I'm told the steam engine is the most mechanically efficient engine ever made

[sdifox]

Originally posted by: ADDAvenger

Originally posted by: Lonyo
We used to use steam engines on trains, then switched to diesel and then electric.
See a pattern?

actually the electric ones still burn diesel, but use electric motors for the actual locomotion. Apparantly it's more efficient to do it that way because electric motors give better torque, etc

Nope, plenty of trains run on third rail/overhead wires.

 

[yhelothar]

I'm thinking a modern steam engine would use some kind of electric power source to emit microwaves to heat up the water to create steam. But it's probably more efficient to just translate that electric energy directly to mechanical energy.

 

[sdifox]

Originally posted by: astroidea
I'm thinking a modern steam engine would use some kind of electric power source to emit microwaves to heat up the water to create steam. But it's probably more efficient to just translate that electric energy directly to mechanical energy.

How is that a steam engine and why would anyone be so convoluted?

 

[yhelothar]

Originally posted by: sdifox

Originally posted by: astroidea
I'm thinking a modern steam engine would use some kind of electric power source to emit microwaves to heat up the water to create steam. But it's probably more efficient to just translate that electric energy directly to mechanical energy.

How is that a steam engine?

Well the basis of the steam engine is to create energy through water vapor pressure?
The steam can be created in any way you could imagine and it'd still be a steam engine.

 

[yhelothar]

maybe we can harness the heat energy wasted by the combustion engine and use it for a steam engine on the side?
hybrid steam?

 

[Ruptga]

Originally posted by: sdifox

Originally posted by: ADDAvenger

Originally posted by: Lonyo
We used to use steam engines on trains, then switched to diesel and then electric.
See a pattern?

actually the electric ones still burn diesel, but use electric motors for the actual locomotion. Apparantly it's more efficient to do it that way because electric motors give better torque, etc

Nope, plenty of trains run on third rail/overhead wires.

I'm aware of that, but that's not what they use for freight trains, the heavy lifters. Well, not around here anyway, dunno about your neck of the woods

 

[sdifox]

Originally posted by: astroidea
maybe we can harness the heat energy wasted by the combustion engine and use it for a steam engine on the side?
hybrid steam?

Quite a bit of heat is wasted and we actually have to cool down the engine before it overheats. Wonder if we can do a hybrid car that run small conduits around the outside of the engine, pipe steam into turbine coupled with alternator to create electricity for the motor in the wheel.

 

[Mark R]

Originally posted by: JDub02

In a pressurized water reactor (PWR), the steam process is very efficient. The turbines are something like 97% efficient. The problem is nuclear->steam conversion.

LOL.

The heating efficiency of nuclear fission is nearly 100%, of which nearly 100% is delivered in the steam.

The problem is the steam to kinetic energy conversion in the turbine, which has an efficiency of only around 35% or so. The fundamental limit, as I alluded to earlier, is the Carnot efficiency. The 2nd law of thermodynamics places a fundamental limit on the efficiency of a heat engine (such as a steam turbine) which depends on the temperature of the steam and condensate. In the case of a nuke plant, a '100% efficient' turbine would only convert about 45% of the steam's energy into kinetic energy.

 

[JakwoW]

Originally posted by: ADDAvenger

Originally posted by: sdifox

Originally posted by: ADDAvenger

Originally posted by: Lonyo
We used to use steam engines on trains, then switched to diesel and then electric.
See a pattern?

actually the electric ones still burn diesel, but use electric motors for the actual locomotion. Apparantly it's more efficient to do it that way because electric motors give better torque, etc

Nope, plenty of trains run on third rail/overhead wires.

I'm aware of that, but that's not what they use for freight trains, the heavy lifters. Well, not around here anyway, dunno about your neck of the woods

This is standard for freight trains pretty much throughout the US.

EDIT: Added bolded words for clarification.

 

[sdifox]

Originally posted by: ADDAvenger

Originally posted by: sdifox

Originally posted by: ADDAvenger

Originally posted by: Lonyo
We used to use steam engines on trains, then switched to diesel and then electric.
See a pattern?

actually the electric ones still burn diesel, but use electric motors for the actual locomotion. Apparantly it's more efficient to do it that way because electric motors give better torque, etc

Nope, plenty of trains run on third rail/overhead wires.

I'm aware of that, but that's not what they use for freight trains, the heavy lifters. Well, not around here anyway, dunno about your neck of the woods

Electric locomotives are actually a lot more powerful than Diesel/Diesel electric. Problem with states is the lack of electrified rail network due to cost. Europe is basically all electric.

 

[LordMorpheus]

it's true that they are very efficient, that's why every fuel burning power plant in the world uses them to turn heat into mechanical work (coal, gas, oil, nuke).

However, the large turbines have to be carefully controlled to generate that kind of efficiency and would not be good for use in a car.

We're talking about the steam engine in terms of power plant use - giant boilers burning fuel to make high pressure steam, discharging through a turbine the size of your house to make mechanical work.

We aren't talking about an old steam locomotive. That is not high efficiency, and it is also very heavy.

The only modern moving objects that use steam turbines I can think of are various coal or nuke powered ships.

 

[sdifox]

Originally posted by: LordMorpheus
it's true that they are very efficient, that's why every fuel burning power plant in the world uses them to turn heat into mechanical work (coal, gas, oil, nuke).

However, the large turbines have to be carefully controlled to generate that kind of efficiency and would not be good for use in a car.

We're talking about the steam engine in terms of power plant use - giant boilers burning fuel to make high pressure steam, discharging through a turbine the size of your house to make mechanical work.

We aren't talking about an old steam locomotive. That is not high efficiency, and it is also very heavy.

The only modern moving objects that use steam turbines I can think of are various coal or nuke powered ships.

OP was talking about Double Expansion piston steam engine, not turbine.

 

[TastesLikeChicken]

Originally posted by: sdifox

Originally posted by: TastesLikeChicken

Originally posted by: sdifox

Originally posted by: TastesLikeChicken

Originally posted by: sdifox
wtf, steam engine is not efficient...

I think the key word that people are overlooking is "mechanically." For energy efficiency a steam engine is far from the best. For mechanical efficiency it's hard to beat simply because of its simplicity.

turbine beats piston any day of the week in terms of power conversion.

Only at high RPMs. A steam piston engine will kick the snot out of a turbine at low RPMs. That's why steam turbines were never really adapted for use in cars, trucks, or trains. Makes no sense to have a turbine spinning at thousands of RPMs while you're idling or going slow and you end up losing mechanical efficiency through the gearing/transmission that would be required.

We were talking about steam piston engine efficiency and not practical adaptation to automotive propulsion.

I was merely giving examples and reasoning why turbines have not been adopted for those types of vehicles. While turbines ARE more efficient at very high RPMs they are not at low RPMs, so the blanket statement that "turbines beat pistons any day of the week" doesn't really stand. That's the point I was making.

 

[sdifox]

Originally posted by: TastesLikeChicken

Originally posted by: sdifox

Originally posted by: TastesLikeChicken

Originally posted by: sdifox

Originally posted by: TastesLikeChicken

Originally posted by: sdifox
wtf, steam engine is not efficient...

I think the key word that people are overlooking is "mechanically." For energy efficiency a steam engine is far from the best. For mechanical efficiency it's hard to beat simply because of its simplicity.

turbine beats piston any day of the week in terms of power conversion.

Only at high RPMs. A steam piston engine will kick the snot out of a turbine at low RPMs. That's why steam turbines were never really adapted for use in cars, trucks, or trains. Makes no sense to have a turbine spinning at thousands of RPMs while you're idling or going slow and you end up losing mechanical efficiency through the gearing/transmission that would be required.

We were talking about steam piston engine efficiency and not practical adaptation to automotive propulsion.

I was merely giving examples and reasoning why turbines have not been adopted for those types of vehicles. While turbines ARE more efficient at very high RPMs they are not at low RPMs, so the blanket statement that "turbines beat pistons any day of the week" doesn't really stand. That's the point I was making.

But the op was talking about 2 piston compound steam engine being efficient and implementing that in a car, not a turbine. I was just taking exception at steam piston engine being considered efficient.

 

[torpid]

Originally posted by: JohnOfSheffield

Originally posted by: JohnOfSheffield
It's not even close to the efficiency of a normal ICE.

The most effective motor to date is the electrical engines.

You could build yourself a CO engine burning wood and using the CO in a combustion motor with some adjustments, that would be more efficient than any steam engine.

Originally posted by: JohnOfSheffield
Hydrogen is a better alternative and it's been in production for a few years by now, we need better production methods and storage for it though.

The Hindenburg somehow still lingers in the minds of some idiots.

Everything I've read to date, isn't even close to what you said. You have any links to back up the efficiency of ICE versus Steam? Did you know that hydrogen has the least amount of energy capability than any other fuel alternative, creating major disadvantages in storing enough for it to be useful?

Stop talking to yourself.