Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 20

年份

2023 1

2022 1

2020 1

2018 2

2016 1

2015 1

2013 2

2012 2

2010 1

2009 3

2008 1

2007 2

2006 1

2005 1

展开︾

关键词

DX桩 2

Lagrange方程 1

上限法 1

传热过程 1

伺服驱动 1

切削碾压 1

大型多支承 1

封盖 1

工艺 1

强化效应 1

托轮偏斜 1

承载力 1

挤扩 1

接触应力 1

施工 1

旋挖挤扩 1

旋挖挤扩灌注桩 1

旋挖钻机 1

旋转倒立摆 1

展开︾

检索范围：

排序：展示方式：

Effectiveness analysis and optimum design of the rotary regenerator for thermophotovoltaic (TPV) system

Xi WU, Hong YE, Jianxiang WANG, Jie HE, Jian YANG

《能源前沿（英文）》 2012年第6卷第2期页码 193-199 doi: 10.1007/s11708-012-0184-z

摘要： The influence of the period of rotation on the effectiveness of the thermophotovoltaic (TPV) rotary regenerator was theoretically and experimentally investigated. It was found that the deviations of the theoretical results from the experimental ones decrease with the increase of the period of rotation. To the TPV system of 10 kW combustion power, the deviation is 3.5% when the rotation period is 3 s; while the deviation decreases to 1.5% when the rotation period increases to 15 s. The deviation could be mainly attributed to the cold and hot fluids carryover loss which was not considered in the model. With a new model taking account of the carryover loss established, the predicted results were greatly improved. Based on the modified model, the influence of geometrical parameters of rotary regenerator on the effectiveness was analyzed for TPV systems of various combustion power. The results demonstrate that the effectiveness increases with the increase of the rotary regenerator diameter and height, while fluid carryover loss increases at the same time, which weakens the impact of geometrical parameters.

关键词： thermophotovoltaic (TPV) system rotary regenerator effectiveness carryover loss

HTML PDF 收藏

Comparative study of oscillating flow characteristics of cryocooler regenerator at low temperatures

Yonglin JU , Qingqing SHEN ,

《能源前沿（英文）》 2009年第3卷第1期页码 80-84 doi: 10.1007/s11708-009-0008-y

摘要： A brief review is presented on previous experimental results and correlations on the friction factor of cryocooler regenerators operating at oscillating flow and pulsating pressure conditions, for different mesh sizes of packed woven screens, focusing on the effects of different operating frequencies ranging from 20 to 80 Hz, at room and cryogenic temperatures. A comparison of the friction factor data with those of other studies is presented to clarify the reason for the difference. Finally, a new oscillating flow correlation of regenerators, in terms of several non-dimensional parameters, is discussed and compared.

关键词： friction factor regenerator oscillating flow high frequency

HTML PDF 收藏

Soybean drying characteristics in microwave rotary dryer with forced convection

Ruifang WANG, Zhanyong LI, Yanhua LI, Jingsheng YE

《化学科学与工程前沿（英文）》 2009年第3卷第3期页码 289-292 doi: 10.1007/s11705-009-0022-y

摘要： A new hybrid drying technique by combining microwave and forced convection drying within a rotary drum, i.e., microwave rotary drying, was developed with the purpose to improve the uniformity of microwave drying. In a laboratory microwave rotary dryer, rewetted soybean was utilized as experimental material to study the effects of drum rotating speed, ventilation flow rate, and specific microwave power on the drying kinetics and cracking ratio of soybean. It was found that, with rotation, the cracking ratio can be lowered but without distinct improvement in the drying rate. Increasing ventilation flow rate and specific microwave power can improve the drying rate, but the cracking ratio also increases as a negative result. The cracking ratio lower than 10% can be attained for ventilation flow rate lower than 2.0 m ·h or specific microwave energy lower than 0.4 kW·kg in the present experiments.

关键词： cracking microwave rotary drying soybean

HTML PDF 收藏

Design and analysis of a new high frequency double-servo direct drive rotary valve

Muzhi ZHU,Shengdun ZHAO,Jingxiang LI

《机械工程前沿（英文）》 2016年第11卷第4期页码 344-350 doi: 10.1007/s11465-016-0406-x

摘要：

Researchers have investigated direct drive valve for many years to solve problems, such as fluid force imbalance and switching frequency. The structure of the rotary valve has received considerable research interest because of its favorable dynamic properties and simple structure. This paper studied the high frequency double-servo direct drive rotary valve (DDRV), and proposed a novel structure and drive method satisfying high reversing frequency and adequate quantity of flow. Servo motors are integrated into the valve by the innovative structure, which is designed to equilibrate the unbalanced radial fluid force with the symmetric distributed oil ports. Aside from the fast reversing function of the valve, the DDRV presented high performance in linearity of the flow quantity and valve opening as a result of the fan-shaped flow ports. In addition, a computational fluid dynamics (CFD) method based on Fluent was conducted to verify the flux regulation effect of the height change of the adjustable boss.

关键词： direct drive rotary valve computational fluid dynamics (CFD) flow regulation

HTML PDF 收藏

DX挤扩灌注桩技术在铁路桥梁工程中的应用

张德华,王梦恕

《中国工程科学》 2009年第11卷第7期页码 92-96

摘要：

DX桩是近年来新兴的一种变截面新桩型。是在钻孔灌注桩的基础上，使用专用挤扩设备在桩底和桩身挤扩成为支盘状，然后浇灌混凝土后形成的桩身、分承力盘和桩根共同承载的桩型。DX桩可较大幅度提高单桩承载力。试验表明单桩承载力比同等条件下的直孔灌注桩提高80 %以上。DX桩可在粘性土、粉土、砂土层、强风化岩、残积土中挤扩承力盘，也可在卵砾石层的上层面挤扩成盘，更适宜在粘性土、粉土或砂土交互分层的地基中使用。DX桩的桩身直径可为400～2 000 mm,桩长可达60多米。是一种值得推广应用的新桩型，已在高层建筑、公路桥

关键词： DX桩旋挖挤扩灌注桩承载力

HTML PDF 收藏

Performance of rolling piston type rotary compressor using fullerenes (C70) and NiFe

Ruixiang WANG,Yihao ZHANG,Yi LIAO

《能源前沿（英文）》 2020年第14卷第3期页码 644-648 doi: 10.1007/s11708-017-0453-y

摘要： A novel way for a compressor to improve its coefficient of performance was proposed in this paper. Fullerenes (C70) and NiFe O nanocomposites were modified by span 80 and dispersed in refrigeration oil by solid grinding (SG). Besides, the tribological properties of the nanocomposites were investigated using a four ball friction tester. The results show that when the mass concentration of fullerenes nanocomposite is higher than 60 ppm and the concentration of nano-oil is 2 g/L, the friction coefficient decreases from 0.13 to 0.06 which means the wear is reduced. The coefficient of performance of the compressor under the air conditioning test condition can be raised by 1.23%.

关键词： rotary compressor friction coefficient nanocomposite materials coefficient of performance fullerenes (C70)

HTML PDF 收藏

Co-pyrolysis of sludge and kaolin/zeolite in a rotary kiln: Analysis of stabilizing heavy metals

《环境科学与工程前沿（英文）》 2022年第16卷第7期 doi: 10.1007/s11783-021-1488-1

摘要：

• Adding kaolin/zeolite promotes the formation of stable heavy metals.

关键词： Co-pyrolysis Sewage sludge Heavy metals Rotary kiln Immobilization mechanism

HTML PDF 收藏

Novel precision piezoelectric step rotary actuator

LIU Jianfang, YANG Zhigang, ZHAO Hongwei, CHENG Guangming

《机械工程前沿（英文）》 2007年第2卷第3期页码 356-360 doi: 10.1007/s11465-007-0062-2

摘要： A novel piezoelectric (PZT) precision step rotary actuator was developed on the basis of PZT technology. It adopts the principle of bionics and works with an inside anchoring/loosening of the stator and a distortion structure of the uniformly distributed thin flexible hinge to solve problems such as ineffective anchoring/loosening, low step rotary frequency, small travel, poor resolution, low speed and unsteady output. The developed actuator is characterized by high frequency (30 Hz), high speed (380 μrad/s), large travel (>270º), high resolution (1 μrad/step), and work stability. It greatly improves the ability to drive the existing PZT step rotary actuator. The new actuator can be applied in the field of micromanipulation and precision engineering, including precision driving and positioning and optics engineering.

关键词： developed stability ineffective anchoring/loosening technology piezoelectric

HTML PDF 收藏

Modeling and analysis of steady-state vibration induced by backlash in servo rotary table

Xiao YANG,Dun LU,Sanli LIU,Jun ZHANG,Wanhua ZHAO

《机械工程前沿（英文）》 2015年第10卷第1期页码 43-47 doi: 10.1007/s11465-015-0327-0

摘要：

Backlash cannot be always avoided in mechanical systems because of wear or looseness. Steady-state vibration may be induced by backlash in closed loop feed drive systems. This paper presents a mathematical model of a servo rotary table, considering the effect of backlash. The accuracy of this model is verified by an experiment. The influences of the parameters, such as position controller gain, velocity controller gain, load and the magnitude of backlash, on steady-state vibration are discussed. The steady-state vibration amplitude increases with the position controller gain, load and the magnitude of backlash. The steady-state vibration frequency increases with the position controller gain and the velocity controller gain, while an increase in load leads to a decrease in the frequency.

关键词： backlash servo rotary table steady-state vibration

HTML PDF 收藏

旋挖钻机施工钻孔灌注桩的工艺研究

李林,闵峰

《中国工程科学》 2010年第12卷第4期页码 33-36

摘要：

泰州大桥夹江左汊桥主跨采用87.5 m+3×125 m+87.5 m的五跨连续梁桥，水中主墩基础采用-2.0 m桩径的钻孔灌注桩,最大设计桩长为94 m，采用旋挖钻机施工。文章结合泰州大桥的施工实例，阐述了旋挖钻机成孔的工艺原理，按照工艺流程，重点叙述了泥浆配置、安装钻孔、钻机钻进等工艺，并重点总结了旋挖钻机施工钻孔桩的施工特点，为今后类似工程施工提供了借鉴。

关键词：旋挖钻机施工钻孔灌注桩工艺特点

HTML PDF 收藏

general parameterized time--frequency transform and its application in the feature extraction of a rotary

Peng ZHOU, Zhike PENG, Shiqian CHEN, Yang YANG, Wenming ZHANG

《机械工程前沿（英文）》 2018年第13卷第2期页码 292-300 doi: 10.1007/s11465-017-0443-0

摘要：

With the development of large rotary machines for faster and more integrated performance, the condition monitoring and fault diagnosis for them are becoming more challenging. Since the time-frequency (TF) pattern of the vibration signal from the rotary machine often contains condition information and fault feature, the methods based on TF analysis have been widely-used to solve these two problems in the industrial community. This article introduces an effective non-stationary signal analysis method based on the general parameterized time–frequency transform (GPTFT). The GPTFT is achieved by inserting a rotation operator and a shift operator in the short-time Fourier transform. This method can produce a high-concentrated TF pattern with a general kernel. A multi-component instantaneous frequency (IF) extraction method is proposed based on it. The estimation for the IF of every component is accomplished by defining a spectrum concentration index (SCI). Moreover, such an IF estimation process is iteratively operated until all the components are extracted. The tests on three simulation examples and a real vibration signal demonstrate the effectiveness and superiority of our method.

关键词： rotary machines condition monitoring fault diagnosis GPTFT SCI

HTML PDF 收藏

Impact drive rotary precision actuator with piezoelectric bimorphs

ZHANG Hongzhuang, ZENG Ping, HUA Shunming, CHENG Guangming, YANG Zhigang

《机械工程前沿（英文）》 2008年第3卷第1期页码 71-75 doi: 10.1007/s11465-008-0008-3

摘要： An impact drive rotary precision actuator with end-loaded piezoelectric cantilever bimorphs is proposed. According to finite element analysis and experiments of the dynamic characteristics of end-loaded piezoelectric cantilever bimorphs, a specific fixed-frequency and adjustable-amplitude is confirmed to control the actuator. The results show that an actuator excited by fixed-frequency and the adjustable-amplitude ramp voltage waveform works with a large travel range (180°), high resolution (1 ?rad), speed (0.2 rad/min) and heavy-load ability (0.02 Nm). With advantages of high-precision positioning ability, simple structure and only one percent the cost of traditional impact drive mechanisms, the actuator is expected to be widely used in precision industries.

关键词： specific fixed-frequency waveform piezoelectric cantilever mechanisms adjustable-amplitude

HTML PDF 收藏

交流伺服直驱式旋锻机的动力学理论研究

宋涛,赵升吨,闫观海,刘红宝

《中国工程科学》 2013年第15卷第1期页码 63-67

摘要：

提出了高速伺服直驱式旋锻机结构，分析设计了基于摆线运动曲线的锤头轮廓曲线，采用上限法确定了旋锻机在极限工况下的最大输出载荷上限的变化规律。研究表明，随着进料角的增大，锻机负载有所降低，但同时工件需要更大的推进力，因此实际中采用的进料角的范围为5°~15°。

关键词：旋转锻造伺服驱动上限法

HTML PDF 收藏

多目标自适应优化模型预测控制——降低氧化锌回转窑的碳排放 Article

Ke Wei, Keke Huang, Chunhua Yang, Weihua Gui

《工程（英文）》 2023年第27卷第8期页码 96-105 doi: 10.1016/j.eng.2023.01.017

摘要：

The zinc oxide rotary kiln, as an essential piece of equipment in the zinc smelting industrial process, is presenting new challenges in process control. China's strategy of achieving a carbon peak and carbon neutrality is putting new demands on the industry, including green production and the use of fewer resources; thus, traditional stability control is no longer suitable for multi-objective control tasks. Although researchers have revealed the principle of the rotary kiln and set up computational fluid dynamics (CFD) simulation models to study its dynamics, these models cannot be directly applied to process control due to their high computational complexity. To address these issues, this paper proposes a multi-objective adaptive optimization model predictive control (MAO-MPC) method based on sparse identification. More specifically, with a large amount of data collected from a CFD model, a sparse regression problem is first formulated and solved to obtain a reduction model. Then, a two-layered control framework including real-time optimization (RTO) and model predictive control (MPC) is designed. In the RTO layer, an optimization problem with the goal of achieving optimal operation performance and the lowest possible resource consumption is set up. By solving the optimization problem in real time, a suitable setting value is sent to the MPC layer to ensure that the zinc oxide rotary kiln always functions in an optimal state. Our experiments show the strength and reliability of the proposed method, which reduces the usage of coal while maintaining high profits.

关键词： Zinc oxide rotary kiln Model reduction Sparse identification Real-time optimization Model predictive control Process control

HTML PDF 收藏

Exergy analysis and simulation of a 30MW cogeneration cycle

Nikhil Dev, Samsher, S. S. Kachhwaha, Rajesh Attri

《机械工程前沿（英文）》 2013年第8卷第2期页码 169-180 doi: 10.1007/s11465-013-0263-9

摘要：

Cogeneration cycle is an efficient mean to recover the waste heat from the flue gases coming out of gas turbine. With the help of computer simulation, design parameters may be selected for the best performance of cogeneration cycle. In the present work a program is executed in software EES on the basis of mathematical modelling described in paper to study cogeneration cycle performance for different parameters. Results obtained are compared with the results available in literature and are found in good agreement with them. Real gas and water properties are inbuilt in the software. Results show that enthalpy of air entering the combustion chamber is higher than that of the flue gases at combustion chamber outlet. For different operative conditions, energy and exergy efficiencies follow similar trends; although, exergy efficiency values are always lower than the corresponding energy efficiency ones. From the results it is found that turbine outlet temperature (TIT) of 524°C is uniquely suited to efficient cogeneration cycle because it enables the transfer of heat from exhaust gas to the steam cycle to take place over a minimal temperature difference. This temperature range results in the maximum thermodynamic availability while operating with highest temperature and highest efficiency cogeneration cycle. Effect of cycle pressure ratio (CR), inlet air temperature (IAT) and water pressure at heat recovery steam generator (HRSG) inlet on the 30 MW cogeneration cycle is also studied.

关键词： Cogeneration cycle air compressor HRSG gas turbine regenerator CR IAT