ORNL-2106 - the Molten Salt Energy Technologies Web Site

ANP PROJECT PROGRESS REPORT
INLET MIXING CHAMBER\ HEATER\ /INCONEL TEST SECTION
BEAM
SUPPORT
WEIGH BEAM
I
MICROFORMER
Fig. 4.1.12. System for Thermal Cycling of lnconel Tubing in o Fuel Environment.
temperature fluctuations as the fluid moves down-
stream. Effects of the thermal cycling will be
determined by metallographic examination of the
lnconel surface subsequent to the test.
The heater and the test section are fabricated
from a single 10-in. length of lnconel tubing
(kin* OD, OJ35in. wall). The heater comprises
the first 4 in. of this tube and will be supplied
with a pulsed current through a device designed to
provide a range of pulse frequencies. In order
that the stresses imposed on the test section will
result only from the thermal cycling of the tube
surface, the heater electrodes are floated in
pools of molten tin to eliminate tube bending, and
228
- .
ORNL-LR-OWG 14743
a bellows is provided at the outlet end of the test
section to take up the over-all thermal expansion.
Preliminary tests with NaN0,-NaN0,-KNO
(40-7-53 wt 96) as the heated fluid were terminate d
when oxidation at the electrodes resulted in loss
I
of power. This situation is now being corrected.
The results of these first experiments for a 1 ksec
power-on - ~l/-sec power-off cycle are given in
Fig. 4.1.13. the amplitude of the temperature
fluctuation at two points in the test section is
shown as a function of the heater power. The
"tailing-off" of the data at high heater powers is
caused by the slow response of the measuring
equipment. The cycle period will be varied in *
future experiments.