Practical? Stirling engine applications

[RonT]

A couple of applications come to mind where I think a Stirling engine may be practical, here are a couple;
- a low power electrical generator built into a pellet stove, to power the pellet auger/feed system and electronic controls
- already mentioned here, a low power generator for use on a wood fire or wood stove while camping or at the cottage
- and my favourite, a variant of the Espar engine heaters ( http://www.espar.com/ ) which would be self powered instead of drawing battery power to run, heating the vehicle cooling system while providing a trickle charge to the vehicle battery. I'd like something like that for the winters where I live.
Now if someone would prototype one :-)
Ron, who is heading back to Yellowknife this weekend, and -30C temperatures :-(

[theropod2]

Pumping water. The old Rider-Ericcson engines were pretty good water pumps.

R

[RonT]

At least in the case of the engine heater, engine efficiency isn't as critical as waste heat isn't wasted but used to heat the vehicle engine coolant. The idea being that the vehicle engine coolant is heated as its circulated in the coolant jacket of the Stirling engine. Mechanical output of the engine is used to power a small electrical generator, the coolant pump, and if required the fuel pump. There are few moving parts and it shouldn't be very complicated.
Ron

[fullofhotair]

RonT,
That seems like a really good use of a stirling engine. I was just thinking why not use the stirling directly to pump the fluids? The stirling is good as an air mover, the fan works great as the flywheel. Example,fan heated on the woodstove. I read a while back someone was thinking about using the stirling engine as an electric hybrid. It seems to be a good match.The three big problems with using the stirling in a car are negated, low torque,unable to change load quickly and size.You dont need a large engine just to extend the battery charge up.

[fullofhotair]

Energy comes in several different forms. Whenever you change from one form to another you get great losses. Mechanical to electrical is really inefficient. These days you don’t need the electrical. You have thermal diodes, sensitive metallic thermostats and memory metals. Do you really need the electrical component? Valves and switches can all be mechanical. Wouldn’t this make your stirling heater concept simpler and more efficient?

[RonT]

You've lost me on some of the terms you've used, they're not familiar. Perhaps you're thinking of thermo-electric generators using the Seebeck effect. Using a Stirling engine and cycling the Stirling engine cooling water through the engine to me seems about the simplest mechanical way to pre-heat a liquid cooled internal combustion engine, and it wouldn't have to use any expensive components or processes and could have a very high mean time between failures.

I'm back in Yellowknife, at 8PM tonight its officially -35C. Yellowknife weather can be found at http://www.weatheroffice.gc.ca/city/pag ... ric_e.html
Its nice to back home, where I can sleep in my own warm bed at night.

Ron

[fullofhotair]

RonT;
The heat source ,the hot water , must be moved stopped and directed to the stirling engine .Once there it must be returned. How are these tasks carried out in the most efficient way? This is just another loop from the water pump. A thermostat is the gate. A heat pipe could also be used. They insulate themselves and carry heat many times better than copper or water .super simple device with low failure rate. A thermal diode is just a one way heat pipe. The Wiki reference below speaks of several different types of thermal diodes but Iam just referring to the one way heat pipe . Shape memory metal is an alternative to conventional actuators such as hydraulic, pneumatic and motor systems. It just gives you another way to use your heat and refrain from adding an electrical component. The hot obviously could be moved by the stirling engine flywheel fan. I just thought this was an option to having the stirling run an electrical generator. Ya, its pretty cold here too 62f with 90% humidity this morning but it will get up 81f by noon.
http://en.wikipedia.org/wiki/Shape-memory_alloy
http://en.wikipedia.org/wiki/Thermal_diode

[RonT]

Thanks for the info, I'd heard of the muscle wires before, but thermal diodes was new to me. To keep the engine preheater simple even basic convection flow of the coolant would work if the heater were placed below the engine, although a simple pump would help. The muscle wire could be used to regulate coolant flow and even fuel flow. At this point its beyond me to build one, but I could start with a basic Stirling engine, perhaps a kit, to get it running and go from there. Winter is good time to learn new things indoors as at this time of year we might have around 5 hours between sunrise and sunset, and on the colder days like today where the daytime temperature sat around -38C for a few hours, who wants to go outside.
Ron

[fullofhotair]

RonT;
Well good luck in your winter endeavors .Hope you come up with a good kit engine. Let us know if you do .I see a lot of people looking but not much finding.

[nwolf2000]

i think that supply submarine power is the most sucessful application for stirling engine,as we know by Kockums, and then maybe the solar power transfer engine and the micro-chp engine, however i think they both at the beginning, need lots of resources to develop them.Besides,small fpse maybe the potential of many kinds of application, of course nees plenty of energy to deserve it.
wish good luck in looking for changes of application.