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Effects of structure parameter and material property on thermal performance of on-board hydrogen storage tanks during fast refueling

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2024年 81卷 1145-1155页

作者： Yuan, Kaifeng Liu, Zhan Li, Xiaozhao China Univ Min & Technol State Key Lab Geomech & Deep Underground Engn Xuzhou 221116 Peoples R China

As a power generation fuel, high-pressure hydrogen gas is widely used in transportation, and significantly contributed to development of hydrogen fuel cell electric vehicles. However, obvious temperature rise generated during fast refueling causes serious safety risk to reliable operation of fuel cell stacks. Therefore, it is necessary to conduct in-depth research on fast filling process. Based on safety reasons, the SAE J2601/ISO 15869 strictly regulates the maximum temperature limit of 85 degrees C in specifications for refueling hydrogen gas tanks. In this study, a 70 MPa, Type IV on-board hydrogen storage tank is adopted as the research object, and a 2-dimensional axisymmetric numerical model is established to study the temperature rise of the vapor within storage tanks during fast refueling. The Realizable k-epsilon turbulence model is employed to simulate high intensity turbulent fluctuation during fast filling. Considering the compressibility of vapor, the state of equation for real hydrogen gas is used by obtaining fluid thermodynamic properties from the National Institute of Standards and Technology database. Three groups of fast filling experiments are selected to validate the developed numerical model. The comparison result shows that the numerical model has good prediction ability on hydrogen fast refueling. The final mass average temperature differences between numerical results and experimental data are 2.6 K, 4.3 K, and 0.03 K, respectively. Based on the developed numerical model, the influences of structure parameters and material properties on the temperature rise of hydrogen storage tanks are investigated. The results indicate that the inlet diameter and wall thickness of the inner and outer layers of the storage tank have weaken impacts on the temperature rise during rapid charging, with the maximum temperature differences of 1.8 K, 0.74 K, and 0.54 K, respectively. Due to the influence of heat capacity, the material properties of different layers

关键词： On-board hydrogen storage tank Fast refueling Thermal performance structure parameter Material property

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structure parameter as an intrinsic property of thin-film composite forward osmosis membrane

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DESALINATION 2024年 581卷

作者： Zhao, Shuwei Sun, Nan Dou, Pengjia Lin, Saisai He, Tao Chinese Acad Sci Shanghai Adv Res Inst Lab Membrane Mat & Separat Technol Shanghai 201210 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China ShanghaiTech Univ Sch Phys Sci & Technol Shanghai 201210 Peoples R China Univ Sci & Technol China Dept Environm Sci & Engn Hefei 230052 Peoples R China Zhejiang Univ State Key Lab Clean Energy Utilizat 38 Zheda Rd Hangzhou 310027 Peoples R China

The structure parameter of the forward osmosis membrane has been defined as the characteristics of the support membrane, not related to the separation layer. Therefore, studies for improving the performance of the forward osmosis (FO) membranes have been focused on the optimization of the support structure. This study demonstrates that the separation thin-film polyamide (PA) layer has a strong impact on the performance of the FO membrane thus the structure parameters (S). We intentionally utilized a polyethersulfone hollow fiber substrate and two types of active separation skin were prepared at the inner surface: the first MPD/TMC and the second by adding triethylamine (TEA) into the aqueous phase during the interfacial polymerization (IP). By adding TEA, a rough PA layer with a leaf-like structure and a high crosslinking degree was obtained followed with high FO flux and low reverse salt flux attributed to the increased effective filtration area and crosslinking degree. The structure parameter of the FO membrane was reduced from 0.78 mm (for MPD/TMC system) to 0.45 mm (for MPD-TEA/TMC system). The result indicated that for the same substrate, lower structure parameter corresponded to the skin layer with higher permeance and rejection. This study confirmed that the structure parameter is more an inherent property of the entire TFC FO membrane than the character of the porous substrate. Future design for FO membranes needs to regulate the substrate, but more importantly to optimize the separation layer.

关键词： Forward osmosis structure parameter Thin-film composite membrane Triethylamine Hollow fiber

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Normalized structure parameter of magnetorheological fluids under unidirectional monotonous squeeze

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MATERIALS TODAY COMMUNICATIONS 2023年 36卷

作者： Wang, Hongyun Bi, Cheng Wang, Yun Zhang, Ziyuan Taizhou Univ Coll Intelligent Mfg Taizhou 318000 Zhejiang Peoples R China

The evolution of chain structure parameters for magnetorheological (MR) fluids under unidirectional monotonous squeeze were studied. A normalized structure parameter SnT was proposed. The compressive behavior of MR fluids was experimentally researched under compressive speeds v in squeeze flow and the nominal shear yield stress was calculated according to the squeeze flow theory. So SnT can be derived. It showed that SnT rapidly increases with increasing compressive strain under a high magnetic field and low v. As an analogy for friction, the correspondence between & tau;y/B2 and friction coefficient suggests a possible origin of friction in the mechanical behaviors of MR fluids. Moreover, the results at lower v seem to deviate from the predictions of Deborah number De and the Kelvin model. The aggregation of chain structure leading to much longer relaxation times at lower v was thought to result in the high De in squeeze flow.

关键词： Magnetorheological fluid Compression mode structure parameter Yield stress Deborah number

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Effects of the ambient medium and structure parameter on the optical properties of tapered silicon nanowire

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OPTICS COMMUNICATIONS 2020年 454卷 124515-000页

作者： Tong, Jie Zhang, Minghao Zhang, Shuhua Lei, Yuqing Li, Meicheng Qin, Mingde Li, Yingfeng China Elect Power Res Inst Beijing 100192 Peoples R China North China Elect Power Univ State Key Lab Alternate Elect Power Syst Renewabl Beijing 102206 Peoples R China Univ Calif San Diego Program Mat Sci & Engn La Jolla CA 92093 USA

Tapered silicon nanowire (T-SiNW) is expected to have a wider application than a cylindrical one in optical sensors, photovoltaics, etc. due to its broadband light-trapping. However, there is little research on the effect of ambient medium and structure parameters on the optical properties of T-SiNW. First, based on numerical simulations it is found that, compared with that in air, when a T-SiNW is embedded in ambient medium with refraction index of 1.284: the absorbed light by it under given irradiation becomes much less;the scattered light by it shows a wider angular distribution;the nearfield light around it becomes stronger in a wider area. These mean that T-SiNW is more desirable for light-trapping in the ambient medium. Then, as the bottom diameter of T-SiNW increases, its light-collecting waveband red-shifts;at the same time, its scattered light shows a broadened angular distribution range. Hence, T-SiNW with larger bottom diameter is more desirable for light-trapping, especially for longwave light which is sometimes difficult to be utilized in photovoltaic devices. Besides, we found that the light-collecting and -absorption multiples of T-SiNW are both proportional to its length approximatively, which provides a very convenient way to regulate its light-trapping performance. The insights in this work are helpful to the design of devices using T-SiNW as the main block.

关键词： Tapered silicon nanowire Ambient medium structure parameter Optical property

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Observations of the Temperature and Humidity structure parameter Over Heterogeneous Terrain by Airborne Measurements During the LITFASS-2003 Campaign

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BOUNDARY-LAYER METEOROLOGY 2017年第3期165卷 447-473页

作者： Platis, Andreas Moene, Arnold F. Martinez Villagrasa, Daniel Beyrich, Frank Tupman, David Bange, Jens Univ Tubingen Zentrum Angew Geowissensch Holderlinstr 12 D-72074 Tubingen Germany Wageningen Univ Dept Environm Sci Meteorol & Air Qual Grp POB 47 Wageningen Netherlands Univ Balearic Isl Dept Phys Cra Valldemossa Palma De Mallorca 07122 Mallorca Spain Deutsch Wetterdienst DWD Meteorol Observ Lindenberg Observ 12 D-15848 Tauche Germany

The turbulent structure parameters of temperature (C-T(2)) and humidity (C-Q(2)), and their cross-structure parameter (C-QT), are investigated using data collected with the airborne-measurement platform Helipod during the LITFASS-2003 campaign. The flights took place within the atmospheric surface layer over heterogeneous terrain including forests, a lake and farmland. We find variability in C-T(2) along such flight legs, with values of C-T(2) over forested surfaces one order of magnitude larger than over farmland, and two orders of magnitude larger than over the lake. However, a quantitative relationship between the magnitude of C-Q(2) and the surface type is not found, most likely due to a similar surface latent heat flux between the land-use types. However, when the different flight legs are taken together and data grouped by land-use type, values of C-Q(2) are significantly lower over the lake than over the other surfaces. A classification of C-QT is only possible between water and land surfaces, with lower values over water. We find the correlation coefficient R-QT in the range of 0.4-1.0, which is less than unity, and thus violates the assumption of unity in Monin-Obukhov similarity theory.

关键词： Helipod Heterogeneous terrain Lake Lower convective boundary layer structure parameter

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Laser diode to circular core graded index single mode fiber excitation via quadric interface microlens on the fiber tip and identification of the suitable refractive index profile for maximum coupling efficiency with optimization of structure parameter

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JOURNAL OF OPTICS-INDIA 2017年第4期46卷 359-367页

作者： Mukhopadhyay, Sumanta St Pauls Cathedral Mission Coll Dept Phys 33-1 Raja Rammohan Roy Sarani Kolkata 700009 W Bengal India

We report what to our knowledge is the first theoretical prediction of the optimum coupling efficiency of a laser diode emitting two wavelengths either 1.3 or 1.5 mu m to a series of circular core graded index single mode fibers with different profile exponents via quadric interface microlens of four different focal lengths on the fiber tip to predict the nature of suitable refractive index profile. Instead of considering special ABCD matrix for individual microlens like hyperbolic, parabolic and elliptical (hemispherical included) one, a simple, accurate, and popular unified transfer ABCD matrix for refraction of quadric microlens under paraxial approximation is utilized to analyze the theoretical coupling efficiency, based on Gaussian beam approximation. Further, it is observed that out of the studied refractive index profiles, the step index profile comes out to be the most suitable profile to couple laser diode to circular core graded index single mode fiber for both wavelengths of practical interest. Moreover, the coupling efficiency can reach nearly 100 % with optimizing structure parameters of specific lensed fiber in both cases. The analysis should find use in ongoing investigations for optimum launch optics for the design of quadric interface microlens either directly on the circular core graded index single mode fiber tip or such fiber attached to single mode fiber.

关键词： ABCD matrix Quadric interface-lensed fiber structure parameter Circular core graded index fiber Coupling efficiency

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Effects of membrane transport properties and structure parameter on pressure-retarded osmosis performance

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DESALINATION AND WATER TREATMENT 2016年第22期57卷 10111-10120页

作者： Kim, Yu Chang Lee, Sungyun Park, Sang-Jin Korea Inst Machinery & Mat Dept Extreme Thermal Syst Daejeon 305343 South Korea Korea Univ Sci & Technol Environm & Energy Mech Engn Daejeon 305350 South Korea

For salinity gradient power generation, a pressure-retarded osmosis (PRO) process uses a semipermeable membrane as a means of energy conversion. The performance of a PRO membrane is evaluated by the power density determined in a particular PRO condition. The membrane power density, which is the power generated per unit membrane surface area, can be calculated from the experimentally measured water flux and operating pressure difference. To fabricate a high-performance PRO membrane, both the transport properties and the structure parameter of the membrane should be balanced delicately. Water permeability (A) and salt permeability (B) are both transport properties of the active layer, while the structure parameter (S) is a distinct feature of the support layer. Thus, the PRO membrane should be designed to have three good parameters together. In addition, these A, B, and S parameters can be used in a PRO performance simulation to verify experimental results. In this study, the magnitude of effective osmotic pressures and reverse salt buildup factor is analyzed and a systematic investigation of the effect of the membrane transport properties and structure parameter on PRO performance is presented. The numerical simulation was performed for a number of actual and imaginary membranes. The imaginary membranes were both on A and B trade-off relationship and off the relationship. The A and S values affected the water flux value at a low pressure difference, while the B and S values influenced the water flux at high pressure. In addition, the effect of the mass transfer coefficient (k) in close connection with the experimental condition was examined. The k value was not an important variable in simulation, but it will play a significant role in a real-life process.

关键词： structure parameter Power density Membrane transport property Trade-off Pressure-retarded osmosis

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Experimental Estimates of the structure parameter of the Refractive Index for Optical Waves in the Surface Air Layer

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ATMOSPHERIC AND OCEANIC OPTICS 2015年第5期28卷 426-435页

作者： Gladkikh, V. A. Mamyshev, V. P. Odintsov, S. L. Russian Acad Sci VE Zuev Inst Atmospher Opt Siberian Branch Pl Akad Zueva 1 Tomsk 634055 Russia

The structure parameter of the refractive index of optical waves C-n(2) in the surface air layer is analyzed in the context of results calculated from the structure parameter of the air temperature C-T(2).The estimates for C-n(2) based on an optical differential turbulence meter and ultrasonic anemometer-thermometers are compared. The systematic difference between these estimates at a high degree of correlation is noted. The diurnal mean profile of C-n(2) in different seasons in territories with a natural landscape and urban territory is obtained and analyzed.

关键词： refractive index surface air layer structure parameter diurnal behavior ultrasonic anemometer-thermometer

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Passive Optical Methods in Measurement of the structure parameter of the Air Refractive Index

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ATMOSPHERIC AND OCEANIC OPTICS 2015年第6期28卷 522-525页

作者： Konyaev, P. A. Botygina, N. N. Antoshkin, L. V. Emaleev, O. N. Lukin, V. P. Russian Acad Sci Siberian Branch Zuev Inst Atmospher Opt Pl Akad Zueva 1 Tomsk 634055 Russia

A passive optical method for estimating the level of atmospheric turbulence (structure parameter of the air refractive index C-n(2)) from the image jitter is considered. It is proposed to use a high-speed digital video camera and effective two-dimensional parallel algorithms of image processing for measuring C-n(2) in real time. Results obtained by the active and passive optical methods, as well as by an acoustic method, are compared.

关键词： atmospheric turbulence structure parameter image jitter radial target

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Ethanol mass transfer model of spiral-wound membrane module with PDMS membrane for pervaporation considering module structure parameters

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SEPARATION AND PURIFICATION TECHNOLOGY 2025年第PartB期353卷

作者： Liu, Wenda Jiang, Haoji Tang, Guoxuan Liu, Lin Wen, Haocun Xiao, Zeyi Liu, Jingyun Fan, Senqing Sichuan Univ Sch Chem Engn Chengdu 610065 Peoples R China

Pervaporation mass transfer model of spiral-wound membrane module with polydimethylsiloxane (PDMS) membrane considering module structure parameters has been developed for ethanol separation. Membrane intrinsic parameters involved mass transfer including limiting diffusivity of ethanol, plasticization coefficient of ethanol and partition coefficient were firstly determined, and then the model was verified by the experimental results with a correlation coefficient of 0.998. It has been calculated that bulk ethanol concentration (xe) would be decreased from 9 v/v% to 7.26 v/v% along the flow direction, under the ethanol feeding concentration of 9 v/ v%, feeding velocity of 0.008 ms-1, membrane length of 1 m, membrane width of 1.5 m, channel height of 1.2 mm, if polydimethylsiloxane/polyamide (PDMS/PA) membrane was applied. Owing to the concentrationdependence of the membrane mass transfer coefficient (km), km and local ethanol flux (Je) was also decreased from 7.20 x 10-6 m & sdot;s-1to 7.07 x 10-6 m & sdot;s- 1, and 386 g & sdot;m- 2 & sdot;h- 1 to 306 g & sdot;m- 2 & sdot;h- 1, respectively. For polydimethylsiloxane/polyvinylidene difluoride/Polyethylene terephthalate (PDMS/PVDF/PET) membrane, km and Je were decreased from 7.72 x 10-7 m & sdot;s-1to 7.65 x 10-7 m & sdot;s- 1, and 137 g & sdot;m- 2 & sdot;h-1to 128 g & sdot;m- 2 & sdot;h- 1, respectively, under the same condition. Higher ethanol feeding concentration and longer module would lead to more obvious change in xe, km and Je. While higher feeding velocity would lead to weaker change in xe, km and Je.

关键词： Ethanol pervaporation Mass transfer model Spiral -wound membrane module structure parameter

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