مجال
التميز
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تميز دراسي و بحثي
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البحوث المنشورة
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البحث (1):
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عنوان البحث:
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Technical
feasibility study of passive and active cooling for concentrator PV in harsh
environment
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رابط إلى البحث:
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Click
here
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تاريخ النشر:
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15/02/2016
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موجز عن البحث:
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Concentrator PV (CPV) has the potential to replace the expensive
PV material with cheaper optical elements which also enhance the overall
electrical output. The triple junction III-V solar cells are integrated with
CPV systems as they are more efficient, have a better response to high
concentration, and lower temperature coefficient. However, using high solar
concentration ratios will increase the solar cell surface temperature which
is inversely proportional to the PV electrical efficiency. This work investigates
the feasibility of passive and active cooling to maintain a single triple
junction PV cell surface temperature and electrical performance under high
solar concentration in the harsh environment like Saudi Arabia where ambient
temperature can reach up to 50 °C in summertime. To study the feasibility of
passive cooling in such an environment, CPV thermal simulation is undertaken
to examine the performance of two heat sink designs, namely, Round Pin Heat
Sink (RPHS) and Straight Fins Heat Sink (SFHS) under different ambient
temperatures. The simulation reveals that passive cooling using those two
heat sinks with concentration ratio of 500x is insufficient to maintain a
single PV surface temperature below the operational limit set by the
manufacturer, i.e. 80 °C, especially at high ambient temperatures which may
degrade the life of the solar cell. On the other hand, 0.01 m/s water active
cooling simulation results prove its ability to maintain the solar cell
surface temperature around 60 °C and electrical efficiency at 39.5%
regardless of the ambient temperature. Also, the outlet water average
temperature for a single and multiple CPVs were examined and results show
that placing 14 single CPVs above the cooling channel will raise the
temperature to 90 °C which makes the coupling to a single stage absorption
heat pump for cooling demand applicable.
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المؤتمرات العلمية:
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المؤتمر (1):
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عنوان المؤتمر:
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The 6th International Conference on Applied Energy – ICAE2014
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تاريخ الإنعقاد:
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30/05/2014
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مكان
الإنعقاد:
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Taipei. Taiwan
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طبيعة المشاركة:
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Paper presentation
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عنوان المشاركة:
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Performance of Multi Junction
Photovoltaic Cells with High Concentration Ratio in Saudi Arabia
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ملخص المشاركة:
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Concentrating solar radiation on
Photovoltaic (PV) has the potential to replace the expensive PV material with
cheaper optical elements which also enhance the overall electrical output.
The use of high solar concentration ratios with the triple junction III-V
solar cells offers potential of high solar cell efficiency and power output.
However, using high concentration ratios will increase the solar cell surface
temperature which is inversely proportional to the PV electrical efficiency.
This work investigates the effect of cooling on the performance of triple
junction PV cells with high solar concentration (up to 500 suns) in the harsh
environment of Saudi Arabia where ambient temperatures can exceed 50o C in
summer time, but with good clearance index of 0.6 and high yearly solar
radiation of up to 2200 kWh/m2. Simulation results showed that as the
concentration ratio increases, the effect of cooling on the PV efficiency
increases.
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المؤتمر (2):
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عنوان المؤتمر:
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8th Saudi Students’ Conference
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تاريخ الإنعقاد:
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31/01/2015
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مكان
الإنعقاد:
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London.UK
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طبيعة المشاركة:
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Paper presentation
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عنوان المشاركة:
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Alleviating non-uniform illumination of high concentration
Fresnel lens
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ملخص المشاركة:
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Concentrating
Photovoltaic (CPV) has the potential to replace the expensive PV material
with cheaper optical elements. However, non-uniformity of the incident flux
is detrimental to the CPV technology as this tends to cause hot spots and
current mismatch leading to reduced electrical efficiency of the system.
Using advanced ray tracing software, this work investigates the optical
performance of a high concentration ratio Fresnel lens at various distance
from the receiver and groove facet angle. Also, the effect of using a small
square reflector placed above the receiver as a Second Optical Element (SOE)
was investigated. Results showed that a combination of introducing a 60mm
height reflector above the receiver and increasing the distance from the
receiver to 500mm significantly improved the surface illumination uniformity
with minimum loss in received power.
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المؤتمر (3):
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عنوان المؤتمر:
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14th International
Conference on Sustainable Energy Technologies
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تاريخ الإنعقاد:
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25/08/2015
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مكان
الإنعقاد:
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Nottingham.uk
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طبيعة المشاركة:
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Poster presentation
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عنوان المشاركة:
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Improving illumination and temperature distribution uniformity in
high concentrating solar cells
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ملخص المشاركة:
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High concentrating Photovoltaic (HCPV) has the potential to
replace the expensive PV material with cheaper optical elements. The use of
high solar concentration ratios with the triple junction III-V solar cells
offers potential of high solar cell efficiency and power output. However,
non-uniformity of the incident flux is detrimental to the CPV technology as
this tends to cause hot spots and current mismatch leading to reduced
electrical efficiency of the system and degrade the life of the solar cell.
In this work, a point focus Fresnel lens was developed and the influence of
using a small square reflector placed above the PV surface as a Secondary
Optical Element (SOE) in alleviating the non-uniform illumination and
temperature distribution was investigated. Also, the SOE height and material
reflectivity influence on the optical performance was examined. This was done
by implementing optical and thermal simulations using advanced ray tracing
method and Multi-physics finite element software respectively. Incident rays
distribution uniformity was evaluated using the standard deviation from the
mean value. A low standard deviation indicates that most received rays by the
solar cell are close to the mean value i.e. more uniform. Results show that a
combination of introducing a short SOE (60mm) made from 95% reflective
material above the PV and increasing the distance between the PV and the
Fresnel lens (l) to 500mm significantly improve the surface illumination
uniformity. The achieved uniformity standard deviation is less than 3 with
minimum loss in received power i.e. 48.25W in case of introducing SOE and
l=500mm compared to 49.07W where receiver placed at focus point.
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المؤتمر (4):
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عنوان المؤتمر:
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9th Saudi Students’ Conference
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تاريخ الإنعقاد:
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13/02/2016
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مكان
الإنعقاد:
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Birmingham.
UK
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طبيعة المشاركة:
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Paper
presentation
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عنوان المشاركة:
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Electrical
performance of high Concentrating Photovoltaic in harsh environment under
passive cooling
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ملخص المشاركة:
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Concentrator
PV (CPV) has the potential to replace the expensive PV material with cheaper
optical elements. However, high solar concentration ratios will increase the
solar cell surface temperature which is inversely proportional to the PV
electrical efficiency. This work investigates the feasibility of passive
cooling to maintain a single CPV electrical power output in harsh environment
like Saudi Arabia where ambient temperature reaches up to 50oC in summer
time. This is done by examining the heat dissipation performance of four
developed heat sinks attached to the back of the PV. Thermal simulation is
undertaken to solve heat conduction, convection, and radiation equations; the
resulted PV surface average temperature is considered in a mathematical model
developed to predict the PV electrical output. The study reveals that by
optimising the heat sink geometry, the CPV electrical power output drop at
high ambient temperature can be reduced from 21% to 6%.
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