NRCC Experimental Fire Tower for Studies on Smoke Movement and Smoke Control in Tall Buildings

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NRCC Experimental Fire Tower for Studies on Smoke Movement and

Smoke Control in Tall Buildings

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NRCC EXPERIMENTAL FIRE TOWER FOR STULlIES ON SMOKE MOVEMENT AND SMOKE CONTROL I N TALL BUILDINGS

Table of Contents Page

iii L i s t of Tables L i s t of F i g u r e s A b s t r a c t I n t r o d u c t i o n and Background N a t i o n a l F i r e Laboratory Experimental F i r e Tower 3.1

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Experimental Tower 3.2

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S e r v i c e Tower 3.3

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F e a t u r e s of t h e Tower

Mechanical P r e s s u r i z a t i o n and Exhaust Systems

4.1

-

A i r Systems C o n f i g u r a t i o n 4.2

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A i r Plow Measuring Systems

I n s t r u m e n t a t i o n and Measuring Techniques Data A c q u i s i t i o n and C o n t r o l System

6.1

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Sensors and Devices D e s c r i p t i o n

6.2

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System F u n c t i o n and User

-

System I n t e r f a c e 6.3

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System Hardware

6.4

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System Software

6.5

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System Performance

F i r e S i m u l a t i o n Using Gas Burners System

7.1 Burners System

7.2 S a f e t y F e a t u r e s

Summary of t h e Tower's Research and Development C a p a b i l i t i e s

References

Acknowledgements Tables

Figures

Appendix A

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Calibration of the Air Flow Measuring System Appendix B

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Instrumentation and Measuring Techniques

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Detailed Description

Appendix C

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Fire Tower Database Reference Lists

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Data Acquisition and Control System

Page 20 2 2 23 28 49 5 3

iii

L i s t of Tables

T a b l e 1 D e s c r i p t i o n of t h e Experimental F i r e Tower Table 2 _{Flow Area of S h a f t s and W a l l Openings}

Table 3 Fan Performance Data

Table 4 Sensors and Devices f o r t h e Experimental F i r e Tower

-

Data A c q u i s i t i o n System

Table 5 F i r e Tower Computer L i n e s

L i s t of F i g u r e s F i g u r e 1 NRC N a t i o n a l F i r e Laboratory

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A e r i a l View. F i g u r e 2 N a t i o n a l F i r e Laboratory

-

P l a n View. F i g u r e 3 N a t i o n a l F i r e Laboratory

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E l e v a t i o n View. F i g u r e 4 S e r v i c e Unit F l o o r Plan. F i g u r e 5 T y p i c a l F l o o r P l a n

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Experimental F i r e Tower. F i g u r e 6 Ground F l o o r Plan View.

F i g u r e 7 Cross s e c t i o n a l e l e v a t i o n view of t h e Tower and Mechanical Room.

F i g u r e 8 Schematic Diagram of t h e Tower's A i r Flow Systems. F i g u r e 9 A Layout of t h e A i r Handling Equipment i n t h e Tower's

Mechanical Room.

F i g u r e 10 View of T y p i c a l A i r Flow Measuring S t a t i o n , Am-5 of Supply Fan84.

F i g u r e 1 1 View of t h e Air Handling Operation C o n t r o l System

-

C o n t r o l Room.

F i g u r e 12 Locations of P r e s s u r e Taps, T h e r m c o u p l e s and Gas Sampling f o r a T y p i c a l Floor.

F i g u r e 13 Thermocouples Locations on t h e F i r e F l o o r (2nd f l o o r )

F i g u r e 14 Schematic R e p r e s e n t a t i o n of t h e I n s t r u m e n t a t i o n System f o r a T y p i c a l F l o o r .

F i g u r e 15 I n s t r u m e n t a t i o n Arrangement i n t h e F i r e F l o o r ' s Observation Room (2nd f l o o r ) .

F i g u r e 16 A Close Up View of t h e P r e s s u r e S c a n i v a l v e Unit. F i g u r e 17 A Close Up View of t h e Gas Samplivalve Unit.

F i g u r e 18 Schematic R e p r e s e n t a t i o n of t h e Minicomputer-Based Data A c q u i s i t i o n and C o n t r o l System of t h e NRC-NFL.

F i g u r e 19 Schematic R e p r e s e n t a t i o n of t h e Tower's Data A c q u i s i t i o n and Control-System Hardware C o n f i g u r a t i o n .

F i g u r e 20 Schematic R e p r e s e n t a t i o n of t h e Gas Burners System.

F i g u r e 21 I n s t a l l a t i o n of Two S e t s of Propane Gas Burners

-

F i r e F l o o r (2nd f l o o r ) .

F i g u r e 22 Thermocouples Locations on Gas Burners. F i g u r e 23 Gas Burner T r a i n Stand No.1, Ground F l o o r . F i g u r e 24 G a s Burner T r a i n Stand No. 2, Ground F l o o r .

F i g u r e 25 Burner's S e t P o i n t C o n t r o l l e r s and Set-Point Programmer.

F i g u r e s

-

Appendix A

F i g u r e A 1 C a l i b r a t i o n Curves f o r B u i l d i n g A i r Supply, B u i l d i n g Return A i r , and B u i l d i n g Exhaust (Fan #1,2 & 3, AM-7,8,9).

F i g u r e A2 C a l i b r a t i o n Curves f o r t h e S t a i r A i r Supply, E l e v a t o r A i r Supply, and V e s t i b u l e A i r Supply. (Fan #4, AM-1,2,3), and S t a i r Exhaust (Fan 85, AM-6).

ABSTRACT

A n a t i o n a l experimental f a c i l i t y , t h e NRC National F i r e Laboratory

(NFL)

-

formerly t h e F i r e Research F i e l d S t a t i o n (FRFS)

-

was designed, constructed and instrumented f o r conducting l a r g e s c a l e f i r e experiments. The l a b o r a t o r y c o n s i s t s of two major experimental f a c i l i t i e s ; t h e burn h a l l and t h e 10-storey f i r e tower, which a r e interconnected by a s e r v i c e

building. The f i r e tower i s designed mainly f o r research on smoke movement and c o n t r o l methods i n t a l l buildings. This r e p o r t describes t h e f i r e tower, a s p a r t of t h e NFL, including t h e s t r u c t u r e and l a y o u t , mechanical p r e s s u r i z a t i o n and exhaust systems, instrumentation and measuring

techniques, d a t a a c q u i s i t i a n system, and t h e gas burner system used f o r f i r e simulation. The tower's research and development c a p a b i l i t i e s a r e a l s o summarized.

Un c e n t r e n a t i o n a l d1exp6rimentation a 6tE consu, c o n s t n i t e t Equip6 pour mener des experiences d'incendie .3 grande 6 c h e l l e ; c r e s t l e Laboratoire n a t i o n a l e de l ' i n c e n d i e (LNI) du CNRC, q u i s ' a p p e l a i t auparavant l a S t a t i o n de recherche exp6rimentale s u r l ' i n c e n d i e . Ce c e n t r e cornprend deux grandes i n s t a l l a t i o n s d'expdrimentation: l a s a l l e de combustion e t l a t o u r d'incendie de 10 &ages, qui sont r e l i 6 e s par un bstiment de s e r v i c e . La tour d'incendie e s t s u r t o u t destin6e aux recherches s u r l e d6placement de l a furnee e t l e s m6thodes de dgsenfumage dans l e s hstiments 6lev6s. Ce

rapport f o u r n i t une d e s c r i p t i o n de l a tour d'incendie: s t r u c t u r e e t amgnagement, systPmes m6caniques de mise en pression e t d16vacuation,

techniques d'instrumentation e t de mesurage u t i l i s 6 e s , d i s p o s i t i f de s a i s i e de donnees, e t systPme de brtlleurs au gaz employe pour simuler des

incendies. On y donne a u s s i un apercu des ressources dont dispose c e t t e i n s t a l l a t i o n au plan de l a recherche-d6veloppement.

1. INTRODUCTION

AND

BACKGROUND

I n high-rise buildings, smoke i s t h e main cause of c a s u a l t i e s during a f i r e ; a l a r g e number of deaths1-' a r e caused by asphyxiation, smoke

i n h a l a t i o n , and carbon monoxide poisoning. The smoke spreads r a p i d l y from t h e f i r e compartment t o o t h e r a r e a s i n t h e building, reduces t h e

v i s i b i l i t y , hinders t h e f i r e f i g h t i n g , and i n t e r f e r e s with t h e evacuation from t h e building. I n tall buildings, t h e time a v a i l a b l e f o r t o t a l

before escape r o u t e s a r e f i l l e d with smoke i s c r i t i c a l t o l i f e s a f e t y .

The Associate Committee on t h e National Building Code of canada7 recognized t h e hazard of smoke t o l i f e and introduced requirements f o r t h e c o n t r o l of smoke movement i n high buildings i n t h e 1970 e d i t i o n of t h e NBC. The recommended methods of smoke c o n t r o l i n high buildings a r e described i n t h e Supplement t o t h e NBC

-

Chapter 3, Measures f o r P i r e ' S a f e t y i n High ~ u i l d i n ~ s * . The I n s t i t u t e f o r Research i n Construction (IRC) of NRC

-

formerly t h e Division of Building Research (DBR) has d i r e c t e d considerable e f f o r t towards t h e study of smoke movement and c o n t r o l methods t o improve l i f e s a f e t y i n t a l l buildings. During t h e p a s t s e v e r a l y e a r s , I R C has developed information using mathematical models9,10, and conducted f i e l d t e s t s under non-fire conditions; a review of IRCINRC s t u d i e s on c o n t r o l of

smoke has been presented by ~ a m u r a l l . Such research techniques have proven t o be valuable; however, t h e f i e l d t e s t s do not t a k e i n t o account t h e

e f f e c t s of f i r e temperature and the r e s u l t s obtained a r e limited t o a

s p e c i f i c system and b u i l d i n g configuration. On t h e other hand, t h e computer simulation programs have some assumptions with regard t o smoke movement which need t o be v e r i f i e d .

A s p e c i a l l y designed f a c i l i t y , t h e NRC experimental f i r e tower, was developed t o simulate t h e e f f e c t of f i r e temperature on t h e c h a r a c t e r i s t i c s of smoke movement and on t h e performance of various smoke c o n t r o l measures. Measurements made i n t h e tower can a l s o be u t i l i z e d t o v a l i d a t e o r v e r i f y

t h e r e s u l t s of t h e mathematical models. Currently, research work i s

underway,using t h e f a c i l i t y t o develop and a s s e s s concepts of smoke c o n t r o l systems which can o f f e r e f f e c t i v e p r o t e c t i o n of escape r o u t e s ( s t a i r s h a f t and e l e v a t o r s h a f t ) from smoke migration during f i r e s .

The purpose of t h i s r e p o r t i s t o provide researchers and p o t e n t i a l u s e r s with background t e c h n i c a l information and g u i d e l i n e s on t h e tower f a c i l i t y and i t s c a p a b i l i t i e s . It w i l l a l s o s e r v e a s a r e f e r e n c e f o r r e p o r t i n g work conducted i n t h e f a c i l i t y . The r e p o r t d e s c r i b e s t h e

experimental f i r e tower a s p a r t of t h e N F L i n c l u d i n g t h e s t r u c t u r e and layout, mechanical p r e s s u r i z a t i o n and exhaust systems, instrumentation and measuring techniques, d a t a a c q u i s i t i o n system, and gas burner system used f o r f i r e simulation, and provides a summary of t h e tower's research and development c a p a b i l i t i e s .

2.0 NATIONAL FIRE LABORATORY

NFL i s located west of Ottawa between Carleton Place and Almonte, Ontario. The s i t e is about 90 ha and r e l a t i v e l y i s o l a t e d from l a r g e concentrations of population, an a e r i a l view of t h e NFL s i t e i s shown i n Figure 1. The l a r g e s i t e provides an adequate b u f f e r zone between t h e l a b o r a t o r y and built-up a r e a s , t o prevent any adverse e f f e c t s due t o smoke from f u l l - s c a l e f i r e experiments. Dispersion c a l c u l a t i o n s showed t h a t a i r q u a l i t y standards would be s a t i s f i e d , provided t h a t experiments were c a r r i e d out under weather conditions permitting good d i s p e r s i o n and t h a t burns were never conducted simultaneously i n both buildings12.

NFL was o f f i c i a l l y opened on September 23, 1981. It comprises t h r e e b u i l d i n g s , a burn h a l l , a 10-storey experimental f i r e tower and a s e r v i c e u n i t a s shown i n Figures 2 and 3. The buildings a r e interconnected a t ground f l o o r l e v e l through t h e s e r v i c e u n i t f o r simulation of a l a r g e complex b u i l d i n g and f o r convenience during winter operation.

Service Unit

The s e r v i c e u n i t c o n s i s t s o f ; a n air-conditioned d a t a room provided with a PDP-11/73 mini-computer f o r recording and analyzing measurements, a c o n t r o l room f o r t h e o p e r a t i o n of t h e tower's a i r handling and

p r e s s u r i z a t i o n systems, a small chemistry l a b o r a t o r y , a mechanical room f o r t h e burn h a l l and t h e s e r v i c e u n i t , a workshop and o f f i c e s . A f l o o r plan of t h e s e r v i c e u n i t i s shown i n Figure 4.

Burn Hall

The burn h a l l i s an adaptable open-plan building with 1650 m 2

of column-free f l o o r a r e a , a t 55 m long, 30 m wide and 12 m high t o t h e f i r e r e s i s t a n t c e i l i n g . The bum h a l l s h e l t e r s l a r g e - s c a l e f i r e experiments from t h e weather. The smoke removal from t h e Hall i s provided by two means:

a ) Mechanically with f o u r exhaust f a n s located i n t h e corners below c e i l i n g l e v e l . The t o t a l f a n capacity i s 56 m3/s.

b) Power operated louvres extending t h e f u l l l e n g t h of each s i d e of t h e building.

The f r e s h a i r t o t h e burn h a l l is admitted through numerous doors along t h e e x t e r i o r w a l l s of t h e h a l l . The burn h a l l can accommodate a wide v a r i e t y of experimental s e t - u p s , including room and c o r r i d o r arrangements, simulated apartment o r h o s p i t a l s u i t e s , a t r i a and shopping malls, and 2-storey dwellings. The possible i n v e s t i g a t i o n s include; f i r e and smoke spread i n buildings and between buildings, t h e e f f e c t of v e n t i l a t i o n and f u e l loads on compartment f i r e s , f i r e i n c a v i t y w a l l s , and t h e production of t o x i c products of combustion. More d e t a i l e d information, on t h e bum h a l l research a c t i v i t i e s and c a p a b i l i t i e s can be obtained from t h e NFL Xanager.

3.0

EXPERIMENTAL

FIRE TOWER

The experimental f i r e tower c o n s i s t s of an experimental tower and a protected s e r v i c e tower. Both a r e 10 s t o r e y s high and s t r u c t u r a l l y independent f o r s a f e t y reasons. The c o n s t r u c t i o n i s monolitic reinforced concrete with 200 m w a l l and f l o o r thickness which provides minimum a i r leakage through walls and f l o o r s . The s t r u c t u r a l elements of t h e tower a r e designed f o r 4 hour f i r e - r e s i s t a n c e r a t i n g . To a s s u r e a long s e r v i c e l i f e , a d d i t i o n a l p r o t e c t i o n i s provided t o t h e bum a r e a on t h e second f l o o r ( f i r e f l o o r ) by t h e i n s t a l l a t i o n of high temperature i n s u l a t i o n m a t e r i a l s , and i n s i d e t h e smoke s h a f t by t h e i n s t a l l a t i o n of f i r e bricks. The major physical dimensions of the tower a r e a l s o given i n Table 1.

3.1 Experimental Tower

The experimental tower, a s shown i n Figure 5, has a t o t a l a r e a of

130 m2 f o r each f l o o r

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including a c e n t r a l core a r e a of 6 2 . 7 m2. Each f l o o r has an open a r e a (burn a r e a ) of about 36 m2 where controlled experimental f i r e s can be conducted. The f i r s t and second f l o o r s a r e

3.6 m high and t h e remainder a r e 2.6 m high.

The e x t e r i o r cladding adjacent t o t h e burn a r e a i s removable, permitting i n s t a l l a t i o n of t y p i c a l building facades a d window assemblies f o r study of e x t e r i o r f i r e spread. Four openable s l i d i n g s t e e l "panels" a r e located on t h e e x t e r i o r walls around t h e c o r r i d o r s , a l a r g e one i n t h e e a s t and west wall and two small ones on t h e n o r t h wall. The south wall (viewing w a l l ) s e p a r a t e s t h e experimental and t h e s e r v i c e tower, and i s provided with a double door and f i v e viewing windows.

The c e n t r a l core contains s e v e r a l v e r t i c a l s h a f t s . They a r e t h e s t a i r s h a f t , e l e v a t o r s h a f t , s e r v i c e s h a f t , building supply a i r s h a f t . returnlexhaust s h a f t , and smoke s h a f t . Also, t h e r e a r e t h r e e o t h e r v e r t i c a l s h a f t s ; one f o r d i s t r i b u t i n g p r e s s u r i z i n g a i r t o t h e s t a i r s h a f t , another one f o r exhausting a i r from t h e s t a i r s h a f t t o o u t s i d e a t

t h e top, and a t h i r d one f o r supplying p r e s s u r i z a t i o n a i r t o t h e e l e v a t o r and t h e s t a i r v e s t i b u l e s .

A l l s h a f t s terminate a t roof l e v e l . The s t a i r , e l e v a t o r and s e r v i c e s h a f t s can be vented a t t h e top o r a t t h e bottom of t h e s h a f t a s required f o r experiments. The s t a i r s h a f t e x i t s t o an o u t s i d e door a t t h e ground f l o o r a s shown i n Figure 6 , and t h e e l e v a t o r and s e r v i c e s h a f t s a r e a l s o connected t o o u t s i d e doors a t t h e basement l e v e l . A c r o s s

s e c t i o n a l e l e v a t i o n view of t h e tower and mechanical building i s shown i n Figure 7.

A l l t h e s h a f t s have v a r i a b l e openings i n t h e w a l l s on each f l o o r . The maxirm a r e a s of openings f o r all s h a f t s a r e given i n Table 2. The required amount of opening can be s e t by p o s i t i o n i n g s h u t t e r provided a t each opening. On every f l o o r , t h e s t a i r and e l e v a t o r s h a f t s have a v e s t i b u l e with a door t o t h e burn a r e a . Each s t a i r v e s t i b u l e i s

connected t o t h e outside wall by a h o r i z o n t a l duct with a manual damper. The s t a i r and t h e a s s o c i a t e d v e s t i b u l e doors a r e provided with pneumatic door openers which can be manually operated remotely from t h e switch panel on t h e second f l o o r , o r programmed t o operate automatically i n a s p e c i f i e d sequence with t h e d a t a a c q u i s i t i o n and c o n t r o l system. The automatic door operation w i l l be used t o simulate t h e use of t h e s t a i r doors f o r evacuation during a f i r e .

3.2 Service Tower

The s e r v i c e tower provides a s a f e a r e a from which t o conduct and t o observe t e s t s i n t h e experimental a r e a s . It comprises a s t a i r w e l l , a

f r e i g h t e l e v a t o r , and observation area. The observation a r e a i s i s o l a t e d from t h e smoke and t o x i c gases i n t h e experimental a r e a s , and provides s a f e working spaces f o r t h e instruments and t h e people. A propane gas s e r v i c e

l i n e , heat d e t e c t o r , hose r e e l , f i r e alarm and public address/intercom system with a s t a r t t e s t warning alarm a r e i n s t a l l e d on a l l f l o o r s . The s e r v i c e a r e a i s provided with a s e p a r a t e a i r p r e s s u r i z a t i o n system, with f a n c a p a c i t y of 5.5 m3/s. This system which s u p p l i e s 100% o u t s i d e a i r i s

operated during an experiment t o prevent combustion products from e n t e r i n g t h e observation area.

3.3 Features of t h e Tower

The following i s a summary of t h e major f e a t u r e s of t h e tower. They a r e described i n d e t a i l i n various s e c t i o n s of t h i s report.

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F u l l s c a l e simulation of a b u i l d i n g i n terms o f :

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a i r leakage c h a r a c t e r i s t i c s

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v e r t i c a l s h a f t s ( s t a i r , e l e v a t o r , s e r v i c e , smoke)

-

heating and v e n t i l a t i o n systems

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Provisions f o r experimental f i r e s and f i r e temperature simulation with programmable gas burners

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Provisions f o r venting of f i r e f l o o r

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Provisions f o r n a t u r a l and mechanical p r e s s u r i z a t i o n of v e r t i c a l s h a f t s and f l o o r spaces

-

S t a i r doors with remote c o n t r o l f o r simulation of s t a i r use during evacuation

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Sensors f o r measurement of pressure d i f f e r e n c e , a i r v e l o c i t y , temperature, carbon dioxide, carbon monoxide and smoke d e n s i t y

-

Automatic d a t a a c q u i s i t i o n system

The f i r e t e s t s a r e conducted using two progrannnable gas burners. located i n t h e burn a r e a of t h e 2nd f l o o r , capable of simulating various f i r e s i z e s up t o 5 MU. The carbon dioxide produced by these burners

r e p r e s e n t s smoke and t o x i c gas developed from a f i r e , and i s monitored with i n f r a r e d gas analyzers along with t h e measurements of pressure d i f f e r e n c e s , temperatures and flow r a t e s throughout t h e tower.

4.0 MECRANICAL PRESSURIZATION AM) EXHAUST SYSTEMS

The major approach t o c o n t r o l l i n g smoke movement and p r o t e c t i n g escape r o u t e s during a f i r e i n t a l l buildings i s based on c o n t r o l l i n g t h e pressure d i f f e r e n c e s a c r o s s t h e i n t e r n a l and e x t e r n a l s e p a r a t i o n s of a building by means of mechanical p r e s s u r i z a t i o n and exhaust of s p e c i f i c

spaces depending on t h e method of smoke c o n t r o l used. The experimental f i r e tower i s provided with mechanical a i r supply and exhaust systems t o permit s t u d i e s on t h e various methods of smoke c o n t r o l t h a t a r e being i n s t a l l e d i n buildings. This s e c t i o n d e s c r i b e s i n d e t a i l the mechanical a i r handling systems and a l s o t h e a i r flow measuring u n i t s associated with t h e s e systems.

4.1 Air System Configuration

The experimental tower i s provided with two major a i r systems, one f o r building heating and p r e s s u r i z a t i o n and t h e o t h e r f o r s h a f t

p r e s s u r i z a t i o n . A schematic diagram of t h e a i r flow systems i s shown i n Figure 8 and a layout of t h e a i r handling equipment i n s t a l l e d i n t h e Tower's mechanical room is shown i n Figure 9.

The building h e a t i n g and p r e s s u r i z a t i o n system c o n s i s t s of supply f a n B1 (14 m3/s) which provides heated a i r t o building a i r supply s h a f t b l , r e t u r n f a n 82 (17 m3/s) which e x t r a c t s a i r from t h e tower through

returnlexhaust s h a f t 82, and exhaust f a n

83

( 9 m3/s) which exhausts a i r from t h e b u i l d i n g through s h a f t #2 t o o u t s i d e a t t h e roof. Fans 81 and 82 a r e located i n t h e adjacent mechanical building and f a n

83

i s located a t t h e roof on top of t h e r e t u r n s h a f t . This system can operate a s a c e n t r a l

heating system f o r t h e tower during non-testing periods and can a l s o be used f o r t e s t purposes.

The s h a f t p r e s s u r i z a t i o n system c o n s i s t s of supply f a n 64 (18 m3/s) located i n t h e mechanical b u i l d i n g , and exhaust f a n 65 ( 4 m3/s) which i s mounted on t h e roof of t h e s t a i r exhaust s h a f t #6. The supply f a n 84 provides tempered o u t s i d e a i r a t any o r a l l f l o o r s through v e r t i c a l d i s t r i b u t i o n s h a f t t o t h e experimental s t a i r s h a f t , and through another v e r t i c a l s h a f t t o t h e e l e v a t o r and s t a i r v e s t i b u l e s , and a l s o provides tempered o u t s i d e a i r d i r e c t l y t o t h e e l e v a t o r s h a f t a t t h e bottom of t h e s h a f t . Fan

85

exhausts a i r i n t h e s t a i r s h a f t a t any o r a l l f l o o r s .

The mechanical building which houses t h e f a n s and h e a t i n g systems i s located on t h e north s i d e of t h e tower. The f a n ducts from che mechanical building t r a v e l underground and connect t o t h e various s h a f t s a t t h e

basement l e v e l (Figure 7 ) . The supply a i r f o r both systems i s heated by gas-fired duct furnaces provided with discharge a i r temperature c o n t r o l l e r

and o t h e r s a f e t y devices. I n w i n t e r , t h e a i r supplied t o t h e s h a f t s can be heated t o 10°C a t an o u t s i d e a i r temperature of -28OC. The f a n performance d a t a i s provided i n Table 3.

4.2 Air Flow Measuring System

The t o t a l a i r flow r a t e s supplied o r e x t r a c t e d from any i n d i v i d u a l s h a f t a r e measured by a i r flow measuring s t a t i o n s (AM1 t o AM9) i n s t a l l e d i n t h e a i r d u c t s a t p o s i t i o n s a s f a r away from t h e f a n and duct bends a s

p r a c t i c a b l e (Figs. 8 and 9). Each s t a t i o n c o n s i s t s of m u l t i point

self-averaging t o t a l pressure tubes and t h e i r a s s o c i a t e d s t a t i c p r e s s u r e taps. An a i r s t r a i g h t e n e r of honeycomb panel i s located immediately upstream of t h e averaging tubes, t h e honeycomb c e l l s reduce t h e a i r turbulence and d i r e c t s t h e flow p a r a l l e l t o t h e ductwork. The t o t a l and s t a t i c pressure s i g n a l s a r e t r a n s m i t t e d by p l a s t i c tubes t o t h e i r r e s p e c t i v e a i r flow meters i n t h e f a n c o n t r o l room i n t h e s e r v i c e u n i t and recorded by t h e d a t a a c q u i s i t i o n system. A t y p i c a l i n s t a l l a t i o n of an a i r flow

measuring s t a t i o n i s shown i n Figure 10. A view of t h e f a n c o n t r o l panel

i s

the pitot traverse method13. The calibration curve for each station and the

method used are given in Appendix

A.

5.0

INSTRUMENTATION

AND

MEASURING TECIINIQUES

The instrumentation of the tower was designed to provide permanent

instrumentation set-up for measuring and recording the basic parameters

required for tests in the fire tower. The measurements include air/gas

temperatures, pressure differentials, concentrations of carbon dioxide and

carbon monoxide, air/gas velocity, and the airflow rates for building

supply, shaft exhaust, and shaft and vestibule pressurization, barometric

pressure at the ground floor, and wind speed and direction at the roof. In

addition, there are provisions for adding other sensors such as smoke

meters, heat flux meters, etc.

The instrumentation consists of the following three basic measuring

systems that are typical on every floor

-

the locations of the measuring

points are shown in Figure 12:

1)

Temperature measurements

-

Temperatures are measured in 10

different locations on each floor using 20 gauge type

K

chrome1

-

alumel thermocouples. Also, additional temperature measurements

are made in the burn area of the 2nd floor at the ceiling, side

walls, and at various heights above the floor as indicated in

Figure 13 and just above the gas burners as indicated in Section

7.0.

2) Pressure differential measurements

-

Pressure differential across

the various walls of the building are measured using

18

static

pressure taps (of 6.3

mu O.D. copper tubing) flush mounted to the

walls on each floor (Fig. 12).

All pressure lines for each floor

are connected to a twenty four-port scanivalve equipped with a

pressure transducer located on the same floor in the service

area.

3)

Gas sampling measurements

-

Carbon dioxide gas concentrations are

measured at 6 locations on each floor (Fig. 12); in the shafts,

vestibules and the b u m areas by copper sampling tubes. The

sampling tubes on each floor are connected to a twelve-port

samplivalve unit with

an

infrared gas analyzer, which are also

located on the same floor in the service area. Additional

C 0 2

and CO gas concentrations are measured at the thermocouple stands

in the burn area of the 2nd floor (Fig. 13).

All devices of t h e t h r e e systems a r e c o n t r o l l e d and monitored by a computer based d a t a a c q u i s i t i o n and c o n t r o l system (DACS) described i n t h e following s e c t i o n . A schematic r e p r e s e n t a t i o n of t h e instrumentation system f o r a t y p i c a l f l o o r i s shown i n Figure 14, and an i l l u s t r a t i o n of t h e

instrumentation arrangement i n t h e 2nd f l o o r s e r v i c e room i s shown i n Figure

15; a l s o , close-up views of t h e pressure scanivalve and t h e gas samplivalve u n i t s a r e shown i n Figs. 16 and 17, r e s p e c t i v e l y . Detailed d e s c r i p t i o n s of t h e instrumentation and measuring techniques f o r temperature, p r e s s u r e d i f f e r e n t i a l s , gas sampling, gas v e l o c i t y measurements, and wind speed and d i r e c t i o n a r e presented i n Appendix B.

6.0 DATA ACQUISITION AND CONTROL SYSTEM

This s e c t i o n d e s c r i b e s t h e d a t a a c q u i s i t i o n and c o n t r o l system (DACS) with emphasis on t h e f i r e tower system, and i t includes t h e following: d e s c r i p t i o n of sensors and devices, system f u n c t i o n ,

operator-system i n t e r f a c e , system hardware and system software. The system software was designed by Systemhouse Ltd. (SHL), based on t h e Building Energy Management System Software (BEMS) which was modified t o c o n t r o l t h e experimental devices and sensors, and t o monitor, record and d i s p l a y d a t a f o r experiments i n both t h e experimental f i r e tower and t h e burn h a l l .

Extensive v e r i f i c a t i o n t e s t s were performed on t h e computer-based d a t a a c q u i s i t i o n t o ensure proper system operation and complete

softwarelhardware i n t e g r a t i o n . The t e s t s included t h e following: i ) wiring check out of a l l sensors and devices, i i ) d a t a s t r u c t u r e and communications, t o ensure t h a t software programs a r e functioning c o r r e c t l y

-

t h i s p a r t

included "Experiment Set-up Program, Monitor Function, Data Logging Function and Conversion Algorithms, Data Storage Functions, and P l o t Features",

i i i ) proper system operation and c o n t r o l of a l l devices and sensors ( i . e . thermocouples, pressure scanivalves, gas samplivalves and door o p e r a t i o n ) .

6.1 Description of Sensors and Devices

The sensors and devices provided f o r t h e F i r e Tower a r e l i s t e d i n Table 4 and they f a l l i n t o t h e following categories:

1. Sensors t h a t r e q u i r e no c o n t r o l and output an analog v o l t a g e ; a ) Thermocouples

-

outputs a v o l t a g e a s a f u n c t i o n of t h e

temperature of t h e sensor.

b ) Gas Velocity Probe

-

outputs a voltage r e l a t e d t o the v e l o c i t y of gas flow a t t h e sensor.

Provisions were a l s o made i n t h e system t o accommodate o t h e r s e n s o r s i n t h i s category and they a r e photocells (smoke d e n s i t y ) , radiometers o r heat f l u x gauges, load c e l l s and s t r a i n gauges.

2. Sensors t h a t r e q u i r e automatic c o n t r o l and output an analog v o l t age :

a ) Scanivalve

-

r e q u i r e s a s i g n a l t o s t e p t o t h e next port of 2 4 pressure p o r t s per f l o o r . The p r e s s u r e

transducer outputs a voltage proportional t o t h e d i f f e r e n t i a l pressure a c r o s s t h e diaphragm of

t h e tranducer.

b ) Samplivalve

-

r e q u i r e s a s i g n a l t o s t e p t o t h e next p o r t of 1 2 gas p o r t s per f l o o r . The gas analyzer outputs a voltage proportional t o t h e gas concentration.

3. Sensors t h a t s e t a binary voltage l e v e l ( i . e . , open, closed): a ) Samplivalve, Scanivalve

-

outputs a voltage l e v e l when t h e

switch i s i n t h e 'home' position.

b) Door sensor

-

outputs a voltage l e v e l i n d i c a t i n g an open o r closed s t a t e of a door.

The sensors and devices of t h e f i r e tower a r e connected t o t h e i r corresponding d a t a a c q u i s i t i o n u n i t a s described i n Section 6.3.

6.2 System Function and User

-

System I n t e r f a c e

The experiments i n t h e f i r e tower may involve s e v e r a l o r a l l f l o o r s . It i s p o s s i b l e t o run t h e system and monitor d a t a from any observation s t a t i o n i n t h e f i r e tower o r from t h e s t a t i o n i n t h e burn h a l l .

In preparation f o r t h e experiment, a complete and c o r r e c t i n i t i a l i z a t i o n of t h e system database must be provided f o r a l l sensors required. The u s e r w i l l then perform a simple s e t up f o r t h e t e s t specifying a p a r t i c u l a r parameter f i l e . The system program provides a c h e c k l i s t of necessary u s e r a c t i o n s and menu of u s e r commands.

A t t h e beginning of any experiment, t h e u s e r must s p e c i f y t h e sensors required and t h e r a t e s of c o l l e c t i n g t h e readings. A s e t of

readings can be taken i n time i n t e r v a l s ranging from 10 t o 30 seconds o r longer, depending on t h e number of sensors required and t h e d u r a t i o n of the experiment. During t h e experiment, t h e u s e r w i l l be a b l e t o c a l l up a

d i s p l a y of real-time sensor d a t a from any sensor o r combination of s e n s o r s (up t o s i x sensors a t one time), and a d i s p l a y of t h e system s t a t u s .

The system software allows t h e u s e r t o l o g a message e n t r y recording t h e time of any s i g n i f i c a n t events (i.e., " s t a r t of f i r e " , " s t a r t of

evacuation

",

e t c . ) . It i s a l s o provided with alarm s e t t i n g f e a t u r e s which allows t h e u s e r t o s e t maximum o r minimum l i m i t s (eg. maximum temperature, gas concentration, pressure d i f f e r e n c e , e t c . ) , f o r any number of a c t i v e sensors during t h e experiment. Further d e t a i l e d information i s provided i n DACS User Manual

-

Ref. 14.

Doors Operation

The door operation can be programmed t o open and c l o s e according t o u s e r s p e c i f i e d schedules. A d a t a f i l e provided i n t h e database c o n t a i n s a

schedule f o r opening o r c l o s i n g each door a t s p e c i f i e d times a f t e r t h e s t a r t of an experiment. The same schedule may be used f o r a s many doors a s

desired. A l l door schedules can be examined o r modified during t h e SET UP r o u t i n e of an experiment. I n modifying a schedule t h e u s e r may s e l e c t a r e g u l a r o r i r r e g u l a r schedule and can e n t e r t h e time a s elapsed time from t h e s t a r t of t h e experiment o r a s t h e i n t e r v a l time between successive open o r c l o s e a c t i o n s .

6.3 System Hardware

6.3.1 Computer Room

The computer room l o c a t e d i n t h e s e r v i c e u n i t is used f o r experiments i n both t h e f i r e tower and t h e burn h a l l . A schematic

r e p r e s e n t a t i o n of t h e computer-based d a t a a c q u i s i t i o n and c o n t r o l system i s given i n Figure 18. The system has a DEC PDP-11/73 with 256 K bytes of memory. The d a t a s t o r a g e i s provided by two RLO1 r i g i d d i s k s ( 5 MB each)

f o r system and u s e r software s t o r a g e , a magnetic tape (TM 111, and two floppy d i s k u n i t s RX02 (512

K

bytes each). A video terminal (VT52) and a hard copy terminal LA 120 serve a s t h e system console and p r i n t e r

r e s p e c t i v e l y . I n a d d i t i o n , two remote videoscreen t e r m i n a l s (ISC 80011 Colour graphics) provide computer c o n t r o l from t h e f i r e tower and burn h a l l .

6.3.2 F i r e Tower Configuration

Five remote d a t a a c q u i s i t i o n and c o n t r o l u n i t s (DAU's) type Rewlett Packard W3497A a r e located on f l o o r s 2,3,6,7, and 9 of t h e s e r v i c e tower.

Each DAU i s capable of managing t h e sensors and devices of two f l o o r s ( i . e . , 20 thermocouples, 2 p r e s s u r e scanivalves and 2 pressure transducers, 2 samplivalves and 2 gas a n a l y z e r s ) . The d i s t r i b u t i o n of sensors and devices i n t h e f i r e tower i s given i n Table 5, and a schematic r e p r e s e n t a t i o n of t h e tower's data a c q u i s i t i o n and c o n t r o l system

-

hardware configuration is shown i n Figure 19.

Each DAU i s i d e n t i c a l , and includes a f r o n t panel keyboard, d i s p l a y , r e a l time clock, and HP-IB i n t e r f a c e . It a l s o contains t h e following modules:

a ) Programmable d i g i t a l voltmeter HP44420A

b) 20 channel r e l a y multiplexer with thermocouple compensation RP44422A f o r type K thermocouple input

c ) 20 channel r e l a y multiplexer IIP44421A f o r analog input d) 16 channel d i g i t a l input assembly HP44425A

e ) 16 channel a c t u a t o r l d i g i t a l output assembly HP44428A.

DAUbl, on t h e second f l o o r , i s provided with an HP3498A extender u n i t , allowing t h e c o n t r o l of door operation and t h e a d d i t i o n a l sensors and devices of t h e 2nd f l o o r .

The computer addresses each d a t a a c q u i s i t i o n u n i t a s a s e p a r a t e ' l o g i c a l u n i t ' , and t h e d a t a t r a n s f e r and communication between t h e DAU's a r e handled over t h e HP-IB 37203A bus extenders with Belden type 9248 coaxial cables. The i n t e r f a c e between t h e DAU's and PDP 11/73 i s made through a DEC I B V l l A bus i n t e r f a c e card. One cable and p a i r of extenders a r e used t o connect t h e PDP 11/73 t o DAU%l on t h e ground f l o o r of t h e tower. These l i n e s transmit d i g i t a l data and a r e i s o l a t e d from e x t e r n a l e l e c t r i c a l i n t e r f e r e n c e using coaxial cables.

6.4 System Software

6.4.1 Operating System

The DEC PDP-11/73 computer i s configured t o run under t h e RSX-11M V4.1D operating system. The f u n c t i o n s of command processing and t a s k scheduling a r e performed by i n t e r a c t i o n with t h e operating system. The system responds t o u s e r i n p u t commands t o c a l l up and s t a r t t h e a p p r o p r i a t e programs.

6.4.2 Software Package

The SHL-BEMS software package i s used t o c o n t r o l t h e experimental devices and sensors, and t o c o l l e c t and d i s p l a y t h e experimental data. The

performance of t h e SM-BEMS software i s described i n terms of t h e following s e r v i c e s : Set-up, Monitor, Data Log, S t o r e , and Display.

a ) Set-Up

The set-up process allows t h e u s e r t o i d e n t i f y a l l a c t i v e s e n s o r s , s p e c i f y t h e d a t a a c q u i s i t i o n r a t e s , t h e d a t a conversion algorithms, t h e d a t a recording r a t e , and s p e c i f y any o t h e r r e l e v a n t device parameters. It i s a l s o p o s s i b l e t o use a previous s e t - u p

s p e c i f i c a t i o n from a parameter f i l e and o p t i o n a l l y modify t h e values f o r t h e c u r r e n t experiment. These modified parameter values w i l l be s t o r e d i n a new parameter f i l e a t t h e termination of t h e set-up process. The s e t - u p process must be completed before t h e s t a r t of any experiment. A u s e r may request Set-Up before a c t u a l l y

connecting t h e sensors and devices. b) Monitor

The monitor process, when c a l l e d up by t h e u s e r , w i l l access t h e a c t i v e sensor l i s t f i l e , v e r i f y by passive data readings t h a t a l l t h e a c t i v e sensors a r e functioning, and provides t h e c u r r e n t d a t a reading of a l l a c t i v e sensors during an experiment. This a l s o allows t h e u s e r t o check and v e r i f y t h e readings from c a l i b r a t i o n channels on pressure scanivalves and gas samplivalves p r i o r t o t h e s t a r t of t h e experiment.

C ) Data Log

This process accesses a l l t h e a c t i v e d a t a sensors and t h e analog devices, a t u s e r s p e c i f i e d r a t e s . The d a t a l o g a l s o accesses t h e c o r r e c t algorithm ( s p e c i f i e d by t h e u s e r ) f o r converting t h e raw sensor d a t a t o engineering u n i t s . I n a d d i t i o n , as t h e d a t a l o g i s accessing t h e raw sensor d a t a , i t w i l l be checking t h e values

a g a i n s t t h e u s e r pre-set alarm l e v e l s , and a message w i l l be p r i n t e d on t h e p r i n t e r i f any alarm l e v e l i s reached.

d ) Data Storage

The s t o r a g e f u n c t i o n i s a c t i v a t e d automatically a t t h e s t a r t of

t h e experiment, o r by user command. This function s t o r e s t h e raw o r converted d a t a from t h e a c t i v e sensors i n d a t a f i l e s on d i s k a s s p e c i f i e d by t h e user. There a r e f i v e a v a i l a b l e d a t a s t o r a g e f i l e s , and s i x a v a i l a b l e groups of twenty s l o t s w i t h i n each f i l e ( a t o t a l of 600 points a r e a v a i l a b l e ) . Each s l o t r e f e r s t o an i n d i v i d u a l measuring point ( o r d a t a sensor) and can hold up t o 1200 samples per sensor. The u s e r must ensure t h a t a s u i t a b l e recording r a t e i s s e l e c t e d so t h e recording c a p a c i t y i s not exceeded during t h e course

of an experiment, e.g., with a s e l e c t e d recording r a t e of 5 seconds ( i n t e r v a l s ) , t h e recording capacity of t h e experiment w i l l be 100 minutes, and with a r a t e of 10 seconds t h e capacity w i l l be 200 minutes.

e ) P l o t

-

The p l o t program can produce up t o s i x p l o t s on a s i n g l e d i s p l a y image on t h e ISC800II colour graphic terminal. Each of t h e p l o t s may be a d i s p l a y of engineering u n i t s , o r may be t h e r e s u l t of a d a t a transformation ( i n t e g r a t e d curve, logarithm, i n v e r s e o r r a t i o of two s e l e c t e d sensor readings) s e l e c t e d by t h e user during p l o t i n i t i a l i z a t i o n . A l l p l o t s a r e displayed a s a function of time. Real-time d a t a and previously recorded d a t a may be displayed

simultaneously. Each of t h e s i x p o s s i b l e p l o t s may have independent

Y a x i s s c a l i n g . Although only two of t h e p o s s i b l e s i x Y a x i s s c a l e s a r e displayed a t t h e screen, t h e u s e r may s t e p through a l l p o s s i b l e Y a x i s s c a l e d i s p l a y s by pressing t h e function keys

F1

o r F2 on t h e keyboard.

6 . 4 . 3 Instrument I / O Control

All 110 devices, described i n s e c t i o n 6 . 2 , provide raw sensor d a t a which a r e then converted t o engineering u n i t s f o r d i s p l a y purposes and f o r storage. A l l sensors and devices a r e c o n t r o l l e d by t h e software handling r o u t i n e s described i n t h e DACS System Management Manual1'.

The samplivalve gas analyzer i s serviced by two r o u t i n e s ; one r o u t i n e ( d i g i t a l output of t h e DACS) t o s t e p t h e samplivalve and t h e o t h e r r o u t i n e (analog i n p u t of t h e DACS) t o o b t a i n t h e d a t a reading from t h e gas analyzer. The scanivalve pressure i s a l s o serviced by two s i m i l a r

routines;one t o s t e p t h e scanivalve and another r o u t i n e t o o b t a i n t h e d a t a measurement from t h e pressure transducer. For o t h e r sensors and devices

t h a t r e q u i r e no c o n t r o l (i.e. thermocouples and v e l o c i t y p r o f i l e s ) only one r o u t i n e ( t h e analog i n p u t ) i s required t o o b t a i n t h e d a t a reading from t h e sensor.

6 . 4 . 4 Database

The DACS i s s t r u c t u r e d with a database which defines t h e d a t a organization of all sensors and devices i n t h e system and c o n t r o l s t h e i r operation through t h e various programs i n t h e system. Within t h e database, t h e r e i s a d a t a t a b l e f o r every device o r sensor i n t h e system. The

o t h e r and exchange d a t a and c o n t r o l parameters through t h e database. A l l i n t e r a c t i o n s with t h e database a r e handled through a Central Database Manager Program (CDBMGR). This modularity of t h e system software provides f l e x i b i l i t y i n changing t h e experimental set-up and allows e a s i e r sys tem modification and development. Detailed information on t h e s t r u c t u r e of t h e database i s provided i n t h e DACS Manual1'.

A c r o s s r e f e r e n c e between a l l t h e p o i n t s i n t h e system and t h e assigned database numbers i s kept i n t h e KEY f i l e s . A t y p i c a l database reference l i s t , of t h e tower, i s presented i n Appendix C. The r e f e r e n c e l i s t includes all t h e d a t a a c q u i s i t i o n p o i n t s which a r e connected t o DAU#l and i n d i c a t e s t h e i r a s s o c i a t e d system, f l o o r l e v e l , s l o t number (on t h e DAD) and t h e assigned database number. A l l t h e points ( i n t h i s l i s t ) a r e

repeated i d e n t i c a l l y f o r a l l DAU's i n t h e tower, except f o r t h e points connected t o t h e extender and t h e p o i n t s with database numbers over 106.

6.5 System Performance

Performance t e s t s were conducted t o determine t h e speed and accuracy of t h e d a t a g a t h e r i n g and t o v e r i f y t h e system o p e r a t i o n s with regard t o the requirements of smoke c o n t r o l t e s t i n g i n t h e tower.

The following i s t h e r e s u l t i n g experimental s e t - u p and system performance, with all measuring p o i n t s and devices enabled:

-

100 thermocouples

-

t h e d a t a sampling i n t e r v a l i s 30 seconds.

-

_{11 pressure scanivalves - w i t h t h e stepping r a t e s e t a t 10}

seconds, t h e a c t u a l s t e p p i n g i s 10 t o 13 seconds, and t h e d a t a sampling i n t e r v a l i s 10 seconds;

-

11 gas samplivalves and 11 gas analyzers

-

with t h e s t e p p i n g r a t e s e t a t 30 seconds, t h e a c t u a l stepping i s 30 t o 34 seconds, and t h e d a t a sampling i n t e r v a l i s 30 seconds;

-

20 doors operating a t 60 seconds r e g u l a r schedule;

-

The d a t a s t o r a g e (recording) i n t e r v a l f o r a l l p o i n t s i s 30 seconds.

7.0

FIRE

SIMULATION USING GAS

BURNERS

Various methods can be used f o r simulating a f i r e i n a building by using s o l i d , l i q u i d , o r gas f u e l s . The most r e p r e s e n t a t i v e method i s t h e use of a c t u a l combustible m a t e r i a l s with a d i s t r i b u t i o n arrangement a s i n t y p i c a l o f f i c e , apartment o r h o t e l room and a t y p i c a l v e n t i l a t i o n condition. Such a method would provide a r e a l i s t i c r e p r e s e n t a t i o n both q u a n t i t a t i v e l y and q u a l i t a t i v e l y of a f u l l - s c a l e f i r e i n terms of t h e heat r e l e a s e d , t h e

r a t e of smoke produced, t h e temperature of combustion g a s L 6 , and t h e gas pressure developed i n t h e f i r e compartment.

However, t h e use of a c t u a l combustible m a t e r i a l s i s not convenient f o r conducting experiments t h a t would r e q u i r e r e p r o d u c i b i l i t y and c o n t r o l of t h e f i r e . I n a d d i t i o n , burning of a c t u a l m a t e r i a l s r e q u i r e time f o r

p r e p a r a t i o n and c l e a n up between t h e t e s t s . I n t h e f i r e tower, most of the experiments w i l l be conducted using propane gas f u e l mixed with a i r f o r combustion and i n some f i r e t e s t s , s o l i d f u e l s w i l l a l s o be used a s needed. The migration of smoke and o t h e r combustion products w i l l be monitored by taking measurements of carbon dioxide gas concentrations i n t h e f i r e compartment (burn a r e a ) and o t h e r a r e a s of a l l f l o o r s of t h e tower, a s described i n Section 5.0 of Instrumentation.

The f i r e temperature i s c o n t r o l l e d by t h e burner c o n t r o l l e r according t o a s p e c i f i e d time-temperature curve. Curves of v a r i o u s f i r e s e v e r i t i e s can be s e t based on t h e standard f i r e t e s t f o r building

c o n s t r u c t i o n and m a t e r i a l s NFPA 251 and d a t a of a c t u a l temperature curves recorded i n f i r e

test^'^,^^,

19.

7.1 Burner System

A programmable gas burner system has a t o t a l capacity of 5

MW

with gas f u e l l a i r r a t i o of 1 t o 24 by volume. The burner system c o n s i s t s of t h e following:

-

Two s e t s of propane f i r e d gas burners

-

Two gas t r a i n s t a n d s

-

Two set-point c o n t r o l l e r s

-

A set-point programmer

The propane gas i s s t o r e d i n t h r e e tanks (4500 l i t e r s each) l o c a t e d o u t s i d e t h e building f o r s a f e t y reasons. The propane i s admitted through s t e e l pipe l i n e s t o t h e gas t r a i n s t a n d s on t h e ground f l o o r . Also, t h e supply a i r f o r combustion i s provided from o u t s i d e t o t h e gas t r a i n stands (by a c e n t r i f u g a l fan). The propane gas flow r a t e and t h e combustion a i r supply a r e monitored and recorded during an experiment.

The gas flow r a t e i s measured by a turbo flow meter (Rockwell model 2" TPL-9, turbo-meter) which is connected t o a t o t a l i z e r and flow r a t e

i n d i c a t o r , (Rockwell model ACT-PAK 1000D). The t o t a l i z e r accepts e l e c t r o n i c pulses from t h e meter and provides an output i n t h e form of v i s u a l d i s p l a y s of t h e cumulative volume flow and t h e instantaneous flow r a t e . The

temperature and pressure of t h e propane gas supply a r e a l s o measured and recorded during burner operation f o r t h e flow c o r r e c t i o n t o standard

condition. The combustion a i r flow r a t e i s measured using a v e l o c i t y

pressure averaging tubes i n s t a l l e d i n t h e i n l e t a i r duct located o u t s i d e t h e tower and connected by tubing t o a pressure transducer located i n s i d e t h e tower. The v e l o c i t y pressure averaging tube system was c a l i b r a t e d using a p i t o t traverse13. A schematic r e p r e s e n t a t i o n of t h e gas burner system is provided i n Figure

20;

d e t a i l s of t h e burner system a r e described next.

7.1.1 Burner stands

The two s e t s of propane f i r e d gas burners a r e i n s t a l l e d i n t h e burn a r e a of t h e second f l o o r a s shown i n Figure 21. Each s e t c o n s i s t s of f i v e ribbon type burners i d e n t i f i e d a s number 1 t o 5, as shown i n Figure 22.

Burner No. 1 i s t h e p i l o t burner and i s c o n t r o l l e d by t h e flame s a f e t y c o n t r o l s . Burners

2, 3,

4,

5

a r e c o n t r o l l e d i n d i v i d u a l l y , i n sequence, by manual o r automatic operation of t h e s e t point programmer. Temperature l i m i t sensors a r e provided a t each burner f o r proving t h e flame before t h e next sequenced burner i s provided with combustion a i r and gas. The h e a t output of t h e burner i s c o n t r o l l e d by varying t h e amount of a i r supplied by t h e combustion a i r f a n t o t h e v e n t u r i tube ( a i r l g a s proportional mixer) which i n t u r n c o n t r o l s t h e supply r a t e of propane gas. A motorized valve (downstream of t h e f a n ) i s adjusted by e l e c t r i c s i g n a l s s e n t t o t h e damper motor by t h e c o n t r o l l e r . P o s i t i o n of t h e valve opening may be e s t a h l i s h e d by manual o r automatic o p e r a t i o n of t h e c o n t r o l l e r .

7.1.2

Gas Train Stands

Two gas t r a i n s t a n d s , a r e i n s t a l l e d on t h e ground f l o o r , below t h e burner stands a s shown i n Figures 2 3 and

24.

S t e e l pipes

4

inches i n diameter connect t h e g a s l a i r mixture o u t l e t s of t h e gas t r a i n r i g s t o t h e burners on t h e f l o o r above. Each gas t r a i n stand i s provided with t h e following:

-

Combustion a i r fan; 0.76 m 3 / s a t 657 mm water column pressure,

-

Motorized a i r discharge damper f o r p r o p o r t i o n a l c o n t r o l of combustion a i r ,

-

Propane gas pressure r e g u l a t o r s and low and high pressure gas switches with manual r e s e t s ,

-

Low pressure gas r e g u l a t o r and solenoid valves f o r supply of gas t o t h e a i r / g a s mixers,

-

Air/gas proportional mixer assembly c o n s i s t s of a v e n t u r i tube with a b u t t e r f l y valve and a zero pressure cock f o r maintaining t h e g a s l a i r r a t i o throughout t h e range of o p e r a t i o n ,

-

Flame s a f e t y c o n t r o l valves,

7.1.3 C o n t r o l l e r s

The burner system can be operated on manual o r automatic mode u s i n g t h e two set-point c o n t r o l l e r s , type Barber-Colman 560 s e r i e s microprocessor, and set-point programmer UP55 s e r i e s which a r e l o c a t e d i n t h e s e r v i c e a r e a of t h e second f l o o r , a s shown i n Figure 25. One c o n t r o l l e r i s used t o c o n t r o l t h e f i r i n g r a t e of each s e t of burners by a d j u s t i n g t h e cornhustion a i r damper. The temperature required i s r e f e r r e d t o a s t h e s e t point which

can be e n t e r e d e i t h e r d i r e c t l y i n t o t h e c o n t r o l l e r f o r manual operation o r programmed through t h e programmer f o r automatic operation. The temperature achieved which i s r e f e r r e d t o

as

t h e process temperature i s provided by t h e thermocouples i n s t a l l e d a t t h e c e i l i n g above t h e burners. Both t h e s e

temperatures a r e i n d i c a t e d continuously by t h e d i g i t a l read-outs of t h e c o n t r o l l e r s . When t h e process temperature d e v i a t e s from t h e s e t p o i n t temperature t h e c o n t r o l l e r s i g n a l s t h e damper motor t o reduce o r i n c r e a s e t h e combustion a i r supply valve opening, thereby reducing o r i n c r e a s i n g t h e f i r i n g r a t e u n t i l t h e process temperature reaches t h e s e t p o i n t

temperature.

7.1.4 Programmer

A set-point programmer i s i n s t a l l e d alongside t h e two c o n t r o l l e r s (Fig. 25) f o r automatic operation.

The programmer has two channels, one f o r each c o n t r o l l e r . Each channel has f o u r event r e l a y s which a r e used t o switch on and off burners number 2,3,4, and 5 of one burner s e t . The time-temperature curve i s entered i n t o t h e programmer, and during t e s t s , t h e programmer sends s e t point s i g n a l s t o t h e c o n t r o l l e r ( s ) , which a d j u s t t h e f i r i n g r a t e so t h a t process temperature follow t h e required curve. F u r t h e r d e t a i l e d information on t h e programming c a p a b i l i t y and t h e c o n t r o l l e r s a r e provided i n t h e

i n s t r u c t i o n manuals (Refs. 20, 21). 7.2 Safety f e a t u r e s

The system i s provided with s a f e t y i n t e r l o c k c o n t a c t s designed t o s h u t down t h e e n t i r e system, except f o r combustion a i r supply, i f any of t h e following conditions e x i s t during t h e burner operation:

i ) d e t e c t i o n of propane gas i n t h e gas t r a i n room (ground f l o o r ) o r a t t h e bottom of t h e smoke s h a f t a t t h e basement l e v e l .

i i ) f a i l u r e of t h e combustion a i r supply o r a i r pressure switch i i i ) propane gas p r e s s u r e i s too low

i v ) propane gas pressure i s too high

I n a d d i t i o n t o t h e above, f o u r temperature l i m i t c o n t r o l s ( r e l a y s ) a r e provided i n t h e consoles f o r t h e c o n t r o l l e r s . The purpose of t h e s e c o n t r o l l e r s i s t o a s s u r e flame and temperature a r e s a t i s f a c t o r y before an a d d i t i o n a l burner i s a c t i v a t e d . The temperature i s sensed hy thermocouples i n s t a l l e d a t t h e burners (Figs. 21 & 22). The p i l o t burner of each hurner s e t i s provided with flame s a f e t y c o n t r o l s . Should t h e flame go out a t any time f o r any reason then t h e gas w i l l be shutoff a t t h e gas t r a i n stand.

Also, t h e burners nos. 2, 3, 4, 5 w i l l not l i g h t u n t i l two conditions a r e s a t i s f i e d :

-

t h e s e t temperature l i m i t is achieved and t h e temperature r e l a y operated t o a s s u r e t h a t t h e next burner i s s a f e t o i g n i t e .

-

t h e programmable c o n t r o l l e r has t o be s e t a t i t s proper point i n t h e program, and t h e event r e l a y s have closed t h e i r c o n t a c t s t o allow t h e burners t o be "on".

Further d e t a i l s on t h e system o p e r a t i o n , procedures and emergency s h u t down a r e provided i n NRC Gas Burners I n s t r u c t i o n Manual.

8.0 SUMMARY OF

THE

TOWER'S

RESEARCH

AND DEVELOPMENT CAPABILITIES

The Tower F a c i l i t y has unique c a p a b i l i t i e s f o r conducting r e s e a r c h and development i n t h e smoke c o n t r o l area. Typical a p p l i c a t i o n s a r e :

-

The concepts of smoke movement and c o n t r o l which involve s t u d i e s of t h e e f f e c t of f i r e temperature on t h e movement of smoke,

v e r i f i c a t i o n of mathematical m d e l s , development of v a r i o u s smoke c o n t r o l techniques involving mechanical p r e s s u r i z a t i o n of

v e r t i c a l s h a f t s and f l o o r spaces, and e s t a b l i s h i n g design requirements, such a s t h e design pressure d i f f e r e n c e and a i r v e l o c i t y required t o overcome t h e adverse pressure caused by t h e f i r e , 04

-

The study%ethods of venting smoke and heat using t h e smoke s h a f t

,

e x t e r i o r wall vents o r mechanical exhaust,

-

Testing of v a r i o u s system components (e.g. smoke and f i r e dampers, a i r pressure r e l i e f dampers, f a n s

,

e t c . ) ,

-

The development of g u i d e l i n e s f o r t h e commissioning of systems, acceptance of t e s t procedures, t e s t methods and measuring

-

Training and demonstration purposes.

Studies o t h e r than smoke movements and c o n t r o l t h a t can be conducted a r e e x t e r i o r spread of f i r e from f l o o r t o f l o o r , f i r e propagation and

suppression i n v e r t i c a l s h a f t s , and column performance under f i r e conditions. Also, s t u d i e s of a i r flow around b u i l d i n g s involving determination of wind pressure c o e f f i c i e n t s and wind e f f e c t s on t h e o p e r a t i o n of v e n t i l a t i o n and smoke c o n t r o l systems can be conducted.

REFERENCES

1. F i r e Commissioner of Canada, " F i r e Losses i n Canada

-

Annual Report 1982", Public Works Canada, Ministry of Supply & Services 1983 Cat. No. W51-1982.

2. F i r e P r o t e c t i o n Handbook, NPPA, F i f t e e n t h e d i t i o n , 1981 Section 2, Chapter 2, by t h e National F i r e P r o t e c t i o n Association.

3. M.J. Karter, F i r e Loss i n t h e United S t a t e s During 1982, F i r e J o u r n a l , September 1983, NFPA.

4. M.J. Karter and J.L. Grancarski, F i r e Loss i n t h e United S t a t e s During 1983, F i r e Journal, September 1984, NFPA.

5. Pauls, J.L. and B.K. Jones, Building Evacuation Research Methods and Case Studies. F i r e s and Human Behaviour, 1980, Chapter 13, John Wiley and Sons Ltd.

6. Pauls, J.L., Building Evacuation: Research Findings and Recommendations. F i r e s and Human Behaviour, 1980, Chapter 14, John Wiley and Sons Ltd. 7. The National Building Code of Canada, 1985, NRCC No. 23174.

8. The Supplement t o t h e National Building Code of Canada, 1985, NRCC

No. 23178, Chapter 3, Measures f o r F i r e Safety i n High Buildings, by t h e Associate Committee on t h e National Building Code, 1985, National

Research Council Canada.

9

.

G.T. Tamura, Computer Analysis of Smoke Movement i n T a l l Buildings, ASHRAE Transactions, Vol. 75, P a r t 11, 1962 NRCC 11542.

10. H. Yoshida, C.Y. Shaw and G.T. Tamura, A Fortran I V Program t o Calculate Smoke Concentration i n a Multi-Storey Building, National Research

Council, DBR Computer Program No. 45, 1979.

11. G.T. Tamura, Review of t h e DBRINRCC Studies on Control of Smoke from a F i r e i n High Buildings, ASHRAE Transactions 1983, Vol. 89, P a r t 1. 12. A.M. P h i l l i p s and L.W. Gold, DBRINRC F i r e Research Field S t a t i o n ,

Proceedings of a Symposium Held i n September 1981 a t t h e Opening of the DBR F i r e Research F i e l d S t a t i o n , National Research Council Canada, NRCC 21127, Ottawa, April 1983.

13. ASHRAE Handbook of Fundamentals, 1981, Chapter 13.

14. Data Acquisition System

-

DACS Users Manual, (Special i n t e r n a l manual f o r NRCIFRFS, by Systemhouse Ltd.), National Research Council, Division of Building Research, Ottawa, August 1981.