DE102008004485A1 - Covering of organic and inorganic phase change material, comprises introducing the phase change material into a porous, open-cellular carrier structure and providing the filled porous granulates with water vapor-tight layer - Google Patents

Abstract

The method comprises introducing organic and inorganic phase change material (PCM) into a porous, open-cellular carrier structure and providing the PCM filled porous granulates having grain size of 1-10 mm with a water vapor-tight layer. The liquid latent heat storage material is filled in a 1-10 mm large container and then locked. The container is diffusion-tight or covered with a diffusion-tight layer. The layer and/or the container are polymer. The layer is applied in fluidization process. The spraying solution has process temperatures adapted to the fusion point of the PCM. The method comprises introducing organic and inorganic phase change material (PCM) into a porous, open-cellular carrier structure and providing the PCM filled porous granulates having grain size of 1-10 mm with a water vapor-tight layer. The liquid latent heat storage material is filled in a 1-10 mm large container and then locked. The container is diffusion-tight or covered with a diffusion-tight layer. The layer and/or the container are polymer. The layer is applied in fluidization process. The spraying solution has process temperatures adapted to the fusion point of the PCM. The PCM and organic additives are added for adjusting the fusion point.

Description

The The invention relates to the encapsulation of organic and inorganic Latent heat storage materials (also phase change materials or Phase Change Materials called PCMs for short). Organic and inorganic PCMs are transformed into suitable porous and open-cell support structures with dimensions in the range of 1 mm-10 mm introduced. To the leakage of the liquid PCM and the diffusion of To prevent water vapor into the PCM (especially with the salt hydrates) become the filled carrier structures with a Polymer z. B. encased in the fluidized bed process.

alternative Can the liquid PCM in diffusion-tight container (without support structure) are filled, which then be encapsulated diffusion-tight.

[State of the art]

For now many office buildings are being built in lightweight construction. The shortening of the construction times due to a high degree of prefabrication and the reduction of component costs are decisive. Disadvantage of this design is the lack of heat capacity, which causes the temperature fluctuations inside increase, summer temperature peaks occur and controllability the indoor temperature is difficult by means of building management technology becomes.

Suitable latent heat storage materials have a phase transition in the room temperature range (about 25 ° C). They can absorb and release large amounts of heat energy (100 ... 400 kJ / dm ³ , depending on the material) reversibly. Thus, these materials are ideal to bring a large heat capacity almost massless in lightweight structures. Depending on the PCM used, an amount of heat per millimeter PCM layer thickness can be recorded, which corresponds to the heat absorption of equivalent 10 mm to 40 mm concrete at a temperature increase of 5 ° C. For example, if a 10 cm-thick concrete wall warms by 5 ° C, then the temperature of a 3 mm thick PCM layer with a melting enthalpy of 333 kJ / dm ³ has not yet increased.

By the avoidance of summertime temperature peaks will thus be a better one Room climate created. Above all, this is the energy consumption for the air conditioning of lightweight buildings significantly reduced. In a combination of the PCM elements with a efficient night ventilation, can be on air conditioning even completely dispensed with.

at However, pilot testing has shown that PCMs are not easy can be integrated in building boards or materials.

to Sheathing PCM there are currently two options: On the one hand, organic materials, especially paraffins, in a few micrometers large polymer shells in one Emulsion process microencapsulated. On the other hand, paraffins, as well as the inorganic salt hydrates in macroscopically large Containers (foil bags, plastic containers or else in web multiple plates) are macro-encapsulated. While The microcapsules lend themselves to PCM safely in building materials and buildings to integrate, the macroscopic container have disadvantages in terms of integration and cycle stability. In the larger hollow chambers with dimensions of several Cubic centimeters, the composition of the salt-based PCMs may be in the components separate, which reduces the enthalpy of fusion and the phase transition temperature changes. Another Disadvantage of macroscopic encapsulation is that in case of damage to the Containers leak larger amounts of PCM and components can affect.

For the microencapsulation of organic latent heat storage (paraffins) based on an oil-in-water emulsion is, for example DE10163162A1 (2003) of BASF AG. US7037582B2 (2006) of the Hong Kong Polytechnic University deals with the microencapsulation of paraffins by a reaction between polypropylene glycols with bifunctional polyisocyanates and bifunctional polyisocyanates with polyamines.

DE 10 2005 002 169 A1 (2006) the Fraunhofergesellschaft describes a microencapsulated salt hydrate, wherein the capsule wall consists of an amino resin or amino resin-containing mixed resin. The mean particle size is given at a PCM content of 75% -98% with 3 μm-30 μm. An embodiment based on encapsulated calcium chloride hexahydrate comes in the range of 25 ° C-40 ° C to a melting enthalpy of 97.8 kJ / kg, wherein the melting range of the core is given at 38 ° C-41 ° C.

DE19954771A1 (2001) by Remmers Bauchemie GmbH deals with microcapsules with a silicone wall structure, which are supposed to enclose water-soluble solids, in particular salt hydrates, in a diffusion-tight manner.

As an alternative to the solid-liquid phase transitions z. In DE10018938A1 (2001) of the Merck Patent GmbH of heat storage materials the speech, which have in the application, a phase transition of solid - and should have an enthalpy of 50 J / g-150 J / g. These are monoalkylammonium tetrachlorochro mate, monoalkylammonium tetrachlorormane, monoalkylammonium tetrachlorocadmates etc. or dialkylammonium salts of the empirical formula (C _n H _{2n + 1} ) ₂ NH ₂ ] with the anions Cl, Br ^- and NO ₃ ^- .

Applications of microencapsulated PCM in the textile sector are z. In DE10330841A1 (2004) of the China Textile Institute, US6660667B2 (2003) DE69823690T2 (2005) and EP0766720B1 (1995) by Gutlast Technologies as well CA2511177A1 (2004) by Nanosports Technologies.

Encapsulated PCM pellets (without support structure) are incorporated in US4513053 (1985) by Pennwalt Corporation. Here solid PCM (salt hydrates and paraffins) is pressed in the form of pellets (with a residual porosity, so that the volume of the solid tablet corresponds to the volume in the molten state) and then encapsulated in a drum with various polymers in a multi-layer system water vapor barrier. The encapsulated pellets should then be mixed with various building materials.

The use of organic PCMs in the construction sector is the subject of numerous writings:
EP0981675B1 (1998) by Gutlast Technologies describes the use of PCM (eg heptadekane and octadecane) in the floor and ceiling area to reduce the temperature gradient in the form of special panels (ceiling tiles / floor tiles).

DE 10 2004 025 994 A1 (2004) the Saint Gobain Oberland AG describes latent heat storage for wall elements.

In DE 10 2004 025 996 A1 (2004) is called a transparent hollow brick with latent heat storage.

DE 10 2004 017 021 A1 (2004) the Ardex GmbH has a loaded with PCM (paraffin and / or salt hydrate) and flowed through by a fluid component.

US6835334B2 (2004) by Microtek Laboratories uses macrocapsules consisting of microcapsules based on paraffins in the construction sector.

The application of PCMs as temperature stabilizing thermal barriers for building construction, equipment manufacturing, textiles and other paraffinic hydrocarbon based insulation applications is described in DE69533394T2 (2005) by Gutlast Technologies.

In EP1277801A1 (2002) call polyurethane gel materials with PCM for heat regulation (better comfort) in shoe soles, bicycle seats, chair cushions and so on.

For temperature regulation in fibers, fabrics and textiles, PCM in US6689466B2 (2004) used the Gutlast Technologies.

In garments PCM also finds in US6855410B2 (2005) Use.

For the application of PCMs in the automotive sector is z. B. DE 20320026U1 (2004) of Daimler Chrysler AG for the purpose of improved temperature control of vehicle interior components (such as steering wheel, belt buckles, shifter, etc.) with heat storage medium (plastic-encapsulated phase transfer agent with a phase transition solid-liquid, preferably from 20 ° C to 25 ° C) lead. Also WO02083440A2 (2002) is about automotive applications.

The flammability of paraffins is said to be in US 6270836B1 (2001) of Frisby Technologies by providing the paraffin microcapsules with an inorganic shell by a sol-gel process.

A package provided with PCM for temperature stabilization is the subject of US6482332B1 (2002).

In WO2007040395A1 (2007) of Kobato Polytechnologie is called PCM in a polymer up to an application temperature of 200 ° C.

PCM with polymer is called "thermal interface material" between heat source and cold sink in EP1783169A2 (2003) by Dow Corning.

Pure PCM particles are in US4708812 (1987) encapsulated by Union Carbide. Drops of liquid PCM fall from 1.5 m height into liquid nitrogen, thereby creating PCM particles of various sizes (1 mm-10 mm), which are then coated with various polymers.

For cooling electronic components, PCM is used in WO2006053405A1 (2006).

Worth mentioning is also still DE10114998A1 (2002) of the company Merck. In this case, PCM is arranged on or in the cooler so that a significant heat flow from the CPU on the carrier to the PCM takes place only when the cooler exceeds the phase change temperature of the PCM. Thus, the PCM absorbs only the power peaks. To increase the thermal conductivity of the PCM aids (metals, graphite) are added. Also PCMs with a phase transition of fixed-solid who the one discussed here.

In WO2006053405A1 (2006) by KU Leuven Research and Development, PCM is incorporated into electrodeposited metals, thereby achieving high thermal conductivity in a unit with high heat capacity. A use as an actuator is conceivable, since the phase transition is associated with a change in volume. With PCM in microencapsulated form in a stable coating suspension, Cu coatings with 35% PCM by volume could be realized. The latent heat of these coatings was 10 J / g (with thinner layers of the microcapsules reach 20 J / g).

In the published patent application DE 10 2004 011 541 A1 ZAE Bayern encapsulates latent heat storage material in a building board, which in turn is surrounded by water vapor barrier materials (high barrier films, epoxy resin based coatings, etc.). In contrast, can be dispensed with in the present invention on the one hand to a support structure, on the other hand, PCM capsules can be incorporated into films, membranes or tissue and used as granular beds in air-flow cavities. Special requirements for the matrix (in the mentioned document to the building board) are not provided.

DESCRIPTION OF THE INVENTION

• • Einbringung in Gipsprodukte zur passiven Nutzung mittels freier Konvektion,
• • Einbringung als Granulatschüttung in Hohlräume zur aktiven Nutzung durch Zu- und/oder Abluft,
• • Kombination von PCM in abgehängten Decken zur Nutzung in Kombination mit Hinterlüftung oder Wasserdurchströmung,
• • oder Einarbeitung der PCM-Kapseln in Folien, Membranen oder Geweben in Kombination mit Gipsputzen oder Deckensystemen.

The invention describes a process for the permanent encapsulation of paraffins, salt hydrates or salt hydrates provided with organic additives in inexpensive materials with dimensions between 1 mm and 10 mm. Uses of such encapsulated PCMs are z. B .:

• Incorporation into gypsum products for passive use by means of free convection,
• • introduction as granulate fill in cavities for active use by supply and / or exhaust air,
• • Combination of PCM in suspended ceilings for use in combination with rear ventilation or water flow,
• • or incorporation of PCM capsules in films, membranes or fabrics in combination with gypsum plaster or ceiling systems.

• • Formstabil auch bei größeren Schütthöhen (z. B. bei der Verarbeitung in Rührbehältern und der Aufbringung einer Ummantelung), sowie statisch stabil gegenüber inneren Kräften der Ausdehnung und Kristallisation,
• • chemisch inert gegenüber PCM-Materialien und PCM-Compounds insbesondere Salzen und Paraffinen, sowie entsprechender Additive,
• • granulierbar,
• • hohe Saugfähigkeit bei gleichermaßen hoher Rückhaltekraft,
• • hohes Beladungsvermögen (> 30 VOL-%) bei stabiler, homogener Porenstruktur,
• • thermisch stabil im Anwendungsbereich,
• • nicht brennbar bzw. schwer entflammbar,
• • und preisgünstig.

While paraffins are expected to prevent leakage and eventual outgassing of lighter components, water-vapor-tight casing must be used in salt hydrate-containing PCMs in order to avoid a change in the chemical composition and an associated altered thermophysical behavior with regard to melting point, solidification behavior and enthalpy of fusion. Liquid PCM is introduced in a special process in support structures, which must meet the following criteria:

• • Dimensionally stable even at high bed heights (eg during processing in stirred tanks and the application of a jacket), as well as statically stable against internal forces of expansion and crystallization,
• • chemically inert towards PCM materials and PCM compounds, especially salts and paraffins, as well as corresponding additives,
• • granular,
• • high absorbency with equally high retention force,
• • high loading capacity (> 30 VOL-%) with stable, homogeneous pore structure,
• • thermally stable in the field of application,
• • non-flammable or flame retardant,
• • and reasonably priced.

When Examples of suitable support structures could for paraffins diatomaceous earth and for salt hydrate PCMs phenolic resin foams are identified. The filled Carrier structures are in the fluidized bed process with suitable Encased polymers. For higher melting paraffins can For example, water-based materials z. B. based on polyurethane or a water-diluted resin are used. at a filled with Salzhydathaltigem PCM support structure should a solvent be used which is a Processing below the melting point of the PCM allowed. For room temperature melting PCMs could be a polymer based on methacrylic acid and methyl methacrylate Propan-2-ol as a solvent or a bio-based polymer Material with a high content of nonpolar, hydrophobic amino acids be used with propan-2-ol as a solvent. There the evaporation of the solvent and the curing the polymer already takes place at relatively low temperatures, are hereby coatings already below a temperature of 20 ° C possible.

at In an alternative approach, epoxy containers become small containers made with the liquid salt hydrate without carrier structure filled and then encapsulated. to Preparation of these capsules is first with the help of a negative (eg from silicone) an open epoxy hypodermic pot produced, in which the liquid salt hydrate (without carrier structure) is filled. To the containers with epoxy resin At first, the PCM will freeze and then the container with epoxy resin locked.

[Embodiment]

As a template for coating in the fluidized bed, 800 g-1000 g of granules GR41 loaded with paraffin RT52 and having dimensions of 1 mm-3 mm were used by Rubitherm GmbH. As a formulation for sheath Alberdingk ^® U 5200 VP, a polyurethane dispersion with 38% solids content of Alberdingk Boley GmbH was chosen. As a fluidized bed system, the model Glatt GPCG 3.1, a top spray & Wurster with a capacity of 800 g-4500 g was used. The spray solutions (sprayed amount: 1333 g-1866 g) with a solids content of 15% -25% were sprayed by means of the Topspray process in the fluidized bed granulator through a nozzle with a diameter of 2 mm at a spray pressure of 2 bar. The supply air temperatures were 65 ° C-106 ° C, the exhaust air temperatures reached 42 ° C-68 ° C at product temperatures of 30 ° C-90 ° C, preferably from 30 ° C-45 ° C, with preferred for 5-10 minutes 45 ° C-50 ° C was dried. The air throughput was 190 m ³ / h-274 m ³ / h, the spray solution was tempered to room temperature. The screen bottom material used was a polyester fleece.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 10163162 A1 [0008]
• - US 7037582 B2 [0008]
• DE 102005002169 A1 [0009]
• DE 19954771 A1 [0010]
• - DE 10018938 A1 [0011]
• DE 10330841 A1 [0012]
• - US 6660667 B2 [0012]
• - DE 69823690 T2 [0012]
• EP 0766720 B1 [0012]
• - CA 2511177 A1 [0012]
• US 4513053 [0013]
• EP 0981675 B1 [0014]
• - DE 102004025994 A1 [0015]
• - DE 102004025996 A1 [0016]
• - DE 102004017021 A1 [0017]
• US 6835334 B2 [0018]
• - DE 69533394 T2 [0019]
• - EP 1277801 A1 [0020]
• - US 6689466 B2 [0021]
• US 6855410 B2 [0022]
• - DE 20320026 U1 [0023]
• WO 02083440 A2 [0023]
• - US 6270836 B1 [0024]
• - US 6482332 B1 [0025]
• WO 2007040395 A1 [0026]
• - EP 1783169 A2 [0027]
• - US 4708812 [0028]
• WO 2006053405 A1 [0029, 0031]
• DE 10114998 A1 [0030]
• DE 102004011541 A1 [0032]

Claims (13)

A method for encasing organic and inorganic latent heat storage materials, characterized in that the liquid latent heat storage material is introduced into a porous, open-cell support structure and the PCM-filled porous granules are then provided with grain sizes of 1 mm to 10 mm with a water vapor-tight layer. Method for coating organic and inorganic Latent heat storage materials characterized that the liquid latent heat storage material filled into a 1 mm to 10 mm container and this is then closed and either the container is diffusion-tight or subsequently with a diffusion-tight Layer is coated. Method according to claim 1, characterized the support structure is a phenolic foam. Method according to one of claims 1 to 3 characterized in that the sheath is based on epoxy resin. Method according to claim 2, characterized that the container is made of epoxy resin. Method according to claim 1 or 3, characterized the layer or the container is a polymer. Method according to one of claims 1, 2, 3 or 6, characterized in that the layer in the fluidized bed process is applied. Method according to claim 7, characterized that the spray solution at at the melting point of PCMs adapted process temperatures from a PU dispersion, a water-dilutable resin, one soluble in ethanol Protein-based biopolymer or methacrylic acid-based biopolymer and methyl methacrylate with propan-2-ol as solvent based material. Method according to one of claims 1 to 8 characterized in that as organic PCM a paraffin with a melting temperature between -3 ° C to 99 ° C is used. Method according to claim 9, characterized the support structure consists of diatomaceous earth. Method according to claim 9, characterized that the paraffin-loaded support structure in the fluidized bed process with a material from the group of a copolymer latex of butadiene-acrylonitrile, a copolymer of vinylidene chloride-acrylic, of resinous latices, Rubber latices, epoxy polymers, polyurethane polymers, acrylic polymers, Cellulose acetate, polyamides or a water-soluble Resin is sheathed Method according to one of claims 1 to 8, characterized in that as inorganic PCM calcium chloride hexahydrate (CaCl ₂ · 6H ₂ O), lithium nitrate trihydrate (LiNO ₃ · 3H ₂ O), sodium sulfate decahydrate (Na ₂ SO ₄ · 10H ₂ O), sodium thiosulfate pentahydrate (Na ₂ S ₂ O ₃ .5H ₂ O), magnesium nitrate hexahydrate (Mg (NO ₃ ) ₂ .6H ₂ O), potassium fluoride tetrahydrate (KF · 4H ₂ O), potassium fluoride dihydrate (KF · 2H ₂ O), sodium acetate trihydrate (Na (CH ₃ COO) · 3H ₂ O), magnesium chloride hexahydrate (MgCl ₂ · 6H ₂ O) or mixtures of these substances having a melting point between 8 ° C and 117 ° C becomes. Method according to one of claims 1 to 8 or 12, characterized in that the PCM nucleating agent and organic Additives are added to adjust the melting point.