Amount of fuel required in 1 tph boiler depends on type of fuel used in boiler i.e. different fuel have different calorific value.
Formula for calculating fuel:
Fuel Consumption = steam quantity* latent heat / Efficiency * Calorific Value
For 1 tph wood fired boiler-
Fuel Consumption = 1000*540 / 0.75 *3500 = 205 kg/ hr