Graphene coating heat collecting tube applied to photo-thermal power generation

Abstract

The invention belongs to the technical field of graphene energy storage equipment, and particularly relates to a graphene coating heat collection tube applied to photo-thermal power generation, which comprises an outer glass tube, an inner glass tube and a heat preservation rubber plug, one end of the outer glass tube is an open end, the other end of the outer glass tube is a closed end, and the inner glass tube is sleeved in the outer glass tube; the heat preservation rubber plug is arranged in the open end of the outer glass tube, and the space between the outer glass tube and the inner glass tube is vacuum. The outer wall of the inner glass tube is coated with a graphene coating, a heat absorption material layer is arranged on the outer wall of the graphene coating, a first metal electrode and a second metal electrode are arranged between the graphene coating and the heat absorption material layer, two external electrodes are arranged on the heat preservation rubber plug, one external electrode is connected with the first metal electrode, and the other external electrode is connected with the second metal electrode. And the other external electrode is connected with the second metal electrode. The graphene coating heat collecting tube applied to photo-thermal power generation is high in light absorptivity and small in heat dissipation loss.

Description

Technical Field

[0001] The present invention belongs to the technical field of graphene energy storage equipment, and in particular relates to a graphene-coated heat collecting tube used for photothermal power generation. Background Art

[0002] Graphene has very high electrical and thermal conductivity, and its resistivity is about 2×10 -6 Ω·cm, the electron mobility can reach 2×10 5 cm 2 / (V·S), the horizontal thermal conductivity at room temperature is about 5×10 3 W / (m·K), and also has high thermal stability, chemical stability, and excellent anti-permeability and anti-wear properties. In addition, graphene films of a certain thickness have very high light absorption function, and the absorption rate of electromagnetic waves in various bands is close to 100%, which can be considered to absorb sunlight in all bands. Therefore, in recent years, it has been widely used in various fields such as mechanics, electronics, optics, thermal science, and new energy, especially in heating devices and solar thermal collectors. It has a very great application prospect.

[0003] In our previous study CN111578541B, a wind-solar complementary graphene heat collecting device was developed, including an outer glass tube, an inner glass tube, and a heat-insulating rubber plug. One end of the outer glass tube is an open end, and the other end is a closed end. The inner glass tube is sleeved inside the outer glass tube, and the heat-insulating rubber plug is arranged inside the open end of the outer glass tube. There are vacuum components between the outer glass tube and the inner glass tube. The device uses solar heat absorption for heating, and can also use wind energy and photovoltaic power generation for heating. Although the light absorption rate is high, the heat dissipation loss is also high, and the heat dissipation loss needs to be reduced. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a graphene-coated heat collecting tube for use in solar thermal power generation, which can reduce heat dissipation losses.

[0005] The object of the present invention is to provide a graphene-coated heat collecting tube for use in solar thermal power generation, comprising an outer glass tube, an inner glass tube, and a thermal insulation rubber plug, wherein one end of the outer glass tube is an open end and the other end is a closed end, the inner glass tube is sleeved inside the outer glass tube, the thermal insulation rubber plug is arranged inside the open end of the outer glass tube, and there is a vacuum between the outer glass tube and the inner glass tube; the outer wall of the inner glass tube is coated with a graphene coating, the outer wall of the graphene coating is provided with a heat-absorbing material layer, a first metal electrode and a second metal electrode are provided between the graphene coating and the heat-absorbing material layer, and two external electrodes are provided on the thermal insulation rubber plug, one of the external electrodes is connected to the first metal electrode, and the other external electrode is connected to the second metal electrode.

[0006] Preferably, in the above-mentioned graphene-coated solar collector tube applied to solar thermal power generation, the graphene coating and the heat-absorbing material layer are both arranged around the outer wall of the inner glass tube, the first metal electrode and the second metal electrode are respectively located on both sides of the inner glass tube, and the first metal electrode and the second metal electrode are symmetrically distributed on both sides of the inner glass tube.

[0007] Preferably, in the above-mentioned graphene-coated heat collecting tube applied to solar thermal power generation, the thickness of the graphene coating and the heat-absorbing material layer are both 1 μm to 20 μm.

[0008] Preferably, the graphene coating used for coating the heat absorbing material layer of the graphene-coated heat collecting tube for photothermal power generation is prepared according to the following method:

[0009] Prepare a 1 g / ml silicone-acrylic emulsion dispersion in deionized water;

[0010] Add 70mg-80mg of sulfonated graphene, 70mg-80mg of silica sol, 70mg-80mg of ultrafine iron powder, 70mg-80mg of silicon carbide powder to each milliliter of silicone-acrylic emulsion dispersion, and then add 50mg-80mg of worm graphite, and ultrasonicate for 2h-5h to disperse the materials to obtain graphene slurry, then add 10mg-20mg of polyethylene glycol-2000 and stir for 0.5h-1h, add 5mg of leveling agent and 5mg of wetting agent to obtain a uniformly dispersed graphene coating.

[0011] Among them, the silicone-acrylic emulsion was purchased from Jinan Huijinchuan Chemical Co., Ltd. with a specification of 50KG / barrel.

[0012] Sulfonated graphene was purchased from Chihe New Materials Technology Nanjing Co., Ltd.

[0013] The silica sol was purchased from Yantai Hengxin Chemical Technology Co., Ltd. and is alkaline silica sol with SiO2 content of 30%.

[0014] The worm graphite was purchased from Qingdao Hexinda Carbon Material Co., Ltd. with a fixed carbon content of 99.9%.

[0015] Preferably, in the above-mentioned graphene-coated collector tube applied to solar thermal power generation, the leveling agent is EFKA3570, which is purchased from Shenzhen Huixin Plastic Chemical Co., Ltd. and is a liquid.

[0016] Preferably, in the above-mentioned graphene-coated solar collector tube used for solar thermal power generation, the wetting agent is SN-5027 purchased from Shanghai Hongtu Industrial Co., Ltd.

[0017] Preferably, in the above-mentioned graphene-coated solar collector tube used for solar thermal power generation, the particle sizes of sulfonated graphene, ultrafine iron powder, silicon carbide powder and worm graphite are all configured to be 1 μm to 10 μm.

[0018] The heat-absorbing coating material used for coating the heat-absorbing material layer is prepared with reference to the existing technology, for example, it is made of the following raw materials: 40 to 50 parts of silicone resin, 2 to 7 parts of curing agent, 11 to 12 parts of absorbent, 2 to 4 parts of absorption enhancer, 33 to 45 parts of auxiliary agent, 13 to 17 parts of metal ceramic material and 7 to 13 parts of thermal conductive material; the silicone resin adopts epoxy modified silicone resin, the curing agent adopts meta-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

[0019] The preparation method of the heat absorbing coating is as follows:

[0020] After mixing the organic silicone resin, the absorbent and the absorption enhancer, reacting them at a temperature of 60° C. to 80° C., a pressure of 7 MPa to 13 MPa, and a stirring rate of 800 r / min to 1400 r / min for 3 h to 7 h to obtain a reaction solution;

[0021] After mixing the curing agent and the auxiliary agent, add them into the reaction solution and stir evenly;

[0022] Add metal ceramic material and thermal conductive material respectively, reflux for 3h to 5h at a temperature of 90℃ to 105℃, a reflux rate of 10mL / min to 30mL / min, and a stirring rate of 400r / min to 700r / min, and then react by reduced pressure distillation at 70℃ to 90℃ for 1h to 2h to obtain the heat-absorbing coating material.

[0023] Preferably, the preparation method of the heat absorbing coating is as follows:

[0024] After mixing the organic silicon resin, the absorbent and the absorption enhancer, the mixture was reacted at a temperature of 60° C., a pressure of 7 MPa and a stirring rate of 800 r / min for 3 h to obtain a reaction solution;

[0025] After mixing the curing agent and the auxiliary agent, add them into the reaction solution and stir evenly;

[0026] The metal ceramic material and the thermal conductive material were added respectively, refluxed for 3 hours at a temperature of 90° C., a reflux rate of 10 mL / min, and a stirring rate of 400 r / min, and then subjected to reduced pressure distillation reaction at 70° C. for 1 hour to obtain the heat-absorbing coating material.

[0027] Preferably, the method for preparing a graphene-coated heat collecting tube for photothermal power generation comprises the following steps:

[0028] A graphene coating, a first metal electrode, a second metal electrode and a heat absorbing material layer are arranged on the outer wall of the inner glass tube;

[0029] A graphene-coated heat collecting tube for solar thermal power generation is manufactured. The graphene-coated heat collecting tube for solar thermal power generation comprises an inner glass tube provided with a graphene coating, a first metal electrode, a second metal electrode and a heat-absorbing material layer, an outer glass tube and a heat-insulating rubber plug. One end of the outer glass tube is an open end and the other end is a closed end. The inner glass tube is sleeved inside the outer glass tube. The heat-insulating rubber plug is arranged inside the open end of the outer glass tube, and there is a vacuum between the outer glass tube and the inner glass tube.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The graphene-coated heat collecting tube for photothermal power generation provided by the present invention has the following main innovative inventive concepts: the outer glass tube is light-transmitting, and light is irradiated onto the heat-absorbing material layer of the inner glass tube, and the heat generated by the light is absorbed by the heat-absorbing material layer and the graphene coating in turn; the graphene coating absorbs heat, and the graphene material has a conductive effect, the heat-absorbing material layer is a nano-scale metal ceramic heat-absorbing coating material, which has a good heat-absorbing effect and low heat radiation, and the first metal electrode, the second metal electrode, and the two external electrodes have a conductive effect, and after they are connected to the power storage device, they can convert solar energy into electrical energy.

[0032] In order to reduce heat dissipation loss, the present invention simultaneously provides a heat-absorbing material layer and a graphene coating. On the one hand, the dual heat absorption effect improves the heat absorption rate. On the other hand, the high heat absorption effect of the heat-absorbing material layer can absorb the heat dissipation of the graphene coating, reduce the heat dissipation radiation of the graphene coating, and thus reduce the heat dissipation loss of the graphene coated collector tube used for solar thermal power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the graphene-coated heat collecting tube applied to photothermal power generation of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and drawings.

[0035] In the description of the present invention, unless otherwise specified, all reagents used are commercially available and all methods used are conventional techniques in the art.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0037] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] Example 1

[0039] A graphene-coated heat collecting tube for solar thermal power generation, see Figure 1 , comprising an outer glass tube 1, an inner glass tube 2, and an insulating rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the insulating rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, the outer wall of the inner glass tube 2 is coated with a graphene coating 4, the outer wall of the graphene coating 4 is provided with a heat-absorbing material layer 5, a first metal electrode 21 and a second metal electrode 22 are provided between the graphene coating 4 and the heat-absorbing material layer 5, two external electrodes 31 are provided on the insulating rubber plug 3, one of the external electrodes 31 is connected to the first metal electrode 21, and the other external electrode 31 is connected to the second metal electrode 22, and the external electrode 31 is also used to connect to an electricity storage device.

[0040] The outer glass tube 1 is light-transmissive, and the light is irradiated onto the graphene coating 4 of the inner glass tube 2, and the heat generated by the light is absorbed; the heat-absorbing material layer 5 also receives light and absorbs heat; in order to reduce heat dissipation loss while collecting heat, the present invention is provided with a two-layer structure of the graphene coating 4 and the heat-absorbing material layer 5. Exemplarily, the power storage device is a battery, or a device containing a battery. For example, referring to the research results of our CN111578541B, the graphene-coated heat-collecting tube used for photothermal power generation is connected with the solar cell backplane, wind turbine, battery, inverter, temperature sensor, control circuit, distribution box, insulated water tank, and bracket. The open end of the outer glass tube 1 of the graphene-coated heat-collecting tube used for photothermal power generation is connected to the insulated water tank, and the temperature sensor is arranged inside the insulated water tank, and the bracket supports the graphene-coated heat-collecting tube used for photothermal power generation, the solar cell backplane, wind turbine, battery, inverter, control circuit, distribution box, and insulated water tank. Under the control of the control circuit, when the internal temperature of the insulated water tank is lower than the set temperature, the external electrode 31 is electrically connected to the above-mentioned battery via the inverter, or is directly electrically connected to the solar cell back panel and the wind turbine, and electrically heats the graphene-coated collector tube used for solar thermal power generation; when the internal temperature of the insulated water tank is higher than the set temperature, the external electrode 31 is electrically disconnected from the above-mentioned battery, the solar cell back panel and the wind turbine, and the solar cell back panel and the wind turbine charge and store energy in the above-mentioned battery.

[0041] In this embodiment, the graphene coating 4 and the heat absorbing material layer 5 are both arranged around the outer wall of the inner glass tube 2, and the first metal electrode 21 and the second metal electrode 22 are respectively located on both sides of the inner glass tube 2. The thickness of the graphene coating 4 and the heat absorbing material layer 5 are both 1 μm.

[0042] The graphene coating for coating the heat absorbing material layer 5 is prepared as follows:

[0043] Prepare a 1g / ml silicone-acrylic emulsion dispersion in deionized water; add 70mg sulfonated graphene, 70mg silica sol, 70mg ultrafine iron powder, 70mg silicon carbide powder, and 50mg worm graphite per milliliter of silicone-acrylic emulsion dispersion, and disperse the materials at 400W ultrasound for 2h to obtain graphene slurry, then add 10mg polyethylene glycol-2000 and stir for 0.5h, add 5mg leveling agent and 5mg wetting agent to obtain a uniformly dispersed graphene coating. The leveling agent is EFKA3570, and the wetting agent is SN-5027. The particle size of sulfonated graphene, ultrafine iron powder, silicon carbide powder, and worm graphite is all configured to be 1μm.

[0044] The heat-absorbing coating material used for coating the heat-absorbing material layer is made of the following raw materials: 40 parts of silicone resin, 2 parts of curing agent, 11 parts of absorbent, 2 parts of absorption enhancer, 33 parts of auxiliary agent, 13 parts of metal ceramic material and 7 parts of thermal conductive material; the silicone resin adopts epoxy modified silicone resin, the curing agent adopts meta-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

[0045] The raw materials and preparation method of the heat-absorbing coating refer specifically to the method of Example 1 of the prior art CN106752915B.

[0046] Based on the same inventive concept, the present invention also provides a method for manufacturing a graphene-coated solar collector tube for solar thermal power generation, wherein the graphene-coated solar collector tube for solar thermal power generation comprises an outer glass tube 1 provided with a heat-absorbing material layer 5 and a thermoelectric material coating 6, an inner glass tube 2, and an insulating rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the insulating rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, and the outer wall of the inner glass tube 2 is coated with a graphene coating 4.

[0047] After testing in accordance with the current "General Requirements and Test Methods for Collector Tubes in Solar Thermal Power Plants", compared with our previous research in CN111578541B, the graphene-coated collector tubes used in this embodiment for solar thermal power generation have increased by 8.3%, the light absorption rate can reach 92.21%, and the heat loss coefficient has decreased by 45.27%. Among them, the light absorption rate, i.e., optical efficiency, refers to the ratio of the radiation energy absorbed by the collector tube to the total radiation energy projected onto the entire surface of the collector tube.

[0048] Example 2

[0049] A graphene-coated heat collecting tube for photothermal power generation comprises an outer glass tube 1, an inner glass tube 2 and a thermal insulation rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the thermal insulation rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, the outer wall of the inner glass tube 2 is coated with a graphene coating 4, the outer wall of the graphene coating 4 is provided with a heat absorbing material layer 5, a first metal electrode 21 and a second metal electrode 22 are provided between the graphene coating 4 and the heat absorbing material layer 5, two external electrodes 31 are provided on the thermal insulation rubber plug 3, one of the external electrodes 31 is connected to the first metal electrode 21, and the other external electrode 31 is connected to the second metal electrode 22, and the external electrode 31 is also used to connect to a power storage device.

[0050] In this embodiment, the graphene coating 4 and the heat absorbing material layer 5 are both arranged around the outer wall of the inner glass tube 2, and the first metal electrode 21 and the second metal electrode 22 are respectively located on both sides of the inner glass tube 2. The thickness of the graphene coating 4 and the heat absorbing material layer 5 are both 20 μm.

[0051] The working principle refers to that of Example 1 of the present invention.

[0052] The graphene coating for coating the heat absorbing material layer 5 is prepared as follows:

[0053] Prepare a 1g / ml silicone-acrylic emulsion dispersion in deionized water; add 70mg sulfonated graphene, 70mg silica sol, 70mg ultrafine iron powder, 70mg silicon carbide powder, and 50mg worm graphite per milliliter of silicone-acrylic emulsion dispersion, and disperse the materials at 400W ultrasound for 2h to obtain graphene slurry, then add 10mg polyethylene glycol-2000 and stir for 0.5h, add 5mg leveling agent and 5mg wetting agent to obtain a uniformly dispersed graphene coating. The leveling agent is EFKA3570, and the wetting agent is SN-5027. The particle size of sulfonated graphene, ultrafine iron powder, silicon carbide powder, and worm graphite is all configured to be 1μm.

[0054] The heat-absorbing coating material used for coating the heat-absorbing material layer is made of the following raw materials: 40 parts of silicone resin, 2 parts of curing agent, 11 parts of absorbent, 2 parts of absorption enhancer, 33 parts of auxiliary agent, 13 parts of metal ceramic material and 7 parts of thermal conductive material; the silicone resin adopts epoxy modified silicone resin, the curing agent adopts meta-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

[0055] The raw materials and preparation method of the heat-absorbing coating refer specifically to the method of Example 1 of the prior art CN106752915B.

[0056] Based on the same inventive concept, the present invention also provides a method for manufacturing a graphene-coated solar collector tube for solar thermal power generation, wherein the graphene-coated solar collector tube for solar thermal power generation comprises an outer glass tube 1 provided with a heat-absorbing material layer 5 and a thermoelectric material coating 6, an inner glass tube 2, and an insulating rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the insulating rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, and the outer wall of the inner glass tube 2 is coated with a graphene coating 4.

[0057] After testing according to the current "General Requirements and Test Methods for Collector Tubes of Solar Thermal Power Stations", the light absorption rate of the graphene-coated collector tubes used for solar thermal power generation in this embodiment can reach 95.88%. Compared with our previous research on CN111578541B, the heat loss coefficient of the graphene-coated collector tubes used for solar thermal power generation in this embodiment is reduced by 66.20%.

[0058] Example 3

[0059] A graphene-coated heat collecting tube for photothermal power generation comprises an outer glass tube 1, an inner glass tube 2 and a thermal insulation rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the thermal insulation rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, the outer wall of the inner glass tube 2 is coated with a graphene coating 4, the outer wall of the graphene coating 4 is provided with a heat absorbing material layer 5, a first metal electrode 21 and a second metal electrode 22 are provided between the graphene coating 4 and the heat absorbing material layer 5, two external electrodes 31 are provided on the thermal insulation rubber plug 3, one of the external electrodes 31 is connected to the first metal electrode 21, and the other external electrode 31 is connected to the second metal electrode 22, and the external electrode 31 is also used to connect to a power storage device.

[0060] In this embodiment, the graphene coating 4 and the heat absorbing material layer 5 are both arranged around the outer wall of the inner glass tube 2, and the first metal electrode 21 and the second metal electrode 22 are respectively located on both sides of the inner glass tube 2. The thickness of the graphene coating 4 and the heat absorbing material layer 5 are both 1 μm.

[0061] The working principle refers to that of Example 1 of the present invention.

[0062] The graphene coating for coating the heat absorbing material layer 5 is prepared as follows:

[0063] Prepare a 1g / ml silicone-acrylic emulsion dispersion in deionized water; add 80mg of sulfonated graphene, 80mg of silica sol, 80mg of ultrafine iron powder, 80mg of silicon carbide powder, and then add 80mg of worm graphite per milliliter of silicone-acrylic emulsion dispersion, and ultrasonicate at 400W for 2h to disperse the materials to obtain graphene slurry, then add 80mg of polyethylene glycol-2000 and stir for 0.5h, add 5mg of leveling agent and 5mg of wetting agent to obtain a uniformly dispersed graphene coating. The leveling agent is EFKA3570, and the wetting agent is SN-5027. The particle size of sulfonated graphene, ultrafine iron powder, silicon carbide powder, and worm graphite is all configured to be 1μm.

[0064] The heat-absorbing coating material used for coating the heat-absorbing material layer is made of the following raw materials: 40 parts of silicone resin, 2 parts of curing agent, 11 parts of absorbent, 2 parts of absorption enhancer, 33 parts of auxiliary agent, 13 parts of metal ceramic material and 7 parts of thermal conductive material; the silicone resin adopts epoxy modified silicone resin, the curing agent adopts meta-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

[0065] The raw materials and preparation method of the heat-absorbing coating refer specifically to the method of Example 1 of the prior art CN106752915B.

[0066] Based on the same inventive concept, the present invention also provides a method for manufacturing a graphene-coated solar collector tube for solar thermal power generation, wherein the graphene-coated solar collector tube for solar thermal power generation comprises an outer glass tube 1 provided with a heat-absorbing material layer 5 and a thermoelectric material coating 6, an inner glass tube 2, and an insulating rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the insulating rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, and the outer wall of the inner glass tube 2 is coated with a graphene coating 4.

[0067] After testing according to the current "General Requirements and Test Methods for Collector Tubes of Solar Thermal Power Stations", the light absorption rate of the graphene-coated collector tubes used for solar thermal power generation in this embodiment can reach 92.87%. Compared with our previous research on CN111578541B, the heat loss coefficient of the graphene-coated collector tubes used for solar thermal power generation in this embodiment is reduced by 46.44%.

[0068] Example 4

[0069] A graphene-coated heat collecting tube for photothermal power generation comprises an outer glass tube 1, an inner glass tube 2 and a thermal insulation rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the thermal insulation rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, the outer wall of the inner glass tube 2 is coated with a graphene coating 4, the outer wall of the graphene coating 4 is provided with a heat absorbing material layer 5, a first metal electrode 21 and a second metal electrode 22 are provided between the graphene coating 4 and the heat absorbing material layer 5, two external electrodes 31 are provided on the thermal insulation rubber plug 3, one of the external electrodes 31 is connected to the first metal electrode 21, and the other external electrode 31 is connected to the second metal electrode 22, and the external electrode 31 is also used to connect to a power storage device.

[0070] In this embodiment, the graphene coating 4 and the heat absorbing material layer 5 are both arranged around the outer wall of the inner glass tube 2, and the first metal electrode 21 and the second metal electrode 22 are respectively located on both sides of the inner glass tube 2. The thickness of the graphene coating 4 and the heat absorbing material layer 5 are both 20 μm.

[0071] The working principle refers to that of Example 1 of the present invention.

[0072] The graphene coating for coating the heat absorbing material layer 5 is prepared as follows:

[0073] Prepare a 1g / ml silicone-acrylic emulsion dispersion in deionized water; add 80mg of sulfonated graphene, 80mg of silica sol, 80mg of ultrafine iron powder, 80mg of silicon carbide powder, and then add 80mg of worm graphite per milliliter of silicone-acrylic emulsion dispersion, and ultrasonicate at 400W for 2h to disperse the materials to obtain graphene slurry, then add 80mg of polyethylene glycol-2000 and stir for 0.5h, add 5mg of leveling agent and 5mg of wetting agent to obtain a uniformly dispersed graphene coating. The leveling agent is EFKA3570, and the wetting agent is SN-5027. The particle size of sulfonated graphene, ultrafine iron powder, silicon carbide powder, and worm graphite is all configured to be 1μm.

[0074] The heat-absorbing coating material used for coating the heat-absorbing material layer is made of the following raw materials: 40 parts of silicone resin, 2 parts of curing agent, 11 parts of absorbent, 2 parts of absorption enhancer, 33 parts of auxiliary agent, 13 parts of metal ceramic material and 7 parts of thermal conductive material; the silicone resin adopts epoxy modified silicone resin, the curing agent adopts meta-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

[0075] The raw materials and preparation method of the heat-absorbing coating refer specifically to the method of Example 1 of the prior art CN106752915B.

[0076] Based on the same inventive concept, the present invention also provides a method for manufacturing a graphene-coated solar collector tube for solar thermal power generation, wherein the graphene-coated solar collector tube for solar thermal power generation comprises an outer glass tube 1 provided with a heat-absorbing material layer 5 and a thermoelectric material coating 6, an inner glass tube 2, and an insulating rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the insulating rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, and the outer wall of the inner glass tube 2 is coated with a graphene coating 4.

[0077] After testing in accordance with the current "General Requirements and Test Methods for Collector Tubes of Solar Thermal Power Stations", the light absorption rate of the graphene-coated collector tubes used for solar thermal power generation in this embodiment can reach 95.10%. Compared with our previous research on CN111578541B, the heat loss coefficient of the graphene-coated collector tubes used for solar thermal power generation in this embodiment is reduced by 65.75%.

[0078] Example 5

[0079] A graphene-coated heat collecting tube for photothermal power generation comprises an outer glass tube 1, an inner glass tube 2 and a thermal insulation rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the thermal insulation rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, the outer wall of the inner glass tube 2 is coated with a graphene coating 4, the outer wall of the graphene coating 4 is provided with a heat absorbing material layer 5, a first metal electrode 21 and a second metal electrode 22 are provided between the graphene coating 4 and the heat absorbing material layer 5, two external electrodes 31 are provided on the thermal insulation rubber plug 3, one of the external electrodes 31 is connected to the first metal electrode 21, and the other external electrode 31 is connected to the second metal electrode 22, and the external electrode 31 is also used to connect to a power storage device.

[0080] In this embodiment, the graphene coating 4 and the heat absorbing material layer 5 are both arranged around the outer wall of the inner glass tube 2, and the first metal electrode 21 and the second metal electrode 22 are respectively located on both sides of the inner glass tube 2. The thickness of the graphene coating 4 and the heat absorbing material layer 5 are both 20 μm.

[0081] The working principle refers to that of Example 1 of the present invention.

[0082] The graphene coating for coating the heat absorbing material layer 5 is prepared as follows:

[0083] Prepare a 1g / ml silicone-acrylic emulsion dispersion in deionized water; add 70mg sulfonated graphene, 70mg silica sol, 70mg ultrafine iron powder, 70mg silicon carbide powder, and 50mg worm graphite per milliliter of silicone-acrylic emulsion dispersion, and perform ultrasonic treatment at 400W for 2h to disperse the materials to obtain graphene slurry, then add 20mg polyethylene glycol-2000 and stir for 1h, add 5mg leveling agent and 5mg wetting agent to obtain a uniformly dispersed graphene coating. The leveling agent is EFKA3570, and the wetting agent is SN-5027. The particle sizes of sulfonated graphene, ultrafine iron powder, silicon carbide powder, and worm graphite are all configured to be 10μm.

[0084] The heat-absorbing coating material used for coating the heat-absorbing material layer is made of the following raw materials: 50 parts of silicone resin, 7 parts of curing agent, 12 parts of absorbent, 4 parts of absorption enhancer, 45 parts of auxiliary agent, 17 parts of metal ceramic material and 13 parts of thermal conductive material; the silicone resin adopts epoxy modified silicone resin, the curing agent adopts meta-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

[0085] The raw materials and preparation method of the heat-absorbing coating refer specifically to the method of Example 1 of the prior art CN106752915B.

[0086] Based on the same inventive concept, the present invention also provides a method for manufacturing a graphene-coated solar collector tube for solar thermal power generation, wherein the graphene-coated solar collector tube for solar thermal power generation comprises an outer glass tube 1 provided with a heat-absorbing material layer 5 and a thermoelectric material coating 6, an inner glass tube 2, and an insulating rubber plug 3, wherein one end of the outer glass tube 1 is an open end and the other end is a closed end, the inner glass tube 2 is sleeved inside the outer glass tube 1, the insulating rubber plug 3 is arranged inside the open end of the outer glass tube 1, and there is a vacuum between the outer glass tube 1 and the inner glass tube 2, and the outer wall of the inner glass tube 2 is coated with a graphene coating 4.

[0087] After testing in accordance with the current "General Requirements and Test Methods for Collector Tubes of Solar Thermal Power Stations", the light absorption rate of the graphene-coated collector tubes used for solar thermal power generation in this embodiment can reach 92.00%. Compared with our previous research on CN111578541B, the heat loss coefficient of the graphene-coated collector tubes used for solar thermal power generation in this embodiment is reduced by 44.76%.

[0088] It should be noted that the component connection relationships not specifically mentioned in the present invention are assumed to adopt the existing technology. Since they do not involve the invention point and are widely used in the existing technology, the structural connection relationships are not described in detail.

[0089] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, once those skilled in the art know the basic inventive concept, they can make other changes and modifications to these embodiments, and these changes and modifications all fall within the scope of the present invention.

[0090] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. If these modifications and variations of the present invention fall within the scope of the equivalent technology of the present invention, the present invention is also intended to include these modifications and variations.

Claims

1. A graphene-coated heat collecting tube for solar thermal power generation, comprising an outer glass tube (1), an inner glass tube (2), and a heat-insulating rubber plug (3), wherein one end of the outer glass tube (1) is an open end and the other end is a closed end, the inner glass tube (2) is sleeved inside the outer glass tube (1), the heat-insulating rubber plug (3) is arranged inside the open end of the outer glass tube (1), and a vacuum is formed between the outer glass tube (1) and the inner glass tube (2), characterized in that: The outer wall of the inner glass tube (2) is coated with a graphene coating (4), the outer wall of the graphene coating (4) is provided with a heat-absorbing material layer (5), a first metal electrode (21) and a second metal electrode (22) are provided between the graphene coating (4) and the heat-absorbing material layer (5), and two external electrodes (31) are provided on the thermal insulation rubber plug (3), one of the external electrodes (31) is connected to the first metal electrode (21), and the other external electrode (31) is connected to the second metal electrode (22).

2. The graphene-coated heat collecting tube for photothermal power generation according to claim 1, characterized in that: The graphene coating (4) and the heat-absorbing material layer (5) are both arranged around the outer wall of the inner glass tube (2), and the first metal electrode (21) and the second metal electrode (22) are respectively located on both sides of the inner glass tube (2).

3. The graphene-coated heat collecting tube for photothermal power generation according to claim 1, characterized in that: The thickness of the graphene coating (4) and the heat absorbing material layer (5) are both 1 μm to 20 μm.

4. The graphene-coated heat collecting tube for photothermal power generation according to claim 1, characterized in that: The graphene coating used for coating the heat absorbing material layer (5) is prepared according to the following method: Prepare a 1 g / ml silicone-acrylic emulsion dispersion in deionized water; Add 70mg-80mg of sulfonated graphene, 70mg-80mg of silica sol, 70mg-80mg of ultrafine iron powder, 70mg-80mg of silicon carbide powder to each milliliter of silicone-acrylic emulsion dispersion, and then add 50mg-80mg of worm graphite, ultrasonicate for 2h-5h to obtain graphene slurry, then add 10mg-20mg of polyethylene glycol-2000 and stir for 0.5h-1h, add 5mg of leveling agent and 5mg of wetting agent to obtain a uniformly dispersed graphene coating.

5. The graphene-coated heat collecting tube for photothermal power generation according to claim 4, characterized in that: The leveling agent is EFKA3570.

6. The graphene-coated heat collecting tube for photothermal power generation according to claim 4, characterized in that: The wetting agent is SN-5027.

7. The graphene-coated heat collecting tube for solar thermal power generation according to claim 4, characterized in that: The particle sizes of sulfonated graphene, ultrafine iron powder, silicon carbide powder and worm graphite are all configured to be 1 μm to 10 μm.

8. The graphene-coated heat collecting tube for solar thermal power generation according to claim 1, characterized in that: The heat-absorbing coating material used for coating the heat-absorbing material layer (5) is made of the following raw materials: 40 to 50 parts of organic silicone resin, 2 to 7 parts of curing agent, 11 to 12 parts of absorbent, 2 to 4 parts of absorption enhancer, 33 to 45 parts of auxiliary agent, 13 to 17 parts of metal ceramic material and 7 to 13 parts of heat-conducting material; The organic silicon resin adopts epoxy modified organic silicon resin, the curing agent adopts m-phenylenediamine, the absorbent adopts nano titanium dioxide doped with silicon dioxide and calcium carbonate, the absorption enhancer adopts 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone, the auxiliary agent adopts ethyl acetate, the metal ceramic material adopts tungsten boride ceramic material, and the thermal conductive material adopts graphene.

9. The graphene-coated heat collecting tube for solar thermal power generation according to claim 1, characterized in that: The method for preparing a graphene-coated heat collecting tube for photothermal power generation comprises the following steps: A graphene coating (4), a first metal electrode (21), a second metal electrode (22) and a heat absorbing material layer (5) are arranged on the outer wall of the inner glass tube (2); A graphene-coated heat collecting tube for use in solar thermal power generation is manufactured. The graphene-coated heat collecting tube for use in solar thermal power generation comprises an inner glass tube (2) provided with a graphene coating (4), a first metal electrode (21), a second metal electrode (22) and a heat absorbing material layer (5), an outer glass tube (1), and a heat-insulating rubber plug (3). One end of the outer glass tube (1) is an open end, and the other end is a closed end. The inner glass tube (2) is sleeved inside the outer glass tube (1), the heat-insulating rubber plug (3) is arranged inside the open end of the outer glass tube (1), and a vacuum is provided between the outer glass tube (1) and the inner glass tube (2).

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