ABSTRACT: – The solar energy in Iraq is available, but till now little application for using it. The parabolic trough solar collector (PTSC) technology, which considers being one of the low-cost and most operative technologies for solar power plant. In the present work, the performance of a PTSC with solar tracking system has been experimentally investigated under Kut city (Iraq) climate conditions. The experimental work focused on changing horizontal axis, it started with (0o, 30o, 60o) receptively. The angle zero represents an east direction, then rotate toward the south. Instantaneous efficiency was employed in this study to evaluate the thermal performance of the PTSC system. The study process was completed by using equation engineering solver (EES). The results showed that Kut city holds a good potential for such energy generation technology with an average efficiency of 38.8% and instantaneous efficiency that can reach as high as 70% This study highly encourage the Iraq government to invest in the PTSC technology in the southern region of Iraq to meet the increasing demand on electric power. The experimental concerned about the change of axis with angle. The best efficiency is zero angle which represents the east direction.
Keywords: Solar; PTSC; EES; Solar tracking.
1. INTRODUCTION
Solar energy is the major source of energy, it is the friend of the environment. The earth receives during one hour an amount of energy that can meet the global energy consumption for almost a year “this is about 5000 times the input to the earth’s energy budget from all other sources.
Recently, technologies have been developed to control and manage the application of clean energy to keep the sustainability requirement of the world and prevent or reduce the climate change. It can be used for electricity production and solar heating, thus by collecting the sun’s radiation through solar collectors. The researchers studied different type of PTSC experimentally and theoretically for fixed and sun tracking system. Pradeep et al. (1) Experimented work of PTSC with a solar tracking system for mirror and aluminum parabolic trough. The result certainly showed the intensity of radiation for the mirror system intensified when compared to Aluminum. The performance of PTSC depends mainly on water mass flow rate, and there was no significant change when the mass flow rate becomes more than ten kilograms per hour (2). Dudley et al. (3) derived theoretically equation with experimentally work of PTSC. The efficiency of PTSC has been calculated as well as the thermal losses. The work conducted on two types of absorber. Three different receiver configurations; glass envelope with either vacuum or air in the receiver annulus, and glass envelope removed from the receiver. They concluded the enhance performance when the cermet selective coating with envelope and vacuum annulus. Valan and Samokumer (4) developed a computer simulation program for modeling a parabolic trough collector with a hot water generation system with a storage tank. The modelling was validated with experimental work which has been achieved. The result showed the efficiency of the simulation was greater than six percent of experimental efficiency. Umamaheswaran (5) presented a study of PTSC for desalination application. It submitted details and analysis of PTSC for cleaning water purpose. He concluded at available solar energy can use it for purification of water. Iraq is considered the second level of solar exposure radiation, the annual averaged of energy received daily from the sun ranges between 4.5 – 5.4 kWh/m2 thus; Iraq is most suitable for solar applications (6). Tadahmun (7) conducted experimental work with simulated modelling for fixed parapolic trough collector. It found the performance of collector in cold season little better than hot season. Also no effect mass flowrate after 40 kg/hr on efficiency. Adel et al. (8) studied and investigated the performance of PTSC, solar heating and cooling systems. They conducted the system had more effort for domestic application. The efficiency enhanced by reducing heat transfer losses by adjusting the parameter of collector.
The crisis of energy with the increasing in oil prices, the awareness to use alternate energy sources, including solar energy, has gained momentum in Iraq.
2. THERMAL ANALYSIS OF PTSC
The generalized thermal analysis of a concentrating solar collector is similar to that of a flat-plate collector. Thermal losses from the absorber must be estimated, usually in terms of the loss coefficient, UL, which is based on the area of the absorber. The calculations must include radiation, conduction, and convection losses. The loss coefficient considering convection from the surface through the support structure is given by:
UL=hw+hr,r_a (1)
The radiation heat transfer coefficient between absorber tube and ambient can be written in equation as:
hr,r_a=εσ(Tr+Ta)(Tr^2+Ta^2 ) (2)
The convection heat transfer coefficient between absorber and ambient air due to the wind can be calculated as:
hw=Nu(a)k(a)/Do (3)
Nu(a)=0.3Re(a)^0.6 For 1000 < Re (a) <50000 (4)
And the convection heat transfer coefficient is given as:
hc,i=k*Nu/Di (5)
The Nusselt number can be used:
Nu=3.6+0.0668[(Di/L)*Re*pr]/((1+0.04[(Di/L)*Re*pr]^(2/3) ) ) (6)
The efficiency of the PTSC is given by: THE EFFICIENCY OF PARAPOLIC TROUGH SOLAR COLLECTOR WITH DIFFERENT HORIZONTAL AXIS BY USING TRACKING SYSTEM
Dr. Ali A. F. Al- Hamadani
Lecturer, Mechanical Engineering Dep.
Eng. Coll.- University of Wasit
Email: alirudhaengmec@uowasit.edu.iq
ABSTRACT: – The solar energy in Iraq is available, but till now little application for using it. The parabolic trough solar collector (PTSC) technology, which considers being one of the low-cost and most operative technologies for solar power plant. In the present work, the performance of a PTSC with solar tracking system has been experimentally investigated under Kut city (Iraq) climate conditions. The experimental work focused on changing horizontal axis, it started with (0o, 30o, 60o) receptively. The angle zero represent east direction then rotate toward south. Instantaneous efficiency was employed in this study to evaluate the thermal performance of the PTSC system. The study process was completed by using equation engineering solver (EES). The results showed that Kut city holds a good potential for such energy generation technology with an average efficiency of 38.8% and instantaneous efficiency that can reach as high as 70% This study highly encourage the Iraq government to invest in the PTSC technology in the southern region of Iraq to meet the increasing demand on electric power. The experimental concerned about the change of axis with angle. The best efficiency is zero angle which represents the east direction.
Keywords: Solar; PTSC; EES; Solar tracking.
1. INTRODUCTION
Solar energy is the major source of energy, it is the friend of the environment. The earth receives during one hour an amount of energy that can meet the global energy consumption for almost a year “this is about 5000 times the input to the earth’s energy budget from all other sources.
Recently, technologies have been developed to control and manage the application of clean energy to keep the sustainability requirement of the world and prevent or reduce the climate change. It can be used for electricity production and solar heating, thus by collecting the sun’s radiation through solar collectors. The researchers studied different type of PTSC experimentally and theoretically for fixed and sun tracking system. Pradeep et al. (1) Experimented work of PTSC with a solar tracking system for mirror and aluminum parabolic trough. The result certainly showed the intensity of radiation for the mirror system intensified when compared to Aluminum. The performance of PTSC depends mainly on water mass flow rate, and there was no significant change when the mass flow rate becomes more than ten kilograms per hour (2). Dudley et al. (3) derived theoretically equation with experimentally work of PTSC. The efficiency of PTSC has been calculated as well as the thermal losses. The work conducted on two types of absorber. Three different receiver configurations; glass envelope with either vacuum or air in the receiver annulus, and glass envelope removed from the receiver. They concluded the enhance performance when the cermet selective coating with envelope and vacuum annulus. Valan and Samokumer (4) developed a computer simulation program to modeling a parabolic trough collector with hot water generation system with a storage tank. The modelling was validated with experimental work which has been achieved. The result showed the efficiency of the simulation was greater than six percent of experimental efficiency. Umamaheswaran (5) presented a study of PTSC for desalination application. It submitted details and analysis of PTSC for cleaning water purpose. He concluded at available solar energy can use it for purification of water. Iraq is considered the second level of solar exposure radiation, the annual averaged of energy received daily from the sun ranges between 4.5 – 5.4 kWh/m2 thus; Iraq is most suitable for solar applications (6). Tadahmun (7) conducted experimental work with simulated modelling for fixed parapolic trough collector. It found the performance of collector in cold season little better than hot season. Also no effect mass flowrate after 40 kg/hr on efficiency. Adel et al. (8) studied and investigated the performance of PTSC, solar heating and cooling systems. They conducted the system had more effort for domestic application. The efficiency enhanced by reducing heat transfer losses by adjusting the parameter of collector.
The crisis of energy with the increasing in oil prices, the awareness to use alternate energy sources, including solar energy, has gained momentum in Iraq.
2. THERMAL ANALYSIS OF PTSC
The generalized thermal analysis of a concentrating solar collector is similar to that of a flat-plate collector. Thermal losses from the absorber must be estimated, usually in terms of the loss coefficient, UL, which is based on the area of the absorber. The calculations must include radiation, conduction, and convection losses. The loss coefficient considering convection from the surface through the support structure is given by:
UL=hw+hr,r_a (1)
The radiation heat transfer coefficient between absorber tube and ambient can be written in equation as:
hr,r_a=εσ(Tr+Ta)(Tr^2+Ta^2 ) (2)
The convection heat transfer coefficient between absorber and ambient air due to the wind can be calculated as:
hw=Nu(a)k(a)/Do (3)
Nu(a)=0.3Re(a)^0.6 For 1000 < Re (a) <50000 (4)
And the convection heat transfer coefficient is given as:
hc,i=k*Nu/Di (5)
The Nusselt number can be used:
Nu=3.6+0.0668[(Di/L)*Re*pr]/((1+0.04[(Di/L)*Re*pr]^(2/3) ) ) (6)
The efficiency of the PTSC is given by:
Q_u=m ̇*C_p*(T_fo- T_fi) (7)
η=Q_u/(I_b*A) (8)
Where Ib and A represent solar radiation and area of collector respectively.
3. EXPERIMENTAL WORK
The Figure (1) shows one-axis parabolic trough wuth solar tracking.
According to the size limitation of the highly polished nickel sheet, 2.5 m long, 0.9 m wide and rim angle of 180°, makes the vocal line in place with the cord line. Simple parabolic equation can be applied to solve the above condition, where x is axial to parabolic curve, y is center line of focal, R is radius of parabolic curve, and f is focal line, as shown in Figure 1. The support stand was made of Mild Steel. It consists of ‘L’ and rectangle shaped cross sectioned bars welded together and two ball bearings fixed with the inner race with a rod. The outer race is rotary and mounted in the housing of absorber supporting plate as shown in Table 2. The PTSC parts and automated sun tracking mechanism are integrated, the required assembly configured. The data collected from 11:00 AM to 03:00 PM every day. The PTSC repositioned perpendicular to the sun, the next day and automatically rotated using sun tracking mechanism. The experimental setups used for testing the PTSC’s are shown schematically in Figure (4). In this experiment, fed water from one end of the copper absorber pipe. The temperature of water was measured by using thermometers (model Italy). The PTSC was rotated using a solar tracking of mechanism to keep the sun perpendicular to the absorber pipe. The mass flowrate has been measured. The battery supplies required power to the stepper motor to function. The exact control system (microcontroller) is a circuit exists inside electrical elements with sensors strapped to the light where it receives the signal from these sensors when exposed to sunlight and the circuit converts this signal to the motor of electrical device which drives the direction of the sun, as shown in Figures 5 and 6. A solar cell (or a “photovoltaic” cell) charged the battery as shown in Figure 7 . Solar power meter to measure the intensity of the radiation is shown in Figure (9). Solar energy radiation sensors fitted on the aperture of the collector send electric signals to the motor which, in turn, adjust the position of the dish until maximum solar radiation intensity is received at the aperture. The change of axis of the system was taken with three angles (0o,30o,60o).
4. EES PROGRAM
Engineering Equation Solver (EES) is a powerful scientific program. It also contains the thermophysical properties of many common substances used in thermal science application. Using EES eliminates to search in tables and not need multiple interpolations. This program solved the equation of the system.
5. RESULTS
Testing was done on three different days and different angle. The various results were tabulated and analyzed with graphs. The temperature of water in absorbing pipe using nickel trough collector with tracking system had been measured. Fig-11 show the efficiencies of PTSC for a different angle (from east to west). The efficiency of PTSC with solar tracking was 70%, 35% and 56% for 0o, 30o and 60o respectively. Thus the efficiency of zero angle is higher than another, however, the increasing trend because the tracking system is suitable with 0o for more efficient to get more radiation. Fig-12 show the radiation of PTSC for a different angle (from east to west). It is shown the radiation of zero angle is the high radiation, but the other angle is low radiation this increasing in radiation due to the direction of solar radiation is vertical on the system at zero angle at all times. but the other angles the solar radiation disnot vertical at the all times. The clouded sky is causing the scatter data and not continuous curve. The inlet and outlet temperature of steam for different angles as shown in Fig. 13. The temperature of the collector started as highat angle zero and increased gradually, it reached 28 oC. The study performance of the collector canbe justified by the stability of the climate condition throughout the day. Figure (13): Shows the efficiency of (PTSC) increase with increase in mass flow rate of water (23 – 34 kg/hr). It is due to the fact that more mass flow rate of water relatively will give more energy, but after 26.5 kg/hr the efficiency not increase. Figure (14): The variation of efficiency for PTSC with and without tracking with a different mass flow rate of water has been plotted. It is observed that the efficiency of (PTSC) with tracking is higher than of fixed (PTSC); however, the increasing trend because the tracking system will follow the sun with more solar radiation. Figure (15): The experimental results are plotted, to show the variation of heat transfer coefficient for PTSC at 0o and PTSC at 30o.It reveal that the heat transfer coefficient at 0o in more than at 30o, It is due to fact that at 0o works better.
6. CONCLUSIONS
The application of solar energy for PTSC with solar tracking system can be used in Kut city, as a result of the availability of solar energy around more 700 W/m2 . The change was starting zero angle which is represented (east-west), after that (30o,60o) respectively. The experimental concerned about the change of axis with angle the work started with (0o,30o,60o) respectively. The efficiency of these angles is investigated, then it compared between it.I found from my experiment the optimum zero angle is which represent the east direction.
References
[1]- Pradeep Kumar K V1, Srinath T., Venkatesh Reddy “Design, Fabrication and Experimental Testing of SolarParabolic Trough Collectors with Automated Tracking Mechanism’’.international journal of research in aeronautical and mechanical engineering, Vol.1, Issue.4,August, 2013. pp: 37-55.
[2]- Faik A. Hamad, “The Performance Of Cylindrical Parabolic Solar Concentrator’’,Solar Energy Res., Vol. 5, No. 2, Basrah, Iraq, 1987. pp:1-19,.
[3]- V.E. Dudley, G.J. Kolb, A.R. Mahoney, T.R. Mancini, C.W. Matthews, M. Sloan, D. Kearney, “Test results: SEGS LS-2 solar collector, Report of Sandia National Laboratories (SANDIA-94-1884)’’, 1994.
[4]- A. Valan Arasu, S. T. Sornakumar, “Theoretical Analysis And Experimental Verification off Parabolic Trough Solar Collector With Hot Water Generation System’’’،’THERMAL SCIENCE, Vol. 11, No. 1, 2007.pp:119-126,.
[5]- Umamaheswaran M.. “Solar Based Distillation System for Domestic Application”, Ninth International Water Technology Conference, IWTC9, Sharm El-Sheikh, Egypt, 2005.
[6]- NASA. “Surface Meteorology and Solar Energy – Available Table” Atmospheric science Data Center, US., 2008.
[7] Tadahmun . A . Y “Experimental and Theoretical study of a parabolic Trough Collector” AJES, VOL .5 , NO .1. 2012.
[8] Adel .A. G, Adel. M.M and Kindle .M .K “Performance Analysis of Parabolic Trough collector in Hot Climate”, Journal of applied science and Technology 4(14),2014.pp:2038-2058
Table (1): Nomenclature
C
D
h
I
K
L
Nu
Pr
Ra
T
Heat capacity, kJ/Kg oC
Diameter
heat transfer coefficient, W/m2.oC
Solar radiation W/m2
Thermal conductivity of fluid, W/m.oC
Length, m
Nusselt number
Prandtl number
Rayliegh number
Temperature oC Greek symbol
σ Stefan Boltzmann, 5.67E-8 W/m2 oC4
ɛ Emissivity, 0.90
Subscripts
i Inner
o Outer
fo Outlet fluid
fi Inlet fluid
b Beam
c Convection
r radiation
p Pressure
u Useful
Table (2): PTSC system specifications
ITEM Value Type
Mode of tracking E-W horizontal
Collector aperture area 2.25 m2
Collector aperture 0.9 m
Aperture to Length ratio 2.5 m
Tracking mechanism type Electronic
Inner diameter of the absorber pipe 2.5 cm
Outer diameter of the absorber pipe 2.9 cm
Length of the absorber pipe 230 cm
Fig.(1) : One-Axis tracking parabolic trough
Fig.(2): parabolic trough solar collectortrator
Fig.(3) : micro controller and block Diagram of the microcontroller
Fig.(4) : Solar cells and Battery
Fig.(5) the efficiencies of CPS for different angle (from east to west).
Fig.(6): The radiation of CPS for different angle (from east to west).
Fig.(7): The difference of temperature for different PTSC
Fig.(8): variation of thermal efficiency of collector with mass flow rate at angle zero
Fig.(10): variation of experimental thermal efficiency with hours of summer days
Fig.(11): variation of heat transfer coefficient for PTSC at 0 ^0and PTSC at 30 ^0
الكفائة’ ‘لمجمع’ ‘شمسي’ ‘ذي’ ‘قطع’ ‘مكافئ’ ‘بأختلاف’ ‘الاحداثي’ ‘الأفقي’ ‘وباستخدم’ ‘معقب’ ‘شمسي
علي’ ‘عبد’ ‘الرضا’ ‘فرحان
مدرس
قسم’ ‘الهندسة’ ‘الميكانيكية’-‘كلية’ ‘الهندسة’-‘جمعة’ ‘واسط
الخلاصة
الطاقة’ ‘الشمسية’ ‘متوفرة’ ‘في’ ‘العراق’ ‘لكن’ ‘تطبيقاتهاقليلة’. ‘البحث’ ‘يتناول’ ‘دراسة’ ‘عملية’ ‘لمجمع’ ‘شمسي’ ‘ذي’ ‘قطع’ ‘مكفئ’ ‘مع’ ‘منظومة’ ‘تعقب’. ‘البحث’ ‘تم’ ‘في’ ‘الظروف’ ‘الجوية’ ‘لمدينة’ ‘الكوت’-‘العراق’. ‘الكفائة’ ‘الحرارية’ ‘والانية’ ‘تم’ ‘توضيفها’ ‘لمعرفة’ ‘الاداء’ ‘الحراري’ ‘لجهاز’. ‘الاحداثي’ ‘الافقي’ ‘تم’ ‘تغييره’ ‘للجهاز’ ‘وللزوايا’ 0’،’30’،’60 ‘حيث’ ‘ان’ ‘الزاوية’ ‘ضفر’ ‘تمثل’ ‘الشرق’ ‘ومن’ ‘ثم’ ‘التدوير’ ‘باتجه’ ‘الجنوب’. ‘النتائج’ ‘بينت’ ‘ان’ ‘مدينة’ ‘الكوت’ ‘جيدة’ ‘لتوليد’ ‘الطاقة’ ‘الكهربائية’ ‘وان’ ‘كفائة’ ‘الجهاز’ 38.8% ‘والكفائة’ ‘الانية’ 70%. ‘النتائج’ ‘مشجعة’ ‘للتطبيقات’ ‘الشمسية’ ‘في’ ‘هذه’ ‘المنطقة’ ‘لسد’ ‘النقص’ ‘في’ ‘الطلب’ ‘على’ ‘الطاقة’. ‘النتائج’ ‘العملية’ ‘وضحت’ ‘ان’ ‘اضل’ ‘زاوية’ ‘هي’ ‘الصفر’.
الكلمات’ ‘الدلالية’:- ‘الشمسي،المجمع’ ‘الشمسي،المعادلات’ ‘الهندسية،’ ‘المعقب’ ‘الشمسي
Q_u=m ̇*C_p*(T_fo- T_fi) (7)
η=Q_u/(I_b*A) (8)
Where Ib and A represent solar radiation and area of collector respectively.
3. EXPERIMENTAL WORK
The Figure (1) shows one-axis parabolic trough with solar tracking.
According to the size limitation of the highly polished nickel sheet, 2.5 m long, 0.9 m wide and rim angle of 180°, makes the vocal line in place with the cord line. Simple parabolic equation can be applied to solve the above condition, where x is axial to parabolic curve, y is center line of focal, R is radius of parabolic curve, and f is focal line, as shown in Figure 1. The support stand was made of Mild Steel. It consists of ‘L’ and rectangular shaped cross sectioned bars welded together and two ball bearings fixed with the inner race with a rod. The outer race is rotary and mounted in the housing of absorber supporting plate as shown in Table 2. The PTSC parts and automated sun tracking mechanism are integrated, the required assembly configured. The data collected from 11:00 AM to 03:00 PM every day. The PTSC repositioned perpendicular to the sun, the next day and automatically rotated using sun tracking mechanism. The experimental setups used for testing the PTSC’s are shown schematically in Figure (4). In this experiment, fed water from one end of the copper absorber pipe. The temperature of water was measured by using thermometers (model Italy). The PTSC was rotated using a solar tracking of mechanism to keep the sun perpendicular to the absorber pipe. The mass flowrate has been measured. The battery supplies required power to the stepper motor to function. The exact control system (microcontroller) is a circuit exists inside electrical elements with sensors strapped to the light where it receives the signal from these sensors when exposed to sunlight and the circuit converts this signal to the motor of electrical device which drives the direction of the sun, as shown in Figures 5 and 6. A solar cell (or a “photovoltaic” cell) charged the battery as shown in Figure 7 . Solar power meter to measure the intensity of the radiation is shown in Figure (9). Solar energy radiation sensors fitted on the aperture of the collector send electric signals to the motor which, in turn, adjust the position of the dish until maximum solar radiation intensity is received at the aperture. The change of axis of the system was taken with three angles (0o,30o,60o).
4. EES PROGRAM
Engineering Equation Solver (EES) is a powerful scientific program. It also contains the thermophysical properties of many common substances used in thermal science application. Using EES eliminates to search in tables and not need multiple interpolations. This program solved the equation of the system.
5. RESULTS
Testing was done on three different days and different angle. The various results were tabulated and analyzed with graphs. The temperature of water in absorbing pipe using nickel trough collector with tracking system had been measured. Fig-11 show the efficiencies of PTSC for a different angle (from east to west). The efficiency of PTSC with solar tracking was 70%, 35% and 56% for 0o, 30o and 60o respectively. Thus the efficiency of zero angle is higher than another, however, the increasing trend because the tracking system is suitable with 0o for more efficient to get more radiation. Fig-12 show the radiation of PTSC for a different angle (from east to west). It is shown the radiation of zero angle is the high radiation, but the other angle is low radiation this increasing in radiation due to the direction of solar radiation is vertical on the system at zero angle at all times. but the other angles the solar radiation disnot vertical at the all times. The clouded sky is causing the scatter data and not continuous curve. The inlet and outlet temperature of steam for different angles as shown in Fig. 13. The temperature of the collector started as highat angle zero and increased gradually, it reached 28 oC. The study performance of the collector canbe justified by the stability of the climate condition throughout the day. Figure (13): Shows the efficiency of (PTSC) increase with increase in mass flow rate of water (23 – 34 kg/hr). It is due to the fact that more mass flow rate of water relatively will give more energy, but after 26.5 kg/hr the efficiency not increase. Figure (14): The variation of efficiency for PTSC with and without tracking with a different mass flow rate of water has been plotted. It is observed that the efficiency of (PTSC) with tracking is higher than of fixed (PTSC); however, the increasing trend because the tracking system will follow the sun with more solar radiation. Figure (15): The experimental results are plotted, to show the variation of heat transfer coefficient for PTSC at 0o and PTSC at 30o.It reveal that the heat transfer coefficient at 0o in more than at 30o, It is due to fact that at 0o works better.
6. CONCLUSIONS
The application of solar energy for PTSC with solar tracking system can be used in Kut city, as a result of the availability of solar energy around more 700 W/m2 . The change was starting zero angle which is represented (east-west), after that (30o,60o) respectively. The experimental concerned about the change of axis with angle the work started with (0o,30o,60o) respectively. The efficiency of these angles is investigated, then it compared between it.I found from my experiment the optimum zero angle is which represent the east direction.
References
[1]- Pradeep Kumar K V1, Srinath T., Venkatesh Reddy “Design, Fabrication and Experimental Testing of SolarParabolic Trough Collectors with Automated Tracking Mechanism’’.international journal of research in aeronautical and mechanical engineering, Vol.1, Issue.4,August, 2013. pp: 37-55.
[2]- Faik A. Hamad, “The Performance Of Cylindrical Parabolic Solar Concentrator’’,Solar Energy Res., Vol. 5, No. 2, Basrah, Iraq, 1987. pp:1-19,.
[3]- V.E. Dudley, G.J. Kolb, A.R. Mahoney, T.R. Mancini, C.W. Matthews, M. Sloan, D. Kearney, “Test results: SEGS LS-2 solar collector, Report of Sandia National Laboratories (SANDIA-94-1884)’’, 1994.
[4]- A. Valan Arasu, S. T. Sornakumar, “Theoretical Analysis And Experimental Verification off Parabolic Trough Solar Collector With Hot Water Generation System’’’،’THERMAL SCIENCE, Vol. 11, No. 1, 2007.pp:119-126,.
[5]- Umamaheswaran M.. “Solar Based Distillation System for Domestic Application”, Ninth International Water Technology Conference, IWTC9, Sharm El-Sheikh, Egypt, 2005.
[6]- NASA. “Surface Meteorology and Solar Energy – Available Table” Atmospheric science Data Center, US., 2008.
[7] Tadahmun . A . Y “Experimental and Theoretical study of a parabolic Trough Collector” AJES, VOL .5 , NO .1. 2012.
[8] Adel .A. G, Adel. M.M and Kindle .M .K “Performance Analysis of Parabolic Trough collector in Hot Climate”, Journal of applied science and Technology 4(14),2014.pp:2038-2058
Table (1): Nomenclature
C
D
h
I
K
L
Nu
Pr
Ra
T
Heat capacity, kJ/Kg oC
Diameter
heat transfer coefficient, W/m2.oC
Solar radiation W/m2
Thermal conductivity of fluid, W/m.oC
Length, m
Nusselt number
Prandtl number
Rayliegh number
Temperature oC Greek symbol
σ Stefan Boltzmann, 5.67E-8 W/m2 oC4
ɛ Emissivity, 0.90
Subscripts
i Inner
o Outer
fo Outlet fluid
fi Inlet fluid
b Beam
c Convection
r radiation
p Pressure
u Useful
Table (2): PTSC system specifications
ITEM Value Type
Mode of tracking E-W horizontal
Collector aperture area 2.25 m2
Collector aperture 0.9 m
Aperture to Length ratio 2.5 m
Tracking mechanism type Electronic
Inner diameter of the absorber pipe 2.5 cm
Outer diameter of the absorber pipe 2.9 cm
Length of the absorber pipe 230 cm
Fig.(1) : One-Axis tracking parabolic trough
Fig.(2): parabolic trough solar collectortrator
Fig.(3) : micro controller and block Diagram of the microcontroller
Fig.(4) : Solar cells and Battery
Fig.(5) the efficiencies of CPS for different angle (from east to west).
Fig.(6): The radiation of CPS for different angle (from east to west).
Fig.(7): The difference of temperature for different PTSC
Fig.(8): variation of thermal efficiency of collector with mass flow rate at angle zero
Fig.(10): variation of experimental thermal efficiency with hours of summer days
Fig.(11): variation of heat transfer coefficient for PTSC at 0 ^0and PTSC at 30 ^0
الكفائة’ ‘لمجمع’ ‘شمسي’ ‘ذي’ ‘قطع’ ‘مكافئ’ ‘بأختلاف’ ‘الاحداثي’ ‘الأفقي’ ‘وباستخدم’ ‘معقب’ ‘شمسي
علي’ ‘عبد’ ‘الرضا’ ‘فرحان
مدرس
قسم’ ‘الهندسة’ ‘الميكانيكية’-‘كلية’ ‘الهندسة’-‘جمعة’ ‘واسط
الخلاصة
الطاقة’ ‘الشمسية’ ‘متوفرة’ ‘في’ ‘العراق’ ‘لكن’ ‘تطبيقاتهاقليلة’. ‘البحث’ ‘يتناول’ ‘دراسة’ ‘عملية’ ‘لمجمع’ ‘شمسي’ ‘ذي’ ‘قطع’ ‘مكفئ’ ‘مع’ ‘منظومة’ ‘تعقب’. ‘البحث’ ‘تم’ ‘في’ ‘الظروف’ ‘الجوية’ ‘لمدينة’ ‘الكوت’-‘العراق’. ‘الكفائة’ ‘الحرارية’ ‘والانية’ ‘تم’ ‘توضيفها’ ‘لمعرفة’ ‘الاداء’ ‘الحراري’ ‘لجهاز’. ‘الاحداثي’ ‘الافقي’ ‘تم’ ‘تغييره’ ‘للجهاز’ ‘وللزوايا’ 0’،’30’،’60 ‘حيث’ ‘ان’ ‘الزاوية’ ‘ضفر’ ‘تمثل’ ‘الشرق’ ‘ومن’ ‘ثم’ ‘التدوير’ ‘باتجه’ ‘الجنوب’. ‘النتائج’ ‘بينت’ ‘ان’ ‘مدينة’ ‘الكوت’ ‘جيدة’ ‘لتوليد’ ‘الطاقة’ ‘الكهربائية’ ‘وان’ ‘كفائة’ ‘الجهاز’ 38.8% ‘والكفائة’ ‘الانية’ 70%. ‘النتائج’ ‘مشجعة’ ‘للتطبيقات’ ‘الشمسية’ ‘في’ ‘هذه’ ‘المنطقة’ ‘لسد’ ‘النقص’ ‘في’ ‘الطلب’ ‘على’ ‘الطاقة’. ‘النتائج’ ‘العملية’ ‘وضحت’ ‘ان’ ‘اضل’ ‘زاوية’ ‘هي’ ‘الصفر’.
الكلمات’ ‘الدلالية’:- ‘الشمسي،المجمع’ ‘الشمسي،المعادلات’ ‘الهندسية،’ ‘المعقب’ ‘الشمسي