Research On The Leakage Of The Mechanical Rotating Seal And Test Under The Condition Of Deep Well

The gas of petroleum under ground is still a very important source of energy in the21st century. However, this kind of resource in the superficial zone is almost exhaustedwith the continuously developing in the superficial zone, and the left mainly buried inthe deep ground. The study of the high-reliability and high-timeliness seal apparatus,which can endure the high temperature and high pressure seems more important becauseof the extreme condition in the deep ground. Nevertheless, on one hand, the cost of thefield test of seal apparatus is extremely high; On the other hand, it is impossible tosimulate the high temperature and high pressure condition and repeat the field test undersuch a extreme condition over and over. In order to settle the difficulties mentionedabove, I start the following research in my graduation project.In my research, I build the leakage prediction mathmatical model of the rotatingseal composed of O-ring seal and spindle under the high temperature and high pressurecondition in the deep well on which the rotating seal works according to thehydrodynamics theory and fractal contact theory; At the same time, I also study therelationship between the leakage of rotating seal and the seal surface topography, theseal wear, the assembly alignment error, different initial dimension of O-ring under thehigh temperature and high pressure condition; What is more, I build the contact modelof the O-ring seal and spindle using discrete element method according to fractalcontact theory, and then simulate the friction process using discrete software PFC2Dand calculate the fractal value; In addition, according the wear theory, I build the finiteelement contact model of seal wear and the finite element contact model of the sealwhen different initial pressure ratios of the seal are assembled on the spindle anddistinct assembly alignment errors occure, and then I simulate the working process ofthe rotating seal in finite element software Ansys using the contact finite element modelI have built. In the following, I calculate the values of pressure gradient in the sealingclearance using MATLAB and draw the diagram of varying patterns of the maximumpressure and the pressure gradient in the sealing clearance. Finally, I calculate theleakage prediction mathmatical model with the values gotten from modelling andsimulating through utility softwares and also draw the varying patterns of values ofmaximum pressure and pressure gradient.In order to verify the discrete element model and the finite element model I havebuilt, I also design and set up the simulating rotating seal test apparatus in laboratory. Inthe meantime, I design the hardware system and program the softeware system to servecontrolling and measuring the test apparatus. After finishing the assembling anddebugging of the simulating rotaing seal test apparatus and its hardware and sotfwaresystem, I begin to proceed the test and measure and record the leakage value of simulating rotating seal. In the final, I compare the leakage value gotten from modellingand simulating of the rotating seal with that of simulating rotating seal test apparatus,and analyze the results.