Review (distorted) on heat pumps and refrigerators machinery

[Other]

Hello, Bolt

and it's like diesel engines, if they are used unless the full load their efficiency decreases again

You slipped a shell to find out if the reader of the forum sleep?

On a diesel
Contrary to what happens in the explosion engine, the efficiency is better at low load than at full power.
The specific consumption therefore decreases with the speed up to a speed or the friction taking a greater relative imporance, make it increase.
this is one of the reasons that the panton on a diesel does not perform well at low speed, the reactor has its significance where the diesel enters its poor performance .. strong injection poor combustion ..
and that gave us the false impression that it is only the
lack of heat, that I learned by comparison on the petrol engine ..

Regarding pumping in a hollow well it is true provided you make a hermetic loop of liquid which is exchanged in the depths
When I made my first wells for the heat pump, I thought of the same thing pumping water into the tablecloth at 4 meters and discharging it into the tablecloth at 20 meters after working like a savage to sink along tube when I started pumping at 4 meters was easy but the discharge at 20 meters was more painful than pumping (nature of the sand or layer that does not communicate? But I had to give up this idea of ​​easy pumping or of water transfer from an upper table to a lower table, it was beautiful on paper this principle of communicating vases.
The least energy-consuming pumps are the old DURO piston pump with a 1/4 hp motor. It pumps the same volume as a good 1/2 hp centrifugal pump but there is more maintenance.
Certain centrifugal pump for wells deeper than 7 meters, we lower a venturi and with water, we accelerate that of the bottom, to the detriment of the flow.

Andre

[Philippe Schutt]

Like what we are lucky in Alsace, the water is about 4 meters away, in a soil composed mainly of gravel. you have to pump a lot to get the level down significantly. Despite this, PACs are still rare, they are just beginning to be known!

[Capt_Maloche]

If you re-inject the water at the same depth as you pumped it, and your pipes are large enough not to have too much pressure drop, the consumption of your pump should not be very bad ...

See therefore, what heat pump capacity can we rotate with eg 3 m3 / h at 11 ° C start
or 3 m3 / h at 17 ° C flow

what do you think Capt_Maloche?

bolt

Answer for Philippe: this would be true for wells less than 9m deep, otherwise large power.

Answer for Bolt: 11 ° C leaving well water?
In heating mode
3m3 / h = approx. 0.83 Kg / s
Consider an ideal evaporation temperature at + 7 ° C and a good COP of 4 for condensation at 35 ° C, i.e. a rejection temperature at the evaporator of + 3 ° C (thermostatic valve set to +3, risk of freezing in the circuit if lower)

With water at 11 ° C, P. Heating possible = 0.83x4.18x (11-3) = 27 KW allow 20KW
With water at 17 ° C, P. Heating possible = 0.83x4.18x (17-3) = 48 KW allow 35KW

here, there, I hope I answered your question, friend

[bolt]

Thank Capt_Maloche

So in the first case (11 ° C), we have 20 kw / COP 4 = 5 kw for the compressor
+ a water pump of 0,37 kw (approximately 3 m3 / h at 2,5 bar) = 5,37 kw
The COP of 4 becomes: 20 / 5.37 = 3,72
It drops by 7%: it's a shame but reasonable, and you can pump up to a small 25 m., Even a small 35 m. deep with re-aspiration in a 2nd borehole (not too close, the latter, so as not to cool the sample water, by the way, how far should the 2nd borehole be so as not to lower the T ° of the borehole by sampling of more than, say 0,5 ° C, after a long winter, if e.g. the water from the aquifer would flow in the opposite direction (from the 2nd to the first)?)

Like what we are lucky in Alsace, the water is about 4 meters away, in a soil composed mainly of gravel. you have to pump a lot to get the level down significantly.

this is true, but in this case, you must find a suitable pump with the best performance for the given flow and pressure: difficult to find as standard

perhaps the PAC constuctors offer

or see André's suggestion: piston pump
or even a piston piston pump like a sprayer, but designed for very low pressures

You slipped a shell to find out if the reader of the forum sleep?

On a diesel
Contrary to what happens in the explosion engine, the efficiency is better at low load than at full power.
The specific consumption therefore decreases with the speed up to a speed or the friction taking a greater relative imporance, make it increase.

Is it not you who wants to check whether the readers of forum sleep

The efficiency (specific consumption) (quantity of fuel required for a given job) of a diesel engine is always better the closer you get to the maximum load and at the same time not too high a diet often we say the maximum torque regime

You must have already seen this:
Remember: the dung horses (you have to make them work so as not to waste)

https://www.econologie.com/forums/public2/essaiconsojd4255.xls

especially not at low load

[MBenoit]

For that he is right, that says an electric heater with consumes 5 times less than an electric heater so it's more advantageous ...

... can hardly be altarpiece given the investment ... That said if it allows to save energy I do not see why it would be scandalous to tax it

This saves energy, ... I don't really think it does that much:

In fact, the majority of electricity production in France comes from nuclear power. Reactor efficiency is around 30%
Calculation for a heat pump with a COP of 3:
1 kWh of thermal power delivered by nuclear fuel
0,3kwh is recovered in electricity and consumed by the heat pump
The heat pump recovers 0,3 kWh x 3 = 0,9 kWh of thermal power

Economy = negative !! and again, I do not count the losses due to the transport of electricity which are far from being negligible.

To have an economy, you would need a COP of at least 4, and again, if we take into account the lifetime of the heat pump (10 years, some speak of 15a), therefore the energy it takes to manufacture and transport the product ...

The heat pump therefore increases the efficiency of an electric heating installation ... but it is far from being the ideal solution.

To be compared to the best gas or wood boilers which show yields of more than 90%

[Capt_Maloche]

A CAP is very good, but it is very expensive

the concern is that the investment will not be profitable until the energy is even more expensive, but I feel that it comes