Just came across this. A company in Germany called DeVeTec is building reciprocating 'steam' engines to generate electricity from industrial waste heat. Their website is at
http://www.devetec.de/index.php/company
They call it a steam engine but instead of water they use ethanol as the working fluid. The engines are built on the short blocks of diesels (possibly Deutz) in V8, 12 and 16 models with 133, 200 and 266 kW generators.
There's an introductory video at
https://www.youtube.com/watch?v=HUjAvWM1mUs Not much detail, but it looks like they are using the diesel engine pistons as crossheads and steam pistons in single acting mode. I'm guessing they are using this layout to seal the piston rods tightly against ethanol vapor leaking out of the cylinder.
There's an artistic video at
https://www.youtube.com/watch?v=cVKAtsL_QSs showing their facility. Fanciest industrial building I've ever seen, but the shots have been set up to hide the details of any parts they are making.
Here's a picture of the V8 engine with the valve covers off:
Pressure is on the outside of the head and exhaust is on the inside. Now here's what's odd: each cylinder only has one pushrod coming up from the camshaft in the engine V. Zoomed in to just the head:
It looks like one rocker arm per cylinder that's forked with two lash adjustment screws. The two valves are on the exhaust side of the head. I'm wondering if they are using a bump valve for admission and cam operated valves for exhaust.
Here's a presentation (in German)
http://www.izes.de/cms/upload/pdf/BMUB_Abwaermenutzung_Schmidt.pdf that shows a 200 kW unit in a 20 foot container. Page 8 has some numbers. Electricity production (Betriebsstunden) is 7000 hours per year. Initial cost is 820,000 Euros which is about $870,000. Life of the plant (Lebensdauer der Anlage) is 15 years. It was mentioned in one document the intial installation has been running since 2009, so maybe they have enough data to predict a 15 year life. 15 years times 7000 hours per year is 105,000 total running hours. Not bad.
Tim