Aspen Fired Heater
(formerly Aspen FiredHeater)
Aspen Properties Package Option Added
Additional power has been added to the property options available in FiredHeater.
Users may now select components, VLE methods and mixture calculations from Aspen
Properties® in addition to COMThermo® and the B-JAC property databanks.
Fired Heater Inlet Pressure and Checking Calculation Options
For Fired Heater V7.0, in addition to the existing calculation where outlet
pressure is calculated from a specified inlet pressure, there are several new
pressure calculation options for each process stream. These are:
- Calculation of inlet pressure given a specified outlet pressure
- Checking of pressure change (inlet and outlet pressures fixed)
- Calculation of inlet pressure given a specified outlet pressure and a specified maximum pressure drop
- Calculation of outlet pressure given a specified inlet pressure and a specified maximum pressure drop.
Fired Heater Diagrams
Three types of diagrams have been added to FiredHeater for V7.0. These are developments of
diagrams seen in the heritage FIHR program.
a) Overall layout diagram is located on the Heater Geometry|Gas Flow|Heater diagram tab. This
shows the: basic firebox layout; number of convection banks; presence of stack and air-preheat.
b) Connections diagram: located on the Heater Geometry|Convection Banks|Connections diagram
tab. This shows the flow of each process stream through the firebox and convection banks (e.g., Figure 1).
c) Firebox diagram: located on the Heater Geometry|Firebox |Firebox diagram tab, is a detailed
scale diagram of the tube arrangement in the firebox. It shows: tube diameter; number; location;
orientation and separation (e.g., Figure 2).
Figure 1: Typical Connections Diagram
Figure 2: Typical Firebox Diagram views
Aspen Shell & Tube Mechanical
(formerly Aspen Teams)
Stress Analysis Improved
The stress analysis of a shell-and-tube heat exchanger has been improved with these
ASME code changes:
- The assembly tubesheet/shell/tubes is now analyzed for shell compression
stresses. Prior models only included the calculation and analysis of shell
tension stresses.
- The calculation of tube stresses across the tubesheet diameter has been
expanded. Tension and compression stresses are shown as well as the location of
such stresses in reference to parameter Xa (periphery).
- Added tubesheet shear stress calculations across the bundle diameter.
Similar to the tube stresses and tubesheet bending stresses, the shear
stresses are now calculated at all locations across the tubesheet diameter.
Added Calculation of Maximum Positive/Negative Axial Expansion
Aspen Shell & Tube Mechanical can now calculate the maximum positive and negative axial
expansion. This calculation is performed for fixed tubesheet units without expansion
joints. The program can now provide the maximum positive and negative axial expansion
(the amount the tubes can move in reference to the shell without the exchanger being
overstressed).
Expanded Design/Operating Load Conditions to 13
Aspen Shell & Tube Mechanical can simultaneously perform the calculations for up to 13
design/operating load conditions. The user can now enter operating pressures and temperatures
to cover a range of conditions that an exchanger will experience during operation. The design
selected by the program will satisfy all stated conditions of pressures and temperatures. This
capability will greatly simplify designs that need to comply with many different conditions.
The overall mechanical design quality is highly dependent on the correct thermal data transferred
to Shell & Tube Mechanical, thus emphasizing the importance of transfer of information from
Shell & Tube Exchanger.
Wind and Seismic Load Calculations Updated
The wind and seismic loads calculation methods have been updated to the latest standards,
the International Building Code (2006) and the Minimum Design Loads for Buildings
and Other Structures (ASCE 7-05).
Improved the Tube-to-Tubesheet Joint Load Calculations
The tube-to-tubesheet joint loads calculations for floating tubesheet exchangers have
been improved in completeness and presentation. The factor ¦T, used to account for
the relative thermal expansion of the tubes and tubesheet, has been further
refined. It can now take account of the condition where an expanded-only joint can weaken to the point
at which it no longer provides adequate joint strength. In such cases, a message will be issued
to alert the user of this potential danger.
Learn more about V7
- Sign up for the webinar series, request a demo, and see what else is new in this game-changing release.
Click here
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Aspen HTFS Research Network
Since its formation in 1968 HTFS has worked with the industry to develop state
of the art models and methods for process heat transfer and related equipment
using both in-house and collaborative research. This essential requirement of research
has continued after HTFS became part of Aspen Technology in 2002. Much of
the modeling information that is generated through the continuing programme
of analytical and experimental research is proprietary in nature. Our software
licensees benefit from this modeling information because it forms the basis of
technical developments in our software.
Our research brings improved design which offers capital and operating savings whilst
still providing assurance on specification performance. Some recent direct
benefits we can demonstrate include:
- Advanced flooded evaporator model for Shell&Tube (potential 30% capital saving)
- Improved airside pressure drop methods for AirCooled (demonstrating around 20% lower operating cost - see our description on Aspen Air Cooled Exchanger above)
- Advanced handling of multicomponent condensation (showing potential 19% capital saving)
- Post dryout heat transfer modelling (similar capital savings to the above)
The above are just of few examples of the competitive advantage our research can bring to our customers.
In addition to these benefits delivered through our software releases, there is another, more
immediate way of tapping into the benefits of our
on-going research activity and that is through the Aspen HTFS
Research Network. Using the Research Network our customers can have direct
on-line access to the research based modeling and design information. In addition
the Research Network licensees can also enjoys some special privileges. They can
participate in the Aspen HTFS Industrial Review Panels, which discuss the on-going
development of software and research before it reaches the wider customer base.
Following are some of the unique benefits that can be derived by subscribing to the Research Network.
- Access to core HTFS technology and expertise developed over the years
- Insight into the methods and models that are used in our heat transfer equipment design programs
- Partnership with Aspen HTFS through participation in the Industrial Review Panels
- Validation and QA of the models and methods in software
- Other practical uses of the Research Network information, e.g, for troubleshooting or
performance monitoring of heat exchangers
The information available in the Aspen HTFS Research Network can be grouped in four different areas:
HTFS Handbook: a comprehensive reference to heat exchanger theory and practice. It contains
142 process sheets which describe various physical processes such as boiling and condensation,
52 equipment sheets which describe various equipments such as fired heaters, reboilers etc and
244 method sheets which describe calculation procedures in stepwise manner, along with a worked
example. There are some 35 Handbook sheets which cover other important topics.
HTFS Design Reports: detailed derivation and comparisons of design methods; validation
of design procedures and description of the technical methods used in the Aspen Exchanger Design & Rating (EDR) programs.
HTFS Research Reports: generated from our extensive and on-going research
programme over the years. Currently there are more than 1200 Research reports, with more
being added each year.
HTFS HEATFLO: a database containing bibliographic references to over 120,000 high quality
experimental and theoretical research papers in the field of applied heat transfer and fluid
flow relevant to the needs of the chemical process and power industries.
This wealth of information facilitates:
- Improved design: by enabling full understanding of the heat exchange models, assumptions
and correlations used within AspenTech's heat exchanger software, to help ensure quality designs.
- Improved process operations: by providing access to a knowledge base to optimize and
troubleshoot plant performance.
- Increased engineering efficiency: by providing data for the development or update
of in-house models, correlations and tools to ensure these are based on the latest and
most accurate methodology.
The Aspen HTFS Research Network can thus be regarded as a comprehensive reference to
the science and technology supporting the Aspen EDR thermal design programs.
Searching the Aspen HTFS Research Network
To enable fast and easy retrieval of the relevant information the contents can be searched
using the powerful Google Search Application.
This has also been enhanced recently to allow the user to target their search to
specific document types such as the Handbook, Research Reports, Design Reports.
By clicking the link "or Search by section (Handbook etc)" which appears underneath the search box;
a new window will open allowing the user to select the required section(s) to search.
Once in the Google results page you can further refine your results by accessing
additional advanced search features such as searching within the results, restricting
the search words to the document title only etc.
Search Example
Suppose we want to find a research report on two-phase pressure drop models and
correlation for serrated fins which are commonly used for boiling applications
in plate fin heat exchangers. We enter the search string "serrated fin two-phase
pressure drop" and restrict the search to the Aspen HTFS Research Reports section.
From the search results we find that the most relevant Research Report is RS1125.
We open the RS1125 and obtain information on modeling methodology for two-phase
pressure drop in serrated fins. However, the two-phase correlations need information
for single phase friction factors which is documented in Aspen HTFS Handbook Sheet YM12.
The cross linking allows the user to click on the link for YM12 to open that document too.
The search facility and cross links make it so easy to find the information that you need!
If you do not have a license to access the Aspen HTFS Research Network already then
contact your nearest AspenTech sales office for a quote or e-mail us at htfs@aspentech.com.
