What is HPT in turbine?
During service, high pressure turbine (HPT) blades undergo various types of time- dependent degradation due to exposure in the operating environment and are considered as the most important rotational components of gas turbine engine.
What are the common problem of a gas turbine?
Gas turbine engines may be affected in a number of ways, including: (a) increased deterioration of seals and bearings, (b) increased operation under low load conditions giving rise to the risk of blade flutter and fatigue damage, (c) increasing amounts of fatigue damage due to more frequent starts, load fluctuations …
What is turbine blade failure?
Failure of the blade results in performance and turbine efficiency. The cause of failure on the blade is influenced by several factors, including fatigue, creep, oxidation, degradation of the coating on the turbine blade, corrosion, erosion, and surface degradation due to working at high temperatures.
What is HP IP and LP turbine?
high pressure, intermediate pressure and low pressure turbine. All three are mounted on the same shaft which rotates at 3600 rpm in a generator to make electricity. Here’s a simplified steam flow path through HP, IP and LP turbines. (
What is Hptacc?
High Pressure Turbine Active Clearance Control (HPTACC) is a system that controls the temperature of the shroud of the high pressure turbine rotor (HPT).
What are the common troubles in working of a turbine?
Major steam turbine problems, such as stress corrosion cracking of rotors and discs, corrosion fatigue of blades, pitting, and flow accelerated corrosion are analyzed, and their root causes and solutions discussed. Also covered are: life prediction, inspection, and turbine monitoring.
How gas turbine is shut down?
Method for performing shutdown of gas turbine, involves holding gas turbine at full speed-no load conditions for preset time during shutdown to reduce thermal stresses in limiting component of gas turbine at full speed-no load conditions.
What are the three main causes of turbine blade failures?
The most common failure mechanism modes in the nozzle and blade are fatigue, creep, erosion, and corrosion (1,4). The first stage blade in a gas turbine functions as a guide of hot gas supplied from the combustion chamber towards the turbine blade so that the blade experiences high heat pressure (5).
What is the primary cause of turbine blade damage?
Turbine blades are subjected to very strenuous environments inside a gas turbine. They face high temperatures, high stresses, and a potentially high vibration environment. All these factors can lead to blade failure, resulting in catastrophic failure of turbine.
Why compressor is used in gas turbine?
All turbine engines have a compressor to increase the pressure of the incoming air before it enters the combustor. Compressor performance has a large influence on total engine performance.
What is ESV turbine?
One part of the steam turbine that has a vital function is the Emergency stop valve (ESV). Emergency stop valve (ESV) steam turbine has the main function as a valve (throttle valve). This component must be able to drain and stop the vapor flow quickly and completely, either automatically or manually when needed.
What are stages in turbine?
In modern turbines, three types of staging are employed, either separately or in combination: (1) pressure (or impulse) staging, (2) reaction staging, and (3) velocity-compound staging.
What is tip clearance turbine?
Tip clearance is the distance between the tip of a rotating airfoil and a stationary part. Gas turbine: Rotor blade and casing.
What is DN DT in turbine?
Dn/Dt monitoring :- The KWU turbine has two critical speed between 700 rpm and 2850 rpm hence it is not advisable to run the turbine for prolonged time in this speed zone. To fulfill this requirement this loop detects the low acceleration rate and bring back the turbine to safe speed (600 rpm).
What is the air standard cycle for a gas turbine called?
5 Joule (or Brayton) Cycle. The Joule cycle is the air-standard cycle which describes the processes in the gas turbine. The Joule cycle has constant pressure combustion and constant pressure heat rejection.
What can cause turbine blade creep?
The creep rate of the blade depends on material properties, exposure time, exposure temperature, and applied structural load. Creep causes the blade to come into contact with the shell, which will cause turbine blade failure.
What is a borescope inspection of a turbine?
Borescope inspection offers an economical method of visually inspecting the innermost parts of a turbine such as the gas path, rotor, or the impeller blades.
What are the most common failures of gas turbines?
The testing methods are designed to detect some of the most common failure modes for gas turbines, including corrosion, cracking, fatigue, weld defects, and leaks, allowing businesses to make crucial asset management decisions with a view of optimizing maintenance resources. Some of the common NDT/NDE techniques include:
What are the most surveillance and condition monitoring intensive components of turbine engines?
Some of the most surveillance and condition monitoring intensive components of a gas turbine engine are those that are exposed to the system’s high temperature gases discharged from the hot combustion section.
What is included in the inspection of a turbine?
The inspection generally includes that of the combustion chamber outlet ducts, covers and turbine fuel nozzle for blockages, cracks, pits and corrosion in addition to the inspection of the first stage turbine blades and nozzle guide vanes for warping, cracks, or foreign object damage.