Unified Liquid Cooling Heat Solution

The objective of this Senior Design project is to design a thermal management system for a multi-kilowatt, multi-phase, power converter based around a unified thermal core with liquid cooling. This will require that the semiconductor transistor dies to be removed from the normal packaging found in a commercial device to maximize heat transfer to the thermal core and into the coolant. We will adapt a heat sink to the newly configured shape and use math models and simulation to fine the optimum design. After completion of this modeling we will be manufacturing a sink and then using experimental methods to determine the best option for our Heat sink to properly manage the systems waist heat as efficiently as possible.

Problem Statement
The objective of this Senior Design project is to design a thermal management system for a multi-kilowatt, multi-phase, power converter based around a unified thermal core with liquid cooling. –Rachel Peterson

The first phase of the process will be designing a heat sink to fit within the constraints for the thermal and physical properties defined by board configuration and MOSFET placement.

The second phase will be focused around testing for the purpose of refining heat dissipation, functionality, and efficiency.

Project Goals
Our Project Goals are to Complete a robust heat removal system to fit within the constraints required by the project. We will design the heat sink to be able attach securely to the MOSFETS with a pressure of at least 10 PSI.The current goal is to explore natural convection if this is not feasible forced convection will be explored. We hope to be able to manufacture the Heat sink in house, but will evaluate all options. In addition we will preform tests and gather on the various sinks both as simulation and in an experimental capacity, with the aim of finding the optimum solution.

Heat Sink CAD Design
We began my making various solidmodels of our heat sink based on the mechanical specifications. We ended up with 4 basic models which we presented at the Snapshot day. We tried to maximize the surface are of the heat sink while deceasing the weight and making it machinable. Currently two of these models, the triangular design and crossed fin design, are being simulated as potential candidates. If favorable data is found then machining will begin on each model.

We have since narrowed down our designs to include the Triangular Sink Design and the Cross Hatched Sink Design.

Heat Sink Math Modeling and Simulations
We began by creating models to determine how much heat the sinks would need to draw as well as how air would flow through them. Grad student Rachel Peterson has been modeling these designs and helping us determine there eligibility as working heat sinks.

Manufacturing
After choosing our Final Two Air Cooled Heat Sink Designs we began to finalize there drawing and determine how we would manufacture them

Triangular Heat sink
We began with the triangular heat sink using a slitting saw.

Slotted Heat Sink
We looked at the Slotted heat sink as the

Drilled Heat Sink
We were partway through machining our first air cooling system

Experimental Designs
For our experimentation we plan to a combination of thermocouples and thermal imaging cameras to best test how well the Heat sink operates within the system. We plan to encase the the board and sink and using a controlled environment model how well each Heat sink works. Models such as the one shown bellow have been made modeling the case fort the experimental design

Liquid Cooling Option
There is a possibility that we may switch to using a liquid cooled system if we don't get favorable results with our air cooled system. we have begin looking into the alternative of a liquid cooled system and how we might implement one into our system. There are various considerations that need to be taken into account if we switch to a liquid cooling system.These are: Mass Considerations- Switching to a liquid cooling system will greatly increase our weight. We plan to try to choose a design that minimizes our added weight and stays within our limit. Leak considerations- liquid cooling has a much greater risk of issues like leaks and pump failure. We plan to make sure everything stands up to durability testing. Size considerations- there is an added increase in size with new components being added. We plan to redesign the case to compensate for this increase in size and minimize it. Thermoelectric generator considerations- If excess cooling capacity is achieved a Thermoelectric generator may be added to convert waist heat to power. Will design case to integrate generator design and minimize size effects.

Document Archive
Documents (Schedule, Meeting Minutes, Presentations,ect)