Thermal Network

The thermal network is the central object in DHNx. It provides a container class that holds a number of components. All available components are defined in components.csv, which is rendered in the following table.

component_class	list_name	description
Environment	environment	Environment
Producer	producers	Heat producer
Consumer	consumers	Heat consumer
Fork	forks	Node where several pipes meet
Pipe	pipes	Pipes representing double pipes (feed and return) that connect nodes

Every component has a number of attributes which are defined in components_attrs/. Each attribute is given a name, type (int, float, str etc.), unit, default value, a description, a status (Input or Output) and requirement (required or optional).

The attributes are presented in detail in the following sections.

Consumer

Consumers are the nodes where the heat provided by the district heating network is actually used. They are characterized by these attributes:

attribute	type	unit	default	description	status	requirement
id	int	n/a	n/a	Unique id	Input	required
component_type	str	–	Consumer	Component type	Input	optional
lat	float	n/a	n/a	Geographic latitude	Input	optional
lon	float	n/a	n/a	Geographic longitude	Input	optional
mass_flow	float/sequence	kg/s	n/a	Mass flow	Input	optional
delta_temp_drop	float/sequence	kg/s	n/a	Temperature drop from inlet to return	Input	optional
zeta_inlet	float	–	n/a	Localized pressure loss coefficient for inlet flow	Input	optional
zeta_return	float	–	n/a	Localized pressure loss coefficient for return flow	Input	optional

Producer

A producer is a general node that provides heat to the district heating network. Producers are described with the following attributes:

attribute	type	unit	default	description	status	requirement
id	int	n/a	n/a	Unique id	Input	required
component_type	str	–	Producer	Component type	Input	optional
lat	float	n/a	n/a	Geographic latitude	Input	optional
lon	float	n/a	n/a	Geographic longitude	Input	optional
temp_inlet	float/sequence	deg C or K	n/a	Inlet temperature at producer	Input	optional
zeta_inlet	float	–	n/a	Localized pressure loss coefficient for inlet flow	Input	optional
zeta_return	float	–	n/a	Localized pressure loss coefficient for return flow	Input	optional

Fork

Forks are the nodes where several pipes of the network meet. Forks have the attributes described in the following table:

attribute	type	unit	default	description	status	requirement
id	int	n/a	n/a	Unique id	Input	required
component_type	str	–	Fork	Component type	Input	optional
lat	float	n/a	n/a	Geographic latitude	Input	optional
lon	float	n/a	n/a	Geographic longitude	Input	optional
zeta_inlet	float	–	n/a	Localized pressure loss coefficient for inlet flow	Input	optional
zeta_return	float	–	n/a	Localized pressure loss coefficient for return flow	Input	optional

Pipe

Pipes imply the feed and return pipes connecting the different nodes of the network. They are characterized by these attributes:

attribute	type	unit	default	description	status	requirement
id	int	n/a	n/a	Unique id	Input	required
component_type	str	–	Pipe	Component type	Input	optional
from_node	int	n/a	n/a	Node where Pipe begins	Input	required
to_node	int	n/a	n/a	Node where Pipe ends	Input	required
length	float	m	n/a	Length of the Pipe	Input	optional
diameter	float	mm	n/a	Inner diameter of the pipes	Input	optional
heat_transfer_coeff	float	W/(m*K)	n/a	Heat transfer coefficient	Input	optional
roughness	float	mm	n/a	Roughness of pipes	Input	optional