surface coating

1. A FIRST REVIEW PROJECT SUBMITTED BY
NAGARAJAN S (421313114022)
VIGNESHVARAN.S (421313114044)
Under the guidance of
Mr.S.KARTHIKEYAN Associate professor

2. ABSTRACT
In this work, we proposed a low cost material to
be used as an excellent absorber for solar collectors, to
increase its thermal efficiency by the high capacity to absorb
solar radiation. A comparative analysis between the optical
properties (reflectance, absorbance, and emissivity)
measured on four various materials like Aluminium sheet,
Stainless Steel sheet, Copper sheet and Mild Steel sheet. It
has been observed that the yield is very low upto noon but
increased at after noon.

3. INTRODUCTION
 The main aim of this research work is to compare four
different absorber plates and determine optimum absorber
plate which can increase the yield from( solar still, solar
water heater, solar furnace, like that).To increase the
absorbance of the surface coating in order to improve the
thermal efficiency. Metal makes a good thermal conductor,
especially copper and aluminium. In high performance
collectors, a "selective surface" is used in which the
collector surface is coated with a material having properties
of high- absorption and low-emissivity. The selective
surface reduces heat-loss caused by infrared radiant
emission from the collector to ambient.

4. Literature review 1:
 An investigation on the performance characteristics of
solar flat plate collector with different selective surface
coatings(ES PRAKASH)
 In the present work, investigations are made to study
performance characteristics of solar flat plate collector
with different selective surface coatings. Flat plate
collector is one of the important solar energy trapping
device which uses air or water as working fluid. Of the
many solar collector concepts presently being developed,
the relative simple flat plate solar collector has found the
widest application so far.
 Keywords: Selective surface coatings; Solar flat plate
collector; Collector performance.

5. Literature review 2:
 A high absorbance material for solar collectors’
applications (A I Oliva, R D Maldonado, E A Díaz, A I
Montalvo)
 In this work, we proposed a low cost material to be used
as an excellent absorber for solar collectors, to increase its
thermal efficiency by the high capacity to absorb solar
radiation. The material, known as “smoke black” (soot)
can be obtained by the incomplete combustion of organic
materials, such as the oxygen-acetylene, paraffin, or
candles. A comparative analysis between the optical
properties (reflectance, absorbance, and emissivity)
measured on three covered copper surfaces (without paint,
with a commercial matte black paint, and with smoke
black) shows amazing optical results for the smoke black.

6. Literature review 3:
 Solar Absorptance and Thermal Emittance of Some
Common Spacecraft (John H. Hemmer)
 Solar absorptance and thermal emittance of spacecraft
materials are critical parameters in determining spacecraft
temperature control. Because thickness, surface
preparation, coatings formulation manufacturing
techniques, etc. affect these parameters, it is usually
necessary to measure the absorbtance and emittance of
materials before they are used. Also, because most
materials exhibit some amount of degradation dye to
outgassing, ultraviolet, and or particle damage, it is
necessary to conduct laboratory testing on these materials
before certifying them for use in space.

7. Literature review 4:
 Solar Selective Coatings for High Temperature
Applications(Donald A. Jaworske and Dean A. Shumway )
 Solar selective coatings are envisioned for use on minisatellites,
for applications where solar energy is to be used to power heat
engines or to provide thermal energy for remote regions in the
interior of the spacecraft. These coatings are designed to have
the combined properties of high solar absorptance and low
infrared emittance. The coatings must be durable at elevated
temperatures. For thermal bus applications, the temperature
during operation is likely to be near 100°C. For heat engine
applications, the temperature is expected to be much greater.
The objective of this work was to screen candidate solar
selective coatings for their high temperature durability.

8. Emissivity and Absorptivity
 Main article: Kirchoff's law of thermal radiation
The term “emissivity” is used to describe
radiation efficiency of a target compared
to a blackbody at the same wavelength,
angle and temperature.
ɛ

9. Absorptivity
20% emission
80% absorptivity
Actual
Temperature
40°C
Apparent
Temperature
May be
absorptivity
Apparent
Temperature
1500°C
>
TOTAL
>0.2ɛ

10. Solar Absorptance:
 A Beckman DK-2A spectrophotometer modified with a
Gier-Dunkle absolute integrating sphere is used for
making absolute reflectance, absorptance, and
transmittance measurements. This instrument covers the
wavelength region from 300 to 2400 nanometers (nm).
Their is coupled to a microcomputer for data reduction.
The manufacturer's data lists an accuracy of total
measurement range.

11. Kirchhoff's law of thermal radiation
 For a body of any arbitrary material emitting and
absorbing thermal electromagnetic radiation at every
wavelength in thermodynamic equilibrium, the ratio of its
emissive power to its dimensionless coefficient of
absorption is equal to a universal function only of
radioactive wavelength and temperature. That universal
function describes the perfect black-body emissive power.

12. HOW YOU MEASURE TEMPERATURE
 All temperature measuring devices accomplish this
by measuring an effect of temperature:
• Thermistor: resistance changes with temperature
• Thermometer: volume changes with temperature
• Thermocouple: voltage changes with temperature
• IR Thermometers: voltage changes with
temperature
• IR Camera: resistance changes with temperature

13. Experimental Setup
 Samples preparation Groups of four samples of copper ,
 aluminium ,mild steel and stainless steel .All the material
dimensions are125 mm x125 mm of 1.5 mm thickness used
for solar collectors were prepared. The first group of
samples were analysed with high temp spray paint coating
on the all sample material. The second group of samples
was totally coated with ultra-cover black paint. Third group
of samples was completely covered with industrial paint.
Similarly the fourth group of sample materials were
analysed with the paint of block chrome now compare the
group of materials and different types of paints, which set of
material and paint gives more efficiency take that particular
paint and material.

14. Copper
Copper as an elements
Periodic symbol: Cu.
Density: 8930kg/m3.
Melting point: 1083˚C.
Thermal expansion:
0.0168mm/m/˚C (20-100˚).
Tensile strength: 210 - 240
N/mm2

15. ALUMINIUM

16. ALUMINIUM
Properties Aluminium is a very light metal with a
specific weight of 2.7 g/cm3, about a third that of steel.
For example, the use of aluminium in vehicles reduces
dead-weight and energy consumption while increasing
load capacity.

17. Electrical and Thermal Conductivity
 Aluminium is an excellent heat and electricity
conductor and in relation to its weight is almost twice
as good a conductor as copper. This has made
aluminium the most commonly used material in major
power transmission lines

18. MILD STEEL
 Mild steel is the most widely used steel which is not
brittle and cheap in price. Mild steel is not readily
tempered or hardened but possesses enough strength.
 consist of iron alloyed with less than 0.3% carbon most
commonly between 0.1 to 0.25%. The building
industry frequently uses mild steel in construction
because of its ductility and malleability.

19. Properties :
 Solid strength
 Rust free
 Abrasions resistant
 Long lasting
 User friendly
 Tensile strength
 Temperature Tolerance
 Durable and long lasting

20. Stainless Steel
 Very hard, making it difficult to create a profile
 Should not be blasted with steel grit or shot
 Causes corrosion problems
 Non-carbon blast materials, brushes or grinding
disks should be used.

21. General Properties of Stainless Steels
 Electrical Resistivity
 Surface & bulk resistance is
higher than that for plain-
carbon steels
 Thermal Conductivity
 About 40 to 50 percent that
of plain-carbon steel
 Melting Temperature
 Plain-carbon:1480-1540 °C
 Martensitic: 1400-1530 °C
 Ferritic: 1400-1530 °C
 Austenitic: 1370-1450 °C
 Coefficient of Thermal
Expansion
 Greater coefficient than
plain-carbon steels
 High Strength
 Exhibit high strength at
room and elevated
temperatures
 Surface Preparation
 Surface films must be
removed prior to welding
 Spot Spacing
 Less shunting is observed
than plain-carbon steels

22. control the corrosion in low cost

23. Coating system method:

24. BLOCK CHROME
 100% mirror like chromed effect
 very good lasting
 application easiness with special equipment
 practically applicable on any surface

25. RUST OLIUM
The ultimate protection for industrial environments. Formulated
with the highest quality pigments and resins, the High
Performance brand of coatings has the highest paint solids in the
industry.
These proprietary formulations are designed for severe industrial
environments and are backed by a Rust-Proof Guarantee.
The High Performance brand is the foundation of Rust-Oleum
Corporation.

26. RUST OLEUM

27. BOSNY SPRAY PAINT

28. Features
 Resists outgassing to 400°F (204°C)
 Heat resistant to 1,500°F (538°C)
 Doesn't peel, flake or chalk
 Won't bleach or discolour
 Withstands repeated thermal cycling
 Resistant to UV degradation
 Dries for handling in 30 minutes
 Air dry or heat cure
 Long lasting

29. PRINCIPLES OF CORROSION

30.  Corrosion is the disintegration of an engineered material
into its constituent atom due to chemical reactions with its
surroundings. In the most common use of the word, this
means electrochemical oxidation of metals in reaction
with an oxidant such as O2.

31. Effects of corrosion
 Reduces strength
 Life time is reduced
 Metallic properties are lost
 Wastage of metal

32. IMPORTANCE OF CORROSION DATA
5 mpy Good corrosion
resistant material
5 to 50 mpy Low corrosion
resistant material
50 mpy Unsuitable as
constructional
material

33. CORROSION DAMAGE
 Disfiguration or loss of appearance
 Loss of material
 Maintenance cost
 Extractive metallurgy in reverse- Loss of precious
minerals, power, water and man-power
 Loss in reliability & safety
 Plant shutdown, contamination of product etc

34. WORK IS TO BE DONE:
 The equipment and material was purchased.
 The purchased equipment were
1. Rest olium paint
2. Bosney spray paint
3. Industrial paint
4. Copper, aluminium,mild steel,stainless steel plate.

35. FUTURE WORK:
 To start the fabrication work of selective surface coating.
 To analyze the experimental investigation of absorptivity
and then low emissivity.

37. Any Question?