燐酸ソーダの過冷却度に及ぼす超音波振動の影響
2002 年 81 巻 2 号 p. 123-132
詳細
2002 年 81 巻 2 号 p. 123-132
The influence of ultrasonic vibration on the degree of supercooling was investigated for disodium hydrogenphosphate dodecahydrate, which is used in longterm, supercooled thermal energy storage (Super-TES). Super-TES stores thermal energy at temperatures lower than the melting point of the phase-change material, which reduces heat loss from the storage system. The supercooled hydrate in a test tube was experimentally vibrated at four different frequencies, 24kHz, 43kHz, 90kHz, and 996kHz, and different sound power. Experimental results show that the degree of supercooling is independent of the ultrasonic vibration. No bubbles were observed in the hydrate though tiny bubbles by cavitation were observed in the water outside of the test tube. When a stainless steel rod existed in the supercooled hydrate, however, the rod was vibrated by the ultrasonic vibration and rubbed the surface of the test tube, which promoted nucleation in the hydrate.
