Measurement Method of Equivalent Water Level for Nuclear Steam Generator Based on Data Fusion

The nuclear U-tube steam generator (UTSG) is a key component for nuclear power plant, and the water level of UTSG must maintain a desired value. In order to overcome the impact of the false water level, an equivalent water level is proposed based on data fusion to simplify the water level control of UTSG. The equivalent water level is composed of steady and dynamic compositions, which are got through the water level sensor of UTSG and flow rate sensors for feed water and steam of UTSG respectively. The steady and dynamic compositions are generated by a low-pass filter and a high-pass filter according to the measuring data characteristics on frequency domain. The false water level characteristics of UTSG have been removed through the equivalent water level application, and then the impact of non-minimum phase characteristic of UTSG has been weakened remarkably. A simulation of water level control is conducted based on the equivalent water level, and the result indicates that a simple PID controller can make the UTSG run with a satisfied water level control performance. It is usually difficult to gain a satisfied control effect through a simple PID controller without equivalent water level, so the measurement method of equivalent water level will benefit the operation of UTSG by simplifying the control process obviously.