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Research on the THMC Coupling Model for Enhanced Geothermal Systems Based on the Framework of EDFM 29th

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Research on the THMC Coupling Model for Enhanced Geothermal ...

29th International Conference on Computational and Experimental engineering and Sciences, ICCES 2023

作者： Zhang, Weitao Han, Dongxu Jiao, Kaituo Chen, Yujie Yuan, Qing Gong, Liang Yu, Bo Qingdao266580 China Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil and Gas Development School of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing102617 China State Key Laboratory of Multiphase Flow in Power Engineering School of Chemical Engineering and Technology Xi’an Jiaotong University Xi’an710049 China

ISBN: (纸本)9783031429866

The Enhanced Geothermal System (EGS) involves a complex thermo-hydro-mechanical-chemical (THMC) coupling process during long-term heat extraction. However, many models used to solve fractured reservoir problems are computationally time-consuming, especially when dealing with reservoir-scale engineering problems. To address this challenge, this paper proposes a novel THMC coupling model that solves the governing equations using a unified FVM framework based on the embedded discrete fracture model (EDFM). The accuracy of the model is confirmed by comparing the THC coupling and displacement (M) results with the Fully Resolved Solution Method (FRSM) from MRST software and COMSOL, respectively. Moreover, the model developed is utilized to simulate and analyze the spatiotemporal behavior of pressure, temperature, concentration, and mechanical deformation in EGS. The results suggest that the model is appropriate for effectively assessing the long-term production performance of EGS. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Finite volume method

Thermodynamic Analysis of a Supercritical Water Partial Oxidation Autothermal Cogeneration System of Coal

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SSRN 2024年

作者： Xing, Guowei Li, Yifeng Ren, Changyifan Ge, Zhiwei Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

Supercritical water partial oxidation (SCWPO) is a very efficient technology for the environmentally sound treatment of resources. Currently, there are few thermodynamic studies of SCWPO cogeneration system. In this study, a new supercritical water partial oxidation autothermal cogeneration system of coal is proposed. The system was evaluated for energy and exergy under typical operating conditions. The efficiencies achieved were 86% for energy and 47.6% for exergy. Due to the mixed working fluid is a mixture of H2O and CO2, the CO2 is very easy to capture. The exergy analysis revealed that the most significant exergy loss within the system occurred in the SCWPO reactor, which accounted for 78.2%% of the total exergy loss. Further sensitivity analysis of the system indicates that optimum values identified for both back pressure and carbon capture and storage unit (CCS) first stage pressure (PV-pump1), which are 8.5 kPa and 0.03 MPa. Additionally, increasing both the flow rate and temperature of preheated water can significantly enhance system efficiency. An increase in the flow rate of preheated water can lead to a reduction of the maximum system temperature;however, an elevation in the temperature of preheated water may cause a significant rise of the maximum system temperature, which is not conducive to the stable operation of the system. Finally, this paper compares the proposed system with the systems that have been reported in the literature. The results show that the system represents an innovative cogeneration solution with considerable advantages. © 2024, The Authors. All rights reserved.

关键词： Exergy

Heat Transfer Enhancement of Air flow Through New Types of Perforated Dimple/Protrusion Fins

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SSRN 2024年

作者： Sen, Palash Chen, Mengjie Bai, Bofeng State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

Heat transfer enhancement technologies of air flow are of critical to energy conservation and emission reduction in industrial applications. This paper explores the numerical simulation analysis of 18 kinds of perforated dimple/protrusion fins. The wind speed varies within the range of 2~6m/s, and the investigation delves into the impact of different structural parameters on strengthening factor Nu/Nu0, resistance factor f/f0 and other comprehensive evaluation factor performance evaluation criteria (PEC) of perforated dimple/protrusion fins. The study specifically explores the influence of structural parameters, including intercepting perforated dimple/protrusion height (S0), aperture (D), hole structure offset (a), and the arrangement of perforated dimple/protrusion structure, on heat transfer performance. The overall heat transfer performance of the perforated dimple/protrusion fins rises with height under the same operating conditions. It first increases and then declines with the increasing aperture, and first drops and then increases with the increasing offset. The hole structure offset is better on the inflowing leeward side than on the inflowing side. The fins with both perforated dimple and perforated protrusion structures have advantages over the one with either of two structures, and the alignment arrangements are identified as the optimal configuration. © 2024, The Authors. All rights reserved.

关键词： Air

Excellent Energy Storage Performance Achieved in Sr(Sc0.5Nb0.5)O3-Doped Bi0.5Na0.5TiO3-Based Lead-Free Relaxor Ferroelectric Ceramics

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ACS Applied Energy Materials 2024年第5期7卷 2030-2038页

作者： Liu, Jinnan Li, Da Zhao, Weichen Xu, Diming Shi, Zhongqi Liu, Wenfeng Su, Jinzhan Zhou, Tao Chen, Guohua Zhou, Di Electronic Materials Research Laboratory & Multifunctional Materials and Structures Key Laboratory of the Ministry of Education International Center for Dielectric Research School of Electronic Science and Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China State Key Laboratory for Mechanical Behaviour of Materials Xi’an Jiaotong University Xi’an710049 China State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University Shaanxi Xi’an710049 China International Research Centre for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China School of Electronic and Information Engineering Hangzhou Dianzi University Hangzhou310018 China Electronical Information Materials Devices Engineering Research Center of Ministry of Education Guangxi Key Laboratory of Information Materials School of Material Science and Engineering Guilin University of Electronic Technology Guilin541004 China

Dielectric energy storage ceramics have received significant attention as the primary component for high-pulse power capacitors. Currently, their development is limited by poor energy storage performance, which affects the miniaturization and lightweighting of electronic devices. In this study, a comprehensive optimization approach was adopted to enhance the storage performance (recoverable energy density Wrec and conversion efficiency η) of 0.8Bi0.5Na0.5TiO3-0.2NaNbO3 (BNT-NN) through component optimization design and repeated rolling process (RRP). A series of Sr(Sc0.5Nb0.5)O3 (SSN) was introduced into BNT-NN to modulate the phase structure and improve the relaxation properties. The repeated rolling process was applied to refine the grain and enhance the dense property to boost the breakdown of the electric field. Following the mentioned strategy, we have succeeded in simultaneously obtaining ultrahigh Wrec (∼7.22 J·cm-3) and outstanding η (∼95.32%) under 515 kV·cm-1 for 0.8(BNT-NN)-0.2SSN (RRP) ceramic. More importantly, the ceramic sample possesses outstanding stability over a wide range of temperatures (25-60 °C) and frequencies (1-100 Hz). This study proposes a viable route to better performance of dielectric ceramics for energy storage, and the outstanding performance of the 0.8(BNT-NN)-0.2SSN (RRP) ceramic indicates its promising applicability in high- and high-pulse-power electronic devices. © 2024 American Chemical Society.

关键词： Energy storage

Calcium Looping Sorption-Enhanced Electrified Steam Methane Reforming for Efficient Hydrogen Production with Short- and Long-Duration Cooperative Energy Storage

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SSRN 2024年

作者： Song, Huchao Zhang, Xinyue Lin, Xiaolong Bian, Hao Liu, Yinhe State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

Currently, the dominant hydrogen production technology is steam methane reforming, but both the reforming reaction and the combustion for driving the reaction produce significant CO2 emissions. Sorption-enhanced methane reforming enables the in-situ removal of CO2 produced by the reforming reaction and promotes higher hydrogen yields, however, CO2 emissions from combustion cannot be avoided. Renewable electricity instead of combustion for reaction heating can eliminate combustion carbon emissions and flue gas heat loss, but its dependence on renewable electricity supply prevents continuous and stable operation. This study proposes a sorption-enhanced electrified steam methane reforming technology based on short- and long-duration cooperative energy storage and calcium looping carbon capture. This technology utilizes the CO2 adsorption and energy storage property of the absorbent to absorb CO2 in situ in the reformer and transform renewable electricity to chemical and thermal energy in the regenerator as short- duration energy storage. The energy stored in the absorbent can be used to drive the methane reforming reaction and transformed into chemical energy in hydrogen continuously as long- duration energy storage. Through First law and Second law analysis, this study has found that the novel process improves thermal efficiency by 8.5 percentage points and reduces the exergy loss of the overall process by 53.2% compared with the sorption-enhanced steam methane reforming process. Based on current fuel prices in China, the novel process is more economical than the other steam methane reforming processes simulated in this study. Sensitivity analysis has found that low electricity and high methane prices benefit the economic performance of the novel process. This study may provide a stable, efficient, and economical way of clean hydrogen energy production. © 2024, The Authors. All rights reserved.

关键词： Hydrogen production

High Concentration of CO and CO2 Inhibits Coal Gasification in Supercritical Water

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SSRN 2024年

作者： Zhang, Rui Zhao, Shuaiqi Huang, Han Zhao, Kunpeng Bai, Bofeng State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

Supercritical water gasification technology achieves efficient resource utilization of lignite and produces H2, CO and CO2. In this study, we experimentally investigated the impact of gas product generated from high concentration (>30 wt%) formic acid decomposition on the gasification of Tiebei lignite in the supercritical water. H2 promotes the pyrolysis of carbon structures, the increase in CO promotes CO2 generation through the water-gas shift reactions, and the enrichment of CO2 hinders gas diffusion. We found that high concentration of formic acid(H2, CO and CO2) inhibits the gasification of Tiebei lignite in the supercritical water. Compared with coal gasification in the supercritical water without formic acid, 30wt% formic acid reduces the carbon efficiency of lignite by 7.66%, and the mass conversion of coal by 3.97%. When the concentration of formic acid is 30wt% to 70wt%, the higher concentration of formic acid(H2, CO and CO2), the worse gasification performance of Tiebei lignite. © 2024, The Authors. All rights reserved.

关键词： Water gas shift

Effect of Fuel System on the Heat Releasing Method and flow-Path Design of Rocket-Based Combined Cycle Engine 14

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Effect of Fuel System on the Heat Releasing Method and Flow-...

14th International Conference on Mechanical and Aerospace engineering, ICMAE 2023

作者： Liu, Xiao Wang, Yinhu Yang, Yiyan Shi, Lei Yan, Dekun Xi'An Jiaotong University State Key Laboratory of Multiphase Flow in Power Engineering Xi'an China Beijing Institute of Long March Vehicle Beijing China Northwestern Polytechnical University Science and Technology on Combustion Internal Flow and Thermal-structure Laboratory Xi'an China

ISBN: (纸本)9798350340327

Multi-components rocket-based combined cycle (RBCC) engine is widely applied in most two-stage-To-orbit program due to stable operation performance under variable flight conditions. Present researches numerically compared RBCC's performance under ramjet mode and scramjet mode, respectively, by using two fuel system, hydrogen and kerosene together with a \mathrm{k}-\omega SST turbulence model. Researches showed that the combustor area ratio should be increased to keep stable pressure difference balance between inflow and flame because of higher caloric value using hydrogen. Distributed heat addition method is benifit for overall performance improvement when using hydrogen. Different from using kerosene, head should be delayedly added in combustor downtream under scramjet mode. Moreover, the advanced heat addition amount should be decreased under ramjet mode to ensure effective isolator operation. © 2023 IEEE.

关键词： Hydrogen

Thermal mechanical response analysis of the first wall in laser initial confinement fusion reactors

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International Journal of Advanced Nuclear Reactor Design and Technology 2025年第2期7卷 147-155页

作者： Xinze Li Bingqian Zhang Chengcheng Tong Ronghua Chen Dalin Zhang Wenxi Tian Suizheng Qiu State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi'an Jiaotong University Xi'an 710049 China

This paper investigates the thermo-mechanical response characteristics of the first wall of a laser initial confinement fusion reactor under periodic transient heat flux loads. The first wall of the reactor experiences extremely high instantaneous heat loads during the target compression process, leading to temperature and thermal stress oscillations, which can cause material fatigue damage. Finite element analysis is employed to model the first wall under various chamber sizes and target energies, and the thermal-mechanical response characteristics of W, W/Cu functional gradient materials, and blanket materials are studied under thermal shock and cyclic loading conditions. The results indicate that W/Cu functional gradient materials can effectively alleviate thermal stresses on the first wall, especially in addressing the stress concentration at the interface. Fatigue life of the first wall is assessed using the Basquin model, and it is found that increasing the chamber size and increasing the target frequency can significantly reduce temperature oscillations and thermal stresses, thus extending the service life of the first wall. This study provides valuable design references for the optimization and design of the first wall in laser initial confinement fusion reactor.

关键词： Laser inertial confinement fusion reactor First wall Heat oscillation Thermal fatigue

Experimental Study on flow Boiling and Circumferential Non-Uniform Heat Transfer Characteristics in Helically-Coiled Tube Under Coupled Heat Transfer Conditions

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SSRN 2024年

作者： Wang, Hengyuan Xuan, Qiyu Lei, Hailin Li, Xi Li, Zhibin Li, Huixiong State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China

Because of its compact structure and high energy conversion efficiency, helically-coiled tube steam generator has been widely used in nuclear reactor, energy power, petrochemical and other systems. In the liquid metal reactor, the liquid metal on the primary side of the helically-coiled tube steam generator washes the helically-coiled tube bundles, and exchanges heat with the water on the secondary side. Due to the coupled heat transfer between liquid metal and water, the distribution of the wall temperature or heat transfer coefficient of helically-coiled tube are significant different in the circumference direction of the tube cross-section. An experimental system of helically-coiled tube steam generator was set up in this paper. The non-uniform heat transfer characteristics of secondary side fluid of helically-coiled tube steam generator were studied under the coupled heat transfer conditions between the heat transfer of primary side and secondary sides fluid. It was found the local wall temperature or local heat transfer coefficient in the circumferential direction of the tube cross-section was significantly different, and they showed different change trends with the change of the parameters such as subcooling degree, mass flux of the secondary side fluid, system pressure of secondary side fluid, heating temperature of primary side fluid, etc. Secondly, ηt and ηh were defined to represent the degree of local non-uniformity of local wall temperature or local heat transfer coefficient in the circumferential distribution of the tube cross-section, respectively. δt and δh were defined to characterize the degree of overall non-uniformity of wall temperature or heat transfer coefficient in the circumferential distribution of the tube cross-section, respectively. The variation rules of ηt and ηh, δt and δh with subcooling degree、system pressure、mass flux of primary side fluid、mass flux of secondary side fluid and heating temperature of primary side fluid were obtained.

关键词： Steam generators