密闭空间内有机化学品挥发动力学在线检测系统  

An Online System for Determining the Volatilization Kinetics of Organic Compounds in an Airtight Chamber

作　　者：费瑞银 翁文庆 喻奇 孙江枫 姬亚军 延卫[3] 杨鸿辉[3] FEI Ruiyin;WENG Wenqing;YU Qi;SUN Jiangfeng;JI Yajun;YAN Wei;YANG Honghui(Department of Medium and Long Term Reconstruction Project,Daya Bay Nuclear Power Operations and Management Co.Ltd.,Shenzhen,Guangdong 518124,China;System Engineering and Renovation Center,Nuclear Power Technology Research Institute Co.Ltd.,Shenzhen,Guangdong 518000,China;Department of Environmental Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]大亚湾核电运营管理有限责任公司中长期改造项目部,广东深圳518124 [2]中广核研究院有限公司系统工程与改造中心,广东深圳518000 [3]西安交通大学环境科学与工程系,西安710049

出　　处：《西安交通大学学报》2019年第12期177-182,共6页Journal of Xi'an Jiaotong University

基　　金：陕西省重点研发计划资助项目（2018SF-372）

摘　　要：针对核电安全壳检修实验期间难以动态定量测定多种挥发性有机化学品、进而难以评估其火灾风险的问题,构建了一种密闭空间内有机化学品挥发动力学在线检测系统。采用密封腔体为化学品挥发腔、以气相色谱仪为气相中有机化学品浓度的在线检测仪、以气体循环泵为系统内气体循环的驱动单元、以质量流量计为气体循环流速的精确控制器来提供化学品挥发所需的气相对流条件;通过在线的自动六通阀采集密封腔体内的气体样品并实现对气相色谱仪进行自动进样,实现了气相中有机物浓度的在线定量测定;整个样品挥发和循环管路系统置于恒温箱内,可实现温度和气压的可调控制。测定了正丁醇和乙苯的挥发动力学特性及平衡蒸气压,并将平衡蒸气压与理论值进行对比,结果表明:在20~30℃的范围内,气相中的正丁醇和乙苯挥发曲线遵循准一级挥发动力学方程,且所测得的平衡蒸气压与理论值相近。该测试系统稳定性好、测试结果准确度较高,利用该系统测定的化学品挥发速率值可用于计算评估核电安全壳内挥发性化学品在打压期间的累积情况,进而评估其火灾风险。An online system for determining the volatilization kinetics of volatile organic compounds(VOCs)is constructed to solve the problem that it is difficult to dynamically determine the concentrations of VOCs in the atmosphere of nuclear power containment and to evaluate the consequent fire disaster risk during pressure test.A seal cavity is used as the volatilization container,and a gas chromatograph is used to determine the gaseous concentrations of chemicals in the atmosphere.A gas pump is used to circulate the gas with the gas flow rate controlled by a mass flow controller to offer convection condition for chemical volatilization.The gas chromatograph samples gas via a six-way automatic injection valve to determine the concentrations of VOCs online.Components of the system except for gas chromatograph are placed in an incubator for temperature and pressure control.The stability and accuracy of the proposed system are tested based on the volatilization curves and equilibrium vapor pressure values using n-butanol and ethylbenzene as the model chemicals.The results show that the volatilization curves of n-butanol and ethylbenzene fit pseudo-first-order kinetics in the range of 20℃-30℃,and the equilibrium concentrations are close to the theoretical data.These results show that the online system is stable and accurate,and its resulting volatilization rates could be used to evaluate the VOCs accumulation and fire disaster risk.

关 键 词：挥发性有机化学品 挥发动力学 核电安全壳检修实验 在线检测系统 

分 类 号：O643.32[理学—物理化学]