Question

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

Answer 1

Step-by-step explanation:

The given data is as follows.

Boiler capacity =
`1 MT/hr * 1000 kg/MT` = 1000 kg/hr

Steam pressure = 12
`kg/cm^(2)`

For saturated steam, from steam table :

Steam temperature =
`187^(o)C`

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 =
`\text{boiler capacity} * \frac{\text{enthalpy difference}}{\text{boiler efficiency}}`

=
`1000 kg/hr * 1988.45 kJ/kg`

= 1988450 kJ/hr

Also, Fuel required =
`\frac{\text{heat required}}{\text{calorific value}}`

=
`(1988450 kJ/hr)/(150000 kJ/kg)`

= 13.25 kg/hr

Hence, Volumetric flow rate of hydrogen require =
`\frac{\text{fuel required}}{\text{density}}`

=
`(13.25 kg/hr)/(0.0899 kg/nm^(3))`

= 147.45
`nm^(3)/hr`

Thus, we can conclude that 147.45
`nm^(3)/hr` hydrogen as a fuel will be burnt.