Development and Characterization of Thermal Flow Sensors for Non-Invasive Measurements in HVAC Systems

Sensors

Roman Beigelbeck¹  Thomas Glatzl¹  Thilo Sauter¹  Albert Treytl¹  Samir Cerimovic¹  Franz Keplinger² 

[1] Department for Integrated Sensor Systems, Danube University Krems, A-2700 Wiener Neustadt, Austria;Institute of Sensor and Actuator Systems, Vienna University of Technology, A-1040 Vienna, Austria;

关键词: thermal flow sensor;    non-invasive flow rate measurement;    HVAC systems;   

DOI  :  10.3390/s19061397

来源: DOAJ

【 摘 要 】

We investigated non-invasive flow rate measurements in heating, ventilation, and air conditioning (HVAC) systems utilizing thermal transduction instead of commonly used ultrasonic techniques. The proposed thermal flow transduction comprises two temperature sensors and a heater, all mounted non-invasively on the outer surface of metal-pipes and, therefore, not disturbing the fluid flow inside. One temperature sensor measures the heater temperature, whereas the other one, mounted upstream of the heater, follows the fluid temperature for reference. The temperature difference (i.e., the heater excess temperature) depends on the fluid flow velocity and can be used to derive the mean volume flow inside the pipe. Experimental characterizations were conducted using two sensor prototypes. Beside output characteristics, other main issues such as dynamic behavior and noise density were investigated in detail. Special attention was paid to error compensation allowing measurements within a large range of fluid temperatures. Measurement results confirm the feasibility of this approach, however with some constraints regarding response time.

【 授权许可】

Unknown