Diagram of the operating principle of the solar water heater
1. Cold water enters the solar water heater through the pipe, passes through the heat collecting plate, and the heat collecting plate can collect solar energy, convert the solar energy into thermal energy, and then heat the Cold water. Since the density of cold water is higher than that of hot water, the hot water will automatically increase and then form circulating power. The water will gradually heat up on the heat collecting plate. After reaching a certain temperature, it can enter. the hot water tank. Those who need hot water will be able to get hot water at any time.
Heating scheme
2. In fact, the principle of solar water heaters mainly includes the following two principles:
(1) The principle of water circulation, that is, the water will flow automatically. In fact, the water froide is denser than hot water, cold water sinks and hot water rises, forming a natural convection cycle, causing the water in the water tank to gradually heat up until it reaches the set level. the water temperature. When the intensity of the sun is not sufficient to meet circulation needs, a water pump can be added to the closed water circulation circuit to obtain forced circulation.
(2) Collector heat absorption principle: There is a special coating on the collector surface of the solar water heater. This coating has a high absorption rate in the visible range of solar energy. absorbing it as heat, the wavelength of thermal radiation from the collector is in the long-wave range, and the coating has low long-wave emissivity, thereby effectively retaining solar heat. This heat is then used to heat progressturn cold water into hot water.
Solar collector tube
The following is a detailed description of the collector tube on this collector. The collector tube is actually like an elongated kettle liner, consisting of a large one and a small one. is made up of two glass tubes. The outer layer is transparent and the inner layer is covered with a spectrum-selective absorption coating. There is a straight space between the inner and outer tubes. used to maximize absorption of sunlight. Thermal energy after light radiation; Because the vacuum glass tube is round, it has the characteristics of naturally following the broad source of the sun. Coupled with the reflection principle of the reflector, the glass tube receives the light. on all sides, the heat collection effect lasts longer and the water temperature is higher, it can work normally all year round, even in alpine areas.
Thiswhich they said before is good, but there is one most critical thing they didn't notice: the solar collector tube is below the water collecting tank, and the hot water is above , although lowering the water temperature in the heat collecting tube will not have much impact on the hot water in the water collecting tank. Water is a poor conductor of heat, and the temperature of the water in the heat collecting tube is low and its density is low. high, so it will not form with hot water in the water tank. Convection, even if it drops to a very low temperature, will not lower the temperature in the tank. During the day, because the water temperature in the collecting tube becomes higher and the water temperature in the water tank is lower, the lower temperature water in the water tank continues to enter the collecting tube, and the water at temperature pThe high pressure in the collector tube continues to enter the water tank, so that heat is absorbed and drawn away, but this process cannot be reversed at night.