Heat pump driven by a mill wheel

[Pierre17800]

Hello everyone.
I have the project to use my waterfall (an old mill that I renovate) to train a compressor heat pump. I intend to capture the calories directly in the water to inject them into a low temperature heating floor (already realized)
I have on the shaft of the wheel a minimum of 5 CV (3,7 KW). The power can go up to 8KW (this winter with a lot of water).
The maximum winter losses of the house amount to 14 KW / h.
I am looking for advice (or solutions) to calculate the sizing of the compressor, evaporator and condenser. I have a friend who is equipped to make me 2 exchangers.
Thank you for your help.
Best regards. Pierre.

[bobono]

Here are two exchangers in fridge energy recovery that have worked for some ten years.

But why go through exchangers.



It is this system that works best no auxiliary pump no exchanger. Just a system for the return of oil and its function

It is easy to find pulley compressors in good condition.

The disadvantage with respect to the hermetic group is of course the leakage of gas by the pulley shaft

[Christophe]

The heat pump powered by renewable energy is really good! I hope for my part to test too but I'm far from having your potential power (0.5kW big max!)

Nothing prevents to drive a heat pump compressor with a direct mechanical coupling but ... for various reasons of reliability, speed of rotation and distance (it is harder to "transport" a mechanical torque than to electricity): I think that by going through a small generator of 5 to 10 kW you will be much quieter and you can especially use the electricity generated for something else and put an inverter motor thus optimizing consumption.

How did you estimate the power available?

[Pierre17800]

thank you for these first contributions.
BOBONO, I can not read your diagram: a pity because if there is an even simpler solution I am a taker. If you can send it to me by any other means ... thank you.
CHRISTOPHE, The waterfall is in the house. I do not have a problem of distance: the collector of the underfloor heating is less than a meter! I can install everything in a radius of 2m max.
I already have a generator 22O volts TRI but considering the losses generated by the multiplier of speed and the output of the generator I lose about 20 with 30% of power. In addition I want to do heating because regulators to get 220 V 50 hz are very expensive.

[chatelot16]

why exchanger?

theoretically the efficiency will be better by directly condensing the refrigerating gas in the heating plaster: but it would be necessary that this floor is absolutely perfectly sealed, otherwise pollution by loss of expensive gas is sweltering

to avoid costly gases my favorite is propane, called R290 by the heat pump dealer not to scare: the exchanger is essential not to drag fuel gas everywhere

for the refrigeration system this R290 is the most efficient of all the gases: even better than the currently prohibited R22 freon

it has an additional advantage: it is compatible with ordinary steel: there is no need to make copper exchangers

[Other]

Hello

to avoid costly gases my favorite is propane, called R290 by the heat pump dealer not to scare: the exchanger is essential not to drag fuel gas everywhere

Many years ago I had tests with an old system 12 freon and hermetic compressor I put propane, the winding of the engine did not resist this gas, although the system was functional malgrés the danger of the risk of leakage in the evaporator, (it was experimental in the open air outside)

Probably a system with external driven compressor and external Antifreeze liquid exchangers should be functional
I'm just wondering the tightness of the compressor resists it to propane?
Because the option of propane interests me, freons are a sinecure to get (some speaks of a mix of butane?)

Andre

[bobono]

Do not forget the CO 2 GAS can be expensive and abundantly available in beer merchants.

[chatelot16]

the R12 freon must be replaced by R600a which is isobutane: it operates at a lower pressure than the R290 propane

it may have been the exessive pressure that demanded more power from the engine that killed your engine

I do not worry too much about the rotating joint: even for the freon the shaft seal is entirely metalic: it is a metal bellows that allows the displacement of one of the parts of the joint

[chatelot16]

Do not forget the CO 2 GAS can be expensive and abundantly available in beer merchants.

the problem is that the CO2 works at a higher temperature so we can not use the current refrigerant compressor: the pipes must be much thicker

[Surfeurseb]

And why not an oil pump, with "shearing" of the oil?
On industrial machines with hydraulic unit, the oil is heated up to its operating temperature thanks to this.
The principle is to pass the oil in an auxiliary circuit or there is an important restriction, of or auto-heating.
Then oil water exchanger, and voila

Well in fact it may not be the simplest (so not the most econological ), but this has the advantage of directly transforming mechanical energy into thermal energy.