Page 356 - Fluid Power Engineering

316 Chapter Fourteen

Erection
Turbine manufacturer provides an erection plan along with crane re-
quirements for erection. Normally, two cranes are used: A main crane
with a rated capacity of 500– to 650 metric tons (for utility-scale tur-
bines), and an auxiliary (or tail) crane with a rated capacity of 90
metric tons. Typically, the main crane is a mobile crawler crane, while
the auxiliary crane is a mobile hydraulic crane.
Turbine erection is a 2- or 3-day process per turbine. The first
step in the process is to assemble the tower, which is in three or more
sections.Figure14-5isaphotographshowingliftingofatowersection.
Two cranes are used to lift the sections and stack them. After the tower
sections have been stacked and bolted, the nacelle is lifted. Depending
ontheturbinemanufacturer,therearetwooptionsforliftingofnacelle:
(i) Single lift of nacelle with generator or (ii) two lifts: first, the nacelle
is raised without a generator, then the generator is lifted and placed
in the nacelle. The final assembly to be lifted is the rotor with blades.
In order to prevent the blades from swinging and hitting the tower
during the lift, various strategies are used including using two cranes
working in tandem.

FIGURE 14-5 Lifting
of tower sections
by the main crane
(right). Auxiliary
crane (left) assists
with the lift.
(Courtesy Vensys
Energy AG.)