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responds to changes in these conditions. Thecurves can then be programmed into yourperformance monitoring system, and used todetermine the corrected performance of your

unit: the current operating data for your gasturbine (and/or plant) corrected to referenceambient conditions.

You can then compare your corrected per-formance values (normally output andheat rate) to your design (or baseline) val-ues, and you can also trend them to see howthe unit is degrading over time.

Because corrected performance values nolonger include the expected changes in per-formance due to ambient conditions, anyvariances observed are due to other

(potentially controllable) influences. Some ofthe differences could be normal wear & tear(degradation), but changes could also meansomething significant has occurred in the op-eration - either software/controls or hard-ware.

When trends show large step changes in cor-rected performance, an investigation shouldbe initiated ASAP to determine the cause ofthe change. Step changes in corrected per-formance normally indicate somethingneeds attention whether thats just an in-strument failure, a plug in a fuel filter, or for-eign object damage (FOD) needs to be deter-mined.

The cause of the change needs to be identi-fied to verify that continuing to run in thecurrent state will not cause additional damage.

By monitoring your corrected perform-ance, you are on your way to finding theclues to a more reliable and more efficientplant.

Previous newsletters have dealt with planning andmaintaining your performance monitoring system,but one thing which has not yet been discussed indetail is Corrected Performance.

Once you have your raw data selected, your sen-sors all calibrated and the data being read, ana-lyzed and archived without a hitch, youre ready tolook at trends. But, the first thing you may notice,is that trends for maximum capacity and heatrate will vary depending on the current ambi-ent conditions (especially for gas turbine basedplants).

Operators are quick to identify the deficiencies oftheir plants noting that on hot days, the gas tur-bine is output limited. But is this MW limit due tothe ambient conditions alone, or is there some-

thing else going on? The only way to know, is tohave a baseline set of expectations for the unit asambient conditions change. These expectationsare most often presented to the user as a set ofperformance correction curves, such as the fol-lowing:

Gas turbine output and heat rate vary with thedensity of the air entering the compressor or,more directly, with compressor inlet temperature,humidity and pressure. The OEM normally pro-vides performance curves for how the gas turbine

Products & Services

Analysis Tools

Excel Workbooks,

Macros andAdd-Ins:

Corrected Performance Compressor Efficiency

Steam & Water Flow

Moist Air Properties

Training Seminars

Compressor Efficiency

Tracking Software

Performance Monitor-

ing Program Design,

Support and Evaluation

Read & Comment

at Tinas Blog:

www.t2e3.com/blog

Next LM6000 Seminar

Scheduled for Septem-

ber 2009 - see details

on page 2

Spring is Here

BY TINA L. TOBUREN P.E.

EfficiencyExtraEdition

T2E3 Newsletter

May 2009

Monitoring Corrected PerformanceAnnouncements

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performance due to ambient condi-

tions and operating constraints.

These tools can also lead to a

greater understanding of the long-

term economic outlook for your

facility.

Unlock the potential of your opera-

tion. Call for more information on

how we can work together, today!

Analysis Tools & Software fromcustomized spreadsheets to add-ins

for Excel or complete compiled pro-

grams, T2E3 can develop software

tools and analyses to support all your

performance monitoring needs, in-

cluding integrating your existing

tools with available site data systems,

to create online systems providing

data and results in real-time.

Training both public seminars andcustomized options are available.

Highly interactive sessions increase

attendees knowledge and under-

standing of the thermodynamic cy-

cles, instrumentation and analyses

needed to improve equipment per-

formance and reliability.

Performance Test Support if yoursite is required to perform annual

capacity or PPA performance tests,

having Tina Toburen from T2E3 on

site to direct the testing can lead to a

smoother test execution with more

consistent performance results. Pro-

fessional reports can also be pro-

duced to communicate the results to

all required parties.

Site Marketing and Dispatch Sup-

port Do your marketers and/or dis-patchers understand the operation of

your facility? Do they constantly dis-

patch the plant at loads which are

difficult or impossible to maintain?

T2E3 can help you build tools and

training programs to help all parties

understand the expected changes in

T2E3 Performance Analysis Services for Power PlantsIncluding:

T2E3 Add-ins for MS ExcelStreamline your analysis spreadsheets by using functions fromthe T2E3 Automation Add-ins. Available functions include ASMEsteam tables, ASHRAE air properties, orifice flow meter calcula-tions and select performance functions, including: compressorefficiency and evaporative cooler effectiveness.

For a complete function listing, available options or a trial

version of an add-in contact T2E3 at 425-821-6036

14260 120th PL NE

Kirkland, WA 98034

Phone: 425-821-6036

Fax: 253-550-6992

E-mail: performance@t2e3.com

T2E3Tina ToburensEnergy Efficiency Enterprises

To receive a copy of this newsletter,along with other announcements for

T2E3 products and services, send anemail to:

performance@t2e3.com

and mention this newsletter in the subjector body of the message.

Your email address will be held in strictconfidence and not be shared with anyother parties.

To view this or other T2E3 newslettersonline, visit:

http://www.t2e3.com/news.php

Seminar: LM6000 Performance Characteristics,

Testing and Long-Term Condition Monitoring

The next LM6000 Performance Seminar is currently scheduledfor September 2009, to be convenient for attendees to the AeroUsers Group Annual Conference (http://lm6000.users-groups.com/Events/2009/Info/).

I am currently looking at holding the seminar on either Mon-

day & Tuesday before the conference (September 7 & 8) orthe Monday & Tuesday after the conference (September 14 &15). If you would like to attend, and have a preference for thedates, please let me know by sending an email toseminars@t2e3.com.

Additional information on the seminar, including an agenda, canbe found on atwww.t2e3.com/LM6000.php.