Hy Coating

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SXHTM - Coating

A solution for hydro-abrasive erosion

www.andritz.com



02 SXH TM- Coating for hydropower plants

The ReasonHydro-abrasive erosion is dependant of

the particle parameters (concentration,mineral composition, particle size dis-

tribution and shape) and on the turbine

and operation parameters. The particle

parameters are dependant on the water

source. Rivers in relative young geological

formation have a high particle load during

the monsoon season or the snow melt-

ing period. In addition, the abrasiveness

of these particles highly depends on the

constitution of the rocks in the catchment

area, so that these particles can be mainly

hard particles like quartz, magnetite, feld-

spar and zircon. In addition, based on the

geography, hydro power plants have often

no extensive reservoir in which a substan-

tial sedimentation can take place, but are

run-of-the-river hydro power plants.

The CauseHydro-abrasive erosion due to high con-

centration of hard particles results in high

revenue losses due to productivity losses,

efciency reduction, repair work and out-

age times. The damages can be so high

that the mechanical integrity of the tur-

bines is not given anymore, which could

lead to severe accidents.



SXH TM- Coating for hydropower plants 03

The Objective

SXHTM are coatings by ANDRITZ HYDRO

to signicantly reduce the damages due

to hydro-abrasive erosion.

SXHTM70 and SXHTM7X:

Type: WC-CoCr Coatings

Micro hardness: 900-1´200HV0.3

Adhesive strength: min 70 MPa

Roughness: as sprayed: 4.5-8mm

polished: 0.5-1.2mm

The Solutions

Pelton (1)

since 1996

199 runner

> 1,650 needles and mouthpiece

> 300 other components

(1) - all gures by 12/2010

The objective is to realize long opera-

tion time with high efciency. This is to

help the customer to achieve his aim of

maximising the productivity, reducing the

down time and achieving a high reliability

Wear Theory

&-Models

Material science

Communication

network

R&D on coating

PracticalExperience

Customer

Feedback

Prototype testing

Coating know-how

Hydraulic

know-how

Customers objective:

high efcency and

long operation time

of the energy production.

This is only possible by interdisciplinary

collaboration as many factors play a sig-

nicant role. Based on the R&D in differ-

ent elds, know-how can be build up. But

Francis/Kaplan (1)

since 1996

198 runner

> 1,800 guide vanes

> 280 labyrinths

(1) - all gures by 12/2010

without the help of customers for proto-

type testing and also feedback, a devel-

opment is not possible.




Beneft Higher productivity due to a much

smaller decrease in efciency over a

longer period

Increase of operation time between two

overhauls

Reduction of overhaul period due to

less welding

Nearly no risk of subsequent damages

due to hydro-abrasive erosion

1992/93 uncoated,

X5CrNi13-4 1600kg

welding material

2000/01 SXHTM

70

coated 400kg welding

material

85

86

87

88

89

90

91

00 20.000 40.000 60.000 80.000

new hydraulic design

Loss in revenue(production loss and repair)

Amount of particles

Pelton Turbine - Alfalfal

Turbined particle load, t

M a x . p o s s i b l e p o w e r , M W




Calculation and Theory

Research and Development

Thanks to the close collaboration withcustomers, ANDRITZ HYDRO has exten-

sive knowledge of the performance of the

SXHTM-coating in operation. Due to this, the

damage progression has been analysed

and the areas where an improvement would

make a high impact on the operation (TBO,

efciency) are known.

Based on the needs of the customers to

achieve their aim for a high productivity,

the following research targets have been

decided:

In general, new coatings with an in-creased TBO (time between overhaul

will be developed.

The stability of the splitter of Pelton run-

ners is a main critical area determining

the TBO (time between overhaul). The

development in 2009 showed already

an enhancement but further reseach

will aim at a further increase.

We invest for your success!

A formula for the direct calculation of the

amount of wear is under development and

already exists for Francis components.

ANDRITZ HYDRO developed the refer-

ence model (Index model) in which power

plants are compared to a reference proto-

type from which all major parameters are

known.

Major parameters are:

the particle parameters like concentra-

tion, mineral composition etc.

the turbine parameters like design and

operation data etc.

The comparison calculates from the

known TBO (time between overhaul) from

the reference turbine the expected TBO

of the compared turbine, given therefore

information about the necessity of a coat-

ing and information to the customer how

to plan his overhaul concept.

The gure to the right shows a compari-

son of the TBO between different power

houses but also the inuence of differ-ent parameters can be evaluated: HPP 1

In small Francis runners the space islimited. Due to this, hard coating is nor-

mally only possible in certain areas of

the runner. A polymer coating is a solu-

tion for these cases.

shows the different turbines in an operat-

ing powerhouse; HPP 2 shows the inu-

ence of different nozzle numbers; HPP 3of different particle concentrations and

HPP 4 for 3 different designs for the same

HPP. The model is part of the IEC guideline

for hydro-abrasive erosion.




New DevelopmentsFully coated Francis runnersNew fully coated Francis runner with coat-

ing of the whole waterpassage and laby-

rinth by a robot.

Nathpa Jhakri, India

Karcham Wangtoo, India

Damages after one year of operation are

on a fully coated runner very small com-

pared to the uncoated runner. Nearly no

efciency losses occur due to these small

damages.

Coated:

After 1 year of operat ion

Uncoated:

After 1 year of operation




SXH TM7X - Stabilised splitter for Pelton runner

For Pelton runners with high hydro-abra-

sive erosion, the splitter is usually worn

away rst and is the main reason for anecessary overhaul. Due to this problem,

ANDRITZ HYDRO started a research pro-

gram in 2009 to enhance the stability of

the splitter.

SXHTM70 - worldwide Standard SXHTM7X - 20% higher TBO

Pelton runner with SXHTM7X

Uncoated

A new process was developed for this

stabilisation. In collaboration with a cu-

stomer this new coating was tested in aprototype test. One runner with uncoated

buckets and with buckets coated with the

standard SXHTM70 as well as with the new

SXHTM7X was tested simultaneously.

A 20% improvement of the new coating to

the standard SXHTM70 coating was found.

Further runners with this new coating arein operation since the beginning of 2010

and rst inspections show excellent re-

sults.




ANDRITZ HYDRO AG

Obernauerstrasse 4

6010 Kriens, Switzerland

Phone: +41 (41) 3295111

Fax: +41 (41) 3295152

E-Mail: [email protected] AH.COATING.01.en02.1 1

Canada: 36

USA: 2

Mexico: 12

Guatemala: 54

Costa Rica: 4

Venecuela: 62

Colombia: 192

Ecuador: 62

Peru: 137

Chile: 1002

Figures present the number of coated parts by ANDRITZ HYDRO.

Coating workshops of ANDRITZ HYDRO and subsuppliers:

- Switzerland (Center of Competence)

- India

- Chile

- Brazil

(1) - all gures by 12/2010

Madagascar: 24

China: 73Nepal: 4

India: 526Laos: 2

Philippines: 8

Norway: 51

Germany: 1

France: 33 Austria: 75

Romania: 6

Italy: 32Portugal: 40

Andorra: 16Bulgaria: 32

Azoren: 8

Peltonrunners Francisrunners Kaplanrunners other parts

199 194 4 4660

Switzerland: 2567

Coated parts by ANDRITZ HYDRO

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