Network Formulations

Type Hierarchy

We begin with the top of the hierarchy, where we can distinguish between gas flow models. Currently, there are two variations of the weymouth equations, one where the directions of flux are known and one where they are unknown.

AbstractDirectedGasFormulation <: AbstractGasFormulation
AbstractUndirectedGasFormulation <: AbstractGasFormulation

Each of these have a disjunctive form of the weymouth equations: The full non convex formulation and its conic relaxation.

AbstractMINLPForm <: AbstractUndirectedGasFormulation
AbstractMISOCPForm <: AbstractUndirectedGasFormulation
AbstractMINLPDirectedForm <: AbstractDirectedGasFormulation
AbstractMISOCPDirectedForm <: AbstractDirectedGasFormulation

Gas Models

Each of these forms can be used as the type parameter for a GasModel, i.e.:

MINLPGasModel = GenericGasModel(StandardMINLPForm)
MISOCPGasModel = GenericGasModel(StandardMISOCPForm)

For details on GenericGasModel, see the section on Gas Model.

User-Defined Abstractions

The user-defined abstractions begin from a root abstract like the AbstractGasFormulation abstract type, i.e.

AbstractMyFooForm <: AbstractGasFormulation

StandardMyFooForm <: AbstractFooForm
FooGasModel = GenericGasModel{StandardFooForm}

Directed Models

GasModels.constraint_on_off_compressor_flow_direction — Method.

constraints on flow across compressors when directions are constants

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GasModels.constraint_on_off_compressor_flow_direction_ne — Method.

constraints on flow across compressors when the directions are constants

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GasModels.constraint_on_off_compressor_ratios — Method.

on/off constraint for compressors when the flow direction is constant

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GasModels.constraint_on_off_control_valve_flow_direction — Method.

constraints on flow across control valves when directions are constants

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GasModels.constraint_on_off_control_valve_pressure_drop — Method.

constraints on pressure drop across control valves when directions are constants

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GasModels.constraint_on_off_pipe_flow_direction — Method.

constraints on flow across pipes where the directions are fixed

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GasModels.constraint_on_off_pipe_flow_direction_ne — Method.

constraints on flow across pipes when directions are fixed

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GasModels.constraint_on_off_pressure_drop — Method.

constraints on pressure drop across pipes

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GasModels.constraint_on_off_pressure_drop_ne — Method.

constraints on pressure drop across pipes when the direction is fixed

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GasModels.constraint_on_off_short_pipe_flow_direction — Method.

constraints on flow across short pipes when the directions are constants

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GasModels.constraint_on_off_valve_flow_direction — Method.

constraints on flow across valves when directions are constants

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Undirected Models

GasModels.constraint_conserve_flow — Method.

This constraint is intended to ensure that flow is on direction through a node with degree 2 and no production or consumption

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GasModels.constraint_conserve_flow_ne — Method.

This constraint is intended to ensure that flow is on direction through a node with degree 2 and no production or consumption

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GasModels.constraint_on_off_compressor_flow_direction — Method.

constraints on flow across compressors

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GasModels.constraint_on_off_compressor_flow_direction_ne — Method.

constraints on flow across compressors

source

GasModels.constraint_on_off_compressor_ratios — Method.

enforces pressure changes bounds that obey compression ratios

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GasModels.constraint_on_off_control_valve_flow_direction — Method.

constraints on flow across control valves

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GasModels.constraint_on_off_control_valve_pressure_drop — Method.

constraints on pressure drop across control valves

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GasModels.constraint_on_off_pipe_flow_direction — Method.

constraints on flow across pipes

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GasModels.constraint_on_off_pipe_flow_direction_ne — Method.

constraints on flow across pipes

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GasModels.constraint_on_off_pressure_drop — Method.

constraints on pressure drop across pipes

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GasModels.constraint_on_off_pressure_drop_ne — Method.

constraints on pressure drop across pipes

source

GasModels.constraint_on_off_short_pipe_flow_direction — Method.

constraints on flow across short pipes

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GasModels.constraint_on_off_valve_flow_direction — Method.

constraints on flow across valves

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GasModels.constraint_parallel_flow — Method.

ensures that parallel lines have flow in the same direction

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GasModels.constraint_parallel_flow_ne — Method.

ensures that parallel lines have flow in the same direction

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GasModels.constraint_sink_flow — Method.

Make sure there is at least one direction set to take flow to a junction (typically used on sink nodes)

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GasModels.constraint_sink_flow_ne — Method.

Make sure there is at least one direction set to take flow to a junction (typically used on sink nodes)

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GasModels.constraint_source_flow — Method.

Make sure there is at least one direction set to take flow away from a junction (typically used on source nodes)

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GasModels.constraint_source_flow_ne — Method.

Make sure there is at least one direction set to take flow away from a junction (typically used on source nodes)

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GasModels.variable_connection_direction — Method.

variables associated with direction of flow on the connections. yp = 1 imples flow goes from fjunction to tjunction. yn = 1 imples flow goes from tjunction to fjunction

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GasModels.variable_connection_direction_ne — Method.

variables associated with direction of flow on the connections

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