Page 266 - Design of Solar Thermal Power Plants

248 4. DESIGN OF THE CONCENTRATION SYSTEM

FIGURE 4.15 Required space for collisionless rotation of heliostat.

2. Layout pattern of the heliostat: the heliostat field is arranged by
applying radial-staggered pattern, the advantage of which is the
avoidance of significant optical losses caused by reflected solar
beams from heliostats that are blocked by adjacent heliostats located
straight ahead of them. In a radial-staggered design, the heat-
receiving tower is located at the origin of the coordinates while the
heliostats are placed on rings with varying distances from the
receiving tower. In this method, an essential ring is defined as a ring
with a heliostat on the axis straight ahead of the tower, and a
staggered ring is defined as a ring without any heliostat on the axis
straight ahead of the tower, as shown in Fig. 4.16. The first ring is
defined as the essential ring, the radius of which is normally related

Receiving tower
x

R min

D m
Staggered ring
ΔR Essential ring

-y
FIGURE 4.16 Schematic diagram of radial-staggered layout.