Hi to all.

I stumbled across Tomwol’s post “compressor for wind powered heat pump”, and found it to be very interesting. I too am not refrigeration professional, but hope that some of you will take the time to share your expertise.
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Here’s my situation: I want to use heat stored in a thermal mass ( outdoor wood furnace – possibly some solar ) to expand a refrigerant which will be converted into mechanical energy by means of a turbine or expander to drive an alternator and generate electricity.
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Based on the availability and cost of materials I’m looking at the following, and have added my thoughts about them:>
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Automotive turbocharger – lubrication, leakage, lack of torque at lower rpm’s ?>>
Automotive air conditioner scroll compressor ( from a big car) run backwards as an expander – may be able to use its clutch to engage / disengage & can use multiple expanders as needed, lubrication ?>>
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Ammonia – cheap, potentially dangerous, corrosive>
R134 – expensive>
Butane or propane – less expensive, potentially dangerous>
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Heat source – storage mass from wood furnace: 55 – 100+ deg C>
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Condensing (possibly ambient air in winter) >
Probably water from a shallow well: 10 – 18 deg C >>
Output – hopefully 3000 – 4000 KVA >
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I hope that by making a fairly compact system I can keep refrigerant safety considerations and costs to a minimum. The cooling water may need to be pumped to the condenser. >
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I’m sorry for being so vague. At this point I’m hoping to get some advice, and constructive criticism to point me in the right direction. At some point I will need to buy some (hopefully) good used components, and start testing. >
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Thank you in advance for any assistance.>
Pete>
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