Environmental Engineering Reference
In-Depth Information
components and back again. This process is repeated throughout the design phases
to ensure the best of all requirements are considered and optimized, while remaining
agile to ever changing external factors; e.g. markets, emergent technologies, etc.
Table 3 provides a simplifi ed listing of considerations as a starting point for the
turbine designer and illustrates just how challenging this process can be. There are
additional levels of systems and sub-systems and all of these and their inter-
relationships should be thoroughly understood. Many of the items in the system
level have direct counterparts in the component level, while others must be con-
sidered in both systems and components. Without exception, truly optimized
MW WT products have component level characteristics that are performance
enablers for meeting overall system level requirements.
4 MW WT design techniques
This section pulls together all of the pieces that go into a well-organized new
turbine design. Requirements are emphasized and optional approaches presented.
The 10-turbine analysis group is used together with the value analysis methodol-
ogy to estimate turbine loads and their effect on component mass and cost. Com-
ponent and turbine results are plotted for the 10-turbine analysis group against the
backdrop of the entire industry.
4.1 Requirements
The customer's highest priority is investing in equipment and power plant infra-
structure that is affordable to fi nance and continues to operate cost effectively for
its entire 20-year lifetime. Thus, it is imperative that new turbine designs consider
reliability, availability and maintenance from the very beginning. The ease of oper-
ating and deriving profi ts from the WPP is as important as the initial cost. The need
for specially trained personnel or specialists is another important consideration early
in the equipment selection process. The successful turbine designer accounts for all
of these and the individual signifi cant requirements of prospective customers.
4.1.1 Turbine
While there are numerous possibilities for WT system confi gurations, the major-
ity of modern equipment consists of a horizontally confi gured drivetrain with two
or three blades attached to an upstream facing rotor. The rotor is supported at the
tower top using at least one rotor bearing and a main shaft that drives a generator
system for power conversion. The drivetrain and power conversion system are
located on top of the tower within a nacelle enclosure to protect the power conver-
sion equipment from the environment. The nacelle is equipped with a yaw system
that is used under normal operating conditions to point and maintain the rotor facing
upstream into the wind.
It is beyond the scope of this article to discuss the details for why this confi gura-
tion has become the de-facto standard. Suffi ce to say that many other confi gurations
have been investigated, and in almost all cases, the reasons boil down to longevity
(through relentless unsteady operational conditions and extremes), reliability and
Search WWH ::
Custom Search