Jones Beene wrote:
We presume (hope) that the Swedes will not use a hose connected to plumbing
where you get free water pressure, and will use a pump. The pump's power
must be included in P-in.
A liter/sec pump seems to require one horsepower or about .75 kW.
As I pointed out in another thread, this cannot be measured because the
energy is added to the flowing water before the water passes the inlet
temperature sensor.
Only a tiny fraction of the power going into a pump shows up the cooling
water loop. Most of it is lost in waste heat from the pump housing. A
small fraction goes into the water emerging from the pump. As I said,
this cannot be detected because it is already in the water when it
passes the inlet sensor. The rest is generated as the water splashes out
of the hose down the drain, or back into a reservoir tank, when it stops
moving.
If you recycle the water back into a tank, it has to be a laboratory
grade cooler or the temperature in it will rise as heat from the cell
and pump are added to it. If you do not have a laboratory grade cooler,
it is better to use a large reservoir of tap water which is dumped down
the drain, or a continuous flow of tap water. This is what Levi et al.
did. Anyone who has dealt with laboratory-grade cools knows why. Those
things are more temperamental than computer printers. Tap water
temperature in a city is remarkably stable over hours or days.
Measuring the flow rate is no easier or harder with a pump or with tap
water. It is exactly the same.
- Jed
