Abstract:
In view of the large temperature difference between the upper part and the bottom of the pressurizer when the electric heating element heats the pressurizer, which leads to the large measurement error of the liquid level measurement of the traditional pressurizer differential pressure method, a pressurizer liquid level measurement method based on sub-regional density compensation is proposed. Firstly, according to the actual situation, the pressurizer is divided into saturated area and unsaturated area. The saturated area is the area where the saturated steam is located. The measured temperature is used to compensate the saturated steam density; the unsaturated area is the area where the medium water is located, and the average temperature of the unsaturated area is used to compensate the medium water density. Secondly, a polynomial fitting model based on the least square method is established in the saturated and unsaturated areas of the pressurizer to compensate the density variable, and then the liquid level is calculated by combining the density of the cold water section. Finally, the experiment is carried out on the experimental device and compared with the reference liquid level. The experiment shows that the pressurizer liquid level measurement method proposed in this paper can obtain reliable measurement results, so this method can be widely applied to pressure vessel liquid level measurement in industrial fields including nuclear industry.