Results from first stratification test and first overnight cool down test
Add one gallon of cold water (with pics and temp plot)
Add one gallon of hot water (with temp plot)
Record temp inside GWHX overnight.
Add One Gallon of Cold Water Test
Next few pics show one gallon of cold water ( 53F )being added. The flow rate was 1 gallon in about 45 seconds. The water was dyed with some writing ink. The pictures were taken during the period the dyed water was flowing into the drum.
Visually it seemed like there was a little leakage of the cold fluid out the sides of the GW entry tube, but that most of the flow made it to near the bottom of drum.
This last picture is of the drum sidewall after the dyed water had been in a couple minutes. Point is that the top 2/3rds or so of drum water appear to be pretty clear -- ie cold water does seem to enter on bottom and not mix much with top part.
Temperature plot for the cold water add. The little triangles are a button press on logger just before starting.
Temps logged every 10 secs. Sensors mounted 4, 10, 16, 22 and 28 inches from bottom of drum.
Looks like bottom sensor actually showed an increase in temp -- I am guessing that this is because the cold GW entering (53F) gets warmed some as it goes down the entry tube.
The 10 inch from bottom sensor shows a couple degree drop, but the 16, 22 and 28 show very little change.
Seems to me that this indicates that the cold water pretty much ends up near the bottom as hoped.
Add 1 Gallon of Hot Water Test
I added 1 gallon of hot water (about 124F) over 45 second period -- it was dyed in the same way.
The pictures take during the add don't show where the water comes out as well as the for the cold water add. Part of this is just because there was already some dye in water, and partly because the camera angle is not as good. I did appear visually that the hot dyed water was coming out over a wider area than the cold water, and that it was not making it to the bottom. The picture below is taken of the side of drum after all the hot water was added, and shows much more red in top part of drum than the similar picture after the cold water add.
Temperature plot during hot water add.
No change in bottom trace, indicating that hardly any of the hot water made it to bottom.
Biggest change is in the 10 inches off the bottom trace Indicating that while the hot water did not make the it all the way to bottom, it got quite a ways down.
This may be in part because the drum does not start getting cold until you get to 10 inches and less from the bottom -- ie, I probably should have made the temp stratification in drum initially more even??
Or, maybe the holes in GW down tube might benefit by being larger?? Or ??
Overnight Temperature Plot -- 050421-> 22:
The insulation of top of tank was not probably as effective as it could be (its a lose bat of perhaps 3 inch thick FG -- not fitted all that well to top of barrel) -- but, this plot still looks interesting:
The top three lines ( 28, 22, 16 inches from bottom) track almost together -- indicating that the whole upper half of tank cools as a unit and stays the same temp. The 10 inch above bottom follows nearly the same cooling slope. The 4 inch from the bottom one warms -- indicating some transfer (of what kind I wonder?) from lowest cool part of barrel to hotter part.