【作者】 于玲；

【导师】 苏东海；

【作者基本信息】 沈阳工业大学 ， 机械工程， 2022， 博士

【摘要】 液压支架是煤矿综采工作面用于安全支护的核心部件,其可靠性直接影响着整套综采设备能否实现安全高效采煤。乳化液作为液压支架液压系统的工作介质,其品质是保障液压支架能否正常运行的关键。由于乳化液成分特殊性和支架液压系统的庞大复杂性以及采煤工况的恶劣性,乳化液品质保障问题已成为影响综采工作面实现高产高效自动化安全采煤的瓶颈环节。本文以实现支架液压系统乳化液品质保障为目标,构建了一套面向乳化液品质控制的全周期保障系统,研究了乳化液配比用水的水质处理、乳化液浓度在线监测与自动配比和乳化液高压反冲洗过滤控制等关键技术问题。主要研究内容包括:(1)详细分析了支架液压系统乳化液的品质问题及其来源,构建了一套面向乳化液品质控制的全周期保障系统,给出了包括乳化液输入污染控制、工作面纯水处理系统控制、乳化液自动配比、基于反冲洗的乳化液污染过滤和乳化液参数监控等在内的乳化液保障控制策略,为高效保障乳化液品质,提高支架液压系统的使用寿命和稳定性奠定了必要的理论基础。(2)在全面总结煤矿工作面乳化液配制用水基本要求的基础上,详细分析目前乳化液配制用水的应用现状,研究乳化液配制用水的硬度、氯离子、硫酸根离子含量对乳化液稳定性及防锈性能的影响。在此基础上分析了制备纯水的工作原理,优化了工艺流程,开发了面向煤矿支架液压系统乳化液配制的工作面纯水处理系统。试验结果表明,该系统可有效滤除矿井水中的各种杂质,软化中高硬度水质,并减小水中各种溶解性盐类含量,使出水品质远高于乳化液配制用水要求,为工作面支架液压系统提供可靠的水质保障。(3)针对工程实践中乳化液混合不均匀、配比浓度不稳定等瓶颈问题,在深入分析乳化液物理特性与工作性能之间关系的基础上,基于超声辅助制备了不同粒径分布及大小的乳化液,试验研究了乳化液粒径分布及大小对乳化液润滑性、热稳定性和防腐性等性能的影响规律,为超声制备乳化液的参数配置提供了必要的理论支撑。同时,在综合现有乳化液浓度检测方法优缺点的基础上,提出了一种基于电磁理论的乳化液浓度计算方法,利用标定的乳化液特性参数,实现了乳化液浓度计算的温度补偿,确保了乳化液浓度的检测稳定性,并用试验进行了验证。在上述研究基础上开发了基于浓度在线检测和超声乳化的乳化液自动配比装置,为支架液压系统乳化液品质的优化奠定了必要的基础。(4)为掌握反冲洗过滤器在工作过程中的过滤特性,基于污染控制理论,引入重复过滤因子、反冲洗效率和反冲分流系数等参数,建立了具有正向过滤和反向冲洗双重功能的反冲洗过滤站污染控制模型,确立了过滤器压差-纳污量计算模型,并以此为基础建立了AMESim仿真模型,研究了重复过滤因子、超声波作用下的反冲洗效率及反冲分流系数等参数对反冲洗效果的影响规律,得出了过滤站出口污染度随反冲洗时间的变化规律。在此基础上开发了一种基于超声清洗的高压自动反冲洗过滤装置,并通过压差试验和反冲洗试验验证了反冲洗污染控制模型的有效性,从而为过滤站的性能优化设计及保障乳化液清洁度奠定了必要的理论基础。更多还原

【Abstract】 Hydraulic support is the core component of safety support in fully mechanized coal face.Its reliability directly affects whether the whole set of fully mechanized mining equipment can realize safe and efficient mining.As the working medium of the hydraulic system of the hydraulic support,the quality of emulsion is the key to ensure the normal operation of the hydraulic support.Due to the particularity of emulsion composition,the huge complexity of support hydraulic system and the bad working conditions of coal mining,the quality assurance of emulsion has become the bottleneck of realizing high-yield,high-efficiency,automatic and safe coal mining in fully mechanized face.In order to ensure the emulsion quality of the support hydraulic system,this paper constructs a set of full cycle guarantee system for emulsion quality control,and studies the key technical problems such as water quality treatment of emulsion proportioning water,on-line monitoring and automatic proportioning of emulsion concentration,and emulsion high-pressure back flush filter control.The main research contents include:(1)The quality problems and sources of emulsion in support hydraulic system are analyzed in detail,and a set of full cycle guarantee system for emulsion quality control is constructed.The emulsion guarantee control strategies including emulsion input pollution control,working face pure water treatment system control,emulsion automatic proportioning,emulsion pollution filtration based on back flush and emulsion parameter monitoring are given,so as to ensure the emulsion quality efficiently,it lays a necessary theoretical foundation for improving the service life and stability of the support hydraulic system.(2)Based on the comprehensive summary of the basic requirements of emulsion preparation water in fully mechanized coal face,the application status of emulsion preparation water at present is analyzed in detail,and the effects of hardness,chloride ion and sulfate ion content of emulsion preparation water on emulsion stability and antirust performance are studied.On this basis,the working principle of preparing pure water is analyzed,the process flow is optimized,and a pure water treatment system for emulsion preparation of coal mine support hydraulic system is developed.The test results show that the system can effectively filter various impurities in the mine water,soften the medium and high hardness water quality,reduce the content of various soluble salts in the water,make the water quality far higher than the requirements of emulsion preparation water,and provide a reliable water quality guarantee for the support hydraulic system in the coal face.(3)Aiming at the bottleneck problems such as uneven mixing and unstable ratio concentration of emulsion in engineering practice,based on the in-depth analysis of the relationship between the physical characteristics and working performance of emulsion,emulsions with different particle size distribution and size were prepared based on ultrasonic assistance.The effects of particle size distribution and size of emulsion on the lubricity,thermal stability and corrosion resistance of emulsion were experimentally studied,it provides necessary theoretical support for the parameter configuration of ultrasonic emulsion preparation.At the same time,based on the advantages and disadvantages of the existing emulsion concentration detection methods,an emulsion concentration calculation method based on electromagnetic theory is proposed.Using the calibrated emulsion characteristic parameters,the temperature compensation of emulsion concentration calculation is realized,and the detection stability of emulsion concentration is ensured.It is verified by experiments.An automatic emulsion proportioning device based on on-line concentration detection and ultrasonic emulsification is developed,which lays a necessary foundation for the optimization of emulsion quality of support hydraulic system.(4)In order to master the filtration characteristics of back flush filter in the working process,based on the pollution control theory,the parameters such as repeated filtration factor,back flush efficiency and back flush diversion coefficient are introduced,the pollution control model of back flush filter station with dual functions of forward filtration and back flush is established,and the calculation model of filter differential pressure and pollutant capacity is established.Based on this,AMESim simulation model is established,and the repeated filtration factor,back flush efficiency and back flush diversion coefficient are studied The influence law of parameters such as back flush efficiency and back flush diversion coefficient on back flush effect under the action of ultrasonic wave,and the variation law of outlet pollution degree of filter station with back flush time is obtained.On this basis,a high-pressure automatic back flush filter device based on ultrasonic cleaning is developed,and the effectiveness of the back flush pollution control model is verified by differential pressure test and back flush test,which lays a necessary theoretical foundation for the performance optimization design of the filter station and ensuring the cleanliness of emulsion.更多还原