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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

Model Predictive Control for Automatic Operation of Space Nuclear Reactors: Design, Simulation, and Performance Evaluation

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SSRN 2023年

作者： Fu, Jianghan Jin, Zhao Dai, Zhiwen Su, Guanghui Wang, Chenglong Tian, Wenxi 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

Space nuclear reactors possess the inherent benefits of independence from solar energy and the capability to withstand intricate external circumstances. Consequently, the establishment of a dependable automatic control system assumes utmost significance. In this paper, a high-fidelity nonlinear space thermionic nuclear reactor system model is established. An automatic control system with a model predictive control (MPC) controller is designed based on the system. In the case of a nuclear power step response, the MPC controller achieves an overshoot of 0.07% and a settling time of 0.65s. For an electric power step response, the MPC controller yields an overshoot of 0.28% and a settling time of 36.6s. These control performances are better than those achieved by the PID controller. In power tracking control, the MPC controller demonstrates virtually error-free tracking performance. When external reactivity disturbances are introduced, the MPC controller swiftly compensates for the disturbances at the desired level. © 2023, The Authors. All rights reserved.

关键词： Model predictive control

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

Numerical Study on Thermal-Hydraulic Characteristics of Lead-Bismuth Loop System Under Moving Conditions

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SSRN 2022年

作者： Yuan, Lanfei Wang, Chenglong Liu, Zhipeng 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 Shaanxi Xi'An710049 China

The investigation of flow and heat transfer of lead-bismuth eutectic (LBE) under moving conditions is vital to the design optimization of LBE loop system in offshore engineering. In this paper, the calculation model of lead-bismuth loop system and the calculation method of moving conditions are developed by using commercial CFD software, and experiments were carried out to verify the numerical results. The calculation results demonstrate that the moving conditions will cause periodic fluctuations in the natural circulation flow rate of the loop system. The period of the flow rate fluctuation is consistent with the motion period, and the amplitude of the fluctuation will increase with the increase of the maximum range of motion and the decrease of the motion period. When the maximum heaving amplitude is 0.3m and the period is 8s, the instantaneous fluctuation of the flow rate reaches a maximum of 0.8%, and the reverse flow phenomenon occurs under rolling motion. Rolling and heaving motion also make heat transfer characteristic parameters of the system have periodic instantaneous fluctuation. The maximum instantaneous fluctuation of Nu number reaches 4.63%, and the maximum time average Nu can reach -2.15% under heaving motion of 0.3m-8s. In addition, the influence of rolling on system parameters is more severe than that of heaving. These results obtained in this study have important engineering application value for the design of LBE loop system under moving conditions. © 2022, The Authors. All rights reserved.

关键词： Computational fluid dynamics

Experimental Study on Thermoelectric Characteristics of Heat Pipe Reactor (Nuster-100) Single Assembly

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SSRN 2022年

作者： Yang, Haiwang Wang, Chenglong Tian, Wenxi Qiu, Suizheng Su, Guanghui 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 Shaanxi Xi’an710049 China

The heat pipe cooled reactor has the advantages of miniaturization,modularization and high inherent safety,having broad application prospects in the fields of national defense and military,space exploration and energy supply in remote *** this paper, a heat pipe-thermoelectric generator integrated experimental device similar to the heat pipe cooled reactor (NUSTER-100) Single Assembly is *** heat transfer performance of sodium heat pipe and thermoelectric performance of Half-Heusler thermoelectric generator are *** results show that after the sodium heat pipe is started,the axial temperature difference of the heat pipe is 85°C,the equivalent heat transfer coefficient is 40886W/K·m,which can provide stable heat to the thermoelectric *** performance parameters of thermoelectric generator such as open voltage,output power increase with the hot side temperature *** maximum thermoelectric conversion efficiency of single thermoelectric generator reaches 7.2%,but the efficiency of integrated experimental device is only 3.5%. © 2022, The Authors. All rights reserved.

关键词： Heat pipes

Clogging failure in microfilter for blood cell separation and Its novel improvements tao dong

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Clogging failure in microfilter for blood cell separation an...

2009 16th IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits, IPFA 2009

作者： Yang, Zhaochu Egeland, Eirik Bentzen Karlsen, Frank Jakobsen, Henrik Norwegian Center of Expertise on Micro- and Nanotechnology Vestfold University College I.M.S.T./R.I. Norway State Key Lab. of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China NorChipTM A.S. Industriveien 8 N-3490 Klokkarstra Norway

ISBN: (纸本)9781424439102

Clogging failure is common for microfilter utilizing the flat membrane structure. To reduce clogging failure in microfilters, the turbine blade-like micropillar is introduced in microfilter design. Two improved cross-flow microfilter designs employing the blade-like micropillar barrier are presented, one with varied cross-section channels, and the other with Archimedes' spiral channels. Analogy experimental-data based simulations show that the two aforementioned novel microfilters have good filtrating efficiency and fantastic anti-clogging characteristics. and the commercial value of the turbine blade-like barriers is affirmed by the industry Partners. © 2009 IEEE.

关键词： Turbomachine blades

Study in steam-water two-phase flow heat transfer at high mass velocity of flow in vertical helical coiled tube

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Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2008年第3期29卷 423-428页

作者： Guo, Meng Zhao, Liang Mao, Yu-Fei Zhen, Fei-Qiang Zhang, Wen-Bin Guo, Lie-Jin Peng, Xiao-Feng State Key Lab. of Multiphase Flow in Power Engineering Xi'an 710049 China

Experiments were conducted to further understand the heat transfer in two-phase flow in vertical helically-coiled tubes. The experiments covered a wide range of pressure 8.0-15.0 MPa, mass flow rate 2500-4000 kg/(m2s), heat flux 200-800 kW/m2. The experimental segment is 2.335 meter long and made by φ14 × 2 mm steel tube. The diameter ratio D/d is 30.1. Through analyzing the influence of heat flux, mass velocity on average heat transfer coefficient, we acknowledge the activities of nucleate boiling and forced convection two mechanism on steam-water two-phase heat transfer in helical coils tubes at high mass flow rate. The average and local heat transfer coefficient correlations were obtained. At high mass flow rate conditions, the effect of heat transfer in the steam-water two-phase flow in helically coils is inclined to that of straight tube at same conditions and the results are compared.

关键词： Heat exchangers

Characterization of High-Performance Nanostructured Wick for Heat Pipes

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SSRN 2023年

作者： Sun, Qishi Han, Ruiyu Guo, Kailun Wang, Chenglong Zhang, Jing He, Xiaoqiang Qiu, Suizheng Su, Guanghui Tian, Wenxi 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 Key Lab. of Nuclear Reactor System Design Technology China Nuclear Power Research and Design Institute Chengdu610213 China

To investigate the best performance wick forms to support the design and fabrication of high-performance heat pipes, in this paper, two kinds of nanostructured wick were prepared by the oxidation-reduction method. The effect of surface nanostructure on the wick performance was investigated by comparing the surface characteristics, capillary properties, permeability, and evaporation properties. The result shows that the nanostructured wick presented excellent super hydrophilic properties. A liquid-lift visualization experimental method for measuring the capillary performance factor M was proposed, and it was verified to be correct by the separation effect of the capillary pumping experiment under a vacuum environment. With the increasing oxidized degree, the densification of nanoparticles on the wick surface increased the capillary performance factor M from 8.68 μm to 13.81 μm, with a maximum enhancement of 59.1%. The effective capillary radius decreased from 4.70×10-5 m to 4.01×10-5 m, with a maximum reduction of 14.9%. The permeability increased from 4.33×10-10 m2 to 5.83×10-10 m2, with a maximum enhancement of 34.7%. The increase in porosity made the effective capillary radius dominate the competition for permeability, and the capillary performance factor decreased by 17.1%. The thermal resistance of the wick decreased with the enhancement of the capillary performance factor, which fell from 2.03×10-3 m2·K/W to 1.26×10-3 m2·K/W. The current study provides a reference for the future design and preparation of high-performance heat pipe wicks. © 2023, The Authors. All rights reserved.

关键词： Heat resistance

Preliminary Conceptual Design with Neutronics and Thermal-Hydraulics Assessments of Fustar

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SSRN 2023年

作者： Zhou, Xingguang Zhang, Dalin Li, Xinyu Lv, Xindi Jiang, Dianqiang Tian, Wenxi Qiu, Suizheng State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi'an Jiaotong University Xi'An710049 China

The fluoride-salt-cooled high-temperature advanced reactor (FuSTAR) is an advanced small modular reactor, which aims to the electric supplement and clean heat production to western China. In this study, neutronics and thermal-hydraulics analysis are also carried out, and established the core layout and material ratio under the near-critical condition. The parameters of the designed core are evaluated quantitatively from various aspects. The results show that FuSTAR has sufficient shutdown depth, the equilibrium cycle is 3.24 years, and the discharge burnup depth is 106 GWd/MtU. The analysis of 1/6 core porous media shows that the peak fuel temperature under normal operating condition is 1009.3 K, which is far below the limit of 1573 K. Relevant design and analysis results can provide the reference for the subsequent small modular FHR design and construction. © 2023, The Authors. All rights reserved.

关键词： Computational fluid dynamics