基于出风温湿度检测的冷却塔防白雾控制装置设计

设计一种基于出风温湿度检测的冷却塔防白雾控制装置,该装置可实现出风温湿度参数的实时采集,并进行相应计算,根据计算结果判断冷却塔是否处于雾区,从而实现防白雾水泵的自动变压控制,利用电动阀控制最大进水量,实现较小混水量的消雾,节约成本。     

物理填加法回收利用泡沫塑料边角废料

介绍了物理填加法回收利用泡沫塑料边角废料,其中重点介绍了用物理填加法回收利用软质泡沫塑料边角废料的生产工艺及设备,并对填加废料与不填加废料生产的经济性进行比较。     

基于正交试验的加工过程伺服系统参数优选

针对加工过程伺服系统参数优选问题,提出一种基于正交试验的伺服系统参数优选方法。在分析、建立加工过程模型的基础上,选取伺服系统参数优选正交试验的因素与水平、指标,进而搭建伺服系统仿真平台并进行仿真试验,通过数据分析、参数优选得到伺服系统的最优参数,以改善系统动态性能和稳定性能。结果表明:对于n=600 r/min、Kn=1 mm/(V·s)、Ks=1670 N/mm2、Ke=2 mm、p=1的加工系统,其伺服系统的最优参数是指数m=0.6、阻尼系数ζ=0.8、自然频率ωn=30 rad/s。     

基于显著性分析的气缸盖结构优化设计

为了改变缸盖的结构,提高气缸盖运行工况下的温度分布及结构可靠性,进行了以鼻梁区宽度等六组参数为设计变量、以其许用范围约束条件、以等效热应力最低为优化目标的汽缸盖结构优化。基于正交实验法,构建了6因素5水平的正交实验表,并建立相应的三维模型,仿真得到了温度场及热应力。通过均值化法去量纲,分析得到了各因素的显著性水平,基于各因素的显著性水平选取了最优方案,并进行对比。结果表明,优化尺寸优选后方案的最大热应力比原始结构降低了13.48%,为缸盖的结构设计提供了一定的参考。     

Deep mine cooling,a case for Northern Ontario:Part Ⅰ

Cooling energy needs,for mines in Northern Ontario,are mainly driven by the mining depth and its operation.Part I of this research focusses on the thermal energy loads in deep mines as a result of the virgin rock temperature,mining operations and climatic conditions.A breakdown of the various heat sources is outlined,for an underground mine producing 3500 tonnes per day of broken rock,taking into consideration the latent and sensible portions of that heat to properly assess the wet bulb global temperature.The resulting thermal loads indicate that cooling efforts would be needed both at surface and underground to maintain the temperature underground within the legal threshold.In winter the air might also have to be heated at surface and cooled underground,to ensure that icing does not occur in the inlet ventilation shaft-the main reason why cooling cannot be focussed solely at surface.     

提升试验设计与数据处理教学效果的研究与实践

结合试验设计与数据处理教学实践,提出了提升其教学效果的几点体会。认为在本课程的教学中,强调课程学习重要性、激发学生学习热情,以注重实用性,优化教学内容,不断改进教学方法,加强实践教学和计算机技术应用将有利于提升该课程的教学效果。     

拖拉机液压悬挂系统模糊控制的研究

该文对拖拉机液压悬挂系统的模糊控制器进行了设计，采用MATLAB软件进行了仿真分析，并进行了试验研究，结果表明模糊控制对液压悬挂系统控制是适应的，对改善拖拉机作业质量提供了可靠的理论和试验依据。     

Refrigerated cooling air cutting of difficult-to-cut materials

One approach to enhance machining performance is to apply cutting fluids during cutting process. However, the use of cutting fluids in machining process has caused some problems such as high cost, pollution, and hazards to operator's health. All the problems related to the use of cutting fluids have urged researchers to search for some alternatives to minimize or even avoid the use of cutting fluids in machining operations. Cooling gas cutting is one of these alternatives. This paper investigates the effect of cooling air cutting on tool wear, surface finish and chip shape in finish turning of Inconel 718 nickel-base super alloy and high-speed milling of AISI D2 cold work tool steel. Comparative experiments were conducted under different cooling/lubrication conditions, i.e. dry cutting, minimal quantity lubrication (MQL), cooling air, and cooling air and minimal quantity lubrication (CAMQL). For this research, composite refrigeration method was adopted to develop a new cooling gas equipment which was used to lower the temperature of compressed gas. The significant experimental results were: (i) application of cooing air and CAMQL resulted in drastic reduction in tool wear and surface roughness, and significant improvement in chip shape in finish turning of Inconel 718, (ii) in the high-speed milling of AISI D2, cooling air cutting presented longer tool life and slightly higher surface roughness than dry cutting and MQL. Therefore, it appears that cooling air cutting can provide not only environment friendliness but also great improvement in machinability of difficult-to-cut materials.     

锻造液压机实验研究

分析了使用大流量比例阀作为主控阀的锻造液压机的加载与卸载特性,对影响液压机快速性和平稳性的因素进行了实验研究,提出了提高与改善液压机性能的具体措施。     

新型穿孔顶头的研究

介绍了穿孔顶头的工作条件和主要失效形式，以及新型穿孔顶头的设计。确定了顶头的生产工艺。使用结果表明，新型穿孔顶头在穿孔中能保持良好的流线型外形，产生光滑的再生氧化层，防止塌鼻失效，提高了使用寿命。