Geosource Heating
Geosource Heating
(OP)
Hello all;
I have before me an interesting problem.
We are sinking a PVC frame approx 10 feet Wide by 30 Length x 4 feet High. No problem to place it floating in the ocean. The frame will fill with saltwater once there. The frame will hold 9 coils of 2" HDPE approx 200 feet per coil. Eventually the coils will be filled with a glycol solution serving as a heat exchange medium for a bank of compressors.
The frame will rest on a sandy, gentle slope at approx 40 feet below the surface.
Question is ...what is the best way to control a slow, accurate descent for this large frame?
Thanks, TAB
I have before me an interesting problem.
We are sinking a PVC frame approx 10 feet Wide by 30 Length x 4 feet High. No problem to place it floating in the ocean. The frame will fill with saltwater once there. The frame will hold 9 coils of 2" HDPE approx 200 feet per coil. Eventually the coils will be filled with a glycol solution serving as a heat exchange medium for a bank of compressors.
The frame will rest on a sandy, gentle slope at approx 40 feet below the surface.
Question is ...what is the best way to control a slow, accurate descent for this large frame?
Thanks, TAB





RE: Geosource Heating
RE: Geosource Heating
FIRST> You DO NOT want to use HDPE. It develops cracks when coiled like this. You want PEX-A, engel method. This is a cross linked polyethylene made with a hydrogen peroxide process yielding more cross linking than PEX-B, or PEX-C.
See http://www.REHAU.com
Second> Use a vertical tube at each corner with a second tube inside. The outside tube has some relatively large holes in the side wall at the bottom end, and the holes get smaller as you go up the tube. ... Now we have a gradually increasing resistance as the unit finds bottom.... The free descent rate is controlled by an air bag on each corner with an air valve that is remotely controlled.
Have Fun ( OTEC MAN )
RE: Geosource Heating
Hope you have thought about how to anchor it all to the bottom, sand migration, tidal movement etc. Any decent storm will create sufficient surge at 40ft to wreck any PVC frame!
RE: Geosource Heating
Let us know how this thing went, will you?
RE: Geosource Heating
Just something to consider. Good Luck
Jason
RE: Geosource Heating
To drop it down slowly I would use a crane. Provide connections at multiple points, if not surrounding it, so that it can level out automatically whether lowered or lifted. A crane operator has a lot of experience with moving things slowly into place, and (s)he can stop when connection points are reached to hold it in place while it is lashed down and doesn't slip during placement.
www.eypmcf.com
RE: Geosource Heating
Sinking this frame could be done similar to the way oil rigs are sunk for installation. Put a couple of valves on the PVC pipes and slowly open them to flood the pipes and it should sink.
Just my humble opinions.
RE: Geosource Heating
The coil fields are located in the small protected Depature Bay adjacent to BC Ferry terminal, Nanaimo, BC, Canada There is no surge although small waves (2 feet) can be expected. The substrate is sand ( we did squish one starfish but they can wriggle out and grow more arms) and I expect our field will sink about 6 inches over time.
We used a small crane on a barge to lower the coil fields. Each field was filled with freshwater slowly from the local fire hydrant. It sank slowly and perfectly level... about an hour from start of fill to bottom placement. We sank five fields over four days as we couldn't have a diver in the water when a ferry boat was in. The diver basically watched but was ready to halt the drop if things went tilt-y.
Start-up is in about two months.
Thanks, Tom