Page 240 - Design of Solar Thermal Power Plants

3.10 NOTICES FOR CONCENTRATION FIELD LAYOUT 223

of the shape, height of the wall, and the distance between the wall and
the concentration field; otherwise, the negative pressure area created by
the wind striding over the wall may aggravate the dust accumulation
in the concentration field.

3.10 NOTICES FOR CONCENTRATION FIELD LAYOUT

A concentration field serves as the unit for collecting, reflecting, and
concentrating solar energy. During design of a heliostat field, attention
shall be paid to the harms to its neighboring buildings and personnel. It is
better not to construct any tall buildings on other directions around the
tower besides the north direction in the concentration field.
Road layout in the concentration field and the space between concen-
trators shall be designed by considering the service request of equipment.
For large-area heliostats, requirements for 20 t-level crane car land and
road widths shall be fully considered; whereas for small-area heliostats,
less large-scale transportation equipment is required for erection and
hoisting. However, due to large quantity of mirrors, multiple linkage
mechanisms and numerous fault points, the space necessary for frequent
service shall also be fully considered.
Concentrator in the concentration field has extremely high requirement
on precision; a slight shaking may have an impact on the precision. Thus
when analyzing the geological conditions of the concentration field,
construction site shall be free of significant geologic hazards, such as
earthquake and underground cave collapse. It shall be fully considered
during the foundation design for the concentrator and receiver tower.
Diameter and volume of the receiver tower shall be as small as
possible. It is better to apply the scheme of steel structure tower that is
permeable to light, which could minimize the shade caused the tower
during functioning of the northward concentration field.
Communication and power cables in the concentration field shall be
rat-proof. By using rat-proof heavy-armored cables, cable costs will be
greatly increased. For areas with severe rat problems, it is suggested to
apply wireless communication to achieve the connection between the
concentration field and the host computer.
For a parabolic trough system, the concentration field has been inte-
grated with the collector field; thus soil pollution caused by evacuated
tube oil leakage and the respective safety preventive measures shall be
fully considered. In order to facilitate the treatment for oil leakage and
prevent the spilled materials from being spread, it is normally not
suggested to perform any concrete or asphalt hardening on the ground