煤矿主提升机平衡尾绳更换工艺的改进

更换煤矿主提升机平衡尾绳是煤矿重大检修项目之一,原施工方案为两条平衡尾绳同时更换,存在较多不合理之处,改进为以新绳带旧绳、单绳依次更换的方案,实现了安全、快捷地更换平衡尾绳,同时减少施工对矿井生产的影响,提高煤矿经济效益。     

超(超)临界主给水调节阀流场特性分析

针对某超(超)临界主给水调节阀在运行工况条件下出现的空化汽蚀现象,结合多级节流降压原理与多相流理论,采用Schnerr and Sauer空化模型和Mixture两相流模型,对调节阀内部流场进行数值模拟,研究了笼罩层数与导流槽宽度对流场空化的影响。结果表明,随着笼罩层数的增加,调节阀内的最低压强由0.015MPa上升至0.717 MPa,最大流速由147.1 m/s降至49.36 m/s,空化的汽相最大体积分数由0.979降至0.160,多级笼罩有助于实现逐级降压、限制流速及抑制空化的目的;同时在阀门结构尺寸允许条件下,适当增加导流槽宽度也有利于抑制空化。研究结果为该类调节阀的设计提供了参考。     

原油包裹体中芳香烃组分类型与成熟度关系——以三肇凹陷扶余油层为例

为了明确油包裹体中芳香烃组分与原油成熟度的关系，基于原油的荧光性，利用单个包裹体组分无损分析的荧光光谱方法，对松辽盆地三肇凹陷扶余油层油包裹体荧光光谱进行了定量化描述。首先获取了储层油包裹体荧光颜色类型，然后获得了单个油包裹体荧光光谱图，并对比标准芳香烃在波长为365 nm单色光激发下的荧光光谱主峰波长特征值，最终划分了油气充注幕次及不同幕次油包裹体芳香烃组分类型。研究结果表明：扶余油层发育黄色、黄绿色、蓝绿色和蓝色4种荧光颜色油包裹体，代表了不同成熟度的油气充注。其中第1幕黄色荧光油包裹体主峰对应的波长（λ_max）为576.0~584.5 nm，为低成熟度油充注；第2幕黄绿色荧光油包裹体λ_max为528.7~546.3 nm，为中等成熟度油充注；第3幕蓝绿色荧光油包裹体λ_max为491.6~516.1 nm，为中等成熟度油充注；第4幕蓝色荧光油包裹体λ_max为440.6~456.5 nm，为高成熟度油充注。综合判定得出，三肇凹陷扶余油层在地质历史时期经历了4幕油气充注。油包裹体中芳香烃组分主要有十环芳香烃、并四苯，其次含有红荧烯，并含有少量的胆蒽、蒽；储层油包裹体总体表现出小分子量芳香烃少、大分子量芳香烃多的特征，说明储层包裹体中原油以低-中等成熟度原油为主。通过拟定油包裹体荧光光谱特征与芳香烃组分关系，从而为原油芳香烃组分类型及成熟度研究提供一定依据。     

煤矿井下主排水系统的设计与实现

针对煤矿井下主排水系统人工就地操作的问题，介绍了一种基于PLC的水泵控制方式，该系统选用PLC为控制核心，通过液位、压力、流量、温度等传感器采集水泵运行参数，对水泵及管路阀门、高压开关等设备进行控制与监测，使设备在无人干涉的情况下实现了多台水泵和关联设备的联动运行和参数采集、状态监测、数据处理、故障报警、报表查询等，使设备达到最佳运行状态，满足了煤矿生产环境及安全生产的需要，提高了煤矿自动化水平，降低了劳动力强度，为实现煤矿数字化矿井打下良好的基础。     

南海西部北部湾区域地层原油黏度预测方法

目前海上油田受多方面因素制约,地层流体取样少或无取样,而南海西部北部湾区域油藏流体性质变化较大,导致地层原油黏度难以准确预测。针对上述问题,通过收集北部湾区域已开发油藏地面及地层流体性质资料,分析影响原油黏度的主控因素,从主到次依次为含硫量、胶质含量、沥青质含量、含蜡量,其中胶质含量、沥青质含量和含硫量组合因素对原油性质影响显著,原油黏度对温度敏感,原油脱气前,压力对其影响小;运用数理统计学原理,建立了地面原油参数团、原油密度、地面脱气原油黏度与地层原油黏度间的3种评价方法,经乌石油田群15个样本点检验,平均绝对误差在0.5 mPa·s左右。该预测方法可为流体评价和油藏开发提供较为科学可靠的地层原油黏度资料。     

LF精炼废渣水热浸出过程中主要矿相的溶解行为

通过水热浸出实验分别研究了精炼废渣及合成的废渣中2种主要单一矿相12CaO?7Al2O3和2CaO?SiO2的溶解行为，并将二者进行对比分析，探究了LF精炼废渣在水热浸出过程中的溶解行为。结果表明，废渣浸出过程中浸出液的pH?12，且随浸出时间增加，电导率和Ca浓度增加，Al浓度急剧下降，Si浓度低于0.1 mg/L且保持不变；12CaO?7Al2O3浸出过程中，随时间增加，浸出液pH值稳定在约11.3，浸出液中Al浓度增加，Ca浓度略微下降。2CaO?SiO2浸出液中主要为Ca2+，Si浓度低于0.6 mg/L；废渣与单一矿相浸出过程的pH值及Al, Si浓度较接近，可以通过单一矿相的溶解行为研究精炼废渣在水热浸出过程中的溶解行为，但废渣浸出液的Al和Si浓度均低于单一矿相，表明废渣中CaO等其它组分溶解抑制了12CaO?7Al2O3和2CaO?SiO2溶解。     

Multi-objective iterative optimization algorithm based optimal wavelet filter selection for multi-fault diagnosis of rolling element bearings

Rolling element bearings (REBs) play an essential role in modern machinery and their condition monitoring is significant in predictive maintenance. Due to the harsh operating conditions, multi-fault may co-exist in one bearing and vibration signal always exhibits low signal-to-noise ratio (SNR), which causes difficulties in detecting fault. In the previous studies, maximum correlated kurtosis deconvolution (MCKD) has been validated as an efficient method to extract fault feature in the fault signals. Nonetheless, there are still some challenges when MCKD is applied to fault detection owing to the rigorous requirements of multiple input parameters. To overcome limitation, a multi-objective iterative optimization algorithm (MOIOA) for multi-fault diagnosis is proposed. In this method, correlated kurtosis (CK) is taken as a criterion to select optimal Morlet wavelet filter using the whale optimization algorithm (WOA). Meanwhile, to further eliminate the effect of the inaccurate period on CK, the update process of period is incorporated. After that, the simulated and experimental signals are utilized to testify the validity and superiority of the MOIOA for multiple faults detection by the comparison with MCKD. The results indicate that MOIOA is efficient to extract weak fault features even with heavy noise and harmonic interferences.     

Drag Power Loss Investigation in Cylindrical Roller Bearings Using CFD Approach

In high-speed rolling element bearings, the drag forces can be prominent and it is demonstrated in this investigation that the classical models may not be appropriate for correctly estimating this power loss contribution. A modification of the models is thus proposed, including the usual drag forces formulation relying upon the drag coefficient to be evaluated from a numerical computational fluid dynamics (CFD) approach. A three-dimensional approach that considers both the rings and the cylinder ends seems the only adequate approach to be used because a two-dimensional approach predicts a drag coefficient value that is too low. When using the former computed drag coefficient for the evaluation of the total power losses, high values of oil volume fraction must be employed to recover the measured power losses.     

Experimental Analysis and Modeling of the Effects of Oil–Air Lubrication Parameters on Bearings Friction Loss of High-Speed Motorized Spindle

The friction loss of an angular contact ball bearing is a key factor restricting the development of a high-speed motorized spindle. To quantitatively calculate the effects of the oil–air lubrication parameters on the friction loss of high-speed bearings, the drag resistance and the churning resistance generated by the movement of the rolling elements in the lubricant are theoretically modeled and the percentage volume of the lubricant in the bearing cavity (XCAV) is used to characterize the effects. The friction loss of bearings is tested by two novel methods: the free deceleration method and the energy-balance method. The experimental results show that the viscous resistance loss is a major component of bearing friction loss and oil–air lubrication parameters have important influence on it. A comparison of the theoretical calculations and the experimental results is used for deriving the empirical formula of XCAV with respect to the lubricant flow, gas pressure, rotating speed, and pitch diameter. The research results of this study have important significance for the measurement, prediction and reduction of the friction loss of high-speed bearings.