The Experts below are selected from a list of 24138 Experts worldwide ranked by ideXlab platform
Xiaokang Yang - One of the best experts on this subject based on the ideXlab platform.
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study on the temperature distribution and its effect on self start of large Area proton exchange membrane fuel cells at subzero temperatures
Electrochimica Acta, 2021Co-Authors: Xiaokang Yang, Jiaqi Sun, Shucheng Sun, Zhigang ShaoAbstract:Abstract A rapid and safe cold start is essential for the commercialisation of proton exchange membrane fuel cell (PEMFC) vehicles, and self-start is considered as the optimal way to fulfil this expectation. In this study, the self-start of large-Area PEMFCs is investigated. It is found that there exists a severe temperature distribution nonuniformity along the flow direction during one-way air-supply self-start, and the cold-start capability is limited by the fact that most of the heat is concentrated in the Inlet Area, while less heat is in the outlet Area, which makes it difficult to start at −15°C. To solve this issue, an alternating air-supply strategy is suggested. By applying this strategy, temperature distribution uniformity and cold-start performance are significantly improved. Self-start from −15°C and −20°C can be achieved in 165 s and 142 s with starting voltages of 0.8 V and 0.6 V, respectively. The alternating interval has a negligible impact on start-up time but will affect the temperature distribution and fluctuation. The advantages of alternate air supply are analysed based on the calculation of heat generation and water production. A performance degradation test indicates that cell performance is well preserved after 20 cold starts
Yupeng Yang - One of the best experts on this subject based on the ideXlab platform.
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local degradation in proton exchange membrane fuel cells with dead ended anode
Journal of Power Sources, 2020Co-Authors: Yupeng Yang, Xu Zhang, Liejin Guo, Hongtan LiuAbstract:Abstract The dead-ended anode (DEA) configuration can simplify proton exchange membrane fuel cell (PEMFC) systems and reduce system cost. However, the DEA configuration can also accelerate fuel cell degradation during long-term operations. Understanding the degradation mechanisms is crucial to improve fuel cell durability. In this study, experiments are performed to investigate the local degradation phenomena in PEMFCs during DEA operations. The detailed degradation mechanisms are revealed through various electrochemical analysis. The local polarization curves show that the local fuel cell performance decreases are very non-uniform and the Inlet Area suffers the most severe performance decrease. Electrochemical measurements indicate that the most serious carbon corrosion in catalyst layer occurs near the anode outlet. However, the most severe local membrane degradation is observed near the anode Inlet. Furthermore, we observe that the pressure swing anode supply mode can significantly mitigate fuel cell degradation during DEA operation. The water and gas distributions in the anode are much more uniform with the periodical oscillatory flow under pressure swing mode, reducing local membrane dehydration and avoiding local hydrogen starvation. Thus, both the local membrane degradation and local carbon corrosion are significantly mitigated under the pressure swing mode.
Peiyun Yi - One of the best experts on this subject based on the ideXlab platform.
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in situ measurement of temperature and humidity distribution in gas channels for commercial size proton exchange membrane fuel cells
Journal of Power Sources, 2019Co-Authors: Heng Shao, Linfa Peng, Peiyun YiAbstract:Abstract It is necessary to obtain internal heat and water distribution of proton exchange membrane fuel cells in order to perform water-heat management. Most of the existing works focus on the measurement in small experimental fuel cells, which cannot effectively guide the development of large-Area fuel cells. In this study, an in-situ measurement method using micro-sensors is developed to observe the temperature and relative humidity in a commercial-size fuel cell with parallel flow fields and an active Area of 250 cm2. A sensor array is incorporated into the cathode flow field, and well-designed waterproof and sealing structures protect sensors from liquid water. The sensors are verified with accuracy and response speed. The fuel cell performance and electrochemical impedance spectroscopy under co-flow and counter-flow configurations considering anode gas humidification are investigated. The results show that the temperature distribution is more uneven in the cases with lower output voltage, and the fuel cell performance is significantly affected by the humidity near the air Inlet Area. As current density increases, the relative humidity drops while dew point temperature keeps almost unchanged. The experimental method and analysis are beneficial to the understanding of the water-heat state and optimization of fuel cell stack design.
Rezki Rochmayanti - One of the best experts on this subject based on the ideXlab platform.
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STRUKTUR KOMUNITAS ZOOPLANKTON PADA Inlet Area PERTAMBAKAN KALISODO DESA PADEAN KECAMATAN REJOSO KABUPATEN PASURUAN
SKRIPSI Jurusan Biologi - Fakultas MIPA UM, 2013Co-Authors: Rezki RochmayantiAbstract:ABSTRAK Rochmayanti, Rezki. 2013. Struktur Komunitas Zooplankton Pada Inlet Area Pertambakan Kalisodo Desa Padean Kecamatan Rejoso Kabupaten Pasuruan. Skripsi. Jurusan Biologi FMIPA Universitas Negeri Malang. Pembimbing (I)Drs. Agus Dharmawan, M. Si., (II)Dra. Hawa Tuarita, M. S. Kata Kunci: Zooplankton, Densitas Relatif, Dominansi Relatif, Frekuensi Relatif, Indeks Nilai Penting Pantai di Jawa Timur memiliki tipe pantai landai, banyak muara sungai serta adanya hutan bakau sehingga kawasan pesisirnya banyak dimanfaatkan oleh masyarakat untuk budidaya ikan dengan sistem pertambakan tradisional. Sistem pertambakan di Pasuruan khususnya Kecamatan Rejoso juga merupakan sistem pertambakan tradisional. Tambak tradisional mengandalkan pakan alami berupa zooplankton maupun fitoplankton sehingga air yag masuk ke tambak sangat mennetukan produktivitas tambak. Tujuan dari penelitian ini adalah untuk mengetahui struktur komunitas zooplankton pada Inlet Area pertambakan Kalisodo Desa Padean Kecamatan Rejoso Kabupaten Pasuruan serta hubungan faktor abiotik yang berpengaruh terhadap struktur komunitas zooplankton. Penelitian ini merupakan penelitian deskripstif eksploratif dengan pendekatan kuantitatif tentang perhitungan kerapatan, kelimpahan, frekuensi dan indeks nilai penting. Pengambilan data dilakukan pada bulan Februari 2012, yang berlokasi pada Inlet Area pertambakan Kalisodo Desa Padean Kecamatan Rejoso Kabupaten Pasuruan. Pengambilan sampel dilakukan menggunakan jaring plankton dengan diameter 25cm dan mata jala ukuran 200 mesh/inchi atau 5 mikron.Untuk melihat perbedaan densitas, dominansi, dan indeks nilai penting dari Inlet satu dengan yang lain menggunakan uji Anava, jika ada beda nyata dilanjutkan dengan uji Duncan.Untuk menghitung pengaruh faktor abiotik yang berpengaruh terhadap nilai penting dihitung dengan anava sekaligus regresi ganda. Hasil dari penelitian ini ditemukan 26 spesies dari 13 stasiun pengambilan sampel pada Inlet Area pertambakan Kalisodo Desa Padean Kecamatan Rejoso Kabupaten Pasuruan yaitu Nauplius copepod, Nauplius balanus, Brachionus plicatilis, Brachionus pala, Brachionus sp, Brachionus caliclyflorus, Brachionus falcatus, Platyas polyacanthus, Platyas quadricormis, Platyas patulus, Obelia sp, Keratella serrulata, Cyclops sp, Diaptomus minute, Pompholyx sulcata, Alona bicolor, Cladocera, Nereis sp, Balanus Amphitrite, Arcella sp, Favella sp, Philodina roseola, Eucyclop agilis, Filinia terminalis, Globigerina sp, Ceriodaphnia quadrangular. Indeks Nilai penting tertinggi pada stasiun 1,2,3 adalah Nauplis copepod sedangkan stasiun 4 hingga 13 adalah Brachionus sp dan Brachionus falcatus. Faktor abiotik yang paling berpengaruh terhadap struktur komunitas adalah salinitas
Zhigang Shao - One of the best experts on this subject based on the ideXlab platform.
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study on the temperature distribution and its effect on self start of large Area proton exchange membrane fuel cells at subzero temperatures
Electrochimica Acta, 2021Co-Authors: Xiaokang Yang, Jiaqi Sun, Shucheng Sun, Zhigang ShaoAbstract:Abstract A rapid and safe cold start is essential for the commercialisation of proton exchange membrane fuel cell (PEMFC) vehicles, and self-start is considered as the optimal way to fulfil this expectation. In this study, the self-start of large-Area PEMFCs is investigated. It is found that there exists a severe temperature distribution nonuniformity along the flow direction during one-way air-supply self-start, and the cold-start capability is limited by the fact that most of the heat is concentrated in the Inlet Area, while less heat is in the outlet Area, which makes it difficult to start at −15°C. To solve this issue, an alternating air-supply strategy is suggested. By applying this strategy, temperature distribution uniformity and cold-start performance are significantly improved. Self-start from −15°C and −20°C can be achieved in 165 s and 142 s with starting voltages of 0.8 V and 0.6 V, respectively. The alternating interval has a negligible impact on start-up time but will affect the temperature distribution and fluctuation. The advantages of alternate air supply are analysed based on the calculation of heat generation and water production. A performance degradation test indicates that cell performance is well preserved after 20 cold starts