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6. THE DEFINITION OF THE HEAT REGENERATOR AREA
OF A GAS TURBINE

6.1 Available specific heat, which theoretically can be transferred to the heat exchange
from a hot fluid to cold fluid, is determined from formula

q rmax = C pm·(T 4 – T 2) (6.1)

where C pm - is the specific heat of the fluid (in this case, WF);
T 4 - is the temperature of the WF at the end of the adiabatic expansion;
T 1 - is the temperature of the WF at the beginning of adiabatic
compression.

6.2 For heat transfer exchange between hot and cold fluids required temperature
difference. Therefore, the transferred heat q p at heat exchange less available heat q p max .
The amount of the transferred heat at the heat exchange is determined by the formula

q r = σ · q r max , (6.2)

where σ - degree of regeneration.

6.3 The surface area of the heat exchange is determined by the formula
q  G
F  p k   t  , (6.3)
T
where G - fluid flow rate, kg/s;
k Т - is the average value of the heat transfer coefficient for the heat exchange,
W/(m•K);
Δt - is the log mean temperature difference of the heat exchange, K.

6.4 Thermal efficiency of the cycle gas turbine with the heat exchange
q  q 
  1 2 (6.4)
t q  q 
1 p

6,5 The average temperature difference (temperature difference) for heat exchangers
with the parallel flow (Fig.6.1, a) and with the counter flow (Fig.6.1, b) heat transfer is
determined from the ratios

 t   t'  ' ' t  (6.5)
' t 
ln
' ' t 
for the parallel fluid flow

' (t f 1 ' t  f 2 )  (t " f 1 " t  f 2 )
t  , (6.6)
' t ' t 
ln f 1 f 2
" t " t 
f 1 f 2
for the counter fluid flow

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