联合循环、STIG循环、HAT循环及其相关循环的热力性能比较

1引言本文分析并比较了燃气一蒸汽联合循环（CC）（图川山、注蒸汽燃气轮机（STIG）循环z图2）l’］、湿空气透平（HAT）循环（图3）［’1及采用中冷或再热手段后相应循环的性能．为了不使系统过于复杂，只采用一级中冷、一级再热，中冷器和再燃室的位置与通常的设计相同。中冷器所用冷却水来自环境，吸收热量后又回到环境。选用余热锅炉型CC，HAT循环选用文献［3］提供的结构。2计算结果及分析计算条件：（a）环境温度20”C，压力0．101325MPa，湿度sg／bgDA；（b）压气机绝热效率0．88，燃气透平相对内效率0．9，蒸汽透平相对内效…     

基于三种气化炉的整体煤气化湿化燃气轮机循环热力性能分析

将燃料湿化和空气湿化应用到整体煤气化燃气轮机循环中,以降低NOx排放并有效利用系统低品位热。基于水煤浆、干煤粉及输运床三种气化炉,构建了多种整体煤气化湿化燃气轮机循环,分析了其热力性能并给出了湿化方式建议。研究表明：燃料湿化循环系统效率较高;空气湿化循环燃气轮机比功较大;整体煤气化湿化燃气轮机循环具有利用系统外部中低品...     

整体煤气化湿空气透平(IGHAT)循环的参数优化

本文采用非线性优化方法,分析了整体煤气化湿空气透平（ＩＧＨＡＴ）循环的热力性能,研究了温化器出口空气含 湿量、间冷压比及空分集成程度等主要参数对循环性能的影响。结果指出较之湿空气透平（ＨＡＴ）循环,ＩＧＨＡＴ循环的 空气含湿量有了大幅度的提高,从而使得循环比功大大增加。     

PG9351FA燃机建模及改烧合成气的通流调整分析

在透平冷却空气量估算的基础上,建立了透平逐级计算、考虑IGV角度对压气机特性曲线影响的PG9351FA燃机变工况模型.针对改烧合成气带来的压气机喘振、通流匹配等问题,分析了关小IGV角度、增大透平通流面积、降低燃气轮机T3温度等几种不同的通流调整措施对燃气轮机最大出力、压气机喘振裕度以及燃气轮机整体性能的影响,提出了一...     

注蒸汽燃气轮机燃烧室和后燃室中燃料系数的计算方法

注蒸汽燃气轮机燃烧室和后燃室中燃料系数的计算方法杨玉顺，周伏秋，严家（哈尔滨工业大学动力工程系哈尔滨１５０００１）关键词：注蒸汽燃气轮机循环，湿燃气，燃料系数，注蒸汽比一、前言燃气轮机燃烧室（或后燃室）出口的燃气温度，是一个很重要的性能参数。它受设备...     

新型微燃机分布式冷热电联供系统热力性能分析

本文提出了一种新型微型燃气轮机分布式冷热电联供系统,集成了微型燃气轮机、氨水Rankine循环,单双效复合溴化锂吸收式制冷机,烟气热水换热器。氨水Rankine循环中,混合工质升温蒸发过程回收微燃机烟气余热,降温冷凝过程热量用于驱动吸收式制冷机。研究了新系统的热力性能、与没有集成氨水Rankine循环的典型微燃机分布式冷热电系统进行了对比分析,并对关键过程进行了能量品位(EUD)分析。热力性能结果表明,集成了氨水Rankine循环的新型系统热力性能优异,相对节能率为22.41%,(?)效率为31.64%,新系统可以在不影响系统相对节能率的前提下调整系统的冷负荷(35.6~51 kW)。能量品位分析表明,新系统性能提升的原因在于新系统氨水Rankine循环的吸热、放热过程与冷热源的能量品位差减小。     

氨水工质浓度可调型功冷联供循环

本文提出一个新型氨水工质功冷联供循环,由氨水Rankine子循环和氨吸收式制冷子循环通过吸收、分离及换热过程耦合而成,可采用燃气轮机排烟等中低温热源驱动.通过设置分流、吸收式冷凝实现系统内氨水工质浓度变换,兼顾动力子循环加热蒸发和冷凝过程不同的浓度需求,达到改善换热过程匹配和提高透平作功能力的目的.计算表明,当透平进气温度为450℃时,循环热效率达25%～28%,??效率达45%～53%;且存在最佳分流比使热效率及??效率达到最佳.     

一种新型分布式功冷联产系统性能研究

提出一种新型分布式功冷联产系统,有机整合了小型燃气轮机、氨水蒸汽动力装置和吸收式制冷装置。燃机排烟的高温热量用于驱动氨水蒸汽动力装置做功,烟气低温热量和氨水透平排汽热量用于驱动吸收式制冷装置,实现了烟气余热的梯级利用。模拟结果表明,新系统的等效发电效率和(火用)效率分别为45.3%和35.5%,比参比系统分别高出7.5和8.6个百分点。系统(火用)分析和参数敏感性分析表明,燃机排烟余热的梯级利用是系统性能提高的主要原因。新系统为提高分布式供能系统的总体性能提供了一种新方法。     

SOFC/MGT混合系统耦合特性研究

在SOFC/MGT混合分布式能源系统中,选择不同的系统参数将对SOFC乃至SOFC/MGT混合系统的输出特性、安全运行等造成很大的影响。本文建立了一个典型的SOFC/MGT混合系统计算模型,研究了透平入口温度及燃气轮机压比对混合系统性能的影响。结果表明,透平入口温度和压比增大时,系统的输出功率和效率都会下降,而透平入口...     

喷水对半闭环燃气轮机循环的影响

本文对燃气轮机的简单循环、开环和半闭环系统,分别以空气和CO2作为工质、纯氧为氧化物、天然气为燃料时的热力循环过程,在喷水及不喷水条件下,利用自行设计的分析软件进行了较为系统的数值分析和性能评估,详尽分析了喷水量对使用空气或CO2作为工质的半闭环燃气轮机循环的影响,揭示了适量喷水有助于提高循环效率和输出功率的客观规律,为研制CO2零排放的高效燃气轮机装置奠定了坚实的理论基础.     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.