The flat plate heat pipe solar water heater uses a heat pipe instead of a water pipe in an ordinary flat plate collector. Antifreeze liquid can be used in the working fluid inside the heat pipe. The longitudinal ribs are welded on both sides of the evaporating section of the heat pipe, and the fins and the heat pipe are coated with selective coatings to absorb solar radiation energy. The condensing section of the heat pipe inserted in the water tank, when the evaporator of sunlight heat. Heat wall into the heat pipe internal coating by heat pipe and metal pipe, the working liquid is heated and vaporized steam flowing into the condensing zone of the heat pipe heat to heat the water in the tank, the steam condenses to liquid return to an evaporation section of the heat pipe for solar heat to the vaporization of steam, then flows into the condensing section of heat, so repeatedly.
Compared with the general flat plate solar water heater, flat plate heat pipe solar water heater has the following advantages
1, the heat pipe flat plate heat pipe solar water heater is generally gravity thermosyphon Straw. It has characteristics of one-way heat conductivity, heat only from the evaporation section oriented condensing section, and not from the condensation section guiding evaporation section in the northern region. Therefore, when the night outside temperature is below the water tank temperature, heat is not lost to the environment from the water tank through the heat pipe;
2. The working fluid of the heat pipe can be made of antifreeze. In the cold areas of the north, winter heat pipes can be avoided because of the low temperature;
3, each heat pipe is a separate heat pipe element. If there is a single heat pipe breakage can be replaced, and has nothing to do with the system, the installation and maintenance are convenient, long service life.
The disadvantage of heat pipe plate solar water heater is the high price. In order to improve the heat transfer efficiency, the heat pipes and fins are best made of non-ferrous metals such as copper and aluminum, which increases the manufacturing cost. If carbon steel is used as the material of the heat pipe and rib, the price may be different from that of the flat plate solar water heater.