岩石工程长尺寸钻孔偏斜控制技术的研究及应用

钻孔偏斜控制对地下油库水幕孔工程、岩石锚固工程等具有显著意义.以黄岛地下水封油库水幕孔工程施工项目为依托,研究深度45 ～105 m的水平钻孔偏斜控制技术,形成了一套较完整的能有效控制钻孔偏斜的综合方法,主要技术要点包括：采用导向性好的钻机;选用刚度大的钻杆;合理配置钻杆扶正器;牢固固定钻机;精心测量放样;根据岩层条件变化适时调整钻进工艺参数;测斜紧跟钻进;实施钻孔电视成像等.应用表明：长20,40 m的钻孔偏斜率总体分别可控制在0.45％,0.9％以内,达到了国际领先水平;长60 m钻孔的偏斜率可总体控制在2％以内,达到国际先进水平;长80,100 m钻孔的偏斜率总体分别控制在3％,4％以内.

直膨式地源热泵单U埋地换热器传热数值模拟

针对直接膨胀式地源热泵单U埋地换热器的传热特性,建立换热器及周围土壤温度场的数学物理模型。模拟计算分析制冷剂进口温度、钻孔几何尺寸与回填材料等因素对单U埋地换热器周围土壤温度的影响。研究结果为合理设计直接膨胀式地源热泵提供了理论参考。

多功能播种机的播种部分的装配工艺的改进

为了促进多功能程控自动烟草育种机的开发与应用,该文对振动式穴盘播种机的工作原理及装配工艺进行了分析与研究,并提出改进方案。

Analysis and optimization of drilling parameters for tool wear and hole dimensional accuracy in B_4C reinforced Al-alloy

Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi＇s L27, 3-level, 4-factor orthogonal array was used for the tests. It is shown that generally abrasive wear and built up edge （BUE） formation were seen in the tool wear, and the comer wear was also of major importance. Flank wear of the cutting tool was found to be mostly dependent upon particle mass fraction, followed by feed rate, drill hardness and spindle speed, respectively. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the tool wear as well as hole size. Grey relational analysis indicated that drill material was the more influential parameter than feed rate and spindle speed. The results revealed that optimal combination of the drilling parameters could be used to obtain both minimum tool wear and diametral error.