diesel engine starting a gas turbine
diesel engine starting a gas turbine
(OP)
hi, I'm a mechanical engineer..I'm new to turbines, I don't know alot about them....we have an old gas turbine that is started by a diesel
engine coupled through a torque converter... it's a very old engine and we don't have any documents about it..I'm trying to understand the
starting sequence of the turbine.. i found in the torque converter documents this chart but i couldn't understand it. So basically I need
an explanation of this chart and of the turbine starting sequence by a diesel engine
engine coupled through a torque converter... it's a very old engine and we don't have any documents about it..I'm trying to understand the
starting sequence of the turbine.. i found in the torque converter documents this chart but i couldn't understand it. So basically I need
an explanation of this chart and of the turbine starting sequence by a diesel engine





RE: diesel engine starting a gas turbine
The only interesting thing about this the hand written note in french at 1250 rpm which appears to say speed before firing. it seems a reasonable speed for the turbine to be at a minimum before you introduce the fuel and start the ignitor.
I don't know what this is driving, but most GT's start on no load or recycle if driving a gas compressor so that the turbine doesn't take a huge engine to wind it up to speed.
Basically you turn on the diesel engine, connect it to the turbine which then slowly winds up to speed flushing any fuel out of the system (seemingly minimum speed here is 1250, but normally you go a bit more), introduce the fuel, ignite it and then hopefully you get fire in the turbine and then you can de-couple your diesel engine. There is normally an automated start sequence in the turbine controller
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: diesel engine starting a gas turbine
is about 305 hp...if we calculate the input speed at the starting according to this torque and power we find it N= 3990 rpm which does not
make sense...
RE: diesel engine starting a gas turbine
How are you "calculating the input speed"?. Are you using another page of this manual? There's nothing in this graph that I can see about the input speed.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: diesel engine starting a gas turbine
where
P = power (W)
T = torque or moment (Nm)
ω = angular velocity (rad/s)
N(rpm) = π/30ω
RE: diesel engine starting a gas turbine
Does that make more sense?
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: diesel engine starting a gas turbine
In the starting sequence, does the engine starts to turn alone then it's coupled to the TC when it reaches a some rpm or they are
coupled frome the beginning?
RE: diesel engine starting a gas turbine
You will then need some sort of decoupling once the turbine fires to slow the Fidel engine to stop and not overspeed. How it does that is within your system somewhere.
Hope this helps.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: diesel engine starting a gas turbine
Torque converters and fluid couplings are hydrodynamic devices, and their ability to transmit torque over a wide range of input/output speed differential comes from converting varying amounts of the input power to hydraulic flow losses (or slip). Right at startup, when the output speed is zero and the input speed is nominal, the TC has 100% slip and 100% of the input power is converted to heat in the hydraulic fluid. Torque converters are usually limited by their capability to reject the heat transferred to the hydraulic fluid due to slip. That's probably why the input power curve shown in the OP is mostly flat over the operating range.