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Assignment 1
Assignment 3 a)
b) Q = 200W A = 002 002 m = 00004 m2
Tw = 115oC Tsat = Tsat(1 atm) = 100oC ∆T = 115-100 = 15K h = Q(A∆T) = 200(0000415) = 33333 W(m2K)
c) When several tubes are located above each other condensate from the upper tubes drain onto the lower tubes thereby increasing the condensate film thickness on the lower tubes Heat transfer drops with increasing film thickness thus reducing the overall heat transfer coefficient in case of several tubes above each other d) In the laminar region film thickness increases with Reynolds number thus reducing the heat transfer coefficient In laminar flow heat is conducted through the liquid film and thicker film means lower heat transfer coefficient In the turbulent region film thickness still continues to increase but increasing turbulence in the film gives convective heat transfer Thus heat transfer increases with increasing Reynolds number after transition to turbulent flow Assignment 4 Plate-fin heat exchanger geometry
Herringbone fins perforated fins or offset strip fins increase heat transfer due to secondary flows or breaking up of boundary layers Assignment 5
Assignment 3 a)
b) Q = 200W A = 002 002 m = 00004 m2
Tw = 115oC Tsat = Tsat(1 atm) = 100oC ∆T = 115-100 = 15K h = Q(A∆T) = 200(0000415) = 33333 W(m2K)
c) When several tubes are located above each other condensate from the upper tubes drain onto the lower tubes thereby increasing the condensate film thickness on the lower tubes Heat transfer drops with increasing film thickness thus reducing the overall heat transfer coefficient in case of several tubes above each other d) In the laminar region film thickness increases with Reynolds number thus reducing the heat transfer coefficient In laminar flow heat is conducted through the liquid film and thicker film means lower heat transfer coefficient In the turbulent region film thickness still continues to increase but increasing turbulence in the film gives convective heat transfer Thus heat transfer increases with increasing Reynolds number after transition to turbulent flow Assignment 4 Plate-fin heat exchanger geometry
Herringbone fins perforated fins or offset strip fins increase heat transfer due to secondary flows or breaking up of boundary layers Assignment 5
b) Q = 200W A = 002 002 m = 00004 m2
Tw = 115oC Tsat = Tsat(1 atm) = 100oC ∆T = 115-100 = 15K h = Q(A∆T) = 200(0000415) = 33333 W(m2K)
c) When several tubes are located above each other condensate from the upper tubes drain onto the lower tubes thereby increasing the condensate film thickness on the lower tubes Heat transfer drops with increasing film thickness thus reducing the overall heat transfer coefficient in case of several tubes above each other d) In the laminar region film thickness increases with Reynolds number thus reducing the heat transfer coefficient In laminar flow heat is conducted through the liquid film and thicker film means lower heat transfer coefficient In the turbulent region film thickness still continues to increase but increasing turbulence in the film gives convective heat transfer Thus heat transfer increases with increasing Reynolds number after transition to turbulent flow Assignment 4 Plate-fin heat exchanger geometry
Herringbone fins perforated fins or offset strip fins increase heat transfer due to secondary flows or breaking up of boundary layers Assignment 5
c) When several tubes are located above each other condensate from the upper tubes drain onto the lower tubes thereby increasing the condensate film thickness on the lower tubes Heat transfer drops with increasing film thickness thus reducing the overall heat transfer coefficient in case of several tubes above each other d) In the laminar region film thickness increases with Reynolds number thus reducing the heat transfer coefficient In laminar flow heat is conducted through the liquid film and thicker film means lower heat transfer coefficient In the turbulent region film thickness still continues to increase but increasing turbulence in the film gives convective heat transfer Thus heat transfer increases with increasing Reynolds number after transition to turbulent flow Assignment 4 Plate-fin heat exchanger geometry
Herringbone fins perforated fins or offset strip fins increase heat transfer due to secondary flows or breaking up of boundary layers Assignment 5
Herringbone fins perforated fins or offset strip fins increase heat transfer due to secondary flows or breaking up of boundary layers Assignment 5
