Study On Flow Field Analysis Of Labyrinth Seal And Typical Seal Structure Optimization Design For Reciprocating Compressor

With the development of the non-contact seal, non-contact seals are widely adoptedin the machinery manufacturing industry instead of the traditional static seals. Andespecially the labyrinth seal is widely used in petrochemical industry, coal gas and otherindustrial mechanical equipment. The method of Labyrinth seal makes the machineavoid the excessive friction contact when the equipment is powered. By the advantagesof non-lubricated, environmental protection and no pollution, the labyrinth compressorcan compress and transport clean gas or even poisonous gas. However the deficiency oflabyrinth seal is that the non-contact seal inevitably lead to produce leakage to influenton the efficiency and energy consumption of the machine. In particular, the leakage issignificantly affected by the change of labyrinth internal flow field and labyrinthstructure size. It is of great significance on analysis for the internal flow field oflabyrinth seal and structure optimization.2D and local3D models were established on the labyrinth seal structure of6K-375MG labyrinth compressor, and the mathematical model was selected accurately.The model was meshed and numerical simulated by the CFD software, which analyzedthe internal flow field of typical labyrinth seal structure, and finally completed theoptimization research. The main work of the research is as followings:Firstly, state the status of labyrinth seal’s theory research, and focus on the theory oflabyrinth compressors and straight type labyrinth seals.Secondly, the physical model and computational fluid dynamics model of labyrinthseal are set up. The internal flow field of initial labyrinth structure has been simulated,which further reveals the essence of the flowing gas in the labyrinth channels from theview of three-dimensional and vorticity.Thirdly, several kinds of structure factors which affect the labyrinth sealperformance were simulated. Through observation and analysis on the internal flowfield, the influence of different sizes of sealing structure on sealing performance was analyzed. And the typical labyrinth seal structure was optimized, Including the gapwidth, the depth and width of the cavity, depth-to-width ratio, the number of teeth, etc.It reduces the leakage effectively, and provides a reliable reference for engineeringpracticing design.Finally, the final optimization model was simulated mathematically. The leakage ofsimulation was compared with calculation results by empirical formula. The sealperformance of the optimized labyrinth seal structure is analyzed, the result shows thatthe sealing effect of the optimized sealing structure is much better than the originalsealing structures’.