Evacuated tube solar power (open circuit system) does not have this problem. The problem that the solar water heater has no hot water after the water tower is pressurized can only occur with flat panel solar water heaters.
The water circulation of the flat panel solar water heater is a closed circuit system (the structure of the water tank is as shown below).
As shown in the picture above, the hot water in the water tank needs the pressure of the cold water to come out. And since the density of hot water is lower than that of cold water, whenever water is released, the hot water from the top layer flows out first.
The water tower is under pressure, causing excessive cold water pressure, which will cause two results:
First, hot water and water cold water in the water tank mix too quickly, causing theoverall temperature of the body of water in the water tank drops.
Second, because the cold water pressure is too high and the water tank of the flat panel solar water heater is installed at a low level, an imbalance between hot water and cold water is formed at the mixer (or thermostatic valve). ), which makes hot water unable to flow.