冷热电联产CCHP综合评价模型的研究

为了科学评价冷热电联产系统,本文提出了一种考虑工程多方面属性的综合评价方法—混合灰色关联多层次综合评价法。该方法综合了几种常用评价方法的优点,建立评价冷热电联产系统的综合评判模型,采用层次分析和灰色关联相结合的方法进行数据分析,并用模糊隶属关系将定性指标定量化,从而提高了优选方案的准确性。     

100 kW微型燃机冷热电联产的经济性分析

微型燃气轮机冷热电(CHP)联产系统,能够实现天然气清洁、高效、灵活利用,目前已得到重视和应用。本文以某酒店冷热电系统为研究对象,根据实际冷热电年负荷变化曲线,设计了100 kw微犁燃机冷热电联产方案。对CHP联产系统的一次能耗率(PER)和无最纲费用比进行了计算,并与分产系统作了对比,最后讨论了微型燃机回热度和电/气价格比对CHP联产系统经济性的影响。     

冷热电联产系统的评价准则

本文通过对以燃气轮机回热循环为动力系统的冷热电联产系统进行热力学分析,对几种常用的评价准则进行了比较。通过分析,认为能量利用系数将冷、热、电等各股能量等价看待,(火用)效率过分看重能量的作功能力,折合发电效率过分关注冷、热能的输出,均不适于冷热电联产系统的评价;节能率反映的是输入能量的使用情况,经济(火用)效率在某种程度上是经济性的表现,比较适于冷热电联产系统的评价。研究中发现,燃气轮机温比有利于系统性能的提高,但针对不同的目标有不同的最佳压比;在节能率的使用中需要明确参照系统的性能。     

微型冷热电联产系统热力学分析

根据一套10kw级微型分布式冷热电联产系统(采用燃气内燃机发电,地板辐射采暖,吸附制冷机提供空调制冷)在冬夏两季实验研究获得的数据,从热力学第一及第二定律角度,进行热力学分析,与传统的冷、热、电分产系统进行比较,并对不同评价标准得出的结果展开了进一步的探讨。分析揭示了冷热电联产系统高效节能的原因,得出的相关结论为实验系统的改进以及未来实际应用系统的设计,提供了理论依据.     

基于太阳能甲醇分解的冷热电联产系统

本文从太阳能与化石能源综合互补利用的思路出发,将中低温太阳能利用与冷热电联产系统有机结合,研究提出了一种太阳能甲醇分解冷热电联产系统.该联产系统能够提高现有太阳能系统在中低温范围内的能源利用效率,并能部分替代化石能源.(火用)分析表明,系统节能关键在于太阳能供热甲醇分解过程有效减少了燃烧过程能量损失.本文的研究可为太阳能系统的发展及化石能源的替代提供新的思路.     

基于电动汽车V2B模式的多联产系统两阶段优化

随着电动汽车接入造成建筑动态负荷变化,致使传统面向建筑的分布式多联产系统无法适用于电动汽车大规模接入情景。本文提出一种基于电动汽车V2B模式的可再生分布式多联产系统两阶段优化模型。第一阶段调度电动汽车参与V2B模式进行充放电,第二阶段提出谷时蓄电运行策略,运用多种群遗传算法进行优化。选择模型关键参数为优化变量(原动机容量、地源热泵输出冷/热量占总冷/热负荷的比例、蓄电池容量),以一次能源节约率、年总成本节约率和二氧化碳减排率为指标评价系统综合性能。经与参比系统对比分析,结果表明该多联产系统的能源、环境、经济性指标分别为：48.68%、43.04%和44.87%。本文为考虑电动汽车V2B模式的多联产系统集成与优化研究提供了新思路。     

考虑冷气掺混的涡轮分层次气动优化设计体系

通过将优化理论引申到涡轮气动设计体系中,建立具有自动优化设计能力的燃气涡轮分层次优化设计体系,给出优化设计体系框图和计算系统的基本架构,分析了各层次优化设计解决的问题和解决问题的过程.为了实现三维多级优化,介绍了基于流场分析的局部优化策略和参数组群组合优化.为适应燃气轮机涡轮的气动设计,在这一体系中每一个程序都要考虑冷气掺混.实例表明,该设计体系下的设计过程快速高效.     

中温太阳能驱动甲烷化学链重整冷热电系统及性能研究

针对高温太阳能与天然气热化学互补分布式能源系统存在聚光比高、互补反应温度高、变工况性能不稳定的技术瓶颈,本文探索了一种能实现主动调控的中温太阳能与天然气互补的化学链重整冷热电联产系统。利用约500℃太阳热能驱动天然气基-氧化镍化学链重整,生成合成气太阳能燃料,通过燃气轮机冷热电联产系统,实现中温太阳能与天然气综合梯级利用.研究结果表明:在设计点工况条件下,系统的总能效率可达到80.9%,太阳能集热面积节约率达到53.2%,太阳能净发电效率可达27.3%.分析了关键参数如NiO和甲烷摩尔比(Ni/C)和太阳辐照强度(DNI)对系统热力学性能的影响。     

微型燃气轮机热力系统的设计分析

对典型的100kw微型燃气轮机系统进行了热力设计及分析,包括对微型燃气轮机回热循环、热电联产和电冷联产热力系统的分析研究。计算了不同压比和温比条件下系统的性能特性,探讨了燃气轮机余热分别应用于供热和制冷时的系统特性,为微型燃气轮机热力系统的设计和参数选择提供了参考依据。     

冷热电联产系统节能特性分析

本文分析各子系统性能和补燃量对冷热电联产系统总体性能的影响,得到了与分产系统相比联产系统节能所需满足的条件,并建议采用以联产系统燃料量为基准的节能系数评价联产系统性能。通过对回收的热量在制冷子系统和供热子系统中的分配情况研究,确定了回收热量优先利用的原则。补燃量的增加将导致联产系统性能下降,到一定程度使联产系统与分产系统相比不具有优势;随着电网供电效率的提高,确保联产系统节能所需的联产系统发电效率也不断提高。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.