Environmental Engineering Reference
In-Depth Information
Similar with the wind turbine adopting vapor-cycle cooling method, the cooling
medium runs sequentially through the heat exchangers outside the gearbox, the
generator and the control converter, taking away the heat produced by these com-
ponents. The heated cooling medium is then delivered to the refrigerating engine
in the wind power plant through the cooling medium return pipe to get centralized
refrigerated and once again delivered back to every wind turbine through the
carrier pipe to perform the next round of cooling.
In a practical application, different types of air coolers or refrigeration units can
be selected for the cooling unit according to the cooling demands of the generator.
Compared with air coolers, refrigeration units are able to obtain lower cooling tem-
perature. When the individual refrigeration unit cannot suffi ce to the cooling
demands, multiple refrigeration units can be adopted; when the cooling demands are
changed because of climate, season and other factors, they can be fl exibly regulated
by just changing the number of devices in operation. As to the wind power plant with
a large-scale geographical area and a large number of generators, an alternative
option is to set several centralized refrigeration units at different proper locations,
according to the practical situation, to better satisfy the cooling demands and ratio-
nalize the distribution of the cooling medium delivery lines, aiming at obtaining high
dependability and economy. With regard to wind turbines under low operating tem-
perature, in order to reduce the cooling capacity wastage in the delivery of cooling
medium, the system can adopt those pipe lines with good heat-insulating property
and conduct some treatments of thermal insulation, such as coating the pipe with
heat-insulating layers etc. The carrier and return pipes of the cooling medium can be
laid out along with electric cables within the pylon so as to avoid corrosion of blown
sand and rain to the pipeline. Besides, the joint of the cooling medium carrier and
return pipe lines and the wind turbines can also be connected with bellows.
Compared with the forced air cooling and the liquid cooling systems, although the
initial cost and the operating cost of the centralized cooled wind power generating sys-
tem is higher, it has its own advantages, such as huge cooling capacity and fl exible
adaptability. Besides, the refrigeration units can aptly adopt various cooling manners
according to the operating requirements of the wind power devices so as to suffi ce to the
high-power cooling demands, which pave the way for the new generation of high-power
wind turbine sets. Comparing to the vapor-cycle cooling method, this system simplifi es
the internal cooling devices of the wind turbine, and lowers the operating weight to make
it suitable for the operation of wind turbines at a high altitude, which, thereby, eases the
maintenance of the devices. In addition, when dealing with cooling demand fl uctuation
caused by changing of season, climate or other factors, no adjustments to individual
wind turbines are required, but simply the adjustment to refrigeration units is needed.
5.3 Jet cooling system with solar power assistance
The cooling technologies and solutions mentioned above are all driven by elec-
tricity but the solar power as a clean energy from the atmosphere is omitted. This
omission, to some extent, lowers the generating effi ciency. Actually, the cur-
rent heat-driven cooling technique is fairly mature. Because of these, the solar
power jet cooling method can be implemented in the wind turbine cooling system.
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