Question

A steam turbine inlet is at 1200 kpa, 400 ÌŠc. The exit is at 200 kpa, 200 ÌŠc. What is the isentropic efficiency of the turbine?

Answer 1

The isentropic efficiency of a steam turbine can be calculated using specific enthalpy values at the turbine inlet and exit. The formula is (h1 - h2s) / (h1 - h2).

Step-by-step explanation:

The isentropic efficiency of a steam turbine can be calculated using the formula:

Isentropic efficiency = (h1 - h2s) / (h1 - h2)

Where:

• h1 is the specific enthalpy at the turbine inlet (1200 kPa, 400°C)
• h2 is the specific enthalpy at the turbine exit (200 kPa, 200°C)
• h2s is the specific enthalpy at the turbine exit assuming isentropic conditions

To find the values of h1, h2, and h2s, you can use steam tables or steam property calculators. Once you have these values, plug them into the equation above to calculate the isentropic efficiency.