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Validation of Lead-Bismuth Thermal Hydraulic Facilities Based on Modified Relap5

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SSRN 2022年

作者： Zhang, Yixin Zhang, Jiaxin Wang, Chenglong Tian, Wenxi Qiu, Suizheng Su, G.H. Department of Nuclear Science and Technology State Key Lab. of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University Xi'An710049 China

On the basis of not affecting the original computing power of RELAP5, the physical properties of lead and bismuth are added and verified. The important content of this paper is to use the modified RELAP5 to simulate the transient operating conditions carried out on the three lead-bismuth eutectic experimental devices of NACIE, TALL and NCCL, and compare it with the experimental data. The results show that the temperature error of the heating section of the NACIE facility under transient power conditions is within 7%. The error between the calculated value and the experimental value of the final core temperature under each working condition of the TALL facility is within 5%. The temperature simulation error of the experimental section of the NCCL circular tube heat transfer test is within 4%. The research in this paper can provide data and verification support for the development of the lead-bismuth fast reactor project. © 2022, The Authors. All rights reserved.

关键词： Fast reactors

Aeroderivative Gas Turbine and Composite Sco2 power Cycle Integrated System: Towards Large-Scale Gas-to-power Efficient Conversion

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SSRN 2023年

作者： Jiang, Yuemao Wang, Shunsen Su, Wen Li, Bo Wang, Zhe State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China School of Energy Science and Engineering Central South University Changsha410083 China National Center for International Research of Subsea Engineering Technology and Equipment Dalian Maritime University Dalian116026 China

power-to-Gas is proving to be an effective means of storing electricity from renewables on a large scale. Nevertheless, there is yet to be a clear technical route for large-scale hydrogen-enriched gas conversion into electricity (Gas-to-power). This paper proposed a novel integrated power system consisting of an aeroderivative gas turbine and a composite supercritical CO2 (sCO2) power cycle. In addition, a new evaluation indicator based on exergy was also proposed to reveal the real waste heat recovery capacity and select the sCO2 cycles. After that, a comprehensive energy, exergy, exergoeconomic, and environment (4E) analysis and global parametric studies were conducted for the integrated system. Finally, an entropy-based TOPSIS decision-maker was combined with the tri-objective optimization algorithm for the combined cycle integrated design. Thermodynamic optimization results show that, unlike the thermal efficiency, the exergy efficiency of the partial heating sCO2 cycle of 48.3% is higher than that of the recuperated one. With the exhaust gas carrying 21% of fuel exergy, the total exergy recovery efficiency is 51.7%, and the fuel efficiency of the integrated system is over 50%. As for the exergoeconomic, the combustor alone is responsible for 77.1% of the total exergy destruction, the initial cost of the bottoming cycle is less than half that of the gas turbine, and the high-pressure turbine has the highest exergoeconomic factor of 91.5%. The key parameters of the gas turbine significantly influence the performance of the sCO2 cycle and the integrated system 4E performance. There is an optimal gas turbine inlet temperature of about 1500 K to minimize the LCOE. After the multi-objective integrated optimization, the overall efficiency, LCOE, and specific gas emissions are 50.2%, 7.8 cents/kWh, and 396.8 g/kWh, respectively, which are all higher than those from optimizing the bottoming cycle alone. It is considered that the technical solutions and research results

关键词： Gas turbines

Enhanced Heat Transfer of flow Boiling Combined with Jet Impingement

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Enhanced Heat Transfer of Flow Boiling Combined with Jet Imp...

第七届天地应用两相系统国际研讨会

作者： J.J.Wei J.F.Zhao D.Guo Y.H.Zhang State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University28 Xianning XiluXi’an 710049China 2National Microgravity LaboratoryInstitute of MechanicsChinese Academy of Sciences 15 Beisihuan XiluBeijing 100190China

Influence Study of the Anisotropic Scattering and Solar Radiation on the Radiation Working Performance of Liquid Droplet Radiator

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SSRN 2024年

作者： Fei, Yiheng Fu, Jianghan Wang, Chenglong Tian, Wenxi Guanghui, S.U. Qiu, Suizheng Department of Nuclear Science and Technology State Key Lab. of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University Xi’an710049 China

The Liquid Droplet Radiator (LDR), a lightweight frameless radiant heat rejection system, is widely regarded as the optimal heat rejection solution for megawatt-scale space nuclear power systems. The LDR dissipates heat to space through its droplet layer, which plays a crucial role in determining its radiative rejection capacity. Radiation beams undergo a series of emission, scattering, and absorption processes within the layer before being emitted into space. Prior studies typically assume isotropic scattering in this process. However, this study introduces a 3D model of the LDR layer based on Mie theory and Monte-Carlo methods to investigate the impact of anisotropic scattering and solar radiation. Our calculations reveal that the working fluid exhibits strong forward anisotropic scattering characteristics. Under the anisotropic assumption, the heat rejection capability of the LDR is 27-33% higher compared to the isotropic assumption. Regarding the temperature distribution within the LDR, under the anisotropic assumption, the layer's temperature is 6 K lower at the XY boundary surface and 3 K higher at the layer median, as opposed to the isotropic assumption. We introduce the concept of the probability of a light beam escape to elucidate the distinct beam transmission mechanisms and temperature distribution. When the distance between the LDR and the sun is in the vicinity of 1 AU, the impact of solar radiation on the LDR's ability to operate is on the order of 1E-5, which is almost negligible. This study provides a theoretical foundation for calculating the heat rejection capacity during the LDR design phase. © 2024, The Authors. All rights reserved.

关键词： Solar radiation

Optimizing Interfacial Environment of Triphasic Zno-Cu-Zro2 Confined Inside Mesoporous Silica Spheres for Enhancing Co2 Hydrogenation to Methanol

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SSRN 2022年

作者： Chen, Changwei Kosari, Mohammadreza Xi, Shibo Lim, Alvin M.H. He, Chi Zeng, Hua Chun Department of Chemical and Biomolecular Engineering Faculty of Engineering National University of Singapore 10 Kent Ridge Crescent 119260 Singapore State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Shaanxi Xi'An710049 China 1 Pesek Road Jurong Island 627833 Singapore

Herein, the well-known ternary Cu 0 -ZnO-ZrO 2 (CZZ) was spatially sequestered as fine, uniformly-dispersed optimized active interfaces onto an engineered mesoporous silica sphere (MSS), giving rise to Cu 0 -ZnO-ZrO 2 /MSS (CZZ-MSS) with confined binary Cu 0 -ZnO/Cu 0 -ZrO 2 and ternary interfaces that fostered methanol production under moderate conditions. By systematically investigating the CZZ-MSS performance. Besides, the strong metal-support interaction arising from interacting metallic Cu and metal oxides (ZnO and ZrO 2 ) within the confined, ultrasmall nanoparticles ( © 2022, The Authors. All rights reserved.

关键词： Zinc oxide

Thermodynamic Analysis of a Hybrid Energy System Coupling Solar Organic Rankine Cycle and Ground Source Heat Pump: Exploring Heat Cascade Utilization

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SSRN 2023年

作者： Chen, Liangqi Yue, Huifeng Wang, Jiangfeng Lou, Juwei Wang, Shunsen Guo, Yumin Deng, Bohao Sun, Lu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China China United Northwest Institute for Engineering Design & Research Co. Ltd Xi’an710077 China School of Human Settlements and Civil Engineering Xi'an Jiaotong University Xi’an710049 China

The demand for efficient utilization of renewable energy is growing and the hybrid energy system driven by solar and geothermal energy is a significant way to minimize carbon emission and achieve carbon neutrality. This paper presents a hybrid energy system coupling solar organic Rankine cycle (S-ORC) with ground source heat pump (GSHP) for heating and power supply to further increase thermal efficiency and explore the heat cascade utilization of hybrid energy system during the heating season. In the hybrid energy system, the ground heat exchanger (GHE) is shared by the S-ORC and GSHP systems and the waste heat from the condenser of S-ORC is recovered to enhance the coefficient of performance (COP) of GSHP. A mathematical model is optimized to analyze the parametric effects on thermodynamic performance under different operating conditions. The comparison between the hybrid energy system and the stand-alone GSHP system is performed to present the superiority of energy recycling. The results indicate that the COP of the hybrid energy system can be improved up to 6.5 which shows the obvious advantage compared to 2.8 of the stand-alone GSHP system under the given system conditions. In addition, the increase of turbine inlet pressure can not only reduce the area of solar fields and length of buried tubes, but also contribute to the thermodynamic performance of the hybrid energy system. Furthermore, the hybrid energy system can obtain optimum exergy efficiency by matching ground source temperature and condensation temperature in the ORC unit. For a building of 3000m2 with heating and power supply, multi-objective optimization by means of a genetic algorithm is carried out to obtain the optimal design performance that the net power output, thermal efficiency and exergy efficiency are 180.0kW, 27.5%, and 9.2% respectively. © 2023, The Authors. All rights reserved.

关键词： Geothermal heat pumps

Capillary Limit of a Sodium Screen-Wick Heat Pipe

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SSRN 2022年

作者： Ma, Yugao Wang, Xueqing Yu, Hongxing Huang, Shanfang Zhang, Yingnan Huang, Jian Su, Guanghui Deng, Jian Chai, Xiaoming Hu, Wenzhen School of Nuclear Science and Technology Xi’an Jiaotong University Shanxi Xi’an710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Department of Engineering Physics Tsinghua University Beijing100084 China State Key Laboratory of Multiphase Flow in Power Engineering China

High-temperature alkali-metal heat pipes are passive heat transfer devices, where the capillary pressure created by the menisci in the wick pumps the condensed fluid back to the evaporator. Thus, the heat pipe heat transfer capacity is limited by the maximum capillary pressure at high heat fluxes. This work presents a two-dimensional heat and mass transfer model that includes the capillary and gravitational forces that are used to predict the capillary limit which is then validated by experimental data. The predicted critical heat flux temperature has an error of less than 20℃ and a relative error of 6%. The predicted transient sequences are consistent with the measurements. The model shows that capillary limit is affected by inclination angle, heat flux, and wick structure. For inclinations, the critical heat flux at the capillary limit is linearly related to the inclination angle with the predicted temperature rising 2 ~10℃/s during the early stage of the capillary limit critical heat flux condition. The evaporator temperature oscillates before the capillary limit with positive inclinations. For heat fluxes, increasing the heat flux by 17% increases the temperature increase rate 10 fold with a longer dryout length. The evaporator exhibits hysteresis after the capillary limit due to partial dryout of evaporator. For wick structures, reducing the mesh screen pitch from 80 μm to 15 μm reduces the critical heat flux to 10% of the CHF at 80 μm. This model can accurately predict the heat pipe temperature variations at the capillary limit and can explain the physical mechanisms for the dryout oscillations and recovery hysteresis at the capillary limit. Thus, the measurements and model provide analytical guidelines for designing heat pipe cooling systems. © 2022, The Authors. All rights reserved.

关键词： Heat flux

Novel doped barium cerate-carbonate composite electrolyte material for low temperature solid oxide fuel cells

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Novel doped barium cerate-carbonate composite electrolyte ma...

第五届世界氢能技术大会(WHTC2013)

作者： Yuanfei Hei Cheng Wang Jianbing Huang Zongqiang Mao Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084P.R. China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049P.R. China

Propagation and Burning Velocity of Iron-Methane-Oxygen-Nitrogen Turbulent Expanding Flames

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SSRN 2023年

作者： Cai, Xiao Su, Limin Su, Shouguo Wang, Jinhua Alden, Marcus Li, Zhongshan Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Division of Combustion Physics Lund University P.O. Box 118 LundS221 00 Sweden

The propagation and burning velocity of iron-methane-oxygen-nitrogen turbulent expanding flames were experimentally studied by employing a newly optimized spark-ignition, fan-stirred combustion chamber, in which micron-sized iron particles can be dispersed homogeneously. Fine iron particles with averaged diameter of 1.9 μm was used in the present study. The flame trajectory of iron-methane mixture at different turbulence intensities and iron concentrations was recorded using a high-speed camera. It was found that the flame propagation speed increases as iron-methane turbulent flame expands. The acceleration process is mainly caused by the extension of flame surface dissipation spectrum by increasing the largest flame scales (flame radius). The turbulent burning velocity, ST increases significantly with the turbulence intensity, which is well known feature in gaseous flames. However, the iron concentration does not have an obvious effect on the ST, which is unique to iron flame in turbulence environment. Because the turbulent flame propagation is dominated by turbulent heat transfer, which is characterized by turbulence intensity. In addition, the formation of iron flame front is controlled by the couple effects of iron concentration and turbulence intensity in turbulent environment. Furthermore, the laminar burning velocity, SL was accurately determined using a nonlinear extraction method. A correlation of turbulent burning velocity was obtained based on the experimental iron-methane data. The measured ST and its correlation would be used to develop practical iron burners and to validate turbulent combustion models of iron flames. © 2023, The Authors. All rights reserved.

关键词： Iron