ML20115F353

From kanterella
Jump to navigation Jump to search
Verification of Models for Fire-Wrapped Conduits & Cable Trays Against Test Data
ML20115F353
Person / Time
Site: Byron, Braidwood  Constellation icon.png
Issue date: 04/19/1996
From:
COMMONWEALTH EDISON CO.
To:
Shared Package
ML20115F333 List:
References
BYR-96-059, BYR-96-059-R00, BYR-96-59, BYR-96-59-R, G-70-96-092, G-70-96-92, NUDOCS 9607170213
Download: ML20115F353 (36)
v • d • e


Text

_

l.

Exhibit C NEP-12-02 Revision 0 COMt40NWEALTH EDISON COMPANY l

CALCULATION TITLE PAGE l

F Calculation No.: BYR 96-059 / G-70-96-092 Page No.: 1 of 40

@ Safety Related O Regulatory Related O Non-Safety Related Calculation

Title:

Verification of Models for Fke-Htapped ConduMs and Cable Trays against Test Data Station / Unit: Byron / Braidwood, Units 1 & 2 System Abbreviation: AP Equipment No. (rappt):

Project No. Orappt) 09050-051 & 09135-200 Rev.:0 Status: QA Serial No. or Chron No.

Date:

Prepared by: kM h/

Date:

/ f, /9((

Revision Summary:

Initialissue forallpages.

i Electronic Calculation Data Files Revised:

(Name ext /stre/date/ hour /: mnWenreaton methoWremarks)

<DIR>

04-19-96 3:01p modval doc 2701824 04-19-96 3:00p simptra5 med 34946 04-18-96 1:50p tva4-750 med 36581 04-18-96 1:55p l

5 file (s) 2773351 bytes Do any assumptions in this calculation require later verification? O Yes @ No Reviewed by:,((/M h //I Date:

  1. ///f//fId Review Method:

Comments (C or NC): A/ 6 feri

.) Orj un N c~ I C v lU 0 n Approved by:

I.

Date:

4 //f/ 95

/

/

/

i l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION TABLE OF CONTENTS PROJECT NO. 09050-051/09135-200 CALCULATION NO. BYR 96-059 REV. NO. O PAGE NO. 2 OF 40 DESCRIPTION PAGE NO.

SUB-PAGE NO.

TITLE PAGE 1

REVISION

SUMMARY

TABLE OF CONTENTS 2

4 PURPOSE / OBJECTIVE 3

METHODOLOGY AND ACCEPTANCE CRITERIA 4

ASSUMPTIONS a

DESIGN INPUT 8

REFERENCES 15 CALCULATIONS 17

SUMMARY

AND CONCLUSIONS ATTACHMENTS:

A-Data on Cable for Conduit Test A1-A3 B-Data Sheet for SilTemp@

81-82

Exhibit C

~

NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 i PAGE NO. 3 OF 40 G-70-96-092 09135 200 PURPOSE / OBJECTIVE The purpose of this calculation is to develop mathematical models for determming the conductor temperature f:r cables installed in a conduit or cable tray that is wrapped with a material such as 'ISI Thermolag@. 'Ihe v:lidity of the mathematical modelis then verified by demonstrating that the conductor temperatures c:lculated by the model match the conductor temperatures found in industry testing conducted by'the Tennessee Valley Authc;.ty (TVA) and by Texas Utilities (Comanche Peak).

9 l REVISION NO.: 0 l

1 i

~

l Exhibit C NEP-12-02 Revision 0 i

COMMONWEALTH EDISON COMPANY ii CALCULATION NO. : BYR 96459 09050-051/

PAGE NO. 4 OF 40 j

G-70-96-092 09135-200 METHODOLOGY AND ACCEPTANCE CRITERIA Methodology for Conduits The model for conduits uses basic heat transfer relation '

outside of the conduit and the Neher-McGrath i

equations inside the conduit (Ref.1). The heat dissi ated the cables inside of the conduit is calculated first.

I Energy balance equations can then tie written at eac$ in ace or discontinuity in the fire wrap system. The temperature at the interfaces can then be determined so that the amount of heat being transferred across the j

interface is equal to the amount of heat being generated by the cables.

j The first interface is at the surface of the conduit. Heat will be dissipated from the surface of the conduit by r:diation and convection. The radiation relationship assumes that the conduit is located in free space, and the i

area dissipating heat per unitlen is equal to the circumference of the wrapped conduit Equation 8-43a of ted usmg the simplified relationship for a horizontal cyl(inder in air Tab Ref:rence 2 7-2 of Refere). Convection is ca i

nce 2). The resulting non-linear equations are solved using the solve block feature of Math (cad i

j (Reference 3).

i Th2 outer layer of fire wrap is treated as a cylindrical shell. The temperature drop can be calculated using j

Equ: tion 2-8 of Reference 2.

1-Heat conduction across the air gap between the inner and outer layer of fire wrap is assumed to be by i

r:distion, conduction, and in some cases convection 'Ihe heat transferred by radiation is taken into account by treating the two layers of fire wrap material as concentric cylinders (Equation 8-43 of Reference 2). & heat transferred by conduction is calculated by treating the gap as a cylindncal shell. Since the thermal conductivity of air is a function of temperature, a section of the calculation makes a hnearinterpolation of the c:nductivity based on data points taken from Reference 2. The conductivity is calculated for the average of the

{

temperatures on either side of the gap. Depending on the size of the gap and the temperature difference, convechon may or may not be sigruncant m the air gap.

convech.on is taken into account by an i

cdjustment factor to the thermal conductivity of air. This ustment multiplier is given in Sechon 7-2, Equations 7-49 and 7-60, and Table 7-3 of Reference 2. The andt! number and the'kmematic viscosity of air are non-linear functions of the temperature. Cubic splines are used to perform interpolations of the values of these quantities taken from Table A-5 of Reference 2. The function for the adjustment of the conductivity of air is placed in an "if' statement so that its muumum value is 1 (no additional heat transfer due to convechon). A l

M:thcad solve block is used to solve the heat transfer equations at the gap.

i

'Ihe temperature drop across the inner layer of fire wrap materialis calculated in the same way that the j

temperature drop was calculated across the outer layer of fire wrap material. The temperature drop across the g pletween the conduit and the inner layer of fire wrap material as calculated in the same manner as was used for the air gap between the inner and outer layers of fire wrap material. In cases where there is no gap between the conduit and the fire wrap or where there is only a single layer of fire wrap material, the gap between the conduit and the inner layer of fire wrap material or the gap between the mner and outerlayers of fire wrap material can be made infuutesimally small.

i The temperature drop across the conduit is calculated by treating the conduit as a cylindrical shell.

'The temperature drop in the gap between the outside of the cable and the inner wall of the conduit is c:.lculated using Equation 41 A of Reference 1. This equation is partly based on experimental data. Since the t

cable rests on the bottom of the conduit, an analysis of this temperature drop based on simple heat transfer theory is not possible. The circumscribed diameier of the conductors can be calculated by tngonometry, and th2 numeric value of the multiplier is tabulated in Table 1 on page 80 of Reference 4.

The temperature rise through the insulation is calculated using Equation 39 of Reference 1. The coeffnent of l

i 0.00522 used in this equation includes various unit conversion factors. Since the Mathcad calculation uses j

f consistent nits, the appropriate coefficient is I. Because of the presence of the other three conductors of the 2r l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 l

COMMONWEALTH EDISON COMPANY l

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 5 OF 40 G-70 96-092 09135-200 1

l l

f:ur conductor bundle, a geometric factor from Figum 2 of Reference 5 is used, as recommended in Reference 1.

The various temperatum drops are summanzed in the following figure:

Surfoce temperature i

of the fire wrap Temperature drop through (heat dissipoted by the outer layer of fire wrap rodiotion and convection)

)

l h

Temperature drop through ff.4 s

9ep between layers of fire il n n is is si o is is n is si n d

g wrap material is is si si si is se n ei is is is si sy i

A n si n n y m

o ie n n o h fn ny A sqn n o n o r

j,l ll ll "g:A ::: ::: ::: : ::M ll,' l l' d,l Temperature drop through

m :::: p%,e is o

[ln ll X::::

ll ll

,' i

'""'Y

"'"'P

/l'/ ::-

l

/::::V

/

x:::A n

ll ll l'/:::t x::: A ' trpl l:

o o o o

A::7 T- _

i is o is is is Temperoture drop through is is o i

i,

/ _ _ _/

Y__4 oir gop between conduit i.p.+r si n j

  1. (

[ m}::::

I u o is ond inner layer of fire

,' l ll ll e ','

j l' ll l wrap e','

n i, n 7

o I

i h is is si D_-_k

/___-/

N i o is i

n is si Temperature drop i:::\\

l ll s' ii \\ :: A

/'

e'$'

/:b y i ll ll rought conduit is is is l,'

gi "l ll ll\\:\\:::A.

j:::/

h

\\ : : _N n n o A:::/

l ll gl, n

4 n g' N : : : A

//

/ :::

I k

ey x

n n n

n Temperature crop N',klqll hlp'l/

'--.._T:::::J/

ullQ:x:::-Q :

4

,, 3 through air gap between

y'Iisis n x

~

is cables onc conduit wall

)

27 p1 o

si h is u

si / \\

hw_

s si is is le it si si di si it it is is is is is is o o si si o o /

Temperature drop q

is is si si is o n is is is n is si y q

through Cable.in sulot s.on

.u p /

Q il la is is is is is li si is y% n n n n n ii m

o s

Methodology for Cable Trays The model for cable trays is similar to the model for conduits from the surface of the fire wrap to the surface

~

of the cable mass. The cables in the tray are modeled as a cable mass using Stolpe's method (Reference 6). The h::t generated by the cables in the tray is first calculated. Energy balance equations are then developed at ecch interface or discontinuity in the fire wrap system. The temperatures at the interfaces are calculated so l

th:t the amount of heat transmitted across the interface is equal to the heat generated by the cables.

Hr.ct is dissipated at the interface between the outside of the fire wrap and the ambient by convection and r:diation. The outer surface of the fire wrap is treated as an isothermal surface. The radiation relationship l REV!SION NO.: 0 l

Exhibit C NEP-12 02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 6 OF 40 G-70-96-092 09135-200.

essumes that the cable tray is located in free space and the area dissipating heat is equal to the curumference I

of the fire wrap (Equation 8-43a of Reference 2). Convection is calculated for the top, bottom, and sides of the fire wrap using the simplified expressions for heated plates in air (Table 7-2 of Reference 2). The resulting non-linear equations are solved using the solve block feature of Mathcad (Reference 3).

Tha layer of fire wrap is treated as flat plates on each side of the fire wrap enclosure, with the inner surface of the fire wrap also treated as an isothermal surface (Equation 2-1 of Reference 2). In calculating the size of the phtes, the inside dimensions of the fire wrap are used for conservatism. (In effect, the materialin the comers of the " box" of fire wrap material are Qnored.) The temperature drop through the layer of fire wrap material is cdculated so that the amount of heat transmitted through the fire wrap materialis equi to the heat generated by the cables. The temperature of the inside surface of the fire wrap can then be calculated from the temperature of the outside surface of the fire wrap calculated in the previous step and the temperature drop through the fire wrap.

H:ct transfer between the outer surface of the cable mass and the inside of the fire wrap materialis pnmarily by radiation and conduction. Under some circumstances conduction may be augmented by convection. %e exposed surface of the cable mass along with the sides and bottom of the cable tray are treated as another isothermal surface. Another assumption that is made in the calculation of heat transfer by radiation is that all helt radiated from the cable mass and associated surfaces reaches the inside of the cable wrap. Derefore, the view factors are only functions of the area of the surfaces and the emissivities, and are not sensitive to the d; tails of the configuration. In the test configuration, a sheet of SilTemp glass fiber cloth was laid on top of the ecble mass. The temperature drop through this blanket is taken into account in calculating the heat being dissipated from the top of the cable tray and calculating the temperature drop of the SilTemp blanket. %e basic method used is to calculate cable mass temperature required to transfer an amount of heat to the inside of the fire wrap material by conduction and radiation. The linear and non-linear equations are solved using the solve block feature of Mathcad. He conductivity of air is deternuned by linear interpolation using the ev rage of the temperatures of the cable mass and the inside of the fire wrap material. Convection (if any)is taken into account by adjusting the thermal conductivity of air, as was done for the conduit temperature cdculation. The kinematic viscosity and the Prandtl number of air are determmed by interpolating data using cubic splines. These quantities are evaluated at the average of the surface *emperature and the temperature at the inside of the fire wrap. The expression for the conductivity adjustment checks to see if the product of the Gr:shof and Prandtl numbers is high enough for the expression to be valid. Also, the nurumum value of the conductivity adjustment is forced to be 1. In order to solve the equations, the surface temperature of the cable mass is written as a function of the surface temperature of the SilTemp blanket. As a result, the solve block only needs to solve for one unknown. The surface temperature of the cable mass can then be solved by back substitution.

The temperature drop through the cable mass is calculated using Equation 5 of Reference 6, which is equivalent to Equation 2-23 of Reference 2. The conductor temperature is then calculated by adding the temperature rise in the cable mass to the surface temperature of the cable mass.

1 l

4 l REVISION NO.: 0 l

1 1 '

l Exhibit C NEP-12-02 l -

Revision 0 l

COMMONWEALTH EDISON COMPANY l

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 7 OF 40 l

G-70-96-092 09135-200 l

The various components of the model can be summarized as follows:

)

\\

\\

Haot transferred Heat dissipated from Temperature by conduct, ion, surface of fire wrap by drop through convection. and convection and radiction SilTemp blanket radiation across air gap at the top of the tray Temperature drop through fire wrap F

1 l

\\

:::: ::::y:::::::::::_g::::::::

_ _ _ _ _ _ _ - _x_ - _ - _ _ _ _ _ _ _ _ $ _ _ _ _ _ _ _

\\

Heat transferred by conduction, convection. and Temperature drop radiation across through the cable

mass, a r gap at the Heat transferred bottom of the by conduction, convection, and "UY' radiation across air aop at the sides.

Acc;ptance Criterion

~

l The calculated conductor temperature should agree to within 3 K (3 *C) of the conductor temperature obtained by test.

l REVISION NO.: 0 l

l

Exhibit C NEP-1242 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 8 OF 40 G-70-96-092 09135-200 ASSUMPTIONS Nrne l

i l

i i

l l REVISION NO.: 0 l

Exhibit C NEP-12 42 l

Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 9 OF 40 i

G-70-96 092 09135-200 DESIGN INPUT Ccaduit Test 1.

The test was of 4-750 MCM cables in a 4 inch (trade size) conduit (Reference 7) 2.

'Ihe cables used in the test wem Rockbestos 1/C, 750 MCM, with XLPE insulation and CSPE jackets (Refemnce 7, page 4).

3.

The thickness of the cable insulation is 80 mils and the thickness of the cable jacket is 65 mils (Reference 8, pages UP-7 and UP-8) 4.

The thermal msistivity of" rubber-like" insulation is 500 *C.cm.W-1 (5 K.m.W 1) (Refemnce 9, page III) 5.

The inside diameter of a 4' conduit is 4.05 inches and its outside diameter is 4.5 inches. (R.i..ce 10, Table 2, page 5) 6.

The emissivity of a galvamzed steel surface is 0.33 (Reference 11, Page 17) 7.

The thermal conductivity of Thermolag is 0.1 BTU.hrt.ft4.R4. The emissivity of Thermolag is OM.45 (Reference 12) 8.

he thermal conductivity of a steel conduit is 2.08 *C.cm.W4 (Reference 13) 9.

The conduit was wrapped with a 3/8" (nommal) and a 5/8" (nominal) layer of Thermolag. h overall circumference of the completed assembly was 22.51' (Reference 7, pages 1,2,3, C-1, D-11, and I-2)

~ 10.

The Thermolag sections are coated with trowel grade Thermolag to fill any gaps between the conduit and the inner layer of Thermolag and between the two hermolag layers. (Reference 7, page 4) 11.

The test current was 431.52 amperes (Reference 7, pages F-6 and I-2) 12.

The ambient temperature was 40.3 *C (Reference 7, pages F-6 and I-2) j 13.

The conductor temperature is 91.4 *C (Reference 7, pages F-6 and I-2) 14.

The surface temperature of the fire wrap was 47.95-48.75 *C (Reference 7, page I 4) 15.

The value of the Stefan-Boltzmann constant is 5.669710

  • W mtK 4 (Reference 14, page F-158) 16.

The characteristics of Air are as follows (Reference 2, Table A-5):

Temperature (K)

'IhermalConductivity, Kinematic Viscosity, Prandtl Number, k (W.m4.K4)

(mts4)

Pr 300 0.02624 16.84 104 0.708 350 0.03003 20.76 104 0.697 400 0.03365 25.90 104 0.689 l

l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.10 OF 40 G-70-96-092 09135 200 Temperature (K)

Thermal Conductivity, Kinematic Viscosity, Prandtl Number, k (W.m-2 K 2)

(m2 s-2)

Pr 450 0.03707 31.71 104 0.683 l

1 I

I l

l I

~

l REVISION NO.: 0 l

l I

Exhibit C

{

NEP-12-02 Revision 0 COMMONWEALTH EDlSON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.11 OF 40 i

G-70 96-092 09135-200 l

17.

The geometric factors for calculating the temperature drop through the cable insulation are as follows (Reference 5):

""".'.Y....i.i.,,......a

,....o o

-...,..o a u 1II III

"~~~

o 1

g I

=

l' l

.ggl1ji:

se h

l 88 n;l aa aa

^^ 38 )

aa =

%f n'i

' :_- as as as--

,,y.,.

.=

sa sa-Q

=

aa -

a, a,-

g z:

+i+

..i.

i i'

a.-

m

=

l-si u--

i i

a 4

=

l as a-

..23 as *:

2-

-n y,FL.

4

~

.V l

ss =-

,g

_z a

g 34,.-

=

g F

[-

4 g

g e

q lll lll::33 330mg

~n 1

g

., E 3!

l

=

l

s a.

as t j

u L' ' ' '

4 ai a.i.= 7

,,l..

g..

F I '"+'-

q aa =

li ll! lb l

h)E

'D

' 5ll!!l j

48 t.

,=ii ina s i

I i,"M g

U.

!L 3

_,h I

..6:

-~

j ji 9

E 9 iM'

'+'

i i

i :.]

. ---I; "

1.

.L.

-- =

i a

'3l

_f ii,-~m=

L; as a-

=

6 l

n' x'l b$

d

~

--[

.c 6

g

_ga as x

  • ^

=f=l

, um

+

' ~-

='"',_

r_-

1

. /

2I

mi us, l

ill ii!l 1

j l:

$)

.....,.................,.,,,,,,,,a i

i i

Fig,, 3-Oeosmetric factore for sing *= --=d

-ter sable and smulehter belted cable with remad er eacter conductees l

Geesmetri,c factors can be obesmed by calsulating the easies (T + O/d and f/T (4 beins deAned for sessor cablas as the dsometer ed a round conductor et the enese area as the sessee), and them readams eine amared value et geometric ineser frean a cerve above. The value thus mais d will be the sorrest geomettric factor for a round-conductor enkte. For sector com-ductors she values so obtained shmund be enukayEed by the escoor correcteen f actor. In tables of the nam-eype H fores weshnut behe.

ameh as inski-sendecaer rubber cables, the rateo I,ecuenes T/d, and s/T== at

}

e l REVISION NO.: 0 l

4

Exhibit C NEP-12 42 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.12 OF 40 G-70-96-092 09135-200 18.

The resistance of a 750 MCM copper conductor at 90"C is 0.0018710 2 aft-2. The conductor diameter is 0.998". (Reference 15)

Cable Tray Test 19.

The cable tray was covered with %" muumum (" i") Thermolag panels (Reference 16, pages 9-10).

Also, see Reference 7, page 1 for an explanation of the dimension tolerances on Thermolag material.

i 20.

A skim coat, approximately 1/16" thick, of trowel grade Thermolag was applied where the comers of the Thermolag enclosure was reinforced. Additional material was also applied where sections of the i

i Thermolag panels were spliced together (Reference 16. Page 10).

I 21.

The cable tray is filled with 126 lengths of 3/C, #6 AWG,600 V cable to a depth of fill of 2.95". The cable had cross-linked polyethylene insulation and a polyvinyl chloride jacket. (Reference 16, pages 8, 20, and 22) 22.

The cable tray is a B-Line Model 248P0924144. This is a 24" wide ladder-type cable tray with rungs a

spaced 9" apart. (Reference 16, Page 4).

23.

The configuration of the tray railis as follows (Reference 17):

i d

A-.luesw sa.

a e

c o

a se s.

j gig m-,e i res.

4 smise o e6 ena saa paJ ema sea ei om.i smi f/sts m

g,,,

4

'm 3,2 m

67 '2s.o00

.su

.it as 248 4

4 ss 3 34 oss i

346 4

4. ins s.ts

.o6o i.so 6ss w

i or 22.400 44, i 64 as E

444 4

4. ins
u o7s 2.s0 l

.67 4

28 1 000 set 2 02 ' se TCY im l s,2 l

258 s

sim

4. i4

.oes ai,

inmo

.x ; t.34 ao

-c

'776lmsoo 356 s

s.sse 4.is

.o6o im 6

see i a6 4o a

454 s

s ies

4. :

ots i.so ' 67 a's r ie 27.s00 6x 22, 40 i

o 268 6

6 ins a is oss iaolser 37 in is ouo sov

i.,2 42 i,

6 ass s is ces i.so l.41 42{2av y_

368 it. coo 4s7 i 70 42 366 6

6 saa s is

,o6o i so l.ss

2 74 it ouo see 2 os

.4 c2 7

[

464 6

6 ass s is o7s i.so ; 67 27

' s 42 2s.000 7

2 56 44 C-"*'","""'

378 7

7 ins e is

.nas a so 643 l

  • 2 9e is.soo sus i as 46 476 7

7im 6 is

.o6o i so ass l i is s 74 : ts soo si, 2.3o 46 l u7 4 67 l22 suo 574 7

7 ins 6 si

.o7s i so 67 792 t.ss 46

.. - = o6. o 6

8 l REVISION NO.: 0 l

Exhibit w NEP-12-02 Revision 0 l

COMMONWEALTH EDISON COMPANY l

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.13 OF 40 G-70-96-092 09135-200 Total height of tray rails, including rungs: 4.188" Height of tray available for cables: 3.14" Gap as side of tray formed by the tray rails: 0.344" 24.

The tray rungs are 1.5 inches wide. (Reference 17):

Ladder Type Rungs SaNGtiRUNG LCMD CTTY(8N 136J l

6 9

we 03o w See 0707W 3.5 2066 1846 1356 552 660 A

us*

DS 15.000 pas.

==.I.

Der 81. 2 8 swM D5 e 20.000' set 2.0 2146 1385 1017 661 496 h

ser s 7 I si s.

In e.0432 an*

i

$s e.ON77 W

!.5 661 540 l

f.3 D6e 15.000 met.

1 Nar 51. 3.9 l

W-DS e 20.000 pet.

2.0 45 406 Alensteens sur 55.1S as he laa 0249W l

Q 5es.06as m*

r703 1769 1314 868 647 l

ter DEe 30.000 pm.

~~

l Car 51. 2 9 6MM DSe 26.700 pm.

2.0 2027 1327 ses 661 406 l'*"seest v., sf. t m -

i

)

l

.a p s,. 03n2e h e.0861 W T,,

5 646 537 l

DS e 30.000 pm.

g I

Rur 81. 2.9 senes '4 06e 26J00 p

2.0 404 403 SM4 ser 5 F.1.56 is e.044 is' 5sa.077 W 1.5 2100 1355 998 653 4e6 3a6 320

'b g.

D$.10.000 pas.

~~

use $1. 2 m 1'

D5e L3 se 2.0 1575 1016 743 490 364 290 240

.04

$se 077W g.5 4992 3267 2427 1602 1196 954 793

~

Der 5 F G D5s 33,233 set.

20 3744 2450 1820 1201 997 715 595 Seest War 5 F 151 i

.c r

,,,,,.. w s

. es,. e.. u w.

25.

The emissivity of cable jackets is 0.95. (Reference 11, page 17) 26.

The thermal resistivity of the cable mass in a cable tray is 400 *C<m.W 2. (Reference 6, page 964) l 27.

The cable mass is covered with a sheet of SilTemp@ glass fiber cloth (Reference 16, page 682) 28.

SilTemp@ is essentially silicon dioxide (quartz or glass). (Reference 18) 29.

SilTemp@ 188CH cloth is 0.054" thick (Reference 18) 30.

The emissivity of glass (silicon dioxide) is 0.94. (Reference 2, Table A-10) l 1

l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.14 OF 40 G 70-96-092 09135-200 31.

The thermal conductivity of SilTemp@ is as follows (Reference 19):

TYPICAL APPARENT THERMAL CONDUCTIVITY zw _

2.as -

7 SILTEleP 180CH l.

1 10 --

/

2Je -

SILTEMPSeCM

{ Lle -

t. -

3 v.se =

l

. i.as -

GUAADED 640T PLATE

[ t.70 -

4 g

u.

i.es -

m,,,,, gen,

a t.50 -

Weh I 8 80 "

AgTM C177.M E

j

.so -

I t.40 -

l 3.to -

.se -

l l 1 l i I I I l J, l, I I 1 I J,, J, I, I ),

2 ili f il illi'i k iill f E R I

)

MEAN TEMPGRATURE. 'F.

Based on the above, use a value of thermal conductivity of 0.8 BTU in.hr2 ft-2.*F4 32.

The resistance of a #6 AWG conductor is 0.0513102 O ft4 at 90 *C:The conductor diameter is 0.184*.

(Reference 15).

4 I

33.

The ambient temperature is 39.9 *C (Reference 16, page 11).

34.

The test current is 15.9 amperes (Reference 16, page 11).

35.

The measured conductor temperature is 90.3 *C (Reference 16, page 11).

a 1

i l

l REVISION NO.: 0 l

A

_ ~ _ _

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.15 OF 40 G-70-96-092 09135-200 REFERENCES l

1.

Neher, J. H. and Mc Grath, M. H.1957. The Calculation of the Temperature Rise and Load Capability of Cable Systems. AIEE Transactions, Part III Power Apparatus and Systems 76 (October):752-772.

2.

Holman, J. P.1981. Heat Transfer. (5th Edition,4th printing,1983) New York and Tokyo: McGraw-Hill Kogakusha, Ltd.

3.

Mathsoft, Inc.1993. Mathcad 4.0 User's Guide. Cambridge, Massachusetts: Mathsoft, Inc.

4.

Horton, H. L; Schubert, P. B.; and Garratt, G. (ed.) 1973 Machinery's Handbook (19th Edition). New York: Industrial Press, Inc.

5.

Simmons, D. M.1932. Calculation of the Electrical Problems of Underground Cables. The Electric Journal. (May-November).

6.

Stolpe, J.1971. Ampacities for Cables in Randomly Filled Trays. IEEE Transactions on Power Apparatus and Systems. 90 (May/ June):%2-974.

7.

Rutledge, C. L and Devmey, F. A.1993. Final Report-Testing to Determine Ampacity Derating Factors for Fire Protected Cablesfor Watts Bar Nuclear Plant. Chattanooga, Tennessee: Tennessee Valley Authority Central Laboratory Service (TVA-CLS).

8.

The Rockbestos Co.1989. Catalogue for Firewall Ill-J Cable, Specification RSS-3-021.

9.

Insulated Power Cable Engmeers Association (IPCEA) 1%2. Power Cable Ampacities, VolumeI-Copper Conductors (AIEE Publication S 135-1/ iPCEA Publication P-46-426). New York: American Institute of Electrical Engmeers (AIEE).

10.

National Electrical Manufacturers Association (NEMA) 1990. American National Standardfor Rigid Steel Conduit-Zinc Coated (ANSI Standard C80.1). New York: American National Standards Institute, Inc.

11.

Insulated Cable Engmeers Association (ICEA) 1986. Ampacities ofCables in Open-Top Cable Trays. (ICEA Publication P-54-440 / NEMA Publication WC-51). Washington, D. C.: National Electrical Manufacturers Association.

12.

Q/A Calculation 0020-EAD-1, " Check for Ampacity Derating for TSI's 3-Hour Fire Barrier Used on Trays", Revision 0, and prepared on May 8,1984 by G. A. Poletto.

13.

Hudson, R. G.1%1. The Engineer's Manual. New York: John Wiley & Sons.

14.

Weast, R. C. (Ed.) 1%7. Handbook of Chemistry and Physics. Cleveland, Ohio: The Chemical Rubber Co.

15.

Sargent & Lundy Standard ESA-102, dated April 14,1993.

j 16.

Stansbury, H. W. II; Humphrey, C. A.; and Priest, D. N.1993. Ampacity Derating ofFire Protected Cables - Electrb ' Test to Determine the Ampacity Derating ofa Protective Enoelopefor Class 1F Electrical Cables. San Antonio, Texas: Omega Point Laboratories.

l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.16 OF 40 G-70 96-092 09135-200 17.

B-Line Systems, Inc.1984. Cable Tray Systems. (Catalogue CT2) Highland, Illinois: B-Line Systems, Inc.

18.

Industrial Energy Products, Inc.1984. Product Bulletin HS-108, "SilTemp Fabric-CH 'Ihermal Barrier".

Little Ferry, N. J. : Industrial Energy Products, Inc.

i 1

19.

Industrial Energy Products, Inc.1982. Product Bulletin HS-117, "SilTemp Fabric-CH-SR Thermal Barrier". Little Ferry, N. J. : Industrial Energy Products, Inc.

l REVISION NO.: 0 l

Exhibit C NEP-12-02 Hevision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.17 OF 40 G-70-96-092 09135-200 CALCULATIONS Model for a Themolag Wrapped Condud Cable Data Cable is 4-1/C,750 MCM Rockbestos XLPE-CSPE cable Conductor Resotance and Diameter cab.= 0.0018710 2 ohm ff Conductor resistance at 90 *C I

r dcab.= 0.998 in Conductor diameter tinsd := 0.08 in insulabon thickness tjacket = 0.065 in Jacket thickness j

Thermal ResetMbes pinsul = 5 K m wau'I insulation pjacket = 5 K m watt'3 Jacket Condut Data 1

Inner and Outer Diameters, Thermal Conductivity, and Emisemty i

d g = 4.05 in inside diameter of a 4" trade size condut dcondo = 4.5 in Outside diameter of a 4" trade size conduit p cond = 2.08 K cm watt'I Conduit thermalconducruty econd = 0.33 Condurt emissmty Thermolag Data Thermal Conductmty k wi,g = 0.1 BTUhf ' ff R' 3 I

Emissmty is in the range 0.3 to 0.45; use 0.4 based on the range and the relatively low measured surface temperature eThermolag = 0.4 l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.18 OF 40 G-70-96-092 09135-200 i

Thicknesses of Thermolag Outer Layer i

t g 0 375 in Use nominal thickness for calculebon Inner Layer (calculate from circumference of wrapped conduit of 22.51")

i 4

l 22.51 in dg D*

]

2r h-2 t g =0.958 in i

i l

Gap Thidr.er.

Gap between Conduit and Inner Thermolag Layer g w = 0.000001 in Since the gaps between the layers of Thermolag were eEmnetedin the TVA Gap between the Two Thermolag Layers instatation, the gap size wil be set to an infiniteseimalvalue so that the 8 outer = 0.000001 in temperature drop awoes the " air Test Parameters Test Current 1 = 431.52 amp i

Amtnent Temperature Tamb = 40.3 K + 273.16-K Tamb = 313.46 K Conductor Temperature Determined by Test Ttest = 914 K + 273.16 K Ttest = 364.56 K Miscellaneous Constants Stefan-Boltzmann Constant a = 5.6697-10' 8 watt m,g

-2 a

Acceleration due to gravity g = 9.8 m sec 2 Conversion factor between degrees Celsius and Kelvin CtoK = 273.16 K l REVISION NO.: 0 l

4

)

Exhibit C NEP-12 42 Revision O COMMONWEALTH EDISON COMPANY i

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO.19 OF 40 G-70-96-092 09135-200 l

Develop interpolaton Funcbons for the Characteristics of Air wtuch are Funcbons of Temperature. These persmeters are required for the calculabon of heat transfer by conducbon and convectonin air gaps.

j ThermalconductMtyof air i

'300'

'0.02624 350 0.03003 1

Lookup tables of T,7 =

^4 "

temperehre and 400 0.03365 thermal conductMty 450 0.03707 (Table A-5 of Ref.2) i = 0. 3 0.04 y

Since the varimbon of the conductmty with j

a035 g *'8i temperature is nearly linear, the use of linear interpolation is appropriate.

0.03 0.025 300 350 400 450 T,,,;

f T,+Tb air (T,,T ) = linterp T,g,k Function to find the thermal conductmty of k

b ag, 2

/

air by linear interpolation of the average of A

two temperatures l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 20 OF 40 G-70-96-092 09135-200 l

l interpolate to calculate the kinematic viscoedy of air 4

16 h 10 Lookup table for kinematic viscoady. The 20.76 10-6 temperatures for these points were defined m SCC'

@ the thermal Conductivity of air (Table A-5 F

5 arg 25.9106 of Reference 2) 31.71 10

-5 4 10 Plot shows that the kinematic

-5 3 10 viscosityis not a linear funcbon of ars temperature. Therefore, the use of v

- 2 10 cubic spline interpolation is appropriate.

-5

-5 1

1 3 30 300 350 400 450 T,,,i aux *c8Pne(Targ Farg)

Aux 6ery vector for cubic spline interpolation li F

j I

T,+Tb air (T,,T ) = interP F aux,Targ.Farg' 2

/

b for kinematic viscoedy F

B(T,,T ) =

Volume coefficient of expansion (assuming air b

T+Tb behaves as an ideal gas) l REVISION NO.: 0 l

Exhibit C NEP-1242 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 21 OF 40 G-70-96-092 09135-200 Prandt! Number 0.708 m fw kW taw. h cwresponding %

{

values are shown in the sechon on the thermal conductMty of air.

0.697 (Table A-5 of Reference 2) g "'E 0.689 0.683 0.71 07 h

Since the Prandtl number is a non-linear arsi function of temperature, cubic spline interpolation Will be used.

0.69 N

I I

0.68 300 35G 400 450

  • C8P me(Targ,Prarg) Auxiliary vector for cubic spline interpolation Pr i

aux

/

T,+T )

Interpolation function using cubic b

Pr ir(T,,T ) = inW Praux,Targ,Prarg.

2 a

b splines for the Prandtlnumber l

I 1

i l

l l REVISION NO.: 0 l

1

1 Exhibit C NEP-12-02 1

Redsion 0 COMMONWEALTH EDISON COMPANY 1

CALCULATION NO. : BYR 96-059 09050 051 /

PAGE NO. 22 OF 40 G-70-96-092 09135-200 Outer Diameter of Wrapped Condun d,,,, = da + 2-(t fa+g e +tg +g w) d

=7.165 in assem i

Heat Generated by Cables I

I Q cab

  • 4'I 'Tcab Q cab = 13.928 watt ff Calculate the Surface Temperature of the Wrapped Assembly Note: In order to solve the energy balance equations, the equations for the heat dissipated by the wrapped assembly will be written as funcbons of the surface temperature. The area of the wrapped condun per unit length is equal to a times the diameter of the wrapped assembly.

Heat Dampated by Radation 1

Q r(T) = u d,,,,, elbermolag o-

-Tamb Heat Desipated by Convection 1

'(

m.,4. T - T 2

amb d

wdassem (T - Tamb)

Qc(T) = 1.32 watt K i assem j l REVISION NO.: 0 l

Exhibit C NEP-12-02 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 23 OF 40 G-70-96-092 09135-200 Initial guess for iterstrve solubon of the surface temperche of the wrapped conduit Tguess = 330 K l

Giwn Q cab"Q r(Tguess) + Q c(Tguess)

Heat dissipated by radiabon and convection must equalheat generated by cables.

Touter '= Find (Tguess)

Touter = 325.368 K Touter - CtoK = 52.208 K *C Surface temperature of the wrapped conduit Temperature Drop Across the Outer Thermolag Layer dIh = dg + 2-(t m + ginner + 8 outer) inside diameter oflayer d g =6.415 in (d

I I

I assem Where Qcab s in watts per foot i

3Tg =2xk In

-Q cab

%;,g (d g j ATh = 4 646 K Temperature drop through the outer Thermolag Layer Temperature on the inside of the Outer Thermolag Layer Tg = Tw. + ATh l

TIb = 33.nl5 K T gg - 273.16 K = 56.855 K

'C I

i Grashof Number g B(T,,T )-(T,- T )-(d2 - d )3 Grashof number for a l

b b

g Gr(T,,T,d j,d ) =

cylindricalspace b

2

" air (T,,T )

@quabon 7-21 of f

b Reference 2) The Grashof l

numberis a major parameterin determining convection.

l REVISION NO.: 0 l

^

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051/

PAGE NO. 24 OF 40 G-70-96-092 09135-200 l

Heat Transferred across an Air Gap Heat Transfer by Conduchon Funcbon for heat transferred air (T,,T ) (T,- T )

2 rk b

Q cond(T,,T,d ;,d ) =

Id I b

by N anos a g

b 2

2 cylindncel shel(Equation j

in 2-8 of Reference 2)

Adjustment of the Heat Transferred by Conduchon to Account for Any Convection The IF funcbon is used to force the minimum value of the adjustment to be 1.

]

(Conduction and convection cant be worse than conduchon alone.) The convection i

correistion is given in Equation 7-60 and Table 7-3 of Reference 2.

i ratio (T,,T,d,d ) = 0.Il-(Gr(T,,T,d ;,d ) Pr ir(T,,T ))

k b g 2 b

2 a

b ratio (T,,T,d ;,d )'I) kfianc(T,.T,d,d ) = if(k ratio (T,,T,d ;,d )>1,k b

2 b j2 b

2 l

Q conv(T,,T,d,d ) Q d(T,,T,d ;,d ) kfunc(T,,T,d ;,d )

g b j 2 g

b 2

b 2

l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 25 OF 40 G-70-96-092 09135-200 Heat Transferred by Radiation Heat transfer by radiation between concentnc b) cylinders. Since the heat o w d g T,4 4

-T Q rad (T,,T,d,d.8 182) '"

transferred per unitlength g

b y 2 d

I j fl

)

l is desired, circumference eg d2 (8 2 j'

is area per unitlength. See Equation 8-43 of Reference 2.

Heat Transferred across the Air Gap between the Thermolag Layers dOni=dcondo + 2-(tThi + 8 h) Outside diameter of the inner layer of Thermolag dOThi =6.4IS in Find the temperature of the outside of the inner Thermolag layer Tguesst = 335 K Initialvalue foriterative solubon Given Heat transferred across the gap equals heat generated by cables.

Q cab"Q oonv(Tgo,,,;,TITho,d ui,dflho).

Conduchon/convechor.

g O

+Q rad (Tguess!.TITho,dOui,d FTho.8nennolag.8'Ihennolag) Rah g

TOThi = Find (Tguessi)

TOlhi = 330.015 K TOThi - T yggo = 7.952 10-5,g emP ss ga h

there is no gap)

Review the relative contnbution of the various mechanisms to heat transfer Qcond(TOThi TITho,d ni dTIho) = 13.928 watt fr ' Heat transferred by conducbon g

O Gr(TOThi,T pggo,dOni,d gno) Pr ir(TOThi,TITho) =0 Grashof number a

~7 kratio(TOui,T jg,dOlhi,d !Tho) = 5.716 10 Raw multiplier for convection value indicates no convectio I

Qoonv(TOThi,TITho,dOThi,d Ih) = 13.928 watt ff Conduction / Convection g

Q rad (TOni,TITho,dOThi,dIh,e Thermolag.8holag) = 2.52810 ' watt fr

~

I g

Radiation l

l REVISION NO.: 0 l

1 Exhibit C 4

2 NEP-12-02 Resisios 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 1 PAGE NO. 26 OF 40 G 70-96-092 09135-200 1

1 j

Temperature Dmp through the inner Thermolag t.myer i

\\

dIThi = da +2g g Heide diameter of the inner Thermolag layer l

i dgg; =4.5 in

(

' g 1

(d OTM AT In

-Q cab Temperature drop (Equation 2-8 of 1

Thi = 2 x k g,, moi,g(dIThi /

Reference 2)

ATTM " I4 9*K T ggi > TOThi + ATThi Temperature of the inner surface of the inner fire wrap layer T gn; = 344.915 K j

Temperature at the Outer Surface of the Condun Tguess = 375 K Ir&lvalue foriterative solulbon Given J

The amount of heat trans-9 cab"9 oonv(,Tguess.T ggj,o. condo.dIni)-

g ferred across the air gap

+9 rad (Tguess,TIThi,dcondo,d IThi.8 cond.8 hermolag)between the conduit and the T

g innerlayer of Thermolag must equalthe amount of heat Tcondo = Find (Tguess) generated by the cables.

j Tcondo = 344.915 K Temperature of the outer surface of the conduit i

Tcondo - TIThi = 1.09 10 K

Since there is no gap in this case, the temperature drop is negligible.

l 4

l i

l REVISION NO.: 0 l

I.

r Exhibit C NEP-12 42 l -

Revision 0 l

COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 27 OF 40 G-70-96-092 09135-200 Review the breakdown of how the heat was transferred I

Q oond(Tcondo,TTIhi,dcondo d IN) = 13.928 watt.E Conduchon g

Gr(Tcondo T gm,dcondo,dflhi) Pr ir(Tcondo,T gg) = 0 Grashof number a

-7 kratio(Tcondo,TTIhi,d g,d g) = 5.947 10 Raw muleplier for convecton-value g

indicates no convection 3

Q oonv(Tcondo,TTlhi,dg,d g.g3;) = 13.928 watt E Heat transferred by cotwection g

Q rad (Tcondo TIThi,dcondo,drIbi 8cond.8Thennolag) =2.451 10 watt E '

g Heat transferred by radiabon Temperature Drop through the Conduit ld I

i condo ATcond * --' # cond in

-Q cab See Equabon 2-8 of Reference 2 (dcondi)

ATcond =0.016*K Tcondi Tcondo + ATcond 1

Tcondi = 344.931 K Temperature of the inside wall of the corxiuit Temperature Drop through the Air Gap inside the Condut Diameter of a Single Cable d Icab = dcab + 2-(tinsul + ' jacket) d Icab = 1.288 in Circumsenbed Diameter of Four Cables 4 cab *(1+

-d d Icab l

d4 cab = 3.Il in l

l l REVISION NO.: 0 l

l Exhibit C NEP-12 02 l.

Revision 0 COMMONWEALTH EDISON COMPANY

~ CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 28 OF 40 G-70-96-092 09135-200 i

Constants for Neher-McGrath Formula for Temperature Drop in the Conduit Air Gap A' = 3.2 K A watt in B' = 0.19 in A'

AT oondpp '* B' + d 4 cab ATcondgap = 13 508 K f

Tjacket = Tcondi + ATcondgap Temperature at the outsule surface of the cable Tjacket =358.44 K Tjacket - 273.16 K = 85.28 K (*C)

Geometric Factor for Four Cables Ratio (t+T)/d tinsul * ' jacket g,

dcab Ratioinsul =0145 G g = 0.79 This value is obtained by looking it up on the curve in Reference 5 Temperature Rise through the Cable insulation and Jacket ATinsul

  • A insul G Qcab 1

= 3.482 watt ff '

4 ATinsul = 7.182 K Temperature drop through the cable insulation. See Equation 39 of Reference 1 Tconductor = Tjacket + AT nsul Conductor temperature

(

Tconductor = 365 622 K Tconductor 273.16 K =92.462 K

'C l

l REVISION NO.: 0 l

~

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 29 OF 40 G-70-96-092 09135-200 Model for a Wrapped Cable Trey 4,% Tray Dimenosors my = 24 in inside width of tray w

htray_ rail = 4.188 in Total height of tray rails (including rungs) htray_actiw = 3.14 in Height of area in tray available for cables g tray _ side = 0.344.in Width of gap formed by lip at side of tray Depth of Fil IX)F = 2.95 in Dimenosons of Thermolag wrap = 0.63 in Thickness of Thermolag; The value of 5/8" nominal (1/2" mnumum)

I is increased slightly due to the buildup of Thermolag at the edges andjoints Emiesmty of cable mass cable _ top = 0.95 Cable jackets e

esteel.= 0.33 Gaiv nizedsteel 8 cable _ side ' 8 steel EmsesMty of cable tray rei s

=9-in Spacing between cable tray rungs rung w

i1.5in Width of rungs rung Emiesmty of Thermolag Wrap eThermolag = 0.4 8 wrap _ top 8 Thermolag 8 wrap _ side ** 8Thermolag 8 wrap _ bottom ' 8Thermolag l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 30 OF 40 G-70-96-092 09135-200 Emissivity of the Outaxle of the Fire Wrap:

8 out wrap " 8 Thermolag Themal Conductmty of Thermolag Wrap I

k

= 0.1 B1Uhi' ff R'I op Chara eristics of SilTemp SilTemp = 0.054 in Thickness of SETemp 188CH t

3 SilTemp = 0.8 BTU hi in It R

Thermal conductivity of SilTemp k

e SilTemp = 0.94 Emissivity of glass (chemically almost idenbcal to SirTemp)

Cable Mass Thermal Ressbvity p mass 400 K cm. watt This is the standard value from the Stolpe paper i

CtoK = 273.16 K Conversion factor between 'C and K Test Condebons Ambient Temperature Tambient = 39.9 K + CtoK Tambient = 313.06 K s

Test Current I = 15.9 amp Cable Data cab = 0.051310 2 ohm ffCable is 3/C, #6 AWG,600V I

r cab = 3 Three conductor cable n

my = 126 Number of cables in tray n

Physical Constants Stefan-Boltzman Constant o = 5.6697 10,,,,,- 2, g. 4 s

Acceleration due to Gravity g = 9.8 m sec.2 l REVISION NO.: 0 l

i I

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 31 OF 40 G-70 96-092 09135-200 PhysicalCharactensbcs of Air Since the charactensbcs of air are funcbons of temperature, and since the temperature is unknown until the calculabon is complete, develop interpolation funcbons that will make the entcal charactensbcs for convection functions ot temperature that can be iisi,r,,vieted into the heat transfer equations and evaluated dunng the solution Thermal conductivity

'300 ~

'0~02624 -

up of temPmue aM thermal conductMay(Table A-5 of 350 0.03003 Reference 2)

T arg 400 arg 0.03365

,450 0.03707, i = 0. 3 0.04 g

Variation of conductivity is nearly Enear with 0.035 temperature

~

0.03 0 025 300 350 400 450 "si Funcbon to find the thermal cenductMty of air by T,+Tb linear interpolation of the average of the two k,;,(T.T ) ' linterp Targ,karg-2

/

b te p a u n Kinematic Viscosity of Air l

16.84 10 Lookup table for kinematic viscosity. The corresponding 6

temperatures were defined in the section on the thermal 20.76 10'3 conductmty of air. (See Table A-5 of Reference 2) 2

.I si,g =

g

.m sec 25.9 10',

31.71 10~ '

i l

l REVISION NO.: 0 l

I Exhibit C NEP-12 02 Revision 0 COMMONWEALTH EDISON COMPANY 1

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 32 OF 40 G-70-96-092 09135-200 4a10~

g The plot shows that the Idnema6c viscoelty is

-5 3'30 not a linear funcbon of temperature. Therefore,

' arsi cubic sphne interpolation wil be used.

-3

- 2 30

-3 I

I 3 30 300 350 400 450 T,,,;

aux = cspline(Targ,Farg ry W for M spUne derph F

1 i Funcbon to perform cubic spine interpoletxm I

T +Tb to determine the kinematic viscosity of air at

]

air (T,,T ) = intap(Faux,Targarg, F

b 2

/ the average of two temperatures.

Volume coefficient of expansion 2

B(T,,T)*

b T,+Tb Prandit Number 0.708 Data points for the lookup table for the Prandtl number of air.

carespoW tempe ature values are shown in the section 0.697 on the thermal conductMty of air. See Table A-5 of Reference 2.

Pr arE 0.689 0.683 0.71 The plot shows that the Prandtl number is not N

a linear function of temperature, so cubic spline "7

interpolation wiu be used.

  • *rsi i

0.69 06s 300 350 400 450 T,,

Pr

= cspline(Targ,Prarg) Auxiliary vector for cubic spline interpolation aux TPMon for & sph 'nterpolan i f

T,+Tb for the Prandtl number Pr,;,(T,,T ) ' intP Praux.Targ,Prarg*

2 j

b t

l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0

~

COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 33 OF 40 G-70 96-092 09135-200 Gap at bottom of cable tray for rungs 8 tray _ bottom = htray_ rail-htray_ actin 8 tray _ bottom = 1.048 *in Gap at top of tray between cable mass and Thermolag B top = htray_acdve - DOF g top = 0.19 in Part of this gap is taken up by the SitTemp blanket Miscegeneous Dimenmons of the Cable Wrap " Box"

  • in_ wrap "
  • tray + 2 g tray _ side inside width of Thermolag box w in_unp = 24.688 +in
  • out_ wrap "
  • in_ wrap + 21unp e of h&g box out_wnp " 25 948 *i" w

h in_wnp = htray_ rail inside height of Thermolag box hout_wnp = hin_ wrap + 2 twrap outside height of Thermolag box hout_wnp = 5.448 *in l REVISION NO.: 0 l

Exhibit C NEP-12 42 Revisiem e COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 34 OF 40 G-70-96-092 09135-200 Take a weigted average of the emiservibes at the bottom of the tray to account for the cable tray rungs

.

  • runge,t,j+(s

-

  • rung)'8 cable _ top ning ecable_, bottom
  • 8 ning cable _ bottom =0.847 8

Heat Generated in Tray Q ray * " tray " cab t

~

rcab Q ray =49.023 watt ft'I t

Grashof Number Funchon to calculate the Greehof number g B(T T )-(T,- T )iS*P)3 for en air gap.The product of the Greehof b

b Gr(T,,T.PP) ~*

and Prendil numbers is a major parameter for b

  1. air (T,,T )2 corwecton calculabons. See Equation 7 21 of b

Reference 2.

Funcbon for the product of the Grashof and Prandtl numbers GrPr(T,,T, gap),= Gr(T,,T, gap) Pr,;,(T,,T )

b b

b Calculate an adjustment to the conductivity of air to take convecton in the top air gap into account Since the correlation is ordy valid for GrPr>1700, check if valid first. See Table 7-2 and Equabon 7-60 of Reference 2.

ratio _ top (T,,T.PP) = if GrPr(T,,T,gsp)>l700,0.059-(GrPr(T,,T >S*P))

.I k

b b

b I

Conduchon plus convection can never be less than conducbon alone, so force the adjustment mulbpher to be at least 1, representng conduchon with no convection.

kfunc_ top (T,,T, gap) = if(kratio_ top (T,,T, gap)>l,k ratio _ top (T,,T, gap),1) b b

b l REVISION NO.: 0 l

1 Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY l

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 35 OF 40 G-70-96-092 09135 200 Adjustment to the the thermal conductmty of air for the side air gaps to account for convection.

Since the correlation is orW valid for GrPr > 2000, check first. The development is similar to that for the air gap at the top.

I Efy*.

U GrPr(T,,T, gap)>2000,0.197-(GrPr(T,,T, gap))d-

-SnP kratio side (T,,T, gap) = if b

b

,3 b

t PP /

Convection plus conduchon must transfer at least as much heat as conduchon alone, so the minimum value of the adjustmentis 1.

4 kfunc_ side (T,T, gap) = if(k ratio _ side (T,,T,gsp)>1,kratio_ side (T,,T, gap),1) l b

b b

Temperature at the Outade of the Tray Wrap Heat transferred by radiation as a function of the wrap and ambient temperatures Q rad _ wrap (T.T ) = (2 hg gnp+2wg,,p) eout_wnp o (T j#

2) 4

-T g

2 (Equation 8-43a of Reference 2)

Heat transfened by convection from the outade of the fire wrap as a funcbon of the wrap and ambient temperatures and the dimenmons of the surfaces (See Table 7-2 of Reference 2)

.1.? 1 h.(T g - T )4 d

d d

Q conv_ wrap (T.T,h,w) = 1.42 watt K 2

2.

Sides i

2 m

.!.1 1 1

+ 1.32 watt K m w-(T i - T )"

Top d

d d 2

.f.I 1

+ 0.61 watt K., s.,3,(7 _ 7,)s 5

sottom l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 36 OF 40 G 70-96-092 09135-200 Perform iterative solubon

]

T

= 325 K Intitial guess of the temperature at the outssde of the fire wrap guess Giwn i

The heat dissipated by radiation and convection must equal the heat generated by the cables j

Q ray"9 rad _ wrap (Tguess,Tambient) + Q conv_ wrap (Tgu=ss,Tambient.hout_wnp

  • out_vaap) t Tout _wnp = W(Tguess)

Tout wrap =330.949 K Tout wap - CtoK = $7.789 K *C 1

Show the breakdown of the amount of heat dissipated by radiation and the amount of heat dissipated by convection 3

Q rad _wnp(Tout _ wrap,Tambient) = 26.359 watt K Radiation I

Qcony wrap (Tout wrap,Tambient.hout wnp

  • out unp) = 22.664 watt 6 g,

Temperature Drop through the Thermolag Wrap Q

-t The formula is for conducbon through a flat I ""E plate with dimensions equal to the inside of the AT

=

wap k,,,p.2-(w in_ wrap + hin_ wrap) box. For conservatism, the comers of the box are neglected.

AT,3p = 10.138 K Tin _ wrap = Tout _ wrap + ATwrap Tin _wnp = 341.086 K Tin _ wrap - Ct K = 67.926 K 'C i

l REVISION NO.: 0 l

Exhibit C

~

NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 37 OF 40 G-70 96-092 09135-200 Heat Transfer amoes the Air Gap Heat Transfer by Radiabon The heat dissipated by redsabon win be calculated consdering each surface separately.

Because the air gap is smal compared to the linear dimensions of the tray, the view factor between the surfaces of the tray and the inside of the fire wrap wil approedt unity. Therefore, the view factors are neglected. Because heat is transferred from the SNTemp sheet rather than the cable mass at the top, the top surface must be treated separately, my-(T 3-T2 d

aw 9 rad _gapb(T g,T )

hm 2

[,

3g 3

i I

+

y

-1 Bottom and sides 8 cable _, bottom

(* in_ wrap)

(8 wrap _ bottom

)

Tj is the surface Q rad _ gaps (T,T ) ~"

-rail)-(T 3-T2 tephe oN 4

a-(2h tra 2

Sides cable mass and fhmy_,,;;)

g i

I

@ tray I

cable _ side (h n_wnp)

(8 wrap _ side j

8 Re a-(wtray)-(T3 -T2 4

Q rad _gapt(T,T ) =

Top 3 3 1

  • tray

,,1 T is the 3

temmak oN I* trav) i wrap _ top

/

8 e

SilTemp top of the SHTemp sheet Heat transferred by conduchon and convechon in the gap Heat transferred by conduchon and convection in the gap at the top of the tray. The gap at the top is reduced by the thschness of the SNTemp sheet.

Q op(,T,T '8 S) "

k,;,(T,T ) kfune top {T,T '(8 t-t 3)[(T3-T)

  • tray 3 2 t

3 2 t 3 2 2

g_

Heat dissipated by conduchon and convechon in the gaps at the sides of the tray Q side (T g,T 8 s) =

k,(T,T ) (T - T ) kfune_ side (T,T '8 s) 2h tray rail 3 2 2

2 2

8s l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revisios O COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 38 OF 40 G-70-96-092 09135-200 Total heat transferred by coruktion and convection across the air gap 9 conv_ gap (T g.T *l 3'8 '8 s'8 b,t ) = Q gop(T,T 8,t3).

Top 2

t 3

3 2 t N

+Q side (T T,g,).

3 2

  • tray kair(T g,T ) (T 3-T )

only) 2 Bottom (conduchon

+

2 8b Thermal resistance of SMTemp Sheet t SilTemp

  • trayk SilTg Express the temperature of the cable mass and cable tray in terms of the temperature of the SilTemp sheet. T was identdied as Tj in developing the heat transfer funcbons g

T (Tg3)=Tg3 + (Q rad _gapt(Tg3, Tin _wap) + Q top (Tg3, Tin _ map'8 top l SilTemp)) S g

Perform an iterative soluton to find the temperature of the cable mass. Initially, the temperature of the top of the SMTemp sheet wiH be found.

Tguess3 355.K Initial guess for solubon Given The amount of heat transferred across the air gap must equal the amount of heat generated by the cable mass

+Qconv_ gap ((T (guess 3),T Q ray"Qrad_gapb(T (T in_ wrap) -

t g

SilTemp) -

Tguess3), Tin wrap,TBuess3 'S top 8 tray) side 8 tray) bottom,t g

+ 9 rad _gapt Tguess3 Tin _wrapf + Q rad _ gaps (T (T g guess 3,Tio_w,,p TSitTemp = Find (Tguess3) Temperature of the top surface of the SilTemp sheet Tout _ cab = T (TSilTemp)

Temperature g

TSitTemp = 354.246 *K TSilTemp - CtoK = 81.086 K

'C SMTemp surface Tout _ cab = 356.18.r.

Tm_ cab - CtoK = 83.02 *K 'C Cable mass surface l REVISION NO.: 0 l

Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 39 OF 40 G-70-96-092 09135-200 Show the breakdown of the amount of heat dissipated by radalon and conduc6on / convec6on Q rad _gapb(Tout _ cab, Tin _ wrap) = 10.216 watt KRadabon from the bottom 3

3 9 rad _ gaps (Tout _ cab, Tin _ wrap) = 2.077 watt E Rad stion from the sides 3

Q rad _gapt(TSilTemp, Tin,w7,p) =9.093 watt E Radiabon from the top Conducbon and convecbon 3

Qconv_ gap (Tout _ cab, Tin _ wrap,TSilTemp B top'8 truy_ side'8 tray _ bottom ' SilTemp) = 27.637 watt E -

kfune_ top (Tout _ cab, Tin _ wrap E top) = 1 Value of 1 Indicates no convec6on at top knmc_ side (Tout _ cab,T in_ wrap'8 ray _ side) = 1 No convection at the sides, either t

Temperature Rise through the Cable Mass

'I 2 # mass AT

-DOF Equation 5 of Reference 6 (See also Equebon

=

mass

  • trayDOF 8

2 23 of Reference 2)

AT

= 9.885 K mass Conductor Temperature Tconductor = Tout _ cab + AT mass TM uctor = 366.065 K Tconductor - CtoK = 92.905 K 'C l REVISION NO.: 0 l

Exhibit C NEP-1242 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. 40 OF 40 G-70-96-092 09135-200

SUMMARY

AND CONCLUSIONS The models predicted the conductor temperature for the conduit and cable tray test with an accuracy that is within the acceptance criterion:

Installation Conductor Temperature Conductor Temperature Difference ('C) from Model ('C) by Test (*C)

Conduit (TVA) 92.46 91.4 1.06 Cable Tray (TU) 92.90 90.3 2.60 The temperature differences between the models and the test values are within the acceptance criterion.

1 4

l l REVISION NO.: 0 l

i o

1 Exhibit C NEP-12-02 Revision 0 COMMONWEALTH EDISON COMPANY CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. A1 OF A3 G-70-96-092 09135-200 Appendix A-Data on Cable for Conduit Test i

e 1

i l REVISION NO.: 0 l

i i

J

.irewa l@lII-J j

30 wet Cab e

l Conductor Jacket

.. _.. Tin coated copper, l

Hypolon1(CSPE)

Class "B'_ strand

\\

.I I

l l

i 4

l l

l j

j

''''L,.

I i

i l

l (XLPE csPE) i I

~

Ip, F

90*C,600 Volt j

3 c.

Class 1E Nuclear

\\'

I l ll l l

)

I sm ass.s.on

.]

j l

l

miaWation Flame retardant, cross 4nked polyethylene (XLPE)

,i 1

Scope Firewall*!!! J is a jacketed one conductor power cable designed for applica-tions in Utility generating plants and substations. It is intended for use in

)

harsh and demanding environments including Class IE nuclear applications.

4 lt may be installed in trays, ducts, conduits or in direct burial

  • applications to j

perform a variety of low voltage power or lighting functions.

i Q

4 Features Performance Standards Construction i

j

  • Insulation in accordance with ICEA Conductor:

enhanced thermal stability standard S-66 524 Annealed tin coated copper, Class "B"

  • Speciallyformulatedinsulationforsupe-
  • Jackets in accordance with !CEA stan.

strand (ASTM B-8 & B 33) l rior long term water resistance dard S.19 81 for heavy-duty chlorosul-Insulation:

I

  • Extremely flame retardant fonated polyethylene (CSPE)
  • Nuclear qualified with a minimum 40
  • Class IE qualified in accordance with Proprietary heat, moisture and radiation year thermallife expectancy at 90*C IEEE 383 and IEEE 323 (Rockbestos resistant, flame retardant cross-linked polyethylene o Radiation resistant (up to 200 Reports QR 5804 and QR 5805)

Jacket:

megarads)

  • Full traceability
  1. Cd *V Black heavy-duty Hypalont I
  • Excellent mechanical properties
  • Cable passes ICEA 210,000 BTU ver-tical tray flame test (Standard T 29-520)
  • Tin coated copper conductors for im-proved tenninations and corrosion resis-
  • Cable passes the vertical flame tests tance specified in IEEE 383 Para. 2.5.6 (ICEA S-19-81 Section 6.19.6),1CEA S66-524 l
  • All singles pass a wet dielectric (tank)

Para. 6.12.5 and UL VW 1 test prior tojacket application to verify L;

insulation integnty

]

  • Easy strippability for installation case Comed Proj. No. 09050-051/ 09135-200 Calc. No.96-059 / G-70-96-092 Page A2 of A3
  • The Rockbestos Cornpany 285 Nicou Street New Haven, Connecticut 06511 (203) 772 2250 800 327 7625 UP.7
j. __

MNEWWur Firewall@III-J 90*C,600 Volt Power Cable Class 1E Nuclear 1

(XLPE/CSPE)

Spec. RSS-3-021 i

l Nominal Insulation Jacket Overall Approximate Product Code Conductor Number of Thickness Thickness Diameter Net Weight Size Strands (Mils)

(Mils)

(In)

(Lbs/M')

P62 3834 14 AWG 7

30 15

.18 25 P62 3835 12 A W G 7

30 15

.20 35 i

l P62 3922 10 A W G 7

30 15

.22 50 l

P62 3848 8AWG 7

45 15

.29 80 P62 3847 6AWG 7

45 30

.35 125 P62 5090 4AWG 7

45 30

.40 180 P62 3973 2AWG 7

45 30

.46 270 P62 5091 1AWG 19 55 45

.55 360 P62 3902 1/0 A W G 19 55 45

.59 430 P62 3901 2/0 A W G 19 55 45

.63 530

/

P62 5092 3/0 A W G 19 55 45

.68 650 l

P62 5093 4/0 A W G 19 55 45

.74 790 P62 3954 250 kemil 37 65 65

.85 970 P62 3846 350 kcmil 37 65 65

.95 1310 i

P62 3806 500 kcmil 37 65 65 1.08 1810 P62 5094 750 kcmil 61 80 65 1.31 2690 1

Comed see. e Awo nd.m.ner are noi recommeno.d va, d"""'"

Proj. No. 09050-051/ 09135-200 Calc. No.96-059 / G-70-96-092

'DQ%"/,'lcN' d

Page A3 of A3 UPS co ae m

  • The Rockbe.io. Company 285 Nicon Street New Hawn. Connecticut 06511 (203) 772 2250 800 327 7625

Firewall@lII-J wc,600 voit Power Cable Class IE Nuclear (XLPE/CSPE)

Spec. RSS-3-021 Nominal Insulation Jacket Overall Approximate Product Code Conductor Number of Thickness Thickness Diameter Net Weight Size Strands (Mils)

(Mils)

On)

(Lbs/M')

P62 3834 14 AWG 7

30 15

.18 25 P62 3835 12 A W G 7

30 15

.20 35 P62-3922 10 AWG 7

30 15

.22 50 P62 3848 8AWG 7

45 15 79 80 P62 3847 6AWG 7

45 30

.35 125 P62 5090 4AWG 7

45 30

.40 180 P62 3973 2AWG 7

45 30

.46 270 P62 5091 1AWG 19 55 45

.55 360 P62 3902 1/0 A W G 19 55 45

.59 430 P62 3901 2/0 A W G 19 55 45

.63 530 P62-5092 3/0AWG 19 55 45

.68 650 P62 5093 4/0AWG 19 55 45

.74 790 P62 3954 250 kcmil 37 65 65

.85 970 P62 3846 350 kcmil 37 65 65

.95 1310 P62-3806 500 kcmil 37 65 65 1.08 1810 P62 5094 750 kcmil 61 80 65 1.31 2690 Comed

  • Saes 9 AWG and smaller are not recommended w d"'"'"'*"-

Proj. No. 09050-051/ 09135-200

'"Ce! *,J'I'G'd 'lN'" ' " "" **

Calc. No.96-059 / G-70 96-092 e

Page A3 of A3 UP8 Eoanm erhe Rocks,.io. Company 285 Nicou Street New Haven, Connecticut 06511 (203) 772 2250 800 327 7625

k Exhibit C NEP-12 02 COMMONWEALTH EDISON COMPANY

~

CALCULATION NO. : BYR 96-059 09050-051 /

PAGE NO. B1 OF B2 G-70-96-092 09135-200 Appendix B-Data Sheet for SilTemp@

l REVISION NO.: 0 g

Y'.

~

v.._

yz i

e'NDUSTRIAL NERGYPRODUCTS,INC.:

i I

203 Gates Reed, Little Ferry, N.! 07643 l.

puoNc: sos.ese-eur rAx:2os.ess.ssos FABRIC-CH Pnooucr 207-22s.o444 ros.22s-odod THERMAL BARRIER JAN I

i CONTAIN8 NO ASBESTOS THE ALTERNATIVE TO ASSESTOS CLOTH FOR HIGH TEMPERATURE IR J

1 j

DESCRIPTION APPUCATIONS SILTEMP is a family of flexible silica tuules with ocellent SILTEMP is uses primarily in hot work such as welding and breat strength and improved abrasion resistance. SILTEMP burning operations. panicularly (or repfacement of asbestos l

has been especally developed to replace asbestos cloth m ap-cloth. It is also useful for thermal and electrical lesentation in l

plicanons where prosecuon against estreme heat is required, stress. relieving. SILTEMP can also help conserve energy by

{

SILTEMP has excellent thermalinsulasion charmerenstics over reducing heat loss at openings in even and furnace operations.

3 a very wnde temperature range and does not melt until remperature exceeds 3.000'F. SILTEMP also offers eweilerit ehemical resistaaec ano ciectrical insulation pre,eriors. soth AVAlualuTY SILTEMP 84CH and 188CH can be certified to meet military j

spectfication %1IL-1242448 on request.

SILTE P is also atailable as sleeving. mar. tape, and cord.

(

[4Ip')4

//WJs'b TYPICAL PROPERTIES OF SILTEMP 84CH ND 188CH SILTEMP 4ACH

$iLftMP 186CH Color Tan Ten 8

l l Weight. oLfyd.s 3g 3g j

)

Thickness. in.

.030

.054 l

Breast strength,lbsJin.

Warp 90 220 Fill 70 170 Silica content. %

> 9e

> 96 Metting temperature. 'F

> 3.000

> 3.000 Rolt width m.

36 38

~

Roli sengtn. vos.

50 50

..,)UI n c f- {~ g 'h,ft r ( tjy:-

$~ > I/!/ 4

// // I f

y Comed Proj. No. 09050-051/ 09135-200 Calc. No.96-059 / G-70 %-092 Page B2 of B2

Retrieved from "https://kanterella.com/w/index.php?title=ML20115F353&oldid=4288536"