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What is eccentricity in steam turbine shaft?

Eccentricity is the deflection in the shaft away from truly straight. The turbine shaft when not turning will settle into a bowed shape (measured in thousandths of an inch), this is the deflection from straight. Large turbines are placed on turning gears as they are cooled or warmed up to minimize this deflection. As a turbine is started this eccentricity produces vibration as the deflection changes rotational position, if the turbine is started up too quickly this deflection will increase as a result of inertia trying to deflect the weight of the deflected shaft outward. Eventually the deflection, as a result of rolling the turbine up slowly, will straighten to the true center of the turbine shaft.


What is turbine overspeed trip?

Typically two balls with springs holding them down, When the turbine spins too fast, the centrifugal force pushes the balls past the resistance of the springs at which point they hit a lever that stops steam/compressed gas flow to the turbine and the turbine shuts down. They are designed to keep the turbine from going so fast that it damages itself or the piece of equipment it is driving.


Can you tell how emergency stop valve of turbine operates?

Unless it is an electronic governor on the turbine, there is a mechanical overspeed trip device which closes the trip valve (or trip throttle valve [TTV] on small turbines). This device is a spring loaded weighted pin set into the turbine shaft. At a particular set speed (110% of maximum operating speed, typically) the pin overcomes the force of the spring, flying part way out of the shaft and striking the trip mechanism linkage. This linkage up to that point was holding the trip valve open, now with the release of the linkage the spring on the trip valve instantly closes the valve stopping all flow of steam to the turbine. On electronic governors, when the set point on the turbine speed is reached it opens a solenoid valve (which requires a manual reset) which dumps all hydraulic pressure from the trip valve, allowing it to close.


How does A bootstrap air cycle machine in an aircraft work?

The air cycle machine (ACM) is driven by turbine engine bleed air that first passes through a primary heat exhanger (much like an intercooler for a turbocharged automotive engine) that significantly lowers the temperature of the 300-500 degree bleed air. After leaving the primary heat exchanger the air flows into a compression turbine that increases the pressure of the air and also increases the temperature. After leaving the compression turbine, the air flows into a secondary heat exchanger that once again lowers the temperature of the air. At this point, the air is at extremely high pressure and relatively low temperature. From the secondary heat exchanger the air flows into the "expansion turbine" where this high pressure air is used to drive a turbine wheel that performs several functions: 1. It extracts energy from the high pressure air, 2. Allows the pressurized air to expand, 3. Drives the compression turbine. The extraction of energy from the air and subsequent expansion of the gases drastically lower the temperatures of the air. In fact, the air temperature is lowered so much that often times hot bleed air is bypassed around the ACM and ducted to the air coming out of the expansion turbine to raise the temperature above freezing. The output air that is coming out of the ACM is then sent through a moisture removal system that essentially uses a fine mesh weave to collect small droplets of water. This removal of moisture helps to control the humidity of the air entering the cabin and it also prevents icing downstream in the system.


What is a fixed reference point?

A set point where all measurements can be taken from

Related Questions

Do yaw bearings theeth point outward or inward?

Outward


Do yaw bearings' point outward or inward?

On some yaw bearings the teeth point outwards, while on others they are turned inwards.


Do yaw bearings teeth point outward or inward?

On some yaw bearings the teeth point outwards, while on others they are turned inwards.


Define shell temperature monitoring in turbine?

measurement of how much the turbine's case expands from its fixed point outward as it is heated


What is it called when your eyes point outward?

wall eyed


What is eccentricity in steam turbine shaft?

Eccentricity is the deflection in the shaft away from truly straight. The turbine shaft when not turning will settle into a bowed shape (measured in thousandths of an inch), this is the deflection from straight. Large turbines are placed on turning gears as they are cooled or warmed up to minimize this deflection. As a turbine is started this eccentricity produces vibration as the deflection changes rotational position, if the turbine is started up too quickly this deflection will increase as a result of inertia trying to deflect the weight of the deflected shaft outward. Eventually the deflection, as a result of rolling the turbine up slowly, will straighten to the true center of the turbine shaft.


Where is the starting point in a circle?

the centre as a circle expnds outward


What is the meaning of Arrived at Outward OE?

OE where the point of customs exchange happen.~point of checking..


What is a crack in glass that extends outward is called?

A crack in glass that extends outward is called a radial crack. This type of crack usually starts at a point of impact and radiates outward in a straight line.


Has body parts extend outward from a central point?

radial symmetry


How can angular bearings be used to show directions?

Only if there is a point of reference.


What do you mean by turbine synchronization?

During a typical power plant startup, all components of the power plant are started slowly. The turbine is first rolled at a slow rpm. Then the rpm is increased gradually to a point where it can match the frequency of the grid. At this point, the turbine can be synchronized with the grid and start outputting electricity into the grid.