Flexible active cooling pad based on dissolving pressure-blocking effect

Abstract

The invention relates to a flexible active cooling pad based on a dissolution pressing and clamping effect. The cooling pad comprises a flexible pressure container made of a flexible pressure-resistant material, and a salt solution capable of generating dissolution / precipitation phase change is packaged in the flexible pressure container to serve as an active working medium; the pressure driving module is connected with the flexible pressure container and is used for applying or releasing pressure; the flexible heat conduction layer is arranged on the surface of the container. The pressure blocking effect is expanded to a solution dissolution balance system for the first time, the salt solubility is changed through pressure driving, and rapid refrigeration is achieved through the'dissolution pressure blocking effect 'of dissolution heat absorption and precipitation heat release. The device has the advantages of flexible fitting, rapid cooling, recyclability, no need of large fixed equipment and refrigerants and the like, and is suitable for the fields of human body local cooling, exercise rehabilitation, heatstroke first aid, electronic equipment heat dissipation and the like.

Description

Technical Field

[0001] This invention belongs to the field of thermal management and refrigeration technology, specifically relating to a flexible active cooling pad based on the dissolution-pressure effect, which is particularly suitable for scenarios such as local cooling of the human body, sports rehabilitation, heatstroke emergency treatment, and heat dissipation of electronic devices. Background Technology

[0002] The pressure-clamping effect refers to the heat absorption and release phenomenon that occurs when a material undergoes a phase change under pressure, accompanied by entropy change. As a novel green refrigeration technology, its volume entropy change characteristics are of great significance for system lightweighting. Research and patent applications of related solid pressure-clamping materials have been gradually carried out, such as solid pressure-clamping materials based on "spin cross-coordination compounds" and novel high-energy-density solid pressure-clamping materials, which have laid a scientific foundation for the application of the pressure-clamping effect in the refrigeration field.

[0003] Currently, cooling of the human body or equipment mainly relies on the following methods, but all of them have obvious limitations: 1. Traditional ice packs / gel cooling patches: based on the heat absorption of melting phase change materials (such as water). The disadvantages are that they need to be pre-frozen, the release of cold is uncontrollable, the low temperature may cause frostbite to the skin, and they cannot be reused.

[0004] 2. Semiconductor cooling (Peltier effect): Requires continuous power supply, the equipment is usually heavy, and heat dissipation is difficult to handle, resulting in poor portability.

[0005] 3. Solid pressure refrigeration materials: Although they rely on the pressure effect to achieve environmentally friendly refrigeration, they generally suffer from slow heat conduction, high interfacial thermal resistance, and difficulty in making flexible devices, which limits their application in scenarios such as conforming to the curved surfaces of the human body and irregular electronic device surfaces.

[0006] 4. Fluid circulation cooling pads: These achieve cooling by circulating coolant through a micro-pump or by connecting to an external heat source. They rely on an external cold source and have a complex structure and poor portability. Various cooling pads that combine different structures and applications only optimize the heat dissipation structure and do not change the inherent defects of traditional refrigeration principles.

[0007] In existing technologies, the application of the pressure-clamping effect is mostly limited to solid-state phase change systems. There is no technical solution to extend the pressure-clamping effect to solution dissolution equilibrium systems and combine it with flexible structures to achieve efficient and portable cooling. Therefore, there is an urgent need for a new cooling technology that can start up quickly, fit flexibly, be reusable, and does not require large fixed equipment. This invention is based on the existing scientific research foundation of the pressure-clamping effect and innovatively proposes an application scheme for the dissolution pressure-clamping effect to solve the above-mentioned technical pain points. Summary of the Invention Purpose of the invention

[0008] The purpose of this invention is to provide a flexible active cooling pad based on the dissolution compression effect, so as to solve the problem that the existing cooling devices cannot simultaneously meet the requirements of "rapid large-capacity cooling", "flexible portability" and "efficient heat exchange", and fill the gap in the application of the compression effect in solution systems and the research and development of flexible cooling devices. Technical solution

[0009] To achieve the above objectives, the present invention provides the following technical solution: a flexible active cooling pad based on the dissolution-pressure effect, characterized in that it comprises: • Flexible pressure vessel: Made of highly elastic, pressure-resistant flexible material, forming a sealed cavity inside; • Active working medium: Encapsulated within the sealed cavity of the flexible pressure vessel, the active working medium comprises a salt solution capable of undergoing a dissolution / precipitation phase change; • Pressure drive module: connected to the flexible pressure vessel, used to apply or release pressure to the interior of the flexible pressure vessel; • Flexible heat-conducting layer: disposed on the surface of the flexible pressure vessel for contact with the human body or the object to be cooled and for conducting cold energy.

[0010] Preferably, the salt solution is an aqueous solution of ammonium thiocyanate or a mixed solution of it with other inorganic salts, wherein the aqueous solution of ammonium thiocyanate is a saturated aqueous solution with a concentration range of 60% to 70% (mass fraction).

[0011] Preferably, the flexible pressure vessel is a retractable and foldable bladder structure, or a flexible substrate integrated with a micro hydraulic / pneumatic drive device, specifically a corrugated tubular structure or a folded bladder structure.

[0012] Preferably, the flexible thermally conductive layer is a high thermal conductivity silicone layer, a graphene coating, or a metal mesh composite layer, which has good flexibility and thermal conductivity.

[0013] Preferably, the pressure drive module is a miniature air pump or hydraulic pump that can provide a pressure of not less than 0.8 MPa; a one-way valve or pressure holding valve is provided between the flexible pressure vessel and the pressure drive module to achieve precise control and stable pressure maintenance.

[0014] Preferably, it also includes a temperature sensor and a control unit, wherein the control unit controls the working state of the pressure drive module according to the signal from the temperature sensor, thereby realizing intelligent regulation of the refrigeration process. Working principle

[0015] Based on the scientific principle of the pressure effect, this invention innovatively proposes the "dissolution pressure effect" and applies it to the field of refrigeration. The dissolution pressure effect refers to the shift in the dissolution equilibrium of a salt solution under the action of a pressure field, accompanied by a dissolution / precipitation phase transition that generates an entropy change, thereby realizing a physicochemical process of endothermic and exothermic reactions.

[0016] The specific working process is as follows: Under normal pressure, the dissolution of salts (such as ammonium thiocyanate) in a solvent (such as water) is an endothermic process. When high pressure (≥0.5MPa) is applied to the flexible pressure vessel through the pressure drive module, the solubility of the salt decreases, the dissolution equilibrium shifts towards precipitation, and the salt crystallizes out. This process is accompanied by entropy reduction and heat release, which is rapidly dissipated into the environment through the flexible heat-conducting layer. When the pressure is released, the solubility of the salt increases again, and the crystalline salt quickly dissolves in the aqueous solution. This process is accompanied by entropy increase and a large amount of heat absorption, causing the temperature of the flexible pressure vessel and the surface in contact with the heat-conducting layer to drop sharply, thereby achieving rapid cooling of the human body or object. The entire process achieves efficient heat exchange through the flexible heat-conducting layer, utilizes the fluidity of the solution to reduce interfacial thermal resistance, and combines the structural characteristics of the flexible pressure vessel to meet the dual needs of cooling and bonding. Beneficial effects

[0017] 1. Innovative expansion of the application field of the piezocation effect: This invention is the first to extend the piezocation effect from solid phase change systems to solution dissolution equilibrium systems, and proposes a refrigeration application scheme for the dissolution piezocation effect, filling the gap in related technical fields.

[0018] 2. Breaking the impossible triangle of refrigeration technology: This invention combines the refrigerant and the heat exchange medium into one, utilizing the fluidity of the solution to achieve efficient heat transfer, while providing a huge amount of cooling capacity through the dissolution / precipitation process, thus solving the problem of the difficulty in achieving low carbon, large cooling capacity and high heat exchange efficiency at the same time.

[0019] 3. Rapid cooling and fast response: The depressurization and dissolution process can achieve a significant cooling effect within seconds to tens of seconds. Based on the adiabatic temperature change data of similar salt solution systems in publicly available scientific reports, the theoretical cooling range of this solution can reach more than 30°C, meeting emergency needs such as heatstroke first aid and rapid heat dissipation.

[0020] 4. Flexible fit and safe to use: The pressure vessel and heat-conducting layer are encapsulated with flexible materials, which can be bent at will to fit human skin or irregular object surfaces, making it comfortable to use and eliminating the risk of frostbite from low temperatures, making it suitable for a variety of application scenarios.

[0021] 5. Reversible cycle and no consumables required: By repeatedly pressurizing / depressurizing, the dissolution / precipitation phase change can be switched cyclically, thereby achieving the cyclic output of cooling capacity. No consumables need to be replaced, resulting in low operating costs.

[0022] 6. Green, environmentally friendly, energy-saving and portable: It does not use greenhouse gases such as Freon, has no high-energy-consuming compressors, and only requires a micro pump to provide pressure drive. It is environmentally friendly and energy-saving, and the equipment is small in size, light in weight and highly portable. Attached Figure Description Figure 1 This is a schematic diagram of the structure of the flexible active cooling pad provided in an embodiment of the present invention. Figure 2 This is a schematic cross-sectional view of the flexible active cooling pad provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the system connection of the flexible active cooling pad provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the flexible active cooling pad provided in this embodiment of the invention in a wearable application scenario. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. This embodiment is based on the core principle of the dissolution-pressure effect, and clarifies the specific structural parameters and operation process, so that the technical solution is feasible.

[0024] 1. Fabrication of Flexible Pressure Vessels: A rectangular folded pouch-shaped flexible bladder is fabricated using a multi-layer composite process to serve as a flexible pressure vessel. Its inner layer is made of corrosion-resistant fluororubber, achieving airtight sealing and resistance to solution corrosion; the middle layer is a tensile-resistant nylon mesh, which enhances structural strength and pressure resistance, and can withstand pressures of ≥1.0MPa; the outer layer is a highly thermally conductive silicone coating, which also serves as a flexible heat-conducting layer, enabling flexible contact with the object to be cooled and efficient heat transfer.

[0025] 2. Filling with active working fluid: Injecting a saturated ammonium thiocyanate aqueous solution into the sealed cavity of the flexible capsule, wherein the mass fraction of the aqueous solution is 65%, providing a sufficient working fluid basis for dissolution / precipitation phase change.

[0026] 3. Connecting the pressure drive module: The flexible bladder is connected to a micro electric air pump via a flexible pipeline. A one-way pressure holding valve is installed at the connection point between the flexible pipeline and the bladder. The micro electric air pump can provide an adjustable pressure of 0~1.0MPa to achieve precise application and maintenance of pressure.

[0027] 4. Assembly of auxiliary control components: A temperature sensor is set on the surface of the flexible heat-conducting layer. The temperature sensor and the micro electric air pump are electrically connected to the micro control unit. The control unit can automatically control the pressurization, pressure holding and depressurization operations of the air pump according to the surface temperature collected by the temperature sensor.

[0028] 5. Refrigeration operation process: (1) The flexible heat-conducting layer of the cooling pad is tightly attached to the local skin of the human body that needs cooling or the heat dissipation surface of electronic devices; (2) The micro electric air pump is started by the control unit to pressurize the flexible pressure vessel to 0.6MPa. At this time, the solubility of ammonium thiocyanate decreases, the salt crystallizes and precipitates, releasing heat. The heat is quickly dissipated to the environment through the flexible heat-conducting layer, completing the heat dissipation step. (3) After the heat dissipation is completed, the pressure holding valve is opened by the control unit to quickly release the pressure in the flexible pressure vessel to normal pressure. At this time, the ammonium thiocyanate crystals quickly dissolve in the aqueous solution and absorb a large amount of heat, so that the temperature of the cooling pad contact surface drops significantly within 20 seconds, achieving rapid physical cooling. (4) When the temperature sensor detects that the temperature of the bonding surface rises back to the set threshold, the control unit automatically starts the next pressurization-depressurization cycle to achieve continuous cyclic output of cooling capacity.

Claims

1. A flexible active cooling pad based on the dissolution-pressure effect, characterized in that, include: • Flexible pressure vessels are made of highly elastic, pressure-resistant flexible materials, forming a sealed cavity inside; • An active working medium, encapsulated within the sealed cavity of the flexible pressure vessel, the active working medium comprising a salt solution capable of undergoing a dissolution / precipitation phase change; • A pressure drive module, connected to the flexible pressure vessel, for applying or releasing pressure inside the flexible pressure vessel; • A flexible heat-conducting layer is disposed on the surface of the flexible pressure vessel for contact with the human body or the object to be cooled and for conducting cold energy.

2. The flexible active cooling pad according to claim 1, characterized in that, The salt solution is an aqueous solution of ammonium thiocyanate, which is a saturated aqueous solution with a mass fraction of 60% to 70%.

3. The flexible active cooling pad according to claim 1, characterized in that, The flexible pressure vessel has a corrugated tubular structure or a folded bladder structure, and the pressure drive module is a micro air pump or a hydraulic pump, which can provide a pressure of not less than 0.8 MPa.

4. The flexible active cooling pad according to claim 1, characterized in that, The flexible thermally conductive layer is a high thermal conductivity silicone layer, a graphene coating, or a metal mesh composite layer.

5. The flexible active cooling pad according to claim 1, characterized in that, A one-way valve or a pressure holding valve is provided between the flexible pressure vessel and the pressure drive module.

6. The flexible active cooling pad according to claim 1, characterized in that, It also includes a temperature sensor and a control unit, the control unit controlling the working state of the pressure drive module based on the signal from the temperature sensor.

7. The flexible active cooling pad according to claim 1, characterized in that, The flexible pressure vessel has a multi-layer composite structure, with an inner fluororubber layer, a middle nylon mesh layer, and an outer high thermal conductivity silicone layer.

8. A cooling method for a flexible active cooling pad as described in any one of claims 1-7, characterized in that, Includes the following steps: Pressurization step: The flexible pressure vessel is pressurized to ≥0.5MPa through the pressure drive module, causing the salts in the active working fluid to precipitate and release heat; Heat dissipation steps: The heat generated during the pressurization process is dissipated into the environment through a flexible thermally conductive layer; Depressurization step: Release the pressure inside the flexible pressure vessel to atmospheric pressure, allowing the salts to dissolve rapidly and absorb heat, thus achieving cooling.

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