Junction

Create Function

For creating a single junction:

create_junction(net, pn_bar, tfluid_k, height_m=0, name=None, index=None, in_service=True, type='junction', geodata=None, **kwargs)

Adds one junction in table net[“junction”]. Junctions are the nodes of the network that all other elements connect to.

Parameters:
  • net (pandapipesNet) – The pandapipes network in which the element is created

  • pn_bar (float) – The nominal pressure in [bar]. Used as an initial value for pressure calculation.

  • tfluid_k (float) – The fluid temperature in [K]. Used as parameter for gas calculations and as initial value for temperature calculations.

  • height_m (float, default 0) – Height of node above sea level in [m]

  • name (string, default None) – The name for this junction

  • index (int, default None) – Force a specified ID if it is available. If None, the index one higher than the highest already existing index is selected.

  • in_service (boolean, default True) – True if the junction is in service or False if it is out of service

  • type (string, default "junction") – not used yet - Designed for type differentiation on pandas lookups (e.g. household connection vs. crossing)

  • geodata ((x,y)-tuple, default None) – Coordinates used for plotting

  • kwargs – Additional keyword arguments will be added as further columns to the net[“junction”] table

Returns:

index - The unique ID of the created element

Return type:

int

Example:
>>> create_junction(net, pn_bar=5, tfluid_k=320)

For creating multiple junctions at once:

create_junctions(net, nr_junctions, pn_bar, tfluid_k, height_m=0, name=None, index=None, in_service=True, type='junction', geodata=None, **kwargs)

Convenience function for creating many junctions at once. Parameter ‘nr_junctions’ specifies the number of junctions created. Other parameters may be either arrays of length ‘nr_junctions’ or single values.

Parameters:
  • net (pandapipesNet) – The pandapipes network in which the element is created

  • nr_junctions (int) – Number of junctions to be created.

  • pn_bar (Iterable or float) – The nominal pressure in [bar]. Used as an initial value for pressure calculation.

  • tfluid_k (Iterable or float) – The fluid temperature in [K]. Used as parameter for gas calculations and as initial value for temperature calculations.

  • height_m (Iterable or float, default 0) – Heights of nodes above sea level in [m]

  • name (Iterable or string, default None) – The names for these junctions

  • index (Iterable(int), default None) – Force specified IDs if they are available. If None, the index one higher than the highest already existing index is selected and counted onwards.

  • in_service (Iterable or boolean, default True) – True if the junctions are in service or False if they are out of service

  • type (Iterable or string, default "junction") – not used yet - Designed for type differentiation on pandas lookups (e.g. household connection vs. crossing)

  • geodata (Iterable of (x,y)-tuples, default None) – Coordinates used for plotting

  • kwargs – Additional keyword arguments will be added as further columns to the net[“junction”] table

Returns:

index - The unique IDs of the created elements

Return type:

array(int)

Example:
>>> create_junctions(net, 200, pn_bar=5, tfluid_k=320,
>>>                  height_m=np.arange(200))

Component Table Data

net.junction

Parameter

Datatype

Value Range

Explanation

name

string

Name of the junction

pn_bar

float

\(>\) 0

Rated pressure of the junction [bar]. Also the initial value for the calculation.

tfluid_k

float

\(\ge\) 0

Fluid temperature at junction [K]

height_m

float

\(\ge\) 0

The height above sea level of the junction [m]

in_service

boolean

True / False

Specifies if the bus is in service.

type

string

p or t or pt

Type variable to classify junctions

net.junction_geodata

Parameter

Datatype

Explanation

x

float

x coordinate of bus location

y

float

y coordinate of bus location

Physical Model

The equations added by a junction correspond to a mass flow balance for hydraulic calculations.

alternate Text
\begin{align*} \sum_{n=0}^N \dot{m}_{in_n} - \sum_{l=0}^M \dot{m}_{out_l} = 0 \end{align*}

For temperature calculations, the thermal power carried by the incoming fluids is balanced:

alternate Text
\begin{align*} \sum_{n=0}^N \dot{m}_{in_n}c_p T_{in_n} - \sum_{l=0}^M \dot{m}_{out_l} c_p T_{m} = 0 \end{align*}

Result Table Data

net.res_junction

Parameter

Datatype

Explanation

p_bar

float

The junction pressure [bar]

t_k

float

The junction temperature [K]