Heating Capacity of DBR/NRC Furnace Equipment

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Publisher’s version / Version de l'éditeur:

Technical Note (National Research Council of Canada. Division of Building Research), 1973-05-01

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Heating Capacity of DBR/NRC Furnace Equipment

Stanzak, W. W.; Berndt, J. E.

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..

DIVISION OF BUILDING RESEARCH

No.

574

NOTlE

,. COpy

｜ＨＩＬＢＬｾＺＱ

_{' .}

＿ｾｬ

_. -. ::..

"

. r; >.i • .-'.

NATIONAL RESEARCH COUNCIL OF CANADA

PREPARED BY W. W. Stanzak and CHECKED BY

J. E. Berndt

GWS APPROVED BY NBH

.QAI§.. May 1973 PREPARED FOR

Record Purposes - LiInited Interest

SUBJECT HEATING CAPACITY OF DBR!NRC FURNACE EQUIPMENT

A detailed description of the DBR/NRC furnace facilities is available 1,:3. The se facilitie s are progra.rnnled to automatically follow

the standard tempe rature -time curve pre scribed by CSA and ASTM 3,4 •

As this curve is not usually representative of actual building fires, the authors exa.xnined the available equipment for its ability to follow

temperature-tiIne functions that rise more rapidly than the standard curve.

Small Furnaces

The Division's Fire Research Section possesses two small electrical (star-connected) furnaces that accept a plane speciInen of approximately 31 x 33 in. One of these was calibrated to determine the power consumption vs the voltage input to the saturable core

reactor. The calibration and the resulting furnace temperature curve is shown in Figure s 1 and 2.

Following the calibration, five fire te sts were run on the standard assembly shown in Figure 3. The thermal properties of the superstructure remain constant in successive tests and the asbestos-cement board membrane was renewed for each test. The temperature-tiIne curves for the furnace and supporting steel-are plotted in Figures 4-7. Figure 8 shows some of these curves superiInposed for comparison

purposes.

This study showed that for normal building construction assemblies, the small furnace is capable of produc ing tempe rature -tiIne functions that are representative of rapidly developing building fires.

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."

-2-It was also of intere st to examine the heat input limitations of the furnace in a standard fire test. The water-filled steel panel in Figure 9 was subjected to such a te st and it was found that the furnace was unable to follow the prescribed curve by about 30 minutes

(Figure 10). Figure 11 shows that at steady-state operation the average rate of water consumption Was

ｾｾ

= 1.48 litres/min. Thus the rate of heat input into the specimen was 56KW. Since the maximum power input to the furnace was 86 KW, this shows a loss of 30 KW to the furnace itselfj i. e. about 35 per cent of the input power. Since temperatures in the furnace always remained relatively close to the standard pre-scribed furnace temperatures, the power input into any specirrien may be approximately calculated by the expression

p

=

0.7 (KW), where

P

=

power input into specimen, KW (KW)= power input into furnace, KW. Floor Furnace

Because of the principles of the gas burner and flue design, the floor furnace has very limited versatility. Two fire tests were conducted with the top of the furnace closed by a refractory concrete lid.

The fir st te st attempted to follow a simple temperature -time function

T

=

70

+

275Jt , where T

=

furnace temperature, of

t

=

time, min.

The furnace curve obtained is shown in Figure 12 and shows that the equipment was unable to follow the prescribed function after

t

=

30 min.

In the second test, the valves were fully opened to determine the maximum capacity of the equipment. Figure 13 shows the temperature s measured in the furnace gases (shielded thermocouples) and on the

inner wall and ceiling surface s (unshielded thermocouple s). The

re suIts indicate that the equipment is unsuitable for simulating rapidly developing building fires. However, improved performance may be obtained by insulating the furnace surfaces with a reflective liner.

During the second test, furnace pressures and gas analyses were taken at the observation ports 35 in. below the ceiling slab. These are shown in Tables I and II.

Acknowledgement

The authors wish to thank D. H. Shearer for carrying out the fire te sts in the small furnace.

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.'

-3-References

1. Shorter, G. W. and T. Z. Harmathy. Fire Endurance Test Facilities at the National Research Council. NRC/DBR Fire Study No.1, Ottawa, July 1960 (NRC 5732).

2. Blanchard, J.A.C. andT.Z. Harmathy. Small-ScaleFireTest Facilities of the National Research Council. NRC/DBR Fire Study No. 14, Ottawa, November 1964 (NRC 8207).

3. Fire Tests of Building Construction and Materials, ASTM

Designation E1l9-71. American Society for Testing and Materials, Philadelphia, Pa. U. S. A.

4. Methods of Fire Tests of Walls, Partitions, Floors, Roofs,

Ceilings, Columns, Beams and Girders. CSA Standard B54. 3-1964. Canadian Standards Association, Ottawa, Ontario.

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"

TABLE I FURNACE PRESSURES

TIME PRESSURE(in HZ 0) TIME PRESSURE(in HZ 0)

0

+

Z.5 60 - 0.3 5 .. 1.1 70 - 0.3 10 .. 0.9 80 - 0.3 15 .. 0.8 90 ZO - 0.7 100 Z5 .. 0.75 110 30 - 0.5 1Z0 40 - 0.5 50 - 0.3

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TABLE II GAS ANALYSIS Sample Tim.e

O

2 N2

CO

2

C

3H8 (min. ) 1 20 4.64 75.70 0.04 10.00 Nil 2 50 7.75 78.88 2.42 7.76 Nil 3 80 10.25 79.17 2.20 6.76 Nil " : .

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•

I

1 I

1 --

5

-I

4 I -

-I -

-ｾ

-3 ｾ

-ｾ ₂

-ｾ

---

-I I I I 100 80

a->

ｾ U.J u ₆₀

«

Z C<: ::> LL 0 40 l

-•

I -::> aI -::> 0 20 MAX

o

POWER INPUT TO REACTOR

FIG UREI

FUR NACE CAL I BRA TION

(8)

e

2400

i i i i i i I i i i I I i i i i i I i r

,120

20

40

e:(

60 >

ｾ

80

100 ._.

_<;FU

RNACE TEMPERATU RE ;: F

_{"".---.-.-...}

.""".

•

/./'---.-.--...

.---.---:...

"-/

.

. / '

POWER INPUT

KVA

2000

u...

ｾ

0

.

LLJ

I"·

c::::

1600

I => l -e:( c:::: LLJ Q..

1200

ｾ LLJ I -LLJ U e:(

./,-'_.

__

. /

:z:

800

c:::: => u...

400 I-t

/

•

2

4

6

8

10 TIME, MIN

12

14

16

18

20 FIGURE

2 POWER INPUT CALIBRATION CURVE

(9)

31"

FIRE BRICK

®THERMOCOUPlES ON UNDERSIDE OF SUPPORTING STEEL DECK

(10)

2200

2000

1800

1600

::- 1400

-I.l.J 0:::

ｾ

1200

<: 0::: I.l.J CL :E

1000

I.l.J

...

800

600 1 AUTO/SETTING FOR INITIAL 5 MIN

TO 1000°F

2 SET MANUAL TO (4)

-\.

-FURNACE

Ｌ｟ｾ｟ＮＭＭＭＭＭﾷ｟Ｎ｟Ｎｔｳ

(AVG. STEEL TEMP.)

/

.

,.

I

./.

• .

--400

200

10 . 20

30 TIME, MIN

40

50

60 FIGURE

4 ELECTRIC FURNACE CURVE NO.1

(11)

2200

/\.

1 MANUAL SETTING (6) TO 2000°F

2 AT 8 MIN. CUT BACK MANUAL

2000

SETTING TO

(5)

.

\

1800

/

.

1600

I

\,\

u...

₁₄₀₀

"-°

"'.

.

U.J e::: ::::l

1200

' . FURNACE

I

-<

e::: U.J c..

1000

:!: U.J I

-800

,

.

,_1'-

_---

T

s

(A VG. STEE L TEM

P)

/

./

_/

600

400

200 -10

20

30 TIME. MIN

40

50

60 FIGURE

5 ELECTRIC FURNACE CURVE NO.2

(12)

2200

1 AUTO SETTING FOR INITIAL

5 MI N

2000

_{/ ,}

2 SET MANUAL TO

(3)

/ .

.

\

1800

.

/

.

\

/

.

1600

.

\

/

•

u..

1400

ｾＮ

0

-UJ a:::

1200

=> •

t-" t-" . F U RNACE

«

•

a:::

/

UJ 0-

₁₀₀₀

ｾ • UJ

I

t-800

60

50

30

40 TIME, MIN

20

10 /.--._----.

,.

...

...

/ "

"

T

_s

IAV";--STEEL TEMP.l

400 •

/ "

,.

...

/

200

600 FIGURE

6 ELECTRIC FURNACE CURVE NO.3

(13)

60

50 T

_s

(AVG. STEEL TEMP. )

30

40 TIME, MIN.

1 AUTO SETTING FOR INITIAL

5 MI N

2 MANUAL SETTING (3.5)

".--.-._

...

,.

.--.

ｾ

...

.

---..-.

20 .

\

/

.

\

• \

_•

10

400

800

600 2200

2000

1800

1600

u.

1400

0

.

LU 0:: :::>

₁₂₀₀

...

<:

·'.FU RNAC E

0:: LU CL.

e

:E

1000

LU

...

FIGURE

7 ELECTRIC FURNACE CURVE NO.4

(14)

-

e

•

100 90 80 70 60 40 50 TIME, MIN 30 20 10

IVV'

AVERAGE UNEXPOSED SURFACE

ｾ

- - - NO. 5 2000 STANDARD CURVE· 1500 _{ｾｕｒｎａｃｅ} u. THERMOCOUPLES 0 NO.5

...

a:: ;:) l -e:( a:: 1000

I

1111/

""NO.1 NOTE: ...

a.. _{• THI SIS NOT A TEST CURVE}

:2::

...

l

-I

f

_ｾｾ

ｾ _T_{5 •} NO.5 500

WI

ｾ T5 , NO.2 T 5_ NO.1 8R5099-8

(15)

.'

31"

PANEL

I

PAN EL 4

3111

EACH PA NEL 0F _1/4II STEE L PL ATE

(TOP, BOTTOM, SIDES)

1/1611 ASBESTOS GASKET

PANE L 2

BOLTED CONNECT ION

5'/₈II B_{OL S,}T 611

_o.c.

PANEL 3

-"""r-- 2" ROUND VENTPIPE 211ROUND WATER SUPPLY PIPE

FIGURE 9

ISOMETRIC

OF PANEL ASSEMBLY

(16)

,"

1600

1400

I

1200

I

u..

,

0

,

uooi

1000

_I

I a:: _I => I--

I

<C I a::

_I

LLJ

800

0-

f

:;E

,

LLJ

_I

I--I

600 f

I

,

1

400 ,

1 ...

ｾ

....

ｾ

-

--"."., (2)

,,'"

/

....

/ ...J

(1) PRESCRIBED FURNACE TEMPERATURE (2) AVERAGE FURNACE TEMPERATURE (3) AVERAGE TEMPERATURE OF EXPOSE

FACE (4) AVERAGE TEMPERATURE OF UNEXPOSED FACE (3 )

60

50

(4 )

20

30

40 TI ME, MI NUTES

10

OL.----I"---L_--L._...L.._-'-_..&-_...L...._..L.-_I---I_..._ ...

o

200 FIGURE 10

GENERAL TEMPERATURE VS TIME PLOT

(17)

e

'.

60 56 52 48 0.85 1

44

dW

Cit

= 0.63 LITRE/MINUTE

ｾｾ

= 0.85 UTREIMI NUTE 40 36 dW

AVERAGE

Cit=

1.48 L1TRES/MINUTE

24 28 32 TIME, MINUTES 20 16

12

8 4 12

ＳＲｾｲＭｲｲｲＭｲｲｲＭｲｲｲＭｲｲｲＭｲｲｾｾＬＮＮＭＭＭＭＭＬＭＭＭｲＭＮＮＭＭＭＭＮＭＭＭＭ

4 8 20 24 28 - I 14 ｾ u.J l -e(

::

Vl u.J ｾ

I-FIGURE 11 TOTAL WATER CONSUMPTION FOR FIRST RUN

(18)

800 1800

1400

1600

ｾ

20 00

ｲＭＭＭＭｲＭＭＭｾＺＭｲＭＭＭＭＭｲＭＭＭｾＭＭＬｾｪｦｬｰＭＭＭＭｾ . fi"