What changes occur to steam when passing through the stationary nozzles in a Curtis Stage steam turbine?

What changes occur to steam when passing through the stationary nozzles in a Curtis Stage steam turbine?

• A. Pressure increases, volume decreases, velocity stays the same
• B. Pressure drops, volume increases, and velocity increases
• C. Pressure remains constant, volume increases, velocity decreases
• D. Pressure drop, constant volume, and increased velocity

Answer: (B)

In a Curtis Stage steam turbine, when steam passes through stationary nozzles, the fundamental thermodynamic principles at play lead to specific changes in pressure, volume, and velocity. As the steam enters the nozzles, it undergoes an expansion process. In this process, the pressure of the steam decreases significantly due to the conversion of thermal energy into kinetic energy. As the steam expands through the nozzles, the increase in the cross-sectional area allows the steam molecules to spread out, thus resulting in an increase in volume. Alongside the drop in pressure, this expansion also causes the velocity of the steam to increase sharply. This is because the conversion of internal energy (from the decline in pressure and increase in volume) yields high exit velocities, which are crucial for driving the turbine blades that are located downstream. The combination of lowered pressure and volume increase occurring with a corresponding increase in velocity is essential in maximizing the efficiency and output of the turbine. This process illustrates the effective use of the principles of fluid dynamics and thermodynamics to enhance the performance of a steam turbine.

In a Curtis Stage steam turbine, when steam passes through stationary nozzles, the fundamental thermodynamic principles at play lead to specific changes in pressure, volume, and velocity. As the steam enters the nozzles, it undergoes an expansion process. In this process, the pressure of the steam decreases significantly due to the conversion of thermal energy into kinetic energy.

As the steam expands through the nozzles, the increase in the cross-sectional area allows the steam molecules to spread out, thus resulting in an increase in volume. Alongside the drop in pressure, this expansion also causes the velocity of the steam to increase sharply. This is because the conversion of internal energy (from the decline in pressure and increase in volume) yields high exit velocities, which are crucial for driving the turbine blades that are located downstream.

The combination of lowered pressure and volume increase occurring with a corresponding increase in velocity is essential in maximizing the efficiency and output of the turbine. This process illustrates the effective use of the principles of fluid dynamics and thermodynamics to enhance the performance of a steam turbine.