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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 293.1. K to 31..1. 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

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 (1.65-1.00 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 2.1.%, respectively. © 2022, The Authors. All rights reserved.

关键词： Temperature

Comparison of chemical composition and acidity of size-resolved inorganic aerosols at the top and foot of Mt. Hua, Northwest China: The role of the gas-particle distribution of ammonia

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Science of the Total Environment 2023年 905卷 166985页

作者： Feng, Qiao Liu, Haijiao Dai, Wenting Cao, Yue Shen, Minxia Liu, Yali Qi, Weining Chen, Yukun Guo, Xiao Zhang, Yifan Li, Lu Zhou, Bianhong Li, Jianjun State Key Laboratory of Loess and Quaternary Geology Key Lab of Aerosol Chemistry and Physics Institute of Earth Environment Chinese Academy of Sciences Xi'an710061 China College of Geography and Environment Baoji University of Arts and Sciences Shaanxi Key Laboratory of Disaster Monitoring and Mechanism Simulation Baoji721013 China Xi'an Institute for Innovative Earth Environment Research Xi'an710061 China National Observation and Research Station of Regional Ecological Environment Change and Comprehensive Management in the Guanzhong Plain Shaanxi China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

Aerosol pH is not only a diagnostic indicator of secondary aerosol formation, but also a key factor in the specific chemical reaction routes that produce sulfate and nitrate. To understand the characteristics of aerosol acidity in the Mt. Hua, the chemical fractions of water-soluble inorganic ions in the atmospheric PM2.5 and size-resolved particle at the top and foot of Mt. Hua in summer 2020 were studied. The results showed the mass concentrations of PM2.5 and water-soluble ions at the foot were 2.0–2.6 times higher than those at the top. The secondary inorganic ions, i.e., SO42−, NO3−, and NH4+ (SNA) were 56 %–61.% higher by day than by night. SO42− was mainly distributed in the fine particles (Dp 3− showed a unimodal size distribution (peaking at 0.7–1.1.μm) at the foot and a bimodal (0.7–1.1.μm and 4.7–5.8 μm) size distribution at the top. At the top site, the distribution of NO3− in coarse particles (> 2.1.μm) was mainly attributed to the gaseous HNO3 volatilized from fine particles reacting with cations in coarse particles to form non-volatile salts (such as Ca(NO3)2). The pH values of PM2.5 were 2.7 ± 1.3 and 3.3 ± 0.42 at the top and foot, respectively. NH4+/NH3(g) plays a decisive role in stabilizing aerosol acidity. In addition, the increase of the liquid water content (LWC) at the foot facilitates the gas-particle conversion of NH3, while the H+ concentration was diluted, resulting in a decrease in acidity at the foot. NH4+/NH3 had good linear correlations with SO42−, NO3−, and LWC during the daytime at both sites, indicating that SO42−, NO3−, and LWC together affect the gas-particle distribution of ammonia by day: however, the effect of LWC at night was not evident. © 2023

关键词： Ammonia

A 3d Ptco Degradation Model for Long-Term Performance Prediction of a Scaled-Up Pemfc Under Constant Voltage Operation

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SSRN 2023年

作者： Yang, Yunjie Bai, Minli Zhou, Zhifu Wu, Wei-Tao Zhao, Jian Wei, Lei Li, Yang Li, Yubai Song, Yongchen Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education Dalian University of Technology Dalian116024 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'An710049 China School of Mechanical Engineering Nanjing University of Science and Technology Nanjing210094 China Center for Advanced Vehicular Systems Mississippi State University Starkville39762 United States Department of Mechanical and Energy Engineering Southern University of Science and Technology Shenzhen518055 China

The non-uniform distribution of reactants, pressure, temperature, and reaction rate, in a scaled-up proton exchange membrane fuel cell (PEMFC) can lead to different catalyst degradation rate, impacting the long-term performance of PEMFCs. However, the local catalyst degradation behaviors in a PEMFC stack have not yet been fully understood due to the lack of experimental approaches and catalyst degradation model. In the present study, a numerical model is established for a 200 cm2 commercial-sized PEMFC stack with realistic anode and cathode flow fields. PtCo is employed as the cathode catalyst, and a 3D PtCo catalyst degradation model is developed to analyze the non-uniform evolution of the electrochemical active surface area (ECSA), current density, and Co2+ in the catalyst layers under the constant voltage conditions. The modeling results demonstrated that catalyst degradation is more severe downstream as well as under land of the cathode flow field, and the cathode catalyst layer (CCL) is the area most contaminated by the Co2+. The non-uniform catalyst degradation as well as Co2+ contamination increased the activation losses and local oxygen transport resistance. The catalyst degradation leads to a total power loss of 43.3% after 80,000 hours operation. The aging model provides a better understanding for large scale PEMFC stacks regarding its nonuniform PtCo degradation and can assist the future design of commercial PEMFCs with better lifetime. © 2023, The Authors. All rights reserved.

关键词： Proton exchange membrane fuel cells (PEMFC)

Numerical Investigations for the Pcm and Liquid Immersion Cooling Effects on Lithium Ion Battery Thermal Runaway Mitigation

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SSRN 2023年

作者： Liu, Xinyu Zhou, Zhifu Wu, Wei-Tao Wei, Lei Wu, Weixiong Li, Yang Gao, Linsong Li, Yubai Song, Yongchen Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education Dalian University of Technology Dalian116024 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi’an710049 China School of Mechanical Engineering Nanjing University of Science and Technology Nanjing210094 China Department of Mechanical and Energy Engineering Southern University of Science and Technology Shenzhen518055 China Energy and Electricity Research Center Jinan University Zhuhai519070 China

In this study, a three-dimensional (3D) thermal runaway (TR) model with conjugate heat transfer submodel is adopted. TR behaviors for a battery pack with 1. prismatic LIBs are then simulated. Three thermal safety measures of TR protection from internal shorting in Cell 1.to pack level configuration are compared and evaluated. Paraffin phase change material (PPCM) is firstly proposed to delay the TR propagation between LIBs with solid-liquid phase change as heat transfer mechanism. Different thicknesses of PPCMs are compared to verify the TR mitigation performance of the PPCM under thermal abuse condition. The TR time for the Cell 2 is delayed to be 64 s, 266 s and 41. corresponding to PPCM thickness of 1.8 mm, 3.6 mm and 5.4 mm. As the simulation results shows, this TR time can be further delayed to 798 s by a strategy with combing PPCM with insulation. In addition, this work proposes a novel thermal safety protection based on immersion cooling with pool boiling of fluorinated liquid as heat transfer mechanism. We observe that the average temperature of Cell 2 - Cell 1. tends to be within 34oC under immersive cooling condition, which indicates the possibility to prevent the TR. © 2023, The Authors. All rights reserved.

关键词： Lithium-ion batteries

A Coupled Bioheat Transfer Model for Customized Whole-Eye Modeling in Retinal Laser Surgery

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SSRN 2022年

作者： Zhao, P.H. Li, K. Zhang, H. Li, Dong Chen, B. Zheng, Y.P. Li, W.P. Wang, G.X. Fan, L.H. Yao, L. State Key Laboratory of Multiphase Flow in Power Engineering Xi 'an Jiaotong University Shaanxi Xi'An710049 China Department of Ophthalmology The Second Affiliated Hospital of Xi 'an Jiaotong University Shaanxi Xi'An710004 China The First Affiliated Hospital of Xi'an Joao Tong University Shaanxi Xi'An710061 China Department of Mechanical Engineering The University of Akron Akron United States

The photo-thermal effects of laser on tissue is widely used in ophthalmology to treat retinal diseases. By adjusting the pulse duration from nano to tens of seconds, the multi-scale retinal lesion from micro to millimeter size can be thermally targeted. Large scale difference among the target lesions brought extra challenge for retinal laser surgery modeling. In this study, we developed a coupled whole eye model for retinal laser surgery. In the model, Penens bioheat transfer equation was adapted for the whole eye temperature modeling. Simultaneously, we treat the fundus as a multi-layered porous medium made of a tissue matrix buried with highly-absorbing chromophores (melanin or blood). Two-temperature equations, one for the chromophore and the other for the surrounding tissue, will be developed based on the local thermal non-equilibrium theory of porous media. The Pennes model and the two-temperature model was coupled together to calculated the thermal responses of eye during several laser retinal surgery process with pulse duration from nano to tens of seconds. The simulation results proved our model is capable of modeling laser retinal surgery process in different time scale. Furthermore, the present coupled model was applied in a real fundus anatomy from a patient with diabetic retinopathy to illustrate its feasibility in customized laser protocol planning. © 2022, The Authors. All rights reserved.

关键词： Ophthalmology