Engine testing

[Andre Blanchard]

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2005/session6/2005_deer_vuk.pdf

Check out page 18 and tell me if it would be fun to have that setup with a Lister.

[aqmxv]

I've been trying to come up with a reasonably efficiient way to get the rest of the kinetic and pressure energy out of the exhaust on a listeroid.  The problem is that one cylinder at 600 rpm, or even two cylinders at 1000 RPM isn't going to deliver a very even flow of gas, which is what turbines like to have as an input.

My best guess right now is a big two-vane pneumatic motor made of materials that can stand being breathed on by a lister (probably mostly cast iron).  The idea is that the displacement of one vane through one revolution should equal the total volume of what comes out of the lister in one exhaust stroke.  The vane motor then runs synchronous with the listeroid, and you couple it to a generator or some other shaft load.  The good news is that diesel soot should make a decent lubricant - the environment is relatively mild compared to a wankel engine, for instance.

Given the numbers I've seen, you're not going to get a lot of power out of it.  I was actually thinking of it as a dynamic muffler that would also run a water pump or PM generator for starting battery charging.  Now if your energy recovery is pretty good, there's no reason you couldn't run a vane supercharger on the shaft and make a synchronous pulse turbo.

I've seen one of the turbo-compounded Wright airplane engines mentioned in the forward of that PDF.  The "power recovery turbine" was popularly known as a "parts recovery turbine" by mechanics of the day.  It was the last gasp of high tech recip aircraft engine design before jets came along and changed the rules.

[GuyFawkes]

I've been trying to come up with a reasonably efficiient way to get the rest of the kinetic and pressure energy out of the exhaust on a listeroid.  The problem is that one cylinder at 600 rpm, or even two cylinders at 1000 RPM isn't going to deliver a very even flow of gas, which is what turbines like to have as an input.

not really, turbines are heat energy, turbos etc work on the heat in the exhaust gas, not the pulses of exhaust gas, pulses from a single make it more wakward to turbo, but at fixed rpm on a stationary engine it is EASY cured with a small plenum chamber.

You real problem is that there isn't a lot of heat energy in a lister exhaust to work with, if you work with the 3 x 1/3rd splits as traditional, one third of fuel energy goes to work, one third to exhaust, one third to other forms of thermal rejection, you come back to the physics I mentioned in the other thread.

a thousand bucks gets you a listeroid 6/1 that converts 1/3 of fuel into work, so unless your exhaust gas power reclamation system is 100% efficient and costs 1000 bucks, you are on a loser.

if your exhaust gas power reclamation system is 25% efficient, which is going to be HARD to achieve, it better cost 250 bucks or it works out a worse deal than the listeroid itself.

if it is 25% efficient and costs 2000 bucks, which is going to be more like real world figures, you are into the land of diminishing returns, the next 25% of efficiency will likely cost you 10,000 bucks, and so on........

at 4 hours to the gallon for a 6/1 if you run 12 hours a day 365 days a year you will burn 1460 gallons in a year.

A if 1/3rd of the fuel energy goes out the exhaust pipe that is 487 gallons, if you get 25% of that energy back that is 121 gallons worth, if you spend a very conservative 2000 bucks capital investment only (no ongoing maintenance and repairs) on that system then you are spending 16 bucks 50 a gallon, the next 25% works out at 80 bucks a gallon.

So UNTIL your fuel costs you 16 bucks a gallon or 80 bucks a gallon it ain't worth it on money alone.

================================

As others have done, apart from the carbon monixide problem, stick it in the basement and run plenty of ducting as passive radiators for the exhaust before exiting outisde and you'll recover a lot more useful heat, minimal maintenance or things to go wrong, minimal expense.

So if it is an economy drive and not a financial drive, this is the way to go.

see fiat economy thread for a new comment on this.

[Guy_Incognito]

Hmmm. I wonder how a rankine-cycle (that is, steam) engine would go off the waste exhaust? Not for anything real serious - as Guy_F's pointed out, there's not a great deal of energy that you could easily extract -  more of just a shits'n'giggles thing.

You'd need a small feedpump to keep the boiler full of liquid, but you've got an engine already whirring away there....
You could run a little turbine, or a more traditional reciprocating setup to extract power from the vapour under pressure.
For those in colder climes, you could then direct the spent vapour around the place to condense it back down to liquid which returns to the boiler via the feedpump. Or you could just place the condensor in a central heating duct if you've got one nearby. Or use all that extra power you've just reclaimed to drive a fan for the condensor. 

If nothing else , it'd make an interesting talking point.

On a slightly different topic, I was looking at building an ammonia-salt cycle refrigerator. Relatively easy to construct, and the waste exhaust heat would be/should be good to drive the system along. Google for "crosley icyball" for an idea of the setup. If you cook off the ammonia out of the salt by running the genny for 8 hours a day, you could then use it in a coldbox (or an electric freezer that normally runs off the genset) for the other 16 hours when the genny's off. There's some good home-brew designs with check valves and correct orifices ,etc to make the refrigeration cycle work pretty well.