标准表法车载式LNG加气机在线计量检定装置的设计与应用

Design of On-Line Metering Verification Device for Vehicle-Mounted LNG Dispenser Based on Master Meter Method

针对目前国内LNG加气机缺少科学的后续计量检定方法,致使LNG加气机计量准确性降低,存在计量风险的问题,设计了一套具备超低温保温能力、高精度采集能力、高可靠性和数据分析能力强的标准表法车载式LNG加气机在线计量检定装置。该装置包括:由标准液相流量计、标准气相流量计等组成的现场仪表层;由可编程控制器、流量检定采集器组成的现场控制层;由具有系统监控和报表生成功能组成的管理层。该装置应用标准表法,采用液相流量检定,整机流量检定等方法,实现了检定过程的“一键启停”在线自动检定,检测精度可以达到0.2%,达到行业先进水平。该技术已经应用于北京公交LNG加气机检定,具有良好的推广应用价值。

In view of the lack of scientific follow-up measurement and verification methods for LNG dispenser in China, which reduces the measurement accuracy of LNG dispenser and causes measurement risks, an on-line measurement and verification device based on master meter method for LNG dispenser with ultra-low temperature insulation capacity, high precision collecting capacity, high reliability and data analysis capability is designed. The device includes: field instrument layer composed of standard liquid flowmeter and standard gas flowmeter, field control layer composed of programmable controller and flow verification collector, management layer with system monitoring and report generation function. The device uses master meter methcxl, liquid flow calibration, whole machine flow calibration and other methods to realize on-line automatic verification of "one-key start-stop" in the verification process. The detection accuracy of the device can reach 0.2%, which fills the gaps in the domestic verification business of gas dispenser, and the overall technology has reached the advanced international level. This technology has been applied to the verification of LNG dispensers in Beijing Public Transport Company, showing a good popularization value.