Xukai Ren^1,2,*, Huanwei Yu², Xianfeng Chen², Yantong Tang², Guobiao Wang^1,*, Xiyong Du²

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 647-663, 2024, DOI:10.32604/cmes.2024.048782

Abstract Stirred reactors are key equipment in production, and unpredictable failures will result in significant economic losses and safety issues. Therefore, it is necessary to monitor its health state. To achieve this goal, in this study, five states of the stirred reactor were firstly preset: normal, shaft bending, blade eccentricity, bearing wear, and bolt looseness. Vibration signals along x, y and z axes were collected and analyzed in both the time domain and frequency domain. Secondly, 93 statistical features were extracted and evaluated by ReliefF, Maximal Information Coefficient (MIC) and XGBoost. The above evaluation results were then fused by D-S evidence… More >

Muhd Hadi Iskandar Abd Razak^*, Motoki Tsuda, Yukio Hayakawa, Shinji Kambara

Energy Engineering, Vol.121, No.2, pp. 259-272, 2024, DOI:10.32604/ee.2023.043615

Abstract Hydrogen is an alternative energy source that has the potential to replace fossil fuels. One of the hydrogen applications is as a material for Polymer Electrolyte Membrane Fuel Cells (PEMFC) in fuel cell vehicles. High-purity hydrogen can be obtained using a hydrogen separation membrane to prevent unwanted contaminants from potentially harming the PEMFC components. In this study, we fabricated a plasma membrane reactor and investigated the permeation performance of a hydrogen separation membrane in a plasma membrane reactor utilizing atmospheric pressure plasma. The result showed the hydrogen permeation rate increasing with time as reactor temperature is increased through joule heating.… More >

Yonggang Zheng^1,*, Hanbo Zhang¹, Jingyan Li¹, Hui Li², Hongfei Ye¹, Hongwu Zhang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.1, pp. 1-2, 2023, DOI:10.32604/icces.2023.010050

Abstract The reactor pressure vessels (RPV), a typical kind of axisymmetric structures, usually serve under high temperature and pressure conditions. The numerical analysis of the mechanical behaviors of these structures plays a dominant role for their structural design, advanced manufacture and safety assessment in practical engineering applications[1-2]. However, the extremely conditions bring great challenges for the numerical analysis of structures undergo ablation, plastic, damage and even fracture during an accident[3]. Based on the superior performance of peridynamics model in predicting fracture behaviors [4-7], a coupled axisymmetric non-ordinary state-based peridynamics (CA-NOSB-PD) model is proposed in this work to predict the ablation, plastic… More >

Danyang Shao¹, Xiaojia Wang^1,*, Delu Chen¹, Fengxia An^1,2

Journal of Renewable Materials, Vol.11, No.10, pp. 3659-3680, 2023, DOI:10.32604/jrm.2023.029220

Abstract Methanation is an effective way to efficiently utilize product gas generated from the pyrolysis and gasification of organic solid wastes. To deeply study the heat transfer and mass transfer mechanisms in the reactor, a successful three-dimensional comprehensive model has been established. Multiphase flow behavior and heat transfer mechanisms were investigated under reference working conditions. Temperature is determined by the heat release of the reaction and the heat transfer of the gas-solid flow. The maximum temperature can reach 951 K where the catalyst gathers. In the simulation, changes in the gas inlet velocity and catalyst flow rate were made to explore… More >

Dalia S. Makki¹, Hasan Sh. Majdi², Amer A. Abdulrahman¹, Abbas J. Sultan^1,3,*, Zahraa W. Hasan¹, Laith S. Sabri^1,3, Bashar J. Kadhim¹, Muthanna H. Al-Dahhan³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2613-2637, 2023, DOI:10.32604/fdmp.2023.028081

Abstract Bubble and slurry bubble column reactors (BCRs/SBCRs) are used for various chemical, biochemical, and petrochemical applications. They have several operational and maintenance advantages, including excellent heat and mass transfer rates, simplicity, and low operating and maintenance cost. Typically, a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products. Since most applications involve complicated gas-liquid, gas-liquid-solid, and exothermic processes, the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor’s overall performance. In this review, past and very recent experimental and numerical investigations on such systems are critically discussed.… More >

Xiaojia Wang^1,*, Danyang Shao¹, Delu Chen¹, Yutong Gong¹, Fengxia An^1,2

Journal of Renewable Materials, Vol.11, No.7, pp. 3155-3175, 2023, DOI:10.32604/jrm.2023.027535

Abstract Organic solid waste (OSW) contains many renewable materials. The pyrolysis and gasification of OSW can realize resource utilization, and its products can be used for methanation reaction to produce synthetic natural gas in the specific reactor. In order to understand the dynamic characteristics of the reactor, a three-dimensional numerical model has been established by the method of Computational Fluid Dynamics (CFD). Along the height of the reactor, the particle distribution in the bed becomes thinner and the mean solid volume fraction decreases from 4.18% to 0.37%. Meanwhile, the pressure fluctuation range decreased from 398.76 Pa at the entrance to a… More > Graphic Abstract

Xun Liu, Li Chen^* , Wen-Quan Tao

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-9, 2020, DOI:10.5098/hmt.14.16

Abstract Fluid flow, mass transport and catalytic reaction in micro-reactors with catalyst are studied. Optimized structures of the catalyst generating the maximum reaction rate are explored by numerically solving the reactive transport processes combined with topology optimization schemes in COMSOL 5.3a. Effects of several physicochemical parameters including pressure drop, reaction rate constant, permeability of the porous catalyst and radius of the reactor are investigated. Distributions of the optimized structures, velocity, pressure and concentration are discussed in detail. Results show that the four physicochemical parameters have significant effects on the optimized structures of the catalyst obtained, indicating that generally there does not… More >

Hui Li^*, Liping Zhang, Yixiong Zhang, Xiaolong Fu, Xuejiao Shao, Juan Du

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.3, pp. 1997-2019, 2023, DOI:10.32604/cmes.2022.020792

Abstract In this paper, the evaluations of metal ablation processes under high temperature, i.e., the Al plate ablated by a laser and a heat carrier and the reactor pressure vessel ablated by a core melt, are studied by a novel peridynamic method. Above all, the peridynamic formulation for the heat conduction problem is obtained by Taylor’s expansion technique. Then, a simple and efficient moving boundary model in the peridynamic framework is proposed to handle the variable geometries, in which the ablated states of material points are described by an additional scalar field. Next, due to the automatic non-interpenetration properties of peridynamic… More > Graphic Abstract

Aman Santoso^1,*, Amirotus Sholikhah¹, Sumari Sumari¹, Muhammad Roy Asrori¹, Anugrah Ricky Wijaya¹, Rini Retnosari^1,2, Ihsan Budi Rachman^1,3

Journal of Renewable Materials, Vol.10, No.11, pp. 2781-2789, 2022, DOI:10.32604/jrm.2022.021401

Abstract Plastic is a basic need for humans, but it has also caused big problems for the environment. Then, the purpose of this study was to determine the effect of the type of plastic and the addition of a zeolite catalyst on the oil yield from the pyrolysis of plastic waste. The research stages were natural zeolite activation, pyrolysis reactor settings, pyrolysis of plastic waste (PP and LDPE types), and characterization. The results showed that the used natural zeolite had a mordenite phase and activated natural zeolite had a higher Si/Al ratio than the inactivated one. The addition of a zeolite… More > Graphic Abstract

Ibrahim M. Mehedi^1,2,*, Maher H. AL-Sereihy², Asmaa Ubaid Al-Saggaf², Ubaid M. Al-Saggaf^1,2

CMC-Computers, Materials & Continua, Vol.72, No.1, pp. 651-662, 2022, DOI:10.32604/cmc.2022.022013

Abstract Tracking load changes in a pressurized water reactor (PWR) with the help of an efficient core power control scheme in a nuclear power station is very important. The reason is that it is challenging to maintain a stable core power according to the reference value within an acceptable tolerance for the safety of PWR. To overcome the uncertainties, a non-integer-based fractional order control method is demonstrated to control the core power of PWR. The available dynamic model of the reactor core is used in this analysis. Core power is controlled using a modified state feedback approach with a non-integer integral… More >