THE EFFECT OF PRESSURE ON BOILING DENSITY IN MULTIPLE RECTANGULAR CHANNELS (thesis)
The effect of pressure on the density of steam-water mixtures in natural circulation boiling inraultiple rectangular channels was studied to 600 psig with saturated inlet conditions. The effect of pressure on flow rate was also studied. The ratio of the velocity of the steam to the velocity of the water was found to be correlated by the inlet velocity. For a fixed average steam volume fraction, no effect of pressure onflow rate could be found. Neither velocity ratio nor steam volume fraction
... volume fraction could be correlated in terms of quality if a sufficient velocity range was studied. The assumption of constant velocity ratio over the channel length seems to be valid. The experimental work was confined to boiling density measurements for a test section consisting of 4 multiple rectangular channels, 7/16" X 3-11/16" X 48", and to the measurement of pressure drops over a 44" section of the 4-ft heated section. The approximate ranges of variables covered in the experimental work were: Power Density: 1 3 to 50 kw/liter Pressure: 114.7 to 614.7 psia Inlet Velocity: 1.52 to 1.83 ft/sec Exit Quality: 1,9% to 8.2%. The inlet water was near saturation temperature. The exit quality is a thermodynamic weight quality computed from a heat balance. Schwarz^-^^' presented data for the calculation of water circulation in natural circulation boilers. Experimental data were taken at 20, 40, 60 and 80 atmospheres. Densities were determined by the attenuation of gannraa rays from an iridium-192 source. Considerable deviations from the results of Behringer and Schurig were found.