Speed control in steam turbines The engineering term for maintaining turbine speed essentially constant over a range of load conditions is what?

Introduction / Context:
Power systems require prime movers to hold speed nearly constant despite load fluctuations. In steam turbines, specialized control systems modulate steam flow to maintain set speed, ensuring frequency stability for generators and mechanical drivetrains.

Given Data / Assumptions:

• Turbine connected to a load (e.g., electrical generator) with variable demand.
• Control elements available: throttle valves, nozzle control valves, or governing valves.
• Feedback based on speed or frequency deviation.

Concept / Approach:

Governing is the collective term for speed-control methods in turbines. Common schemes include throttle governing (varying inlet pressure), nozzle control governing (varying the number of active nozzles), and bypass or combination systems. The governor senses speed error and adjusts steam admission to keep speed at the setpoint within a specified droop, maintaining stability and sharing load among parallel units.

Step-by-Step Solution:

Verification / Alternative check:

Frequency control in grids uses droop characteristics; turbine governing systems are tuned to share loads according to droop while keeping speed/frequency within standards.

Why Other Options Are Wrong:

Bleeding extracts steam for feed heating, not speed control.Reheating raises steam temperature between turbine sections, not a speed regulator.Condensing refers to the condenser process downstream, unrelated to speed regulation.

Common Pitfalls:

Assuming throttle governing is the only method; many large turbines use nozzle control or combination systems for better efficiency under part load.

Final Answer:

governing