UWE Bristol Engineering showcase 2015

Joshua Giffin
BEng – Mechanical Engineering
Project Supervisor
Rohitha Weerasinghe
DESIGN OF A PRODUCT CAPEABLE OF UTILISING COMPUTER WASTE HEAT
Introduction
The computer industry is a very large one with the vast majority of people using them daily. Such computers generate and output heat due to
inefficiency's. My project is based around designing a component to utilize this waste heat converting it back into useable power. This component is
designed to be set up and left within a computer case, charging reusable battery's overtime, these can be detached and taken around with the user to
charge devices on the go.
While it is true that almost all components within a computer that run on electricity generate heat, it’s clear that the main heat emitting components
within modern computers are the CPU and GPU, due to the fact that in comparison to the other components they need much more power in order to
operate, after initially looking at ways to capture and utilise the heat from each component individually, I discovered water-cooling and started creating a
design capable of utilising the heat from all components as it’s being transferred through a water-cooling loop.
Concept
This project investigates and leads to the design of a closed loop design that has similarity's
with the Rankine cycle. The design consists of a shell and tube heat exchanger that transfers
heat into the closed loop design from the computers water-cooling loop, a generator to take
advantage of generated velocity's and a water-cooling radiator to cool the coolant , allowing
pressure differentials to occur and movement within the loop to occur.
Background Research
My initial research was into computers and their main heat
emitting components. This lead me into water-cooling
designs and hence ultimately to my final design idea.
I was then able to look into and determine values such as
the water-cooling loops mass flow rate alongside average
ambient / computer running temperatures. Which were
later used within the heat exchanger design process.
Heat Exchanger Design
An eight step design process was used to design the heat exchanger, this started off with
me specifying the mass flow rate and each flows inlet and outlet temperatures which were
determined by research and logical evaluation. A shell and tube design was used due to it
being compact, this feature ties in nicely with this design due to the limited space available.
Following this the LMTD correction factor was determined. I decided to I chose to use a
staggered flow pipe design over an in-line design due to the fact that staggered flow
designs create more turbulence, something my design logically does not have much of due
to low flow speeds and compact spaces. Turbulence will theoretically help my design
transfer heat more efficiently.
Further Work
Future work for this project includes additional investigations into generators alongside optimizations in order to improve how much
power can be generated over a given time period. Additionally, methods of velocity manipulation could be investigated and if suitable
implemented into the design.
Project summary
The project revolved around the design of a
component that is capable of generating
useable power over time, this component is
to be set up within a computer case and run
using a computers waste heat.
Project Objectives
• The component is to be designed to take
advantage of the current mounting system
within computer cases, that are otherwise
used for attaching radiators or fans.
• To fully investigate all factors that would
impact my design, including; mass flow rate
of a computers water-cooling loop,
standard pipe sizing's, heat dissipation
techniques in a small area.
• Design of a closed loop system, that
involves a heat exchanger, generator and
cooling system, in order to run in a similar
fashion to the Rankine cycle.
• To have the fluid flow throughout my
design naturally through pressure
differentials due to temperature changes.
Project Conclusion
In conclusion, the conducted background
research and investigations have been
informative and successful ultimately leading
me to my current design, involving a heavily
optimized heat exchanger that is well suited,
size and performance wise to being used with
computer cases after many iterations and
optimizations throughout the process.