuration and steady-state calculation

This tutorial demonstrates how to edit the system configuration, perform a steady-state calculation, and size the pump. The starting point is the network created in the first tutorial.

Checking the system configuration ▶ 0:25

Systems view with assigned systems at the network points — Systems view: overview of the systems assigned at each point in the network

In the Systems view, it is shown which systems are assigned at which point.

House transfer station ▶ 0:38

System editor with house transfer station: heat exchanger and valve — Simple house transfer station in the system editor: heat exchanger (0.5 bar) with valve (20 K control)

Double-clicking the entry opens the system editor. The simple house transfer station contains:

A heat exchanger with a pressure loss of 0.5 bar
A valve that regulates a temperature difference of 20 Kelvin across the heat exchanger

Energy plant ▶ 1:07

System editor of the energy plant with circulation pump and heat generator — Energy plant: circulation pump (2 bar pressure increase) and heat generator (80 °C supply temperature)

The energy plant contains:

A circulation pump with an initially constant pressure increase of 2 bar (it will be sized afterwards)
A simple heat generator with a constant supply temperature of 80 °C

Performing the steady-state calculation ▶ 1:37

Steady-state calculation dialog with supply temperature and simultaneity — Steady-state calculation: configure supply temperature, temperature difference, static pressure, and simultaneity

Switch to the Steady-state analysis tab.
Open the dialog — here you can configure supply temperature, temperature difference, static pressure (pressure in the pressure maintenance system), and the simultaneity.
Create the steady-state calculation.

Results of the steady-state calculation ▶ 2:12

Results with pressure loss at the worst point and color-coded critical path — Results: pressure loss at the worst point with color-coded critical path and pressure profile

The results show:

The pressure loss at the worst point and the critical path displayed in color
By selecting different entries in the table, the pressure losses at each consumer can be displayed
The pressure profile along the branch, optionally with or without geodetic height
The pressure limits of the pipes (e.g. PN16 with 16 bar pressure rating)

Additional display options ▶ 3:15

Color-coded display of various calculation results in the network — Color-coded display of pressure loss, mass flow, and volume flow directly on the network plan

Additional quantities can be displayed in color in the network: specific pressure loss, mass flow, volume flow, and further results. Selecting an element shows additional results on the right side.

Detail results ▶ 3:41

Tabular detail overview of all components with pressure loss and mass flow — Detail results: tabular overview of each component with pressure loss, mass flow, and absolute pressure

Under Details you find a tabular overview of every component in the network — i.e. every component in the systems and in the pipe network, including pipe fittings, with the respective pressure loss, mass flow, volume flow, and absolute pressure.

Sizing the pump ▶ 4:10

Pump sizing with suggested pumps and curves — Pump sizing: suitable pumps are suggested and can be assigned directly

Switch to Pump sizing.
In the upper table the energy plant is displayed. Below it, suitable pumps are suggested.
Select the desired pump and click Assign pump.
The pump from the database is automatically stored in the system — the correct curves are assigned directly.

Verifying the pump in the system ▶ 4:40

System editor with assigned pump and stored pump curves — Verification of the assigned pump: the correct pump curves are automatically stored

Via Edit system and double-clicking the energy plant, you can verify that the correct pump curves are stored.