Jingjing Gao, Xingkai Zhang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 109-127, 2024, DOI:10.32604/fdmp.2023.030106

Abstract A new approach and a new related distribution system are proposed to address the issue of uneven steam injection caused by the different suction capacities of the used wells during the application of steam “stimulation” methods for enhanced oil recovery. The new distribution system consists of a swirler, spiral dividing baffles, and critical flow nozzles. Numerical simulations are used to analyze the flow-field and degree of steam homogeneity obtained with such an approach. The results indicate that a higher inlet pressure leads to better results. Additionally, the internal flow field becomes more stable, and the deviation from an even distribution… More >

Ruyi Luo, Yanyan Hu^*, Tingshu He^*, Xiaodong Ma, Yongdong Xu

Journal of Renewable Materials, Vol.11, No.9, pp. 3485-3500, 2023, DOI:10.32604/jrm.2023.027592

Abstract The measures of steam curing and early-strengthening agents to promote the precast components to reach the target strength quickly can bring different degrees of damage to the concrete. Based on this, the new nanomaterial CSH-the hydration product of cement effectively solves these measures’ disadvantages, such as excessive energy consumption, thermal stress damage, and the introduction of external ions. In this paper, the effect of CSH on the early strength of precast fly ash concrete components was investigated in terms of setting time, workability, and mechanical properties and analyzed at the microscopic level using hydration temperature, XRD, and SEM. The results… More >

Qiushi Li^1,2,#, Ronggang Luo^1,2,#, Yu Chen³, Jinhui Xiong³, Bei Qiao¹, Xijuan Chai^1,2, Linkun Xie^1,2, Juan Wang³, Lianpeng Zhang^1,2,*, Siqun Wang⁴, Guanben Du^1,2, Kaimeng Xu^1,2,*

Journal of Renewable Materials, Vol.11, No.6, pp. 2809-2822, 2023, DOI:10.32604/jrm.2023.026184

Abstract To overcome the shortage of wood resources as well as to develop novel natural fibers materials, the Chimonobambusa quadrangularis (CQ) and Qiongzhuea tumidinoda (QT) planted in Southwest China were effectively isolated by the steam explosion (SE). The fine and uniform bamboo microfibers derived from CQ and QT were obtained, and their smallest average widths were 12.62 μm and 16.05 μm, respectively. The effects of steam explosion on the micro-morphology, chemical composition, thermal stability, crystallinity, surface wettability, and mechanical properties of bamboo microfibers were comprehensively investigated. The results showed that the relative content of cellulose in bamboo microfibers increased but the… More > Graphic Abstract

Zhao Wang¹, Su Yan¹, Mingfeng Zhu¹, Wen Zhu¹, Han Zhang², Xiang Gou^2,*

Energy Engineering, Vol.119, No.6, pp. 2569-2584, 2022, DOI:10.32604/ee.2022.020644

Abstract Aiming at improving the performance of Organic Rankine Cycle (ORC) system with low-grade steam as heat source, this work studied and optimized the main operating parameters of the ORC system. The effects of evaporation temperature, superheat degree, condensation temperature and regenerator pinch temperature difference on the system performance were obtained. The optimization for the operating parameters is based on the indicators of specific net power output, waste heat pollution, cycle exergy efficiency, and total UA value (the product of overall heat transfer coefficient and heat transfer area of heat exchanger). The results show that the increase of the evaporation temperature… More >

Yukun Lv¹, Fan Yang^1,*, Zi’an Wei¹, Quan Lu²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 379-397, 2023, DOI:10.32604/fdmp.2022.020373

Abstract Leakage occurring in the tube sockets of the main steam thermometers can seriously threaten the safe operation of coal-fired power plants. Here, assuming a 300 MW unit as a relevant testbed, this problem is investigated numerically through solution of the equations of fluid-dynamics in synergy with the mathematical treatment of relevant statistics. The results indicate that the steam can form a large-scale spiral flow inside the tube socket and continuously scour the inner wall. In the model with the protective casing setting angle of 60°, the average tangential fluid velocity can reach up to 4.8 m/s, which is about twice higher… More > Graphic Abstract

Xin Han^1,4, Zhichao Lou^1,3,4,*, Chenglong Yuan^1,4, Xinwu Wu^1,4, Jie Liu^1,4, Fujin Weng², Yanjun Li^1,4,*

Journal of Renewable Materials, Vol.10, No.12, pp. 3313-3334, 2022, DOI:10.32604/jrm.2022.021066

Abstract With the aim of utilizing reconstituted bamboo as a carbon cycle-oriented material, the improvement of physical and mechanical properties has been actively studied to solve using problems. The saturated steam heat treatment process has been widely used in worldwide. With the development and exploration of this technology, two-step saturated steam heat treatment process appears in some practical production, that is, after a period of saturated steam heat treatment at a lower temperature, the bamboo bundles are taken out and seasoned for a period of time, and then put back into the heat tank again, and heated at a higher temperature… More >

Shaher Alshammrei¹, Sahbi Boubaker^2,*, Lioua Kolsi^1,3

CMC-Computers, Materials & Continua, Vol.72, No.3, pp. 5939-5954, 2022, DOI:10.32604/cmc.2022.028165

Abstract Optimal path planning avoiding obstacles is among the most attractive applications of mobile robots (MRs) in both research and education. In this paper, an optimal collision-free algorithm is designed and implemented practically based on an improved Dijkstra algorithm. To achieve this research objectives, first, the MR obstacle-free environment is modeled as a diagraph including nodes, edges and weights. Second, Dijkstra algorithm is used offline to generate the shortest path driving the MR from a starting point to a target point. During its movement, the robot should follow the previously obtained path and stop at each node to test if there… More >

M. Gh. Mohammed Kamil^1,*, M. S. Kassim¹, R. A. Mahmood^2,3, L. AZ Mahdi⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 985-998, 2022, DOI:10.32604/fdmp.2022.018938

Abstract This work investigates the steam condensation phenomena in an air-cooled condenser. The considered horizontal flattened tube has a 30 mm hydraulic diameter, and its length is a function of the steam quality with a limit value between 0.95 and 0.05. The mass flow rate ranges from 4 to 40 kg/m².s with a saturated temperature spanning an interval from 40°C to 80°C. A special approach has been implemented using the Engineering Equation Solver (EES) to solve a series of equations for the two-phase flow pattern and the related heat transfer coefficients. A wavy-stratified structure of the two-phase flow has been found when… More >

Saad Nader^1,2, Felipe Guzman³, Raphael Becar¹, César Segovia⁴, Cecilia Fuentealba³, Miguel Peirera³, Evelyne Mauret², Nicolas Brosse^1,*

Journal of Renewable Materials, Vol.10, No.2, pp. 263-271, 2022, DOI:10.32604/jrm.2022.017923

Abstract The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose (L-MNFCs) obtained from Eucalyptus Globulus bark in Urea-Formaldehyde UF adhesive was tested. L-MNFCs were prepared by an environmentally friendly, low-cost process using a combination process involving steam explosion followed by refining and ultra-fine grinding. Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets. They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20 μm, respectively. The effects of the addition of low amounts of L-MNFCs (1% wt.) on the properties of three different adhesives (Urea-Formaldehyde UF, Phenol-Formaldehyde PF, and Tannin-Hexamine TH)… More > Graphic Abstract

Wenli Gu¹, Shiyi Zeng¹, Assima Dauletbek², Bin Xu^1,3,*, Xinzhou Wang¹, Man Yuan¹, Yanni Gu¹

Journal of Renewable Materials, Vol.10, No.2, pp. 385-399, 2022, DOI:10.32604/jrm.2022.016457

Abstract Bamboo vascular bundle fiber and parenchyma (BP) are separated by high-temperature treatment with saturated steam. Bamboo vascular bundle fiber is widely used in the market, but how to develop and utilize parenchyma tissue is a difficult problem. The sulfated cellulose nanofibers (ANFs) were obtained by sulfating BP with a deep eutectic solvent (DES), which provided a theoretical basis for the value-added utilization of BP. Using DES as the reaction medium and reagent, the BP was grafted with a sulfonic acid group to form a gel substance in water, ANFs and nanocellulose gel were obtained by ultrasonic cell crusher. The highest… More > Graphic Abstract