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Heat of Reaction

Steam with sp...

Question

Steam with specific enthalpy (h) 3214 kJ/kg enters an adiabatic turbine operating at steady state with a flow rate 10 kg/s. As it expands, at a point where h is 2920 kJ/kg, 1.5kg/s is extracted for heating purposes. The remaining 8.5\ kg/s further expands to the turbine exit, where h=2374 kJ/kg. Neglectign changes in kinetic and potential energies, the net power output (in kW) of the turbine is
7581

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Solution

The correct option is A 7581

$m_{1} = 10 k g / s; m_{2} = 1.5 k g / s; m_{3} = 8.5 k g / s$
$h_{1} = 3214 k J / k g; h_{2} = 2920 k J / k g$
$h_{3} = 2374 k J / k g$
$W_{1} = m_{1} (h_{1} - h_{2}) + m_{2} (h_{2} - h_{3}$
$= 10 (3214 - 2920) + 8.5 (2920 - 2374)$
$= 7581 k W$

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