ashrae qatar oryx chapter:...
TRANSCRIPT
ASHRAE Qatar Oryx Chapter: 09.04.2016
Introduction to Design of Car Park ventilation using JetFans & CFD analysis as QCD
Presented by Paul Mason Business Development Manager Soler & Palau
Ventilation Fundamentals
Why ventilate?
Where & When Ventilate?
Fire; Risk or Not?
Basic Principles
Ducted System
Impulse Ventilation / JetFan System
How Does It Work?
Comparison Ducted v Impulse / JetFan.
Regulations by Country
Qatar CD FSS requirements
AGENDA
Smoke Control
Road Tunnel
Car Park
Car Fire Heat Release Rate HRR
Impulse Ventilation; Fundamentals for Design
Required Information
Fundamentals for Design
Impulse Ventilation – Comissioning
Fan products
CFD Project examples
Questions
AGENDA
WHY VENTILATE?
POLLUTION, FIRE SMOKE, FIRE HAZARDS, FIRE SAFETY.
• Pollution:- Typical pollutant:- Carbon Monoxide CO A colourless, odourless toxic gas produced by incomplete combustion
of fuels such as petrol and diesel. Indoor CO guidelines:- 15 minutes: 100mg/m3 86ppm. 1 hour: 35mg/m3 30ppm. 8 hours: 10mg/m3 9ppm.
Source: World Health Organisation (WHO) Guidelines for indoor air quality, 2009.
For enclosed car parking:- UK BS 7346-7:2013 refers:- 15 min: 90ppm. 8 hour average: 30ppm. ASHRAE Handbook refers:- 8 hour: 25ppm.
Other Pollutants:- CO2, NOx, NO2, Soot etc… Consider:- Is incoming air, FRESH?
Fire smoke
• Fire smoke:-
The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass.
Source:
NFPA 92 – 2012, Chapter 3.3.13
ASHRAE Chapter 53
Fire smoke
Smoke Inhalation
Fire smoke
• Smoke inhalation: Is the primary cause of death in victims of indoor
fires. It is estimated that 50–80% of fire deaths are the
result of smoke inhalation injuries, including burns to the respiratory system.
The hot smoke injures or kills by a combination of thermal damage, poisoning and pulmonary irritation and swelling, caused by carbon monoxide, cyanide and other combustion products.
Source: eMedicineHealth
Smoke…causes the most deaths in fires. Source ASHRAE Chapter 53
Flashover
Fire Hazards
• Flashover:-
Is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. Flashover occurs when the majority of the exposed surfaces in a space are heated to their auto-ignition temperature and emit flammable gases. Flashover normally occurs at 500°C +
Source: Backdraft and flashover; what's the difference?, V.Dunn, Deputy Chief, F. D. N. Y. (Ret.), 2011
• Backdraft:-
Is an explosive event at a fire resulting from rapid re-introduction of oxygen to combustion in an oxygen-starved environment, for example, the breaking of a window or opening of a door to an enclosed space. Backdrafts present a serious threat to firefighters, even those with a high level of experience
Source: Backdraft and flashover;
what's the difference?
V.Dunn, Deputy Chief, FDNY. 2011
Backdraft
Fire Hazards
WHERE & WHEN VENTILATE?
Design Fundamentals:- Includes one or more of the following
1. Containing the smoke to the zone of fire origin. 2. Maintaining a tenable environment within exit
stairwells for the time necessary to allow occupants to exit the building.
3. Maintaining a tenable environment within all exit access and smoke refuge area access paths for the time necessary to allow occupants to reach an exit or smoke refuge area.
4. Maintaining the smoke layer interface to a predetermined elevation in large volume spaces.
Source: NFPA 92: 2012 Chapter 4.1.2.
• Where to use: – Staircase Pressurization – Atria – Car Park
• When to use: – To assist safe evacuation of occupants – To assist fire fighter access
• Typical Design guidance: Europe: BS 7346-7, EN 12101-6, CEN/TR12101-5 USA: NFPA 88A Standard for Parking structures, NFPA 92 Standard for Smoke Control Systems. ASHRAE Handbook smoke Control
Emergency Extract
Fire safety
Pressure differential:-
• Protection of emergency escape routes
• Create positive pressure to resist smoke
entry to escape route (+50Pa)
• Use of pressure relief to atmosphere to
balance door openings
• Provide sufficient airflow through door
openings to resist smoke flow. (0.75 / 2.0 m/s)
Pressure differential systems
• Design guidance refer EN12101-6:
• NFPA 92.
Large spaces, Atrium:
• Design guidance refer TR12101-5:
• NFPA 92.
Staircase Pressurisation & Atria
Fire safety
FIRE, RISK OR NOT?
• Place Vendome, Paris, France • 2012.03.08
• Car park, 35,000m², on 5 floors
• Ducted ventilation, no sprinklers
• 1,400 car spaces
• 40+ cars burnt. Source: news web
Real Risk - FIRE
Fire risk?
Source: Pompier de Paris
• Parking del Ensanche, Spain
• 2012.12.24
• Car park, 7,400m² on 3 floors.
• Ducted ventilation, no sprinklers Source: EITB news web
Real Risk - FIRE
Fire risk?
Source: EITB
• Car Park, Brighton UK
• 2015.04.04.
• No sprinklers. Source: Brighton & Hove News web
Real Risk - FIRE
Fire risk?
Real Risk - FIRE
Fire risk?
• Parking, Tesco supermarket, Oldham, UK
• 2015.07.29
• Fireman;- “Three cars were on fire. The store evacuated everyone really quickly and thankfully there were no casualties”
• No sprinklers.
BASIC PRINCIPLES DUCTED SYSTEM
Historical use of ducts for extract ventilation.
Fresh air inlet may be uncontrolled
Historical Ducted Car Park Ventilation
Basic Principles
EXHAUST FANS
5 ACH LOW LEVEL
DUCT
Fresh air
Extract fans 6 -10 ACH
50 % air at
low level
NPV 6 ACH – Normal Pollution Ventilation at high and low level
EM 10 ACH – Emergency extract 50% high and 50% low level
50 % air at high level
Basic Principles
Ducted Method
Duct Installation
Basic Principles
Examples of ducting within car parking
area, to show conflict with other services.
More examples of ducting within car parking area,
to show conflict with other services!
Basic Principles
Duct Installation
Ducted System
• Extract Ducts:
– Take up space
– Increase fan pressure
– May conflict with other services: • Pipes
• Sprinklers
• Electrical
• Lighting
Basic Principles
BASIC PRINCIPLES IMPULSE VENTILATION SYSTEM
Jet Fan
Jet Fan System
Basic Principles
What is a Jetfan?
Jetfan system
Impulse fan
Induction fan
Thrust fan
In this presentation all these are referred to as: Jetfan
Fresh air
Jet Fan
NPV 6 ACH – Normal Pollution Ventilation
EM 10 ACH – Emergency Smoke Clearance
EM Calculated – Emergency Smoke Control
Jet Fan System
Basic Principles
Extract fans 6 - 10 ACH or Calculated for Smoke Control
Jet Fans System – Without Ducting
BASIC PRINCIPLES IMPULSE VENTILATION SYSTEM
HOW DOES IT WORK?
• Main Extract Fans provide – Required Air Changes per Hour (ACH) – Flow rate per car parking space – Required Smoke Control extract rate
• Air is drawn in via – Ramps – Louvers – Shafts – Or supplied by fans
• Jet Fans Induce the air/smoke towards extract points
Jet Fan System
Basic Principles
Jet Fan System – Smoke Clearance
Basic Principles
Air is drawn in, and Jetfans local to the fire operate to induce air and smoke toward the extract points
• No ducting in the parking area – Reduced fan pressure – Reduced power consumption (kW) – Reduced cost
• No ducting to be damaged, cleaned, maintained, or obstruct other services, piping, electrical, sprinklers…
• More space for parking • Improved visibility, CCTV, and appearance in parking
area • May reduce height of car park, saving building cost • Jetfan ventilation can provide Smoke Clearance, as ducts • Jetfan ventilation can also be sized for Smoke Control
Jet Fan VS. Ducted Ventilation
Potential Benefits
Jet Fans System – Without Ducting
Potential Benefits
COMPARISON DUCTED V IMPULSE
CFD –Technologies Comparison
Car park – Spain comparrison.
Description:
• Fire Simulation in Basement -2
• Height: 2.84m
• Floor Area: 1,910 m2
• Air inlet through interconnecting ramp
• Flat Ceiling
• Extract points quantity: Variable
• Radiation 25%
• Fire Size:
• Width 2m
• Length 5m
• Jet fans Delay: 180s (130s after fire ignition)
• CFD End Time: 500s
Location 1
Location 2
Ducted System
Description:
• Smoke Clearance – Fire location 2
• 2 Ducts
• 47,530 m3/h to Spain Regulations
• 13 extract grilles of 500 x 300mm
CFD –Technologies Comparison
Impulse Ventilation System
Description:
• Smoke Clearance – Fire Location 2
• 1 Extract Point
• Extract Airflow 53,960 m3/h (10ACH)
• 1 Extract Grille of 3000 x 1000mm
• 3 x TJHU/2/4-315-BC 0,8/0,2kW F400
• 1 x IFHT-75N 4/8-C 2,2/0,37kW F400
CFD –Technologies Comparison
Impulse Ventilation System
Descripción:
• Smoke Control – Fire Location 2
• 1 Extract Point
• Extract Airflow 155,000 m3/h
• 1 Extract Grille of 4000 x 2000mm
• 2 x TJHU/2/4-315-BC 0,8/0,2kW F400
• 4 x IFHT-75N 4/8-C 2,2/0,37kW F400
CFD –Technologies Comparison
CFD – TECHNOLOGIES COMPARISON FIRE LOCATION 2
Ducted System – Smoke clearance
Main Conclusions
• Low air velocities on the right side
• Low Visibility
• High Temperature
Velocity
Visibility
Temperatures
CFD –Technologies Comparison
CFD – Comparación Tecnologías Impulse Ventilation System
Smoke clearance
Main Conclusions:
• No significant stagnant air areas
• Homogeneous Visibility
• Lower Upstream Temperature
Velocity
Visibility
Temperatures
Impulse Ventilation System
Smoke Control
Main Conclusions:
• No stagnant areas
• Visibility more than 10m
• Temperature lower than 60° C
• Firefighter access from lower left stair
Velocity
Visibility
Temperatures
CFD –Technologies Comparison
REGULATIONS BY COUNTRY DESIGN & ACCEPTANCE CRITERIA
Ventilation requirements by country
Regulation Ventilation NPV Pollution Smoke EM Temp deg C
Europe
UK BS 7346-7:2013 6 ac/h CO 30ppm-8h 10 ach 300 / 1h
CO 90ppm-15min
ROW
Bahrain 6 ac/h 10 ach 300 / 1h
Dubai DCD 6 ac/h 10 ach 300 / 1h
DCD 6 ac/h Performance Based
Oman 6 ac/h 10 ach 300 / 1h
Qatar NFPA 88A 300L/min/m2
ASHRAE ch15 6 ac/h CO 25ppm
QCD FSS 6 ac/h 10 ach 300 / 2h Ducted systems - Smoke Clearance
QCD FSS 6 ac/h Performance based 300 / 2h Jetfan systems - Smoke Control
Jordan 6 ac/h 10 ach
Egypt 6 ac/h 8 ach 200 / 2h With sprinklers
USA ASHRAE 7.6 l/s / m2 CO 25ppm-8h
CO 35ppm-1h
USA NFPA 5 l/s / m2 300 l/min / m2 NFPA 88A 2011
QATAR CD FSS REQUIREMENTS
Qatar CD GA 7.0 : Guidelines Annex – Ventilation and Smoke Control
4.7 Car Parks
4.7.1-3 Car park ventilation systems employing thrust fans shall be confirmed through performance based analysis. The use of CFD fire modeling and the following input parameters shall be considered in the design.
4.7.1-4 Design fire size: 4 MW (2m x 5m) with automatic sprinklers
8 MW (5m x 5m without sprinklers
4.7.1-6 Design fire: Flaming polyurethane
4.7.1-7 Design fire: Most onerous location
4.7.1-8 Acceptance criteria 1.8m above floor, 10m radius of fire, 20 minutes.
a) Minimum 10m visibility upstream
b) Temperature of smoke layer not exceed 60°C
4.7.1-9 CFD simulation must be minimum 30 mins
grid size max 0.2 x 0.2 x 0.2m within 10m of fire, and max 0.4 x 0.4 x 0.4m elsewhere
4,7.1-10 Sensitivity study for loss of Jetfan.
FIRE SMOKE CONTROL
EXAMPLE ROAD TUNNEL
Smoke control - Road Tunnels
Smoke Velocity (Vs) Typical 1 – 1.5 m/s
where: Tunnel: 10m (w) x 5m (h)
Car Fire 8MW
Basic Principles
• Based on Heselden’s method of predicting smoke velocity
• Refer: ASHRAE Handbook Chapter 15.
NFPA 502,
Critical velocity of 1 - 1.5m/s
CAR FIRE – 3MW
Induced air
JETFAN
Velocity > 18m/s
Jet Fan Energy from fire
moves smoke
Vs = 2.8m/s
Smoke Velocity (Vs)
Smoke control - Road Tunnels
Basic Principles
FIRE SMOKE CONTROL
CAR PARK
Smoke Perimeter
Ps
Inlet air via ramp
Extract Fans
Fire-fighters
access
Smoke control – Car parks
Basic Principles
For Car Park the tunnel theory is adapted to take Ps to be Smoke Perimeter
Fire fighter access to within 10m in tenable conditions
Smoke control – Car parks
Basic Principles
Extract Fans
Inlet air via ramp
Fire-fighters
access
Smoke Perimeter
BASIC PRINCIPLES – SMOKE CONTROL
HOW MUCH HEAT AND SMOKE IS PRODUCED BY A CAR FIRE?
where:
M = Mass rate of smoke production (kg/sec) = 11.62
P = Perimeter of fire (m) 14m
Y = Height of smoke layer (m) 2.5m
Ce = Constant 0.19 / 0.21 / 0.34
M
Y
M = CePY3/2
P
Source: BRE 368:Large Plume Model
M
Fire smoke Calculation of the rate of fire smoke
production
(K) mpambient te Absolute x kg/m³ 1.22
(K) layer temp smoke Absolute x (kg/s) production Smoke (m³/s) smoke of Volume
where:
• Effective height of Car Park = 3 m
• Effective height of Clear Layer Y = 2.5 m
• Fire perimeter P = 14 m source GA _7.0 or BS 7346-7:2013
• Design Fire size HRR = 4MW source GA_7.0 or BS 73467:2006 (with sprinklers)
• Radiation to structure ? To obtain Convective heat flow in gas kW
• Absolute ambient temp (K) ? = 273 + 46 = 319K
Smoke Control
Calculate Smoke Volume Flow
where:
c = 1.012 [kW / (kg·K)]
Q = convective heat release rate [kW]
M = mass of smoke production [kg/s]
θ = temperature of smoke layer, above ambient [K]
(K) mpambient te Absolute x kg/m³ 1.22
(K) layer temp smoke Absolute x (kg/s) production Smoke (m³/s) smoke of Volume
where:
• Effective height of Car Park = 3 m
• Effective height of Clear Layer Y = 2.5 m
• Fire perimeter P = 14 m source GA _7.0 or BS 7346-7:2013
• Design Fire size HRR = 4MW source GA_7.0 or BS 73467:2006 (with sprinklers)
• Convective Radiation to structure
• Absolute ambient temp (K) = 273 + 46 = 319K
• Volume of smoke = 16.84 m³/s
• Absolute smoke layer = 557K (557 – 273 = 284° C)
• Refer:- H Morgan Technical paper – formulas, NFPA 92, ASHRAE Handbook
Smoke Control
Calculate Smoke Volume Flow
Actual car fire tests Source: BRE Report Fire spread in car parks BD 2552: 2010
Source: UK CLG / BRE report BD2552 Fire spread in car parks.
Fire Testing
HRR VS. time
Fire Test
Test 1 – 3 cars, no sprinklers
Heat Release Rate (HRR)
Test 1: 16MW @ 21 min from ignition
Source: UK CLG / BRE research 2006-9
Test 2 – 3 cars, sprinklers
Fire Test
Source: UK CLG / BRE research 2006-9
Heat Release Rate (HRR)
Test 2:
• <1MW @ 41 min from ignition
• 7MW @ 54 min from ignition
CAR PARK IMPULSE VENTILATION
FUNDAMENTALS FOR SMOKE CONTROL
Fundamentals for Design
• AutoCAD Drawings – Layout
– Sections
• Down-stand obstructions
• Sprinklers system
• Identify aceptable extract / supply air points.
• Zoning (virtual / physical)
• Fireman access points
Required Information
• Impulse fans location according to:
a. Geometry
b. Supply points
c. Exhaust points
Exhaust
Supply
Final Design
Pre Study (PS)
• Analysis of inputs: a. Geometry:
a. Surface
b. Height
c. Obstructions
b. Mark locations: a. Ramps
b. Supply Points
c. Exhaust Points
d. Suggest if N/E
c. Suggest / Consider: a. Zoning (Physical / Virtual)
b. Openings
c. Escape routes
d. Access for fire-fighters
Exhaust
Supply
Partial Design
Airflow
Fundamentals for Design
Desgin Criteria
Boundary Conditions
• FA and EA should not be too close
– Avoid short-circuit
– Avoid non natural
air movement
– Avoid risk of outflow, or compromising ramps
If unable to achieve acceptable cross flow ventilation, to allow fireman access, or air flow rate, then maybe not possible for Smoke Control ?
• Jet Fans Activation System
– Manual
– Timer
– Pollution Detection System
• Low Pollution
• High Pollution
– Fire Detection System
• Smoke
• Rapid Temperature Rise
• Multicriteria
• Jet fans Operation System – Delay?
Control the System
Fundamentals for Design
Calculation :-
Now consider Car Park Calculation :-
Refer Technical paper:-
Extending the principles of Impulse Ventilation in Tunnels to apply to smoke control in car parks.
H.P. Morgan http://www.bse.polyu.edu.hk/researchCentre/Fire_Engineering/summary_of_output/journal/IJEPBFC/V6/p.53-71.pdf
Also NFPA 502
Calculate air / smoke flow
Extract Fans’ Airflow
Smoke Production
Smoke reservoir
Advance Nose Velocity + JF cooling effect
Advance Nose Velocity
M = CePY3/2
Flat Ceiling
Longitudinal Beams
Transversal Beams
hg
vFr
as
a
..
.²
2
Real Test
NFPA 502
CAR PARK IMPULSE VENTILATION
COMISSIONING
Real Fire Tests: IKEA, Caen
Cold Smoke Tests: San Mames, Bilbao
http://www.youtube.com/user/SyPVentilation?feature=mhsn#p/u/5/pj-ScGU_TX8
Jet Fan Operation
TYPICAL FAN PRODUCTS FOR CAR PARK VENTILATION
Product
Qatar requirement:- QCD FSS 1.1 Basic Requirements, Item 19.0. 28.06.2010 Temperature rating of fans for Smoke Control Systems “Smoke control fans must be UL Listed, FM approved, CE mark or LPC certified” “Fans must be capable of operating at minimum 250°C for 2 hours”
Product
QCD FSS 1.1 Basic Requirements Item 19.0 Temperature rating of fans for Smoke Control Systems UL Listed, FM approved: Unable to identify an applicable test for powered ventilation fans. UL 793 refers to “automatically operated roof vents” Refer: UL web http://ulstandards.ul.com/standard/?id=793 FM has no entry for powered ventilating fan. Refer: FM web http://www.fmapprovals.com/ ASHRAE 149-2000 applicable?
Product
QCD FSS 1.1 Basic Requirements Item 19.0 Temperature rating of fans for Smoke Control Systems EN 12101-3 is specifically for “Smoke and heat control systems. Specification for powered smoke and heat exhaust ventilators” This is a series of prescribed tests by an independent Test house to approve a range of products. This is mandatory in Europe to obtain CE mark. This is mandatory to obtain LPC listing.
Product
EN 12101-3 • Applicable to powered smoke and heat control ventilators. • Typical JetFan test is completely submerged in the furnace. • Independent test of highest stressed samples from range. • After 15 mins, switch off fan for 2 min, then restart. • Typical test temperatures: F200, F250, F300, F400 • Ongoing inspection of factory production. • Certification enables use of:-
Product
Fan Types • Applicable to:- • Axial, • Centrifugal, • Roof, • JetFans,
Product
Typical EN 12101-3 Independent test approval:-
The following examples are made with:- Fire Dynamics Simulator (FDS) and Smokeview (SMV) has been developed by NIST – USA. FDS is a large-eddy simulation (LES) code for low-speed flows, with an emphasis on smoke and heat transport from fires. SMV is a visulization program used to display the output of FDS and CFAST simulations Refer validation test reports from NIST and 3rd parties Refer https://pages.nist.gov/fds-smv/index.html There are other CFD tools that may also be suitable. The user should ensure that any tool used is validated for application, especially if used for smoke analysis.
CFD is a powerful, rapidly evolving tool used for the prediction and analysis of fluid flows. The technique is able to provide a time-dependent three dimensional approximate solution to the highly coupled differential equations that govern fluid flows. However, a number of assumptions and approximations are made throughout. Source: HSL Buxton, UK – Guidance for HSE Inspectors. “poor information in = poor information out”
Key points for assessing CFD results:- The practitioner must have an in-depth understanding of mechanical ventilation, CFD, fire and smoke dynamics. The CFD code employed should be validated for application to fire and smoke movement. The level of geometric detail represented should include anything that might significantly affect the flow. The design of the computational grid – disposition of grid cells and their size should be based on an understanding of the key flow phenomena and experience. Boundary conditions, Smoke transport….. Source: HSL Buxton, UK – Guidance for HSE Inspectors. “poor information in = poor information out”
Example CFD projects for Smoke Control:-
Future?
QUESTIONS?
Introduction to Design of Car Park ventilation using JetFans & CFD analysis as QCD
Presented by Paul Mason Business Development Manager Soler & Palau
Technical paper H Morgan:- http://www.bse.polyu.edu.hk/researchCentre/Fire_Engineering/summary_of_output/journal/IJEPBFC/V6/p.53-71.pdf