Leakage loss is different in both Impulse and reaction turbine. In Impulse turbine, leakage loss occurs between the shaft, bearings, nozzles and stationary diaphragms. For Reaction turbine, it may occur at the blade tips. This loss is due to the leakage of steam on each stage of the turbine.
What are the 3 types of steam turbine?
Steam Turbines. Three basic types of steam turbine are used to generate power as a by-product of process or exhaust steamml: condensing, pass-out condensing, and back-pressure .
Which of the following loss in steam turbines is negligible?
Radiation Loss – Though this loss is negligible, as turbine casings are insulated, it occurs due to heat leakage from turbine to ambient air which is at a much lower temperature than the turbine.
What are the disadvantages of steam turbine?
- Relatively high overnight cost.
- Steam turbines are less efficient than reciprocating engines at part load operation.
- They have longer startup than gas turbines and surely than reciprocating engines.
- Less responsive to changes in power demand compared with gas turbines and with reciprocating engines.
What is throttling losses in steam turbine?
THROTTLE GOVERNING NOZZLE GOVERNING Because of throttling of the steam at the inlet of the turbine there are important throttling losses. The degree of losses in the nozzle governing valves is negligible . It has smaller losses due to partial admission of steam. It has large partial admission losses.
Which loss is very small in steam turbine?
1. Nozzle Friction Loss :- It is a very important loss for Impulse Turbine. When steam passes through the nozzles, friction loss occurs and the formation of eddies.
What is throttle loss?
The point at which the intake valves close is selected in a way that appears to reduce an engine’s displacement . Engine power output is prevented from falling by opening the throttle, ultimately diminishing throttling losses.
Where is steam turbine used?
Currently, steam turbines are widely used in different driver applications for mechanical drives and power generation units and produce nearly 1 million (MW) of capacity worldwide. The steam turbine rotor is the spinning component that has wheels and blades attached to it.
What are the main parts of steam turbine?
The main parts of a steam turbine are (1) the rotor that carries the blading to convert the thermal energy of the steam into the rotary motion of the shaft , (2) the casing, inside of which the rotor turns, that serves as a pressure vessel for containing the steam (it also accommodates fixed nozzle passages or stator ...
Why is steam turbine efficiency so low?
The compressor efficiency decrease is due primarily to the effects of compressor fouling . Any reduction in the turbine efficiency is due to the decrease in the turbine non-dimensional speed resulting from the increase in the turbine entry temperatures, as observed in Fig. 18.15.
What is speed ratio in steam turbine?
The axial component i.e. velocity of flow causes the steam to flow through the turbine and has no contribution in work. ... Explanation: Blade speed ratio (ρ) is the ratio of blade speed to the steam speed at the entrance of the moving blade .
Which of the following is an example of impulse turbine?
Example: Pelton wheel turbine . Pelton Wheel Turbine: It is a tangential flow impulse turbine in which the pressure energy of water is converted into kinetic energy to form a high-speed water jet and this jet strikes the wheel tangentially to make it rotate.
What is primary objective of steam turbine governing?
Explanation: The primary objective of steam turbine governing is to maintain a constant speed at varying loads . That means, irrespective of the load that is developed in the turbine, the speed remains a constant.
What are disadvantages of steam?
Disadvantages: Steam engines are usually huge and heavy . Because of this, it is tough to transport them from one place to another. Steam engines have a lower efficiency as compared to other heat engines.
What are the disadvantages of taking steam?
They may reduce blood supply to eye muscle and cause future major eye-sight problems. Steam can cause swelling of the eye , redness of the eye, dry eye, continuous watering of the eye, etc. Skin: Due to steam, face and neck skin become dry and causes many fungal or bacterial skin infections.
What are the types of steam turbine?
- Small/Mid-sized Condensing Turbines.
- Extraction-condensing Turbines.
- Extraction Back-pressure Turbines.
- Mixed-pressure Turbines.
- Geared Turbines.
