1 / 26

Strömningsteknisk modellering och konstruktion av pelletsbrännare och kaminer

Strömningsteknisk modellering och konstruktion av pelletsbrännare och kaminer. Henrik Wiinikka 1 , Stefan Westerlund 1 , Roger Hermansson 2 , Lars Westerlund 2 , Ida-Linn Nyström 2 och Marcus Öhman 2. 1 Energitekniskt centrum, 2 Luleå Tekniska Universitet (Energiteknik).

brinly
Download Presentation

Strömningsteknisk modellering och konstruktion av pelletsbrännare och kaminer

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Strömningsteknisk modellering och konstruktion av pelletsbrännare och kaminer Henrik Wiinikka1, Stefan Westerlund1, Roger Hermansson2, Lars Westerlund2 , Ida-Linn Nyström2 och Marcus Öhman2 1Energitekniskt centrum, 2Luleå Tekniska Universitet (Energiteknik) STEM programkonferens 2009-10-20

  2. Målsättning • Demonstrera CFD (Computational Fluid Dynamics) som praktiskt verktyg för förbränningsoptimering av småskalig pelletsteknik (brännare och kaminer) • Demonstrera generella konstruktionslösningar för småskalig pelletsteknik som möjliggör minimal skötsel (enkel askutmatning) och estetiskt tilltalande flamma som fortfarande ger låga emissioner

  3. Industripartner Piteå Kaminen SWEBO Bioenergy

  4. Genomförande

  5. Numerical and Experimental Investigation of Ash Transport during Wood Pellets Combustion Stefan Westerlund (ETC) and Ida-Linn Näzelius (LTU) 5

  6. Background • Furnaces does not have automatic ash removal • Leads to disposal issues • Is it possible to design the internal fluid flow for automatic ash removal? • CFD is a tool to investigate this. • Combined with experiments for validation 6

  7. CFD model, geometry 7

  8. CFD model, geometry Insulated wall 30° slice Burner cup Total length: 1695 mm 8

  9. CFD model, boundary conditions T = 600°C Periodic interface Ash trap Tertiary inlets Secondary inlet Primary inlet 9

  10. CFD model, mesh 30° slice # of Nodes: 1 132 643 # of Elements: 5 649 458 10

  11. Simulation cases • Parametric study = 7 cases • In order to determine the controlling parameters for particle carryover • One-way coupled particles introduced at the grate 11

  12. Simulation conditions • Simulations are performed with two different settings for the particle introduction: • Zero slip velocity; particles are given the initial velocity equal to the gaseous phase. • Fixed velocity particles are given higher initial velocity than the gaseous phase (5 m/s). 12

  13. Simulated cases 13

  14. Global Reactions (Jones-Lindstedt) Mathematical Models Tar Modeling (Klason, Bai, 2007) 14

  15. Mathematical Models • Combustion Model • EDCM (Magnusen and Hjerthager) • EDC coefficient A = 2.5 (default = 4) • Turbulence Model • k-epsilon • Radiation • P1 Thermal radiation model (Ansys) • Heat transfer • Thermal energy • Particles • Lagrangian particle transport, one-way coupled 15

  16. General aerodynamics Streamlines Particle tracks Temperatures/Ignition 16

  17. General aerodynamicsStreamlines 17

  18. General aerodynamicsTemperatures 18

  19. General aerodynamicsparticles Ash tray openings Grate 19

  20. Results 20

  21. Results 21

  22. Results 22

  23. Results Exp 23

  24. Results Exp 24

  25. Results Exp 25

  26. Conclusions The simulation with no secondary air shows that no particles are trapped in the ash tray. Increased oxygen content in the flue gas result in improved performance of trapping particles in the ash tray. Particles trapped in the ash tray increases with increased power output. Simulation and experiments generally show the right trends 26

More Related