At present, the common solar collectors in solar water heating projects mainly include flat plate solar collectors, all-glass evacuated solar collectors, heat pipe solar collectors and U-tube evacuated solar collectors.
For medium and large solar hot water systems used throughout the year, solar collectors are required to have a certain bearing pressure, high heat collection efficiency, relatively small pipe resistance, strong frost resistance and easy maintenance.
Among these types of solar collectors, although the all-glass evacuated solar collectors has high heat collection efficiency and a large market share, it cannot operate under pressure. It is not suitable for use in large solar water heating systems, most of which are used as heat collecting parts of domestic solar water heaters. The other solar collectors, all of which are metal heat absorbers, can be operated under pressure and are suitable for application in large-scale solar water heating projects.
Flat plate solar collector
It is a kind of solar heat collection device that has been applied relatively early, and it has always been a leading product in the world solar market, widely used in various low-temperature hot water heating fields.
However, with the emergence of evacuated solar collectors, due to the limitation of its own structure, it has no advantages in heat collection efficiency. Due to antifreeze issues and heat collection performance are greatly affected by seasons and the environment, it is currently mainly used in areas with higher temperatures. In the north, the operation effect is not good in winter. It is not recommended to be used in large-scale hot water projects.
Heat pipe solar collector and U-tube evacuated solar collector
They developed products based on all-glass evacuated solar collectors. The common characteristics of both have relatively high heat collection efficiency, and metal can be used as a heat absorber to operate under pressure.
However, from the comprehensive evaluation of heat collection efficiency, leakage prevention, scale prevention, durability, safety, reliability, and difficulty in installation and maintenance, heat pipe solar collectors are the most suitable solar collectors used in central hot water supply systems. The type of collector is followed by U-tube evacuated solar collector.
Heat pipe solar collectors use heat pipes to transfer heat, and there is no water in the tube. It has the advantages of small heat capacity, fast heat transfer, freezing resistance, thermal shock resistance, pressure resistance, good insulation, no leakage, and easy maintenance.
The U-tube evacuated solar collector uses the integrated pipeline in the vacuum tube to directly heat the working medium. It also has the characteristics of high operating temperature, strong pressure bearing capacity and good thermal shock resistance. However, the installation procedure is more complicated than that of the heat pipe solar collector, and the system maintenance cost is relatively high.
It is necessary to select a suitable solar collector to be used in solar heating projects according to the actual situation. Sunflower Solar will help you make the right choice.