The gland sealing steam system provides low-pressure steam to the turbine gland in the final sets of labyrinth packing. This assists
the labyrinth packing in sealing the turbine to prevent the entrance of air from reducing or destroying the vacuum in the associated condenser
.
What is the function of gland steam in steam turbine?
gland steam
providing a seal between turbine shaft and turbine casing
. so gland steam protect the leakage of steam outside of the turbine and also and suck the ambient air inside . In a turbine, rotor rotates inside the casing. Rotor extended outside the casing at both side and rear side .
How the gland packing seal prevents the air from entering the turbine casing?
To prevent air from entering into the turbine casing,
sealing steam is led to the turbine glands
. The sealing steam first passes through the throttle steam valve and then the safety orifice in order to reduce its pressure to 0.01~0.08MPaG before reaching the turbine glands.
Why is gland land sealing steam is used during steam turbine operation?
The turbine gland sealing system (TGSS)
prevents the escape of steam from the turbine shaft and casing penetrations and the glands
of main steam stop and control valves. This system also prevents air leakage into the low pressure turbine glands.
What is a steam seal?
Sealing Steam is
used to help in creating vacuum
. It seals the narrow gap between the rotating part and stationary part: that’s why its called sealing steam. One part goes inside and outside part is sucked by gland condenser.
What are the reasons for high vibrations in steam turbines?
Uneven cooling and warming of rotors can
also increase vibration in the unit. Uneven cooling can cause the rotor to contact stationary surfaces, meaning that a high-temperature rotor could bend due to its mass if it is left to cool in a stationary position.
What is the purpose of casing sealing glands?
The main and auxiliary gland seal systems enable the turbine to be sealed where the shaft exits the casing; in effect keeping “air out and steam in.” The purpose of gland seal system is
to prevent the leakage of air from the atmosphere into turbine casings and prevent the escape of steam from turbine casings into the
…
What is turbine gland sealing?
The turbine gland sealing system (TGSS)
prevents the escape of steam from the turbine shaft and casing penetrations and the glands
of main steam stop and control valves. This system also prevents air leakage into the low pressure turbine glands.
What material is used in turbine glands?
To date, nobody has discovered, produced or invented a material for turbine glands that can better
carbon
. For this reason, carbon is widely employed in this capacity, except in one or two countries like Italy and the U.S.A. where soft packing glands arc preferred.
What is leak off steam in turbine?
Leak-off steam from the seals of the main stop and control valves is also discharged into the TGSS header. The steam seal leak-off valve is
a pneumatically actuated pressure control valve
, which fails to the position designated by the turbine supplier.
What is a seal in engineering?
A mechanical seal is
a device that helps join systems or mechanisms together by preventing leakage
(e.g. in a pumping system), containing pressure, or excluding contamination. The effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the case of gaskets.
What are steam turbines made of?
The nickel-based blades are
alloyed with aluminum and titanium
to improve strength and creep resistance. The microstructure of these alloys is composed of different regions of composition.
What are the factors that contribute to bearing failure in steam turbine?
It has been reported sixteen damaging mechanisms for failure of steam turbine journal bearings as well as;
abrasion, bond failure, cavitations erosion, corrosion, electrical pitting, erosion, fatigue, fretting, high chromium damage, non-homogeneity, overheating, seizure, structural damage, surface wear, tin oxide
…
What are the main cause of turbine vibration?
The vibration is caused by
insufficient clearance between stationary and rotating parts
, as well as a shaft located off-center in its bearing. … Again, the rubbing causes friction between stationary and rotating parts, localized heating of the rotor metal at the contact point, and shaft bending.
What is a reaction turbine?
A reaction turbine is
constructed of rows of fixed blades and rows of moving blades
. The fixed blades act as nozzles. The moving blades move as a result of the impulse of steam received (caused by a change in momentum) and also as a result of expansion and acceleration of the steam relative to them.
