CN202660792U - Whole-face convection flat solar heat-collecting plate core - Google Patents

Abstract

The utility model discloses a whole convective flat solar heat collecting plate core. It consists of the following structure: two parallel fluid inlet and outlet pipes; slots are provided at the matching positions on the opposite sides of the fluid inlet and fluid outlet pipes, and between the slotted positions There is a closed cavity formed by heat collecting plates parallel to each other in the axial direction and side sealing plates at both ends, and at least one side of the outer surface of the two heat collecting plates is provided with a spectrally selective coating; inside the closed cavity A number of S-shaped flow channels are formed by connecting several vertical baffles and horizontal baffles at staggered heights. The utility model effectively improves the heat transfer performance of the flat solar heat collecting plate core, reduces the radiation loss of the heat collecting plate core, not only increases the flow of the fluid working medium, but also ensures the relative uniformity of the fluid temperature in the heat collecting plate core , The fluid capacity is small, and the heating starts quickly. Simultaneously, the utility model has the advantages of simple processing, low cost , long service life and good economic and social benefits.

Description

A whole convective flat solar collector plate core

technical field

The utility model relates to a flat solar heat collecting board core, in particular to a flat solar heat collecting board core with whole convection flow. It belongs to the technical field of solar thermal utilization.

Background technique

Energy, environment and sustainable development are the themes of the survival and development of human society in the 21st century. In the field of solar thermal utilization technology, flat-panel solar energy has the advantages of long service life, pressure-bearing operation, no system failure, and easy building integration, so it is favored by more and more construction engineers. The research on flat-panel solar energy focuses on four aspects: selective coating process, enhanced heat transfer of heat collector plate core, performance improvement of light-transmitting material and heat preservation.

The flat-panel solar panel cores on the international and domestic markets basically adopt the form of welding a heat-absorbing panel with a selective coating and a side-by-side copper tube. Although the form of the flat solar panel core is relatively convenient in terms of processing, it is unreasonable from the perspective of heat transfer. In this form, the heat-absorbing panel can be regarded as a surface heat source, and the fluid working medium in the collector flows in the tube. Since the contact area between the copper tube and the heat-absorbing panel is limited, the heat absorbed by the heat-absorbing surface needs to be transferred in the form of heat conduction first. Transferred to the place in contact with the copper tube, and further transferred to the inner wall of the tube, the heat-absorbing fluid can take away the solar heat by convection. Due to the limited heat transfer capacity and the high temperature of the heat-absorbing surface, it will inevitably cause a large heat loss.

In 2001, Li Jianhong, Guangzhou Institute of Energy Research, Chinese Academy of Sciences and others conducted a comparative test by adding a polycarbonate (PC) transparent heat insulation board above the core of the flat solar heat collector, and achieved good test results. The coefficient is only 2.90W/ (m2 ℃ ) (Acta Solaris). In addition, there are some researchers (such as Wang Yanwei and Zhang Hongmin of Harbin Institute of Technology; India's N. Akhtar) to reduce heat loss by means of double-layer glass and vacuum glass. It should be pointed out that adding new light-transmitting materials will inevitably increase the cost . As early as 1992, Chen Lijun of the Beijing Institute of Solar Energy Research trial-produced heat pipe-type flat solar energy (Acta Solar Energy Sinica). In 2011, Zhao Yaohua of Beijing University of Technology studied a flat micro-heat pipe array, which can be used for solar heat collector cores; University of Science and Technology of China Pei Gang has researched a heat pipe flat panel solar heat collector (thermal science and technology). The research on using heat pipes as the core of heat collectors has achieved good results, but heat pipes also have problems of high price and effectiveness.

In 2002, Avraham I. Kudish of Israel reported the entire convective flat solar collector in the journal Energy Conversion and Management. The thermal resistance of form convective heat transfer is small, and the solar heat collection efficiency is about 50–60%. In 2010, A. Alvarez of Spain reported the development of a serpentine channel flat sun in the journal Solar Energy. Because the fluid working medium travels a long distance in the plate core, the heat exchange is sufficient, and the outlet water temperature is relatively high. The studies of Avraham I. Kudish and A. Alvarez have their own advantages and limitations. Avraham I. Kudish's design process is partial; The heat transfer temperature difference is larger, while the heat transfer temperature difference at the end is smaller.

Contents of the invention

The utility model is proposed in response to the above problems, and the purpose is to provide a process that not only increases the fluid working medium, but also ensures the relative uniformity of the fluid temperature in the heat collecting plate core, and effectively improves the transfer heat of the flat solar heat collecting plate core. Ability to reduce the radiation loss of the collector plate core of a whole convective flat solar collector plate core.

In order to achieve the above object, the technical solution of the utility model to solve technical problems is:

A whole convective flat-plate solar collector plate core is composed of the following structures: two parallel fluid inlet main pipes and fluid outlet main pipes; the adaptation of the fluid inlet main pipe and the fluid outlet main pipe Each position is provided with slots, and a closed cavity formed by heat collecting plates parallel to each other in the axial direction and side sealing plates at both ends is provided between the slots, and the outer surfaces of at least one side of the two heat collecting plates A spectrally selective coating is provided; several vertical baffles and horizontal baffles are connected at staggered heights in the closed cavity to form several S-shaped flow channels.

The fluid inlet main pipe and the fluid outlet main pipe are circular pipes.

One end of the fluid inlet main pipe is provided with a fluid inlet, and the end of the fluid outlet main pipe opposite to the fluid inlet is provided with a fluid outlet.

The distance between the two heat collecting plates is less than 1/3 of the diameter of the fluid inlet and outlet main pipes.

Compared with the prior art, the utility model has the following advantages and effects:

Because the utility model adopts the design of co-direction side-by-side flow channels and single flow channel S process, the heat transfer performance of the flat solar collector plate core is effectively improved, the radiation loss of the heat collector plate core is reduced, and the efficiency of the fluid working medium is increased. The process ensures the relative uniformity of the fluid temperature in the heat collecting plate core. And because the utility model adopts the form of 1/3 of the diameter of the fluid inlet and outlet main pipes, the fluid capacity is small and the heating starts quickly. Simultaneously, the utility model has the advantages of simple processing, low cost , long service life and good economic and social benefits.

In order to verify the heat transfer performance of the utility model's full convective flat solar collector core, a comparative test between the utility model (A) and the conventional solar collector core (B) was carried out. A is all made of alloy materials, the heat-absorbing plate of B is made of alloy materials, the heat exchange flow channel is made of copper tubes, and the outer frames of A and B have the same area. The test was carried out indoors under the same test environment. The same electric heating film was pasted on the surface of A and B to simulate solar radiation. The electric heating intensity was 1000w/m ² . The channel resistance is different, and the test flow rate is slightly different). When the outlet water temperature of the system is stable, it is found that the outlet water temperature of A is 2.2°C higher than that of B. It is calculated that the ability of A to transfer heat is 10.2% higher than that of B.

Description of drawings

Fig. 1 is the structural representation of the heat collecting board core of the present utility model;

Fig. 2 is the A-A cross-sectional structure schematic diagram of Fig. 1 of heat collecting plate core of the present utility model;

Fig. 3 is a schematic diagram of the B-B sectional structure of the heat collecting plate core of the present invention shown in Fig. 2 .

In the figure: fluid inlet 1, fluid inlet main pipe 2, heat collecting plate 3, spectral selective coating 4, fluid outlet main pipe 5, horizontal baffle 6, side sealing plate 7, vertical baffle 8, S-shaped flow channel 9. Fluid outlet 10.

Detailed ways

Below, referring to the accompanying drawings of the utility model and combining specific embodiments, the utility model will be further described in detail, but the protection scope of the utility model is not limited by the specific embodiments, and the claims shall prevail. In addition, under the premise of not violating the scheme of the utility model, any modification or change made to the utility model that can be easily realized by those skilled in the art will fall within the scope of the claims of the utility model.

Example 1:

As shown in Figures 1, 2, and 3, a whole-convection flat-plate solar collector plate core of the utility model is composed of the following structures: two axially parallel circular fluid inlet pipes 2 and fluid outlet pipes. Dry pipe 5; slots are provided at the matching positions of the fluid inlet dry pipe 2 and the fluid outlet dry pipe 5 opposite surfaces, and heat collecting plates 3 parallel to each other in the axial direction and heat collecting plates 3 at both ends are arranged between the slotted positions. The closed cavity formed by the side sealing plate 7, the outer surface of the two heat collecting plates 3 on one side is provided with a spectrally selective coating 4; the distance between the two heat collecting plates 3 is less than the fluid inlet, 1/3 of the diameter of the stem pipe 2 and 5. In the closed cavity, several vertical baffles 8 and horizontal baffles 6 are connected at staggered heights to form several S-shaped flow channels 9 . A fluid inlet 1 is provided at one end of the fluid inlet main pipe 2 , and a fluid outlet 10 is provided at the opposite end of the fluid outlet main pipe 5 to the fluid inlet 1 .

The operating principle of the utility model using process is as follows:

Sunlight shines on the outer surface of the heat collecting plate 3 with a spectrally selective coating 4. Due to the effect of the selective absorption coating, the heat collecting plate 3 converts solar energy into heat energy, and the overall temperature rises under the action of heat conduction. Under the action of the pump, the heat exchange fluid enters the fluid inlet main pipe 2 from the fluid inlet 1, and then enters several S-shaped flow channel 9 units in sequence. Due to the function of the vertical baffles 8 and the horizontal baffles 6 in each S-shaped flow channel 9 unit, the fluid advances according to the S-shaped flow, and exchanges heat with the surrounding wall face-to-face. After sufficient heat exchange, each S-shaped flow channel 9 The fluid in the unit converges at the fluid outlet main pipe 5, and finally the heated fluid comes out from the fluid outlet 10 to achieve the purpose of transferring heat energy.

The utility model has the advantages of simple and reasonable structure, strong practicability and good effect, and is beneficial to popularization and application.

Claims (4)

1. whole flat panel solar heat collecting plate core in the face of stream, it is characterized in that being made of following structure: two fluids that are parallel to each other advance main (2) and fluid goes out main (5); This fluid advances the adapting position that main (2) and fluid go out main (5) opposite face and is equipped with fluting, be provided with the enclosed cavity that the side seal board (7) at the collecting plate (3) that axially is parallel to each other and two ends consists of between described slotting position, the outer surface of at least one side of described two collecting plates (3) is provided with spectrum selective paint (4); Push the wrong high several S shape runners (9) of formation that link to each other by some vertical baffles (8) and horizontal baffle (6) in the described enclosed cavity.

2. a kind of whole flat panel solar heat collecting plate core in the face of stream according to claim 1, it is characterized in that advancing main (2) and fluid by described fluid, to go out main (5) be round tube.

According to claim 1 and 2 a kind of whole in the face of stream flat panel solar heat collecting plate core, it is characterized in that described fluid advances main (2) one ends and is provided with fluid intake (1), described fluid goes out the upper end opposite with fluid intake (1) one end of main (5) and is provided with fluid issuing (10).

4. a kind of whole flat panel solar heat collecting plate core in the face of stream according to claim 1 is characterized in that the distance between described two collecting plates (3) is into and out of 1/3 of main (2,5) diameter less than described fluid.

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