Page 260 - Design of Solar Thermal Power Plants

4.3 DESIGN OF THE SOLAR TOWER POWER PLANT 243

should be designed within the parabolic trough field. Especially in
the case of a heat-collection system that uses oil as its heat-transfer
medium, a fire-prevention trench shall be designed between the
solar field and main powerhouse, where weeds and other
inflammable goods shall be cleaned regularly.
10. For peripheral parabolic solar trough connectors within the solar
field, due to the need for wind resistance, a large wind-resistance
load shall be designed, including within the transmission design.
The concentrators in the field center suffer weak wind load so the
design wind load for these concentrators can be reduced to save
structure cost.
11. The length of each line of concentrators in a parabolic trough
concentrator field can be determined according to the
temperature of the working fluid and the local ambient
temperature using technical and economic comparisons. A long
concentrator requires a greater site leveling cost and has a
higher requirement for axial installation precision of the
concentrator.
12. Rodent pest prevention within the solar-concentrating field is
also a topic to focus on during cable-laying design. In the event
of a rodent pest problem, cable trenches must not be used and the
piping shaft must be tightly sealed. The wiring of the
concentrator’s control cabinet shall be protected from rodents.
Qualified projects can either consider applying wireless
communication in place of wire transmission or substituting
the cable layout by using photovoltaic cells to drive the
concentrator.

4.3 DESIGN OF THE SOLAR TOWER POWER PLANT
CONCENTRATING FIELD

The heliostat is important equipment in the solar thermal power
generation system during the initial stage of energy conversion. In a solar
tower power system, hundreds or thousands of heliostats are typically
used to continuously track solar radiation through respective indepen-
dent control systems and concentrate solar energy onto the receiver
mounted on top of the tower to utilize energy in the form of heat. The
design of the heliostat field serves as a major step in the design of a solar
thermal tower power generation system and can reduce the overall scale
of electricity-generating costs while demonstrating a certain theoretical
foundation for the application of solar thermal power generation
techniques.