Radiation plate based on silicon carbide composite material and preparation method thereof
By using silicon carbide composite materials with different thermal conductivity and special mold pressing technology, combined with hot pressing method sintering and infrared absorbing film coating, the problems of low heat exchange efficiency and complex structure of traditional radiation plates are solved, and an efficient and lightweight radiation plate design is achieved.
Patent Information
- Application Number
- CN202510059618.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2025-04-25
AI Technical Summary
Due to the small contact area between the built-in pipeline and the radiation panel and the limited material performance, traditional radiation plates have large spacing between the pipes and low heat conduction performance, resulting in low heat exchange efficiency of refrigerant, complex structure, large weight, and poor practicality.
The radiation plate is made of silicon carbide composite materials with different thermal conductivity, and the sheet with built-in semicircular pipe structure is formed by pressing a special mold, and the composite plate is sintered by hot pressing method, and finally an infrared absorbing film is coated on the surface.
The contact area and heat exchange effect between the radiating plate and the refrigerant are improved, the resistance of the pipeline system is reduced, and the advantages of simple structure, light weight, thin thickness and high heat exchange efficiency are achieved.
Smart Images
Figure CN119874378A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of radiant air conditioning systems and thermal management technology, and in particular to a radiant plate made of silicon carbide composite materials with different thermal conductivity coefficients, and a pipeline structure is designed inside the radiant plate to improve the heat exchange performance, and in particular to a radiant plate based on silicon carbide composite materials and a preparation method thereof. Background Art
[0002] In practical applications, radiation panels are usually installed on walls or ceilings as wall or ceiling radiation systems. This structural form generally requires the radiation panel to radiate on one side to ensure that all heat is radiated to the indoor environment. In the traditional radiation panel processing technology, the radiation panel is usually composed of a metal panel and a built-in metal / plastic pipe structure or a gypsum panel and a built-in metal / plastic pipe structure, and a thermal insulation material is added to the back of the radiation panel to avoid heat loss. The thermal insulation material generally uses an insulating material such as polypropylene plastic foam material. Although traditional radiation panels have certain thermal conductivity, they still have problems such as heavy weight and low heat exchange efficiency. In particular, the actual contact area between the built-in pipeline of the radiation panel and the radiation panel is small, the built-in pipeline itself is limited by material properties, resulting in a large pipe spacing, and the thermal conductivity of the pipe itself is too low, resulting in low refrigerant heat exchange efficiency between the radiation panel and the built-in pipeline. At the same time, the overall structure of the radiation panel is complex and thick, heavy, and poor in practicality.
[0003] To this end, the present invention provides a radiation plate based on a silicon carbide composite material and a preparation method thereof. Summary of the invention
[0004] Based on this, it is necessary to provide a radiation plate based on silicon carbide composite materials and a preparation method thereof in order to solve the above technical problems.
[0005] In order to achieve the above object, the technical solution of the present invention is as follows: According to a first aspect of the present invention, a method for preparing a radiation plate based on a silicon carbide composite material is provided, comprising the following steps: preparing an upper half sheet of silicon carbide composite material and a lower half sheet of silicon carbide composite material, and controlling the thermal conductivity of the upper half sheet of silicon carbide composite material to be smaller than the thermal conductivity of the lower half sheet of silicon carbide composite material, wherein the thermal conductivity of the upper half sheet of silicon carbide composite material is less than or equal to 0.3 W / m·K, and the thermal conductivity of the lower half sheet of silicon carbide composite material is greater than or equal to 450 W / m·K; The material is pressed through a special mold; wherein the special mold is composed of an upper mold and a lower mold, the upper mold includes a first bottom mold, a first frame mold and a first pressing mold from bottom to top, the first bottom mold is provided with a first core groove, and a hollow cylinder for facilitating the circulation of the sheet A is arranged at a diagonal position of the first core groove, the number of the hollow cylinders is 2, and the position of the upper mold corresponding to the hollow cylinder is also provided with a first punching mold and a second punching mold, the lower mold includes a second bottom mold, a second frame mold and a second pressing mold from bottom to top, The second bottom mold is provided with a second core groove, and a plurality of semicircular pipeline modules with a diameter of 4 mm are respectively provided in the first core groove and the second core groove, and the interval between two adjacent semicircular pipeline modules is 10 mm. The semicircular pipeline modules of the first core groove and the semicircular pipeline modules of the second core groove correspond to each other one by one. The upper half of the silicon carbide composite material is pressed through the upper mold plate to obtain a sheet A with a semicircular pipeline structure built in. A matching cylindrical interface is provided at the position of the sheet A corresponding to the hollow cylinder, and the lower half of the silicon carbide composite material is pressed. The material is pressed through a lower template to obtain a sheet B with a semicircular pipe structure built in; the sheet A and the sheet B are stacked, and the stacked sheets A and B are pre-pressed, and the pre-pressed sheets A and B are sintered by a hot pressing method to obtain a composite plate blank with a circular pipe structure built in; the sintered composite plate blank is surface treated to obtain a composite plate that meets size requirements and surface finish; a layer of infrared absorption film is coated on the surface of the composite plate by physical vapor deposition technology to obtain a radiation plate.
[0006] In some optional implementations of some embodiments, the preparation method of the upper half of the silicon carbide composite material includes: gradually adding ceramic fibers to an ethanol solution or deionized water with a purity of 99%, performing initial stirring, the initial stirring speed is 600-800rpm, and the initial stirring time is 30min. After the initial stirring is completed, gradually adding silicon carbide powder for a second stirring, the second stirring speed is 200-1500rpm, and the second stirring time is 2.5min. After the second stirring is completed, adding polyvinyl alcohol for a third stirring, the third stirring speed is 200-1500rpm, and the third stirring time is 15-30min. The amount of polyvinyl alcohol added is measured at 0.5%-1% of the weight of the silicon carbide powder. After the third stirring is completed, a mixture A is obtained, and it is placed in a vacuum drying oven for drying. The drying temperature of the mixture A is 60-80°C, and the drying time of the mixture A is 8h to obtain the upper half of the silicon carbide composite material.
[0007] In some optional implementations of some embodiments, the upper half of the silicon carbide composite material is made of the following raw materials in the following mass percentages: 88% silicon carbide powder with a purity of 99% and 12% ceramic fiber, the silicon carbide powder has a particle size of 1-5 μm, the ceramic fiber is alumina fiber, and the fiber length of the alumina fiber is 50-200 μm.
[0008] In some optional implementations of some embodiments, the preparation method of the lower half of the silicon carbide composite material includes: dissolving graphene or carbon nanotubes in an ethanol solution with a purity of 99% or deionized water, and performing mechanical stirring at a speed of 300 r / min for 15 minutes. After the mechanical stirring is completed, a suspension is obtained, and ultrasonic stirring technology is used to perform a first ultrasonic stirring on the suspension. The first ultrasonic stirring time is 30 minutes. After the first ultrasonic stirring is completed, silicon carbide powder is gradually added for a second ultrasonic stirring. The second ultrasonic stirring time is 40 minutes. After the second ultrasonic stirring is completed, add The polyvinyl alcohol is subjected to a third ultrasonic stirring, wherein the amount of the polyvinyl alcohol added is measured at 0.5%-1% of the weight of the silicon carbide powder, and the time of the third ultrasonic stirring is 15 minutes. After the third ultrasonic stirring is completed, a mixture B is obtained, and the mixture is placed in a vacuum drying oven for drying. The drying temperature of the mixture B is 60-80° C. The drying time of the mixture B is 8 hours to obtain a lower half piece of silicon carbide composite material, wherein the ultrasonic frequencies of the first ultrasonic stirring, the second ultrasonic stirring and the third ultrasonic stirring are all 20-40kHz, and the ultrasonic powers of the first ultrasonic stirring, the second ultrasonic stirring and the third ultrasonic stirring are all 300-500W.
[0009] In some optional implementations of some embodiments, the lower half of the silicon carbide composite material is made of raw materials in the following mass percentages: 90% silicon carbide powder with a purity of 99% and 10% carbon nanotubes or 95% silicon carbide powder with a purity of 99% and 5% graphene, the particle size of the silicon carbide powder is 1-5 μm, and the graphene is single-layer graphene or few-layer graphene.
[0010] In some optional implementations of some embodiments, the pressure for pressing the upper half of the silicon carbide composite material and the lower half of the silicon carbide composite material is 100-200 MPa, the pressing time is 60 s, and the temperature of the upper template and the lower template is room temperature or 50-80°C.
[0011] In some optional implementations of some embodiments, the pre-pressing pressure of the pre-pressing treatment is 50-100MPa, the pre-pressing time of the pre-pressing treatment is 30-45s, the sintering environment of the sintering treatment is protected by inert gas, the heating rate of the sintering treatment is 5°C / min, the temperature is raised to 1600°C-1800°C, the insulation time is 2-4h, the sintering pressure is 20-50MPa, and under the sintering temperature condition, pressure is applied to sheet A and sheet B by hydraulic pressure. After the sintering treatment is completed, the cooling rate is controlled to 2-3°C / min until it is cooled to room temperature, and the composite plate blank with a built-in circular pipe structure is taken out.
[0012] In some optional implementations of some embodiments, the surface treatment includes surface grinding, polishing and cutting.
[0013] In some optional implementations of some embodiments, the thickness of the infrared absorption film is 200 nm.
[0014] According to a second aspect of the present invention, a radiation plate based on a silicon carbide composite material is provided, wherein the radiation plate is prepared by the preparation method.
[0015] The advantages and beneficial effects of the present invention are: the present invention provides a radiation panel based on silicon carbide composite material and a preparation method thereof, the radiation panel is composed of an integrally formed sheet A and sheet B, and has the advantages of simple structure, light weight, thin thickness and high heat exchange efficiency, wherein sheet A has low thermal conductivity, can effectively reduce the back radiation heat exchange effect, avoid heat loss, and thereby ensure that heat is effectively radiated to the indoor environment, sheet B has high thermal conductivity, can effectively improve the radiation efficiency of the radiation surface, and at the same time, through the built-in pipe structure of the radiation panel, not only can the contact area and heat exchange effect between the radiation panel and the refrigerant be greatly increased, greatly improving the comprehensive heat exchange effect of the radiation panel, but also can reduce the resistance of the radiation panel pipeline system, thereby greatly alleviating the pressure of the traditional metal radiation panel pipeline system. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 Schematic diagram of the structure of the A1 surface of the sheet A in an embodiment of the present invention.
[0017] Figure 2 Schematic diagram of the structure of the A2 surface of the sheet A in an embodiment of the present invention.
[0018] Figure 3 Schematic diagram of the structure of the B1 surface of the sheet B in an embodiment of the present invention.
[0019] Figure 4 Schematic diagram of the structure of the B2 surface of the sheet B in an embodiment of the present invention.
[0020] Figure 5 Schematic diagram of the structure of the radiation plate in the embodiment of the present invention.
[0021] Figure 6 It is a schematic structural diagram of the upper template in an embodiment of the present invention.
[0022] Figure 7 It is a schematic structural diagram of the lower template in an embodiment of the present invention.
[0023] Figure markings: 1-A1 surface, 2-A2 surface, 3-B1 surface, 4-B2 surface, 5-cylindrical interface, 6-semicircular pipe structure, 7-sheet A, 8-sheet B, 9-first bottom mold, 10-first frame mold, 11-first pressure mold, 12-first hole punching mold, 13-second hole punching mold, 14-first core groove, 15-semicircular pipe module, 16-hollow cylinder, 17-second bottom mold, 18-second frame mold, 19-second pressure mold, 20-second core groove. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through specific implementation methods in conjunction with 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.
[0025] Example 1 This embodiment provides a method for manufacturing a radiation plate based on a silicon carbide composite material. The manufacturing method includes:
[0026] S1. Prepare an upper half sheet of silicon carbide composite material and a lower half sheet of silicon carbide composite material.
[0027] In this embodiment, an upper half piece of silicon carbide composite material with low thermal conductivity is selected as sheet A7, and a lower half piece of silicon carbide composite material with high thermal conductivity is selected as sheet B8. At the same time, it is necessary to control the thermal conductivity of the upper half piece of silicon carbide composite material to be smaller than the thermal conductivity of the lower half piece of silicon carbide composite material, wherein the thermal conductivity of the upper half piece of silicon carbide composite material is less than or equal to 0.3W / m·K, and the thermal conductivity of the lower half piece of silicon carbide composite material is greater than or equal to 450W / m·K.
[0028] In this embodiment, by selecting the upper half of the silicon carbide composite material with low thermal conductivity as the sheet A7, a thermal insulation layer can be formed on the back of the radiation plate. At the same time, by selecting the lower half of the silicon carbide composite material with high thermal conductivity as the sheet B8, the radiation heat exchange efficiency can be effectively enhanced.
[0029] In this embodiment, the upper half of the silicon carbide composite material is prepared by the following preparation method, specifically including: gradually adding ceramic fibers to an ethanol solution or deionized water with a purity of 99%, performing initial stirring, the initial stirring speed is 600-800rpm, and the initial stirring time is 30min, so as to ensure that the ceramic fibers are evenly dispersed, after the initial stirring is completed, gradually adding silicon carbide powder for a second stirring, the second stirring speed is 200-1500rpm, and the second stirring time is 2.5min, so as to ensure that the mixture is evenly dispersed, after the second stirring is completed, adding polyvinyl alcohol for a third stirring, the third stirring speed is 200-1500rpm, and the third stirring time is 15-30min, the amount of polyvinyl alcohol added is measured at 0.5%-1% of the weight of the silicon carbide powder, after the third stirring is completed, a mixture A is obtained, and placed in a vacuum drying oven for drying to remove ethanol or moisture to ensure that the mixture A is dried without residual moisture, the drying temperature of the mixture A is 60-80°C, and the drying time of the mixture A is 8h, to obtain the upper half of the silicon carbide composite material.
[0030] In this embodiment, the upper half of the silicon carbide composite material is made of the following raw materials in percentage by mass: 88% silicon carbide powder with a purity of 99% and 12% ceramic fiber, the particle size of the silicon carbide powder is 1-5 μm, and the ceramic fiber is alumina fiber, and the fiber length of the alumina fiber is 50-200 μm.
[0031] In this embodiment, the preparation method of the lower half of the silicon carbide composite material includes: dissolving graphene in an ethanol solution with a purity of 99% or deionized water, and performing mechanical stirring. The speed of the mechanical stirring is 300r / min, and the mechanical stirring time is 15min. After the mechanical stirring is completed, a suspension is obtained, and an ultrasonic stirring technology is used to perform a first ultrasonic stirring on the suspension. The first ultrasonic stirring time is 30min. After the first ultrasonic stirring is completed, silicon carbide powder is gradually added for a second ultrasonic stirring. The second ultrasonic stirring time is 40min. After the second ultrasonic stirring is completed, polyvinyl alcohol is added for In the third ultrasonic stirring, the amount of polyvinyl alcohol added is measured at 0.5%-1% of the weight of the silicon carbide powder, and the time of the third ultrasonic stirring is 15 minutes. After the third ultrasonic stirring is completed, a mixture B is obtained and placed in a vacuum drying oven for drying. The drying temperature of the mixture B is 60-80°C, and the drying time of the mixture B is 8 hours to obtain the lower half of the silicon carbide composite material, wherein the ultrasonic frequencies of the first ultrasonic stirring, the second ultrasonic stirring and the third ultrasonic stirring are all 20-40kHz, and the ultrasonic powers of the first ultrasonic stirring, the second ultrasonic stirring and the third ultrasonic stirring are all 300-500W.
[0032] In this embodiment, the lower half of the silicon carbide composite material is made of the following raw materials in percentage by mass: 95% silicon carbide powder with a purity of 99% and 5% graphene, the silicon carbide powder has a particle size of 1-5 μm, and the graphene is single-layer graphene or few-layer graphene.
[0033] S2. The upper half of the silicon carbide composite material and the lower half of the silicon carbide composite material are pressed by a special mold.
[0034] In this embodiment, the special mold is composed of an upper mold plate and a lower mold plate, wherein the Figure 6-7 The upper template includes, from bottom to top, a first bottom mold 9, a first frame mold 10 and a first pressing mold 10. The first bottom mold 9 is provided with a first core groove 14. A hollow cylinder 16 for facilitating the circulation of the sheet A is arranged at the diagonal position of the first core groove 14. The number of the hollow cylinders 16 is 2. The positions of the upper template corresponding to the hollow cylinders 16 are also provided with a first punching mold 12 and a second punching mold 13. The lower template includes, from bottom to top, a second bottom mold 17, a second frame mold 18 and a second pressing mold 19. The second bottom mold 17 is provided with a second core groove 20. A plurality of semicircular pipe modules 15 with a diameter of 4 mm are respectively provided in the first core groove 14 and the second core groove 20. The spacing distance between two adjacent semicircular pipe modules 15 is 10 mm. The semicircular pipe modules 15 of the first core groove 14 correspond to the semicircular pipe modules 15 of the second core groove 20 one by one.
[0035] In this embodiment, the upper half of the silicon carbide composite material is pressed through the upper template to obtain a sheet A7 with a semicircular pipe structure 6 built in. Figure 1-2 As shown, the sheet A7 includes an upper surface and a lower surface, which are represented by A2 surface 2 and A1 surface 1 respectively, wherein A1 surface 1 includes a plurality of semicircular pipe structures 6 with a diameter of 4 mm, and the semicircular pipe structure 6 matches the semicircular pipe module 15 in the first core groove 14, and the spacing distance between two adjacent semicircular pipe structures 6 is 10 mm, which is the same as the spacing distance between two adjacent semicircular pipe modules 15. The semicircular pipe structure 6 adopts a dense structural design, which is similar to the pipeline system of a traditional radiation plate, and can greatly increase the contact area between the medium and the plate, increase the circulation flow of the medium, and reduce the resistance of the pipeline system; at the same time, two cylindrical interfaces 5 that penetrate the sheet A7 and extend to A2 surface 2 are also provided at the diagonal position of A1 surface 1, and the two cylindrical interfaces 5 match the hollow cylinder 16 inside the first core groove 14. By setting two cylindrical interfaces 5, it is convenient to circulate the medium.
[0036] In this embodiment, the lower half of the silicon carbide composite material is pressed through the lower template to obtain a sheet B8 with a semicircular pipe structure 6 built in. Figure 3-4 As shown, the sheet B8 includes an upper side and a lower side, represented by B1 side 3 and B2 side 4 respectively, wherein the B1 side 3 includes a plurality of semicircular pipe structures 6 with a diameter of 4 mm, and the semicircular pipe structure 6 matches the semicircular pipe module 15 in the second core groove 20, and the spacing distance between two adjacent semicircular pipe structures 6 is 10 mm, which is the same as the spacing distance between two adjacent semicircular pipe modules 15. At the same time, the semicircular pipe structure 6 on the A1 side 1 corresponds one to the semicircular pipe structure 6 on the B1 side 3, and the semicircular pipe structure 6 on the A1 side 1 and the corresponding semicircular pipe structure 6 on the B1 side 3 together constitute a circular pipe structure.
[0037] In this embodiment, when the upper half of the silicon carbide composite material and the lower half of the silicon carbide composite material are pressed, the pressing pressure used is 100-200 MPa, the pressing time is 60 s, and the temperature of the upper template and the lower template is room temperature or 50-80°C.
[0038] S3, stacking the sheet A7 and the sheet B8, pre-pressing the stacked sheets A7 and B8, and sintering the pre-pressed sheets A7 and B8 by hot pressing to obtain a composite plate blank with a built-in circular pipe structure.
[0039] In this embodiment, sheet A7 and sheet B8 are combined and stacked, and then pre-pressing technology is used to slightly pre-press the stacked sheets A7 and B8. The pre-pressing pressure is 50-100 MPa and the pre-pressing time is 30-45 seconds to ensure close contact between the two.
[0040] In this embodiment, after the pre-pressing treatment is completed, sintering treatment is performed by hot pressing. The sintering environment is protected by an inert gas (such as argon). The heating rate is 5°C / min. The temperature is gradually increased, which can effectively prevent material cracks. The temperature is increased to 1600°C-1800°C and sintered at this temperature for 2-4 hours to ensure that sheet A7 and sheet B8 are fully combined. The sintering pressure is 20-50MPa, and under the sintering temperature condition, pressure is applied to sheet A7 and sheet B8 by hydraulic pressure. After sintering is completed, the cooling rate is controlled to 2-3°C / min to avoid rapid cooling and thermal cracking of the material until it is cooled to room temperature and taken out to obtain a composite plate blank with a built-in circular pipe structure.
[0041] S4. Surface treatment is performed on the composite plate blank after sintering to obtain a composite plate that meets the size requirements and surface finish.
[0042] In this embodiment, the composite plate blank is subjected to surface grinding, polishing and cutting to obtain a composite plate that meets the size requirements and surface finish, so as to improve its surface flatness and smoothness.
[0043] S5. Use physical vapor deposition technology to coat a layer of infrared absorption film on the surface of the composite board to obtain a radiation board. The structure of the radiation board refers to the attached Figure 5 shown.
[0044] In this embodiment, a layer of infrared absorption film with a thickness of 200 nm is coated on the surface of the composite board by physical vapor deposition (PVD) to enhance its radiation performance.
[0045] In this embodiment, before performing the physical vapor deposition (PVD) step, the surface of the composite board needs to be ultrasonically cleaned, pickled and plasma cleaned to ensure that there are no pollutants on the surface of the composite board. Subsequently, a layer of infrared absorption film is deposited on the surface of the composite board using PECVD equipment. The infrared absorption film uses a single-layer silicon nitride film (SiNx) with a film thickness of 200nm. The deposition gas is silane (SiH4) and ammonia (NH3), and a small amount of nitrogen (N2) is added. The reaction is carried out at a temperature of 200-400°C in a nitrogen atmosphere for 40 minutes to obtain a radiation plate.
[0046] Example 2 In this embodiment, the manufacturing method of the radiation plate based on the silicon carbide composite material involved in this embodiment is the same as that in Example 1, except that: the lower half of the silicon carbide composite material is made of the following raw materials in percentage by mass: 90% silicon carbide powder with a purity of 99% and 10% carbon nanotubes, the particle size of the silicon carbide powder is 1-5 μm, and the physical properties of the carbon nanotubes are shown in Table 1 below.
[0047] Table 1 Physical properties of carbon nanotubes
[0048] Comparative Example 1 In this comparative example, a commercially available metal radiation plate is used as a control group, wherein the metal radiation plate is made of metal copper material.
[0049] Comparative Example 2 In this comparative example, a commercially available metal radiation plate is used as a control group, wherein the metal radiation plate is made of metal aluminum material.
[0050] Performance test: The above embodiments and comparative examples were evaluated for performance with the same size.
[0051] (1) Physical properties test The physical properties of the above embodiments and comparative examples were tested using an electronic scale, a Vickers hardness tester, a tensile tester, a pressure strength tester, a thermal constant analyzer, a Young's modulus tester, a corrosion tester, and a liquid tightness tester. The test results are shown in Table 2 below.
[0052] Table 2 Physical properties test results
[0053] It can be seen from Table 2 that, under the same size conditions, the density of Example 1 is only 36% of that of Comparative Example 1, which is close to the density of Comparative Example 2, indicating that the weight of Example 1 is 36% of that of Comparative Example 1, which is equivalent to the weight of Comparative Example 2. At the same time, the physical properties such as mechanical strength of Example 1 and Example 2 are better than those of Comparative Example 1 and Comparative Example 2. Moreover, it can be seen from Example 1 that the high thermal conductivity surface can achieve a thermal conductivity capacity of 450 W / m·K, which is significantly higher than the thermal conductivity of Comparative Example 1, and the low thermal conductivity surface can achieve a thermal conductivity capacity of 0.3 W / m·K.
[0054] (2) Radiant panel heating performance test According to the European standard "EN14240-Ventilation for buildings - Chilled ceilings -Testing and rating", the heating performance of Example 1, Example 2 and Comparative Example 1 was tested, and the test results are shown in Tables 3-8 below. It should be noted that in this experiment, transparent films of the same material were placed at the same place on the board surface to avoid low-temperature condensation affecting the test.
[0055] Table 3 Heating performance test results of Example 1 under the conditions of indoor constant temperature of 24°C and 240L / h circulation flow rate
[0056] Table 4 Heating performance test results of Example 1 under the conditions of indoor constant temperature of 26°C and 240L / h circulation flow rate
[0057] Table 5 Heating performance test results of Example 2 under the conditions of indoor constant temperature of 24°C and 240L / h circulation flow rate
[0058] Table 6 Heating performance test results of Example 2 under the conditions of indoor constant temperature of 24°C and 240L / h circulation flow rate
[0059] Table 7 Heating performance test results of comparative example 1 under indoor constant temperature of 24°C and 240L / h circulation flow rate
[0060] Table 8 Heating performance test results of comparative example 1 under the conditions of indoor constant temperature of 26°C and 240L / h circulation flow rate
[0061] It can be seen from Tables 3-8 that under the conditions of indoor constant temperature of 24°C or 26°C and circulation flow rate of 240L / h, the heat exchange per unit area of Example 1 and the heat exchange per unit area of Example 2 are significantly higher than the heat exchange per unit area of Comparative Example 1. At the same time, under the conditions of indoor constant temperature of 24°C and circulation flow rate of 240L / h, the comprehensive radiation heat exchange effect of Example 1 is improved by 52% compared with the comprehensive radiation heat exchange effect of the comparative example. Under the conditions of indoor constant temperature of 26°C and circulation flow rate of 240L / h, the comprehensive radiation heat exchange effect of Example 1 is improved by 61% compared with the comprehensive radiation heat exchange effect of the comparative example. It should be noted that the comprehensive radiation heat exchange effect means that under the conditions of indoor constant temperature of 24°C or 26°C and circulation flow rate of 240L / h, all heat exchanges per unit area are summed to obtain the comprehensive radiation heat exchange effect under the corresponding conditions.
[0062] (3) Resistance pressure test of radiation panel The resistance pressure test was performed on Example 1, Example 2 and Comparative Example 1 using the pressure reduction method. The test results are shown in Table 9 below.
[0063] Table 9 Resistance pressure test results of Example 1, Example 2 and Comparative Example 1
[0064] It can be seen from Table 9 that the resistance data of Example 1 and the resistance data of Example 2 are significantly smaller than the resistance data of Comparative Example 1, indicating that the use of the radiation panel of the present application can effectively reduce the resistance of the radiation panel pipeline system, so as to alleviate the pressure of the traditional metal radiation panel pipeline system. It should be noted that since the structures of Example 1 and Example 2 are the same and the material properties of the two are similar, the resistance data of the two are consistent.
[0065] The above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.
Claims
1. A method for preparing a radiation panel based on silicon carbide composite material, characterized in that: The following steps are involved: Preparing an upper half sheet of silicon carbide composite material and a lower half sheet of silicon carbide composite material, and controlling the thermal conductivity of the upper half sheet of silicon carbide composite material to be smaller than the thermal conductivity of the lower half sheet of silicon carbide composite material, the thermal conductivity of the upper half sheet of silicon carbide composite material is less than or equal to 0.3 W / m·K, and the thermal conductivity of the lower half sheet of silicon carbide composite material is greater than or equal to 450 W / m·K; The upper half sheet of silicon carbide composite material and the lower half sheet of silicon carbide composite material are pressed by a special mold; wherein the special mold is composed of an upper mold and a lower mold, and the upper mold includes, from bottom to top, a first bottom mold, a first frame mold and a first pressing mold, and the first bottom mold is provided with a first core groove, and a hollow cylinder for facilitating the circulation of the sheet A is arranged at a diagonal position of the first core groove, and the number of the hollow cylinders is 2, and the positions of the upper mold corresponding to the hollow cylinders are also provided with a first punching mold and a second punching mold, and the lower mold includes, from bottom to top, a second bottom mold, a second frame mold and a second pressing mold, and the second bottom mold is provided with a first core groove, and a hollow cylinder for facilitating the circulation of the sheet A is arranged at a diagonal position of the first core groove, and the number of the hollow cylinders is 2. A second core groove is provided on the mold, and a plurality of semicircular pipe modules with a diameter of 4 mm are respectively provided in the first core groove and the second core groove, and the interval between two adjacent semicircular pipe modules is 10 mm. The semicircular pipe modules of the first core groove and the semicircular pipe modules of the second core groove correspond to each other one by one, and the upper half of the silicon carbide composite material is pressed through the upper template to obtain a sheet A with a semicircular pipe structure built in, and a matching cylindrical interface is provided at a position of the sheet A corresponding to the hollow cylinder, and the lower half of the silicon carbide composite material is pressed through the lower template to obtain a sheet B with a semicircular pipe structure built in; The sheet A and the sheet B are stacked, and the stacked sheets A and B are pre-pressed, and the pre-pressed sheets A and B are sintered by hot pressing to obtain a composite plate blank with a circular pipe structure built in. Performing surface treatment on the composite plate blank after sintering to obtain a composite plate that meets the size requirements and surface finish; A layer of infrared absorption film is coated on the surface of the composite board by physical vapor deposition technology to obtain a radiation board.
2. The method for preparing a radiation panel based on silicon carbide composite material according to claim 1, characterized in that: The preparation method of the upper half silicon carbide composite material comprises: The ceramic fiber is gradually added to an ethanol solution or deionized water with a purity of 99%, and the initial stirring is performed. The speed of the initial stirring is 600-800rpm, and the time of the initial stirring is 30min. After the initial stirring is completed, the silicon carbide powder is gradually added for a second stirring. The speed of the second stirring is 200-1500rpm, and the time of the second stirring is 2.5min. After the second stirring is completed, polyvinyl alcohol is added for a third stirring. The speed of the third stirring is 200-1500rpm, and the time of the third stirring is 15-30min. The amount of polyvinyl alcohol added is measured at 0.5%-1% of the weight of the silicon carbide powder. After the third stirring is completed, a mixture A is obtained, and it is placed in a vacuum drying oven for drying. The drying temperature of the mixture A is 60-80°C, and the drying time of the mixture A is 8h to obtain the upper half of the silicon carbide composite material.
3. The method for preparing a radiation panel based on silicon carbide composite material according to claim 2, characterized in that: The upper half of the silicon carbide composite material is made of the following raw materials in percentage by mass: 88% silicon carbide powder with a purity of 99% and 12% ceramic fiber, the silicon carbide powder has a particle size of 1-5 μm, the ceramic fiber is alumina fiber, and the fiber length of the alumina fiber is 50-200 μm.
4. The method for preparing a radiation panel based on silicon carbide composite material according to claim 1, characterized in that: The preparation method of the lower half silicon carbide composite material comprises: Graphene or carbon nanotubes are dissolved in 99% pure ethanol solution or deionized water, and mechanical stirring is performed, the speed of mechanical stirring is 300r / min, and the time of mechanical stirring is 15min. After the mechanical stirring is completed, a suspension is obtained, and ultrasonic stirring technology is used to perform the first ultrasonic stirring of the suspension, and the time of the first ultrasonic stirring is 30min. After the first ultrasonic stirring is completed, silicon carbide powder is gradually added to perform the second ultrasonic stirring, and the time of the second ultrasonic stirring is 40min. After the second ultrasonic stirring is completed, polyvinyl alcohol is added to perform the third ultrasonic stirring, and the polyvinyl alcohol The amount of enol added is measured at 0.5%-1% of the weight of the silicon carbide powder, the time of the third ultrasonic stirring is 15 minutes, after the third ultrasonic stirring is completed, a mixture B is obtained, and it is placed in a vacuum drying oven for drying, the drying temperature of the mixture B is 60-80°C, and the drying time of the mixture B is 8 hours to obtain the lower half of the silicon carbide composite material, wherein the ultrasonic frequencies of the first ultrasonic stirring, the second ultrasonic stirring and the third ultrasonic stirring are all 20-40kHz, and the ultrasonic powers of the first ultrasonic stirring, the second ultrasonic stirring and the third ultrasonic stirring are all 300-500W.
5. The method for preparing a radiation panel based on silicon carbide composite material according to claim 4, characterized in that: The lower half of the silicon carbide composite material is made of the following raw materials in percentage by mass: 90% silicon carbide powder with a purity of 99% and 10% carbon nanotubes or 95% silicon carbide powder with a purity of 99% and 5% graphene, the particle size of the silicon carbide powder is 1-5 μm, and the graphene is single-layer graphene or few-layer graphene.
6. The method for preparing a radiation panel based on silicon carbide composite material according to claim 1, characterized in that: The pressure for pressing the upper and lower silicon carbide composite materials is 100-200 MPa, the pressing time is 60 seconds, and the temperature of the upper and lower templates is room temperature or 50-80°C.
7. The method for preparing a radiation panel based on silicon carbide composite material according to claim 1, characterized in that: The pre-pressing pressure of the pre-pressing treatment is 50-100MPa, the pre-pressing time of the pre-pressing treatment is 30-45s, the sintering environment of the sintering treatment is protected by inert gas, the heating rate of the sintering treatment is 5°C / min, the temperature is raised to 1600°C-1800°C, the insulation time is 2-4h, the sintering pressure is 20-50MPa, and under the sintering temperature condition, pressure is applied to sheet A and sheet B by hydraulic pressure. After the sintering treatment is completed, the cooling rate is controlled to 2-3°C / min until it is cooled to room temperature, and the composite plate blank with a built-in circular pipe structure is taken out.
8. The method for preparing a radiation panel based on silicon carbide composite material according to claim 1, characterized in that: The surface treatment includes surface grinding, polishing and cutting.
9. The method for preparing a radiation panel based on silicon carbide composite material according to claim 1, characterized in that: The infrared absorption film has a thickness of 200 nm.
10. A radiation panel based on silicon carbide composite material, characterized in that: The radiation plate is prepared by the preparation method described in any one of claims 1 to 9.