WAN, Huaxin (336 Yaoxin Avenue, Netdz, Nanjing, CN)
LI, Yuqian (336 Yaoxin Avenue, Netdz, Nanjing, CN)
ZHANG, Yougen (336 Yaoxin Avenue, Netdz, Nanjing, CN)
AO, Kaiping (336 Yaoxin Avenue, Netdz, Nanjing, CN)
WAN, Huaxin (336 Yaoxin Avenue, Netdz, Nanjing, CN)
LI, Yuqian (336 Yaoxin Avenue, Netdz, Nanjing, CN)
ZHANG, Yougen (336 Yaoxin Avenue, Netdz, Nanjing, CN)
| CLAIMS 1. A pressurized solar water heater comprising a solar heat collection device with a filling port and a return port, a water storage tank having a bottom, and a heat exchange cavity with an inlet and an outlet, an upper surface of the heat exchange cavity being coextensive with a bottom surface of the tank, and the filling port and the return port of the solar heat collection device being respectively connected to an outlet and an inlet of the heat exchange cavity, thus forming a cyclical loop. 2. The pressurized solar water heater according to Claim 1 wherein the upper surface of the heat exchange cavity and the bottom surface of the tank are formed by an upper convex spherical crown. 3. The pressurized solar water heater according to Claim 1 wherein the tank bottom is formed by a wall that has an upwardly convex upper surface defining the bottom of the tank, and wherein the wall also has a downwardly concave lower surface that defines the top of the heat exchange cavity. 4. The pressurized solar water heater according to Claim 1 wherein the heat exchange cavity is connected to an expansion tank. 5. The pressurized solar water heater according to Claim 1 wherein the solar heat collection device is wall-hung and includes a group of horizontal vacuum pipes. 6. The pressurized solar water heater according to Claim 5 wherein ends of the vacuum pipes are plug-in mounted and supported by a vertical end bracket and by a header shell of a header. 7. The pressurized solar water heater according to Claim 6 wherein an inner pipe of the header is connected to heat exchange medium liquid in the vacuum pipes, wherein the inner pipe of the header includes the filling port and the return port. 8. The pressurized solar water heater according to Claim 1 wherein the tank is cylindrical with a vertical center axis. 9. The pressurized solar water heater according to Claim 8 wherein the tank has upper and lower ends and has a hot water outlet near the upper end of the tank and a cold water inlet near the lower end of the tank. 10. The pressurized solar water heater according to Claim 9 wherein the tank has a cylindrical side wall that has an inner surface and that is connected to the bottom of the tank, and wherein the tank bottom forms an upper convex spherical crown and has a downwardly extending cylindrical portion that has an outer surface and that is centered on the vertical axis of the tank, the outer surface of the cylindrical portion and the inner surface of the side wall being tightly fitted. 11. The pressurized solar water heater according to Claim 10 wherein the side wall has a bottom edge sealingly connected to the outer surface of the cylindrical portion by fillet welding. 12. The pressurized solar water heater according to Claim 11 wherein the cylindrical portion of the tank bottom has an inner surface and is connected to a lower cap having an outer surface, the outer surface of the lower cap and the inner surface of the cylindrical portion being tightly fitted. 13. The pressurized solar water heater according to Claim 11 wherein the cylindrical portion has a bottom edge sealingly connected to the outer surface of the lower cap by fillet welding. 14. The pressurized solar water heater according to Claim 11 wherein the heat exchange cavity is formed at the bottom of the tank, beneath and inside the tank bottom and above the lower cap. 15. A pressurized solar water heater comprising a solar heat collection device with a filling port and a return port, a water storage tank having an end, and a heat exchange cavity with an inlet and an outlet, a surface of the heat exchange cavity being coextensive with a surface of the tank, and the filling port and the return port of the solar heat collection device being respectively connected to an outlet and an inlet of the heat exchange cavity, thus forming a cyclical loop. 16. The pressurized solar water heater according to Claim 15 wherein the surface of the heat exchange cavity and the surface of the tank are formed by a convex spherical crown. 17. The pressurized solar water heater according to Claim 15 wherein the tank end is formed by a wall that has a convex surface defining the end of the tank, and wherein the wall also has a concave surface that partially defines the heat exchange cavity. 18. The pressurized solar water heater according to Claim 15 wherein the heat exchange cavity is connected to an expansion tank. 19. The pressurized solar water heater according to Claim 15 wherein the solar heat collection device is wall-hung and includes a group of horizontal vacuum pipes. 20. The pressurized solar water heater according to Claim 19 wherein ends of the vacuum pipes are plug-in mounted and supported by a vertical end bracket and by a header shell of a header. 21. The pressurized solar water heater according to Claim 20 wherein an inner pipe of the header is connected to heat exchange medium liquid in the vacuum pipes, wherein the inner pipe of the header includes the filling port and the return port. 22. The pressurized solar water heater according to Claim 15 wherein the tank is cylindrical. |
Field of the invention
This invention relates to a kind of solar water heater, in particular to a kind of pressurized solar water heater, which belongs to the technology field of solar energy application.
Background
According to understanding of the inventors, the existing solar water heater mainly comprises two kinds: non pressurized and pressurized. The tank of the non pressurized solar water heater is connected to the solar heat collection pipe directly, so people can use the hot water directly heated by solar energy, having no intermediate heat exchange link. As there is no pressure in the tank, the device has a disadvantage of the lack of the stream impact force when it is under use. In addition, it is impossible to add antifreeze to the water, and therefore there is a possibility of freeze of the outer water pipe in cold season which is connected with the solar heat collection pipe. The tank of the pressurized solar water heater (commonly referred to as inner tank) is cyclical heat-absorption coupling with the solar heat collection pipe through heat exchange structure. As the inner tank is not connected with solar heat collection pipe directly, it has internal pressure to deliver stream with strong impact force. As the same time, adding the antifreeze into the cyclical heat-transfer medium of solar heat collection pipe can protect from freezing.
According to review, a Chinese patent application of No. 200620087250.4 published a kind of pressurized Wall-hung solar water heater. This kind of water heater contains water tank and heat collector. The heat collector is located under the water tank. The tank is equipped with cold water inlet tube connected to the lower of the water tank cavity and with hot water outlet tube connected to the upper of the water tank cavity. The heat collector contains a heat collecting medium cavity and a heating collecting tube which is connected to the heat collecting medium cavity. There is a heat exchange medium cavity sealed with the water tank cavity in the water tank cavity. The heat exchange medium cavity is connected with the heat collecting medium cavity through hot medium pipe and cold medium pipe. The cold water inlet tube and the hot water outlet tube enter into the water tank cavity through the lower surface of the water tank in a sealed manner. The hot medium tube and the cold medium tube enter into the heat exchange cavity through the lower surface of the tank in a sealed way. The upper of the hot medium tube is located in the middle and upper of the heat exchange medium cavity and the lower of the cold medium tube is located in the lower part of the heat collecting medium cavity. Heat insulated sleeve is installed on the part of the hot medium tube which is in the heat exchange medium cavity.
Experiments has proved that although this kind of water heater is convenient for installing, the process structure is complex because of the structure of "inner tank inside the inner tank", the water storage space of the inner tank is reduced, and heat exchange efficiency and the hot water supply is not good enough.
Summary of the invention
One purpose of this invention is to provide a kind of pressurized solar water heater with high heat exchange efficiency to improve the hot water supply in response to the disadvantages of the said existing pressurized solar water heater above and on the basis of the improvement of the structure.
To achieve the purpose above, the pressurized solar water heater of this invention comprises a water storage tank and a solar heat collection device with filling opening and liquid port. At the bottom of the tank there is a heat exchange cavity with water inlet and water outlet. The upper surface of the heat exchange cavity is coextensive with the bottom surface of the inner tank. The filling opening and return opening of the solar heat collection device are connected to the water inlet and water outlet of the heat exchange cavity separately, thus forming a cyclical loop. Putting the heat exchange cavity at the bottom of the tank makes the structure easier and does not reduce the space of the water storage. More importantly, in the tank and the heat exchange cavity, as the high temperature water has a upward trend and the low temperature water has a dropping trend, the upper coextensive surface connects with the water with the lowest temperature in the tank all the time and the lower coextensive surface connects with the water with the highest temperature in the heat exchange cavity all the time. Therefore the coextensive upper surface and lower surface have a maximum difference in temperature to obtain best heat exchange efficiency, increasing the hot water supply greatly.
The further improvement of the invention is that the said coextensive surfaces are formed by an upper convex spherical crown. This will not only increase the heat exchange area as far as possible, but also make the hot water on the upper surface have the trend of getting together from nearby to the middle of the spherical crown to further improve the efficiency of the heat exchange.
Description of the drawings
Figure 1 is the structure diagram of one embodiment of this invention. Figure 2 is the structure diagram of another embodiment of this invention.
Description of illustrated embodiments
Embodiment 1
This embodiment is a kind of wall-hung solar water heater, see Figure 1. It mainly comprises a water storage tank and a solar heat collection device. Inner tank 2 covered with the insulating layer 1 is cylindrical with a vertical center axis. There is a hot water outlet tube 3 connected with the hot water tap near the upper end of the tank and a cold water inlet tube 4 connected with the water supply source near the lower end of the tank. So there must be internal pressure in the tank 2. The bottom of the cylindrical body or side wall 7 of the tank 2 is connected to the bottom or lower head 6 of the tank 2. The tank bottom 6 forms an upper convex spherical crown and has a downwardly extending cylindrical portion 6a centered on the vertical axis of the tank 2. The outer surface of the cylindrical portion 6a and the inner surface of the side wall 7 are tightly fitted; the bottom edge of the side wall 7 and the outer surface of the cylindrical portion 6a have a sealed connection by fillet welding. Similarly, the cylindrical portion 6a is connected to a lower cap 8. The outer surface of lower cap 8 and the inner surface of the cylindrical portion 6a are tightly fitted too, so the bottom edge of the cylindrical portion 6a and the outer surface of the lower cap have a sealed connection by fillet welding. The manufacturing process is feasible. Thus, a heat exchange cavity 20 is formed at the bottom of the tank 2, beneath and inside the tank bottom 6 and above the lower cap 8. At the bottom of the heat exchange cavity there are an inlet 19 and an outlet 18. The upper surface of the heat exchange cavity 20 is coextensive with the bottom surface of the tank 2. In other words, the tank bottom 6 is formed by a wall that has an upwardly convex upper surface defining the bottom of the tank 2, and the wall also having a downwardly concave lower surface that defines the top of the heat exchange cavity 20. The solar heat collection device is a kind of wall-hung solar heat collector which is suitable for placing on the outside of a balcony, for example. The heat collector contains a group of horizontal vacuum pipes 10. The ends of the horizontal vacuum pipes are plug-in mounted and supported on a vertical end bracket 9 and a header shell 12. The inner pipe 11 of the header is connected to the heat exchange medium liquid in the inner cavity of the vacuum pipes separately is fixed in the header shell 12. The inner pipe 11 has a filling opening 16 and a return opening 17, which are respectively connected to the outlet 18 and inlet 19 of the heat exchange cavity 20, forming a cyclical loop of heat exchange.
The solar energy absorbed by all vacuum pipes 10 gathered to the inner pipe of the header 11 by the siphoning of the heat exchange liquid in the pipe. Then the heat exchange medium liquid with high temperature flows up to the heat exchange cavity 20 through the thermal circulation liquid pipe and the heat exchange medium liquid with low temperature reflows to the inner pipe of the header 11 through the cold cycle liquid pipe 14. The heat exchange medium liquid which is into the heat exchange cavity 20 is in a trend of going up and gathering to the middle all the time, thus forming a great difference in temperature with the low temperature water near the bottom of the tank 2, thus achieving a optimum heat exchange effect. The experimental results show that the hot water supply in this embodiment has increased 30-50% relative to existing products and the effect is very significant. In addition, in order to resist heat expansion of heat exchange medium liquid leading to the internal pressure in the vacuum pipes and reduction of the heat exchange effect caused by the loss of the heat exchange medium liquid, the heat exchange cavity 20 is also connected with an expansion tank 22 through a refill tube 21.
Some of the advantages of this embodiment are:
1. Effective heat exchange: As the bottom of the inner tank and the top of the heat exchange cavity form the convection heat exchange effect, and the heat exchange surface of the spherical crown increases the area of the effective heat exchange, the heat exchange effect is better than the common heat exchange of transmission or radiation, increasing the hot water supply remarkably.
2. Inexpensive: Simple structure, feasible in the industry, manufacturing cost lower than the existing structure of "inner tank inside the inner tank" or coil heat exchange structure and without reducing the storage space of the inner tank. 3. Semi-automatic refilling: requires half tank of heat exchange liquid with addition of antifreeze in the expansion tank to achieve semi-automatic refilling by the drop.
In addition to the embodiment above, this invention can also have other embodiments. Any technical scheme adopting the similar modes or the equivalent modes can be in the protection range of this invention.
Embodiment 2
The embodiment has a horizontal pressurized solar water heater whose water tank is pressurized. As is shown in Fig. 2, it comprises a horizontal water tank which has two horizontally spaced or side ends and a solar heat collection device which has a fluid input port and a fluid output port. The horizontal water tank 2 encapsulated with a thermal insulated layer 1 is like a horizontal cylinder. The horizontal water tank 2 with a certain inner pressure has a water input pipe 4 connected with the cold water source and a water output pipe 3 connected with the port where hot water is taken and used. The height of the water output pipe 3 is higher than the water input pipe 4. A heat exchange cavity 20 is disposed on one of the ends of the horizontal water tank 2. The heat exchange cavity has an input port 19 and an output port 18. The convex spherical crown like inner surface 6 of the heat exchange cavity is the same as the outside surface of one side of the horizontal water tank 2. The convex spherical crown like inner surface 6 has an extended cylinder part which is mated tightly with the inner side of the cylinder body of the horizontal water tank 2, so the edge of the cylinder body and the outer circle of the cylinder part may form an ideal sealed space by angle welding. A bottom cover 8 is inserted into the concave part formed by the cylinder part of the inner surface 6. The outer edge of the bottom cover 8 is mated tightly with the inner side of the cylinder part. So the side end of the cylinder part and the outside of the bottom cover may form an ideal sealed space by angle welding, which is practical when manufacturing.
The solar heat collection device is a horizontal one with a pressurized tank, which is especially suited to be disposed outside on a balcony, for example. The heat collector comprises of a set of vacuum tubes 10 which are inserted into and supported at two ends by a vertical bracket 9 and by the connection tank 12. The connection tank has a fluid input port 16 and a fluid return port 17 which respectively communicate with the output port 18 and inlet port 19, forming a heat exchange circulation.
During operation, the solar energy absorbed by each vacuum pipe 10 will accumulate in the connection tank under the thermosyphon effect of the heat exchange medium in the pipes. Then, the heat exchange medium with higher temperature will rise into the heat exchange cavity 20 through the hot fluid circulation pipe 15, and the heat exchange medium with lower temperature will return to the connection tank through the cold fluid circulation pipe 14. Due to the characteristics that both the heat exchange medium and water with higher temperature will stay in a high position, and vice versa, the heat exchange medium H with higher temperature that enters the heat exchange cavity 20 may exchange heat efficiently with the water H' in the upper-middle of the horizontal water tank, thus hot water with high temperature being established to meet the users' needs of hot water in time.
Further, to avoid the inner pressure produced by the heat expansion of the heat exchange medium, and the degradation of heat exchange efficiency caused by the consumption of the heat exchange medium, the heat exchange cavity 20 is further connected with the expansion container 22. In this way, the two problems are solved simply.
Some of advantages of this embodiment are: 1 ) Heating layer by layer: the heat exchange medium will heat the upper water in the water tank firstly and then heat the lower water in the water tank since the water tank is horizontal and the hot and water mediums stay in different layer. So the water in the upper-middle of the water tank can still be heated to meet the bath need when the sunshine is not enough;
2) Anti-scale: water scales can be prevented efficiently since the heat exchange medium is separated from the horizontal tank totally and the heat exchange cavity is glass-lined on both sides;
3) Low cost: it is advantageous significantly in cost when compared with the common heat exchange ways: tank in tank or coil pipe heat exchange, since it only use its side cover for heat exchange.
The invention may be implemented in other ways rather than the above embodiments. The technical schemes that are formed by employing the equal replacements or equivalent transformations are both within the scope of the invention.