507 results about "Radiative cooling" patented technology

The invention discloses a preparation method of a flexible material with double functions of radiation refrigeration and photothermal conversion storage, and relates to the field of composite phase change materials. The preparation method comprises the following steps: 1) preparing the flexible phase change material matrix by utilizing n-octadecane, SEBS and POE through hot pressing; 2) preparing a BaSO4 solution by using absolute ethyl alcohol, deionized water, a water-based defoaming agent, a water-based dispersing agent and an acrylic resin emulsion; (3) preparing an MXene solution; and 4) spraying the BaSO4 solution on the surface of one side of the flexible composite phase change material matrix by using a spray gun, and spraying the MXene solution on the surface of the other side of the flexible composite phase change material matrix to obtain the flexible composite phase change material. The radiation refrigeration layer can strongly reflect visible light and near-infrared light, has high emissivity in an infrared light area, especially in an atmospheric window wave band, reduces absorbed atmospheric heat radiation, reduces urban heat island effect caused by dense building groups in cities, and can effectively solve the problems of large day and night temperature difference and heat supply and demand in summer and winter.

The invention relates to a preparation method of a radiation refrigeration coating with super-hydrophobic performance. According to the method, hydrophobic modified nano-particles and nano-particles with high reflectivity and high emissivity are blended in an adhesive solution, an adhesive is separated out to form a micron-sized aggregate through a non-solvent induced phase separation technology, and meanwhile, various nano-particles are uniformly coated on the surface of the aggregate, so that a stable suspension system is prepared. The radiation refrigeration coating has excellent radiation refrigeration performance, excellent super-hydrophobicity and good durability, the preparation process is simple, the radiation refrigeration coating is suitable for large-scale industrial application of outdoor scenes such as building outer walls, and a new technical solution is provided for developing efficient and lasting radiation refrigeration materials.

The invention discloses a passive radiation refrigeration coating and a preparation method thereof, and relates to the technical field of industrial coatings. Comprising a fluoroacrylate emulsion, hollow glass beads, nano titanium dioxide, flaky silicon dioxide aerogel powder, polytetrafluoroethylene micro powder, hydroxyl-terminated polydimethylsiloxane, a hydroxyl acrylic acid modified silane coupling agent, a super-hydrophobic modified fluorosilicone surface additive, nano cerium oxide, aluminum fluoride doped zinc oxide infrared enhancement powder and deionized water. The paint is prepared on the basis of the formula. According to the invention, a multi-scale spectrum regulation and control and surface self-cleaning system is constructed cooperatively, so that the synergistic effect of high reflection of a sunlight region and high emission of a middle infrared region is realized. The coating can maintain continuous passive refrigeration in a day and night period, the surface of the coating has self-cleaning capability and excellent ultraviolet aging resistance, and high reflectivity and high radiation emissivity can be maintained for a long time in a complex outdoor environment, so that the thermal management efficiency of buildings and equipment is remarkably improved.

The invention relates to the technical field of refrigeration material preparation, in particular to an efficient passive radiation refrigeration material suitable for a sub-super environment and a preparation method and application of the efficient passive radiation refrigeration material. The method comprises the following steps: uniformly mixing thermoplastic polyurethane, sunlight high-reflection inorganic particles and a phase change material in a solvent; after a chemical foaming agent is added, the obtained suspension liquid is heated and foamed in a confinement mold, and wet gel is formed; and finally, carrying out freeze drying treatment to obtain the composite porous aerogel. The prepared material has a micro-nano porous skeleton formed by TPU, and inorganic particles and PCM are uniformly dispersed in the skeleton wall. Through component cooperation and a special porous structure, the material has extremely high sunlight reflectivity and mid-infrared emissivity, self-adaptive temperature regulation and control are achieved through PCM phase change, the problem that refrigeration of a traditional material fails in the sub-environment such as the vertical surface is effectively solved, and efficient sub-super-environment heat management is achieved.

A composite radiative cooling material includes a first layer including a reflective material, a second layer including a porous material, and a third layer including an emissive material. The optical properties of the respective materials and the arrangement of the respective layers cause the radiative cooling material to exhibit a total solar reflectance greater than 85%, and a thermal emissivity greater than 85% in a wavelength range of 8 to 13 μm. The layers may be in a vertically stacked arrangement, with the third layer capable of directly facing the sky when the composite radiative cooling material is installed for cooling a load, the second layer arranged under the third layer, and the first layer arranged under the second layer. The composite radiative cooling material may be thermally coupled to a cooling load to provide radiative cooling to the cooling load.

This invention belongs to the field of passive radiative cooling materials, specifically relating to a thermal management film that integrates both radiative cooling and heating functions, and its preparation method. It is characterized by preparing a black PPY modified cotton as the heating surface and a white PMMA / NaH2PO2 composite film as the cooling surface, which are then combined by coating and drying to produce a double-sided thermal management film capable of both heating and cooling. This invention addresses the difficulty people have in regulating their temperature in hot or cold environments. The entire temperature regulation process is environmentally friendly and energy-saving, and the preparation method is simple, making it suitable for large-scale production.

The invention relates to a coating, in particular to a radiation refrigeration heat insulation coating and a preparation method thereof, and the radiation refrigeration coating comprises a water-based emulsion, a reflective inorganic filler, a radiation inorganic filler water-based emulsion, a radiation inorganic filler, functional nanocellulose and a functional additive. The radiation refrigeration coating can reflect energy of a sunlight wave band (0.3-2.5 [mu] m) and perform radiation heat exchange with the universe by utilizing an atmospheric window (8-13 [mu] m), and the cooling effect lower than the environment temperature can be achieved. In high-temperature weather in summer, the surface temperature of a building can be effectively reduced, and the use frequency of an air conditioner is reduced, so that energy consumption is remarkably reduced. Meanwhile, by adding heat insulation type inorganic filler (such as hollow glass beads, silicon dioxide aerogel and the like), the heat conductivity of the coating is reduced, the loss of heat in a building is reduced, and the heating energy consumption in winter is reduced. Due to the dual functions, the coating can achieve an energy-saving effect throughout the year, and the environment-friendly concept of energy conservation and carbon reduction is met.

The invention relates to an intelligent printing method for a thermal temperature-adjusting wall and the thermal temperature-adjusting wall printed by adopting the method, and solves the problems that the printing process lacks real-time dynamic adjustment capability and is difficult to cope with complex and changeable printing environments and wall performance requirements due to the fact that the prior art mostly depends on fixed preset parameters. The method comprises the steps that in the aggregate switching process, the opening degree of a valve and the pressure of a conveying pipeline are regulated and controlled through a preset regulation and control method, so that new aggregate enters a printing spray head, and in the aggregate switching process, the rotating speed of a stirring paddle and the conveying amount of the aggregate are synchronously regulated through a self-adaptive fuzzy PID algorithm; the particle size distribution of the aggregate after the new aggregate and the radiation cooling enhanced cement-based material are mixed is within a preset aggregate particle size distribution standard range. The method has the following effect that the printing quality and performance of the thermal temperature adjusting wall are improved.

The present invention relates to a radiative cooling paint consisting of ceramic fine particles as pigments, a polymer resin as a binder, and a solvent. According to the present invention, a substrate is coated with the radiative cooling paint, and then a paint film layer is formed. The paint film layer performs a radiative cooling function by preventing energy inflow from incident sunlight by maximizing reflection of incident sunlight; minimizing absorption of incident sunlight; and maximizing emission of long-wavelength infrared light corresponding to 8 μm to 13 μm and increasing energy discharge through emission of long-wavelength infrared light, and pores with a volume of 3% to 50% are formed inside the paint film layer to enhance reflection of incident sunlight without reducing emission of long-wavelength infrared light.

The invention relates to the cross technical field of intelligent traffic and heat management, and discloses an airplane air-conditioned vehicle anti-overheating protection system based on a radiation refrigeration coating, comprising: a multilayer composite structure module, the multilayer composite structure module comprising a radiation refrigeration coating, a spectrum regulation and control structure layer and a heat conduction structure layer with adjustable heat conductivity; the environment sensing module is used for collecting the solar irradiation intensity and the temperature state outside the airplane air conditioner vehicle; the control module is used for generating a control instruction for adjusting the spectrum regulation and control structure layer and the heat conduction structure layer; the response execution module is used for outputting a control instruction according to the control module; and the state feedback module is used for monitoring the thermal physical state of the structure after adjustment in real time. A multi-layer composite heat management scheme based on a radiation refrigeration coating and a spectrum regulation and control structure is adopted, and effective reflection of external heat radiation and optimized dissipation of internal heat are achieved by intelligently and dynamically adjusting a heat flow path and radiation emission.

The invention discloses a multi-layer flexible radiation cooling composite diaphragm which structurally comprises a flexible base layer film, and a SiO2 inorganic coating, a first layer of polyvinylidene fluoride (PVDF), a nano-silver layer deposited by magnetron sputtering and a second layer of PVDF which are sequentially coated to form a base layer film / SiO2 / PVDF / Ag / PVDF sandwich structure. The SiO2 layer is prepared through a sol-gel method, the surface roughness is smaller than 2 nm, and the visible light transmittance is larger than 95%; the thickness of the silver layer is 50 + / -5 nm, and the total thickness of SiO2 / PVDF / Ag does not exceed 150 nm. According to the composite diaphragm, ultraviolet reflection, visible light high transmission (greater than 92%) and near-infrared high reflection (greater than 88%) are realized through spectrum selective regulation and control, and meanwhile, SiO2 and PVDF synergistically enhance the infrared emissivity of an atmospheric window wave band (8-13 [mu] m). The flexible PET base material is combined with the PVDF interlayer design to restrain silver layer oxidation and interface stripping, the recovery rate is larger than 95% after 1000 times of bending circulation, and the NIR reflectivity attenuation is smaller than or equal to 5%. The composite diaphragm disclosed by the invention has the advantages of high light transmission, efficient cooling, excellent flexibility and long-term stability, and is suitable for flexible scenes such as agricultural greenhouses and the like.

The invention relates to a high-reflection-high-emissivity radiation refrigeration coating for power equipment and a preparation method of the high-reflection-high-emissivity radiation refrigeration coating. The coating comprises deionized water, styrene-acrylic emulsion, titanium dioxide, hollow glass beads, zinc oxide, hexacyclic stone powder, a dispersing agent, a defoaming agent, a coalescing agent and a mildew preventive, and mica powder, calcined kaolin, talcum powder, silicon oxide micro powder or block copolymer emulsion can be optionally added. According to the coating, the synergistic effect of various infrared functional fillers and an emulsion matrix is optimized, so that high reflection of sunlight and high emission of middle and far infrared bands are realized. The coating has excellent cooling capacity, self-cleaning performance and environmental adaptability.

The invention relates to a colored radiation refrigeration coating and a colored cooling coating, the colored radiation refrigeration coating comprises a white prime coating and a colored surface coating which are matched for use, the sunlight reflectivity of a white bottom layer formed by the white prime coating at the wave band of 0.3-2.5 microns is greater than or equal to 95%, and the sunlight reflectivity of the colored surface coating at the wave band of 0.3-2.5 microns is greater than or equal to 95%. The atmospheric window emissivity at the wave band of 8-13 [mu] m is greater than or equal to 95%; the colored surface coating comprises a first filler, yttrium gallium garnet and first resin, the yttrium gallium garnet is doped with chromium, and the mass fraction of the chromium in the yttrium gallium garnet is 5%-15%. A color cooling coating formed by the color radiation refrigeration coating is bright in color, the sunlight reflectivity at the wave band of 0.3-2.5 microns is larger than or equal to 82%, the atmospheric window emissivity at the wave band of 8-13 microns is larger than or equal to 95%, and the color radiation refrigeration coating has an excellent cooling effect.

Paint compositions and paint coatings for radiative cooling, as well as related methods of manufacturing and use of such paint compositions. A composition for paint to be used in radiative cooling, in a wet coating phase, includes nanoplatelets of hexagonal boron nitride, an acrylic binder, and a solvent. A coating of a dried paint on a surface to be cooled by radiative cooling includes nanoplatelets of hexagonal boron nitride and an acrylic binder. A method of manufacturing the composition for paint in the wet paint phase includes forming a first mixture by adding the nanoplatelets of hexagonal boron nitride to the solvent, uniformly distributing the nanoplatelets in the first mixture, and forming a second mixture by adding the acrylic binder to the first mixture.

The invention discloses a dynamic self-adaptive radiation refrigeration material which comprises the following components in percentage by mass: 15-30% of matrix resin, 40-60% of a ternary function system, 1-3% of a dispersing agent, 2-5% of a cross-linking agent and the balance of deionized water, the ternary function system is composed of a temperature-sensitive block copolymer, phase change microcapsules and rare earth doped infrared emission particles according to the mass ratio of (1-2): (2-3): (1-1.5). According to the refrigeration material, when the environment temperature is higher than the low critical solution temperature of the temperature-sensitive copolymer, the temperature-sensitive chain segment shrinks to expose the rare earth particles, so that high reflectivity of sunlight and high emissivity of an atmospheric window are realized, and refrigeration is enhanced; when the temperature is lower than the phase-change temperature of the phase-change material, the temperature-sensitive chain segments stretch and wrap the rare earth particles, the infrared emissivity is reduced, heat loss is reduced through phase-change heat release, the dual functions of efficient refrigeration in summer and heat loss reduction in winter are achieved, and the applicability of the coating in an area with the large temperature difference is improved.

The invention relates to a photovoltaic heat dissipation enhanced radiation refrigeration cement-based composite material as well as a preparation method and application thereof. The composite material comprises white Portland cement, radiation refrigeration particles and water, the radiation refrigeration particles comprise alpha aluminum oxide and barium sulfate, the mass fraction of the radiation refrigeration particles relative to the total solid content in the composite material is 30%-60%, and the mass ratio of the alpha aluminum oxide to the barium sulfate is 1: 1-2: 1; the average particle size of the radiation refrigeration particles is 0.3-10 [mu] m; the mass fraction of the white Portland cement relative to the total solid content in the composite material is 40-70%. Compared with the prior art, the reflectivity and emissivity of the material are improved, efficient photovoltaic thermal management is achieved, meanwhile, the material has the advantages of being low in cost, simple in process, high in stability and the like, development of the building photovoltaic integrated technology is expected to be promoted, and the energy utilization efficiency is improved.

The invention discloses a method for preparing a lignin hard carbon negative electrode material through Joule thermal flash evaporation, and belongs to the technical field of negative electrode material preparation. The method mainly comprises the following steps: (1) reacting lignin with alkali liquor, adding acid, washing with water, and drying to obtain dried lignin; (2) preheating the dried lignin in a tubular furnace to obtain a hard carbon precursor; and (3) putting the hard carbon precursor into a graphite mold, and carbonizing through Joule heat flash evaporation to obtain the lignin-based hard carbon negative electrode material. According to the method, rapid temperature rise is realized by Joule heating, and the method is short in reaction time and high in reaction temperature. Compared with a radiation cooling mode of a traditional high-temperature furnace, black-body radiation can release most heat within milliseconds. Under the action of an electric field, lignin is recombined and stacked into a vortex layer carbon layer, and a three-dimensional continuous carbon network is formed. The ultrafast method can relieve the carbon layer accumulation phenomenon in the lignin pyrolysis process.

The invention discloses a high-reflection magnesium phosphate / aluminum phosphate radiation refrigeration material and a preparation method thereof, and relates to the technical field of radiation refrigeration materials. The preparation method of the high-reflection magnesium phosphate / aluminum phosphate radiation refrigeration material comprises the following steps: (1) mixing aluminum sec-butoxide and deionized water to prepare a solution A; mgCl2. 6H2O and deionized water are mixed to prepare a solution B; mixing the solution A and the solution B to obtain a solution C; (2) adding 3-sulfopropyl tetradecyl dimethyl betaine into the solution C to obtain a solution D; (3) stirring sodium pyrophosphate and deionized water into a solution E; mixing the solution E and the solution D to obtain a solution F; and (4) reacting the solution F at 150-180 DEG C, cooling, freeze-drying and grinding to obtain H, heating H to 300-400 DEG C at the rate of 3-4 DEG C / min, then heating H to 800-1300 DEG C at the rate of 7-10 DEG C / min, and keeping the temperature for 1-3 hours to obtain the product. The material prepared by the invention has excellent sunlight reflectivity and excellent mid-infrared emissivity, and shows excellent performance in the field of radiation refrigeration.

The invention discloses a coated fabric with radiation cooling and infrared stealth functions and a preparation method of the coated fabric. The coated fabric with the radiation cooling and infrared stealth functions comprises a fabric substrate, and a radiation cooling coating and an infrared stealth coating which are respectively coated on two side surfaces of the fabric substrate, the radiation cooling coating is a water-based environment-friendly coating coated with inorganic nanoparticles; and the infrared stealth coating is a binder polymer coating coated with reflective particles. According to the coated fabric with the radiation cooling and infrared stealth functions, the two contradictory functions of infrared stealth and radiation cooling are combined together in a double-sided coating mode.

The invention belongs to the technical field of glass for buildings, and discloses a thermochromic intelligent window based on a vanadium dioxide nanoparticle film concentration gradient structure and a preparation method thereof.The preparation method comprises the steps that firstly, two parts of W-VO2 nanoparticles with different masses and PVP are added into absolute ethyl alcohol to be subjected to ultrasonic oscillation, and the W-VO2 nanoparticles and PVP are stirred to be evenly distributed and then stand for use; the method comprises the following steps: sequentially coating the surface of a pretreated glass substrate with W-VO2amp with relatively high concentration from bottom to top; a PVP dispersion liquid, a PMMA dispersion liquid, and low-concentration W-VO2amp are added; a PVP dispersion liquid; therefore, a W-VO2 gradient structure with low concentration at the top layer and high concentration at the bottom layer is formed on the surface of the glass substrate. The visible light transmittance of the thermochromic intelligent window is greatly improved, meanwhile, the solar modulation capacity is improved, the antagonism between the two optical properties of the visible light transmittance and the solar modulation efficiency is weakened or even broken through, and thermochromic development of the intelligent window and the radiation refrigeration field is further promoted.

The invention relates to the technical field of refrigeration fibers, and particularly discloses a radiation refrigeration textile fiber and a preparation method thereof.The preparation method comprises the steps that a fluorine modifier and a styrene-maleic anhydride copolymer are dissolved in an organic solvent under the stirring and heating conditions, then fiber master batches are added, stirring continues to be conducted for 30-60 min to enable the fiber master batches to be partially dissolved, and then the radiation refrigeration textile fiber is obtained; a material A is obtained; uniformly mixing a silane coupling agent with deionized water and absolute ethyl alcohol, and then adding a pH regulator to regulate the pH value of the system to a preset value, so as to obtain a material B; uniformly stirring the material A and the material B, reacting at 60-70 DEG C for 2-5 hours, and drying to obtain modified fiber master batch; and preparing the modified fiber master batch into the radiation refrigeration textile fiber by adopting a melt spinning process. According to the method, on the premise that the mechanical strength of the fiber is not affected, the thermal emissivity of the traditional fiber in an atmospheric transparent window interval and the sunlight reflecting capacity of the fiber are greatly improved.

The invention relates to the technical field of radiation refrigeration coatings, and discloses a daytime radiation refrigeration coating and a preparation method thereof.The daytime radiation refrigeration coating is attached to the surface of a base material and comprises an interface thermal buffer layer, a directional scattering reflection layer and an infrared selective emission layer from inside to outside; the interface thermal buffer layer comprises zinc oxide arrays grown on the surface of the base material in situ through a hydrothermal reaction, and graphene oxide distributed among the zinc oxide arrays; the directional scattering reflection layer comprises barium sulfate particles and titanium dioxide particles; the infrared selective emission layer comprises a core-shell structure formed by coating silicon dioxide with titanium dioxide, and polydimethylsiloxane; the base material is an aluminum plate, a stainless steel plate or glass. By constructing the interface thermal buffer layer containing the zinc oxide array and the graphene oxide, heat conduction and interface thermal stress between the scattering layer and the infrared selective emission layer are effectively relieved, and the thermal stability and long-term refrigeration performance of the coating are improved.

Permafrost thawing prevention may involve deploying a cooling geotextile onto a permafrost soil. The geotextile may include a biomass scaffold comprising natural plant-based fibers. The geotextile may further include a cellulose layer comprising cellulose fibers laminated onto the biomass scaffold such that the cellulose fibers are physically entangled with the plant-based fibers. The geotextile may further include a hydrophobic and biodegradable coating which defines at least one surface of the geotextile. The geotextile may be optically opaque, exhibits high solar reflectivity, and maintains high mid-infrared emissivity to enable passive radiative cooling.

The invention discloses a preparation method and application of a PLA (polylactic acid) / PTFE (polytetrafluoroethylene) radiation refrigeration composite film based on an electrostatic spinning method, and belongs to the field of radiation refrigeration materials. And preparing the polymer radiation composite fiber membrane by adopting an electrostatic spinning technology. The obtained micro-nano size fiber film has a porous structure, can realize a strong Mie scattering effect on solar wavelength, improves the solar reflectivity of the radiation film, and realizes the reflectivity of 85% or above within the wavelength of 400-1400 nm and the relatively high infrared emissivity of 90% within the wavelength of 8-13 [mu] m. The radiation cooling composite film has great application potential value in the field of low-temperature grain storage.

The invention discloses a Janus type flexible radiation refrigeration material and a preparation method thereof.The Janus type flexible radiation refrigeration material is characterized in that a modified radiation refrigeration layer and a functional layer are arranged on the upper surface and the lower surface of a substrate fiber layer with specific functional groups, and on one hand, the substrate fiber layer can be subjected to esterification or silanization bonding with the amino silane modified radiation refrigeration layer; the material can be subjected to an esterification reaction with a carboxylation modified functional layer, so that the three-layer material interface is chemically bonded, the bonding force of the interface is effectively improved, the dynamic stability is effectively improved on the basis of ensuring the optical performance and the mechanical flexibility, and the application of the radiation refrigeration material is promoted.

The invention discloses a wide-spectrum emission lanthanum-doped aluminum phosphate radiation refrigeration material and a preparation method thereof.The lanthanum-doped aluminum phosphate is synthesized by modifying aluminum phosphate with the lanthanum element through a hydrothermal method, the preparation process is simple, the reaction period is short, raw materials are common, the cost is low, controllability is high, a large number of target products can be prepared, and industrial production is easy to achieve; the lanthanum-doped synthesized aluminum phosphate powder has high sunlight reflectivity and high and medium infrared radiance at the same time, and has excellent refrigeration performance; according to the invention, the lanthanum-doped aluminum phosphate powder is dissolved in the tree trunk whitening agent and is applied to the surfaces of trees so as to reduce the temperature of the tree trunks, and the lanthanum-doped aluminum phosphate powder can play a certain role in inhibiting fire disasters when being applied to the trees in forests.

The invention provides a multifunctional radiation refrigeration material and application thereof, and the multifunctional radiation refrigeration material is used for releasing heat to space through an atmosphere window in an infrared radiation form and reflecting ultraviolet light and / or visible light and / or near-infrared light in sunlight at the same time. The multifunctional radiation refrigeration material comprises a base material and a flame-retardant material, wherein the flame-retardant material comprises one or more of a phosphorus-based material, a nitrogen-based material and a phosphorus-nitrogen-based composite material; the mass percent of the flame-retardant material in the multifunctional radiation refrigeration material is 9%-60%. The multifunctional radiation refrigeration material provided by the invention has excellent flame retardant property and radiation refrigeration effect at the same time.

The present invention relates to a flexible thermoelectric device that may be combined and attached to a curved surface and generates an electromotive force based on a temperature difference between one surface and the other surface, and more particularly, to a flexible thermoelectric device having a radiative cooling part which improves power generation performance by increasing cooling efficiency of a cooling side through radiative cooling and minimizes a volume of a heat dissipating part, and a method of manufacturing a radiative cooling part.

The invention relates to the field of energy-saving and environment-friendly new materials, in particular to a passive cooling radiation refrigeration light-transmitting film and a preparation method thereof. Comprising a first release protective film layer, a back adhesive layer, a first base material film layer, a second base material film layer, an IR reflecting layer, an IR selective emitting layer, a third base material film layer, a self-cleaning and self-repairing functional coating and a second release protective film layer which are sequentially stacked. The passive cooling radiation refrigeration light-transmitting film provided by the invention is moderate in thickness, strong in flexibility and large in stretchability, and can be tightly attached to any surface part. Under the condition that the appearance color is not influenced, the visible light wave band transmittance is greater than 70%, the infrared light reflectivity is greater than 68%, the 8-13 [mu] m atmosphere window emissivity is greater than 97%, the radiation refrigeration power is greater than 140 W / m < 2 >, and the heat insulation performance is good; as the used base material is TPU or PET, the tensile property is large, the flexibility is strong, and the product has good flexibility and contractibility, and is not easy to wrinkle and blister during film pasting construction.

The invention relates to the technical field of radiation refrigeration films, and discloses a porous polyvinylidene fluoride based composite radiation refrigeration film and a preparation method thereof. The method comprises the following steps: firstly, carrying out melt blending on PVDF, NaCl and ZnO nanoparticles and forming a film, then dissolving out NaCl through water washing, and constructing a continuous three-dimensional porous structure in a PVDF matrix; and immersing the obtained porous PVDF / ZnO membrane material into a methanol aqueous solution containing 2-methylimidazole, so that ZnO is subjected to a coordination reaction at the pore wall and is converted into the ZIF-8 nanocrystal in situ. In the thin film prepared by the steps, the micron-sized salt-induced pore structure, the nano-sized ZIF-8 particles and the interface of the ZIF-8 particles jointly form a multi-stage scattering network, so that the scattering ability of the thin film in the solar spectrum range of 0.25-2.5 microns can be remarkably enhanced, the high infrared emission performance of the PVDF matrix in an atmospheric window of 8-13 microns is maintained, and the thin film has high solar reflectivity and high infrared emissivity, and can be used for preparing the solar film. An excellent radiation refrigeration effect can be achieved, and the heat-dissipating material is suitable for being applied to building outer surfaces, equipment heat dissipation, individual heat management and the like.