Experimental Validation and Design Simulations of a Passive Two-Phase Cooling System for Datacenters

2021 ◽  
Author(s):  
Jackson Braz Marcinichen ◽  
Raffaele Luca Amalfi ◽  
Filippo Cataldo ◽  
John Richard Thome
1983 ◽  
Author(s):  
S. Ollendorf ◽  
F. A. Costello

Author(s):  
Oyuna Angatkina ◽  
Andrew Alleyne

Two-phase cooling systems provide a viable technology for high–heat flux rejection in electronic systems. They provide high cooling capacity and uniform surface temperature. However, a major restriction of their application is the critical heat flux condition (CHF). This work presents model predictive control (MPC) design for CHF avoidance in two-phase pump driven cooling systems. The system under study includes multiple microchannel heat exchangers in series. The MPC controller performance is compared to the performance of a baseline PI controller. Simulation results show that while both controllers are able to maintain the two-phase cooling system below CHF, MPC has significant reduction in power consumption compared to the baseline controller.


1983 ◽  
Author(s):  
Robert H. Hamasaki ◽  
Janet L. Abe ◽  
James L. Franklin

Author(s):  
Jackson B. Marcinichen ◽  
John R. Thome ◽  
Raffaele L. Amalfi ◽  
Filippo Cataldo

Abstract Thermosyphon cooling systems represent the future of datacenter cooling, and electronics cooling in general, as they provide high thermal performance, reliability and energy efficiency, as well as capture the heat at high temperatures suitable for many heat reuse applications. On the other hand, the design of passive two-phase thermosyphons is extremely challenging because of the complex physics involved in the boiling and condensation processes; in particular, the most important challenge is to accurately predict the flow rate in the thermosyphon and thus the thermal performance. This paper presents an experimental validation to assess the predictive capabilities of JJ Cooling Innovation’s thermosyphon simulator against one independent data set that includes a wide range of operating conditions and system sizes, i.e. thermosyphon data for server-level cooling gathered at Nokia Bell Labs. Comparison between test data and simulated results show good agreement, confirming that the simulator accurately predicts heat transfer performance and pressure drops in each individual component of a thermosyphon cooling system (cold plate, riser, evaporator, downcomer (with no fitting parameters), and eventually a liquid accumulator) coupled with operational characteristics and flow regimes. In addition, the simulator is able to design a single loop thermosyphon (e.g. for cooling a single server’s processor), as shown in this study, but also able to model more complex cooling architectures, where many thermosyphons at server-level and rack-level have to operate in parallel (e.g. for cooling an entire server rack). This task will be performed as future work.


2019 ◽  
Vol 163 ◽  
pp. 114338 ◽  
Author(s):  
Fengze Hou ◽  
Wenbo Wang ◽  
Hengyun Zhang ◽  
Cheng Chen ◽  
Chuan Chen ◽  
...  

1992 ◽  
Vol 114 (3) ◽  
pp. 290-299 ◽  
Author(s):  
C. O. Gersey ◽  
I. Mudawar

Boiling experiments were performed with FC-72 on a series of nine in-line simulated microelectronic chips in a flow channel to ascertain the effects of channel orientation on critical heat flux (CHF). The simulated chips, measuring 10 mm × 10 mm, were flush-mounted to one wall of a 20 mm × 5 mm flow channel. The channel was rotated in increments of 45 degrees through 360 degrees such that the chips were subjected to coolant in upflow, downflow, or horizontal flow with the chips on the top or bottom walls of the channel with respect to gravity. Flow velocity was varied between 13 and 400 cm/s for subcoolings of 3, 14, 25, and 36°C and an inlet pressure of 1.36 bar. While changes in angle of orientation produced insignificant variations in the single-phase heat transfer coefficient, these changes had considerable effects on the boiling pattern in the flow channel and on CHF for velocities below 200 cm/s,’ with some chips reaching CHF at fluxes as low as 18 percent of those corresponding to vertical upflow. Increased subcooling was found to slightly dampen this adverse effect of orientation. The highest CHF values were measured with near vertical upflow and/or upward-facing chips, while the lowest values were measured with near vertical downflow and/or downward-facing chips. These variations in CHF were attributed to differences in flow boiling regime and vapor layer development on the surfaces of the chips between the different orientations. The results of the present study reveal that, while some flexibility is available in the packaging of multi-chip modules in a two-phase cooling system, some orientations should always be avoided.


Author(s):  
Tie Jun Zhang ◽  
Yoav Peles ◽  
John T. Wen ◽  
Michael K. Jensen

Because of increasing power densities, refrigeration systems are being explored for two-phase cooling of ultra high power electronic components. Flow instabilities are potential problems in any two-phase refrigeration cooling system especially in transient applications. Oscillatory two-phase flow in a boiling channel can trigger transition to the critical heat flux (CHF). Active control methods can help better dynamic thermal management of electronic systems, even though transient two-phase boiling flow mechanisms are complicated. This paper presents a framework for the transient analysis and active control of pressure-drop flow instabilities under varying imposed heat loads. The first part of the paper is to study the external effects on boiling flow characteristics and the boiling oscillatory flow responses to transient heat load changes. Then based on the theoretical analysis of boiling flow oscillations, a set of active control schemes are developed and studied to suppress flow oscillations and, therefore, to increase the CHF. With the available control devices (i.e., inlet valve and supply pump), different active control schemes are studied to improve the transient two-phase cooling performance. Finally, a discussion is included to address potential future research.


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