http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yang Guogang,Wang Hao,Su Fengmin,Li Shian,Zhang Guoling,Sun Juncai,Shen Qiuwan,Jiang Ziheng,Liao Jiadong,Chen Pengyu 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.7
Proton exchange nembrane fuel cells (PEMFCs) are highly promising energy devices for future transportation and distributed power stations. The electrochemical performance of PEMFCs assembled with gas diffusion layer (GDL) of different porosity gradient distributions has been analyzed using the lattice Boltzmann method. A single-phase multi-component lattice Boltzmann model employing the active approach was developed to investigate the reactive gas flow within the GDL. Two types of GDLs with the same porosity, namely multilayer porosity gradient GDLs and linear porosity gradient GDLs, were generated to investigate the effect of the porosity gradient of the GDL on the electrochemical performance of PEMFC. The results show that the two types of porosity gradient GDL improve oxygen starvation problems and enhance water management, and that the GDLs with smaller porosity gradients can increase the mean current density. This paper develops the study of pore-scale analysis of PEMFC performance and can provide guidance for the design of GDL structures.
Yang Guogang,Liao Jiadong,Shen Qiuwan,Li Shian,Jiang Ziheng,Wang Hao,Li Zheng,Zhang Guoling,Huang Naibao 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.7
Droplet purging in the gas diffusion layer (GDL) is the key to improving the performance of proton exchange membrane fuel cells (PEMFCs). Lattice Boltzmann method (LBM) is used to study the dynamic behavior of multiple droplets randomly distributed in the GDL under air purging. The GDL is randomly reconstructed. The effects of rib width, initial water content, contact angle and air velocity are studied. By analyzing the dynamic distribution of droplets in the GDL and the change of the remaining water content with time, it is found that the droplets are only a small amount under the rib and accumulated mostly on both sides of the GDL at stabilization, which is caused by the large velocity under the rib. The residual water content in the GDL increases with the increase of the initial water content, and decreases with the increase of the rib width, contact angle and air velocity. However, when the rib to channel width ratio exceeds 1, the improvement of purging effect is not obvious, the purging time increases significantly, and the increase of air velocity does not help much to remove the droplets accumulated on both sides of the GDL.
Qiuwan Shen,Naibao Huang,Guogang Yang,Shian Li,Jinliang Yuan 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.2
SrCo0.8Fe0.2O3-δ (SCF) nanopowders have been successfully synthesized by rapid microwave-assisted sol-gel combustion(MWSG) method. For comparison, SCF were also synthesized by conventional heating synthesis method: liquid citrate sol-gelcombustion (LC) method and EDTA sol-gel combustion (EDTA) method. All obtained samples were characterized by X-raydiffraction (XRD), environmental scanning electron microscopy (ESEM) analyses and specific surface area (BET) analyses. The results shows that SCF182 prepared by MWSG method showed the greatest oxygen production properties with smallestparticle size and largest surface are compared to those synthesized by LC and EDTA methods. Moreover, the SCF synthesizedvia MWSG method showed excellent cyclic performance after cycles. Thus, MWSG is a novel, time saving, energy-efficientand promising method to synthesize SCF perovskites. The MWSG reported in this paper is expected to be extended to thepreparation of other perovskite nano-powders.
Shian Li,Zhiyu Yao,Facai Yang,Guogang Yang,Qiuwan Shen 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.4
Methane steam reforming (MSR) reaction is a promising industrial hydrogen production technology. Mg-Ni/CeO2 catalysts atdifferent Mg/Ni ratios of 6/4, 7/3, 8/2 and 9/1 with total loading of 10 wt% were used as catalysts for hydrogen production. The characterization techniques such as XRD, SEM and EDS were carried out on fresh and spent samples. Results showedthat the optimum Mg addition content for Mg/Ni-CeO2 is 2%. The process optimization of reaction parameters wereconducted by evaluating the catalytic activity. The stability of optimal Mg-Ni/CeO2 catalyst at 700 oC is examined for 8 h onstreamreaction. It reveals that Mg/Ni-CeO2 still maintains a relatively high catalytic activity after 8 h stability test.
Ma Yanyan,Zhang Weida,CHENGSHAOBO,Yang Wanting,Liu Yuxing,Yang Shengyu,Zhang Xinling,Guo Minrui,Chen Guogang 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.6
Prunus domestica L. cv. Ximei fruit perishes quickly due to intense metabolic activity after being harvested. To prolong shelf life and maintain fruit quality, the eff ects of 1-methylcyclopropene (1-MCP) treatment on P. domestica fruit during storage at 4 ± 1 °C were investigated. The results showed that the soluble solid content (SSC), respiratory rate (29.8%), ethylene production (27.2%), anthocyanin content, malonaldehyde content (MDA), hydrogen peroxide content (H 2O2), and superoxide anion activity (O 2·−) of P. domestica fruit were all signifi cantly reduced by 1-MCP treatment (1.0 μL L −1), while the content of ascorbic acid and total phenol, and the activity of SUPEROXIDE DISMUTASE (SOD, 61.3%), CATALASE (CAT, 39.0%), ASCORBATE PEROXIDASE (APX, 23.7%), and PEROXIDASE (POD, 38.0%) increased compared to untreated fruit after 35 days of cold storage. Overall, 1-MCP treatment could maintain high postharvest quality and anti- oxidant activity in P. domestica fruit
Qiuwan Shen,Zicheng Shao,Yuhang Jiang,Shian Li,Guogang Yang,Naibao Huang,Xinxiang Pan 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.5
The oxyfuel combustion process is used as a potential technique to CO2 capture and the oxygen carries play a crucial role ofthis technology. Ba-Co based perovskites are promising materials to producing O2/CO2 gas for oxyfuel combustion. In thisstudy, perovskite oxides BaCo0.8M0.2O3-δ (M = Ce, Al, Fe, Cu) were prepared via an EDTA sol-gel method. Scanning electronmicroscope (SEM) was used to study the surface morphology and structure of the fresh and the used perovskite powders. Oxygen adsorption/desorption experiments were carried out in a fixed-bed system; and the oxygen desorption property ofBaCo0.8Ce0.2O3-δ was studied in details. The oxygen production amount of 1g BaCo0.8Ce0.2O3-δ perovskite powders can reach101.07 mg after one adsorption and desorption cycle. SEM results showed that the fresh samples had a porous structure;however the particles were covered by impurities after cycles due to the sintering. Experiments results indicated that theoptimal desorption temperature is 850oC. The optimal volume flow rate of carbon dioxide and partial pressures of carbondioxide were determined to be 200 ml·min1, 100% CO2 partial pressure, respectively. Furthermore, the results of cyclicperformance indicate that BaCo0.8Ce0.2O3-δ perovskite powder shows high cyclic stability for producing O2-enriched CO2stream.
Shian Li,Rongqiang Wei,Yuhang Jiang,Qiuwan Shen,Guogang Yang,Naibao Huang 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.1
Oxy-fuel combustion is one of the proposed technologies which have the potential to achieve a zero CO2 emission. To enhancethe oxygen production performance of the oxygen carrier, different LaBO3-δ (B=Co, Ni, Fe, Cr) and metal oxide (CeO2, Al2O3,ZrO2) supported BaCoO3-δ perovskites have been successfully synthesized by the EDTA sol-gel method and further applied forproducing oxygen. The oxygen desorption/production performance of synthesized perovskites were studied in a fixed-bedreactor system. Furthermore, the effects of H2O and air as regeneration gas of metal oxide supported BaCoO3-δ perovskiteoxygen carrier were investigated in detail. Results shows that the oxygen desorption amount of different B-site substitutedLaBO3-δ (B=Co, Ni, Fe, Cr) perovskites decrease in the order of LaNiO3-δ > LaCoO3-δ > LaCrO3-δ > LaFeO3-δ.While comparedwith pure BaCoO3-δ and different metal oxide supported BaCoO3-δ, CeO2 supported BaCoO3-δ features higher productionamount of oxygen. Multiple cycles demonstrated that BaCoO3/CeO2 displays higher stability and regeneration capacity, whichis the key factor to provide stable O2/CO2 gas stream for oxyfuel combustion application. In short, the novel BaCoO3/CeO2oxygen carrier developed in this work exhibits high oxygen desorption capacity and stability. In addition, it provides apromising potential for oxygen production in industrial application.
Weiqiang Kong,Qiuwan Shen,Jiadong Liao,Ziheng Jiang,Naibao Huang,Guogang Yang,Shian Li 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.2
A three-dimensional numerical model of a methanol steam reforming micro-channel reactor for hydrogen production based onCu/ZnO/Al2O3 catalyst was established. The effects of different inlet mass flow rate, reaction temperature and steam to carbonratio (S/C) on the mass change of each component, chemical reaction rate and hydrogen production performance of microchannelreformer were studied. The results show that with the increase of inlet mass flow rate, the mass fraction of CH3OH atthe outlet of reforming channel increases gradually, and the methanol conversion rate decreases gradually. The mass fractionof CO at the outlet of reforming channel decreases gradually, and the CO selectivity decreases gradually. With the increase ofreaction temperature, the mass fraction of CH3OH at the outlet of reforming channel decreases gradually, and the methanolconversion rate increases. The mass fraction of CO at the outlet of reforming channel increases rapidly, and the CO selectivityincreases rapidly. With the increase of S/C, the methanol conversion rate increased and the CO selectivity decreased. In thisstudy, the influence of reaction conditions on methanol reformer was obtained, and the reasons behind it were clarified, whichprovided more valuable insights for the operating conditions of hydrogen production from MSR.