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Latent heat thermal energy storage is one of the most efficient ways to store the thermal energy for heating air by energy received from the sun. This project is investigation and analysis of thermal energy storage incorporating with phase change materials (PCM) and integrated solar collector plate for use in solar air heater. The integrated collector storage (ICS) concept is applicable as direction in increasing the economic feasibility and more attractive for space heating, cooling in domestic, agricultural and industrial applications in buildings, solar applications, off-peak energy storage, and heat exchanger improvements. It focuses mostly on applications involving a reduction of electric power consumption. A system of this combines collection and storage of thermal energy in a single unit. Compared with the other conventional domestic air heating system, the integrated collector heating system has the more advantage of simplicity, both in erection and in operation. The thermal performance of this solar air heater with phase change material and integrated collector plate are more than conventional type because large surface area for heat transfer is obtained. When the sun ray falls on the solar collector plate, the panel or surface area is responsible for the amount of heat storage. This heat energy is transferred with the help of aluminium fins to the stored paraffin wax which is used as a latent heat storage system. In this project reflector plate with stand and paraffin wax is used. The latent heat storage capacity of paraffin wax is more. So that the amount of heat energy is increased with the help of this reflector. Due to this more amount of heat energy the difference of inlet air temperature and outlet air temperature is more, so that high temperature of hot air is obtained and efficiency of collector plate is increased. This improved collector efficiency by reducing heat loss to the environment, and help achieve an overall efficiency, which accosts of pumping loss for moving air through the collector.TRANSCRIPT
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
ISSN: 2349-8862
www.ijsres.com Page 50
Experimental Investigation Of Forced Circulation Solar Air Heater
Along With Integrated Solar Collector And Phase Change Material
(Paraffin Wax)
Mr. Kaushal Kishore
M.Tech student
Prof. (Dr.) S. C. Roy
HOD and Professor
Prof. J. N. Mahto
Prof. R. S. Prasad
Assistant Professor in Department of Mechanical
engineering, BIT Sindri
Abstract: Latent heat thermal energy storage is one of
the most efficient ways to store the thermal energy for
heating air by energy received from the sun. This project is
investigation and analysis of thermal energy storage
incorporating with phase change materials (PCM) and
integrated solar collector plate for use in solar air heater.
The integrated collector storage (ICS) concept is applicable
as direction in increasing the economic feasibility and more
attractive for space heating, cooling in domestic, agricultural
and industrial applications in buildings, solar applications,
off-peak energy storage, and heat exchanger improvements.
It focuses mostly on applications involving a reduction of
electric power consumption. A system of this combines
collection and storage of thermal energy in a single unit.
Compared with the other conventional domestic air heating
system, the integrated collector heating system has the more
advantage of simplicity, both in erection and in operation.
The thermal performance of this solar air heater with phase
change material and integrated collector plate are more than
conventional type because large surface area for heat
transfer is obtained. When the sun ray falls on the solar
collector plate, the panel or surface area is responsible for
the amount of heat storage. This heat energy is transferred
with the help of aluminium fins to the stored paraffin wax
which is used as a latent heat storage system. In this project
reflector plate with stand and paraffin wax is used. The
latent heat storage capacity of paraffin wax is more. So that
the amount of heat energy is increased with the help of this
reflector. Due to this more amount of heat energy the
difference of inlet air temperature and outlet air temperature
is more, so that high temperature of hot air is obtained and
efficiency of collector plate is increased. This improved
collector efficiency by reducing heat loss to the environment,
and help achieve an overall efficiency, which accosts of
pumping loss for moving air through the collector.
I. INTRODUCTION
Solar energy developed as a means of cheap energy for
Drying grains, fruits, vegetables, tea, and building heating,
space heating, drying for industrial & agriculture purposes.
The increasing need for renewable energy sources, specifically
solar energy, requires that research be conducted to improve
the efficiency of solar systems. Energy storage is not only
plays an important role in conservation the energy but also
improves the performance and reliability of wide range of
energy systems. Solar air heater is a simple device to heat air
by utilizing solar energy. Such heater is implemented in many
applications which require low temperature below 60°C. Solar
air heating (solar collector) is a renewable heating technology
and provides heat using solar energy. With fuel costs and other
factors, solar air heater is getting more attention. The
performance of SAH depends on a number of factors. There
are many advantages of solar air heater systems. Firstly, they
are simple to maintain and design. After the set-up cost, a
solar air heater system has no fuel expenditure. There is less
leakage and corrosion when compared to the systems that use
liquid. It is also an eco-friendly system which has zero
greenhouse gas emissions. It is really cost effective and simple
way to get 75% more power from any ordinary solar panel.
Modern air heater design, focused mainly on improves
conductive heat transfer and absorber plate temperature. Most
of the time a solar panel is working well below peak power,
and when the sun is lower in the sky, early morning and late
afternoon. The light levels are just not so enough. To boost the
sun light level so introduce a mirror or reflector plate to reflect
more Solar irradiation onto the solar collector plate. This is
probably one of the cheapest and easiest ways to boost the
power of a small solar collector plate. The greatest limitations
to increasing the use of conventional collectors are their
relatively low average efficiency and high investment cost.
For this reason, significant research on improving the
efficiency of collector plate has been carried out. It indicate
that the greatest theoretical improvements to the collector
efficiency can be achieved by utilizing internal fins in the
collector plates, reflective surface and phase change material
(paraffin wax). Phase change materials (PCM) are „„Latent
heat‟‟ storage materials. The thermal energy transfer occurs
when a material changes from solid to liquid, or liquid to
solid. Initially, these solid–liquid PCMs perform like
conventional storage materials; their temperature rises as they
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
ISSN: 2349-8862
www.ijsres.com Page 51
absorb heat. Unlike conventional (sensible) storage materials,
PCM absorbs and release heat at a nearly constant
temperature. They store 5–14 times more heat per unit volume
than sensible storage materials such as water etc.
II. LITERATURE REVIEW
O. V. Ekechukwu. et.al [1]
they proposed designs and
performance technique of a flat plate solar energy air heating
collectors for low temperature. The design and construction of
solar air heating collectors at critical to overall performance
for either active or passive solar energy.
Gawlik Keith .et.al[2]
they developed an unglazed,
transparent-plate solar air heater for heating air directly. The
collector temperature was low, relative to systems that
recalculate the air. They used low cost materials like plastic to
reduce the cost of solar air heater.
Jaurker AR et.al[3]
They studied the heat transfer and
friction characteristics of collector plate in solar air heater. At
low flow rates the solar air heater with roughness elements
gives better performance. At high flow rate, the smooth duct
solar air heater had better efficiency.
Cemil Yamal. et.al[4]
They were investigate theoretically
the effect of different system operating conditions like types of
air heater, different design parameters and different weather
condition on a solar air heater. They used Runge-Kutta
method to solve the energy balance equations numerically
with double-pass solar air heater under the same operating
conditions.
E. Zambolin. .et.al [5]
were developed a glazed flat plate
collector usually present a metal absorber in a flat rectangular
housing. The glass covers on the upper surface and the
insulation on the other sides. The solar energy absorbed by the
plate is transferred to the liquid flowing within the collector
plate.
Ljiljana T. Kostic. et.al [6]
they proposed the influence of
reflectance from flat plate solar radiation concentrators made
of Al sheet. With the increase of solar radiation intensity
concentration factor and total daily thermal energy generated
by Thermal collector with concentrators increase.
III. EXPERIMENTAL PROCEDURE
Figure 1: experimental Set up
The solar collector along with its inlet and outlet ducts
was installed at an angle of 20.58º south to the horizontal. A
centrifugal air blower was attached to the inlet and placed with
a voltage regulator so that the inlet air flow rate can be varied
precisely across a wide scale. However, in this test
measurement range was limited to 1.5-4 m/s.
A flow straightener (Triangular) was used at the inlet and
outlet, to guarantee uniform flow into the solar collector. A
pyranometer measuring short wave radiation was connected at
the same slope to as the collector to read solar radiation flux
(W/m2) on the inclined surface.
A hot wire anemometer was installed, and its reading was
taken at several locations across the perpendicular plane to the
flow direction so that an average velocity is measured. This
measurement is used to determine the air flow rate across the
unit.
Reading were obtained for two inlet air temperature
values and two outlet air temperature values, in addition to six
reading of the temperature of the absorber plate at different
location along the length and across the width. These ten
reading were taken by the use of J-Type thermocouple. The
thermocouples were connected to 6-channel thermocouple
amplifier. In addition, another J-type thermocouple was
connected to measure the ambient air temperature. The
pyranometer output reading was converted into a heat flux
using the calibration relation (1mV=129.31W/ as per
specification).
Once the unit was connected, it was left to run for about 2
days before the measurements were taken, in order to
overcome the initial transient effects and to confirm reliable
operation of the unit. Then, the experiment was run at steady
state for a period of 9 days at PG Hostel B.I.T, Sindri.
IV. OBSERVATION AND CALCULATION
The reading was taken for first three days in one mass
flow rate (0.015 Kg/s) and for next three days in second mass
flow rate (0.020 Kg/s) and same for next three days in third
mass flow rate (0.025 Kg/s).Observation was taken from 6:00
am to 5:00 am next day with one hour interval, for 24 hour
(Day and night).
The obtain data with corresponding date are given in
below mentioned tables Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp.
( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 22 23 23 30 30 27 28 33 34 36 36 0
07 28 30 30 38 39 34 36 35 38 42 44 437.551
08 31 32 32 43 44 36 38 40 44 47 49 621.1712
09 37 39 38 49 50 42 44 46 48 52 55 723.3261
10 40 42 43 53 53 47 49 50 52 55 59 772.4639
11 42 45 44 55 56 48 50 52 54 58 61 839.7051
12 45 44 43 57 58 47 50 54 58 60 63 895.3084
13 46 46 45 60 60 49 52 56 60 64 66 969.0151
14 45 44 45 58 58 49 51 55 59 64 64 906.9463
15 44 46 45 52 52 49 50 55 58 62 58 808.6707
16 40 45 45 48 48 49 54 56 58 60 54 716.8606
17 39 43 42 46 46 46 49 52 56 60 52 622.4643
18 38 40 39 45 45 43 46 50 54 57 51 453.0682
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
ISSN: 2349-8862
www.ijsres.com Page 52
19 35 36 37 44 44 41 44 47 50 52 50 0
20 32 32 34 43 43 38 40 42 46 50 49 0
21 29 30 32 43 43 36 38 41 44 48 49 0
22 28 30 30 42 42 34 37 40 42 45 48 0
23 28 28 30 42 42 34 36 39 39 44 48 0
00 27 27 28 42 42 32 34 37 40 44 48 0
01 26 27 27 41 41 31 33 35 38 40 47 0
02 25 26 27 36 36 31 31 35 36 38 42 0
03 23 25 24 32 33 28 30 30 34 36 38 0
04 23 24 22 29 29 26 29 31 33 36 35 0
05 22 23 22 27 27 26 29 33 36 37 33 0
Observation Table1: First Day Mass flow rate (ṁ1) =0.015
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outle
Temp.
( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 25 25 26 31 31 30 33 34 37 39 37 0
07 29 29 29 40 41 33 35 36 40 44 46 456.481
08 34 35 37 48 48 41 45 52 56 50 54 647.0332
09 39 40 41 54 54 45 45 46 50 55 60 652.2056
10 41 42 43 54 55 47 49 52 55 59 60 794.4466
11 42 43 43 56 56 47 50 53 56 60 62 944.4462
12 45 46 47 58 58 51 52 54 56 60 64 824.317
13 46 47 46 60 61 50 54 57 60 63 66 944.4462
14 47 48 47 60 60 51 55 58 62 63 66 837.1189
15 47 46 47 56 56 51 55 59 61 63 62 787.9811
16 44 45 46 52 52 50 52 57 60 62 58 648.3262
17 41 42 44 48 48 48 50 54 57 60 54 468.5854
18 36 37 38 46 46 42 44 47 52 54 52 325.0513
19 33 35 36 44 44 40 42 46 50 52 50 0
20 31 33 34 43 43 38 41 45 46 50 49 0
21 30 32 33 43 43 37 40 44 45 50 49 0
22 29 31 31 42 42 35 38 43 45 47 48 0
23 29 30 31 41 42 35 40 41 42 43 47 0
00 28 30 29 41 43 33 36 40 42 44 47 0
01 26 28 29 39 39 33 35 38 41 43 45 0
02 25 27 28 34 34 32 35 37 39 40 40 0
03 25 27 27 32 32 31 35 36 38 39 38 0
04 24 24 23 29 29 27 30 34 37 37 35 0
05 24 23 24 28 28 28 30 34 34 36 34 0
Observation Table2: Second Day Mass flow rate (ṁ1) =0.015
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp.
( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 23 24 25 29 30 35 35 35 35 37 38 0
07 25 24 26 30 30 33 34 35 35 35 36 511.2577
08 29 30 28 42 42 35 33 34 35 40 40 636.6884
09 32 31 33 46 46 37 38 40 44 43 44 773.757
10 36 36 37 51 53 41 42 46 50 52 57 838.412
11 40 42 42 56 56 46 43 54 56 58 62 928.929
12 44 46 44 59 59 51 54 57 60 63 65 869.4464
13 45 46 45 59 60 56 60 63 64 65 65 878.4981
14 45 44 43 53 53 54 56 58 60 62 59 852.6361
15 43 42 43 48 48 52 55 57 59 61 54 710.3951
16 42 42 41 47 48 49 53 55 58 60 53 569.4472
17 39 40 41 46 46 45 47 51 54 56 52 464.7061
18 36 37 38 46 46 42 44 48 50 53 52 441.4303
19 33 33 35 45 45 39 40 44 48 51 52 0
20 30 30 31 45 45 36 38 41 44 46 48 0
21 29 30 29 43 43 34 36 38 41 42 44 0
22 27 28 28 41 42 34 35 37 38 41 47 0
23 27 28 27 38 37 33 35 37 37 40 44 0
00 25 25 26 34 34 32 34 35 36 38 40 0
01 25 25 25 31 31 32 33 34 35 37 37 0
02 24 24 24 30 30 31 32 33 34 35 37 0
03 24 24 23 3 30 31 32 33 34 34 36 0
04 23 23 24 29 29 30 31 32 33 34 36 0
05 22 22 23 28 28 27 30 32 33 34 34 0
Observation Table3: Third Day Mass flow rate (ṁ1) =0.015
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp.
( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 22 23 22 30 30 26 28 30 30 31 35 0
07 28 28 29 39 39 33 34 36 38 40 44 468.5854
08 32 32 33 45 45 37 38 40 41 44 50 609.5333
09 38 38 39 51 51 43 43 47 49 52 56 678.0676
10 40 40 41 52 52 45 47 49 50 54 57 793.1535
11 43 43 44 55 55 48 50 53 57 58 60 825.481
12 45 45 46 55 56 50 54 56 60 62 61 904.3601
13 46 46 46 56 56 50 53 58 61 62 61 984.5323
14 46 45 45 55 55 49 51 55 58 61 60 939.2738
15 45 46 47 52 52 51 56 60 60 63 57 894.0153
16 44 45 46 49 49 50 52 56 58 60 54 696.171
17 42 42 42 45 45 46 50 53 57 61 50 667.7228
18 39 42 41 43 43 45 47 50 55 58 48 556.5162
19 38 40 39 42 42 43 40 46 54 57 47 0
20 36 37 38 42 42 42 44 48 50 55 47 0
21 34 34 35 41 41 39 41 45 48 48 46 0
22 32 32 33 41 45 37 38 40 44 48 50 0
23 31 32 32 40 40 36 38 40 42 46 45 0
00 29 30 30 40 40 34 35 38 42 45 45 0
01 29 30 30 39 39 34 32 34 37 40 44 0
02 28 29 29 35 35 33 33 36 39 40 40 0
03 24 24 25 31 32 29 30 32 34 37 37 0
04 22 25 25 30 30 29 30 30 34 35 35 0
05 22 24 23 29 29 27 28 30 33 35 34 0
Observation Table4: Fourth Day Mass flow rate (ṁ2) =020
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp. ( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 23 25 24 32 32 28 29 31 31 32 28 0
07 29 29 29 37 37 33 31 34 36 38 33 517.7232
08 31 33 32 44 44 36 36 37 39 44 36 675.4814
09 36 38 37 50 50 41 41 44 47 50 41 723.3261
10 37 41 40 54 54 44 45 47 53 56 44 802.2052
11 39 43 42 56 56 46 49 52 56 58 46 869.4464
12 42 44 43 52 52 47 50 55 57 58 47 892.7222
13 43 45 46 51 51 50 53 56 58 61 50 930.2221
14 43 46 45 48 48 49 52 55 58 60 49 903.067
15 43 43 43 48 48 47 53 56 59 61 47 842.2913
16 39 39 39 44 44 43 52 55 58 60 43 772.4639
17 38 38 38 43 43 42 50 54 56 59 42 658.6711
18 37 37 37 42 42 41 48 50 52 55 41 495.7405
19 36 37 36 41 41 40 44 46 50 52 40 0
20 35 35 36 40 41 40 43 45 46 50 40 0
21 35 35 33 40 40 37 40 42 44 48 37 0
22 32 33 34 40 40 38 40 42 45 47 38 0
23 31 33 33 39 39 37 39 40 44 47 37 0
00 29 30 31 39 39 35 36 39 42 44 35 0
01 28 29 30 36 36 34 36 38 40 41 34 0
02 26 28 28 32 32 32 34 37 39 40 32 0
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
ISSN: 2349-8862
www.ijsres.com Page 53
03 25 26 27 31 31 31 31 34 35 37 31 0
04 25 26 25 30 30 29 30 33 35 37 29 0
05 25 26 24 29 29 28 29 31 34 36 28 0
Observation Table5: Fifth Day Mass flow rate (ṁ2) =0.020
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp. ( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 25 27 26 34 34 30 32 34 37 37 39 0
07 30 30 29 39 39 33 34 36 38 40 44 517.7232
08 35 37 38 47 47 42 43 43 44 46 52 669.0159
09 38 40 41 50 50 45 45 47 49 52 55 755.6536
10 39 42 44 52 52 48 51 52 55 58 57 833.2396
11 39 45 46 56 56 50 52 54 58 60 61 921.1704
12 40 45 44 55 55 48 50 55 58 60 60 914.7049
13 40 45 46 53 53 50 54 56 60 62 58 958.6703
14 41 42 42 48 48 46 55 57 61 63 53 909.5325
15 41 41 41 46 46 45 54 56 58 60 51 855.2223
16 38 38 38 43 43 42 55 57 58 60 48 703.9296
17 35 36 36 41 41 40 50 52 55 58 46 582.3782
18 34 35 35 41 41 39 46 48 49 52 46 503.4991
19 34 34 34 41 41 38 40 42 44 47 46 0
20 33 32 34 40 40 38 39 40 40 42 45 0
21 30 32 32 40 40 36 39 38 40 42 45 0
22 29 30 30 39 39 34 37 37 39 41 44 0
23 28 30 29 39 39 33 35 36 36 39 44 0
00 28 29 30 38 38 34 34 36 38 40 43 0
01 26 28 28 34 34 32 33 35 37 40 39 0
02 25 28 27 31 31 31 33 36 40 41 36 0
03 25 26 26 30 30 30 30 33 34 35 35 0
04 24 26 26 29 30 30 30 31 33 36 35 0
05 24 24 24 29 29 28 30 30 33 35 34 0
Observation Table6: Sixth Day Mass flow rate (ṁ2) =0.020
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp. ( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 22 23 22 27 27 26 26 28 30 31 31 0
07 26 27 28 35 36 32 34 36 38 39 40 489.275
08 31 31 31 40 41 35 36 37 39 43 45 659.9642
09 35 36 35 44 45 39 41 43 44 46 49 806.0845
10 40 41 42 49 50 46 45 45 48 50 54 820.3086
11 43 43 44 53 52 48 49 51 56 56 56 927.6359
12 44 44 45 54 55 49 50 53 55 57 59 931.5152
13 45 45 46 55 55 50 52 55 58 60 59 939.2738
14 45 45 45 54 54 49 50 54 57 58 58 897.8946
15 45 45 45 52 52 49 50 52 55 58 56 800.9121
16 43 44 44 48 48 48 49 53 55 57 52 564.2748
17 41 41 41 45 45 45 46 49 51 55 49 504.7922
18 39 39 39 43 43 43 48 48 50 52 47 450.482
19 37 38 38 41 41 42 46 47 49 51 45 0
20 37 38 38 40 40 42 43 45 48 50 44 0
21 36 37 37 40 40 41 41 43 44 48 44 0
22 36 37 37 39 39 41 39 40 43 47 43 0
23 34 35 35 39 39 39 36 39 41 42 43 0
00 32 33 33 38 38 37 36 37 40 41 42 0
01 29 30 30 35 35 34 35 36 38 40 39 0
02 28 29 29 33 33 33 33 34 36 38 37 0
03 26 27 27 31 31 31 32 34 35 36 35 0
04 25 25 25 30 30 29 30 32 33 34 34 0
05 24 24 25 29 29 29 30 31 33 34 33 0
Observation Table7: Seventh Day Mass flow rate (ṁ3) =0.025
kg/s
Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp. ( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 23 23 23 26 27 27 27 28 29 30 27 0
07 27 28 29 34 34 33 36 36 38 39 33 463.413
08 30 30 31 37 37 35 37 39 40 43 35 610.8264
09 35 36 37 44 46 41 42 44 46 48 41 679.3607
10 41 41 41 48 48 45 49 50 52 54 45 764.7053
11 42 42 42 50 50 46 50 53 56 58 46 839.7051
12 43 43 43 52 52 47 52 54 58 59 47 894.0153
13 44 44 44 53 53 48 53 54 59 60 48 904.3601
14 44 45 45 51 51 49 51 53 56 58 49 840.9982
15 45 45 45 48 48 49 50 52 55 57 49 798.3259
16 41 41 41 45 46 45 48 50 52 55 45 706.5158
17 37 37 37 41 41 41 47 49 51 54 41 640.5677
18 36 36 36 40 40 40 46 47 49 52 40 546.1714
19 34 34 34 40 40 38 43 45 47 50 38 0
20 34 34 34 39 39 38 39 41 45 46 38 0
21 33 33 33 39 39 37 37 38 40 42 37 0
22 33 33 33 38 38 37 34 36 38 40 37 0
23 31 31 31 38 38 35 33 35 37 39 35 0
00 30 31 31 36 36 35 34 37 37 39 35 0
01 28 28 29 33 33 33 33 35 36 38 33 0
02 25 26 26 30 30 30 30 33 36 37 30 0
03 24 24 24 30 31 28 29 30 32 34 28 0
04 24 24 23 27 28 27 28 29 31 33 27 0
05 22 23 22 26 27 26 27 27 29 30 26 0
Observation Table8: Eighth Day Mass flow rate (ṁ3) =0.025
kg/s Time
(hr)
Tamb
( )
Inlet
Temp.
( )
Outlet
Temp. ( )
Absorber plate temperature
( )
Solar
Irradiation
(W/m2)
Ti1 Ti2 To1 To2 TP1 TP2 TP3 TP4 TP5 TP6
06 22 23 22 25 25 26 26 27 28 30 29 0
07 28 29 30 35 35 34 32 36 38 38 39 528.068
08 33 34 36 41 41 40 41 41 42 46 45 566.861
09 37 38 39 45 45 43 42 44 47 50 49 662.5504
10 40 40 40 48 48 44 45 47 50 53 52 809.9638
11 41 42 42 50 53 46 51 52 55 57 57 921.1704
12 42 43 43 53 53 47 52 54 58 60 57 918.5842
13 42 44 44 53 53 48 54 57 60 62 57 956.0841
14 43 43 43 50 50 47 53 54 56 59 54 895.3084
15 43 43 43 46 46 47 52 55 58 61 50 781.5156
16 40 40 40 43 43 44 51 56 58 60 47 581.0851
17 39 40 39 41 41 43 45 49 50 53 45 528.068
18 35 35 36 39 39 40 42 46 48 50 43 463.413
19 32 32 33 39 39 37 41 44 45 46 43 0
20 31 32 33 38 38 37 38 40 42 44 42 0
21 31 32 33 38 38 37 38 39 40 42 42 0
22 30 30 31 37 37 35 37 39 40 43 41 0
23 28 29 30 36 36 34 34 36 38 40 40 0
00 27 28 28 33 33 32 33 36 38 39 37 0
01 26 27 28 31 31 32 33 34 35 37 35 0
02 25 25 27 30 30 31 33 33 36 36 34 0
03 24 25 26 29 30 30 30 31 32 34 34 0
04 23 24 24 28 28 28 30 31 33 32 32 0
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
ISSN: 2349-8862
www.ijsres.com Page 54
05 23 23 23 26 26 27 28 30 32 31 30 0
Observation Table9: Ninth Day Mass flow rate (ṁ3) =0.025
kg/s
Sample Calculation: for second Reading of third day
Data from: Reading
= 25 ºC I = 5.95 mv = (3.95× 129.31)
= 511.25 W/m2
= 25 ºC V= 1.5 m/s
= 30 ºC = 1.175 Kg/m3
= 27.5ºC
Data from: (Data Hand book by Domkundwar &
Domkundwar)
= 1.205 Kg/
= 1.165 Kg/
= 1.167 Kg/
= 1.120 Kg/
= 1.6120× /s
= 0.02647 W/m K
Pr = 0.699
Cp = 1005 J/Kg K
Geometrical Data:
Cross-section Area of duct ( ) = (w × d) = (0.30×0.03) =
0.009
Perimeter of duct = 2(0.30+0.03) = 0.66 m
Panel Area (AP ) = ( l × w ) = (2× 0.30) = 0.6 m2
Equivalent Diameter ( ) = = 0.05454 m
Hydraulic Radius ( ) = = 0.013636 m
ASSUMPTION:
Mass flow rate (ṁ1) of air is taken on average temperature
of flowing air stream at 38.94 ºC.
Mass flow rate (ṁ2) of air is taken on average temperature
of flowing air stream at 38.51 ºC.
Mass flow rate (ṁ3) of air is taken on average temperature
of flowing air stream at 37.16 ºC.
CALCULATION:
1. Mass flow rate (ṁ1) = × V × AC) = 0.015 Kg/s
2. Mass flow rate (ṁ2) = × V × AC) = 0.020 Kg/s
3. Mass flow rate (ṁ3) = × V × AC) = 0.025 Kg/s
4. Reynolds number ( = = = =
5075.434
5. Friction Factor ( ) =
= = 0.038387
6. Nusselt Number (Nu) =
=
=16.81001
7. Convective Heat Transfer Coefficient (h) =
= =
8.2366 W/m2k
8. Efficiency (η) =
= = 24.572%
Time(hrs.)
DAY 1
Re f Nu H
06 5276.239 0.03793 17.40431 8.294172
07 4950.145 0.038686 16.43478 8.068529
08 4872.321 0.038877 16.19992 8.012027
09 4713.989 0.039281 15.71759 7.891648
10 4615.267 0.039543 15.41371 7.814381
11 4567.994 0.039698 15.23626 7.768983
12 4525.847 0.039787 15.13627 7.742631
13 4520.616 0.039712 15.33441 7.794074
14 4525.847 0.039787 15.13627 7.742631
15 4539.636 0.039612 15.33441 7.794074
16 4615.267 0.039543 15.41371 7.814381
17 4628.191 0.039508 15.45363 7.824499
18 4688.786 0.039421 15.61401 7.851713
19 4817.027 0.039016 16.03215 7.971321
20 4879.294 0.038869 16.22141 8.017112
21 4907.392 0.038791 16.30591 8.037553
22 4950.145 0.038686 16.43478 8.068529
23 4950.145 0.038686 16.43478 8.068529
00 4971.804 0.038634 16.49992 8.084162
01 4993.652 0.038581 16.56548 8.09893
02 5075.434 0.038387 16.81001 8.158435
03 5236.559 0.038018 17.28755 8.267847
04 5236.559 0.038018 17.28755 8.267847
05 5276.239 0.03793 17.40431 8.294172
Table 1: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ1
Time(hrs.)
DAY 2
Re f Nu H
06 5075.434 0.038387 16.81001 8.158435
07 4907.392 0.038791 16.30591 8.037553
08 4768.388 0.039141 15.88399 7.933838
09 4628.191 0.039508 15.45363 7.824499
10 4596.017 0.039595 15035416 7.79912
11 4567.994 0.039698 15.23626 7.768983
12 4525.847 0.039787 15.13627 7.742631
13 4520.616 0.039712 15.33441 7.794074
14 4487.864 0.039893 15.01778 7.711343
15 4487.864 0.039893 15.01778 7.711343
16 4539.636 0.039612 15.33441 7.794074
17 4596.017 0.039595 15.35416 7.79912
18 4775.276 0.039122 15.9051 7.93916
19
4830.893
0.038981 16.07 428 7.981808
20 4872.321 0.038877 16.19992 8.012027
21 4886.288 0.0338843 16.24215 8.022207
22 4907.392 0.038791 16.30591 8.037553
23 4907.392 0.038791 16.30591 8.037553
00 4950.145 0.038686 16.43478 8.068529
01 4993.652 0.038581 16.56548 8.09893
02 5075.434 0.038387 16.81001 8.158435
International Journal of Scientific Research and Engineering Studies (IJSRES)
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03 5075.434 0.038387 16.81001 8.158435
04 5228.695 0.038036 17.26436 8.262616
05 5228.695 0.038036 17.26436 8.262616
Table 2: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ1
Time(hrs.)
DAY 3
Re F Nu H
06 5276.239 0.03793 17.40431 8.294172
07 5075.434 0.038387 16.81001 8.158435
08 4907.392 0.038791 16.30591 8.037553
09 4879.294 0.038869 16.22141 8.017112
10 4775.276 0.039122 15.9051 7.93916
11 4615.267 0.039543 15.41371 7.814381
12 4539.636 0.039612 15.33441 7.794074
13 4525.847 0.039787 15.13627 7.742631
14 4525.847 0.039787 15.13627 7.742631
15 4560.616 0.039368 15.61514 7.865618
16 4567.994 0.039698 15.23626 7.768983
17 4628.191 0.039508 15.45363 7.824499
18 4775.276 0.039122 15.9051 7.93916
19 4830.893 0.038981 16.07 428 7.981808
20 4886.288 0.0338843 16.24215 8.022207
21 4907.392 0.038791 16.30591 8.037553
22 4971.804 0.038634 16.49992 8.084162
23 4971.804 0.038634 16.49992 8.084162
00 5075.434 0.038387 16.81001 8.158435
01 5075.434 0.038387 16.81001 8.158435
02 5228.695 0.038036 17.26436 8.262616
03 5228.695 0.038036 17.26436 8.262616
04 5236.559 0.038018 17.28755 8.267847
05 5276.239 0.03793 17.40431 8.294172
Table 3: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ1
Time(hrs.)
DAY 4
Re f Nu H
06 6971.593 0.034874 22.13868 10.59543
07 6667.971 0.035337 21.32259 10.4189
08 6477.911 0.035643 20.80543 10.30353
09 6258.545 0.035812 20.20214 10.16302
10 6303.296 0.036104 20.05566 10.12849
11 6102.569 0.036286 19.76877 10.06082
12 6060.108 0.036363 19.65014 10.03242
13 6042.987 0.036394 19.60223 10.02071
14 6042.987 0.036394 19.60223 10.02071
15 6060.108 0.036363 19.65014 10.03242
16 6170.921 0.036165 19.95914 10.10574
17 6205 .674 0.036135 20.32579 10.19215
18 6348.693 0.035858 20.45092 10.22161
19 6258.545 0.035812 20.20214 10.16302
20 6441.191 0.035703 20.70494 10.28119
21 6487.155 0.035628 20.83071 10.30975
22 6477.911 0.035643 20.80543 10.30353
23 6581.081 0.035575 21.08678 10.36632
00 6619.417 0.035475 21.28678 10.36632
01 6619.417 0.035475 21.28678 10.36632
02 6667.971 0.035337 21.32259 10.4189
03 6888.826 0.034997 21.91741 10.43668
04 6971.593 0.034874 22.13868 10.59543
05 6971.593 0.034874 22.13868 10.59543
Table 4: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ2
Time(hrs.)
DAY 5
Re f Nu H
06 6919.632 0.034951 21.99986 10.56631
07 6619.417 0.035475 21.28678 10.36632
08 6581.081 0.035575 21.08678 10.36632
09 6441.191 0.035703 20.70494 10.28119
10 6413.357 0.035751 20.62863 10.26344
11 6348.693 0.035858 20.45092 10.22161
12 6205 .674 0.036135 20.32579 10.19215
13 6102.569 0.036286 19.76877 10.06082
14 6102.569 0.036286 19.76877 10.06082
15 6102.569 0.036286 19.76877 10.06082
16 6348.693 0.035858 20.45092 10.22161
17 6258.545 0.035812 20.20214 10.16302
18 6413.357 0.035751 20.62863 10.26344
19 6441.191 0.035703 20.70494 10.28119
20 6450.331 0.035688 20.72997 10.28688
21 6450.331 0.035688 20.72997 10.28688
22 6477.911 0.03 5643 20.80543 10.30353
23 6581.081 0.035575 21.08678 10.36632
00 6619.417 0.035475 21.28678 10.36632
01 6667.971 0.035337 21.32259 10.4189
02 6858.292 0.035043 21.83554 10.53263
03 6899.064 0.034982 21.94482 10.55637
04 6899.064 0.034982 21.94482 10.55637
05 6899.064 0.034982 21.94482 10.55637
Table 5: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ2
Time(hrs.)
DAY 6
Re f Nu H
06 6899.064 0.034982 21.94482 10.55637
07 6629.071 0.035399 21.11715 10.39539
08 6450.331 0.035688 20.72997 10.28688
09 6258.545 0.035812 20.20214 10.16302
10 6348.693 0.035858 20.45092 10.22161
11 6348.693 0.035858 20.45092 10.22161
12 6303.296 0.036104 20.05566 10.12849
13 6303.296 0.036104 20.05566 10.12849
14 6231.997 0.036058 20.12864 10.14571
15 6231.997 0.036058 20.12864 10.14571
16 6258.545 0.035812 20.20214 10.16302
17 6450.331 0.035688 20.72997 10.28688
18 6487.155 0.035628 20.83071 10.30975
19 6487.155 0.035628 20.83071 10.30975
20 6496.427 0.035612 20.85604 10.31483
21 6629.071
0.035399
21.11715 10.39539
22 6619.417 0.035475 21.28678 10.36632
23 6667.971 0.035337 21.32259 10.41891
00 6667.971 0.035337 21.32259 10.41891
01
6858.292
0.035043
21.83554 10.53263
International Journal of Scientific Research and Engineering Studies (IJSRES)
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02 6899.064 0.034982 21.94482 10.55637
03 6899.064 0.034982 21.94482 10.55637
04 6888.826 0.034997 21.91741 10.43668
05 6888.826 0.034997 21.91741 10.43668
Table 6 : Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ2
Time(hrs.)
DAY 7
Re f Nu H
06 8807.079 0.032587 26.85125 12.78708
07 8446.482 0.032979 25.95171 12.60376
08 8238.279 0.033217 25.42698 12.49158
09 8040.094 0.033351 24.92367 12.38415
10 7789.997 0.033759 24.28294 12.23965
11 7681.388 0.033897 24.00269 12.17651
12 7617.664 0.033979 23.83767 12.13934
13 7585.881 0.034021 23.75521 12.12053
14 7585.881 0.034021 23.75521 12.12053
15 7585.881 0.034021 23.75521 12.12053
16 7681.388 0.033897 24.00269 12.17651
17 7702.867 0.033869 24.05821 12.18901
18 7856.649 0.033675 24.45432 12.27828
19 8085.863 0.033396 25.04024 12.40947
20 8085.863 0.033396 25.04024 12.40947
21 8108.944 0.033369 25.09895 12.42154
22 8108.944 0.033369 25.09895 12.42154
23 8132.156 0.033341 25.15794 12.43505
00 8226.351 0.033231 25.39681 12.48513
01 8347.209 0.033091 25.70202 12.55035
02 8396.552 0.033035 25.82624 12.57692
03 8446.482 0.032979 25.95171 12.60376
04 8649.542 0.032755 26.45967 12.70831
05 8688.394 0.032714 26.55644 12.72776
Table 7: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ3
Time(hrs.)
DAY 8
Re f Nu H
06 8793.732 0.032601 26.18161 12.78042
07 8459.057 0.032965 25.38328 12.61051
08 8250.242 0.033203 25.45724 12.49804
09 8040.094 0.033351 24.92367 12.38415
10 7702.867 0.033869 24.05821 12.18901
11 7746.187 0.033814 24.17004 12.21421
12 7681.388 0.033897 24.00269 12.17651
13 7617.664 0.033979 23.83767 12.13934
14 7617.664 0.033979 23.83767 12.13934
15 7585.881 0.034021 23.75521 12.12053
16 7702.867 0.033869 24.05821 12.18901
17 8085.863 0.033396 25.04024 12.40947
18 8108.944 0.033369 25.09895 12.42154
19 8132.156 0.033341 25.15794 12.43505
20 8132.156 0.033341 25.15794 12.43505
21 8178.983 0.033286 25.27679 12.46089
22 8178.983 0.033286 25.27679 12.46089
23 8238.279 0.033217 25.42698 12.49158
00 8250.242 0.033203 25.45724 12.49804
01 8396.552 0.033035 25.82624 12.57692
02 8649.542 0.032755 26.45967 12.70831
03 8688.394 0.032714 26.55644 12.72776
04 8688.394 0.032714 26.55644 12.72776
05 8807.079 0.032587 26.85125 12.78708
Table 8: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ3
Time(hrs.)
DAY 9
Re f Nu H
06 8807.079 0.032587 26.85125 12.78708
07 8396.552 0.033035 25.82624 12.57692
08 8178.983 0.033286 25.27679 12.46089
09 8085.863 0.033396 25.04024 12.40947
10 7789.997 0.033759 24.28294 12.23965
11 7702.867 0.033869 24.05821 12.18901
12 7746.187 0.033814 24.17004 12.21421
13 7746.187 0.033814 24.17004 12.21421
14 7681.388 0.033897 24.00269 12.17651
15 7681.388 0.033897 24.00269 12.17651
16 7789.997 0.033759 24.28294 12.23965
17 7856.649 0.033675 24.45432 12.27828
18 8040.094 0.033351 24.92367 12.38415
19 8226.351 0.033231 25.39681 12.48513
20 8238.279 0.033217 25.42698 12.49158
21 8238.279 0.033217 25.42698 12.49158
22 8250.242 0.033203 25.45724 12.49804
23 8396.552 0.033035 25.82624 12.57692
00 8459.057 0.032965 25.38328 12.61051
01 8446.482 0.032979 25.95171 12.60376
02 8649.542 0.032755 26.45967 12.70831
International Journal of Scientific Research and Engineering Studies (IJSRES)
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03 8688.394 0.032714 26.55644 12.72776
04 8793.732 0.032601 26.18161 12.78042
05 8793.732 0.032601 26.18161 12.78042
Table 9: Calculated values of Reynolds number, friction
factor, Nusselt number and Convective heat transfer
coefficient for mass flow rate ṁ3 Tim
e
(hrs
.)
DAY
1
DAY
2
DAY
3
DAY
4
DAY
5
DAY
6
DAY
7
DAY
8
DAY
9
ɳ
(%)
ɳ (%) ɳ
(%)
ɳ
(%)
ɳ
(%)
ɳ
(%)
ɳ
(%)
ɳ (%) ɳ
(%)
07 44.50 46.78 24.57 64.34 50.14 55.00 53.4
9
40.66 31.71
08 40.44 45.62 33.54 63.20 48.35 47.56 55.5
2
41.13 42.47
09 39.07 49.11 42.21 61.75 55.57 42.11 48.0
5
43.14 39.50
10 34.96 40.32 44.20 50.68 52.19 37.18 43.3
9
39.70 37.48
11 32.16 33.25 39.89 46.66 48.16 35.45 38.3
7
37.40 36.36
12 35.07 37.33 40.45 39.82 39.40 38.45 42.7
0
39.81 41.02
13 36.94 33.91 40.03 34.03 25.20 31.44 43.4
6
41.67 41.60
14 38.78 39.76 34.62 35.66 15.76 24.86 43.1
3
37.34 37.41
15 31.06 35.07 26.52 29.04 15.90 21.54 41.8
2
23.60 26.79
16 16.64 31.00 25.37 21.65 21.68 23.79 40.8
1
22.22 21.61
17 13.11 30.83 33.79 16.30 25.42 28.76 33.1
8
27.78 35.68
18 24.95 52.17 42.68 13.54 33.78 36.59 37.1
8
30.66 54.21
Av
g
32.13 39.60 35.66 39.72 35.76 35.23 43.4
3
35.42 37.15
Table No 10: Calculated values of Collector Efficiency in day
time for mass flow rate ṁ1 (0.015 Kg/s)
Local measured data of global solar radiation incident on
inclined surface and meteorological data (Temperature) on
nine days are obtained by direct measurement at B.I.T.Sindri
campus (latitude). The hourly variation of solar intensity (I)
and ambient temperature (Ta) for the testing days are shown in
figures 2 and 3 respectively.
Figure 2: Hourly variation of solar radiation in all run days.
Figure 3: Ambient air temperature in all run days.
From the fig. 2 it is seen that for the fourth day, the solar
radiation increases to maximum value of 984.53 W/m2
at 1
pm. similar behavior have been observed during all run days.
From the fig. 3 ambient temperature exhibits the same
behavior as the solar radiation. However, they achieve their
maximum values of 47 ºC at 3 pm, and having minimum value
of 22ºC in morning at 5 am, during the period of
experimentation. Daily average values of solar radiation and
ambient temperature are obtained as 730.48W/m2 and
33.75ºC, respectively.
Figure 4: Outlet temperature Vs. Time for run days
As from the fig. 12 it is observed that the outlet
temperature of the system decreases with the increase in mass
flow rate of the air. For, mass flow rate(ṁ1), maximum outlet
temperature is 60.5 ºC, at 12 pm of second day and minimum
outlet temperature is 27ºC,at 6am in first day. For, mass flow
rate(ṁ2), maximum outlet temperature is 56 ºC, at 11am of
third day and minimum outlet temperature is 29ºC,at 5 am in
second day. Similarly for mass flow rate(ṁ3), maximum outlet
temperature is 55 ºC, at 1 pm of first day and minimum outlet
temperature is 25ºC,at 5 am in third day. So, it may concluded
that the outlet temperature increases with the decrease in mass
flow rate of air or vice versa.
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
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Figure 5: Variation of mean temperature of absorber plate
and air stream for test day 1 of mass flow rate 0.015 Kg/s
Figure 6: Variation of mean temperature of absorber plate
and air stream for test day 1 of mass flow rate 0.020 Kg/s
Figure 7: Variation of mean temperature of absorber plate
and air stream for test day 1 of mass flow rate 0.025 Kg/s
From fig. 5, 6 and 7 it is seen that the average temperature
difference is maximum for mass flow rate of 0.015 Kg/s and it
is minimum for mass flow rate of 0.025 Kg/s. So, it is
concluded that as the mass flow rate of air increases, the mean
temperature difference of absorber plate and air stream
decreases.
Figure 8: variation of efficiency with Mass flow rate
It is shown from fig. 8 that the air heater efficiency is
strongly depends on mass flow rate; it increases with
increasing mass flow rate (ṁ). Increasing the mass flow rate
causes a consequent increase of the time average
instantaneous collector efficiency. Average efficiency of the
collector are 35.79 %, 36.91 %, and 38.66%, on three different
mass flow rate (i.e. ṁ1= 0.015 Kg/s, ṁ2=0.020 Kg/s, and ṁ3=
0.025 Kg/s) of air respectively.
Figure 9: Variation of Nusselt number with Reynolds number
Figure 10: Variation of Nusselt number with Reynolds number
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
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Figure 11: Variation of Nusselt number with Reynolds number
Fig. 9, 10 and 11 show the variation of Nusselt number
with Reynolds number As, per the graphs it is seen that
Nusselt number is minimum (15.01778), when the Reynolds
number is minimum (4487.864) and it is maximum (26.8125),
when the Reynolds number is maximum (8807.079).So, it may
concluded that the heat transfer decreases as the mass flow
rate and Reynolds number increases.
Figure 12: Variation of convective heat transfer coefficient
with respect to Reynolds number for mass flow rate of 0.015
Kg/s.
Figure 13: variation of Convective heat transfer coefficient
with respect to Reynolds number for mass flow rate of
0.020Kg/s.
Figure 14: variation of Convective heat transfer coefficient
with respect to Reynolds number for mass flow rate of
0.025Kg/s.
Fig. 12, 13, and 14 illustrate the variation of convective
heat transfer coefficient with Reynolds number. It is seen that
convective heat transfer coefficient is maximum
(12.7708W/m2 k), when the mass flow rate(0.025 Kg/s) and
Reynolds number (8807.079).It may concluded that the heat
transfer decreases by increasing the mass flow rate. As the
mass flow rate increases, the temperature difference between
absorber plate and air stream increases, so higher the absorber
plate temperature. Higher the plate temperature leads to
increase the air viscosity. The increase in air viscosity affects
the wall shear stress and decrease the local Reynolds number
as well which cause an increase in thermal boundary layer
thickness, and results in decreasing the convective heat
transfer coefficient.
Figure 15: Variation of Friction factor with Reynolds number
for mass flow rate of ṁ1
Fig. 15, 16 and 17 shows the variation of friction factor
with Reynolds number. Friction factor attain the maximum
value, when the mass flow rate is minimum (0.015 Kg/s) and
Reynolds number is also minimum (4487.864). Same as it
attain minimum value, when mass flow rate (0.025 Kg/s) at
maximum Reynolds number (8807.079). So, it may conclude
that as the mass low rate and Reynolds number increases the
friction factor decreases, this is due more turbulence of
flowing fluid less the skin friction.
International Journal of Scientific Research and Engineering Studies (IJSRES)
Volume 1 Issue 4, October 2014
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Figure 16: Variation of Friction factor with Reynolds number
for mass flow rate of ṁ2
Figure 17: Variation of Friction factor with Reynolds number
for mass flow rate of ṁ3
V. CONCLUSION
On the basis of the experimental results obtained for nine
run days on three different mass flow rate of air, for force
convection solar air heating system with phase change
material (Paraffin wax) energy storage, manufactured and
tested in B.I.T.Sindri, Dhanbad, Jharkhand, India, the
following conclusion can be drawn.
Air and plate temperature in general increases along the
air heater.
Air mass flow rate and solar radiation are predominant
factor which affect the performance of air heater.
Increasing the mass flow rate causes a consequent
decrease of air and plate temperatures.
This air heater is capable to produce hot air consistently
for 24 hours, the average temperature rise of 9.60 ºC, 7.19
ºC and 5.61 ºC, for all three different mass flow rate of air
respectively, from the atmospheric air temperature.
Increasing the mass flow rate causes a consequent
increase of the time average instantaneous collector
efficiency. Average efficiency of the collector are 35.79
%, 36.903 %, and 38.66%, on three different mass flow
rate (i.e. ṁ1= 0.015 Kg/s, ṁ2=0.020 Kg/s, and ṁ3= 0.025
Kg/s) of air respectively.
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