Answer to Question #289446 in Thermal Power Engineering for aman

Question

Two boilers one with super heater and other without super heater are delivering equal quantities of steam into a common main. The pressure in the boilers and main is18 bar. The temperature of steam from a boiler with a super heater is 350°C and temperature of

the steam in the main is 250°C.

Determine the quality of steam supplied by the other boiler. Take Cpsteam = 2.25 kJ/kgK.

Answer 1

Let the quality of steam supplied by the other boiler be x

Moisture in 1kg $=(1-x)$ kg

From saturated steam table at 18 bar;

(a) Saturated steam temperature $=209.8°C$

(b) Latent heat of steam $(h_{fg})=1900.28kJ/kg$

Heat gained by wet steam $=$ Heat lost by superheated steam

$(1-x)h_{fg}+c_{ps}(t_m-t_s)=c_{ps}(t_{sup}-t_m)$

$(1-x)1900.28+2.25(250-209.8)=2.25(350-250)$

Solving

$x=0.9219$