Answer:
the rate of heat loss from the steam turbine is Q = 200 kW
Step-by-step explanation:
From the first law of thermodynamics applied to open systems
Q-W₀ = F*(ΔH + ΔK + ΔV)
where
Q= heat loss
W₀= power generated by the turbine
F= mass flow
ΔH = enthalpy change
ΔK = kinetic energy change
ΔV = potencial energy change
If we neglect the changes in potential and kinetic energy compared with the change in enthalpy , then
Q-W₀ = F*ΔH
Q = F*ΔH+ W₀
replacing values
Q = F*ΔH+ W₀ = 420 kg/min * (-600 kJ/kg) * 1 min/60 s * 1 MW/1000 kW + 4 MW = -0.2 MW = -200 kW (negative sign comes from outflow of energy)