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A valveless piezoelectric pump with novel flow path design of function of rectification to improve energy

《机械工程前沿（英文）》 2022年第17卷第3期 doi: 10.1007/s11465-022-0685-3

摘要： Existing valveless piezoelectric pumps are mostly based on the flow resistance mechanism to generate unidirectional fluid pumping, resulting in inefficient energy conversion because the majority of mechanical energy is consumed in terms of parasitic loss. In this paper, a novel tube structure composed of a Y-shaped tube and a ȹ-shaped tube was proposed considering theory of jet inertia and vortex dissipation for the first time to improve energy efficiency. After verifying its feasibility through the flow field simulation, the proposed tubes were integrated into a piezo-driven chamber, and a novel valveless piezoelectric pump with the function of rectification (NVPPFR) was reported. Unlike previous pumps, the reported pump directed the reflux fluid to another flow channel different from the pumping fluid, thus improving pumping efficiency. Then, mathematical modeling was established, including the kinetic analysis of vibrator, flow loss analysis of fluid, and pumping efficiency. Eventually, experiments were designed, and results showed that NVPPFR had the function of rectification and net pumping effect. The maximum flow rate reached 6.89 mL/min, and the pumping efficiency was up to 27%. The development of NVPPFR compensated for the inefficiency of traditional valveless piezoelectric pumps, broadening the application prospect in biomedicine and biology fields.

关键词： composite tube valveless piezoelectric pump rectification energy efficiency

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Theoretical analysis and experimental investigation of valveless piezoelectric pump with unsymmetrical

ZHANG Jianhui, LU Jizhuang, XIA Qixiao, LI Hong

《机械工程前沿（英文）》 2007年第2卷第1期页码 13-19 doi: 10.1007/s11465-007-0002-1

摘要： A novel valveless piezoelectric pump with unsymmetrical ridges is presented at first. It ingeniously utilizes the inner space of its chamber by developing its chamber bottom into unsymmetrical ridges along the direction of the inlet and outlet of the pump. Hence, a series of cuneiform channels are asymmetrically and alternately formed between the unsymmetrical ridges and the piezoelectric vibrator, which enables the pump to form a one-way flow instead of the function of the traditional diffuse or nozzle elements fitted outside the chamber. Then, by analyzing the vibration of the piezoelectric vibrator, the vibration deformation function and the equation of volume change are established. Meanwhile, the theoretical equation of the pump flow rate is established. Finally, a real valveless piezoelectric pump with unsymmetrical ridges is manufactured, and the flow rate of the pump is measured through experiments. It is proved that the theory is rational and correct by comparing the experimental flow rate and the theoretical flow rate. In addition, for calculating the theoretical flow rate, the positive and converse flow resistance coefficients of unsymmetrical ridges are measured through experiments, when one slope angle of the unsymmetrical ridges is 90º and another is changing from 20º to 60º, respectively.

关键词： unsymmetrical theoretical flow theoretical equation pump flow converse flow

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Extended two-fluid model applied to analysis of bubbly flow in multiphase rotodynamic pump impeller

Zhiyi YU, Guoyu WANG, Shuliang CAO

《机械工程前沿（英文）》 2009年第4卷第1期页码 53-59 doi: 10.1007/s11465-009-0006-0

摘要： This paper presents an extended two-fluid model based on the Navier-Stokes equations and the standard turbulence model, to simulate the three-dimensional air-water bubbly flow in turbo machinery. In the governing equations, the drag force and added mass force are added and the additional source terms arising from fluctuations of gas volume fraction are considered. The discrete equations are solved using a developed two-phase semi-implicit method for pressure-linked equations, consistent (SIMPLEC) algorithm in body-fitted coordinates with a staggered grid system. Simulation is then carried out for the pure liquid flow and air-water two-phase flow with the inlet gas volume fraction being 15% in a multiphase rotodynamic pump impeller and the pump head performance is predicted. Comparison with experimental results shows the reliability and commonality of the numerical model.

关键词： two-fluid model multiphase rotodynamic pump SIMPLEC algorithm numerical simulation

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Characteristics of force acting on adjustable axial flow pump blade

WEI Peiru, CHEN Hongxun, LU Wei

《能源前沿（英文）》 2008年第2卷第4期页码 508-513 doi: 10.1007/s11708-008-0054-x

摘要： The internal three-dimensional turbulent flow of adjustable axial-flow pump arrangement was simulated, and the force acting on the blade surface was calculated under different operating conditions. Based on the calculated results, finite element method (FEM) was adopted to analyze stress and strain distributions of the adjustment blade in different operations. Hydraulic moment, centrifugal moment and friction moment which must be conquered by adjusting the blades were also calculated.

关键词： three-dimensional adjustable axial-flow calculated FEM centrifugal

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Elliptical lobe shape gerotor pump design to minimize wear

Mohammad Reza KARAMOOZ RAVARI

《机械工程前沿（英文）》 2011年第6卷第4期页码 429-434 doi: 10.1007/s11465-011-0247-6

摘要：

The gerotor pumps are the most important parts of mechanical equipment that have a vast number of applications in industries and automobiles. Because the gerotor pumps cannot be adjusted for wear so it is important to reduce the wear as much as possible. In this paper first mathematical equations for elliptical lobe shape rotors profile and curvature of them have been derived and then Specific flow and wear rate proportional factor (WRPF) have been formulated. To reach the minimum wear in rotors teeth, the ellipse shape factor is changed for each value of number of outer rotor teeth in a feasible range and wear rate proportional factor has been resulted. Also in order to have better comparison specific flow has been presented. The obtained results have been compared with circular pumps with similar geometrical parameters and show the significant improvement in wear of the rotors with negligible changes in the specific flow.

关键词： gerotor pump elliptical lobe shape pump wear rate proportional factor (WRPF) specific flow

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中国水泵水轮机流动不稳定性研究

左志钢,刘树红

《工程（英文）》 2017年第3卷第4期页码 504-511 doi: 10.1016/J.ENG.2017.04.010

摘要：

水泵水轮机的稳定性对于抽水蓄能电站的运行有着重要意义，在中国的抽水蓄能电站中水力稳定性和运行稳定性均有报道。为了给水泵水轮机方面的工程师和科学家提供参考，本文总结了中国抽水蓄能电站中水泵水轮机运行遇到的水力不稳定性，以及容易诱发运行不稳定的运行特性。我们解释了术语的定义和分析方法，并基于对已公开发表文献的回顾，提出了注意事项和解决措施，指出了当前研究现状与工程实践需求之间的差距。

关键词：水泵水轮机流动不稳定性压力脉动 S 特性正斜率

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R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

《能源前沿（英文）》 2010年第4卷第1期页码 47-54 doi: 10.1007/s11708-009-0080-3

摘要： The ground-coupled heat pump (GCHP) systems have been identified as one of the best sustainable energy technologies for space heating and cooling in residential and commercial buildings. In this paper, research on and development of the GCHP technology in China are summarized. New models are presented for efficient thermal analysis of ground heat exchangers, of which one- and two-dimensional solid cylindrical source models and their analytical solutions are devised to deal with pile ground heat exchangers. Analytical solutions are also derived for vertical and inclined finite line source models as well as for a groundwater advection model. Explicit solutions of a quasi-three-dimensional model can be used to better evaluate the thermal resistance inside boreholes. Studies on hybrid GCHP systems and the thermal response test in China are also commented.

关键词： ground source heat pump ground heat exchanger HVAC China

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Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

《能源前沿（英文）》 2014年第8卷第3期页码 394-402 doi: 10.1007/s11708-014-0310-1

摘要： The aim of this study is to evaluate the performance of a centralized open-loop ground-water heat pump (GWHP) system for climate conditioning in Beijing with a cold climate in China. Thus, a long-time test was conducted on a running GWHP system for the heating season from December 2011 to March 2012. The analysis of the testing data indicates that the average heat-pump coefficient of performance (COP) and the COP of the system (COPs) are 4.27 and 2.59. The low value and large fluctuation in the range of COP are found to be caused by the heat transfixion in the aquifer and the bypass in the circulation loop. Therefore, some suggestions are proposed to improve the performance for GWHPs in the cold climate region in China.

关键词： ground-water heat pump (GWHP) actual coefficient of performance heat transfixion

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Absorption heat pump for waste heat reuse: current states and future development

Zhenyuan XU, Ruzhu WANG

《能源前沿（英文）》 2017年第11卷第4期页码 414-436 doi: 10.1007/s11708-017-0507-1

摘要： Absorption heat pump attracts increasing attention due to its advantages in low grade thermal energy utilization. It can be applied for waste heat reuse to save energy consumption, reduce environment pollution, and bring considerable economic benefit. In this paper, three important aspects for absorption heat pump for waste heat reuse are reviewed. In the first part, different absorption heat pump cycles are classified and introduced. Absorption heat pumps for heat amplification and absorption heat transformer for temperature upgrading are included. Both basic single effect cycles and advanced cycles for better performance are introduced. In the second part, different working pairs, including the water based working pairs, ammonia based working pairs, alcohol based working pairs, and halogenated hydrocarbon based working pairs, for absorption heat pump are classified based on the refrigerant. In the third part, the applications of the absorption heat pump and absorption heat transformer for waste heat reuse in different industries are introduced. Based on the reviews in the three aspects, essential summary and future perspective are presented at last.

关键词： absorption heat pump heat transformer waste heat working pair

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design of novel proton-pump inhibitors with reduced adverse effects

Xiaoyi Li, Hong Kang, Wensheng Liu, Sarita Singhal, Na Jiao, Yong Wang, Lixin Zhu, Ruixin Zhu

《医学前沿（英文）》 2019年第13卷第2期页码 277-284 doi: 10.1007/s11684-018-0630-3

摘要： The development of new proton-pump inhibitors (PPIs) with less adverse effects by lowering the pKa values of nitrogen atoms in pyrimidine rings has been previously suggested by our group. In this work, we proposed that new PPIs should have the following features: (1) number of ring II= number of ring I+ 1; (2) preferably five, six, or seven-membered heteroatomic ring for stability; and (3) 1

关键词： proton-pump inhibitor adverse effect pharmacological mechanism toxicological mechanism pKa calculation

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Efficiency characteristics of piezostack pump for linear actuators

Junwu KAN, Kehong TANG, Chenghui SHAO, Guoren ZHU, Taijiang PENG,

《机械工程前沿（英文）》 2009年第4卷第4期页码 407-414 doi: 10.1007/s11465-009-0049-2

摘要： A piezostack pump for linear actuators is presented and studied in terms of mechanical energy efficiency (MEE), energy conversion efficiency (ECE) and design method. MEE is defined as the ratio of the output mechanical energy to that converted from input electrical energy, and ECE is the ratio of output mechanical energy to input electrical energy. The analysis results show that both MEE and ECE decrease with the increase of stiffness of the chamber diaphragm (), which is a function of the radius ratio (rigid disk radius to chamber radius). There is respective optimal external load () for them to achieve peak value for a given piezostack with blocked force () and stiffness (). The optimal force ratio (/) is a constant of 0.5 for maximum MEE, and between 0.57 and 0.5 for maximum ECE. Considering the deflection of the pump chamber and dynamic response of the piezostack, the stiffness ratio (/) should be limited between 0.3 and 1, and the relative radius ratio is between 0.7 and 0.8. With the increase of the radius ratio in the range, the maximal MEE decreases from 0.38 to 0.25, and the peak ECE decreases from 0.20 to 0.14.

关键词： piezostack actuator piezostack pump mechanical efficiency energy conversion efficiency (ECE)

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Design and analysis of linear oscillating motor for linear pump application-magnetic field, dynamics

Zongxia JIAO,Tianyi WANG,Liang YAN

《机械工程前沿（英文）》 2016年第11卷第4期页码 351-362 doi: 10.1007/s11465-016-0407-9

摘要：

A linear oscillating motor is an electromagnetic actuator that can achieve short-stroke reciprocating movement directly without auxiliary transmission mechanisms. It has been widely used in linear pump applications as the source of power and motion. However, because of the demand of high power density in a linear actuation system, the performance of linear oscillating motors has been the focus of studies and deserves further research for high power density. In this paper, a general framework of linear oscillating motor design and optimization is addressed in detail, including the electromagnetic, dynamics, and thermal aspects. First, the electromagnetic and dynamics characteristics are modeled to reveal the principle for optimization. Then, optimization and analysis on magnetic structure, resonant system, and thermal features are conducted, which provide the foundation for prototype development. Finally, experimental results are provided for validation. As a whole, this process offers complete guidance for high power density linear oscillating motors in linear pump applications.

关键词： linear oscillating motor linear pump magnetic field motor optimization

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A solar assisted heat pump drying system for grain in-store drying

Haifeng LI, Yanjun DAI, Jianguo DAI, Xibo WANG, Lei WEI,

《能源前沿（英文）》 2010年第4卷第3期页码 386-391 doi: 10.1007/s11708-010-0003-3

摘要： For grain in-store drying, a solar assisted drying process has been developed, which consists of a set including a solar-assisted heat pump, a ventilation system, a grain stirrer, etc. In this way, low power consumption, short cycle time and water content uniformity can be achieved in comparison with the conventional method. A solar-assisted heat pump drying system has been designed and manufactured for a practical granary, and the energy consumption performance of the unit is analyzed. The analysis result shows that the solar fraction of the unit is higher than 20%, the coefficient of performance about system (COP) is 5.19, and the specific moisture extraction rate (SMER) can reach 3.05 kg/kWh.

关键词： solar energy heat pump airflow in-store drying

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Performance analysis of an air-source heat pump using an immersed water condenser

Jie JI, Huide FU, Hanfeng HE, Gang PEI,

《能源前沿（英文）》 2010年第4卷第2期页码 234-245 doi: 10.1007/s11708-009-0056-3

摘要： A distributed model of an air-source heat pump (ASHP) system and its experimental setup using an immersed water condenser were presented. Dynamic performance of the ASHP was then evaluated by both simulation and experiment. The results indicated that the system coefficient of performance (COP) decreased as the condenser temperature increased, ranging from 4.41 to 2.32 with the average COP equaling 3.29 during the experiment. Comparisons between simulation results and experimental measurements demonstrated that the model was able to yield satisfactory predictions. Furthermore, temperature profiles of the refrigerant in the evaporator and condenser were also given. This paper provides the theoretical and experimental background for ASHP system optimization and a valuable reference for a solar air-source heat pump water heater when the solar irradiation energy is insufficient on cloudy or rainy days.

关键词： air-source heat pump distributed model immersed water condenser

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Optimization model analysis of centralized groundwater source heat pump system in heating season

Shilei LU,Yunfang QI,Zhe CAI,Yiran LI

《能源前沿（英文）》 2015年第9卷第3期页码 343-361 doi: 10.1007/s11708-015-0372-8

摘要： The ground-water heat-pump system (GWHP) provides a high efficient way for heating and cooling while consuming a little electrical energy. Due to the lack of scientific guidance for operating control strategy, the coefficient of performance (COP) of the system and units are still very low. In this paper, the running strategy of GWHP was studied. First, the groundwater thermal transfer calculation under slow heat transfixion and transient heat transfixion was established by calculating the heat transfer simulation software Flow Heat and using correction factor. Next, heating parameters were calculated based on the building heat load and the terminal equipment characteristic equation. Then, the energy consumption calculation model for units and pumps were established, based on which the optimization method and constraints were established. Finally, a field test on a GWHP system in Beijing was conducted and the model was applied. The new system operation optimization idea for taking every part of the GWHP into account that put forward in this paper has an important guiding significance to the actual operation of underground water source heat pump.

关键词： optimization model groundwater source heat pump system theoretical analysis example verification heating season