Research And Optimization Of Thermodynamic Behavior Of Mechanical Seal Of Strong Self-priming Centrifugal Pump

In the petrochemical production process,a large amount of oily sewage is collected and transported to a sewage treatment device for centralized treatment.The oily sewage in the underground sewage pool is generally lifted and sent through a long-shaft submerged pump.In recent years,accidents caused by long-axis submerged pump failures have occurred frequently,and the direct cause of the accidents is mostly due to structural design defects of the long-shaft submerged pump.In order to avoid such accidents,most domestic chemical companies began to stop using long-axis submerged pumps to transport oily media.A new type of strong self-priming centrifugal pump was used to replace a large number of long axis submerged pumps.Due to the large difference in the depth of the lagoon of different production devices,the use of the pump after installation is not ideal,especially the leakage of mechanical seals frequently occurs,which seriously affects the safe production of the device.In this paper,the problem of the failure of the mechanical seal of the strong self-priming pump newly installed in the rainwater regulation tank of the aromatics extraction unit is studied in depth.First of all,according to the operating principle of the strong self-priming pump,the working state of the failed mechanical seal is divided into two stages:pumping and normal operation.The finite element analysis method was used to study the temperature field of the self-priming pump seal,and the thermal deformation and Thermos-mechanical coupling deformation caused by temperature change were analyzed.It has been found that when a single-end mechanical seal is used in a strong self-priming pump,the frictional heat generated by dry friction is the root cause of the failure of the machine seal due to dry friction during the pumping stage.The mechanical seal is thermally cracked at high temperature,and the sealing effect is lost The strong self-priming pump cannot complete the pumping,and as a result,the pump cannot work normally.According to the analysis results of the failed mechanical seal,the seal is optimized and the hot crack failure of the seal ring is solved.The seal was re-selected from single end to double end and added to the cooling split.At the same time,the ANSYS Workbench is used to simulate and optimize the temperature field and thermal coupling deformation of the new mechanical seal.Finally,after the actual field test,the results show that the optimized seal fully meets the requirements of use,completely solves the problem of the operation of the strong self-priming pump in the harsh environment of low liquid level.