3D Reconstruction of Slug Flow in Mini-Channels with a Simple and Low-Cost Optical Sensor.

Huajun Li,Haifeng Ji,Shanen Yu,Yandan Jiang,Guangyu Liu

doi:10.3390/s19204573

Huajun Li, Haifeng Ji + Show 3 more

Open Access

https://doi.org/10.3390/s19204573

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Abstract

The present work provides a new approach for 3D image reconstruction of gas-liquid two-phase flow (GLF) in mini-channels based on a new optical sensor. The sensor consists of a vertical and a horizontal photodiode array. Firstly, with the optical signals obtained by the vertical array, a measurement model developed by Support Vector Regression (SVR) was used to determine the cross-sectional information. The determined information was further used to reconstruct cross-sectional 2D images. Then, the gas velocity was calculated according to the signals obtained by the horizontal array, and the spatial interval of the 2D images was determined. Finally, 3D images were reconstructed by piling up the 2D images. In this work, the cross-sectional gas-liquid interface was considered as circular, and high-speed visualization was utilized to provide the reference values. The image deformation caused by channel wall was also considered. Experiments of slug flow in a channel with an inner diameter of 4.0 mm were carried out. The results verify the feasibility of the proposed 3D reconstruction method. The proposed method has the advantages of simple construct, low cost, and easily multipliable. The reconstructed 3D images can provide detailed and undistorted information of flow structure, which could further improve the measurement accuracy of other important parameters of gas-liquid two-phase flow, such as void fraction, pressure drop, and flow pattern.

Highlights

Gas-liquid two-phase flow (GLF) in micro-channels and mini-channels has been getting more attention recently due to the rapid development of miniature equipment applied in medical devices, heat exchangers, cooling systems, and chemical reactors, etc. [1,2]
The present work presents a new approach for 3D visualization of GLF in mini-channels based on a new optical sensor with a horizontal and vertical photodiode array
The present work proposes a new method for 3D image reconstruction of slug flow in mini-channels based on a new optical sensor

Summary

Introduction

Gas-liquid two-phase flow (GLF) in micro-channels and mini-channels has been getting more attention recently due to the rapid development of miniature equipment applied in medical devices, heat exchangers, cooling systems, and chemical reactors, etc. [1,2]. Gas-liquid two-phase flow (GLF) in micro-channels and mini-channels has been getting more attention recently due to the rapid development of miniature equipment applied in medical devices, heat exchangers, cooling systems, and chemical reactors, etc. In the past few decades, researchers have proved that miniature equipment with integrated channels intensifies heat and mass transfer, and, has better process performance. A better understanding of GLF in micro-/mini-channels is essential for flow mechanism research, process control, and monitoring, which depends on accurate and real-time measurement methods [3,4]. There is an urgent need for developing effective measurement methods, which should be low-cost, fast, multipliable, and suitable for miniature equipment. Flow visualization is an effective approach for having a direct understanding of the flow, which can provide detailed information about flow structure, flow pattern, and phase interface, etc

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Results

Conclusion