Question 6.53: Reconsider Prob. 6–52. Using EES (or other) software, invest......
Reconsider Prob. 6-52. Using EES (or other) software, investigate the effect of the turbine exit pressure on the power output of the turbine. Let the exit pressure vary from 10 to 200 \mathrm{kPa}. Plot the power output against the exit pressure, and discuss the results.
Problem 6-52 is reconsidered. The effect of the turbine exit pressure on the power output of the turbine as the exit pressure varies from 10 \mathrm{kPa} to 200 \mathrm{kPa} is to be investigated. The power output is to be plotted against the exit pressure.
Analysis The problem is solved using EES, and the solution is given below.
“Knowns “
T[1] = 450 [C]
P[1] = 10000 [kPa]
Vel[1] = 80 [m/s]
P[2] = 10 [kPa]
X_2=0.92
Vel[2] = 50 [m/s]
m_dot[1]=12 [kg/s]
Fluid$=’Steam_IAPWS’
“Property Data”
h[1]=enthalpy(Fluid$,T=T[1],P=P[1])
h[2]=enthalpy(Fluid$,P=P[2],x=x_2)
T[2]=temperature(Fluid$,P=P[2],x=x_2)
v[1]=volume(Fluid$,T=T[1],p=P[1])
v[2]=volume(Fluid$,P=P[2],x=x_2)
“Conservation of mass: “
m_dot[1]= m_dot[2]
“Mass flow rate”
m_dot[1]=A[1]*Vel[1]/v[1]
m_dot[2]= A[2]*Vel[2]/v[2]
“Conservation of Energy – Steady Flow energy balance”
m_dot[1]*(h[1]+Vel[1]^2/2*Convert(m^2/s^2, kJ/kg)) =
m_dot[2]*(h[2]+Vel[2]^2/2*Convert(m^2/s^2, kJ/kg))+W_dot_turb*convert(MW,kJ/s)
DELTAke=Vel[2]^2/2*Convert(m^2/s^2, kJ/kg)-Vel[1]^2/2*Convert(m^2/s^2, kJ/kg)
