The On-Line Monitoring and Diagnosis System for Thermal Performance of Secondary Loop in Daya Bay Nuclear Power Plant

The turbine flow capacity and thermal economy of regenerative system are the difficulty and key points for the monitoring and analysis system in Daya Bay nuclear power plant. Characteristics of flow area are used as the parameters to characterize the turbine flow capacity in monitoring system. And the quantitative analysis models of secondary loop thermal system is proposed using the theory of equivalent enthalpy drop theory and cyclic functional method. These models effectively represented that the heater terminal temperature difference, system internal-leak, condensate sub-cooling and many other factors impact on the power. And then the structure and function of on-line monitoring and analysis system in Daya Bay nuclear power station is described. The monitor system can be applied for on-line monitoring operating state of the equipments and diagnosing economy of the second loop and guiding diagnosis report to operators, which ensure a safe and economical operation to a nuclear power plant.