F1technical.net

gruntguru wrote: ↑

30 Mar 2020, 00:33

subcritical71 wrote: ↑

30 Mar 2020, 00:01

GE’s H class gas turbine has >61% thermal efficiency https://www.ge.com/content/dam/gepower ... -oct15.pdf. Guinness has it at 63.08%

That is a gas turbine plus a steam powerplant heated by the turbine exhaust. (Combined cycle)
The gas turbine alone would be about 43%.

a 43% efficient gas turbine won't give 61% on combined cycle
you need a 50% efficient gas turbine to reach or exceed 60% on combined cycle
43% is about the best an aviation gas turbine can do

the biggest gas turbines for power generation are about 50% efficient
(though velocities at the blade tips are significantly supersonic)

there was a German company that proposed cars using piston-engine ICEs on combined cycle
the BMW TurboSteamer

btw
traditionally a 50% efficient heat engine was called 50% efficient (not 50% thermally efficient)
thermal efficiency TE is the % conversion efficiency of in-cylinder heat to work
of course there's indicated thermal efficiency ITE and brake thermal efficiency BTE

ITE seems to be what many posters intend when they (wrongly) speak of combustion efficiency
in F1 ITE is about 50% but CE is about 95%

BTE (even if called thermal efficiency) is anyway a somewhat skewed measure
eg the combustion of (most) fuels 'traps' heat primarily as the latent heat in the water vapour content of the exhaust
eg gasoline traps about 7%, methane traps about 10%, and hydrogen traps about 15%
this trapping is by engineering convention ignored (ie in using the lower calorific value LCV)

I am not sure where this confusion comes from, the text book thermal efficiency is a simple function of heat added to a system and heat rejected. It accounts for all other system efficiencies (combustion, mechanical, etc).

Just_a_fan wrote: ↑

30 Mar 2020, 10:31

OO7 wrote: ↑

30 Mar 2020, 04:53

Also Mercedes' claims of achieving =>50% T.E were based on tightly controlled dyno conditions, at the time they hadn't managed to do so on the race track.

Did they ever claim otherwise? I mean the engineers, not the management/PR machine.

Not as far as I'm aware.

We ran the MAN engines on combined cycle when i was in power plant. It was dirty fuel so steam system was a bit compromised efficiency wise for durability. Parts were also comprised to be beefier for reliability.

The F1 engines dont have a steam system, but if they had the efficiency would be even higher. Note a huge boiler and a little steam turbine and condenser and pumps plus extra radiator would be required though and it would add a lot of weight. But definitley the F1 exaust is close to a dream for heat recovery. Its fairly soot free, very high temperatures (anything over 290C can be used to good effect). F1 exhaust temps and flows should return about an extra 50hp at peak outputs.

Wasn't sure where to put this

Yet another Merc innovation?
https://www.essentiallysports.com/f1-ne ... -2021/amp/

Anyone else got some info on this?

ENGINE TUNER wrote: ↑

30 Mar 2020, 22:01

Wasn't sure where to put this

Yet another Merc innovation?
https://www.essentiallysports.com/f1-ne ... -2021/amp/

Anyone else got some info on this?

i don't know anything about it but lol, Ferrari and Red Bull apparently don't want the gearbox frozen for next year because Uberraschunggggg Mercedes have come up with one that only needs 4 studs (why is that significant? they're not bulky are they) and is slimmer and gives an aero benefit. Not sure if the rearward suspension mounts are part of this as well?

So the other teams want to save the money but they can't, at this point. Personally i just hope that whatever happens for next year Mercedes get to have the advantage that they've earned, for a season

izzy wrote: ↑

30 Mar 2020, 22:30

ENGINE TUNER wrote: ↑

30 Mar 2020, 22:01

Wasn't sure where to put this

Yet another Merc innovation?
https://www.essentiallysports.com/f1-ne ... -2021/amp/

Anyone else got some info on this?

i don't know anything about it but lol, Ferrari and Red Bull apparently don't want the gearbox frozen for next year because Uberraschunggggg Mercedes have come up with one that only needs 4 studs (why is that significant? they're not bulky are they) and is slimmer and gives an aero benefit. Not sure if the rearward suspension mounts are part of this as well?

So the other teams want to save the money but they can't, at this point. Personally i just hope that whatever happens for next year Mercedes get to have the advantage that they've earned, for a season

The mounting points(studs) of the transmission to the back of the engine are a specified standard as per the regs so theoretically any gearbox can mount up to any PU. But Merc seem to have been able to streamline their trans to a point where they only need to utilize 4 of the 6 mounting points, thus giving them an important advantage in an extremely aerodynamically critical area of the car. And now that advantage may also be locked in for 2021 as well if transmissions are frozen for next year.

A standard gearbox should be a nonstarter for F1. A standard gear cluster would be acceptable, but not the trans casing.

Does Merc still run the trans "cassette" that they pioneered a couple years ago?

ENGINE TUNER wrote: ↑

30 Mar 2020, 22:46

izzy wrote: ↑

30 Mar 2020, 22:30

ENGINE TUNER wrote: ↑

30 Mar 2020, 22:01

Wasn't sure where to put this

Yet another Merc innovation?
https://www.essentiallysports.com/f1-ne ... -2021/amp/

Anyone else got some info on this?

i don't know anything about it but lol, Ferrari and Red Bull apparently don't want the gearbox frozen for next year because Uberraschunggggg Mercedes have come up with one that only needs 4 studs (why is that significant? they're not bulky are they) and is slimmer and gives an aero benefit. Not sure if the rearward suspension mounts are part of this as well?

So the other teams want to save the money but they can't, at this point. Personally i just hope that whatever happens for next year Mercedes get to have the advantage that they've earned, for a season

The mounting points(studs) of the transmission to the back of the engine are a specified standard as per the regs so theoretically any gearbox can mount up to any PU. But Merc seem to have been able to streamline their trans to a point where they only need to utilize 4 of the 6 mounting points, thus giving them an important advantage in an extremely aerodynamic area of the car. And now that advantage may also be locked in for 2021 as well if transmissions are frozen for next year.

A standard gearbox should be a nonstarter for F1. A standard gear cluster would be acceptable, but not the trans casing.

Does Merc still run the trans "cassette" that they pioneered a couple years ago?

Not sure how that would comply with the regs. I have bolded the relevant section.

5.3.8 Power unit mountings may only comprise six M12 studs for connection to the survival cell and six M12 studs for connection to the transmission. All studs must be used and may be fitted on the survival cell, power unit or transmission. The installed end of the studs must be M12 and the free end may be a different diameter.

henry wrote: ↑

30 Mar 2020, 23:30

ENGINE TUNER wrote: ↑

30 Mar 2020, 22:46

The mounting points(studs) of the transmission to the back of the engine are a specified standard as per the regs so theoretically any gearbox can mount up to any PU. But Merc seem to have been able to streamline their trans to a point where they only need to utilize 4 of the 6 mounting points, thus giving them an important advantage in an extremely aerodynamic area of the car. And now that advantage may also be locked in for 2021 as well if transmissions are frozen for next year.

Not sure how that would comply with the regs. I have bolded the relevant section.

5.3.8 Power unit mountings may only comprise six M12 studs for connection to the survival cell and six M12 studs for connection to the transmission. All studs must be used and may be fitted on the survival cell, power unit or transmission. The installed end of the studs must be M12 and the free end may be a different diameter.

oh nice, so it's a workaround surprise! the exposed end of the middle studs can be M2 and 'used' for cable clips

henry wrote: ↑

30 Mar 2020, 23:30

Not sure how that would comply with the regs. I have bolded the relevant section.

5.3.8 Power unit mountings may only comprise six M12 studs for connection to the survival cell and six M12 studs for connection to the transmission. All studs must be used and may be fitted on the survival cell, power unit or transmission. The installed end of the studs must be M12 and the free end may be a different diameter.

Used, but to what extent? They could be "used", but only on a nonstructural "ear", to comply with the written reg, but still allowing a slimline transmission

Tommy Cookers wrote: ↑

30 Mar 2020, 10:58

gruntguru wrote: ↑

30 Mar 2020, 00:33

subcritical71 wrote: ↑

30 Mar 2020, 00:01

GE’s H class gas turbine has >61% thermal efficiency https://www.ge.com/content/dam/gepower ... -oct15.pdf. Guinness has it at 63.08%

That is a gas turbine plus a steam powerplant heated by the turbine exhaust. (Combined cycle)
The gas turbine alone would be about 43%.

a 43% efficient gas turbine won't give 61% on combined cycle
you need a 50% efficient gas turbine to reach or exceed 60% on combined cycle
43% is about the best an aviation gas turbine can do

the biggest gas turbines for power generation are about 50% efficient
(though velocities at the blade tips are significantly supersonic)

The GE H class mentioned by subcritical71 has a base TE of 43 point something % and a combined cycle efficiency of 63 point something %. I haven't heard of any gas turbine with 50% TE.

TE is a term which defaults to BTE for heat engines with a mechanical output. (For thermo-electric devices and the like there is no such thing as BTE). ITE is only relevant to gas-cycle heat engines (in particular piston engines where the "Indicator" diagram dates back to the steam era.)

Just_a_fan wrote: ↑

30 Mar 2020, 01:43

gruntguru wrote: ↑

30 Mar 2020, 00:33

subcritical71 wrote: ↑

30 Mar 2020, 00:01

GE’s H class gas turbine has >61% thermal efficiency https://www.ge.com/content/dam/gepower ... -oct15.pdf. Guinness has it at 63.08%

That is a gas turbine plus a steam powerplant heated by the turbine exhaust. (Combined cycle)

The gas turbine alone would be about 43%.

The total energy obtained from burning the fuel is the important bit. That it uses two devices doesn't alter the fact that they make use of 60+% of the available thermal energy released from the fuel.

There is another important bit. Somewhere around 53% TE is the highest number for any internal combustion heat engine (as claimed for the best marine diesels). F1 spark ignition engines are challenging that number which is an astonishing feat.

A combined cycle gas turbine is not an internal combustion engine. The gas turbine is - but the steam engine tacked onto the exhaust is an "external combustion" engine - combustion does not take place within the working fluid (the steam).

The highest efficiency for a commercially available external combustion engine is about 47% for ultra-super-critical steam power (a massive utility-scale heat engine).

gruntguru wrote: ↑

31 Mar 2020, 00:28

The GE H class mentioned by subcritical71 has a base TE of 43 point something % and a combined cycle efficiency of 63 point something %. I haven't heard of any gas turbine with 50% TE

Gruntguru, I hope you don’t take this as argumentative, I have just worked in this space for more years than I care to admit. But there is a Alstom unit in NJ that reaches 56% efficiency (GT24). This unit is simple cycle and doesn’t have a HRSG attached. I’ve actually worked on that project...once upon a time. This one is the highest I know of.

subcritical71 wrote: ↑

31 Mar 2020, 01:17

gruntguru wrote: ↑

31 Mar 2020, 00:28

The GE H class mentioned by subcritical71 has a base TE of 43 point something % and a combined cycle efficiency of 63 point something %. I haven't heard of any gas turbine with 50% TE

Gruntguru, I hope you don’t take this as argumentative, I have just worked in this space for more years than I care to admit. But there is a Alstom unit in NJ that reaches 56% efficiency (GT24). This unit is simple cycle and doesn’t have a HRSG attached. I’ve actually worked on that project...once upon a time. This one is the highest I know of.

Just because I haven't heard of a GT with 50% doesn't mean they don't exist - I was hoping someone would show me one! A link would have been good.

gruntguru wrote: ↑

31 Mar 2020, 03:57

subcritical71 wrote: ↑

31 Mar 2020, 01:17

gruntguru wrote: ↑

31 Mar 2020, 00:28

The GE H class mentioned by subcritical71 has a base TE of 43 point something % and a combined cycle efficiency of 63 point something %. I haven't heard of any gas turbine with 50% TE

Gruntguru, I hope you don’t take this as argumentative, I have just worked in this space for more years than I care to admit. But there is a Alstom unit in NJ that reaches 56% efficiency (GT24). This unit is simple cycle and doesn’t have a HRSG attached. I’ve actually worked on that project...once upon a time. This one is the highest I know of.

Just because I haven't heard of a GT with 50% doesn't mean they don't exist - I was hoping someone would show me one! A link would have been good.

Scroll down to 1997;
https://www.powermag.com/a-brief-histo ... urbines-2/