A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...

of zones follows a “law of diminishing returns.” The default values offer a good
compromise:
NRAD = 12 INORTH = 0
NAZM = 12 AMAXN = 82.5
The default field option is IUSERF=O for an initial performance calculation
and IUSERF=2 for a performance rerun where ITAPE=3. The default field lim-
its encompass most designs:
RADMIN = 0.75
RADMAX = 7.5
I1.B-3. Rotating Fields-DELSOL can analyze central receiver systems that
rotate (IROTFLZO). The rotation is synchronous with the azimuthal motion of
the sun. An observer rotating with the field will only see the sun move vertically
in one dimension. There is no apparent azimuthal motion of the sun. DELSOL
also assumes that the receiver is in synchronous rotation. When using rotating
fields, the azimuthal angle of the sun (when viewed from the field) always appears
to be due sauth. (Note: In optimizing rotating field systems, DELSOL does not
include the cost of the extra land required to allow the field to rotate.)
l1.B-4. Land Constrained Heliostat Field-DELSOL allows the user to sub-
ject the heliostat field (not including the tower) to an existing land constraint.
If NLANDrO (namelist FIELD for performance calculations; namelist OPT for
design optimizations), then all heliostats must be within one of NLAND user de-
fined rectangles. The rectangles can have arbitrary size, displacement, and ori-
entation and may or may not overlap, as illustrated in Figure 11-8. The center
of the Ith rectangle is CLE(1) meters east and CLN(1) meters north of the first
rectangle; therefore, CLE(l)=CLN(l)=O. ALP(1) is the angle, in degrees, that
the sides of the Ith rectangle are rotated from the N-S and E-W axes. ALP(1)
is positive for a clockwise rotation view from above. SLNS(1) and SLEW(1) are
the length, in meters, of the sides of the Ith rectangle, which, prior to rotation by
ALP(I), were parallel to the N-S and E-W axes, respectively.
In a land constrained field it is necessary to specify the location of the tower.
In performance calculations a single tower position is considered. The center of
the tower is YTOWER meters north and XTOWER meters east of the center of
the first land constraint rectangle. In design optimization calculations DELSOL
can search to find the optimum tower location. DELSOL considers NUMPOS
equally spaced tower locations along a line from a first tower position of XTPST
meters east, YTPST meters north to a final tower position XTPEND meters east,
YTPEND meters north.
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