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Experimental Study on Deliquification with Atomizing Nozzle in Gas Well

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Experimental Study on Deliquification with Atomizing Nozzle ...

2020 International Conference on Green Energy, Environment and Sustainable Development, GEESD 2020

作者： Gao, Yutang Li, Xiaobai Chang, Peng Liu, Lei State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Shaanxi710049 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. © Published under licence by IOP Publishing Ltd.

关键词： Two phase flow

Experiments and Predictions for Severe Slugging of Gas-Liquid Two-Phase flows in a Long-Distance Pipeline-Riser System

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SSRN 2023年

作者： Chang, Yingjie Xu, Qiang Zou, Suifeng Zhao, Xiangyuan Wu, Quanhong Wang, Yechun Thévenin, Dominique Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Laboratory of Fluid Dynamics and Technical Flows Otto-von-Guericke-Universität Magdeburg Magdeburg39106 Germany

Experiments concerning the flow regimes observed in gas-liquid two-phase flows in a long pipeline-riser system have been carried out and are analyzed in this paper. The test loop with 0.075 m inner diameter consists of a 314 m horizontal pipeline, followed by a 25 m downward-inclined pipe, and finally a 21.5 m riser pipe. An industrial-scale global flow regime map is derived from differential pressure measurements in the riser. Electrical capacitance volume tomography installed in the horizontal section was used to reconstruct the phase interface in order to calculate the average gas void fraction (GVF). An appropriate model for this system is selected by comparing the experimental GVF with different, widely used models. The occurrence of a severe slugging flow (SS) can be well predicted using the model involving additional corrections (taking into account pipeline length, accurate GVF results, and gas density). This study supports the development of a suitable SS prediction model enabling safe design, operation, and control of practical systems. © 2023, The Authors. All rights reserved.

关键词： Pipelines

Experimental Study and Theoretical Development of Liquid Entrainment in T-Junction with Double Inlets and Single Inlet of Gas Phase

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SSRN 2023年

作者： Li, Kepiao Shi, Yanggen Zhang, Kui Tian, Wenxi Qiu, Suizheng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi’an710049 China School of Nuclear Science and Technology Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology Xi'an Jiaotong University Xi’an710049 China

The liquid phase entrainment through vertical-up branch had been analyzed through scaled and full size of experiment since ADS-4 (the fourth-stage Automatic Depressurization System) valve adopted in advanced PWR (Pressurized Water Reactor). Most of the existed studies focus on the single inlet of gas whereas steam may flow from two sides of the T-junction during the blowdown of primary system. Hence the experimental study on liquid entrainment with double end inlets are carried out. The data on the onset of entrainment (OLE) turns out that double end inlets show small difference with single inlet, whereas the entrainment rate research have great difference with single inlet and there is more than 50% error between the data and existing theoretical models. According to the visible flow phenomenon and flow instability, a new entrainment rate model was proposed which can well predict the double-end inlets and single-inlet entrainment phenomenon with the error within ±20%. © 2023, The Authors. All rights reserved.

关键词： Pressurized water reactors

Experimental Study on Electrocatalytic Reduction of CO2 to Methanol over Cu2O and Cu2O/ZnO films

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Experimental Study on Electrocatalytic Reduction of CO2 to M...

International Conference on power engineering 2021, ICOPE 2021

作者： Zhang, Wenfei Zhou, Qulan Qi, Ji Li, Na State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China China Mobile System Integration Co. Ltd Beijing100052 China

The Cu2O film electrodes were prepared by solution immersion method, the ZnO/Cu2O film electrodes were prepared by electrodeposition method. Then the pure Cu2O film electrodes and ZnO/Cu2O film electrodes were used to reduce CO2 to CH3OH. The crystal structure, morphology, particle size and specific surface area of pure Cu2O films prepared under different immersion time and ZnO/Cu2O films prepared under different deposition time and Zn2+ concentration were analyzed by XRD, SEM, and BET. The electrolytic activity of the pure Cu2O film electrodes and ZnO/Cu2O film electrodes were studied. Under the same reaction conditions, the Cu2O film electrode with 2 h preparation time has the best electrolysis effect in the three groups of pure Cu2O electrode. The increase of reaction temperature can significantly promote the reduction of CO2 to CH3OH on Cu2O film electrodes. the ZnO/Cu2O film electrode with the Zn2+ concentration of 0.05 M and the deposition time of 30 min had the highest total CH3OH yields. This study highlights that the ZnO have a very good promotion of electrolytic CO2 reduction on Cu2O film. © 2021 The Japan Society of Mechanical Engineers.

关键词： Carbon dioxide

Jet Impingement Boiling Heat Transfer Performance of Refrigerant Hp-1 in Micro-Pin-Finned Surfaces for High-power Chips

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SSRN 2023年

作者： Ma, Xiang Gui, Liangxin Song, Gege Hu, Chengyu Yang, Xiaoping Zhang, Yonghai Wei, Jinjia School of Chemical Engineering and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

In this paper, jet impingement boiling heat transfer performance was studied using a novel new environmentally friendly refrigerant medium (HP-1) based on a high-power chip heat sink. A series of experimental investigations of jet impingement boiling were conducted on smooth and micro-pin-finned surfaces (PF0.5-0.5-1, PF0.5-0.5-2 and PF0.3-0.3-1). Heat transfer performances were evaluated over the saturated pressures from 450 to 590 kPa, liquid subcoolings from 2 to 15 K, nozzle sizes from 1 to 2 mm, mass fluxes from 71 to 858 kg/(m2s). The results show that critical heat flux (CHF) and heat transfer coefficient (HTC) increases with the increase of mass flux and saturated pressure. At ΔTsub=15 K, the CHF of the micro-pin-finned surfaces can be increased by 63% compared with smooth surface, in which the CHF of PF0.5-0.5-2 surface is up to 1532 kW/m2. Boiling heat transfer coefficient first increases and then decreases with the increase of heat flux. Due to the increase of the inlet liquid subcooling, leading to a large temperature difference, so the heat transfer coefficient is smaller at a high liquid subcooling. Several factors, such as mass flux, saturated pressure and liquid subcooling, have a great impact on pressure drop. With the increase of vapor quality, the shear action between the vapor-liquid phase is enhanced, and the pressure drop will gradually increase. Bubble behaviors have also been captured by a high-speed camera to help analyze the mechanism of jet impingement boiling heat transfer in a confined space for high-power chips. © 2023, The Authors. All rights reserved.

关键词： Heat flux

Exploration of the Responsiveness of the Atomization Field in a Centrifugal Nozzle to Variations in Inlet Pressure

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SSRN 2023年

作者： Xu, Wen Yang, Jianwen Yang, Bin Wang, Ying Shanghai Key Laboratory of Multiphase Flow and Heat Transfer of Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai China Xi’an Aerospace Propulsion Institute Xi’an710100 China

As the crucial atomization unit in the propellant supply system for liquid rocket engines, the centrifugal nozzle's atomization performance is of paramount importance. However, due to flow oscillations within the propellant supply system, the resulting spray from nozzle atomization tends to oscillate, adversely impacting fuel atomization efficiency. This paper employs a VOF-to-DPM multiphase flow model to simulate the nozzle's atomization field under different inlet pressures, which is subsequently compared with experimental results. Next, the UDF is used to introduce pressure pulsation sources with varying frequency sizes at the nozzle inlet, from which the following conclusions are drawn: (1) The numerical simulation-derived atomization angle of the nozzle under different inlet pressures slightly deviates below the experimental value, but consistently maintains a similar trend, with errors not exceeding 5%;(2) Under constant inlet pressure, the nozzle's atomization field exhibits a stable, smooth, hollow cone liquid film formation, and particle droplets produced by liquid film atomization coalesce at the hollow cone's lower end;(3) When pressure pulsations with diverse frequencies and magnitudes are loaded at the nozzle inlet, the atomization field undergoes varying degrees of oscillation. When f = 100 Hz, the hollow cone liquid film disappears completely after undergoing initial formation during a pulsation cycle, and the atomized particles' number experiences the most significant change relative to constant inlet pressure. When f = 400 Hz, the broken droplets gradually reform the hollow cone liquid film within a pulsation period and maintain its form but undergo subsequent breaking. When f = 800 Hz, there is no apparent alteration in the shape of the hollow cone liquid film or total particle count during a pulsation cycle. However, the liquid film's surface appears uneven, showing wavy water marks. © 2023, The Authors. All rights reserved.

关键词： Atomization

Analysis of Different Control Strategies Considering Individual Regulation of Heat User

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Analysis of Different Control Strategies Considering Individ...

Electrical engineering and Mechatronics Technology (ICEEMT), IEEE International Conference on

作者： Zhiwei Xun Huijie Wang Liyuan Wang Long Yang Yunfang Gao Ming Liu Guoneng Jinjie Energy Co. Ltd Yulin China Xi’an Jiaotong University Xi’an China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

In the process of outdoor temperature change, it is beneficial to improve the comfort of thermal users to formulate adjustment and control strategies according to the actual needs of each user. In this paper, different adjustment modes are established according to the thermal comfort of users, and the control strategies of rising and cooling within 0, 30 and 60 minutes are proposed, and the indoor temperature control effect and heating energy consumption of each adjustment mode under different control strategies are analyzed. The results show that: in different modes, when the rise and cooling time increase, compared with the design room temperature, the indoor temperature difference under the control mode is smaller, but the time needed to reach stability is longer. At the same time, the total heat load is unchanged, but the total pump work decreases.

关键词：

On Accelerative Propagation of Premixed Hydrogen/Air Laminar and Turbulent Expanding Flames

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SSRN 2022年

作者： Zhao, Haoran Wang, Jinhua Cai, Xiao Dai, Hongchao Liu, Xiao Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong Universit Xi’an710049 China College of Power and Energy Engineering Harbin Engineering University Harbin150001 China

The accelerative propagation of laminar and turbulent premixed hydrogen/air flames are investigated using a constant volume combustion chamber. Turbulent burning velocity ( S T ) of hydrogen/air mixtures are determined in a wide range of conditions, more importantly the flame propagation dynamics and acceleration exponents are analyzed in detail. Results show that three distinct stages, namely quasi steady, transition acceleration and saturation acceleration stages are distinguished in laminar flame propagation process, and transient acceleration exponent ( a R ) increases in transition acceleration stage while nearly remains as a constant between 1.1~1.25 in saturation acceleration stage. Turbulent flame propagation follows a self-similar acceleration law, and transient acceleration exponent increases continuously as flame propagates outwardly. Furthermore, the empirical correlatio n is obtained to describe the development of turbulent flame acceleration with flame radius. Additionally, global acceleration exponents ( a ) of turbulent flames increase continuously with u ’ / S L and no significant trend variation occurs in different regimes. It appears that the accelerative propagation of turbulent expanding flames is mainly controlled by turbulence stretch, while the effect of flame intrinsic instability is nearly covered in current study. © 2022, The Authors. All rights reserved.

关键词： Acceleration

Numerical Study on the Effect of Rim Seal Slot Filleting on Turbine Endwall Cooling Performance

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SSRN 2023年

作者： Shi, Liuliu Di, Wentao School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Key Laboratory of Power Machinery and Engineering Ministry of Education Shanghai Jiao Tong University Shanghai200240 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China

In the present study, the effect of rim seal slot filleting on turbine endwall cooling performance is numerically investigated. Based on validation of the numerical method, the Reynolds-averaged Navier-Stokes (RANS) equations combined with the standard turbulence model are adopted in this study. For comparison with the baseline case, five different fillet radii are adopted, i.e. R/W=1.25, 2.5, 3.75, 5 and 6.25. The results indicate that the overall film cooling effectiveness on the turbine endwall can be improved by up to 10% with smaller fillet radii. However, this effect diminishes as the fillet radius increases and it becomes negative at R/W=6.25. By examining the contours of the endwall film cooling effectiveness in filleted cases with the baseline, a prominent strip can be observed across the blade passage. This reveals that the primary contributor to the variation of the film cooling performance is the pressure-side leg horseshoe vortex. Besides, the film cooling effectiveness is slightly improved near the suction side of the leading edge owing to the suppression of endwall separation at this area. The rim seal slot filleting eliminates the slot leakage separation, which in turn speeds up the endwall coolant flow. Ultimately, this weakens the pressure-side leg horseshoe vortex and subsequently enhances the film cooling performance. As the fillet radius continues to increase, the through-flow area for the coolant flow enlarges, resulting in a gradual decrease in film cooling performance. © 2023, The Authors. All rights reserved.

关键词： Turbulence models