大倾角综放工作面液压支架稳定性控制技术

叙述了了支架在大倾角工作面上的受力特征和稳定性状况,提出,大倾角综放工作面液压支架防倒防滑装置以及提高支架稳定性和支护可靠性的措施,拓宽了综放支架的适用范围.     

大倾角综采工作面液压支架稳定性及过断层技术

大倾角煤层综采工作面液压支架的稳定性成为研究的重点和难点。分析了液压支架受力状态和围岩之间的关系以及影响支架稳定性的因素,进行了液压支架防滑和防倒研究,并对过断层技术进行了探讨。     

煤矿工作面液压支架的选型

综采液压支架选型对于工作面的设计十分重要.通过介绍液压支架工作阻力的计算方法,结合斜沟煤矿23105综放工作面的实际情况对液压支架选型进行了具体分析,可为煤矿工作面液压支架选型提供一定的参考.     

回采面合理采煤方法的确定

以8601回采面开采8号煤层为研究对象,分析地质构造、顶板、煤层倾角、硬度和泥岩夹矸对不同采煤方法的影响。由于8601回采面内陷落柱发育,且顶板破碎、有淋水现象,煤质松软,不适宜采用大采高综采的采煤方法。从经济、安全、适用性等方面综合考虑,确定8601回采面最佳的采煤方式为综放开采,同时,从采面煤壁稳定性、顶煤冒落性、夹矸位置和厚度等方面综合确定了综放开采合理的割煤高度为3.3 m,采放比为1∶1.2。     

大倾角条件下液压支架的稳定性研究

在矿井生产过程中,保持液压支架的稳定性一直困扰着煤矿安全与生产。通过对大倾角工作面液压支架防滑、防倒及尾部抗扭稳定性分析,找出影响支架稳定的主要因素,提出在实际生产过程中一些比较实用的支架防倒和防滑措施。     

龙王沟煤矿61601综放工作面回撤技术方案研究

随着煤矿综合机械化生产的推进,综放工作面的回撤极为频繁,往往造成综放工作面的脱节,影响矿井生产的经济效益.结合龙王沟煤矿61601综放工作面回撤设备实践,论述了综放工作面回撤概况、回撤前主要设备及安设、回撤方式及方法,重点以设备列车、采煤机、转载破碎机、液压支架为例研究了工作面设备的拆除顺序、方法等回撤工艺,为节省工作...     

新型端头支架在司马矿的应用

司马煤业公司在1112综放工作面两端头推广应用了端头支护支架.叙述了1112工作面概况、1112工作面端头支护支架的主要技术特点及其在巷道中的布置,分析了端头支护支架操作及端头支架应用情况.     

综放开采覆岩结构分析与支架工作阻力确定

针对仰斜综放工作面围岩控制难题,以瑞隆煤矿8101仰斜综放工作面为背景,建立倾斜岩梁力学模型对顶板破断位置进行分析,运用UDEC对采场围岩运移规律进行数值模拟,得出了8101仰斜综放工作面初次来压步距和支架合理工作阻力的计算公式。结果表明：仰斜综放条件下,上覆岩层受层向分力作用,有向采空区滑移的趋势,煤壁上方顶板受拉破断,破断位置相对靠后,支架稳定性降低,容易导致煤壁片帮、冒顶;通过现场实测,8101仰斜综放工作面初次来压步距为46 m,支架额定工作阻力9 000 kN、最大工作阻力7 932 kN,高于同等条件下水平工作面的来压步距和工作阻力。     

大倾角综采工作面开采探索与实践

2302工作面所开采的煤层倾角平均32°,属于典型的大倾角综采工作面,为了防止在以往开采大倾角工作面时出现液压支架、刮板输送机、溜子等综采设备下滑、倾倒现象发生,特进行了工作面配套设备的合理选择。最后根据2303工作面的实际开采情况提出布置伪斜开采工作面和改进综采设备等两个方面来控制设备下滑,结果表明通过对设备的合理选择、采取设备防滑措施并遵循一定的安全辅助措施完全可以保证该工作面正常回采工作。     

缓斜破碎顶板综放面回收机械手应用技术浅析

为提高破碎顶板液压支架撤除机械化水平,采用理论与实践结合的方法,浅析了机械手在较大倾角破碎顶板的应用技术。根据支架结构和重量、煤层倾角、顶板破碎等条件,合理设计和匹配机械手结构形式和参数,通过工作面乳化泵驱动,待回支架、机械手及3台掩护支架相互配合,合理护顶、防倒、抽出、调整间距、爬坡、吐煤和前移,将大倾角支架从支护位置安全快速转向抽出,掩护支架及时支护回架通道顶板,实现了支架调向与外运平行作业,加快了回收速度,提高了支架撤除安全可靠性,经济和社会效益显著,对类似工作面的回收具有很好的参考价值。     

烘焙对生物质热化学转化特性影响的研究进展

生物质是可再生能源的重要组成部分,储量巨大,但其含水量高、能量密度和热值低等缺点致使其研磨难度大、存储运输不便,难以资源化利用。本文对烘焙预处理技术的过程及特点、能耗分析和较为理想的烘焙标准进行了简述;并重点阐述了烘焙对生物质燃烧、热解和气化特性影响的研究进展。经烘焙处理后的生物质在炉膛内可快速、稳定燃烧,炉内温度迅速升高,产生的烟气量减少;热解产生的生物质焦油中水和乙酸含量明显减少,苯酚含量增加,热值总体升高;气化合成气品质明显提升,能量密度增大,总气化效率显著提高。此外,对烘焙预处理技术在城市固体废弃物处理的应用进行了简要的概述,并对其在生物质和城市固体废弃物研究方向上进行了展望。     

Research progress on hydrate plugging in multiphase mixed rich-liquid transportation pipelines

The plugging mechanism of multiphase mixed rich-liquid transportation in submarine pipeline is a prerequisite for maintaining the fluid flow in the pipeline and ensuring safe fluid flow. This paper introduced the common experimental devices used to study multiphase flow, and summarized the plugging progress and mechanism in the liquid-rich system. Besides, it divided the rich-liquid phase system into an oil-based system, a partially dispersed system, and a water-based system according to the different water cuts, and discussed the mechanism of hydrate plugging. Moreover, it summarized the mechanism and the use of anti-agglomerates in different systems. Furthermore, it proposed some suggestions for future research on hydrate plugging. First, in the oil-based system, the effect factors of hydrates are combined with the mechanical properties of hydrate deposit layer, and the hydrate plugging mechanism models at inclined and elbow pipes should be established. Second, the mechanism of oil-water emulsion breaking in partially dispersed system and the reason for the migration of the oil-water interface should be analyzed, and the property of the free water layer on the hydrate plugging process should be quantified. Third, a complete model of the effect of the synergy of liquid bridge force and van der Waals force in the water-based system on the hydrate particle coalescence frequency model is needed, and the coalescence frequency model should be summarized. Next, the dynamic analysis of a multiphase mixed rich-liquid transportation pipeline should be coupled with the process of hydrate coalescence, deposition, and blockage decomposition. Finally, the effects of anti-agglomerates on the morphological evolution of hydrate under different systems and pipeline plugging conditions in different media should be further explored.     

山水气林田湖草城系统治理工程技术研究

本文对“山水气林田湖草城”系统治理的理论与工程技术进行了全面深入地研究.提出了修复山形地貌、净化水体质量、调节大气成分、优化森林结构、改良农田土质、重建湖域生态、扩大种草面积、完善城市规划的方法.对“山水气林田湖草城”进行整体保护、系统恢复、综合治理;量化生态资源的隐性价值;发展新气候经济;实施碳热氧产品交易;设立碳热氧税制度;建立经济生产总值与生态生产总值平衡发展体系;创建零碳模式;使人与植物、动物、微生物和自然环境之间,生物各个种群之间,生态诸子系统之间,通过能量流动、物质循环和信息传递达到高度适应、协调和统一的平衡状态,减弱减少自然灾害,延长人类在地球上的生存时间.     

A critical review of ash slagging mechanisms and viscosity measurement for low-rank coal and bio-slags

Gasification or combustion of coal and biomass is the most important form of power generation today. However, the use of coal/biomass at high temperatures has an inherent problem related to the ash generated. The formation of ash leads to a problematic phenomenon called slagging. Slagging is the accumulation of molten ash on the walls of the furnace, gasifier, or boiler and is detrimental as it reduces the heat transfer rate, and the combustion/gasification rate of unburnt carbon, causes mechanical failure, high-temperature corrosion and on occasions, superheater explosions. To improve the gasifier/combustor facility, it is very important to understand the key ash properties, slag characteristics, viscosity and critical viscosity temperature. This paper reviews the content, compositions, and melting characteristics of ashes in differently ranked coal and biomass, and discusses the formation mechanism, characteristics, and structure of slag. In particular, this paper focuses on low-rank coal and biomass that have been receiving increased attention recently. Besides, it reviews the available methodologies and formulae for slag viscosity measurement/prediction and summarizes the current limitations and potential applications. Moreover, it discusses the slagging behavior of different ranks of coal and biomass by examining the applicability of the current viscosity measurement methods to these fuels, and the viscosity prediction models and factors that affect the slag viscosity. This review shows that the existing viscosity models and slagging indices can only satisfactorily predict the viscosity and slagging propensity of high-rank coals but cannot predict the slagging propensity and slag viscosity of low-rank coal, and especially biomass ashes, even if they are limited to a particular composition only. Thus, there is a critical need for the development of an index, or a model or even a measurement method, which can predict/measure the slagging propensity and slag viscosity correctly for all low-rank coal and biomass ashes.     

Combustion characteristics and flame stability of linear esters of palmitic acid based on OH-PLIF technology

Experimental study on combustion characteristics and method for evaluating flame stability was carried out. Methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, and amyl palmitate were prepared using pyridine n-butyl bisulfate ionic liquid as catalyst in a self-designed reactor to catalyze esterification reaction of palmitic acid with methanol, ethanol, propanol, butanol, and pentanol, respectively. Combustion characteristics including the flame height, flame front area, and flame speed were analyzed; and OH-PLIF time-average total signal strength by the OH-PLIF technique and cold flow properties of linear-chain alkyl esters of palmitic acid were also studied. Image diagnosis was applied to the study of flame stability, and an image segmentation method using three color feature matrices of flame corresponding to the red, green, and blue components was proposed. A color was selected as the evaluation color and the iterative method was used to obtain the optimal threshold for the area where the flame was located. Each pixel in the matrix was compared with an optimal threshold, and the flame stability was evaluated by calculating the ratio variance under continuous conditions. The method is simple in operation, accurate in repeatability, less interfered, and provides some guidance for analysis and optimization of biodiesel combustion process.     

生物质燃烧过程中结焦、积灰及腐蚀形成机理及其制剂开发研究进展

大力发展生活垃圾及农林废弃物等生物质直接燃烧发电和煤炭掺烧生物质燃烧发电对缓解我国能源安全问题和实现“双碳”战略目标具有重要意义。然而生活垃圾和农林废弃物中较高含量的碱/碱土金属、硫、氯和硅等元素在高温燃烧过程中会发生复杂交互反应,导致锅炉结焦、积灰和腐蚀等一系列问题,严重影响锅炉的安全稳定运行。通过系统分析生活垃圾和农林废弃物等固体燃料燃烧过程中可能的结焦、积灰和腐蚀形成机理,探讨了原料灰分组成和结焦、积灰、腐蚀形成的关联关系和预测方法,在此基础上比较了不同类型结焦、积灰和腐蚀抑制剂的作用机制及其施加效果,并对未来高效抑制剂的开发进行了展望。     

Investigation of the gas injection rate shape on combustion,knock and emissions behavior of a rotary engine with hydrogen direct-injection enrichment

The application of hydrogen direct-injection enrichment improves the performance of gasoline Wankel rotary engine, and the hydrogen injection strategy has a significant impact on combustion, knock, and emissions. The Z160F Wankel rotary engine was used as the investigated compact engine, and the simulation model was developed using CONVERGE software. The combustion, knock and emissions characteristics of the engine were studied with the different mass flow of hydrogen injection, i.e., the trapezoid, wedge, slope, triangle and rectangle type of gas injection rate shape. In the numerical simulations, the in-cylinder pressure oscillations were monitored using monitoring points, and the knock index (KI) was used as an evaluation indicator. The study revealed that the gas injection rate shape significantly affected the mixture of hydrogen and air, thus impacting combustion, knock and emissions. When the injection rate shape was rectangle, the flame speed was faster, the peak pressure in the cylinder was higher, and the corresponding crank angle was earlier, which led to higher pressure oscillations in the cylinder and larger KI. Based on the rectangle injection rate shape, the KI decreased by 75.81%, 33.47%, 26.46% and 76.58% for trapezoid, wedge, slope, and triangle, respectively, and the indicated mean effective pressure increased by 15.68%, 5.07%, 0.56% and 14.98%, respectively. Due to the small difference in maximum temperature, which resulted in very little variation in nitrogen oxides for each injection rate shape, the total hydrocarbon emissions of the trapezoid and triangle injection rate shape was high due to the delayed combustion phase. This paper provides a solution for direct hydrogen injection to improve the combustion, knock and emissions behavior of the rotary engine.     

钻井液处理剂现状分析及合成设计探讨

近年来,国内钻井液处理剂新品种逐年上升,而投入生产及应用的产品却很少。对于聚合物处理剂,尽管从上世纪70年代到90年代相继研制应用了不少新产品,特别是AMPS聚合物的应用,使聚合物处理剂的水平上了一个新台阶,但处理剂主体结构与基团没有变,只是基团与相对分子质量的优化而已,产品性能没有取得突破性进展。对于沥青、褐煤、单宁等类产品,虽然名称没有变,而有效物减少,且大多数产品通过复配而得,产品质量大幅下滑。淀粉、纤维素、植物胶改性产品,由于改性难度大,研究多、应用少。阳离子黏土稳定剂,正电胶,乳化沥青/石蜡,聚合醇或多元醇,凝胶聚合物,"不渗透"产品和"聚胺"等产品得到了一定应用和发展。纵观上世纪70年代以来钻井液处理剂的发展,整体情况是从初期具有明确化学名称及成分的产品,逐步出现了产品成分模糊,以代号为主体的现象,特别是90年代以来,随意编代号的现象越发严重。由于存在较多制约因素,国内钻井液处理剂研制出现停滞不前的局面。应从研制专用原料、聚合物优化设计、SMP改性、天然高分子材料改性等方面出发,结合钻井液发展需要,研制新单体、适用于高钙环境下合成聚合物、传统产品的替代品、超支化聚合物、天然材料改性产品、固相控剂(清洁剂)、润滑剂、沥青类产品、高性能凝胶材料及油基泥浆处理剂,以及工业废料的利用等,推动钻井液技术进步。     

锅炉与炉窑燃料油使用中的常见问题及解决方法

对燃油锅炉与炉窑使用中的常见问题以及燃料油主要质量指标的优劣对燃烧工况的关联影响进行分析，并提出一种经济实用简便的解决方法，达到改善燃油锅炉与炉窑燃烧工况与抑制硫、钒的腐蚀，灰分积焦、积炭、油泥生成等，又达到降低能耗、减少烟气排放的目的。