Two-Phase Evaporative Cooling Research Proposal - PhD Project

This document presents a PhD research proposal focused on two-phase evaporative cooling technologies, with potential applications in the automotive and power generation sectors. The research aims to investigate fundamental heat and mass transfer processes during pool-boiling and flow-boiling using a high-speed optical diagnostic system. The project involves developing accurate models to predict heat flux and surface temperature distributions. The proposed research seeks to bridge the gap between current needs and system capabilities, examining the use of infrared techniques to measure energy transfer during bubble formation. The study also explores the impact of nanofluids on bubble dynamics and heat transfer, aiming to optimize cooling efficiency. The research includes experimental investigations, model development, and industry collaboration to advance the understanding and application of two-phase evaporative cooling systems. This research is conducted at Loughborough University and includes the researcher's career objective, educational background, and project experience.

Name
Personal Statement
Attaining PhD in thermodynamics is my next major aim. I am interested to research on
the future cooling technique.I thought 2-phase evaporative cooling system techniques might
become a future cooling system that will be used by cars and industries. The proposed research
intended to develop the model to assess the pool boiling and flow boiling heat transfer rates
through the excessive speed optical diagnostic system. This cooling option is considerably more
energy efficient than cooling with refrigerant (standard air conditioning), but it's unsuitable for
all cooling applications. In terms of phases the evaporative cooling occurs in two steps, initial
phase cooling and secondary phase cooling. In the first phase hot air is passed through a heat
exchanger which is cooled by evaporation on the outside of heat exchanger. The air current from
outside of the heat exchanger helps in cooling by convection. In the initial phase the air doesn't
collect any excess moisture. In the second step the air from the heat exchanger is passed through
a water-soaked pad that helps in extra cooling of the air and the air picks up extra humidity. A 2-
phase evaporative cooling system provides cool indoor air that has humidity range of 50%-60%,
while the typical direct evaporative system delivers cool indoor air with humidity range around
70 % .The reason is that 2 phase evaporative cooling system consist of both evaporation and
condensation though heat exchanger, while for the single phase the cold plate helps to ensure the
cooling process.
The majority of people know about siphoned single stage cooling. It's utilized in vehicle
radiators and as cold plates to cool electronic components and automotive systems. In such
frameworks, a liquid, for example, water, ethylene glycol, or a refrigerant is transmitted from a
siphon through a cold plate where it expels the waste warmth from the device. Now the working
fluid at an elevated temperature is carried out to a heat exchanger, where the waste heat is
vanished. After this the working fluid is deployed to a reservoir tank from where it prepares and
proceeds to the next cycle. These systems work effectively in many applications, but for a place
that has significantly high amount of enthalpy then it becomes necessary to have a high amount
of liquid flow rate, which requires larger pumps and consume more power. As the liquid passes
through the cold plate passage, it gains heat. The gain in enthalpy delta T from inlet to outlet is
significant. Two phase evaporative cooling system use the same fundamental components of a

single phase cooling system, but two phase system use only refrigerant as working fluid and no
other. The working fluid is specialized in such a way that it boils as it extract heat from the
surface of a hot device. Boiling process removes more heat (latent heat) than single phase
cooling system. Boiling helps to maintain uniform temperature across the surface. Such
processes of not changing temperature are called isothermal process, the innovation heat control
system helps to maintain the surface of an electronic device uniform, which remains a significant
aspect of devices like laser devices which are highly sensitive due to wavelength emission.
The friendly point about two phases cooling system is that it doesn't require high cooling
rate unlike single phase cooling system due to the presence of the heat control regulators. Such
systems additionally require lower energy that the conventional single phase system. This
application is used in portable pumps of relatively reduced weight removing high loads of heat
improvising the C.O.P. (coefficient of performance). Such pumps are used in compact situation,
it consumes minimal power. In here there is no similar work has been conducted elsewhere on
the same topic using the same methodology. The proposed research intended to decrease the gap
between the present need as well as the capability of the present system. This examination
investigated this issue and uncovered that the infrared strategy can be utilized to properly
measure the amount of energy transmitted under an increasing bubble by vaporizing the micro
layer. Verified research demonstrated that the overheated translucent layer that exists around the
air pocket is the principle vitality hotspot for air pocket development. It was observed that
bubbling warm exchange nucleate began to decay in water-based Nano fluids. The conclusion
was established that a reduction in the static contact point superficially during bubbling as a
result of the collection of nanoparticles produced a more prominent vitality limit for nucleation
which eventually prompted the decrease of air pocket release and thickness of the bubbling
region, which helps to attain decline in temperature.