wind turbine fire protection - nfpa

© Prof. Dipl. - Ing. Henry Seifert, Hochschule Bremerhaven 18 April 2016 1

Wind Turbine Fire Protection

Symposium on Fire Protection for a Changing WorldMunich 18 April 2016

Prof. Dipl. - Ing. Henry SeifertUniversity of Applied Sciences Bremerhaven

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Content:

• My background• Development of wind energy • Technology used today• Are proper Standards available?• Which are the risks concerning fire?• How can fire develop in wind turbines?• How can fire be prevented, detected, protected?• Which are the “wind energy specific challenges”?• Conclusion, Recommendations


Hochschule BremerhavenUniversity of

Applied Sciences

Wind energy research and education


Study Wind Energy at Bremerhaven

WETWET

MARMARBachelor Study Course: Maritime TechnologiesMaster Study Course: Wind Energy Techniques


Institute for Wind Energy

with the motto

„To understand the wind turbine as a whole“



Content:



In the last 25 years the rotor diameter of a

serial produced wind turbine has been grown

by a factor of 5 the installed power has been grown by a factor of 20 in the same period

Wind energy is a fast growing industryin quantity and size


Development of size in Germany

Time

Rot

or D

iam

eter

, m

Airbus A 380

Ulm Cathedral

Largest serial turbine

Prototype

6 MW5 MW

3 MW1.5 MW

0.5 MW0.3 MW

0.05 MW


Status wind energy development in Germany

As of end of 2015

25 980 WT

41 652 MWinst

from those more than 3 295 MWinstOffshore*)

Source: BWE / Windguard 2016


Status wind energy world wide

Source: BWE, 2016



Content:



The technology used today

Today’s wind turbines are characterized by:

• MegaWatt to Multi MegaWatt size• horizontal axis• upwind rotor with 3 blades• rotor blades in composite design• full span pitch control• variable speed operation• tip speed less than 80 m/s• grid connected operation• Direct drive, with gearbox or “multibrid”• Steel, concrete or hybrid towers• tripods, tripiles, jackets as offshore foundations


The technology used today

furthermore:

• low noise operation• high efficiency of the components• high technical availability• low investment and low O&M*) costs• long entire life time (20 years) of all

components under extreme external conditions

*) O&M operation and maintenance


Hub

Rotor

Shaft

Gear

Generator

Tower

Nacelle

Today‘s wind turbine concepts

Foundation


Complex terrain

Flat terrain

Offshore

Typical sites where wind farms are located


Typical wind farms in complex terrain

flat terrain

offshore



Content:



Are proper Standards concerning fire protection for wind turbines available?

Wind energy is an international business and fast growing world wide, especially off-shore

The development of the size and technology grows faster than the standardisation work

Only a relatively few number of wind turbines burned down up to now, the pressure on the industry and the authorities is not very high

HSE1 and fire protection are usually national affairs1 HSE health safety and environment


Statistics of failures

Source: IWES 2016


Harmonisation of Standards for fire protection in a new field of technology is difficult on national level

It is more difficult on an European level

It is nearly impossible on an international level

Many stakeholders must be involved!

Industry, authorities, associations, standardisation committees, certification bodies, unions, ................


Which Standards could be useful?

On an international level the IEC TC 88 is responsible for wind turbine design and operation: With reference to fire protection:

IEC 61400 - 1 Design requirements IEC 61400 - 24 Lightning protection for wind turbinesNew work item proposal under IEC TC 88: “Wind Turbines - Safety of the WTGs General principles for Design”

The International Electrotechnical Vocabulary IEV 415 (wind turbines)



1 FprEN: Draft European Standard for formal vote

On European level the CENELEC is responsible for wind turbines E.g. for safety at work for on-shore wind turbines:

EN 50308 Wind turbines - Protective measures - Requirements for design, operation and maintenance; German version FprEN1 50308:2013

For off-shore wind farms no Standard is availible



On national German level there are some recommendations available:

VdS Schadenverhütung GmbHPublication by the German Insures (GDV e.V.) on the issue of loss prevention

VdS 3522en: 2016-01 (01) Offshore Wind Powerhttp://vds.de/fileadmin/vds_publikationen/vds_3522en_web.pdf

VdS 3523en : 2008-07 (01) Wind turbines: Fire protection guidelinehttp://vds.de/fileadmin/vds_publikationen/vds_3523en_web.pdf

Deutscher Feuerwehrverband e. V. (DFV)Fachempfehlung Nr. 1 März 2008 Einsatzstrategien an Windenergieanlagenwww.dfv.org



Content:



Which are the risks concerning fire?

Due to different sites, sizes and type of operation of wind turbines the answers are different:

In principle on- and off-shore wind farms need to be handled differently.

The size of the present serial-production on-shore is 2 to 3 MW, off-shore 5 MW. The rotor diameter as well as the hub height is more than 100 m.

Two types of operation has to be taken into account:Manned and unmanned operation.



Sites:

Generally wind farms are erected far away from settlements due to noise and shadow flicker

Offshore wind farms are mostly far away from beaches and shipping lanes

No high risk for humans when the wind turbine is on fire?



If the nacelle and the blades are on fire, burning and possibly harmful debris can be drifted by the wind.

On-shore there is a risk in the warmseasons with dry crop or woods around the wind turbine

Distance between turbine 5D to 7D



If the nacelle and the blades are on fire, burning and possibly harmful debris can be drifted by the wind.

Off-shore there is a risk to pollute the water



Sizes:

Generally wind turbines are high structures. The fire endangered nacelle is normally based on a tubular steel or concrete tower (chimney effect)

Ground based extinction is not possibledue to the height

Fire protection is absolutely necessary



Type of operation:

The technical availability of today’s on-shore wind turbines is more than 97 per cent.

Most of the time the wind turbines run in unattended automatic operation.

The wind farms are monitored by remote supervision

Most of the time the wind turbine runs unmanned



Manned Operation during erection, commissioning,maintenance and repair.

In the towerIn the blade



Manned Operation:

Rescue from height must alwaysbe guaranteed.

Escape routes are long and vertical !!!

In the blades and in the hub only one exit is available

From the nacelle roping down is possible, needs time



Manned Operation:

The risk for fire is high if the turbine is not under normal conditions, e.g. in case of failures or during erection and commissioning the electrical system

Automatic CO2 extinguishing systems shall not be used


Which are basic requirements for the staff?

• Adequate personal protective equipment PPE• Limited number of persons at the nacelle, hub,

rotor blade • Adequate escape routes• Safety equipment• Communication systems• Speak one language • Education• Repeated safety instruction

• Training, training, training, training, .....



Content:



How can fire develop in wind turbines?

Sources of the fire on a wind turbine:

Lightning strokes: Wind turbines are exposed structures.

Overheating of components(bearings, gears, windings, .....)

Short circuits

Sabotage by opponents


Components of a wind turbine which can burn

Rotor blade: composite structures with resin

Gearbox: Grease, oil

Generator: Insulation material

Nacelle: Housing (GRP), cables, hydraulic oil

Inverter systems: Electronics, cables

Transformers: Oil, cables, insulation material



Content:



How can fire be prevented, detected and protected?

Due to the unattended operation for along period the wind turbines must be monitored automatically by a huge amount of sensors:

Monitoring systems: e.g. CMS Systems

Data acquisition systems with automatic alarms

Camera monitoring

Regular inspection and maintenance


Example: Sensors of today‘s wind turbines

Power transducer

Rotor speed indicator

Wind vaneAnemometer

Blade pitch positionOil temperatures

Outside temperature Rotor azimuth positionNacelle position Accelerometer

Displacement transducer Strain gauges

Current transformer Temperature gaugesIcing sensor

Switches and contactorsPressure transducer

Lightning detectors


Example: IEC 61400 - 24 Lightning protection

Steel wire

Metal meshDown conductor

Down conductor

receptor

Ref.: IEC 61400-24



Content:



Which are the “wind energy specific challenges”?

Due to the unattended operation for along period the wind turbines must be monitored automatically by a huge amount of sensors:



Content:



Conclusion

Wind energy is a relatively young but fast growing branch. The development of Standards is far behind the wind turbine techniques.

The wind turbines have been grown in numbers and sizes very fast. Effort by the manufacturers is always laid on the development of the latest model.

The technology of the “old models” has been not improved. This is mostly true for the safety equipment.

The branch is not very sensitive for fire protection


Recommendations

Bring stakeholders together for the development of international procedures and standards

Harmonised training of O&M staff has to be pushed

Safety equipment has to be harmonised

Install a data base for accidents and incidents

More research is necessary

wind turbine fire protection - nfpa

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