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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,<br />
The most appropriate aiming strategy on the receiver should be used during<br />
optimization. For designing flux limited receivers during system optimization, a<br />
field of flux points can be specified in Namelist NLFLUX. However, during opti-<br />
mization, flux will only be calculated and examined at four specified points out of<br />
the field of flux points. It is suggested that the allowable fluxes <strong>for</strong> each of these<br />
four points be specified individually, since the allowable flux will be different at<br />
different receiver locations due to different receiver temperatures and flow rates.<br />
It is further suggested that the four points checked during optimization also be<br />
checked during the final per<strong>for</strong>mance run to determine the effect of the optimiza-<br />
tion assumptions on the flux calculation during optimization.<br />
During optimization DELSOL also sizes the heliostat field to meet the re-<br />
quested design point power. This means that zones of heliostats are added by<br />
the code to get the required power at the best energy cost. If heliostat density<br />
optimization is not requested, the code will add zones or portions of zones of he-<br />
liostats at the default heliostat densities until the power is reached. The result<br />
of this process is a heliostat field which is no longer a uni<strong>for</strong>m circular or north<br />
biased field (IUSERF = 0 or l), but is instead a heliostat field specified zone by<br />
zone (IUSERF = 2). Thus the value of IUSERF will be changed during system<br />
optimization.<br />
As a further step in field design, heliostat densities can be optimized as de-<br />
scribed in Section 1V.B-l. DELSOL can simultaneously optimize the heliostat<br />
densities and receiver dimensions. However, DELSOL cannot vary the tower<br />
height while optimizing the densities. There<strong>for</strong>e, the user must first do the above<br />
system optimizations to find an optimum tower height <strong>for</strong> use during heliostat<br />
density optimization. Unless the optimum tower height is the same as was chosen<br />
during the initial per<strong>for</strong>mance calculation, a new per<strong>for</strong>mance calculation is also<br />
required be<strong>for</strong>e optimizing the heliostat densities. Note that if optimizing helio-<br />
stat densities results in a higher levelized energy cost at that design point power<br />
level, then that optimization did not help, despite the fact that <strong>for</strong> a constant an-<br />
nual energy the heliostat density optimization would have given a lower energy<br />
cost.<br />
Once an optimized system has been chosen, DELSOL will assign component<br />
costs to each part of the system, based on its internal cost algorithms. This is<br />
done at the end of system optimization, and is the only place in DELSOL where<br />
component costs are determined, other than <strong>for</strong> the exception below.<br />
If it is desired to optimize storage size <strong>for</strong> a fixed field size, that option should<br />
be requested during the system optimization procedure. However, the actual cal-<br />
culation is not done until a final per<strong>for</strong>mance run is done. Thus, output from sys-<br />
tem optimization will always refer to the default calculated storage size, and costs<br />
will be set accordingly. During a final per<strong>for</strong>mance calculation, the code will then<br />
trade off the cost of storage against the cost of discarding energy and determine<br />
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