ep2005 turbine upgrades

7/29/2019 EP2005 Turbine Upgrades

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A Babcock Power Inc. Company

Electric Power 2005Track 8Gas Turbine Based Power Plants

Session 8C

Keith C. KaufmanSenior Thermal Engineer

Vogt Power International, Inc.

Options for Performance Enhancement II

- Turbine Upgrades -

Considerations for the HRSG


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EP 2005Vogt Power International 4/6/05Page 2

Upgrading the gas turbine can have significant impacts on an

existing HRSG:

Thermal design and performance

Gas-side effect on ductwork

Burner systems

supplementary firing

Emissions systems CO and SCR catalysts

Changes in start-up procedure

Sound emissions requirements and control

Need to evaluate impacts early in upgrade process


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Thermal Performance:

Tube metal temperatures

Fin metal temperatures

Steam/water velocities

Design pressures => related wall

thickness calculations

Circulation

Drum and steam separation design

(e.g. number of separators)

Safety valve capacities

Valve class

Recirculation system capacity

In addition to the change in delivered steam flow conditions, the followingalso need to be considered-


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Gas-side Impacts:

Change in gas-side pressure drop across modules

Overall inlet duct design => flow distribution to

tube modules

Axial- vs. side-discharge GT

Need for distribution grid?

Liner and liner attachment design

Liner and attachment materials

Higher flow rates => higher velocities& turbulence

Structural vibration considerations

Duct insulation (exterior casing temperature

requirements)

Change in GT typically means higher exhaust gas flow rates & temperatures

to the HRSG -


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Supplementary firing and duct burner:

Change in GT exhaust gas conditions can impactsupplementary firing -

Flow distribution into burner must meet burner

vendor requirements for proper operation across

load range

Is the burner upstream of heating surfaceor interstage?

Requirement for distribution grid?

Is same level of supplementary firing still

required more or less?

Impact on tube metal temperatures

Combined change in GT and burner operation

will affect thermal performance


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Emissions control systems:

Is there a change in plant permitting for CO

or NOx?

Does existing CO and/or SCR catalyst

handle new turbine exhaust?

Need to evaluate effect of change in exhaust

gas temperature on catalyst performance

Does new GT change gas velocity

distribution into the catalyst or the AIG?

If ammonia flow rates need to change, are

the AIG, valving, and fans adequately sized?

GSPD across catalyst will increase withhigher GT flow rates


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Engineering tools are required to evaluate these impacts:

Thermal performance software for detailed evaluation of impact to,

and performance of, tube modules

Flow modeling to evaluate effect of new GT flow conditions on flow

distribution into heating surface, burners, and emissions equipment

Structural/FEM analysis to evaluate any required changes in

equipment loading or structural steel

ep2005 turbine upgrades

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