hotlineheat transfer software & research

®

No. 57 September 2001

HTFS is pleased to announce release of TASC v5.00.

TASC v5.00 users will immediately notice the newinteractive Tube Layout Drawing, which appears inChecking and Simulation modes. We haveincorporated the functionality of the OPTU program(and more) directly into TASC. The drawing isgenerated by a completely new tube count packagewhich means that TASC will now work with an exacttube count that you can preview and adjust. You willbe able to add or delete tubes, tie rods and sealingstrips, and make positional adjustments, prior to thethermal calculations. There are new input items toallow users to specify the tube bundle bandorientation, select options for bundle symmetry andgenerally define the bundle layout much moreprecisely than could be done previously.

The TASC thermal calculations and the new tubelayout drawing are fully linked with the optional TASC-Mechanical package (formerly MECHX). The completeTASC package now provides a powerful one-stopsolution to complete thermal and mechanical design.

Another major new benefit to TASC v5.00 users isthe inclusion of the Hyprotech COMThermoTM physicalproperties package. COMThermoTM, provided at noextra cost, greatly extends the number of componentsavailable and the wide range of VLE methods allowsaccurate calculations of temperature/enthalpy curvesto be performed within the TASC environment. The

user interface allows display and review of thecalculated properties before running the TASC thermalcalculations.

There are also significant enhancements andextensions to the TASC calculations.

� Specification of Performance Data. TASC v5.00allows the user to supply performance data for in-tubeenhancement devices in the form of tables of Reynoldsnumber, friction factor, and Colburn j-factor. You canenter data for up to 20 geometries/surfaces in a defaultdata set and then select which one you wish to use in aparticular case. The option is also available for axialshellside flow.

� Improved condensate cooling calculations. Forhorizontal shellside condensation TASC v5.00calculates the surface area required for condensatecooling both above and below the bubble point. It willcompare the required surface with either a new inputitem, the fraction of the surface flooded by condensate,

Major New Release - TASC v5.00

cont’d

or with a calculated meanliquid level from hydraulicconsiderations. It is alsopossible to request a falling-film calculation for subcoolingbelow the bubble point invertical tubeside condensers.

� Extended simulationoptions. In Simulation modethe user can enter any validcombination of inlet, outletconditions and flowrate forboth the hot and the coldstreams, and the program willcalculate the remainingvariables.

� Reflux condenser model.Flooding and heat transfercalculations are provided forDesign or Performancecalculations on tubeside refluxcondensers.

� Shellside critical heatflux. A new method for theprediction of shellside criticalheat flux, has been included.Based on recent research, thenew method will generallypredict higher values of thecritical heat flux than theprevious method. In somecases the increase can be verysignificant.

The opportunity has alsobeen taken to update andimprove other aspects of thecritical heat flux and boilingmethods, particularly whenliquid heating is a significantfraction of the duty.

For the TASC Mechanicaloption the following featureshave been added:

� External pressure as perASME VIII Div 1. UG-28

� Cone Reinforcement as perASME VIII Div 1. Appendix1-5.

FIHR 2.00 has been released with updated documentation on CD-ROM.

New features in 2.00 are:

• variable tube dimensions and tube to tube separations in the firebox;

• U-bend areas can be included in the firebox heat transfer area;

• automatic zoning option in the Long Furnace Model;

• calculation of circumferential heat flux and maximum tube metaltemperature based on methods in API 530;

• improved treatment of radiation to shield banks;

• addition of database of thermal conductivities of steels;

• more detailed output, including tube wall temperature profiles and updatedAPI Datasheets;

• inclusion of the latest HTFS standard packages;

• extensive restructuring of the Windows Input Forms.

One question asked frequently is ‘How has FIHR been validated?’. This isnot easy to answer for two reasons: firstly, input data and the performance ofoperational plant are difficult to measure and secondly, many of the successfulapplications of FIHR are classified Commercial -in - Confidence. However, theseveral FIHR Beginners Examples are based on real plant with modificationsto conceal their original commercial origins.

In Research Report RS1075 comparisons have been made betweencalculations and measurements on the 6MW BP Burner Test Rig for gas firing.The rig, which has been used over many years to evaluate burners, is abottom-fired cabin with horizontal tubes on opposite side walls, andrepresents a section through a refinery heater. However, rather than justpresenting results which are in good agreement with the availablemeasurements, this Report has been written as a Tutorial to help users set-upand run the code. Some of the new features in FIHR 2.00 are illustrated andSensitivity Studies are also carried out.

One of the main uncertainties in the FIHR input data is the emissivity of thecombustion gas. A Spreadsheet was therefore written to compare the defaultin FIHR with a highly rigorous 3 grey gas model evaluated (EML and EMU) atlower and upper gas temperatures of 500 and 1200oC respectively. Thecoefficients in the FIHR model were then fitted (EMFF) to give much betteragreement, as shown in the graph.

FIHR 2.00 releasedTASC v5.00 cont�d

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

L

EG

EML

EMU

EMFF

As more emphasis has been placed on heatrecovery, accurate correlations for heat transfer andpressure drop in tube banks have become morecritical. As many of the standard correlations werederived from data not directly relevant to tubes in firedheaters, extensive measurement programmes havebeen carried out on the High Temperature WindTunnel (HTWT) with banks of large tubes (up to 5 inchn.b.) with different extended surfaces and layouts. TheHTWT has recently been modified to allow lower massfluxes, typical of those in heaters, and the datacollection system has been improved, so that a tubebundle can be tested in about a week! Results are nowbeing used to re-evaluate HTFS and other correlations,and plans are also in-hand to study the effects ofcorbels.

FIHR 2.10 is currently scheduled to be released inSpring 2002. The main emphasis will be placed on:

� steam injection into the firebox process stream

� improved handling of roof tubes and directradiation to shield tubes

• description of the fuel, allowing for incineration ofwaste gas streams or recirculated flue gases

and

• designs of fireboxes with multiple cells.

The main advantages of using data from test rigs,such as the NEL Furnace, are that many moremeasurements can be made over a greater range offiring conditions and with greater accuracy than inoperational plant. A Review has recently been writtenof all the measurements and the instruments used onthe NEL furnace since the installation of refractory-backed tubes in 1993. A database containing all themeasurements is currently being set up, which in duecourse will be available to HTFS Research Networkmembers.

The inclusion of flue gas recirculation in FIHR willenable comparisons to be made with the

Other significant releasesACOL 6.20

• COMThermoTM Properties Package

• Up to 4 Tube Diameters in a single bundle

• Budget Cost Application

• Improvements to default values

• Handling of X-side temperature down to -200C

• Input filename added to LP and 80-columnoutputs

• Improved handling of pressure dependance indesign mode

� Single row exchangers can now be handled

• Calculation of steam coil pressure drop

• Improved convergence for deep bundles

• Heating of humid air

� Fan power absorbed added to table ofalternative designs

• Additional Windows Output

• Addition of new Input items

MUSE 3.20• Layer Type Definitions

• End-zone crossflow

• Checking by repeated simulation

• Double-banking options in Design

• Link with HYSYS

• COMThermoTM Properties Package

Improved model (EMFF) for calculating the gas emissivityEG versus radiation path length L (m)

measurements on the furnace for firing rates of 240 and400 kW reported in RS 1014 (1997) and 1051 (1999)respectively.

EMISSIONS FROM COMBUSTION PLANTIt is no longer sufficient for combustion plant operators and contractors, whether evaluating retrofits or newdesigns, to consider thermal performance alone. Legislation on emissions is becoming increasinglymore stringent in many countries and for example in European the new Directive on Integrated PollutionPrevention and Control (IPPC) is now being implemented.

There is a complicated relationship between energy efficiency and emissions, and safety also has to be takeninto account. For example, improving the efficiency by reducing the fuel required for a process reduces theemissions of the greenhouse gas CO

2. On the other hand, using hot flue gases to pre-heat the combustion air also

improves the efficiency but tends to increase the gas temperature and consequently the NOx.

Codes such as FIHR are playing a significant role in helping to improve efficiency in design and operation byeither reducing the fuel fired and/or increasing the product throughput. However, there are no simple reliablemodels for predicting emissions, such as NO

x, CO and particulates.

In order to bridge this gap, a few years ago the scope of the Radiative Heat Transfer and Flames Section of theHTFS Handbook was extended to include reviews of emissions from combustion plant. Sheets RP14, RP15and RP16 discuss techniques for reducing NO

x, SO

2 and CO

2 respectively. Another Sheet RP17 covers control of

CO, unburnt hydrocarbons and particulate emissions.

The main purposes of these Sheets are to review:

• the mechanisms for pollutant formation;

• their dependence on fuel properties, firing conditions and plant design;

• strategies for reducing them;

• emission levels which can be achieved in different types of operational plant;

• areas where more data are required (e.g. firing with HFO).

The Sheets are comprehensive. RP16 for example starts by comparing CO2 emissions produced by firingdifferent fuels, as shown below, and ends with a discussion of methods for removing CO

2 from gas streams and its

subsequent disposal.

50

84

58

58

65

67

74

78

79

107

100

96

94

94

94

99

105

0 10 20 30 40 50 60 70 80 90 100 110 120

Coke Oven(53.4)

Landfill(45.3)

Groningen NG(58.2)

NthSea NG(72.2)

Comm.Prop(82.0)

CommBut(82.8)

Gas Oil(85.7)

MFO(85.3)

HFO(85.1)

Peat(57.5)

Lignite(70.0)

Bit902(81.0)

Bit802(82.0)

Bit701(84.5)

Bit301a(90.4)

Anthracite(94.4)

Coke(96.5)Fuel (%C)

Carbon dioxide emission factor (g/netMJ)

CO2 emission factors as a function of fuel type

Member RepresentativeHTFS is delighted to announcethe election of Ray Sacks asMember Representative. Raytook up the role effective from 1April 2001 for the next 4 years.He will be involved in HTFSmanagement liaison and will bethe official member spokesmanfor all issues relating to HTFSproducts and services.

HTFS

ANNU

AL ME

ETING

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1

ContactPascale HicklinPhone: +44 1235 448330Fax: +44 1235 448350E-mail: htfs@hyprotech.com

Date:8-12 October 2001Venue:Manchester, UK

Highlights

� 8-9 October: trainingcourses.

� Focus on new & improveddesign methods.

� Meet the HTFS researchers& software developers togive them your needs andrequirements first hand.

� Application presentationsby HTFS customers

HTFS invites you toview presentationson current researchand mainstreamprograms such as:TASC, ACOL,FIHR &MUSE. Join in anddiscuss practicalapplications ofresearch results andimproved designmethodology.

®

HTFS Update Forums

Early this year Tom Ralston andVishwas Wadekar conductedseminars in Mumbai, Chennai andDelhi, three principal cities of India.KLG Systel, our agents in India, andHyprotech India provided valuablesupport in organising theseseminars. The seminars weremodelled on the HTFS forums inEurope and provided a broadoverview of the HTFS software andresearch activities. Judging by thehigh attendance (over 100) andcomments received from theparticipants these seminar were ahuge success.

For the second year running VishwasWadekar conducted a one day shortcourse on Compact Heat Exchangersat the Spring National Meeting ofAIChE in Houston. User feedbackcollected by AIChE rated the courseas excellent in the presentationmaterial as well as contents. On hisway back to England Vishwas visitedBallard Generation Systems inVancouver, Canada to hold a trainingcourse on heat transfer theoryunderpinning the TASC and MUSEprograms.

Other HTFS activities

Recently HTFS has held anumber of update forumsaround Europe. Duringthese one day overviews ofrecent developments onHTFS products andservices, our customersquickly get an appreciationof how our software canhelp your company with theproblems of today, as well as seehow our research is bringingimproved design and simulationmethods to practising engineers.

Up to now there have beenforums in the UK; Italy (hosted byEni Tecnologie); Sweden;Netherlands (hosted by Fluor

HTFS Japanese User Meeting26-27 November 2001Tokyo, Japan

Contact: Yukio OhtaTel: 45 476 5051E-mail: yukio.ohta@hyprotech.com

Daniel); and Spain (hosted byRepsol YPF) with 116 customersattending in total.

Forthcoming Update Forums22 October - Calgary, Canada24 October - Houston, USA26 October - Tulsa, USANovember - Paris, France

Other Offices

HTFS Headquarters

HTFS solutions

shell & tube heat exchangers

air cooled heat exchangers

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other equipment

TASCThermal

TASCMechanical

A powerful, internationally recognised program for design andperformance simulation of all your shell and tube heat exchangersrequirements, including thermosyphons

Mechanical design of shell and tube heat exchangers to ASME VIII,either standalone or linked with TASC

5.00

5.00

AEA TechnologyEngineering Software,HyprotechGemini Building, Fermi Avenue,Harwell International BusinessCentre, Didcot, Oxon OX11 0QRUnited Kingdom

Tel: 44 1235 448330Fax: 44 1235 448350

E-mail: htfs@hyprotech.com

Web: www.htfs.com

Calgary, CanadaTel: 1 800 661 8696Fax: (403) 520 6040/6060

Houston, USATel: 1 800 475 0011Fax: (713) 339 9601

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Kuala Lumpur, MalaysiaTel: (603) 4270 3880Fax: (603) 4270 3811

Seoul, KoreaTel: 82 2 3453 3144Fax: 82 2 34539772

Yokohama, JapanTel: 81 45 476 5051Fax: 81 45 476 3055

Software for design and performance simulation of air cooled heatexchangers and simulation of heat recovery units, air conditioningand refrigeration exchangers

6.20ACOL

APLE

MUSE

A single package for design, rating and performance simulation ofgasketed plate and frame heat exchangers

Performance simulation layer by layer, crossflow calculation and'first-shot' thermal design of multistream plate-fin heat exchangers

2.10

3.20

FIHR Simulation of fired process heaters 2.00

FRAN

PIPE

TICP

Rating and performance simulation of power plant feedwater heaters

Single phase and two phase flashing flow calculations in unbranchedpipeline systems

Thermal insulation calculation

2.01

5.20

1.00

Check out our training web site at:www.software.aeat.com/htfs/tech_support/training

Full course descriptions can be viewed and you can register online.

training

technical support support@hyprotech.com

Technical Support Centres

Location Local calls International calls

Oxford, UK 0800 731 7643 +44 1235 448355

Barcelona, Spain 900 161 900 +34 93 215 68 84

Calgary, Canada 888 757 7836 +1 403 520 6181

Yokohama, Japan 45 476 5051 +81 45 476 5051

Kuala Lumpur, Malaysia 3 4270 3880 +60 3 4270 3880

Seoul, Korea 2 3453 3144 5 +82 2 3453 3144 5

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research network

The research network provides access to all our knowledge base and expertise developed

over the past 30 years. Electronic versions of the Handbook, design reports associated

with our 4 main programs, and the most recent research reports are available on-line via

the web at www.software.aeat.com/htfs/resnet.htm. In addition, users can run the heat

exchanger selection program ‘HEAd’, download our basic shell & tube design program

‘DEVIZE’ and search for papers on heat transfer in the open literature using HTFS -

HEATFLO. Customers can also have a close involvement in directing our research and

the evolution of our products through participation on Review Panels.