CN115962586B - A direct solar energy adsorption brine concentration refrigeration system and its use method - Google Patents

Abstract

The invention provides a direct solar energy adsorption brine concentration refrigeration system and a method of use, belonging to the technical field of resource utilization. The invention includes: an evaporator; a condenser; a first adsorber, one end of which is connected to the evaporator, and the other end to the condenser; a second adsorber, one end of which is connected to the evaporator, and the other end is connected to the condenser. Through; both the first adsorber and the second adsorber are integrated with solar collectors, and adsorbents with direct photothermal properties are arranged inside them; the evaporator, the condenser, the first adsorber and the second adsorber are connected Valves are provided on the pipelines, and valves are also provided on the condenser. The present invention integrates a solar collector on the adsorber and sets an adsorbent with direct photothermal performance in the adsorber to continuously adsorb and desorb the evaporated brine, and directly uses solar energy to concentrate the brine, thereby realizing the concentration of the brine. While utilizing the ions present in the system, it can also achieve refrigeration and direct drinking water.

Description

A direct solar energy adsorption brine concentration refrigeration system and its use method

Technical field

The present invention relates to the technical field of resource utilization, and in particular to a direct solar energy adsorption brine concentration refrigeration system and its use method and co-production of direct drinking water.

Background technique

There are quite abundant seawater and salt lake brine resources in the world, and the seawater area accounts for about 71% of the total surface area. Salt lake brine is a water resource with a high concentration of mineral salts. Lithium-rich salt lakes are widely distributed around the world, mainly in the Andean Plateau of South America, the Tibetan Plateau in China, and the northwest region of North America. Seawater (brine) is rich in sodium, potassium, magnesium, lithium, chlorine, bromine and other resources. The existing seawater (brine) resource utilization methods mainly include seawater (brine) desalination, seawater (brine) concentration salt production, seawater (brine) extracts lithium, seawater (brine) extracts magnesium, etc.

At this stage, the seawater desalination methods that have been installed in the world are mainly divided into two categories: one is the heat treatment process, which mainly includes multi-stage flash evaporation (MSF) and multi-effect evaporation (MED); the other is the membrane treatment process, such as electrodialysis ( ED) and reverse osmosis (SWRO). Practical application shows that the existing technology still has some obvious shortcomings, such as the consumption of high-grade energy and the emission of pollutants at the expense of consuming electricity or a large amount of fuel, corrosion and blockage of membrane/mass exchangers, corrosion or blockage of membranes due to pipeline corrosion or High maintenance costs caused by salt or scale accumulation on the outer surface of the heat exchanger, and with the increasing shortage of energy, will lead to high costs of fresh water prepared by these two methods.

Existing brine concentration salt production technologies mainly include sun salt method, vacuum salt production method, electrodialysis method, etc. The solar salt method has a low utilization rate of solar energy, low production efficiency, and is easily affected by weather. The salt field occupies a large area and is harmful to the soil to a certain extent. The utility model with the publication number CN212315564U discloses a device for accelerating seawater salt drying. It uses an array of light-absorbing material vertical plates to increase the absorption rate of seawater for solar energy, while fully contacting the natural wind and accelerating the evaporation of water; the publication number is CN205709901U. The utility model discloses an integrated seawater salt and desalination system that is not affected by the weather and can produce salt all year round. A condensation system is added to collect evaporated water to obtain fresh water, but the system is still affected by sunlight. , unable to work at night. Modern vacuum salt production technology can quickly separate water through multi-stage flash evaporation technology and has high salt production efficiency. However, this technology has a complicated process and high energy consumption. Electrodialysis uses an ion exchange membrane to separate and concentrate brine under the driving force of potential difference. It has high salt production efficiency and high energy consumption. The utility model with the publication number CN213679909U discloses an adsorption-type seawater desalination system. This system promotes the evaporation of brine through adsorbent adsorption to achieve refrigeration. The water vapor desorbed by the adsorbent condenses and releases heat in the condenser and obtains fresh water, which has the characteristics of seawater. Desalination and cold/heat storage functions. The utility model with the publication number CN202430029U discloses a solar adsorption seawater desalination device with heat and mass return circulation. The hot water obtained from the solar collector drives the adsorbent desorption process. However, the existing adsorption desalination technology requires indirect use of solar energy through solar collectors and cannot directly and efficiently utilize solar energy. At the same time, this technology ignores the resource utilization of concentrated brine.

Contents of the invention

In view of this, in order to solve the technical problem that the existing adsorption seawater desalination technology requires indirect use of solar energy through solar collectors and cannot directly and efficiently utilize solar energy, on the one hand, the present invention provides a direct solar energy adsorption brine concentration refrigeration system. By integrating a solar collector on the adsorber and setting up an adsorbent with direct photothermal properties in the adsorber, it continuously adsorbs and desorbs the evaporated brine, directly uses solar energy to concentrate the brine, and realizes the concentration of concentrated brine. The existing ions can be utilized as resources while also achieving refrigeration and direct drinking water.

In order to solve the above technical problems, the present invention provides the following technical solutions:

A direct solar energy adsorption brine concentration refrigeration system, including:

Evaporator;

condenser;

A first adsorber has one end connected to the evaporator and the other end connected to the condenser;

a second adsorber, one end of which is connected to the evaporator, and the other end of which is connected to the condenser;

Both the first adsorber and the second adsorber are integrated with solar collectors, and adsorbents with direct photothermal properties are provided inside them;

Valves are provided on the pipelines connecting the evaporator, the condenser, the first adsorber and the second adsorber, and the condenser is also provided with valves.

Preferably, it also includes auxiliary devices;

The auxiliary device is used to cool down or heat the first adsorber and the second adsorber.

Preferably, the auxiliary device has a cold/hot water inlet and a cold/hot water outlet, which are respectively connected to the heat exchange tubes in the first adsorber and the second adsorber through pipelines.

Preferably, the adsorbent is a metal foam solidified composite adsorbent coated with a photothermal material on the surface, which is composed of a water-absorbing adsorbent, a foam metal and a photothermal material coating material.

Preferably, the mass percentage of the photothermal material coating material is 0.5-5%, the mass percentage of the foam metal is 31-62%, and the mass percentage of the water-absorbing adsorbent is 37-64%.

Preferably, the adsorbent is a foam metal cured MIL-101 composite adsorbent with a photothermal material coating on the surface, wherein the mass percentage of MIL-101 is 37%, the mass percentage of foam metal is 62%, and the mass percentage of the photothermal material The mass percentage is 1%;

Among them, the photothermal material is preferably graphene oxide, and the foam metal is copper foam.

Preferably, the adsorbent is a foam metal-cured silica gel composite adsorbent with a photothermal material coating on the surface, wherein the mass percentage of silica gel is 44%-64%, the mass percentage of photothermal material is 1%-5%, and the foam The mass percentage of metal is 31%-47%;

Preferably, the mass percentage of silica gel is 55%, the foam metal is copper foam, the mass percentage of copper foam is 44%, the photothermal material is carbon black, and the mass percentage of carbon black is 1%.

Preferably, the adsorbent is a foam metal SAPO-34 composite adsorbent or a CuSO ₄ composite adsorbent with a photothermal material coating on the surface. When the adsorbent is a foam metal cured SAPO-34 composite with a photothermal material coating on the surface, When used as an adsorbent, the mass percentage of SAPO-34 is 58%-58.5%, the mass percentage of foam metal is 41%, and the mass percentage of photothermal materials is 0.5-1%;

When the adsorbent is a foam metal solidified CuSO ₄ composite adsorbent with a photothermal material coating on the surface, the mass percentage of CuSO ₄ is 44%, the mass percentage of foam metal is 55%, and the mass percentage of photothermal material is 1% .

On the other hand, the present invention also provides a method for using the above-mentioned direct solar energy adsorption brine concentration refrigeration system, which includes the following steps:

1) Add brine into the evaporator and open the valve between the evaporator and the first adsorber for adsorption;

2) After the adsorption is completed, close the valve between the evaporator and the first adsorber. When the temperature of the first adsorber reaches the desorption temperature, open the valve between the first adsorber and the condenser and the valve on the condenser. With this At the same time, open the valve between the evaporator and the second adsorber to allow the second adsorber to adsorb;

3) When the second adsorber reaches adsorption completion, close the valve between the evaporator, the first adsorber and the second adsorber, close the valve on the condenser, and open the first adsorber, second adsorber and condenser. The valves between the first adsorber and the second adsorber are connected for mass return, and after the mass return is completed, the valves between the first adsorber, the second adsorber and the condenser are closed;

4) When the first adsorber and the second adsorber reach the adsorption and desorption temperatures respectively, open the valve between the evaporator and the first adsorber, open the valve between the second adsorber and the condenser, and open the valve on the condenser. valve.

Preferably, when the light is insufficient, the auxiliary device introduces heat medium into the second adsorber as an auxiliary energy source to heat the analytical water;

The auxiliary device introduces the cold medium into the first adsorber to cool the first adsorber.

Compared with the prior art, the present invention has the following beneficial effects:

The direct solar energy adsorption brine concentration refrigeration system provided by the present invention integrates a solar collector on the adsorber and sets an adsorbent with direct photothermal properties in the adsorber to continuously adsorb and desorb the evaporated brine and directly use it. Solar energy concentrates the brine, realizing resource utilization of the ions present in the concentrated brine, while also achieving refrigeration and direct drinking water.

The direct solar energy adsorption brine concentration and refrigeration system and its use method provided by the present invention are adsorption-type brine concentration and refrigeration combined with fresh water production systems that can be directly heated and desorbed by solar energy. They use solar energy to concentrate, cool and produce brine, killing four birds with one stone; and the system It has a simple structure, is easy to operate, is less affected by weather, and can be operated continuously day and night.

Description of drawings

Figure 1 is a schematic structural diagram of the direct solar energy adsorption brine concentration refrigeration system of the present invention;

In the figure, 1. First adsorber, 2. Second adsorber, 3. Evaporator, 4. Evaporator inlet pipe, 5. Evaporator outlet pipe, 6. Heat exchange coil, 7. Condenser, 8. Condensate water inlet, 9. Condensate water outlet, 10. Direct drinking water outlet pipeline, 11. Cold/hot water inlet, 12. Cold/hot water outlet, 13. First valve, 14. Second valve, 15. The third valve, 16. The fourth valve, 17. Condenser valve, 18. Direct drinking water storage tank.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on The embodiments of the present invention and all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top/bottom", etc. are based on the orientation shown in the drawings. or positional relationships are only for the convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installed", "provided with", "set/connected", "connected", etc., should be understood in a broad sense, such as " "Connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, or it can be inside two components of connectivity. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

As shown in Figure 1, the present invention provides a direct solar energy adsorption brine concentration refrigeration system, including:

Evaporator 3;

Condenser 7;

The first adsorber 1 has one end connected with the evaporator 3 and the other end connected with the condenser 7;

The second adsorber 2 has one end connected with the evaporator 3 and the other end connected with the condenser 7;

The first adsorber 1 and the second adsorber 2 are both integrated with solar collectors, and adsorbents with direct photothermal properties are installed inside them;

The evaporator 3, the condenser 7, the first adsorber 1 and the second adsorber 2 are all provided with valves on the pipelines connected to each other, and the condenser 7 is also provided with a valve.

In the present invention, auxiliary devices are also included;

The auxiliary device is used to cool down or heat the first adsorber 1 and the second adsorber 2 .

In the present invention, the auxiliary device has a cold/hot water inlet 11 and a cold/hot water outlet 12, which are connected to the heat exchange tubes in the first adsorber 1 and the second adsorber 2 through pipelines respectively. Connected.

In the above-mentioned direct solar adsorption brine concentration refrigeration system provided by the present invention, the evaporator 3 preferably has an evaporator inlet pipeline 4 and an evaporator outlet pipeline 5. The brine is introduced into the evaporator 3 through the evaporator inlet pipeline 4, and the concentrated The brine is discharged through the evaporator outlet pipe 5;

A heat exchange coil 6 is preferably provided in the evaporator 3, and the heat exchange coil 6 can obtain low-temperature cooling water.

The condenser 7 can be air-cooled or water-cooled, and the condensation temperature can be 10-35°C. It has a condensed water inlet 8 and a condensed water outlet 9. The condensed water enters the condenser from the condensed water inlet 8 and flows out from the condensed water outlet 9. The water vapor desorbed from the first adsorber 1 and the second adsorber 2 enters the condenser 7 and is condensed to obtain purified fresh water, which flows into the direct drinking water storage tank 18 for storage through the direct drinking water outlet pipeline.

The valve between the evaporator 3 and the first adsorber 1 is the first valve 13, the valve between the evaporator 3 and the second adsorber 2 is the second valve 14, and the valve between the first adsorber 1 and the condenser 7 The valve is the third valve 15, the valve between the second adsorber 2 and the condenser 7 is the fourth valve 16, and the valve on the condenser 7 is the condenser valve 17.

In the present invention, the adsorbent is a metal foam solidified composite adsorbent coated with a photothermal material on the surface, which is composed of a water-absorbing adsorbent, a foam metal and a photothermal material coating material.

In the present invention, the mass percentage of the photothermal material coating material is 0.5-5%, the mass percentage of the foam metal is 31-62%, and the mass percentage of the water-absorbing adsorbent is 37-64%.

In the present invention, the adsorbent is a metal foam solidified MIL-101 composite adsorbent coated with a photothermal material coating on the surface. The mass percentage of MIL-101 is 37%, the mass percentage of foam metal is 62%, and the photothermal material coating is on the surface. The mass percentage of the material is 1%;

In the present invention, the photothermal material is preferably graphene oxide, and the metal foam is copper foam.

In the present invention, the adsorbent is a metal foam solidified silica gel composite adsorbent with a photothermal material coating on the surface, wherein the mass percentage of silica gel is 44%-64%, and the mass percentage of photothermal material is 1%-5% , the mass percentage of foam metal is 31%-47%;

In the present invention, the mass percentage of silica gel is 55%, the metal foam is copper foam, the mass percentage of copper foam is 44%, the photothermal material is carbon black, and the mass percentage of carbon black is 1%.

In the present invention, the adsorbent is a foam metal SAPO-34 composite adsorbent or a CuSO ₄ composite adsorbent with a photothermal material coating on the surface. When the adsorbent is a foam metal solidified SAPO-34 with a photothermal material coating on the surface, 34 composite adsorbent, the mass percentage of SAPO-34 is 58%-58.5%, the mass percentage of foam metal is 41%, and the mass percentage of photothermal material is 0.5-1%;

When the adsorbent is a foam metal solidified CuSO ₄ composite adsorbent with a photothermal material coating on the surface, the mass percentage of CuSO ₄ is 44%, the mass percentage of foam metal is 55%, and the mass percentage of photothermal material is 1% .

In the present invention, an adsorbent with direct photothermal properties is installed in the adsorber to adsorb the brine in the evaporator 3. The adsorbent absorbs water to concentrate the brine and drives the evaporation of the brine in the evaporator 3 to absorb heat and refrigeration; the adsorbent is saturated with water. Finally, solar energy directly illuminates the adsorber to achieve photothermal conversion. The temperature of the adsorbent causes the water vapor in the adsorbent to desorb. After condensation in the condenser 7, purified direct drinking water that meets the national standard can be obtained, which can achieve continuous brine concentration and solar adsorption refrigeration. Parallel production of direct drinking water.

In the present invention, an insulation layer can also be provided outside the first adsorber 1, the first adsorber 2, the evaporator 3 and various types of pipelines. The first adsorber 1 and the first adsorber 2 can be of flat plate type or circular tube type. , the tube wall is made of vacuum glass; the first adsorber 1 and the first adsorber 2 are equipped with heat exchange tubes, temperature and pressure sensors inside.

In the present invention, the brine can be salt lake brine, sea water, geothermal water, salty wastewater, etc., and there are no special requirements for this; the heat medium can be hot water, the cold medium can be cooling water, and the cooling water temperature used for cooling the adsorber is The temperature can be 20-35°C. The hot water can be heated by any one or two methods such as solar energy, geothermal energy, wind energy, etc. The hot water temperature can be 55-95°C. The evaporation temperature of the evaporator 3 can be 10-50°C.

In the present invention, the water-absorbing adsorbent is any one or two of silica gel, MIL-101, SAPO-34, and copper sulfate, the foam metal is any one or two of copper foam, aluminum foam, and nickel foam, and the photothermal material The coating material is any one or two of carbon black, graphene, graphene oxide, carbon nanotubes, perovskite, and nanometals;

On the other hand, the present invention also provides a method of using the above-mentioned direct solar energy adsorption brine concentration refrigeration system, specifically as follows:

1) Before the system is operated, the entire system and adsorber must be evacuated and all valves must be closed. Add the brine into the evaporator 3, open the first valve 13, the evaporator 3 is connected with the first adsorber 1, the brine in the evaporator 3 is continuously evaporated and concentrated, and at the same time the evaporation takes away the heat, and the heat exchange coil 6 can be cooled at low temperature water.

2) After adsorption for a certain period of time, close the first valve 13, and the first adsorber 1 is integrated with the solar collector. When there is insufficient light at night, rainy days, etc., the copper pipe at the bottom of the first adsorber 1 can be connected from the cold/hot water inlet 11 to Hot water (heat storage tank) is introduced as an auxiliary heat source.

3) When the temperature of the first adsorber 1 reaches the desorption temperature, open the third valve 15 and the condenser valve 17. The water vapor desorbed from the first adsorber 1 enters the condenser 7 and is condensed to obtain purified fresh water through direct drinking water. The outlet pipeline 10 flows into the direct drinking water storage tank 18 for storage. At the same time, the second valve 14 is opened, and the evaporator 3 is connected with the second adsorber 2. The brine in the evaporator 3 is continuously evaporated and concentrated and takes away heat.

4) When a certain adsorption/desorption time is reached, the first valve 13, the second valve 14 and the condenser valve 17 are closed, and the third valve 15 and the fourth valve 16 are opened, so that the first adsorber 1 and the second adsorber 2 After the mass return is completed, the third valve 15 and the fourth valve 16 are closed.

5) Pour cooling water from the cold/hot water inlet 11 into the copper pipe at the bottom of the first adsorber 1 to cool down the first adsorber 1, and then flow out from the cold/hot water outlet 12. The second adsorber 2 is integrated with the solar collector. When the light is insufficient, hot water can be introduced from the cold/hot water inlet 11 into the copper tube at the bottom of the second adsorber 2 as an auxiliary heat source.

6) Stop flowing cooling water to the first adsorber 1 after the first adsorber 1 and the second adsorber 2 reach the adsorption/desorption temperature respectively. Open the first valve 13, the evaporator 3 is connected with the first adsorber 1, the brine in the evaporator 4 is continuously evaporated, concentrated and takes away heat; at the same time, the fourth valve 16 is opened, and the water vapor desorbed from the second adsorber 2 enters Purified fresh water is condensed in the condenser 7 and flows into the direct drinking water storage tank 18 through the direct drinking water outlet pipeline 10 for storage.

Repeat steps 3-6 to achieve double-bed continuous solar adsorption brine concentration and co-production of fresh water.

When the brine reaches the required concentration, close the first valve 13 and the second valve 14, and discharge the concentrated brine from the evaporator outlet pipe 5. Re-add the degassed pre-treated fresh brine into the evaporator 4, perform steps 1-2 and then repeat steps 3-6 again to realize the double-bed continuous solar adsorption brine concentration and co-production of fresh water.

The technical solution of the present invention will be explained clearly and in detail below with reference to specific embodiments.

GO in the following examples is the abbreviation of graphene oxide, among which MIL-101 is preferably MIL-101 (Cr), SAPO-34 can be selected from commercially available conventional products, and GrO is reduced graphene oxide.

Example 1

The adsorbent is copper foam cured silica gel composite adsorbent coated with 1% GO photothermal material coating. The mass percentage of silica gel is 55%, the mass percentage of copper foam is 44%, and the solid-liquid ratio of silica gel and brine is 2.2. Cycle Time 5h. Before running the system, vacuum the entire system and adsorber and close all valves. Add the degassed pre-treated brine into the evaporator 3, control the evaporation temperature to 15°C, open the first valve 13, the evaporator 3 is connected to the first adsorber 1, and the brine in the evaporator 3 continues to evaporate and take away heat. Low-temperature cooling water can be obtained from the heat exchange coil 6, and at the same time, the brine in the evaporator 3 begins to be continuously concentrated. After the adsorption time reaches 2.5 hours, close the first valve 13 and expose the first adsorber 1 to the sun. When the temperature of the first adsorber 1 reaches 60°C, the third valve 15 and the condenser valve 17 are opened. The water vapor desorbed from the first adsorber 1 enters the condenser 7 and is condensed to obtain purified fresh water, which flows into the direct drinking water storage tank. 18 stored in. At the same time, the second valve 14 is opened, and the evaporator 3 is connected to the second adsorber 2. The brine in the evaporator 3 continues to evaporate and takes away heat, and the brine is also continuously concentrated. When the half-cycle time is reached (adsorption time 2.5h, total heating, desorption, and cooling time 2.5h), close the first valve 13, the second valve 14, and the condenser valve 17, leaving the third valve 15 and the fourth valve 16 open. state, connect the first adsorber 1 and the second adsorber 2, and perform a mass return operation for 1 minute. After the mass return is completed, close the third valve 15 and the fourth valve 16. Pour 25°C cooling water from the cold/hot water inlet 11 into the copper pipe at the bottom of the first adsorber 1 to cool down the first adsorber 1. The second adsorber 2 is exposed to the sun. When the first adsorber 1 reaches 30°C and the second adsorber 2 reaches 60°C, the flow of cooling water to the first adsorber 1 is stopped. Open the first valve 13, and the evaporator 3 is connected to the first adsorber 1. The brine in the evaporator 3 continues to evaporate and takes away heat, and the brine is also continuously concentrated. At the same time, the fourth valve 16 is opened, and the water vapor desorbed from the second adsorber 2 enters the condenser 7 and is condensed to obtain purified fresh water, which flows into the direct drinking water storage tank 18 for storage. When the predetermined half-cycle time is reached, the first valve 13, the second valve 14, and the condenser valve 17 are closed, leaving the third valve 15 and the fourth valve 16 open, so that the first adsorber 1 and the second adsorber 2 The mass return operation is performed continuously for 1 minute. After the mass return is completed, the third valve 15 and the fourth valve 16 are closed. After the process is completed, 113.6g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 278.3kJ/kg.

Example 2

The specific operation process is the same as in Example 1; when the adsorbent is a nickel foam cured silica gel composite adsorbent coated with a 3% GrO photothermal material coating, the mass percentage of silica gel is 50%, the mass percentage of nickel foam is 47%, and the silica gel The solid-liquid ratio to brine is 2.2, the evaporation temperature is 15°C, and after a circulation time of 5 hours, 95.6g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 234.2kJ/kg.

Example 3

The specific operation process is the same as in Example 1; when the adsorbent is a foam aluminum cured silica gel composite adsorbent coated with a carbon nanotube photothermal material coating, the mass percentage of the carbon nanotube photothermal material coating material is 5%, and the adsorption The solid-liquid ratio of the agent and brine is 4, the mass percentage of silica gel is 64%, the mass percentage of aluminum foam is 31%, the solid-liquid ratio of silica gel and brine is 2.2, the evaporation temperature is 15°C, and 104.4g can be obtained after 5 hours of circulation time. /kg _ads purifies fresh water, with a cooling capacity of 255.8kJ/kg.

Example 4

The specific operation process is the same as in Example 1; when the adsorbent is coated with a copper foam cured MIL-101 (Cr) composite adsorbent coated with a nano-metal photothermal material coating, the mass percentage of the nano-metal photothermal material coating material is 1%. The mass percentage of MIL-101 (Cr) is 37%, the mass percentage of copper foam is 62%, the solid-liquid ratio of MIL-101 (Cr) and brine is 1.3, the evaporation temperature is 15°C, and 322.8g can be obtained after a cycle time of 5 hours. /kg _ads purifies fresh water, with a cooling capacity of 790.9kJ/kg.

Example 5

The specific operation process is the same as in Example 1; when the adsorbent is a foamed copper-cured MIL-101 (Cr) composite adsorbent coated with a GO photothermal material coating, the mass percentage of the GO photothermal material coating material is 1%, MIL The mass percentage of -101(Cr) is 37%, the mass percentage of copper foam is 62%, the solid-liquid ratio of MIL-101MIL-101(Cr) and brine is 1.3, the evaporation temperature is 20°C, and 429.3 can be obtained after 5 hours of cycle time g/kg _ads purifies fresh water, with a cooling capacity of 1051.8kJ/kg.

Example 6

The specific operation process is the same as Example 1; when the copper foam coated with GO photothermal material coating solidifies the SAPO-34 composite adsorbent, the mass percentage of the GO photothermal material coating material is 0.5%, and the mass percentage of SAPO-34 is 58.5%, the mass percentage of copper foam is 41%, the solid-liquid ratio of SAPO-34 and brine is 2.0, the evaporation temperature is 15°C, and 53.3g/kg _ads purified fresh water can be obtained after 5 hours of cycle time, with a cooling capacity of 130.6kJ/kg. .

Example 7

The specific operation process is the same as in Example 1; when the adsorbent is a copper foam solidified SAPO-34 composite adsorbent coated with a carbon nanotube photothermal material coating, the mass percentage of the carbon nanotube photothermal material coating material is 1%. The mass percentage of SAPO-34 is 58%, the mass percentage of copper foam is 41%, the solid-liquid ratio of SAPO-34 and brine is 2.0, the evaporation temperature is 10°C, and 50.7g/kg _ads purified fresh water can be obtained after 5 hours of circulation time. The cooling capacity reaches 124.1kJ/kg.

Example 8

The specific operation process is the same as in Example 1; when the adsorbent is a copper foam solidified CuSO ₄ composite adsorbent coated with a GO photothermal material coating, the mass percentage of the GO photothermal material coating material is 1%, and the mass percentage of CuSO ₄ is 44%, the mass percentage of copper foam is 55%, the solid-liquid ratio of CuSO ₄ to brine is 1.7, the evaporation temperature is 15°C, and after a cycle time of 5 hours, 382.5g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 937.1kJ/kg .

Example 9

The specific operation process is the same as in Example 1; when the adsorbent is a copper foam solidified silica gel composite adsorbent coated with a GO photothermal material coating, the mass percentage of the GO photothermal material coating material is 1%, and the mass percentage of the silica gel is 55 %, the mass percentage of copper foam is 44%, the solid-liquid ratio of silica gel to brine is 2.2, the evaporation temperature is 20°C, and 130.0g/kg _ads purified fresh water can be obtained after a cycle time of 5 hours, with a cooling capacity of 318.5kJ/kg.

Example 10

The specific operation process is the same as in Example 1; when the adsorbent is copper foam cured silica gel coated with a perovskite photothermal material coating, the mass percentage of the perovskite photothermal material coating material is 1%, and the mass percentage of the silica gel is 55%, the mass percentage of copper foam is 44%, the solid-liquid ratio of silica gel and brine is 2.2, the evaporation temperature is 15°C, and after a cycle time of 2 hours, 67.2g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 164.6kJ/kg.

Example 11

The specific operation process is the same as in Example 1; when the adsorbent is copper foam cured silica gel coated with carbon black photothermal material coating, the evaporation temperature is 15°C, the mass percentage of carbon black photothermal material coating material is 1%, and the silica gel The mass percentage is 55%, and the mass percentage of copper foam is 44%. After a cycle time of 12 hours, 133.2g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 326.3kJ/kg.

Comparative example 1

The specific operation process is the same as in Example 1; when the adsorbent is coated with a silica gel composite adsorbent coated with GO photothermal material, the mass percentage of the GO photothermal material coating material is 0.5%, the mass percentage of silica gel is 99.5%, and the silica gel and The solid-to-liquid ratio of the brine is 2.2, the evaporation temperature is 15°C, and after a circulation time of 5 hours, 64.0g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 161.4kJ/kg.

Comparative example 2

The specific operation process is the same as in Example 1; when the adsorbent is copper foam solidified silica gel composite adsorbent, the mass percentage of silica gel is 55%, the mass percentage of copper foam is 45%, the solid-liquid ratio of silica gel and brine is 2.2, and the evaporation temperature 15℃, after 5 hours of circulation time, 39.6g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 97.0kJ/kg.

Comparative example 3

The specific operation process is the same as in Example 1; when the adsorbent is a nickel foam solidified silica gel composite adsorbent, the mass percentage of silica gel is 52%, the mass percentage of nickel foam is 48%, the solid-liquid ratio of silica gel to brine is 2.2, and the evaporation temperature 15℃, after 5 hours of circulation time, 36.0g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 88.2kJ/kg.

Comparative example 4

The specific operation process is the same as in Example 1; when the adsorbent is aluminum foam cured silica gel composite adsorbent, the mass percentage of silica gel is 65%, the mass percentage of foam aluminum is 35%, the solid-liquid ratio of silica gel and brine is 2.2, and the evaporation temperature 15℃, after 5 hours of circulation time, 38.8g/kg _ads purified fresh water can be obtained, and the cooling capacity reaches 95.1kJ/kg.

The concentrated brine ion concentrations of Examples 1-11 and Comparative Examples 1-4 were tested, and the results are shown in Table 1.

Table 1 Main ion concentrations in brine

The present invention can use adsorbent to effectively and quickly concentrate brine, and the adsorption process is not affected by the environment such as weather. The adsorbent can be desorbed and regenerated by using low-grade heat sources such as solar energy, which has the advantage of low energy consumption.

The concentrations of main ions in the fresh water of Examples 1-11 and Comparative Examples 1-4 were tested, and the results are shown in Table 2.

Table 2 Main ion concentrations in fresh water

According to the national standard for drinking mineral water (GB 8537-2018), the Li ⁺ ion concentration is 0.30-1.34mg/L, which meets the limit indicators in physical and chemical standards. According to the World Health Organization's drinking water standards, the concentrations of sodium, potassium, calcium, and magnesium ions must all meet the requirements of less than 200 mg/L. According to the national standard for drinking mineral water (GB 8537-2018), the Li ⁺ ion concentration is 0.30-1.34mg/L, which meets the limit indicators in physical and chemical standards. According to the group standard "Drinking Natural Mineral Water (Suitable for Infants and Young Children)", the mineral elements of the physical and chemical standards are further stipulated. The ion concentrations of fresh water in Table 2 can meet the requirements of sodium ≤ 20 mg/L and potassium ≤ 10 mg/L. Calcium ≤ 100mg/L, magnesium ≤ 40mg/L.

The above are only preferred specific embodiments of the present invention; however, the protection scope of the present invention is not limited thereto. Any person familiar with the technical field who is familiar with the technical field shall make equivalent substitutions or changes based on the technical solutions and improvement concepts of the present invention within the technical scope disclosed in the present invention, and shall be covered by the protection scope of the present invention.

Claims (5)

1. A direct solar energy adsorption brine concentration refrigeration system, characterized by including: Evaporator; condenser; A first adsorber has one end connected to the evaporator and the other end connected to the condenser; a second adsorber, one end of which is connected to the evaporator, and the other end of which is connected to the condenser; Both the first adsorber and the second adsorber are integrated with solar collectors, and adsorbents with direct photothermal properties are provided inside them; Valves are provided on the pipelines connecting the evaporator, the condenser, the first adsorber and the second adsorber, and the condenser is also provided with a valve; The adsorbent is a foam metal solidified composite adsorbent with a photothermal material coating on the surface, which is composed of a water-absorbing adsorbent, foam metal and photothermal coating material; The mass percentage of the photothermal material is 0.5-5%, the mass percentage of the foam metal is 31-62%, and the mass percentage of the water-absorbing adsorbent is 37-64%; The adsorbent is a foam metal-cured MIL-101 (Cr) composite adsorbent coated with a photothermal material coating on the surface. The mass percentage of MIL-101 (Cr) is 37%, the mass percentage of foam metal is 62%, and the mass percentage of photothermal material is 62%. The mass percentage of thermal material is 1%; Among them, the photothermal material is graphene oxide or nanometal, and the foam metal is copper foam; or The adsorbent is a foam metal cured silica gel composite adsorbent with a photothermal material coating on the surface, in which the mass percentage of silica gel is 55%, the photothermal material is carbon black, its mass percentage is 1%, and the foam metal is copper foam. Its mass percentage is 44%; or The adsorbent is a foam metal CuSO ₄ composite adsorbent with a photothermal material coating on the surface. The mass percentage of CuSO ₄ is 44%, the mass percentage of foam metal is 55%, and the photothermal material is graphene oxide, and its mass percentage is 1%. 2. A direct solar energy adsorption brine concentration refrigeration system according to claim 1, characterized in that it also includes an auxiliary device; The auxiliary device is used to cool down or heat the first adsorber and the second adsorber. 3. A direct solar energy adsorption brine concentration refrigeration system according to claim 2, characterized in that the auxiliary device has a cold/hot water inlet and a cold/hot water outlet, which are respectively connected to the first through pipelines. The adsorber is connected with the heat exchange tube in the second adsorber. 4. A method of using a direct solar energy adsorption brine concentration refrigeration system according to any one of claims 1-3, characterized in that it includes the following steps: 1) Add brine into the evaporator and open the valve between the evaporator and the first adsorber for adsorption; 2) After the adsorption is completed, close the valve between the evaporator and the first adsorber. When the temperature of the first adsorber reaches the desorption temperature, open the valve between the first adsorber and the condenser and the valve on the condenser. With this At the same time, open the valve between the evaporator and the second adsorber to allow the second adsorber to adsorb; 3) When the second adsorber reaches adsorption completion, close the valve between the evaporator, the first adsorber and the second adsorber, close the valve on the condenser, and open the first adsorber, second adsorber and condenser. The valves between the first adsorber and the second adsorber are connected for mass return, and after the mass return is completed, the valves between the first adsorber, the second adsorber and the condenser are closed; 4) When the first adsorber and the second adsorber reach the adsorption and desorption temperatures respectively, open the valve between the evaporator and the first adsorber, open the valve between the second adsorber and the condenser, and open the valve on the condenser. valve. 5. A method of using a direct solar energy adsorption brine concentration refrigeration system according to claim 4, characterized in that when the light is insufficient, the auxiliary device passes the heat medium into the second adsorber as an auxiliary energy source to heat and desorb water; The auxiliary device introduces the cold medium into the first adsorber to cool the first adsorber.