基于P-V自动调节的活塞式气体流量装置研究  

Research on Piston Gas Flow Device Based on P-V Automatic Adjustment

作　　者：林明星 沈文新 江航成[1] LIN Mingxing;SHEN Wenxin;JIANG Hangcheng(Goldcard Smart Group Co.,Ltd.,Hangzhou 310018,China;Zhejiang Province Institute of Metrology,Hangzhou 310018,China)

机构地区：[1]金卡智能集团股份有限公司,浙江杭州310018 [2]浙江省计量科学研究院,浙江杭州310018

出　　处：《自动化仪表》2024年第8期108-111,116,共5页Process Automation Instrumentation

摘　　要：为研究超声波、热式燃气表在空气介质与天然气介质条件下的流量特性及差异,设计了一种基于压力-体积(P-V)自动调节的活塞式气体循环流量标准装置。介绍了装置基本架构、工作原理。分析了流体流动闭合回路中影响测量精度的原因。建立了实现定常流的P-V自动调节控制数学模型。该装置采用主动盘形活塞式流量标准器,体积扩展不确定度U r=0.07%;配置柱形活塞作为容积补偿,通过监测气体压力变化调节活塞运动方向及速度,以达到压力恒定的目的。装置配置了六表位工装台架,并设置最大工作压力为0.1 MPa、最大流量为10 m^(3)/h、量程比为1000∶1;通过测试六台G2.5超声波燃气表,得出压力波动小于5 Pa、流量稳定性优于0.02%。在流量测试领域,P-V自动调节方法可以为实现定常流提供新的解决思路。To research the flow characteristics and differences between ultrasonic and thermal gas meters under the conditions of air medium and natural gas medium,a piston gas cycle flow standard device based on pressure-volume(P-V)automatic adjustment is designed.The basic architecture and working principle of the device are introduced.The reasons affecting the measurement accuracy in the closed loop of fluid flow are analyzed.A mathematical model of P-V automatic adjustment control for realizing constant flow is established.The device adopts an active disk-shaped piston flow standard with volume expansion uncertainty U r=0.07%;configures a column-shaped piston as volume compensation,and adjusts the direction and speed of the piston movement by monitoring the change of gas pressure to achieve the purpose of constant pressure.The device is equipped with a six-meter station work bench,with a maximum working pressure of 0.1 MPa,a maximum flow rate of 10 m^(3)/h,and a range ratio of 1000∶1;by testing six G2.5 ultrasonic gas meters,the pressure fluctuation obtained is less than 5 Pa,and the stability of flow rate is better than 0.02%.In the field of flow testing,the P-V automatic adjustment method can provide a new solution idea for realizing constant flow.

关 键 词：计量学 燃气表检测 活塞式气体流量标准装置 压力-体积自动调节 流量稳定性 定常流 

分 类 号：TH814[机械工程—仪器科学与技术]