Research And Application On Rapid Cooling Of The Turbine In Nuclear Power Plant

With the development of clean energy in society,nuclear power generation occupies the market advantage.In recent years,high-parameter and large-capacity steam turbines have developed rapidly because of their high economic value and long-term benefits.At the same time,how to shorten the downtime,reduce the unit maintenance period and increase the efficiency of power generation has become an urgent problem to be solved.Starting from the working principle and structural characteristics of nuclear power plant steam turbine,combined with the cooling methods commonly used in the power industry at home and abroad,this paper analyses the technical differences of nuclear power plant steam turbine system.Then put forward a fast cooling scheme suitable for this power plant,and demonstrates it from the selection of cooling medium,the direction of medium flow and important control parameters.The structure characteristics,energy transfer process and boundary conditions of rotor are analyzed.Simplify the geometric structure and make reasonable assumptions about the heat transfer path.A finite element model for thermodynamic analysis is established.Three-dimensional modeling and finite element analysis software are used for numerical calculation.Temperature and stress changes are output as a result.Through the analysis of the results,the rotor temperature of the high-pressure cylinder drops below 100 ? in the expected time range,and the maximum stress peak is about 100 MPa,so the purpose of rapid cooling is achieved.At the same time,the life loss of the rotor in the process is analyzed.It is estimated that the rapid cooling process will not affect the life of the rotor in the high pressure cylinder of the steam turbine as long as the parameters are reasonably selected.Combining with the unique operation mode of nuclear power plant,several optimization and adjustment schemes are put forward.The temperature and stress changes are calculated.Through analysis,the optimized scheme can ensure the safe and stable operation of the unit and achieve the desired purpose.Finally,the experimental platform was built,and it was successfully applied to practical work.Through the analysis of the test results,it is concluded that effective control of the important parameters in the test process can not only achieve the purpose of rapid cooling,but also ensure that the important monitoring parameters of the high-pressure cylinder rotor in a controllable range.At the same time,the experimental data are compared with the theoretical data.The cause of deviation is analyzed and the effect of deviation on the steam turbine is evaluated.