Parametric CFD analysis of an EMbaffle Heat Exchanger. EMbaffle B.V. The Netherlands

Transcription

1 Parametric CFD analysis of an EMbaffle Heat Exchanger EMbaffle B.V. The Netherlands

2 Brembana&Rolle Group

3 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

4 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

5 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

6 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

7 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

8 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

9 Brembana&Rolle Group Reactors Pressure Vessels & Columns Conventional Heat Exchangers Advanced Heat Exchangers Waste Heat Recovery Units Fired Heaters ORC Systems

10 Brembana&Rolle Group Step 1: Original concepts and patents 2002/04 Shell Global Solutions Step 2: Full-scale manufacturing and field tests in Shell operating plants 2004/06 Netherlands and USA Step 3: Initial commercial licensing agreements Step 4: EMbaffle B.V. owned by Shell Technology Ventures Fund I 2004/06 Globally 2007 Step 5: EMbaffle B.V. owned by B&R 2012

11 Grid Production Process: A sheet of metal is passed through a cutter It is simultaneously cut and expanded EMbaffle Technology The resulting expanded sheet is welded to a support ring

12 EMbaffle Characteristics: EMbaffle Technology

13 EMbaffle Characteristics: Full tube support EMbaffle Technology Segmental baffle EMbaffle

14 EMbaffle Characteristics: EMbaffle Technology Full tube support Open structure allowing pure longitudinal flow Segmental baffle EMbaffle

15 EMbaffle Characteristics: EMbaffle Technology Full tube support Open structure allowing pure longitudinal flow No tubes vibration

16 EMbaffle Characteristics: EMbaffle Technology Full tube support Open structure allowing pure longitudinal flow Enhanced turbulence hence heat transfer coefficient

17 EMbaffle Characteristics: EMbaffle Technology Full tube support Open structure allowing pure longitudinal flow Enhanced turbulence hence heat transfer coefficient More compact design

18 EMbaffle Characteristics: EMbaffle Technology Geometry (EMbaffle) Fluid Dynamics (Turbulence) Thermodynamics (Heat Transfer) Low Shell side Fouling No Tube Vibration Low Pressure Drop Energy & CO 2 Savings

19 EMbaffle Applications: EMbaffle Technology 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

20 CFD Parametric Model

21 CFD Parametric Model LWD SWD BL SW MT Psi TOD TT BS n Long Way of the grid Diamond Short Way of the grid Diamond Bond Length Strand Width Material Thickness Deviation angle of the Strand Width Tube Outer Diameter Tube Thickness Baffle Spacing Number of consecutive grids

22 CFD Parametric Model

23 CFD Parametric Model a) TubeFluid domain b) Tube domain c) ShellFluid domain

24 CFD Parametric Model

25 CFD Parametric Model ShellFluid: Symmetry TubeFluid: translational periodicity

26 Analysis Cases 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:

27 Analysis Cases Shell-side (n-pentane) Tube-side (water) Flow direction Countercurrent T in (C) v in (m/s) P in (kpa) T in (C) v in (m/s) P in (kpa)

28 Analysis Cases

29 Analysis Cases 1) Influence of the turbulence model on the performance

30 Analysis Cases 1) Influence of the turbulence model on the performance 2) Influence of the baffle spacing on the performance

31 Influence of the turbulence model on the performance: Analysis A: Analysis Case 1 ShellFluid domain: Shear Stress Transport TubeFluid domain: Shear Stress Transport Analysis B: ShellFluid domain: Detached Eddy Simulation TubeFluid domain: Shear Stress Transport

32 Results Case 1

33 Results Case 1

34 Results Case 1 Experimental data CFD Case 1 CFD Case 2 Units Fluid n-pentane - Turbulence Model - RANS-SST URANS-DES - SHELLSIDE (COLD FLUID) Boundary Conditions Mass flow rate Kg/s Inlet velocity m/s Inlet temperature 48 C Outlet temperature C Heat Transfer Coefficient W/m2 K Outside Temperature - 85 C COMPARISON DATA Exchanged duty W Duty mismatch %

35 Analysis Case 2 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

36 Results Case 2 FLOW DIRECTION BS = 50 mm BS = 100 mm BS = 200 mm T.K.E [m^2/s^2] X direction [mm]

37 Results Case 2 Baffle spacing [mm] Turbulence decay distance from baffle [%]

38 Conclusion 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 shellside 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.

39 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

40 Thank you for your attention For further information: