Automotive static temperature control system combining coupled radiative cooling car cover and phase change thermal storage module

Abstract

This invention discloses a static temperature control system for automobiles that couples a radiative cooling car cover with a phase change heat storage module, belonging to the field of thermal management materials. A radiative cooling car cover is placed on the car, and a phase change heat storage module is placed inside. During the daytime, when the temperature rises, the radiative cooling car cover insulates off most of the heat through reflecting solar radiation, high-density infrared radiation, and low thermal conductivity. When the remaining heat enters the passenger compartment, it is absorbed at a constant temperature by the phase change heat storage module, maintaining a low temperature inside the passenger compartment. During the daytime, when the temperature drops and at night, the heat stored in the phase change heat storage module is rapidly transferred to the outside through the high-density infrared radiation of the radiative cooling car cover, keeping the passenger compartment at a low temperature. This dual-function coupling achieves a low-temperature environment inside the passenger compartment, reduces energy consumption for temperature control during vehicle start-up, improves passenger comfort, and reduces the risk of aging of in-vehicle components and spontaneous combustion of the power battery caused by high temperatures.

Description

Technical Field

[0001] This invention relates to the field of thermal management materials for passenger vehicles, specifically to a high-efficiency temperature control system for passenger vehicles under static conditions that couples a radiant cooling car cover with a phase change heat storage module. Background Technology

[0002] Passenger vehicles parked outdoors, especially under direct sunlight during hot summer days, absorb significant amounts of solar and ambient infrared radiation. A large amount of heat from the air also enters the vehicle through convection and conduction, causing a rapid rise in the temperature of the interior space and components. Prolonged exposure to high temperatures and ultraviolet radiation can lead to serious damage, including interior aging, tire and rubber component deterioration, the production of toxic gases, and damage to electronic devices. This is particularly problematic in new energy passenger vehicles, where high temperatures can cause circuit aging, chip damage, and increase the risk of battery fires. Furthermore, the high temperature inside the vehicle increases cooling energy consumption during startup, resulting in lower comfort levels for passengers. Therefore, efficient temperature control technology for passenger vehicles in static conditions is a technology that urgently needs development and application. When a passenger vehicle is stationary, thermal management equipment such as air conditioning is usually off, requiring passive thermal management materials to address this issue.

[0003] Radiant cooling technology isolates external heat through the reflection of sunlight, high infrared radiation, and low thermal conductivity, achieving efficient temperature control. By using a radiant cooling car cover to cover the exterior of passenger vehicles, it can achieve a certain degree of insulation against external heat during the day when temperatures rise (through reflecting solar radiation, high-density infrared radiation, and low thermal conductivity), and dissipate heat from the interior through high-density thermal radiation during the night and when temperatures drop, thus achieving cooling and refrigeration in the parked mode of the passenger vehicle. However, when daytime temperatures rise rapidly, radiant cooling technology cannot completely isolate external heat and will still absorb a certain amount of solar radiation. A small amount of heat in the enclosed cabin can cause the interior temperature to rise, resulting in an unsatisfactory cooling effect.

[0004] Phase change thermal energy storage (PCE) can absorb a large amount of heat at a constant temperature through a phase change, using latent heat to achieve temperature regulation. Placing PCE modules inside a vehicle allows the heat absorbed by the car cabin (mainly solar radiation) during the daytime when temperatures rise to be stored at a constant temperature within the PCE modules, thus maintaining a constant temperature inside the cabin. However, during the daytime warming period, the car cabin absorbs a significant amount of solar radiation, requiring a large number of PCE modules to store this heat for sustained temperature control. On the other hand, when temperatures drop or at night, the enclosed environment of a car has very low heat dissipation efficiency, making it difficult for the heat stored in the PCE modules to be quickly transferred to the outside, resulting in the cabin remaining at a high temperature.

[0005] Radiation-cooling car covers consist of a commercial car cover base and a radiation-cooling coating on the surface. They possess the basic functions of radiation cooling, such as high solar reflectivity, high infrared emissivity, and low thermal conductivity, while also needing good weather resistance and flexibility. CN219136684U discloses a car cover film with radiation cooling function, which achieves cooling by being attached to the surface of the car paint. However, this film cannot cover the entire surface of the car; solar radiation can still enter the passenger compartment through the windshield, resulting in limited cooling effect when the car is stationary. Furthermore, it differs from the technical form of this invention. On the other hand, many published patent documents on radiation-cooling coatings are for applications on the outer layers of buildings or fixed objects, such as CN116640486A and CN115449252A. When used on the surface of buildings or other fixed objects, the basic functions of radiation cooling and weather resistance need to be considered, but the flexibility of the coating is not required.

[0006] There are currently no public reports on the functional coupling of radiant cooling car covers and phase change thermal storage modules for use in vehicle static mode for cooling and temperature control. Summary of the Invention

[0007] To meet the efficient cooling and heat dissipation needs of vehicles parked in direct sunlight, this invention aims to provide a material system for outdoor vehicle cooling and heat dissipation, consisting of an external radiative cooling car cover and an internal phase change heat storage module. During daytime warming, the radiative cooling car cover insulates most of the heat through reflecting solar radiation, high-density infrared radiation, and low thermal conductivity. When the remaining heat enters the vehicle cabin, it is absorbed at a constant temperature by the phase change heat storage module, maintaining a low temperature inside the cabin. In this case, the phase change heat storage module enhances the cooling effect of the radiative cooling car cover, reducing the amount of phase change material used. During temperature drops and at night, a small amount of heat stored by the phase change heat storage module is rapidly transferred to the outside through the high-density infrared radiation of the radiative cooling car cover, keeping the interior of the cabin at a low temperature. This dual-function coupling achieves a low-temperature environment inside the vehicle cabin, reducing energy consumption for temperature control during vehicle start-up, improving passenger comfort, and reducing the risk of aging of in-vehicle components and spontaneous combustion of the power battery caused by high temperatures.

[0008] The radiation-cooling car cover of this invention can use an ordinary commercial vehicle cover as a base, and then spray or brush a radiation-cooling coating onto its surface. The radiation-cooling coating is composed of binders, plasticizers, and inorganic components, and meets the requirements of high solar reflectivity, high infrared emissivity, low thermal conductivity, weather resistance, and high flexibility.

[0009] Preferably, the radiation-cooling car cover is prepared based on commercially available aluminum film car covers, with a radiation-cooling coating applied to the outer layer. This coating, in addition to possessing radiation-cooling properties, also exhibits weather resistance and flexibility. The radiation-cooling coating of this invention is formed by mixing an adhesive, plasticizer, and inorganic components in water to form a coating, which is then applied to the surface of the car cover by spraying or brushing and allowed to air dry naturally. The adhesive can be a water-based acrylic resin, providing high adhesion and high infrared emissivity. The plasticizer can be selected from one or more of polypropylene glycol, polyvinyl acetate, and carboxymethyl cellulose, enhancing the flexibility of the coating. The inorganic component consists of high-refractive-index micron-sized particles or hollow microspheres, preferably with a particle size less than 3 μm, and its chemical composition is an inorganic oxide, such as zinc oxide, aluminum oxide, silicon dioxide, titanium dioxide, magnesium oxide, etc., providing high solar spectral reflectivity and infrared emissivity, improving weather resistance, and reducing thermal conductivity.

[0010] Preferably, the binder, plasticizer, and inorganic components are formulated in a mass ratio of (40-60):(5-10):(30-55). First, a specific mass of the inorganic component is weighed and mixed with water, stirred for at least 2 hours to ensure uniform dispersion of the inorganic particles, with water comprising 30%-50% of the total mass. Then, a specific proportion of binder and plasticizer is weighed and added to the aforementioned dispersion, stirred for 12-24 hours to ensure complete dissolution of the binder and plasticizer, resulting in a uniform coating. The coating is applied to the surface of the car cover using spraying or brushing methods and allowed to air dry naturally. Through proper formulation, this car cover achieves a solar spectral reflectance greater than 80% and an infrared emissivity greater than 90%. The inorganic component enhances weather resistance, while the plasticizer component enhances the coating's flexibility, allowing it to be folded and stored within the car cover without falling off.

[0011] The phase change thermal storage module comprises a phase change material, a porous thermally conductive framework, a polymer, and a flame retardant. It is intended for in-vehicle temperature control and should possess characteristics such as good shape retention, suitable phase change temperature, high heat transfer efficiency, malleable shape, and flame retardancy. The phase change material can be one or more of hexadecane, octadecane, eicosane, polyethylene glycol 800, and dodecanol, with a phase change temperature of 15℃-35℃, providing constant-temperature thermal storage characteristics and achieving internal low-temperature regulation near room temperature. The porous thermally conductive framework can be one of expanded graphite or graphene framework, providing encapsulation and high heat transfer efficiency. The polymer is polyethylene and / or polyethylene oxide, which provides molecular bond encapsulation, improving the shape retention and malleability of the phase change material. The flame retardant can be one or more of aluminum hydroxide and magnesium hydroxide particles, providing flame retardancy.

[0012] Preferably, the phase change material, porous thermally conductive skeleton, polymer, and flame retardant are mixed in a mass ratio of (50-60):(10-20):(10-30)(10-20), stirred evenly by mechanical stirring, heated to 80℃-150℃, and kept at a constant temperature for 2 hours. After cooling, the mixture is pressed into tablets to obtain a phase change thermal storage module with a specific shape, high thermal conductivity, and good shape retention. The phase change temperature is 15℃-35℃, and the thermal storage density is 100J / g-180 J / g. The phase change thermal storage module is then embedded in the interior space of the vehicle.

[0013] This invention functionally couples a radiant cooling car cover with a phase change thermal storage module. During daytime warming, the radiant cooling car cover reflects solar radiation, high-density infrared radiation, and has low thermal conductivity, blocking most of the heat. When the remaining heat enters the vehicle, it is absorbed at a constant temperature by the phase change thermal storage module, maintaining a low temperature inside the vehicle. In this case, the phase change thermal storage module enhances the cooling effect of the radiant cooling car cover, reducing the amount of phase change material used. During colder weather and at night, a small amount of heat stored by the phase change thermal storage module is rapidly transferred to the outside through the high-density infrared radiation of the radiant cooling car cover, keeping the interior of the vehicle at a low temperature. This dual-functional coupling achieves a low-temperature environment inside the vehicle, reducing energy consumption for temperature control during vehicle start-up, improving passenger comfort, and reducing the risk of aging of in-vehicle components and spontaneous combustion of the power battery caused by high temperatures. The radiative cooling coating used in the car cover possesses high solar reflectivity, high infrared emissivity, low thermal conductivity, weather resistance, and flexibility. The phase change thermal storage module exhibits good shape retention, suitable phase change temperature, high heat transfer efficiency, malleable shape, and flame retardancy. The preparation method is safe and reliable, and can be mass-produced. Attached Figure Description

[0014] Figure 1 A schematic diagram of the radiation-cooled car cover prepared in Example 1 and its functions.

[0015] Figure 2 Example 1: Solar reflectance spectrum (a) and solar reflectance (b) of a radiation-cooled car cover before and after coating application.

[0016] Figure 3 Example 1: Infrared emission spectrum (a) and infrared emissivity (b) of a radiation-cooled car cover before and after coating application.

[0017] Figure 4 The appearance (top image) and microstructure (bottom image) of the phase change thermal energy storage module prepared in Example 1.

[0018] Figure 5 Experimental results of temperature control of a vehicle using the radiation-cooled car cover prepared in Example 1 coupled with a phase change thermal storage module. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] Example 1

[0021] A mixture of water-based acrylic resin, polypropylene glycol, hollow silica, and water was prepared in a mass ratio of 30:5:15:50. A specific mass of hollow silica microspheres was weighed and mixed with a specific mass of water, and stirred for at least 2 hours to ensure uniform dispersion of the hollow silica. Specific masses of water-based acrylic resin and polypropylene glycol were weighed and added to the dispersion, and stirred for 12-24 hours to ensure complete dissolution of the water-based acrylic resin and polypropylene glycol, resulting in a uniform coating. The coating was applied to the surface of the aluminum foil car cover using spraying or brushing methods and allowed to air dry naturally. This car cover achieves a solar spectral reflectance greater than 80%. Figure 2 Infrared emissivity greater than 90% Figure 3 Silica enhances weather resistance, while polypropylene glycol enhances the flexibility of the coating, allowing it to be folded and stored in a car cover without falling off.

[0022] The mixture was prepared by mixing eicosane, expanded graphite, polyethylene, and aluminum hydroxide in a mass ratio of 60:20:10:10. After being stirred evenly by mechanical stirring, it was heated to 120°C and kept at that temperature for 2 hours for adsorption. After cooling, it was pressed into tablets to obtain a phase change thermal storage module with high thermal conductivity and good shape retention in a specific shape. Figure 4 The phase change temperature is 30℃-32℃, and the heat storage density is 140J / g. The phase change heat storage module is then embedded in the interior space of the vehicle.

[0023] By covering the exterior of the vehicle with a radiant cooling car cover and placing phase change heat storage modules inside the vehicle (such as under the seats and in the gaps between the seats), compared to a bare vehicle, a single radiant cooling car cover, or a commercial vehicle cover, the dual-function driver's seat has the lowest peak daytime temperature and dissipates heat quickly at night, allowing the vehicle to maintain a low temperature continuously, thus achieving a super cooling and heat dissipation function. Figure 5 ).

[0024] Example 2

[0025] The water-based acrylic resin, carboxymethyl cellulose, alumina, and water are mixed in a mass ratio of 25:5:20:50. A specific mass of alumina particles is weighed and mixed with a specific mass of water, and stirred for at least 2 hours to ensure uniform dispersion of the alumina particles. A specific mass of water-based acrylic resin and carboxymethyl cellulose are then weighed and added to the dispersion, and stirred for 12-24 hours to ensure complete dissolution of the water-based acrylic resin and polypropylene glycol, resulting in a uniform coating. The coating is applied to the surface of the aluminum foil car cover using spraying or brushing methods and allowed to air dry. This car cover achieves a solar spectral reflectance greater than 80% and an infrared emissivity greater than 90%. Alumina enhances weather resistance, and carboxymethyl cellulose enhances the coating's flexibility, allowing it to be folded and stored in the car cover without falling off.

[0026] A phase change thermal storage module is prepared by mixing polyethylene glycol 800, graphene, polyethylene oxide, and aluminum hydroxide in a mass ratio of 50:15:20:15. After being stirred evenly by mechanical stirring, the mixture is heated to 100°C and kept at a constant temperature for 2 hours. After cooling, it is pressed into tablets to obtain a phase change thermal storage module with a specific shape, high thermal conductivity, and good shape retention. The phase change temperature is 28°C-30°C, and the thermal storage density is 110 J / g. The phase change thermal storage module is then embedded in the interior space of a vehicle.

[0027] By covering the exterior of the vehicle with a radiant cooling car cover and placing phase change heat storage modules inside the vehicle (such as under the seats and in the gaps between the seats), a super cooling and heat dissipation function is achieved.

[0028] Example 3

[0029] A mixture of water-based acrylic resin, polyvinyl acetate, titanium dioxide, and water in a mass ratio of 20:5:25:50 was prepared. A specific mass of titanium dioxide particles was weighed and mixed with a specific mass of water, and stirred for at least 2 hours to ensure uniform dispersion. A specific mass of water-based acrylic resin and polyvinyl acetate were then weighed and added to the dispersion, and stirred for 12-24 hours to ensure complete dissolution of the acrylic resin and polyvinyl acetate, resulting in a uniform coating. The coating was applied to the surface of the aluminum foil car cover using spraying or brushing methods and allowed to air dry. This car cover achieves a solar spectral reflectance greater than 80% and an infrared emissivity greater than 90%. Titanium dioxide enhances weather resistance, and polyvinyl acetate enhances the coating's flexibility, allowing it to be folded and stored in the car cover without falling off.

[0030] The phase change thermal storage module is prepared by mixing dodecanol, expanded graphite, polyethylene oxide, and magnesium hydroxide in a mass ratio of 55:10:20:15. After being stirred evenly by mechanical stirring, the mixture is heated to 80°C and kept at a constant temperature for 2 hours. After cooling, it is pressed into tablets to obtain a phase change thermal storage module with a specific shape, high thermal conductivity, and good shape retention. The phase change temperature is 20°C-25°C, and the thermal storage density is 130 J / g. The phase change thermal storage module is then embedded in the interior space of a vehicle.

[0031] By covering the exterior of the vehicle with a radiant cooling car cover and placing phase change heat storage modules inside the vehicle (such as under the seats and in the gaps between the seats), a super cooling and heat dissipation function is achieved through the coupling of these two functions.

[0032] The embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are only some embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A static temperature control system for automobiles, comprising a radiant cooling car cover over the automobile and a phase change heat storage module placed inside the automobile, characterized in that, The surface of the radiation-cooling car cover is a radiation-cooling coating with a solar spectral reflectance greater than 80% and an infrared emissivity greater than 90%. The phase change thermal storage module has a phase change temperature of 15℃-35℃ and a thermal storage density of 100J / g-180 J / g. The phase change thermal storage module is composed of a phase change material, a porous thermally conductive skeleton, a polymer, and a flame retardant. The phase change material is selected from one or more of hexadecane, octadecane, eicosane, polyethylene glycol 800, and dodecanol. The porous thermally conductive skeleton is expanded graphite or graphene. The polymer is polyethylene and / or polyethylene oxide. The flame retardant is aluminum hydroxide and / or magnesium hydroxide particles. The mass ratio of the phase change material, porous thermally conductive skeleton, polymer, and flame retardant in the phase change thermal storage module is (50-60):(10-20):(10-30)(10-20). The radiation-cooling car cover is prepared by spraying or brushing a radiation-cooling coating onto the surface of an ordinary car cover. The radiation-cooling coating consists of a binder, a plasticizer, and inorganic components. The binder is a water-based acrylic resin; the plasticizer is selected from one or more of polypropylene glycol, polyvinyl acetate, and carboxymethyl cellulose; the inorganic components are micron-sized inorganic oxide particles or hollow microspheres. The phase change heat storage module is placed in the car, including under the seats and in the gaps of the passenger compartment. The radiation-cooling car cover is prepared by the following method: weighing the inorganic components and mixing them with water (30%-50% by mass), stirring for more than 2 hours to form a uniform dispersion; weighing the binder and plasticizer and mixing them into the dispersion, stirring for 12-24 hours to fully dissolve the binder and plasticizer, obtaining a uniform coating; applying the coating to the surface of an ordinary car cover by spraying or brushing, and allowing it to air dry naturally to obtain the radiation-cooling car cover. The phase change thermal storage module is prepared by the following method: the phase change material, porous thermally conductive framework, polymer and flame retardant are mechanically stirred and mixed, then heated to 80℃-150℃, and adsorbed at a constant temperature for 2 hours. After cooling, the module is pressed into tablets to obtain the phase change thermal storage module of a specific shape. The chemical composition of the inorganic component is selected from one or more of zinc oxide, aluminum oxide, silicon dioxide, titanium dioxide and magnesium oxide.

2. The automotive static temperature control system as described in claim 1, characterized in that, The inorganic oxide particles or hollow microspheres have a particle size of less than 3 μm.

3. The automotive static temperature control system as described in claim 1, characterized in that, The mass ratio of binder, plasticizer and inorganic components in the radiation cooling coating is (40-60):(5-10):(30-55).

4. A method for preparing a static temperature control system for automobiles as described in claim 1, wherein the static temperature control system comprises a radiant cooling car cover applied to the automobile and a phase change heat storage module placed inside the automobile, characterized in that, The preparation method of the automotive static temperature control system includes: the preparation method of the radiative cooling car cover and the phase change heat storage module; The radiation-cooling car cover is prepared by the following method: weighing the inorganic components and mixing them with water, wherein the water accounts for 30%-50% of the mass, and stirring for more than 2 hours to form a uniform dispersion; weighing the binder and plasticizer and mixing them into the dispersion, stirring for 12-24 hours to fully dissolve the binder and plasticizer to obtain a uniform coating; applying the coating to the surface of an ordinary car cover by spraying or brushing, and air drying naturally to obtain the radiation-cooling car cover; The phase change thermal storage module is prepared by the following method: the phase change material, porous thermally conductive skeleton, polymer and flame retardant are mixed by mechanical stirring, then heated to 80℃-150℃, and adsorbed at a constant temperature for 2 hours. After cooling, the module is pressed into tablets to obtain the phase change thermal storage module of a specific shape. The radiation-cooling car cover is prepared by spraying or brushing a radiation-cooling coating onto the surface of an ordinary car cover. The radiation-cooling coating consists of an adhesive, a plasticizer, and inorganic components. The adhesive is an aqueous acrylic resin; the plasticizer is selected from one or more of polypropylene glycol, polyvinyl acetate, and carboxymethyl cellulose; and the inorganic components are micron-sized inorganic oxide particles or hollow microspheres. The surface of the radiation-cooling car cover is a radiation-cooling coating with a solar spectrum reflectance greater than 80% and an infrared emissivity greater than 90%. The phase change thermal storage module has a phase change temperature of 15℃-35℃ and a thermal storage density of 100J / g-180J / g. The phase change thermal storage module is composed of a phase change material, a porous thermally conductive framework, a polymer, and a flame retardant. The phase change material is selected from one or more of hexadecane, octadecane, eicosane, polyethylene glycol 800, and dodecanol. The porous thermally conductive framework is expanded graphite or graphene. The polymer is polyethylene and / or polyethylene oxide. The flame retardant is aluminum hydroxide and / or magnesium hydroxide particles. The mass ratio of phase change material, porous thermally conductive skeleton, polymer and flame retardant in the phase change thermal storage module is (50-60):(10-20):(10-30):(10-20).

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