A new water collection device and method based on MOF material

Abstract

The present invention discloses a novel water collection device and method based on MOF material, the device specifically includes a radiation cooling film, a conversion cavity, a solar reflective film, a heat conducting plate, a MOF adsorption material, a heat medium cavity, a water collection cavity, a refrigerant cavity, a water tank, a movable partition, a temperature sensor, a piston, a valve stem, a valve, a pressure regulating valve, and an exhaust valve. The present invention combines MOF adsorption material with radiation cooling technology and solar heat collection technology, and utilizes the cold obtained by heat exchange between the radiation cooling film and the outer space to improve the adsorption performance of the MOF material. At the same time, the heat medium is utilized to enhance the absorption capacity of the MOF material to solar thermal radiation, thereby improving the desorption performance of the MOF material, thereby improving the ability of the MOF material to absorb moisture in the air while fully utilizing the natural capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of passive energy utilization, and specifically relates to a novel water collection device and method based on MOF materials. Background Art

[0002] In the 21st century, due to the overuse and pollution of limited clean water resources, more than 4 billion people are suffering from water shortages worldwide, and the situation is even worse in underdeveloped areas. In the context of the lack of fresh water resources, the issue of water collection has attracted much attention and has become the focus of human attention. However, a large amount of water in the atmosphere exists in the form of water vapor, so collecting this part of water is particularly important. In recent years, metal organic framework (MOF) materials have come into people's field of vision. Since there are many tiny pores on the surface of MOF materials, these porous structures increase the specific surface area of ​​the material, so MOF materials have good adsorption properties. The adsorption performance of MOF materials is affected by ambient temperature, humidity, specific surface area of ​​the material, porosity of the material, and the properties of the adsorbed gas. When the temperature of the MOF material decreases, the adsorption performance will be enhanced, and when the temperature of the MOF material increases, the desorption performance will be enhanced. Using MOF materials to collect water usually uses the lower ambient temperature at night for adsorption, and during the day, it can absorb solar thermal radiation to increase the temperature and then desorb. When this method is used, due to the limited temperature difference between day and night, the adsorption and desorption performance of MOF materials are low.

[0003] In recent years, radiative cooling has received increasing attention as a passive cooling technology. This passive cooling technology transmits heat to outer space in the form of electromagnetic waves through the "atmospheric window" (8-13μm band), that is, through the radiation heat exchange between the surface of the radiative cooling material and the outer space, so that the temperature of the material itself is reduced to below the ambient temperature. If radiative cooling is combined with MOF materials, the adsorption temperature of MOF materials at night can be effectively reduced, thereby improving the adsorption performance. At the same time, if the solar absorption rate of the material in the (0.25-2.5μm) band can be improved (greater than 0.8), the desorption performance of MOF materials can be effectively improved. Therefore, if MOF adsorption materials can be effectively combined with radiative cooling technology and solar thermal collection technology, the adsorption and desorption performance of MOF adsorption materials can be further improved under the condition of making full use of natural cold and heat sources.

[0004] Among the existing technologies disclosed about water collection devices, patent CN113896264A discloses a radiation cooling water resource acquisition device, which combines a condensation water collection device with a radiation cooling coating, and sets a specific radiation cooling coating in the condensation chamber, so that the surface temperature of the radiation cooling coating is much lower than the air temperature, providing the temperature difference required for condensing water vapor, thereby improving the condensation efficiency. The surface of the radiation cooling coating in the condensation chamber is subjected to a specific surface hydrophilic and hydrophobic treatment, so that the water condensed on the surface of the radiation cooling coating can spontaneously fall off the surface and be collected, thereby improving the condensation water collection efficiency. However, this technology requires the radiation surface temperature to be lowered to below the dew point temperature before water can be collected, and its application is limited.

[0005] Compared with the existing disclosed technology, the present invention is a new type of water collection device based on MOF material. The device combines radiation refrigeration technology, solar energy heat collection technology and MOF material adsorption technology, utilizes radiation refrigeration film to exchange heat with outer space to obtain cold energy, makes full use of natural cold sources, enhances the adsorption performance of MOF, and utilizes heat medium to enhance the absorption capacity of solar thermal radiation, so that the desorption efficiency is enhanced. It can be carried out at ambient temperature without lowering the ambient temperature to below the dew point temperature, and has broader application prospects. Summary of the invention

[0006] The present invention provides a novel water collection device and method based on MOF materials. The purpose of the present invention is to provide a novel water collection device with simple structure and good water collection effect.

[0007] To achieve the purpose of the present invention, the embodiment of the present invention adopts the following technical solutions:

[0008] The technical solution to achieve the purpose of the present invention is to provide a new water collection device based on MOF material, the system comprising: a radiation cooling film, a conversion cavity, a solar reflective film, a heat conducting plate, a MOF adsorption material, a heat medium cavity, a water collection cavity, a refrigerant cavity, a water tank, a movable partition, a temperature sensor, a first piston, a second piston, a first valve stem, a second valve stem, a valve, a pressure regulating valve, and an exhaust valve;

[0009] As a preferred example, the connection method of the various components of the novel water collection device based on MOF material is as follows:

[0010] The bottom of the radiation cooling film is tightly connected to the top of the conversion chamber, the bottom of the conversion chamber is tightly connected to the top of the solar reflective film, the bottom of the solar reflective film is tightly connected to the top of the heat conducting plate, and the bottom of the heat conducting plate is tightly connected to the top of the MOF adsorption material;

[0011] The movable partition is located inside the conversion chamber and divides the conversion chamber into two non-communicating parts. The movable partition can move along the first pipeline and the second pipeline in the conversion chamber under the push of the refrigerant and the heat medium.

[0012] The heat medium chamber, water collecting chamber and cold medium chamber are tightly connected to form a whole;

[0013] The first piston and the first valve stem are tightly connected to form a whole, and the first piston is located inside the heat medium chamber;

[0014] The second piston and the second valve stem are tightly connected to form a whole, and the second piston is located inside the refrigerant cavity;

[0015] The heat medium chamber is connected to the conversion chamber via a first pipe;

[0016] The refrigerant chamber is connected to the conversion chamber via a second pipe;

[0017] The MOF adsorption material is connected to the water collection chamber via a third pipe;

[0018] The heat medium chamber is connected to the output end of the first valve via a fifth pipeline, and the fourth pipeline is connected to the input end of the first valve;

[0019] The refrigerant chamber is connected to the output end of the second valve via a seventh pipe, and the sixth pipe is connected to the input end of the second valve;

[0020] The water collecting chamber is connected to the input end of the pressure regulating valve via an eighth pipeline;

[0021] The water tank is connected to the output end of the pressure regulating valve via a ninth pipeline;

[0022] The exhaust valve is installed at the upper part of the water collecting chamber to exhaust the air inside the water collecting chamber;

[0023] The first valve stem and the second valve stem control the first piston and the second piston to reciprocate in the heat medium cavity and the cold medium cavity respectively through the temperature sensor;

[0024] The fourth pipe is used to fill the heat medium cavity with heat medium;

[0025] The sixth pipe is used to fill the refrigerant cavity with refrigerant;

[0026] The heat transfer device of the pressure regulating valve is installed in the water collecting chamber, and the opening of the pressure regulating valve is adjusted according to the pressure in the water collecting chamber.

[0027] As a preferred example, the emissivity of the radiation cooling film in the 8-13 μm band is greater than 0.9 and the solar transmittance in the 0.25-2.5 μm band is greater than 0.9; the radiation cooling film can be a polymer radiation cooling film, an inorganic coating film, or a nanoparticle-based radiation cooling film.

[0028] As a preferred example, the specific surface area of ​​the MOF adsorption material is not less than 3800m 2 / g -1 , the adsorption amount is not less than 35 mg / g; the MOF adsorption material can be one of MOF-74-Mg, MOF-801, and MOF-803.

[0029] As a preferred example, the heat medium has a solar absorptivity greater than 0.8 in the 0.25-2.5 μm band and a thermal conductivity not less than 0.5 W / m·K; the heat medium can be a mixed solution of multi-walled carbon nanotubes and ethylene glycol, or a mixed solution of carbon fiber graphene and ethylene glycol.

[0030] As a preferred example, the refrigerant has a solar transmittance greater than 0.8 in the 0.25-2.5 μm band and a thermal conductivity not less than 0.5 W / m·K; the refrigerant can be one of deionized water, pure water, and a liquid containing metallic potassium and sodium.

[0031] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0032] The present invention combines MOF adsorption materials with radiation refrigeration technology and solar energy heat collection technology, and utilizes the cold energy obtained by heat exchange between the radiation refrigeration film and the outer space to improve the adsorption capacity of the MOF material. At the same time, the heat medium can absorb most of the solar thermal radiation and thus improve the desorption capacity of the MOF material. In this way, the ability of the MOF material to absorb moisture in the air can be improved while making full use of natural capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of an embodiment of the present invention;

[0034] Figure 2 is a three-dimensional schematic diagram of an embodiment of the present invention; DETAILED DESCRIPTION

[0035] The technical solution of the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0036] like Figure 1 As shown, the connection method of the various components of a novel water collection device based on MOF material in an embodiment of the present invention is as follows:

[0037] The bottom of the radiation cooling film (1) is tightly connected to the top of the conversion chamber (2), the bottom of the conversion chamber (2) is tightly connected to the top of the solar reflective film (3), the bottom of the solar reflective film (3) is tightly connected to the top of the heat conducting plate (4), and the bottom of the heat conducting plate (4) is tightly connected to the top of the MOF adsorption material (5);

[0038] The movable partition (10) is located inside the conversion chamber (2) and divides the conversion chamber (2) into two non-interconnected parts. The movable partition (10) can move along the first pipe (1201) and the second pipe (1202) in the conversion chamber (2) under the impetus of the refrigerant and the heat medium.

[0039] The heat medium chamber (6), the water collecting chamber (7), and the cold medium chamber (8) are tightly connected to form a whole;

[0040] The first piston (1301) and the first valve stem (1401) are tightly connected to form a whole, and the first piston (1301) is located inside the heat medium chamber (6);

[0041] The second piston (1302) and the second valve stem (1402) are tightly connected to form a whole, and the second piston (1302) is located inside the refrigerant cavity (8);

[0042] The heat medium chamber (6) is connected to the conversion chamber (2) via a first pipe (1201);

[0043] The refrigerant chamber (8) is connected to the conversion chamber (2) via a second pipe (1202);

[0044] The MOF adsorption material (5) is connected to the water collection chamber (7) via a third pipe (1203);

[0045] The heat medium chamber (6) is connected to the output end of the first valve (1501) via a fifth pipe (1205), and the fourth pipe (1204) is connected to the input end of the first valve (1501);

[0046] The refrigerant chamber (8) is connected to the output end of the second valve (1502) via a seventh pipe (1207), and the sixth pipe (1206) is connected to the input end of the second valve (1502);

[0047] The water collecting chamber (7) is connected to the input end of the pressure regulating valve (16) via an eighth pipeline (1208);

[0048] The water tank (9) is connected to the output end of the pressure regulating valve (16) via a ninth pipeline (1209);

[0049] The exhaust valve (17) is installed at the upper part of the water collecting chamber (7) and is used to exhaust the air inside the water collecting chamber (7);

[0050] The first valve stem (1401) and the second valve stem (1402) respectively control the first piston (1301) and the second piston (1302) to perform reciprocating motion in the heat medium chamber (6) and the cold medium chamber (8) via the temperature sensor (11);

[0051] The fourth pipe (1204) is used to fill the heat medium chamber (6) with heat medium;

[0052] The sixth pipe (1206) is used to fill the refrigerant cavity (8) with refrigerant;

[0053] The heat transfer device of the pressure regulating valve (16) is installed in the water collecting chamber (7), and the opening of the pressure regulating valve (16) is adjusted according to the pressure in the water collecting chamber (7).

[0054] The working principle and working process of the present invention are as follows:

[0055] Adsorption mode:

[0056] When the ambient temperature measured by the temperature sensor (11) is lower than 18°C, the second valve stem (1402) pushes the second piston (1302) to move toward the wall of the water collecting chamber (7), and the refrigerant in the refrigerant chamber (8) enters the conversion chamber (2) along the second pipe (1202) under the push of the second piston (1302), and pushes the movable partition (10) to move toward the first pipe (1201), until the movable partition (10) is completely in contact with the wall of the first pipe (1201), the second valve stem (1402) and the second piston (1302) stop moving, and the conversion chamber (2) is filled with refrigerant;

[0057] When the movable partition (10) moves toward the first pipe (1201), the heat medium in the conversion chamber (2) flows into the heat medium chamber (6) along the first pipe (1201), and pushes the first piston (1301) and the first valve stem (1401) to move in a direction away from the wall of the water collecting chamber (7), until the movable partition (10) is completely in contact with the wall surface of the first pipe (1201), at which time the first piston (1301) and the first valve stem (1401) stop moving, and are in adsorption mode;

[0058] When in the adsorption mode, the radiation cooling film (1) obtains cold by exchanging heat with the outer space, and the cold energy is transferred to the MOF adsorption material (5) by heat conduction through the refrigerant in the conversion chamber (2), the solar reflective film (3), and the heat conduction plate (4). The temperature of the MOF adsorption material (5) is reduced and the water absorption efficiency is enhanced. At the same time, the refrigerant can pass most of the solar thermal radiation, and the solar reflective film (3) can reflect most of the solar thermal radiation, so the cooling efficiency of the radiation cooling film (1) is enhanced.

[0059] Desorption mode:

[0060] When the ambient temperature measured by the temperature sensor (11) is higher than 30° C., the first valve stem (1401) pushes the first piston (1301) to move toward the wall of the water collecting chamber (7), and the heat medium in the heat medium chamber (6) enters the conversion chamber (2) along the first pipe (1201) under the push of the first piston (1301), and pushes the movable partition (10) to move toward the second pipe (1202), until the movable partition (10) is completely in contact with the wall of the second pipe (1202), the first valve stem (1401) and the first piston (1301) stop moving, and the conversion chamber (2) is filled with heat medium;

[0061] When the movable partition (10) moves toward the second pipe (1202), the refrigerant in the conversion chamber (2) flows into the refrigerant chamber (8) along the second pipe (1202), and pushes the second piston (1302) and the second valve stem (1402) to move away from the wall of the water collecting chamber (7), until the movable partition (10) is completely in contact with the wall of the second pipe (1202), and the second piston (1302) and the second valve stem (1402) stop moving, and are now in the desorption mode;

[0062] When in the desorption mode, sunlight passes through the radiation cooling film (1) to exchange heat with the heat medium in the conversion chamber (2) to obtain heat, and then the heat is transferred to the MOF adsorption material (5) by heat conduction through the solar reflective film (3) and the heat conduction plate (4). The temperature of the MOF adsorption material (5) increases, and the desorption efficiency is enhanced. At the same time, the heat medium with high absorption rate in the conversion chamber (2) can absorb most of the solar thermal radiation, so that the desorption efficiency is enhanced.

[0063] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is 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 in the protection scope of the present invention.

Claims

1. A new water collection method based on MOF materials, characterized in that: The invention comprises a novel water collection device based on MOF material, wherein the water collection device comprises a radiation cooling film (1), a conversion chamber (2), a solar reflective film (3), a heat conducting plate (4), a MOF adsorption material (5), a heat medium chamber (6), a water collection chamber (7), a cold medium chamber (8), a water tank (9), a movable partition (10), a temperature sensor (11), a first piston (1301), a second piston (1302), a first valve stem (1401), a second valve stem (1402), a first valve (1501), a second valve (1502), a pressure regulating valve (16), and an exhaust valve (17); The bottom of the radiation cooling film (1) is tightly connected to the top of the conversion chamber (2), the bottom of the conversion chamber (2) is tightly connected to the top of the solar reflective film (3), the bottom of the solar reflective film (3) is tightly connected to the top of the heat conducting plate (4), and the bottom of the heat conducting plate (4) is tightly connected to the top of the MOF adsorption material (5); The movable partition (10) is located inside the conversion chamber (2) and divides the conversion chamber (2) into two non-interconnected parts. The movable partition (10) can move along the first pipe (1201) and the second pipe (1202) in the conversion chamber (2) under the impetus of the refrigerant and the heat medium. The heat medium chamber (6), the water collecting chamber (7), and the cold medium chamber (8) are tightly connected to form a whole; The first piston (1301) and the first valve stem (1401) are tightly connected to form a whole, and the first piston (1301) is located inside the heat medium chamber (6); The second piston (1302) and the second valve stem (1402) are tightly connected to form a whole, and the second piston (1302) is located inside the refrigerant cavity (8); The heat medium chamber (6) is connected to the conversion chamber (2) via a first pipe (1201); The refrigerant chamber (8) is connected to the conversion chamber (2) via a second pipe (1202); The MOF adsorption material (5) is connected to the water collection chamber (7) via a third pipe (1203); The heat medium chamber (6) is connected to the output end of the first valve (1501) via a fifth pipe (1205), and the fourth pipe (1204) is connected to the input end of the first valve (1501); The refrigerant chamber (8) is connected to the output end of the second valve (1502) via a seventh pipe (1207), and the sixth pipe (1206) is connected to the input end of the second valve (1502); The water collecting chamber (7) is connected to the input end of the pressure regulating valve (16) via an eighth pipeline (1208); The water tank (9) is connected to the output end of the pressure regulating valve (16) via a ninth pipeline (1209); The exhaust valve (17) is installed at the upper part of the water collecting chamber (7) and is used to exhaust the air inside the water collecting chamber (7); The first valve stem (1401) and the second valve stem (1402) respectively control the first piston (1301) and the second piston (1302) to perform reciprocating motion in the heat medium chamber (6) and the cold medium chamber (8) via the temperature sensor (11); The fourth pipe (1204) is used to fill the heat medium chamber (6) with heat medium; The sixth pipe (1206) is used to fill the refrigerant cavity (8) with refrigerant; The sensor of the pressure regulating valve (16) is installed in the water collecting chamber (7), and the opening of the pressure regulating valve (16) is adjusted according to the pressure in the water collecting chamber (7); The novel water collection method based on MOF materials includes: adsorption mode and desorption mode; Adsorption mode: When the ambient temperature measured by the temperature sensor (11) is lower than 18°C, the second valve stem (1402) pushes the second piston (1302) to move toward the wall of the water collecting chamber (7), and the refrigerant in the refrigerant chamber (8) enters the conversion chamber (2) along the second pipe (1202) under the push of the second piston (1302), and pushes the movable partition (10) to move toward the first pipe (1201), until the movable partition (10) is completely in contact with the wall of the first pipe (1201), the second valve stem (1402) and the second piston (1302) stop moving, and the conversion chamber (2) is filled with refrigerant; When the movable baffle (10) moves toward the first pipe (1201), the heat medium in the conversion chamber (2) flows into the heat medium chamber (6) along the first pipe (1201), and pushes the first piston (1301) and the first valve stem (1401) to move in a direction away from the wall of the water collecting chamber (7), until the movable baffle (10) is completely in contact with the wall surface of the first pipe (1201), at which time the first piston (1301) and the first valve stem (1401) stop moving, and are in adsorption mode; When in the adsorption mode, after the radiation cooling film (1) obtains cold energy by exchanging heat with the outer space, the cold energy is transferred to the MOF adsorption material (5) by heat conduction through the refrigerant in the conversion chamber (2), the solar reflective film (3), and the heat conduction plate (4). The temperature of the MOF adsorption material (5) is reduced and the water absorption efficiency is enhanced. At the same time, the refrigerant can transmit most of the solar thermal radiation, and the transmitted solar thermal radiation is reflected back into the atmosphere through the solar reflective film (3), thereby improving the cooling efficiency of the radiation cooling film (1); Desorption mode: When the ambient temperature measured by the temperature sensor (11) is higher than 30°C, the first valve stem (1401) pushes the first piston (1301) to move toward the wall of the water collecting chamber (7), and the heat medium in the heat medium chamber (6) enters the conversion chamber (2) along the first pipe (1201) under the push of the first piston (1301), and pushes the movable partition (10) to move toward the second pipe (1202), until the movable partition (10) is completely in contact with the wall of the second pipe (1202), the first valve stem (1401) and the first piston (1301) stop moving, and the conversion chamber (2) is filled with heat medium; When the movable partition (10) moves toward the second pipe (1202), the refrigerant in the conversion chamber (2) flows into the refrigerant chamber (8) along the second pipe (1202), and pushes the second piston (1302) and the second valve stem (1402) to move away from the wall of the water collecting chamber (7), until the movable partition (10) is completely in contact with the wall of the second pipe (1202), at which point the second piston (1302) and the second valve stem (1402) stop moving, and are now in a desorption mode; When in the desorption mode, sunlight passes through the radiation cooling film (1) to exchange heat with the heat medium in the conversion chamber (2) to obtain heat, and then the heat is transferred to the MOF adsorption material (5) by heat conduction through the solar reflective film (3) and the heat conduction plate (4). The temperature of the MOF adsorption material (5) increases, and the desorption efficiency is enhanced. At the same time, the heat medium in the conversion chamber (2) can absorb most of the solar thermal radiation, and the temperature increases, so that the desorption efficiency is enhanced.

2. A novel water collection method based on MOF materials according to claim 1, characterized in that: The radiation cooling film (1) has an emissivity greater than 0.9 in the 8-13 μm band and a solar transmittance greater than 0.9 in the 0.25-2.5 μm band; The radiation cooling film (1) is one of a polymer radiation cooling film, an inorganic coating film, and a radiation cooling film based on nanoparticles.

3. A novel water collection method based on MOF materials according to claim 1, characterized in that: The reflectivity of the solar reflective film (3) in the 0.25-2.5 μm band is greater than 0.9; The solar reflective film (3) is one of white paint, mirror silver film, and polished aluminum oxide film.

4. A novel water collection method based on MOF materials according to claim 1, characterized in that: The thermal conductivity of the heat conducting plate (4) is not less than 50 W / m·K; The heat conducting plate (4) is made of one of silver, copper and aluminum.

5. A novel water collection method based on MOF materials according to claim 1, characterized in that: The heat medium has a solar absorptivity greater than 0.8 in the 0.25-2.5 μm band and a thermal conductivity not less than 0.5 W / m·K; The heat medium is one of a mixed solution of multi-walled carbon nanotubes and ethylene glycol, and a mixed solution of carbon fiber graphene and ethylene glycol.

6. A novel water collection method based on MOF materials according to claim 1, characterized in that: The refrigerant has a solar transmittance greater than 0.8 in the 0.25-2.5 μm band and a thermal conductivity not less than 0.5 W / m·K; The refrigerant is one of deionized water, pure water, and liquid containing metallic potassium and sodium.

7. A novel water collection method based on MOF materials according to claim 1, characterized in that: The specific surface area of ​​the MOF material is not less than 3800m 2 / g -1 , the adsorption capacity is not less than 35mg / g; The MOF material is one of MOF-74-Mg, MOF-801 and MOF-803.

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