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Proposal and thermodynamic analysis of a steam methane reforming system integrated with thermochemical energy storage and a SCO2 brayton cycle

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Journal of Energy Storage 2025年 127卷

作者： Fu, Yu Liu, Ming Wang, Zhu Xie, Tao Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Institute of Industrial Catalysis School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an710049 China

Solar energy is a promising alternative to fossil fuels for providing heat in steam methane reforming (SMR) hydrogen production. However, the variability of solar energy requires effective storage solutions. This study presents a new SMR hydrogen production system that integrates thermochemical energy storage (TCES) utilizing a CaO/CaCO3 cycle with a SCO2 Brayton cycle. The system converts fluctuating solar energy into the stable chemical energy of CaO by calcinating CaCO3 in the solar calciner, with the SMR reaction mainly heated by the exothermic reaction of CaO and CO2. The SCO₂ Brayton cycle efficiently recovers heat from the high-temperature SMR products. Comprehensive thermodynamic analysis and evaluation models are developed. Results show that the proposed system performs well, achieving energy and exergy efficiencies of 73.49 % and 78.46 %, respectively, under benchmark conditions. The energy storage efficiency of TCES is 81.55 %, and the solar-to-chemical energy efficiency is 48.21 %. Integrating TCES significantly enhances the system's steady operation under fluctuating solar energy conditions. The calciner accounts for the largest share of exergy destruction at 31.63 %, followed by the carbonator at 17.50 %. Sensitive analyses of key operating parameters indicate that higher CaO conversion rate and storage temperature enhance energy storage, energy, and exergy efficiencies. Besides, the energy and exergy efficiencies decrease with the increasing SMR reaction pressure but increase with rising reaction temperature. When the S/C is 2.0, these efficiencies reach their maximum values of 75.42 % and 78.63 %, respectively. © 2025 Elsevier Ltd

关键词： Brayton cycle

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Investigation on the Parallel Computing Technique Using on the Numerical Simulation of Carbon Free Fuel

Investigation on the Parallel Computing Technique Using on t...

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Information Science, Parallel and Distributed Systems (ISPDS), International Conference on

作者： Weibin Wang Xutao Wei Department of Computer Science Xi'an Fanyi University Xi'an China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China

The numerical simulation of the turbulent combustion is identified as one of the most promising methods on the designs of the combustion devices, for example: the internal combustion engine and gas turbine. This mainly depends on the development of parallel computing technique. However, the computational efficiency for different cases on different compute nodes and number of cores still needs to be studied. On the other hand, due to the requirements from the aim of peaking carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060, modern energy system is requesting low carbon or carbon free fuels, such as ammonia (NH3). Therefore, the simulations of ammonia/air flame were performed in present investigation. The comparison between simulation cases on different compute nodes and number of cores illustrates that different cases requires different number of cores to achieve the best computational efficiency. The computational efficiency of each compute nodes are dissimilar, which can decrease the efficiency. Meanwhile, the methods in present study can predict the ammonia/air flames. The initial condition of velocity fluctuation is necessary for simulating turbulent flame. The wrinkles of the flames can be well predicted by the velocity fluctuation initial boundary condition.

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Experimental and Numerical Study of Hydraulic Characteristics and Pressurization Deterioration Mechanism of a Three-Stage Mixed-flow multiphase Pump Under Gas Liquid Condition

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SSRN 2023年

作者： Dai, Xiaoyu Xu, Qiang Yang, Chenyu Su, Xiaobin Chang, Liang Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Shanghai Institute of Satellite Engineering Shanghai201109 China

The mixed-flow multiphase pump may experience pressurization deterioration due to the high Gas Volume Fraction, resulting in pressurization failure and posing a threat to the pressurization unit's safety. In this paper, a three-stage mixed-flow multiphase pump with closed impeller structure is designed and developed. The hydraulic characteristics and pressurization deterioration mechanism of the multiphase pump were investigated at various rotational speeds and inlet conditions using the experiment and simulation. As the liquid flow rate rises, the multiphase pump experiences a 'three-stage' downward trend in pressurization. The first booster stage has a greater capacity for pressurizing the liquid phase. The gas-liquid pressurization exhibits a wave-shaped downward trend due to significant deterioration in stage-wise pressurization when the liquid flow rate is low. Once the Inlet Gas Volume Fraction reaches the initial critical Gas Volume Fraction, the gas aggregates on the impeller’s suction surface is removed at the impeller outlet, creating an annular air mass. When this mass of air meets the fluid behind it, it creates a chaotic vortex that absorbs the fluids' kinetic energy. As a result, the first booster stage experiences a significant reduction in its pressurization ability, causing an abrupt decrease in the pressurization curve. © 2023, The Authors. All rights reserved.

关键词： Computational fluid dynamics

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Experiments and predictions for severe slugging of gas-liquid two-phase flows in a long-distance pipeline-riser system

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Ocean Engineering 2024年 301卷

作者： Chang, Yingjie Xu, Qiang Zou, Suifeng Zhao, Xiangyuan Wu, Quanhong Wang, Yechun Thévenin, Dominique Guo, Liejin Shaanxi Key Laboratory of New Transportation Energy and Automotive Energy Saving Chang'an University Xi'an710064 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Laboratory of Fluid Dynamics and Technical Flows Otto-von-Guericke-Universität Magdeburg Magdeburg39106 Germany

Experiments concerning the flow regimes observed in gas-liquid two-phase flows in a long-distance pipeline-riser system were carried out and analyzed in this paper. The test loop with 0.075 m inner diameter consisted of a 314 m horizontal pipeline, followed by a 25 m downward-inclined pipe, and finally a 21.5 m riser pipe. An industrial-scale global flow regime map including 5 flow regimes was derived from differential pressure measurements in the riser and was used as a reference for improvements. Electrical capacitance volume tomography installed in the horizontal section was used to reconstruct the phase interface and calculate the average gas void fraction (GVF). An appropriate model for this system was selected by comparing the experimental GVF with different, widely used models. The occurrence of severe slugging flow (SS) can be predicted accurately using an improved model involving additional corrections that consider pipeline length, accurate GVF calculation, and gas density. This study supports the development of a suitable SS prediction model enabling safe design, operation, and control of practical systems. © 2024 Elsevier Ltd

关键词： Pipelines

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Boosting photocatalytic water vapor splitting by the integration of porous g-C_(3)N_(4)and carbonized melamine foam

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Science China Materials 2024年第9期67卷 2957-2964页

作者： Shujian Wang Dongjie Liu Chunyang Zhang Jie Huang Shidong Zhao Kejian Lu Biao Wang Hao Peng Yitao Si Maochang Liu International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an710049China School of Chemistry and Chemical Engineering Southeast UniversityNanjing211189China Suzhou Academy of Xi’an Jiaotong University Suzhou215123China Gree Altairnano New Energy Inc. Zhuhai519040China

We report a photothermally-induced liquid-solid/gas-solid-decoupling photocatalytic water-splitting system,where a carbonized melamine foam(CMF)and a porous g-C_(3)N_(4)(PCN)serve as the photothermal substrate and model photocatalyst,***,liquid water is transformed into the gaseous phase over the CMF due to the photothermal effect,and the generated vapor can be split into hydrogen by PCN via the *** unique biphasic photocatalytic system exhibits a high hydrogen production rate of 368.1µmol h^(-1),which is 2.4 and 25.6 times larger than those of the traditional triphasic PCN system(151.7µmol h^(-1))and g-C_(3)N_(4)(CN)system(14.4µmol h^(-1)),*** improved photocatalytic performance is mainly attributed to the optimized energy and mass transfer at the gas-liquid-solid reaction interface,where gas products are rapidly desorbed in the photocatalytic *** work provides a novel strategy to enhance the photocatalytic performance from the perspectives of energy and mass flow.

关键词： photocatalytic photothermal mass transfer g-C_(3)N_(4) gas-solid

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Proposal design and thermodynamic analysis on a novel coal-based power generation system integrated with CO2 capture

Proposal design and thermodynamic analysis on a novel coal-b...

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Electrical Engineering and Mechatronics Technology (ICEEMT), IEEE International Conference on

作者： Guobin Gao Ruiqi Mu Yali Yang Lei Yan Jun Gao Ming Liu Guoneng Jinjie Energy Co. Ltd Yulin China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

To enhance the energy efficiency and decrease the carbon emissions, a novel coal-based power generation system integrated with CO 2 capture is proposed in this study. The S-CO 2 cycle is integrated to recover the waster heat of system effectively. The heat transfer processes are well matched, and the irreversibility of heat exchangers in the system is reduced by splitting working medium appropriately. The system simulation and thermodynamic analysis models are developed. The energy and exergy efficiency of system are 51.32% and 50.07%, respectively. The system efficiency increases with the increase of the coal water slurry concentration (CWSC) and the decrease of the gasification temperature. When the CWSC is 35% and gasification temperature is 500 °C, the exergy efficiency of system reaches 51.74% and 50.59%, respectively.

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Waste heat recovery in the coal-fired power generation integrated with post-combustion

Waste heat recovery in the coal-fired power generation integ...

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Electrical Engineering and Mechatronics Technology (ICEEMT), IEEE International Conference on

作者： Yali Yang Guiwen Wang Yan Li Yongping Liu Yue Fu Ming Liu Guoneng Jinjie Energy Co. Ltd Yulin China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

Post combustion systems (PCS) are a viable technology option to reduce carbon dioxide in the electricity production. However, the energy-intensive of PCC precludes its wide scale application. As for the optimization of the post combustion system, there is an optimal inlet temperature of the stripper. By optimizing the parameter of the post combustion system, the energy consumption rate of the post combustion system decreased by 1.4 GJ/t CO 2 under 100% THA compared to the original post combustion system. The needed heat by the stripper shows a fall with the decrease of the unit load ratio. However, the heat changes of the post combustion system decrease with the decrease of the unit load ratio under 90% absorption rate. The efficiency penalty can be as low as 4.1% through waste heat recovery.

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Hierarchically mesoporous carbon spheres coated with a single atomic Fe-N-C layer for balancing activity and mass transfer in fuel cells

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Carbon Energy 2022年第1期4卷 1-11页

作者： Chengyong Shu Qiang Tan Chengwei Deng Wei Du Zhuofan Gan Yan Liu Chao Fan Hui Jin Wei Tang Xiao-dong Yang Xiaohua Yang Yuping Wu School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'anChina State Key Laboratory for Mechanical Behavior of Materials School of Material Science and EngineeringXi'an Jiaotong UniversityXi'anChina State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power SourcesShanghaiChina State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'anChina College of Materials Science and Engineering Huaqiao UniversityXiamenChina Institute of Quantum and Sustainable Technology(IQST) School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiangChina State Key Laboratory of Materials-Oriented Chemical Engineering School of Energy Science and Engineering and Institute of Advanced MaterialsNanjing Tech UniversityNanjingChina

Novel cost-effective fuel cells have become more attractive due to the demands for rare and expensive platinum-group metal(PGM)catalysts for mitigating the sluggish kinetics of the oxygen reduction reaction(ORR).The high-cost PGM catalyst in fuel cells can be replaced by earth-abundant transition-metalbased catalysts,that is,an Fe-N-C catalyst,which is considered one of the most promising ***,the performance of the Fe-N-C catalyst is hindered by the low catalytic activity and poor stability,which is caused by insufficient active sites and the lack of optimization of the triple-phase interface for mass ***,a novel Fe–N–C catalyst consisting of mono-dispersed hierarchically mesoporous carbon sphere cores and single Fe atom-dispersed functional shells are *** synergistic effect between highly dispersed Fe-active sites and well-organized porous structures yields the combination of high ORR activity and high mass transfer *** half-wave potential of the catalyst in 0.1M H_(2)SO_(4) is 0.82 V versus reversible hydrogen electrode,and the peak power density is 812 mW·cm^(−2) in H_(2)–O_(2) fuel ***,it shows superior methanol tolerance,which is almost immune to methanol poisoning and generates up to 162 mW·cm^(−2) power density in direct methanol fuel cells.

关键词： fuel cell hierarchically mesoporous carbon spheres oxygen reduction reaction single‐atom catalysts

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Thermodynamic Performance of Cacl2 Absorption Heat Pump Thermal Energy Storage System with Triple Storage Tanks

SSRN

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SSRN 2023年

作者： Chen, Jinsen Zhou, Yuan Liu, Jiping Zhao, Yongliang Zhang, Shunqi Yan, Junjie MOE Key Laboratory of Thermal Fluid Science Engineering Xi'an Jiaotong University Xi’an710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi’an710049 China

Absorption thermal energy storage has the characteristics of high thermal energy storage density (ESD) and low heat loss for long-term storage. To solve the coal-fired combined heat and power plant heat-power-coupling problem, in this work, an absorption heat pump thermal energy storage system (AHPTES) using CaCl2-water solution as the working fluid is proposed. A steady-state thermodynamic model of the system was constructed using Aspen Plus. Under the design conditions, the AHPTES system requires a tank volume of 464.61 m3 for one hour of operation, an ESD of 29.81 kW·h/m3, a thermal energy storage ratio of 46.50%, and a heating ratio of 53.54%. Compared to the dual-tank thermal energy storage system with H2O and CaCl2-water solutions as working fluids, the AHPTES system has 1.43 and 1.25 times higher ESD and 0.7 and 0.8 times lower tank volume, respectively. Then, the effects of CaCl2 mass fraction, driving pressure, evaporator outlet temperature, preheating temperature, and condensing temperature on the system performance are simulated. Improving the CaCl2 mass fraction, lowering the evaporator outlet temperature, and raising the condensing temperature and preheating temperature can boost the system's performance. At the optimal system performance, the required tank volume for one hour of system operation is 439.56m3, ESD can reach up to 37.39 kW·h/m3, heating ratio to 44.83%, and the energy storage ratio to 55.17%. Besides, raising the mass fraction of CaCl2 to 52% and decreasing the evaporator outlet temperature to 30 °C at 50% mass fraction resulted in crystallization of the system. © 2023, The Authors. All rights reserved.

关键词： Thermal energy

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Non-Hermitian Delocalization in a Two-Dimensional Photonic Quasicrystal

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Physical Review Letters 2024年第26期132卷 263801-263801页

作者： Zhaoyang Zhang Shun Liang Ismaël Septembre Jiawei Yu Yongping Huang Maochang Liu Yanpeng Zhang Min Xiao Guillaume Malpuech Dmitry Solnyshkov Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique School of Electronic Science and Engineering Faculty of Electronics and Information PHOTON-N2 Université Clermont Auvergne CNRS Clermont INP F-63000 Clermont-Ferrand France International Research Center for Renewable Energy and State Key Laboratory of Multiphase Flow in Power Engineering Department of Physics National Laboratory of Solid State Microstructures and School of Physics 75231 Paris France

Theoretical and experimental studies suggest that both Hermitian and non-Hermitian quasicrystals show localization due to the fractal spectrum and to the transition to diffusive bands via exceptional points, respectively. Here, we present an experimental study of a dodecagonal photonic quasicrystal based on electromagnetically induced transparency in a Rb vapor cell. First, we observe the suppression of the wave packet expansion in the Hermitian case. We then discover a new regime, where increasing the non-Hermiticity leads to delocalization, demonstrating that the behavior in non-Hermitian quasicrystals is richer than previously thought.

关键词： Electromagnetically induced transparency Localization Photonics Non-Hermitian systems Quasicrystals

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