Wind Energy

308 L. Battisti et al.
Q t [W/m 2 ]
6000
4800
3600
2400
AoA 2˚
1200
0
AoA
M3 M5 M6
(a)
Q t [kW]
100
80
60
40
20
0
AoA 12˚
AoA 2˚
M3 M5 M6
(b)
Q t / P r [%]
5
4
3
2
1
0
AoA 12˚
AoA 2˚
M3 M5 M6
Fig. 57.2. Specific anti-icing power requirement (a), total anti-icing power requirement
(b), and anti-icing-power to rated-power (c) for the two extreme angles of
attack
a running wet condition, require an anti-icing power at the leading edge region
increasing with the size and ranging between 10% and 15% of the turbine’s
rated power output. This ratio is lower for larger size turbines compared
to small ones. The anti-icing power decreases more or less proportionally to
the number of blades for turbines having the same solidity and size. The
same conclusions, not shown here can be drawn for rotors of different solidity,
although other physical mechanisms are involved. It is worth to mention that
the above results concern the heat flux requirement and no considerations
were developed at this stage on the adopted ice prevention system technology.
The transfer of the results for their design must be carefully evaluated as the
efficiency of the ice prevention system plays a basic role in defining the actual
power requirement.
References
1. W.B.Wright,UserManualfortheNASAGlennIceAccretionCodeLEWICE
version 2.2.2, CR-2002-211793, pp. 260–270, 363–366
2. L. Makkonen, T. Laakso, M. Marjaniemi, K.J. Finstad, Modeling and prevention
of ice accretion on wind turbines, Wind Engineering, 2001, 25(1), 3–21
3. L. Battisti, R. Fedrizzi, M. Rialti, S. Dal Savio, A model for the design of
hot-air based wind turbine ice prevention system, WREC05, 22–27 May 2005,
Aberdeen, UK
(c)