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3 years ago

5

Steam flows steadily through a turbine at a rate of 420 kg/min. The enthalpy of the steam decreases by 600 kJ/kg as it flows ste

adily through the turbine. If the power generated by the turbine is 4 MW, determine the rate of heat loss from the steam turbine [kW).

1 answer:

Ghella [55]3 years ago

4 0

Answer:

the rate of heat loss from the steam turbine is Q = 200 kW

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)

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$\frac{\theta _{solid}}{\theta _{hollow}}=\frac{\frac{LT}{I_{solid}}}{\frac{LT}{I_{hollow}}}=\frac{I_{hollow}}{I_{solid}}=1.316$

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$1\times 100+1.5\times 120+2\times 500=4.5\times h$

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