【作者】 袁丹青；

【导师】 杨敏官；

【作者基本信息】 江苏大学 ， 流体机械及工程， 2009， 博士

【摘要】 射流泵是利用射流紊动扩散作用,来传递能量和质量的流体机械,已被广泛应用于水利、电力、交通、冶金、石油、化工、环境保护、海洋开发、核能利用、航空及航天等部门。随着流体力学和空气动力学的发展,推动了射流技术的应用和研究工作,射流泵的广泛应用及高效节能特点显著提高,并且在人类工农业生产中越来越显示出其重要的作用。本文对射流泵理论与设计方法进行了较为系统的研究,开展的主要工作及取得的研究成果有:1.多喷嘴射流泵理论研究:推导了射流泵的基本方程,给出了射流泵装置效率为最高时的最优参数计算方法。为了提高射流泵的效率,可以采取的措施有:采用脉冲射流或多股射流。采用脉冲射流,兼有射流紊动扩散作用和活塞泵的作用,采用多股射流使工作与被吸流体在较短的喉管内得到充分混合,减少了喉管的摩阻损失,改善了扩散管的入口流速分布,从而减小了扩散损失,本文重点研究多喷嘴射流,得出了几点重要结论。2.设计方法研究:射流泵的设计遵循效率最优原则,即在给定的工作条件下,得到尽可能高的效率。射流泵的性能、性能曲线、射流泵基本方程以及射流泵的相似定律的描述采用无量纲参数,喷射流泵的特性根据面积比R,流量比M,扬程比(也称为压力比)N来确定,多喷嘴射流泵的最优参数的确定根据相同工况下的单喷嘴射流泵的特性曲线和特性方程来求得。3.射流泵内部流动研究:通过射流泵内部流场的PIV测量结果,初步揭示了内部流动的基本规律。对单喷嘴射流泵和多喷嘴射流泵进行了内部三维湍流流场的数值模拟,得出了多喷嘴射流泵的性能,结果表明:模拟值与实测值吻合较好,为进一步实验研究提供了依据。4.射流泵实验研究:通过正交试验设计,测出不同流量比下的进出口流量,进出口压力,并探索不同的喷嘴个数,喷嘴角度和喉嘴距对多喷嘴射流泵的效率影响,找出最优的设计方案,指出为达到最优设计方案进一步研究的方向。正交试验的试验因素有:喷嘴个数,喷嘴角度,喉嘴距。采用正交试验方法,共做了9次试验,通过深入研究不同的试验因素对多喷嘴射流泵的影响得出:喷嘴数,喷嘴角度,喉嘴距对多喷嘴射流泵的影响依次增大;通过试验比较分析,当喷嘴数为4个,喷嘴角度为10°,喉嘴距为50mm时的方案最好。5.高汽蚀性能多喷嘴射流泵离心泵设计研究:通过对多喷嘴射流泵的研究,为了使多喷嘴射流泵应用到生产中去,对离心泵各种喷嘴情况下进行试验,得出离心泵加装多喷嘴射流装置后,进口压力增加,通过多股高速射流来提升低速被吸液体的能量,使其在短喉管中能迅速均匀混合,从而大幅度地改善了离心泵的汽蚀性能,离心泵进口加装射流装置后扬程也明显提高。更多还原

【Abstract】 Jet pump is the fluid machinery by use of jet turbulent diffusion to transfer the energy and quality,the fluid machinery has been widely used in water conservancy, electricity,transportation,metallurgy,petroleum,chemical,environmental protection, marine development,nuclear power utilization,aviation and aerospace sectors.With the development of fluid mechanics and aerodynamics,promotion of the jet technology applications and research work made a big progress,jet pump is a very cost-effective general-purpose equipment and technology,and it shows great importance in economic life of mankind.In this paper,jet pump theory and design methods are systematic studied.Main work and research results are:1.Research on Multi-nozzle jet pump theory:derive out the jet pump’s basic equation;and give a method to calculate the optimal parameters when the efficiency of jet pump device is the highest.In order to improve the efficiency of the jet pump,the measures can be taken includes:the use of pulse-jet or multi-shares Jet.Pulse jet,which have the functions of turbulent diffusing and piston pumps,use the multi-shares jet unit which makes the work fluid and the fluid being sucked fully mixed in a short period of the pipe,as a result of reducing the pipe’s friction loss and improving entrance velocity distribution of the diffusion tube,then reducing the diffusion loss.2.Design Method:jet pump designs follow the optimal principle,that is in a given working conditions,get the highest possible efficiency.The performance of jet pump, performance curve,the basic equation of the jet pump and the description of jet pump similar to the law of the use of more convenient dimensionless parameters,the characteristics of jet pump is in accordance with the area ratio R,the flow ratio M,head ratio(also called pressure ratio) N to define.Obtain of the multi-nozzle jet pump’s optimal parameters depend on single nozzle jet pump’s characteristic curve and the characteristic equation when it under the same conditions.3.Study on jet pump’s internal flow:study on the inside flow of the jet pump by three-dimensional numerical simulation,through the PIV measurement results of jet pump internal flow,then get the basic law of the internal flow.Have conducting an internal numerical simulation of flow field on single and multi-nozzle jet pump jet pump nozzles,it obtained a performance of multi-nozzle jet pump.The results show that:the simulation and experimental values agree well,and it provide a basis for further experiments.4.Study on jet pump experiment:by the design of orthogonal test,the different traffic flow at the import and export have been texted,as well as the import and export pressures,exploration based on a different number of nozzles,nozzle angles and throat from the mouth work on the multi-nozzle jet pump,then find out the optimal design of the program,and point out the further study direction that to achieve the optimal design. Orthogonal test pilot factors are as follows:the number of nozzles,nozzle angle,and nozzle from the hose.With orthogonal test method,9 times of test,and the study of the impact of the jet pump,we found that the number of nozzles,nozzle angle and throat from the mouth of the multi-nozzle have the increase impact;and when it have 4 nozzles,nozzle angle is 10°,and the hose nozzles is 50mm,the pump is best.5.Study on high-altitude performance of multi-nozzle jet pump centrifugal pump design:Researching on multi-nozzle jet pump,in order to enable the multi-nozzle jet pump applied to the production,tests centrifugal pump under the case of variety of multi-nozzle jet,the centrifugal pump installed multi-nozzle jet,have an increased import pressure.A multi-unit high-speed jet is used to enhance the energy of low-speed liquid being sucked,which make it rapidly mixed in the short pipes,thus substantially improved the cavitations performance of centrifugal pumps,and the installation of jet at the imports of centrifugal pumps can significantly improve the total head.更多还原