| The country put forward the project of developing the nuclear power, in order to control the pollution of the environment and amounts of carbon emissions. The mechanical seal of the nuclear pump is important to the safety of the nuclear power, however our country can’t make it. What’s more, the whole world locked the techniques to our country. So it greatly influences the development of the nuclear power and the safety of the nuclear power. The project was based on the National Science&Technology Pillar Program during the12th Five-year Plan period. It can fundamentally develop the reactor coolant pump mechanical seal by designing the experiment devices and mechanical seal. The paper researched the mounted hydrodynamic seal with straight line deep groove (MSL-MS for short) in nuclear main pump by theoretical and experimental research independently.The use of the mechanical seal in nuclear pump was demanding situations of high pressure, and so on. So the distortion of the pressure will greatly affect the sealing performance. The paper built a solid-fluid coupling model of MSL-MS and the laws of the sealing performance were analyzed. And the MSL-MS was experimentally studied. Let show the research contents and the conclusions as follows:1) It can call the data of the software and the program each other by the program of the Matlab. It can establish the complete coupling model of the fluid-solid. The equations of the distortion about the mechanical seal and the pressure were solved by the finite method and the difference method, while the cavitations of the film and the mounted of the mechanical seal were considered. It can lay the foundation for the study on the latter numerical simulation.2) Based on the coupling model of the MSL-MS, the change of the sealing performance with the operation parameter was studied. The results show that the higher the pressure is, the larger the leakage and the smaller the coefficient of friction.3) The effect of the geometry parameters of the mechanical seal and the straight line deep groove on the distortion of the mechanical end face and the sealing performance was studied. The results show that the geometry parameters which affect the distortion of the taper and the waviness were independent of each other. The outer diameter of the static ring, the position of the O ring of the static ring and the interference fit of the seal ring mainly affect the distortion of the taper. And the number and the ratio of the groove and the diameter about the groove mainly influence the distortion of the waviness. The recommended match tolerances were given. We recommended that the number of the groove was8-12and the ratio of the groove and the diameter was0.9553.4) The hydrostatic pressure testing, the operating testing and the operating testing after100hours were made on the sealing experiment devices of the nuclear main pump. The effect of the sealing performance was studied with the operating parameters. And the surface texture of the mechanical seal after the experiment was analyzed. The results of the electrostatic experiment showed that the higher the pressure was, the less the leakage was. The results of the running-in experiment and after a wearing in experiment show that the leakage increased and then decreased with raising the pressure.The sealing performance of the MSL-MS was studied by the theoretical and experimental method. The method of the design of the mechanical seal with deep groove was preliminary mastered. It can help deeply develop the deep groove mechanical seal in the nuclear main pump with the theoretical and experimental foundations. |
