Rhombic heat pipe type heat collecting pipe and heat collector thereof

Abstract

The invention provides a rhombic heat pipe type heat collecting pipe which is characterized in that a sealed vacuumizing space is formed among an upper cavity, a lower cavity, an ascending pipe and a descending pipe, and the lower cavity is filled with liquid; the condenser is arranged on the lower portion of the heat collecting pipe and used for concentrating sunlight to the lower portion of the lower cavity and heating liquid in the lower cavity, and the liquid evaporates along the ascending pipe after absorbing heat, enters the upper cavity and then returns to the lower cavity along the descending pipe. And at least one part of the ascending pipe, the descending pipe and the upper cavity exchanges heat with a cold source in the heat collecting pipe. The structure of the heat collector is improved, the upper cavity, the lower cavity, the ascending pipe and the descending pipe are arranged, liquid in the cavities can be rapidly evaporated, the whole ascending pipe, the whole descending pipe and the whole heat collecting pipe are filled with steam, a cold source in a base pipe is rapidly heated, and the absorption speed of solar energy is greatly increased.

Description

Technical Field

[0001] The invention belongs to the field of solar energy, and in particular relates to a rhombus heat pipe type heat collecting tube and a heat collector thereof. Background Art

[0002] With the rapid development of modern social economy, human beings have an increasing demand for energy. However, the reserves of traditional energy such as coal, oil, and natural gas are constantly decreasing and becoming increasingly scarce, causing prices to continue to rise. At the same time, the environmental pollution caused by conventional fossil fuels is becoming more and more serious, which greatly restricts the development of society and the improvement of human quality of life. The energy problem has become one of the most prominent problems in the contemporary world. Therefore, seeking new energy, especially pollution-free clean energy, has become a hot topic of research.

[0003] Solar energy is an inexhaustible clean energy source with huge resources. The total amount of solar radiation energy received by the earth’s surface each year is 1×10 18 kW·h, which is more than 10,000 times the world's total annual energy consumption. Countries around the world have already regarded the use of solar energy as an important part of new energy development. However, since the energy density of solar radiation reaching the earth is low (about 1 kilowatt per square meter) and it is discontinuous, this brings certain difficulties to large-scale development and utilization. Therefore, in order to widely use solar energy, not only technical problems must be solved, but also it must be able to compete with conventional energy in terms of economy.

[0004] According to records, human beings have been using solar energy for more than 3,000 years. The use of solar energy as a source of energy and power has only been around for more than 300 years. It is only in recent years that solar energy has been truly used as "an urgently needed supplementary energy source" and "the foundation of the future energy structure". Since the 1970s, solar energy technology has made great progress, and the use of solar energy has changed with each passing day. The history of modern solar energy use can be traced back to 1615, when French engineer Solomon de Cox invented the world's first solar-driven engine. The invention is a machine that uses solar energy to heat air to expand and pump water. Between 1615 and 1900, many solar power devices and some other solar power devices were developed in the world. Almost all of these power devices use concentrating methods to collect sunlight, the engine power is not large, the working fluid is mainly water vapor, the price is expensive, and the practical value is not great. Most of them are researched and manufactured by solar energy enthusiasts.

[0005] Solar collectors use solar energy to provide heat sources such as domestic hot water, saving energy, but the existing solar water heaters have low heat collection efficiency and cannot meet the requirements. In addition, the existing solar energy is basically heated by the flow of fluid in the heat collecting tube, and the heat is absorbed by the heat collecting tube, which has low heating efficiency.

[0006] The prior art provides solar water heaters with natural circulation hot and cold diversion, for example, a solution is proposed in CN104296395A. A solar drinking water heater, comprising an insulated water tank installed on an indoor wall, characterized in that: a downcomer connected in parallel is vertically arranged in the insulated water tank, and the insulated water tank is divided into four chambers in total along three layers of metal partition plates, each of which is provided with a water hole connecting adjacent chambers, and the four chambers from top to bottom serve as a tap water inlet chamber, a first hot water chamber, a second hot water chamber, and a drinking water chamber, respectively. The downcomer passes through the three layers of metal partition plates to penetrate into each chamber, and the downcomer is welded to each layer of metal partition plates as a whole, a tap water interface connected to the tap water inlet chamber is installed on the top of the insulated water tank, and a boiling water outlet connected to the drinking water chamber is installed on the bottom of the insulated water tank, wherein an electric heater extending into the drinking water chamber is installed on the side of the insulated water tank corresponding to the drinking water chamber, and the insulated water A hot water outlet connected to the second hot water cavity is also installed on the side of the box. The bottom end of the downpipe is connected to a delivery pipe. The delivery pipe passes vertically downward from the bottom of the insulated water tank and then extends to the outdoor wall. The lower end of the delivery pipe hangs down to the outdoor wall and is connected to the connecting pipe. The upper end of the delivery pipe is connected to the lower end interface of the downpipe, and the lower end of the delivery pipe is connected to the upper end interface of the connecting pipe. The height of the lower end interface of the downpipe is greater than the height of the upper end interface of the connecting pipe. The connecting pipe is arranged on the outdoor wall perpendicular to the horizontal plane. The connecting pipe is respectively welded with pipe interfaces side by side along the axial direction. The pipe interfaces are connected to the metal heat collecting pipes. The multiple metal heat collecting pipes are respectively parallel to the horizontal plane and are located in the same vertical plane perpendicular to the horizontal plane. Each metal heat collecting pipe is respectively covered with a double-layer vacuum transparent glass insulation pipe, and all the pipe openings of the double-layer vacuum transparent glass insulation pipes are respectively equipped with air plugs. The above technical solution adopts a split natural circulation hot and cold shunt structure, which causes the shunt structure of the water heater to be large in size, long in flow path, and large in heat loss. Moreover, because most of the pipes are exposed to the outside, the cold source cannot be directly heated, resulting in a low heating effect.

[0007] Therefore, in view of the above problems, the present invention provides a collector with a new structure, which greatly improves the heat absorption effect of solar energy. Summary of the invention

[0008] The present invention provides a new structure of the heat collector, thereby solving the above-mentioned technical problems.

[0009] In order to achieve the above object, the technical solution of the present invention is as follows:

[0010] A rhombus heat pipe type heat collecting tube, the heat collecting tube comprises a rhombus-shaped base tube, characterized in that two diagonals of the rhombus are respectively located at the upper part and the lower part; an upper chamber, a lower chamber, and an ascending tube and a downcomer connecting the upper chamber and the lower chamber are arranged in the base tube, the upper chamber is arranged in the upper part of the base tube, the lower chamber is arranged in the lower part of the base tube, the ascending tube connects the middle position of the upper chamber and the lower chamber, and the downcomer is arranged on both sides of the ascending tube; a closed vacuum space is formed between the upper chamber, the lower chamber, the ascending tube and the downcomer, and the lower chamber is filled with liquid; the concentrator is arranged in the lower part of the heat collecting tube, for concentrating sunlight to the lower part of the lower chamber, for heating the liquid in the lower chamber, the liquid evaporates along the ascending tube after absorbing heat, enters the upper chamber, and then returns to the lower chamber along the downcomer; at least a part of the ascending tube, the downcomer and the upper chamber exchanges heat with a cold source in the heat collecting tube.

[0011] Preferably, the centerline of the riser passes through the center of the base pipe.

[0012] Preferably, the center line of the downcomer is parallel to the sides of the rhombus.

[0013] Preferably, the upper chamber and the lower chamber are rhombus-shaped structures.

[0014] Preferably, a line connecting the centers of the rhombuses of the upper chamber and the lower chamber passes through the center of the substrate tube.

[0015] Preferably, the diameter of the ascending pipe is larger than that of the descending pipe.

[0016] Preferably, the diameter of the ascending pipe is 2-3 times the diameter of the descending pipe.

[0017] Preferably, the riser pipe extends into the upper chamber to a certain height.

[0018] Preferably, the length of the riser extending into the upper chamber is 30-50% of the height of the upper chamber.

[0019] A heat collector comprises the above-mentioned heat collecting tube.

[0020] A solar energy system includes a thermal collector.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The prior art basically directly collects the fluid in the heat collecting tube, and the heating position is the position where a single light is focused. The present invention improves the collector structure, and by setting the upper and lower chambers and the riser and downcomer, the liquid in the chamber can be evaporated quickly so that the steam and the heat source fluid fill the entire riser and downcomer, and fill the entire heat collecting tube. The heat source is distributed throughout the heat collecting tube, so that the heat source distribution range is wide, the heat exchange area with the cold source is large, and the cold source in the base tube is quickly heated, which greatly improves the absorption rate of solar energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the cross-sectional structure of the heat collector of the present invention;

[0024] Figure 2 is a schematic diagram of the cross-sectional structure of the improved collector of the present invention;

[0025] Figure 3 The present invention Figure 1 Schematic diagram of the cross section of the collector tube axis;

[0026] Figure 4 It is a schematic diagram of the structure of the solar energy system of the present invention. DETAILED DESCRIPTION

[0027] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Figure 1-2 A rhombus heat pipe solar collector is shown, the collector comprises a rhombus heat collecting tube, the heat collecting tube comprises a rhombus base tube 1, the two diagonal angles of the rhombus are respectively located at the upper part and the lower part, forming the upper angle and the lower angle, and the other two diagonal angles are respectively located at the left side and the right side, forming the left angle and the right angle. An upper chamber 2, a lower chamber 3, and an ascending tube 4 and a descending tube 5 connecting the upper chamber and the lower chamber are arranged in the base tube, the upper chamber 2 is arranged at the upper part of the base tube 1, the lower chamber 3 is arranged at the lower part of the base tube, the ascending tube 4 is connected to the middle position of the upper chamber 2 and the lower chamber 3, and the descending tube 5 is arranged on both sides of the ascending tube 4; a closed vacuum space is formed between the upper chamber, the lower chamber, the ascending tube and the descending tube, and the lower chamber 3 is filled with liquid.

[0029] The concentrator is arranged at the lower part of the heat collecting tube, and is used to concentrate sunlight to the lower part of the lower chamber, and is used to heat the liquid in the lower chamber. After absorbing heat, the liquid evaporates along the ascending tube, enters the upper chamber, and then returns to the lower chamber along the descending tube; at least a part of the ascending tube, the descending tube and the upper chamber exchanges heat with the fluid in the heat collecting tube. Generally, the downward flow in the descending tube is the condensed liquid or vapor-liquid mixture after heat exchange.

[0030] In the prior art, the cold source fluid in the heat collecting tube is basically directly collected, and the heating position is the position where a single light is focused. The present invention improves the collector structure. By setting the upper and lower chambers and the riser and downcomer, the liquid in the chamber can be evaporated quickly so that the steam fills the entire riser and downcomer, and fills the entire heat collecting tube. The heat source is distributed in the entire heat collecting tube, so that the heat source distribution range is wide, the heat exchange area with the cold source is large, and the cold source in the base tube is quickly heated, which greatly improves the absorption rate of solar energy.

[0031] As an improvement, Figure 1 As shown, the centerline of the riser passes through the center of the base pipe. Figure 1 As shown, the center line of the downcomer is parallel to the side of the rhombus, so that the downcomer forms a bent structure. The above arrangement can make the overall heat evenly distributed in the heat collecting tube, making the overall heat exchange effect uniform and improving the heat exchange effect.

[0032] As an improvement, Figure 1 As shown, the upper chamber and the lower chamber are diamond-shaped structures, the upper chamber includes two sides of the upper corner, and the lower chamber includes two sides of the lower corner. The lower part of the upper chamber is bent downward, and the upper part of the lower chamber is bent upward. By setting the bending shape, the liquid can evaporate quickly and achieve the effect of suction.

[0033] As an improvement, the line connecting the centers of the upper chamber and the lower chamber passes through the center of the base tube 1. The above arrangement can make the overall heat evenly distributed in the heat collecting tube, making the overall heat exchange effect uniform and improving the heat exchange effect.

[0034] As an improvement, the diameter of the riser is larger than that of the downcomer, which is 2-3 times the diameter of the downcomer. By setting the diameter of the riser to be larger than that of the downcomer, the flow resistance of the riser is smaller than that of the downcomer, which can promote steam to flow from the riser and downcomer, thereby promoting the circulation of the fluid.

[0035] As an improvement, the angle between the upper and lower corners is greater than that between the left and right corners. The above arrangement allows the base pipe to be distributed to both sides, which enables the riser and downcomer to circulate fully, and avoids the riser steam from being difficult to reach the upper part due to the base pipe being too high.

[0036] As an improvement, Figure 2 As shown, the riser goes deep into the upper chamber to a certain height, which is 30-50% of the height of the upper chamber. By rising to a certain height, it can be ensured that the evaporation enters the upper chamber, and the condensed liquid in the upper chamber is prevented from entering the riser.

[0037] As an improvement, Figure 2As shown, multiple rows of downcomers are arranged around the center of the base tube, wherein the closer the distance to the center, the smaller the diameter of the downcomer. By setting the downcomer to have a smaller diameter as it is closer to the center, the flow resistance of the downcomer close to the riser can be increased to prevent steam from entering the downcomer, thereby enhancing fluid circulation. As the distance from the center increases, it is less likely for steam to enter the downcomer, so the diameter of the tube is set larger to achieve the purpose of enhancing heat transfer while preventing steam from entering the downcomer.

[0038] As an improvement, the diameter of the downcomer decreases more and more as the distance from the center increases. The above arrangement can further prevent steam from entering the downcomer and simultaneously enhance heat transfer.

[0039] The present invention also discloses a solar energy system, such as Figure 4 As shown, the system includes a heat collector and a heat exchanger, and the fluid heated in the heat collector enters the heat exchanger for heat exchange. The heat collector is the heat collector mentioned above.

[0040] As an improvement, the heat exchanger is a horizontal shell and tube heat exchanger. As an improvement, a baffle is arranged in the tube side of the heat exchanger. The hot fluid flows in the tube side, and the cold fluid flows in the shell side. The shell side and the tube side are countercurrent flows, and along the flow direction of the fluid in the tube side, the spacing of the baffles increases continuously from the tube side inlet to the middle position of the tube side. Then from the middle position of the tube side to the tube side outlet, the spacing of the baffles decreases continuously. Because in the countercurrent process, the heat exchange of the shell side and the tube side per unit length along the flow process of the fluid is relatively uniform, so that the overall heat exchange effect is the best. However, it was found in experiments and simulations that the heat exchange in the middle is significantly greater than the heat exchange at the inlet and outlet of the tube side. Therefore, by changing the spacing between the baffles, the heat exchange area between the tube side fluid in the baffle and the shell side fluid source also changes. Therefore, the uneven heat exchange is compensated by the change in area, thereby further improving the heat exchange efficiency.

[0041] As an improvement, along the flow direction of the fluid in the tube, from the tube entrance to the middle of the tube, the distance between the baffles increases continuously. Then, from the middle of the tube to the tube exit, the distance between the baffles decreases continuously. The above changes in the range can make the heat exchange per unit length of the entire fluid movement more uniform, further improving the heat exchange efficiency.

[0042] As an improvement, Figure 3 As shown, the upper chamber and the lower chamber extend along the axial extension direction of the heat collecting tube.

[0043] As an improvement, multiple rows of risers and downcomers are arranged along the axial direction of the heat collecting tube (the direction of the cold source flow), for example Figure 3Multiple rows of risers are shown in the figure. Along the flow direction of the cold source, the diameters of the risers and downcomers are getting larger and larger. By setting the diameter of the pipe to gradually increase, the heat transfer is enhanced at the back, because as the cold source continues to flow, the temperature becomes higher and higher, and the heat exchange effect becomes worse and worse. By increasing the diameter of the pipe and increasing the heat transfer area, the overall heat exchange in the flow direction of the cold source is uniform, and a heat exchange effect similar to countercurrent is achieved, thereby achieving the purpose of enhanced heat transfer. In addition, by increasing the diameter of the pipe, as the pressure of the fluid flows, more steam moves in the direction of the fluid flow, which can also relieve the front pressure and balance the overall pressure. Moreover, because the fluid distribution increases, the heat exchange efficiency along the flow direction of the fluid is increased, which further makes the overall heat exchange uniform, achieving a heat exchange effect similar to countercurrent, thereby achieving the purpose of enhanced heat transfer.

[0044] Along the flow direction of the cold source, the diameters of the riser and downcomer are increased more and more, which can further achieve a heat exchange effect similar to counterflow and achieve the purpose of enhanced heat transfer.

[0045] As an improvement, multiple rows of risers and downcomers are arranged along the axial direction of the heat collecting tube (the flow direction of the cold source), wherein the distance between adjacent rows of risers is getting smaller and smaller along the flow direction of the cold source, and the distance between adjacent rows of downcomers is getting smaller and smaller. This strengthens the heat transfer at the back, because as the cold source continues to flow, the temperature is getting higher and higher, and the heat exchange effect is getting worse and worse. By increasing the distribution density and enlarging the heat transfer area, the overall heat exchange in the flow direction of the cold source is uniform, achieving a heat exchange effect similar to countercurrent, and achieving the purpose of strengthening heat transfer. In addition, by increasing the density, as the fluid flow pressure decreases, more steam moves in the direction of fluid flow, which can also relieve the front end pressure and balance the overall pressure. Moreover, because the fluid distribution increases, the heat exchange efficiency along the flow direction of the fluid is increased, further making the overall heat exchange uniform, achieving a heat exchange effect similar to countercurrent, and achieving the purpose of strengthening heat transfer.

[0046] Along the flow direction of the cold source, the distance between the adjacent rows of risers is getting smaller and larger, and the distance between the adjacent rows of downcomers is getting smaller and larger. This can further achieve a heat exchange effect similar to countercurrent flow and achieve the purpose of enhanced heat transfer.

[0047] Although the present invention has been disclosed as above with preferred embodiments, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A rhombus heat pipe type heat collecting tube, the heat collecting tube comprising a rhombus base tube, characterized in that: The two diagonals of the rhombus are located at the upper part and the lower part respectively; an upper chamber, a lower chamber, and an ascending pipe and a downcomer connecting the upper chamber and the lower chamber are arranged in the base tube, the upper chamber is arranged at the upper part of the base tube, the lower chamber is arranged at the lower part of the base tube, the ascending pipe is connected to the middle position of the upper chamber and the lower chamber, and the downcomer is arranged on both sides of the ascending pipe; a closed vacuum space is formed between the upper chamber, the lower chamber, the ascending pipe and the downcomer, and the lower chamber is filled with liquid; the concentrator is arranged at the lower part of the heat collecting tube, for concentrating sunlight to the lower part of the lower chamber, for heating the liquid in the lower chamber, and the liquid evaporates along the ascending pipe after absorbing heat, enters the upper chamber, and then returns to the lower chamber along the downcomer; at least a part of the ascending pipe, the downcomer and the upper chamber exchanges heat with the cold source in the heat collecting tube.

2. The heat collector according to claim 1, characterized in that: The centerline of the riser pipe passes through the center of the base pipe.

3. The heat collector according to claim 1, characterized in that: The centerline of the downcomer is parallel to the sides of the rhombus.

4. The heat collector according to claim 1, characterized in that: The upper chamber and the lower chamber are rhombus-shaped structures.

5. The heat collector according to claim 4, characterized in that: A line connecting the centers of the rhombuses of the upper and lower chambers passes through the center of the substrate tube.

6. The heat collector according to claim 1, characterized in that: The diameter of the riser is larger than that of the downcomer.

7. The heat collector according to claim 6, characterized in that: The diameter of the riser is 2-3 times that of the downcomer.

8. The heat collector according to claim 1, characterized in that: The riser pipe extends into the upper chamber to a certain height.

9. The heat collector according to claim 8, characterized in that: The length of the riser extending into the upper chamber is 30-50% of the height of the upper chamber.

10. A heat collector, comprising a heat collecting tube, wherein the heat collecting tube is the heat collector according to any one of claims 1 to 9.

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