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Thermal Design and Performance Analysis of a Cross Flow Heat Exchanger Using Plain and Almond Dimple Tubes

  • Yogesh Pradeep Bhatt
  • Ashutosh Arun Joglekar
  • Dattatray B. Hulwan
Conference paper

Abstract

Thermal performance analysis of a cross-flow heat exchanger using plain and almond dimple tubes has been investigated. Hot air and water are used as fluids on shell and tube side respectively. Reynolds Number is obtained in the range of 9000–30,000 by varying the mass flow rate of air on the shell side of cross-flow heat exchanger. The performance parameters such as overall heat transfer coefficient, water side heat duty, effectiveness, pressure drop are calculated for both the plain and dimple tubes. The dimpled tubes show heat transfer enhancement by 30% and more efficient heat recovery over plain tubes at the cost of small pressure drop penalty.

Keywords

Cross flow heat exchange Dimple Heat transfer coefficient Pressure drop 

Nomenclature

B

Breadth of shell

(s)

The effectiveness of the heat exchanger

μ

Absolute viscosity

ρ

Density

A

Area available for heat transfer

As

Actual shell side flow area

At

Area of flow through each tube

As1

Area of shell

As2

Tube area blocking the flow on the shell side

C

Ratio of heat capacity

CL

Clearance between shell and tube

Cmax

Maximum heat capacity rate

Cmin

Minimum heat capacity rate

cps

Specific heat capacity of air on the shell side

cpt

Specific heat capacity of water on the tube side

di

Tube inner diameter

do

Tube outer diameter

Dht

Hydraulic diameter on the tube side

F

Factor for shell side heat transfer coefficient

F

Friction factor

tts

Gas mass velocity on the shell side

H

Height of shell

hs

Heat transfer coefficient on the shell side

ht

Heat transfer coefficient on the tube side

ks

Thermal conductivity of air on the shell side

kt

Thermal conductivity of water on the tube side

L

Tube length and Length of shell

LMTD

Log Mean Temperature Difference

ms

Mass flow rate of air on the shell side

mt

Mass flow rate of water on the tube side

Nd

Number of tube columns

Nw

Number of tube rows

Nus

Nusselt number on the shell side

Nut

Nusselt number on the tube side

NTU

Number of Transfer Units.

PL

Longitudinal Pitch

Ps

Pressure drop on the shell side

PT

Transverse Pitch

Pld

Dimensionless Longitudinal Pitch

Prs

Prandtl number on the shell side

Prt

Prandtl number on the tube side

Ptd

Dimensionless Transverse Pitch

Q

Overall heat duty

Qs

Heat duty on the shell side

Qt

Heat duty on the tube side

R

Capacity ratio

Res

Reynolds number on the shell side

Re

Reynolds number on the tube side

S

Temperature ratio

(s)

Tube thickness

Ti

Air inlet temperature on the shell side

ti

Water inlet temperature on the tube side

To

Air outlet temperature on the shell side

to

Water outlet temperature on the tube side

Tavg

Average (bulk) temperature on the shell side

Tavg

Average (bulk) temperature on the tube side

U

Overall heat transfer coefficient

Vs

Velocity of flow of air on the shell side

Vt

Velocity of flow of water through the tube

wt

Mass flow rate through each tube

Ft

Temperature difference correction factor

C

Factor for tube side heat transfer coefficient

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Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  • Yogesh Pradeep Bhatt
    • 1
  • Ashutosh Arun Joglekar
    • 1
  • Dattatray B. Hulwan
    • 2
  1. 1.Department of Mechanical Engineering, Suman Ramesh Tulsiani Technical Campus Faculty of Engineering KamshetSavitribai Phule Pune UniversityPuneIndia
  2. 2.Department of Mechanical EngineeringVishwakarma Institute of TechnologyPuneIndia

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