In recent years, our country's economy continues to develop steadily, and at the same time, the demand for power supply is increasing continuously, and now the main channel of power production is the hydropower plant, so the hydropower plant is now closely connected with the people's life. Water turbine is an important part of hydropower plants. And as for water turbine, the main shaft seal is its indispensable component. But the main shaft seal is easy to fail, and its safety cannot be guaranteed, so it is a problem to be solved urgently in the current domestic hydropower industry. At present, the water turbines usually operate in high pressure and high-speed environment, which causes great pressure on the pump seals . The pump sealing parts of the turbine are easily worn by the sediment in the water, and the leakage often occurs, which makes the working efficiency of the water turbine decline rapidly and its reliability is also reduced, so regular sealing part replacement is needed. In view of this situation, the main shaft seal of the water turbine is invented, and it replaces the traditional sealing components of the water turbine, it can make the water turbine operate properly and improve the working efficiency and working quality of the water turbine.
Water turbine is a kind of energy conversion machine. It transforms the water energy into the mechanical energy of the rotating wheel by a certain way. After the mechanical energy is generated, the generator is driven by the rotation of the wheel to generate electric energy. The power of the water turbine comes from the water. Because of the characteristics of our country and the rivers, the sediment in the river is pretty much, especially in the rainy season, and a large amount of sediment will bring damage to the traditional sealing. Many sealing methods will have serious wear and tear after a period of time, thus affecting the seals’ normal use and the devices will begin to leak.
At present, there are two main classifications of water turbine main shaft seal:
(1) according to the nature of work, it can be divided into maintenance seal and working seal. There are many categories in the working seal, according to the seal structure, working seal can be divided into flat seal, disk seal, end seal, etc.;
(2) according to the structural division of water turbine main shaft seal, it can be divided into contact seal and non-contact seal. The non-contact seal includes reverse spiral seal and centrifugal seal.