二氧化碳压缩机组异常情况分析与对策

针对二氧化碳压缩机运行过程中出现的振动和轴温异常的情况进行分析，提出相应的检修处理建议和具体的工艺调整措施。     

A high-pressure atomic force microscope for imaging in supercritical carbon dioxide

A high-pressure atomic force microscope (AFM) that enables in situ, atomic scale measurements of topography of solid surfaces in contact with supercritical CO(2) (scCO(2)) fluids has been developed. This apparatus overcomes the pressure limitations of the hydrothermal AFM and is designed to handle pressures up to 100 atm at temperatures up to ～350 K. A standard optically-based cantilever deflection detection system was chosen. When imaging in compressible supercritical fluids such as scCO(2), precise control of pressure and temperature in the fluid cell is the primary technical challenge. Noise levels and imaging resolution depend on minimization of fluid density fluctuations that change the fluid refractive index and hence the laser path. We demonstrate with our apparatus in situ atomic scale imaging of a calcite (CaCO(3)) mineral surface in scCO(2); both single, monatomic steps and dynamic processes occurring on the (1014) surface are presented. This new AFM provides unprecedented in situ access to interfacial phenomena at solid-fluid interfaces under pressure.     

CO2气瓶阀的结构与性能分析

阐述了CO2气瓶阀的设计、结构特点、工作原理、发展和分类。     

Arc welding of butt joints in carbon dioxide

A method of calculating the welding conditions in carbon dioxide is proposed. Its validity is confirmed by comparing the calculation results and experimental data     

二氧化碳探测仪的热控系统

根据二氧化碳探测仪所处的空间环境、结构特点和工作模式,采用被动热控和主动热控相结合的方法设计了它的热控系统。首先,介绍了探测仪结构及内热源,同时分析了探测仪的外热流,从而得到了热控任务难点。然后,对探测仪的各个部分进行了热设计,采用被动热控与主动热控相结合的方式进行了热隔离、热疏导和热补偿;根据探测仪所处的空间环境和采取的热控措施利用TMG软件进行了热分析。仿真分析结果表明,光学系统主体框架的温度为13.3~21.7℃,满足了设计要求。最后,通过真空条件下的热平衡试验对热设计进行了试验验证,试验结果显示光学系统主体框架的温度为13.0~20.3℃,试验值与计算值基本一致,满足热控指标要求。得到的数据表明提出的热设计方案合理可行。     

二氧化碳压缩机管线振动原因分析及减振措施

对新疆泽普石化厂二氧化碳压缩机管线振动的原因进行了测试和分析，提出了减振措施，取得了预期效果。     

碳卫星CO_2探测仪发射前的漫反射板定标

为了提高CO_2探测仪的在轨辐射定标精度,建立了在轨辐射校正原理,并对关键环节漫反射板的制备、BRDF定标和应用进行了系统的研究。根据CO_2探测仪的工作原理与系统组成,介绍了星上定标设备和在轨辐射定标策略,确定了漫反射板的制备方法和优化工艺参数,制定了以标准灯和标准探测器为传递链路的漫反射板BRDF的精确定标方法。对漫反射板基准BRDF、角度修正因子和半球反射率进行了测试,对其实验室定标精度进行了分析,并通过在轨初期的应用结果予以验证。发射前的定标结果表明,漫反射板在760nm、1 610nm和2 060nm 3个波段的定标精度均优于3%。在轨初期的测试结果表明CO_2探测仪1 610nm波段在轨绝对辐射定标精度优于5%。CO_2探测仪漫反射板的定标结果满足仪器辐射定标对漫反射板定标的精度要求。     

碳卫星高光谱CO_2探测仪发射前光谱定标

为了完成碳卫星高光谱CO_2探测仪的发射前光谱定标,建立了光谱定标系统,并对定标系统设计、所采用的自动化数据采集和数据处理算法等进行了研究。根据CO_2探测仪的探测原理介绍了载荷的光谱性能要求,描述了定标系统的设计与所采用的仪器设备,说明了采用自动化数据采集、旋转积分球、功率校正与暗背景校正等改进的定标方法。最后,介绍了光谱定标的数据处理方法。发射前定标结果表明:载荷三个波段的ILS能量集中度分别大于0.80,0.81和0.78;FWHM分别为0.039 2~0.042 4nm,0.123~0.128nm和0.157~0.168nm;光谱采样率区间分别为2.12~2.95、1.97~2.27和1.92~2.26。对发射后实测太阳夫朗禾费光谱进行了评估,结果表明:中心波长偏差小于0.0013,0.058和0.065nm。CO_2探测仪整体的光谱性能指标能够达到系统设计要求。     

二氧化碳压缩机振动原因分析及解决措施

河南龙宇煤化工的二氧化碳压缩机采用活塞压缩机,其管道振动十分严重,导致压缩机不能长周期稳定运行。就活塞压缩机管道振动产生的原因及防振措施作了分析,提出防振措施。     

西门子WinCC在二氧化碳回收系统中的应用

针对二氧化碳排放量不断增长的趋势,利用自动化技术使其变废为宝,意义重大。论文介绍了二氧化碳回收的工艺流程,分析了系统需求,借鉴FCS思想设计了基于S7-300 PLC、Win CC组态软件、冗余技术的监控系统。给出了系统Win CC组态步骤及冗余组态过程。阐述了运用组态软件Win CC V7.0设计的开发界面,并对开发过程中遇到的问题及解决方法进行了讨论。应用结果表明:该系统具有实时动态显示和操作功能,能够实现二氧化碳回收工艺流程再现,并能实现对现场设备的远程操作控制,减轻了劳动强度,提高了生产效率。     

呼气末二氧化碳监测在老年全麻患者中应用价值

目的:探讨呼气末二氧化碳监测在老年全麻患者中的应用。方法:60例拟在全麻下行腹腔镜手术治疗的老年患者随机分为实验组(A)和对照组(B),各30例,行二氧化碳气腹时调整A组患者的呼吸频率和潮气量使呼气末二氧化碳分压(P_(ET)CO_2)在正常范围(35~45mm Hg),B组患者不调整呼吸参数,分析2组患者气腹前5min(T1)、气腹后5min(T2)、10min(T3)、30min(T4),放气后5min(T5)、10min(T6)动脉血二氧化碳分压(PaCO_2)和A组P_(ET)CO_2的变化,并比较2组患者术后苏醒情况。结果:A组通过监测P_(ET)CO_2调整呼吸参数的变化,2组患者T1时点PaCO_2差异无统计学意义,T2~T6时间点A组患者PaCO_2明显低于B组,差异有统计学意义,且A组患者的苏醒时间明显短于B组患者,差异有统计学意义。结论:老年全麻患者使用P_(ET)CO_2监测不仅能够减少CO_2蓄积而且能够提高苏醒质量。     

Detection of occupancy profile based on carbon dioxide concentration pattern matching

Occupancy is one of major factors influencing indoor microclimate. The aim of this work was to determine the influence of this factor on indoor air quality (IAQ) on the basis of CO₂ concentration measurements and statistical analysis. We wanted to identify periods of time when IAQ was strongly affected by the occupancy described by the given profile. The proposed approach consisted of several stages. The CO₂ concentration was measured and recorded in the form of univariate time series. Then, the relationship between occupancy and internal structure of the time series was disclosed. There were distinguished segments based on sample periodogram. Each segment was associated with a particular occupancy profile. In order to detect how human factor represented by a given occupancy profile influences IAQ we proposed to use pattern matching. In this approach there was examined the similarity between segments of the time series and the pattern of CO₂ variability, which represented a selected occupancy profile. The analysis was performed in time domain using moving time window technique. The similarity was judged based on two types of indexes, namely correlation coefficients and distance measures. It was shown that our approach may be applied to successfully detect a particular occupancy profile. The best performance was achieved when using angular distance as the similarity index. In this case we reached 82% true positive and 22% false positive detections. The proposed method may be applied in diagnostics problems to reveal sources of indoor air quality problems.     

超临界CO_2萃取胡萝卜中胡萝卜素的研究

本文对胡萝卜中胡萝卜素的超临界CO2提取条件进行研究。分别对不同压力、 温度及夹带剂等几个影响因素进行试验。确定了最佳提取条件为压力5000psi(340大气 压),温度60℃,二氧化碳流量1.5L/min,时间4h。     

超临界二氧化碳D型管内对流换热研究

D型管换热器应用于快速气冷堆超临界二氧化碳循环中,对超临界二氧化碳在竖直D型管中的对流换热进行了计算研究.分析二氧化碳质量流量、冷却水质量流量以及当量直径等参数对超临界二氧化碳对流换热的影响.结果表明,由于准临界点附近剧烈变物性的影响超临界二氧化碳在D型管内的对流换热非常复杂.对流换热随着温度远离准临界温度,热流密度的增加不断减弱.流量对对流换热的影响比较复杂.在准临界温度附近,浮升力对换热有一定的影响.     

基于时序控制算法的二氧化碳洗涤器的研究与应用

针对市场需求,在时序控制算法的基础上,提出了一种活性炭为洗涤媒体的二氧化碳洗涤器的设计原理。以TXF-125型二氧化碳洗涤器为实例,阐述了其系统架构、关键技术。已有公司将该二氧化碳洗涤器批量生产,且产生可观的社会效益和经济效益。     

超临界CO2环境下线路板分层机理的模拟与分析

建立线路板试样的有限元模型,利用有限元分析软件ANSYS8.0对超临界CO2环境下的线路板内应力分布及大小进行模拟分析,计算出树脂层的最大剪切应力和最大剥离应力的大小并分析其变化规律,据此推测内应力在线路板分层破坏中的作用及破坏机理,并将分析结果与实验结果对比,以优化回收工艺过程参数.     

Turbulent heat transfer of supercritical carbon dioxide in square cross-sectional duct flow

Numerical simulations are performed to develop a new heat transfer coefficient correlation applicable to the gas cooler design of a trans-critical carbon dioxide air-conditioner. Thermodynamic and transport properties of the supercritical gas cooling process change dramatically and significantly vary heat transfer coefficients to be much different from those of single or two phase flows. In the present study, the elliptic blending second moment turbulent closure precisely reflecting the effects of these thermo-physical property variations on the turbulent heat transfer is employed to model the Reynolds stresses and turbulent heat fluxes in the momentum and energy equations. Computational results related to the development of turbulent heat transfer during in-duct cooling of supercritical carbon dioxide were used to establish a new heat transfer coefficient correlation that would be widely applicable to a gas cooler design involving turbulent heat transfer of supercritical carbon dioxide in square cross-sectional duct flows. This paper was recommended for publication in revised form by Associate Editor Kyung-Soo Yang Seong Ho, Han received a B.S. degree in Mechanical Engineering from Kookmin University in 2003. He then went on to receive his M.S. degree from Korea University in 2005. He is currently in a Ph. D. course at Mechanical Engineering at Korea University in Seoul, Korea. His research interests are in the area of hydrogen energy, polymer electrolyte membrane fuel cell.     

Measurements of the flow of supercritical pressure carbon dioxide through Venturi flow meter

The Venturi flow meter exhibits relatively low pressure loss, simple design, and low manufacturing costs. This study describes flow rates measurements for supercritical pressure CO₂ using the Venturi flow meter with pressure ranging 7.379–7.836 MPa and 5.84–7.272 MPa for in supercritical and gaseous regions, respectively. The flow rates of supercritical pressure CO₂ were accurately measured using a Venturi flow meter with a diameter ratio of 0.6468, having large and small diameters of 87.32 mm and 56.48 mm, respectively. The convergent and divergent angles were 21 $°$ ± 1 $°$ and 15 $°$ ± 1 $°$, respectively. The averaged discharge coefficient of 0.9975 was obtained, which was independent of the pressure ratio. Additionally, the expansion factors were also calculated using the experimental results, which ranged from 0.99976 to 0.99987 and 0.99945–0.99995 for the supercritical and gaseous regions, respectively. The experimental results showed that the Venturi flow meter had uncertainties ranging from 0.1 to 2.8%.     

氢中微量一氧化碳、甲烷、二氧化碳标准样品的研制及不确定度评定

介绍了氢中一氧化碳、甲烷、二氧化碳标准样品制备过程，建立了标准样品杂质组分的分析方法，对该标准样品性能进行了考察，分析和评定了标准样品的不确定度，通过不同实验室的比对分析说明量值可靠。     

A feasible process tomography and spectroscopy measurement system to determine carbon dioxide absorption

The present study has demonstrated that Electrical Impedance Spectroscopy (EIS) and Electrical Impedance Tomography (EIT) are viable measurement techniques to be used in the measurement and monitoring of carbon dioxide absorption across the scales.EIS is able to provide information regarding the absorption of carbon dioxide gas on the molecular level hence can be used to search for the optimal system by studying the kinetics of the absorption process and measuring the solubility of carbon dioxide in different solvents of interest.EIT, however, is more suited to studying the absorption on the macro-scale of the process in terms of aspects such as homogeneity of absorption thus can be used to look at the design of the absorption columns themselves. In the present study the experiments were restricted to studying the absorption of carbon dioxide in water as it was found that the conductivity of industrially relevant solvents such as monoethanolamine was too high for use with the conventional EIT hardware.