Abstract: The aim of this research is to design a LHP with low thermal resistance and low condenser temperature. A Self-designed cascade LHP was tested by using biomaterial, sintered copper powder, and aluminum screen mesh as the wick. Using pure water as the working fluid for the first level of the LHP and 96% alcohol as the working fluid for the second level of LHP, the experiments were run with 10W, 20W, and 30W heat input. Experimental result shows that the usage of biomaterial as wick could reduce more temperature at evaporator than by using sintered copper powder and screen mesh up to 22.63% and 37.41% respectively. The lowest thermal resistance occurred during the usage of biomaterial as wick of heat pipe, which is 2.06 oC/W. The usage of cascade system could be applied to LHP to reduce the temperature at condenser and reduced thermal resistance up to 17.6%.
Abstract: Water is essential for life and fresh water is a finite
resource that is becoming scarce day by day even though it is
recycled by hydrological cycle. The fresh water reserves are being
polluted due to expanding irrigation, industries, urban population and
its development. Contaminated water leads to several health
problems. With the increasing demand of fresh water, solar
distillation is an alternate solution which uses solar energy to
evaporate water and then to condense it, thereby collecting distilled
water within or outside the same system to use it as potable water.
The structure that houses the process is known as a 'solar still'. In this
paper, ‘Modified double slope solar still (MDSSS)’ & 'Modified
double slope basin type multiwick solar still (MDSBMSS)' have been
designed to convert saline, brackish water into drinking water. In this
work two different modified solar stills are fabricated to study the
performance of these solar stills. For modification of solar stills,
Fibre Reinforced Plastic (FRP) and Acrylic sheets are used. The
experiments in MDSBMSS and MDSSS was carried on 10
September 2015 & 5 November 2015 respectively. Performances of
the stills were investigated. The amount of distillate has been found
3624 Ml/day in MDSBMSS on 10 September 2015 and 2400 Ml/day
in MDSSS on 5 November 2015.
Abstract: The development of electric vehicle batteries have
resulted in very high energy density lithium-ion batteries. However,
this progress is accompanied by the risk of thermal runaway, which
can result in serious accidents. Heat pipes are heat exchangers that
are suitable to be applied in electric vehicle battery thermal
management for their lightweight, compact size and do not require
external power supply. This paper aims to examine experimentally a
Flat Plate Loop Heat Pipe (FPLHP) performance as a heat exchanger
in thermal management system of lithium-ion battery for electric
vehicle application. The heat generation of the battery was simulated
using a cartridge heater. Stainless steel screen mesh was used as the
capillary wick. Distilled water, alcohol and acetone were used as
working fluids with a filling ratio of 60%. It was found that acetone
gives the best performance that produces thermal resistance of 0.22
W/°C with 50°C evaporator temperature at heat flux load of 1.61
W/cm2.
Abstract: This paper deals with the theoretical and numerical
investigation of magneto hydrodynamic boundary layer flow of a
nanofluid past a wedge shaped wick in heat pipe used for the cooling
of electronic components and different type of machines. To
incorporate the effect of nanoparticle diameter, concentration of
nanoparticles in the pure fluid, nanothermal layer formed around the
nanoparticle and Brownian motion of nanoparticles etc., appropriate
models are used for the effective thermal and physical properties of
nanofluids. To model the rotation of nanoparticles inside the base
fluid, microfluidics theory is used. In this investigation ethylene
glycol (EG) based nanofluids, are taken into account. The non-linear
equations governing the flow and heat transfer are solved by using a
very effective particle swarm optimization technique along with
Runge-Kutta method. The values of heat transfer coefficient are
found for different parameters involved in the formulation viz.
nanoparticle concentration, nanoparticle size, magnetic field and
wedge angle etc. It is found that, the wedge angle, presence of
magnetic field, nanoparticle size and nanoparticle concentration etc.
have prominent effects on fluid flow and heat transfer characteristics
for the considered configuration.
Abstract: Theoretical optimization of a copper-water negative
inclination heat pipe with internal composite wick structure had been
performed, regarding a new introduced parameter: the ratio between
the coarse mesh wraps and the fine mesh wraps of the composite
wick. Since in many cases, the design of a heat pipe matches specific
thermal requirements and physical limitations, this work
demonstrates the optimization of a 1m length, 8mm internal diameter
heat pipe without an adiabatic section, at a negative inclination angle
of -10º. The optimization is based on a new introduced parameter, LR:
the ratio between the coarse mesh wraps and the fine mesh wraps.