The document discusses heat transfer in shell and tube heat exchangers using nanofluids. It describes how baffle geometry, including baffle angle and spacing, affects heat transfer performance. Experiments were conducted using boehmite alumina nanoparticles suspended in a water/ethylene glycol mixture flowing through the tubes, with flue gas on the shell side. The results showed that a baffle angle of 200 provided the highest overall heat transfer coefficient and heat transfer rate. Cylindrical nanoparticles performed better than other shapes. The minimum entropy generation also occurred for a 200 baffle angle. Overall, the study demonstrated that nanofluids can enhance heat transfer in shell and tube heat exchangers, with performance dependent on baffle design and nanop

1. 1

3. CONTENTS
• INTRODUCTION
• NANO PARTICLE PRODUCTION
• WHY NANOFLUIDS
• SPECIFIC BAFFLE ARRANGEMENT AND BAFFLE
SPACING
• ROLE OF BAFFLE CUT
• GEOMETRY OF BAFFLES
• ANALYSIS
• RESULT
• EXPERIMENTAL RESULTS
3

4. INTRODUCTION
• TO IMPROVE THE EFFICIENCY OF STHE
• INCREASE HEAT TRANSFER AREA
• INCREASING NUMBER OF TUBES
• PROVIDING FINS
• EQUIPMENT BECOME BULKY
• INCREASE TIME OF CONTACT OF FLUID ELEMENT PASSING
THROUGH THE HEAT EXCHANGER
• PROVIDING BAFFLES
• USE SOLID PARTICLES (HIGH THERMAL CONDUCTIVITY) IN
CONVECTIONAL FLUID
• LEAD TO FOULING, SEDIMENTATION, INCREASED PRESSURE
DROP
4

5. STHE WITH BAFFLE ANGLE
5

6. NANOPARTICLE PRODUCTION
• RAPID PYROLYSIS
• IN THE PRESENCE OF SURFACTANTS (TOPO, OA)
• SHAPE DEPEND ON
• SURFACTANTS, OPTIMIZING PARAMETERS
• SHAPE STUDIED BY HIGH RESOLUTION
TRANSMISSION ELECTRON MICROSCOPE
• TECHAI G2 (200KV) MICROSCOPE 6

7. WHY NANOFLUIDS
• REDUCES FOULING, SEDIMENTATION,
CLOGGING OF FLOW CHANNELS DUE TO POOR
SUSPENSION STABILITY, EROSION OF HEAT
TRANSFER DEVICE, AND INCREASING IN
PRESSURE DROP.
• THE SUSPENDED NANOPARTICLES INCREASE
THE SURFACE AREA AND THE HEAT CAPACITY
OF THE FLUID.
• THE SUSPENDED NANOPARTICLES INCREASE
THE EFFECTIVE (OR APPARENT) THERMAL
CONDUCTIVITY OF THE FLUID.
7

8. • THE DISPERSION OF NANOPARTICLES FLATTENS
THE TRANSVERSE TEMPERATURE GRADIENT OF
THE FLUID.
8

9. WHY SPECIFIC BAFFLE
ARRANGEMENT
9
THE MAIN ROLES OF A BAFFLE IN A SHELL AND TUBE
HEAT EXCHANGER ARE TO:
• HOLD TUBES IN POSITION (PREVENTING SAGGING),
BOTH IN PRODUCTION AND OPERATION
• PREVENT THE EFFECTS OF VIBRATION, WHICH IS
INCREASED WITH BOTH FLUID VELOCITY AND THE
LENGTH OF THE EXCHANGER
• DIRECT SHELL-SIDE FLUID FLOW ALONG TUBE
FIELD. THIS INCREASES THE EFFECTIVE HEAT
TRANSFER CO-EFFICIENT OF THE EXCHANGER

10. • IN A STATIC MIXER, BAFFLES ARE USED TO
PROMOTE MIXING.
• IN A CHEMICAL REACTOR, BAFFLES ARE OFTEN
ATTACHED TO THE INTERIOR WALLS TO
PROMOTE MIXING AND THUS INCREASE HEAT
TRANSFER AND POSSIBLY CHEMICAL REACTION
RATES
10

11. BAFFLE SPACING
• BAFFLE SPACING IS AMONG THE MOST
IMPORTANT PARAMETERS USED IN THE DESIGN
OF SHELL AND TUBE HEAT EXCHANGERS.
• CLOSER SPACING CAUSES HIGHER HEAT
TRANSFER, BUT THIS LEADS TO POOR STREAM
DISTRIBUTION AND HIGHER PRESSURE DROP.
• ON THE OTHER HAND, HIGHER BAFFLE SPACING
REDUCES THE PRESSURE DROP, BUT THIS WILL
ALLOW MORE LONGITUDINAL FLOW, WHICH
DECREASES THE COEFFICIENT OF HEAT
TRANSFER.
11

12. • IT IS, THUS, DIFFICULT TO REALIZE THE
ADVANTAGE OF BAFFLE ARRANGEMENTS.
• DP PROPOTIONAL TO 1/B4 AND H TO 1/B0.55
12

13. GEOMETRY
13

14. • DOTL : DIAMETER OF CIRCLE TOUCHING THE
OUTER SURFACE OF OUTERMOST TUBES.
• DCTL : DIAMETER OF CIRCLE PASSING THROUGH
THE CENTERS OF OUTERMOST TUBES.
• LBB: DIAMETRIC CLEARANCE BETWEEN TUBE
BUNDLE AND SHELL INSIDE DIAMETER.
• QCTL: THE ANGLE INTERSECTING DCTL DUE TO
BAFFLE CUT.
• QDS: THE ANGLE INTERSECTING DS DUE TO
EXTENDED BAFFLE CUT.
14

15. BAFFLES SPACING TO BAFFLE
WINDOW
15
• Connection with the baffle
window dimensioning, the
maximum baffle spacing
should not exceed the shell
diameter Ds.
So, Bmax = Ds

16. ROLE OF BAFFLE CUT ON FLOW
DISTRIBUTION
• IF THE BAFFLE CUT IS TOO SMALL, THE FLOW WILL JET
THROUGH THE WINDOW AREA AND FLOW UNEVENLY
THROUGH THE BAFFLE COMPARTMENT.
• IF THE BAFFLE CUT IS TOO LARGE, THE FLOW WILL
SHORT-CUT CLOSE TO THE BAFFLE EDGE AND AVOID
CROSS-MIXING WITHIN THE BAFFLE COMPARTMENT.
• A BAFFLE CUT THAT IS EITHER TOO LARGE OR TOO
SMALL CAN INCREASE THE POTENTIAL FOR FOULING IN
THE SHELL.
16

17. • THIS REQUIRES A BAFFLE
CUT THAT IS LESS THAN
ONE-HALF OF THE SHELL
INSIDE DIAMETER.
17

18. BAFFLE CUT
• BAFFLE CUT IS THE HEIGHT OF
THE SEGMENT THAT IS CUT IN
EACH BAFFLE TO PERMIT THE
SHELL SIDE FLUID TO FLOW
ACROSS THE BAFFLE.
• THIS IS EXPRESSED AS A
PERCENTAGE OF THE SHELL
INSIDE DIAMETER.
18

19. • ALTHOUGH THIS, TOO, IS AN IMPORTANT
PARAMETER FOR STHE DESIGN, ITS EFFECT IS
LESS PROFOUND THAN THAT OF BAFFLE
SPACING.
19

20. SEGMENTAL BAFFLE CUT
GEOMETRY
20
• SEGMENTAL BAFFLE CUT
HEIGHT :LBCH
• ASSUMING THAT THE
SEGMENTAL BAFFLE IS
CENTERED WITHIN THE
SHELL INSIDE DIAMETER.

21. • THE SMALL DIFFERENCE BETWEEN THE SHELL
AND BAFFLE DIAMETER IS CALLED THE
CLEARANCE LSB AND IT IS IMPORTANT FOR
LEAKAGE CORRECTIONS
21

22. STUDY DONE AT
• DEPARTMENT OF MECHANICAL ENGINEERING,
UNIVERSITY OF MALAYA, 50603 KUALA LUMPUR,
MALAYSIA
• PROF. M.M. ELIAS ,PROF. I.M. SHAHRUL , PROF.I.M.
MAHBUL , PROF. R. SAIDUR , PROF.N.A. RAHIM
22

23. ANALYSIS
23
• HEAT EXCHANGER OPERATED WITH BOEHMITE
ALUMINA (ALOOH) NANOPARTICLES OF 0 TO 1 %
VOLUME CONCENTRATION WHICH ARE
SUSPENDED IN A MIXTURE OF WATER/ETHYLENE
GLYCOL (50/50 MIXTURE OF ETHYLENE GLYCOL
AND WATER) AT 365 K WERE USED.
• BOTH FLUIDS ARE UNMIXED
• SINGLE PASS TUBE CROSS FLOW HEAT
EXCHANGER IS USED

24. • MASS FLOW RATE IS CONSTANT TO GET LAMINAR
FLOW
• E-TYPE SHELL AND TUBE HEAT EXCHANGER IS USED
• ALOOH PRESENT IN MANY FORMS (PLATELETS,
BLADES, CYLINDRICAL AND BRICKS)
• NANOFLUIDS AND FLUE GAS ARE THE WORKING
FLUID
• FLUE GAS INCLUDE NITROGEN (60.3%), WATER
(24.4%), CARBON DIOXIDE (12.1%), AND OXYGEN
(3.2%).
• CONSTANT MASS FLOW RATE IS MAINTAINED TO GET
LAMINAR FLOW 24

25. SPECIFICATIONS OF E TYPE
STHE
25
Parameter Value
Tube inside diameter 22.9mm
Tube outside diameter 25.4 mm
Shell inner diameter 2090 mm
Total number of tubes 1024
Pitch 1.75
Baffle spacing 1776 mm
Shell thickness 14mm
Length 5m
Flue gas mass flow rate 26.3 kg/s
Nanofluid mass flow rate 35 kg/s
Nanofluid inlet temperature 30⁰C
Flue gas inlet temperature 100⁰C

26. RESULTS
26
1. EFFECTS OF OVERALL HEAT TRANSFER
COEFFICIENT-DIFFERENT BAFFLE ANGLE
• FOR ALL THE SHAPES, THE OVERALL HEAT TRANSFER
COEFFICIENT INCREASES WITH THE INCREASE OF
VOLUME CONCENTRATION.
• NANOFLUID WITH EVERY NANO-PARTICLE SHAPE OF
200 BAFFLE ANGLE SHOWS GREATER OVERALL HEAT
TRANSFER COEFFICIENT COMPARED WITH OTHER
BAFFLE ANGLES.

27. • FOR COMPARING THE ALL FOUR TYPES OF BAFFLE
ANGLES, NANOFLUID CONTAINING CYLINDRICAL
SHAPE NANOPARTICLE SHOWS BETTER OVERALL
HEAT TRANSFER COEFFICIENT IN COMPARISON
WITH OTHER SHAPES.
• THE OTHER SHAPES BRICKS, BLADES, AND
PLATELETS. BLADES AND PLATELETS SHOW
ALMOST SIMILAR INCREASING TREND FOR ALL
BAFFLE ANGLES WITH THE INCREASE OF VOLUME
CONCENTRATION
• LOWEST PERFORMANCE WAS FOUND FOR
PLATELETS SHAPE BASED NANOFLUID AMONG THE
OTHER CONSIDERED NANOPARTICLES SHAPES
FOR ALL BAFFLE ANGLES.
27

28. 28
20° 30°
40° 50°

29. 29
EFFECTS OF OVERALL HEAT TRANSFER COEFFICIENT-
SEGMENTED BAFFLES
• FOR SEGMENTAL BAFFLES,NANOFLUID HAVING
CYLINDRICAL SHAPE SHOWS HIGHER OVERALL HEAT
TRANSFER COEFFICIENT
• THE OVERALL HEAT TRANSFER COEFFICIENT BY
USING NANOFLUID WITH CYLINDRICAL SHAPE FOR
SEGMENTAL BAFFLE IN CORRESPONDING TO 1 VOL.%
CONCENTRATION IS FOUND 2.5% AND
• IT IS 1.2% HIGHER THAN 400 AND 500 BAFFLE ANGLES
RESPECTIVELY, AND 17.8% AND 6.8% LOWER THAN 200
AND 300 BAFFLE ANGLES RESPECTIVELY.

30. • ALL THE CASES SEGMENTAL BAFFLES AND
BAFFLE ANGLE OVERALL HEAT TRANSFER
COEFFICIENT IS ESTABLISHED HIGHER FOR 200
BAFFLE ANGLE.
30
0°

31. 31
2. EFFECTS OF HEAT RATE-DIFFERENT BAFFLE
ANGLE
• HEAT TRANSFER RATE MOSTLY DEPENDS ON
EFFECTIVENESS
• HEAT TRANSFER RATE IS FOUND HIGHER FOR
NANOFLUID CONTAINING CYLINDRICAL SHAPE
• RATE IS LOWER FOR PLATELETS SHAPE.
• AT 1 VOL.% CONCENTRATION, HEAT TRANSFER
RATE FOR CYLINDRICAL SHAPE IS FOUND 0.5%
GREATER THAN PLATELETS SHAPES.

32. 32
20° 30°
40° 50°

33. 33
EFFECTS OF HEAT RATE-SEGMENTED BAFFLE
• FOR SEGMENTAL BAFFLES, NANOFLUID HAVING
CYLINDRICAL SHAPE SHOWS HIGHER HEAT
TRANSFER RATE
• THE HEAT TRANSFER RATE AT 1 VOL.%
CONCENTRATION, CYLINDRICAL SHAPE NANOFLUID
IS FOUND APPROXIMATELY 0.5% HIGHER THAN
BOTH BLADES AND PLATELETS SHAPE NANOFLUID.
• NANOFLUID HAVING CYLINDRICAL SHAPE FOR
SEGMENTAL BAFFLE IS FOUND 0.8% AND 8.95%
HIGHER THAN 400 AND 500 BAFFLE ANGLES
RESPECTIVELY

34. • AND 14.6% AND 6.96% LOWER THAN 200 AND 300
BAFFLE ANGLES RESPECTIVELY IN
CORRESPONDING TO 1 VOL.%
CONCENTRATION.
NANOFLUID CONTAINING BLADES AND
PLATELETS SHAPE PERFORMS ALMOST
SIMILAR INCREASING TREND WITH THE
INCREASE OF VOLUME CONCENTRATION.
34

35. 35
0°

36. 36
3. EFFECT ON ENTROPY GENERATION-DIFFERENT
BAFFLE ANGLES
• MINIMIZATION OF THE ENTROPY GENERATION
HAPPENS FOR ALL NANOPARTICLE SHAPES WITH
THE INCREASE OF NANOPARTICLE VOLUME
FRACTION.
• THE ENTROPY GENERATION FOR THE 200BAFFLE
ANGLE IS FOUND HIGHER.
• THE MAXIMUM ENTROPY GENERATION RATE FOUND
TO BE AT 0 VOL.% CONCENTRATION (MEANS BASE
FLUID) FOR ALL BAFFLE ANGLES.

37. • THE MINIMIZATION OF ENTROPY GENERATION IS
FOUND TO SUPERIOR FOR THE CYLINDRICAL
SHAPE IN COMPARISON WITH THE ALL OTHER
SHAPE FOR ALL BAFFLE ANGLES.
• THE MINIMIZATION OF ENTROPY GENERATION IS
FOUND HIGHER FOR THE BRICKS THAN BLADE
AND PLATELETS BUT LOWER THAN THE
CYLINDRICAL SHAPE.
37

38. 38
20°
50°
30°
40°

39. 39
EFFECT ON ENTROPY GENERATION-SEGMENTED
BAFFLES
• FOR SEGMENTAL BAFFLES, THE MINIMIZATION OF
ENTROPY WILL OCCURRED WITH THE
INCREASING OF NANOPARTICLE VOLUME
FRACTION
• THE ENTROPY GENERATION RATE DECREASES
WITH INCREASE OF THE VOLUME
CONCENTRATION AND THE
• MINIMIZATION OF ENTROPY GENERATION
DECREASES WITH THE INCREASE OF BAFFLE
ANGLE.

40. 40
0°

41. EXPERIMENTAL RESULTS
• (AL2O3, SIO2, CUO, ZNO) HEAT TRANSFER COEFFICIENT
IMPROVE BY 39% WHEN COMPARED WITH WATER
• BY USING 2.5 WT.% OF GRAPHITE NANOPARTICLES 22%
HIGHER CONVECTIVE HEAT TRANSFER IS OBTAINED
• 0.3 VOL.% OF AL2O3 ,TIO2–WATER NANOFLUID SHOWS
BETTER HEAT TRANSFER PERFORMANCE
41

42. CONCLUSION
42
• FOR NANOFLUIDS OF CYLINDRICAL SHAPES HAVE
BETTER OVERALL HEAT TRANSFER COEFFICIENT
• THE MAXIMUM OVERALL HEAT TRANSFER
COEFFICIENT WAS FOUND FOR 200 BAFFLE ANGLE
THAN ANY OTHER BAFFLE ANGLE AS WELL AS
SEGMENTAL BAFFLE.
• BY THE USAGE OF 1 VOL.% CONCENTRATION OF
BOEHMITE ALUMINA (ALOOH) NANOPARTICLE SHOWS
THE ENHANCEMENT OF 12%, 19.9%, 28.23% AND
17.85% FOR CYLINDRICAL SHAPE NANOPARTICLE AT
200 BAFFLE ANGLE COMPARED TO 300, 400, 500 BAFFLE
ANGLES AND SEGMENTAL BAFFLE.

43. • AND THE LOWER OVERALL HEAT TRANSFER
COEFFICIENT WAS FOUND FOR BLADES AND
PLATELETS SHAPES OF THE NANOPARTICLES,
• THE HEAT TRANSFER RATE FOR EVERY SHAPE OF
NANOPARTICLES WAS FOUND HIGHER FOR 200
BAFFLE ANGLE BY COMPARED WITH THE OTHER
BAFFLE ANGLE AND SEGMENTAL BAFFLES.
• BY THE USAGE OF 1VOL.% CONCENTRATION OF
BOEHMITE ALUMINA (C-ALOOH) NANOPARTICLE
SHOWS THE INCREMENT OF 8.2%,15.37%, 22.3%
AND 14.6% FOR CYLINDRICAL SHAPE
NANOPARTICLE AT 200 BAFFLE ANGLE COMPARED
TO 300, 400, 500BAFFLE ANGLES AND SEGMENTAL
BAFFLE.
43

44. • THE NANOFLUIDS HAVING BLADES AND
PLATELETS SHAPES OF NANOPARTICLES
SHOWED LOWER HEAT TRANSFER RATE.
• THE ENTROPY MINIMIZATION RATE WAS FOUND
TO BE HIGHER FOR THE CYLINDRICAL SHAPE
COMPARED TO ANY OTHER SHAPES AT AN 200
BAFFLE ANGLE.
44

45. REFERENCE
1. D.P. KULKARNI, R.S. VAJJHA, D.K. DAS, D. OLIVA, APPLICATION OF
ALUMINUM OXIDE NANOFLUIDS IN DIESEL ELECTRIC GENERATOR AS
JACKET WATER COOLANT, APPL. THERM.
2. S. CHOI, ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH
NANOPARTICLES, IN: D.A.SIGINER, H.P. WANG (EDS.), DEVELOPMENTS
APPLICATIONS OF NON-NEWTONIAN FLOWS, ASME, NEW YORK, 1995, PP.
99–105. FED-VOL 231/MD-VOL 66.
3. I.M. MAHBUBUL, R. SAIDUR, M.A. AMALINA, LATEST DEVELOPMENTS ON
THE VISCOSITY OF NANOFLUIDS, INT. J. HEAT MASS TRANSFER 55 (4) (2012)
877–888.
4. J.-Y. JUNG, C. CHO, W.H. LEE, Y.T. KANG, THERMAL CONDUCTIVITY
MEASUREMENT AND CHARACTERIZATION OF BINARY NANOFLUIDS, INT. J.
HEAT MASS TRANSFER 54 (9–10) (2011) 1728–1733.
5. J. LEE, K. HWANG, S. JANG, B. LEE, J. KIM, S. CHOI, C. CHOI, EFFECTIVE
VISCOSITIES AND THERMAL CONDUCTIVITIES OF AQUEOUS NANOFLUIDS
CONTAINING LOW VOLUME
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