to produce 1mt /hr of steam in a boiler of capacity 12 kg/cm2 how much hydrogen as a fuel to be burnt in nm3/hr

Respuesta :

Explanation:

The given data is as follows.

         Boiler capacity = [tex]1 MT/hr \times 1000 kg/MT[/tex] = 1000 kg/hr

          Steam pressure = 12 [tex]kg/cm^{2}[/tex]

For saturated steam, from steam table :

          Steam temperature = [tex]187^{o}C[/tex]

         Specific enthalpy of water = 794.65 kJ/kg

         Specific enthalpy of steam = 2783.10 kJ/kg

Therefore, difference between enthalpy of steam and water  will be calculated as follows.

                         = 2783.10 - 794.65

                         = 1988.45 kJ/kg

So, heat required will be calculated as follows.

      Heat required = [tex]\text{boiler capacity} \times \frac{\text{enthalpy difference}}{\text{boiler efficiency}}[/tex]

                                 = [tex]1000 kg/hr \times 1988.45 kJ/kg[/tex]

                                 = 1988450 kJ/hr

Also,   Fuel required = [tex]\frac{\text{heat required}}{\text{calorific value}}[/tex]

                               = [tex]\frac{1988450 kJ/hr}{150000 kJ/kg}[/tex]

                               = 13.25 kg/hr

Hence,  Volumetric flow rate of hydrogen require  = [tex]\frac{\text{fuel required}}{\text{density}}[/tex]

                       = [tex]\frac{13.25 kg/hr}{0.0899 kg/nm^{3}}[/tex]

                      = 147.45 [tex]nm^{3}/hr[/tex]

Thus, we can conclude that 147.45 [tex]nm^{3}/hr[/tex] hydrogen as a fuel will be burnt.