30120130406007

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 6, November - December (2013) © IAEME

AND TECHNOLOGY (IJMET)

ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 4, Issue 6, November - December (2013), pp. 55-63
© IAEME: www.iaeme.com/ijmet.asp
Journal Impact Factor (2013): 5.7731 (Calculated by GISI)
www.jifactor.com

IJMET
©IAEME

DESIGN AND ANALYSIS OF PARABOLIC DISH COLLECTOR’S
EFFICIENCY UNDER DIFFERENT SEASONS IN BHOPAL (M.P)
1

Ajay Vardhan,

1

A.C. Tiwari,

2

Sunil Hotchandani,

3

Arvind Kaushal

1

2

University Institute of Technology-RGPV, Bhopal (M.P.)-462001
Department of Civil Engineering (Environment Engineering), Bhagwant University,
Ajmer (Raj)-305009
3
Samrat Ashok Institute of Technology, Vidisha (M.P.)-464001

ABSTRACT
Concentrated Solar Power (CSP) harnesses the sun’s solar energy to produce electricity. This
report provides a technical analysis of the potential for CSP to provide low cost renewable electricity
in Bhopal (M.P.) and outlines the impact of different seasons on Collector’s efficiency. Yields of
CSP Plants depend strongly on site-specific meteorological conditions. Meteorological parameters
that can influence the performance of CSP plant are Direct Normal Irradiance (DNI), wind, ambient
air temperature and humidity. The concentrated solar thermal power system constructed for this
system follows that of conventional design of a parabolic concentrator with the receiver place along
the line between the center of the concentrator and the sun. For the current system, with a C.R. of 77,
the concentrator is theoretically capable of producing temperature upwards to 658 degrees
centigrade. This study investigates the potential for our intervention to accelerate the deployment of
small-scale concentrated solar power (CSP) in various parts of Bhopal (M.P.)
Keywords: Concentrated Solar Power (CSP), DNI-Direct Normal Irradiance, Insolation,
Concentration Ratio (CR)
INTRODUCTION
The basic principle of solar thermal collection is that when solar radiation is incident on a
surface (such as black body) a part of this radiation is absorbed and causes to increase the
temperature of the surface. The typical solar flux concentration ratio typically obtained is at the level
of 30–100, 100–1000, and 1000–10000 for trough, tower and dish systems, respectively. The solar
radiation incident on the Earth’s surface is comprised of two types of radiation- beam and diffuse,
ranging in the wavelengths from the ultraviolet to the infrared (300 to 200 nm), which is
characterized by an average solar surface temperature of approximately 6000 degree Kelvin. The
55


amount of this solar energy that is intercepted is 5000 times greater than the sum of all other inputs –
terrestrial, nuclear, geothermal and gravitational energies and lunar gravitational energy.
When dealing with solar energy, there are two basic choices. The first is photovoltaics, which is
direct energy conversion that converts solar radiation to electricity. The second is solar thermal, in
which the solar radiation is used to provide heat to a thermodynamic system, thus creating
mechanical energy that can be converted to electricity. In commercially available photovoltaic
system, efficiencies are on the order of 10 to 15 percent, where in a solar thermal system, efficiencies
as high as 30 percent are achievable. This work focuses on the electric power generation of a
parabolic concentrating solar thermal system
PARABOLIC GEOMETRY
A parabola is the locus of points that moves equal distance from a fixed line and a fixed
point. As shown in Fig.1, the fixed line is called the directory and the fixed point is the focus F. The
line perpendicular to the directory and passing through the focus F is called the axis of the parabola.
The parabola intersects its axis at a point V which called the vertex, which is exactly midway
between the focus and the directory.

Fig.1 Parabolic Geometry
EXPERIMENTAL APPARATUS AND PROCEDURES
1. Introduction
This work was focused on the development of a system for converting incoming solar
radiation to electrical energy. The system concentrated the incoming solar radiation to power a
thermal cycle in which the energy was converted to mechanical power, and subsequently to electrical
power. This chapter contains a description of this system and a detailed explanation of how the
individual components of the system work. The design, implementation, and testing of the system
were conducted at the University Institute of Technology, RGPV, Bhopal, Madhya Pradesh.
2. Solar Collector
To obtain the high temperatures necessary, a concentrating solar collector is needed due to
solar radiation being a low entropy heat source. The type chosen was that of the parabolic „dish
type. The parabolic dish is a 3.99 meter diameter Channel Master Satellite dish.The dish consists of
six fiberglass, pie- shaped, sections which are assembled together to form the parabolic structure of
the dish
‟

56


3. The Receiver
The receiver of the solar concentrator system serves as the boiler in the Rankine cycle, thus it
needed to be able to handle high temperatures. This first generation receiver was designed with
simplicity in mind for characterization of the system. An external type receiver was decided upon for
use with the concentrator. The basis behind the design of the receiver was a standard D-type boiler,
with a mud (water) drum, steam drum, and down-corners. Because of the extreme temperatures
expected at the focal region, in excess of 900 K, the outer housing of the receiver was constructed of
stainless steel. The receiver consists of a stainless steel cylindrical water drum and two sets of
stainless steel coils housed within a stainless steel welded tube. The outer shell of the boiler is 250m
long and 195m in diameter, with an internal volume of 3.245 liters. The water drum is 38.1 mm (1.5
in) tall and 133.5 mm (5.25in) in diameter, with a volume of 0.0402 liters. The inner coils consists of
25.4mm (1/4 inch) stainless steel tubing, one set coiled within the other, with the outer and inner
coils consisting of fourteen windings with a diameter of 133.35 mm (5.25in) and six windings with a
diameter of 63.5 mm (2.5in), respectively.
The outer shell is filled with a molten salt into which the water drum and coils are
submerged. The molten salt is known as Draw Salt, which consists of a 1:1 molar ratio of Potassium
Nitrate (KNO3 – 101.11 grams per mol) and Sodium Nitrate (NaNO3 – 84.99 grams per mol). There
is a total of 19.39 Moles of Draw Salt in the thermal bath; The Draw Salt serves as latent heat storage
to allow for continuous heat transfer in the case of intermittent cloud cover and for equal thermal
distribution over the water drum and the coils. The receiver is set up to record the inlet, outlet, and
thermal bath temperatures, along with the outlet steam pressure. Three stainless steel sleeved K-type
thermocouples, with ceramic connectors, are used for temperature measurements.
The thermocouples are located at the inlet and exit of the receiver to measure the incoming water and
exiting steam temperature. The third thermocouple is submerged halfway into the thermal Draw Salt
bath. Figure shows the location of the thermocouples on the receiver. With the receiver assembled, it
was then placed at the focal region of the concentrator. The supporting structure for the receiver and
the area of the receiver not subject to concentrated solar intensity was then covered with Kaowool
Superwool insulation;
4. Steam Turbine
It was decided that a single stage impulse turbine would best meet the system requirements of
simplicity and use in developing areas. Design plans were purchased from Reliable Industries, Inc.
for the T-500 turbine.
5. Working Fluid of Solar Thermal System
Since the design of this system was to be kept as simple as possible, water was chosen as the
working fluid. If the system were set up off-grid in a field, then a well could be used to supply water
for the solar thermal system. In the event that a water-well is unavailable, as was the case here, a
reservoir for the water is needed. A steel constructed tank, with a capacity of 13 litres (approx. 3.43
gallons) is used. Because of the conditions for which the system was designed, such as off-grid and
emergency use, the water does not need filtered. However, if the water being used is full of debris,
maintenance of the system will need to be performed more frequently, thus the use of a screen over
the inlet supply line of the pump is suggested, but not necessary.
6. Pump
The water is supplied to the system from the tank by use of a Fluid-O-Tech pump located on
the underside of the dish. The pump has a small foot print, with the motor having dimensions of
127mm * 114 mm * 109 mm, and the controller, 93 mm * 115 mm * 83mm. The pump has variable
speed and power settings, ranging from speeds of 1000 rpm to 3500 rpm, and power settings from 30
57


percent to 85 percent. The pump runs off of 100 volt to 110 volt AC, with a maximum power usage
of 250 Watts. The power setting on the pump has no affect on the flow rate; it affects the amount of
pressure that the pump can overcome at a particular speed. The speeds of the pump, however,
directly correspond to the flow rate; the pump is designed for longevity by having an absence of
moving parts within the motor, with only a short single shaft inside the pump. The control unit of the
pump utilizes a double protection system on the circuit board, with a thermal „cutout to protect the
pump and control unit from overheating and current protection for moments of high current peaks
caused by overload or seizure of the pump. The original design of the pump was for espresso coffee
machines, reverse osmosis system, cooling systems, circuit washing, and/or solar heating systems,
thus it was deemed ideal for use in the solar thermal system discussed in this work.
‟

7. Tracking
Tracking of the parabolic dish is done by a combination of satellite dish linear actuators and
photo-sensing control units that are commercially available. Due to the need for two axis tracking,
two heavy duty linear actuators were used. The actuator for altitude tracking was a SuperJack Pro
Brand HARL3018, and the azimuth actuator is a SuperJack Pro Brand VBRL3024. The HARL3018
is a medium duty model, rated for a dynamic load of 600lbs, with an 18 inch stroke length equipped
with limit switches. The VBRL3024, a heavy duty actuator, is rated at a dynamic load of 1500 lbs,
with a 24inch stroke length and is also limit switch equipped. The heavy duty model was required for
the azimuth tracking because of the East and West directional extremes required of the actuator.
Each actuator requires 12 to 36 volts and up to 7.5 amps, depending on loading, for operation.
8. Data Acquisition
Temperature and pressure had to be constantly monitored and logged throughout the day for
numerous days to be able to characterize the solar thermal system. A data acquisition system was
implemented in order to avoid having to manually log these values by hand. The data acquisition
system consisted of a Windows XP based personal computer, and a National Instruments Signal
Conditioning Board (SCB-68). The PC used a Lab VIEW-based program named Surya after the
Hindu Sun god, to acquire the temperatures of interest from the solar thermal system. The program
displayed the data for quick reference of system operation throughout the day, and it logged all of the
measurements with a stamp of when the data was acquired.
9. Power Supply
Although the system is designed to produce power, some power must be consumed in order
to do so. Power was needed for the linear actuators for positioning of the dish, as well as for
operation of the pump. This power was being provided by two 12-volt, valve regulated, deep cycle
batteries. The batteries were wired in series to increase the voltage to 24 volts for control of the
tracking.
10. Generator/Alternator
In order to produce electrical power from the system, a generator has to be coupled with the
output shaft of the steam turbine. The generator used was a 443541-10Amp Permanent Magnet DC
Generator from Wind stream Power LLC. The generator is capable of producing power at speeds
ranging from 0 to 5000 rpm at voltages between 12 and 48 volts. Maximum power production for
this particular generator, for 12, 24 and 48 volts is 120,240 and 480 watts, respectively.

58


ANALYSIS/RESULTS
Formula use for design of collector and analysis
1. Area of collector
Surface area of concentrator is calculated by: ‫ܣ‬௖௢௡௖௘௡௧௥௔௧௢௥ ൌ
Where

஽మ

ܲ ൌ ଼ு

ଶగ
ଷ௉

Where D is diameter of the collector
And d is the depth of the collector
4. Area of receiver
5. Area of base given by

஽మ

‫ܨ‬ൌ

ଷ

െ ܲଷ ൩

గ

ଵ଺ௗ

‫ܣ‬௥௘௖௘௩௘௥ ൌ ‫ܣ‬௕௔௦௘ ൅ ‫ܣ‬௦௜ௗ௘
‫ܣ‬௕௔௦௘ ൌ

గௗ మ
ସ

‫ܣ‬௦௜ௗ௘ ൌ ߨ݄݀௥

6. Area of the side given by
For Solar calculation

δs ൌ 23.45 sin ቂ360

7. Angle of Declination (δs)
8. Solar Altitude angle

൥ටቀ ସ ൅

ܲଶ ቁ

‫ܣ‬௔ ൌ ସ ൈ ‫ ܦ‬ଶ

2. Aperture area of solar collector/concentrator Aa
3. Focal length of collector F

஽మ

ଶ଼ସା୒ౚ
ଷ଺ହ

ቃ

Sin (αs) = sin(L) sin(δs) + cos(L) cos(δs) cos(hs)
ି‫ܖܑܛ‬ሺ‫ ܛܐ‬ሻ ‫ܛܗ܋‬ሺ઼‫ ܛ‬ሻ
‫ܛܗ܋‬ሺહ‫ ܛ‬ሻ

9. Azimuthal angle γz

γz =

10. Sun rise and Sun set angle

Cos(hss) = -tan(L)tan(δs)

11. Time from solar noon

Tsn = hss × ௗ௘௚௥௘௘

ସ௠௜௡

12. Sunrises = 12 - Tsn
13. Sunset 12 + Tsn
14. Length of the day

DL = 2

௛ೞೞ

ଵହ

೏೐೒
೘೔೙

For Radiation calculations
15. Incident angle (i)
Cos(i) = cos(ߙ௦ ).cos(ߛ௭ െ ߛ௪ ).sin(ߚ௣ ) + sin(ߙ௦ ). cos(ߚ௣ )
For collector facing the sun
The panel tilt angle ߚ௣ is same as the solar altitude angle ߙ௦ i.e ߚ௣ ൌ ߙ௦ and

Panel azimuthal angle ߛ௪ is same as solar azimuthal angleߛ௭ i.e ߛ௪ ൌ ߛ௭

16. Extraterrestrial radiation (Io)

ே

೏
‫ܫ‬௢ ൌ ‫ܫ‬௦௖ ቂ1 ൅ 0.034 cos ቀ360 ଷ଺ହቁቃ

షೖ

17. Terrestrial solar radiation at normal incidence (Ibn)
‫ܫ‬௕௡ ൌ ‫ܫ‬௢ ݁‫݌ݔ‬౩౟౤ ഀೞ
Value of k taken from the table 1.1
18. Radiation incident on the collector ࡵ࢈ࢉ
‫ܫ‬௕௖ ൌ ‫ܫ‬௕௡ ܿ‫݅ ݏ݋‬
59


19. Diffuse radiation ࡵࢊࢉ

ఈ

‫ܫ‬ௗ௖ ൌ ‫ܥ‬௔௩௘௥௔௚௘ ൈ ‫ܫ‬௕௡ ܿ‫ ݏ݋‬ቀ ೞ ቁ

Value of C taken from the table 1.1

ଶ

‫ܥ‬௔௩௘௥௔௚௘ = 0.058

ଶ

‫ܫ‬௖௧ ൌ ‫ܫ‬௕௖ ൅ ‫ܫ‬ௗ௖

20. Total isolation ࡵࢉ࢚
Efficiency Calculations
21. Energy losses from the receiver Qloss
ܳ௟௢௦௦ ൌ ‫ܣ‬௥ ܷ௟ ሺܶ௜௡௡௘௥ ௥௘௖௘௩௘௥ ൅ ܶ௔௜௥ ሻ Watt
22. Energy absorber by the receiver
ܳ௢௣௧௜௖௔௟ ൌ ‫ܣ‬௔ ߩߙ߬‫ܫݏ‬௕ି௖ watt

23. Total thermal energy produce by the solar collector is calculated by
Qout = ܳ௢௣௧௜௖௔௟ െ ܳ௟௢௦௦ watt
ߟ௖௢௟௟௘௖௧௢௥ ൌ

24. Efficiency of collector

Table 1.1 Average value of optical depth (k) and sky diffuse factor (C)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct

Sky diffuse
factor ‘C’
optical depth ‘k’

0.05

Nov Dec

0.06

0.07

0.09

0.12 0.13 0.13 0.12 0.09 0.07 0.06 0.05

0.14 0.14

0.15

0.18

0.19 0.20 0.20 0.20 0.17 0.16 0.14 0.14

0.25

0.2

0.15
Sky diffuse factor (C)
0.1

Atmospheric optical depth
(k)

0.05

Dec

Nov

Oct

Sep

Aug

Jul

Jun

May

Apr

Mar

Jan

0
Feb

Month

ொ೚ೠ೟

஺ೌ ூ್೎

Fig.2 variation of sky diffuse factor (C) and Atmospheric optical depth (k)

60


Calculating efficiency of collector with location:
Latitude (L) =23.28oN,

Longitude (Llong) =77.35oE

MONTH
No. of day(Nd)
Hour angle (hs)
Declination angle (δs)
Altitude angle (αs)
Azimuthal angle (ࢽz)
Sun rise and sun set angle (hss)
Time from solar noon (TSN)
(HH:MM:SS)
Sunrise (HH:MM:SS)
Sunset (HH:MM:SS)
DL (HH:MM:SS)
Incidence angle Cos (i)
Optical depth (k)
Diffuse factor (C)
Extraterrestrial radiation (Io)
W/m2
Terrestrial radiation Ibn W/m2
Beam radiation Ibc (W/m2)
Diffuse radiation Idc (W/m2)
Total insolation Ict (W/m2)
Outer temp. Touter (K)
Inner temp. Tinner (K)
Ambient temp. Tambient (K)
Velocity of wind V (m/s)
Energy loss Qloss (Watt)
Optical energy Qoptical (Watt)
Energy out Qout (Watt)
ࣁcollector (%)

JANUARY
1
0
-23.01
44.06
0
79.47
5:17:52

APRIL
112
0
11.92
78.17
0
95.21
6:20:50

JUNE
173
-30
23.44
62.48
0.97
100.75
6:43:00

AUGUST
229
30
13.12
59.74
-0.96
95.75
6:23:10

OCTOBER
295
60
-12.10
21.53
-0.91
84.70
5:38:49

6:42:50
17:17:00
10:35:42
0.99
0.14
0.05
1398.99

5:43:90
18:20:50
12:41:40
0.40
0.18
0.097
1336.90

5:17:24
18:24:36
13:26:00
0.918
0.20
0.13
1307.61

5:36:58
18:22:48
12:46:00
0.87
0.20
0.12
1320.96

6:43:12
17:16:48
11:17:36
0.682
0.16
0.07
1369.45

1145.39
1133.94
-38.40
1095.53
900
293
293
4.1
999.19
8186.00
7186.81
86.91

1116.67
448.13
4.46
452.59
900
305
302
1.75
615.55
3235.08
2619.53
80

1038.94
850.89
-34.07
816.81
900
370
305
6.52
282.44
6142.64
5860.20
94.44

1049.54
913.10
-126.86
786.24
900
400
297
2.83
1882.88
6591.77
5638.45
86.68

890.83
608.22
-28.39
579.82
900
450
299
2.36
1790.32
4390.78
2591.69
58.43

Declination angle
(δs)
40
20
0
-20
-40

Standard meridian (Lsm)=75o

Altitude angle (αs)
100
80
60
40
20
0

Declinatio
n angle
(δs)

Fig.3 variation of Declination angle (δs)

Altitude
angle (αs)

Fig.4 variation of Altitude angle (αs)

61


Azimuthal Angle

Sun rise and sun set
angle (hss)

1.5
1

120
100
80
60
40
20
0

0.5
Azimuthal
Angle

0
-0.5

Sun rise
and sun
set angle
(hss)

-1
-1.5

Fig.5 variation of Declination angle ࢽz

Fig.6 variation of Sun rise and Sunset angle

Total insolation Ict
(W/m2)

COLLECTOR'S
EFFICIENCY

Fig.7 Variation of Total insolation

OCTOBER

AUGUST

JUNE

COLLECTO
R'S
EFFICIENC
Y

APRIL

1200
1000
800
600
400
200
0
JANUARY

OCTOBER

AUGUST

JUNE

APRIL

JANUARY

100
80
60
40
20
0

Total
insolation
Ict (W/m2)

Fig.8 variation of collector efficiency

From the above equations
1.
2.
3.
4.

Surface area of concentrator A concentrator is 8.05m2
Aperture area of concentrator Aaperture is 7.29m2
Focal length of collector ‘F’ is 1.14m.
Area of receiver 0.11m2

CONCLUSION
This paper determines the influence of different seasons on collector’s efficiency of CSP. We can
conclude that the collector’s efficiency is maximum in month of June at hour angle -30 degree (10
AM) and move from the month June to October efficiency of collector’s subsequently decreases due
to decreases in temperature.

62


REFERENCES
1.

H. Clifford K and K. Gregory J, “Incorporating Uncertainty into Probabilistic Performance
Models of Concentrating Solar Power Plants,” Journal of Solar Energy Engineering, vol. 132,
Aug. 2010
2. Wagner, M., and C Kutscher. 2010. The Impact of
3. Hybrid Wet/Dry Cooling on Concentrating Solar Power Plant Performance. In Proceedings of
the 4th International Conference on Energy Sustainability, ASME. Arizona, USA.
4. Barea, J., Sara, M., and. Silva,M. 2010. Analysis of the influence of the monthly distribution
of direct normal radiation in the production of parabolic trough plants using EOS. In
Proceedings of SolarPACES 2010. Perpignan, France.
5. Remund, J., Wald, L , Lefèvre, M , Ranchin, T and Page, J 2003. Worldwide Linke turbidity
information. In Proceedings of the ISES Solar World Congress 2003. Göteborg, Sweden
6. Hoyer-Klick, C., Hustig,F., Schwandt, M.and Meyer,R., 2009. Characteristic Meteorological
Years from Ground and Satellite Data. In Proceedings of SolarPACES 2009. Berlin, Germany.
7. Bella, E., Ramirez, L., Drews, A., Beyer, H.G., Zarzalejo, L.F.., J. Polo, and Martin, “Analysis
of different comparison parameters applied to solarline radiation data from satellite and
German radiometric stations,” Solar Energy, vol. 83 (2009), Jul. 2008, pp. 118–125.
8. Dharmendra Waiker and Dr. A. C. Tiwari, “An Investigation on Inclination Steam Flowing
Tubes on Steam Condensation in a Thermal Power Plant”, International Journal of Mechanical
Engineering & Technology (IJMET), Volume 3, Issue 2, 2012, pp. 437 - 446, ISSN Print:
0976 – 6340, ISSN Online: 0976 – 6359.
9. Prakash Kumar Sahu and Prof.Dr.A.C.Tiwari, “Implement of Solar Energy in Thermal Power
Station for Increase Sensible Heat of Makeup Water for Save the Conventional Energy, A
Review & Case Study”, International Journal of Mechanical Engineering & Technology
(IJMET), Volume 3, Issue 3, 2012, pp. 180 - 186, ISSN Print: 0976 – 6340, ISSN Online:
0976 – 6359.
10. Ramnarayan Sahu, Dr. A.C.Tiwari and Anupama Yadav, “Implementation of Preventive
Maintenance Program in Thermal Power Station: A Review and Case Study”, International
Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012,
pp. 685 - 692, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.

63

30120130406007

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to 30120130406007

Similar to 30120130406007 (20)

More from IAEME Publication

More from IAEME Publication (20)

Recently uploaded

Recently uploaded (20)

30120130406007