自动回流破壳(PVC)沼气池的构造与建造

针对我国传统户用沼气池存在的诸多问题,采用PVC塑料材料设计、建造了一种自动回流破壳沼气池。文章介绍了沼气池的构造、工作原理及结构性能,详述了建造该沼气池的操作过程。     

分压式孔底局部反循环钻具设计

在破碎地层中进行金刚石钻探,普遍存在有岩芯采取率不足的问题。本文通过对普通单动双管钻具的分水接头、卡簧、卡簧座、及钻头水路的改进,从而改变钻具内外环空间隙,强迫冲洗液在孔底形成分流,造成孔底局部反循环。利用内循环冲洗液对岩芯的浮托力,使岩芯顺利进入岩芯管上部,消除了钻头入口处挤压的岩芯,从而保证岩心采取率。     

含蜡原油石蜡沉积模拟方法研究

对从苏丹Unity油田现场取得有代表性的原油样品进行了原油组分分析和析蜡点测试。并针对油田的生产状况,利用与美国德士古石油公司合作建立的自动化高压石蜡沉积循环管道模拟系统,采用冷却实验步骤测试了苏丹原油从高于原油析蜡点温度到较低环境温度范围内在现场流速、油温和环境温度下的石蜡沉积速率,定量研究了流速和油温对石蜡沉积速率的影响,并采用分子扩散和剪切效应的总效应来描述石蜡沉积机理。利用临界蜡张力作为模拟放大因子,采用半经验的石蜡沉积数学模型,预测了Unity油田21井的生产井筒在现场生产条件下的石蜡沉积情况,模拟了不同产量和不同时间的蜡沉积剖面。结果表明,该油井在目前高产条件下,未发生石蜡沉积问题;在低产时,须考虑清蜡和防蜡措施。     

预留瓦斯抽放钻场中钻场间距及布孔参数的确定

为达到工作面瓦斯灾害防治和采空区瓦斯资源有效开采的双重目的,在分析采空区顶板覆岩空间垮落规律的基础上,阐述了采空区顶板连续“O”型圈特征和边界顶板上相邻两“O”型圈交界位置处的变异特征,探讨了在高位钻场水平钻孔瓦斯抽放技术中将原钻场继续留用的可行性及合理位置,据此给出了预留钻场高度、间距,以及钻孔长度的理论计算公式.     

影响煤层深孔打钻的原因分析和防治措施

通过对煤层钻孔存在问题的分析,提出钻头导向技术和钻进合理给进压力的方法,在鹤煤十矿应用后取得了良好效果。     

小口径火炮窥膛仪的研制

提出了一种可实现30mm～5．8mm小口径火炮炮膛（枪膛）表面自动检测的新方法;详细介绍了以“光纤传感器-光电转换器-数据采集卡-微机”为核心的窥膛仪系统的设计方案,比较了此方法与传统检测方法的优缺点,并对其中的难题做了深入的研究;从根本上解决了由于小口径火炮内膛空间小而无法自动检测及不能得到清晰内膛表面图像的问题;在实际检测诊断中的使用证明,这种方法可以较好地完成小口径火炮内膛表面自动检测的任务。     

缸盖螺栓连接副结构对柴油机铝合金缸体缸孔变形的影响

通过建立缸盖–缸垫–缸体耦合模型，采用数值仿真方法，研究了柴油机铸铁缸体和铝合金缸体在施加相同缸盖螺栓预紧力时，改变螺栓孔设计参数对缸孔关键截面失圆变形和平均圆度、圆柱度、同轴度和漏光率4个评价指标的影响。研究发现，铸铁缸体和铝合金缸体的关键截面在傅里叶变换下变形趋势基本一致，除了漏光率基本不变外，平均圆度、圆柱度、同轴度分别增大了54.40%、38.39%、27.08%；对于铝合金缸体，减小沉孔和螺栓孔比值能减小各截面的综合变形，同时平均圆度、圆柱度、同轴度也会减小，但处于螺纹主要受力段以下的截面在傅里叶四阶变形的极值相位角一致性变差；保持沉孔深度不变，适当增加螺纹旋合长度方案下缸体缸孔平均圆度、圆柱度、同轴度下降速率最明显；保持螺纹不变，减小沉孔深度方案下缸体缸孔平均圆度、圆柱度、同轴度的值最小，相较于原始缸体分别下降了32.74%、31.24%、39.34%。     

鄂北气田小井眼钻完井关键技术研究及应用

针对鄂尔多斯北部气田小井眼存在钻井及固井泵压高、机械钻速低、钻井技术不完善等技术问题，通过对井身结构和轨道剖面优化，钻杆、动力钻具和PDC钻头优选，水泥浆密度和套管扶正器数量及加放位置优化，形成低成本小井眼优快钻完井技术。该技术现场试验200口井，钻井周期年缩短率12%以上，机械钻速提高至18 m/h以上，钻井废弃物和固井水泥浆用量平均减少了27%和41%，平均单井钻井工程费用降低50万元左右，达到了降本增效和保护环境的目的，为鄂北气田低成本高效开发探明了方向。     

Combined effect of multi-injection scheme,injector nozzle bore,and biodiesel blends on combustion and performance characteristics of diesel engine

Many researchers have conducted extensive experimental and numerical studies to explore the influences of multiple types of fuels. The high demand of energy in the world has led to the growing crisis and depletion of fossil fuels. Therefore, the researchers have focused on investigating renewable energy sources like biodiesel with the aim of suggesting, which energy is more friendly to the environment. Biodiesel has specifications for using it as an alternative fuel to traditional fossil fuels. Whereas, the use of biodiesel fuel in the original design of Diesel engine can emit a higher percentage of nitrogen oxides (NO_x). Therefore, to reduce the harmful emissions of the fuel, the injection schemes and injector nozzle bore (INB) of the engine were modified. The present research combines the effect of the nozzle hole diameters and split injection scheme on the performance and combustion parameters of compression ignition (CI) engine was investigated. The engine was fueled with diesel blended of different proportions (Sp20, Sp40, Sp60, and Sp100) of spirulina biodiesel to prove the suitability of this blend as an alternative fuel. The injector nozzle has three injection holes, and the diameter of the three modified holes of the nozzle is changing (from 0.20 to 0.28 mm, step 0.02 mm) along with two types of scheme injection (double and triple). Furthermore, the influence of the direct injection Diesel-RK model, single-cylinder, four-stroke engine; constant compression ratio (17.5:1), engine speed (1500 rpm), and naturally aspired engine at full load condition are studied. A comparison of the present simulation is compared with published results to validate the present simulation model for conventional baseline Diesel for validation. The simulation was done to investigate and present a comparative study with the conventional baseline Diesel engine. The double injection scheme shows a decrease by 1.8%, 1.7%, and 1.9% for parameters of peak cylinder pressure (PCP), peak cylinder temperature (PCT), and maximum rate of pressure rise, respectively. Whereas, the specific fuel consumption (SFC) and break thermal efficiency are increased by 8.7% and 9.33%, respectively. The results showed a reduction by 2.1%, 20.5%, 22.1%, and 3.2% in PCP, PCT, maximum rate of pressure rise, and break thermal efficiency, respectively. Moreover, the SFC is increased by 3.1% with the modified INB 0.28 (mm).     

串行12位ADC MAX1247及其应用

阐述了ＭＡＸ１２４７的特性和工作原理，介绍了单片机与ＭＡＸ１２４７的硬件接口设计以及软件编程的方法，最后简述了该模／数转换技术在螺杆钻具密封性能测试台架中的应用。