The Research On Magnetic Fluid Seal Technology Of Turbine Spindle

Magnetic fluid seal is a sealing form of zero leakages, no attrition and long life. It has good applying effects and prospects in space seal, vacuum seal and toxic gases seal, but numerous problems in the field of water seal also exist. The principal axis seal is one of the hydraulic turbine's critical parts and its performance quality relates directly to the operation safety and maintenance cycle of units, thus relates to power station's economic benefits and Manufacturer's quality credibility. This issue designed a magnetic fluid seal which can be used for medium and small-size hydraulic turbine principal axis seal, comparing with tradition hydraulic turbine principal axis seal it has better sealed performance, longer-lived form, self-repair capability and no attrition. But it still has not stronger compression resistance than mechanism seal or filling seal when apply it to large hydraulic turbine spindle, that is to say how to improve the compression resistance of magnetic fluid seal is need to be resolved in the future.Based on the previous studies and aimed at magnetic fluid sealing water, this paper mainly complete the following work. First, it introduces the development and inadequate of magnetic fluid sealing technology and turbine spindle seal technology, then make some conclusions and analysis of magnetic fluid's physical and chemical properties, manufacturing methods and advantage and type of sealing structure. According to the theory of magnetic fluid dynamics, this article analyzes the magnetic fluid sealing principle. After derived momentum equation and Bernoulli's equation of the magnetic fluid, paper establish the pressure formula of static magnetic fluid sealing and rotating magnetic fluid sealing. For the magnetic fluid sealing structure, this paper provides size design, reasonable selection of material and optimization of some important parameters of the magnetic circuit, all above is the focus of this paper. Based on the tooth profile research of single seal, article presents a new tooth profile of multi-stage seal, trying to improve the compressive property of the magnetic fluid seal.Finally, the paper simulates the working conditions of turbine and designs the experimental device of magnetic fluid sealing water to verify the correctness of the theoretical analysis from seven areas: the influence of magnetization to seals the bearing pressure ability; the influence of magnetic field strength to bearing pressure ability; the influence of Seal gap to bearing pressure ability; the influence of temperature to bearing pressure ability; the influence of rotational speed to bearing pressure ability; the influence of Magnetic fluid volume to bearing pressure ability; the relations between magnetic pole progression and bearing pressure ability.Paper also sums up a series of measures the end to improve magnetic fluid sealing performance.