CN111321776A - An efficient and anti-frost air convection controllable dew acquisition device - Google Patents

Abstract

The invention discloses a high-efficiency and anti-frost air convection controllable dew acquisition device, comprising a vacuum box, a pipeline arranged in the vacuum box, a radiation refrigeration layer arranged above the pipeline in direct contact with it, and a vacuum box arranged in the vacuum box. Infrared transparent cover capped above the body. The vacuum box can be evacuated internally to isolate the heat exchange inside and outside the device and serve as a protective shell for the entire device; the pipe acts as a channel for the flow of air and generated dew; It is made of material to ensure that the air temperature in the pipeline is lower than the dew point temperature to generate dew; the invention can control the air flow rate in the pipeline to adjust the air convection on the radiation cooling surface to ensure that the device can ensure the highest water production in different environments, and at the same time Ensure that the temperature of the radiant cooling layer is above the frost point to prevent frost formation.

Description

An efficient and anti-frost air convection controllable dew acquisition device

technical field

The invention belongs to the technical field of new energy, and in particular relates to an efficient and anti-frost air convection controllable dew acquisition device.

Background technique

The sustainable acquisition of freshwater resources has been listed as one of the biggest engineering problems of the 21st century, and the importance of freshwater acquisition technology cannot be overstated. However, most of the freshwater acquisition technologies in the world currently use electricity or fuel to desalinate seawater. However, this process not only consumes huge energy, but also produces polluting gases that are harmful to the environment. In addition, there are some seawater desalination methods such as membrane filtration of seawater to separate salts, which have low desalination efficiency and high maintenance costs. On the other hand, in non-coastal areas, there are no abundant seawater resources, and it is not suitable to apply the above technologies to obtain fresh water.

Dew is produced because the temperature of the air is lower than the dew point temperature, and the water vapor in the air is saturated and liquefied into liquid water. The production of dew in nature is essentially due to the effect of radiative cooling, for example, the temperature of leaves at night is lower than the ambient temperature, or even lower than the dew point temperature, which produces dew on the surface. Radiation refrigeration technology uses the outer space of -270°C as a cold source, and dissipates the heat of objects to outer space through thermal radiation heat transfer, so as to achieve the effect of spontaneous cooling of objects on the surface of the earth without consuming energy.

Because the use of radiation refrigeration technology to obtain dew does not consume energy, and does not need to rely on seawater resources, it has received extensive attention from all walks of life. However, the existing methods for obtaining dew based on radiation refrigeration technology have low water yield and are greatly affected by the environment (ambient temperature, humidity, etc.).

Therefore, the current freshwater dew acquisition technology has the following five problems;

1. The technology of consuming energy to produce fresh water has problems such as high cost, complex structure and pollution.

2. The existing methods of obtaining fresh water based on radiation refrigeration technology cannot artificially adjust the air convection on the surface of the radiation refrigeration material, so that the best water production effect cannot be maintained in different environments.

3. The existing method of obtaining fresh water based on radiation refrigeration technology is to condense the dew on the upper surface of the radiation refrigeration material, and then collect it. However, the dew remaining on the upper surface of the material will affect the radiation characteristics of the material, thereby affecting the effect of dew production.

4. The existing method of obtaining fresh water based on radiation refrigeration technology may cause frost formation in some environments, which cannot be avoided.

5. The existing method of obtaining fresh water based on radiation refrigeration technology requires the device to be inclined at a certain angle to facilitate the collection of dew, but the inclination of the radiation refrigeration plate will affect the cooling effect, thereby affecting the effect of dew acquisition.

6. The heat exchange (parasitic heat) between the radiation cooling material and the surrounding environment is too large in the existing method for obtaining fresh water based on the radiation cooling technology.

SUMMARY OF THE INVENTION

The present invention provides an efficient and anti-frosting air convection controllable dew water acquisition device, which can effectively solve the above problems. The device directly condenses dew water from the atmosphere, and this process does not consume energy, and does not discharge greenhouse gases and harmful substances. ; It can also adjust the air flow rate in the duct to control the air convection on the surface of the radiating material.

Technical solutions

The invention provides an efficient and anti-frost air convection controllable dew acquisition device, comprising a vacuum box, a pipeline arranged inside the vacuum box, a radiation refrigeration layer arranged above the pipeline in direct contact with it, and a vacuum box arranged in the vacuum box. Infrared transparent cover capped above the body.

Preferably, the vacuum box body is capped by an infrared transparent cover plate, and the vacuum box body is made of one of gold, silver, aluminum, iron, copper, molybdenum, tin, titanium or chromium, and if required When vacuuming, the thickness of the vacuum box should meet the requirements of vacuuming inside.

Preferably, the pipeline adopts a hollow design, the two ends of the pipeline are respectively connected to the air pump and the dew collecting container, the top of the pipeline is close to the radiation refrigeration layer, and the pipeline material is made of gold, silver, aluminum, iron, copper, molybdenum, tin, titanium or chromium. one of them.

Preferably, the infrared transparent cover plate is used as the top of the box, and the infrared transparent cover plate is made of one of polyethylene, polymethylpentene, silicon, germanium, zinc selenide, zinc sulfide and aluminum oxide.

Preferably, the upper surface of the radiation cooling layer has high emissivity in the 8-13 micron waveband, and low emissivity outside the 8-13 micron waveband; the lower surface has low emissivity and excellent thermal conductivity in the entire waveband.

Beneficial effects:

1. The present invention uses radiation refrigeration technology to reduce the air temperature to below the dew point temperature, so as to obtain dew (fresh water) from the air.

2. The present invention can adjust the air flow rate in the device so as to control the air convection on the surface of the radiation material, so that the device can be at the highest dew amount in different environments.

3. By controlling the air convection on the surface of the radiation material, the temperature of the radiation cooling layer can be adjusted to be always higher than the frost point, thereby preventing frost formation.

4. Unlike the previous use of radiation refrigeration technology to make water on the upper surface of the radiation refrigeration material, the dew of the device condenses in the pipeline below the radiation refrigeration material, thereby avoiding the dew on the upper surface to reduce the cooling effect of the radiation refrigeration material. water production.

5. Different from the previous use of radiant refrigeration technology to produce water on the upper surface of the radiant refrigeration material, which requires an inclined radiant refrigeration layer to collect dew, resulting in a reduced water production effect, the device does not need to incline the radiant refrigeration layer.

Description of drawings

Fig. 1 is the structural representation of the device of the present invention;

Fig. 2 is the top view of the device of the present invention;

Fig. 3 is the emissivity diagram of ideal radiation layer and black body radiation layer;

Fig. 4 is the emissivity map of the selective radiation layer;

Figure 5 shows the relationship between the water production and the air convection heat transfer coefficient of the ideal radiation layer, the black body radiation layer and the selective radiation layer in different environments;

Figure 6 is the relationship between the water production of the ideal radiation layer, the black body radiation layer and the selective radiation layer with the tilt angle of the radiation layer;

Among them, 1-infrared transparent cover plate; 2-radiation refrigeration layer; 3-pipeline; 4-vacuum box.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clearly understood, the embodiments of the present application will be described in further detail below with reference to the embodiments and the accompanying drawings. Here, the exemplary embodiments and descriptions of the embodiments of the present application are used to explain the embodiments of the present application, but are not intended to limit the embodiments of the present application.

The specific implementations of the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 and FIG. 2 , an efficient and anti-frost air convection controllable dew acquisition device of this embodiment includes a vacuum box 4, a pipeline 3 arranged inside the vacuum box, and a device arranged above the pipeline. The radiation refrigeration layer 2 in direct contact with it and the infrared transparent cover plate 1 arranged above the vacuum box and capped.

The vacuum box body 4 is capped by an infrared transparent cover plate 1, and the material of the vacuum box body 4 is one of gold, silver, aluminum, iron, copper, molybdenum, tin, titanium or chromium, and when vacuuming is required The thickness of the vacuum box 4 meets the requirement of vacuuming the inside thereof.

The pipeline 3 adopts a hollow design, and the two ends of the pipeline are respectively connected to the air pump and the dew collecting device. The top of the pipeline is close to the radiation refrigeration layer 2, and the pipeline material is made of gold, silver, aluminum, iron, copper, molybdenum, tin, titanium or chromium. A sort of

The infrared transparent cover 1 is used as the top of the box, and the cover material is one of polyethylene, polymethylpentene, silicon, germanium, zinc selenide, zinc sulfide and aluminum oxide; when the interior of the device needs to be evacuated When the thickness of the cover plate should meet the requirements of vacuuming.

The upper surface of the radiation refrigeration layer 2 has high emissivity in the 8-13 micron waveband, and low emissivity outside the 8-13 micron waveband; the lower surface has low emissivity and excellent thermal conductivity in the entire waveband.

When this embodiment works, the inside of the device is evacuated to 10-6 Torr to isolate the heat exchange inside and outside the device. The air is blown into the pipeline by the air pump. Due to the cooling effect of the radiation cooling layer 2, when the air convection on the surface of the radiation cooling layer 2 meets the requirements, the temperature of the pipeline 3 in close contact with the radiation cooling layer 2 and the air in it will be lower. At the dew point temperature, the water vapor in the air will liquefy and be blown out with the air. The difference is that the previous technologies all produce dew above the radiative cooling layer. However, due to the high absorption rate of dew in the infrared band, it will affect the radiative cooling effect of the radiative cooling layer and thus affect the dew production effect. The problem is solved by changing the location where the dew is made.

Referring to Figure 3, the ideal radiation layer has an emissivity of 1 in the 8-13 micron band, and 0 outside this band. Since the atmospheric transmittance has a very high transmittance in the 8-13 micron band, so The ideal radiant layer has the highest dew gain. The emissivity of the black body radiation layer is 1 in the entire waveband, and its water-making effect represents the dew acquisition of most vegetation in nature.

The above-mentioned ideal radiation layer and black body radiation layer represent the best water-making effect and the water-making effect of general natural vegetation, respectively. However, after photonics design, a radiation layer that is superior to the water-making effect of natural vegetation can be synthesized, as shown in Figure 4. , is the emissivity of a synthetic selective radiation layer.

The air convection on the surface of the radiation cooling layer affects the dew acquisition amount. Referring to Figure 5, the air convection intensity can be characterized by the convective heat transfer coefficient. decrease, that is, where the best convective heat transfer coefficient corresponds to the highest dew gain. In different environments, the optimal convective heat transfer coefficient is different, and the device can keep the device at the highest dew acquisition amount by controlling the air convection.

On the other hand, the dotted line in Fig. 5 represents the frosting situation, that is, the temperature of the radiative cooling layer is lower than 0°C, and the device can prevent frosting by reducing air convection, thereby avoiding the reduction of dew acquisition.

Referring to FIG. 6 , with the inclination of the radiation cooling layer, the amount of dew obtained continuously decreases, that is, the inclination of the radiation cooling layer is not conducive to the water production effect. Different from the previous technology for producing dew, which collects dew in an inclined manner, the device collects dew by means of ventilation through pipes, so as to solve the problem that the inclined method is not conducive to water production.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific examples of the embodiments of the present application and are not intended to limit the present application The protection scope of the application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application, shall be included in the protection scope of the application.

On the other hand, the dotted line in Fig. 5 represents the frosting situation, that is, the temperature of the radiative cooling layer is lower than 0°C, and the device can prevent frosting by reducing air convection, thereby avoiding the reduction of dew acquisition.

Referring to FIG. 6 , with the inclination of the radiation cooling layer, the amount of dew obtained continuously decreases, that is, the inclination of the radiation cooling layer is not conducive to the water production effect. Different from the previous technology for producing dew, which collects dew in an inclined manner, the device collects dew by means of ventilation through pipes, so as to solve the problem that the inclined method is not conducive to water production.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific examples of the embodiments of the present application and are not intended to limit the present application The protection scope of the application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application, shall be included in the protection scope of the application.

Claims (5)

1. An efficient and anti-frost air convection controllable dew acquisition device, characterized in that it comprises a vacuum box (4), a pipeline (3) arranged inside the vacuum box (4), a pipeline (3) arranged in the pipeline (4). 3) The radiation refrigeration layer (2) directly in contact with the upper part and the infrared transparent cover plate (1) arranged above the vacuum box (4) and capped. 2. An efficient and anti-frost air convection controllable dew acquisition device according to claim 1, characterized in that: the vacuum box (1) is capped by an infrared transparent cover plate (1), the The material of the vacuum box body (1) is one of gold, silver, aluminum, iron, copper, molybdenum, tin, titanium or chromium, and the thickness of the vacuum box body (1) meets the requirement of vacuuming inside. 3. The highly efficient and frost-proof air convection controllable dew acquisition device according to claim 1, wherein the pipe (3) adopts a hollow design, and the two ends of the pipe (3) are respectively Connect the air pump and the dew collecting container, the top of the pipe (3) is close to the radiant cooling layer (2), and the material of the pipe (3) is gold, silver, aluminum, iron, copper, molybdenum, tin, titanium or chromium. one of them. 4. An efficient and anti-frost air convection controllable dew acquisition device according to claim 1, characterized in that: the infrared transparent cover plate (1) is used as the top of the vacuum box (1), so The material of the infrared transparent cover (1) is one of polyethylene, polymethylpentene, silicon, germanium, zinc selenide, zinc sulfide and aluminum oxide. The high-efficiency and anti-frost air convection controllable dew acquisition device according to claim 1, characterized in that: the upper surface of the radiation cooling layer (2) has high radiation in the 8-13 micron waveband It has low emissivity outside the 8-13 micron band; the lower surface has low emissivity and excellent thermal conductivity in the entire band.

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