A steam turbine operates between 500°C and 3.5 MPa to 200°C and 0.3 MPa. If the turbine generates 750 kW and the heat loss is 100 kW, what is the flow rate of steam through the turbine

Respuesta :

Answer:

1.757 kg/s

Explanation:

According to the First Law of Thermodynamics

T₁ = 500⁰C

P₁ = 3.5 Mpa

T₂ = 200⁰c

P₂ = 0.3 Mpa

W = 750 kW

Q = 100KW

M = ?

using the formula

Q - W = M (h₂ - h₁)

Q = heat loss =100 kW or 100 kJ/s

W = heat generated = 750 kW or 750 kJ/s

h₂ = specific enthalpy of superheated water leaving the turbine

    = Steam enters the turbine at 3.5 MPa and 500 degrees Celsius. From thermodynamic tables of superheated water, the value of the specific enthalpy is:

    h₂ = h₂₀₀⁰C ,0.3 Mpa = 2967.9 kJ/kg

h₁ = specific enthalpy of superheated water entering the turbine

Similarly h₁=h₅₀₀⁰C, 3.5 Mpa = 3451.7 kJ/kg

Finally, the flow rate is calculated:

[tex]in = \frac{100 - 750}{3451.7 - 2967.9} \\ = 1.757kg/s[/tex]