Study on Water Level Detector Composed of Encoded Thermal Resistance

The water level in a nuclear reactor pressure vessel is an important operating parameter. Based on the differences of heat transfer coefficient between liquid phase and gas phase, a new level detector, which includes encoded thermal resistances, has been developed. The monitoring principle, theory analysis and experimental results under pressure of 0.1~3.0MPa were described. The analysis and experiments have shown that the new system is correct in principle, reliable and feasible in structure for monitoring the water level in NHR-200 reactor and other vessels.