How to Steam Turbine components work? Power Engineering

Summary

This video script provides a detailed explanation of the components and functioning of a steam turbine. It describes how turbines convert steam energy into mechanical energy to power generators, highlighting the key parts like the rotor, diaphragm, and nozzles. The script covers the turbine's operation, including impulse and reaction mechanisms, the roles of control, stop, and intercept valves, and the importance of regulating turbine speed. It also discusses turbine sections, steam reheating, and the protection mechanisms that prevent turbine over-speeding, ensuring safe and efficient turbine operation in power plants.

Takeaways

• 😀 A turbine converts energy from steam into mechanical energy to power a generator.
• 😀 Turbines are delicate and precise pieces of equipment, despite their large size.
• 😀 The main components of a turbine include moving parts (shaft and wheels), stationary parts (diaphragms and casing), and piping systems.
• 😀 The rotor consists of the turbine shaft and the connected rotating blades or wheels.
• 😀 Diaphragms direct steam flow between rotating blades and control steam movement within the turbine.
• 😀 A turbine may have up to 25 or more stages, each comprising a diaphragm and a rotating wheel.
• 😀 Steam must pass through stop valves (throttle valves) and control valves before entering the turbine.
• 😀 Stop valves shut off steam flow during shutdowns or emergencies, while control valves regulate the steam flow during normal operation.
• 😀 Turbines use either impulse, reaction, or a combination of both types of blades to convert steam energy into mechanical energy.
• 😀 Most turbines are divided into sections (high-pressure, intermediate-pressure, and low-pressure), and some have cross-compounded sections for better efficiency.
• 😀 Reheating steam between turbine sections helps maintain efficiency, and special valves (reheat stop and intercept valves) protect the turbine from over-speeding during abnormal conditions.

Q & A

What is the primary function of a turbine in a power plant?

The primary function of a turbine is to convert the energy contained in steam into mechanical energy, which is used to turn a generator.

What are the moving parts of a turbine?

The moving parts of a turbine include the shaft and the turbine wheels (also called buckets), which are connected to the shaft.

What is the rotor in a turbine composed of?

The rotor of a turbine is composed of the turbine shaft and the wheels (buckets), which are supported by bearings and housed in a casing.

What is the function of the diaphragms in a turbine?

The diaphragms in a turbine are stationary and direct the flow of steam from one set of rotating blades to the next set of rotating blades.

What is the distinction between a diaphragm and a turbine wheel?

A diaphragm is stationary with fixed blades (nozzles) that direct the steam flow, while a turbine wheel (rotating blade) is designed to turn as the steam passes through it.

What are the stop valves and control valves used for in a turbine?

Stop valves (throttle valves) control the steam supply to the turbine during shutdowns or emergencies, while control valves regulate the amount of steam flowing to the turbine during normal operation.

How does a steam chest help with the steam flow to the turbine?

A steam chest allows the steam to spread out and slow down, reducing turbulence before it enters the control valves.

What are the three methods of turbine operation for converting steam energy into mechanical energy?

The three methods of turbine operation are impulse, reaction, or a combination of both. Most turbines use a combination of both methods.

How do impulse blades in a turbine operate?

Impulse blades work similarly to the blades of a pinwheel, where high-pressure steam strikes the blades, causing the wheel to turn and rotate the shaft.

What happens when a turbine begins to over-speed?

If a turbine begins to over-speed, control valves close to limit steam flow. If the speed continues to increase, reheat stop valves and intercept valves close, cutting off steam to the turbine to prevent damage.