Optimizing The Outlet Temperature Control System Of High Temperature Gas-cooled Reactor Steam Generator

High Temperature Reactor-Pebblebed Modules(HTR-PM)is the first independently developed nuclear power plant with the fourth generation nuclear power characteristics in China.It uses two nuclear steam supply system modules to drive a turbogenerator to run and generate electricity.The power control system of the whole plant realized by DCS is the core of the whole plant power control system.The temperature control system of the steam generator outlet is one of the typical subsystems of the whole plant power control system.The steam generator and the main helium blower involved in the system are manufactured for the first time.The characteristic curves and setting values are not given.At present,the designer hopes that they can be obtained directly by the field test of the debugger.There are some risks of equipment damage and personal injury when the debugger blindly tests the field equipment without thorough knowledge of it.In order to explore the characteristic curve and control parameters of the system,this paper chooses the outlet temperature control system of steam generator as a breakthrough point to analyze and optimize.By analyzing the parameters of the main helium blower in the primary loop of HTR-PM,this paper calculates and establishes the helium mass flow and speed model in the primary loop of high temperature gas-cooled reactor,obtains the characteristic table of theoretical flow and speed,and obtains the mass flow compensation formula by analyzing the influence of pressure and temperature on mass flow rate.By analyzing the special structure of the steam generator of high temperature gas cooled reactor,the heat transfer model of the steam generator is established by using the heat transfer formula,and the relationship between the steam temperature at the outlet of the steam generator and the helium flow rate in the first loop is obtained.The cascade control model of steam generator outlet steam temperature control and helium flow control system is built by using MATLAB simulation tool.By comparing the step response curve of the system,the theoretical parameters of the secondary and main circuits of the cascade control are tuned.After repeated tests,the theoretical setting value is finally obtained,and the program adjustment standard with steady-state deviation less than ±2°C and dynamic deviation less than 5 C/-10? is theoretically realized.By modifying the parameters of the model to analyze the step response of the system,the applicable range of the theoretical setting value is obtained.The optimization of hardware and logic configuration of the system is also analyzed and put forward to ensure the safe and stable operation of the field control system.According to the results of theoretical analysis and calculation,we can accumulates many debugging experience which means a lot for future work.