Guowei Li^1,*, Shujuan Bu², Xinle Yang², Kaijie Liang¹, Zhengri Shao¹, Xiaobei Song¹, Yitian Tang³, Dejing Zong⁴

Energy Engineering, Vol.121, No.12, pp. 3843-3874, 2024, DOI:10.32604/ee.2024.056195 - 22 November 2024

Abstract A novel dual-pressure organic Rankine cycle system (DPORC) with a dual-stage ejector (DE-DPORC) is proposed. The system incorporates a dual-stage ejector that utilizes a small amount of extraction steam from the high-pressure expander to pressurize a large quantity of exhaust gas to perform work for the low-pressure expander. This innovative approach addresses condensing pressure limitations, reduces power consumption during pressurization, minimizes heat loss, and enhances the utilization efficiency of waste heat steam. A thermodynamic model is developed with net output work, thermal efficiency, and exergy efficiency (W_net, η_t, η_ex) as evaluation criteria, an economic model is established… More >

Guanglu Xie¹, Zhimin Xue¹, Bo Xiong¹, Yaowen Huang¹, Chaoming Chen¹, Qing Liao¹, Cheng Yang^2,*, Xiaoqian Ma²

Energy Engineering, Vol.121, No.6, pp. 1495-1519, 2024, DOI:10.32604/ee.2024.047832 - 21 May 2024

Abstract The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems. This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units, the hydraulic and thermodynamic characteristics of the heating network, and the energy loads. Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case, the interaction effect among the source-side prime movers, the heating networks, and the terminal demand thermal parameters were investigated based on the designed values, the… More >

Jingjing Gao, Xingkai Zhang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 109-127, 2024, DOI:10.32604/fdmp.2023.030106 - 08 November 2023

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 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 - 20 July 2023

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, 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 - 27 April 2023

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 More > Graphic Abstract

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 - 29 August 2022

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,… 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 - 14 September 2022

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 More >

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 - 14 July 2022

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… 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 - 21 April 2022

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… 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 - 06 April 2022

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 More >