Solar heat collection is the core component of the solar heat utilization system. The solar collector absorbs light from solar radiation, generates a large amount of thermal energy and provides a constant flow of energy. human "heart" Once the beating stops, people can no longer live, and once the solar collector is damaged, these hot water systems will also lose their vitality. The solar collectors used in different hot water systems are different. The sensors have the appearance of a flat plate or vacuum tube. They all have special heat absorption devices to absorb solar radiation, convert it into thermal energy, and then transfer the thermal energy to water (water is only one type of heat transfer ). medium, and there are others. Distilled water and gas, etc.) to continuously increase the water temperature and obtain the desired hot water. The sound collectorst divided into low temperature, medium temperature and high temperature according to different temperatures. Solar collectors are low temperature types. Of course, different standards have different classifications. For example, there are tracking collectors and non-tracking collectors, which are divided depending on whether the sensor moves around the sun throughout the day. In our lives, the most common solar collectors are flat panel solar collectors and vacuum tube solar collectors. In short, a solar collector is a device that absorbs energy from solar radiation and transfers heat to the working fluid.
Diagram of the operating principle of the solar water heater
1. Cold water enters the solar water heater through the pipe and passes through the heat collector plate. The collector plate can collect solar energy and convert solar energy into thermal energy, then heat the eau cold. 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. This is because cold water 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 warm up until until it reaches the defined level. the water temperature. When the intensity of the sun is not sufficient to respondre the 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 gradually heat the 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 one large and one small. 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 the absorption of sunlight after light radiation, because the vacuum glass tube is round, it has the characteristics of naturally following the wide source of the sun, moreThe reflection principle of the upper reflector allows the tube to glass to receive light from all sides, the heat collection effect lasts longer, the water temperature is higher and it can work normally all year round, even in alpine areas.