this is presentation about extended surface fins for heat transfer. advantages, disadvantages and many more about fins

1. 1. Manthan Kanani 140050119028
2. Ishant Kalra 140050119027
3. Pratik Kanani 140050119029
Guided by-
Jagruti Shah

2. • By increasing the surface area in contact with
air or providing fins.
• By increasing the heat transfer coefficient for the
surface.
• By increasing the temp of the hot surface or by
increasing the temperature difference between
hot and cold bodies.

3. • In many engineering situation, means are
often sought to improve heat dissipation
from a surface to its surrounding
• Whenever the available surface is found
inadequate transfer the required quantity
of heat with available temperature drop
and convective heat transfer coefficient,
extended surfaces or fins are used.

4. • In many engineering application, large
quantities of heat have to be dissipated from
small areas.
• The fins increases the effective area of the
surface thereby increasing the heat transfer
by convection.
• In other words, the shape of fins must be
optimized such that the heat transfer density
is maximized when the space and the
materials used for the finned surfaces are
constraints.

5. • The fins are designed and manufactured in
many shapes and forms.
• They manufactured in different geometries,
depending upon the practical applications.
• The ribs attached along the length of a
tubes are called longitudinal fins.
• The concentric annular disc around a tube
are termed as circular or annular fins
• Pin fins or spines are rods protrading from a
surface.

7. Case Tip condition (x=L) Temperature distribution Fin heat transfer rate
A
Convection heat
transfer
B Adiabatic
C
Constant
Temperature
D Infinite Fin Length

8. Fin performance can be described in three different ways.
1:- The first is fin effectiveness. It is the ratio of the fin heat transfer rate to
the heat transfer rate of the object if it had no fin. The formula for this is
where is the fin cross-
sectional area at the base
2:- Fin performance can also be characterized by fin efficiency. This is the
ratio of the fin heat transfer rate to the heat transfer rate of the fin if the
entire fin were at the base temperature.
in this equation is equal to the surface area of the fin
Fin efficiency will always be less than one

9. 3:- The third way fin performance can be described is with overall surface
efficiency.
where is the total area and is the sum of the heat transfer rates of all
the fins.

10. Comparison of the different
types of extended surfaces
using heat transfer/pressure
drop as the figure of merit.
from a purely size standpoint,
pin fins offer the smallest
design for the best heat
transfer while straight fins are
the most inefficient from a
heat transfer and smallest
size constraint.

11. Advantages:
By using the fins, heat transfer rate can be increased
without any preventive maintenance. It is the
cheapest way for increasing the heat transferring rate
from the hot bodies.
Disadvantages:
We know that the length of fins is directly
proportional to the heat transferring rate. But the
larger length is may be cause of bending in the fins
and also increases the weight of engine. Therefore the
overall efficiency will goes to decrease.

12. • Common applications of finned surfaces
are with,
• Cooling of electronics components
• Condensors and economisers of thermal power
plants
• Dry type cooling towers
• Air cooled cylinders of compressors, IC engines
• Evaporators and condensors of refrigeration and
air conditioning system.
• Electric motor and transformers,

13. Annular Fins
Straight Fins
Splines
Trapazoidal Fins