| As a kind of current power transfer machine,water pump is widely used in the national production and life.It involves in the fields of industry and agriculture,home,fire and so on.Cavitation phenomenon is a phenomenon of the pump in the transmission fluid is more common,especially when the internal flow channel of the pump is slender and narrow,the most prone to occur.Cavitation location is near the impeller blade inlet.This is because the pump in operation if the absolute pressure of pumping liquid down to equal to or lower than the liquid temperature corresponding to the vapor pressure caused by.Vapor will produce a large number of bubble,when the steam bubble with the flow of water from the high pressure zone,the pressure increases the bubble gradually deformation finally burst.This process will lead to a strong water hammer,not only for the impeller and internal flow channel erosion,but also produce a great vibration and noise,and reduce the overall operating efficiency of the pump.How to avoid cavitation and how to reduce the damage caused by the greatest extent of the damage has become the focus of research.For the study of cavitation analysis,it is first necessary to understand the mechanism of cavitation and cavitation generated position.Therefore,it is necessary understanding of water pump,inner flow state,in order to ensure the accurate degree of the research and analysis,this paper selects the most common centrifugal pump as the research object and the internal structure of the pump were corresponding simplified,reduce the influence of other factors of interference on the pump flow,in order to get better effect.The working principle of this pump is simple,it is through the rotation of the impeller of the centrifugal force generated water thrown out.At the same time,suction port formed area of low pressure,reciprocating impeller rotation,complete sustained delivery of fluid.Modern people for cavitation prevention measures have made a lot of research and common preventive measures have improved impeller structure,reduce the flow rate,adopts a double suction impeller and the adding inducer method is one of them.This method compared to other cavitation prevention methods,firstly,it can effectively restrain cavitation phenomenon,in addition has convenient use and simple installation and easy to change.Current people for induction of round of research mostly concentrates on the wheel,the basic size of induction,due to the research content is more than enough to meet the ordinary industrial and agricultural water pump cavitation resistant requirements and on the induction of round of other control variables on a relatively small,but some other controlling factors will of inducer cavitation prevention effect have a greater impact,especially in some high and new research fields such as the aerospace industry and nuclear industry must consider the influence of these factors,for any a tiny influence factors can not be ignored.Considering the current people for study of cavitation more overall analysis.So in this paper the previous analysis foundation for some research too few but for cavitation prevention has a greater impact on the control variables,given the focus of the analysis,mainly related to the different change of the pitch and different pitch changes of different type axle line of anti cavitation effect,and from these analyses compared to get the optimal preventive effect.This paper here to the single-stage single suction centrifugal pump as the research object,causes of cavitation and location analysis is made,and by adding lead and pitch inducer as a measure to solve the cavitation,research and analysis of induced flow state of the wheel.In this paper to round the pitch variation and type axle line changes induced effect of inducer caused give key analysis and comparative analysis in pitch and variable pitch two different states for changes to the cavitation effect influence,Xi Wangwen content for the design,induced wheel to provide certain theoretical reference. |
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