ExergyInfo

R2026b

Information about exergy and exergy rate usage by block in the model

Since R2026b

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Description

An ExergyInfo object contains the categorized exergy and exergy rate usage for the block. The object is empty if the block does not calculate exergy.

Creation

To create an ExergyInfo object, use the getEnergyInfo function.

Properties

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Block name, including the path to the block in the model.

Assumptions used in calculating exergy info for the block, presented as a table. Table rows are exergy types and table columns are exergy categories. For each combination of exergy type and category, the table lists whether this exergy is measured, assumed zero, or derived from energy balance.

Table of the net exergy change during simulation, for the time range available in the simulation log, listed by exergy type and category.

A structure that contains block port names, domains, and the time table of the exergy rate at the ports at each step during simulation.

A time table showing the evolution of cumulative exergy change at each step during simulation, listed by exergy type and category.

A time table showing the evolution of the instantaneous exergy rate, that is, the rate of change of cumulative exergy, at each step during simulation, listed by exergy type and category.

Object Functions

plotPlot data associated with EnergyInfo or ExergyInfo object

Examples

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This example shows how you can get energy and exergy usage for a thermal liquid block in a model.

Open the Optimal Pipeline Geometry for Heated Oil Transportation example model, which already has data logging enabled for the whole model. 

openExample("simscape/OptimalPipelineGeometryForHeatedOilTransportationExample")

Enable energy accounting and run the simulation to create the simulation log variable simlog_OptimalPipelineGeometryForHeatedOilTransportation (as specified by the Workspace variable name model configuration parameter) in your current workspace:

set_param(bdroot,"SimscapeUseEnergyAccounting","on")
sim(bdroot);

Get the energy and exergy usage for the Pipe (TL) block. You can use tab completion to navigate through the simulation log data tree. You can also use the simscape.logging.findNode function to find the node corresponding to the block.

[pipe_energyInfo,pipe_exergyInfo] = getEnergyInfo(simlog_OptimalPipelineGeometryForHeatedOilTransportation.Pipe_TL)
pipe_energyInfo = 

  EnergyInfo with properties:

           Path: "OptimalPipelineGeometryForHeatedOilTransportation/Pipe (TL)"
    Assumptions: [2×5 table]
        Summary: [2×5 table]
          Ports: [1×1 struct]
         Energy: [57×2 timetable]
          Power: [57×2 timetable]


pipe_exergyInfo = 

  ExergyInfo with properties:

           Path: "OptimalPipelineGeometryForHeatedOilTransportation/Pipe (TL)"
    Assumptions: [2×6 table]
        Summary: [2×6 table]
          Ports: [1×1 struct]
         Exergy: [57×2 timetable]
     ExergyRate: [57×2 timetable]

For a thermal fluid block, comparing energy and exergy tables aids in understanding of how the block works. First, view the energy usage summary.

pipe_energyInfo.Summary
ans =

  2×5 table

         Type               Ports         External       Converted         Accumulated  
    _______________    _______________    ________    _______________    _______________

    "Thermal"          -2.3061e+08 (J)     0 (J)       2.3061e+08 (J)              0 (J)
    "ThermalLiquid"     2.2737e+08 (J)     0 (J)      -2.3194e+08 (J)    -4.5711e+06 (J)

The summary shows that the block acquired 2.2737e+08 J of thermal liquid energy through its ports, partially accumulated it and partially converted this energy into thermal. The thermal energy left the block through its thermal port.

Now, view the exergy usage summary.

pipe_exergyInfo.Summary
ans =

  2×6 table

         Type               Ports         External       Converted         Accumulated           Lost     
    _______________    _______________    ________    _______________    _______________    ______________

    "Thermal"          -2.7555e+07 (J)     0 (J)       2.7569e+07 (J)              0 (J)         13718 (J)
    "ThermalLiquid"     2.0573e+08 (J)     0 (J)      -2.8869e+07 (J)    -1.6877e+06 (J)    1.7854e+08 (J)

This summary shows the impact of environmental conditions on the fluid flow. The table contains an additional column, which reports the lost, or wasted, exergy. For more information, see Energy Accounting in Fluid Domains.

You can also check the assumptions used in calculating exergy info for the block. 

pipe_exergyInfo.Assumptions
ans =

  2×6 table

         Type            Ports          External                 Converted               Accumulated         Lost   
    _______________    __________    ______________    _____________________________    ______________    __________

    "Thermal"          "Measured"    "Assumed zero"    "Derived from energy balance"    "Assumed zero"    "Measured"
    "ThermalLiquid"    "Measured"    "Assumed zero"    "Derived from energy balance"    "Measured"        "Measured"

The assumptions table shows that the energy usage tool measures thermal liquid exergy and thermal exergy through the ports, accumulated thermal liquid exergy, and lost exergy of both types. External exergy of both types and accumulated thermal exergy are assumed zero. Converted exergy of both types is derived from energy balance.

Version History

Introduced in R2026b

See Also

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