GT water wash impacts on driven equipment efficiency?

Hi All,

It is a routine task to carry out a water wash to clean up turbine compressor and this will increase turbine efficiency. Then, what about a driven equipment? If the driver (GT) improves its efficiency, will it also improve driven equipment (alternator or compressor) efficiency?

I think as long as the driver provides sufficient speed then the driven equipment efficiency totally depends on the driven equipment itself. Please advise if it is correct.

Thanks.
 
Hi All,

It is a routine task to carry out a water wash to clean up turbine compressor and this will increase turbine efficiency. Then, what about a driven equipment? If the driver (GT) improves its efficiency, will it also improve driven equipment (alternator or compressor) efficiency?

I think as long as the driver provides sufficient speed then the driven equipment efficiency totally depends on the driven equipment itself. Please advise if it is correct.

Thanks.
You're going to Water Wash a Generator ? ? ?
 
koeick,

A gas turbine is a prime mover--a device (engine) that produces torque that is supplied to a driven device to do work (compress a fluid/gas or produce electricity). The driven device (compressor or generator) converts the torque provided by the prime mover. A driven device has its own efficiency that is separate from the prime mover.

In the case of a gas turbine driving a generator, the efficiency of the turbine-generator is usually measured in what's called the heat rate: the amount of fuel required to produce a unit of electricity (usually a MW, sometimes a MW hour). It's also called the "heat rate."

Because the axial compressor is a key component of the gas turbine and is driven by the gas turbine (as well as the driven device (compressor or generator) if the compressor can push more air through the gas turbine using less energy from the gas turbine then the efficiency of the turbine-generator is improved. In other words, it takes less fuel to make the same amount of MW--or more MW can be made from a lesser amount of fuel. This is improved efficiency.

Generators have their own efficiency--separate from the torque that is provided to them by the prime mover. The generator doesn't care where it gets the torque from (a gas turbine or a steam turbine or a hydro turbine or a reciprocating engine)--it converts that torque to amperes that become MW. If I recall correctly, generators are more than 90% efficient at converting torque to amperes, and there are ways to improve generator efficiency but they usually involve serious modifications to the generator and/or the generator rotor. But, improving the turbine efficiency (heat rate) does not improve the efficiency of the generator. The generator is going to convert the torque that is provided to it. If that torque can be produced more efficiently the efficiency of the turbine-generator is improved.

Most compressors driven by turbines are centrifugal compressors, and they have their own efficiency--which works in the same way as generator efficiency--the centrifugal compressor driven by a turbine can't be improved by improving the turbine efficiency. The centrifugal compressor converts the torque supplied to it by its prime mover into flow and pressure--and moving a fluid/gas is work, so the centrifugal compressor converts the torque supplied by the turbine into the work required to move the fluid/gas.

So, turbines produce torque. Driven devices convert torque to work/energy. If the torque can be produced more efficiently, it means more electrical energy can be produced for less fuel, and more fluid/gas can be moved/compressed for less fuel.

You're almost correct--it's not exactly speed, it's torque. Driven devices convert torque (at some speed or speed range) to electrical energy (by the generator) or fluid/gas flow/compression (centrifugal compressor).

Hope this helps!!!
 
koeick,

A gas turbine is a prime mover--a device (engine) that produces torque that is supplied to a driven device to do work (compress a fluid/gas or produce electricity). The driven device (compressor or generator) converts the torque provided by the prime mover. A driven device has its own efficiency that is separate from the prime mover.

In the case of a gas turbine driving a generator, the efficiency of the turbine-generator is usually measured in what's called the heat rate: the amount of fuel required to produce a unit of electricity (usually a MW, sometimes a MW hour). It's also called the "heat rate."

Because the axial compressor is a key component of the gas turbine and is driven by the gas turbine (as well as the driven device (compressor or generator) if the compressor can push more air through the gas turbine using less energy from the gas turbine then the efficiency of the turbine-generator is improved. In other words, it takes less fuel to make the same amount of MW--or more MW can be made from a lesser amount of fuel. This is improved efficiency.

Generators have their own efficiency--separate from the torque that is provided to them by the prime mover. The generator doesn't care where it gets the torque from (a gas turbine or a steam turbine or a hydro turbine or a reciprocating engine)--it converts that torque to amperes that become MW. If I recall correctly, generators are more than 90% efficient at converting torque to amperes, and there are ways to improve generator efficiency but they usually involve serious modifications to the generator and/or the generator rotor. But, improving the turbine efficiency (heat rate) does not improve the efficiency of the generator. The generator is going to convert the torque that is provided to it. If that torque can be produced more efficiently the efficiency of the turbine-generator is improved.

Most compressors driven by turbines are centrifugal compressors, and they have their own efficiency--which works in the same way as generator efficiency--the centrifugal compressor driven by a turbine can't be improved by improving the turbine efficiency. The centrifugal compressor converts the torque supplied to it by its prime mover into flow and pressure--and moving a fluid/gas is work, so the centrifugal compressor converts the torque supplied by the turbine into the work required to move the fluid/gas.

So, turbines produce torque. Driven devices convert torque to work/energy. If the torque can be produced more efficiently, it means more electrical energy can be produced for less fuel, and more fluid/gas can be moved/compressed for less fuel.

You're almost correct--it's not exactly speed, it's torque. Driven devices convert torque (at some speed or speed range) to electrical energy (by the generator) or fluid/gas flow/compression (centrifugal compressor).

Hope this helps!!!
Much appreciated CSA!! Now I am clear that the driver efficiency has no direct relation to driven equipment efficiency.
 
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