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

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

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

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

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

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

J.N. Chung^a,†, Tailian Chen^b, Shalabh C. Maroo^c

Frontiers in Heat and Mass Transfer, Vol.2, No.2, pp. 1-19, 2011, DOI:10.5098/hmt.v2.2.3004

Abstract Recent research progress in the area of nano/micro scale nucleate boiling is reviewed and an up-to-date summary is provided with a focus on the advances of fundamental boiling physics. This review examines nano/micro scale pool boiling experimental and theoretical/numerical work reported in the open literature. On the experimental side, the topics covered are moving contact line, critical heat flux, boiling curve, nucleation, single bubble boiling cycle, bubble coalescence boiling cycle, heater size effect, nanofluid, and nanoscale-structured heater surface. For the theoretical/numerical work, continuum mechanics modeling of the micro-region and molecular dynamics modeling of the nano-region More >

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

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

Wenbo Zhu¹, Neng Liu¹, Zhengjun Zhu^2,*, Haibing Li¹, Weijie Fu¹, Zhongbo Zhang¹, Xinghao Zhang¹

Intelligent Automation & Soft Computing, Vol.38, No.3, pp. 259-273, 2023, DOI:10.32604/iasc.2023.041860

Abstract The detection of ash content in coal slime flotation tailings using deep learning can be hindered by various factors such as foam, impurities, and changing lighting conditions that disrupt the collection of tailings images. To address this challenge, we present a method for ash content detection in coal slime flotation tailings. This method utilizes chromatographic filter paper sampling and a multi-scale residual network, which we refer to as MRCN. Initially, tailings are sampled using chromatographic filter paper to obtain static tailings images, effectively isolating interference factors at the flotation site. Subsequently, the MRCN, consisting of… More >

Xiaoqian Ma^a , Mo Yang^a,*, Yuwen Zhang^b

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-8, 2016, DOI:10.5098/hmt.7.36

Abstract Combustion mechanism of a 300 MW pulverized coal boiler is analyzed and the optimization of the performance of the boiler is carried out. The flow field, temperature field, devolatilization, char combustion and CO generation in the boiler furnace under actual condition is obtained by using Fluent. Three methods to improve the efficiency of boiler combustion are proposed based on the pulverized coal combustion mechanism; their feasibilities are verified through numerical simulation and analysis. The three proposed methods to increase the combustion efficiency may give theoretical reference for air arrangement and combustion optimization of the same More >

Hu Shi, Wei Cai, Xin Wang^*, Lei Song, Yuan Hu^*

Journal of Renewable Materials, Vol.11, No.12, pp. 3991-4006, 2023, DOI:10.32604/jrm.2023.029888

Abstract To solve the fire accidents caused by coal combustion, this work prepared four hybrid hydrogel materials using bio-based polymers, flame retardants, and inorganic materials. Compared to pure water and 3.5 wt% MgCl₂ solution, the as-prepared hydrogel presents good fire prevention performance. In addition, it is found that CO and CO₂ are not produced by coal when the pyrolysis temperature is lower than 200°C. During low-temperature pyrolysis, CO is more likely to be produced than CO₂, indicating inadequate pyrolysis behavior. At the same time, the addition of fire-preventing hydrogel can not only decrease the maximum CO₂ concentration before… More > Graphic Abstract