Session: 11-01: Micro/Miniature Two-Phase Devices/ Systems

Paper Number: 121519

121519 - An Experimental and Modeling Study on Device- and System-Level Micro-Channel Two-Phase Cooling for High-Heat-Flux Application 

Abstract: 

A multi-microchannel two-phase two-phase cold plate made of copper is tested for temperature rise and flow resistance to verify its feasibility for heat dissipation in high-heat-flux devices such as GPU, as well as programmed with EES (Engineering Equation Solver) to predict its temperature profile and pressure drop across the device. To conduct the test for the device, a complete two-phase system has been built up. The system is composed of pump, quick-connectors, pre-heater, test section, plate-fin condenser, etc. The microchannel cold plate has a channel height of 3mm, a channel width of 0.3mm, a fin thickness of 0.2mm, a total width of 50mm, and a total length of 60mm. A micro-heater is embedded into the test section to simulate a GPU heat source (up to 1000W), which has a printed area of 50mm by 50mm. The 3D model of the cold plate and heat source was imported into COMSOL to complete the three dimensional heat conduction analysis based on the heat flux boundary conditions calculated with EES. The cold plate is located in series with a pre-heater, which serves as providing a certain inlet sub-cooling or vapor quality for the test section. A differential pressure transmitter (full scale 500kPa) is installed at both ends of the test device to measure its overall pressure drop. The surface temperatures of the micro-channel cooling device under test are monitored by a series of thermocouples. The valve and DC power supply can be adjusted to get certain flow rates and heat fluxes. Adiabatic pressure drop tests and three power heating tests were performed under the condition that the inlet to the cold plate was saturated; combination tests of two flow rates and three heating power were performed when the inlet was subcooled. Through correlation-based EES coding for thermal and hydraulic behaviors in the cold plate, the heat transfer and flow resistance have been predicted very well. Among the components of the overall pressure drop across the cold plate, the local two phase flow resistances, especially the abrupt bend and restriction of the outlet, play an extremely vital role. In addition, it is noted that the adiabatic pressure drop in the two-phase flow from the outlet of cold plate to the condenser inlet is almost the same. The reason for this phenomenon is analyzed through the adiabatic pressure drop correlations. While the cold plate flow rate increases, the outlet vapor quality becomes smaller; as the flow rate and quality are the most important two factors affecting the pressure drop, there might exists a constant pressure drop for two-phase flows with different flow rates or vapor quality (transfering the same amount of disspated heat). Moreover, the adiabatic pressure drop between the micro-channel cold plate and condenser is proved to be a key factor that affects the working pressure or saturation fluid temperature in the cold plate, which in turn determines the temperature rise of the cold plate over the atmosphere.  This study provides not only a feasibility analysis for the high-heat-flux cooling solution, but also a reliable and easy-to-use tool for predicting multi-microchannel cooling device and system.

Presenting Author: Zhaozan Feng Zhuzhou CRRC Times Electric UK Innovation Center

Presenting Author Biography: Zhaozan Feng received the B.Sc. Degree and Ph.D. degree in thermal engineering from Zhejiang University, in 2010 and 2015, respectively. Since 2016, he had been working at the CRRC Zhuzhou Institute, where he focused on the research topics of two-phase thermal management system for power electronics. In 2022, he joined the Zhuzhou CRRC Times Electric UK Innovation Center, as a lead thermal engineer, where his research interests include transient modeling of single/two-phase cooling system and distributable thermal modeling program.

Authors:

Zhaozan Feng Zhuzhou CRRC Times Electric UK Innovation Center
Guomeng Song Zhuzhou CRRC Times Electric UK Innovation Center
Fan Xia Zhuzhou CRRC Times Electric Co., Ltd.
Bin Liu Zhuzhou CRRC Times Electric UK Innovation Center
Jinfeng Yang Zhuzhou CRRC Times Electric Co., Ltd.
Kai He Zhuzhou CRRC Times Electric Co., Ltd.