This is my final year presentation of FYP and it is prove much helpful to those who are in FYP

1. Final Year
Project
Presentation

2. Project Advisor
Group Members
Design and Development of Desiccant Wheel for
Solar Assisted Desiccant Cooling System :
 M. Faisal Ayyaz Bsme-
01163148
 Waleed Raza Bsme-01163227
 M. Abdullah Bsme-01163177
 Hassan Shahzad Bsme-01163172
 Dr. Shafqat Hussain (Asisstant
Professor MED,UOL)
 Co-operative , Well Versed

3. 1
2
3
4
5
Project Introduction
Literature Review
Aim and Objective
Features of Project
Block Diagram

4. 6
7
8
9
10
Flow Chart
Mathematical
Modeling
CAD Modeling
Experimental Setup
Results and
Discussion

5. 11
12
13
14
Project Applications
Project Cost
Conclusion
References

6. Desiccant Cooling Systems: Desiccant cooling
systems are heat-driven cooling units and they can be
used as an alternative to the conventional vapor
compression and absorption cooling systems.
.
Desiccant Wheel: Desiccant cooling systems operate
on the principle of adsorption, dehumidification
and evaporative cooling. A desiccant wheel with a grid
of small air passages, similar to a large bundle of coffee
straws, is impregnated with silica gel (the same silica that
is used in the packets that keep shoes dry). The desiccant
wheel rotates slowly through the different airflow zones
of the desiccant, as it works to remove moisture.

7. • Adsorption is a surface process, the
accumulation of a gas or liquid on
a liquid or solid.
• Adsorption takes place when
ambient air passes through the
desiccant wheel and its moisture is
removed.
Adsorption
• The principle underlying evaporative
cooling is the fact that water must
have heat applied to it to change from
a liquid to a vapor. When evaporation
occurs, this heat is taken from the
water that remains in the liquid state,
resulting in a cooler liquid.
Evaporative Cooling
• Desorption is the release of one
substance from another, either from
the surface or through the surface.
• Desorption is done in the
regeneration section where we
supply hot air to remove humidity
from the silica gel
Desorption

9. OPTION 01
OPTION 01
OPTION 01
OPTION 01
Solid desiccant dehumidification employs the porous and strong
hydrophilic materials to adsorb moisture from the air stream. The
generally used solid desiccants include silica gel etc.
Desiccant/evaporative cooling systems offer a potential alternative to
environmentally-benign conventional vapor compression chillers.
Desiccant cooling systems are energy efficient and environmentally
benign. According to one estimate, desiccant dehumidification could
reduce total residential electricity demand by 25% or more in humid
regions
The most commonly used cooling system is vapor compression
system. In food processing industry, applications require RH and
temperature within the specific limit but by using cold coil
dehumidification we can’t achieve required RH and temperature
economically.
[1]
[2]
[3]
[4]

10. 01
02
03
04
To provide Environment-friendly because there is no
use of CFCs to provide a cool and dry air.
To provide Energy saving because it saves about 75%
energy compared to VCS and VAS.
To provide a healthy environment.
Solid desiccant cooling system (SDC) is operated based on
solid desiccant, which has strong affinity to water to control air
temperature, reduce humidity and provide high quality air..

11. Project
Features
Cheapest way to
remove
humidity
Can be
regenerated with
minimum cost
Low
maintenance
cost
No
Environmental
hazard
Saves
Electricity up
to 75%

13. Mathematical
Modeling

15. D
O
Design Parameters
• Wheel dimension (wheel depth, wheel diameter
and split between adsorption and desorption
sections)
• Channel dimension (channel shape and size)
• Desiccant composite (desiccant material properties)
Operating Variables
• The speed of the wheel
• The inlet process air properties (temperature,
humidity and flow rate)
• The inlet regeneration air properties (temperature,
humidity and flow rate)

16. Cross sectional
area
𝐴𝑓 =
1
2
(2a)(2b) = 2ab
Total Cross
Sectional
Area
𝐴𝑡 =
1
2
(2a + δ)(2b + δ)
Perimeter of
flow
passage
𝑃𝑒
≈ 2b + 2 𝑏2 + (𝑎𝜋2)
3 + (
2𝑏
𝑎𝜋
)2
4 + (
2𝑏
𝑎𝜋
)2
Area Ratio
𝐴𝑟 =
𝐴𝑓
𝐴𝑡
Hydraulic Diameter of
flow passage
𝐷ℎ = 4𝑃𝑒
𝐴𝑓
Porosity in
Desiccant
∈ =
𝑉
𝑝𝑜𝑟𝑒𝑠
𝑉𝑡𝑜𝑡𝑎𝑙
𝑉𝑡𝑜𝑡𝑎𝑙 = 𝑉
𝑝𝑜𝑟𝑒𝑠 + 𝑉𝑑 + 𝑉
𝑚
Volume
Ratio in
desiccant
𝜑 =
𝑉𝑑
𝑉𝑑 + 𝑉
𝑚

17. Cross sectional
area of matrix 𝐴𝑚 = (1 −∈)(1 − 𝐴𝑟)𝐴𝑡(1 −
𝜑)
Moisture
Removal
Capacity MRC
𝑀𝑅𝐶 = 𝜌1𝑉
𝑝𝑟𝑜𝑐(𝜔𝑎 − 𝜔𝑑)
latent heat of
vaporization of
water
∆ℎ𝑣𝑠
= −0.614342 × 10−4𝑡1
3
+ 0.158927 × 10−2
𝑡1
2
− 0.236418
× 10𝑡1 + 0.250079 × 104
Dehumidification
effectiveness
𝜂𝑑𝑒ℎ =
𝜔𝑎 − 𝜔𝑑
𝜔𝑑
Cross sectional area of
desiccant
𝐴𝑑 = (1 −∈)(1 − 𝐴𝑟)𝐴𝑡𝜑
Dehumidification
Coefficient of
Performance, DCOP
𝐷𝐶𝑂𝑃 =
𝜌1𝑉
𝑝𝑟𝑜𝑐∆ℎ𝑣𝑠(𝜔𝑎 − 𝜔𝑑)
𝜌1𝑉
𝑟𝑒𝑔(ℎ𝑎 − ℎ𝑑)
Sensible
Energy
Ratio SER
𝑆𝐸𝑅 =
𝜌1𝑉
𝑝𝑟𝑜𝑐𝑐𝑝(𝑇2 − 𝑇1)
𝜌1𝑉
𝑟𝑒𝑔𝑐𝑝(𝑇4 − 𝑇1)

18. Parameter Involve in Designing of
Desiccant Wheel
Wheel Diameter (mm) 305 mm
Wheel Depth (mm) 64 mm
Wheel Split Ratio 23
Channel Size (mm) 1.5*3.4
Desiccant Thickness
(microns)
65
Desiccant Material Silica Gel
Substrate Material Fiber Glass Paper

19. List of Components : 12V DC Motor, 12V DC Fans
• Used to rotate the desiccant wheel inside the
casing.
• Fitted inside the air tunnels to suck air through
the desiccant wheel.
Silica Gel, Strips
• Main material to absorb moisture, pasted on
Aluminum sheet strips using temperature
resistant, non-volatile epoxy resin
Hygrometer, Volt-Meter, Temp. Sensor
• Used to measure RH%
• Used to measure volts supplied
• Used to measure Temp of flowing air
Plywood Sheet, Aluminum Sheet
• Used to make the shell for desiccant wheel.
• Used to make strips that are fitted inside the
Desiccant wheel shell

20. Heating Filament
Desiccant Wheel
Outer Casing A view of Wheel
inside Casing
DC Dimmer

21. Exhaust Tunnel
Heater Tunnel
Volt-meter
Temperature
sensor
Hygrometer
Desiccant Wheel Testing
Model

22. Input Condition Value
Inlet Air Velocity 0.8m/s
Inlet Air Temperature 30-36°C (303-309K)
Inlet Air RH 41-93%
Regeneration Air Velocity 0.8m/s
Regeneration Air Temperature 72°C (345K)
Rotation Speed 4.5-5rpm
Desiccant Material Silica Gel
No. of Plates 20
Properties of air channels
and Experiment: • The ambient air of the room was measured
as 36C and was determined to be suitable.
• The ambient relative humidity of the
laboratory air was approximately 61%.
This was increased by using a humidifier,
directing water vapors onto the mesh
cloths used to provide uniformity to the air
flow. This increased the relative humidity
inside the channel to a maximum of 80-
90%.
• The increase in relative humidity reduced
the air temperature to 30C due to the
evaporative cooling effect. The full
properties of the experiment can be seen in
Table .

23. Days
Humidity
[%rH]
Temp. [C]
Humidity
[%rH]
Temp. [C]
Monday 56 37 48 40
Tuesday 45 40 36 42
Wednesday 66 37 56 39
Thursday 79 31 68 35
Friday 63 34 54 37
Saturday 72 31 63 35
Sunday 61 33 53 36
Monday 50 39 42 42
Tuesday 60 37 50 40
Wednesday 56 37 45 41
Thursday 52 38 40 43
%RH Reduction = 9.55%
Increase in Air Temperature due to Latent Transfer = 3.25 C
Reduction in regeneration air Temp. = 3.82 C
64
Inlet Air Channel
Before Wheel After Wheel Before Wheel
Temp. [C] Temp. [C]
Regeneration Air Channel
63
60
After Wheel
64
61
59
66
65
68
64
63
60
57
61
60
62
63
65
Mean/
Average
60 35.81 50.45 39.09 65.45 61.63
70
70
67
All functions operated well.
However, the air flow was only
dehumidified between 8%-9% in
each test - which isn't too bad
considering the rotor is only 2"
deep.
There was also a small transfer
of heat from the regeneration
chamber to the
dehumidification chamber that
was stored by the desiccant
beads after they were dried,
and subsequently the
dehumidified air temperature
was raised a few degrees more
than the intake temperature
Experimental Readings and
Calculations

24. 56
45
66
79
63
72
61
50
60
56
48
36
56
68
54
63
53
42
50
45
37
40
37
31
34
31 33
39 37 37
40 42
39
35 37 35 36
42 40 41
0
10
20
30
40
50
60
70
80
90
MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY SUNDAY MONDAY TUESDAY WEDNESDAY
%rH
%rh Redution
Air temp Befor Wheel C
Air Temp after Wheel C
%rH Before wheel %rH reduction (After
Wheel)
Air Temp. Before
Wheel
Air Temp After Wheel

25. %rH Line
2

26. M
I
P
H
Medical Related Use
• surgery rooms
• laboratories
• dry storage, archive rooms etc.
Industrial Use
• Industries where compressed air is required
• Textile Industries
• FMCGs Industries
Pharmaceutical Industries
• Plays a vital role because moisture can spoil the chemical formulas of
medicines by making chemical reaction with them
Household Use
• Many household applications require air free from moisture
• To supply fresh dry air without any environmental hazard

27. Components Price
Silica Gel 460-RSKg
Plywood Sheets 1100 Rs-/
Aluminum Sheet 510 Rs-/
Chip Board 1100 Rs-/
Mechanical Parts 4000 Rs-/
Electronic Parts 6500 Rs-/
Total 13,670 Rs-/

28. From experimentation we have been concluded that, the use of Solid Desiccant
Cooling instead of traditional HVAC would be beneficial in many ways.
We can also save electricity up to 75%, which is a heavy breakthrough in
enhancing countries economy.
This type of Cooling ensures Human Health and no Environmental Hazard.
From experimentation we have been concluded that there is slight increase in
activated air temperature due to latent heat transfer.
From experimentation we come to know that Silica gel would be the cheapest
material to be used for moisture removal.
By performing experiment and making Graphs it is cleared that Silica Gel
removes moisture and then it can be regenerated by means of hot air.

29. Thank You!