Review (distorted) on heat pumps and refrigerators machinery

[PITMIX]

hi Andrew
Very few people think to do a double use of water for heating and hot water. Especially since in reality a heat pump is stronger in winter than summer logically the cop is better in winter than in summer. Just because the heat returned to the condenser is the result of the thermodynamic cycle (condensation) and in addition evacuation of heat from the compressor (Joule effect mechanical and electrical). A heat pump heating 15kw produces only cold 12kW. In reccuperant part of the hot summer you do go the COP.
For your overheating problem with the exchangers should you doing you a secondary exchanger tube. A aerotherme. That you explain to your water exchanger is very logical it is a problem we have in the fridge facilities. Condenser heat accumulates and raises the temperature of the water. After several cycle the group cut HP. In older refrigerator plant we install cooling towers. These towers were used to evacuate the calories stored in water. At the top of the tower water spray or fog was very finely then flowed along a paroie reccupérée to be lower and return to the water condenser. This system was aboandonné because in case of poor maintenance could cause pollution of the air evironnant (Georges Pompidou hospital in Paris salmonellosis).
The advantage of this system is the significant power of heat removal in a rather restricted device, and no noisy and power-hungry ventilation system. These systems have been replaced by air heaters, which are like forced air condensers. More bulky and with a powerful fan, but the water remains in a closed circuit.
So much for your house you should try the aero turn. You doing a top 2m rectangular box by 1m wide with a spray ramp up a reccuperation tray down. Think treating the water regularly. Otherwise reccupère an old air condenser.
If your compressor is open type, you can equip it with a secondary pulley that would drive the helix of a condenser fan at a lower cost.

[Capt_Maloche]

Hello
I admit that the New fluids to obtain lower evaporation temperature pressure atmo in that a lower pressure in hp and thus a compressor that less force, but are t there a big difference to intensity absorbed to the compressor in this case?

not because more pressure is low in the aspi compressor, the less in mass flow, so less power in the system

The intensity absorbed depends essentially on the delta of pressure brought to the fluid, it is variable according to the fluids;
but it appears that the fluids whose evaporation temperature is low Pressure atmo offer better yields when employing them in the center of the Mollier diagram (to 0 ° C), says the new systems based CO2, pressure the circuit is 100 35 against Bar for R410

From what I have observed the conso a compressor varies in 10 20% following fluid loading.
So the machine moves from one cop to 4 4,8 Cop but is it still valid if we do not take into account only the compressor capacity but the entire system?

Yes, poor load is forcing the compressor is less troublesome when the circuit has a fluid reservoir bottle.

Even taking into account the peak hours being given that Pac are calculated as accurately as their elevé price high power, turning the latter longer than traditional boilers. The calculation is valid ??

Whatever the power of the CAP, COP remains the same at constant operating conditions (T ° evaporation and condensation), it is of course properly size the installation.
A PAC 5KW turn 2 times longer than 10KW cap to maintain the temperature of a network for example. (If the installation does not need more 5KW)

Bolt you trying to reinvent the perpetual motion machine !!!
This is the closed circuit principle take pleasure in fridges but unfortunately the energy reccuperé the pressure regulator how you never meant to allow trourner a compressor with enough force to compress the fluid.
It would have to invent the machine fridge that turns upside down.
A device that converts electric power fridge or mechanical energy.

Theoretically we can get some of that energy, but I do not see how to do it mechanically.

Stirling product of eletricity or a driving force but the hot condenser and the evaporator of the cold they would be enough to run a stirling coupled to a compressor fridge ???

What's the Stirling?

[Capt_Maloche]

Especially since in reality a heat pump is stronger in winter than summer logically the cop is better in winter than in summer. Just because the heat returned to the condenser is the result of the thermodynamic cycle (condensation) and in addition evacuation of heat from the compressor (Joule effect mechanical and electrical). A heat pump heating 15kw produces only cold 12kW. In reccuperant part of the hot summer you do go the COP.

Beware of ideas

The COP of a thermodynamic system (PAC or air conditioning) varies from 0,5 5 to as a condition of use. It is a bit better than in warm condition not to go too high temperature.

[bolt]

phase liquid only and the rate is relatively low compared to the gas phase
Although R410A a very high density in the gas phase, there will be around 40 10 ° C times less liquid phase flow.
It seems difficult to get some work connected with compressors that rotate 1500 and 3000tr / min.

goodnight Capt_Maloche
Therefore, the compressor, such as compression of an engine, reduces a large volume of gas (which is heated in amount in pressure)

while the regulator is working the same amount of gas (necessarily because it is a closed circuit), but already come in liquid form, as taken after the condenser

indeed, the volume flow is very different:
one raises the pressure, for example, to 3 bar, while the other lowers it by 3 bar (neglecting the pressure drops of the condenser, evaporator and supply lines)

talk about a difference of 10 compared with R410A
For water: one liter of liquid water 100 1800 ° C gives approx liters of water vapor

If we imagine rotation with water, the compressor would compress water vapor with a meter-1800 times the water flow after the condenser:

it is clear that there is not much energy to recover from the simple loss of load of this regulator (if I have drawn correctly): negligible flow

in this case: eg compressor 2 kw; loss of energy to the regulator 2 / 1800 1,1 = watt (say some LEDs)

Apparently not enough to make a perpetual motion machine, is not it PITMIX

If the ratio is 10 with R410A, there would still 200 W to recover, but how ?, and probably too expensive investment (Pelton wheel instead of the regulator)

bolt

[Capt_Maloche]

In fact, there is very exactly the same "work" or energy which is used to compress and to relax the fluid (except the pressure losses of the circuit)

it is the volume flow rates that change, gas compressor fluid to the regulator.

the regulator, the fluid passes immediately to high pressure to low pressure, the fluid not having enough energy to evaporate, remains in a liquid state and sees its temperature drop to the value corresponding to the low pressure ( example + 40 20 ° C bar ° C to -10 2bar, different according to each fluid, see diagrams corresponding Mollier)

The liquid flow rate is still much lower than the gas volume flow, despite the significant density of the refrigerant in the gaseous state

Difficult to create a system which would allow relaxation by providing mechanical work, without adding too many "calories" to the fluid

The bets are open ...

[bolt]

In fact, there is very exactly the same "work" or energy which is used to compress and to relax the fluid (except the pressure losses of the circuit)

I'm not so convinced anymore:
The compressor increases not only the pressure but also the T ° and the difference between the energy transmitted by the compressor relative to the holder comes from the fact that has a gaseous fluid at the compressor and liquid fluid at the valve :

the compressor compresses virtually more gas that does not arrive, since the compression of a gas increases its T °, ​​and when increasing the T ° of a gas, it increases its volume for a given pressure

For example, for a diesel engine, a compression of a compression ratio of 20 / 1 gives a pressure of 66 bar (theoretical adiabatic: no heat exchange) and 49 bar with heat exchange (à1000 rev / min) and 30 bar with heat exchange (only 100 r / min), but not 20 bar (note: in 0,01 r / min without leakage supposed to segments and therefore almost all the heat could have exchanged these 20 bar)

So, first, to exhaust the compressor was an energy 2 or 3 times the mere energy it would take to compress isothermal, but it will not reach the regulator, seen the cooling in the condenser

secondly, the gas is condensed to liquid (and here, here counts for a lot more than just gas cooling gas), it still pert lot of energy before reaching the regulator

in fact, it happens almost nothing in power in the expander, but if we could get it back, here diminurait COP

When you push the water through a pipe, there is always a loss, so warm

If the regulator was replaced by a hydraulic motor, the liquid would spend would warm much less than in an expansion valve (which only depressurize without palpable expansion fluid therefrom) this liquid so arrive a little colder in the evaporator (thus would capture more calories) and the hydraulic motor could give a little hand to the compressor motor

the regulator, the fluid passes immediately to high pressure to low pressure, the fluid not having enough energy to evaporate, remains in a liquid state and sees its temperature drop to the value corresponding to the low pressure ( example + 40 20 ° C bar ° C to -10 2bar, different according to each fluid, see diagrams corresponding Mollier)

it is not when ironing in gaseous form that it cools (after the regulator)

bolt

[PITMIX]

Hello
For the stirling engine I made a post on it forum.
https://www.econologie.com/forums/moteur-stirling-t1244.html
This is an engine that can turn thanks to the warmth of the sun or the heat of a cigarette lighter. It uses hot and cold to turn. That is why I mention it.
Now I have trouble understanding how a compressor gets to shoot less intensity by turning to a diet 0 35 ° C ° C under 10-100 bars rather than 5-35 bars. Indeed the performance of a compressor is best if used in diet positive rather than negative for the same fluid because the volume swept higher in the first case, but here the pressure differences are enormous. And how much a system whose pipes resisted to such pressure?
It's true that I do not work in study office and I'm not used to working with the fridge diagram. So I think your word. Now I understand why the Carrefour store near my turns CO2. The maintenance guy are pissed to work with such pressures. Fortunately the network as a whole does not have as CO2 but uses a coolant.
Thank you for the information.

[Capt_Maloche]

Hello

Now I have trouble understanding how a compressor gets to shoot less intensity by turning to a diet 0 35 ° C ° C under 10-100 bars rather than 5-35 bars. .

It is rather the CO2 50 / 100 bars

[PITMIX]

Awesome !!!

[Capt_Maloche]

The pressure in the circuit is 3 times higher than traditional channels, but the compression ratio is only 2 !!

Hence an improved COP

To return to the proposal of Boulon, to recover mechanical energy to the regulator:
creating a mechanical stress (work), it necessarily creates a pressure drop
we can determine the amount of energy to recover from the Delta P and the fluid flow rate, on balance and after reflection, it is not so stupid !!

The Molier chart does not represent the mechanical energy of relaxation since the fluid does not change state (liquid = incompressible but just change the equilibrium state PxV / T ° = const) so for the refrigeration cylcle ( carnot cycle) delta enthalpy of the fluid = 0

But to achieve this relaxation, you have a mechanical force

Relaxation (pressure drop) is the result of a pressure drop (strong reduction in diameter) there to thus a permanent effort of moving fluid on the walls of the necked theoretically recoverable effort in a kind of displacement pump

To adjust the filling of the evaporator, the compressor clutch / pressure is magnetic and slippery
This would require that the evaporator is close to the compressor.

Who wants to start?