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© Copyright KSB Aktiengesellschaft 2015

Mechanical Analysis of a Boiler Water Circulation Pump (BWCP)

M. Haßlöcher, PU-GP513October 6th.2015

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Content

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 20152

1. Application for FEM at KSB

2. Evaluation of BWCP prior Staudinger

3. Current FEM Calculation of a BWCP

4. Outlook and Set of Problems

MPA Seminar

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1. Application for FEM at KSB

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• Design

• Optimization

• Stress Analysis and Proof of Safety (incl. Seismic Qualification) for existing Design acc. relevant Codes as ASME, KTA, RCC-M, API, DIN, AD-Merkblatt

• Feasibility Study

• Failure Analysis

• Structural Safety

• Operability

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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2. Evaluation of BWCP prior Staudinger

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• Standard: Evaluation of static load cases

=> Operating Condition + Pressure Test

=> Evaluation acc. ASME Sec. VIII Div.2

• Special: Fatigue analysis (state of the art)

=> Bexbach, Kentucky, Ivanpah, Ibbenbühren

=> Evaluation acc. ASME Sec. VIII Div.2KTA 3211.2

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3. Current FEM Calculation of a BWCP

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• Calculation to evaluate fatique strength of new bowls

• LUV Az (350bar / 380°C Design) with 1000mm bowl

• Considering of transients (Temperature + Pressure),bolt preload and nozzle loads if available (small influence!)

• Evaluation of further parts, e.g. bolts, heat barrier andupper motorflange possible

• Evaluation acc. KTA 3211.2 (very conservative in comparison to DIN)

• ANSYS 15.0 SP1

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Halfmodel

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Modeled Parts:

• Pump Housing

• Upper Motorflange

• Heat Barrier incl.Insulatingmaterial (Ceramic)

• Main Closure Studs

• Nuts

Decay Length = 2.5 (R·t)1/2

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Halfmodel

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approx. 73000 Elements

approx. 330000 Nodes

Hexaeder Mesh with Skin Layer

Solid 90 Temperature

Solid 186 Stress

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Boundary Conditions

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Film Coefficients:

alfiso = 5 W/m²K

alfpg = 21861 W/m²K (100%)

alfpg2 = 0.5 · alfpg

alfpg3 = 0.5 · alfpg2

alfds = 35555 W/m²K (100%)

alfss = 22444 W/m²K (100%)

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Boundary Conditions

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Film Coefficients:

alfluft1 = 23 W/m²K

alfluft2 = 10 W/m²K

alfmotor = 2000 W/m²K

alfws = 241 W/m²K

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Boundary Conditions

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Stress Model generated from Temperature Model

=> same Nodes!!!!

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Boundary Conditions

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Contacts were been defined axial as well as radial!

Clearance Fits have been considered!

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Boundary Conditions

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Fv = 1700 kN per Stud

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Boundary Conditions

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Considered Loads:

• System Pressure

• End Cap Loads

• Reset Force of Sealing

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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Transients

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Description TStart in °C TEnd in °C vT in K/min

PStart in bar

PEnd in bar

N

Cold Start Step 1 immediately after pump start

30 140 20 1 4 2000

Cold Start Step 2 140 350 1 4 196 2000

Shutdown 350 30 0.3 196 1 2000

Warm Start 200 350 4 50 196 1000

Load Changes fromBenson Operating

270 310 20 90 90 9400

Hot Start 250 350 20 50 196 6000

Additional 10 x Assembly

MPA Seminar

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Results

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Temperature Distribution

Stationary Condition

TSYS = 350°C

TMotor = 60°C

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Results

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Temperature Distribution

Stationary Condition

TSYS = 350°C

TMotor = 60°C

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Results

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Stress Distribution (SEQV) in MPa

Stationary Condition

PSYS = 196bar

FV = 1700kN per Stud

TSYS = 350°C

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Results

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Stress Distribution (SEQV) in MPa

Stationary Condition

PSYS = 196bar

FV = 1700kN per Stud

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Evaluation Points

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237 SCL

(Stress Classification Lines)

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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3D FEM Evaluation Points

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Evaluation at new increased Radius:

UF1 = 0.7

UF2 = 0.7

UF3 = 0.8

UF4 = 0.7

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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4. Outlook and Set of Problems

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• The fatigue strength of new pump housings will be determinedwith this procedure.

• The aim is a “standardization“ of the modeling and thecalculation, to save time.

• It is possible to evaluate further parts, e.g. bolts and/orheat barrier.

• Evaluation acc. DIN 12952-3 will be realized

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

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4. Outlook and Set of Problems

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• The specification of the transients has to be improved. Abetter coordination is needed here.

• Current => Transfer of records of the control room and ahuge amount of data in Excel Tables for number ofoccurences and operation mode.

=> A lot of Time is needed to evaluate the data=> Expensive and defective

• “Warming during Hot Stand By“ not defined yet

=> Temperature Layer?

Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

MPA Seminar

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23Mechanical Analysis of a BWCPM. Haßlöcher I PU-GP513 I October 6th 2015

MPA Seminar

Thank you very much for your attention!

Questions?