ORNL-2106 - the Molten Salt Energy Technologies Web Site

ANP PROJECT PROGRESS REPORT
The recent system modification resulted in a
temperature rise of 33OF for the sodium coolant
stream and a maximum boron carbide temperature
of 1526OF for a sodium inlet temperature of 12OOOF.
These values may be compared with the previous
results for a system without the copper-boron
carbide matrix in which the sodium temperature
rise was 24OF and the boron carbide attained a
maximum temperature of 1586OF. The sodium
temperature rise was found to vary 10% (decreasing
from 36 to 33OF) when the sodium inlet temper-
ature was changed from 1150 to 1200OF. Typical
temperature profiles at the inlet and outlet ends
of the system for a sodium inlet temperature of
1175’F are presented ih Fig. 4.1.15, and the
temperature profiles for the system without the
Cu-B,C (System 8) are also shown for comparison.
13C. J. Barton, Fused Salt Compositions, ORNL
CF-55-9-78 (Sew. 16, 1955).
230
NaF-LiF-ZrF,(22-55-23 mole %)
Beta form (106 to 3680C)
HT - H30°C
c
P
Alpha form (407 to 556OC)
The system modification increased the temper-
ature drop across the inner lnconel shell by 30 to
35°F. The temperature gradient in the outer
lnconel shell was essentially unchanged.
HEAT CAPACITY
W. D. Powers
The enthalpies and heat capacities of two
mixtures were determined in the liquid and solid
states. For one mixture, NaF-LiF-ZrF, (22-55-23
mole %), two distinct discontinuities in the temper-
ature-enthalpy relationship were found; one was at
370 to 380°C and the other was at 565 to 585°C.
The reported13 fiquidus temperature is 57OoC.
The lower discontinuity is assumed to be a phase
transition from the alpha form to the beta form, the
beta form being stable below 375OC. The dis-
continuity at the higher temperature is the fusion
of the alpha form to the liquid at 570°C. Enthalpy
and heat capacity measurements of a second salt
mixture, LiF-NoF (60-40 mole %), showed no
unusual characteristics. The enthalpy and heat
capacity equations for these two salts follow:
= -8.7 + 0.2392T + (7.20 x 10-’)T2
= 0.2392 + (14.39 x lO-’)T
HT - H30°C = 64.2 - 0.009165T + (41.82 x 10m5)T2
c = -0.009165 + (83.64 x lO”)T
P
Liquid (603 to 897°C)
HT - H3,,oC = -20.2 + 0.4526T - (5.95 x 10-’)T2
At 375OC
At 57OOC
c = 0.4526 - (11.89 x lO-’)T
P
Ha- Hg = 28
Hliq - Ha = 24
LiFNaF (60-40 mole %)
Solid (1 12 to 572OC)
HT - H30°C
c
P
= -9.8 + 0.3191T + (9.94 x 10”)T2
= 0.3191 - (19.87 x lO”)T
-
W
..-
t
c
.