The natural circulation compact household solar water heater is generally composed of four major parts: a high-level thermal insulation circulating water tank, a flat-panel solar collector (or a vacuum tube collector), a floating ball supply water tank and a bracket system. The flat plate collector is connected with the high-level thermal insulation circulating water tank through the cold water lower circulation pipe and the hot water upper circulation pipe, and forms a closed temperature difference convection circulation heat exchange circuit. The high-level thermal insulation circulating water tank is connected to the upper water pipe of tap water and cold water through the floating ball supply water tank to ensure a constant water level in the water tank. The advantage of this system is that it has a high degree of automation. Using the physical phenomenon of temperature difference convection circulation, the solar thermal energy irradiated on the collector can be automatically converted into hot water and continuously collected into the high-level thermal insulation circulating water tank. internal storage. When the user needs hot water, he only needs to open the hot water faucet to get hot water. After the hot water in the heat preservation circulating water tank flows out, the system automatically and synchronously supplies the corresponding amount of cold water to the heat preservation circulating water tank through the replenishment water tank controlled by the floating ball valve. This compact circular horizontal water tank and flat-panel household solar water heater has been popularized and applied on the largest scale for more than 30 years since it was first introduced in Yunnan in the late 1970s. This aspect shows the reliability of the original structural design of the system. sex and rationality. On the other hand, after the extensive use of millions of sorties, it was found that this system does have some areas that need further improvement and perfection.
First, the pipeline cannot be automatically delayed emptying. With the increase of floors, every time users on the lower floors open the valve to take hot water, they must first discharge a large amount of heat-dissipating and clean residual water accumulated in the hot water sewer pipe before they can get hot water, which invisibly causes a large amount of water resources. waste disposal. Second, the system sewage is difficult. After a period of use, sediment and dirt will inevitably accumulate in the lower header of the flat plate collector, which not only affects the heat exchange of the system, but also seriously affects the cleanliness and hygiene of the water quality. Special personnel must be invited to climb on the roof and use special tools to open the blowdown valve at the lower part of the core for blowdown (some systems do not even have blowdown valves installed at all). Third, flat-panel collectors are not frost-resistant. Fourth, the installation angle of the system must be fixed for life when it leaves the factory. Not only can it not be based on the objective conditions of the installation site, but also cannot make any necessary adjustments to the installation angle of the collector according to the changes in the height angle of the sun throughout the year, so as to improve the collection of sunlight by the system. s efficiency. Fifth, the supply water tank controlled by the float valve is often frozen in winter, and the float valve is often not closed tightly, causing the system to leak. In addition, China’s circular horizontal water tank and flat-plate solar water heaters have long been used to assemble flat-plate collectors with the traditional frame structure of thin metal grooves and benzene plates or aluminum profile plug insulation strips. The long-term lack of technological progress in the light-to-heat conversion efficiency of the flat-panel hot box has resulted in the low thermal efficiency of this type of water heater, serious leakage and leakage, as well as a series of other problems involving mechanization, automation, molding, and high-standard production technology. There is no reasonable solution for a long time. Affected by the above-mentioned various factors and performance defects, China’s flat-panel solar collectors have lost their competitiveness in the markets of various countries. After entering the 21st century, due to the sharp rise in metal prices and the increase in labor costs, China’s traditional flat-panel collectors were eventually marginalized and squeezed out of the mainstream market under the strong competition of standardized mass production of vacuum tube modern assembly lines.
In view of the above-mentioned series of performance defects in the product of round horizontal water tank plus flat plate, which has been popular with users for many years, the consortium of China Kunming Nankai Energy Research Institute and Yunnan Jimin Sunshine Company Factory Institute, in order to overcome the shortcomings of the existing product technology, Developed an improved “water-saving four-function compact flat-panel solar water heating system”. This improved new product can greatly improve the technical performance of the product on the basis of the original product. The popularization and application of this new technology can basically realize the existing round horizontal water tank plus flat plate series products: First, the hot water pipeline can realize automatic delay emptying, and users can realize the “valve open, hot water” when using hot water. “Water comes”, reducing the waste of heat dissipation and clean residual water resources. Second, the collector and the cold water supply pipeline can be remotely controlled indoors to achieve reverse sewage self-cleaning. Third, when the climate suddenly cools down, operating indoors can realize emergency emptying and anti-freezing of the entire system. Fourth, the installation angle of the collector can be easily adjusted to the installation angle facing the sun in winter and summer to improve the light-to-heat conversion efficiency. The new technology has improved the thermal performance and use function of traditional products; compared with the original system, the new system saves a set of float supply water tank, adds several pipe valve accessories, and replaces a pair of adjustable installation angle. New tripod. When the material cost is almost the same as that of traditional products, the water-saving performance and other use effects of the system have been effectively and greatly improved.
On the basis of retaining the structural characteristics of the flat plate collector and the high-level thermal insulation heat storage circulating water tank, the new system uses a (tap water) cold water upper water pipe from the user’s toilet to the water inlet of the roof thermal insulation circulating water tank, and the solar water heater placed on the roof. The system is directly connected to replace the original float valve supply tank to supply water to the system; the end of the cold water supply pipe is installed with a manually controlled cold water main valve, that is, a hot water discharge valve (1). At the hot water outlet of the thermal insulation circulating water tank, the hot water down pipe of the system is connected with the hot water down pipe directly connected to the room through a newly added three-way joint, and a patented product air-release water stop valve (5) is installed respectively. The hot water downpipe is first connected to a positive check valve (4) at the end of the room, and then connected to the manual cold water temperature adjustment valve (2) and the shower head through another three-way joint. Connected.
At the cold water inlet of the roof insulation circulating water tank (which is also the outlet of the lower circulation pipe of the system), install in sequence: a tee joint; then at the middle interface of the tee joint, connect with the lower circulation pipe of the collector; and After connecting a small piece of flexible hose (or union) to the lower circulation pipe, it is connected with the lower circulation pipe and the lower header pipe of the heat collector; at the other interface on the tee joint, first install a After the cold water inlet check valve (4) is connected to the other tee, it is connected with the cold water upper water pipe; and a second air release water stop valve (5) is installed at the port of the other tee. Connect a reverse check valve (4) and a flexible hose (or a live connection) through another tee joint in the direction of the cold water upper water pipe close to the lower side of the collector, and finally drain the sewage from the lower header of the collector. The valve (3) is connected.
The upper circulating pipe of the collector hot water also needs to be connected to the upper circulating inlet of the water tank through a flexible hose (or a live connection), so as to complete the pipeline transformation and installation of the entire system.
The system works like this: first, open the cold water main valve, that is, the hot water discharge valve (1), and let the tap water flow along the cold water upper water pipe, through the cold water inlet (ie, the lower circulation pipe outlet) of the thermal insulation circulating water tank, and directly inject it into the thermal insulation circulating storage tank. Hot water tank: When the water tank is filled with cold water, the excess water will overflow into the room from the hot water downpipe; and spray from the shower head. At this time, the user should close the hot water discharge valve (1) in time: the system will automatically enter the heat storage process of receiving solar radiation energy and naturally circulating heating, thermal insulation, and circulating hot water storage tanks. After a certain period of time, when the cold water in the water tank has been heated to a usable temperature by the collector, the user only needs to slowly open the hot water discharge valve (1) and continue to inject cold water into the heat preservation water tank. After a few seconds, the hot water will be released. Along the hot water sewer pipe, it is directly transported to the toilet. The user can control the temperature of the hot water by adjusting the cold water temperature adjusting and mixing valve (2). When the bath is about to end, it is only necessary to turn off the hot water discharge valve (1) dozens of seconds in advance. When the remaining water in the hot water pipe runs out, the system will automatically enter the next one to collect solar radiation energy and heat the water in the thermal insulation tank. The temperature difference cycle heat collection state.
After the system has been running for a period of time, in order to keep the internal circulation pipeline clean and hygienic, the user only needs to close the cold water main valve, that is, the hot water drain valve (1), and then open the manual drain valve (3). The dirt in the core of the collector plate can be reversely flowed down from the cold water upper water pipe and discharged through the sewage outlet in the shower room.
On the days when frost and freezing may occur in winter, the user only needs to prepare the water in the bathroom in advance to recycle the water in the heat preservation water tank of the collector system, and then follow the above procedures to basically empty the water in the heat preservation water tank. , you can achieve the dual purpose of system sewage and water tank emptying and anti-freezing.
The new flat-plate collector made of the multi-functional flat-plate collector frame profile patent product not only has better sealing, thermal insulation, heat loss prevention and anti-leakage performance, but also can be easily installed in the lower direction of the back of the flat-plate collector. The previous set of tripods can be easily retracted and can effectively adjust the height of the collector support. By adjusting the different support heights of the tripod, the collector can adjust the installation angle of the collector facing the sun accordingly according to the sun altitude angle in different seasons of winter and summer, thereby greatly improving the total heat collection efficiency of the system.
The beneficial effect of this patented new technology is that on the basis of the original circular horizontal water tank and the flat-plate solar water heater, the overall structure and cooling of the collector are improved by introducing the patented product air-release water stop valve and the multi-functional flat-plate collector frame profile. , The drainage system of the hot pipeline, after the integrated innovation and transformation, its new products can solve the passive automatic delay emptying pipeline that has not been effectively solved for more than 30 years while retaining the excellent quality of the original compact system. Remaining water, to achieve “valve open, hot water” to reduce the frequent waste of waste water in the pipeline, the system is difficult to discharge, not anti-freeze, and the installation angle of the collector cannot be easily adjusted as needed. The new technology also simplifies the structure of the system and improves the efficiency of heat collection, heat preservation and heat collection of the system.