• Title/Summary/Keyword: Solid bed modeling

Search Result 24, Processing Time 0.016 seconds

Packed Bed Reactor Simulation for the Water Gas Shift Reaction in the Steam Reforming of Natural Gas (천연가스의 수증기 개질에서 수성가스 전환용 충진층 반응기의 전산모사)

  • LEE, DEUKKI
    • Journal of Hydrogen and New Energy
    • /
    • v.27 no.5
    • /
    • pp.494-502
    • /
    • 2016
  • A 1-dimensional heterogeneous reactor model with the gas-solid interfacial phase gradients was developed for the simulation of the packed bed reactor where the exothermic reversible water gas shift reaction for the natural gas steam reformed gas was proceeding in adiabatic mode. Experimental results obtained over the WGS catalyst, C18-HA, were best simulated when the frequency factor of the reaction rate constant was adjusted to a half the value reported over another WGS catalyst, EX-2248, having the same kinds of active components as the C18-HA. For the reactor of the inside diameter 158.4 mm and the bed length 650 mm, the optimum feeding temperature of the reformed gas was simulated to be $194^{\circ}C$, giving the lowest CO content in the product gas by 1.68 mol% on the basis of dried gas. For reactors more extended in the bed length, the possible lowest CO content in the product gas with the optimum feeding temperature of the reformed gas were suggested.

Knowledge from recent investigations on sloshing motion in a liquid pool with solid particles for severe accident analyses of sodium-cooled fast reactor

  • Xu, Ruicong;Cheng, Songbai;Li, Shuo;Cheng, Hui
    • Nuclear Engineering and Technology
    • /
    • v.54 no.2
    • /
    • pp.589-600
    • /
    • 2022
  • Investigations on the molten-pool sloshing behavior are of essential value for improving nuclear safety evaluation of Core Disruptive Accidents (CDA) that would be possibly encountered for Sodium-cooled Fast Reactors (SFR). This paper is aimed at synthesizing the knowledge from our recent studies on molten-pool sloshing behavior with solid particles conducted at the Sun Yat-sen University. To better visualize and clarify the mechanism and characteristics of sloshing induced by local Fuel-Coolant Interaction (FCI), experiments were performed with various parameters by injecting nitrogen gas into a 2-dimensional liquid pool with accumulated solid particles. It was confirmed that under different particle-bed conditions, three representative flow regimes (i.e. the bubble-impulsion dominant, transitional and bed-inertia dominant regimes) are identifiable. Aimed at predicting the regime transitions during sloshing process, a predictive empirical model along with a regime map was proposed on the basis of experiments using single-sized spherical solid particles, and then was extended for covering more complex particle conditions (e.g. non-spherical, mixed-sized and mixed-density spherical particle conditions). To obtain more comprehensive understandings and verify the applicability and reliability of the predictive model under more realistic conditions (e.g. large-scale 3-dimensional condition), further experimental and modeling studies are also being prepared under other more complicated actual conditions.

An Experimental Study for Accuracy Enhancement of SLS (SLS에서의 정밀도 향상을 위한 실험적 연구)

  • 신동훈;전병철;김재도
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.943-946
    • /
    • 2000
  • Selective laser sintering(SLS) is a solid freeform fabrication process whereby a part is built layerwise by scanning a powder bed. The properties of metal powder are dependent on the heat, it is not easy to do the exact error compensation with analysis and estimation by modeling. This paper suggests that the error is compensated by experimental method and then the accuracy of shape is enhanced by revising of STL file. Also bonding force is measured by an experiment with change of process path.

  • PDF

Evaluation of a moving bed biofilm reactor for simultaneous atrazine, carbon and nutrients removal from aquatic environments: Modeling and optimization

  • Derakhshan, Zahra;Ehrampoush, Mohammad Hassan;Mahvi, Amir Hossein;Dehghani, Mansooreh;Faramarzian, Mohammad;Ghaneian, Mohammad Taghi;Mokhtari, Mehdi;Ebrahimi, Ali Asghar;Fallahzadeh, Hossein
    • Journal of Industrial and Engineering Chemistry
    • /
    • v.67
    • /
    • pp.219-230
    • /
    • 2018
  • The present study examined a moving bed biofilm reactor (MBBR) bioreactor on a laboratory scale for simultaneous removal of atrazine, organic carbon, and nutrients from wastewater. The maximum removal efficiency of atrazine, chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN) were 83.57%, 90.36%, 90.74% and 87.93 respectively. Increasing salinity up to 40 g/L NaCl in influent flow could inhibit atrazine biodegradation process strongly in the MBBR reactor.Results showed that MBBR is so suitable process for efficiently biodegrading of atrazine and nitrogen removal process was based on the simultaneous nitrification-denitrification (SND) process.