Session: 07-08: Thermal-Hydraulics General Studies and Analyses - I

Paper Number: 65417

Start Time: August 6, 2021, 03:15 PM

65417 - Study on Flow Boiling of Refrigerants in Micro/Mini-Channels 

The flow boiling heat transfer in microchannels is encountered in many compact heat exchangers such as the once-through steam generator in nuclear reactors due to its high heat transfer efficiency and thus accurately predicting the heat transfer coefficients is of great importance. Currently, for the higher saturation temperature of water, refrigerants are widely used in the flow boiling heat transfer experiments in replacing of water and a lot of heat transfer correlations are raised based on the data of refrigerants. However, there still exist some differences between these two materials especially in the distribution ranges of some important dimensionless numbers, such as the Bond number, Weber number and Reynold number which may influence the predicting accuracy of current heat transfer correlations for water. Therefore, 10 commonly used heat transfer correlations are summarized which can be simply divided into Chen-type and Nusselt type. Then experimental data of refrigerants and water conducted in the microchannels are collected respectively. Finally, the predicting accuracy of these two type heat transfer correlations are evaluated and compared when applied to water and refrigerants respectively. The results show that most of the correlations perform better for refrigerants than water which confirms the influence of the material type on the predicting accuracy.

Presenting Author: Wen He Tsinghua University

Authors:

Wen He Tsinghua University
Chenru Zhao Tsinghua University,Beijing,China
Hanliang Bo Tsinghua University,Beijing,China