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A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method

Wu REN, Yunxin WU, Zhaowei ZHANG

《机械工程前沿（英文）》 2013年 第8卷 第4期   页码 360-366 doi: 10.1007/s11465-013-0280-8

摘要：

Mobile concrete pump boom is typical multi-body large-scale motion manipulator. Due to posture constantly change in working process, kinematic rule and dynamic characteristic are difficult to solve. A dynamics model of a mobile concrete pump boom is established based on discrete time transfer matrix method (DTTMM). The boom system is divided into sub-structure A and sub-structure B. Sub-structure A is composed by the 1st boom and hydraulic actuator as well as the support. And sub-structure B is consists of the other three booms and corresponding hydraulic actuators. In the model, the booms and links are regarded as rigid elements and the hydraulic cylinders are equivalent to spring-damper. The booms are driven by the controllable hydraulic actuators. The overall dynamic equation and transfer matrix of the model can be assembled by sub-structures A and B. To get a precise result, step size and integration parameters are studied then. Next the tip displacement is calculated and compared with the result of ADAMS software. The displacement and rotation angle curves of the proposed method fit well with the ADAMS model. Besides it is convenient in modeling and saves time. So it is suitable for mobile concrete pump boom real-time monitoring and dynamic analysis. All of these provide reference to boom optimize and engineering application of such mechanisms.

关键词： multi-body     mobile concrete pump boom     discrete time transfer matrix method (DTTMM)     kinematic     dynamic     tip displacement    

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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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Research and practice on system engineering management of a mobile payment project

Yongkai ZHOU, Hongfeng CHAI

《工程管理前沿（英文）》 2017年 第4卷 第2期   页码 127-137 doi: 10.15302/J-FEM-2017011

摘要： The popularization of the mobile internet has given rise to demand for flexible and convenient payment methods. For China, it is necessary to keep pace with or even lead the trend of innovation and development in the age of mobile payment. From the perspective of systems engineering, this paper introduces research and implementation of China UnionPay’s mobile payment project. The general requirements and core engineering problems of the mobile payment project are summarized based on analyses of the characteristics and engineering difficulties of this project. Integration of innovative technologies is introduced to resolve the contradiction between ease-of-use and security. A rapid iterative development process is adopted to improve the product release efficiency as well as the users' experience. The launch of the mobile payment project also opens the window to coordinating and upgrading the whole payment industry chains.

关键词： systems engineering     mobile payment     engineering management method     Mobile QuickPass     national information security     rapid iteration process     financial security     coordination and cooperation    

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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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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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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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Motion control of multi-actuator hydraulic systems for mobile machineries: Recent advancements and future

Bing XU, Min CHENG

《机械工程前沿（英文）》 2018年 第13卷 第2期   页码 151-166 doi: 10.1007/s11465-018-0470-5

摘要：

This paper presents a survey of recent advancements and upcoming trends in motion control technologies employed in designing multi-actuator hydraulic systems for mobile machineries. Hydraulic systems have been extensively used in mobile machineries due to their superior power density and robustness. However, motion control technologies of multi-actuator hydraulic systems have faced increasing challenges due to stringent emission regulations. In this study, an overview of the evolution of existing throttling control technologies is presented, including open-center and load sensing controls. Recent advancements in energy-saving hydraulic technologies, such as individual metering, displacement, and hybrid controls, are briefly summarized. The impact of energy-saving hydraulic technologies on dynamic performance and control solutions are also discussed. Then, the advanced operation methods of multi-actuator mobile machineries are reviewed, including coordinated and haptic controls. Finally, challenges and opportunities of advanced motion control technologies are presented by providing an overall consideration of energy efficiency, controllability, cost, reliability, and other aspects.

关键词： motion control     electrohydraulic control     energy efficiency     mobile machineries    

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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    

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标题 作者 时间 类型 操作

A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method

Wu REN, Yunxin WU, Zhaowei ZHANG

期刊论文

Elliptical lobe shape gerotor pump design to minimize wear

Mohammad Reza KARAMOOZ RAVARI

期刊论文

Research and practice on system engineering management of a mobile payment project

Yongkai ZHOU, Hongfeng CHAI

期刊论文

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

Zhiyi YU, Guoyu WANG, Shuliang CAO

期刊论文

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

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

期刊论文

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

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

期刊论文

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

期刊论文

Motion control of multi-actuator hydraulic systems for mobile machineries: Recent advancements and future

Bing XU, Min CHENG

期刊论文

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

Zhenyuan XU, Ruzhu WANG

期刊论文

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

期刊论文

Efficiency characteristics of piezostack pump for linear actuators

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

期刊论文

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

Zongxia JIAO,Tianyi WANG,Liang YAN

期刊论文

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

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

期刊论文

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

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

期刊论文

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

Shilei LU,Yunfang QI,Zhe CAI,Yiran LI

期刊论文