气体中微量一氧化碳、甲烷、二氧化碳的气相色谱分析

建立了甲烷转化气相色谱法测定气体中一氧化碳、甲烷、二氧化碳的分析方法。采用一阀两柱系统,氯气、氯化氢通过十通阀经柱Ⅰ(Hayesep Q)反吹出系统,一氧化碳、甲烷、二氧化碳通过柱Ⅱ(Porapak Q)进入氢火焰离子化检测器进行检测,通过外标法定量,结果表明该方法线性好,各组分的检出限分别为一氧化碳0.02×10-6(mol/mol)、甲烷0.05×10-6(mol/mol)、二氧化碳0.08×10-6(mol/mol)。该方法简便、准确、灵敏、重现好。     

氮气中一氧化碳、二氧化碳、甲烷、乙烷气体标准样品的研制

叙述了气体报警仪标定和检测使用的氮气中一氧化碳、二氧化碳、甲烷、乙烷气体标准样品的制备,以气相色谱法对其均匀性和稳定性进行考核,确保其数据准确可靠。     

气相色谱法测定液氧中微量乙炔

通过实验和数据说明了空分装置生产的液氧经汽化后进入配有气体纯化器、放电离子化检测器和H ayesep S 30″×1/8″填充柱的气相色谱仪,用纯化后的高纯氦作为载气,经色谱系统分离和检测,由色谱工作站采集数据并绘成色谱图,用高纯氦配制的乙炔标准气进行外标法定量,测定液氧中微量乙炔含量的方法。     

高纯永久性气体中微量一氧化碳、甲烷和二氧化碳的甲烷转化法气相色谱法分析

给出了高纯气体中微量一氧化碳、二氧化碳的甲烷化转化气相色谱法分析的工作原理、甲烷化转化率试验,气路流程的比较,仪器的方法检测限,同其他方法进行比对,说明其方法切实可行。     

氦中一氧化碳、二氧化碳和甲烷混合气体标准物质的研制

论述了氮中一氧化碳、二氧化碳和甲烷混合气体标准物质的制备方法，性能考察，不确定度计算，证明组分含量稳定，方法可行。     

氢中氧、氮、甲烷、一氧化碳、二氧化碳的研制

叙述了石油化工生产过程中高纯氢产品使用的氢标样的制备,以及气相色谱法对其均匀性和稳定性进行考核,确保其数据准确可靠。     

高纯氧中痕量甲烷、二氧化碳的气相色谱分析

甲烷和二氧化碳是高纯氧中的主要杂质。通常，这些杂质可用气相色谱法测定。氧中甲烷测定较简单，一般是以纯氮为载气，或以纯氩为载气，用气相色谱FID测定，最小检出量为0．5ppm以下。用直接法测量0.1ppm以下的甲烷较为困难，除了要求所用检测器灵敏度高外，载气必须经过纯化。     

乙烯中一氧化碳、二氧化碳和乙炔混合气体标准物质的研制

论述了乙烯中一氧化碳、二氧化碳和乙炔混合气体标准物质的制备方法、性能考察、不确定度计算,经与国内同类标准物质比较,证明量值准确可靠、方法可行。     

气相色谱法分析高纯二氧化碳中总烃

采用气相色谱法测定食品添加剂液体二氧化碳中总烃,方法简单,准确快速。     

Direct determination of carbothermal reduction temperature for preparing silicon carbide from the vacuum furnace thermobarogram

In this study, we combined the traditional vacuum furnace with a sur-high accuracy vacuum gauge for measuring the change of gas pressure in the furnace as a function of temperature. The modified vacuum furnace was used for preparing silicon carbide (SiC), and the recorded data named thermobarogram were applied to detect the reaction temperature for synthesis of SiC, which, in particular, changes as catalysts are used. The results showed that the carbothermal reduction temperature for synthesizing SiC, under dynamic vacuum condition, would decrease to 850 °C when the mole ratio of Fe/Si=0.06 was employed in the SiC precursor.     

分子筛吸附器出口空气中二氧化碳含量超标分析及防范

因为风向,导致KDON-42500/22700型空分设备的环境大气中二氧化碳浓度较高,使进入分子筛吸附器的空气中二氧化碳含量超标,超出了分子筛正常工作时吸附二氧化碳的能力,二氧化碳进入主换热器并堵塞其换热通道,空分设备被迫停运。介绍故障发生时空分设备运行参数的变化情况和处理措施,阐述为防止类似故障再次发生而采取的防范措施。     

Blends of carbon dioxide and HFCs as working fluids for the low-temperature circuit in cascade refrigerating systems

This paper describes an analysis on the performances of a cascade refrigeration cycle operated with blends of carbon dioxide (CO₂, or R744) and hydrofluorocarbons (HFC) as the low-temperature working fluid. The aim of this work was to study the possibility of using carbon dioxide mixtures in those applications where temperatures below CO₂ triple point (216.58 K) are needed. The analysis was carried out by developing a software based on the Carnahan–Starling–De Santis (CSD) equation of state (EoS) using binary interaction parameters derived from our experimental data. The properties of the investigated blends (R744/R125, R744/R41, R744/R32, R744/R23) were used to simulate the behavior of a cascade cycle using ammonia (R717) as the high-temperature-circuit working fluid and operating at evaporating temperatures down to −70 °C. The use of a suction–liquid heat exchanger on the low-temperature side of the circuit was also investigated. Results show that the R744 blends are an attractive option for the low-temperature circuit of cascade systems operating at temperatures approaching 200 K.