Hoverit14
Hoverit14 None
7/13/14 2:21 a.m.

Hi Grassrooters,

I have posted this here as I do intend to scratch build an engine. I have designed a compressed air engine that has integral regenerative braking. The design is entirely my own and an Australian Patent Application was lodged in 2003. I believe that my engine design has the lowest greenhouse emissions over it's life cycle of any engine design, better than batteries because a compressed air tank has a life cycle about 10 times longer, and compressed air has comparable energy densities to Batteries. There have been several others working on similar lines and the Koeningsegg effort in collaboration with Volvo and Lund University in Sweden is the closest design to mine (Google Compressed Air Cars,or look up Gizmag to learn more).

One thing I found on GSM that is really exiting for me is Russian's efforts to DIY an engine ecu. I will probably order his board at a later stage. I have plenty of other details to sort out first, finding fast acting solenoids is one. I intend to offer my engine design as 'open source' or 'freeware'. I have set out more details in a pdf document that I may attach here if there is interest. Meanwhile, the details of the engine cycle are in my website jude.idx.com.au and I have a post in the LocostUSA forum that is not seeing many views.

Just to prove some credentials as a GSMer I have attached a pic of my Alfa Sud Sprite on a track day at Catalina Racetrack,Katoomba, outside of Sydney; the other pic is of-course of the engine that I hope will send your ICE age engine to the scrap yard.

Looking forward to your comments,

Jude Fernandez

Trans_Maro
Trans_Maro UltraDork
7/13/14 10:19 a.m.

What are you using to compress the air?

Hoverit14 wrote: I believe that my engine design has the lowest greenhouse emissions over it's life cycle of any engine design, better than batteries because a compressed air tank has a life cycle about 10 times longer, and compressed air has comparable energy densities to Batteries.
Hoverit14
Hoverit14 New Reader
7/13/14 4:49 p.m.

UltraDork,

I have made calculations based on the energy used in powering a workshop compressor by electricity generated from coal power, wind power and solar. A better option for an initial charge is using an on-board electric motor to drive the FAE in compressor mode. This would ensure that the heat generated from the compression of the air is conserved as much as possible.

Not sure why the images I copied and pasted don't show.

Jude

SnowMongoose
SnowMongoose Dork
7/13/14 6:17 p.m.
Hoverit14 wrote: Not sure why the images I copied and pasted don't show.

These boards have an, er, 'interesting' system for presenting images.
AKA things that work on every other board won't show here.

Trans_Maro
Trans_Maro UltraDork
7/13/14 8:27 p.m.

Looking at your website, if you're planning on using a piston engine, you need to stop thinking about adopting principles from an internal combustion engine.

You'll gain more efficiency by applying steam engine principles to your design.

You need to think about double-acting pistons and multiple expansion cycles to get the most use out of the potential energy in your compressed air.

RossD
RossD PowerDork
7/14/14 11:07 a.m.

Your calculations say you'll get 62 miles (100km) for just under 6 hours of workshop compressor run time without regen, do you have any estimates for regen taking into account?

The 1000kg compressed air tank you mention is about 2200lbs. That's the weight of a NA Miata. What kind of vehicle are you anticipating this going into and will there be enough horsepower and torque to adequately propel the vehicle (and is this for your 62 mile range)?

Is there any volumetric efficiency to consider? With petrol engines there is, but I'm not sure if it's needed here, but if there is there will be a loss. Also consider a drivetrain loss for range calculations.

I'd say forget about the carbon footprint/green aspect at the moment and keep going at the calculations for getting a real vehicle moving. IE: Pick an actual, used, affordable vehicle with a known drag coefficient,frontal area, with tires with known rolling coefficients, and start doing some real life number crunching. Then when your numbers look good, go and get the vehicle.

Hoverit14
Hoverit14 New Reader
7/14/14 3:12 p.m.

UltraDork, I agree that double acting pistons would work well with my engine cycle. Not so sure about double or triple expansion engines, I just am not familiar with them. I will goggle research this up further.

Powerdork, That 1000kg or 2200lbs is a realistic estimate of the fuel weight for a one hour freeway journey. On a freeway ride there will be no regenerative braking energy. The rest of the car will have to be redesigned to accommodate this weight and volume, and also the large weight variance as the compressed air is used up. The table below should help

Energy Density
     of various fuels per. Wikipedia

Uranium 235 –   79,000,000 Mega Joules/Kilogram
Petrol          47.2 MJ/kg
Coal            24 MJ/Kg
Wood            16.2 MJ/Kg
Li-ion Battery      0.72 MJ/Kg
Compressed Air  0.5 MJ/Kg
Lead Acid Battery   0.1 MJ/Kg
wvumtnbkr
wvumtnbkr Dork
7/14/14 3:19 p.m.

Couple of points: First, the dork status is just that, a status. Their usernames are to the right of the dork status.

In this case, you are talking to Trans-Maro and RossD.

Next: Soooo, your ideal power source has 94.4X less power density than gas? Isnt that a pretty major hurdle to overcome?

May I ask what your first language is?

Thanks!

Rob R.

Trans_Maro
Trans_Maro UltraDork
7/16/14 12:59 a.m.

Where'd he go?

Why do these folks with great ideas vanish when people start asking questions?

Maybe he's working with the go3wheeler guy..

wearymicrobe
wearymicrobe SuperDork
7/16/14 1:28 p.m.
Trans_Maro wrote: Looking at your website, if you're planning on using a piston engine, you need to stop thinking about adopting principles from an internal combustion engine. You'll gain more efficiency by applying steam engine principles to your design. You need to think about double-acting pistons and multiple expansion cycles to get the most use out of the potential energy in your compressed air.

That's why you got a patent, pending pictures, most people are not using standard motors. Of all people FEDEX has a ton of this already patented along with regen braking that they are going to on their next gen trucks with the unltralight bodies. I would find it hard to believe that you could reach the efficiencies that they have with a traditional motor.

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