单螺杆膨胀机散热损失的实验研究

单螺杆膨胀机作为有机朗肯循环系统中最适合的膨胀机类型之一,其性能对循环系统有重要影响。本文实验研究了有机朗肯循环系统中单螺杆膨胀机机壳及润滑油的散热损失及其在不同工况下对膨胀机性能的影响。实验结果表明,当进气温度由80℃升至123℃时,单螺杆膨胀机的散热损失增大,其中润滑油散热损失为主要散热损失,其散热量从0. 5 k W增至1. 05k W。随着膨胀比的增加,各散热损失占比逐渐减小。其中,当进气温度由80℃升至123℃时,机壳散热损失占比为5. 1%～2. 5%,润滑油散热损失占比为16. 1%～9. 5%。说明随着进气温度的增加,膨胀机性能逐渐改善,工质气体通过散热损失的能量比例逐渐减小,散热损失对膨胀机性能的影响逐渐减小。     

Waveguide-based near-eye display with dual-channel exit pupil expander

We propose a waveguide-based near-eye display featuring a dual-channel exit pupil expander, which is composed of an in-coupler, relay gratings, and an out-coupler. Unlike the conventional waveguide-based near-eye displays, whose field of views are usually non-split or partially split, our dual-channel exit pupil expander is able to evenly split the field of view into two halves. The greatest benefit of doing so is that the upper limit of field of view could be significantly increased. The design rules for all components, including the microdisplay, collimating lens, waveguide and gratings, have been studied. The refractive index and dimension of waveguide are identified as two factors that limit the field of view. In what follows, its key specifications are recapitulated. Field of view is 70° (diagonal), eye relief is 15 mm, exit pupil is 20 × 9 mm², modulation transfer function is above 0.591 at 30 cycle/degree, contrast ratio is 13, and distortion is 1.38%.     

Simulation and experimental research on energy conversion efficiency of scroll expander for micro‐Compressed Air Energy Storage system

A scroll expander was applied to the Micro‐Compressed Air Energy Storage system, and its energy conversion efficiency was investigated. In order to study the variation mechanism of the volume, mass, pressure and temperature of the air in different chambers, the mathematical model of the expansion process was developed on the base of the geometric model, mass conservation equation, ideal gas equation and energy conservation equation. Then, the mathematical model was implemented in Matlab, and the simulated energy conversion efficiency defined as the ratio between the output shaft power of the scroll expander and the input compressed air power was obtained. Furthermore, a test system was built in order to validate the mathematical model and study the improvement of the energy conversion efficiency. The prototypes of the scroll expander with different cross‐sectional areas of the intake port or the discharge port were fabricated and tested in the experiments. Results show that the simulated torque and energy conversion efficiency agree well with the experimental results. Also, there is a small deviation between the expansion process and the ideal isentropic process due to the gas leakage, intake and discharge loss. In addition, the air supply pressure and the cross‐sectional area ratio of the discharge port to the intake port are two important parameters for the improvement of the energy conversion efficiency. The experiments show that the energy conversion efficiency varies from 23% to 36% at the air supply pressure of 0.35 to 0.65 MPa, indicating that it is proportional to the air supply pressure. It can also be concluded from the experiments that when the air pressure is higher than 0.45 MPa, the ideal ratio range can be determined as 0.6‐0.8. Copyright © 2013 John Wiley & Sons, Ltd.     

导向钻进非开挖地下管线施工技术的应用

简述了在邯郸市集中供热管道工程中，应用导向钻进非开挖地下管线施工技术穿越中华大街，铺设Φ720mm无缝钢管(内含Φ325mm无缝钢管)，铺设双排Φ377mm(内含Φ219mm无缝钢管)钢制螺旋管获得成功的实例，以对今后同类工程实践提供参考。     

高压气动容积减压系统的模糊控制

根据高压气动容积减压系统的工作原理,应用了模糊控制策略,进行了容积减压系统的模糊控制实验研究。结果表明,模糊控制方法用于高压气动容积减压系统是可行的。     

直缝埋弧焊钢管扩径头的研制

扩径头是直缝埋弧焊钢管生产线扩径机上的关键部件,一直依赖进口,价格昂贵且交货时间长,研制国产扩径头迫在眉睫。从扩径头的技术难点入手,分析了中直径和大直径扩径头的不同结构形式和润滑方式。在结构设计时,针对扩径头各部件的使用要求,选用不同的工具钢和相应的热处理工艺,确保了扩径头的整体使用寿命。新研制的扩径头投入使用两年来,共扩直缝埋弧焊钢管3万多根,合格率100%,满足了扩径的要求。     

堆叠式椎体扩张器“高分子团”形成规律的研究

堆叠式高分子材料椎体扩张器前端的高分子管在工作状态下受轴向压力堆叠成"高分子团"以扩张塌陷椎体,高分子团的形状和尺寸直接影响椎体后凸成形手术的质量和效果。因此研究高分子管管壁切缝尺寸及分布与由其堆叠而成的高分子团尺寸、形状之间的关系,是椎体扩张器研发的关键问题之一。通过建立数学模型,推演出手术要求的高分子团的规格与高分子管管壁上切缝的尺寸及分布的规律,得出数学计算公式,并举例验证了切缝尺寸计算公式和分布规律的正确性,从而提高椎体扩张器的工作可靠性和效果可预测性。     

基于CATIA的活塞膨胀机凸轮设计

活塞膨胀机配气机构工作性能的好坏在很大程度上取决于凸轮的外形。使用CATIA三维建模软件创建凸轮机构虚拟样机,并对两种凸轮设计方法进行比较,对于提高活塞膨胀机配气机构工作的可靠性有一定的借鉴意义。     

膨胀机制冷天然气凝液回收流程模拟

本文分别以PR和LKP方程为相平衡、焓熵计算模型,建立了汽液平衡分离、多股换热器、节流阀、膨胀机、液烃分馏塔等工艺设备的数学模型,编制了相应的计算程序。在此基础上,根据膨胀机制冷的天然气凝液回收流程特点,采用序贯模块方法,用直接迭代法对工艺流程进行了模拟计算,并给出设计实例和计算结果。     

膨胀机密封气综合利用研究与应用

为了提高天然气的利用率,对温米油田轻烃装置膨胀机密封气系统实施了技术改造。将膨胀机密封气进放空系统改为进装置燃气系统合理利用,同时对燃气压力控制系统进行配套改造,确保燃气压力平衡,杜绝密封气放空至火炬系统燃烧掉,实现了膨胀机密封气的全部回收利用。经技术改造后,膨胀机密封气每天可以回收增加天然气0.48万m3,年创效益126.72万元,年净增效益107.78万元,并为油田污染减排工作做出了积极贡献。