利用电容层析成像法测量气力输送中的煤粉流量

采用电容层析成像技术(ECT),对常温下气力输送的固体(如煤粉)浓度、速度和质量流量进行了测试研究.为克服电容传感器敏感场的不均匀对成像造成的影响,实验系统中利用旋风分离作用将固体颗粒集中在近壁面区域,传感器电极布置在分离器直管上.浓度分布采用单层电容传感器,速度分布采用双层电容传感器得出相关信号.由测得的速度及体积分数通过计算得出质量流量.测量结果与称重法测试结果吻合,证明电容层析成像法可获得可靠的测量结果.     

电容层析技术在旋风分离器及料腿中固体颗粒浓度、速度和流量测试中的应用

采用先进的电容层析成像技术和相关分析理论，对常温下旋风分离器及料腿中固体颗粒的浓度、速度和流量进行测试研究。浓度分布采用单层电容传感器，速度分布采用双层电容传感器得出相关流动信号，利用相关理论分析得出速度和流量。这种测试方法的优点在于不破坏原有实验系统的运行特性，属于非侵入式、在线的快速测试技术，能同时得出固体的断面浓度分布和流量。实验结果与称重计量测试结果吻合良好，说明电容相关技术测量流量的可行性和可靠性。图10表3参15     

高温状态下温度场的计算

本文将湍流流场计算的ＳＩＭＰＬＥ算法与辐射传热的热流法计算结合在一起，联立求解了高温状态下炉内的流动及温度分布情况，得到了气体流动的速度场以及由传导，对流和辐射共同作用的温度分布情况。通过计算比较。从定量的角度验证了高温状态下的辐射传热的主导作用。     

基于图像识别的高温熔渣流量测量方法研究

熔渣流量是影响高温熔渣离心粒化效果的关键因素。为了测量熔渣流量,提出了一种流量测量方法,利用高速摄影机拍摄液柱流动图像,采用边缘检测、阈值分割等方法,获得液柱直径及流速,计算流量,采用常温甘油溶液作为测试对象进行实验,研究该方法测量精度的影响因素。结果显示,长曝光时间、合理的拍摄帧率、短物距有利于提高测量精度;同时,感兴趣区域（ROI）的位置为距管口2~5倍管径处、ROI长度为1/3~2/3倍管径时,测量精度较高。通过对实际高温熔渣流动过程的检测,其测量误差约9.0%,证明了该方法的实用性。     

动网格技术在罩式炉流场模拟中的应用

利用动网格技术和流体力学的基本原理,通过计算机模拟罩式炉内保护气体的流场分布,在炉内流场达到稳定状态下,比较循环风机不同转速时气体流量的变化。计算结果表明气体的流量与风机转速呈线性关系,风机进出口的气体的压力与风机转速呈二次方关系,与理论公式一致,说明该方法是可行的。进一步运用该方法对罩式炉流场进行数值模拟,得出在风机转速为1700r/min下罩式炉内不同区域流场分布,结果显示沿罩式炉高度方向无论在钢卷的芯部还是外侧,循环气体的流速沿高度方向衰减,外侧最大气流速度从7.12m/s衰减为2.32m/s,芯部最大气流速度从17.29m/s衰减为3.34m/s。     

双弯管法固相质量流量测量误差的标定

采用弯管流量传感器测量固相质量流量时,固相质量流量与其影响因素之间存在着复杂的非线性关系,这给固相流量的测量带来困难。在双弯管法基础上对其进行优化,利用小波神经网络对实验数据进行训练,给出了固相质量流量与综合流量系数β的复杂非线性关系,并对实验数据进行预测。预测结果与实验结果吻合较好,最终误差不超过5%,实现了对测量误差的标定。     

计算机测控的风冷发动机风扇试验系统的研制

本文介绍的计算机测控的风冷发动机风扇试验系统，采用传感器和计算机技术实现风冷发动机风扇性能试验的数据自动采集、数据自动处理与数据库管理功能，还可配合流场测量装置测量冷却风流场。该系统实现了测试自动化，精度高，应用效果好。     

电站锅炉三通集箱流场的数值研究

根据电站锅炉三通集箱系统的结构特点,采用基于三维实体模型的建模方案,对径向引入引出集箱系统的流场分布进行了数值模拟。采用FLUENT软件分析了集箱流场的分布特点及受热面沿程阻力对集箱速度、静压分布的影响,详细讨论了三通结构、受热面沿程阻力对受热面流量分配的影响。研究结果表明,集箱流场呈三维分布,分为径向引入管下游的冲击射流区和周围的强迫对流区,三通结构直接影响集箱的速度分布;受热面的流量分配直接受三通结构的影响,沿程阻力影响受热面流量偏差的大小。     

三角口旋塞调节阀流量特性的数值分析

为了解决调节阀的设计和选型问题,采用Fluent软件对三角口旋塞调节阀不同开度时的稳态流场进行了模拟,分析了调节阀内流场的参数分布与阀门特性的对应关系,从而得到了不同开度时的阀门流量和相应的流量系数Kv,进而得到流量特性曲线。计算结果可为调节阀设计和选型提供参考。     

水平直管道中气体一颗粒两相流实验研究

使用多普勒激光测速仪测量了水平直管道中气体一颗粒两相流动的流场。实验中，采用三维粒子动态分析仪（Particle Dynamics Analyzer）测量了粒径在0-100μm玻璃微珠的时均速度和脉动速度分布，颗粒相的体积分数在10^-4～10^-5之间。实验结果表明，即使在粒径范围为100μm以下的颗粒，其在气相流场中的存在仍然会引起湍流流场结构的改变，实验还观察到气体一颗粒两相流动的湍流强度会随粒径的减小而增加。而且其脉动速度的分布将会在壁面附近出现脉动和随机分布的特征。     

新型光纤叶轮流速传感器的研制

本文介绍一种新型光纤叶轮流速传感器，它可测量高温，低流速气体，测量范围小2－15m/s,误差为0.1m/s，该传感器与同类顺轮流速计相比，有信号可远距离传送，精度高，体积小，结构简单等特点，适用于大磁场，高温度，空间狭窄等环境的测量。     

应用极性相关技术在线测量高温烟气流动速度

应用单片微机ＭＣＳ５１系列及自行开发的扩展系统研制的测量系统，成功地对管道内高温烟气流速进行了在线测量，该系统采用新颖的过零时刻采样法和过零时刻算法对烟气流动噪声信号作极性相关处理，快速搜寻峰值对应的时延值，并据此求得测量速度。试验表明，测量技术具有测量精度高，测量时间短，且可靠性强，适于工业现场进行在线测量。     

Continuously distributed sensors for steady-state temperature profile measurements: main principles and numerical algorithm

Principally new method for measurements of steady-state temperature field is suggested. This method is based on the use of so-called continuously distributed sensors (CDS). The basic CDS function is the measurement of temperature profile along the sensor length.The CDS can be manufactured my means of microfilm technologies in the form of a rod, flexible thread, or thin film. Only three electrical cables are needed for connection of CDS and measuring equipment. Nevertheless, it is possible to obtain simultaneously the information about temperature profile at several tens space points along the CDS. So, the CDS is equivalent to several tens of conventional discrete sensors, for example, thermocouples.The measuring process with the use of CDS can be described by the following scheme. A temperature field acts on the CDS causing space non-homogeneity of the electrical parameters of thermo-sensitive films. The space distribution of electrical parameters along CDS can be measured by means of electrical signals of different frequencies. Indeed, the distance to which the electrical signal penetrates the sensor depends on the frequency. So, the measuring impedance of the sensor contains information about space distribution of electrical parameters, which are directly related with the temperature profile.Restoration of the space distribution of electrical parameters from frequency characteristics of the measuring impedance is non-trivial task. From the mathematical point of view it is inverse problem. Some algorithms for solving of this inverse problem are developed and are presented in the paper. Numerical simulations demonstrate possibilities to measure temperature fields by means of CDS.     

Experimental study and optimization of flow field structures in proton exchange membrane fuel cell under different anode modes

As one of the critical components in the proton exchange membrane fuel cell (PEMFC), the flow field is crucial to the improvement of cell performance. However, the current research on flow field structure lacks consideration of the influence of different anode modes, which makes the existing flow field structure rules have limitations in the practical application of PEMFC. In this paper, the PEMFC characteristics of parallel flow field, S-shaped flow field, multi-serpentine flow field and single-serpentine flow field at the cathode side are compared experimentally in the dead-end anode (DEA) mode and hydrogen circulation anode (HCA) mode, respectively. Especially, the spatial current density distribution and parasitic power of different flow field structures are measured. The results show that the performance trends of different flow field structures change with the DEA and HCA anode modes. In DEA mode, the PEMFC is prone to flooding, and the flow field with high gas velocity in the channel has better drainage ability, which can obtain higher cell performance. The HCA mode is helpful for the discharge of water in the PEMFC, which effectively alleviates the adverse impact of water accumulation on the overall performance, and the mass transport ability of the flow field structure plays a leading role in the cell performance improvement. In addition, although the high gas flow velocity has better drainage ability in the flow field, it may lead to a decrease in the current density distribution uniformity and PEMFC net output power density. Based on the comprehensive consideration of the experimental results, the multi-serpentine flow field is more suitable for DEA mode, and the S-shaped flow field is more suitable for HCA mode.     

Mathematical Model for Fluid Flow and Heat Transfer in the Cooling Shaft of Coke Dry Quenching Unit

IntroductionCoke Dry Quenching (CDQ) unit is a regenerativesystem whose thermal fUnchon is to cool off the red hotcoke with the circulahng gas and at the same time tOtransfer energy from the incandescent coke to watervapor fOr electricity generation. In comParison toconventional Coke Wet Quenching (CWQ) system, CDQenables not only energy savings, but also environmentalprotection. Further advantage is the imProved quality ofcoke. TherefOre, CDQ technology is becoming theconunon practi…     

可控烟气回流量型低NOx燃烧器流场特性的试验研究

设计了一种预混式可控烟气回流量型低NOx燃烧器,以适应双气头多联产系统中燃料组分、成分变化时燃气轮机发电系统稳定工作的需要.在常压条件下,利用TSI热线风速仪对燃烧室内的速度分布特性进行了直接测量,并利用温度场比拟浓度场的方法,对燃烧室内气流混合特性进行了间接测量.结果表明:燃烧室内的速度分布及回流等特性可满足设计要求,气流之间的混合效果则需作进一步增强.同时,对燃烧器二次风分配器的结构提出了改进方案.     

低速高温风洞设计及性能测试

设计了用于高温部件实验以及气膜冷却实验的低速直流回热风洞。该风洞由动力段、扩散段、稳定段、收缩段、实验段以及加热和回热设备构成,校核并测试了风洞的流场。利用实验段搭载的热电偶在常温工况下测定了风洞出口中心处1 h内的温升。在热态实验中将主流温度提高并利用热电偶测定实验段中心温度,建立校正关系。利用毕托管测定了风洞实验段常温工作的动压分布,计算了平均流速、平均动压以及流速和动压不稳定度。流场校验结果显示,风洞的流速以及动压稳定,常温工作下主流温升不明显,高温工况下温控性能卓越,适用于模拟高温流场、测量高温部件以及气膜冷却实验。     

直接空冷枝状排汽管道系统内导流装置的优化设计

对德国基伊埃(GEA)公司发明专利——枝状直接空冷排汽管道系统进行研究。建立某2×600MW机组直接空冷排汽管道内湿蒸气两相流动和传热的数学模型;利用数值传热学软件Fluent对典型汽轮机工况下的排汽状况进行了数值模拟;对二维管道内湿蒸气速度场、温度场和两相场的模拟、分析和研究。模拟结果表明:专利提出的简单几何原则分流方法,无法实现排汽的均匀分配。针对不同形式的直接空冷枝状排汽管道系统应进行详细的优化设计,并提出了枝状排汽管道系统导流装置的基本设计原则。     

多孔介质中高温气体非稳态渗流传热数值计算

针对水平导管中填充颗粒物料层内的高温气体参流传热现象，考虑渗流与传热的相互作用并采用局部非平衡假设建立多孔介质中的瞬态渗流传热物理数学模型。研究不同情况下填充物料中的渗流速度和气固温度分布。计算结果表明，高温热气体对水平导管中移动颗粒料层的热渗透主要发生在渗流入口端区域，随着渗流时间延长，热渗透深度沿导管推进。增大入口渗流速度以及减小出料速度，将导致物料温度沿导管慢速下降，热渗透深度扩大，热渗透作用区域内的物料温度水平提高。在热渗透作用区域，孔隙率对流场和温度场有很大的影响。研究对于高温反应器的颗粒输运和给料器的设计与运行有一定的参考作用。     

The Dynamic Temperature Field of Two-Stage Underground Coal Gasification (UCG)

Two-stage UCG is an effective technique to produce water gas with high heating value; its gas producing process is mainly determined by temperature. On the basis of the model experiment, via the analysis of the temperature field distribution regularity in the gasified coal layers in the gasifier and the generalization and treatment of the boundary conditions, two-dimension nonlinear unstable mathematical models of the temperature field in the two-stage UCG are established, and the method of selecting model parameters is illustrated. Solution is made through the method of volume controlling. This article also analyzes the results of calculation. In the light of the numerical computation results, the calculation value of the temperature field for coal seams of combustion and gasification can better fit with the experimental one under the condition of the model experiment. Except for some measuring points in the vicinity of the flame working face, where the relative error between computation value and test value is comparatively high, those of other measuring points are all below 15%, which completely meets the accuracy requirements for the numerical simulation on the temperature field of UCG. The consistency between the calculation value and the measurement value indicates that the numerical simulation of dynamic temperature field of coal media in the gasifier is correct, which provides necessary theoretical basis for further quantitative study of the UCG process.