ORNL-1816 - the Molten Salt Energy Technologies Web Site

ANP QUARTERLY PROGRESS REPORT
turbulent liquid metals under high temperature
differentials has been completed, and components
have been fabricated. The first series of tests
will include combinations of lnconel and type 316
stainless steel as loop materials, with sodium as
the circulated liquid metal.
NaturaLGas Heat Sources for Forced-Circulation
Loops
were made in order to
obtain preliminary data for design of a natural-gas
heat source for forced-circulation corrosion test
loops. It was found that exhaust gas temperatures
of between 2800 and 330OoF could be obtained
without initial air preheating, and, by using air
at a rate of 65 to 650 cfm, the equivalent of 100
to 1000 kw of heat was released. Maximum system
thermal efficiencies of 20 to 60% appear to be
feasible.
Tests with electric-resistance heated units indi-
cate a maximum wall temperature of 175OOF with
the tubing lengths required by pressure-drop and
flow considerations. Somewhat higher tube-wall
external element temperatures or proportionately
longer heater sections would be required with gas
heating. An economic study indicates that there
is little choice between providing electrical power
supplies and providing large-capacity air supplies
for gas heating. Therefore, since development of
a gas-heated unit specifically for this purpose
would be expensive and since there is no present
proof of reliability of components and operation
of gas-fired loops, further study of gas firing for
these test loops appears to be unwarranted.
HEAT EXCHANGER DEVELOPMENT
’ Heat Exchanger Tests
R. E. MacPherson
Aircraft Reactor Engineering Division
R. D. Peak
Pratt & Whitney Aircraft
A number of tests of fused salt-to-NaK heat
exchangers are to be made for determining the
fabr icabi I ity, operab i I ity, operating parameters,
and reliability of heat exchanger tube bundles
such as those proposed for the ART. The test
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s are to include reliable pumps, reliable heat
sources, and adequate heat sinks.
A preliminary heat exchanger test reported previ-
ously5 indicated reasonable structural integrity
of the exchanger (1682 hr of operation), but little
data on operating parameters were obtained. For
the next experiment, a regenerative system is to
be used in which the heat exchanger will be an
economizer that will transfer about 4 Mw of heat,
while a heat input and release of only 1 Mw will
Header Leak Test
R. E. MacPherson
Aircraft Reactor Engineering Division
R. D. Peak
Pratt & Whitney Aircraft
It has been postulated that small leaks which
develop in metal walls separating NaK and fluo-
ride fuels may be self-plugging as the result of
the precipitation of high-melting-point react ion
products. A program of tests is currently under i.”
way to check this possibility. To date, one test
has been run, which indicates that self-plugging -
can occur with NaF-ZrF,-UF, fuels. The leaks
are installed between three cells as shown in
Fig. 3.5. The center cell is pressurized to leak
into the end cells under the pressure differentials
shown, 5 and 50 psi.
The test rig was filled with NaF-ZrF,-UF, fuel
in the center cell and NaK in the end cells. The
leaks were about 0.002 in. in diameter. After
12 hr at 13OO0F, there was no apparent leakage,
and x-ray pictures taken at intervals during the
test showed no changes in liquid levels.
Pump for Heat Exchanger Tests
W. G. Cobb
W. R. Huntley
A. G. Grindell R. E. MacPherson
Aircraft Reactor Engineering Division
A series of tests is being made in order to
determine whether an existing model DANA pump
(ARE moderator-coolant-type sump pump) is suitable
for the high-speed operation which will be
required in the intermediate heat exchanger test
loop. Critical shaft-speed determinations made
by K-25 personnel indicated that the pump could
be operated safely at the proposed speed of approximately
3700 rpm.
5A. P. Fraas, R. W. Bussard, and R. E. MacPherson,
ANP Quar. Prog. Rep. June 10, 1954, ORNL-1729, p 22.
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