INVESTIGATION ON THE FLOW AND HEAT-TRANSFER CHARACTERISTICS UNDER SAFETY INJECTION IN PRESSURIZED WATER REACTOR AT XI'AN JIAOTONG UNIVERSITY

摘要

The thermal fatigue or thermal shock is well known as an important damage mechanism in safety injection system of pressurized water reactor (PWR). When the safety injection system works due to the temperature fluctuation or loss of coolant accident (LOCA), some components in PWR will subject to the thermal fatigue or thermal shock, and this will affect the integrity of the reactor system. These components may be the safety injection nozzle in reactor coolant system, or even the pressure vessel. So it is very important to evaluate the system integrity when the safety injection works, and as a basis of evaluation the flow and heat transfer characteristics must be understood. In recent years, a hydraulic test facility was built with high flow rate at Xi'an Jiaotong University. With this test facility a series of model experimental study were carried out to investigate the flow and heat transfer characteristics related to the thermal fatigue or thermal shock issue. The local heat transfer coefficient and near wall temperature were got for different components in PWR. These results provide important basis for the corresponding mechanism analysis and integrity evaluation.