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Boiling of Water Droplet in Glass-Oil-Water multiphase System

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SSRN 2022年

作者： He, Xiaotian Cheng, Yiwei Xu, Jinliang Yu, Xiongjiang Xie, Jian Ma, Xiaojing Ren, Yong Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization North China Electric Power University Beijing102206 China Key Laboratory of Power Station Energy Transfer Conversion and System of Ministry of Education North China Electric Power University Beijing102206 China Research Group for Fluids and Thermal Engineering University of Nottingham Ningbo China Ningbo315100 China

Boiling of a volatile droplet in a non-volatile liquid becomes complex due to various interface interactions in a solid-liquid-liquid system. Available studies reported explosive boiling and attributed the phenomenon to heterogeneous nucleation due to solid-liquid contact. Here, we investigate boiling of ~2 mm diameter water droplet in a silicon oil pool with glass container. Two transition temperatures are observed, with one as the transition from evaporation to boiling (122.5 o C), and the other as the transition from bubble growth in oil side to that in both oil and water side (160.0 o C). Correspondingly, four boiling modes of evaporation (E), boiling in water (BIW: bubble nucleation at glass-water interface and growth inside drop), boiling in oil (BIO: nucleation at oil-water interface and growth in oil), and boiling in oil and water (BIOW: nucleation at oil-water interface and growth in oil and water), are identified. For the first time, boiling bifurcation is found for drop boiling in a three-phase system. For oil temperature T b in the range of (122.5~160.0) o C, boiling mode switches in between BIW and BIO. On the contrary, for T b beyond of 160.0 o C, either BIW or BIOW occurs. This bifurcation is explained by the fact that a droplet prefers to choose smaller activation energy between that for bubble nucleation at solid-water interface and that for bubble nucleation at oil-water interface. Interfacial instabilities are analyzed to explain why BIOW boils more violently than BIW. Our work presents a comprehensive understanding of droplet boiling in the three-phase system. © 2022, The Authors. All rights reserved.

关键词： Bifurcation (mathematics)

Mxene-Derived Ni/Tio2-X/Ti3c2 Catalyst for Enhanced Photothermal Co2 Methanation: Unraveling the Roles of Photoexcited Carriers

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SSRN 2025年

作者： Sun, Fan Xin, Yu Xing, Xueli Lou, Jiahui Wang, Qiliang Hong, Hui International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China School of Aeronautics and Astronautics University of Chinese Academy of Sciences Beijing100049 China Huaneng Clean Energy Research Institute Beijing102209 China Shandong Institute of Advanced Technology Jinan250100 China Department of Architecture and Built Environment University of Nottingham NottinghamNG7 2RD United Kingdom Institute of Engineering Thermophysics China

Photothermal catalysis has emerged as a promising approach for CO2 conversion, which combines photo and thermal energy to drive catalytic reactions efficiently. While light can lower activation barriers and enhance reaction rates, the interplay between light and heat within the catalytic framework remains largely unexplored. In this study, we investigate the critical role of photoexcited carriers in enhancing catalytic performance under solar irradiation, unraveling their contribution to the CO2-to-CH4 conversion process. A multilayer accordion-like Ni/TiO2-x/Ti3C2 catalyst, which exhibits excellent photothermal and photoelectric response characteristics was fabricated for efficient photothermal CO2 methanation. Experimental results demonstrated that introduction of light during thermal catalysis markedly enhanced the CO2 conversion rate, with a 55% increase achieved at 275 ºC. Furthermore, the required temperature for maximum CO2 conversion rate was reduced by 50 ºC compared to the thermal-driven process. Meanwhile, the effects of concentrated ratio and incident wavelength on CO2 conversion were also examined, revealing a synergistic effect between photogenerated carriers and thermal energy. Further characterizations, including steady-state and transient photoluminescence spectroscopy, in-situ XPS, in-situ EPR, in-situ DRITFs, were employed to elucidate the enhancement mechanisms of photogenerated carriers in the catalytic reaction. At the same time, an outdoor experimental prototype was developed to verify the feasibility of photogenerated carrier-thermal synergistically driven CO2 methanation. The findings provide valuable insights into the role of photo-generated carriers in photothermal CO2 methanation, offering new perspectives for the design of efficient photothermal catalysts and advancing solar catalytic CO2 conversion technologies. © 2025, The Authors. All rights reserved.

关键词： Methanation

Experimental and modeling study of low temperature ignition characteristics of methylcyclohexane/ethanol binary fuel 12

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Experimental and modeling study of low temperature ignition ...

12th Asia-Pacific Conference on Combustion, ASPACC 2019

作者： Liu, Yang Tang, Chenglong Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China

The purpose of this work is to investigate the effect of ethanol blending into methylcyclohexane during the ignition at low temperatures. The ignition delay times of the binary fuels with ethanol blending ratio varied from 0% to 100% at = 1.0, Pc = 20 bar, Tc = 680 - 890 K were measured with the rapid compression machine, and the mechanism of Bissoonauth et al. (Proc Combust Inst 2018) well predicts the experimental results. Based on the high quality of the model, the effects of ethanol blending on the pressure and heat release are studied. Both of the maximum pressure and the heat release during the ignition decrease with the ethanol blending ratio increases. The interaction of MCH and ethanol happens in the competition of active radicals like OH, and MCH dominates the ignition process as it occupies about two thirds of the OH to form the fuel radical. © Asia-Pacific Conference on Combustion, ASPACC *** right reserved.

关键词： Ethanol

Corrigendum to ‘Experimental investigation of the microlayer and dry spot dynamic characteristics in a small channel flow boiling by laser interferometry method’ [International Journal of Heat and Mass Transfer 201 (2023) 123585]

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International Journal of Heat and Mass Transfer 2023年 209卷

作者： Zhong-Xiang Shen Ming Gao Wu-han Dong Li-xin Zhang Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China

Thermal management matters in photovoltaic–electrocatalysis for solar hydrogen production

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EcoEnergy

EcoEnergy 2024年

作者： Jie Chen Xin Chen Jie Sun Jingkuo Qu Xiangjiu Guan Shaohua Shen School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China

Photovoltaic–electrolysis (PV-EC) system currently exhibits the highest solar to hydrogen conversion efficiency (STH) among various technical routes. This perspective shifts the focus from the materials exploration in photovoltaics and electrolysis to the critical aspect of thermal management in a PV-EC system. Initially, the theoretical basis that elucidates the relationships between temperature and the performance of both photovoltaics and electrolyzers are presented. Following that, the impact of thermal management on the performance of PV-EC for solar hydrogen production is experimentally demonstrated by designing variables-controlling experiments. It is observed that while utilizing identical PV and EC cells under varying thermal conditions, the highest STH can reach 22.20%, whilst the lowest is only 15.61%. This variation underscores the significance of thermal management in optimizing PV-EC systems. Finally, increased efforts to enhancing heat transfer and optimizing heat distribution are proposed, thus facilitating the design of more efficient PV-EC systems with minimized thermal energy losses.

关键词： device design photovoltaic-electrolysis solar to hydrogen thermal management water electrolyzer

Surface sulfurization activating hematite nanorods for efficient photoelectrochemical water splitting

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Science Bulletin 2019年第17期64卷 1262-1271页

作者： Lianlian Mao Yu-Cheng Huang Yanming Fu Chung-Li Dong Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China Department of Physics Tamkang University Tamsui 25137 Taiwan China

Surface treatment is an effective method to improve the photoelectrochemical(PEC) performance of photoelectrodes. Herein, we introduced a novel strategy of surface sulfurization to modify hematite(a-Fe2 O3)nanorods grown in an aqueous solution, which triggered encouraging improvement in PEC *** comparison to the solution-grown pristine a-Fe2 O3 nanorod photoanode that is PEC inefficient and always needs high temperature(>600 °C) activation, the surface sulfurized a-Fe2 O3 nanorods show photocurrent density increased by orders of magnitude, reaching 0.46 mA cmà2 at 1.23 V vs. RHE(reversible hydrogen electrode) under simulated solar illumination. This improvement in PEC performances should be attributed to the synergy of the increased carrier density, the reduced surface charge carrier recombination and the accelerated water oxidation kinetics at the a-Fe2 O3/electrolyte interface, as induced by the incorporation of S ions and the formation of multi-state S species(Fe-Sx-Oy) at the surface of a-Fe2 O3 nanorods. This study paves a new and facile approach to activate a-Fe2 O3 and even other metal oxides as photoelectrodes for improved PEC water splitting performances, by engineering the surface structure to relieve the bottlenecks of charge transfer dynamics and redox reaction kinetics at the electrode/electrolyte interface.

关键词： Photoelectrochemical Water splitting Hematite nanorods Photoanodes Surface sulfurization

Thermodynamic insight into the integration of supercritical water gasification and solid oxide fuel cells for waste plastic energy recovery

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Energy 2025年 332卷

作者： Bin Bai Xinyue Yu Yujie Wang Jianlong Sun Weihong Zhou Hui Jin School of Civil Engineering University of Science and Technology Liaoning Anshan City 114051 Liaoning China State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF) Xi’an Jiaotong University Xi’an City 710049 Shaanxi China

Supercritical water gasification (SCWG) offers a viable approach for recycling waste plastics by converting them into hydrogen-rich combustible gas. However, the high flammability and explosion risk associated with hydrogen pose critical challenges for practical application. This study proposes an integrated system that couples SCWG with solid oxide fuel cell (SOFC), enabling the direct conversion of hydrogen-rich gas into safe electrical energy. To evaluate the system's performance, a thermodynamic analysis was conducted to examine exergy transfer across different process units. Sensitivity analysis was performed to assess the impact of key process parameters on output performance, while an environmental impact assessment was carried out to determine the system's sustainability. Results indicated that primary exergy losses were attributable to irreversibility arising from thermal transfer, heat dissipation and electrochemical conversion. Among the examined parameters, feedstock concentration was the most significant impact on system output and environmental impact, whereas pressure exhibited a negligible effect, and process temperature had a moderate effect. Finally, a multi-criteria optimization identified the optimal operating conditions as 850 °C, 23 MPa, and 5 wt% feedstock concentration, resulting in a net power output of 197.59 kW with an energy efficiency of 55.16 % and exergy efficiency of 53.52 %.

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Construction of a Transient Multi-Physics Model of Solid Oxide Fuel Cell Fed by Biomass Syngas Considering the Carbon Deposition and Temperature Effect

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SSRN 2022年

作者： Zhu, Pengfei Yao, Jing Wu, Zhen Huang, Si-Min Abu Mansor, Mohd Radzi Yang, Fusheng Zhang, Zaoxiao School of Chemical Engineering and Technology Xi’an Jiaotong University Xi’an710049 China Guangdong Provincial Key Laboratory of Distributed Energy Systems Guangdong Provincial Engineering Research Center of Distributed Energy Systems Dongguan University of Technology Dongguan523808 China Department of Mechanical and Manufacturing Engineering University Kebangsaan Malaysia Selangor43600 Malaysia State Key Laboratory of Multiphase Flow for Power Engineering Xi’an Jiaotong University Xi’an710049 China

Carbon deposition is a thorny issue for the SOFC fueled by low carbon hydrocarbons such as biomass syngas. Moreover, long-term large temperature gradients would reduce SOFC durability. Regarding these two issues, a two dimensional transient multi-physical model considering carbon deposition and temperature effect is developed for SOFC in this work. Typically due to the carbon deposition, the SOFC anode porosity decreases from 0.5 to 0.26, and the reaction activity decreases from 1.0 to about 0.45 after running 140 day. Accordingly, the current density decreases by 1.6 % at t =42 d and 6% at t =140 d, which indicates the damage of SOFC durability compared to the durability target (1%/1000h) of commercial SOFC. The maximum temperature difference of the cell is predicted to be about 106 o C. It was found that the carbon deposition and large temperature gradient are closely related to the operating parameters. With the increase of operating voltage from 0.4 V to 0.8 V, the porosity and reaction activity respectively increase by 50% and 55%, and the maximum temperature difference is reduced from 150 o C to 16 o C after running 140 day. The increase of the inlet temperature could improve the overall temperature and decrease the porosity. Besides, the reduction in the ratio of CH 4 to H 2 O helps to suppress carbon deposition, thus to improving the performance. © 2022, The Authors. All rights reserved.

关键词： Solid oxide fuel cells (SOFC)

Spatial Heterogeneity of Point Defect Properties in Refractory Multi-Principal Element Alloy with Short-Range Order: A First-Principles Study

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SSRN 2022年

作者： Shi, Tan Lyu, Sixin Su, Zhengxiong Wang, Yunpeng Qiu, Xi Sun, Dan Xin, Yong Li, Wenjie Cao, Jiang Peng, Qing Li, Yuanming Lu, Chenyang School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China Nuclear Power Institute of China Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing210094 China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing100190 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

The short-range order is inherently present in the multi-principal element alloys and has a profound impact on the defect behaviour. The effect of short-range order on vacancy and interstitial formation and migration was studied in body-centered cubic multi-principal element alloy NbZrTi by first-principles calculations. Two short-range order structures created by density functional theory and Monte Carlo method at 500 K and 800 K were compared with the random solid solution structure. Both vacancy and interstitial formation energies increase with the degree of short-range order. Point defect formation energies tend to be higher in region enriched in Nb and lower in region enriched in Zr and Ti. Both vacancies and interstitials prefer to migrate towards Zr,Ti-rich regions and away from Nb-rich regions, suggesting that Zr,Ti-rich region can act as recombination center for point defect annihilation. Compared to the random solid solution, the short-range order increases the spatial heterogeneity of point defect energy landscape. Tuning the degree of short-range order can be a viable strategy to optimize the point defect behaviour to achieve enhanced radiation resistance in multi-principal element alloys. © 2022, The Authors. All rights reserved.

关键词： Monte Carlo methods