1 / 6

Geo-Exchange

Save money and protect the environment by cooling your home with a geo-exchange system instead of a conventional AC unit. This article explains how a home can be cooled using heat pump piles, and provides calculations for determining the length of pipes needed for the heat pump piles.

agnesyoung
Download Presentation

Geo-Exchange

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Geo-Exchange Addison Parks and Andy Gerla

  2. Summer Time • Home walls are mainly heated from • the Sun’s radiation and cooled by the • convection of wind. • This results in an uncomfortably warm • home. Due to green initiatives, it would • save money and protect the environment • to cool a home through a geo-exchange • system rather then a conventional • AC Unit. • Here we have a home resting on what • are called heat pump piles. Fluid • circulates through the cooler heat pump • piles and then through the home to absorb • the heat coming from the outside. That • way the outside heat never raises the • internal temperature. Preferred Temperature 72 ̊ F Outside Temperature 92 ̊ F Ground Temperature Constant 60 ̊ F

  3. Heat Pump Piles • The only energy required to run a heat • pump pile is the pump situated at the top. • The energy required to run the pump is • minimal compared to an AC unit. Warm • fluid coming from the home circulates • down the center of the pipe and then • returns to the home passing by the • outer wall of the pipe. • We will now determine how long • the pile will need to be assuming • Tm,i= 92 ̊ F, Tm,o= 61 ̊ F, r1=10cm, • r2=12cm, r3=15cm, and the pipe • is made out of a board of glass fiber.

  4. Wayne in Ground Pump • We will use this Wayne in Ground Pump. • This pump does 6120 GPH or .00643 m^3/s. • Our fluid will be water.

  5. Calculations Table A.3 Glass fiber k=0.058 r1=.010m r2=.012m r3=.015m W Tm,o= 60 ̊ F m ̊ K = 289 ̊ K Table A.6 Water @ 297 ̊ K k=608.8E-3 W m ̊ K Ns µ=917E-6 Pr=6.3 m3 r2 r3 r1 L cp=1.87kJ/kg*K • It is determined that the equivalent diameter is 0.04m • The Reynolds number is 202,660 and therefore turbulent. • Using Seider we find NuD is 854 • h is 21673 W/m^2*K • Rtot is .613 K/W • Therefore the required length is 20,855 meters. This length is • impractical. Tm,i= 92 ̊ F = 306 ̊ K

  6. Corrected Values • A more practical situation would be to decrease • the size to r1=5mm, r2=7mm, r3=8mm. Then • decrease the flow to 1.43 Gallons an hour. • This results in the following: • It is determined that the equivalent diameter is 0.004m • The Reynolds number is 87 and therefore laminar. • NuD is 173 • h is 159 W/m^2*K • Rtot is .509 K/W • Therefore the required length is 4 meters. • In conclusion, we’d determine how much heat comes • from the walls and that would determine how many • Heat Pump Piles a home would need. Additional pipes may be needed to remove internally generated heat. Pipes to Heat Pump Pile

More Related