Solar constant-temperature instant hot water system based on slab-shaped flat pipe

Abstract

The invention discloses a solar constant-temperature instant hot water system based on a slab-shaped flat pipe. The system comprises a solar heat collector provided with the slab-shaped flat pipe, a water tank, a header connected with the flat pipe, a coil pipe arranged in the water tank and connected with the header as well as a water supply system connected with the water tank, wherein when water temperatures in subsidiary water tanks do not reach set values of first temperature control devices, electric heating devices heat water in the subsidiary water tanks to set temperatures, hot water is supplied in a solar heating and electric heating combined manner, stable supply of constant-temperature domestic or industrial hot water can be guaranteed, the structure is practical and reliable, the solar heat collector is high in heat absorption and utilization rate, and intelligent temperature control is realized, so that heating is more efficient, and meanwhile, mounting and maintenance are convenient.

Description

technical field [0001] The invention relates to a solar hot water supply system, more specifically, to a solar constant temperature instant hot water system based on flat tubes. Background technique [0002] The solar collector in the solar water heater is a product with relatively mature technology, the most widely used and the best acceptance rate in the actual society in the utilization of solar energy; from a global perspective, flat-plate solar collectors and vacuum tube solar collectors At the same time, the water tank is supplemented with electric energy auxiliary heating, which is the mainstream technology and product model in the current domestic and international solar water heater product categories. However, due to the limitations of maintenance, installation methods and safety, vacuum tube solar collectors are difficult to adapt to high-rise buildings. The area is only about 10% of its projected area, and the utilization rate of the projected area of ​​the coll...

AI Technical Summary

Problems solved by technology

However, due to the limitations of maintenance, installation methods and safety, vacuum tube solar collectors are difficult to adapt to high-rise buildings. The area is only about 10% of its projected area, and the utilization rate of the projected area of ​​the collector is low. At the same time, there are also problems such as tube explosion or water tank overflow, water output, and water temperature instability when the heat energy income of the collector is excessive in summer. And the heating time is long, especially in winter, repeated electric heating causes energy waste and many other problems

[0003] Although the average thermal efficiency of flat-plate solar collectors is slightly better than that of vacuum glass tube collectors (the thermal efficiency of flat plates is generally 60%, and that of vacuum glass tubes is 50%), the main reason is that the effective area of ​​indirect secondary heat conduction and daylighting is much larger than that of vacuum tubes. Heat collector, thus improving some efficiency through indirect secondary conduction heat transfer; but because the diameter of the fluid channel copper tube is generally 10mm-18mm, the direct net lighting projected area is still very small, less than 10% of the total flat lighting area , only by increasing the indirect lighting area to enhance the function of secondary heat conduction, but failed to directly make full use of the total lighting area to increase the area of ​​primary heat conduction

At the same time, because the antifreeze liquid of ethylene glycol and water has a strong corrosive effect on aluminum alloys, the comparative advantage that it is easier to form through pressure processing cannot be applied to the field of solar collector products. Therefore, at present, international and domestic solar collectors The materials used in heaters are still limited to glass, copper tubes and other materials, and it is still difficult to break through

[0004] The common disadvantage of the above two products is not only that the total lighting area of ​​the heat collector is not fully utilized, but because the direct heat-absorbing working part is a tubular geometry, the cross-sectional area of ​​the heat-conducting working medium cannot be flattened, making it impossible to improve its projection The real-time tracking of the area and the geometric characteristics of capturing light energy, because increasing the diameter of the pipe will inevitably lead to a year-on-year increase in the hydraulic diameter of the water flow, which will lead to a slow temperature rise; during the day, the thermal efficiency of the collector changes greatly due to the continuous change of the illumination angle , in the state of "eating" by the sky; at the same time, when this type of collector "eats" by the sky and cannot reach the set water temperature or prevent freezing, it uses repeated electric heating in a large outdoor water tank to supplement heat energy, so , the cost of hot water has risen suddenly, and it is impossible to form an enhanced heat exchange process in a low-cost operating state. There are no new breakthroughs in heat collection, heat exchange modes and principles of collectors; at the same time, a considerable amount of cold water will be released after entering autumn, winter and spring. Only when hot water comes out, bathers will waste a lot of water while waiting and adjusting the temperature

[0005] From the above analysis, the comparison of the comprehensive performance of traditional solar water heaters with current gas water heaters and electric heating water heaters in terms of energy saving and emission reduction, performance, practicality, and building integration shows that traditional solar water heaters have not yet been used in some climate-specific regions. at a clear advantage

Images