Design and optimization of single-phase liquid cooled heat exchangers for electronics cooling

Thermal management has emerged as a key technology driver in developing electronic systems over the years. Conventional cooling methods employing air-cooled heat sinks fall short in providing the required thermal performance in high heat flux electronics. On the other hand, advanced cooling technologies using two-phase liquid cooling need significant development through modeling and experimentation before large scale implementation in various electronics cooling applications. Single-phase liquid cooling bridges this gap and has been widely accepted as the thermal management solution in modern electronic systems. This work focuses on design optimization of these liquid cooled heat sinks for various electronics cooling applications. Design optimization of the single-phase liquid cooled heat exchangers used in electronics systems is essential considering the natural trade-off between the thermal and hydraulic performance along with size and mass, reliability, serviceability, and cost constraints of the thermal management system. Modern design optimization tools for heat exchangers like Topology Optimization often rely on Computational Fluid Dynamics solvers making them computationally expensive and require significant expertise to use. In this study, we overcome these challenges with the high fidelity design optimization methods with a reduced order design optimization tool for internal-channel type heat exchangers using single-phase liquid coolant, which generates optimal designs on a time scale of 60 seconds, making it an ideal candidate as a modeling and thermal optimizer integrated with electrical-device layout automation tools. Optimal designs generated using the reduced order optimizer developed in this work showed a 22 % higher thermal resistance compared to the designs generated using topology optimization. However, the computation time required to generate the topology optimized design was more than 100 times than the proposed reduced order optimizer. The computational efficiency and ability to rapidly generate a series of designs makes a compelling case for the use of the reduced order optimizer for developing electronics cooling heat sinks. Design optimization approaches need to be complemented with practical applications. To gain a deeper understanding of the electronics cooling using single-phase liquid systems, the design of heat sinks for semiconductor devices was considered. We demonstrated the design of polymer-metal hybrid coolers for power converters using Silicon Carbide devices in discrete TO-247 MOSFET packages. Lack of high-performance cooling solutions restricts the use of discrete semiconductors in power converters. The parametric study of design variables and material thermophysical properties performed in this work resulted in the design of heat sinks capable of 75 W/cm2 heat flux dissipation from discrete MOSFET packages. Like the discrete packages, cooling of semiconductors packaged in multi-chip power modules (MCPMs) is demonstrated in this work. Optimization of both the polymer flow manifold features and base plate integrated fins using topology optimization is demonstrated. Comparison of the topology optimized designs with the conventional channel and fin designs shows the superior thermal-hydraulic performance of the topology optimized designs. This work provides insights on the design and optimization methods for single-phase liquid cooled heat exchangers and can be used as a guide for the design of thermal management solutions for electronics systems of tomorrow.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Lad, Aniket Ajay

Contributors dc:contributor

• Miljkovic, Nenad
• King, William P
• Banerjee, Arijit
• Wang, Pingfeng

• Design Optimization
• Reduced Order Modeling
• Pathfinding
• Gradient Based Optimization
• Topology Optimization
• Power Electronics
• Thermal Management

Statement dc:rights

• Copyright 2023 Aniket Ajay Lad

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/122135

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F122135