A generator which uses wood as a fuel

150 watt net output achieved

Hi monkeys,

The latest news is i have achieved a 150 watt net electrical output from my ORC heat engine.

I'll now be looking to build an engine capable of outputing about 1kWe. I've already identified a load of the parts i'll need so i will hopefully get it under way fairly soon.

I will be experimenting with non flammable R134A refrigerant as an alternative to Butane which will hopefully make the eninge more suitable for indoor domestic use.

I will probaly step the next system up to use 24 or even 48Volts.

You guys got any suggestions for useful features of a 1kWe system? What would you like to see?

Stu.

 

More power captain

I squeezed 190 watts net out of the old girl today.

I have now piped it into the gas boiler so i can get a steady heat delivery, I will add a watt/hr meter to the boiler to tell me its electrical consumption, the meter was donated by a pal of mine. I will then wire the ORC unit into the boiler so it can sustain the boiler.

The max flow temp of my gas boiler is about 75 degrees c, so my system is putting out more power at a lower temp than initially planned for. A UK biomass boiler runs a little hotter at about 80 - 85 Degrees C.

So far i've had the system charging itself from an input temp of 60 derees C, so it is performing better over a wider source temperature than i had expected.

I hope to setup a biomass/solar system delivering about 120 degrees c, that way i can hopefully extract more power from the vapour. The temperature drop over the expander is currently about 15 degrees C, so if i raise the temperature of the heat transfer fluid to 120 Degrees C i should be able to add another expander which will give a lot more power while still allowing the use of a recuperator.

It is fairly clear that microORC can be useful, but it has some limitations. The best domestic locations for this type of system would be the following climates:

Equatorial Islands with a dependable source of heat from the sun and cooling from the sea. Eg, Caribean, Belize, Mauritus, Seyshelles, Fiji, Mediterranean.

Temperate regions with a waste source of biomass or heat and a heat sink such as a lake or stream allowing for a large temoerature difference between boiler flow and condenser flow.

Solar would be the optimum use for this system but i reckon an off grid wood gasifier supplying waste heat to the ORC engine would be a close competitor.

i'm a good few hundred quid short of building a decent gasifier but from what i've seen they give a large amount of waste heat. If that heat could be recuperated into an ORC to give more electrical output it must be a good idea?

Stu.