27 results about "Phase change enthalpy" patented technology

The invention relates to the technical field of fiber reinforced resin-based composite materials, in particular to a two-component sweating type fiber reinforced phenolic aerogel composite material and a preparation method thereof. The method comprises the following steps: (1) modifying phenolic resin; (2) preparing a phenolic resin pregel solution; (3) impregnating the fiber reinforcement; (4) gel curing; (5) drying; (6) filling with an inorganic phase change agent; and (7) filling with an organic phase change agent. The phenolic aerogel is prepared by taking the phenolic resin modified by hot acid treatment as a raw material, so that the curing crosslinking degree of the phenolic resin can be effectively improved, and the skeleton and pore diameter of the aerogel can be refined. According to the invention, the inorganic phase change agent and the organic phase change agent with high phase change enthalpy values are sequentially introduced into pores of the phenolic aerogel, and the hierarchically distributed binary phase change agent can be subjected to solid-liquid-gas phase change in sequence from outside to inside in a high-temperature environment, so that the composite material has comprehensive properties such as ultrahigh temperature resistance, long-term efficient heat insulation and high mechanical strength.

The application relates to preparation and application of inorganic eutectic shaped phase change materials with heat preservation function, belonging to the technical field of phase change energy storage. The inorganic eutectic shaped phase change material takes sodium carbonate decahydrate and disodium hydrogen phosphate dodecahydrate as phase change main body materials, and takes sodium silicate nonahydrate as a nucleating agent, so that the supercooling degree is reduced, and the inorganic eutectic phase change material with low supercooling and no phase separation is prepared. Further, the inorganic eutectic shaped phase change material is prepared by using gaseous SiO2 as supporting material. The material prepared by the application has suitable phase change temperature, higher phase change enthalpy and very low supercooling degree, and has no phase separation phenomenon. Moreover, the synthesis process is simple, and the raw material is low in price. Simulation application test shows that the material has excellent building heat buffering performance, and has wide application prospect in the field of building energy saving.

This invention relates to high-energy-density phase change composite materials, their preparation methods, and applications, belonging to the field of phase change composite material technology. To address the problems of low energy density, insufficient mechanical properties, and poor processability of current phase change materials, this invention provides a high-energy-density phase change composite material, specifically a lightweight porous cellulose phase change composite aerogel. Internally, it consists of a three-dimensional network framework formed by the cross-linking of vinyl-functionalized cellulose nanocrystals and cellulose nanofibers. The phase change material is uniformly loaded within the pores of this three-dimensional network, with a loading amount of 65.53~91.02 wt%. The phase change temperature range of the composite material is 20~80℃. This invention's phase change composite material, relying on a hierarchical confinement structure, achieves efficient encapsulation and high loading of the phase change material, with a phase change enthalpy as high as 133.2 J / g. It also possesses excellent mechanical and thermal cycling stability and 3D printing performance, making it suitable for scenarios with wide temperature fluctuations and applicable to the field of intelligent thermal management.

The invention discloses a low-thermal-conductivity phase change aerogel material as well as a preparation method and application thereof. The phase change enthalpy value of the material is 50J / g to 110J / g; the phase change temperature is 0-60 DEG C; and the heat conductivity coefficient is 0.08 W / (m.K)-0.1 W / (m.K). The novel low-thermal-conductivity phase-change material is generated by curing polydimethylsiloxane (PDMS) and the phase-change microcapsules. The phase change aerogel material is simple in synthesis process, relatively high in phase change enthalpy value and good in phase change cycle stability. The method has important application prospects in the two aspects of heat energy collection and heat insulation temperature control.

This disclosure relates to a composition for preparing phase change composite materials, the phase change composite material itself, a preparation method thereon, and its applications. Based on the total weight of the composition, it comprises: 80-90% by weight of a phase change material, 5-17% by weight of a thermally conductive filler, and 3-15% by weight of a thickener. The phase change composite material has a phase change enthalpy of 80-250 J / g, a phase change enthalpy yield of 80-90%, a thermal conductivity of 1-10 W / m·K, and a melt index of 15-150 g / min. Using the composition of this disclosure to prepare the phase change composite material can improve the phase change enthalpy yield, while also exhibiting high thermal conductivity and a certain degree of plasticity in the molten state. Furthermore, the mixing and molding processes are simplified by using only a heated stirring pan or kneading pan, reducing production costs.

The invention relates to a method for quantitatively designing the functional mix proportion of a phase-change material for SAC. The method comprises the following steps: acquiring a characteristic initial temperature T, a peak temperature T and a characteristic final temperature T of sulphoaluminate cement through an adiabatic temperature rise test; [T, T] is used as a functional targeted phase change interval of the phase change material, and based on the total hydration heat release amount Qcem in the temperature interval and the phase change enthalpy delta Hpcm of the phase change material, the functional mixing amount Mpcm of the phase change material in unit volume of concrete is calculated, then the aggregate dosage is calculated through an absolute volume method, and finally the concrete mix proportion is determined. According to the invention, accurate matching of the phase-change material and sulphoaluminate cement hydration characteristics is realized, and an effective temperature control solution is provided for sulphoaluminate cement concrete construction.

The invention belongs to the field of phase change energy storage temperature control materials of an organic system, and provides a preparation method of a lignin-based organic phase change material, the lignin-based organic phase change material comprises the following raw materials by weight: 86%-97% of erythritol, 2%-5% of hexagonal boron nitride, 0.5%-2% of a lignin compatibilizer and 0.5%-10% of expanded graphite, and the sum of the mass percentages of the raw materials is 100%. By adding the lignin compatibilizer, the compatibility of the phase change material and other components is improved, and the stability of the whole material is improved by regulating and controlling the formula. The energy storage and temperature control phase change material provided by the invention has the advantages of proper phase change temperature, high phase change enthalpy value, low supercooling degree, good cycle stability and no obvious phase separation phenomenon, and is a proper thermal physical energy storage technology.

This invention discloses a gel-based composite phase change energy storage material and its preparation method. The material comprises the following components in the indicated mass fractions: 70%–80% phase change matrix; 5%–10% temperature regulator; 1%–3% nucleating agent; 0.5%–1.5% thermal conductivity enhancer; 10%–15% gel skeleton; and 0.5%–2% thickener. This invention precisely controls the phase change temperature to -25°C to -20°C using the temperature regulator, meeting the requirements for frozen product transportation; it utilizes synergistic nucleating agents and functionalized multi-walled carbon nanotubes to control the supercooling to within 2°C; the carbon aerogel skeleton and surface gel protective layer achieve dual leak prevention, exhibiting excellent cycle stability, with a phase change enthalpy decay rate of less than 5% after 500 cycles; simultaneously, the thermal conductivity is significantly improved, and the raw materials are environmentally friendly and biodegradable, showing broad application prospects in the cold chain logistics field.

Disclosed in the present invention are a novel phase change energy module and a preparation method therefor, belonging to the technical field of phase change energy storage materials. The energy module product consists of a shape-stabilized phase change system having thermal energy storage properties and an encapsulating bag. The preparation method comprises: using a support framework material to realize shape stabilization and adsorption of a phase change matrix and an additive, and performing secondary encapsulation with an aluminum foil bag, so as to solve the problem of liquid leakage during long-term recycling. The present invention involves a simple synthesis process, and is convenient to use. The material exhibits no significant liquid leakage during operation, a high phase change enthalpy value and a low price, and therefore has wide application prospects.

The application belongs to the technical field of energy storage, and relates to a composite phase change material and a preparation method and application thereof.The composite phase change material comprises a paraffin base body and a heat-conducting phase change material dispersed in the paraffin base body; the heat-conducting phase change material comprises at least one of biomass-based graphene, copper nanowire foam and Fe3O4 modified biomass-based graphene. Bamboo powder is converted into few-layer graphene through sandwich microwave plasma technology, then is modified by Fe3O4 nanoparticles, is compounded with paraffin, and finally is packaged with copper nanowire foam to construct a synergistic structure of 'two-dimensional heat-conducting network-three-dimensional metal skeleton-nano light absorber'. The prepared composite phase change material has a photo-thermal conversion efficiency of 73.47%, a heat conductivity of 3.157 W·m ‑1 ·K ‑1 , a phase change enthalpy retention rate of >98% and no leakage. The composite phase change material is suitable for solar heat storage, intelligent building and electronic device heat management, and is produced in a green and low-cost manner through biomass waste resource utilization.

The present application relates to a kind of double-shell high-thermal-conductivity phase change heat storage microcapsules for ultra-deep drilling fluid and its preparation method and application, belong to the drilling fluid chemistry field of petroleum industry.The present application respectively with two high-melting-point phase change materials and two eutectic compounds of phase change material as core material, by twice the coating of outer shell, a kind of double-shell high-thermal-conductivity phase change heat storage microcapsules for ultra-deep drilling fluid is prepared, the material has high phase change temperature, phase change temperature is between 173.3-230.7 DEG C, phase change enthalpy is as high as 211.4J / g, when in phase change temperature range, a large number of heat will be absorbed, play the role of " phase change latent heat", the material is applied to drilling fluid can significantly reduce the temperature of drilling fluid, improve the tolerance of drilling fluid to high temperature formation.

The invention discloses a recyclable flexible composite phase change material as well as a preparation method and application thereof, and relates to the technical field of battery thermal management. The lauric acid, the thermoplastic polyester elastomer and the hexagonal boron nitride are simply blended to prepare the recyclable flexible composite phase-change material with wide-temperature flexibility and excellent electrical insulating property, the phase-change material keeps flexibility in a wide temperature range of-15-60 DEG C, can be tightly attached to a battery, is extremely small in temperature fluctuation under continuous vibration, and can be widely applied to the field of lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries, lithium ion batteries and lithium ion batteries. And the short circuit risk is reduced through high insulativity. In addition, the high phase change enthalpy can significantly reduce the working temperature of the battery. And the material also has excellent recoverability, the performance is not attenuated after 10 times of remodeling, and excellent practicability and reliability are shown.

The application belongs to the technical field of phase change materials, and particularly relates to a mixed graphene / polymer microsphere / alkane composite phase change material and a preparation method thereof. The preparation method comprises the following steps: heating and melting an alkane base to obtain an alkane fluid, adding two kinds of graphene with the same sheet diameter and different thicknesses and a dispersing aid into the alkane fluid, adding polymer microspheres, sealing and placing in a heat treatment device at 50-80 DEG C, and then performing ultrasonic crushing to obtain the graphene / polymer microsphere / alkane composite phase change material. The two kinds of graphene with the same sheet diameter and different thicknesses and the microsphere-assisted heat conduction framework significantly improve the heat conductivity of the alkane phase change material, significantly reduce the viscosity, and minimize the influence of the phase change enthalpy, so that the efficient heat conduction and energy storage efficiency are realized. The preparation process is simple, and the mass production and application can be realized.

The invention discloses an adipic acid-sebacic acid binary eutectic phase change material and a preparation method thereof, and belongs to the field of phase change energy storage materials. The eutectic phase change material is composed of two compounds which are respectively adipic acid and sebacic acid. The eutectic phase change material with the melting point of 124.1 DEG C and the phase change enthalpy of 216.1 J / g is provided by adjusting the molar percentage of adipic acid and sebacic acid in a binary system, and the eutectic phase change material has potential application in the scenes of medium-high temperature electronic device heat management, mold temperature control, solar energy and industrial waste heat energy storage and the like. The adipic acid / sebacic acid eutectic phase-change material has the advantages that (1) the phase-change temperature of the prepared adipic acid / sebacic acid eutectic phase-change material is 124.1 DEG C, and the adipic acid / sebacic acid eutectic phase-change material is suitable for a thermal management scene of medium-high temperature electronic equipment; (2) the adipic acid / sebacic acid eutectic phase change material prepared by the method is homogeneous, free of phase separation and high in phase change enthalpy value; and (3) the preparation method provided by the invention is simple, green, environment-friendly and pollution-free.

The invention discloses a phase change heat storage material storage life testing and evaluating method, system and equipment based on phase change enthalpy and a medium. The method comprises the steps that the phase change enthalpy at the initial moment before accelerated aging is tested; carrying out an accelerated aging test to obtain multiple groups of phase change enthalpy data; aging reaction rate constants under different aging reaction stages are obtained through fitting; determining an optimal reaction stage; fitting to obtain an aging reaction rate factor at the target temperature; calculating the actual storage life required by the phase change material to attenuate from the initial state to the phase change enthalpy retention rate threshold value at normal temperature; and based on the actual storage life and the target life, judging whether the storage life of the phase change heat storage material meets the requirement or not. According to the invention, the test period can be shortened from several years to dozens of days, and the method is suitable for the fields of aerospace, building energy saving, electronic heat dissipation and the like, and has the advantages of high reliability, strong universality and good operability.

The present disclosure provides a composite phase change heat storage material and a preparation method thereof, which uses hydrophilic modified natural graphite as a heat conducting material in the heat storage material, effectively improves the interfacial compatibility between the heat conducting material and the phase change material, and further improves the dispersibility, so that the prepared heat storage material has a higher phase change enthalpy retention rate and thermal conductivity.

The application provides a graphdiyne phase change composite material and a preparation method thereof. The method constructs a graphdiyne phase change composite material through chemical grafting. The material has good phase change energy storage performance and good mechanical properties. Thanks to the unique chemical structure and excellent physical and chemical properties of graphdiyne, and the controllable phase change temperature and high phase change enthalpy value of the composite material, the composite material has considerable application prospect in the field of energy storage and conversion.

The present invention belongs to the technical field of phase-change energy storage. Disclosed are a polyvinyl alcohol-based double-network aerogel shaped organic-inorganic composite phase-change energy-storage material, and a preparation method therefor and the use thereof. The phase-change energy-storage material is composed of 30-70 wt% of an inorganic solid-liquid phase-change material, 40-60 wt% of an organic solid-liquid phase-change material, 0.1-5 wt% of a nucleating agent and 5-20 wt% of a polyvinyl alcohol-based double-network aerogel supporting material, wherein the inorganic solid-liquid phase-change material is a hydrated inorganic salt phase-change material; the organic solid-liquid phase-change material is an organic nitride, an organic acid ester or a long-chain alkane phase-change material; the nucleating agent is a nano oxide or a salt having a similar crystal form; and the supporting material is a polyvinyl alcohol / double-network aerogel. The three components are assembled under a supramolecular acting force and are uniformly compounded with a porous adsorption material. The prepared composite phase-change material (CPCM) has a relatively high phase-change enthalpy value and good cycling stability. In addition, the CPCM further exhibits excellent architectural heat management performance, and is very suitable for large-scale application in architectural heat management in the future.

This invention discloses a method for determining the target phase change temperature and target phase change enthalpy of phase change materials based on the snow melting and de-icing needs of different regions, belonging to the technical field of road snow melting and de-icing and phase change energy storage parameter design. The method includes: obtaining the latitude, altitude, winter minimum temperature, duration near freezing point, snowfall intensity, and total winter solar radiation of the target region; determining the characteristic winter temperature based on latitude and altitude; automatically identifying the snow melting and de-icing demand type by combining the above parameters; inputting the regional parameters and demand type into a phase change material thermal parameter prediction model to obtain the predicted values ​​of the target phase change temperature and target phase change enthalpy; after engineering constraint correction, matching with a candidate phase change material library, and outputting recommended phase change temperature range, phase change enthalpy range, and candidate material category. This invention can provide a basis for determining phase change snow melting and de-icing parameters for transportation infrastructure such as roads, bridge decks, airport runways, and railway turnouts.

The invention discloses a flexible shape-stabilized phase change film which comprises the following components in parts by mass: 50-90 parts of a phase change material; 10 parts of silicon oxide aerogel; 30 to 100 parts of flexible silicon resin; the phase change material is an alkane phase change material containing methyl or ethyl. The invention also discloses a preparation method of the film. The preparation method comprises the following steps: heating the alkane phase-change material in a drying oven until the alkane phase-change material is completely molten into a liquid state; the preparation method comprises the following steps: uniformly mixing a liquid alkane phase change material with silicon oxide aerogel, and naturally cooling to form a shape-stabilized phase change block; crushing the shape-stabilized phase change block to obtain shape-stabilized phase change powder; mixing the shape-stabilized phase change powder and flexible methyl silicone resin, putting the mixture into a mold, and pressing to obtain a phase change film blank; and curing the phase change film blank at room temperature, and demolding to form the flexible shape-stabilized phase change film. The flexible shape-stabilized phase change film is high in phase change enthalpy value and stable in structure after phase change and can be conveniently pasted and fixed to the surface of an arc-shaped structure such as an aircraft bulkhead and the special-shaped surface of instrument equipment, and efficient long-time phase change thermal control over the cabin structure and the special-shaped surface of the instrument equipment is achieved.

The application is a phase change material functional matching quantitative design method for SAC, the characteristic starting temperature T1, peak temperature T2 and characteristic termination temperature T3 of the sulphoaluminate cement are obtained through the adiabatic temperature rise test; [T1, T3] is taken as the functional target phase change interval of the phase change material, and the total hydration heat Q in the temperature interval is calculated cem The phase change enthalpy Delta H of the phase change material pcm The functional content M of the phase change material in unit volume of concrete is calculated pcm The aggregate amount is calculated through the absolute volume method, and the concrete mixing ratio is finally determined. The application realizes the accurate matching of the phase change material and the hydration characteristics of the sulphoaluminate cement, and provides an effective temperature control solution for the sulphoaluminate cement concrete construction.

This invention discloses a recyclable solid-solid phase change material with high enthalpy and its preparation method, belonging to the field of phase change energy storage material preparation technology. The solid-solid phase change material uses polyethylene glycol as the soft segment of the phase change process, and isophorone diisocyanate, a monoisocyanate-modified tetrahydrobonded intermediate (UPy-NCO), 4,4'-diaminodiphenyl sulfide, and melamine as comonomers, which are cross-linked and polymerized to form a polyurethane network. The process includes the following steps: first, synthesizing the UPy-NCO intermediate, then reacting it with the remaining monomers through prepolymerization, chain extension, and cross-linking reactions, and finally obtaining the target material through precipitation and drying. The material of this invention possesses both high phase change enthalpy and excellent cycling thermal stability. Furthermore, the material can be pulverized and heated in an oven to self-melt and reassemble without external pressure, achieving convenient and efficient recyclability. This material is suitable for long-term energy storage applications such as thermal management of electronic devices, battery pack heat dissipation, and building energy conservation.

The application relates to the technical field of phase change heat storage materials, in particular to a method and device for cascade utilization of sugar alcohol phase change heat storage materials, wherein the method comprises the following steps: according to the attenuation law of the melting point and the phase change enthalpy of a target sugar alcohol phase change material in a cascade latent heat storage system and the phase change temperature of each level of phase change heat storage material in the cascade latent heat storage system, the phase change enthalpy of the sugar alcohol phase change material corresponding to each level of phase change temperature is determined; in the case that the cascade latent heat storage system is in an operating state, the actual attenuation degree of the target sugar alcohol phase change material is determined, and the target sugar alcohol phase change material is replaced step by step based on the actual attenuation degree, each level of phase change temperature and the corresponding phase change enthalpy, so that the sugar alcohol phase change heat storage material is utilized in a cascade mode. The application embodiment can prolong the service life of the sugar alcohol phase change heat storage material, improve the economic benefit of the system, and also can realize cascade storage and release of heat in the latent heat storage system, and improve the thermodynamic energy efficiency of the system.

The present application belongs to the technical field of polymer-based phase change heat-conducting composite material, and particularly relates to a phase change microcapsule heat-conducting composite material, a preparation method and application thereof. The present application aims at the defects of existing phase change composite material, such as heat-conducting filler agglomeration, poor interface compatibility, discontinuous heat-conducting network, and easy leakage of phase change material. The surface of the phase change microcapsule is aminated by microfluidic technology, the heat-conducting filler is modified by epoxy group, and the composite material is prepared by synergistic dispersion and dynamic force field hot pressing. The aminated phase change microcapsule filling amount is 10-50wt% of the mass of PDMS, and the modified heat-conducting filler addition amount is 5-10wt%. The material has excellent heat storage, heat conduction and mechanical flexibility, the phase change enthalpy value can be up to 156J / g, and the heat conductivity coefficient can be up to 2.5W / (mK), which can be applied to the fields of flexible electronics, intelligent wear, spacecraft thermal management and the like.

This invention proposes a spherical sodium acetate trihydrate composite phase change material and its microfluidic preparation method. The method includes: mixing and melting sodium acetate trihydrate with a nucleating agent, a thickener, and a thermally conductive filler to form a homogeneous composite liquid; adding the composite liquid dropwise to a silicone oil medium of a specific viscosity using a microfluidic device, utilizing interfacial tension to shape the droplets into spherical shapes and complete controlled phase change solidification; finally, washing and drying to obtain the spherical product. A specific order is used: adding the nucleating agent first, then the thermally conductive filler, and finally the thickener. This invention, through the synergy of microfluidic technology and composite formulation, successfully prepares a composite phase change material with good sphericity and uniform particle size, effectively solving the problems of severe undercooling, easy phase separation, and the inability to controllably prepare spherical particles using traditional methods. The product exhibits low undercooling, high phase change enthalpy, and excellent cycling stability.

The application discloses an expanded graphite-based phase change temperature and humidity control material and an in-situ dry glue synthesis method and application thereof. The synthesis method comprises the following steps: heating an organic phase change material to a molten state, adding hydrophilic modified expanded graphite powder, uniformly mixing, and then cooling and crystallizing to obtain a shaped composite phase change temperature control material powder; mixing an organic carboxylic acid ligand, sodium hydroxide and water to obtain a sodium carboxylic acid solution, adding a metal ion salt solution dropwise, continuously stirring, and forming a thick metal-organic framework sol; mixing the shaped composite phase change temperature control material powder and the metal-organic framework sol, uniformly dispersing, freeze-drying, then carrying out a constant temperature and humidity reaction, and washing, drying to obtain the expanded graphite-based phase change temperature and humidity control material. The expanded graphite-based phase change temperature and humidity control material has the advantages of simple preparation process, mild reaction, controllable temperature and humidity, large phase change enthalpy, good moisture absorption and desorption, high stability, good recyclability and the like, can meet the requirements of human comfort, and is suitable for indoor temperature and humidity control.

The application provides a TiO2@MUF hybrid shell thermochromic phase change microcapsule and a preparation method and application thereof, and belongs to the technical field of functional energy storage materials. The microcapsule comprises a core layer and a shell layer, the core layer is a thermochromic phase change system composed of crystal violet lactone, bisphenol A and n-tetradecanol, the mass ratio of crystal violet lactone, bisphenol A and n-tetradecanol is 1:3-5:60-70, the shell layer is an organic-inorganic hybrid layer formed by stearic acid modified nano TiO2 and melamine-urea-formaldehyde resin, the mass proportion of stearic acid modified nano TiO2 in the shell layer is 0.10-0.25%, the phase change enthalpy of the microcapsule is greater than or equal to 110 J / g, the 24h light aging discoloration rate is less than or equal to 20%, and the light-heat conversion efficiency is greater than or equal to 88%. The microcapsule can be applied to temperature indication, anti-fake encryption, intelligent coating and functional fabric, and is especially suitable for solar energy utilization, electronic equipment heat dissipation and daily safety monitoring fields with high requirements for light resistance and energy storage stability.