A new method for online monitoring of boiling process in mini‐channels

Abstract

A new method for online monitoring of boiling process, which is suitable for conductive fluids in mini‐channels, is proposed with the introduction of contactless conductivity detection (CCD) technique and perceptron algorithm (PA) technique. Series resonance principle and simulated inductor technique were adopted to develop a new CCD sensor. PA was used to implement the boiling stage identification, i.e., to identify the current stage was which stage of the boiling process. Three prototypes of the CCD sensors with inner diameters of 1.6, 2.0, and 2.5 mm were developed. With three kinds of conductive fluids (tap water, ethanol–tap water mixture, and KCl solution), boiling experiments were carried out. The experimental results show that the CCD sensor can effectively track the bubble growth of boiling process. The research results also indicate that the proposed method is effective and the identification accuracies are greater than 90.0%. © 2019 American Institute of Chemical Engineers AIChE J, 65: 1365–1375, 2019

Bubble breakup and boiling heat transfer in Y‐shaped bifurcating microchannels

“…To date, the flow boiling in heated micro/mini channels has also received much attention due to its unique merits comparing with single-phase flow, where the heat transfer enhancement effect, pressure drop, temperature uniformity, and flow stabilities were recognized as the key performance indicators. [20][21][22] Several important affecting parameters such as geometric structure, [23][24][25] mass flow rate, [26][27][28] heating condition, 29,30 surface wettability, 31 and working fluid 32 determined the bubble nucleation and liquid delivery, which significantly affected the flow pattern, pressure drop, and boiling heat transfer. Aside from the above experimental studies, the numerical methods have also been extensively employed, which could reveal the heat and mass transport details that are not easily measurable in experiments.…”

“…To date, the flow boiling in heated micro/mini channels has also received much attention due to its unique merits comparing with single‐phase flow, where the heat transfer enhancement effect, pressure drop, temperature uniformity, and flow stabilities were recognized as the key performance indicators 20–22 . Several important affecting parameters such as geometric structure, 23–25 mass flow rate, 26–28 heating condition, 29,30 surface wettability, 31 and working fluid 32 were investigated by means of experiment and simulation.…”