Redundant heat pump

[dedeleco]

amusing:

It's far from the thermo courses ...

reread on econology all the posts on the air motor for the course of thermo or wikipedia with care !!!

[chatelot16]

when you want to compress a gas heating and harmful: if you press too much pressure in one stage it heats up a lot and consumes significant mechanical power to make a useless heat : So we share the compression in several floors to lose less heat energy in heat

In the end it is kif kif no?

That one compresses at once to 200 bars or on 5 stages, thermodynamically the heating is the same not? Only it will go up a lot less T ° shelves ...

It's far from the thermo courses ...

Easy to check with pv = mRT ...

mR = constant = pv / T

The staged compression is, I think, therefore more related to material resistance issues (structural and T °): the higher you compress, the smaller the piston is ...

it is not kif kif at all: when one compresses with a large number of stage perfectly cooled it produces a calorific energy, simply equal to the consumed mechanical energy:

perfectly cooled means that the heat produced is at room temperature, therefore without energy value as produced by an infinite COP heat pump:

so that the compressor has a large number of stages after the isothermal compressor and transforms all the mechanical energy into potential energy in the compressed air

if the compressor is badly cooled the amount of heat does not increase much but with the increase of temperature the energy cost of this heat increases, and the mechanical power necessary for the compressor increases

[Christophe]

Yes: I was talking "in theory" ... that is to say with a "perfect" cycle, perfect isothermal or adiabatic or other ... And in practice as nothing is perfect ...

Let's have fun bringing out the thermo formulas if you want ... I liked it at the time and I often "increased" the DS

[dedeleco]

Apparently the memory is fading !!

[Christophe]

Rooh is low!

Ben what do you want: I train too much on the internet: https://www.econologie.com/forums/internet-n ... 10992.html

Besides, you also quote a lot wiki ... proof that you go often ... wiki is the best stupid think that humanity has created

[dedeleco]

Internet is full of useful thermo formulas !!!
The websites and wikipedia share the knowledge of 7 billions of men, a great way of collective progress !!

It is not at all harmful to my memory which retains the key elements and landmarks so as not to be saturated by 7 billions of info !!

[Christophe]

So you "function" like me ...

isothrma: pv = cste
adiabatic: pv ^ gamma = cste

I remember it!

By cons the formula for the case of a real air compression must I find it ...

[dedeleco]

Not at all !!
I do not work with formulas, automatic, but with the principles that have allowed to discover them, historically, much more general and who are they, the guiding concepts much more difficult to discover !!! (sometimes a century of work of many).

The formulas with drawers are the fault of the French teaching, which makes that sticks even teachers with questions outside formulas!
Why the gamma with which assumptions is much more important.

I work with thermo physics, the same whether it is gases, liquids, springs, rubber, magnetic or electric fields, piezos, etc ...

A course to read and assimilate is that of Landau Lifschitz, old 50 years, which was the bible of many physicists!

[Alain G]

Hello.
I just read Hic's delusions about internal compression. Wire locked, since stupid, but that asks me a question a little silly too. I assume my ignorance!
The efficiency of a PAC falls with the increase of the temperature delta.
When the delta is big, would it be more profitable to create redundancy. A heat pump heats an external and isolated exchange zone while remaining in a delta with very good COP. For example, it goes from -10 to + 5 ° C. There, a second PAC will change from + 5 to + 20 ° C inside the house. Would the total consumption of the two PACs be higher or lower than that of a single machine filling the same delta with a very poor COP?
What is the buffer zone? A neutral room very well insulated and can store the heat mass. Or a direct interchange between the two PACs. Or a liquid tank ???

I'm waiting for your shots !!!

I mentioned a few times the effectiveness of such a system that is more powerful but it seems that it was relegated to oblivion!


Yes it is more effective!


And it exists commercially with ammonia freezers (-65c) that uses 2 exchange courses to get a differential of more than 100 degrees, as we want to make a lot of money by selling the pac's and well we limit ourselves to a very simple mono compressor system avoiding the secondary heat exchanger and the complexity of gas regulation!

[chatelot16]

if you compress very slowly in a well cooled piston or faster in a large number of different piston with good cooling between each you will be close to the isotherm

you will find the formula that gives the mechanical energy according to P1 V1 and P2 (no need of both P2 V2 since P1V1 = P2V2

it's a formula with a log (P1 / P2)

what is more difficult to find clearly because it is a simple equality without formula, is that the heat released is equal to this mechanical energy, that this heat is worthless, and that the same energy is stored in the pressurized air

I have already made this kind of explanation ... ca meriterai to make it a subject apart for not always start again: calculating compressor and engine with compressed air: and only computation not disgression on the cars