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Han Ding,Yan Guozheng,Kuang Shuai,Wang Wei,Zhao Kai 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4
A wireless power transfer (WPT) system based on inductive resonant coupling makes it possible for endoscope micro robot (EMR) to explore intestine noninvasively. However, due to the increased demand for energy in such micro robot system, such as autonomous movement and drug delivery, the small receiving coil (Φ 15 mm × 13 mm) embedded in limited space on micro robot could not supply enough power as expected. To improve the power supply issue, this article proposes a threecoil WPT system for EMRs system. Based on the refl ected impedance theory, the receiving end of three-coil WPT system is analyzed. Then, according to maximum power transfer principle, parameters relative to performance of WPT system have been optimized through simulation. After that, some bench tests are constructed. A good match is found between analysis results and experimental data. By comparing the three-coil PTW and two-coil WPT systems, it has verifi ed that the transmission effi ciency can be increased signifi cantly to 11.2% by optimized three-coil WPT system and the power dissipation of receiving end could be reduced greatly when the micro robot is under a high power consumption, which is more suitable for endoscope micro robot system with limited space.
Zhang, Liyun,Ding, Yuxiao,Koh, Yoobin Esther,Mun, Bongjin Simon,Wu, Kuang-Hsu,Niu, Yiming,Shi, Wen,Zhang, Bingsen Elsevier 2020 Carbon Vol.156 No.-
<P><B>Abstract</B></P> <P>Tuning the fine structure of carbon support is crucial for modifying the metal-support interface (MSI) in order to harvest a high-performance catalysis. Herein, a core–shell sp<SUP>3</SUP>@sp<SUP>2</SUP> nanocarbon (nanodiamond@graphene, ND@G) and a pure sp<SUP>2</SUP> carbon derivative (onion-like carbon, OLC) were applied to support Pd nanoparticles. We found that Pd/ND@G displayed a superior catalytic activity for CO oxidation reaction with a TOF of 2.9 times higher than that of Pd/OLC at 46 °C. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and ambient pressure X-ray photoelectron spectroscopy (AP-XPS) revealed that, different with the Pd/OLC system, a unique interface microstructure was formed in Pd/ND@G, which not only provides a high exposure of active sites, but also enhances the Pd surface reactivity toward oxygen species, thus leading to a superior catalytic activity of Pd/ND@G. Moreover, the temperature-programmed surface reaction (TPSR) results showed that CO oxidation on Pd/ND@G undergoes an unusual termolecular Eley–Rideal (TER) mechanism, which has a lower energy barrier as compared to the traditional Langmuir-Hinshelwood (LH) and ER mechanism.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Numerical investigation of heat transfer characteristics for Subsea Xmas tree assembly
Biao Hu,Hongwu Zhu,Kuang Ding,Fangling Xu,Youjiang Zhang 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11
This study focuses on the heat transfer characteristic of a horizontal subsea Xmas tree assembly at a high spatial resolution. Computationalfluid dynamics (steady Reynolds-averaged Navier-Stokes) in combination with Low Reynolds number modelling (LRNM) isadopted for heat transfer analysis, which has been validated against a full scale underwater gate valve heat transfer experiment with goodagreements. The characteristics of cold sea water flowing through the subsea tree, and of convection heat transfer between the subsea treeand ambient cold water are obtained. The typical “hot spots,” which have high Convection heat transfer coefficient (CHTC) and creategreat large amounts of heat loss, are numerically determined. Under the designed water depth, the effects of installation orientation, seawater velocity, and inner oil temperature on convection heat transfer are investigated as well. Such work is significant for thermal designof the subsea tree to increase structural reliability and flow assurance level.