A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...
A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...
A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...
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III. A - 9. IPROB=2, Sing1 e Calculational Time-DELS 0 L calculates the per<strong>for</strong>-<br />
mance only at UTIME hours past solar noon (UTIME is negative in the morning)<br />
on the UDAY day of the year (Namelist BASIC).<br />
III. A-4. IPROB=S, Matriz of Sun Angles-Instead of calculating per<strong>for</strong>mances<br />
at certain specified times, this option allows the user to obtain the per<strong>for</strong>mance<br />
at certain specified sun angles. NUAZ values of the azimuthal angle, UAZ, and<br />
NUEL values of the zenith angle, UEL, are considered in all possible pairwise<br />
combinations.<br />
III.A-5. Selection of NYEAR, HRDEL, and Reference Times-Both accuracy<br />
and calculational time of the per<strong>for</strong>mance calculation (but not the optimization<br />
calculational time) increase with the number of day and hourly time steps chosen.<br />
Fortunately, a relatively few days (3 to 5) and a reasonable time step (1 hour)<br />
appear to <strong>prod</strong>uce accuracies better than 1%. Generally, it is better to decrease<br />
HRDEL than to increase NYEAR when attempting to increase accuracy.<br />
Two times of the year have special significance. First, REFTIM hours past<br />
noon on the REFDAY day of the year is called the reference time. This is the<br />
time of the year which is used to determine the design point power levels of the<br />
system, as described in Section 1V.C-1. Second, HCANT hours past noon of the<br />
DCANT day is used to determine the off-axis canting of heliostats, if any, as de-<br />
scribed in Section 1I.D-2. The reference time must correspond to one cal-<br />
culational time. In addition, daily start-up and shutdown times are determined<br />
by the user-specified zenith angle, ASTART (< 90").<br />
Default values are:<br />
NYEAR = 5<br />
HRDEL = 1.0<br />
ASTART = 75.0"<br />
REFTIM = 0.0 (solar noon)<br />
REFDAY = 81.0 (equinox, March 21)<br />
HCANT = 0.0<br />
DCANT = 81.0<br />
1II.B. Seasonal and Daily Variation of Sun Positions and Sunshape<br />
The per<strong>for</strong>mance of a system is dependent on the position of the sun, the ac-<br />
tual insolation, the shape of the sun, and weather effects, all of which can vary<br />
with time.<br />
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