Study On Optimization Of Mechanical Seal Performance Of Pump Based On Temperature Field Analysis

Mechanical face seals are the rotating sealing equipment,which can be realized by elastic force of elastic element and liquid pressure pressing two seal face of moving ring and static ring.Mechanical seals are applicable for a variety of fluids,at present,it's the core device of rotating equipment fluid seal,for example pump?compressor and mixer and so on.Usually,in the thermal power plant boiler system,the feed water pump has good sealing performance is the premise of boiler system safe and stable operation.under the complicated working conditions and loads,local high temperature and high stress are easily exist on the mechanical seal face,leading to the end faces deformation?flash and even hot crack appears.Seriously affect the sealing performance of mechanical seals,even a safety accident.Therefore,the research on the temperature field stress and field of mechanical seal face is very necessary to improve the overall performance of the sealing system.In this thesis,the M7 N mechanical seal for the pump was chosen as the research object,the geometric model of mechanical seal ring?the mechanical analysis model and the model of heat source analysis were built,the temperature field and the stress field of the mechanical seal ring are analyzed theoretically.Finally,a complete set of mechanical seal test rig was designed to experimentalize and confirm the theory,and optimized the sealing performance.1.A mathematical model for the analysis of the temperature field of mechanical seal ring was constructed.By simplifying the sealing structure,a geometric analysis model was constructed,the calculation expression of the main geometrical parameters of the seal face was given;Mechanical analysis model of seal ring was constructed,the force analysis is carried out by using the dynamic ring as the balance body,and the axial force balance is deduced;and established the heat source analysis model of mechanical seal system,and according to the actual conditions of pyrogen simplified model,concluded that: The end face temperature rise of the seal system is mainly derived from the end face friction heat;on the basis of the friction heat calculation formula,the influence factors of the temperature rise of the seal ring face are obtained.2.Based on the theory of thermal stress analysis of ANSYS,the three-dimensional calculation model of the moving ring was established,given the friction density of heat source?heat transfer coefficient?calculation formula of heat distribution coefficient,using indirect coupling method,get the seal face temperature field distribution,stress field distribution,get the end temperature the time needed to reach equilibrium.3.The influence factors of mechanical seal face temperature was analyzed,the results show that the spindle speed?spring pressure?medium pressure can influence face temperature in degrees.The most influential factor is spring pressure,and spindle speed the lesser influence,the least impact factors is medium pressure.4.Experimental study on the characteristics of mechanical seal.The transient temperature on the mechanical seal face was measured in different locations,and compared the simulation and test results,test results and theoretical calculation results show the same trend,the relative error is smaller,verify the correctness of numerical analysis.5.Study on Optimization of mechanical sealing performance.Using temperature and leakage rate as the evaluation index,the sealing performance under different operating conditions were analyzed,pointed out that the same type of mechanical seal in high pressure,low speed,medium pressure range of 0.15Mpa~0.2Mpa has good sealing performance;and studied the optimization of sealing structure,the results showed that: the ring chamfering processing can effectively eliminate the stress concentration at the same time,can effectively reduce the surface temperature,the seal temperature distribution is more uniform.