Liquid nitrogen generator engine

[Eric DUPONT]

the thermodynamic cycle is 100% reversible. the heat is evacuated during the compression towards the ambient environment then recovered during the expansion.

[Eric DUPONT]

It makes energy at 35 euros per MWh, a little cheaper than the old nuclear power plant of EDF

[GuyGadeboisTheBack]

It makes energy at 35 euros per MWh, a little cheaper than the old nuclear power plants of EDF

So much less expensive if we add the astronomical costs of dismantling.

[Remundo]

On paper.

the photovoltaic kWh has long been the most economical.

on the other hand, its intermittence makes it delicate. If we had inexpensive storage with sufficient yield, there would no longer be any need to resort to nuclear or coal.

[sicetaitsimple]

It makes energy at 35 euros per MWh, a little cheaper than the old nuclear power plant of EDF

Yes, that's it ... 35 € / MWh ... Can you explain it to us?

[Eric DUPONT]

it's written on the roadmap of my cofunding campaign, have you seen it?

[moinsdewatt]

it's written on the roadmap of my cofunding campaign, have you seen it?

Here the gogos .......

[Remundo]

I was thinking about the maximum yield that can be expected to liquefy 1 kg of nitrogen under atmospheric pressure.

Need for "frigories"

1) Nitrogen must be brought from ambient temperature Tamb = 20 ° C to that of vaporization Tvap = -200 ° C
Q1 = mx cp x (Tamb - Tvap) = 1 x 1042 J / K / kg x 220 ° C = 229 240 J

2) then it is necessary to liquefy the nitrogen:
Q2 = mx Lvap = 1 x 199 180 J / kg = 199 180 J

We are therefore around QF = 428 J / kg, say 420 J / kg

If we did this with an ideal refrigeration machine, the refrigeration efficiency would be TF / (TC-TF) = 73 ° K / (293 ° K-73 ° K) = 0.333

QF / W = 0.333 => W = QF / 0.333 = 3 x QF = 1 J / kg of liquefied N290 for mechanical work to be provided (that's around 000 kWh)

[Remundo]

after this volume of liquid nitrogen, by returning to the gaseous state, can theoretically provide a mechanical work P x (Vgaz-Vliq) by vaporizing under 1 Bar

by neglecting the volume of the liquid, the gaseous nitrogen has a mass volume Vm = RT / MP

hence Wdetension = mx P x RT / MP = m RT / M = 1 kg x 8.314 J / K / mol x 293 ° K / 0.028 kg / mol = 87 J

it is meager compared to the energy involved for liquefaction (around 7%)

my assumptions are simplistic.

[Bardal]

OKAY. But in what way is this "machine" not a dithermal machine, the hot source being the atmosphere (ie approximately 290 ° k) and the cold source liquid nitrogen (ie approximately 80 ° k); what difference do you make with a steam engine (hot source around 400 ° k and cold source around 290 ° k)?

For me, the only difference is that the cold source is artificially created (which implies an expenditure of additional energy), and that this cold source is closer to 0 ° k, which increases Carnot's efficiency at the cost of difficulties. important techniques related to cryogenic problems (heat exchangers easily iced by atmospheric water and carbon dioxide, in particular).

Concretely, this assembly has almost no chance of working, and if it does, it will be with a yield very little higher than 0, and with incredible complexity. Intermediate storage of heat fluxes by something other than the atmosphere would improve things a little, but not in a decisive way.

It seems to me a complicated rehash of supernumerary engines, accompanied by improbable "economic" considerations on the cost of photovoltaics and energy storage.