- #1

Lewishio

- 19

- 2

- Homework Statement
- Hi,

I have had a go at this question but have gone wrong somewhere, any ideas?

Thanks.

A coal fired steam plant takes in feed water at a temperature of 70°C and produces 15 tonnes of steam per hour at a pressure of 60 bar and temperature 400°C.

The fuel consumption rate is 1.5 tonnes per hour and the calorific value of the fuel is 40MJkgˉ¹.

Determine the power rating of the boiler and its thermal efficiency.

- Relevant Equations
- Q in = E x V

Q out = McΔT

Efficiency = Q out / Q in x 100

A coal fired steam plant takes in feed water at a temperature of 70°C and produces 15 tonnes of steam per hour at a pressure of 60 bar and temperature 400°C.

The fuel consumption rate is 1.5 tonnes per hour and the calorific value of the fuel is 40MJkgˉ¹.

Determine the power rating of the boiler and its thermal efficiency.

Q in = E x V

40,000,000Jkg^-1 x 1500kg p/h / 3600 = 16,666,666,67 J/s

Q out = McΔT

15,000kg x 4.19 KJ/kg

Efficiency = Q out / Q in x 100

5,761.25 J/s / 16,666,666.67 x 100 = 0.034%

The fuel consumption rate is 1.5 tonnes per hour and the calorific value of the fuel is 40MJkgˉ¹.

Determine the power rating of the boiler and its thermal efficiency.

**Power rating:**Q in = E x V

40,000,000Jkg^-1 x 1500kg p/h / 3600 = 16,666,666,67 J/s

Q out = McΔT

15,000kg x 4.19 KJ/kg

**°**c x (400**°**c – 70**°**c) / 3600 = 5,761.25 J/s**Thermal efficiency:**Efficiency = Q out / Q in x 100

5,761.25 J/s / 16,666,666.67 x 100 = 0.034%