Issue 37

E. Mihailov et alii, Frattura ed Integrità Strutturale, 37 (2016) 297-304; DOI: 10.3221/IGF-ESIS.37.39

The shamote insulation (Fig. 7) has a high level of thermal resistance, which at thickness of 0.012m is 0.012 m 2 K/W, the surface temperature increases up to 1040°C and heat losses decrease from 1.76MW to 0.73MW by 60%.

Coefficient of conductivity  , W/m.K

Kind of insulation

Emissivity ε

Silica

0.70 0.38 0.60 0.85 0.82 0.93

1.58+0.00038.T 6.28-0.00270.T 0.88+0.00023.T 1.28+0.00410.T 4.10-0.00160.T 2.80-0.00087.T

Magnesite Shamote Chromite

Magnesite-chromite Chromite-magnesite

Table 1: Thermophysical characteristics of insulating material.[5]

out w sl , , ,

in

, , , ,

m fw r F TT T TTP , ,  l

a

w



F m  v

,

,

ins , , , 

F

D







ef elc fw .

.

elc

a sl



 ,

, , ,

Pr 





s w

w

 D Re .v 

fw m F F F F

   

1

sum

elc F F .



2

0,14

  

  





ww mm TF TF T

 

0,8 Pr 0,027Re

0,33





w

w



 

w

rad

D

s 

F F

w m

 , .

ins el c 

el c     el c ins ins . .  

   

   

   

   

R

 

  

F

  elc . 1 1 1 1 1 67,5

C



 

F





r

ef

sum

l r

el c QQ .



l





k



a

sl

s

l

a

 

  

1

l

l r

RQ T

mw T F .

 

   

.

el c

r

w

  

 

F

 





l

.

elc

1

1

P

k k Q 

k 









 

.

.

.

elc

r elcs

elc r

ef

a

F





sum

ins

ins

c ins  

 2/ 2/ T T T T T T   w ins r

4

   

   

4

,

ir

r

rad TCk



      g

 

r    100

  



1

elc F T .

c

c ins







100

,

ir

r

r

No

4

.      r el c T

 

ins

1 , T T  ins ir

1  

. l Q Q  el c

100 .67,5. 

,

ir

.

el c

Yes

C  ,

w w

No

  in Q m  . w out w ww el c



1  

c

1 , T T  ir c

T T C

,



ir

Yes

,

Tr , ,v, ,

Q

m Re,Pr



.

el c

w

Figure 3: Simplified block diagram of the numerical algorithm.

300