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Energy Loss Analysis of Novel Self-Priming Pump Based on the Entropy Production Theory

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Journal of Thermal Science 2019年第2期28卷 306-318页

作者： CHANG Hao SHI Weidong LI Wei liu jianrui Research Center of Fluid Machinery Engineering and Technology Jiangsu University School of mechanical engineering Nantong University

The conventional method cannot explicitly confirm the location and type of the energy loss, therefore this paper employs the entropy production theory to systematically analyze the category, magnitude and location of hydraulic loss under different blade thickness distribution. Based on the analysis, the turbulent entropy and viscosity entropy produced by the separation of boundary layer at the trialing edge are major factors leading to the hydraulic loss. In addition, the separation of the boundary layer can not only cause the energy loss, but also block the passage of the impeller and reduce the expelling coefficient of the blade. Therefore, the hydraulic performance of the blades with increment thickness distribution is obviously better than the decrement one. Further, the flow rate has different influence on the three types of entropy production. Meanwhile, the pressure pulsation on the working surface was investigated. It was concluded that with flow rates increasing, the amplitude of pressure pulsation firstly decreases and then smoothly improves, and reaches the minimum under design flow rate. Finally, the optimal blade was obtained, and the relevant hydraulic performance test was performed to benchmark the simulation result. This research can provide the theoretical reference for designing the reasonable thickness distribution of the blades.

关键词： entropy production energy loss thickness distribution pressure pulsation

Influence of Cross-Sectional Flow Area of Annular Volute Casing on Transient Characteristics of Ceramic Centrifugal Pump

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Chinese Journal of Mechanical Engineering 2019年第1期32卷 161-173页

作者： Yi Tao Shouqi Yuan jianrui liu Fan Zhang Wuxi Vocational Institute of Arts and Technology National Research Center of Pumps and System Engineering and Technology Jiangsu University

The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annular volutes are available, and there is no systematic design method for annular volutes. In this study, the influence of volute casing cross-sectional flow area on the hydraulic loss, pressure pulsations, and radial force under varying working conditions in a centrifugal ceramic pump are discussed in detail. Experimental tests were conducted to validate the numerical results. The results indicated that, when the volute casing flow area increases, the hydraulic performance decreases marginally under the rated working conditions, but increases at the o-design points, specifically under large flow condition. However, the volute casing with a larger flow area has a wider high-e ciency region. In addition, the increase in the volute casing flow area will decrease the pressure pulsations in the volute, regardless of the working condition, and decrease the radial force on the shaft, therefore, providing an improved pump operational stability. It is anticipated that this study will be of benefit during the design of annular volutes.

关键词： Annular volute Centrifugal pump Cross section Transient characteristics Pressure pulsation Radial force

Influence of Blade Thickness on Transient Flow Characteristics of Centrifugal Slurry Pump with Semi-open Impeller

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Chinese Journal of Mechanical Engineering 2016年第6期29卷 1209-1217页

作者： TAO Yi YUAN Shouqi liu jianrui ZHANG Fan TAO Jianping National Research Center of Pumps and Pumping System Engineering and Technology Jiangsu University Zhenjiang 212013 China Yixing Taoye Nonmetallic Chemical Machinery Factory Co. Ltd. Wuxi 214222 China

As the critical component, the impellers of the slurry pumps usually have blades of a large thickness. The increasing excretion coefficient of the blades affects the flow in the impeller resulting in a relatively higher hydraulic loss, which is rarely reported. In order to investigate the influence of blade thickness on the transient flow characteristics of a centrifugal slurry pump with a semi-open impeller, transient numerical simulations were carried out on six impellers, of which the meridional blade thickness from the leading edge to trailing edge varied from 5-10 mm, 5-15 mm, 5-20 mm, 10-10 mm, 10-15 mm, and 10-20 mm, respectively. Then, two of the six impellers, namely cases 4 and 6, were manufactured and experimentally tested for hydraulic performance to verify the simulation results. Results of these tests agreed reasonably well with those of the numerical simulation. The results demonstrate that when blade thickness increases, pressure fluctuations at the outlet of the impeller become severe. Moreover, the standard deviation of the relative velocity in the middle portion of the suction sides of the blades decreases and that at the outlet of the impeller increases. Thus, the amplitude of the impeller head pulsation for each case increases. Meanwhile, the distribution of the time-averaged relative flow angle becomes less uniform and decreases at the outlet of the impeller. Hence, as the impeUer blade thickness increases, the pump head drops rapidly and the maximum efficiency point is offset to a lower flow rate condition. As the thickness of blade trailing edge increases by 10 mm, the head of the pump drops by approximately 5 m, which is approximately 10 % of the original pump head. Futhermore, it is for the first time that the time-averaged relative flow angle is being considered for the analysis of transient flow in centrifugal pump. The presented work could be a useful guideline in engineering practice when designing a centrifugal slurry pump with thick i

关键词： centrifugal slurry pump blade thickness transient flow characteristics time-averaged relative flow angle semi-openimpeller

Common-mode Electromagnetic Interference Mitigation for Solid-state Transformers

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Chinese Journal of Electrical Engineering 2022年第3期8卷 22-36页

作者： Dong Jiang Zhenyu Wang Wenjie Chen jianrui liu Xuan Zhao Wei Sun State Key Laboratory of Advanced Electromagnets Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an 710049China

Solid-state transformers(SSTs)have been widely used in many areas owing to their advantages of high-frequency isolation and high power ***,high-frequency switching causes severe electromagnetic interference(EMI)***,the common-mode(CM)EMI caused by the switching of the dual active bridge(DAB)converter is conducted through the parasitic capacitances in the high-frequency transformer and impacts the system *** the understanding of the CM EMI model in SSTs,CM EMI mitigation methods have been *** passive mitigation,the coupled inductor can be integrated with the phase-shift inductor function to reduce CM *** active mitigation,variations in the DAB switching frequency can help reduce the CM EMI *** active EMI filter can also be designed to sample and compensate for CM *** these methods,CM EMI can be reduced in SSTs.

关键词： Solid-state transformer(SST) Dual active bridge(DAB) Common-mode Electromagnetic interference(EMI)

Experimental Optimization of Jet Self-Priming Centrifugal Pump Based on Orthogonal Design and Grey-Correlational Method

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Journal of Thermal Science 2020年第1期29卷 241-250页

作者： CHANG Hao SHI Weidong LI Wei WANG Chuan ZHOU Ling liu jianrui YANG Yongfei RAMESH KAgarwal Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China Department of Mechanical Engineering&Materials Science Washington University in St.LouisSt.Louis 63130USA School of Mechanical Engineering Nantong UniversityNantong 226019China School of Hydraulic Energy and Power Engineering Yangzhou UniversityYangzhou 225002China

The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so *** order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming ***,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of ***,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu *** to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was *** relationship between self-priming time and self-priming height was *** test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow *** is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of *** the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national ***,this research could provide reference for designing the structure of jet self-priming centrifugal pump.

关键词： self-priming centrifugal pump design optimization orthogonal experiment grey-correlational

Coordination behavior between zinc salts and L-α-methionine

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Chinese Science Bulletin 1998年第18期43卷 1527-1531页

作者： Shengli Gao jianrui liu Mian Ji Xuwu Yang Fengxing Zhang Zhongjin Li Department of Chemistry Northwest University Xi’an China Department of Chemical Engineering Northwest Institute of Light Industry Xianyang China

The solubility properties of ZnCl\-2/ZnAc\-2/ZnSO\-4MetH\-2O systems at 25℃ in the whole cocentration range have been investigated by phase equilibrium method. The results indicate that ZnAc\-2 and ZnSO\-4 systems are both simple systems, which do not exist any compound; there are 2 complexes formed in ZnCl\-2 system: Zn（Met）Cl\-2 and Zn（Met）\-2Cl\-2·2H\-2O. Under the direction of phase equilibrium result, 2 solid complexes have been prepared in water and characterized by chemical analysis, IR, Xray diffraction. Their combustion energies have also been determined by means of a RBCtype1 rotatingbomb calorimeter, and their standard enthalpies of formation, Δ f, coor（s）H O-, have been calculated which are （-828.32±3.00） kJ·mol -1 and （-1 117.08±6.15） kJ·mol -1, respectively.

关键词： zinc salts L-methionine phase equilibrium complex standard formation enthalpy.

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射流式自吸喷灌泵的研究进展与展望

农业机械学报 2007年第8期38卷 177-180页

作者：刘建瑞周贵平江苏大学流体机械工程技术研究中心

介绍射流式自吸喷灌泵的技术经济特性,叙述射流式自吸喷灌泵的结构优化设计,分析射流式自吸喷灌泵的社会及经济效益,讨论了射流式自吸喷灌泵发展中有待解决的问题,并对发展趋势作了前瞻,为射流式自吸喷灌泵的研究与设计提供参考。

关键词：射流式自吸喷灌泵设计综述

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微量钒对AZ91D镁合金显微组织的影响

稀有金属材料与工程 2011年第7期40卷 1173-1177,1175-1177页

作者：张超刘建睿黄卫东西北工业大学凝固技术国家重点实验室陕西西安710072

研究了添加微量钒对AZ91D镁合金显微组织的影响。在AZ91D镁合金熔炼过程加入AlV55中间合金引入钒元素,用光学显微镜、扫描电镜、能谱仪和X射线衍射等分析研究了加钒前后合金组织的变化以及钒在合金中的存在形式。结果表明:钒的引入使β-... 详细信息

研究了添加微量钒对AZ91D镁合金显微组织的影响。在AZ91D镁合金熔炼过程加入AlV55中间合金引入钒元素,用光学显微镜、扫描电镜、能谱仪和X射线衍射等分析研究了加钒前后合金组织的变化以及钒在合金中的存在形式。结果表明:钒的引入使β-Mg17Al12相由不连续网状逐渐离散化,钒在AZ91D合金中主要以新相Al3V形式溶解或分散于β-Mg17Al12相和α-Mg基体中。高熔点的新相Al3V在AZ91D镁合金凝固过程中先于其他相生成聚集在固液界面前沿,抑制晶粒的长大;同时由于α-Mg相细化而使晶界面积增加,相应的单位面积晶界处发生共晶反应的熔液体积减少,生成的β-Mg17Al12相变得细小。同时由于晶粒尺寸减小以及晶界处Al3V相的强化作用,AZ91D合金的硬度随着添加钒含量的增加呈增大趋势。

关键词：钒 AZ91D镁合金晶粒细化

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自吸泵气液两相流数值模拟分析

农业机械学报 2009年第9期40卷 73-76页

作者：刘建瑞苏起钦江苏大学流体机械工程技术研究中心镇江212013

采用Mixture多相流模型、Realizable湍流模型与SIMPLEC算法,应用CFD软件Fluent对内混式自吸泵自吸过程的气液两相流进行了数值模拟。通过分析不同含气率条件下流场的压力分布、速度分布、气相分布,探讨了气液两相介质在泵内的运动情况,... 详细信息

采用Mixture多相流模型、Realizable湍流模型与SIMPLEC算法,应用CFD软件Fluent对内混式自吸泵自吸过程的气液两相流进行了数值模拟。通过分析不同含气率条件下流场的压力分布、速度分布、气相分布,探讨了气液两相介质在泵内的运动情况,一定程度上揭示了内混式自吸泵自吸过程的内部流场变化规律,为自吸泵的设计提供更多的参考依据。

关键词：自吸泵气液两相流数值模拟自吸性能