Pompe de caldura cu vaporizare directa in sol

In cazul pompelor cu vaporizare (sau detenta) directa, agentul frigorific circula direct prin colectorul din pamant. Astfel nu este mai este necesara o pompa de recirculare a antigelului si nici schimbatorul de caldura dintre circuitul cu antigel si cel intern pompei, cu agent frigorific. Colectorul din pamant este in acest caz realizat din conducte din cupru perfect etanse, laminate, imbracate in material plastic.

https://www.bvc-roma...rizare-directa/

Pompe de căldură cu vaporizare directă în sol
Vaporizarea directă în sol – compromis ideal între eficiență ridicată și fiabilitate!
Este cel mai fiabil tip de pompă de căldură cu eficiență ridicată, apropiată de sistemele de pompe de căldura apă-apă. De ce?

https://pompedecaldu...directa-in-sol/

A direct exchange (DX) geothermal heat pump is a type of ground source heat pump in which refrigerant circulates through copper tubing placed in the ground unlike other ground source heat pumps where refrigerant is restricted to the heat pump itself with a secondary loop in the ground filled with a mixture of water and anti-freeze

https://en.wikipedia...ermal_heat_pump

Propanul mai are si problema ca e inflamabil/exploziv. Parca si ceva potential ca gaz cu efect de sera. Ca refrigerant probabil nu e o idee rea. Punctul de fierbere e mai jos decat va fi vreodata in pamant, si omenirea are in mod colectiv mai multa experienta cu transportul sau prin conducte decat cu orice alt gaz.

In laborator are sens, dar nu se folosesc in realitate pentru ca evaporatoarele ingropate nu sunt fiabile.

De unde ai vazut ca am instalat mai multe?  

exista pompe de caldura cu vaporizare directa care pot asigura o temperatura pe tur de max 35 gr C sau  max 55 gr C.

Cop Max la 55 gr C este  la 1:3,8
Cop Max la 35 gr C este  la 1:5,3 chiar 1:5,6 daca sunt temperaturi de vaporizare favorabile.

Poti utiliza calorifere de joasa temperatura care au o suprafata de radiatie mare (tur 35grade), sau calorifere uzuale (tur 55 grade)

Ar fi fost bine daca inaltimea camerelor ti-ar fi permis o ridicare a nivelului pardoselii cu min 8 cm, atunci puteai sa montezi o incalzire in pardoseala ca sa te bucuri de un COP mai bun   .
la 180 mp si 55grade  ai nevoie de o suprafata de excavat de 360 mp iar la 35grade de 300mp.

Cum stai cu apa freatica?

Passive cooling doesn't work with DV, and active cooling would probably be far too severe, resulting in massive clocking...

Hello Kurt,

your main arguments in your DV advertising are always the low earthworks and the particularly good COP of the devices you offer. In the following I would like to carry out a thermodynamic soil simulation for an exemplary DP design according to your recommendation and compare a horizontal ring trench collector in cooperation with the modulating Nibe 1255-6 with the same excavation volume.

Boundary conditions:
- DWD data from Lübeck-Blankensee from 5.2009 to 4.2010
- sandy soil with 12 m simulation depth
- house with 6 kW heating load at 10 degrees standard AT and 4 residents

DV parameters:
- 16 mx 10 mx 0.8 m collector
- Excavation volume 128 m³
- 3 copper pipese each 80 m long, 16 mm outer diameter and 0.8 mm thick PE sheathing
- COP at E2.5 = 4.8 (E4 does not work in the simulation)

Brine parameters:
- 82 x 1.25 x 1, 25 (optimized for little excavation volume, in reality it is better to be deeper, wider, longer)
- excavation volume 128 m³
- 2 PE-RC pipes , each 300 m long, 32 mm outside diameter and 3 mm thick pipe wall
- COP at B0 = 4.86
- Laminar design, since the WP modulates and fairly low brine temperatures occur. The

result is:
- lowest ground temperature: DV=-9.9 - brine=-3.4
- average weighted ground temperature: DV=0.1 - brine=2.5
- JAZ: DV=4.26 - Sole=4.66

As can be seen here, it makes no sense in this comparison to compare B0 with E4 - in practice we end up with B1.5 (here 1 degree temperature loss through the pipe wall) and E0.1. Thus, with your interpretation recommendations, the alleged COP advantage of the DV-WP sold by you would be gone. Please don't advertise with high COP and low excavation at the same time in the future, they don't go together.

Greetings
crink

https://www.haustech...Forum/p/2408188

https://www.haustech...stSort=1&page=2

Third finding: The advertising that Kurt produces here in the forum is not serious: promising an E4 COP and a mini collector at the same time does not go together.

Greetings
crink

Hello Franke,

let's compare the different pipe diameters and the resulting heat exchanger size. First Kurt with 240 m pipe with 16 mm diameter for 6.64 kW. That is then per kW heat output :

(0.016 * PI * 240) / 6.64 = 1.8 m²/kW

Then your described collector with 490 m for "almost 7 kW" heat output:

(0.01 * PI * 490) / 6.9 = 2.2 m²/kW

A stingy brine collector according to VDI 4640:

(0.025 * PI * 300) / 6 = 3.9 m²/kW

And a ring trench collector according to Forums type:

(0.032 * PI * 600) / 6 = 10.1 m²/kW Kind

regards
, crink

https://www.haustech...Forum/p/2408503

Now a few more simulations with the boundary parameters given above:

Possible VDI 4640 collector:
- 20 mx 12 m = 240 m² at a depth of 1.2 m
- excavation volume = 288 m³
- PE-RC pipe with 25 mm diameter (was common at the time when B0 was introduced) and 3 x 100 m
- Again the modulating Nibe with laminar flow
-> Lowest soil temp=-3.1
-> Mean weighted soil temp=2.4
-> JAZ=4.57

Kurt's DV trench collector as desired by Franke:
- 3 trenches, each 40 m long, 60 cm wide and 80 cm deep with a distance of 60 cm from each other
- Excavation volume = 57.6 m³
- Same DV pipe with 3 x 80 m
- Kurt's WP again with 6, 64kW
-> Lowest soil temperature=-9.9
-> Mean weighted soil temperature=0.2
-> JAZ=4.26

Now the same DV trench collector, but with twice the number of pipes (similar to those implemented by Franke, but still at a depth of 80 cm ):
- In practice, therefore, a single trench 40 m long, 3 m wide and 6 pipes back and forth, resulting in a pipe spacing of approx. 30 cm).
-> Lowest soil temperature=-8.45
-> Mean weighted soil temp=1
-> JAZ=4.44 (better, since the loss through the pipe wall is much lower)

And again the first DV flat collector with 10 x 16 m and double Pipe quantity:
-> Lowest ground temperature=-8.06
-> Mean weighted ground temperature=1.2
-> JAZ=4.46

Incidentally, the annual heating requirement of the simulation house to be covered by the HP is around 13,500 kWh including WW for the winter of 2009/2011. So not that far away from system 2302 of the Lahr field test, which only looked at a single data processing system - apparently from Heliotherm. The 630 m pipe there is opposite to Kurt's 240 m pipe. Even if we break down the 11 kW linearly to the 6.64 kW, that would still be 380 m of pipe.

Greetings
crink

Ps: @Franke, first-time house builder: I like to simulate the collector in comparison if the necessary parameters such as soil type, location, COP and heat output of the HP, number of house occupants, heat load, collector length/width/depth, number, length, diameter and Thickness of the sheathing of the pipes, heating spread and standby consumption of the HP are known. Did I forget something?