Spatially Resolved Spray Scanning System and an Engineering Tool for Evaluating Sprinkler Performance

Transcription

1 Spatially Resolved Spray Scanning System and an Engineering Tool for Evaluating Sprinkler Performance Stephen Jordan SUPDET February 28, 2013 Orlando, FL

2 The Not-so-full-scale Full Scale Test Sitting around after a full scale test making final design preparations Someone asks a question, an awkward silence follows That moment where you realize the geometry of the protected space has changed. How much does 1ft matter? 2ft? Is near full scale close enough?

3 Introduction Stephen Jordan Custom Spray Solutions Principal University of Maryland Graduate Research Assistant

4 Overview The characterization technology. Dispersion modeling. SprayVIZ as an engineering design tool. Custom Spray Solutions and the future of sprinkler system design.

5 Characterization The state of the art facilities at UMD allow for the complete characterization of the spatio-stochastic spray formation. For both fire protection sprinklers and generalized spray nozzles Obtain detailed information about the volume flux, droplet size distribution, and relative spray velocity. Unmatched near field measurements.

6 Characterization Droplet formation differs for each sprinkler arrangement (k-factor, pressure, type).

7 Characterization Versatility of the testing apparatus and methodology allows for measurement optimization.

8 Characterization Tine Slot Reference Droplet ~ 2 mm Flux Measurements Droplet Size Measurements

9 Dispersion Modeling d > 2 mm 1 mm < d < 2 mm d < 1 mm Flux, mm/min Compact set of empirically determined coefficients with physical significance along and analytical Basis Functions are used to generate the spray in the dispersion model.

10 Custom Spray Solutions: Educating Engineering Judgment

11 Prescriptive Design Room Size Fuel Load Water Delivery NFPA13 Flux Layout System Design Existing NFPA13 engineering practices provide the sprinkler system design.

12 Performance Based Design System Design Room Size Fuel Load Quantitative Analysis Performance Evaluation New engineering practices and models are required for performance based sprinkler system design.

13 SprayVIZ Application of ten years of UMD suppression spray group research. Consideration for design variables: Sprinkler type, pressure, and orientation Spray obstructions, shadowing Ceiling slope and height SprayVIZ is an engineering design tool for evaluating the wetting performance of suppression system designs.

14 SprayVIZ

15 SprayVIZ

16 SprayVIZ Full scale testing drawbacks: Expensive Time consuming Limited flexibility and application SprayVIZ Quantitative data benefits: Comparison of alternative designs Design optimization Demonstrate equivalence

17 SprayVIZ Equivalence

18 SprayVIZ Comparisons 4:12 Deflector parallel to ceiling 4:12 Deflector parallel to floor

19 SprayVIZ Comparisons Recent study conducted for NFSA evaluating effect of slope and orientation a specific type of nozzle. White paper available on our website: Customspraysolutions.com

20 Custom Spray Solutions The Future The CSS methodology can be used to address many sprinkler protection challenges facing the industry, namely: Impact of pressure on actual delivered density Variations in the performance of similar sprinklers Sloped, curved, and other ceiling configurations and the impact on spray distribution Cloud and other complex ceiling arrangements and designs Deflector orientation effects on commodity protection and obstruction shadowing High clearance sprinkler problem in industrial operations Sprinkler droplet momentum interaction with fire and plume dynamics High cost of large scale testing

21 Questions Custom Spray Solutions spraysolutions.com