新型双模热感微流量传感器的研究  

Research on a novel dual-mode thermal microflow sensor

作　　者：吴慰 关镐强 李金贝奇 王瑞金[1] 朱泽飞[1] Wu Wei;Guan Haoqiang;Li jin beiqi;Wang Ruijin;Zhu Zefei(School of Mechanical Engineering,Hangzhou Dianzi University,Hongzhou 310016,China)

机构地区：[1]杭州电子科技大学机械工程学院,杭州310016

出　　处：《仪器仪表学报》2021年第7期73-80,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(11572107)项目资助。

摘　　要：微流量传感器是有着功耗低、响应快、精度高等优点,在汽车工业、航空航天、生物研究、临床诊断等多个领域有广泛的应用。量热微流量传感器是通过测量加热器上下游温差来确定流速的,然而当流速超过一定范围后温差响应将不会随流速的增大,限制了流量传感器的量程。本文首先数值模拟了在大流率跨度下(0~160 SCCM)下温差对流速的响应,发现当扩散作用占主导时温差对流速的响应几乎是线性的;随着流速的增大,温差的响应逐渐降低,呈非线性;当流速进一步增加时温差的响应趋于饱和,量热工作模式失灵。然后,在数值模拟基础上提出了在大流速下采用热线工作模式,而中小流速下依然采用量热模式的双模式微热流量传感器。最后,采用0.18μm CMOS-MEMS的工艺制作了微传感器,并以灵敏度为准则划定了工作模式的切换阈值,与标准流量计比较后发现误差在2%之内,符合实际应用要求,但量程扩大了一倍。Due to the advantages of low power consumption,fast response and high measurement accuracy,Micro flowmeter have a wide application in the fields of automotive industry,aerospace engineering,biological research,clinical diagnosis and so on.Calorimetric micro flowmeter determines the flow velocity value by measuring the temperature difference between the upper and lower reaches of heater.However,when the flow velocity exceeds a certain threshold,the temperature difference will not increase with the flow velocity,which limits the measuring range of the micro flowmeter.In this paper,numerical simulations for a wide range of flowrates(0.01-160 SCCM)are firstly carried out to investigate the response of temperature difference to flowrate.It is found that the response of temperature difference to flow velocity is almost linear when diffusion is dominant.With the increase of flow velocity,the response of temperature difference decreases gradually and is nonlinear.As the flow rate increases further,the response of temperature difference becomes saturated and the calorimetric operation mode fails.Secondly,on the basis of numerical simulation,a dual-mode micro-heat flow sensor is proposed,which adopts hot wire operation mode at high flow rate and calorimetric mode at medium and small flow rate.Finally,a micro flowmeter is manufactured by 0.18μm CMOS-MEMS technology,and the threshold for mode-switch is defined by the sensitivity in experiments.Compared with standard flowmeter,the error is less than 2%,which is in line with the practical application requirements,but the range is doubled.

关 键 词：热感式 微流量传感器 双模 量热模式 热线模式 

分 类 号：TH7[机械工程—仪器科学与技术] TH814[机械工程—精密仪器及机械]