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Dolph1983
Hi, I'm running a project at the moment to build DIY heat engines and was hoping someone would have some ideas on sources of waste heat and applications for my machine?
Basically, a heat transfer fluid is supplied to the engine at about 80 degrees C, this fluid is heated by waste heat eg, solar heat or flue/exhaust gases. The engine works in a similar way to a steam engine (rankine cycle), however the water is replaced with refrigerant, so instead of generating steam it generates vapour at <100 degrees C.
The power cycle is called the 'Organic Rankine Cycle' and has been used for donkeys years in industry to recover and convert waste heat to electricity. I am trying to build a micro scale 1kWe unit for domestic use with biomass boilers and solar panels, but there are many other uses.
As a test bed i built a unit which can be piped into a gas boiler heating circuit to run it when the grid power goes down. So when power goes down the engine's battery supplies electricity to the gas boiler via a power inverter to get the boiler heated up. Then the boiler supplies some of its heat to the engine which generates enough electricity to sustain the boiler, recharge its battery and give a net output.
It's fairly easy to build and all the parts are available off the shelf, just needs some basic plumbing tools. I built it into an old washing machine housing!
Some photo's below show the test unit, it gives a shaft power of about 350 watts and a net electrical output of 190 watts. This one is just a baby, when it's fully grown it'll be giving a net output of 1kWe. The fully grown version will be housed in an old fridge freezer.
Stu.
Basically, a heat transfer fluid is supplied to the engine at about 80 degrees C, this fluid is heated by waste heat eg, solar heat or flue/exhaust gases. The engine works in a similar way to a steam engine (rankine cycle), however the water is replaced with refrigerant, so instead of generating steam it generates vapour at <100 degrees C.
The power cycle is called the 'Organic Rankine Cycle' and has been used for donkeys years in industry to recover and convert waste heat to electricity. I am trying to build a micro scale 1kWe unit for domestic use with biomass boilers and solar panels, but there are many other uses.
As a test bed i built a unit which can be piped into a gas boiler heating circuit to run it when the grid power goes down. So when power goes down the engine's battery supplies electricity to the gas boiler via a power inverter to get the boiler heated up. Then the boiler supplies some of its heat to the engine which generates enough electricity to sustain the boiler, recharge its battery and give a net output.
It's fairly easy to build and all the parts are available off the shelf, just needs some basic plumbing tools. I built it into an old washing machine housing!
Some photo's below show the test unit, it gives a shaft power of about 350 watts and a net electrical output of 190 watts. This one is just a baby, when it's fully grown it'll be giving a net output of 1kWe. The fully grown version will be housed in an old fridge freezer.
Stu.
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