Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes Unde

IJIRST –International Journal for Innovative Research in Science & Technology| Volume 3 | Issue 01 | June 2016 ISSN (online): 2349-6010

Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes under Various Flow Rates V. Ajaykumar PG Scholar Department of Thermal Engineering RVS College of Engineering & Technology, Coimbatore – 641402

R. Titus Assistant Professor Department of Mechanical Engineering RVS College of Engineering & Technology, Coimbatore – 641402

T. Sudhakar Assistant Professor Department of Mechanical Engineering RVS College of Engineering & Technology, Coimbatore – 641402

Abstract The objective of this project is to analyze heat transfer, pressure drop, in shell and tube heat exchanger with finned tubes and it is compared with unfinned tubes. Then, the shell and tube heat exchanger using copper is created using CATIA and flow ,thermal analysis is created using ANSYS and it is experimentally investigated under various flow rates.

Keywords: Shell And Tube Hex, Flow Rate, finned tubesANSYS14.5 _______________________________________________________________________________________________________ I.

INTRODUCTION

Heat exchangers have a huge application in various industrial sectors such as oil refining, chemical industries, power plants and refrigeration units. Among the various types of heat exchangers, shell and tube heat exchangers are most widely used about 3540%. The heat transfer rate of heat exchangers can be enhanced by two techniques active and passive methods. In this work, I am going to use one of the passive techniques that is extended surface in the form of fins.

II. DESIGN AND ANALYSIS Table – 1 Design Datas Number of Tubes 6 Outside Dia 0.015m Inside Dia 0.0125m Length of Tube 0.5m Shell Dia, Ds 0.10m Bundle Clearance 0.0225m No of Baffles 6 Baffle Cut 30% Baffle Thickness 2mm Hot Tube Height 50mm Hot Tube Dia 40mm

Calculation: Bundle DIA, Db= do*3.93 =0.058M=58MM Pitch of Tubes, P= 1.25*do =0.01875m=18.75mm Baffle Spacing, Bs=0.8*Ds =0.08M=80MM

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Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes under Various Flow Rates (IJIRST/ Volume 3 / Issue 01/ 032)

Provisional Area, A=Nt*do*3.14*L =6*0.015*3.14*0.5==0.132 m2 III. DESIGN CATIA (Computer Aided Three-dimensional Interactive Application) started as an in house development in 1977 by French aircraft manufacturer Avions Marcel Dassault, at that time it was used to develop Dassult’s Mirage fighter jet. CATIA offers a solution to facillate the design and manufacturing of routed systems including tubing, piping, heating, ventilating & air conditioning. In this work, CATIA V5 software is used to design the shell and tube heat exchanger.

Fig. 1: shell and tube heat exchanger

Fin Design Data’s: NO OF FINS LENGTH THICKNESS HEIGHT

Table - 2 3(ON EACH TUBE) 100 mm 3.5 mm 6mm

Fig. 2: Tube with fin

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Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes under Various Flow Rates (IJIRST/ Volume 3 / Issue 01/ 032)

IV. ANALYSIS The model generated using CATIA is the imported in ANSYS FLUENT. ANSYS is general-purpose finite element analysis (FEA) software package. The basis of thermal analysis in ANSYS is heat balance equation obtained from the principle of conservation of energy. The ANSYS program handles all three modes of heat transfer: conduction, convection, radiation and flow analysis.

A fine mesh is generated using the solver to obtain exact result. The mesh file is shown in the figure.

Fig. 3: Mesh file

Flow Analysis of Shell and Tube Heat Exchanger The flow analysis is carried by fixing static pressure condition and hot fluid inlet temperature 333k, cold fluid inlet 300k.

Fig. 4: Flow model

In this task the flow model is provided with pressure based and gravity is neglected in this analysis. This figure clearly shows flow and temperature distribution.

Now Enable the required residuals and Set the Surface Monitors for Mass-flow rate and Exit-velocity to proceed to calculation.

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Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes under Various Flow Rates (IJIRST/ Volume 3 / Issue 01/ 032)

V. COMPUTATIONAL RESULTS Comparison between Finned and Unfinned Tubes For Unfinned Tubes

For Finned Tubes

By varying the flow the following results have been taken,

S.NO

VELOCITY(m/s)

1 2 3 4

0.09 0.1 0.2 0.3

Table – 3 Temperature Variation between Finned and Unfinned Tubes Net heat Shell inlet Shell outlet temperature(k) transfer temperature(k) unfinned tubes 18.06 335 331 22.47 335 329 25.49 335 328 27.94 335 330

Shell outlet temperature(k) finned tubes 326 321 318 313

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Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes under Various Flow Rates (IJIRST/ Volume 3 / Issue 01/ 032)

Table – 4 Pressure Variation between Finned and Unfinned Tubes S.NO

VELOCIY (m/s)

Shell inlet pressure (pa)

Shell outlet pressure (pa) Unfinned tubes

Shell outlet pressure (pa) Finned tubes

Pressure drop Unfinned (pa)

1 2 3 4

0.09 0.1 0.2 0.3

401325 401325 401325 401325

401174 400840 400659 400345

401123 400986 400865 400325

151 485 680 980

Pressure drop Finned (pa) 202 339 460 1000

From the computational results it is found that finned tubes influences more amount of heat transfer than the unfinned tubes but there is a small variation in pressure drop. We can minimize the pressure drop during experimental analysis by optimum construction and working parameters.

VI. EXPERIMENTAL INVESTIGATION

Fig. 5: Inner section

Fig. 6: Heat exchanger

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Computational and Experimental Investigation of Shell and Tube Heat Exchanger with Finned Tubes under Various Flow Rates (IJIRST/ Volume 3 / Issue 01/ 032)

Sl.NO 1 2 3 4

Table – 5 From the experiment, the following readings has been taken Shell outlet temperature(k) Shell outlet pressure (Pa) Flow rate (Experimental) (Experimental) 0.09 401123 401010 0.1 400986 400850 0.2 400865 400770 0.3 400325 400100

VII. RESULT Comparison between Computational and Experimental Readings Table – 6 Temperature Variation Shell outlet pressure (Pa) Shell outlet pressure (Pa) Sl.NO Flow rate (computational) (experimental) 1 0.09 401123 401010 2 0.1 400986 400850 3 0.2 400865 400770 4 0.3 400325 400100 Table – 7 Pressure Variation Shell outlet temperature (k) Shell outlet temperature (k) Sl.NO Flow rate Variation (computational) (experimental) 1 0.09 326 328 0.61 2 0.1 321 323 0.62 3 0.2 318 320 0.63 4 0.3 313 316 0.95

VIII. CONCLUSION The flow analysis has been performed with ANSYS fluent with different tubes such as finned and unfinned tubes by varying the hot fluid velocity. Then the temperature variation and pressure drop between the two types of tubes have been computationally investigated and it is found that the usage of finned tubes influences the heat transfer between the fluids. After that Shell and tube heat exchanger is constructed with finned tubes and it is experimentally investigated. From the experimental readings it has been found that the fins enhance the heat transfer rate more than 8oC then that of normal tubes used in heat exchanger.

REFERENCES [1] [2] [3] [4] [5] [6]

Tambe Shahanwaj K1, Pandhare Nitin, ‘Experimental investigation of performance of plate heat exchanger for water as working fluid,’ IJRET, eISSN: 2319-1163 | pISSN: 2321-7308 S. Bhanuteja1, D.Azad2,’ thermal performance and flow analysis of nanofluids in a shell and tube heat exchanger,’ International journal of mechanical engineering and technology (ijmet) Volume 4, Issue 5, September - October (2013), pp. 164-172 Design and rating of shell and tube heat exchangers by John E.Edwards, MNL 032A Issued 29 August 08, Prepared by J.E.Edwards of P & I Design Ltd, Teesside B.Jayachandriah, K. Rajasekhar,‘ Thermal Analysis of Tubular Heat Exchangers Using ANSYS,’ Volume No.3 Issue No: Special 1, pp: 21-25.

Sandeep M, U Sathishkumar, ‘CFD Investigation of Influence of Tube Bundle Cross-Section over Pressure Drop and Heat Transfer Rate,’ International Journal of Science, Engineering and Technology Research (IJSETR), Volume 4, Issue 5, May 2015.

Priyanka G, M. R. Nagraj, ‘CFD Analysis of Shell and Tube Heat Exchanger With and Without Fins for Waste Heat RecoveryApplications, International Journal of Science and Research (IJSR), ISSN (Online): 2319-7064,2014.

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