Environmental Engineering Reference
In-Depth Information
CHAPTER 19
Yanlong Jiang
Department of Man-Machine - Environment Engineering,
Nanjing University of Aeronautics and Astronautics, China.
With the increase of the unit capacity of wind turbines, the heat produced by
different components rise signifi cantly. Effective cooling methods should be
adopted in developing larger power wind turbine. In this chapter, the operating
principle and main structure of wind turbines are fi rstly described, following
with the analysis of heat production mechanisms for different components. On
this basis, current cooling methods in wind turbines are presented. Also, optimal
design of a liquid cooling system for 1 MW range wind turbine is conducted.
Finally, some novel cooling systems are introduced and discussed.
1 Operating principle and structure of wind turbines
In brief, the operating principle of a wind turbine is that rotation of impellors
driven by wind power converts the kinetic energy of wind into mechanical energy
of the impellor shaft, which drives the generator. There are mainly two types of
wind turbine operating modes. One is the independent power-supply system,
which is usually used in the remote areas, where electric network is not available.
The terminal electrical equipments are powered by alternating current, which is
converted by a DC-AC converter from the electricity in a storage battery charged
by small scale wind turbines. Generally, the unit capacity is from 100 W to 10 kW.
Or a hybrid power-supply system comprising a middle scale wind turbine and a
diesel generator or solar cells with capacity, range from 10 to 200 kW, is adequate
to meet the need of a small community. In another wind turbine operating mode,
the wind turbines are used as a power resource of an ordinary power network,
paralleling in the electricity grid system. It is the most economic way to utilize
wind power in a large scale. This mode can synchronize and close with a unit inde-
pendently and also can be made of multiple, or even thousands of wind turbines,
called wind farm [1-3].
Search WWH ::
Custom Search