© ebm-papst with Adobe Firefly (AI-supported)
© ebm-papst with Adobe Firefly (AI-supported)

Fans for wind power plants

Of the renew­able ener­gies, wind power is seen as the one with major growth poten­tial, with its share of the energy budget set to increase further. At the same time, the capacity of wind power plants is on the rise, with inno­va­tions in the mate­rials used and opti­mized blade geome­tries, for example, contributing to this. However, every increase in capacity also means a greater amount of waste heat – and this must be dissi­pated as effi­ciently as possible. This is essen­tial to ensure that the tech­nology installed in the wind power plants can work reli­ably and is not damaged. Fans play an impor­tant role here. Effec­tive cooling that consumes as little energy as possible can increase the perfor­mance and there­fore the effi­ciency of the entire plant.

Wind power plants require a lot of cooling. In addi­tion to the elec­tronics, vari­able frequency drives and gener­a­tors, pitch drives, control cabi­nets and trans­mis­sions must also be cooled and the nacelle air-condi­tioned. The require­ments for the fans used are as varied as the indi­vidual appli­ca­tions. In most cases, the required air perfor­mance is not the only crucial factor.

The fans must also excel in terms of energy effi­ciency, acoustics and, above all, reli­a­bility, while often having to cope with cramped instal­la­tion condi­tions. For the various air condi­tioning solu­tions, ebm-papst’s port­folio there­fore includes a wide range of axial and centrifugal fans with energy-saving EC motors that are designed to meet the prop­er­ties required in wind power plants.

Infi­nitely vari­able control, quiet, robust and with condi­tion moni­toring

If the wind power plant produces little or no elec­tricity, the cooling require­ment decreases and the fans have to adapt to the respec­tive oper­ating condi­tions. This is where energy-effi­cient EC fans with infi­nitely vari­able speed control are used. Aero­dy­namic opti­miza­tion ensures low-noise oper­a­tion, which is impor­tant for wind power plants oper­ating close to resi­den­tial areas.

Another impor­tant aspect is that the inte­grated elec­tronics of the EC motors are robust enough to cope with non-sinu­soidal supply currents thanks to their high dielec­tric strength. At the same time, the elec­tronics offer the option of remote moni­toring, where a full set of infor­ma­tion, from speed and motor temper­a­ture to oper­ating and fault messages, is avail­able anytime and anywhere.

The measured values from the vibra­tion and temper­a­ture sensors inte­grated in the motors can be used for condi­tion moni­toring. This forms the basis for preven­tive main­te­nance measures as part of the sched­uled service inter­vals. Unex­pected air condi­tioning fail­ures due to the fan are signif­i­cantly reduced as a result.

If there is a risk of corro­sion because the fans come into contact with salty or humid air, a special coating protects the surfaces. This means that corro­sion protec­tion require­ments up to class C5-M in accor­dance with DIN EN ISO 12944 can be met.

Cabin air condi­tioning

The nacelle is where all the machinery for each wind power plant is housed. The temper­a­ture inside should not exceed 30°C. After all, the power elec­tronics, gener­ator etc. are cooled with the ambient air. Although the systems for nacelle air condi­tioning differ in design, they always require reli­able and robust fans. Depending on the instal­la­tion situ­a­tion in the air condi­tioner and the geom­etry of the heat exchanger, either axial or centrifugal fans can be used.

The nacelle’s air condi­tioning protects compo­nents housed inside it from exces­sive temper­a­tures (1: Fan outside air, 2: Fan internal circuit, 3: Cross heat exchanger). (Photo | ebm-papst)

AxiBlade and AxiEco are two axial fan series that cover different require­ments. The first boasts a high power density with low noise emis­sions, while the second series is partic­u­larly suit­able for appli­ca­tions requiring a partic­u­larly high pres­sure increase, for example due to the instal­la­tion condi­tions or exchanger geome­tries.

AxiEco (Foto | ebm-papst)

Centrifugal fans are also suit­able for nacelle air condi­tioning. When the RadiPac centrifugal fans were devel­oped, for example, the actual, often cramped instal­la­tion situ­a­tion in the customer device was taken into account. In partic­ular, the outflow char­ac­ter­is­tics of the impeller were opti­mized and deflec­tion losses in the air handling unit as well as the outlet losses were reduced thanks to a special design.

This allows the fans to run at a lower speed at the same oper­ating point, which in turn means that less energy is required and the oper­ating noise is lower. Thanks to a wide optimum effi­ciency range and a high static overall effi­ciency level, the fans operate with low power consump­tion in a broad range of oper­ating condi­tions.

The AxiEco series is partic­u­larly suit­able for appli­ca­tions where a high pres­sure increase is required. (Photo | ebm-papst)

Gener­ator cooling

RadiPac 2 (Foto | ebm-papst)

Synchro­nous or asyn­chro­nous gener­a­tors are the “heart” of the wind power plant and should work main­te­nance-free for as long as possible. To achieve this, the gener­a­tors must be kept at a toler­able temper­a­ture level. If they become too hot, their effi­ciency and service life will be decreased. In the worst-case scenario, compo­nents could be damaged, which would result in expen­sive repair work. For this reason, centrifugal fans often convey air over the outer stator of the gener­ator to dissi­pate the heat for cooling purposes.

Here too, the above-mentioned Radi­Pacs have found a typical area of appli­ca­tion thanks to their high power density, robust­ness and large pres­sure increase. Their compact dimen­sions mean that both conven­tional and ring gener­a­tors can be cooled. Demand-based, temper­a­ture-controlled actu­a­tion is then possible via Modbus RTU or analog signals, for example. Thanks to EC motors’ high effi­ciency levels, the gener­ator only needs to generate a small amount of energy for its own cooling. This is partic­u­larly bene­fi­cial when many fans are used on large gener­a­tors.

Switch cabinet cooling and vari­able frequency drive cooling

RadiCal 2 (Foto | ebm-papst)

The smaller RadiCal EC fans were devel­oped with a view to using them for switch cabinet cooling, espe­cially in wind power plants. They are partic­u­larly impres­sive due to their high air flow rates, good noise char­ac­ter­is­tics and compact dimen­sions, which also make it easy to replace previous AC solu­tions. In sizes 133 to 560, they cover air perfor­mance levels of up to approx. 14,000 m³/h (at up to 1,400 Pa).

Powerful RadiPac EC fans are used for cooling vari­able frequency drives in wind power plants. Compact dimen­sions due to what are usually very cramped instal­la­tion condi­tions, dura­bility, robust elec­tronics and energy effi­ciency are also impor­tant argu­ments in favor of centrifugal fans with their high power density. As the RadiPac product range is avail­able in sizes 250 to 1,000 at up to 2,500 Pa and with air perfor­mance levels of up to 37,000 m³/h, the range of appli­ca­tions is broad.

The RadiCal EC fans are partic­u­larly impres­sive due to their high air flow rates, good noise char­ac­ter­is­tics and compact dimen­sions, which also make it easy to replace existing AC solu­tions, for example in switch cabinet cooling. (Photo | ebm-papst)

In addi­tion, there are many other fans that are suit­able for use in wind power plants, and customer-specific modi­fi­ca­tions are also possible. This applies not only to wind power, but also to photo­voltaic systems – like­wise from the renew­able energy sector, where the quiet, energy-effi­cient and reli­able fans have already proven them­selves in many appli­ca­tions.

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