A thermomagnetic reciprocating driven interfacial evaporation device and method for combined hydropower generation

Abstract

This invention provides a thermomagnetic reciprocating drive-driven hydropower cogeneration interface evaporation device and method, utilizing the flow of thermal energy between a seawater desalination subsystem and a thermomagnetic power generation system to achieve dual production of freshwater and electricity. The device consists of several parts, including a rod-shaped permanent magnet, a permanent magnet ring, a thermomagnetic material block, and a coil. The thermomagnetic material block is ferromagnetic in low-temperature seawater, attracted to the permanent magnet ring and heated by sunlight. Simultaneously, the thermomagnetic material block releases heat to absorbent cotton sheets, causing the water in the cotton sheets to evaporate. The resulting water vapor condenses into freshwater at a condenser plate and then flows to a freshwater collection tank for collection. After absorbing heat and heating up, the thermomagnetic material block loses its magnetism and returns to the seawater to dissipate heat under the action of gravity and elasticity. The absorbent cotton sheets absorb seawater, and the thermomagnetic material block cools down, regains its magnetism, and is then magnetically attracted again, repeating the above process. This process, through the thermomagnetic material block and connecting rod driving the rod-shaped permanent magnet to move, generates electricity in the coil, ultimately achieving dual production of freshwater and electricity.

Description

Technical Field

[0001] This invention belongs to the field of seawater desalination and power generation technology, specifically relating to a hydropower cogeneration interface evaporation device and method based on thermomagnetic reciprocating drive. Background Technology

[0002] With the rapid development of industrial technology, my country's demand for various energy and natural resources is increasing daily. While increasing energy production, promoting clean, low-carbon, and sustainable energy development has become a core issue of national strategy. Among these, electricity, as the most widely used energy form, and freshwater, as a strategic resource essential for survival, will inevitably occupy an increasingly important position in my country's future energy development plan. Therefore, exploring technological pathways for the efficient and environmentally friendly co-generation of electricity and freshwater resources is of significant practical importance.

[0003] Against this backdrop, thermomagnetic power generation technology has made significant progress in recent years, gradually shifting from experimental research to practical applications. This technology utilizes the characteristic that the magnetization of thermomagnetic materials changes rapidly with temperature near the Curie temperature, generating electricity through magnetocaloric conversion driven by temperature cycles. It boasts significant advantages such as simple structure, no moving mechanical parts, low noise, and low emissions, and is considered one of the important directions for future green electricity production. However, this technology still faces key bottlenecks in practical applications: on the one hand, a stable external heat source is needed to maintain the thermal cycle; on the other hand, the cooling rate of thermomagnetic materials after demagnetization is slow, limiting the power generation cycle frequency and power density. More critically, a single thermomagnetic power generation system only outputs electrical energy, failing to achieve the cascade utilization of thermal energy, thus limiting energy utilization efficiency.

[0004] Meanwhile, the shortage of freshwater resources is becoming increasingly severe globally, particularly in my country's coastal areas and arid northwest regions. It is noteworthy that these freshwater-scarce areas often possess both saline and solar energy resources, creating naturally compatible conditions for the application of solar-powered seawater desalination technology. This technology drives seawater evaporation through photothermal conversion, demonstrating enormous application potential. However, in actual operation, problems such as insufficient absorption of solar heat by seawater and ineffective utilization of latent heat of water vapor are common, leading to significant energy waste. How to fully capture and efficiently utilize this lost low-grade heat energy has become crucial for improving the energy conversion efficiency of solar-powered seawater desalination systems.

[0005] The comparative analysis of the two technological dilemmas revealed an important opportunity for technological coupling. Thermomagnetic power generation systems require a continuous heat source and efficient cooling, while solar-powered seawater desalination systems possess both solar thermal collection capabilities and low-temperature seawater resources. Conversely, seawater desalination systems suffer from insufficient thermal energy utilization, while thermomagnetic power generation systems can introduce an additional energy conversion stage. More importantly, the operating temperature required by thermomagnetic power generation systems (i.e., the Curie temperature of the thermomagnetic materials) is slightly higher than the evaporation temperature of the seawater desalination subsystem. This natural temperature gradient provides a physical basis for the series utilization of thermal energy. Based on this, the thermal energy generated by solar energy can first flow through the thermomagnetic power generation system to drive power generation, and then flow to the seawater desalination subsystem for evaporation, forming a reasonable energy level configuration of "high-grade thermal energy power generation—low-grade waste heat desalination." Simultaneously, the low-temperature seawater (20-30℃) of the solar-powered seawater desalination subsystem can serve as an ideal cooling medium during the cooling stage of the thermomagnetic materials, solving the technical bottleneck of slow cooling speed. Furthermore, the low-temperature seawater recovers the waste heat from the thermomagnetic power generation during the preheating process, increasing the feed temperature of the seawater desalination system.

[0006] Therefore, coupling thermomagnetic power generation technology with solar desalination technology can not only solve the technical bottlenecks of each technology through a complementary mechanism of "using the waste heat from thermomagnetic power generation to supply seawater desalination, and using the cold source of seawater desalination to promote thermomagnetic cooling," but also achieve the energy cascade utilization and multi-energy co-production effects that cannot be achieved by a single system. This coupled system is entirely based on solar energy, a renewable energy source, and can achieve clean co-production of freshwater and electricity. The entire process consumes no fossil fuels and emits no pollutants. It has crucial strategic significance for promoting the green, environmentally friendly, and efficient nature of energy technologies, as well as alleviating the shortage of freshwater and the tight power supply.

[0007] Currently, no equipment can effectively combine solar desalination with thermomagnetic power generation. This invention aims to propose a device and method that couples solar desalination and thermomagnetic power generation technologies. By achieving orderly flow and energy level matching of thermal energy between the two subsystems, it overcomes the key limitations of using these two technologies individually, enabling emission-free and pollution-free operation of the entire production process, significantly improving overall energy efficiency, and providing a distributed, clean combined water and electricity solution for coastal and arid regions with abundant solar resources. Summary of the Invention

[0008] In view of this, the present invention proposes a hydropower cogeneration interface evaporation device and method based on thermomagnetic reciprocating drive. This device can directly produce fresh water using collected solar energy, and at the same time use the heat energy in the solar energy to supply thermomagnetic materials to generate electricity, thus having a high energy utilization rate.

[0009] The technical solution adopted by this invention to solve the technical problem is: A thermomagnetic reciprocating driven interfacial evaporation device for combined hydropower includes a seawater cavity, a thermomagnetic material block, a permanent magnet ring, a spring, a support body, a condenser lens, a coil, a rod-shaped permanent magnet, a condensation cavity, a condensation plate, a connecting rod, a freshwater collection tank, a support frame, absorbent cotton sheets, seawater pipes, an external circuit, a shell, and an iron core, wherein: The seawater chamber, located at the bottom of the device, is used to store the seawater to be desalinated. The thermomagnetic material block, placed inside the seawater cavity and connected to the connecting rods on all sides, possesses thermomagnetic properties. When the device initially operates, the temperature of the thermomagnetic material block is below the Curie temperature, making it magnetic. It is attracted to the upper part of the seawater cavity by the magnetic force of the permanent magnet ring. After absorbing solar energy, the temperature of the thermomagnetic material block rises above the Curie temperature, and its magnetism disappears. Then, under the influence of the spring force and its own gravity, it moves downwards into the seawater cavity and eventually becomes submerged. Once the thermomagnetic material block is cooled below the Curie temperature by the low-temperature seawater in the cavity, its magnetism is restored, and it is thus attracted by the magnetic force of the permanent magnet ring. It overcomes the elastic force of the spring and the weight of the thermomagnetic material block to move upwards into the seawater cavity and detach from the seawater. At the same time, it drives the water-absorbing cotton sheet attached to the surface of the thermomagnetic material block and the connecting rod welded around the thermomagnetic material block to move up and down reciprocally. When the water-absorbing cotton sheet is driven downwards into the seawater, it absorbs seawater. When it is driven upwards out of the seawater, the absorbed seawater is heated and evaporates to generate water vapor. The water vapor condenses into fresh water at the condenser plate and is finally collected by the fresh water collection tank. When the connecting rod is driven to move up and down reciprocally, it drives the rod-shaped permanent magnet to move up and down in the coil, thereby generating electrical energy in the coil, ultimately realizing the dual production of fresh water and electrical energy. The permanent magnet ring, located between the support body and the support frame, is used to provide a stable magnetic field and attract the thermomagnetic material block that restores magnetism to move upwards towards the seawater cavity. The spring has its upper plate fixed below the support body and its lower plate fixed at the "L"-shaped bend of the connecting rod. When the thermomagnetic material block is in the seawater of the seawater cavity, it does not deform and does not generate elastic force. When the thermomagnetic material block cools down and regains its magnetism, it is attracted upward by the permanent magnet ring and moves upward. It is compressed and deformed, generating an elastic force that resists the upward movement of the thermomagnetic material block. Ultimately, the upward magnetic force, the downward elastic force, and gravity on the thermomagnetic material block are balanced, thus stopping its movement. After the thermomagnetic material block is heated and loses its magnetism, the elastic force applied by the spring accelerates the speed at which the thermomagnetic material block descends back into the seawater cavity. The support body is located between the seawater cavity and the condensation cavity. It is used to place the spring and the coil, and has a small hole concentric with the axis of the spring and the coil, so that the rod-shaped permanent magnet and the connecting rod can pass vertically and move up and down relative to the support body. The concentrating mirror is installed on the top of the device and connected to the condenser plate at the bottom. It is used to concentrate sunlight to irradiate the thermomagnetic material block and the water-absorbing cotton sheet, so that the thermomagnetic material block moves upward and leaves the seawater in the seawater cavity and heats up rapidly, and the seawater in the water-absorbing cotton sheet is heated and evaporates to generate water vapor. The coil is vertically fixed on the support. When the rod-shaped permanent magnet moves back and forth in the coil, the magnetic flux through the coil changes continuously. According to the principle of electromagnetic induction, electrical energy is generated in the coil. The rod-shaped permanent magnet is located inside the coil, with its own central axis coinciding with the central axis of the coil. Its lower end is connected to the upper end of the connecting rod. It can pass through a small hole on the support body and be driven by the connecting rod to move up and down in the coil, thereby causing the magnetic flux passing through the coil to change continuously. The condensation chamber, located above the device, consists of a condenser lens and a condenser plate. It is used to provide a sealed environment for the water vapor generated by the heating and evaporation of seawater, preventing water vapor leakage. The condenser plate, located between the support and the condenser lens, is used to cool the water vapor in the condensation chamber, so that the water vapor condenses into fresh water, and the fresh water generated by condensation flows to the fresh water collection tank. The connecting rod, located inside the spring, has its own central axis coinciding with the central axis of the spring. It is an "L"-shaped rod, with its lower end connected to the thermomagnetic material block and its upper end connected to the lower end of the rod-shaped permanent magnet. It can pass through a small hole on the support body to connect the thermomagnetic material block and the rod-shaped permanent magnet. This allows the reciprocating motion of the thermomagnetic material block to drive the rod-shaped permanent magnet to move together. At the same time, it will be subject to the elastic force of the spring, thereby accelerating the speed at which the thermomagnetic material block descends and returns to the seawater cavity. The freshwater collection tank is located below the condenser plate and is used to collect freshwater from the condenser plate. The support frame is fixed to the inner wall of the seawater cavity and is used to support the permanent magnet ring; The absorbent cotton pad is attached to the surface of the thermomagnetic material block and moves up and down with the thermomagnetic material block. When the thermomagnetic material block returns to the seawater cavity, it absorbs seawater. When the thermomagnetic material block leaves the seawater, it is heated, causing the absorbed seawater to evaporate and produce water vapor.

[0010] The side of the seawater cavity has a groove for the connecting rod to move up and down, and a channel for seawater to flow in.

[0011] The thermomagnetic material block is a thermomagnetic material. When the temperature of the thermomagnetic material block is below the Curie temperature, it is ferromagnetic, and when the temperature is above the Curie temperature, it loses its magnetism. The Curie temperature range of the material used in the thermomagnetic material block is 50°C to 150°C.

[0012] The absorbent cotton pad is a hydrophilic photothermal conversion material, such as cellulose-derived hydrogel, hydrophilic carbon felt, CNTs-CMC-SA composite material, semiconductor material MXene, and rod-shaped alloy nanoclusters, which can quickly absorb seawater and efficiently convert solar energy into heat energy.

[0013] The support body is made of solid buoyancy material, which enables the device to float on the sea surface. With the support body as the boundary, the part of the device in the direction of the seawater cavity is immersed in seawater, while the part in the direction of the condensation cavity is exposed above the water surface.

[0014] The condensation chamber includes a condenser lens, a condenser plate, and a freshwater collection tank. The condenser plate is a ring structure with a larger upper ring and a smaller lower ring, and its cross-section is a parallelogram, thus forming an inclination angle from the outside to the inside. While cooling the water vapor in the condensation chamber, the freshwater generated by condensation is subjected to its own gravity and flows along the inclined slope towards the center of the device, eventually flowing into the freshwater collection tank for collection.

[0015] A desalination and power generation method based on a thermomagnetic reciprocating driven hydropower cogeneration interface evaporation device includes the following steps: When the thermomagnetic material block is in seawater, its temperature is below the Curie temperature, thus exhibiting ferromagnetism. It is attracted upwards by the magnetic force of a permanent magnet ring below a freshwater collection tank. After the thermomagnetic material block leaves the water surface, it is heated by sunlight focused by a concentrator lens. Simultaneously, the seawater in the absorbent cotton attached to the thermomagnetic material block evaporates due to the heat. The evaporated water vapor condenses into freshwater at a condenser plate. Due to the tilt angle of the condenser plate and the gravity of the freshwater, the freshwater converges towards the center of the device and eventually falls into the freshwater collection tank for collection. When the temperature of the thermomagnetic material block rises above the Curie temperature after absorbing heat energy converted from solar energy, its ferromagnetism disappears, and the spring at the connecting rod... Under the combined action of elasticity and the gravity of the thermomagnetic material block, the block moves downwards and returns to the seawater in the seawater cavity, where it is cooled by the low-temperature seawater. The absorbent cotton attached to the block also reabsorbs water. When the block's temperature drops below the Curie temperature, its magnetism is restored, and it is attracted upwards again by the permanent magnet coil, repeating the above process. As the block moves up and down, it drives the connecting rod to move up and down through the small hole in the support body. The connecting rod, in turn, drives the rod-shaped permanent magnet to move up and down through the small hole in the support body. The up and down movement of the rod-shaped permanent magnet occurs within the coil, causing the magnetic flux in the coil to change continuously, thus generating electrical energy in the coil. The coil is connected to an external circuit, and the generated electrical energy can be stored or used. Beneficial effects of the present invention

[0016] (1) Achieving a thermo-magnetic-mechanical coupled freshwater-electricity cogeneration mechanism: This device rationally utilizes the abrupt change in magnetization intensity of the thermomagnetic material block near the Curie temperature, and transforms the thermomagnetic effect into controllable reciprocating motion through mechanical structure design. This motion drives the hydrophilic absorbent cotton sheet to continuously complete the cycle of water absorption and evaporation, achieving efficient interfacial evaporation and significantly improving seawater evaporation efficiency, while eliminating the complex pumping and pipeline transmission links in traditional seawater desalination systems. At the same time, the reciprocating motion of the thermomagnetic material block drives the rod-shaped permanent magnet to cut magnetic field lines in the coil, causing the magnetic flux through the coil to continuously change and generate an induced current, thereby simultaneously realizing the cogeneration of freshwater and electricity in the same mechanical structure, with a compact and efficient energy conversion path.

[0017] (2) Constructing a solar-driven zero-emission cycle system: This device uses solar energy as the sole external energy input, and combined with thermomagnetic power generation technology, it can achieve a continuous supply of energy and fresh water, fully meeting the requirements of sustainable development. The system achieves cost reduction and efficiency improvement through energy-level cascade utilization: the waste heat generated during the thermomagnetic power generation process is directly used to drive seawater evaporation, while the low-temperature seawater, in turn, acts as a cooling medium to accelerate the cooling of the thermomagnetic material block, shortening the thermomagnetic cycle, thereby improving power generation efficiency and fresh water production without consuming additional energy, forming a closed-loop operation mode of energy self-sufficiency and mutual benefit.

[0018] (3) Enhancing energy and water security in remote areas: Since the device operates entirely on solar energy, it does not require connection to an external power grid or fuel supply, making it particularly suitable for remote areas, islands, and coastal areas lacking electricity and water. Through localized, distributed energy-freshwater cogeneration, it can significantly reduce dependence on external infrastructure, improve regional self-sufficiency and emergency response capabilities, and has significant strategic application value.

[0019] (4) Advantages of modular deployment and large-scale promotion: The device has a compact overall design, simple principle, and no complex kinematic pairs. It can float on the sea surface and directly utilize seawater resources, avoiding the land area limitation. Its modular characteristics support flexible combination and large-scale array deployment, and have good economy, maintainability and engineering practicality, laying a technical foundation for commercial promotion. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive. Figure 2 This is a front view schematic diagram of a hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive. Figure 3 for Figure 1 A schematic cross-sectional view of the device shown. Figure 4This is a schematic diagram of another type of interfacial evaporation device for combined hydropower based on thermomagnetic reciprocating drive. Figure 5 for Figure 4 A schematic cross-sectional view of the device shown. Figure 6 for Figure 4 A schematic diagram of the device without its outer casing.

[0021] Among them, 1-seawater cavity, 2-thermomagnetic material block, 3-permanent magnet ring, 4-spring, 5-support body, 6-condensing mirror, 7-coil, 8-rod-shaped permanent magnet, 9-condensation cavity, 10-condensation plate, 11-connecting rod, 12-freshwater collection tank, 13-support frame, 14-absorbent cotton sheet, 15-seawater pipeline, 16-external circuit, 17-outer shell, 18-iron core. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings: As attached Figure 1 , Figure 2 , Figure 3 As shown, this invention provides a thermomagnetic reciprocating hydropower cogeneration interface evaporation device and method. The device includes a seawater chamber 1, a thermomagnetic material block 2, a permanent magnet ring 3, a spring 4, a support body 5, a condensing mirror 6, a coil 7, a rod-shaped permanent magnet 8, a condensation chamber 9, a condensation plate 10, a connecting rod 11, a freshwater collection tank 12, a support frame 13, absorbent cotton sheets 14, a seawater pipeline 15, an external circuit 16, a shell 17, and an iron core 18, wherein: The seawater chamber 1, located at the bottom of the device, is used to store the seawater to be desalinated. The thermomagnetic material block 2, placed inside the seawater cavity 1 and connected to the connecting rod 11 on all sides, possesses thermomagnetic properties. When the device first starts operating, the temperature of the thermomagnetic material block 2 is below the Curie temperature, and it is magnetic. It is attracted to the upper position of the seawater cavity 1 by the magnetic force of the permanent magnet ring 3. After absorbing solar energy, the temperature of the thermomagnetic material block 2 rises above the Curie temperature, and its magnetism disappears. Then, under the action of the elastic force of the spring 4 and the weight of the thermomagnetic material block 2 itself, it moves downwards into the seawater cavity 1, eventually immersing itself in the seawater. After the thermomagnetic material block 2 is cooled to below the Curie temperature by the low-temperature seawater in the seawater cavity 1, its magnetism is restored, and it is thus attracted by the magnetic force of the permanent magnet ring 3, overcoming... The elastic force of spring 4 and the gravity of the thermomagnetic material block 2 move upwards towards the seawater cavity 1 and detach from the seawater. At the same time, it drives the water-absorbing cotton sheet 14 attached to the surface of the thermomagnetic material block 2 and the connecting rod 11 welded around the thermomagnetic material block 2 to move up and down reciprocally. When the water-absorbing cotton sheet 14 is driven downwards into the seawater, it absorbs seawater. When it is driven upwards out of the seawater, the absorbed seawater is heated and evaporates to generate water vapor. The water vapor condenses into fresh water at the condenser plate 10 and is finally collected by the fresh water collection tank 12. When the connecting rod 11 is driven to move up and down reciprocally, it will drive the rod-shaped permanent magnet 8 to move up and down reciprocally in the coil 7, thereby generating electrical energy in the coil 7, and finally realizing the dual production of fresh water and electrical energy. The permanent magnet ring 3 is located between the support body 5 and the support frame 13, and is used to provide a stable magnetic field to attract the thermomagnetic material block 2 that restores magnetism to move upwards towards the seawater cavity 1; The upper plate of the spring 4 is fixed below the support body 5, and the lower plate is fixed at the "L"-shaped bend of the connecting rod 11. When the thermomagnetic material block 2 is in the seawater of the seawater cavity 1, it does not deform and does not generate elastic force. When the thermomagnetic material block 2 cools down and regains its magnetism, it is attracted upward by the permanent magnet ring 3 and is compressed and deformed, generating elastic force that resists the upward movement of the thermomagnetic material block 2. Finally, the upward magnetic force, the downward elastic force, and gravity on the thermomagnetic material block 2 are balanced, thus stopping the movement. After the thermomagnetic material block 2 is heated and loses its magnetism, the elastic force applied by the spring 4 accelerates the speed at which the thermomagnetic material block 2 descends back to the seawater cavity 1. The support body 5 is located between the seawater cavity 1 and the condensation cavity 9. It is used to place the spring 4 and the coil 7, and has a small hole concentric with the axis of the spring 4 and the coil 7, so that the rod-shaped permanent magnet 8 and the connecting rod 11 can pass vertically and move up and down relative to the support body 5. The concentrating mirror 6 is installed on the top of the device and connected to the condenser plate 10 at the bottom. It is used to concentrate sunlight to irradiate the thermomagnetic material block 2 and the water-absorbing cotton sheet 14, so that the thermomagnetic material block 2 moves upward and leaves the seawater in the seawater cavity 1 and heats up rapidly, and the seawater in the water-absorbing cotton sheet 14 is heated and evaporates to generate water vapor. The coil 7 is vertically fixed on the support body 5. When the rod-shaped permanent magnet 8 moves back and forth in the coil 7, the magnetic flux through the coil 7 changes continuously. According to the principle of electromagnetic induction, electrical energy is generated in the coil 7. The rod-shaped permanent magnet 8 is located inside the coil 7, with its own central axis coinciding with the central axis of the coil 7. Its lower end is connected to the upper end of the connecting rod 11. It can pass through the small hole on the support body 5 and be driven by the connecting rod 11 to move up and down in the coil 7, thereby causing the magnetic flux passing through the coil 7 to change continuously. The condensation chamber 9, located above the device, consists of a condenser lens 6 and a condenser plate 10. It is used to provide a sealed environment for the water vapor generated by the heating and evaporation of seawater to prevent water vapor leakage. The condenser plate 10 is located between the support 5 and the condenser lens 6. It is used to cool the water vapor in the condenser chamber 9, so that the water vapor is condensed into fresh water, and the fresh water generated by condensation flows to the fresh water collection tank 12. The connecting rod 11 is located inside the spring 4, and its central axis coincides with the central axis of the spring 4. It is an "L"-shaped rod. Its lower end is connected to the thermomagnetic material block 2, and its upper end is connected to the lower end of the rod-shaped permanent magnet 8. It can pass through the small hole on the support body 5 to connect the thermomagnetic material block 2 and the rod-shaped permanent magnet 8. This allows the reciprocating motion of the thermomagnetic material block 2 to drive the rod-shaped permanent magnet 8 to move together. At the same time, it will be subjected to the elastic force of the spring 4, thereby accelerating the speed at which the thermomagnetic material block 2 descends and returns to the seawater cavity 1. The freshwater collection tank 12 is located below the condenser plate 10 and is used to collect freshwater from the condenser plate 10. The support frame 13 is fixed to the inner wall of the seawater cavity 1 and is used to support the permanent magnet ring 3; The absorbent cotton sheet 14 is attached to the surface of the thermomagnetic material block 2 and moves up and down with the thermomagnetic material block 2. When the thermomagnetic material block 2 returns to the seawater cavity 1, it absorbs seawater. When the thermomagnetic material block 2 leaves the seawater, it is heated, causing the absorbed seawater to evaporate and produce water vapor.

[0023] The embodiment applies to a desalination and power generation method for a hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive. The method includes: when the thermomagnetic material block 2 is in seawater, its temperature is below the Curie temperature, therefore it is ferromagnetic and will be attracted upwards by the magnetic force of the permanent magnet ring 3 below the freshwater collection tank 12. When the thermomagnetic material block 2 leaves the water surface, it will be irradiated by sunlight focused by the concentrator lens 6, thus being heated. Simultaneously, the seawater in the absorbent cotton sheet 14 attached to the thermomagnetic material block 2 will also evaporate due to the heat. The evaporated water vapor will condense into freshwater at the condenser plate 10. Due to the tilt angle of the condenser plate 10 and the gravity of the freshwater itself, the freshwater will converge towards the center of the device and eventually fall into the freshwater collection tank 12 for collection. When the temperature of the thermomagnetic material block 2 rises above the Curie temperature after absorbing heat energy converted from solar energy, its ferromagnetism disappears, and it will be attracted upwards at the connecting rod 11. Under the combined action of the elastic force of spring 4 and the gravity of the thermomagnetic material block 2, the thermomagnetic material block 2 will move downwards and return to the seawater in the seawater cavity 1, where it will be cooled by the low-temperature seawater. The water-absorbing cotton sheet 14 attached to the thermomagnetic material block 2 will also reabsorb water. When the temperature of the thermomagnetic material block 2 drops below the Curie temperature, the magnetism of the thermomagnetic material block 2 will be restored, and it will be attracted upwards again by the permanent magnet coil 3, repeating the above process. When the thermomagnetic material block 2 moves up and down, it will drive the connecting rod 11 to move up and down through the small hole of the support body 5. The connecting rod 11 will then drive the rod-shaped permanent magnet 8 to move up and down through the small hole of the support body 5. The up and down movement of the rod-shaped permanent magnet 8 takes place inside the coil 7, which will cause the magnetic flux in the coil 7 to change continuously, thereby generating electrical energy in the coil 7. The coil 7 is connected to an external circuit, and the generated electrical energy can be stored or used.

[0024] In another embodiment, unlike the above embodiment, an external pipe connects the freshwater collection tank 12 to the electrolytic cell. An electrolysis device and a hydrogen collection system are placed above the electrolytic cell. Electrical energy generated by the thermomagnetic generator system is supplied to the electrolysis device to electrolyze freshwater and produce hydrogen. After the thermomagnetic reciprocating-driven hydropower interface evaporator operates, water vapor condenses at the condenser plate 10 and flows into the freshwater collection tank 12. Freshwater then flows into the electrolytic cell through the external pipe of the freshwater collection tank 12. Electrical energy generated by the thermomagnetic generator system is then supplied to the electrolysis device. As the thermomagnetic reciprocating-driven hydropower interface evaporator operates, the electrolytic cell is continuously replenished with freshwater resources and the electrical energy required for electrolysis. Finally, the produced hydrogen and oxygen are stored in the collection device. This method avoids many problems associated with directly electrolyzing seawater.

[0025] In another embodiment, the difference from the above embodiment is that a propeller and a drive motor are placed in the seawater cavity 1. After the motor is powered on, it drives the propeller to rotate in the seawater, thereby increasing the flow speed of the seawater. This enhances the convective heat transfer between the thermomagnetic material block 2 and the seawater, accelerates the heat transfer rate of the thermomagnetic material block 2, and increases the frequency of the up-and-down reciprocating motion of the thermomagnetic material block 2, thereby ensuring that the thermomagnetic power generation has high efficiency.

[0026] As attached Figure 4 , Figure 5 , Figure 6 In one embodiment shown, the difference from the above embodiments is that the coil 7 is placed in the interlayer of the outer shell 17 that separates the freshwater collection tank 12 from the seawater cavity 1; the coil 7 is connected to the external circuit 16, and the iron core 18 surrounded by the coil 7 is a paramagnetic material that is not magnetic itself, which is used to enhance the magnetic coupling between the coils, improve the efficiency of energy transfer, and generate a higher voltage; seawater needs to be introduced into the seawater cavity 1 through the seawater pipe 15; the condenser plate 10 has no tilt angle and is placed vertically against the wall of the freshwater collection tank 12. When the thermomagnetic material block 2 is in seawater, its temperature is below the Curie temperature, thus exhibiting ferromagnetism. It is attracted upwards by the magnetic force of the permanent magnet ring 3 fixed below the freshwater collection tank 12. After the thermomagnetic material block 2 leaves the water surface, it is heated by sunlight focused by the concentrator lens 6. Simultaneously, the seawater in the absorbent cotton sheet 14 attached to the thermomagnetic material block 2 evaporates, gradually filling the cavity. Upon contact with the condenser plate 10, the water vapor condenses into freshwater and moves downwards under its own gravity, thus being collected by the freshwater collection tank 12. When the thermomagnetic material block 2 absorbs heat energy converted from solar energy and its temperature rises above the Curie temperature, its ferromagnetism disappears, thus... Under the combined action of the elastic force of spring 4 and the gravity of the thermomagnetic material block 2, the thermomagnetic material block 2 will return to the seawater, dissipating its own heat into the seawater, causing its temperature to drop. The absorbent cotton sheet 14 attached to the thermomagnetic material block 2 will also reabsorb water. When the temperature of the thermomagnetic material block 2 drops below the Curie temperature, it will be attracted again by the permanent magnet ring 3, repeating the above process. As the thermomagnetic material block 2 circulates, its own magnetism also changes rapidly, so the magnetic flux through the coil 7 in the outer shell 17 also changes continuously. According to the principle of electromagnetic induction, electrical energy can be generated in the coil 7, and the generated electrical energy is connected to the external circuit 16 for storage or use. This method reduces moving parts, simplifies the device structure, facilitates implementation, and utilizes the iron core 18 to generate higher voltage, improving power generation efficiency and the overall energy utilization rate of the device.

[0027] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0028] Therefore, the description of the specific embodiments in this invention is not intended to limit the concept and scope of the invention. Any modifications and improvements made to the technical solution by those skilled in the art without departing from the technical solution of this invention will still fall within the protection scope of this invention.

Claims

1. A hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive, comprising a seawater chamber (1), a thermomagnetic material block (2), a permanent magnet ring (3), a spring (4), a support body (5), a condenser lens (6), a coil (7), a rod-shaped permanent magnet (8), a condensation chamber (9), a condensation plate (10), a connecting rod (11), a freshwater collection tank (12), a support frame (13), absorbent cotton sheets (14), a seawater pipeline (15), an external circuit (16), a shell (17), and an iron core (18), wherein: The seawater cavity (1) is located at the bottom of the device and is used to store the seawater to be desalinated; The thermomagnetic material block (2) is placed inside the seawater cavity (1) and connected to the connecting rod (11) on all sides. It has thermomagnetic properties. When the device first starts working, the temperature of the thermomagnetic material block (2) is lower than the Curie temperature, and it is magnetic. It is attracted to the position above the seawater cavity (1) by the magnetic force of the permanent magnet ring (3). After absorbing solar energy, the temperature of the thermomagnetic material block (2) rises above the Curie temperature, and the magnetism disappears. Then, under the action of the elastic force of the spring (4) and the gravity of the thermomagnetic material block (2), it moves downward to the seawater cavity (1) and is finally immersed in the seawater in the seawater cavity (1). After the thermomagnetic material block (2) is cooled to below the Curie temperature by the low temperature seawater in the seawater cavity (1), the magnetism is restored. Therefore, it is attracted by the magnetic force of the permanent magnet ring (3) and overcomes the magnetic force of the permanent magnet ring (3). The elastic force of the spring (4) and the gravity of the thermomagnetic material block (2) move upwards towards the seawater cavity (1) and detach from the seawater. At the same time, it drives the water-absorbing cotton sheet (14) attached to the surface of the thermomagnetic material block (2) and the connecting rod (11) welded around the thermomagnetic material block (2) to move up and down. When the water-absorbing cotton sheet (14) is driven downwards into the seawater, it absorbs the seawater. When it is driven upwards out of the seawater, the absorbed seawater is heated and evaporates to generate water vapor. The water vapor is condensed into fresh water at the condenser plate (10) and finally collected by the fresh water collection tank (12). When the connecting rod (11) is driven to move up and down, it will drive the rod-shaped permanent magnet (8) to move up and down in the coil (7), thereby generating electrical energy in the coil (7) and finally realizing the dual production of fresh water and electrical energy. The permanent magnet ring (3) is located between the support body (5) and the support frame (13) to provide a stable magnetic field and attract the thermomagnetic material block (2) that restores magnetism to move upwards towards the seawater cavity (1); The upper plate of the spring (4) is fixed below the support body (5), and the lower plate is fixed at the "L"-shaped bend of the connecting rod (11). When the thermomagnetic material block (2) is in the seawater of the seawater cavity (1), it does not deform and does not generate elastic force. When the thermomagnetic material block (2) cools down and regains its magnetism, it is attracted upward by the permanent magnet ring (3) and is compressed and deformed, generating elastic force that hinders the upward movement of the thermomagnetic material block (2). Finally, the upward magnetic force, the downward elastic force, and gravity of the thermomagnetic material block (2) are balanced, thus stopping the movement. After the thermomagnetic material block (2) is heated and loses its magnetism, the elastic force applied by the spring (4) accelerates the speed at which the thermomagnetic material block (2) descends back to the seawater cavity (1). The support (5) is located between the seawater cavity (1) and the condensation cavity (9) and is used to place the spring (4) and the coil (7). It has a small hole at the same position as the axis of the spring (4) and the coil (7) so that the rod-shaped permanent magnet (8) and the connecting rod (11) can pass vertically and move up and down relative to the support (5). The concentrating mirror (6) is installed on the top of the device and connected to the condenser plate (10) at the bottom. It is used to concentrate sunlight to irradiate the thermomagnetic material block (2) and the absorbent cotton sheet (14), so that the thermomagnetic material block (2) moves upward and leaves the seawater in the seawater cavity (1) and heats up rapidly, and the seawater in the absorbent cotton sheet (14) is heated and evaporates to generate water vapor. The coil (7) is vertically fixed on the support (5). When the rod-shaped permanent magnet (8) moves back and forth in the coil (7), the magnetic flux through the coil (7) changes continuously. According to the law of electromagnetic induction, electrical energy is generated in the coil (7). The rod-shaped permanent magnet (8) is located inside the coil (7), with its own central axis coinciding with the central axis of the coil (7). Its lower end is connected to the upper end of the connecting rod (11). It can pass through the small hole on the support (5) and be driven by the connecting rod (11) to move up and down in the coil (7), thereby causing the magnetic flux passing through the coil (7) to change continuously. The condensation chamber (9), located above the device, is composed of a condenser lens (6) and a condenser plate (10) and is used to provide a sealed environment for the water vapor generated by the heating and evaporation of seawater to prevent water vapor leakage. The condenser plate (10) is located between the support (5) and the condenser lens (6) to cool the water vapor in the condenser chamber (9), so that the water vapor is condensed into fresh water and the fresh water generated by condensation flows to the fresh water collection tank (12). The connecting rod (11) is located inside the spring (4), and its central axis coincides with the central axis of the spring (4). It is an "L"-shaped rod. Its lower end is connected to the thermomagnetic material block (2), and its upper end is connected to the lower end of the rod-shaped permanent magnet (8). It can pass through the small hole on the support body (5) to connect the thermomagnetic material block (2) and the rod-shaped permanent magnet (8). This allows the up-and-down reciprocating motion of the thermomagnetic material block (2) to drive the rod-shaped permanent magnet (8) to move together. At the same time, it will be subjected to the elastic force of the spring (4), thereby accelerating the speed at which the thermomagnetic material block (2) descends and returns to the seawater cavity (1). The freshwater collection tank (12) is located below the condenser plate (10) and is used to collect freshwater from the condenser plate (10); The support frame (13) is fixed to the inner wall of the seawater cavity (1) and is used to support the permanent magnet ring (3). The absorbent cotton sheet (14) is attached to the surface of the thermomagnetic material block (2) and moves up and down with the thermomagnetic material block (2). When the thermomagnetic material block (2) returns to the seawater cavity (1), it absorbs seawater. When the thermomagnetic material block (2) leaves the seawater, it is heated, causing the absorbed seawater to evaporate and produce water vapor.

2. The hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive according to claim 1, characterized in that, The side of the seawater cavity (1) has a groove for the connecting rod (11) to move up and down, and a channel for seawater to flow in.

3. The hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive according to claim 1, characterized in that, The thermomagnetic material block (2) is a thermomagnetic material. When the temperature of the thermomagnetic material block (2) is below the Curie temperature, it has ferromagnetism. When the temperature is above the Curie temperature, it loses its magnetism. The Curie temperature range of the material used in the thermomagnetic material block (2) is 50°C to 150°C.

4. The hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive according to claim 1, characterized in that, The absorbent cotton pad (14) is a hydrophilic photothermal conversion material, such as cellulose-derived hydrogel, hydrophilic carbon felt, CNTs-CMC-SA composite material, semiconductor material MXene, and rod-shaped alloy nanoclusters, which can quickly absorb seawater and efficiently convert solar energy into thermal energy.

5. The hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive according to claim 1, characterized in that, The support (5) is made of solid buoyancy material, which enables the device to float on the sea surface. With the support (5) as the boundary, the part of the device in the direction of the seawater cavity (1) is immersed in seawater, and the part in the direction of the condensation cavity (9) is exposed above the water surface.

6. The hydropower cogeneration interface evaporation device based on thermomagnetic reciprocating drive according to claim 1, characterized in that, The condensation chamber (9) includes a condenser lens (6), a condenser plate (10), and a freshwater collection tank (12). The condenser plate (10) is a ring structure with a larger upper ring and a smaller lower ring. Its cross-section is a parallelogram, which forms an inclined angle from top to bottom and from outside to inside. While cooling the water vapor in the condensation chamber (9), the freshwater generated by condensation will be subjected to its own gravity and flow along the inclined slope towards the center of the device, eventually flowing into the freshwater collection tank (12) for collection.

7. A method for desalination and power generation based on a thermomagnetic reciprocating driven hydropower interfacial evaporation device, applied to the system according to any one of claims 1-6, characterized in that, The method includes: When the thermomagnetic material block (2) is in seawater, its temperature is lower than the Curie temperature, so it is ferromagnetic and will be attracted upward by the magnetic force of the permanent magnet ring (3) below the freshwater collection tank (12). When the thermomagnetic material block (2) leaves the water surface, it will be irradiated by the sunlight focused by the concentrator (6) and thus heated. At the same time, the seawater in the absorbent cotton sheet (14) attached to the thermomagnetic material block (2) will also be heated and evaporated. The evaporated water vapor will condense into freshwater at the condenser plate (10). Due to the tilt angle of the condenser plate (10) and the gravity of the freshwater itself, the freshwater will move towards the center of the device and eventually fall into the freshwater collection tank (12) for collection. When the thermomagnetic material block (2) absorbs the heat energy converted from solar energy and its temperature rises above the Curie temperature, its ferromagnetism disappears. Under the combined action of the elastic force of the spring (4) at the connecting rod (11) and the gravity of the thermomagnetic material block (2), The thermomagnetic material block (2) will move downwards and return to the seawater in the seawater cavity (1), where it will be cooled by the low-temperature seawater. The absorbent cotton sheet (14) attached to the thermomagnetic material block (2) will also absorb water again. When the temperature of the thermomagnetic material block (2) drops below the Curie temperature, the magnetism of the thermomagnetic material block (2) will be restored, and it will be attracted upwards again by the permanent magnet ring (3), repeating the above process. When the thermomagnetic material block (2) moves up and down, it will drive the connecting rod (11) to move up and down through the small hole of the support body (5). The connecting rod (11) will drive the rod-shaped permanent magnet (8) to move up and down through the small hole of the support body (5). The up and down movement of the rod-shaped permanent magnet (8) is carried out in the coil (7), which will cause the magnetic flux in the coil (7) to change continuously, thereby generating electrical energy in the coil (7). The coil (7) is connected to the external circuit, and the generated electrical energy can be stored or used.

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