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

In other words, PLOST,R is the same at any time of the day or year. Implicit
in the assumption is that the same temperature profile is maintained on the receiver
at all times and for any receiver size by adjusting the fluid flow rate, and
that convective losses vary insignificantly with time.
Letting ~RC,R,DP be the design point efficiency dased on receiver radiation and
convection losses, then:
qRC,R,DP =
Pth,R - PLOST,R
Pth,R
=I---- QRAR
Pth,R
(1II.G - 10)
where Pth,R = gross thermal power absorbed by the receiver at the design point.
Similarly, let ~RC,R,AVG be the yearly average efficiency as calculated by:
~RC,R,AVG =
ETOT,R - (HOP x PLOST,R)
ETOT,R
=I- HOP x ~RAR
ETOT, R
where ETOT,R = total gross energy absorbed by the receiver per year
Hop = total number of hours of receiver (not plant) operation.
(1II.G - 11)
CYR is determined from some reference design for which the radiation and con-
vection losses have been calculated in more detail. Rearranging Equation (II1.G-
10) ,
(1II.G - 12)
where the variables have the same meaning as above and the O superscript refers
to the reference. Current default values depend on the type of receiver, but in
all cases flow is from the bottom to the top of the receiver, molten salt flow is
assumed, and q&-.R should be calculated based on the average ambient conditions
(wind speed, temperature, etc.).
82
Defaults for an external receiver (cylindrical or flat plate) are
q&R (REFRC) zz 0.83
P:h,R (REFTHP) = 4.10 X IO8 watts