【摘要】 为准确计量天然气流量,设计了以MSP430单片机为核心的天然气流量积算仪。积算仪接收来自流量变送器输出的模拟信号。积算仪包含有数据存储模块、压力传感器模块和温度传感器模块。开发了系统软件,输入天然气各组分的摩尔质量以及温度、压力值后,根据AGA8-92DC公式建立起压缩因子、温度和压力之间的三维数据表,数据表通过RS-485传输至单片机的Flash中存储。单片机利用埃尔米特插值算法快速求出测量工况下的压缩因子,并将天然气的体积流量转换为工况条件下的体积流量,实现了在线补偿功能。更多还原

【Abstract】 A natural gas flow totalizer based on MSP430 MCU was designed to receive analog signals from the gas flow transmitter. The totalizer includes modules for data storage and pressure and temperature sensor. After inputting molar mass,temperature and pressure of the natural gas components,the three-dimensional datasheet among compressibility factor and pressure and temperature can be established according to AGA8-92DC calculation method,and then be transmitted to MCU’s Flash through RS-485; to guarantee online compensation, the MCU employs Hermite interpolation algorithm to quickly obtain compressibility factor under the measurement condition,and then converters the natural gas’ volume flow into the one at the working condition.更多还原