A thermal insulation rock wool board and a preparation process thereof

Abstract

The present application belongs to the technical field of rock wool board preparation, and particularly relates to a thermal insulation rock wool board and a preparation process thereof, comprising the following steps: after spraying a binder on rock wool fibers, the rock wool fibers are sent into a cotton collector to form a thin felt; the upper and lower layers of the thin felt are stacked, and a layer of phase change material is evenly laid between every two layers of the thin felt; the thin felt on which the phase change material is laid is subjected to solidification treatment to obtain a rock wool board; the phase change material is prepared by the following method: in a low-temperature and low-humidity environment, calcium chloride hexahydrate powder, hydrophobic silicon dioxide powder and hydrogel powder are uniformly mixed to obtain a mixed powder, the mixed powder is filled into the pores of expanded graphite particles, heated, coated with a polyurethane film, and a phase change material is obtained. The present application can effectively inhibit the hygroscopic deliquescence behavior of calcium chloride hexahydrate in a high-humidity environment, improve the heat storage performance of the rock wool board in a high-humidity environment, and further improve the indoor temperature regulation capacity of the rock wool board.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of rock wool board preparation, and particularly relates to a thermal insulation rock wool board and a preparation process thereof. BACKGROUND

[0002] Rock wool board is an inorganic thermal insulation material prepared from natural minerals such as basalt, and has a thermal conductivity of 0.035-0.045 W / (m·K). When applied to the outer wall of a building, it can effectively inhibit heat conduction and reduce the speed of indoor heat escaping in winter and outdoor heat invading in summer. However, the specific heat capacity of rock wool is 0.8-1.0 kJ / (kg·K), and the heat storage capacity is limited. Although rock wool has a low thermal conductivity and can delay the heat conduction process, due to its small specific heat capacity and limited heat capacity, a certain amount of heat will continue to penetrate the rock wool board into the indoor environment under the condition of continuous sunlight in summer, causing the indoor temperature to gradually rise. In order to maintain a comfortable indoor environment, the air conditioning system needs to operate for a long time and at high load, resulting in increased energy consumption.

[0003] Chinese patent application with publication number CN116856567A discloses a rock wool / calcium chloride hexahydrate-based thermal insulation wallboard and a preparation method thereof. The preparation method uses a compounded calcium chloride hexahydrate powder-based phase change material as the energy storage material, and the rock wool board as the carrier of the phase change energy storage material to prepare a thermal function regulating rock wool board. The rock wool board is modified in terms of energy storage and thermal insulation performance through the coupling of the rock wool board and the phase change material, and the heat storage capacity of the rock wool board is improved. When the ambient temperature rises to the phase change temperature range of calcium chloride hexahydrate, the calcium chloride hexahydrate undergoes solid-liquid phase change and absorbs a large amount of latent heat of phase change, reducing the temperature rise speed of the rock wool board, delaying the process of heat transfer to the interior of the wall, reducing the speed of indoor temperature rise, reducing the operating load of the air conditioning system to maintain the indoor comfortable temperature, and achieving the purpose of energy saving and consumption reduction. However, the calcium chloride hexahydrate powder has strong hygroscopic deliquescence. When the humidity outside is high and lasts for a long time, the calcium chloride hexahydrate will absorb water from the outside and undergo deliquescence, changing into a high hydration state or even a liquid state, and its original crystal structure is destroyed. Since the phase change characteristics of calcium chloride hexahydrate depend on the stable crystal structure and hydration state, the phase change capacity of calcium chloride hexahydrate in a high humidity environment for a long time is significantly weakened or even completely lost, and it cannot be used as a phase change material to endow the rock wool board with heat storage performance, and the rock wool board has weak indoor temperature regulating capacity. SUMMARY

[0004] The present application provides a thermal insulation rock wool board and a preparation process thereof, which inhibits the hygroscopic deliquescence behavior of calcium chloride hexahydrate in a high humidity environment, improves the heat storage performance of the rock wool board in a high humidity environment, and further improves the indoor temperature regulating capacity of the rock wool board.

[0005] To solve the above problems, the present application provides the following technical solution:

[0006] A preparation process of a thermal insulation rock wool board, comprising the following steps:

[0007] S1, after spraying the binder on the rock wool fibers, the rock wool fibers are sent into the cotton collector to make thin felt;

[0008] S2, the thin felt is stacked layer by layer, and a layer of phase change material is evenly laid between every two layers of thin felt;

[0009] S3, the thin felt with completed phase change material laying is subjected to curing treatment to obtain the rock wool board;

[0010] The phase change material is prepared by the following method: in a low-temperature and low-humidity environment, calcium chloride hexahydrate powder, hydrophobic silica powder and hydrogel powder are uniformly mixed to obtain a mixed powder, the mixed powder is filled into the pores of expanded graphite particles, heated, coated with a polyurethane film to obtain the phase change material.

[0011] In the application, the calcium chloride hexahydrate powder is enclosed in the expanded graphite particles by the polyurethane film, which effectively blocks the contact and exchange of the calcium chloride hexahydrate powder with moisture in the external environment, so that the calcium chloride hexahydrate powder can maintain the original crystal structure and phase change performance even in a high-humidity environment, and the rock wool board can still have good heat storage capacity in a high-humidity environment, and can effectively slow down the indoor temperature rise when the external environment temperature rises.

[0012] In the application, the mixed powder is prepared in a low-temperature and low-humidity environment, and the mixed powder is filled into the pores of the expanded graphite, the low-temperature condition makes the water in the hydrogel powder into ice crystal state, inhibits the hydrogen bond interaction between molecules, and the hydrogel powder is not easy to agglomerate, showing good dispersibility, which facilitates the mixing of the hydrogel powder with the calcium chloride hexahydrate powder and the hydrophobic silica powder and the smooth filling of the mixed powder into the pores of the expanded graphite; the low-humidity condition can inhibit the absorption of water by the calcium chloride hexahydrate from the external environment, and prevent the calcium chloride hexahydrate from deliquescing.

[0013] The filled expanded graphite particles are subjected to heating treatment, the free water ice crystals in the hydrogel powder melt, the polymer chain segments stretch, and the adjacent hydrogel powders can form a continuous three-dimensional network structure through hydrogen bond interaction or physical entanglement, stably wrapping the calcium chloride hexahydrate powder therein, reducing the flowability of the calcium chloride hexahydrate powder, so that the calcium chloride hexahydrate powder will not fall from the pores due to gravity or inertial force in the subsequent operation, increasing the filling amount of the calcium chloride hexahydrate; during the heating process, the hydrophobic silica powder is located between the calcium chloride hexahydrate powder and the hydrogel powder, acting as a separation layer, reducing the probability of direct contact between them, preventing the calcium chloride hexahydrate powder from absorbing a large amount of water from the hydrogel powder, reducing the loss of the calcium chloride hexahydrate powder while increasing the amount of hydrogel powder with free water in the melted state, which is conducive to the construction of the continuous three-dimensional network structure by the hydrogel powder.

[0014] In use, when the temperature rises, the water in the hydrogel is released, the humidity of the air around the calcium chloride hexahydrate increases, the water released by the hydrogel contacts a small part of the calcium chloride hexahydrate, the crystal structure of the part of the calcium chloride hexahydrate changes, and the phase change performance of the part of the calcium chloride hexahydrate is reduced, but the wrapping effect of the hydrogel can greatly increase the amount of calcium chloride hexahydrate remaining in the internal pores of the expanded graphite, improve the utilization rate of the internal pores of the expanded graphite, and improve the overall heat storage capacity of the rock wool board.

[0015] Further, the preparation method of the calcium chloride hexahydrate is as follows: anhydrous calcium chloride is dissolved in water, and under continuous stirring, the temperature is lowered to 2℃, calcium chloride hexahydrate crystals are precipitated, filtered, dried, crushed, and sieved to obtain calcium chloride hexahydrate powder with an average particle size of 1-1.1 μm.

[0016] Further, the hydrogel powder is prepared by the following method: acrylic acid, distilled water, azobisisobutyronitrile and methacrylamide are added to N-isopropyl acrylamide, and reacted at a temperature of 75℃ for 3h, cooled, washed with deionized water, and then stirred and mixed with distilled water, calcium chloride and PAMAM dendrimer at a temperature of 75℃ for 4h, washed with deionized water to obtain a hydrogel, and then freeze-dried, crushed and sieved to obtain a hydrogel powder with an average particle size of 50-55nm.

[0017] The present application uses N-isopropyl acrylamide, acrylic acid and methacrylamide as a copolymer, and forms a polymer chain through free radical copolymerization to form the skeleton structure of the hydrogel, and the acrylic acid introduces carboxyl groups into the polymer chain, which ionically crosslinks with the calcium ions generated by the dissociation of calcium chloride, limits the free movement of the polymer chain segment, enhances the stability of the skeleton structure of the hydrogel, and after crushing the hydrogel, a hydrogel powder with stable structure can be obtained.

[0018] Further, the hydrogel is freeze-dried by the following method: the hydrogel is divided into 1cm thick slices, and is placed in a liquid nitrogen environment for 90min, and then is taken out and placed in a cold trap at-50℃, and the vacuum degree is maintained at 25Pa, and the temperature is raised to-30℃ for 24h, then to-20℃ for 36h, and then to-5℃ for 7h, to obtain a hydrogel with a free water content of 3wt%-5wt%.

[0019] The hydrogel is freeze-dried by the multi-stage heating method, so that the ice crystals can sublimate slowly and uniformly, avoid the ice crystals sublimating too quickly due to the rapid heating rate, and the generated steam cannot be quickly discharged, which causes the hydrogel to break, protects the skeleton structure of the hydrogel from being damaged, and is beneficial to obtaining a hydrogel powder with complete structure.

[0020] Further, the expanded graphite particles are prepared by the following method: placing expandable graphite in an environment of 850 DEG C for 7s, cooling, crushing, and sieving to obtain expanded graphite particles with an average particle size of 1.4-1.5 mm.

[0021] Further, the average particle size of the hydrophobic silica powder is 50-55 nm.

[0022] Further, in the mixed powder, the mass ratio of the hydrogel powder, the hydrophobic silica powder, and the calcium chloride hexahydrate powder is 1.1-1.2:6.0-6.1:192.0-192.1.

[0023] After the hydrogel powder, the hydrophobic silica powder, and the calcium chloride hexahydrate powder are mixed with each other, the hydrogel powder is located in the gaps between adjacent calcium chloride powders to form a three-dimensional network structure penetrating the gaps, the hydrogel powders are connected with each other by hydrogen bonding or physical entanglement to stabilize the morphology of the three-dimensional network structure, and the calcium chloride hexahydrate powder is confined in the structure to reduce the flowability; the addition of the hydrophobic silica powder reduces the direct contact area between the hydrogel powder and the calcium chloride hexahydrate powder, avoids the absorption of free water in the hydrogel by the calcium chloride hexahydrate, and reduces the loss of the mass of the calcium chloride hexahydrate powder due to moisture absorption and deliquescence while assisting in stabilizing the three-dimensional network structure.

[0024] Further, the process of filling the mixed powder into the pores of the expanded graphite particles is as follows: placing the mixed powder and the expanded graphite particles in a sealed container in an environment of -5 to -4 DEG C and a relative humidity of 30-32%, applying vibration to the sealed container at a frequency of 25-30 Hz and an amplitude of 1-1.2 mm, vacuumizing the sealed container to a vacuum degree of 8-10 kPa and maintaining for 15-20 min, filling the mixed powder into the pores of the expanded graphite, and warming to 20-25 DEG C and maintaining for 25-30 min.

[0025] The hydrogel powder, the hydrophobic silica powder, and the calcium chloride hexahydrate powder are mixed with each other in an environment of -5 to -4 DEG C and a relative humidity of 30-32%, in which humidity, the water absorption driving force of the calcium chloride hexahydrate powder is very small, and the calcium chloride hexahydrate powder hardly absorbs water from the external environment in a short time; in this temperature, the water in the hydrogel powder is in the form of ice crystals, which inhibits the hydrogen bonding between molecules and makes the hydrogel powder less prone to agglomeration, thereby showing good dispersibility, improving the overall flowability of the mixed powder, and facilitating the smooth filling of the mixed powder into the pores of the expanded graphite particles; under vacuum conditions, the air inside the expanded graphite particles is extracted to form a negative pressure environment, which helps the mixed powder enter the pores of the expanded graphite particles more quickly and uniformly, and vibration promotes the discharge of gas in the expanded graphite particles, improves the filling amount of the mixed powder, and increases the latent heat of phase change per unit volume of the phase change material.

[0026] Further, the process of coating the polyurethane film is as follows: the expanded graphite particles are placed in a fluidized bed coater, a nitrogen gas flow of 0.8 m / s is introduced from bottom to top, the inlet air temperature is 45 DEG C, the outlet air temperature is 35 DEG C, and the water-based polyurethane is sprayed onto the outer surface of the expanded graphite particles through a nozzle, so as to coat the polyurethane film on the expanded graphite particles, and the phase change material is obtained.

[0027] The nitrogen forms a uniform upward airflow, the expanded graphite particles are uniformly blown up and fully dispersed, the surface of the expanded graphite particles is constantly renewed, which is conducive to the uniform deposition of water-based polyurethane droplets on the surface, and a continuous and dense coating film is formed; the nitrogen atmosphere can reduce the relative humidity around the expanded graphite particles and inhibit the hygroscopic behavior of calcium chloride hexahydrate powder; the porous structure of the expanded graphite can act as a physical barrier at the initial stage of coating, slowing down the speed of the nitrogen gas flow directly contacting the hydrogel powder, avoiding rapid dehydration of the hydrogel powder, maintaining the stability of the three-dimensional network structure constructed by the hydrogel powder before the polyurethane film completely surrounds the expanded graphite particles, and preventing the calcium chloride hexahydrate powder from being discharged from the pores of the expanded graphite.

[0028] A thermal insulation rock wool board is prepared by the above preparation process of the thermal insulation rock wool board, and includes the following raw materials in mass parts: 54-55 parts of rock wool fiber, 14-15 parts of phase change material and 1.1-1.2 parts of binder; the binder is one or both of phenolic resin and urea-formaldehyde resin; the phase change material includes the following materials in mass parts: 63.4-63.5 parts of expanded graphite particles, 3.1-3.2 parts of hydrogel powder, 8.0-8.1 parts of hydrophobic silica powder, 192.0-192.1 parts of calcium chloride hexahydrate powder and 134.6-134.7 parts of polyurethane.

[0029] The beneficial effects of the present application are:

[0030] The present application encapsulates the calcium chloride hexahydrate powder in the expanded graphite by the polyurethane film, effectively prevents the calcium chloride hexahydrate powder from absorbing moisture from the outside and deliquescing, and enables the rock wool board to still have good heat storage capacity in a high humidity environment.

[0031] The hydrogel powder, hydrophobic silica powder and calcium chloride hexahydrate powder are mixed under low temperature and low humidity conditions, the low temperature condition enables the free water in the hydrogel powder to be in the form of ice crystals, improves the overall flowability of the mixed powder, and facilitates the filling of the mixed powder into the pores of the expanded graphite particles; the low humidity condition can reduce the driving force for the calcium chloride hexahydrate powder to absorb water from the outside, and avoid the calcium chloride hexahydrate powder from deliquescing.

[0032] After the mixed powder is filled into the pores of the expanded graphite particles and heated, the free water ice crystals in the hydrogel powder are melted, cross-linking occurs between adjacent hydrogel powders through hydrogen bonds or physical entanglement, forming a continuous three-dimensional network structure, which confines the calcium chloride hexahydrate powder therein, reduces the flowability of the calcium chloride hexahydrate powder, prevents the calcium chloride hexahydrate powder from escaping from the pores of the expanded graphite particles, and increases the latent heat of phase change per unit volume of the phase change material; the hydrophobic silica powder is located between the hydrogel powder and the calcium chloride hexahydrate powder, preventing the calcium chloride hexahydrate powder from absorbing a large amount of free water from the hydrogel, improving the stability of the three-dimensional network structure, and reducing the mass loss caused by the deliquescence of the calcium chloride hexahydrate powder due to water absorption.

[0033] In the present application, although part of the calcium chloride hexahydrate powder will absorb water from the hydrogel powder and then deliquesce during the preparation and use of the phase change material, the three-dimensional network structure constructed between the hydrogel powders has a confinement effect, which can effectively prevent the calcium chloride hexahydrate powder from escaping from the pores of the expanded graphite, so that even if the calcium chloride hexahydrate powder deliquesces partially, a large amount of calcium chloride hexahydrate powder with normal phase change performance is still stably retained inside the phase change material, so that the overall heat storage capacity of the rock wool board is improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The schematic diagram of the change of the temperature inside and outside the house with the illumination time for the rock wool board prepared in Example 6 and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application, and those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] Preparation Example 1

[0037] The 735 g of anhydrous calcium chloride was added to 1000 g of deionized water, stirred to dissolve at 25℃, and cooled to 2℃ under continuous stirring to precipitate calcium chloride hexahydrate crystals, which were filtered, dried, crushed, and sieved to obtain calcium chloride hexahydrate powder with an average particle size of 1 μm. 100 g of expandable graphite particles were placed in an electric expansion furnace at 850℃ for 7 s, removed, naturally cooled, crushed, and sieved to obtain expanded graphite particles with an average particle size of 1.4 mm. 113 g of N-isopropyl acrylamide and 55 mL of acrylic acid were mixed, 20 mL of distilled water, 0.2 g of azobisisobutyronitrile, and 0.6 g of methacrylamide were added, and the mixture was condensed and refluxed at 75℃ for 3 h under nitrogen protection, cooled to room temperature, washed with deionized water, and then 10 mL of distilled water, 10 g of calcium chloride hexahydrate powder, and 15 g of PAMAM dendrimer were added, and the mixture was condensed and refluxed at 75℃ for 4 h under nitrogen protection, washed with deionized water, and then cut into slices with a thickness of 1 cm, placed in a liquid nitrogen environment for 90 min, removed and placed in a cold trap at -50℃, maintained at a vacuum degree of 25 Pa, and heated at a rate of 0.1℃ / min to -30℃ and maintained for 24 h, then heated to -20℃ and maintained for 36 h, and finally heated to -5℃ and maintained for 7 h, crushed, and sieved to obtain hydrogel powder with an average particle size of 50 nm.

[0038] At -5℃ and a relative humidity of 30%, 12.4 g of hydrogel powder, 32 g of hydrophobic silica powder with a particle size of 50 nm, and 768 g of calcium chloride hexahydrate powder were placed in a mixer and stirred to obtain a mixed powder.

[0039] Preparation Example Two

[0040] The 735 g of anhydrous calcium chloride was added to 1000 g of deionized water, stirred to dissolve at 25 °C, and cooled to 2 °C under continuous stirring to precipitate calcium chloride hexahydrate crystals, which were filtered, dried, crushed, and sieved to obtain calcium chloride hexahydrate powder with an average particle size of 1.1 μm. 100 g of expandable graphite particles were placed in an electric expansion furnace at 850 °C for 7 s, removed, naturally cooled, crushed, and sieved to obtain expanded graphite particles with an average particle size of 1.5 mm. 113 g of N-isopropyl acrylamide and 55 mL of acrylic acid were mixed, 20 mL of distilled water, 0.2 g of azobisisobutyronitrile, and 0.6 g of methacrylamide were added, and the mixture was condensed and refluxed at 75 °C for 3 h under nitrogen protection, cooled to room temperature, washed with deionized water, and then 10 mL of distilled water, 10 g of calcium chloride hexahydrate powder, and 15 g of PAMAM dendrimer were added, and the mixture was condensed and refluxed at 75 °C for 4 h under nitrogen protection, washed with deionized water, and then cut into slices of 1 cm thickness, placed in a single layer in a liquid nitrogen environment for 90 min, removed and placed in a cold trap at -50 °C, maintained at a vacuum of 25 Pa, and heated at a rate of 0.1 °C / min to -30 °C and held for 24 h, then heated to -20 °C and held for 36 h, and finally heated to -5 °C and held for 7 h, crushed, and sieved to obtain hydrogel powder with an average particle size of 53 nm.

[0041] At -5 °C and a relative humidity of 31%, 12.6 g of hydrogel powder, 32.2 g of hydrophobic silica powder with a particle size of 55 nm, and 768.2 g of calcium chloride hexahydrate powder were placed in a mixer and stirred to obtain a mixed powder.

[0042] Preparation Example Three

[0043] The 735 g of anhydrous calcium chloride was added into 1000 g of deionized water, stirred and dissolved at 25 °C, and then cooled to 2 °C under continuous stirring. The calcium chloride hexahydrate crystals were precipitated, filtered, dried, crushed, and sieved to obtain calcium chloride hexahydrate powder with an average particle size of 1.1 μm. 100 g of expandable graphite particles were placed in an electric heating expansion furnace at 850 °C for 7 s, then taken out, naturally cooled, crushed, and sieved to obtain expanded graphite particles with an average particle size of 1.4 mm. 113 g of N-isopropyl acrylamide and 55 mL of acrylic acid were mixed, 20 mL of distilled water, 0.2 g of azobisisobutyronitrile, and 0.6 g of methacrylamide were added, and then the mixture was condensed and refluxed at 75 °C for 3 h under nitrogen protection. After cooling to room temperature, the mixture was washed with deionized water, 10 mL of distilled water, 10 g of calcium chloride hexahydrate powder, and 15 g of PAMAM dendrimer were added, and then the mixture was condensed and refluxed at 75 °C for 4 h under nitrogen protection. After washing with deionized water, the mixture was cut into slices with a thickness of 1 cm, placed in a liquid nitrogen environment for 90 min, and then taken out and placed in a cold trap at -50 °C. The vacuum degree was maintained at 25 Pa, and the temperature was increased at a rate of 0.1 °C / min to -30 °C and maintained for 24 h, then increased to -20 °C and maintained for 36 h, and finally increased to -5 °C and maintained for 7 h. The mixture was crushed and sieved to obtain hydrogel powder with an average particle size of 55 nm.

[0044] At -4 °C and a relative humidity of 32%, 12.8 g of hydrogel powder, 32.4 g of hydrophobic silica powder with a particle size of 53 nm, and 768.4 g of calcium chloride hexahydrate powder were placed in a mixer and stirred uniformly to obtain a mixed powder.

[0045] Example One

[0046] At -5 °C and a relative humidity of 30%, 650 g of the mixed powder and 63.4 g of expanded graphite particles were placed in a sealed container, and the vacuum degree was maintained at 8 kPa for 15 min. While the sealed container was in a vacuum state, vibration was applied to the sealed container at a frequency of 25 Hz and an amplitude of 1 mm. The expanded graphite particles were taken out, the excess powder was sieved out, and the expanded graphite particles were placed in an environment at 25 °C and a relative humidity of 30% for 25 min to obtain expanded graphite particles with completed filling. 617 g of the expanded graphite particles with completed filling were placed in an FPCG-300 type fluidized bed coater, and a nitrogen gas flow of 0.8 m / s was introduced. The inlet air temperature was 45 °C, and the outlet air temperature was 35 °C. 324 mL of aqueous polyurethane Bayhydrol UH 2888 was sprayed through a nozzle, and the spraying was divided into six times with an interval of 3 min between each two times. After the spraying was completed, the fluidized state was maintained for 10 min, and then the mixture was taken out and cooled to room temperature to obtain a phase change material.

[0047] The 74 g of phenolic resin is evenly sprayed on each 3600 g of rock wool fiber, and then the rock wool fiber is sent into a cotton collector to form a 120 cm x 60 cm x 1 cm mat. Nine mats are stacked in layers, and 116 g of phase change material is evenly sprayed between each two layers. The mats are heated and pressurized for curing to obtain a rock wool board.

[0048] The mixed powder in this example is prepared by Preparation Example One.

[0049] Example Two

[0050] Under the condition of -5°C and 30% relative humidity, 650 g of the mixed powder and 63.5 g of the expanded graphite particles are placed in a sealed container, and vacuum is extracted to a vacuum degree of 8 kPa for 15 min. When the sealed container is in a vacuum state, vibration is applied to the sealed container at a frequency of 27 Hz and an amplitude of 1.1 mm. The expanded graphite particles are taken out, the excess powder is sieved out, and the particles are placed in an environment of 20°C and 31% relative humidity for 25 min to obtain the expanded graphite particles filled with the phase change material. 618 g of the expanded graphite particles filled with the phase change material are placed in an FPCG-300 type fluidized bed coater, and a nitrogen gas flow of 0.8 m / s is introduced. The inlet air temperature is 45°C, and the outlet air temperature is 35°C. 325 mL of aqueous polyurethane Bayhydrol UH 2888 is sprayed through a nozzle, and the spraying is divided into six times. Each two times of spraying is separated by 3 min. After the spraying is completed, the fluidized state is maintained for 10 min, and then the particles are taken out and cooled to room temperature to obtain the phase change material.

[0051] The 75 g of phenolic resin is evenly sprayed on each 3615 g of rock wool fiber, and then the rock wool fiber is sent into a cotton collector to form a 120 cm x 60 cm x 1 cm mat. Nine mats are stacked in layers, and 120 g of phase change material is evenly sprayed between each two layers. The mats are heated and pressurized for curing to obtain a rock wool board.

[0052] The mixed powder in this example is prepared by Preparation Example One.

[0053] Example Three

[0054] Under the condition of -5℃ and relative humidity of 31%, 650 g of the mixed powder and 63.4 g of the expanded graphite particles were put into a sealed container, vacuumized to a vacuum degree of 9 kPa for 18 min, and vibration was applied to the sealed container at a frequency of 27 Hz and an amplitude of 1.2 mm when the sealed container was in a vacuum state. The expanded graphite particles were taken out, the excess powder was sieved out, and the expanded graphite particles were placed in an environment of 25℃ and relative humidity of 31% for 28 min to obtain the expanded graphite particles filled. 618 g of the expanded graphite particles filled were put into an FPCG-300 type fluidized bed coater, and 0.8 m / s of a nitrogen gas flow was introduced, with an air inlet temperature of 45℃ and an air outlet temperature of 35℃. 324 mL of the aqueous polyurethane Bayhydrol UH 2888 was sprayed through a nozzle, and the spraying was performed six times with an interval of 3 min between each two spraying. After the spraying was completed, the fluidized state was maintained for 10 min, and then the expanded graphite particles were taken out and cooled to room temperature to obtain the phase change material.

[0055] After 77 g of phenolic resin was uniformly sprayed on each 3650 g of rock wool fibers, the rock wool fibers were sent into a cotton collector to form a thin felt with a size of 120 cm x 60 cm x 1 cm. Nine layers of the thin felt were stacked, and 122 g of the phase change material was uniformly sprayed between each two layers of the thin felt. The thin felt was heated and pressurized for curing treatment to obtain a rock wool board.

[0056] The mixed powder in the example was prepared by the preparation example two.

[0057] Example Four

[0058] Under the condition of -5℃ and relative humidity of 31%, 650 g of the mixed powder and 63.4 g of the expanded graphite particles were put into a sealed container, vacuumized to a vacuum degree of 9 kPa for 18 min, and vibration was applied to the sealed container at a frequency of 27 Hz and an amplitude of 1.2 mm when the sealed container was in a vacuum state. The expanded graphite particles were taken out, the excess powder was sieved out, and the expanded graphite particles were placed in an environment of 25℃ and relative humidity of 31% for 28 min to obtain the expanded graphite particles filled. 618 g of the expanded graphite particles filled were put into an FPCG-300 type fluidized bed coater, and 0.8 m / s of a nitrogen gas flow was introduced, with an air inlet temperature of 45℃ and an air outlet temperature of 35℃. 324 mL of the aqueous polyurethane Bayhydrol UH 2888 was sprayed through a nozzle, and the spraying was performed six times with an interval of 3 min between each two spraying. After the spraying was completed, the fluidized state was maintained for 10 min, and then the expanded graphite particles were taken out and cooled to room temperature to obtain the phase change material.

[0059] After 74 g of phenolic resin was uniformly sprayed on each 3625 g of rock wool fibers, the rock wool fibers were sent into a cotton collector to form a thin felt with a size of 120 cm x 60 cm x 1 cm. Nine layers of the thin felt were stacked, and 120 g of the phase change material was uniformly sprayed between each two layers of the thin felt. The thin felt was heated and pressurized for curing treatment to obtain a rock wool board.

[0060] The mixed powder in this example was prepared by Preparation Example Two.

[0061] Example Five

[0062] Under the condition of -4°C and 32% relative humidity, 650 g of the mixed powder and 63.4 g of the expanded graphite particles were placed into a sealed container, vacuumed to a vacuum degree of 10 kPa for 20 min, and vibration was applied to the sealed container at a frequency of 29 Hz and an amplitude of 1.2 mm while the sealed container was in a vacuum state. The expanded graphite particles were taken out, the excess powder was sieved off, and the expanded graphite particles were placed in an environment of 23°C and 30% relative humidity for 30 min to obtain the expanded graphite particles filled. 570 g of the expanded graphite particles filled were placed into an FPCG-300 type fluidized bed coater, a nitrogen gas flow of 0.8 m / s was introduced, the inlet air temperature was 45°C, and the outlet air temperature was 35°C. 325 mL of the aqueous polyurethane Bayhydrol UH 2888 was sprayed through a nozzle, sprayed six times with an interval of 3 min between each two spraying, and after the spraying was completed, the fluidized state was maintained for 10 min before being taken out and cooled to room temperature to obtain the phase change material.

[0063] After 78 g of phenolic resin was uniformly sprayed on each 3660 g of rock wool fibers, the rock wool fibers were sent into a cotton collector to form a thin felt with a size of 120 cm x 60 cm x 1 cm. Nine layers of the thin felt were stacked, 124 g of the phase change material was uniformly poured between each two layers of the thin felt, and the thin felt was heated and pressurized for curing treatment to obtain a rock wool board.

[0064] The mixed powder in this example was prepared by Preparation Example Three.

[0065] Example Six

[0066] Under the condition of -4°C and 32% relative humidity, 650 g of the mixed powder and 63.4 g of the expanded graphite particles were placed into a sealed container, vacuumed to a vacuum degree of 10 kPa for 20 min, and vibration was applied to the sealed container at a frequency of 29 Hz and an amplitude of 1.2 mm while the sealed container was in a vacuum state. The expanded graphite particles were taken out, the excess powder was sieved off, and the expanded graphite particles were placed in an environment of 23°C and 30% relative humidity for 30 min to obtain the expanded graphite particles filled. 570 g of the expanded graphite particles filled were placed into an FPCG-300 type fluidized bed coater, a nitrogen gas flow of 0.8 m / s was introduced, the inlet air temperature was 45°C, and the outlet air temperature was 35°C. 325 mL of the aqueous polyurethane Bayhydrol UH 2888 was sprayed through a nozzle, sprayed six times with an interval of 3 min between each two spraying, and after the spraying was completed, the fluidized state was maintained for 10 min before being taken out and cooled to room temperature to obtain the phase change material.

[0067] After 79g of phenolic resin is evenly sprayed onto each 3665g of rock wool fiber, it is fed into a cotton collecting machine to make a 120cm×60cm×1cm thin felt. Nine layers of thin felt are stacked one on top of the other, and 124g of phase change material is evenly sprinkled between each two layers of thin felt. The mixture is then heated and pressurized to cure the rock wool board.

[0068] The mixed powder in this embodiment was prepared according to Preparation Example 3.

[0069] The present invention also includes comparative examples and related experiments.

[0070] Comparative Example 1

[0071] The difference from Example 6 is that the expanded graphite particles were not coated with a polyurethane film after filling. 105g of expanded graphite particles were evenly sprinkled between every two layers of thin felt. The other components and preparation process were the same as in Example 6, and rock wool board was obtained.

[0072] Comparative Example 2

[0073] The difference from Example 6 is that no hydrogel is added during the preparation of the mixed powder, while the other components and preparation process are the same as in Example 6, resulting in a rock wool board.

[0074] Comparative Example 3

[0075] Phase change energy storage material was prepared according to the preparation method described in the patent application with publication number CN116856567A. 79g of phenolic resin was evenly sprayed onto each 3665g of rock wool fiber and then fed into a cotton collecting machine to make a thin felt of 120cm×60cm×1cm. Nine layers of thin felt were stacked one on top of the other, and 97g of phase change energy storage material was evenly sprinkled between each two layers of thin felt. The material was then heated and pressurized for curing to obtain a rock wool board.

[0076] Temperature regulation capability test of rock wool board

[0077] The temperature regulation capability of the rock wool board was tested using self-made chambers. Nine chamber samples were prepared using rock wool boards from Examples 1 to 6 and Comparative Examples 1 to 3. The internal space of each chamber was 60cm × 120cm × 60cm, consisting of one 60cm × 120cm × 5cm rock wool board and five EPS boards. The rock wool board was located at the top. Temperature sensors were installed inside and outside the chamber to detect temperature changes. A 300W heating source was placed 35cm above the rock wool board to simulate sunlight. The chambers were placed in an environment with 75% humidity and 25℃ for 72 hours for pretreatment. Then, the heating source was turned on, and the temperature changes inside and outside each chamber with light exposure time were recorded, as shown in Table 1. Based on the experimental data of the chambers prepared using the rock wool boards from Examples 6 and Comparative Examples 1 to 3, schematic diagrams of the temperature changes inside and outside the chamber with light exposure time were plotted, as shown in Table 1. Figure 1 As shown.

[0078] Table 1

[0079]

[0080] According to Table 1 and Figure 1 It can be seen from the analysis that, compared with Example 6, the rock wool board prepared in Comparative Example 1 showed a stronger ability to inhibit the temperature rise in the room before 1 h of illumination, and the temperature in the room of Comparative Example 1 was higher than that of Example 6 during 2 h to 4 h of illumination, and especially after 2.2 h, was also higher than the temperature outside the room, indicating that the rock wool board in Comparative Example 1 mainly relied on the water absorbed by the hydrogel to regulate the indoor temperature, rather than the phase change endothermic of calcium chloride hexahydrate; the indoor temperature of Comparative Example 3 was not much different from the outdoor temperature, and the ability to inhibit the temperature rise was very poor, indicating that calcium chloride hexahydrate had deliquesced and even liquefied after a long time of placement in a high-humidity environment, and almost lost the phase change heat storage ability; and the rock wool boards prepared in Examples 1 to 6 all showed a good ability to inhibit the temperature rise in the room within 4 h of illumination, indicating that the wrapping of the polyurethane film could effectively inhibit the water absorption of calcium chloride hexahydrate from the external environment, the high-humidity environment had little effect on the performance of the phase change material, and the rock wool board still had a good heat storage ability and a strong temperature regulation ability in a high-humidity environment.

[0081] Compared with Example 6, the rock wool board prepared in Comparative Example 2 had a weaker temperature regulation ability, indicating that the presence of the hydrogel could increase the filling amount of calcium chloride hexahydrate, increase the mass of calcium chloride hexahydrate in a unit volume of the rock wool board, and improve the temperature regulation ability of the rock wool board.

[0082] Cycling stability test of phase change material

[0083] 20 g of each of the phase change materials prepared in Examples 1 to 6 were taken and loaded into test tubes, a thermal resistance was inserted into each test tube to be 1 cm away from the bottom end of the test tube, the air humidity was kept at 70%, the test tube was placed into a 50℃ constant-temperature water bath for 60 min, and then was placed into a 10℃ low-temperature constant-temperature tank for 60 min, and was taken out, and a differential scanning calorimeter DSC1 produced by Mettler-Toledo Company in Switzerland was used to test each phase change material to obtain the phase change temperature, peak temperature and phase change latent heat of the phase change material after 1 cycle; then the test tube was repeatedly placed into environments of 50℃ and 10℃ to obtain the phase change temperature, peak temperature and phase change latent heat of each phase change material after the 50th, 100th and 200th cycles, as shown in Table 2.

[0084] Table 2

[0085]

[0086] According to Table 2, the phase change materials prepared in Examples 1 to 6 still exhibit good phase change performance after 200 phase change cycles in a high humidity environment, and when filled in the rock wool board, can give the rock wool board long-term stable heat storage capacity.

[0087] The above is the preferred embodiment of the present application, and those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A process for the production of an insulating rock wool slab, characterized in that, The method comprises the following steps: S1, after spraying the binder on the rock wool fibers, the rock wool fibers are sent into the condenser to make thin felt; S2, the upper and lower layers of the thin felt are stacked, and a layer of phase change material is evenly laid between every two layers of the thin felt; S3, the thin felt on which the phase change material is laid is subjected to curing treatment to obtain the rock wool board; The phase change material is prepared by the following method: in a low-temperature and low-humidity environment, calcium chloride hexahydrate powder, hydrophobic silica powder and hydrogel powder are uniformly mixed to obtain a mixed powder, the mixed powder is filled into the pores of expanded graphite particles, heated, coated with polyurethane film to obtain the phase change material; The process of filling the mixed powder into the pores of the expanded graphite particles is as follows: in an environment of-5~-4℃ and relative humidity of 30%~32%, the mixed powder and expanded graphite particles are placed in a sealed container, the sealed container is subjected to vibration with a frequency of 25~30Hz and an amplitude of 1~1.2mm, vacuumized to a vacuum degree of 8~10kpa and maintained for 15~20min, the mixed powder is filled into the pores of the expanded graphite, heated to 20~25℃ and maintained for 25~30min; The hydrogel powder is prepared by the following method: acrylic acid, distilled water, azobisisobutyronitrile and methacrylamide are added to N-isopropyl acrylamide, reacted at a temperature of 75℃ for 3h, cooled, washed with deionized water, and then stirred and mixed with distilled water, calcium chloride and PAMAM dendrimer, reacted at a temperature of 75℃ for 4h, washed with deionized water to obtain a hydrogel, and then freeze-dried, broken and sieved to obtain a hydrogel powder with an average particle size of 50~55nm.

2. The process for preparing a thermal insulation rock wool board according to claim 1, characterized in that, The preparation method of the calcium chloride hexahydrate is as follows: anhydrous calcium chloride is dissolved in water, and the temperature is lowered to 2℃ under continuous stirring to precipitate calcium chloride hexahydrate crystals, which are filtered, dried, broken and sieved to obtain calcium chloride hexahydrate powder with an average particle size of 1~1.1μm.

3. The process for preparing a thermal insulation rock wool board according to claim 1, characterized in that, The hydrogel is freeze-dried by the following method: the hydrogel is divided into 1cm-thick slices, single-layered and laid in a liquid nitrogen environment for 90min, taken out and placed in a cold trap at-50℃, the vacuum degree is maintained at 25Pa, the temperature is raised to-30℃ for 24h, the temperature is raised to-20℃ for 36h, and the temperature is raised to-5℃ for 7h to obtain a hydrogel with a free water content of 3wt%~5wt%.

4. The process for preparing a thermal insulation rock wool board according to claim 3, characterized in that, The expanded graphite particles are prepared by the following method: the expandable graphite is placed in an environment of 850℃ for 7s, cooled, broken and sieved to obtain expanded graphite particles with an average particle size of 1.4~1.5mm.

5. A process for the preparation of an insulating rock wool panel according to claim 4, characterized in that, The average particle size of the hydrophobic silica powder is 50~55nm.

6. A process for the preparation of an insulating rock wool panel according to claim 5, characterized in that, In the mixed powder, the mass ratio of the hydrogel powder, the hydrophobic silica powder and the calcium chloride hexahydrate powder is 1.1~1.2:6.0~6.1:192.0~192.

1.

7. The process for preparing a thermal insulation rock wool board according to claim 1, characterized in that, The process of coating the polyurethane film in the preparation of the phase change material is as follows: the expanded graphite particles filled with the mixed powder are placed in a fluidized bed coating machine, a nitrogen gas flow of 0.8 m / s is introduced from bottom to top, the inlet air temperature is 45 DEG C, the outlet air temperature is 35 DEG C, and the water-based polyurethane is sprayed to the outer surface of the expanded graphite particles through a nozzle, so that the polyurethane film is coated on the outer surface of the expanded graphite particles, and the phase change material is obtained.

8. A thermal insulation rock wool slab prepared using the process for preparing a thermal insulation rock wool slab according to any one of claims 1 to 7, characterized in that, The raw materials include the following components: 54-55 parts of rock wool fibers, 14-15 parts of phase change material, and 1.1-1.2 parts of adhesive; the adhesive is one or both of phenolic resin and urea-formaldehyde resin; the phase change material includes the following components: 63.4-63.5 parts of expanded graphite particles, 3.1-3.2 parts of hydrogel powder, 8.0-8.1 parts of hydrophobic silica powder, 192.0-192.1 parts of calcium chloride hexahydrate powder, and 134.6-134.7 parts of polyurethane.

Images