检索结果-内蒙古大学图书馆

Experimental Study on flow and Heat Transfer of Medium-Prandtl-Number Fluid Along a Hexagonal Helical Cruciform Seven-Rods

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Jiang, Dianqiang Zhang, Dalin Tian, Wenxi Qiu, Suizheng Su, Guanghui 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’an710049 China

A novel type of nuclear fuel named helical cruciform fuel may realize self-supporting for adjacent elements and improve heat transfer, both of which contribute to increasing the power density of the reactor. The flow and heat transfer characteristics of a hexagonal helical cruciform seven-rod bundle were experimentally investigated in the present work. 200 sets of isothermal frictional resistance experiments and 199 sets of heat transfer experiments were finished. The laminar flow region (200 © 2023, The Authors. All rights reserved.

关键词： Reynolds number

Atomic Insights into Hydrogen Peroxide Decomposition on the Surface of Pure and Pre-Treated Silver: A Reactive Molecular Dynamics Simulation Study

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Zhao, Xiao Feng, Yiming Zhang, Bowei Jin, Hui Wei, Xianggeng State Key Laboratory of Solid Propulsion Northwestern Polytechnical University Shaanxi Xi’an710072 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China

Based on ReaxFF molecular dynamics simulation, H2O2 decomposition on pure and pre-treated silver catalyst is studied at a microscopic level. The pretreatment undergoes a surface annealing with redundant H2O2 on top of catalyst. The simulation results indicate that H2O2 decomposition can be drastically accelerated by elevating temperature. The extent of decomposition is closely related to bond, hydrogen bond, and potential energy of simulation system. It is found that H2O2 decomposition follows a four-stage HO-OH bond break mechanism while it needs three times longer for pre-treated silver catalyst than pure silver catalyst. The activation energy of pre-treated silver catalyst is about 50% lower than pure silver catalyst. However, the overall reaction rate of pre-treated silver catalyst is about an order of magnitude slower than pure silver catalyst, which owes to the much smaller pre-factor. It is believed that although the pretreatment causes silver oxide to be formed on the surface, it leads to more hydrogen and oxygen atoms deposited so that most active sites for catalytic reaction are blocked for further decomposition. This may be helpful to understand the inherent mechanism of H2O2 decomposition on silver-based catalyst and provide instructional advice for further catalyst modification design. © 2023, The Authors. All rights reserved.

关键词： Catalysts

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

学校读者我要写书评

暂无评论

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

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.

关键词：

Development and Validation of Fully-Coupled Subchannel Analysis Code for Lmr within the Moose Framework

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Zhu, Xinyang Chen, Ronghua Wang, Jinshun Niu, Yuhang Wu, Yingwei Zhang, Dalin Tian, Wenxi Qiu, Suizheng Su, Guanghui School of Nuclear Science and Technology Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

As one of the Gen IV advanced reactors, liquid metal reactor(LMR) holds promising prospects for its high fuel efficiency and excellent inherent safety performance. Owing to its complex working conditions and ultra-high operating temperature, a thermal-hydraulic analysis of the reactor core is gradually playing a bigger role in recent years. Therefore, a subchannel code FLARE for LMRs is developed within the MOOSE ***, a hybrid discretization approach involving DG and FEM as well as the JFNK method are employed to solve the equations in a fully-coupled way. To validate the computational accuracy and convergence of FLARE code, comparisons between the calculation values of FLARE, those of other programs and the experimental data are performed using 7-pin, 19-pin and 37-pin assembly experiments. The computational results indicate a good agreement between FLARE, experimental values, and other programs. In conclusion, FLARE code possesses the capability to accurately analyze LMR core. © 2023, The Authors. All rights reserved.

关键词： Reactor cores

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

学校读者我要写书评

暂无评论

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

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.

关键词：

Fluidized bed combustion of high water content alcohol extracted herb residue and the impacts of blending wasted activated coke

学校读者我要写书评

暂无评论

Carbon Resources Conversion 2023年第1期6卷 11-19页

作者： Xuan Liu Xinyu Zhu Wenyan Wang Bowen Shi Guangyi Zhang Jianling Zhang Jiancheng Yang Yanming Shen School of Chemical Engineering Shenyang University of Chemical TechnologyShenyang 110142LiaoningChina School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China China Power Engineering Consulting Group Co. LtdBeijing 100120China

Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue *** alcohol extracted herb residue(AEHR),one special type of HRs,was chosen as the object and was subjected to immediate combustion in a fluidized bed reactor to investigate the characteristics of its resulting NOx *** results showed that,most of the NOx in the flue gas was produced from the char nitrogen(C-N);as the fuel water content increased,the NOx emission concentration exhibited a trend of first decreasing and then increasing;and a properly low combustion temperature inhibited the NOx emission upon the premise of ensuring full *** staging combustion was adopted to effectively control NOx:the NOx emission concentration in the flue gas was reduced to 296 mg⋅m􀀀3 and the NOx emission reduction rate reached 46.51%compared to conventional ***-combustion by blending wasted activated coke(WAC)into the AEHR helped both stabilize the combustion state and reduce further the NOx *** the blending ratio of WAC fell within a proper range of 20-30%,the NOx emission concentration in the flue gas was as low as 231.4 mg⋅m􀀀*** addition to the dilution effect of the combustion flue gas of the blended WAC,the local reducing atmosphere caused by its incomplete combustion as well as its strong absorbability and catalytical effect was accountable for the further decrease of the NOx emission concentration.

关键词： Alcohol extracted herb residue Wasted activated coke Fluidized bed combustion NOx Air staging combustion

Chemical Kinetics Simulation on Nitrogen Migration Characteristics During Co-Combustion of Ammonia and Coal Under Deeply Fuel-Air Multistage Conditions

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Dai, Liangxu Wang, Chang'an Hou, Yujie Ma, Guowei Chen, Yongxu Hurera, Abu Zhou, Lei Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China China Energy Science and Technology Research Institute Co. Ltd. Nanjing210046 China

mmonia, a carbon-free fuel, is attracting an ever-increasing attention. Coal/ammonia co-combustion in coal-fired power plants is considered an effective and fast approach to achieving the global decarbonization goal. However, one bottleneck of the utilization of ammonia fuel is the possible increased NOx emissions. The supply strategy of ammonia can affect the reduction of NOx by NH3. Few studies have explored the influence of ratios of ammonia as a secondary fuel and the secondary air volume on NOx emissions, which could be effective methods to reduce pollution. In this work, a chemical kinetics model was established to study the NOx behaviors during coal/NH3 co-firing in deeply fuel-air multistage conditions. The effects of the ammonia distribution strategies such as the ratio of NH3 as a secondary fuel, the injection position of secondary fuel, and corresponding air distribution with different NH3 co-firing ratios (CR-NH3) on the ammonia reactivity for NOx-reduction were studied. The results show that ammonia should be used as a primary fuel entering the main combustion zone under small CR-NH3 conditions to mitigate the NOx emissions;otherwise, ammonia is inclined to be used as a secondary fuel entering the reduction zone under large CR-NH3 conditions. NOx generation is also found to primarily occur in the burnout zone in fuel-air multistage combustion. Thus, the burnout zone should be given priority to decrease the NOx emissions. With the delay of secondary fuel injection in the reduction zone, the escaping ammonia keeps increasing in the outlet of the reduction zone. Then it is completely burned in the burnout zone, which leads to an increase in NOx emissions. The volume flow rate of NOx shows a downward trend on the whole with the ratio of secondary air increased. The air distribution can alter the function of the reduction zone in both generating and eliminating NO. The findings can provide some guidance to effectively decrease NOx emissions in coal/NH3 co-fi

关键词： Coal

Experimental Study on High-Energy Fluid Jets from a Pipe: Jet Cone Morphology and Impact Force on Flat Plates

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Bi, Qincheng Zhang, Tao Wang, Teng Zhao, Jinle Feng, Fan Liu, Zhaohui State Key Lab Multiphase Flow Power Engn Xi'an Jiaotong University Shaanxi Xian710049 China Department of Power Engineering North China Electric Power University Baoding071003 China

Owing to potential adverse effects such as fatigue, vibration, scouring, and inherent defects, high-pressure pipelines in chemical processes may fail during operation. After failure, high-energy fluid jets into the surrounding space, causing damage to the surrounding equipment and personnel. In extreme cases, the load generated by the jet exerts a reaction force at the pipeline failure point, which causes the pipeline to produce a strong whip, further endangering surrounding systems. To prevent such fundamental and secondary damages, it is important to study the magnitude of the impact force caused by the jetting process and the extent of the impact of the jet cone on surrounding *** this study, an experimental visualization system was utilized that allowed for a continuous and stable heating-jetting-cooling-recovery process for the working fluid. The distance between the nozzle and the impacted target plate can be adjusted on purpose. In this system, deionized water was heated to various conditions (1–8 MPa;20–344 °C) and different states, such as sub-cooled water, two-phase flow, and superheated steam, and then discharged into an atmospheric-pressure environment through pipes of different diameters (2.4–9.2 mm) and length-to-diameter ratios (20–120). Subsequently, the jet cone expanded freely or impacted plates of various sizes and at different distances. Based on the stability and flexibility of this experimental system, new details regarding the jetting process were obtained. Ultimately, a series of experimental data on the jet impact force were obtained, and the expansion morphology of the fluid in the atmospheric-pressure environment was recorded via a high-speed *** experimental results indicate that the water state parameters and the nozzle/pipe structural dimensions significantly affect the shape of the jet cone as well as the magnitude and variation pattern of the jet impact force. Additionally, the jet impact force varies with the distance f

关键词： Atmospheric pressure

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

学校读者我要写书评

暂无评论

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

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.

关键词：