In a boiler test, \(1300 \mathrm{~kg}\) of coal are consumed in 24 hours. The mass of water evaporated is \(13000 \mathrm{~kg}\). Steam pressure is 7 bar. The feed water temperature entering the boiler is \(40^{\circ} \mathrm{C}\). Calorific value of fuel is \(30000 \mathrm{~kJ} / \mathrm{kg}\). Dryness fraction of steam \(=0.95\). Calculate

(a) Equivalent evaporation from and at \(100^{\circ} \mathrm{C}\).

(b) Boiler efficiency. Take \(c_{p}=4.187 \mathrm{~kJ} / \mathrm{kg}\). K for water. Use the following table :

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Pressure bar Enthalpy, kJ/kg Specific volume, m/kg Saturation temperature h hfg h C g Vg 7 697.06 2064.94 2762.0 0.27268 164.84