scholarly journals Effects of Flow Velocity on Transient Behaviour of Liquid CO2 Decompression during Pipeline Transportation

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 192
Author(s):  
Chenghuan Xiao ◽  
Zhaijun Lu ◽  
Liguo Yan ◽  
Jiaqiang Wang ◽  
Shujian Yao
Keyword(s):  
Phase Transition ◽  
Flow Velocity ◽  
Large Scale ◽  
Equilibrium Phase ◽  
Temperature Drop ◽  
Pipeline Transportation ◽  
Initial Flow ◽  
Evaporation Coefficient ◽  
Transient Behaviour ◽  
Liquid Co2

Investigating the transient behaviour of liquid CO2 decompression is of great importance to ensure the safety of pipeline transportation in carbon capture and storage (CCS) technology. A computational fluid dynamics (CFD) decompression model based on the non-equilibrium phase transition and Span–Wagner equation of state (EoS) was developed to study the effects of actual flowing state within the pipeline on the transient behaviour of liquid CO2 decompression. Then, the CFD model was verified by comparing the simulated results to test data of a large-scale “shock tube” with an inner diameter of 146.36 mm. The results showed that the evaporation coefficient had a significant impact on the transition behaviour of CO2 decompression, while the condensation coefficient made no difference. When the evaporation coefficient was 15 s−1, the CFD-predicted results were in good agreement with the test results. Moreover, the effects of flow velocity on transient behaviour of liquid CO2 decompression were further investigated. It was found that the flow velocity affected the temperature drop of liquid CO2 during decompression, thereby affecting the phase transition of liquid CO2. In addition, the initial flow velocity also showed a significant influence on the transient behaviour of CO2 outside the pipe.

scholarly journals Measurement of flow velocity profiles in tank structures using the prototype device OCM Pro LR

2011 ◽  
Vol 64 (1) ◽  
pp. 263-270 ◽  
Author(s):  
K. Klepiszewski ◽  
M. Teufel ◽  
S. Seiffert ◽  
E. Henry
Keyword(s):  
Flow Velocity ◽  
Large Scale ◽  
Fluid Dynamic ◽  
Waste Water Treatment ◽  
Transport Processes ◽  
Treatment Efficiency ◽  
Cleaning Efficiency ◽  
Cfd Modelling ◽  
Ultrasonic Signals ◽  
Cfd Models

Generally, studies investigating the treatment efficiency of tank structures for storm water or waste water treatment observe pollutant flows in connection with conditions of hydraulic loading. Further investigations evaluate internal processes in tank structures using computational fluid dynamic (CFD) modelling or lab scale tests. As flow paths inside of tank structures have a considerable influence on the treatment efficiency, flow velocity profile (FVP) measurements can provide a possibility to calibrate CFD models and contribute to a better understanding of pollutant transport processes in these structures. This study focuses on tests carried out with the prototype FVP measurement device OCM Pro LR by NIVUS in a sedimentation tank with combined sewer overflow (CSO) situated in Petange, Luxembourg. The OCM Pro LR measurement system analyses the echo of ultrasonic signals of different flow depths to get a detailed FVP. A comparison of flow velocity measured by OCM Pro LR with a vane measurement showed good conformity. The FVPs measured by OCM Pro LR point out shortcut flows within the tank structure during CSO events, which could cause a reduction of the cleaning efficiency of the structure. The results prove the applicability of FVP measurements in large-scale structures.

scholarly journals Crystallization of Binary Alloys and Non-Equilibrium Phase Transitions

2019 ◽  
Vol 489 (6) ◽  
pp. 545-551
Author(s):  
E. V. Radkevich ◽  
O. A. Vasil’eva ◽  
M. I. Sidorov
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Numerical Experiments ◽  
Binary Alloys ◽  
Equilibrium Phase ◽  
Homogeneous State ◽  
Nonequilibrium Phase Transition ◽  
Nonequilibrium Phase ◽  
Initial Stage ◽  
Melt Cooling

A model was constructed for the reconstruction of the initial stage of crystallization of binary alloys as a nonequilibrium phase transition, the mechanism of which is diffusion stratification. Numerical experiments were performed. Self-excitation of a homogeneous state by the edge control melt cooling condition.

scholarly journals Mixed-order phase transition in a colloidal crystal

2017 ◽  
Vol 114 (49) ◽  
pp. 12906-12909 ◽  
Author(s):  
Ricard Alert ◽  
Pietro Tierno ◽  
Jaume Casademunt
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Colloidal Particles ◽  
Colloidal Crystal ◽  
Equilibrium Phase ◽  
Mean Field ◽  
Critical Dimension ◽  
Colloidal System ◽  
Test Bed ◽  
Mixed Order

Mixed-order phase transitions display a discontinuity in the order parameter like first-order transitions yet feature critical behavior like second-order transitions. Such transitions have been predicted for a broad range of equilibrium and nonequilibrium systems, but their experimental observation has remained elusive. Here, we analytically predict and experimentally realize a mixed-order equilibrium phase transition. Specifically, a discontinuous solid–solid transition in a 2D crystal of paramagnetic colloidal particles is induced by a magnetic field H. At the transition field Hs, the energy landscape of the system becomes completely flat, which causes diverging fluctuations and correlation length ξ∝|H2−Hs2|−1/2. Mean-field critical exponents are predicted, since the upper critical dimension of the transition is du=2. Our colloidal system provides an experimental test bed to probe the unconventional properties of mixed-order phase transitions.

scholarly journals Database thinking and deep description: designing a digital archive of the National Synchrotron Light Source

2019 ◽  
Vol 34 (Supplement_1) ◽  
pp. i46-i57
Author(s):  
Robert Crease ◽  
Elyse Graham ◽  
Jamie Folsom
Keyword(s):  
Phase Transition ◽  
Large Scale ◽  
Materials Science ◽  
Digital Tools ◽  
Digital Archive ◽  
Big Science ◽  
National Synchrotron Light Source ◽  
The Past ◽  
The Usa ◽  
Synchrotron Light

Abstract Over the past few years, research carried out at large-scale materials science facilities in the USA and elsewhere has undergone a phase transition that affected its character and culture. Research cultures at these facilities now resemble ecosystems, comprising of complex and evolving interactions between individuals, institutions, and the overall research environment. The outcome of this phase transition, which has been gradual and building since the 1980s, is known as the New (or Ecologic) Big Science [Crease, R. and Westfall, C. (2016). The new big science. Physics Today, 69: 30–6]. In this article, we describe this phase transition, review the practical challenges that it poses for historians, review some potential digital tools that might respond to these challenges, and then assess the theoretical implications posed by “database history’.

scholarly journals Terahertz field–induced ferroelectricity in quantum paraelectric SrTiO3

Science ◽  
2019 ◽  
Vol 364 (6445) ◽  
pp. 1079-1082 ◽  
Author(s):  
Xian Li ◽  
Tian Qiu ◽  
Jiahao Zhang ◽  
Edoardo Baldini ◽  
Jian Lu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Coherent Control ◽  
Ferroelectric Phase ◽  
Equilibrium Phase ◽  
Material Structure ◽  
Single Cycle ◽  
Excitation Spectra ◽  
Quantum Paraelectric ◽  
Phonon Excitation ◽  
Field Excitation

“Hidden phases” are metastable collective states of matter that are typically not accessible on equilibrium phase diagrams. These phases can host exotic properties in otherwise conventional materials and hence may enable novel functionality and applications, but their discovery and access are still in early stages. Using intense terahertz electric field excitation, we found that an ultrafast phase transition into a hidden ferroelectric phase can be dynamically induced in quantum paraelectric strontium titanate (SrTiO3). The induced lowering in crystal symmetry yields substantial changes in the phonon excitation spectra. Our results demonstrate collective coherent control over material structure, in which a single-cycle field drives ions along the microscopic pathway leading directly to their locations in a new crystalline phase on an ultrafast time scale.

Impurity-tuned non-equilibrium phase transition in a bacterial carpet

2016 ◽  
Vol 108 (18) ◽  
pp. 183701 ◽  
Author(s):  
Yi-Teng Hsiao ◽  
Kuan-Ting Wu ◽  
Nariya Uchida ◽  
Wei-Yen Woon
Keyword(s):  
Phase Transition ◽  
Equilibrium Phase ◽  
Equilibrium Phase Transition ◽  
Non Equilibrium

scholarly journals Emission Behaviors of Inorganic Ultrafine Particles during Zhundong Coal Oxy-Fuel Combustion with Characterized Oxygen Input Fractions Comparable to Air Combustion

2018 ◽  
Vol 8 (9) ◽  
pp. 1486 ◽  
Author(s):  
Bin Fan ◽  
Chang Wen ◽  
Xianpeng Zeng ◽  
Jianqun Wu ◽  
Xin Yu
Keyword(s):  
Ultrafine Particles ◽  
Large Scale ◽  
Temperature Drop ◽  
Fuel Combustion ◽  
Low Rank ◽  
High Yield ◽  
Drop Tube ◽  
Aerodynamic Diameter ◽  
Ca 50 ◽  
Zhundong Coal

Zhundong low-rank coal is very likely to be utilized extensively in oxy-fired boilers in the near future. Its PM10 (particulate matter with an aerodynamic diameter of ≤10 μm) emission behaviors during oxy-fuel combustion need to be carefully studied before its large-scale use. The present study examines the emission behaviors of inorganic ultrafine particles (PM0.5, with an aerodynamic diameter of ≤0.5 μm), as well as PM10 during the combustion of Zhundong coal in air and oxy-fuel conditions (O2/CO2) at three characterized O2 input fractions, i.e., 21, 27 and 32 vol.%. The combustion experiments were carried out in a high-temperature drop-tube furnace (HDTF) at a combustion temperature of 1500 °C. The results show that PM0.5 is composed of Na, S, Mg and Ca, with total fractions of ~90%, while PM0.5–10 (with an aerodynamic diameter between 0.5 and 10 μm) predominantly contains Ca (~50–65%). At three characterized oxygen fractions during oxy-fuel combustion (OXY21, 27 and 32), the promoted O2 fraction was found to increase the yields of both PM0.5 and PM0.5–10. A higher particle-burning temperature and a lower CO2 fraction promote the reactions of both organically bound elements and inorganic minerals, increasing the partitioning of Mg and Ca and causing an increased yield of PM0.5. The yield of PM0.5 from air is high and similar to that from OXY32 while the yield of PM0.5–10 from air is similar to that from OXY27. The high yield of PM0.5 from air is mainly generated by the highest yields of Ca in four conditions.

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