吸附制冷中的蓄冷研究

本文对一台余热驱动的带有水蓄冷器的单吸附器吸附空调系统进行了实验分析，研究了系统的吸附制冷过程和水蓄冷器的作用与影响，并对该吸附制冷系统中的吸附式蓄冷这种无能量损失的蓄冷方式的放冷过程进行了实验分析，比较了蓄冷式系统和双吸附器连续制冷系统的制冷性能及其优缺点．     

固体吸附式制冷的原理及工质的研究

固体吸附式制冷的原理及工质的研究王宝官，李健敏（南京航空航天大学动力工程系）一、引言为解决能源的短缺，太阳能和工业废热正越来越广泛地被用于生产和日常生活中。吸附式制冷是利用这些能源比较有效的方法之一。目前国内、外正积极开展对固体吸附式制冷的研究［１，...     

回热型吸附式制冷系统的实际循环与循环周期分析

1前言在吸附式制冷系统中，许多因素影响着系统的实际运行，包括运行工况、实际循环与理想循环的偏离程度、循环周期以及工质对的匹配等。要进行系统的设计，并最大限度地利用所设计的机组，就必须首先考虑这些因素。本文以连续回热型吸附式制冷系统为例，分析了系统运行的循环周期，以及实际循环偏高理想循环这两个主要因素，得出了相应的结论。2连续回热型吸附式制冷系统的实际循环和理想循环基本的回热型吸附式制冷循环包括两个吸附器，它的流程图见图1。在这个系统中，阀A、B、C、D交替开启关闭，吸附器1和吸附器2分别加热和冷却，使…     

某型列车司机室眩光仿真与实验测试

在驾驶舱光环境的工效学研究中眩光对人体的影响是一个重要的因素，对于现代列车而言，其操作任务需要驾驶员更多地关注车内各种仪表的运行，及时发现并处理行车中遇到的各种情况。因此，各种情况下的眩光有可能造成危害驾驶安全等问题，该文通过对某型列车的司机室进行光学仿真，用主成分分析法找出对司机室光环境影响较大的因素。结合物理测试以及TracePro软件仿真得到的结果，说明司机台照明灯对于司机室整体光环境影响最大，并且针对主要的影响因素提出了有利于降低司机室内眩光，增加司机室内视觉舒适性的建议。     

连续回热型吸附式空调实际运行与吸附床性能分析

近年来,我们研制了一台连续回热型吸附式空调／热泵,该空调／热泵在１００℃热源驱动下,单位质量制冷功率 ＳＣＰ可达到 １５０ Ｗ／ｋｇ,与此同时 ＣＯＰ达到 ０．４。在系统的实际运行中,吸附床起到了重要的作用。本文介绍了该机组在实际运行中为稳定工况所采取的一系列措施,以及机组运行的实际Ｃｌａｐｅｙｒｏｎ图,着重讨论了系统运行参数对吸附床性能的影响。     

纺织厂空调节能探析

分析了纺织厂空调能耗过高的主要原因,并从车间温湿度基数确定、冷负荷计算、气流组织、新风预处理设备及旁通风道使用和冷冻水管路系统设计等方面介绍了减少空调能耗的系统设计;对喷淋室、挡水板等空调设备进行了节能改造,分析了管式间接蒸发冷却器使用的节能效果。在空调运行方面采用智能调节实现自动控制、合理选择冷水机组台数等措施实现节能目的。测试表明,通过挡水板、喷淋室及管式间接蒸发冷却器节能改造,空调室节能1.91%,10.52%和5.07%;制冷机组由三台在80%制冷量减少为一台在90%制冷量下工作,耗电减少653kW/h,减少率为64.33%;采用自动控制系统空调室能耗日减少477kW.h,与人工调节方式比减少45.60%。     

基于沸石和活性炭的二级吸附式制冷循环系统

二级吸附式制冷循环是降低吸附式制冷机驱动热源温度的有效措施,但是存在传质性能下降的问题。通过一级、二级循环吸附剂循环吸附量分析发现,不同循环采用不同吸附剂,可充分挖掘不同吸附剂吸附性能潜力,能够解决二级吸附式制冷循环系统采用单一吸附剂造成传质恶化的局面。本文选择沸石FAM-Z01、活性炭分别为一级、二级循环对应的吸附剂,建立不同吸附剂二级吸附式制冷循环系统,并开展系统性能研究。     

海水热泵空调系统应用研究

海水热泵空调系统运行可靠、效率高、无污染,运行费用是常规空调系统的40%~50%,与电系统相比节能率在70%以上。文中对海水热泵空调系统的设计应用进行了详细的阐述,包括实施可行性、系统特点和原理,及设计方法等。旨在以一实际工程为例,对海水热泵系统的运行情况进行实验测试和分析,为该技术进一步推广积累工程经验,同时也为沿海地区将海水应用于空调系统提供一定的实验依据。     

吸附式制冷系统中吸附床材料热容对系统运行COP的影响分析

1前言在吸附式制冷系统的理论运行研究中，很少考虑吸附床材料的影响。实际上由于吸附式制冷系统的非连续性，吸附床材料的热容对实际系统运行性能的影响是非常大的。这个影响体现在系统不断地加热和冷却过程中所损失的吸附床材料的显热热量，这个热量的大小直接受吸附床本身设计的影响，另外还受到系统运行过程的影响，如：系统运行的解吸温度、回热所进行的程度等。由于该系统中通常所用的吸附剂均属多孔性材料，其特点是热导率小，密度低，要满足一定的制冷功率，所设计的吸附床往往很大，另外为增强吸附床内的热传递，加快吸附床的冷却…     

电动客车热泵空调系统制冷剂充注量实验研究

作为一种新型环保制冷剂,R407C在客车空调系统中的研究越来越多。为研究制冷剂充注量对纯电动客车热泵空调系统性能的影响,在恒温恒湿测试室进行了充注量实验。分析了制冷剂充注量对系统各性能参数的影响,如换热量、COP、排气温度和过冷度,得出系统制冷剂最佳充注量。     

多普勒计程仪作用距离估计

多普勒计程仪已成功应用于多种载体的导航,而其最大作用距离对于设计和使用都具有重要的意义。根据声纳方程各项的定义并根据多普勒计程仪工作时的特点,推导出不同条件下声纳方程中各项的计算公式,从而对多普勒计程仪的最大作用距离进行估计,最后将某型多普勒计程仪的相关参数代入推导的公式中,并进行计算得到理论计算值。同时还计算了多普勒计程仪在不同条件下的作用距离。     

超音速氧碘化学激光一维预混模型

本文考虑了DOIL体系中关键的化学动力学过程,建立了一维预混简化模型,计算了超音速COIL中小信号增益、输出功率、体积比功率、化学效率等参量随腔压、腔温、工作物质配比的变化,并给出了超音速COIL最佳工作条件。     

Characterization of a fiber lens

A practical method for characterizing microstructure fiber lenses in the near field is described. By detecting the optical power of the light reflected by a mirror and coupled back into the single-mode fiber, one can accurately determine the focal point and the working distance of a fiber lens. The approach is relatively simple and easy to implement. The accuracy in determining the focal point and working distance is better than 2%.     

Possible half metallic antiferromagnet in a hole-doped perovskite cuprate predicted by first-principles calculations

We formulate a scheme to realize a half metallic antiferromagnet (HMAFM), a material conductive in only one spin channel while exhibiting zero macroscopic magnetism, by doping carrier into a class of cuprates. The working rationale is exhibited as taking advantage of Hubbard repulsion of d electrons of Cu atoms and the charge-transfer effect from the associated O ligand to fully polarize the spin of a doped carrier. Specifically, doping one hole into the insulating ferrimagnet Sr8CaRe3Cu4O24 by replacing one of the eight Sr atoms by one Rb atom is predicted to achieve a HMAFM, presumably with room-temperature operation. Since the working rationale is the strong correlations of electrons commonly encountered in cuprates, it is expected that the present findings can shed light on a new way to develop a HMAFM.     

Multiplexing of fiber-optic acoustic sensors in a Michelson interferometer configuration

A new multiplexing method demonstrating the separation of two series of geometrically arranged fiber-optic distributed sensors in a Michelson interferometer (MI) configuration has been developed. This method can acquire data from two sensors, then propagate the data into one channel, and finally separate the data by determining their working point, which is essential for some remote measurements. The working point of one sensor was deflected from the normal MI by introduction of two reference arms. The deflection was extracted electrically and employed to label the sensor. Verification with commercial piezoelectric transducers proves the efficiency of the method.     

A mixed cycle for converting heat to mechanical work

The subject of this study is to compare two different methods of converting heat to mechanical work. The first one is the well known Rankine cycle, which uses a pure substance as the working fluid. The second one is a power cycle which uses a mixture of substances with different boiling points as the working fluid. For convenience, this cycle will be called the mixed cycle hereafter.Since the conventional Rankine cycle has been analyzed by many other authors, we will focus on the mixed cycle. The main difference between the two is that, in the mixed cycle, steam is released by heating a mixture. The initial working fluid is created as the expanded steam is absorbed by a mixture of lower concentration at lower temperature and pressure.The main disadvantages of the mixed cycle are the upper temperature limit and the larger mass circulation.In order to illustrate the “efficiency limits” of the mixed cycle, a theoretical analysis is presented, in which all processes are considered to be ideal.     

CPL复合毛细芯流动性能及工质特性分析

本文分析了两相毛细泵回路(CPL)复合结构毛细芯的流动阻力特性,讨论了影响毛细芯阻力大小的主要因素,计算结果表明,复合毛细芯的流动性能比单一粒径毛细芯优越。另外,还分析了工质物理性质对CPL性能的影响,指出改善工质表面张力特性是研制高性能CPL的方向之一。     

基于模型和神经网络的绝热毛细管快速仿真方法

为简化毛细管模型,采用分相集中参数方法,将平均比容的权重因子作为两相区简化的特征参数,用人工神经网络方法建立特征参数与其影响参数之间的非线性映射。神经网络的学习样本采用工质Ｒ１２,检验样本包括Ｒ１２、Ｒ２２、Ｒ１３４ａ和Ｒ６００ａ等多种工质。在常用制冷空调工况范围内,该简化模型与分布参数模型相比,平均偏差０３％,计算速度提高１个数量级。     

A two-beam method for extending the working range of electrostatic parallel-plate micro-actuators

Electrostatic actuation is widely used because of its rapid speed and low power consumption. The parallel-plate actuator is one of the most basic, but also most common electrostatic actuators for Micro Electro Mechanical System (MEMS) applications. The effective working range of parallel-plate actuator is limited to only one-third of the initial gap owing to the pull-in instability. Different strategies have been reported to extend the stable working range, but are mostly focused on improvement of the control circuit. In this paper, we aim to report some progress toward solution of the working range problem from the design of suspension beam. A suspension beam called “two-beam” is presented to achieve parallel-plate actuator with extended working range, but without penalties of complex control circuit and large actuation voltage. A bumper structure is employed in the design of two-beam to change the spring constant near the critical point of pull-in, and a two-layered polysilicon surface process is used to fabricate this two-beam structure. Theoretical calculation and numerical simulation indicate that the working range can be extended depending on the position and depth of the bumper. The fabrication of a 2×2 array of parallel-plate actuators suspended by four sets of two-beam is implemented, and a somewhat larger working range, i.e. about 50% of the initial gap is achieved in the experiment.     

高速高分辨率圆感应同步器测角系统的研究

本文基于新的思路,突破纯开环或闭环的模式,采用总体开环和数字信号处理部分闭环的方案设计了圆感应同步器测角系统.讨论了其工作原理、硬件框架、典型电路分析,及系统在提高运行速度和减小动态误差方面所采取的措施.整个系统结构简单,并具有较高的跟踪速度、测角精度和工作稳定性.