marc steam turbine.pdf

MARC® Steam TurbinesThe Modular Steam Turbine Generation

MAN TurboEngineering the Future – since 1758.

MTM_MARC_RZ_korr:Layout 1 08.12.2008 16:15 Uhr Seite 1

Originating from the Blohm+Voss shipyard, MAN Turbo AG Hamburg today combines

the experience of a traditional company with state-of-the-art technology.

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The first steam turbines under the name

of Blohm+Voss were manufactured in

1907, initially for ships built in the ship-

yard and subsequently for electric power

generation. Since 1952 the company

concentrated on developing and manu-

facturing industrial steam turbines. The

list of worldwide references encompasses

more than 2,000 turbo generators.

A wide range of renowned companies

and utilities use our turbines, mainly in

Industrial power plants

Cogeneration plants

Waste incineration plants

Biomass power plants

Combined Cycle plants

Our modern manufacturing facilities in

Hamburg are equipped with machine

tools of high performance and cover a

floor area of more than 10,000 m2. The

quality management system is certified

to DIN EN ISO 9001. Centrally situated

in the free-port of Hamburg, MAN Turbo

offers ideal transport links, enabling

even large components to be trans-

ported with ease.

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The concept

The customers’ demand on durability, efficiency and economy has always had

top priority for the development of BVI steam turbines. The result of our perma-

nent development is a solution that sets new standards: The MARC (Modular

ARrangement Concept) turbine series has proven its high quality throughout

more than 100 installations since its market introduction in 1998. This modular

turbine concept allows a flexible arrangement of the auxiliary components and

enables the overall assembly to be set up in line with individual requirements.


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The turbo generator unit comprises the

following modules:

Steam turbine

Gearbox/generator unit

LP lubricating oil system

HP control oil system

Control cabinet

The lubricating oil module, control oil

module and the control cabinet can be

individually arranged around the unit.

Benefits of the modular concept:

Proven turbine design with robust

technology and high availability

Space-saving, low-noise epicyclic

gear generator unit (up to 25 MW)

High level of efficiency thanks to

optimised turbine design and use of

epicyclic gearing

Use of proven system modules for

lubricating oil and control oil

Compact control cabinet as black-

box for connection via bus system

to the central control system

Low investment costs

Five different turbine sizes cover a per-

formance range from 1.5 MW to 50 MW.

The MARC production programme

includes backpressure, heating and

condensing turbines that can also be

fitted with extraction and bleed ports.

Explanation of type codes:

MARC x - A B C

x – Code for turbine size

A – Code for turbine type

C: Condensing

B: Backpressure

H: Heating

B– Number of controlled extractions

C– Number of bleed ports

MARC TurbinesModular ARangement Concept

Electric power up to 3 MW

Max. flange diameterLive steam: 125

Exhaust: 700

Max. live steam conditions 30 bar(a) / 480°C

up to 15,000 1/min


Max. flange diameter Live steam: 200 Exhaust: 1,200


up to 12,000 1/min


Max. flange diameterLive steam: 250Exhaust: 1,500


up to 10,000 1/min


Max. flange diameter Live steam: 300 Exhaust: 2,200


up to 8,000 1/min


Max. flange diameter Live steam: 350Exhaust: 2,600


up to 6,000 1/min

MARC 6MARC 4MARC 2MARC 1 MARC 8


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Turbine type B:

Backpressure

Backpressure turbines are used as gen-

erator drive units in combined heat and

power plants and for on-site electricity

generation of industrial facilities. They

are also used in cogeneration applica-

tions.

Turbine type C:

Condensing

The areas of application for condensa-

tion turbines range from turbo genera-

tors for industrial power plants and

waste incineration systems through to

biomass facilities.

The extraction steam is typically used

for heating, production purposes and

feed water prewarming. To achieve op-

timum part-load efficiency, the LP part

can also provided with a nozzle group

control.

Turbine type H:

Heating

The typical application is electricity

and heat generation. The special feature

of this turbine type is the double-flow

exhaust for connect-ing a two stage

heating system. This design provides

the most efficient way of electricity and

heat production throughout the year.


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With the MARC concept developed in

the mid-1990’s, MAN Turbo has suc-

cessfully established itself in the bio-

mass power plant market sector from

4 - 20 MW electrical output. MAN Turbo’s

operational experience with steam tur-

The new MARC 1

The success formula of the MARC 2 has been transferred to a new MARC model in the power

range of 1.5 - 3 MW. Built on the design principles of proven turbines and the positive opera-

tional experience gained, the new MARC 1 turbo generator has been developed specifically for

use in the smaller segment of biomass applications.

bines previously supplied for biomass

power plants provides compelling evi-

dence of the economic efficiency and

operational reliability of this concept.


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Turbine module

In industrial turbines, part of the steam

often is extracted for production pur-

poses, heating steam systems or gen-

erative feed water heating. In that case,

in addition to several bleedings, two

controlled extractions can also be pro-

vided. The MARC concept allows an

individual and optimized design of the

different turbine elements, according to

specific requirements, such as the pres-

sure level and the extraction steam

quantity.

Depending on the live steam conditions

and the specified operation mode, either

a nozzle group control with or without

bypass or a throttle control may be se-

lected. The control stage, either single

or two-row type, and the number of re-

action stages are especially adapted to

the specific requirements. For all reac-

tion stages the low-loss round-head

profile is used.

The HP blades are provided with milled

shrouds, whereas the last blade rows

are mostly designed with conically twist-

ed blades, the blade ends of which

being tip-thinned on one side.The rotor

blades of the last rows are grouped by

means of damping and bind-ing wires in

conformity with the results of vibration

calculations. Due to the small flow

volume, steam admission of the im-

pulse wheel is only necessary in the

upper casing half, how-ever, the lower

half can also be utilized, if required. In

that case, a bypass leads to the lower

nozzle group.

The exhaust casing is a welded con-

struction and may either be fitted facing

upward or downward, depending on

the site conditions. MARC steam tur-

bines have been designed for highest

operating security and utmost reliability.

As the highest thermal impact on the

steam carrying parts occurs at load

changes, the casing, guide blade carrier

and inner casing have been developed

for a high thermal elasticity.


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The following design features apply

for all turbine types:

multi-stage reaction design

maximum symmetry of the upper

and lower casings

symmetrical temperature distribution

at the circumference in all cross-

sections under all load conditions

single-piece forged rotor

labyrinth sealing glands between

rotor and casing

split tilting pad sleeve bearings

self-aligning axial bearing, for double-

sided loading

nozzle group control

guide blade carrier

Turbine rotors

The reaction turbines are supplied with

a drum-type rotor. The turbine rotors,

the balance piston and the impulse

wheel disc as well as the subsequent

drum parts are solid forging of high tem-

perature material.The rotor design is

based on modern calculation methods

to meet the highest demands regarding

smooth and resonant-free operation.

The bladed rotors are statically and dy-

namically bal-anced at operating speed

in a modern high-speed vacuum balanc-

ing plant, in a way that the shaft vibra-

tions over the whole speed range

are considerably below ISO10816 per-

mitted values.

Bearings

The radial bearings are of multiface

sleeve or tilting pad type. A stable rotor

position is maintained by hydrodynami-

cal oil wedges, equally spaced on the

circumference.The axial forces resulting

from pressure differences in the blading

are mainly absorbed by the balance

piston. A double-sided segmental axial

bearing absorbs the residual thrust and

the coupling forces.


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Bearing Pedestals

The bearings are located in two bearing

pedestals on which the turbine casing

rests by means of brackets on the level

of the horizontal joint. The exhaust con-

nection of condensing turbines rests on

lateral supports on the level of the hori-

zontal joint. Due to this form of arrange-

ment, the position of the rotor to the

casing and thus, the radial blade clear-

ance remain virtually constant under all

load and temperature conditions.

Labyrinth Sealing Glands

The steam sealing between the turbine

rotor and the casing located at the

casing’s ends as well as at the balance

piston is a labyrinth sealing type. The

sealing strips of high-temperature ma-

terial are caulked into the rotor.

Blading

In the blading, consisting of control

stage and reaction part, the potential

energy of the high-pressure steam is

converted into mechanical energy.

Control Stage

Due to partial admission, a high degree

of dynamical tension occurs in the

blades of the control stage. This tension

is reduced by grouping the blades in the

shrouding.Highly loaded control stages

are designed with blade triplets, mean-

ing that three blades having one root

together are machined from one work-

piece.


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Reaction Part

The multi-stage reaction blading ensures

utmost reliability and economy due to

high mechanical and thermal

strengthen both guide blades and

rotor blades to withstand operating

stress

a large sectional modulus to avoid

vibrations.

low flow losses in the blading covering

a wide operating range.

The guide and rotor blades have the

same profile. It was theoretically and

experimentally tested during its devel-

opment. Hereby, the characteristics of

the profile, depending on the cascade

arrangement and the entry angles, were

determined by measurements in a plane

wind tunnel.

A characteristic feature of partload ope-

ration is the entry angle deviating from

the normal line of flow. The impact-free

entry angle range is very large and en-

sures a high part load efficiency at oper-

ating conditions different from those of

rated load.

The clearance and rim losses of back-

pressure turbines and high-pressure

parts of condensing turbines are re-

duced to a minimum by using shrouds.

The blade with root and shroud is

machined from one piece. After blading

the rotor, the shrouding is machined to

its form. Regarding stages with a low

clearance loss factor, the blade tips are

provided with a one-sided thinning.


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Control mechanism

The steam control valves of MARC tur-

bines are of a diffuser type. Small valve

dimensions allow a vast number of val-

ves and nozzle groups. Consequently,

the throttling losses are kept low also at

part load. The cone form of the valve

has been optimized regarding the flow.

Valve spindles, valve cone and valve

bar consist of heat-resistant steel with

hardened, wear-resistant surface. The

hardening is effected via a plasma-

hardening process.

Due to the small valve dimensions, the

steam control valves can be actuated

directly. This so-called group drive is

a compact and reliable solution. The

actuator is a single acting hydraulic

cylinder which is fed by the control oil

system at an oil pressure of 160 bar.

On turbine tripping or full-load dis-

connection the valves are closed by

the pre-loaded spring, thus, protecting

the turbine plant at malfunctions. If the

pressure in the control oil system de-

creases, both the control valves and the

tripping devices will be closed automa-

tically, as they act on the same principle

(single-acting hydraulic piston against

pre-loaded spring). This means double

security for the turbine and the steam

system. A lever system for parallel mo-

tion of both valve spindles precisely

transmits changes of the controller out-

put onto the valve bar and – depending

on the valve lift – on one or more valve

cones. The moving parts are made of

non-corrosive and maintenance-free

self-lubricating material. The valve

spindles are sealed by maintenance-

free, pre-compressed graphite lami-

nated glands, and reinforced carbon

guide bushes.


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Gearbox and generator are installed as

one compact unit. For the MARC 2 and

the MARC 4, generally an epicyclic

gearbox is used which is flanged directly

to the generator. For the types MARC 6

and MARC 8 either an epicyclic or a

helical gearbox is used, depending on

power and speed.

The application of epicyclic gearboxes

bear the following advantages:

The offset usually caused by a helical

gearbox is avoided, which greatly facili-

tates the alignment. Moreover, one

coupling and the high-speed gear

bearing are omitted which improves

the total efficiency.

Gearbox/Generator module


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Lubrication oil module

The lubrication oil system* is a compact

module designed as a low-pressure oil

system for turbine, gearbox and gene-

rator, consisting of:

complete set of 2 main oil pumps

emergency oil pump with DC motor

oil cooler

redundant oil filter

oil mist fan

temperature control valve

pressure control valve

* For MARC1: Combined lubrication

and control oil system.

Diagram of thelubrication oil system

1 Turbine2 Turning gear3 Extraction4 Exhaust steam5 LP control valvel6 HP control valve7 Trip valve8 Gearbox9 Generator

10 Oil tank11 Main oil pump 112 Main oil pump 213 Emergency oil pump14 Oil cooler with cooling

water connections15 Oil filter16 Oil mist fan

Lubrication oil system Turbine Gearbox andgenerator


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Control oil module

The control oil system is a compact

module. The main components are:

oil tank designed as base frame

main oil pump with AC motor

pressure tank

redundant oil filter

bypass pump

oil cooler

measuring and control system

Apart from the control valves, the system

also feeds the live steam trip valve and, if

necessary, the extraction-trip valves and

control devices in the extraction with a

system pressure of 160 bar, commonly

used for hydraulic systems.

Control oil system Turbine Gearbox andgenerator

Diagram of thecontrol oil system

1 Turbine2 Gearbox3 Turning gear4 Generator5 LP control valve6 HP control valve7 HP trip valve8 Extraction non-returnflap

9 Turbine governor10 Generator cooler11 Extraction12 Exhaust steam13 Oil tank14 Circulation pump15 Control oil pump16 Control oil cooler17 Pressure tank


Ethernet

or

Profibus

Data storage

Central Processing Unit

(CPU)

Vibration monitoring

Turbine open-loop controller

Turbine closed-loop controller

Turbine protectionand monitoring

Generatorprotection

Generatorcontroller

FunctionHardware

Overspeed protection

Generatorprotection

Voltagecontroller

coscontroller

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Measuring and Control System

Control cabinet

The turbo set control cabinet is a com-

pact unit that can be arranged flexibly

around the turbine unit. All control

functions and protection of the turbine

and generator are integrated in a single

control box with a user interface on the

front. This saves space and ensures mi-

nimal installation and commissioning

time.

All desired signals can be sent via a

databus (e.g. Ethernet or Profibus) to a

host control system, and operational

commands and setpoint values can be

received from there.

Control system

In order to maintain flexibility when mee-

ting the varied process requirements,

the turbine control system is implemen-

ted in the modern programmable logic

control (PLC) system S7-400. The com-

prehensive range of modules enables

flexible and user-friendly handling of a

wide range of communication options

to other systems and problem-free

expansion, should additional tasks be

required. Startup, shutdown and opera-

tion of the entire turbine unit are com-

pletely automated in the control system,

with ease of use being one of its key

features.

Based on many years of experience in

the field of turbo generator operation,

we have developed a digital steam tur-

bine controller. The inte-gration of this

controller in the existing control system

hardware enables a contin-uous control

concept and optimal integration of the

controller without additional interfaces.

The steam turbine controller is a power-

ful and flexible device. Speed, output,

pressure and temperature are optimally

controlled and critical variables are

limited. All control modes are seam-

lessly integrated.


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Control room

Control cabinet

Measurementtransducer

Emergencyswitch-off

Har

dwire

d

Low voltageswitchgear

Control box

Limit switchTurbinetrip valve

Field

Mean voltage switchgear

Ethernet or Profibus

MP270-B SIMATIC CPU 414 - DP I/O Rack

ISDNRouter

Data LoggerPC

Generatorprotection

Overspeed protection

Voltagecontroller

Hardwired

ExternalTrips

Turbine

Hardwired

Lubrication Oil

Control Oil

Condenser

Pressure

Temperature

Vibrations

PC

Profibus

Operation

The turbo generator can be operated

either via a central control system or lo-

cally, directly via the operator interface

on the control panel. In automatic mode

only the turbine start/stop commands

and specification of the setpoint values

are required. All operating modes and

fault messages are displayed locally and

supplied to the control system via a bus

system. In manual mode, local control

of the auxiliary modules and compo-

nents is possible.

Safety

All turbine units are provided with ex-

tensive safety equipment that safely shuts

down the steam turbine and generator

when critical conditions are reached.

The classification of safety criteria is in

accordance with IEC 61508. Measure-

ment systems, trip and alarm criteria are

specified in such a way that an optimal

balance between machinery protection

and availability is achieved. If desired,

the design also enables unattended

24-hr operation.

Remote access

A datalogger with ISDN interface enables

remote support for your operating

personnel: Important operating data is

saved to a datalogger and can be ana-

lysed by our Service Team, while our

service engineers have direct access to

the control system and control panel.

This enables us to provide you with

quick and cost-effective support.


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Quality Assurance

The most important principle of turbine

manufacture is to ensure high quality

standards for all components. The

turbines are subjected to the follow-

ing checks during the manufacturing

process.

Material inspections

Castings inspection

Production inspection

Assembly inspection

Continuous quality control is ensured

by the ISO 9001 quality management

system.The turbine and baseframe are

erected and the internal piping is instal-

led on the assembly bed. The gear-

ing/generator modular unit is assembled

at the generator manufacturer and

subjected to a functional check. As with

the other modules, both oil modules are

tested at the manufacturer prior to their

installation adjacent to the turbine on

site.

In order to meet the requirements for

quiet running, operational safety and

high availability of the steam turbines,

each turbine rotor is subjected to high-

speed dynamic balancing and spin

testing in a vacuum spin test facility.

After this acceptance test the rotor can

be installed.


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Service

Our experienced Turbine Service

Department ensures the professional

installation of the supplied turbine unit,

including commissioning and trial ope-

ration. The operating personnel concur-

rently receive training as required.

MAN Turbo provides person-al consul-

tancy and optimum support for service

and repair work as well as for retrofit-

ting. Maintenance and revisions are

coordinated between our service

department and the customer. Our

experienced service staff is available

night and day to assure the recommis-

sioning of the plant.


In the interests of technical progress,

subject to change without notice.

Printed in Germany. December 2008

Turbo 1002 e 1208 1.5 ba

MAN Turbo AG

Steinbrinkstrasse 1

46145 Oberhausen/Germany

Phone +49. 208. 6 92-01

Fax +49. 208. 6 92-20 19

www.manturbo.com

MAN Turbo – a member of the MAN Group


marc steam turbine.pdf

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