Multi-field Coupling Analysis Of High Speed Pump Mechanical Seal And Its Structure Optimization

Mechanical seal under high-speed operation can produce high viscous shear heat,which causes high temperature and huge thermal deformation of the sealing ring,as the result of destructing the stability and reliability of the liquid film,it has became a key problem in many large equipment.Use one type of high-speed pump mechanical seal as the research target,on the basis on the structure of sealing evaluation,carried out structural optimization,so as to improve the reliability and stability,and provide theoretical support of design for high-speed pump mechanical seal.As sealing temperature is too high when the rotate speed is very large,which make liquid film easy be cavitation,and reduce the reliability and stability of film.take the high speed pump seal as the research object,establish three dimensional heat transfer across scales system model including sealing ring?liquid membrane and seal chamber.to get the flow field distribution?pressure distribution and temperature distribution of liquid film?sealing ring?seal chamber,using the commercial CFD software Fluent,coupling the fluid-structure interface,solving the energy equation and Naiver-Stokes equation.And analysis the state of sealing face,the results shows that the highest temperature of the sealing is 54.9 ?,and the flow condition is not very well and need to be improved,deformation is convergence which can reduce leakage of sealing,and at the location which near the static ring of inner diameter,due to the high temperature and low pressure,there exists some cavitation;On the basis of numerical calculation of high speed pump seal,some optimizations of the sealing structure had been done to make the temperature decreases.The results show that the static ring side,rotating ring and cavity structure and so on three aspects to make the structure superior all have the certain function to reduce temperature,which the static ring with seat open six hole structure,the diversion Sets and static ring cutting bosses have good coolingeffect;But pump ring cooling effect is most obvious,to 7 ?.To verify the feasibility and correctness of the numerical simulation,established test bench of sealing and experiment several typical optimization of structure under different flow rate? rotational speed?and medium pressure.It shows that the static ring with seat open six hole structure can reduce the highest temperature by 2?,pump ring cooling effect is most obvious,to 5?;Further experimental study is about friction pair,The friction pair pairing studies show that the friction pairs of different materials have a great influence on the temperature,and the impregnated resin graphite ring has better thermal characteristics than the ordinary graphite ring,the ring has better thermal properties.both materials exhibited lower temperatures.While silicon carbide has better thermal characteristics compared with molybdenum alloy.At this paper,three-dimensional coupled heat transfer model was established,on the basis of numerical calculation of the existing structure,some optimization of rotate ring ?static ring and the cavity was done,experiment and theory have good match.To avoid the error of empirical formula of heat transfer,coupling calculation was used.Overall system structure of calculation model and optimization were taken into account,and it has good match compared to the test.it has certain theory and engineering innovation which can provide some theoretical basis and technical support for high-speed pump mechanical seal.