暖通空调节能技术研究

暖通空调的能源消耗已占我国能源消耗的20%,特别是在夏季高峰期,空调用电甚至高达40%以上,因此对暖通空调节能技术的研究有着重要的意义.通过对暖通空调系统的方案选择,并对空调制冷系统,包括蒸发器、冷凝器、膨胀阀,以及冷凝器的节能运行、变频、温度独立控制、蓄冷、热承等新技术的应用,利用系统设计、优化了系统,提高了暖通空调系统的能源利用效率.     

Investigation of the behaviour of a chopped strand mat/woven roving/foam-Klegecell composite lamination structure during Charpy testing

This paper presents the investigation of the characteristic behaviour of polymer matrix composites under Charpy impact conditions with different design configurations of the laminate structure. The aim of this study was to evaluate the capability of different lamination designs for composite materials, in term of contact load, energy absorption, deflection and damage behaviour. In this study, laminated panels were fabricated using chopped strand mat (CSM), woven roving fabric (WR) and foam-PVC Klegecell as reinforcement with a combination of epoxy or polyester resin, respectively. Structural panels of composite laminates were produced using a hand lay-up technique. Each configuration design was impact tested to failure. Finite element analyses (FEA) were employed in this study to correlate the experimental value of energy absorption with simulation results. The characteristics of different reinforcement types, matrix type, hybrid type, architecture and orientation type were studied. These characteristics need to be considered, due to their affecting the characteristic behaviour of the composite lamination structures. Based on the results, it was found that differences in configuration design of the lamination structure of the polymer matrix composites do influence the strength and weakness of the materials.     

Particle swarm optimization procedure in determining parameters in Chaboche kinematic hardening model to assess ratcheting under uniaxial and biaxial loading cycles

As parameters in Chaboche model are difficult to be determined from experimental data, a single objective particle swarm optimization procedure was employed to obtain them. Hysteresis loop and uniaxial and biaxial ratcheting simulations were conducted to validate the determined models. Chaboche models determined by particle swarm optimization give more accurate simulation of ratcheting compared with the model determined by trial and error method. Chaboche models containing different backstress components were studied. Models determined considering uniaxial ratcheting can only predict uniaxial ratcheting precisely, while giving very bad simulation of biaxial ratcheting. The linear hardening rule in the N3L1 model clearly decreases the rate of the accumulation of ratcheting strain, and the N3L1 model gives the best simulations. For biaxial ratcheting, the fourth backstress component can decrease the rate of the accumulation apparently, while it has a little influence on prediction of uniaxial ratcheting.     

洁净系统中激光诱导颗粒污染物的分析与评估

高功率激光系统要求在洁净环境中运行,若光学元件表面在工作过程中附着污染物,将导致光学元件的损伤及整个系统负载能力的下降。针对洁净系统中激光与材料作用而产生的颗粒物,分析其作用机制,探讨用于评估的理论依据,讨论测量的需求和方法,并对系统表面存在的颗粒污染物进行了实际测量分析,提出了深入开展高功率激光系统中颗粒污染物测量与评估的技术途径。     

LIPS-200离子推力器电子反流极限不确定度分析

针对延长离子推力器栅极极限寿命的恒定加速电压和步进调节加速电压两种优化方法的工程应用需求,结合现有LIPS-200离子推力器产品技术参数,基于电子反流极限的Williams解析表达并应用QMU工程方法,定量计算了LIPS-200离子推力器电子反流极限的不确定度.计算结果表明:不确定度主要影响因素包括束流电子温度、加速栅...     

LHT-100霍尔推力器滤波设计与放电震荡关系研究

为了对LHT-100霍尔推力器放电震荡进行抑制,研制了与推力器相匹配的放电震荡抑制装置。结合国内外霍尔推力器放电震荡研制背景,通过仿真分析和集成试验两种手段,对LHT-100霍尔推力器放电震荡情况进行了研究。根据试验结果表明滤波参与下放电回路震荡得到了有效抑制,为电推进系统稳定工作提供了可靠保障。     

膜层的光学薄膜参数测量方法研究

简述了研究膜层光学薄膜参数测量方法的必要性。详细介绍了各种测量方法的理论思想、测量准确度、测量范围。综合比较了各种测量方法的优缺点和适用性,研究了测量不同类型薄膜系统膜层光学薄膜参数的最佳测量方法。最后总结了膜层光学薄膜参数测量方法的发展,并提出了建议。     

Co-existing of dressed non-linear gain and electromagnetically induced absorption

The dressed parametric four-wave mixing (FWM) process has been investigated in hot atomic rubidium vapor. We use a strong pumping field to generate entangled photon pairs of spontaneous parametric FWM (SP-FWM) which can be enhanced by an external dressing effect. Seeding probe beam into the Stokes or anti-Stokes (SP-FWM) channel will form the parametric amplified FWM (PA-FWM) process, then the non-linear gain and electromagnetically induced absorption (EIA) are observed, caused by the internal dressing effect. However, with scanning of pumping field the absorbing background will vanish, which will result in drastic increase in PA-FWM signal gain.     

滚筒跳动对柔性版印刷质量的影响

目的 研究压印滚筒径向跳动对印刷压强与网点变形的影响,为降低柔性版印刷中网点扩大率、提高印品质量提供参考依据。方法 论文以柔性版印刷为例,运用接触力学基础理论分析压印滚筒与印版滚筒间接触状态,构建柔性版最大印刷压强分析模型。运用有限元分析方法,得出印刷压强与柔性版网点压缩变形关系,从而构建出压印滚筒跳动引起柔性版网点扩大率分析模型。通过实测得到柔性版印刷机压印滚筒径向跳动波形。结果 最大印刷压强的增加会增大网点顶端接触面积,使网点扩大率增大;压印滚筒的径向跳动改变了印刷过程中的实际合压量,造成印刷过程中最大印刷压强的波动,因而在柔性版印刷过程中需要严格控制合压量;在合压量为0.1 mm时,径向跳动量为-0.053 99～0.054 48 mm。对于加网线数为69线/厘米、50%网点的印版,网点扩大率在3.639%～9.526%波动。结论 压印滚筒径向跳动改变了滚筒间的实际合压量,引起印刷压强的变化,使网点产生不同的变形,从而严重影响印刷质量。     

镁合金多向转接头等温成形数值模拟及实验研究

采用数值模拟方法研究了高强耐热镁合金多向转接头的等温锻造过程,分析了导套形状、锻造方案对构件成形过程中金属流动行为的影响,根据模拟结果制定了圆形导套、两次下压的成形方案,并采用此方案成功锻造出高强耐热镁合金多向转接头模锻件。对该锻件进行了时效热处理工艺研究,得出最优化的时效处理制度为200℃×63 h。在该时效制度下,材料的室温抗拉强度达到了411 MPa,屈服强度达到331 MPa,延伸率达7.3%。