著者

中山 正人 福田 健一 荒木 拓人 恩田 和夫

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.125, no.2, pp.213-220, 2005 (Released:2005-05-01)

参考文献数

16

被引用文献数

3 2

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The secondary batteries for the electric vehicle (EV) generate much heat during rapid charge and discharge cycles, when the EV starts quickly consuming the battery power and stops suddenly recovering the inertia energy. The generated heat increases significantly the cell temperature and causes possibly bad influences on the battery performance and the safely requirement. So we have studied the thermal behavior of nickel/metal hydride (Ni/MH) battery during rapid charge and discharge cycles, applying our previous battery thermal model, which have been confirmed to agree with the experimental results at smaller charge current than the rated current. The heat sources by the entropy change, the hydrogen occlusion and the side reaction have been referred to the published data, and the overpotential resistance and the current efficiency, the ratio of main reaction current to charge current, have been measured experimentally through the rapid charge and discharge characteristics with constant current. By using these data our thermal model for Ni/MH battery has estimated its temperature increase, which agrees well with the measured temperature rise, with the root mean square error of 1.5°C and 2.1°C for charge and discharge cycles, respectively.

著者

朝岡 洸太 和久田 康平 金本 凌 諏訪 秀樹 荒木 拓人

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.22-00325, (Released:2023-03-02)

参考文献数

24

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Various fields, such as the paper industry, chemical engineering, and renewable energy, are faced with gas-liquid two-phase flows and are being studied by visualization and observation. Although it is necessary to quantitatively evaluate the characteristics of bubbles, there is a limitation in the amount of labor required for detection and measurement by human observation of images. There are no examples for bubbles in polymer electrolyte membrane water electrolysis (PEMWE), where the bubbles in PEMWE have heterogeneous backgrounds, unpatterned patterns, and unclear bubble contours. Existing methods for detecting these bubbles are not expected to be accurate enough. In this study, a deep learning-based bubble detection method using convolutional neural networks (CNN) was developed for bubbles in PEMWE. Our method has two novel approaches: first, we developed an algorithm that automatically draws a pseudo-bubble image based on an actual bubble image on an arbitrary background as a method for automatically generating training data for the CNNs. Second, we developed a CNN-based bubble detection method that uses the motion of bubbles, specifically, the difference between the bubble image and the image from one frame ago, as input. Finally, we tested the algorithm on bubble images in a PEMWE and achieved an F1 score of 0.83 or better for all current densities of 0.5, 1, 2, and 3 A/cm2, and an F1 score of 0.844 for the entire detection.

著者

キム スンヨン 杉本 俊樹 荒木 拓人

出版者

一般社団法人 日本機械学会

雑誌

マイクロ・ナノ工学シンポジウム

巻号頁・発行日

vol.2014, pp._21am2-A6--_21am2-A6-, 2014

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Proton exchange membrane fuel cells (PEMFCs) are useful systems because they operate at lower temperatures than other types of fuel cells. This characteristic causes water management issues. To elucidate effects of water on PEMFC performance, we developed a temperature sensor using micro-electro-mechanical systems (MEMS) techniques. This sensor was placed between the catalyst layer (CL) and the microporous layer (MPL) at the cathode. Slight effects on total cell performance were observed with the insertion of the sensor. This sensor can be applicable to typical PEMFCs without any special equipment such as a transparent separator. In-situ measurement with a temperature sensor showed that the maximum temperature rise at the cathode CL (CCL) was about 9 ℃ at 1.1 A/cm^2. The temperature sensor also showed temperature gradients between the ribs and channels. In addition, we developed a capacitance-type humidity sensor and inserted it in the channel. In-situ measurement with a humidity sensor showed a relative humidity (RH) change in the channel.

著者

中山 正人 福田 健一 荒木 拓人 恩田 和夫

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society (ISSN:03854213)

巻号頁・発行日

vol.125, no.2, pp.213-220, 2005-02-01

参考文献数

11

被引用文献数

2 2

---

The secondary batteries for the electric vehicle (EV) generate much heat during rapid charge and discharge cycles, when the EV starts quickly consuming the battery power and stops suddenly recovering the inertia energy. The generated heat increases significantly the cell temperature and causes possibly bad influences on the battery performance and the safely requirement. So we have studied the thermal behavior of nickel/metal hydride (Ni/MH) battery during rapid charge and discharge cycles, applying our previous battery thermal model, which have been confirmed to agree with the experimental results at smaller charge current than the rated current. The heat sources by the entropy change, the hydrogen occlusion and the side reaction have been referred to the published data, and the overpotential resistance and the current efficiency, the ratio of main reaction current to charge current, have been measured experimentally through the rapid charge and discharge characteristics with constant current. By using these data our thermal model for Ni/MH battery has estimated its temperature increase, which agrees well with the measured temperature rise, with the root mean square error of 1.5°C and 2.1°C for charge and discharge cycles, respectively.