Answer to Question #236688 in Mechanical Engineering for Klynz1

Question

Steam from a superheater at 7 bar, 300 degree Celsius is mixed in steady adiabatic flow with wet steam at 7 bar, dryness fraction 0.9.calculate the mass of wet steam required per kilogram of superheated steam to produce steam at 7 bar, dry saturated.

Answer 1

We have x amount of superheated steam at 7 bar ($700kpa$ ) and $300C=> h=3059kj/kg$ (h of superheated at temp and press)

total energy of the closed system:

$x\times3059+y\times2556.22=z\times2762.8; z=x+y$ (closed system)

$x\times3059+y\times 2556.22=(x+y)\times2762.8$ ; lets assume L is the mass ratioof wet steam to superheated

=> $L=y/x$ $x(3059+L(2556.22)=x(1+L)2762.8$

$(3059+L\times2556.22)=(1+L)\times2762.8$

solve for L and you should get $1.43 kg$ wet steam/kg superheated (itwill be a little off because my steam tables might be different orrounding)