Session: K10-03: MULTI-SCALE MULTI-PHASE HEAT TRANSFER EQUIPMENT II

Paper Number: 142022

142022 - Development of a Liquid Level Indicator Using a Distributed Fiber Optic Sensor by Thermal Capacity Differences 

Abstract: 

Liquid level sensors utilizing differential pressure and buoyancy used in conventional industrial environments suffer from the problem that density changes distort the measured value, reducing the reliability of the results. In addition, Heated Junction ThermoCouple (HJTC) sensors suffer from the limitation of low spatial resolution due to the use of point-type sensors. To overcome these limitations of conventional liquid level sensors, this study proposes a new concept of liquid level sensor that can stably measure the liquid level even in the face of large density changes and enables continuous liquid level measurement. For this purpose, we used a Rayleigh scattering-based distributed fiber optic sensor with high spatial resolution that is independent of high temperature changes. Proof-of-concept experiments of the prototype applying the proposed concept demonstrated that it can detect the phase through the rate of temperature change of the liquid and gas near the interface by utilizing the difference in thermal capacity of the water and air, which can effectively detect the position of the interface. We experimentally verified the sensor performance in a situation where the density of water and air changes with the applied power, and in a dynamic situation where the water level changes with time. The proposed liquid level sensor is capable of accurate level measurement even in environments with significant density variations and is expected to be utilized in various industrial settings requiring continuous liquid level measurement.

Presenting Author: Hyewon Lim Gyeongsang National University

Presenting Author Biography: Hye-Won Lim is the graduate student in School of Mech. Eng. from Gyeongsang National University. She is one of the members of SEED LAB (Surface Engineering and Energy Devices Laboratory).

Authors:

Hyewon Lim Gyeongsang National University
Hyungmo Kim Gyeongsang National University
Hyewon Kim Gyeongsang National University