CFD-based Analysis Of Flow Field And Fault Characteristics Of Reciprocating Mechanical Valves

Reciprocating compressors and reciprocating pumps are key power equipment for fluid pressure conversion and transmission,and are widely used in various basic industries such as petrochemical refining,agriculture,transportation and national defense.Reciprocating machines are characterized by frequent failures during long-cycle operation,which affect the production efficiency and system reliability of enterprises.The analysis of the operating status and performance of the unit under component failure and failure can provide help for fault diagnosis and self-healing regulation.Therefore,the following work is carried out in this paper for CFD simulation analysis of reciprocating machinery containing reciprocating compressors and reciprocating pumps:(1)This paper constructs a reciprocating compressor multi-valve simulation model,using Fluent software to study the three-dimensional flow field and key performance parameters of a single suction valve and exhaust valve leakage fault coupled with variable load conditions,the results show that:the inlet valve leakage fault conditions,expansion becomes faster compression becomes slower,with the reduction of the unit working load,the volumetric efficiency with the increase in the proportion of leakage shows a decreasing gradient becomes larger,with the load The deviation of the discharge volume increases with the decrease of the load;the exhaust valve leakage fault condition,the expansion becomes slower and compression accelerates,coupled with the variable load condition,the indicated work of the unit decreases with the increase of the leakage ratio of the valve piece,and under the same load,the indicated ratio of work to the leakage ratio is first increased and then decreased.(2)Simulation of valve unloader wear failure and failure failure conditions was carried out to study the effects on dynamic pressure and temperature,unit power consumption,load regulation and drag loss of the unit.The resistance loss is positively correlated with the size of the wear of the pressure fork foot;the deviation of load regulation increases by 3.22% when the wear degree is 0.5mm,and the wear of the unloader pressure fork should be less than 0.5mm to ensure the accuracy of operating load;the deviation of load accuracy caused by the failure of the unloader increases by 43.28% under25% load,and it is difficult to ensure the stepless flow regulation within0-100% of the unit.(3)CFD-DPM-based reciprocating pump discharge check valve in solid-liquid two-phase media erosion simulation,to explore the different pump valve structure parameters and media nature parameters on the erosion characteristics of the overflow wall.The results show that the wear position mainly occurs at the bottom corner of the spool and the seat taper,and the lift of the spool has a large effect on the erosion rate compared with the half-taper angle and the seat bore diameter.With the increase of particle size,the wear at the bottom corner of the spool is weakened,and the wear at the cone surface of the valve seat is intensified,and the wear at the valve seat is generally more serious than that at the spool;with the increase of particle mass concentration,there is almost no effect on the maximum velocity of particles,and the wear at the spool and the valve seat is intensified,and the wear area at the spool is not significantly changed,and the wear area at the valve seat is increased.