Study On The Optimization Method Of Sealing Characteristics Of Split Housing Of Turbine Compressor

Turbine compressor is widely used in oil and gas extraction,liquefied natural gas production,chemical industry and power industry,its sealing performance is an important guarantee of the normal operation of the turbine compressor,which directly affects the efficiency and stability of the turbine compressor,domestic and foreign for the turbine compressor rotor dynamic sealing performance has done a lot of research,and achieved satisfactory results,and for the casing flange in the parting surface of the static sealing Performance research is less.The sealing performance of the upper and lower casing of the turbine compressor is ensured by bolt fastening,but because of the existence of elastic interaction of bolts,it is difficult to get a uniform and sufficient amount of target preload after the completion of bolt group preload,and then the uneven contact pressure distribution of the middle part of the casing flange leads to sealing failure.Therefore,it is an important way to improve the performance of the split face seal in the flange of a turbine compressor.In this thesis,the finite element analysis method is used to analyze and study the distribution law of bolt preload force of turbine compressor under the influence of different factors,i.e.material properties of housing flange(modulus of elasticity,Poisson’s ratio),preload process(bolt preload sequence,initial preload force),restraint method,etc.;the finite element model of non-gasket flange bolt connection is established,and the analysis compares the domestic and foreign methods for eliminating bolt elastic interaction,i.e.Finally,considering the influence of gravity factor,the improved four-parameter method was applied to the preload of bolt group of turbine compressor,and the analysis was done to compare the application of the four-parameter method.Finally,considering the effect of gravity,the improved four-parameter method was applied to the preload of turbine compressor bolt sets,and the effect of internal pressure on the sealing performance of the casing was analyzed.The study shows that: elastic modulus,Poisson’s ratio,bolt preload order,initial preload force and restraint method all have certain influence on the distribution of bolt preload force in turbine compressor,among which the elastic modulus of housing material and bolt preload order have a greater influence on the distribution of preload force;the ASMEPCC-1 method and JISB2251 method can effectively eliminate the elastic interaction of bolts at this stage.However,the cost of these two methods is high,and the cost of the elastic interaction coefficient method is greatly reduced compared with the above two methods,while the four-parameter method further reduces the cost on the basis of ensuring the accuracy of the results,and the accuracy of the results is further improved after the improvement of the method;before and after the application of the improved four-parameter method,the preload force distribution of turbine compressor bolts is obviously different,and the optimized With the increase of the internal pressure,the sealing performance of the housing decreases to different degrees,but the sealing performance of the housing is always better than that before the application of the improved four-parameter method.