Test Results – Test Day 2
P08404 – Solar Water Pasteurizer
Date: 4/15/2008
Time: 9:00am – 3:30pm
Test Water Source: J Lot Wetlands
Weather:
Time
Morning
Noon
Afternoon
Sun
Sunny
Sunny
Sunny
Wind
Windy
Windy
Windy
Total Output (L): ~5 Gallons
Dirty Water Coli form Density: (pending)
Output Water Coli form Density: (pending)
Summary
The P08404 solar water pasteurizer was setup and successfully tested. This day was cold and windy with
good sun intensity. The day was characterized by continuous cycling of the flow control subsystem.
Results
(Note: All times relative to “bucket up”, start of test.)
Graph 1: Weather Data
This day had strong sun and wind all day. The high for the day was around 15 C, the low 4 C. Variability
of solar irradiance in the morning was a result of moving the sensor during leak inspection.
Graph 2: Plate Surface Temperature
Once the plat reached around 90 to 100 degrees C, the system began to output water. There was a
sharp increase around 4 hours into testing, due to running out of water in the input bucket.
Graph 3: Valve Temperatures
Once the system came up to temperature, the valve cycled every ~2 minutes. During the beginning of
the day, there were periods of time where the output side of the valve dropped below 71C.
Chart 4: Reservoir Behavior
Once the system came up to temperature, the water in the reservoir remained well above 71 degrees C.
During startup, as with the valve, there was a period when the temperature dropped below this critical
temperature during the low portions of its period.
Chart 5: Valve Behavior
This chart illustrates the cycling that was observed by the temperature sensors in the valve. The period
of this cycle is approximately 2 minutes, of which water was output for approximately 10 seconds.
Chart 6: Reservoir Behavior
The hot water reservoir did not cycle with the valve on this day, as it did on the first day of testing.
Chart 7: Heat Exchanger Performance