Question

Determine the thermal efficiency of the basic cycle of a steam power plant (Rankine Cycle), the specific and hourly steam consumption for a 50 MW steam turbine operating at inlet conditions: pressure 90 bar and temperature 500°C. The condenser pressure is 0.40 bar.

a) 30%
b) 40%
c) 50%
d) 60%

Answer 1

To determine the thermal efficiency of the Rankine Cycle, convert temperatures to Kelvin, use the formula η = 1 - (T_cold / T_hot), and calculate the answer.

Step-by-step explanation:

To determine the thermal efficiency of the basic cycle of a steam power plant (Rankine Cycle), we need to use the formula:

η = 1 - (Tcold / T)

Where η is the thermal efficiency, Tcold is the temperature at the condenser (converted to Kelvin), and T is the temperature at the inlet of the steam turbine (converted to Kelvin).

Given:

• Pressure at the inlet: 90 bar
• Temperature at the inlet: 500°C
• Condenser pressure: 0.40 bar
• Power output of the turbine: 50 MW

First, we need to convert the temperatures from Celsius to Kelvin:

• Tcold = 273 + 27 = 300 K
• T = 273 + 500 = 773 K

Now we can calculate the thermal efficiency:

η = 1 - (300 / 773)

Finally, we can determine the answer by calculating:

η ≈ 61.2%