Domain Model

Once a problem is prepared, OpenPinch operates on a small set of in-memory domain objects. Understanding these classes is the key to using the package as more than a black box.

Core Objects

Zone

Hierarchical analysis boundary containing streams, utilities, targets, and graphs.

Stream

Process or utility stream with supply/target states, shifted temperatures, and active/base dt_cont behavior. A variable-heat-capacity parent owns an immutable ordered view of internal segment records while retaining one physical stream identity.

Segment mutations are transactional and revalidate the complete profile. Stream.update_segments(...) applies sparse changes to several children in one atomic commit; an invalid index, attribute, or resulting profile leaves the parent and every child unchanged. Runtime segment record classes are private; construct them through Stream mappings or StreamSegmentSchema inputs.

For segmented utilities, child prices may differ. The parent price is the duty-weighted effective value for each operating period, so the derived parent cost equals the sum of the child costs. Assigning parent.price is an explicit broadcast to every child; updating one child afterwards may make the prices differ again.

StreamCollection

Ordered container with hot/cold filtering and utility inversion helpers. Ordinary iteration and reports remain parent-based; explicit expanded exports include canonical parent keys and ordered segment identities.

ProblemTable

Numerical temperature-interval table behind composite curves, pinch temperatures, utility cascades, and several advanced targeting routines.

ProcessComponent

Memory-only component attached to a prepared problem when the model needs to be mutated before targeting. The direct process MVR component uses this layer to replace selected hot gas/vapour streams with compressed replacement streams.

HeatExchangerNetwork

Selected heat exchanger network design result with ordered exchanger records, period-aware total-duty helpers, and build_grid_diagram(period_id=...) for Plotly grid inspection. Period identity may be omitted only when the network has exactly one period.

HeatExchanger

One physical parent-level match in a synthesized network. For segmented streams, segment_area_contributions contains ordered diagnostic slices; shared topology, maximum design area, and capital data remain on the exchanger. Operating data is read from state(period_id).

Operating-period records are owned by each HeatExchanger and contain duty, activity, terminal approaches, branch split fractions, and source/sink inlet and outlet temperatures. Their runtime classes are private; multiperiod access always names the period through exchanger.state(period_id).

These are the objects you inspect when you need to understand how a case was prepared or why a target changed after mutating the in-memory model.

Key Classes

class OpenPinch.classes.zone.Zone(name='Zone', type='Process Zone', config=None, parent_zone=None)

Bases: object

Hierarchical analysis boundary containing streams, utilities, and targets.

Zones form the backbone of the in-memory OpenPinch model. Each zone can own process streams, utility streams, solved targets, generated graphs, and nested child zones. Direct and indirect integration routines progressively populate this structure as the analysis moves from local process scopes up to site-style aggregation.

Initialise an empty zone with stream, target, and graph containers.

Parameters:

• name (str)

• type (str)

• config (Optional[Configuration])

• parent_zone (Zone)

property name

Display name used when addressing the zone in the hierarchy.

property type

Zone type type from ZoneType.

property config

Configuration object controlling analysis behaviour for this zone.

property parent_zone

Direct parent zone in the site hierarchy, if any.

property active: bool

Whether the zone participates in the current analysis.

property period_ids: dict[str, int] | None

Canonical period_id -> idx lookup for this zone.

property weights

Canonical period weights for this zone.

property num_periods

Number of distinct states for this zone.

property address: str

Slash-delimited path from the root zone to this zone.

property dt_cont_multiplier: float

Effective multiplier applied to stream and utility dt_cont values.

property hot_streams

Process streams that release heat within this zone.

property cold_streams

Process streams that require heat within this zone.

property net_hot_streams

Net hot streams derived from zonal aggregation.

property net_cold_streams

Net cold streams derived from zonal aggregation.

property hot_utilities

Hot utility streams assigned to the zone.

property cold_utilities

Cold utility streams assigned to the zone.

property graphs

Graphs generated for this zone.

property subzones

Immediate child zones keyed by name.

property targets

Energy targets keyed by target name.

property process_streams

Combined hot and cold process streams for the zone.

property net_process_streams

Combined net hot and net cold process streams for the zone.

property utility_streams

Combined hot and cold utility streams for the zone.

property all_streams

All process and utility streams defined on the zone.

set_period_context(period_ids, weights, num_periods)

Set the canonical period lookup owned by this zone and propagate refs.

Parameters:

• period_ids (dict[str, int] | list[str] | tuple[str, ...] | None)

• num_periods (int | None)

Return type:

None

add_graph(name, result)

Store a graph result under name for later export or display.

Parameters:

name (str)

add_zone(zone_to_add, sub=True)

Add a single zone object keyed by its name.

If the zone name already exists: - If the zone is identical (e.g. same stream and utility objects), skip. - If it’s different, add it with a suffix like ‘_1’, ‘_2’, etc.

Parameters:

sub (bool)

add_target(target_to_add)

Add one target to a specific zone.

Parameters:

target_to_add (BaseTargetModel)

add_targets(targets=None)

Add multiple targets to a specific zone.

Parameters:

targets (list | None)

get_subzone(loc=None)

Resolve a slash-delimited zone path relative to this zone.

Parameters:

loc (str)

Return type:

Zone

calc_utility_cost()

Calculate and cache the annual utility cost across assigned utilities.

import_hot_and_cold_streams_from_sub_zones(get_net_streams=False, is_n_zone_depth=True, is_new_stream_collection=True)

Get referenced hot and cold streams across multiple subzones.

Parameters:

• get_net_streams (bool)

• is_n_zone_depth (bool)

• is_new_stream_collection (bool)

get_target_zone(zone_name)

Resolve zone_name to the concrete zone that should receive a target.

Parameters:

zone_name (str | list | None)

Return type:

Zone

lock_dt_cont_multiplier()

Lock the dt_cont_multiplier to prevent further changes.

class OpenPinch.classes.stream.Stream(name='Stream', t_supply=None, t_target=None, p_supply=None, p_target=None, h_supply=None, h_target=None, dt_cont=0.0, dt_cont_multiplier=1.0, heat_flow=0.0, htc=1.0, price=None, is_process_stream=True, fluid_name=None, fluid_phase=None, segments=None)

Bases: object

Generic thermal stream used for both process and utility duties.

A Stream stores supply/target states together with derived values such as hot/cold classification, shifted temperature bounds, heat-capacity flow rate, and simple economic attributes. The same class is reused for process streams, utilities, and derived net streams created during site- level aggregation.

Initialise a stream and infer hot/cold classification.

Parameters:

• name (str)

• t_supply (Optional[MaybeVU])

• t_target (Optional[MaybeVU])

• p_supply (Optional[MaybeVU])

• p_target (Optional[MaybeVU])

• h_supply (Optional[MaybeVU])

• h_target (Optional[MaybeVU])

• dt_cont (MaybeVU)

• dt_cont_multiplier (float)

• heat_flow (MaybeVU)

• htc (MaybeVU)

• price (Optional[MaybeVU])

• is_process_stream (bool)

• fluid_name (Optional[str])

• fluid_phase (Optional[str | FluidPhase])

• segments (list[object] | tuple[object, ...] | None)

property name: str

Stream name.

property is_process_stream: bool

Process or utility stream.

property fluid_name: str | None

CoolProp fluid name or mixture specification.

property fluid_phase: str | None

sol, sle, liq, vle, sve, or gas.

Type:

Optional fluid-phase flag

property segments: tuple[StreamSegment, ...]

Ordered immutable view of the stream’s piecewise thermal segments.

property has_segments: bool

Return whether this physical stream has an explicit thermal profile.

property segment_count: int

Return the number of explicit thermal segments.

property type: str | None

Stream type (Hot, Cold, Both).

property num_periods: int | None

Number of periods.

property t_supply: Value | None

Supply temperature (e.g., degC).

property t_target: Value | None

Target temperature (e.g., degC).

property p_supply: Value | None

Supply pressure (e.g., kPa).

property p_target: Value | None

Target pressure (e.g., kPa).

property h_supply: Value | None

Supply enthalpy (e.g., kJ/kg).

property h_target: Value | None

Target enthalpy (e.g., kJ/kg).

property dt_cont: Value

Preserved base delta-T contribution before any zone multiplier.

property dt_cont_act: Value

Effective delta-T contribution used in shifted-temperature calculations.

property dt_cont_multiplier: float

Effective delta-T contribution used in shifted-temperature calculations.

property dt_cont_multiplier_locked: bool

Whether the delta-T contribution multiplier is locked against changes.

property heat_flow: Value

Stream heat flow view over a scalar or multiperiod duty value.

property htc: float

Heat transfer coefficient (e.g., kW/m^2/K).

property htr: Value | None

Heat transfer resistance (e.g., m^2.K/kW).

property price: Value

Unit energy price (e.g., $/MWh).

property ut_cost: Value | None

Utility cost (e.g., $/y).

property CP: Value | None

Heat capacity flowrate (e.g., kW/K).

property rCP: Value | None

Resistance-capacity product (1/heat transfer rate).

property active: bool

Whether the stream is active in analysis.

property t_min: Value | None

Minimum temperature (supply or target depending on hot/cold).

property t_max: Value | None

Maximum temperature (supply or target depending on hot/cold).

property t_min_star: Value | None

Shifted minimum temperature.

property t_max_star: Value | None

Shifted maximum temperature.

property t_entr_mean: Value | None

Entropic mean temperature of supply and target temperatures.

property stream_type: str | None

Alias for the stream thermal type.

property is_active: bool

Alias for whether the stream participates in analysis.

property supply_temperature: Value | None

Alias for the supply temperature.

property target_temperature: Value | None

Alias for the target temperature.

property minimum_temperature: Value | None

Alias for the minimum stream temperature.

property maximum_temperature: Value | None

Alias for the maximum stream temperature.

property shifted_minimum_temperature: Value | None

Alias for the shifted minimum stream temperature.

property entropic_mean_temperature: Value | None

Alias for the entropic mean temperature.

property shifted_maximum_temperature: Value | None

Alias for the shifted maximum stream temperature.

property supply_pressure: Value | None

Alias for the supply pressure.

property target_pressure: Value | None

Alias for the target pressure.

property supply_enthalpy: Value | None

Alias for the supply enthalpy.

property target_enthalpy: Value | None

Alias for the target enthalpy.

property delta_t_contribution: Value

Alias for the base shifted-temperature contribution.

property delta_t_contribution_multiplier: float

Alias for the shifted-temperature contribution multiplier.

property effective_delta_t_contribution: Value

Alias for the effective shifted-temperature contribution.

property heat_transfer_coefficient: Value

Alias for the heat transfer coefficient.

property heat_transfer_resistance: Value | None

Alias for the heat-transfer resistance.

property utility_cost: Value | None

Alias for the derived utility cost.

property resistance_capacity_product: Value | None

Alias for the stream resistance-capacity product.

invert()

Flip a utility stream into its generating process-stream analogue.

Return type:

None

replace_segments(segments)

Normalize and atomically replace the piecewise profile.

Return type:

None

update_segment(index, **changes)

Apply one segment update transactionally and revalidate the profile.

Parameters:

index (int)

Return type:

None

update_segments(updates)

Atomically apply sparse attribute changes to ordered child segments.

Parameters:

updates (Mapping[int, Mapping[str, object]])

Return type:

None

classmethod from_temperature_heat_profile(*, name, points, heat_scale=1.0, heat_unit='kW', dt_diff_max=None, **stream_kwargs)

Build one segmented stream from ordered [heat, temperature] points.

Parameters:

• name (str)

• heat_scale (float)

• heat_unit (str)

• dt_diff_max (float | None)

Return type:

Stream

class OpenPinch.classes.stream_collection.StreamCollection(streams=None)

Bases: object

A dynamic, ordered collection of streams.

Key features include:

• Add and remove streams by name.

• Prevent overwriting existing streams by auto-renaming.

• Configure sort keys as attributes or callables.

• Iterate efficiently with lazy sorting.

• Support ascending or descending ordering.

Initialise an empty collection sorted by descending supply temperature.

Parameters:

streams (List['Stream'] | None)

property period_ids: dict[str, int] | None

Return the canonical period identifiers for this collection.

property weights: ndarray | None

Return the canonical period weights for this collection.

property num_periods: int | None

Return the number of periods for this collection.

add(stream, key=None, prevent_overwrite=True)

Insert a stream, optionally renaming the key to avoid collisions.

Parameters:

• stream (Stream)

• key (str)

• prevent_overwrite (bool)

Return type:

str

add_many(streams, keys=None, prevent_overwrite=True)

Insert several streams, optionally using explicit keys for each stream.

Parameters:

• streams (List[Stream])

• prevent_overwrite (bool)

remove(stream_name)

Remove a stream by name.

Parameters:

stream_name (str)

sum_stream_attribute(attr_name, idx=None)

Return the total of a specified attribute for streams in the collection.

Parameters:

• attr_name (str)

• idx (int | None)

Return type:

float

set_common_stream_attribute(attr_name, value, *, idx=None)

Set a common attribute across all streams in the collection.

Parameters:

• attr_name (str)

• value (Any)

• idx (int | None)

set_sort_key(key, reverse=False)

Set the sorting key. Supports attribute names or custom lambdas.

Parameters:

• key (str | List[str] | Callable)

• reverse (bool)

copy(*, deep=False)

Return a copy of the collection, optionally deep-copying streams.

Parameters:

deep (bool)

Return type:

StreamCollection

set_period_context(period_ids, weights, num_periods=None)

Persist the canonical shared period model for this collection.

Parameters:

• period_ids (dict[str, int] | list[str] | tuple[str, ...] | None)

• weights (ndarray | list[float] | tuple[float, ...] | None)

• num_periods (int | None)

Return type:

None

numeric_view(idx=None)

Return a cached dense numeric view for stream-analysis kernels.

Parameters:

idx (int | None)

Return type:

StreamCollectionNumericView

segment_numeric_view(idx=None)

Return a cached numeric view expanded to ordered thermal segments.

Parameters:

idx (int | None)

Return type:

StreamCollectionNumericView

get_index(stream)

Return the position (index) of a stream object in the sorted stream list.

Return type:

int

items()

Return the underlying keyed stream items in insertion order.

export_to_csv(filename='heat pump streams')

Export stream data to results/<filename> and return the path written.

Parameters:

filename (str)

Return type:

Path

to_dict(idx=None, *, expand_segments=False)

Return stream data as serializable rows in standard reporting order.

Parameters:

• idx (int | None)

• expand_segments (bool)

Return type:

dict[str, list[Any]]

get_hot_streams(include_process_streams=True, include_utility_streams=True, invert_utility=False, sort_attr=None)

Return a new collection containing only hot streams.

Parameters:

• include_process_streams (bool)

• include_utility_streams (bool)

• invert_utility (bool)

• sort_attr (str | None)

get_cold_streams(include_process_streams=True, include_utility_streams=True, invert_utility=False, sort_attr=None)

Return a new collection containing only cold streams.

Parameters:

• include_process_streams (bool)

• include_utility_streams (bool)

• invert_utility (bool)

• sort_attr (str | None)

get_process_streams(sort_attr=None)

Return a new collection containing only process streams.

Parameters:

sort_attr (str | None)

get_hot_process_streams(sort_attr=None)

Return a new collection containing only hot process streams.

Parameters:

sort_attr (str | None)

get_cold_process_streams(sort_attr=None)

Return a new collection containing only cold process streams.

Parameters:

sort_attr (str | None)

get_utility_streams(sort_attr=None)

Return a new collection containing only utility streams.

Parameters:

sort_attr (str | None)

get_hot_utility_streams(sort_attr=None)

Return a new collection containing only hot utility streams.

Parameters:

sort_attr (str | None)

get_cold_utility_streams(sort_attr=None)

Return a new collection containing only cold utility streams.

Parameters:

sort_attr (str | None)

get_inverted_hot_utility_streams(sort_attr=None)

Return a new collection containing only inverted hot utility streams.

Parameters:

sort_attr (str | None)

get_inverted_cold_utility_streams(sort_attr=None)

Return a new collection containing only inverted cold utility streams.

Parameters:

sort_attr (str | None)

class OpenPinch.classes.problem_table.ProblemTable(data_input=None, add_default_labels=True)

Bases: object

NumPy-backed pinch problem table with enum-friendly accessors.

Initialise the table from a dictionary or list-of-columns structure.

Parameters:

• data_input (dict[str | ProblemTableLabel, object] | list | None)

• add_default_labels (bool)

class ColumnViewByIndex(parent)

Bases: object

Expose read/write access to columns addressed by integer index.

Parameters:

parent (ProblemTable)

property icol

Return a view for column access by integer position.

class ColumnViewByName(parent)

Bases: object

Expose read/write access to columns addressed by label or enum.

Parameters:

parent (ProblemTable)

property col

Return a view for column access by string label or ProblemTableLabel.

class ColumnsViewByName(parent)

Bases: object

Vectorised view over multiple labelled columns or enums.

Parameters:

parent (ProblemTable)

property cols

Return a vectorised view over multiple labelled columns or enums.

class LocationByRowByColName(parent)

Bases: object

Row/column accessor mirroring DataFrame.loc semantics.

Parameters:

parent (ProblemTable)

property loc

Expose row/column access using label semantics (loc).

class LocationByRowByCol(parent)

Bases: object

Row/column accessor mirroring DataFrame.iloc semantics.

Parameters:

parent (ProblemTable)

property iloc

Expose row/column access using positional semantics (iloc).

slice(keys)

Return a new ProblemTable containing only the requested columns.

Parameters:

keys (str | ProblemTableLabel | Sequence[str | ProblemTableLabel])

Return type:

ProblemTable

property shape

Tuple describing (rows, columns) for the buffer.

property to_dataframe: DataFrame

Convert the buffer into a pandas DataFrame.

property copy

Return a deep copy of the table.

to_list(col=None)

Return table data as Python lists; optionally restrict to a single column.

Parameters:

col (str | ProblemTableLabel | None)

round(decimals)

Round the underlying NumPy buffer in-place.

pinch_idx(col=ProblemTableLabel.H_NET)

Return the row indices of the hot and cold pinch temperatures.

Parameters:

col (int | str | ProblemTableLabel)

Return type:

Tuple[int, int, bool]

pinch_temperatures(col_T=ProblemTableLabel.T, col_H=ProblemTableLabel.H_NET)

Determine the hottest hot and coldest cold pinch temperatures.

Parameters:

• col_T (str | ProblemTableLabel)

• col_H (int | str | ProblemTableLabel)

Return type:

Tuple[float | None, float | None]

shift_heat_cascade(dh, col)

Shift a heat-cascade column by dh and return a table copy.

Parameters:

• dh (float)

• col (int | str | ProblemTableLabel)

Return type:

ProblemTable

share_temperature_intervals(other)

Mutate both tables so they use the union of their temperature intervals.

Returns a tuple containing (rows_inserted_into_self, rows_inserted_into_other).

Parameters:

other (ProblemTable)

Return type:

Tuple[int, int]

insert_temperature_interval(T_ls)

Insert any missing temperature intervals and return count inserted.

Parameters:

T_ls (List[float] | float)

Return type:

int

insert(row_dict, index)

Insert a single row (dict of column: value) at the specified index.

Parameters:

• row_dict (dict)

• index (int)

update_row(index, row_dict)

Update selected columns for one row using values from row_dict.

Parameters:

• index (int)

• row_dict (dict)

update(updates=None, T_col=None)

Assign aligned column values in-place using an explicit source T column.

Parameters:

• updates (dict[str | ProblemTableLabel, ndarray] | None)

• T_col (ndarray | None)

Return type:

ProblemTable

delete_row(index)

Remove a row at index from the buffer.

Parameters:

index (int)

sort_by_column(column, ascending=True)

Sort rows in-place by the given column.

Parameters:

• column (str | ProblemTableLabel)

• ascending (bool)

export(filename='problem_table', sheet_name='ProblemTable', include_index=False)

Export the table to results/<filename>.xlsx and return the path.

Parameters:

• filename (str)

• sheet_name (str)

• include_index (bool)

Return type:

Path

class OpenPinch.classes.heat_exchanger_network.HeatExchangerNetwork(*, exchangers=<factory>, run_id=None, task_id=None, period_id=None, method=None, stage_count=None, objective_value=None, total_annual_cost=None, utility_cost=None, capital_cost=None, summary_metrics=<factory>, solver_axis_metadata=<factory>, source_metadata=<factory>)

Bases: BaseModel

Ordered heat exchanger network result collection.

Create a new model by parsing and validating input data from keyword arguments.

Raises [ValidationError][pydantic_core.ValidationError] if the input data cannot be validated to form a valid model.

self is explicitly positional-only to allow self as a field name.

Parameters:

• exchangers (tuple[HeatExchanger, ...])

• run_id (str | None)

• task_id (str | None)

• period_id (str | None)

• method (str | None)

• stage_count (int | None)

• objective_value (float | None)

• total_annual_cost (float | None)

• utility_cost (float | None)

• capital_cost (float | None)

• summary_metrics (dict[str, float | int | str | bool | None])

• solver_axis_metadata (dict[str, Any])

• source_metadata (dict[str, Any])

model_config = {'extra': 'forbid', 'validate_assignment': True}

Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].

build_grid_diagram(*, period_id=None, stream_line_width=5.0, temperature_scaled=False)

Return a grid diagram for this heat exchanger network.

Parameters:

• period_id (str | None)

• stream_line_width (float)

• temperature_scaled (bool)

Return type:

Any

quantify_controllability(*, period_id=None, **kwargs)

Return steady-state controllability metrics for this network.

Parameters:

• period_id (str | None)

• kwargs (Any)

Return type:

Any

property period_ids: tuple[str, ...]

Return ordered period identities represented by exchanger states.

resolve_period_id(period_id=None)

Resolve an optional period identity without ambiguous multiperiod access.

Parameters:

period_id (str | None)

Return type:

str | None

exchangers_involving_stream(stream_id, *, active_only=False, period_id=None)

Return all exchangers that use stream_id as source or sink.

Parameters:

• stream_id (str)

• active_only (bool)

• period_id (str | None)

Return type:

tuple[HeatExchanger, …]

exchanger_between(*, source_stream, sink_stream, stage=None, kind=None)

Return the unique exchanger for a labelled source/sink/stage link.

Parameters:

• source_stream (str)

• sink_stream (str)

• stage (int | None)

• kind (HeatExchangerKind | str | None)

Return type:

HeatExchanger | None

total_duty(*, kind=None, stream=None, stage=None, active_only=True, period_id=None)

Return duty total filtered by kind, stream identity, and stage.

Parameters:

• kind (HeatExchangerKind | str | None)

• stream (str | None)

• stage (int | None)

• active_only (bool)

• period_id (str | None)

Return type:

float

total_area(*, kind=None, stream=None, stage=None, active_only=True, period_id=None)

Return area total filtered by kind, stream identity, and stage.

Parameters:

• kind (HeatExchangerKind | str | None)

• stream (str | None)

• stage (int | None)

• active_only (bool)

• period_id (str | None)

Return type:

float

total(label, *, kind=None, stream=None, stage=None, active_only=True, period_id=None)

Return a numeric total for a supported heat exchanger network label.

Parameters:

• label (HeatExchangerNetworkLabel | str)

• kind (HeatExchangerKind | str | None)

• stream (str | None)

• stage (int | None)

• active_only (bool)

• period_id (str | None)

Return type:

float

labelled_value(label, *, source_stream, sink_stream, stage=None, kind=None, period_id=None)

Return a labelled value from one source/sink/stage exchanger link.

Parameters:

• label (HeatExchangerNetworkLabel | str)

• source_stream (str)

• sink_stream (str)

• stage (int | None)

• kind (HeatExchangerKind | str | None)

• period_id (str | None)

Return type:

float | bool | None

class OpenPinch.classes.heat_exchanger.HeatExchanger(*, exchanger_id=None, kind, source_stream, sink_stream, source_stream_role, sink_stream_role, stage=None, period_states, area=None, match_allowed=True, capital_cost=None, segment_area_contributions=<factory>, solver_metadata=<factory>, source_metadata=<factory>)

Bases: BaseModel

One labelled heat-transfer link in a heat exchanger network.

Create a new model by parsing and validating input data from keyword arguments.

Raises [ValidationError][pydantic_core.ValidationError] if the input data cannot be validated to form a valid model.

self is explicitly positional-only to allow self as a field name.

Parameters:

• exchanger_id (str | None)

• kind (HeatExchangerKind)

• source_stream (str)

• sink_stream (str)

• source_stream_role (HeatExchangerStreamRole)

• sink_stream_role (HeatExchangerStreamRole)

• stage (int | None)

• period_states (Annotated[tuple[HeatExchangerPeriodState, ...], MinLen(min_length=1)])

• area (float | None)

• match_allowed (bool)

• capital_cost (float | None)

• segment_area_contributions (tuple[HeatExchangerAreaSlice, ...])

• solver_metadata (dict[str, Any])

• source_metadata (dict[str, Any])

model_config = {'extra': 'forbid', 'validate_assignment': True}

Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].

property has_segment_area_contributions: bool

Return whether exact local segment-area slices are available.

property segment_duty_by_period: dict[str, float]

Return local slice duty totals grouped by operating period.

property segment_area_by_period: dict[str, float]

Return local slice area totals grouped by operating period.

property segment_design_area: float | None

Return the maximum period-total slice area when slices are available.

property period_ids: tuple[str, ...]

Return ordered operating-period identities for this exchanger.

state(period_id=None)

Return one period state, requiring identity for multiperiod results.

Parameters:

period_id (str | None)

Return type:

HeatExchangerPeriodState

involves_stream(stream_id)

Return whether this exchanger uses stream_id as source or sink.

Parameters:

stream_id (str)

Return type:

bool

matches(*, source_stream, sink_stream, stage=None)

Return whether this exchanger matches a labelled stream-stage link.

Parameters:

• source_stream (str)

• sink_stream (str)

• stage (int | None)

Return type:

bool

Process Components

Process components are attached to a live PinchProblem and are not part of the external input schema. They are useful for before/after studies where a specific unit operation changes the active process stream set before targeting.

class OpenPinch.services.components.process_components.ProcessComponent(id, problem, component_type, active=True)

Bases: object

Base class for memory-only process components.

Parameters:

• id (str)

• problem (PinchProblem)

• component_type (str)

• active (bool)

activate()

Activate the component.

deactivate()

Deactivate the component.

class OpenPinch.services.components.process_mvr.ProcessMVRComponent(id, problem, component_type='process_mvr', active=True, settings=<factory>, source_selectors=<factory>, stream_records=<factory>)

Bases: ProcessComponent

Memory-only direct process MVR component.

Parameters:

• id (str)

• problem (PinchProblem)

• component_type (str)

• active (bool)

• settings (DirectGasMVRSettings)

• source_selectors (list[Any])

• stream_records (list[_ProcessMVRStreamRecord])

activate()

Use the MVR replacement streams in subsequent targeting.

deactivate()

Restore the original source streams for subsequent targeting.

work_for_zone(zone, *, period_id=None, period_idx=None)

Return active compressor work assigned to streams inside zone.

Parameters:

• zone (Zone)

• period_id (str | None)

• period_idx (int | None)

Return type:

float

Solved Target Records

Targets are stored on zones and normalized through schema models before export. The base target schema is a useful reference when you are programmatically comparing cases or consuming target results in another tool.

class OpenPinch.lib.schemas.targets.BaseTargetModel(*, zone_name=None, period_id=None, period_idx=None, name, type, parent_zone=None, config=<factory>, active=True)

Bases: BaseModel

Shared metadata for all solved target objects.

Create a new model by parsing and validating input data from keyword arguments.

Raises [ValidationError][pydantic_core.ValidationError] if the input data cannot be validated to form a valid model.

self is explicitly positional-only to allow self as a field name.

Parameters:

• zone_name (str | None)

• period_id (str | None)

• period_idx (int | None)

• name (str)

• type (str)

• parent_zone (Any)

• config (Configuration)

• active (bool)

model_config = {'arbitrary_types_allowed': True, 'extra': 'forbid', 'validate_assignment': True}

Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].

to_target_results(isTotal=False)

Convert the runtime target into the exported reporting schema.

Parameters:

isTotal (bool)

Return type:

TargetResults

serialize_json(isTotal=False)

Serialise the reporting-schema view of this target to plain Python.

Parameters:

isTotal (bool)

Return type:

dict[str, Any]

How These Objects Relate

The usual flow is:

1. input schemas describe the external inputs

2. preparation turns those inputs into Zone and Stream objects

3. targeting populates ProblemTable objects, zone targets, and graph data

4. result schemas serialize the solved state back out

That layering is what lets the package support both high-level scripted use and deeper programmatic inspection.