Experimental investigation on flow boiling instability of R1233zd(E) in a parallel mini-channel heat sink for the application of battery thermal management

The present study focused on the flow boiling instability of R1233zd(E) in a 21 parallel mini-channel heat sink designed for the application on battery thermal management. Experiments were conducted under different conditions, including inlet subcoolings (2.5-8 K), mass fluxes (111-276 kg/m(2) s), and heat fluxes (up to 12 W/cm(2)). A high speed camera with the frequency of 2000 fps was used to capture the unstable flow pattern. The results showed that the period and the initial position of reverse flow were shortened with the increase of heat flux, meanwhile four typical reverse flow patterns in the parallel channel were captured. The Parallel Channel Instability (PCI) featured by large inlet pressure oscillation was suppressed when the inlet subcooling was increased, while mass flux had limited influence on the suppression of PCI. The standard deviation of inlet pressure Sigma(p(in)) was increased obviously under the inlet subcooling of 5 K. Beside, faster elevation of Sigma(p(in)) was observed under 111 kg/m(2) s when the heat flux was higher than 3.8 W/cm(2). Finally, the flow instability maps were established based on heat flux, mass flux and dimensionless parameters of subcooling number Nsub and phase change number Npch. The stable, transition and instability regions were divided on the maps based on the operating conditions and the flow patterns captured during the experiment. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

The present study investigated the flow boiling instability of R1233zd(E) in a 21 parallel mini-channel heat sink designed for battery thermal management. Experimental results showed that the period and initial position of reverse flow decreased as heat flux increased, and four typical reverse flow patterns were observed. The Parallel Channel Instability (PCI) featuring large inlet pressure oscillation was suppressed with increased inlet subcooling, while mass flux had limited influence on PCI suppression. Flow instability maps were established based on heat flux, mass flux, and dimensionless parameters, allowing for the categorization of stable, transition, and unstable regions.