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SSRN 2022年

作者： Wang, Xiaoxiao Ma, Zhiyuan Yang, Jie Chen, Haofeng Xuan, Fuzhen Department of Mechanical & Aerospace Engineering University of Strathclyde James Weir Building 75 Montrose Street GlasgowG1 1XJ United Kingdom 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 Shanghai200093 China School of Mechanical and Power Engineering East China University of Science and Technology Shanghai200237 China

To achieve a high-reliability design with a feasible balance between accuracy and efficiency, the physics-based probabilistic assessment for creep-fatigue failure is proposed under the probabilistic Linear Matching Method (pLMM) framework. At the physical level, the structural failure mechanism is reflected in the prepared training database, which is generated by the direct method, extended Direct Steady Cycle Analysis (eDSCA) procedures. And to efficiently express the relationship between design parameters and structural responses implicitly, the extended DSCA-driven neural network (EDDNN) is built with the superior fitting quality of damage and lifetime. With the benchmarks of pressurized structures provided, the applicability of the proposed probabilistic analysis approach in solving practical problems is demonstrated, where the reliability-based evaluation diagram is established according to different requirements. Furthermore, a novel data classification scheme is proposed to deal with the randomness in creep damage-dominated probabilistic assessment. © 2022, The Authors. All rights reserved.

关键词： Failure (mechanical)

Research on the Solution of the Thermo-Hydro-Mechanical-Chemical Coupling Model Based on the Unified Finite Volume Method Framework

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SSRN 2024年

作者： Zhang, Weitao Han, Dongxu Wang, Bohong Chen, Yu-Jie Jiao, Kaituo Gong, Liang Yu, Bo Qingdao266580 China School of Mechanical Engineering Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil and Gas Development Beijing Institute of Petrochemical Technology Beijing102617 China National-Local Joint Engineering Laboratory of Harbour Oil and Gas Storage and Transportation Technology Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control Zhejiang Ocean University No.1 Haida South Road Zhoushan316022 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

Most existing thermo-hydro-chemical-mechanical (THMC) coupling models for enhanced geothermal systems (EGS) employ a combination of finite volume method (FVM) and extended finite element method (XFEM), facing challenges in framework integration, programming complexity, and solution efficiency. To overcome these limitations, this study develops an innovative FVM-XFVM model based on the embedded discrete fracture model (EDFM) that significantly enhances the THMC coupling modeling process for fractured reservoirs with simplicity and efficiency. Rigorous comparative verification demonstrates the new model maintains accuracy while improving computational performance. For EGS applications, this model effectively captures spatiotemporal dynamics of coupled THMC processes with multi-component water-rock reactions. The approximately 3°C temperature deviation between multi-component and single-component models after long-term operation demonstrates the necessity of incorporating multi-component reactions into THMC models for accurate forecasts. This work substantially improves the predictability and efficiency of long-term heat production forecasts for EGS reservoirs. © 2024, The Authors. All rights reserved.

关键词： Finite volume method

Experimental Study on Deliquification with Atomizing Nozzle in Gas Well

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IOP Conference Series: Earth and Environmental Science 2020年第1期555卷

作者： Yutang Gao Xiaobai Li Peng Chang Lei Liu State Key Laboratory of Multiphase Flow in Power Engineering Xi'an 710049 Shaanxi P.R. China

Gas is a clean energy resource in comparison with oil and coal. Liquid-loading problem is frequently encountered in the process of gas production. It would directly cause the production of gas wells decreasing, even off production. A number of deliquification techniques have been suggested for solving this kind of problem, but the available techniques are not yet widely applicable. Based on the analysis, the method of deliquification with atomizing nozzle in gas wells was put forward. The test bench was designed for studying the atomization of nozzles and the liquid entrainment of gas flow. The size distribution of atomized droplets was measured by Malvern laser grain size analyzer. The Sauter mean diameters of atomized droplets were analysed under different two-phase flow conditions. The results indicate that the designed nozzles have good atomization performances and show potential application for reducing liquid loading in gas wells.

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Experimental investigations on flow instabilities in a forced circulation loop at near-critical and supercritical pressures

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AIP Conference Proceedings 2013年第1期1547卷

作者： Lei Zhang Haijun Wang Hongfang Gu Shouxu Qiao Xiaobao Shi Yushan Luo State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiao tong University Xi'an 710049 China

Properties of supercritical water will undergo drastic changes near the "pseudo critical" point which gives rise to a serious concern about flow instabilities under supercritical conditions. To investigate the fluid flow behaviors, experiments with different system pressures (near-critical and supercritical pressure) were conducted on the Xi'an Jiao tong University's (XJTU) supercritical water test facility. Large amplitudes of mass flow flux as well as inlet pressure were found in various operation conditions. Mechanism of this unusual flow instability behavior is discussed. The oscillation behavior occurring in the present work has also been compared with that under the subcritical pressures and parameters effects are also studied.

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Research on condensation of n-octane/n-nonane in throttling flow

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Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2011年第SUPPL. 1期32卷 150-153页

作者： Lü, Xiao-Fei Liu, Hai Li, Ming-Sheng Chang, Chun Bai, Bo-Feng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China First Gas Production Factory Xinjiang Oil field Company Karamay 834000 China

A numerical model was developed to simulate the condensation flow of the n-octane/n-nonane in three dimension throttle. With this model the condensation properties of n-octane/n-nonane in throttle were investigated, it was found that the maximum supersaturation ratio of n-octane/n-nonane vapor in the homogeneous condensation process was very high, in comparison n-nonane was harder to condense. The influence of inlet supersaturation ratio, total pressure and total temperature on the condensation of n-nonanein in throttling flow process was analyzed. From the results, the direct influences of inlet parameters were found on the wilson point location, average droplet radius and liquid phase mass fraction.

关键词： Condensation

Study of thermophysical properties of binary mixtures of N-phenyl ethanolammonium based protic ionic liquids with water and ethanol solvents

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Journal of Ionic Liquids 2022年第1期2卷

作者： Chennuri, Bharath Kumar Losetty, Venkatramana Sreenivasulu, K. Gardas, Ramesh L. Sivakumar, K. A.P. Tirupati517502 India Department of Chemistry VelTech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology Avadi Chennai600062 India Department of Chemistry State Key Laboratory of Multiphase Flow in Power Engineering Xian Jiaotong University Xian710049 China Department of Chemistry Indian Institute of Technology Madras Chennai600036 India

This work reveals that the physicochemical properties such as density, ρ and speed of sound, u for the binary mixtures of N-phenylethanolammonium formate ([NPEA][For]) and N-phenylethanolammonium acetate ([NPEA][Ace] with water and ethanol solvents were experimentally measured for the temperature ranges from 293.15 K to 318.15 K at atmosphere pressure. The apparent molar volume, VΦ and apparent molar isentropic compressibility, κs,Φ were estimated from the experimental data. Redlich-Mayer type empirical equation was applied to calculate the limiting apparent molar properties at infinite dilution (Vω∞ and k∞) and corresponding empirical parameters (Sv, Bv, Sk and Bk). The type of interaction either IL-solvent or IL-IL or solvent-solvent occurring in solution were determined from the data of empirical parameters. Furthermore, the temperature dependent apparent molar volume at infinite dilution, V∞ was used to calculate the apparent molar expansibility at infinite dilution, E∞. Moreover, these E∞ values of the studied binary solutions were found to be positive. The making and breaking structure ability of both PILs were analyzed at all experimental conditions. © 2021 The Authors

关键词： Dilution

Investigation on the flow distribution characteristics of a water-wall intermediate header at a supercritical pressure

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Reneng Dongli Gongcheng/Journal of engineering for Thermal Energy and power 2006年第3期21卷 299-302页

作者： Zhu, Yu-Qin Bi, Qin-Cheng Chen, Ting-Kuan State Key Laboratory of Power Engineering Multi-Phase Flow Xi'an Jiaotong University Xi'an 710049 China

An investigation was conducted of the flow distribution characteristics of distribution header water-wall tubes under a supercritical pressure for a home-made 600 MW once-through boiler. The test parameters can be listed as follows: pressure p=23-25 MPa, mass flow rate G=400-1200 kg/(m2·s), working medium temperature t=10-400°C. An experimental study has been conducted of the impact of working medium pressure, mass flow rate and working medium temperature on the vertical water-wall tube flow distribution characteristics of the distribution header. The test results show that with an increase in mass flow rate, the uniformity of flow distribution among the vertical water-wall tubes could be enhanced. The non-uniformity of flow distribution will undergo a step increase near the quasi-critical points. Moreover, with an increasing pressure, the above-mentioned step increase will become weaker. By employing a discrete model of the parallel-connected branch tubes of the distribution header, the flow distribution among the distribution header vertical water-wall tubes was calculated and the calculation results are in good agreement with the test ones.

关键词： Distribution header Once-through boiler Supercritical pressure Vertical water-wall tubes

Pressure-velocity coupling algorithm on non-orthogonal non-staggered grid

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Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics 2006年第1期23卷 93-96页

作者： Xie, Gong-Nan Wang, Qiu-Wang Zhang, Dong-Sheng Tao, Wen-Quan State Key Laboratory of Multi-phase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

In this paper, a new numerical procedure is proposed for the steady flow of a viscous, incompressible fluid based on SIMPLER algorithm on a non-orthogonal non-staggered grid, together with Cartesian velocity components as dependent variables in the momentum equations. The main feature of the algorithm is that the pressure and pressure correction equations are obtained by explicitly treating pressure cross-derivatives terms in interface contravariant velocities. A collocated arrangement of variables is introduced on numerical grids, and the cell face velocities are calculated by the momentum interpolation. It is proved that this algorithm can be effectively used to simulate fluid flow and heat transfer in complex geometry, by the validation calculation of flow inside branching channel.

关键词： Incompressible flow

Effects of Flue Gas Recirculation on Combustion and Heat Flux Distribution in 660 Mw Double-Reheat Tower-Type Boiler

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SSRN 2022年

作者： Deng, Lei Dong, Lingxiao Bai, Yang Wu, Yuhao Liu, Hu Belošević, Srdjan Tomanović, Ivan Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Guoshen Institute of Technology CHN ENERGY Xi'An710065 China Department of Thermal Engineering and Energy "VINČA" Institute of Nuclear Sciences National Institute of thе Republic of Serbia University of Belgrade Mike Petrovića Alasa 12-14 11351 Vinča PO Box 522 Belgrade11001 Serbia

The ultra-supercritical double-reheat boiler has attracted more attention because of high parameters, low pollution and large capacity. However, there are some difficulties in the development of this technology, such as adjusting the reheat steam temperature. In this study, computational fluid dynamics simulation is used to analyze a 660 MW double-reheat tower-type pulverized coal-fired boiler. The influence of flue gas recirculation (FGR) on heat transfer characteristics and combustion process in the furnace (including heating surfaces in the upper parts of the furnace) are evaluated. The user-defined function approach predicates CO reduction effect on NO x . The results show that the flow at the horizontal section through the centerline of recirculating flus gas nozzles is rotating. The velocity distribution changes into an elliptical rotating flow when FGR ratio is 20%. At higher FGR ratios, the high-temperature area (1565-1700 K) shrinks and both the NO x concentration at the low-temperature superheater outlet and oxygen concentration in the furnace descend. Oxygen concentration at low-temperature superheater outlet first increases and then decreases. In the main combustion zone, the heat flux peak of water-cooled wall is about 330 kW m -2 . As FGR ratio increases from 0% to 20%, the rate of water-cooled wall heat absorption to total boiler decreases by 3.50%. This rate for reheater and superheater increases by 2.53% and 2.13%, respectively. © 2022, The Authors. All rights reserved.

关键词： Temperature

Numerical Simulation of Acoustic Propagation in Gas Ultrasonic flowmeter

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SSRN 2022年

作者： Xiao, Yongqing Zhang, Meng Li, Dong Yang, Yueming Ma, Bingkun Qi, Jianhui School of Energy and Power Engineering Shandong University Jinan250061 China Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization North China Electric Power University Beijing102206 China Suzhou Research Institute Shandong University Suzhou215123 China Shandon Academy of Sciences China

Ultrasonic flowmeter has been widely used in chemical smelting, industrial production and other fields. Through the COMSOL Multiphysics software, the non-linear trajectory of the rays in the non-invasive and intrusive UFW is first simulated by the ray tracing method. Then, the transient ultrasonic propagation process is simulated to analyze the reasons for the error of ultrasonic propagation. Finally, the cause of the error of the transducer is analyzed by the sound pressure signal at the receiving end. It was found that it is precisely because of the high-speed flow that the ultrasonic propagation is distorted, which is manifested as the non-linear trajectory and downstream drift of the sound beam. The signal at the receiving end also fails to hit the correct position due to beam drift, resulting in sound pressure falling below the detected value. © 2022, The Authors. All rights reserved.

关键词： flow measurement