Studv On Coupling Characteristics Of Reactor Coolant Pump And Steam Generator

Compared to the three generation nuclear power technology in China to introduce the type of reactor and other nuclear reactor type has great particularity,which is a major improvement is the abolition of the connecting pipes during the steam generator(SG)and the reactor coolant pump(RCP),the nuclear main pump is directly hung at the end of the steam generator.The turbulent fluid passing through the steam generator is directly injected into two parallel nuclear main pumps without rectifying.The uneven inflow causes the fluid distortion at the inlet of the main pump,which will have an impact on the performance of the nuclear main pump.But before the domestic and foreign research on the nuclear main pump,few can take into account the effect of the steam generator on its performance,and the experimental data are seriously lacking.This paper will combine the method through experiments and numerical simulation,considering the coupling effect between the nuclear main pump and steam generator.The influence of steam generator parameters on the flow field of the main pump inlet is studied.In this paper,the scale model experiment of steam generator was first carried out,and the Delta125 steam generator is reasonably simplified.Then the steam generator heat exchange pipe flow were measured,the experimental results were found that the steam generator tube will be the entrance is part of the heat exchange tubes have a greater impact,so that the partial discharge increases.At the high speed,the relative low velocity zone or even reflux area will be formed,and this phenomenon is more obvious under the large flow rate.When the flow rate is small,the loss of the heat transfer tube will play a leading role in the flow distribution of the heat exchange tube,and the influence of the inlet pipe will be reduced.The uneven flow distribution in the heat exchanger tube of steam generator will affect the inlet flow field of the main pump.The specific performance is that the axial velocity of the outlet pipe of the steam generator will be more disorder,that is to say,the more serious distortion of the inlet flow of the nuclear main pump.In the numerical simulation part,the combined simulation of the simplified Delta125 steam generator and the CAP1400 shielded nuclear main pump,which is independently developed by the project group,is carried out.The results show that the length of export steam generator mainly affects the degree of disorder in the flow field at the entrance of the nuclear main pump,and when the outlet tubes are relatively short obvious effect.The location of the steam generator has little effect on the flow field disturbance of the main pump inlet,but it will have a great impact on the location of the high speed and low speed area.Non uniform flow in the steam generator outlet tube,with the increase of the length gradually stabilized,the reflux phenomenon occurred mainly in the range of steam generator sudden necking 350mm within the region,in this chapter the model is in a double diameter steam generator,when the distance exceeds 350mm,the reflux phenomenon gradually disappear,the change of flow field tends to be stable.