After decades of development, flat-panel solar refrigerators have become more mature and complete in technology, and have advantages that other types of solar energy do not have.
One is particularly suitable for the requirements of building integration. Due to its planar structure characteristics, flat solar refrigerators have flexible shapes and structures in the integrated application of solar energy, and are not restricted by shape or size during design, and are easy to achieve integration with building components. In addition, its heat collector plate is made of metal, which can be easily connected by wire knots and welding, which provides convenience for installation, maintenance and use.
The second is to have higher thermal efficiency. Because the evacuated tube solar collector is composed of a number of evacuated tubes, there are gaps between the tubes. When it is irradiated by sunlight, part of the solar energy is not received by the collector. The flat panel solar collector is a continuous plane, and the entire surface of the collector can receive sunlight. Therefore, under the same lighting area and sunlight intensity, the average daily efficiency of flat solar refrigerators is generally higher than the average daily efficiency of vacuum tube solar refrigerators by more than 6%.
Third, it has good pressure bearing performance. Since the heat absorbing plate of the flat solar heat collector is made of metal material, the connection between the heat collector and the water storage tank also uses metal parts, so it can withstand the pressure from the tap water and the circulating pump. At present, urban water use generally uses a centralized water supply system, and the pressure of tap water is high. This requires that the hot water coming out of the solar refrigerator must have a certain pressure, thus reducing the pressure difference between the refrigerator water outlet and the tap water outlet. It is convenient and comfortable for users to use.
Fourth, stable performance when forming a large system. For some large places, such as hotels, swimming pools, factories, etc., when solar refrigerators are used, many solar collectors are often needed to form a large-scale water supply system. If a flat-plate solar collector is used and the collector and the system are connected with metal instead of rubber and plastic parts like the vacuum tube solar refrigerator, the stability of the entire system can be guaranteed.
Therefore, when building large-scale solar water heating systems, flat-plate solar heat collection is often used. In addition, due to the simple structure, convenient processing and large-scale production of the flat solar refrigerator, it also has the characteristics of low manufacturing cost, low installation cost and long service life.
Of course, the high heat loss and anti-freezing problems of flat-plate solar collectors also need to be further solved through technological innovation. In order to actively participate in international competition and open up the domestic high-end market, we must attach importance to the research and development of flat-panel solar refrigerators, and with a more open mind, improve the technical and international level of solar thermal utilization in my country.