CN111256373B

CN111256373B - Solar air heating device with variable interval of heat release pipe sets

Info

Publication number: CN111256373B
Application number: CN202010127249.4A
Authority: CN
Inventors: 周守军; 张林华
Original assignee: Shandong Jianzhu University
Current assignee: Shandong Jianzhu University
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2021-03-09
Anticipated expiration: 2039-06-25
Also published as: CN110285589A; CN111256374A; CN111256374B; CN110285589B; CN111256373A

Abstract

The invention provides a solar air heating device with variable heat release pipe group spacing, which comprises an air pipeline and a heat collection device, wherein the heat collection device comprises a heat collection component and a heat release component; along the flowing direction of the air in the air pipeline, the left side or the right side heat release pipe group is set to be a plurality of, and from the top down direction, the interval of the left side or the right side adjacent heat release pipe group is constantly reduced. The invention provides a novel solar air heating device with a heat pipe structure, which is arranged in such a way that air is prevented from exchanging heat at the front part, and the heat exchange is increased towards the rear part as much as possible, so that a heat exchange effect similar to counter flow is formed, the vibration is more uniform, and the heat exchange and scale removal effects are enhanced.

Description

Solar air heating device with variable interval of heat release pipe sets

The application is a divisional application of 25/06/2019, application number 2019105519991, and invention name "a solar air heating device".

Technical Field

The invention belongs to the field of solar energy, and particularly relates to a solar air heating device.

Background

With the rapid development of modern socioeconomic, the demand of human beings on energy is increasing. However, the continuous decrease and shortage of traditional energy reserves such as coal, oil, natural gas and the like causes the continuous increase of price, and the environmental pollution problem caused by the conventional fossil fuel is more serious, which greatly limits the development of society and the improvement of the life quality of human beings. Energy problems have become one of the most prominent problems in the modern world. Therefore, the search for new energy sources, especially clean energy sources without pollution, has become a hot spot of research.

Solar energy is inexhaustible clean energy and has huge resource amount, and the total amount of solar radiation energy collected on the surface of the earth every year is 1 multiplied by 10¹⁸kW.h, which is ten thousand times of the total energy consumed in the world year. The utilization of solar energy has been used in all countries of the worldAn important item for the development of new energy. However, the solar radiation has a small energy density (about one kilowatt per square meter) and is discontinuous, which brings certain difficulties for large-scale exploitation and utilization. Therefore, in order to widely use solar energy, not only the technical problems but also the economic competition with conventional energy sources is required.

When the air heating device is heated by solar energy, the air is heated by solar energy or directly or hot air is generated by secondary heat exchange, but in the case, the lower hot fluid is required to naturally convect to the upper part, so that the heat exchange efficiency is low. Aiming at the structure of the solar air heating device, the prior art has been researched and developed a lot, but the whole heat collecting capability is not enough, and the problem that the operation time is long and scaling is easy to happen, so that the heat collecting effect is influenced.

In any form and structure of solar collector, there is an absorption component for absorbing solar radiation, and the structure of the collector plays an important role in absorbing solar energy.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a solar air heating device with a novel structure. The heating device can improve the heat collection effect.

In order to achieve the purpose, the invention adopts the following technical scheme:

a solar air heating device comprises an air pipeline and a heat collecting device, wherein the heat collecting device comprises a heat collecting component and a heat releasing component, the heat releasing component is arranged in the air pipeline, the heat collecting component is arranged outside a box body, the heat collecting component absorbs solar energy and releases heat into the air pipeline through the heat releasing component, and the heat is used for heating air passing through the air pipeline.

Preferably, the heat release tube group is provided in plural along the flow direction of the air in the air duct, and the tube diameter of the heat release tube group is increased along the flow direction of the air in the air duct.

Preferably, the heat collecting component comprises a heat collecting pipe box positioned at the lower part, the heat releasing component comprises a left upper pipe, a right upper pipe and a heat releasing pipe group, the left upper pipe and the right upper pipe are positioned at the upper part of the heat collecting pipe box, the heat releasing pipe group comprises a left heat releasing pipe group and a right heat releasing pipe group, the left heat releasing pipe group is communicated with the left upper pipe and the heat collecting pipe box, the right heat releasing pipe group is communicated with the right upper pipe and the heat collecting pipe box, so that the heat collecting pipe box, the left upper pipe, the right upper pipe and the heat releasing pipe group form a closed circulation of heating fluid, the heat releasing pipe group is one or more, each heat releasing pipe group comprises a plurality of heat releasing pipes in a circular arc shape, the end parts of the adjacent heat; the heat collection tube box comprises a first tube opening and a second tube opening, the first tube opening is connected with an inlet of the left heat release tube group, the second tube opening is connected with an inlet of the right heat release tube group, an outlet of the left heat release tube group is connected with the left upper tube, and an outlet of the right heat release tube group is connected with the right upper tube; the left heat-releasing pipe group and the right heat-releasing pipe group are symmetrical along the middle part of the heat-collecting pipe box.

Preferably, the heat release pipes of the left heat release pipe group are distributed around the axis of the left upper pipe, and the heat release pipes of the right heat release pipe group are distributed around the axis of the right upper pipe.

Preferably, the distance between the center of the upper left tube and the center of the upper right tube is M, the radii of the upper left tube and the upper right tube are the same, B is B, the radius of the axis of the innermost heat radiation tube in the heat radiation tubes is N1, and the radius of the axis of the outermost heat radiation tube is W2, so that the following requirements are satisfied:

N1/W2= a × Ln (B/M) + B; wherein a, b are parameters and Ln is a logarithmic function, wherein 0.5788< a <0.6002, 1.6619< b < 1.6623; preferably, a is 0.5790 and b is 1.6621.

Preferably, 35< B <61 mm; 230< M <385 mm; 69< N1<121mm, 119< W2<201 mm.

Preferably, the number of the heat release pipes of the heat release pipe group is 3 to 5, preferably 3 or 4.

Preferably, 0.55< N1/W2< 0.62; 0.154< B/M < 0.166.

Preferably, 0.57< N1/W2< 0.61; 0.158< B/M < 0.162.

Preferably, an included angle A formed between the midpoint of the bottom of the heat collection box body and the circle centers of the left upper tube and the right upper tube is 40-100 degrees (angle), and preferably 60 degrees (angle).

Preferably, the radius of the heat-radiating pipe is preferably 10-40 mm; preferably 15 to 35mm, more preferably 20 to 30 mm.

The invention has the following advantages:

1. the invention provides a novel solar air heating device with a heat pipe structure, which is provided with a heat collecting component and a heat releasing component, so that the heat transfer speed is high, the heat transfer speed of solar energy is improved, and the heat absorption capacity can be further met.

2. The heat collector with new structure has more heat releasing pipe groups in limited space to increase the vibration range of the pipe bundle, strengthen heat transfer and eliminate scale.

3. The heat exchange efficiency can be further improved by the arrangement of the pipe diameters and the interval distribution of the heat release pipe groups in the fluid flowing direction.

4. The invention optimizes the optimal relation of the parameters of the heat collecting device through a large amount of experiments and numerical simulation, thereby realizing the optimal heating efficiency.

Description of the drawings:

FIG. 1 is a front view of a heat collecting device according to the present invention.

Fig. 2 is a front view of the solar steam apparatus of the present invention.

FIG. 3 is a left side view of the heat collecting device of FIG. 1 according to the present invention.

FIG. 4 is a bottom view of the heat collecting device of FIG. 1 according to the present invention.

FIG. 5 is a schematic view showing the staggered arrangement structure of the heat releasing tube sets of the heat collecting device of the present invention.

FIG. 6 is a schematic diagram of a heat collecting device.

In the figure: 1. the heat-releasing pipe group comprises a left heat-releasing pipe group 11, a right heat-releasing

pipe group

12, 21, a left upper pipe, 22, a right upper pipe, 3, a free end, 4, a free end, 5, a free end, 6, a free end, 7, a heat-releasing pipe, 8, a heat-collecting pipe box, 9, an electric heater, 10 a first pipe orifice, 13 a second pipe orifice, a left backflow pipe 14, a right backflow pipe 15, a 16 reflector, 17 supporting pieces and 18 air pipelines.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

In this document, "/" denotes division and "×", "denotes multiplication, referring to formulas, if not specifically stated.

As shown in fig. 1, a heat collecting device comprises a heat collecting pipe box 8, a left upper pipe 21, a right upper pipe 22 and a heat releasing pipe group 1, wherein the heat releasing pipe group 1 comprises a left heat releasing pipe group 11 and a right heat releasing pipe group 12, the left heat releasing pipe group 11 is communicated with the left upper pipe 21 and the heat collecting pipe box 8, the right heat releasing pipe group 12 is communicated with the right upper pipe 22 and the heat collecting pipe box 8, so that the heat collecting pipe box 8, the left upper pipe 21, the right upper pipe 22 and the heat releasing pipe group 1 form a closed circulation of heating fluid, the heat collecting pipe box 8 is filled with phase change fluid, each heat releasing pipe group 1 comprises a plurality of heat releasing pipes 7 in an arc shape, the end parts of the adjacent heat releasing pipes 7 are communicated, so that the plurality of heat releasing pipes; the heat collecting tube box comprises a first tube opening 10 and a second tube opening 13, the first tube opening 10 is connected with an inlet of a left heat-releasing tube group 11, the second tube opening 13 is connected with an inlet of a right heat-releasing tube group 12, an outlet of the left heat-releasing tube group 11 is connected with a left upper tube 21, and an outlet of the right heat-releasing tube group 12 is connected with a right upper tube 22; the first nozzle 10 and the second nozzle 13 are disposed at one side of the heat collecting tube box 8. Preferably, the left and right heat-releasing

tube groups

11 and 12 are symmetrical along the middle of the heat collecting tube box.

Preferably, the left upper tube 21, the right upper tube 22 and the heat collecting tube box 8 extend in a horizontal direction.

Preferably, a plurality of heat radiation tube groups 1 are arranged along the horizontal direction of the left upper tube 21, the right upper tube 22 and the heat collecting tube box 8, and the heat radiation tube groups 1 are connected in parallel.

Preferably, a left return pipe 14 is disposed between the left upper pipe 21 and the heat collecting tube box 8, and a right return pipe 14 is disposed between the right upper pipe 22 and the heat collecting tube box 8. Preferably, the return pipe is provided at both ends in the horizontal direction.

The heat collecting tube box 8 is filled with phase-change fluid, preferably vapor-liquid phase-change fluid. The fluid heats and evaporates at the heat collecting tube box 8, flows along the heat release tube bundle to the upper left pipe 21 and the upper right pipe 22, and the fluid can produce volume expansion after being heated, thereby forming steam, and the volume of steam is far greater than water, and the steam that consequently forms can carry out the flow of quick impact formula in the coil pipe. Because of volume expansion and steam flow, the free end of the heat-radiating pipe can be induced to vibrate, the vibration is transmitted to the surrounding heat-exchanging fluid by the free end of the heat-exchanging pipe in the vibrating process, and the fluid can also generate disturbance, so that the surrounding heat-exchanging fluid forms disturbance flow, a boundary layer is damaged, and the purpose of enhancing heat transfer is realized. The fluid is condensed and released heat on the left upper pipe and the right upper pipe and then flows back to the heat collecting pipe box through the return pipe.

According to the invention, the prior art is improved, and the upper pipe and the heat release pipe groups are respectively arranged into two groups distributed on the left side and the right side, so that the heat release pipe groups distributed on the left side and the right side can perform vibration heat exchange descaling, the heat exchange vibration area is enlarged, the vibration can be more uniform, the heat exchange effect is more uniform, the heat exchange area is increased, and the heat exchange and descaling effects are enhanced.

Preferably, the heat release pipes of the left heat release pipe group are distributed around the axis of the left upper pipe, and the heat release pipes of the right heat release pipe group are distributed around the axis of the right upper pipe. The left upper pipe and the right upper pipe are arranged as circle centers, so that the distribution of the heat release pipes can be better ensured, and the vibration and the heating are uniform.

Preferably, the left heat-releasing tube group and the right heat-releasing tube group are both plural.

Preferably, the left heat-releasing tube group and the right heat-releasing tube group are mirror-symmetrical along a plane on which a vertical axis of the heat collecting tube box is located. Through such setting, can make the heat release pipe distribution of heat transfer more reasonable even, improve the heat transfer effect.

Preferably, the heat collecting tube box 8 has a flat tube structure. The heat absorption area is increased by arranging the flat tube structure. So that the heat collecting tube box 8 is secured at the focal position of the reflecting mirror even if the installation position is somewhat inexpensive.

Preferably, the left heat-releasing tube group 21 and the right heat-releasing tube group 22 are staggered in the horizontal extending direction, as shown in fig. 5. Through the staggered distribution, can make to vibrate on different length and release heat and scale removal for the vibration is more even, strengthens heat transfer and scale removal effect.

Preferably, a reflecting mirror 16 is provided at a lower portion of the heat collecting device, the heat collecting tube box is located at a focal position of the reflecting mirror 16, and the left and right heat releasing tube groups are located in the air duct. Thereby forming a solar energy collection system.

Preferably, a support 17 is included, and the support 17 supports the heat collecting device.

Preferably, an air duct is included, within which air flows. As shown in fig. 2, the heat collecting tube box 8 is located at a lower end of the air tube, as shown in fig. 2. The left upper tube 21, the right upper tube 22, the left heat releasing tube group 11, and the right heat releasing tube group 12 are disposed in the air duct, and heat the air flowing in the air duct by releasing heat.

Preferably, the air flows in the same direction as the left and right

upper tubes

21 and 22 and the heat collecting tube box 8 extend. Through such setting for the air is when flowing erodees room heat pipe group, especially is put the free end of hot tube group, thereby makes the free end vibration, thereby strengthens heat transfer, reaches the effect of scale removal.

Preferably, the heat release tube group 2 is provided in plural (for example, on the same side (left side or right side)) along the flow direction of the air in the air duct, and the tube diameter of the heat release tube group 2 (for example, on the same side (left side or right side)) along the flow direction of the air in the air duct is increased.

Along the flowing direction of the air, the temperature of the air is continuously improved, so that the heat exchange temperature difference is continuously reduced, and the heat exchange capacity is more and more. Through the pipe diameter grow of heat release nest of tubes, can guarantee that more steam passes through upper portion and gets into heat release nest of tubes, guarantee along the air flow direction, because the steam volume is big and the vibration is effectual to make whole heat transfer even. The distribution of steam in all heat release pipe groups is even, further strengthens heat transfer effect for the whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect.

Preferably, the heat release pipe diameter of the heat release pipe group (for example, the same side (left side or right side)) is increased along the flow direction of the air in the air duct.

Through so setting up, avoid the air all to carry out the heat transfer at front, and the heat transfer of makeing increases to the rear portion to form the heat transfer effect similar to the adverse current. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

Preferably, the heat release pipe groups on the same side (left side or right side) are arranged in plurality along the flowing direction of the air in the air pipeline, and the distance between the adjacent heat release pipe groups on the same side (left side or right side) is gradually reduced from the top to the bottom. The specific effect is similar to the effect of the previous pipe diameter change.

Preferably, the spacing between the heat release pipe groups on the same side (left side or right side) along the flow direction of the air in the air duct is increased in a decreasing range. The specific effect is similar to the effect of the previous pipe diameter change.

In tests, it was found that the tube diameters and distances of the upper left tube 21 and the upper right tube 22 and the tube diameters of the heat release tubes can have an influence on the heat exchange efficiency and uniformity. If the distance between the collector is too big, then heat exchange efficiency is too poor, and the distance between the heat release pipe is too little, then heat release pipe distributes too closely, also can influence heat exchange efficiency, and the pipe diameter size of collector and heat exchange tube influences the volume of the liquid or the steam that holds, then can exert an influence to the vibration of free end to influence the heat transfer. Therefore, the tube diameters and distances of the upper left tube 21 and the upper right tube 22 and the tube diameters of the heat release tubes have a certain relationship.

The invention provides an optimal size relation summarized by numerical simulation and test data of a plurality of heat pipes with different sizes. Starting from the maximum heat exchange amount in the heat exchange effect, nearly 200 forms are calculated. The dimensional relationship is as follows:

the distance between the center of the upper left tube 21 and the center of the upper right tube 21 is M, the tube diameter of the upper left tube 21 and the radius of the upper right tube 22 are the same, B is B, the radius of the axis of the innermost heat radiation tube in the heat radiation tube is N1, and the radius of the axis of the outermost heat radiation tube is W2, so that the following requirements are met:

Preferably, 35< B <61 mm; 230< M <385 mm; 69< N1<121mm, 119< W2<201 mm.

Preferably, 0.55< N1/W2< 0.62; 0.154< B/M < 0.166.

Preferably, 0.57< N1/W2< 0.61; 0.158< B/M < 0.162.

Preferably, an included angle A formed between the midpoint of the bottom of the heat collection box and the circle centers of the upper left tube 21 and the upper right tube 22 is 40-100 degrees (angle), and preferably 60 degrees (angle).

Preferably, the arc between the ends of the free ends 3, 4, centered on the central axis of the left header, is 95-130 degrees, preferably 120 degrees. The same applies to the curvature of the free ends 5, 6 and the free ends 3, 4. Through the design of the preferable included angle, the vibration of the free end is optimal, and therefore the heating efficiency is optimal.

Preferably, the tube bundle of the heat-releasing tube group 1 is an elastic tube bundle.

The heat exchange coefficient can be further improved by arranging the tube bundle of the heat release tube group 1 with an elastic tube bundle.

The number of the heat release pipe groups 1 is plural, and the plurality of the heat release pipe groups 1 are in a parallel structure.

Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A solar air heating device with variable heat release pipe group spacing comprises an air pipeline and a heat collection device, wherein the heat collection device comprises a heat collection component and a heat release component, and the heat release component is arranged in the air pipeline; the heat collection component comprises a heat collection tube box positioned at the lower part, the heat release component comprises a left upper tube, a right upper tube and a heat release tube group, the left upper tube and the right upper tube are positioned at the upper part of the heat collection tube box, the heat release tube group comprises a left heat release tube group and a right heat release tube group, the left heat release tube group is communicated with the left upper tube and the heat collection tube box, and the right heat release tube group is communicated with the right upper tube and the heat collection tube box; the heat-releasing pipe group is characterized in that one or more heat-releasing pipe groups are provided, each heat-releasing pipe group comprises a plurality of arc-shaped heat-releasing pipes, the end parts of the adjacent heat-releasing pipes are communicated, the plurality of heat-releasing pipes form a serial structure, and the end parts of the heat-releasing pipes form the free ends of the heat-releasing pipes; the heat collection tube box comprises a first tube opening and a second tube opening, the first tube opening is connected with an inlet of the left heat release tube group, the second tube opening is connected with an inlet of the right heat release tube group, an outlet of the left heat release tube group is connected with the left upper tube, and an outlet of the right heat release tube group is connected with the right upper tube; the left heat-releasing pipe group and the right heat-releasing pipe group are symmetrical along the middle part of the heat-collecting pipe box; along the flowing direction of the air in the air pipeline, a plurality of left or right heat-releasing pipe groups are arranged, and along the flowing direction of the air in the air pipeline, the distance between the left or right adjacent heat-releasing pipe groups is continuously reduced; a left return pipe is arranged between the upper left pipe and the heat collection pipe box, and a right return pipe is arranged between the upper right pipe and the heat collection pipe box.

2. The solar air heating apparatus of claim 1, wherein the interval between the left or right banks is gradually decreased and gradually increased along the flow direction of the air in the air duct.

3. The solar air heating apparatus as claimed in claim 1, wherein the heat discharging pipes of the left heat discharging pipe group are distributed around the axis of the left upper pipe, and the heat discharging pipes of the right heat discharging pipe group are distributed around the axis of the right upper pipe.