PV / T solar thermal collector

Abstract

The utility model belongs to the technical field of photovoltaic module thermal assemblies, and relates to a PV / T solar thermal collector. Comprising a photovoltaic panel, the bottom of the photovoltaic panel is connected with a heat conduction layer, the bottom of the heat conduction layer is provided with a spiral flow channel, and the outer wall of the spiral flow channel is provided with a plurality of heat conduction fins; an inlet and an outlet of the spiral flow channel are located on the same side and are arranged in parallel, and the spiral flow channel is bent into multiple circles from outside to inside to be wound around the bottom of the heat conduction layer; the distances among the heat-conducting fins are increased in equal proportion from inside to outside on the spiral flow channel; according to the utility model, the surface temperature distribution of the battery pack can be more uniform in the small area in the heat collector, and the problems of non-uniform surface temperature distribution and low heat exchange efficiency of the PV / T heat collector photovoltaic panel are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic module thermal components, and particularly relates to a PV / T solar collector. Background Art

[0002] In solar photovoltaic power generation technology, only less than 18% of the incident solar energy can be converted into electric energy. The vast majority of solar energy will be absorbed by the photovoltaic panel and converted into heat energy. This causes the temperature of the photovoltaic panel to rise sharply and the power generation efficiency to decrease.

[0003] The existing patent CN 109539578 A discloses a solar collector, the pipeline of which is composed of flat pipes arranged at intervals and flat connecting pipes respectively connected to adjacent flat pipes at both ends. In the middle of the upper and lower surfaces of the working medium pipeline in the pipeline, an intermediate partition is provided to divide the flow channel into two through flow channels with opposite internal working medium fluid flow directions. Since the diameter of the internal pipeline of the collector is generally small and the structure inside the flow channel of this patent is too complex, the processing difficulty will be relatively large in actual processing, and it is difficult to realize its function.

[0004] The existing patent CN 107152793 A discloses a solar collector, and a temperature increasing layer is installed between the reflection brackets of the collector pipe to realize an efficient heat collection process. The focus of the invention of this patent is on heat collection, which easily makes the internal power generation components at a high temperature and cannot achieve the purpose of improving the power generation efficiency of the photovoltaic panel.

[0005] However, in the previously involved PV / T collectors, the working medium pipelines are generally serpentine. Since the inlet and outlet are located on both sides of the collector, it will cause uneven temperature on the surface of the photovoltaic panel and poor power generation efficiency. In addition, the heat exchange area of the pipeline is limited, and the heat exchange area can only be increased by increasing the pipe length or the internal structure of the pipe. On the one hand, the effect is not obvious, and on the other hand, the production cost is increased invisibly and the durability is reduced.

[0006] Nowadays, there are still the following deficiencies in the research and application of PV / T technology: for PV / T water-cooled collectors, when the solar radiation is strong, the temperature of the photovoltaic cell is still relatively high. In traditional PV / T collectors, the water flow channel is serpentine, which will cause the problem of uneven temperature distribution on the surface of the photovoltaic panel. At the same time, the heat exchange efficiency of the PV / T collector is not high. Content of the Utility Model

[0007] The utility model overcomes the deficiencies of the prior art and provides a PV / T solar collector to solve the problems of uneven temperature distribution on the surface of the photovoltaic panel and low heat exchange efficiency of the PV / T collector.

[0008] In order to achieve the above purpose, the utility model is realized through the following technical solutions.

[0009] A PV / T solar collector, comprising a photovoltaic panel, a heat conduction layer is connected to the bottom of the photovoltaic panel, a spiral flow channel is arranged at the bottom of the heat conduction layer, and a plurality of heat conduction fins are arranged on the outer wall of the spiral flow channel; the inlet and outlet of the spiral flow channel are located on the same side and are arranged in parallel, and the spiral flow channel is bent from the outside to the inside and wound around the bottom of the heat conduction layer in multiple turns; the fin pitch of the heat conduction fins increases proportionally from the inside to the outside on the spiral flow channel.

[0010] Further, a plurality of spiral flow channels are arranged in sequence at the bottom of the heat conduction layer.

[0011] Further, it further comprises a collector housing, and the photovoltaic panel, the heat conduction layer, the spiral flow channel and the heat conduction fins are arranged inside the collector housing.

[0012] Further, a light-transmitting cover is arranged at the top of the collector housing, and the light-transmitting cover is arranged above the photovoltaic panel; an air layer is arranged between the light-transmitting cover and the lower photovoltaic panel.

[0013] Furthermore, the thickness of the air layer is 30 - 50 mm.

[0014] Further, heat-insulating filling materials are arranged between the spiral flow channel and the inner bottom of the collector housing.

[0015] Further, the inlet and outlet of the spiral flow channel are perpendicular to the short side of one side of the collector housing.

[0016] The beneficial effects of the present utility model compared with the prior art are as follows:

[0017] 1. By arranging the spiral flow channel in the present utility model, compared with the traditional serpentine flow channel, the inlet and outlet of the spiral flow channel are arranged in parallel, and the surface temperature distribution of the battery pack can be made more uniform in a small area inside the collector, thereby being beneficial to improving the power generation efficiency of the photovoltaic panel.

[0018] 2. The heat transfer fins with unequal fin pitches are adopted in the copper pipe, and as the number of turns of the copper pipe increases, the fin pitch gradually increases from the inside to the outside. Such a setting of the fin pitch increases the effective heat exchange area of the inner circle on the one hand, and reduces the mutual influence caused by the over-dense arrangement between the outer circle fins on the other hand, thereby improving the heat exchange efficiency of the fins. Description of the Drawings

[0019] Figure 1 is a cross-sectional view of the PV / T solar collector described in the present utility model;

[0020] Figure 2 is a schematic structural diagram of the spiral flow channel described in the present utility model.

[0021] Figure 3 is a schematic structural diagram of the existing serpentine flow channel;

[0022] In the figure:

[0023] 1-light-transmitting cover; 2-photovoltaic panel; 3-heat-conducting layer; 4-spiral flow channel; 5-heat-conducting fins; 6-filling material; 7-collector housing. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail in combination with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The technical solution of the present invention is described in detail below in combination with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0025] like Figure 1 and Figure 2 As shown, this embodiment proposes a PV / T solar collector, including a collector housing 7, in which a light-transmitting cover 1, a photovoltaic panel 2, a heat-conducting layer 3, a spiral flow channel 4, heat-conducting fins 5, and a filling material 6 are installed.

[0026] The light-transmitting cover 1 is arranged at the top of the frame 7, and adopts a single layer of 3.2 mm thick photovoltaic embossed tempered glass with a light transmittance of 93%. 50 mm below the light-transmitting cover 1 is the photovoltaic panel 2, and the lower part of the photovoltaic panel 2 is the heat-conducting layer 3, which is bonded by thermal lamination technology. The heat-conducting layer 3 mainly absorbs the heat of the photovoltaic panel 2 and transfers the heat to the spiral flow channel 4 and the heat-conducting fins 5, and the heat-conducting fins 5 play a role in absorbing heat. A spiral flow channel 4 is arranged at the lower part of the heat-conducting layer 3. The spiral flow channel 4 is a copper pipe, and the outer wall of the copper pipe is welded with a heat-conducting fin 5 with a thickness of 5 mm. The heat-conducting fin 5 is a copper fin. The spiral flow channel 4 and the heat-conducting layer 3, as well as the heat-conducting fin 5 and the heat-conducting layer 3 are connected by laser welding. The lower part of the spiral flow channel 4 is a filling material 6 of rubber and plastic material with a thickness of 30 mm, which mainly plays a role of heat insulation in summer and heat preservation in winter.

[0027] There is a 50 mm gap between the light-transmitting cover 1 and the photovoltaic panel 2 at the bottom, with air in the middle. The low thermal conductivity of the air layer is used to reduce the influence of the temperature of the photovoltaic panel 2 on the temperature of the solar cell. According to the influence, the thickness of the air layer is preferably between 30-50 mm. The photovoltaic panel 2 can be made of monocrystalline silicon or polycrystalline silicon.

[0028] Furthermore, the lower part of the photovoltaic panel is a heat-conducting layer 3, and the heat-conducting layer 3 is required to have an absorptivity greater than 95% and an emissivity less than 0.1. The surface can be coated with a black chromium coating, a black cobalt coating, a black nickel coating, etc. to improve the absorptivity. The photovoltaic panel 2 and the heat-conducting layer 3 are bonded by a thermal lamination technology.

[0029] The lower part of the heat conduction layer 3 is a spiral flow channel 4 composed of spiral copper tubes. The working medium in the flow channel is water or air. The heat conduction layer 3 and the spiral flow channel 4 are connected by laser welding. The inner diameter of the copper tube is 80 mm, and copper heat conduction fins 5 with a length of 40 mm, a width of 20 mm, and a thickness of 0.5 mm are welded on the outer surface of the pipeline. There are three circles in total inside and outside the spiral flow channel 4. The length of the outermost circle is 0.8 times the length of the outer shell. The tube pitch is 100 mm. The size of the copper tube, the number of circles, and the tube pitch can be adjusted according to the size of the outer shell. When installed, the inlet and outlet of the flow channel should be set at the upper part of the frame 7. When the working medium is water, it is convenient to discharge the air in the copper tube.

[0030] Furthermore, the fin pitch of the heat conduction fins 5 on the spiral flow channel 4 is different due to different positions. The temperature difference between the outermost spiral flow channels 4 is relatively large, which can ensure the heat transfer efficiency, so the fin pitch can be increased. The temperature difference between the tubes in the innermost spiral flow channel 4 is very small, and heat transfer needs to be enhanced, so the fin pitch of the heat conduction fins 5 is small and closely arranged. The fin pitch of the innermost layer is 1.4 to 2.0 mm, the fin pitch of the middle circle is 2.8 to 4.0 mm, and the fin pitch of the outermost circle is 5.6 to 8.0 mm. That is to say, according to the different number of circles of the spiral flow channel 4, the fin pitch of different circles increases proportionally from the inside to the outside. As the number of copper tube circles increases, the fin pitch gradually increases from the inside to the outside. Such a setting of the fin pitch increases the heat transfer area on the one hand and reduces the mutual influence caused by the over-dense arrangement between the outer fins on the other hand, improving the heat transfer efficiency of the fins. The inlet and outlet of the flow channel are perpendicular to the short side of the collector outer shell 7. When installed, the inlet and outlet should all be located at the upper part of the collector, which is convenient for discharging the air in the tube when the working medium is water.

[0031] Compared with Figure 3 the spiral flow channel 4 described in the present utility model is composed of 6 copper tubes with an inner diameter of 80 mm. As the size of the collector increases, copper tubes with an inner diameter of 100 mm can also be used. The length and width of the outermost circle are 0.8 times the length of the collector outer shell 7, that is, 1600 mm. The pitch of the spiral flow channel 4 is 100 mm. As the size of the collector changes, the pitch of the spiral flow channel 4 can be increased to 150 mm. The inlet and outlet of the spiral flow channel 4 are arranged in parallel. Copper fins with a length of 40 mm, a width of 20 mm, and a thickness of 0.5 mm are welded on the outer surface of the spiral flow channel 4. Compared with traditional collectors, the fins increase the heat transfer area of the copper tubes, thereby increasing the heat transfer quantity.

[0032] The specific working process is as follows: sunlight passes through the light-transmitting cover 1, and the photovoltaic panel 2 converts light energy into electrical energy and heat energy, causing the surface temperature of the photovoltaic panel 2 to rise. The heat is absorbed by the heat conduction layer 3 and transferred to the spiral flow channel 4 and the heat conduction fins 5. The temperature of the working medium in the spiral flow channel 4 rises and is discharged from the collector under the push of an external power device. The filling material 6 at the bottom of the collector mainly plays a heat preservation role.

[0033] The above content is a further detailed description of the present utility model in combination with specific preferred embodiments. It cannot be determined that the specific embodiments of the present utility model are limited thereto. For those of ordinary skill in the technical field to which the present utility model pertains, without departing from the present utility model, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the patent protection scope determined by the claims submitted for the present utility model.

Claims

1. A PV / T solar thermal collector, comprising a photovoltaic panel (2), characterized in that: The bottom of the photovoltaic panel (2) is connected to a heat-conducting layer (3), a spiral flow channel (4) is arranged at the bottom of the heat-conducting layer (3), and a plurality of heat-conducting fins (5) are arranged on the outer wall of the spiral flow channel (4); the inlet and outlet of the spiral flow channel (4) are located on the same side and arranged in parallel, and the spiral flow channel (4) is bent from the outside to the inside to form a plurality of circles and is coiled at the bottom of the heat-conducting layer (3); and the distance between the heat-conducting fins (5) increases in equal proportion from the inside to the outside on the spiral flow channel (4).

2. A PV / T solar collector according to claim 1, characterized in that: A plurality of spiral flow channels (4) are arranged in sequence at the bottom of the heat conducting layer (3).

3. A PV / T solar collector according to claim 1, characterized in that: It also comprises a heat collector shell (7), in which the photovoltaic panel (2), the heat-conducting layer (3), the spiral flow channel (4) and the heat-conducting fins (5) are arranged.

4. A PV / T solar collector according to claim 3, characterized in that: A light-transmitting cover (1) is arranged on the top of the collector housing (7), and the light-transmitting cover (1) is arranged above the photovoltaic panel (2); an air layer is arranged between the light-transmitting cover (1) and the photovoltaic panel (2) at the bottom.

5. A PV / T solar thermal collector according to claim 4, characterized in that: The thickness of the air layer is 30-50mm.

6. A PV / T solar thermal collector according to claim 3, characterized in that: A heat-insulating filling material (6) is provided between the spiral flow channel (4) and the inner bottom of the collector housing (7).

7. A PV / T solar thermal collector according to claim 3, characterized in that: The inlet and outlet of the spiral flow channel (4) are perpendicular to the short side of one side of the collector housing (7).

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