11-3085 Energy Analyzer Jump Start

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Jump Start: Aspen Energy Analyzer V8

A Brief Tutorial (and supplement to training and online documentation)

Nicholas Brownrigg, Associate Product Marketing Professional, Aspen Technology, Inc.Jack Zhang, Product Manager – Energy Management, Aspen Technology, Inc


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Table of ContentsIntroduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Activated Energy Analysis in Aspen Plus or Aspen HYSYS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Accessing Activated Energy Analysis Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Performing Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Activated Energy Analysis and Aspen Energy Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Preparing Aspen Plus or Aspen HYSYS Model for Export to Aspen Energy Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Aspen Plus Example Flowsheet: Ethylene Separation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Importing Process Flowsheets into Aspen Energy Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Importing an Excel Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Aspen Energy Analyzer Extraction Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Set Options Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Select Flowsheet Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Modify Utilities Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Modify Heaters Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Modify Coolers Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Economic Data Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Heat Integration Results and Heat Exchanger Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Unit of Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Heat Integration Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Heat Exchanger Network Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Optimization of the Heat Exchanger Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Entering Retrofit Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Performing Optimizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Ethylene Separation Simulation – Add Heat Exchanger Optimization One. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Ethylene Separation Simulation – Add Heat Exchanger Optimization Two . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Ethylene Separation Simulation – Add Heat Exchanger Optimization Three . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Ethylene Separation Simulation – Additional Optimizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24



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IntroductionIn today’s business climate, profitability is of pinnacle importance. One of the challenges facing industrial plants in

reaching profitability is the minimization of annual costs due to utility consumption. In order to achieve a reduction in

utility costs, many plants choose to perform an integration of heat exchangers. The specific network of heat exchangers

that make best use of the available in-house heating and cooling is constructed using pinch calculations. However, these

calculations can be daunting for simple plant setups with little equipment, and only increase in difficulty with a higher

sophistication of plant design.

To respond to this challenge, Aspen Technology has introduced innovative approaches to optimize energy use while

conducting process simulation in its Activated Energy Analysis and Aspen Energy Analyzer products.

Activated Energy Analysis operates inside the Aspen Plus or Aspen HYSYS modeling environment and with a single click,

provides a summary of annual utility and greenhouse gas expenditures, along with potential savings through optimization

of a process. Activated Energy Analysis generates various optimization scenarios that can be implemented to reduce

utility dependence, and shows details relevant to the optimization, including required capital cost, annual reduction in

utility cost, and payback period for investment.

Aspen Energy Analyzer allows a user to upload a process flowsheet created in Aspen Plus or Aspen HYSYS to be analyzed

for heating and cooling efficiency. Aspen Energy Analyzer constructs a pinch diagram for the heat exchanger network that

gives the best organization of process streams and supplied utilities to minimize utility consumption. Utilizing pinch

technology, Aspen Energy Analyzer guides users in designing the network by recovering the heat between heat sources

and sinks and minimizes the usage of heating and cooling mediums in the process plant.

Within a heat integration project, individual heat exchangers can be probed to view important, optimal descriptors, such

as duty, size, approach temperature, and hot and cold side stream names. Using the retrofit option, network topology, and

heat exchanger areas are able to be optimized multiple times to further reduce utility consumption through the relocation,

the resizing of existing heat exchangers, or the addition of new heat exchangers. Aspen Energy Analyzer also provides

capital costing and annualized heating and cooling costing (based on user specific utility input) for both the base case and

optimized cases.

This document is not meant to be used as a stand-alone reference document. We recommend that a range of other

resources be called upon to give the new user a comprehensive view of how to use Aspen Energy Analyzer and Activated

Energy Analysis in Aspen Plus and Aspen HYSYS. These may include:

• AspenTech support website (support.aspentech.com) – this website has a wealth of information on the use of

AspenTech products and provides answers to frequently asked questions.

• AspenTech courseware available in on-line and in-person versions

• AspenTech business consultants

This document will show how to take a process flowsheet from Aspen Plus or Aspen HYSYS and evaluate it using Aspen

Energy Analyzer and its many features. It assumes that the user has Aspen Plus V8 or higher, or Aspen HYSYS V8 or

higher installed on her or his computer and a completed functional process design.


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Activated Energy Analysis in Aspen Plus or Aspen HYSYSWhen Aspen Energy Analyzer is installed, it allows the user to perform quick energy saving optimizations on a completed

simulation in Aspen Plus V8 and Aspen HYSYS V8 using the new Activated Energy Analysis tool. The Activated Energy

Analysis tool provides three optimization scenario suggestions in order to reduce heating or cooling requirement. These

include resizing heat exchangers, adding extra heat exchangers to facilitate heat transfer, or moving heat exchangers to

different locations in the process flowsheet.

Accessing Activated Energy Analysis Tool

In order to begin using Activated Energy Analysis, go to the home tab in the Aspen Plus or Aspen HYSYS toolbar, and

ensure that under the ‘Analysis’ listing, the ‘Activated Analysis’ icon is selected.

Figure 1: How to Select Activated Analysis Icon

Once the ‘Activated Analysis’ icon has been selected, a new palette appears above the process flowsheet. To perform

optimizations, select the ‘Activated Energy Analysis’ icon as pictured below.

Figure 2: Activated Energy Analysis Icon

Performing Optimization

Once the ‘Activated Energy Analysis’ icon has been selected, a summary will appear showing a calculation of current

utility cost and a best-case optimization situation, along with its corresponding percentage change between the two

numbers. Also, if applicable, a total greenhouse gas expenditure of the process will be shown. To find heat integration

optimizations, press the blue arrow, circled in Figure 3 below.

Figure 3: Activated Energy Analysis Summary



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After clicking the arrow, a ‘Potential Design Change’ menu appears. Press the ‘Generate’ button and Activated EnergyAnalysis generates a list of design changes from a heat integration optimization, shown below.

Figure 4: Activated Energy Analysis Potential Design Changes

Once the Activated Energy Analysis tool has finished calculating, clicking a design change suggestion in the ‘Potential

Design Change’ menu will bring up a chart of economic and design details in the Energy Analysis section of Aspen Plus or

Aspen HYSYS. To view the details of the relocation of or area addition to a heat exchanger, either click the corresponding

suggestion in the ‘Potential Design Change’ menu, or select the appropriate scenario in the Energy Analysis listing

window. Figure 5 shows details for the scenario in which a new heat exchanger is added to the process.

Figure 5: Economic and Design Details for Process Optimization Suggestion in Activated Energy Analysis


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To compare the base design to the three new proposed optimization scenarios, click the ‘Compare Scenarios’ button in the

toolbar, and then select the ‘Result Comparison’ option in the Energy Analysis listing window. Those two steps, along with

a sample result comparison table example are shown in Figure 6 below.

Figure 6: Result Comparison for Three Optimization Scenarios

Activated Energy Analysis and Aspen Energy Analyzer

Both Aspen Energy Analyzer and the Activated Energy Analysis tool utilize pinch technology to calculate energy

consumption saving potential for a process and will suggest the same optimizations to reduce heating and cooling need.

The Activated Energy Analysis tool allows Aspen Plus and Aspen HYSYS users to experience process enhancement using

Aspen Energy Analyzer without having to leave the Aspen Plus or Aspen HYSYS modeling environment.

For more information regarding the use of Activated Energy Analysis in Aspen Plus or Aspen HYSYS, please refer to the

respective Jump Start guides covering the application in the Additional Resources section on the last page of this

document. Subsequent sections in this Jump Start will cover importing a process simulation from Aspen Plus or Aspen

HYSYS into the standalone Aspen Energy Analyzer program.

Preparing Aspen Plus or Aspen HYSYS Model for Export to Aspen Energy Analyzer(Note: This section of the Jump Start guide details the exportation of an Aspen Plus or Aspen HYSYS simulation to

Aspen Energy Analyzer. If a functional Aspen Energy Analyzer HI Project is already open, it is recommended to skip to

the ‘Heat Integration Results and Heat Exchanger Network’ section on page 13.)

Once a working process model is created in Aspen Plus, it must be saved in backup file (.bkp) format, as this is the type of

file compatible with Aspen Energy Analyzer. In Aspen HYSYS, the file format read by Aspen Energy Analyzer is ‘HYSYS

case’ (.hsc). To accomplish this, select the file option in Aspen Plus or Aspen HYSYS, then select the ‘Save As’ option. At

the bottom right of the save window that opens, open the scroll and choose the appropriate format.



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Figure 7: How to Save Document as Aspen Plus .bkp File

Figure 8: How to Save Document as Aspen HYSYS .hsc File


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Aspen Plus Example Flowsheet: Ethylene Separation

For the purpose of providing an example to demonstrate the breadth of Aspen Energy Analyzer, the following Aspen Plus

simulation showing the back end separation of an ethylene plant will be used in subsequent sections of this guide.

Equipment layout for this process is displayed in the following figure.

Figure 9: Flowsheet Showing Simulation of Ethylene Plant Separation to Be Analyzed

Importing Process Flowsheets into Aspen Energy Analyzer(Note: This section of the Jump Start guide details the setup of a new Aspen Energy Analyzer HI Project. If a functional

Aspen Energy Analyzer HI Project is already open, it is recommended to skip to the ‘Heat Integration Results and Heat

Exchanger Network’ section on page 13.)

Once Aspen Energy Analyzer has been opened, begin a new heat integration project by selecting the ‘New HI Project’

option as shown in Figure 10 below.

Figure 10: Opening a New Heat Integration Project



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Once a new project is opened, a window is created that will show the results of the heat integration and also allow the

user to optimize the heat exchanger setup. In order to begin the heat integration using Aspen Energy Analyzer, the Aspen

Plus or Aspen HYSYS flowsheet of interest must be imported. To do so, select the appropriate ‘Data Transfer from Aspen

HYSYS’ (left) icon, ‘Data Transfer From Aspen Plus’ (middle) icon. If the file to be uploaded is in Microsoft Excel format,

select the ‘Data Transfer From Excel’ (Right) icon. See figure 11 for these locations. Importing data from Microsoft Excel

requires a certain format, as described in the next subsection.

Figure 11: Extracting Data from Either Aspen Plus, Aspen HYSYS, or Microsoft Excel

Importing an Excel Document

A specifically formatted Microsoft Excel document can be used in lieu of an Aspen Plus or Aspen HYSYS flowsheet

simulation to obtain a heat integration in Aspen Energy Analyzer. An example Excel document displaying the proper

format and information required can be found under the ‘Samples’ folder in the Aspen Energy Analyzer V8 program file on

the computer’s C: drive. Figure 12 shows one of the sample Excel spreadsheets that displays the correct formatting and

process specifics.

Figure 12: Required Microsoft Excel Spreadsheet Formula for Importation

Aspen Energy Analyzer Extraction Wizard

Once an import option is selected, the tabbed Aspen Energy Analyzer extraction wizard will open-

The first tab in the extraction wizard gives tips to help complete the extraction process. After reading the tips, click ‘Next’.

This will bring up the tab in which the specific Aspen Plus or Aspen HYSYS flowsheet is to be chosen. Choose the third

‘Browse’ option down, circled below, then locate and select the appropriate .bkp file (Aspen Plus) or .hsc file (Aspen

HYSYS). Once the file is selected, click ‘Next’ in the extraction wizard.

Figure 13: Importing Specific Aspen Plus or Aspen HYSYS File

Set Options Tab

The next tab allows more detailed options for extraction to be selected. Ensure that the ‘Do not segment’ and ‘Extract live

stream’ boxes are unchecked, unless the specific process being modeled has streams that cannot be split or contains live

streams. Also, in most cases, pumps, recycle blocks, and pipe segments will be ignored. The ‘Set Options’ tab should then

appear as follows in Figure 14.


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Figure 14: Set Tab Allowing User to Provide Specifics

Select Flowsheet Tab

The ‘Select Flowsheet’ tab sorts through the uploaded flowsheet and finds blocks in the process that contain heat

exchangers. If there are no blocks desired to be excluded, ensure that each option is checked on this tab, and click ‘Next’.

Modify Utilities Tab

Under the ‘Modify Utilities’ tab, the type of utilities used to either heat or cool are chosen. Aspen Energy Analyzer

automatically chooses utility options that are suited to carry out the process as specified. However, other utility choices

exist that would alter the areas and as a result the capital costs of the heat exchangers. If a different utility type than the

ones provided is desired, select the modify option at the bottom of the tab (Figure 15). A scroll list of utility options is

available if the ‘<empty>’ box is clicked. After selecting the appropriate supplemental utilities, click ‘Lock’ and then ‘Next’

to continue to the next tab (Figure 16).


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Figure 15: How to Add a Utility Type to Heat Integration

Figure 16: Utility Scroll Menu and Lock Button

Modify Heaters Tab

In the ‘Modify Heaters’ tab, the user selects which utilities will be supplied to the heat exchangers used in heating

streams. Pair the desired utility with its corresponding heat exchanger and select ‘Next’.



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Modify Coolers Tab

The ‘Modify Coolers’ tab is the same as the ‘Modify Heaters’ tab, except the heat exchangers in this tab provide cooling.

Pair the desired utility with its corresponding heat exchanger and select ‘Next’.

Economic Data Tab

Aspen Energy Analyzer has default economic data factors included with the software package. There is no need to change

these factors from their default setting. Ensure that all factors are set to ‘DEFAULT’ and select ‘Next.’ This will lead to the

end of the extraction wizard. Select ‘Finish’ to view the results of the heat integration.

Heat Integration Results and Heat Exchanger NetworkUnit of Measurement

In order to obtain meaningful results, it is important to view results in the proper set of units required by the user of Aspen

Energy Analyzer. To do so, click the ‘Tools’ options, followed by ‘Preferences’. When the ‘Preferences’ menu appears, select

the ‘Variables’ tab, and under ‘Display Units’, select all user-appropriate options.

Heat Integration Results

After completing the extraction wizard, Aspen Energy Analyzer performs a heat integration of the uploaded flowsheet

using pinch technology, as described in the Introduction section of this Jump Start Guide. This heat integration is

displayed in a heat exchanger network diagram, showing which process streams or utilities enter and leave a given heat

exchanger. The result of the heat integration for the ethylene separation example proposed in the ‘Aspen Plus or Aspen

HYSYS Model’ section of this Jump Start guide is shown in Figure 17 and 18.


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Figure 17: Heat Exchanger Network and Details for Ethylene Separation

Figure 18: Zoomed View of Heat Exchanger Network



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On the heat exchanger network diagram, horizontal lines represent a process stream or utility. A blue horizontal line

indicates a cold stream that absorbs energy in a heat exchanger, while a red horizontal line indicates a hot stream that

loses energy in a heat exchanger. The streams are named according to their designation in Aspen Plus or Aspen HYSYS,

either to the left (hot stream) or to the right (cold stream) of the diagram. The starting temperature for cold streams is on

the right of the diagram, while the final temperature is on the left. The starting temperature for hot streams is on the left of

the diagram, while the final temperature is on the right.

The vertical lines and filled circles represent a heat exchanger pairing. Red circles represent a heat exchanger in which a

hot process stream or utility is required; similarly, blue circles represent a heat exchanger in which a cold process stream

or utility is required.

An individual heat exchanger can be probed on the heat exchanger network diagram by double clicking any of the colored

circles. Probing a heat exchanger provides additional details about it, such as its duty, area, and the cold and hot streams

that pass through it. Also provided are the temperature differentials between the two streams at the hot or cold end of the

heat exchanger. This is illustrated in Figure 19, which shows the details of HTR1 from the ethylene separation example.

Figure 19: HTR1 Details from Ethylene Separation Aspen Plus Example

If the user wishes to view a list of heat exchanger details in table form, click the ‘Heat Exchangers’ tab towards the bottom

of the Aspen Energy Analyzer program. The tab to select is circled in Figure 20. Figure 21 contains the table of heat

exchanger details. This table can be verified through the individual probing of each heat exchanger.


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Figure 20: Heat Exchangers Tab Showing Details of Heat Integration in Table Form

Figure 21: Heat Exchanger Detail Table

Heat Exchanger Network Performance

Return back to the ‘Performance’ tab by clicking the tab shown in Figure 22. This will bring up two tables below the heat

exchanger network diagram that detail the effectiveness of the base case heat integration calculation. The specific tables

for the ethylene separation example are shown below in Figure 23.



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Figure 22: Performance Tab Which Shows Performance Tables

Figure 23: Performance Tables for Ethylene Separation Aspen Plus Example

The table on the left provides the annualized cost of heating and cooling utilities, the annualized cost to operate the heat

exchanger network, the capital cost of purchasing the equipment included in the heat exchanger network, and the total

cumulative annualized cost to operate the heat exchanger network.

The table on the right provides the total amount of heating and cooling necessary in energy units, as well as the number of

heat exchangers and their shells. Also included is summation of heat exchanger area in the network.

The ‘% of Target’ column in each table is significant, because it shows whether an optimization to the heat exchanger

network is able to be performed. For the example shown in Figure 23, because 59,810 kW represent 111.9% of the target

heating consumption, heating can be reduced by as much as 11.9% through optimization of the heat exchanger network.

Similarly, since 61,920 kW is 111.4% of the target cooling load, once optimization is performed, the total area of the heat

exchangers in the network will decrease by up to 11.4%.


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Optimization of the Heat Exchanger NetworkEntering Retrofit Mode

Begin optimization of the heat exchanger network by selecting the ‘Enter Retrofit Mode’ option located underneath the

performance tab in the bottom left corner of the Aspen Energy Analyzer program. The ‘Enter Retrofit Mode’ button is

shown in Figure 24 below. Clicking brings up an options screen. Ensure that ‘Create New Retrofit Scenario’ is selected, and

then click ‘Enter Retrofit Environment’.

Figure 24: Enter Retrofit Mode Option

By clicking ‘Enter Retrofit Environment’, a clone of the original heat integration case should appear in the project viewer

box on the left of the Aspen Energy Analyzer program. The original heat integration is named ‘Scenario 1’, while the retrofit

clone is named ‘Scenario 1 1’.

Performing Optimizations

Three options exist for optimizing a heat integration in Aspen Energy Analyzer to further facilitate heat transfer. Area can

be added to existing heat exchangers, new heat exchangers can be added to the process, or one or more streams into a

heat exchanger can be rearranged with another heat exchanger. To begin, ensure that ‘SimulationBaseCase’ is selected

under ‘Scenario 1 1’ in the viewer box, and perform optimization by selecting the ‘Move One End of a Heat Exchanger’,

‘Move Both Ends of a Heat Exchanger’, ‘Add a Heat Exchanger’, or ‘Add Area’ option on the toolbar, as shown in Figure 25.



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Figure 25: Move End of Heat Exchanger, Add Heat Exchanger, and Add Area Options

After selecting one of the optimization options, a screen will prompt the user to provide a maximum investment cost. This

determines whether the optimization that Aspen Energy Analyzer performs is economically feasible within the now

defined budget. It is recommended, for best results, to input a large number, such as 1e9, in order to view all optimization

options available for the process.

After entering the maximum investment cost, Aspen Energy Analyzer performs optimizations and displays up to five

results for the option selected, under the cloned scenario in the viewer box.

Note that this is the same optimization process that occurs in Activated Energy Analysis as described in the first section

of this guide. However, in Aspen Energy Analyzer, once the first round of optimization is completed, further optimization

to the newly created optimized cases can be performed, as long as the target utility use has not been reached. For

instance, by using Aspen Energy Analyzer, a second heat exchanger can be added to a process that already had a new heat

exchanger inserted.

Ethylene Separation Simulation – Add Heat Exchanger Optimization One

For the ethylene separation example, after selecting the ‘Add Heat Exchanger’ option, three optimizations were suggested

by Aspen Energy Analyzer. The first optimization, named ‘SimulationBaseCase-1N-2’, recommends a 1186 m2 heat

exchanger to be added to the process. This allows for the total heating load to be reduced from 59,810 kW to 53,260 kW

while the total cooling load is reduced from 61,920 kW to 55,370 kW. The new heat exchanger network is shown in Figure

26, with the new heat exchanger shown in green.


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Figure 26: Heat Exchanger Network for Heat Exchanger Addition 1N-2

Along with a new heat exchanger network diagram, Aspen Energy Analyzer provides a new performance table that

numerically represents how the optimization would perform versus the original, base case heat integration. The table is

shown in Figure 27.

Figure 27: Performance Table for Heat Exchanger Addition 1N-2

As can be observed from this table, the optimized design’s heating cost index, heating load, cooling cost index, and cooling

load is less than that for the original base case heat integration. Also of interest are the ‘New Area Cost Index’ and

‘Operating Savings’ display windows. These windows quantify how much additional capital cost is necessary to implement

the newly designed optimization, and how much annually the process will save in utility costs for heating or cooling,

respectively. The ‘Payback’ display window tells the user how long it will take for the operating cost savings to intersect

the capital cost expenditure to insert the new optimization, i.e. when the operating cost savings become profit for the

operation of this process.



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Ethylene Separation Simulation – Add Heat Exchanger Optimization Two

In the second of the three heat exchanger addition optimizations, named ‘SimulationBaseCase-1N-3’, a new 3245 m2 heat

exchanger is inserted to the heat exchanger network, shown in green below in Figure 28. Similar to the first optimization,

this reduces fresh utility requirement for the other heat exchangers in the network. From Figure 29, it can be observed that

the optimization decreased heating cost index, heating load, cooling cost index, and cooling load.



Comparing the first optimization to the second optimization, this second optimization reduces heating cost index, heating

load, cooling cost index, and cooling load more than the first optimization. Ultimately, the second optimization reduces

operating cost more significantly than the first. However, the reduction comes at a greater capital cost expenditure, and

thus, optimization two’s payback period is longer than that for the first optimization.


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Ethylene Separation Simulation – Add Heat Exchanger Optimization Three

The third optimization suggested by Aspen Energy Analyzer, named ‘SimulationBaseCase-1N-4’, calls for the addition of a

1008 m2 heat exchanger. The reconfigured heat exchanger network and performance table for this third optimization are

shown below in Figure 30 and Figure 31.



As can be ascertained from the performance table, optimization three does not perform as well as the other two

optimization suggestions, but does represent a decrease in energy consumption and cost when compared to the base case

scenario.

Ultimately, it would be up to the process engineer or company utilizing Aspen Energy Analyzer to decide which

optimization case is most feasible and appropriate to implement, depending on plant life expectancy, desire to save

energy consumption versus cost, and other factors.



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Ethylene Separation Simulation – Additional Optimizations

On top of adding a single heat exchanger to the process as an optimization, any of the other optimization methods

described can be performed on the base case heat integration, either singularly or in concert with the add a heat

exchanger option.

For example, the user may choose to add a heat exchanger and then, assuming extra capital cost may be taken on, add a

second heat exchanger to the previously proposed scenario. Figure 32 and Figure 33 show a new heat exchanger network

and performance table, respectively, of ‘SimulationBaseCase-1N-4’ from the previous section after having the second heat

exchanger placed into the simulation.

Figure 32: Heat Exchanger Network for Heat Exchanger Addition 1N-4 with Second Heat Exchanger

Figure 33: Performance Table for Heat Exchanger Addition 1N-4 with Second Heat Exchanger

By adding the second heat exchanger, the heat integration shows improved performance when compared to the initial

optimization, from page 22, with only a single heat exchanger addition.


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Similarly, if the user had initially chosen to move both ends of a heat exchanger, rather than add a new heat exchanger, a

heat integration (such as in Figure 34) would have been offered showing the new heat exchanger alignment in green. The

accompanying performance table is featured in Figure 35.

Figure 34: Heat Exchanger Network After Moving Ends of Heat Exchanger for Ethylene Separation

Figure 35: Performance Table After Moving Ends of Heat Exchanger for Ethylene Separation

There are many possible optimization arrangements available to the user by using combinations of the ‘Move End of Heat

Exchanger’, ‘Add a Heat Exchanger’, and ‘Add Area’ options to tailor fit a heat integration of process heaters and coolers.

ConclusionAspen Energy Analyzer is an accurate and powerful tool that, in mere minutes, utilizes sophisticated pinch analytical

methods to reduce substantial amounts of heating and cooling costs. These savings in heating and cooling costs

generated will ultimately manifest themselves as profit for the user of Aspen Energy Analyzer. With only a few clicks,

Aspen Energy Analyzer provides a preliminary heat integration of process streams and up to five cases for each

optimization performed thereafter. Optimization further decreases heating and cooling consumption and cost from the

preliminary case. Aspen Energy Analyzer is a must-have accessory to Aspen Plus or Aspen HYSYS for the chemical,

petroleum, or pharmaceutical process looking to maximize revenue and minimize reliance on fresh utility supply and

environmental impact.



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Additional Resources

Public Website:

http://www.aspentech.com/products/aspen-hx-net.aspx

http://www.aspentech.com/products/aspen-hysys.aspx

http://www.aspentech.com/products/aspen-plus.aspx

Online Training:

http://www.aspentech.com/products/aspen-online-training

On-Demand Webinars:

Reduce Energy Costs with Advanced Process Design Demo

Activated Energy Brainshark:

Activated Energy in Aspen Plus

https://www.brainshark.com/aspentech1/activated-energy-aspen-plus

Activated Energy in Aspen HYSYS

https://www.brainshark.com/aspentech1/activated-energy-hysys

Jump Start Tutorials Series:

Jump Start: Activation in Aspen HYSYS V8.0:

http://www.aspentech.com/ActivationAspenHYSYS/

Jump Start: Activation in Aspen Plus V8.0:

http://www.aspentech.com/ActivationAspenPlus/

AspenTech YouTube Channel:

http://www.youtube.com/user/aspentechnologyinc

Activated Analysis in Aspen Plus

http://www.youtube.com/watch?v=f2LbjV7zk7o&list=PL0ADEB58FD49C6EBC&index=11

Activated Analysis in Aspen HYSYS

http://www.youtube.com/watch?v=8-GDWpbKBls&list=PL0ADEB58FD49C6EBC&index=12

https://aspentechevents.webex.com/ec0606l/eventcenter/recording/recordAction.do?theAction=poprecord&AT=pb&renewticket=0&isurlact=true&recordID=39826212&apiname=lsr.php&rKey=90d922f7691a9f06&format=short&needFilter=false&&SP=EC&rID=39826212&siteurl=aspentechevents&actappname=ec0606l&actname=%2Feventcenter%2Fframe%2Fg.do&rnd=5075634749&entappname=url0108l&entactname=%2FnbrRecordingURL.do

http://www.aspentech.com/ActivationAspenPlus/

Worldwide Headquarters

Aspen Technology, Inc.200 Wheeler RoadBurlington, MA 01803United States

phone: +1–781–221–6400fax: +1–781–221–[email protected]

Regional Headquarters

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For a complete list of offices, please visit www.aspentech.com/locations

© 2013 Aspen Technology, Inc. AspenTech®, aspenONE®, the Aspen leaf logo, the aspenONE logo, and OPTIMIZE are trademarks of AspenTechnology, Inc. All rights reserved. 11-3085-0313

About AspenTech

AspenTech is a leading supplier of software that optimizes process manufacturing—for energy, chemicals,

engineering and construction, and other industries that manufacture and produce products from a

chemical process. With integrated aspenONE® solutions, process manufacturers can implement best

practices for optimizing their engineering, manufacturing, and supply chain operations. As a result,

AspenTech customers are better able to increase capacity, improve margins, reduce costs, and become

more energy efficient. To see how the world’s leading process manufacturers rely on AspenTech to

achieve their operational excellence goals, visit www.aspentech.com.

http://www.aspentech.com/locations

[email protected]

Documents

11-3085 Energy Analyzer Jump Start