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Replying to Understanding the 2012 Buick LaCrosse with eAssist System


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Posted Yesterday, 10:28 PM

Sounds like the turbo steamer (if it works financially to be mass produced) could net a substantial gain to all vehicles.  It could be one of those pieces of technology that everyone begins to use if it really can capture as much waste heat as BMW's claims would have us believe.  In conjunction with a mild hybrid system we could potentially see some pretty substantial gains in both city and highway mileage in the future.  Definitely good news!

 

The turbosteamer is designed to capture wasteheat from the exhaust and coolant and transform it into usable energy.  Water injection is designed to cool the intake charge to prevent detonation and allow for higher compression ratios in the engine.  I think someone has proposed an engine that has an extra "water cycle" where water is injected after the exhaust stroke to be turned to steam to convert waste heat into mechanical work, but that would require a decent sized water tank.  A lot of guys use water/methanol injection on their diesels to keep their EGTs down, but some of those systems really use an incredible amount of water/methanol.  I think some inject over 10% water/methanol mixture v/v with diesel into the air charge.  Since most guys use the windshield reservoir for this its a huge pain since it can get emptied pretty darn fast.  If diesels had gone the route of water/methanol injection instead of urea injection to control Nox diesels would be more efficient, have more power, and would have cleaner valves.  Bummer on that one.  If a good set of tuners comes along for Chrysler's ecodiesel that allows the SCR to be shut off and a kit created to use the urea tank for water/methanol injection I would buy one in a heartbeat.


Posted Yesterday, 02:29 PM

yeah, not at all the same as the BMW concept.


Posted Yesterday, 02:05 PM

I remember most of them were in a plate you put under the carburetor and it misted or sprayed water very finely with the fuel so it got sucked down the engine to make the fuel more efficient. Yet it seemed to have issues around specific RPM if memory serves me correct.


Posted Yesterday, 01:03 PM

I think that is a different type of system than what BMW did with the Turbo Steamer.


Posted Yesterday, 12:13 PM

 

What about the BMW Turbo-Steamer that boiled water off the exhaust heat to run.... something?

 

I wonder how much water a system like that would consume?  I guess in theory one could make a closed loop system where boiled water was then condensed and boiled again.  Heck, if a system like that was not used you could probably do away with the entire cooling system since you could just boil water directly from the engine heat as well as from the exhaust.  You would take all of that waste heat that gets dumped into the atmosphere and doing work with it.  I wonder if a water injection system, maybe with an extra couple of strokes could suck enough heat out of the engine to reduce or eliminate the cooling system. 

 

Shame its so expensive to develop new car tech.  Lots of interesting ideas out there.

 

Water injections was a big deal in the late 70's I remember my dad and I trying a number of systems that came to market. But they never really panned out. Course we did not have the computers and the technology then to probably make it a reality. Something very well could work today.


Posted Yesterday, 10:14 AM

It's closed loop


Posted Yesterday, 09:23 AM

What about the BMW Turbo-Steamer that boiled water off the exhaust heat to run.... something?

 

I wonder how much water a system like that would consume?  I guess in theory one could make a closed loop system where boiled water was then condensed and boiled again.  Heck, if a system like that was not used you could probably do away with the entire cooling system since you could just boil water directly from the engine heat as well as from the exhaust.  You would take all of that waste heat that gets dumped into the atmosphere and doing work with it.  I wonder if a water injection system, maybe with an extra couple of strokes could suck enough heat out of the engine to reduce or eliminate the cooling system. 

 

Shame its so expensive to develop new car tech.  Lots of interesting ideas out there.


Posted 19 October 2014 - 08:39 PM

What about the BMW Turbo-Steamer that boiled water off the exhaust heat to run.... something?


Posted 17 October 2014 - 11:21 PM

Also, if its technically too difficult to use exhaust gasses to generate electricity directly, would it be possible to setup some of these hybrids with a smaller engine and small turbo and run a miller cycle?  Are the small turbos still too slow to spin up to be of use for a miller cycle engine?

 

With every manufacturer so anxious to turbo everything (allegedly for CAFE reasons) I have wondered why they don't switch to miller cycle engines.  They're already spending the money on forced induction and they would get better fuel economy out of the system.


Posted 17 October 2014 - 08:16 PM

 


This seems like a great idea, what kind of cost and weight is associated with a 300 lb ft electric motor?  With the fuel economy numbers being released for the mid size truck twins this week and the general underwhelming reaction by the internet at large I wonder what a system like this could do when plugged into trucks like that.  Big torque from the get go would work well, and with no torque converter losses and some regenerative braking I would have to think fuel economy would really out do what they're currently going for.  Has anyone made a commercial alternator or generator that can run off of the exhaust stream?  If possible to implement it would seem like a good fit if the industry is going to keep heading towards electrification of vehicles.

 

 

(1) The weight will be significant, but not so much from the motor as from the battery itself. A 70hp motor itself will be in the order of 70~80 lbs, a battery powerful enough and which stores enough charge to support a 70hp motor however will be on the order of 200~400 lbs. Still that is about what the Prius lugs around and it will not offset the gains from regenerative braking and subsequent motor assist.

 

(2) There isn't much "steam" in the exhaust. Certainly not enough to drive anything. However, there is plenty of heat and plenty of pressurized gas. Another source of "free" power is to use half a turbocharger -- just the turbine section without the compressor -- to drive a generator. This way, the normally wasted energy in the exhaust is converted (at least in part) to electricity. The problem with that is that it is much more of an engineering challenge. Turbos run at up to 100,000~150,000 rpm. Generators generally don't work well at such high frequencies, meaning you have to gear it down to maybe 1/10th or 1/20th of that rotation speed. It's a similar challenge as say Pratt & Whintey faces in commercializing the Geared Turbofan except it is actually worse because the reduction ratio is much greater. Alternatively you can simply work with a very high frequency AC source... that's another challenge by itself (efficiencies aside).

 

 

What kind of duty cycle can these electric motors handle?  Would they be capable of putting out max torque output over and over in a short time, say while towing/hauling through a town with a stretch of lights, or would they begin to overheat?  Is there a need to liquid cool a large enough electric motor when integrated in with the transmission?  I still think a setup like this would seem (at least on paper) to have the biggest benefit in the new mid sized trucks.  The electric motor could give a huge boost to the low rpm area of the torque curve, and the mild hybrid setup could essentially use wasted brake energy to remove the parasitic drain of the power steering pump, alternator, water pump, and torque converter - since all of those things would be electrified.  Could make stop/start systems work better too I suppose.


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