Fan Yang^1,2,*, Honggang Mi^1,2, Jian Wu^1,2, Qi Yang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2637-2656, 2024, DOI:10.32604/fdmp.2024.048574 - 28 October 2024

Abstract The gas production of deep coalbed methane wells in Linxing-Shenfu block decreases rapidly, the water output is high, the supporting effect is poor, the effective supporting fracture size is limited, and the migration mechanism of proppant in deep coal reservoir is not clear at present. To investigate the migration behavior of proppants in complex fractures during the volume reconstruction of deep coal and rock reservoirs, an optimization test on the conductivity of low-density proppants and simulations of proppant migration in complex fractures of deep coal reservoirs were conducted. The study systematically analyzed the impact of… More >

Sumrit Mopoung^*, Narissara Namkaew, Sasiwan Srikasaem

Journal of Renewable Materials, Vol.12, No.8, pp. 1433-1454, 2024, DOI:10.32604/jrm.2024.052925 - 06 September 2024

Abstract Activated carbon preparation from sugarcane leaves and rice straw by carbonization (250°C–400°C) and activation at 500°C were studied. The effects of pre-oxidation, hydrolysis of derived charcoals by boiled KMnO₄ aqueous solution were evaluated. The derived charcoals products were pretreated using oxidation-hydrolysis with 1–5 wt.% KMnO₄ at 100°C and then activated at 500°C. The derived charcoal and activated carbon products were characterized by FTIR, XRD, SEM-EDS and BET. Iodine number and methylene blue number of derived products were also used for the analysis of the products. It was found that fabricated charcoal materials made at 350°C–400°C possess… More > Graphic Abstract

Xulei Wu¹, Hailong Yu^1,*, Panrong Wu¹, Chaoqian Wang¹, Haiqun Chen¹, Yunlan Sun¹, He Zheng²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.7, pp. 1481-1498, 2024, DOI:10.32604/fdmp.2024.047092 - 23 July 2024

Abstract The development of more environment-friendly ways to dispose of oil sludge is currently regarded as a hot topic. In this context, gasification technologies are generally seen as a promising way to combine oil sludge with coal–water slurry (CWS) and generate resourceful fuel. In this study, a novel five-nozzle gasifier reactor was analyzed by means of a CFD (Computational fluid dynamic) method. Among several influential factors, special attention was paid to the height-to-diameter ratio of the gasifier and the mixing ratio of oil sludge, which are known to have a significant impact on the flow field, More >

Xuehui Jing¹, Junchen Guo¹, Zhiyun Wang^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 919-937, 2024, DOI:10.32604/fhmt.2024.049689 - 11 July 2024

Abstract In this paper, the combustion conditions in the boiler furnace of a 660 MW tangential fired pulverized coal boiler are numerically simulated at 15% and 20% rated loads, to study the flexibility of coal-fired power units on ultra-low load operation. The numerical results show that the boiler can operate safely at 15% and 20% ultra-low loads, and the combustion condition in the furnace is better at 20% load, and the tangent circles formed by each characteristic section in the furnace are better, and when the boiler load is decreased to 15%, the tangent circles in… More >

Teng Teng^1,2, Yuhe Cai³, Linchao Wang^3,*, Yanzhao Zhu²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1181-1202, 2024, DOI:10.32604/fdmp.2023.044532 - 27 June 2024

Abstract Liquid nitrogen has shown excellent performances as a good fracturing medium in the extraction of unconventional natural gas, and its application in coalbed methane extraction is currently a research hotspot. This study focuses on the acoustic emission properties of coal specimens treated utilizing liquid nitrogen with varying initial temperatures in a three-point bending environment. Through examination of the load-displacement curves of the considered coal samples, their mechanical properties are also revealed for different initial temperatures and cycling frequencies. The findings demonstrate a gradual decline in the maximum load capacity of coal rock as the temperature… More >

Lei Wang¹, Ziran Ma^1,*, Chunlin Zhao¹, Jiali Zhou¹, Hongyan Wang¹, Ge Li¹, Ningling Zhou²

Journal of Renewable Materials, Vol.12, No.4, pp. 799-814, 2024, DOI:10.32604/jrm.2024.047343 - 12 June 2024

Abstract This study explores the corrosion issues arising from the coupled combustion of coal and biomass and proposes potential solutions. Biomass, as a renewable energy source, offers advantages in energy-saving and carbon reduction. However, the corrosive effects of alkali metal compounds, sulfur (S) and chlorine (Cl) elements in the ash after combustion cannot be underestimated due to the high volatile content of biomass fuels. We investigate the corrosion mechanisms, as well as the transfer of Cl and alkali metal elements during this process. Comparative corrosion analyses are conducted among coal-fired boilers, pure biomass boilers and boilers… More >

Ming Yan¹, Caijiang Lu^2,*, Pan Shi^1,*, Meiling Zhang³, Jiawei Zhang¹, Liang Wang¹

Frontiers in Heat and Mass Transfer, Vol.22, No.2, pp. 615-631, 2024, DOI:10.32604/fhmt.2024.048333 - 20 May 2024

Abstract In response to escalating challenges in energy conservation and emission reduction, this study delves into the complexities of heat transfer in two-phase flows and adjustments to combustion processes within coal-fired boilers. Utilizing a fusion of hybrid modeling and automation technologies, we develop soft measurement models for key combustion parameters, such as the net calorific value of coal, flue gas oxygen content, and fly ash carbon content, within the Distributed Control System (DCS). Validated with performance test data, these models exhibit controlled root mean square error (RMSE) and maximum absolute error (MAXE) values, both within the… More > Graphic Abstract

Zenglun Guan^1,2, Murad S. Alfarzaeai^1,3,*, Eryi Hu^1,3,*, Taqiaden Alshmeri⁴, Wang Peng³

CMC-Computers, Materials & Continua, Vol.79, No.1, pp. 279-306, 2024, DOI:10.32604/cmc.2024.047159 - 25 April 2024

Abstract In the coal mining industry, the gangue separation phase imposes a key challenge due to the high visual similarity between coal and gangue. Recently, separation methods have become more intelligent and efficient, using new technologies and applying different features for recognition. One such method exploits the difference in substance density, leading to excellent coal/gangue recognition. Therefore, this study uses density differences to distinguish coal from gangue by performing volume prediction on the samples. Our training samples maintain a record of 3-side images as input, volume, and weight as the ground truth for the classification. The… More >

Zhongping Liu¹, Enhui Sun^2,*, Jiahao Shi², Lei Zhang², Qi Wang¹, Jiali Dong¹

Energy Engineering, Vol.121, No.4, pp. 913-932, 2024, DOI:10.32604/ee.2023.043973 - 26 March 2024

Abstract There is a growing need to explore the potential of coal-fired power plants (CFPPs) to enhance the utilization rate of wind power (wind) and photovoltaic power (PV) in the green energy field. This study developed a load regulation model for a multi-power generation system comprising wind, PV, and coal energy storage using real-world data. The power supply process was divided into eight fundamental load regulation scenarios, elucidating the influence of each scenario on load regulation. Within the framework of the multi-power generation system with the wind (50 MW) and PV (50 MW) alongside a CFPP… More > Graphic Abstract

Samsudin Anis^1,*, Deni Fajar Fitriyana¹, Aldias Bahatmaka¹, Muhammad Choirul Anwar¹, Arsyad Zanadin Ramadhan¹, Fajar Chairul Anam¹, Raffanel Adi Permana¹, Ahmad Jazilussurur Hakim², Natalino Fonseca Da Silva Guterres³, Mateus De Sousa Da Silva³

Journal of Renewable Materials, Vol.12, No.2, pp. 381-396, 2024, DOI:10.32604/jrm.2023.047128 - 11 March 2024

Abstract Indonesia is one of the largest coconut-producing countries in the world. The utilization of coconut shell waste into briquettes will increase the selling value and become a great export opportunity. However, the effect of adhesives on the quality of coconut shell charcoal briquettes made using screw extruder machine has not been widely studied. This study aims to determine the effect of adhesive type on the quality of coconut shell charcoal briquettes. The process of fabricating briquettes in this study included crushing, mixing, blending, pressing, and drying. In the mixing process, 3 types of adhesives were… More > Graphic Abstract