A boiler plant supplies \(5400 \mathrm{~kg}\) of steam per hour at 7.6 bar pressure. The dryness of steam is 0.98 . The feed water temperature is \(42^{\circ} \mathrm{C}\) when using \(670 \mathrm{~kg}\) of coal/hr. The calorific valve of coal is \(31000 \mathrm{~kJ} / \mathrm{kg}\).

Calculate

(a) The efficiency of the boiler

(b) The equivalent evaporation from and at \(100^{\circ} \mathrm{C}\). The extract from steam table is as under :

Transcribed Image Text:

Absolute pressure Temperature Specific volume, m/kg Specific Enthalpy, kJ/kg bar C vf Vg hf h 0.08198 42 0.0010086 17.69 175.81 2577.9 7.6 168.30 0.0011123 0.25224 711.67 2765.4