摘要
层流流量计适用于气体小流量测量,但传统层流流量传感元件不可避免存在毛细管束进出口压损和毛细管层流起始段压损等非线性部分,导致输出差压不是流量的理想线性关系。基于此,提出了压力位差式层流流量传感技术,该项技术采用层流组件交叉对称的双流道结构,可以将毛细管束进出口局部损失和毛细管层流起始段非线性压力损失部分予以抵消,差压输出有更好的线性。分析了压力位差式层流传感技术原理和传感元件压降特性,设计了压力位差式层流流量传感元件实验模型,基于音速喷嘴气体流量标准装置进行实验测试,流量测量范围为0.015 8~6.350 1 m3/h,在大于0.075 Qmax范围,流量测量误差小于±0.8%,小流量范围内测量误差在±3%以内。
Laminar flowmeter is suitable for the measurement of small gas flow. However, there inevitably exist the non-linear parts of the pressure loss at the inlet and outlet of a capillary bundle and that in the initial section of capillary laminar flow for the traditional laminar flow sensing element, which leads to a non-ideal linear relationship between differential pressure and flowrate. Pressure potential differential(PPD) type laminar flow sensing technique is proposed in this paper, which adopts a double-channel structure of laminar flow component cross-symmetry. In this kind of flow sensing element, the local loss at the inlet and outlet of a capillary bundle and the nonlinear pressure loss in the initial section of capillary laminar flow can be offset;as a result, a better linearity for the pressure differential output is obtained. The principle of PPD type laminar flow sensing technique and the pressure drop characteristics of the sensing element are analyzed, an experiment model of PPD type laminar flow sensing element was designed, and the model was tested based on a sonic nozzle gas flow standard device with the flow test range from 0.015 8 to 6.350 1 m3/h. The results show that in the flowrate range greater than 0.075 Qmax, the flowrate measurement error is less than ±0.8% and in the small flowrate range the flowrate measurement error is within ±3%.
作者
黄浩钦
李国占
赵鹏
张洪军
Huang Haoqin;Li Guozhan;Zhao Peng;Zhang Hongjun(College of Metrology&Measurement Engineering,China Jiliang University,Hangzhou 310018,China)
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2020年第7期72-79,共8页
Chinese Journal of Scientific Instrument
基金
浙江省重点研发计划(2019C01133)项目资助
关键词
流量测量
小流量
层流传感元件
压力位差式
flow measurement
small flow
laminar flow sensing element
pressure potential difference type
