Stirling Engine as Ebike Power Source

[paultrafalgar]

Sterling Engine as Ebike Power Source
http://www.sunpower.com/lib/sitefiles/pdf/publications/Doc0094.pdf

"The high specific power (>90 W/kg) and high efficiency (>30%) of the convertor makes it attractive
for use as a fuel-fired battery replacement. This application is particularly promising because batteries have
extremely low energy density. Even lithium-ion batteries have an amazingly low energy density compared to liquid
fossil fuels; approximately 150 times less.
Thus even considering the efficiency of the convertor combined with a burner, the energy density of a fuel-fired
battery would be significantly greater (more than an order of magnitude) than that possible with batteries. Such a
devise can also be quickly refueled compared to the slow process of recharging batteries."

Imagine this device, mounted on a towed trailer and the dish steered in realtime to point at the sun. Connect the output to an ultracapacitor (and/or battery)on your ebike. Alternatively, station the solar sterling engine at home and charge your batteries. Use another such sterling engine heated by burning bioethanol on the ebike.

 

[gogo]

Temperature difference motors rock! Old satelite dish carcasses are plentiful...

Dogman, let the sun shine brother!

 

[paultrafalgar]

Thanks for posting the pic, gogo, I clean forgot to post it though I referred to it!
Edit:
... due to "little grey cells" drowned in too much biothanol!

 

[spinningmagnets]

I certainly want to encourage your enthusiasm. I have been studying Stirling engines for a couple of years, and there are two problems I see.

The size of the engine/generator you reference is impressively small. But I'm sure you can appreciate how expensive it must be (funded by NASA). Even with mass-production, engines of this type are notoriously expensive regardless of size, and they are produced in many sizes now that the configuration has been optimised.

The other problem is the heating and cooling. If NASA was building an extended range E-bike hybrid, I can imagine them using Propane as the heater fuel. Engines of this configuration typically use a water loop as the cooler, and some method must be employed to cool the water back down to a useable temp. Low-power Stirlings use aluminum fins and an air-fan for cooling, but for high power...

The alternator is a linear cycling magnet array inside a cylinder of stationary coils. A piston separates the alternator from the hot/cold gas which pushes/pulls the piston. The outer tip of the thin protrusion is the heated section, and its neck is the cooled section. Here's an animation:

http://commons.wikimedia.org/wiki/File:Animation_TDC_01_jeff.gif

Stirlings are large per watt produced, but a home-made Solar-heated Stirling can be a viable battery-charging generator for your home. practical questions can be answered at the Hot Air Engine Society (HAES) forum.

 

[paultrafalgar]

Thanks for the link to the animated gif. Marvellous!
With regard to cooling, youtube videos such as:
http://www.youtube.com/watch?v=fUrB7KRvxUk
show finned air-cooling. That video uses a solar-heated hot end at 1000 degrees plus, whereas the NASA pdf talks of 650 degrees for the hot side. I wonder if air-cooling with fins would be possible in a mobile application. They certainly suggest that the technology is applicable to mobile applications and I guess they mean situations other than space where zero kelvin is available on tap. Sunpower free-piston sterling engines are on the brink of commercial exploitation in CHP systems, so the cost can be reduced by mass-production to realistic levels. Just needs a mad inventor to meet a rich entrepreneur.

 

[spinningmagnets]

Paul, I am a big fan of Stirlings. Having a solar-tracking/fan-cooled gen is a clever idea, and could recharge your e-bike batteries while its parked ...but if an application needed propane for heat, a piston engine like a Honda 35cc would get you more watts per gallon.

In Canada and northern Europe there are several companies that make a complete unit about the size of a dishwashing machine that is a Combined Heat & Power (CHP). As a generator, they are very expensive per small watts produced. Rather, they are a home heating unit, that also happens to make a little electricity and hot water as a small side benfit.

You can imagine an apartment building or house that has a brutally cold 6-month winter. As a result it has a natural gas or propane central heating unit that runs for many hours a month. Germany and the Scandinavian countries especially are leaders in efficient heat-saving homes with triple-paned glass and thick walls.

Dean Kamen (Segway) recently added one of these small CHP Stirlings to an electric car sold in Scandinavia (Sweden, Finland, Norway) The winters are so cold, the car has a propane cabin heater/window-defroster, so the addition of the tiny Stirling extends the range of the EV a little. Also if the battery dies away from home, you just run the heater until the battery is charged enough to get you back.

Here's a list of companies that make a small CHP like the one posted: Infinia, Rinnai, ENATECH, MTS, Bosch-Thermotechnik, Microgen

Here's a list of significant Stirlings in many sizes and various configurations from the HAES forum:
http://f1.grp.yahoofs.com/v1/MA4sSmepx_9FTkxFTu88wC4103zDg_KXeVJAMUnYR6qJqf1anBgrwMrdvBZuU3bB455VNtiYvleSJ72abhAZJC4wj_Wi352g4RQ/Ron%20Roberts%20stuff/List%20of%20significant%20modern%20Stirling%20engines

 

[Miles]

There was a short write up on the development of a Stirling engine/generator range extender, by Andy Ross, in the proceedings of the 4th Velomobile seminar.
http://www.futurebike.ch/FB_Web_WM99/events/wm99/english/e_seminar.html

See also:
http://people.ohio.edu/urieli/Dragsters/Dizzy.html

 

[paultrafalgar]

...
Here's a list of significant Stirlings in many sizes and various configurations from the HAES forum:
http://f1.grp.yahoofs.com/v1/MA4sSmepx_9FTkxFTu88wC4103zDg_KXeVJAMUnYR6qJqf1anBgrwMrdvBZuU3bB455VNtiYvleSJ72abhAZJC4wj_Wi352g4RQ/Ron%20Roberts%20stuff/List%20of%20significant%20modern%20Stirling%20engines

I'm getting "Document not found" from that URL

 

[paultrafalgar]

There was a short write up on the development of a Stirling engine/generator range extender, by Andy Ross, in the proceedings of the 4th Velomobile seminar.
http://www.futurebike.ch/FB_Web_WM99/events/wm99/english/e_seminar.html

I'm getting the following from that link (N.B.) the "items above" don't work either):

File Not Found!

The IHPVA Site has been reorganized, please choose from the items above.

 

[Miles]

Hi Paul,

Yes, that webpage is 10 years old The proceedings aren't online, you have to buy the book...

Here's Israel Urieli's homepage:
http://www.ent.ohiou.edu/~urieli/

 

[spinningmagnets]

Looking back through the HAES archives, I'd occasionally see a certain engine referenced, as in "that idea might work, but X tried that, and here are the problems they ran into, and heres what they did to get it to work". Also, I found if you just have a good search term, its easier to find more info, so I compiled them.

The Rider (alpha) and Rider-Ericsson (beta) engines sold over 30,000 units before diesel and electric motors gained widespread use.

Paillard Maestrofoon grammophone (record player) made in Switzerland in the early years of the twentieth century, there is one in a vintage collection in Christchurch New Zealand, despite one web site saying they have the last remaining one

Water-pump BSR (Bomin Solar research) 10' diameter LTD Gamma
100W Saitama University, vertical 2-cyl Alpha
100W SFI Solar dish, mini-SES copy (Solar Space Frame Industrial)
100W SCM-81 SGE-Ecoboy (Suction Gas Engine) Beta
200W Philips MP1002CA (kerosene powered/air fan-cooled generator)
300W ST-05G (0.5-HP Gamma machinist copy of ST-5)
300W Saitama University, LTD Gamma
800W Genoa Stirling, inverted twin Gamma
800W Whispergen CHP 4-square cascading Gammas
1-kW SGE vertical coaxial 1-cyl Alpha
1-kW Baxi CHP
1-kW SPM CHP, 4 radial cascading Gammas (Stirling Power Module)
1-kW Saitama University, vertical Alpha
1-kW EG-1000 Sunpower, Beta
1-kW Norris Bomford small boat engine, vertical 3-cyl Beta's
1.8-kW Jim Dandy #6, 2-1/2 HP twin Gamma
3.0-kW Toshiba NS03T
3.0-kW GM GPU-3 (US Army Generator)
3.0-kW Joanneum, V2 Alpha
3.0-kW Disenco CHP
3.7-kW RHEP USAID, similar to ST-5, made with low tech
3.7-kW Lockwood, machinist copy of ST-5
3.7-kW ST-5 (Ohio, Stirling Technology 5-HP) Horizontal Beta
10-kW Solo Kleinmotoren V-160
10-kW SSPi Solar dish (Stirling Sun Power, international)
10-kW SBP Solar dish (Schlaich, Bergermann, und Partner)
25-kW SPDE,(MTI/Space Power Demonstration Engine)
25-kW Kockums 4-95 (submarine auxiliary generator)
25-kW USAB 4-95 (United Stirling AB)
25-kW SES 4-95 (Stirling Energy Systems)
25-kW STM 4-120 (Stirling Thermal Motors)
30-kW Joanneum, V2 Alpha
35-kW SD3-E CHP (Stirling Denmark)
55-kW STM-Power CHP
75-kW Kockums V4-275R (submarine main engine)
100-kW NASA, SPDE, SPRE, SP-100, HTSSE

Automobiles:
1964 Calvair, GM's modified Corvair. Only a prototype https://books.google.com.au/books?id=6dMDAAAAMBAJ&pg=PA34&dq=popular+mechanics+%22stirling-powered+car%22+calvair&hl=en&sa=X&ei=LxexUZCqNuuhigeX1IC4Bw&ved=0CDkQ6AEwAA#v=onepage&q=popular%20mechanics%20%22stirling-powered%20car%22%20calvair&f=false
1969 GM Stir-Lec Opel Kadett, stirling series-hybrid
1972 Ford, Pinto V4X31
1974 Ford, Taunus V4X35
1975 Ford, Gran Torino V4X1
1979 AMC Spirit, P-40
1982 Lundstrom Porsche V2X36
1985 NASA MOD-II, Chevrolet Celebrity
1987 ASE (Automotive Stirling Engine, US Air Force-SPVP Stirling Powered Van Program, MTI-Mechanical Technology Incorporated)
2007 Sweden, Precer Stirling hybrid
2008 DEKA Revolt, Kamen stirling heater/generator, series plug-in hybrid

"Under the Hood, Stirling Engine Vehicles (Photo Catalogue)"
http://stirlingengineforum.com/viewtopic.php?f=1&t=1618

 

[paultrafalgar]

Thanks for sharing, spinningmagnets. I think the 300W ST-05G (0.5-HP Gamma machinist copy of ST-5) looks about the right size for an ebike. Either parallel or series hybrid. 8NM torque and 600 rpm both seem useful figures. Rather a lot of unnecessary heat though.

 

[LockH]

Sterling pops up again. "San Antonio man has engine that gets 100 mpg" ... in San Antonio, Texas:
http://www.khou.com/features/san-antonino-man-has-engine-that-gets-100-mpg/242673922

"using a Stirling engine, coupled with thermopile"