parametric cfd analysis of an embaffle heat exchanger · embaffle characteristics: full tube...

Parametric CFD analysis of an EMbaffle Heat Exchanger

EMbaffle B.V. The Netherlands

Brembana&Rolle Group


Reactors

Pressure Vessels & Columns

Conventional Heat Exchangers

Advanced Heat Exchangers

Waste Heat Recovery Units

Fired Heaters

ORC Systems


Step 1: Original concepts and patents

Step 2: Full-scale manufacturing and field tests in Shell operating plants

Step 3: Initial commercial licensing agreements

2002/04 Shell Global Solutions

2004/06 Netherlands and USA

2004/06 Globally

2007 Step 4: EMbaffle B.V. owned by Shell Technology Ventures Fund I

2012

Step 5: EMbaffle B.V. owned by B&R

EMbaffle Technology

Grid Production Process:

A sheet of metal is passed through a cutter

It is simultaneously cut and expanded

The resulting expanded sheet is welded to a support ring

EMbaffle Characteristics:

EMbaffle Technology


Full tube support

Segmental baffle EMbaffle

EMbaffle Technology


Full tube support

Open structure allowing pure longitudinal flow

EMbaffle Segmental baffle

EMbaffle Technology


Full tube support


No tubes vibration

EMbaffle Technology


Full tube support


Enhanced turbulence hence heat transfer coefficient

EMbaffle Technology


Full tube support


Enhanced turbulence hence heat transfer coefficient

More compact design

EMbaffle Technology


Geometry

(EMbaffle)

Fluid Dynamics

(Turbulence)

Thermodynamics

(Heat Transfer)

Low Shell side Fouling

No Tube Vibration

Low Pressure Drop

Energy & CO2 Savings

EMbaffle Technology

EMbaffle Applications:

Gas-to-gas (Gas Fields, LNG, etc)

Gas-to-liquid (Gas Coolers)

On-shore and off-shore processing

Refining and petrochemical

Concentrated Solar Power (CSP)

Geothermal

EMbaffle Technology

CFD Parametric Model

LWD Long Way of the grid Diamond

SWD Short Way of the grid Diamond

BL Bond Length

SW Strand Width

MT Material Thickness

Psi Deviation angle of the Strand Width

TOD Tube Outer Diameter

TT Tube Thickness

BS Baffle Spacing

n Number of consecutive grids


a) TubeFluid domain

b) Tube domain

c) ShellFluid domain


ShellFluid:

Symmetry

TubeFluid:

translational periodicity


Starting from 2002, several experimental tests were performed by EMbaffle in collaboration with:

Tests results were used to develop the correlations used to design an EMbaffle heat exchanger by means of the software:

Analysis Cases

Flow direction

Shell-side (n-pentane) Tube-side (water)

Tin (C) vin (m/s) Pin (kPa) Tin (C) vin (m/s) Pin (kPa)

Counter-

current

48 0.223

1636.2 95.64 0.431 665.96

Analysis Cases

Analysis Cases

1) Influence of the turbulence model on the performance

Analysis Cases

1) Influence of the turbulence model on the performance

2) Influence of the baffle spacing on the performance

Analysis Cases

Influence of the turbulence model on the performance:

ShellFluid domain: Shear Stress Transport

Analysis A:

TubeFluid domain: Shear Stress Transport

ShellFluid domain: Detached Eddy Simulation

Analysis B:

TubeFluid domain: Shear Stress Transport

Analysis Case 1

Results Case 1

Results Case 1

Experimental

data CFD Case 1 CFD Case 2 Units

SHELLSIDE

(COLD FLUID)

Fluid n-Pentane -

Turbulence Model - RANS-SST URANS-DES -

Mass flow rate 0.027709 Kg/s

Inlet velocity 0.222937 m/s

Inlet temperature 48 °C

Outlet temperature 83.47 76.7 76.8 °C

Boundary Conditions Heat Transfer Coefficient - 11000 W/m2 K

Outside Temperature - 85 °C

COMPARISON DATA Exchanged duty 2546 2069.9 2110.6 W

Duty mismatch - -18.7 -17.1 %

Influence of the baffle spacing on the performance:

Analysis A: baffle spacing = 50 mm

Analysis B: baffle spacing = 100 mm

Analysis C: baffle spacing = 200 mm

Analysis Case 2

Results Case 2

0.0002

0.0003

0.0004

0.0005

0.0006

0.0007

0.0008

0.0009

0.001

0.0011

0.0012

200 250 300 350 400

T.K

.E [

m^2

/s^2

]

X direction [mm]

BS = 50 mm

BS = 100 mm

BS = 200 mm

FLOW DIRECTION

Results Case 2

Baffle spacing [mm] Turbulence decay distance

from baffle [%]

50 86

100 37

200 18.5

A comparison between some experimental tests and the parametric CFD model was performed in order to validate it.

Two different turbulence models were applied to the shell-side fluid domain to find out which one was better matching the experimental data.

Results show that the CFD model is too conservative in comparison to the real performance of the EMbaffle HEX, even if the DES model seems to better match the real performance.

Conclusion

Performing extensive tests with several fluids (gas, molten salts, etc..) at different Reynolds ranges

Investigating the effect of different grid shapes on the thermal and hydraulic performance

Investigating the optimum baffle spacing in terms of minimum pressure drop and maximum heat transfer coefficient for each application

Simulating two phases flow

Future developments

Thank you for your attention

For further information:

www.EMbaffle.com

[email protected]

http://www.embaffle.com/

mailto:[email protected]

parametric cfd analysis of an embaffle heat exchanger · embaffle characteristics: full tube...

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