Summary of Knowledge Points Related to the Steam Turbine Body

1.What is the working principle of a steam turbine?

Answer: Use the thermal energy of steam to convert into mechanical energy, and accelerate through the steam expansion in the nozzle, impact or push the blades on the rotor, so that the rotor rotates and outputs mechanical work.

2. What is the core role of steam turbines in thermal power plants?

Answer: It converts the thermal energy of steam into rotating mechanical energy and drives generators to generate electricity, which is the key equipment for energy conversion in thermal power plants.

3. What are the main basic parts of the steam turbine body?

Answer: It is mainly composed of rotor, stator, bearing system, adjustment protection system (some of the body includes), etc.

4. What are the main components of a steam turbine rotor?

Answer: Including spindle, impeller (or drum), moving vanes, couplings, thrust discs, etc.

5. What are the key components included in a steam turbine stator?

Answer: Including cylinders, partitions (or static leaf rings), static blades, steam seals, bearing housings, etc.

6. What are the two types of steam turbine blades according to their use?

Answer: It can be divided into moving blades (working blades) and static blades (guide blades).

7. What are the working characteristics of impulse steam turbines?

Answer: The steam mainly expands and accelerates in the nozzle, and the moving vane only changes the direction of steam flow, using impulse force to do work, and the reaction degree is small (usually ≤ 0.2).

8. What is the working principle of a reactionary steam turbine?

Answer: Steam expands in both the nozzle and the moving vane, and the moving vane is not only affected by the impulse force, but also by the reaction force (reaction force) generated by the steam expansion, and the reaction degree is large (usually about 0.5).

9. What is the definition of turbine grade? What are the parts?

Answer: The stage is the basic working unit of a steam turbine, consisting of a row of static blades (or nozzles) and a corresponding row of moving blades.

10. What is the main function of steam turbine partitions?

Answer: Fix the static blade, divide the cylinder into several steam chambers with different pressures, and ensure that the steam flows in a certain direction.

11. What is the main function of a steam seal?

Answer: Reduce steam leakage (such as between cylinder and rotor) or air leakage (such as exhaust cylinder), improve unit efficiency, and protect equipment safety.

12. What are the categories of steam turbines according to their thermal characteristics?

Answer: It is divided into condensation type, back pressure type, extraction condensation type, steam extraction back pressure type, intermediate reheating type, etc.

13. What is the role of a high-pressure cylinder in a steam turbine?

Answer: Withstand high temperature and high pressure steam, and convert part of the thermal energy of steam into mechanical energy, which is the main place for energy conversion of the initial parameters of the unit.

14. What are the structural characteristics of low-pressure cylinders?

Answer: Large volume, low steam inlet pressure, large flow area, usually use symmetrical split structure to balance axial thrust, and the exhaust port is connected to the condenser.

15. What are the main types of steam turbine bearings?

Answer: There are mainly radial support bearings (bearing the weight of the rotor and maintaining the center of rotation) and thrust bearings (balancing axial thrust).

16. What is the function of thrust bearings?

Answer: Withstand the axial thrust generated during the operation of the steam turbine, determine the axial position of the rotor, and prevent the axial movement of the rotor from damaging the equipment.

17. What is the function of a steam turbine nozzle?

Answer: Converting the thermal energy of steam into kinetic energy, the steam is ejected onto the moving blades at high speed and in a specific direction, pushing the rotor to rotate.

18. What are the advantages of multi-stage steam turbines?

Answer: Improve steam utilization (reduce final parameters), increase single machine power, improve efficiency, and reduce blade circumferential speed (avoid strength problems).

19. What is the main cause of axial thrust in steam turbines?

Answer: It is mainly caused by the pressure difference between the front and rear blades of each level and the axial force superposition caused by the recoil degree of the moving blades in the reactionary steam turbine.

20. What are the main methods for balancing axial thrust in steam turbines?

Answer: Including setting up a balanced piston, adopting a reverse flow arrangement, installing thrust bearings, using a dual-flow low-pressure cylinder, etc.