What is the principle of Flat Plate Solar Collector

The more efficient collector consists of a collection and absorption device. Sunlight consists of visible and invisible light of different wavelengths. Different substances and different colors have different absorption and reflection abilities for different wavelengths of light. The black color has the strongest ability to absorb sunlight, so the cotton coat is generally dark or black. White has the strongest ability to reflect sunlight, so summer shirts are mostly light or white. Therefore, the use of black color can gather heat. The parallel sunlight can be collected by a focusing lens at a point, a line or a small area, and the purpose of collecting heat can also be achieved. Paper in the sun, no matter how strong the sun, even in the hot summer, will not be ignited by the sun. However, if the concentrator is used to collect sunlight on the paper, the paper can be ignited. Collectors are generally classified into several types, such as flat plate collectors, concentrating collectors, and plane mirrors.

Flat Plate solar collector
Flat Plate solar collector are generally used in solar water heaters and the like. The concentrating collector can focus the sunlight to obtain high temperature. The focus can be point or line, and it can be used for solar power station, house heating (heating) and air conditioning (air-conditioning), solar furnace and so on. A "Fresnel" lens, a parabolic mirror and a heliostat are constructed by a condenser. Planar mirrors are used in solar tower power generation, with tracking equipment, and are generally used in conjunction with parabolic mirrors. The plane mirror reflects the sunlight on the parabolic mirror, and the parabolic mirror focuses it.
The flat type solar collector mainly comprises a heat absorbing plate, a transparent cover plate, a heat insulation layer and an outer casing. A water heater composed of a flat type solar collector is a flat solar water heater. When the flat type solar collector works, the solar radiation passes through the transparent cover, is projected on the heat absorption plate, is absorbed by the heat absorption plate and converted into heat energy, and then transmitted to the heat transfer medium in the heat absorption plate, so that The temperature of the heat transfer medium rises and is used as a useful energy output of the collector; at the same time, the heat absorbing plate after the temperature rises inevitably radiates heat to the surroundings through conduction, convection and radiation to become a collector. The heat loss.
The flat type solar collector is one of the most basic types of solar collectors. It has simple structure, reliable operation and reasonable cost. It also has the characteristics of strong pressure bearing capacity and large heat absorption area. It is the best combination of solar energy and building. One of the selected collector types.
Solar energy is a very clean green energy source, and it is inexhaustible. You don't have to worry about the excessive exploitation of limited energy. However, because solar energy utilization requires sunlight, solar collectors are not suitable for use in all areas, and solar energy can only be used where there is sufficient light.