Temperature And Stress Field Numerical Simulation Of Quenching Process For Main Pipeline Of AP1000 Nuclear Power

AP1000 nuclear power main piping is one of the key equipment in the nuclear power plant,need to have good mechanical performance and long service life, in order to ensure the normal operation of the power station. At present, the quenching process of main pipe of large forgings mainly rely on experience to develop. With the rapid development of computer technology, the computer simulation have started to used in the quenching process, its simulation results can provide reference for the actual situation. In this paper, the quenching process of AP1000 nuclear power main piping is studied by using the method of the computer simulation,because of it is large and expensive.In this paper, the quenching process of main piping is used in the computer simulation. First, studied the relationship between the main piping and the medium flow field in a quenching tank. And studied the relationship between the temperature field, the stress field and the strain field in the quenching process of AP1000 nuclear power main piping.The finite-element computing model of the medium flow field in quenching tank is set up, according to the actual quenching tank. The medium flow field in a quenching tank with or without main piping was numerical simulation by using the fluid mechanics simulation software FLUENT. The medium flow field in a quenching tank under different quenching tank inlet flow velocity is analyzed, and the medium flow field influence with different location of main piping in quenching tank is analyzed. The fit for position of main piping in the tank and flow velocity distribution inside and outside wall of the main piping is obtained, according to the results of the numerical simulation. The simulation results show that: In the way of the finite-element of CHC1(position size:L1(7.7m),W1(3.5m), H1(4.5m))is more suitable for the quenching process of main piping; With the increase of quenching tank inlet flow velocity, the flow velocity inside and outside wall of main piping is also increased, but the flow rate of the medium in the quenching tank is smaller than that of the inlet velocity.The flow velocity at the inside and outside wall of main piping is obtained by the flow field numerical simulated results. The surface heat transfer coefficient between the sample and medium under different inlet flow velocity is worked out by using the methodof inverse heat conduction and end-quenching. The temperature field, the stress field and the strain field in quenching process of main piping is simulated by the use of the finite-element software ANSYS. The results of numerical simulation is analyzed, it is show that can predicted the problems of quenching process under the existing craft. The simulation results show that: the temperature of main piping will cooling faster by the increase of inlet flow velocity; For the main piping, the temperature of the core part of the pipe is the slowest. By comparing the simulation results of the main piping stress and strain under different inlet flow velocity, it is known that the stress and the strain of main piping are also increase with the increase of inlet flow velocity. The maximum residual stress of the main piping is about30 MPa at the end of quenching under the inlet flow velocity of 2.3m/s,. The maximum deformation zone of the main piping is in the lower part of the interface between the pipe interface and the main piping, and the plastic strain is not more than0.0088 at the end of quenching. Through the temperature measurement in the quenching process of the sample, the temperature field of the numerical simulation is proved.