CFD Projects at the Energy Systems Laboratory IIT Gandhinagar

Transcription

1 CFD Projects at the Energy Systems Laboratory IIT Gandhinagar Atul Bhargav Assistant Professor

2 Energy Systems Research Overview Hydrocarbon based Fuel Cell Systems collaborations with Chemistry and Chemical Engineering Low-cost Wind-powered Brine Pumping Solutions Electronic Thermal Management Laboratory Safety

3 Energy Systems Research Overview Hydrocarbon based Fuel Cell Systems involves reacting flow with fluid mechanics and heat transfer Low-cost Wind-powered Brine Pumping Solutions Electronic Thermal Management Laboratory Safety

4 Electricity grid is unreliable in many parts of the world Remote cellular towers need backup power

5 Strong market need exists for small autonomous energy systems Currently, demand met with IC Engines: can solutions be cleaner, more efficient, silent?

6 Hydrogen-based remote standalone PEMFC systems are currently not practical H 2 Air Fuel Cell Array Stack H 2 -based PEMFC systems have been successfully used in warehousing and other centralized applications H 2 transport and storage is inefficient, especially in remote areas

7 Hydrocarbon-based PEMFC systems combine FC and HC efficiencies Fuel Processor H 2 Fuel Cell Array Stack Air High FC efficiency + HC energy density + Low infrastructure cost

8 Fuel Processing is a combination of several distinct processes

9 HC-based PEMFC systems involve extensive heat and mass recycling heat Burner Fuel Processor Fuel Cell Array Stack water air

10 Energy Systems Laboratory is engaged in CFD-aided research on FP and Burner heat Burner Fuel Processor Fuel Cell Array Stack water air

11 Pre-Catalytic Mixing Chamber Design using Computational Techniques Design Constraints Mixing Efficiency: Measured in terms of surface uniformity index Residence time Even velocity distribution at outlet Manufacturability Models were built in Autodesk Inventor and analyzed using Star CCM+

12 Flow Physics Laminar flow Three dimensional Multi-component gas Non-reacting (Later reactions were simulated using DARS)

13 Design of Pre-Mixer Residence time sec sec sec Surfaceuniformity Of Ethanol at outlet

14 Pre-mixer Design CAD Model

15 Results

16 Results: Chemical reaction simulation using DARS

17 Results: Chemical reaction simulation using DARS Reactions were simulated using DARS for 0.08 seconds to check the occurrence of chemical reaction time less than residence time of mixer (0.067) There is uncertainty in the results obtained because of lack of reference data required for validation Mass fraction of intermediate species was found to be very small (order of 10-2 )

18 Conclusion Final premixerdesign was found to be capable of satisfying design goals DARS can be used for simulating chemical reactions but it is computationally expensive

19 Simulation and Design Improvements to Water-gas Shift Membrane Reactors CO and H 2 O Argon Nakul Nuwal Prateek Nyati 19

20 Upper Half of reactor Pressure outlet (atmospheric pressure ) Water and CO inlet (mole fraction 0.5 each) Symmetry B.C. Nakul Nuwal Prateek Nyati 20

21 The WGS reaction was analyzed using CD-Adapco DARS package Porous WGS catalyst membrane (reaction Zone) Porous Steel Gauge to support the membrane Nakul Nuwal Prateek Nyati 21

22 Lower half of reactor Pressure outlet (atmospheric pressure ) Argon inlet Velocity = 1m/s Nakul Nuwal Prateek Nyati 22

23 Solution Models and Method Laminar flow Model Local time step model (Steady State) with activated source terms. Source terms are defined on the basis of forward and backward kinetic constants as mentioned in next slide. Number of steps run = Nakul Nuwal Prateek Nyati 23

24 Calculations for source terms = e (Forward rate) = e (Backward Rate) = [ ][ ] = + [ ][ ] = [ ][ ] = (Temperature source term) Nakul Nuwal Prateek Nyati 24

25 Results Nakul Nuwal Prateek Nyati 25

26 Velocity magnitude Nakul Nuwal Prateek Nyati 26

27 Molar concentration of Hydrogen Porous WGS catalyst membrane (reaction Zone) Porous Steel Gauge to support the membrane Nakul Nuwal Prateek Nyati 27

28 Experiments Aim to Validate Computational Models 60% Methane conversion vsresidence time CH4 conversion 50% 40% 30% 20% 10% 0% Residence time(s)

29 Energy Systems Research Overview Hydrocarbon based Fuel Cell Systems Low-cost Wind-powered Brine Pumping Solutions Electronic Thermal Management Involves fluid mechanics (laminar and turbulent) and heat transfer Laboratory Safety

30 Thermal Management of Data Centers: CFD Modeling and Control System Design 9/07/2013 Gaurav Mahamuni 30/28

31 Energy Systems Research Overview Hydrocarbon based Fuel Cell Systems Low-cost Wind-powered Brine Pumping Solutions Electronic Thermal Management Laboratory Safety Involves fluid mechanics (laminar and turbulent) and heat transfer

32 CFD is also used to carry out Safety Analysis at the ESL

33 H 2, CO & CH 4 Concentration Predictions Help in Locating Gas Detection Systems