Solar desalination device driven by evaporation of submerged heat pipe

Abstract

The application provides a solar seawater desalination device driven by an immersed heat pipe evaporation, and belongs to the technical field of solar brackish water desalination. The device comprises a seawater desalination unit and a heat pipe unit. The seawater desalination unit has a coaxially nested evaporation cylinder and a condensation cylinder, the condensation cylinder is sleeved outside the evaporation cylinder, and a closed evaporation and condensation cavity is formed between the evaporation cylinder and the condensation cylinder. The heat pipe unit comprises a plurality of heat pipes, a heat pipe condensation section of the heat pipe is located in a water body inside the evaporation cylinder, and a heat pipe evaporation section of the heat pipe extends out of the evaporation cylinder. Feed seawater forms a seawater liquid film on the outer surface of the evaporation cylinder. The condensation latent heat released by the heat pipe condensation section is transmitted to the seawater liquid film through the water body, the seawater liquid film is heated and temperature-increased, and water vapor generated by the seawater liquid film is condensed on the inner wall surface of the condensation cylinder to generate fresh water. The device realizes conversion of light heat into device energy supply through the heat pipe evaporation section absorbing solar radiation, and realizes high integration of heat collection, heat transmission and heat supply through the built-in heat pipe condensation section, so that the heat loss of the device is effectively reduced.

Description

Technical Field

[0001] This invention relates to a seawater desalination device, specifically a solar-powered seawater desalination device with submerged heat pipe-driven evaporation, belonging to the field of solar-powered seawater desalination technology. Background Technology

[0002] With rapid population growth and economic development, the demand for freshwater is becoming more urgent. Seawater desalination technology can effectively alleviate the problem of freshwater shortage. However, traditional seawater desalination technologies such as multi-stage flash distillation, multi-effect distillation, and reverse osmosis require large initial investments, specialized technical personnel, and high infrastructure requirements for remote areas, making them difficult to promote and use in remote and economically underdeveloped regions. These regions often have abundant solar energy resources, such as solar-powered seawater desalination devices. These devices have attracted much attention due to their simple water production process, availability of local materials, low investment and maintenance costs, flexible configuration, and lack of fossil fuel consumption. However, the low water production per unit collector area limits their large-scale application. In traditional solar-powered seawater desalination devices, water vapor condenses mostly on the inner surface of the cover plate, reducing the absorption of solar radiation. When solar collectors are used to heat the device, the heat loss during the heat exchange process with the water to be heated is large, the heat exchange pipeline is long and complex, the thermal response time is slow, the heat source supply and the heat structure for evaporation are mismatched, and the lack of sensible heat recovery and utilization of fresh water and concentrated seawater, as well as the lack of latent heat recovery and utilization of water vapor condensation, all restrict the water production performance of solar-powered seawater desalination devices. Summary of the Invention

[0003] In view of this, the present invention proposes a solar seawater desalination device with immersion heat pipe driven evaporation. The heat pipe evaporation section absorbs solar radiation to convert photothermal energy into energy for the device. The heat pipe condensation section is built-in to achieve a high degree of integration of heat collection, heat transfer and heat supply, effectively reducing the heat loss of the device.

[0004] The technical solution of the present invention is: a solar seawater desalination device with submerged heat pipe driven evaporation, comprising: a seawater desalination unit and a heat pipe unit; The seawater desalination unit has an evaporator and a condenser nested on the same axis. The condenser is fitted outside the evaporator, forming a closed evaporation-condensation chamber between the two. The heat pipe unit includes a plurality of heat pipes, wherein the condensing section of the heat pipe is located in the water inside the evaporation cylinder, and the evaporating section of the heat pipe extends out of the evaporation cylinder; The feed seawater forms a seawater liquid film on the outer surface of the evaporator; the latent heat of condensation released by the heat pipe condensation section is transferred to the seawater liquid film through the water body, the seawater liquid film is heated and the temperature rises, and the generated water vapor condenses on the inner wall of the condenser to form fresh water.

[0005] In a preferred embodiment of the present invention, a parabolic reflective surface is provided axially inside the heat pipe evaporation section, so that the internal space of the heat pipe evaporation section is divided into region A and region B by the parabolic reflective surface; Region A is the area between the parabolic reflector and the inner surface of the corresponding heat pipe evaporation section; Region B is the area between the back surface of the parabolic reflector and the inner surface of the corresponding heat pipe evaporation section. Region A and Region B are connected at the lower and upper ends of the heat pipe evaporation section, and Region B is a reflux channel; both Region A and Region B are filled with working fluid.

[0006] In a preferred embodiment of the present invention, light-absorbing particles are distributed in the working fluid within region A.

[0007] In a preferred embodiment of the present invention, the light-absorbing particles are dark-colored, porous light-absorbing particles.

[0008] In a preferred embodiment of the present invention, both the condenser and the evaporator are conical.

[0009] In a preferred embodiment of the present invention, the heat pipe condensation sections are arranged at different heights and immersed in the water body of the evaporation cylinder.

[0010] In a preferred embodiment of the present invention, the seawater desalination unit includes a regenerating coil and a liquid distribution pipe; The inner surface of the condenser cylinder is spirally provided with a heat recovery coil; The regenerative coil is connected to the liquid distribution pipe arranged circumferentially on the outer surface of the upper end of the evaporator. The liquid distribution pipe has liquid distribution holes distributed circumferentially. The feed seawater enters the distribution pipe through the regenerating coil and flows out through the distribution holes on the distribution pipe to form a seawater liquid film on the outer surface of the evaporator.

[0011] In a preferred embodiment of the present invention, a heat exchange coil B is provided in a freshwater tank for collecting freshwater generated by condensation on the inner surface of the condenser cylinder, and a seawater inlet pipe B equipped with a water pump B is connected to the heat exchange coil B. The concentrated seawater tank used to collect unevaporated concentrated seawater is equipped with a heat exchange coil A, and the feed seawater pipe A, which is equipped with a water pump A, is connected to the heat exchange coil A. The upper half of the inner surface of the condenser cylinder is spirally provided with an upper heat recovery coil, and the lower half of the inner surface of the condenser cylinder is spirally provided with a lower heat recovery coil. An upper liquid distribution pipe is provided on the outer surface of the upper end of the evaporator along the circumference, and a lower liquid distribution pipe is provided on the outer surface of the middle position of the evaporator along the circumference. Both the upper and lower liquid distribution pipes are provided with several liquid distribution holes along the circumference. The heat exchange coil A is connected to the lower regenerating coil, and the lower regenerating coil is connected to the lower liquid distribution pipe; the heat exchange coil B is connected to the upper regenerating coil, and the upper regenerating coil is connected to the upper liquid distribution pipe.

[0012] In a preferred embodiment of the present invention, a tube frame is provided inside the evaporator, and the condensing sections of several heat pipes are placed on the tube frame and submerged in water, while the evaporating sections of the heat pipes extend out of the evaporator.

[0013] In a preferred embodiment of the present invention, the tube rack is a stepped columnar structure, and several heat pipes are arranged circumferentially on each step surface of the tube rack.

[0014] Beneficial effects: (1) The solar seawater desalination device of the present invention uses a heat pipe unit to provide a heat source for the seawater desalination unit. That is, the driving energy of the seawater desalination unit comes from the water in the evaporation cone. The heat of the water comes from the latent heat of condensation released by the condensation section of the heat pipe after absorbing solar radiation in the water. By using the heat pipe condensation section built in, the device achieves a high degree of integration of heat collection, heat transfer and heat supply links, which effectively reduces the heat loss of the device. It avoids the problem of poor evaporation effect caused by the mismatch between the energy supply and demand of the water heating area and the evaporation surface heating area when solar radiation is concentrated by the concentrator and transmitted from top to bottom to the water.

[0015] (2) In the solar seawater desalination device of the present invention, the water in the evaporation cone is heated by the heat pipe condensation section, so that the heat transfer direction of the device is the same as the heat and mass transfer direction, thereby improving the energy utilization efficiency of the device.

[0016] (3) In the solar seawater desalination device of the present invention, the latent heat of condensation released by water vapor on the inner surface of the condenser cylinder, the sensible heat of fresh water and concentrated seawater are used to preheat the feed seawater, thereby increasing the temperature of the seawater entering the device and reducing the heat carried away by the desalination device products; at the same time, the rapid heat transfer properties of the heat pipe phase change medium are used to power the device, avoiding the problems of large heat loss and complex structure caused by the heat exchange process, and improving the thermal energy utilization efficiency of the device.

[0017] (4) In the solar seawater desalination device of the present invention, the feed seawater after heat exchange with fresh water and concentrated seawater is respectively introduced into the liquid distribution pipe located on the evaporation surface and in the middle, so as to realize the staged evaporation of the preheated feed seawater and ensure the matching of the seawater liquid film evaporation area with the feed seawater.

[0018] (5) In the solar seawater desalination device of the present invention, the regenerating coil is spirally attached to the inner surface of the condenser cylinder, which increases the condensation area of ​​the gas-water binary mixed gas in the seawater desalination device. At the same time, the feed seawater absorbs the latent heat of condensation and the temperature rise is shortened, which is beneficial to the temperature rise time of the falling film evaporation process and the evaporation mass transfer is facilitated.

[0019] (6) In the solar seawater desalination device of the present invention, the incident solar radiation energy collected by the heat pipe is used to heat the liquid film area to be evaporated in the device. The tube frame used to place the heat pipe is stepped, so that the distribution and number of heat pipes can be matched according to the liquid film area and the area to be evaporated for heat use, thus avoiding the structural mismatch between the heat source heat supply and the heat used for evaporation in the frustum-shaped seawater desalination process.

[0020] (7) In the solar seawater desalination device of the present invention, both the condenser and the evaporator are conical, so that the surfaces of the evaporator and the condenser are arranged at an angle to each other, which reduces the flow path of water vapor in the evaporation and condensation chamber along the heat and mass transfer direction, slows down the disturbance of the airflow in the evaporation and condensation chamber caused by the rising of water vapor, and reduces the heat transfer resistance; the device is gradually expanded from top to bottom, which creates conditions for staged water intake in different areas of the evaporation surface and ensures the effective evaporation area.

[0021] (8) In the solar seawater desalination device of the present invention, the evaporator and the condenser are in a coaxial nested structure, which can realize multi-effect operation while making the condensation area of ​​each effect of the device larger than the evaporation area, effectively recovering and utilizing the latent heat of condensation of water vapor, and improving the water production rate of the device.

[0022] (9) In the solar seawater desalination device of the present invention, the working fluid in the heat pipe evaporation section contains dark-colored porous light-absorbing particles. The dark-colored porous light-absorbing particles have the dual functions of heat storage and light absorption. At the same time, the "light-trapping" porous structure of the dark-colored porous light-absorbing particles reduces the escape of light and improves the photothermal conversion efficiency of the working fluid. In addition, the light-absorbing particles float and roll when heated to generate bubbles, which increases the evaporation area of ​​the working fluid. At the same time, the particle collision causes the working fluid in the heat pipe evaporation section to mix and circulate rapidly with the working fluid that condenses and flows back in the heat pipe condensation section. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the overall structure of the device of the present invention; Figure 2 This is a three-dimensional view of the device structure of the present invention; Figure 3 This is a schematic diagram of the seawater desalination unit in the device of the present invention; Figure 4 This is a schematic diagram of the heat pipe unit in the device of the present invention; Figure 5 This is a schematic diagram of the heat pipe structure in this invention; Figure 6 This is a cross-sectional view of the heat pipe evaporation section in this invention; Figure 7 This is a diagram showing the heat pipe arrangement in this invention; Figure 8 A schematic diagram of a pyramid-shaped solar-powered seawater desalination device; Figure 9This is a diagram showing the layout of heat pipes in a pyramid-shaped solar desalination device for heating the water.

[0024] Among them, 1-condensing cone; 2-upper regenerating coil; 3-evaporating cone; 4-lower regenerating coil; 5-water baffle ring; 6-concentrated seawater outlet pipe; 7-heat exchange coil A; 8-water pump; 9-concentrated seawater tank; 10-working fluid; 11-heat pipe evaporation section; 12-parabolic reflector; 13-heat exchange coil B; 14-freshwater tank; 15-freshwater outlet pipe; 16-insulation layer; 17-lower liquid distribution pipe; 18-liquid distribution hole; 19-tube rack; 20-water body; 21-heat pipe condensing section; 22-upper liquid distribution pipe; 23-sunlight rays; 24-recirculation channel. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Based on the fundamental idea of ​​reducing heat loss during the water vapor buoyancy process and the rapid heat transfer properties of heat pipes using phase change media, this embodiment designs a solar seawater desalination device driven by an immersion heat pipe. This desalination device can improve the problems of reduced light transmittance caused by water vapor condensation at the cover plate and high heat transfer resistance and heat loss caused by long water vapor buoyancy distance in traditional solar stills.

[0027] The solar-powered seawater desalination device includes a seawater desalination unit and a heat pipe unit. The seawater desalination unit has a coaxially nested evaporator and a condenser, wherein the condenser is coaxially fitted outside the evaporator, forming a closed annular space between the two, which is the evaporation-condensation chamber.

[0028] The heat pipe unit is used to provide heat to the seawater desalination unit. The heat pipe unit includes several heat pipes, and the heat pipe condensation section 21 of each heat pipe is located in the water body 20 inside the evaporation cylinder (i.e., the heat pipe condensation section 21 is immersed in the water body 20 inside the evaporation cylinder). In this scheme, the heat required by the seawater desalination unit comes from the latent heat of condensation released by the heat pipe unit in the water body 20 where the heat pipe condensation section 21 is located after absorbing solar radiation. This avoids the problem of poor evaporation effect caused by the mismatch between the energy supply and demand of the water heating area and the evaporation surface heating area when solar radiation is concentrated from top to bottom and transmitted to the water body by a concentrator.

[0029] The outer circumference of the evaporator is covered with a water-absorbing material. The seawater fed into the evaporator is distributed across its outer circumference through distribution holes (which can also be understood as an annular water distributor) on the distribution pipe. After being absorbed by the water-absorbing material on the outer circumference, a liquid film forms. This seawater film on the outer surface of the evaporator evaporates due to heat (provided by the heat pipe unit), and the resulting water vapor condenses on the lower-temperature inner surface of the condenser to form fresh water.

[0030] In this design, the heat pipe condenser section 21 is embedded within the water body 20 of the evaporation cylinder. The water body 20 absorbs the latent heat of condensation released by the heat pipe condenser section 21 and transfers the heat to the seawater film on the outer wall of the evaporation cylinder. The seawater film heats up and evaporates, and the generated water vapor condenses on the cooler inner wall of the condenser cylinder. The heat pipe condenser section 21 is submerged within the evaporation water body 20, thus integrating heat collection, heat exchange, and heat supply into a single unit. This design features simple structure, short heat transfer distance, and low heat loss.

[0031] The seawater desalination unit and the heat pipe unit will be described in detail below.

[0032] like Figures 1-3 As shown, the seawater desalination unit includes: a condenser, an evaporator, a regenerator coil, and a liquid distribution pipe; as an example, both the condenser and the evaporator are conical, i.e., the condenser is a condenser cone 1 and the evaporator is an evaporator cone 3; the regenerator coil is used to recover and utilize the latent heat of water vapor condensation to preheat the feed seawater.

[0033] Specifically, the condensing cone 1 and the evaporating cone 3 are coaxially nested (their generatrices are parallel). The condensing cone 1 is coaxially fitted onto the outside of the evaporating cone 3, forming an annular space between them. The lower opening of this annular space is closed by an annular plate, thus forming an evaporation-condensation chamber. Both the condensing cone 1 and the evaporating cone 3 are conical, and their surfaces are arranged at an angle relative to each other. This reduces the flow path of water vapor in the evaporation-condensation chamber along the heat and mass transfer direction, slows down the disturbance of the airflow in the evaporation-condensation chamber caused by rising water vapor, reduces the heat transfer resistance, and improves the energy utilization efficiency of the device.

[0034] As an example, both the condenser cone 1 and the evaporator cone 3 are conical cylinders, such as... Figures 1-4 As shown; as another example, both the condensing cone 1 and the evaporating cone 3 are quadrangular pyramidal structures, as shown. Figure 8 and Figure 9 As shown, a pyramid-shaped solar-powered seawater desalination device is formed at this time.

[0035] As an example, the lower end of the annular space formed by the condensing cone 1 and the evaporating cone 3 is provided with a heat insulation layer 16 to reduce heat loss. This can be understood as: the annular plate provided at the lower opening of the annular space formed by the condensing cone 1 and the evaporating cone 3 has a heat insulation layer 16.

[0036] A regenerating coil is spirally installed (attached) on the inner surface of the condensing cone 1; the regenerating coil is connected to a liquid distribution pipe arranged circumferentially on the outer circumferential surface at the upper end of the evaporating cone 3; the liquid distribution pipe has distribution holes distributed circumferentially. The feed seawater (i.e., the seawater to be desalinated) first enters the regenerating coil (used to absorb the latent heat of condensation of water vapor on the inner surface of the condensing cone 1 during the operation of the device), and then enters the liquid distribution pipe, flowing out through the distribution holes on the liquid distribution pipe to form a seawater liquid film on the outer surface of the evaporating cone 3; the seawater liquid film absorbs heat and its temperature rises, and the generated water vapor condenses on the lower temperature inner surface of the condensing cone 1 to generate fresh water.

[0037] Furthermore, the seawater desalination unit also includes: a concentrated seawater tank 9 and a freshwater tank 14; wherein the freshwater tank 14 is used to collect the freshwater condensed on the inner surface of the condensing cone 1; and the concentrated seawater tank 9 is used to collect the unevaporated concentrated seawater. Specifically: a water-blocking ring 5 is provided on the annular plate at the lower end of the annular space formed by the condensing cone 1 and the evaporating cone 3, wherein the part between the water-blocking ring 5 and the condensing cone 1 is the condensed freshwater collection area, and the part between the water-blocking ring 5 and the evaporating cone 3 is the unevaporated concentrated seawater collection area; the condensed freshwater collection area is connected to the freshwater tank 14 through a freshwater outlet pipe 15, and the freshwater condensed on the inner surface of the condensing cone 1 is collected by the freshwater tank 14 through the freshwater outlet pipe 15; the unevaporated concentrated seawater collection area is connected to the concentrated seawater tank 9 through a concentrated seawater outlet pipe 6, and the unevaporated concentrated seawater is collected by the concentrated seawater tank 9 through the concentrated seawater outlet pipe 6.

[0038] Based on this, as an example, before the feed seawater enters the regenerator coil, the feed seawater is preheated by the recovered concentrated seawater in the concentrated seawater tank 9 and the fresh water in the fresh water tank 14, respectively, so as to realize the recovery and utilization of the sensible heat of the recovered concentrated seawater and the fresh water; and the sensible heat of the concentrated seawater and the fresh water is recovered and utilized to preheat the feed seawater in different areas of the evaporation surface.

[0039] Specifically: such as Figure 3 As shown, the concentrated seawater tank 9 is equipped with a heat exchange coil A7, and the feed seawater pipe A, equipped with a water pump A8, is connected to the heat exchange coil A7; the freshwater tank 14 is equipped with a heat exchange coil B13, and the feed seawater pipe B, equipped with a water pump B, is connected to the heat exchange coil B13. The regenerative coils installed on the inner surface of the condensing cone 1 include an upper regenerative coil 2 spirally installed on the upper half of the inner surface of the condensing cone 1 and a lower regenerative coil 4 spirally installed on the lower half of the inner surface of the condensing cone 1; the liquid distribution pipes installed circumferentially on the outer circumferential surface of the evaporating cone 3 include an upper liquid distribution pipe 22 located at the upper end and a lower liquid distribution pipe 17 located in the middle (here, "middle position" refers to the position between the top and bottom, and is not limited to the exact center in the height direction). Both the upper liquid distribution pipe 22 and the lower liquid distribution pipe 17 are provided with several liquid distribution holes 18 circumferentially.

[0040] Heat exchange coil A7 is connected to the lower regenerating coil 4, and the lower regenerating coil 4 is connected to the lower liquid distribution pipe 17; heat exchange coil B13 is connected to the upper regenerating coil 2, and the upper regenerating coil 2 is connected to the upper liquid distribution pipe 22. The feed seawater in feed seawater pipe A exchanges heat with the water in concentrated seawater tank 9 in heat exchange coil A7, and then enters the lower distribution pipe 17 through the lower regenerating coil 4; the feed seawater in feed seawater pipe B exchanges heat with the water in freshwater tank 14 in heat exchange coil B13, and then enters the upper distribution pipe 22 through the upper regenerating coil 2; thus, the sensible heat contained in the water in concentrated seawater tank 9 and freshwater tank 14 can be recovered and utilized. By recovering the sensible heat of concentrated seawater, the feed seawater forming a liquid film to be evaporated in the lower part with a large evaporation surface can be preheated. By recovering the sensible heat of freshwater, the feed seawater forming a liquid film to be evaporated in the upper part with a small evaporation surface can be preheated, thereby improving the thermal energy utilization efficiency and freshwater production rate of the device.

[0041] like Figure 4 and Figure 7 As shown, the heat pipe unit includes several heat pipes and a tube support platform 19; the heat pipes include an evaporation section 11 and a condensation section 21. The tube support platform 19 is located inside the evaporation cone 3. The evaporation cone 3 with the tube support platform 19 is a closed structure, and its closed space is filled with water 20 (which can be understood as: the evaporation cone 3 is a hollow cone structure with a closed bottom, the tube support platform 19 is located inside the evaporation cone 3, and the remaining space inside the evaporation cone 3 is filled with water 20). Several heat pipes are installed on the tube support platform 19, wherein the condensation section 21 of the heat pipe is immersed in the water 20, and the evaporation section 11 of the heat pipe extends out of the evaporation cone 3, that is, the evaporation section 11 of the heat pipe extends out of the bottom surface of the evaporation cone 3.

[0042] As an example, the heat pipe condensation sections 21 are staggered and submerged in the water body 20 of the evaporation cone 3, located below the inner surface of the evaporation cone 3. One implementation involves a stepped columnar structure for the tube frame 19, which can be understood as being formed by connecting several cylinders with gradually increasing diameters from top to bottom. Several heat pipes are arranged circumferentially on each step of the tube frame 19. Thus, these heat pipes are distributed in a stepped manner inside the evaporation cone 3 (specifically, the heat pipe condensation sections 21 are arranged at varying heights), with the diameter of the cylinders gradually increasing from top to bottom, and the number of heat pipes arranged circumferentially also increasing. This arrangement ensures that the heat pipe condensation sections 21 are located directly below the inner wall of the evaporation cone 3, guaranteeing that the water inside the evaporation cone 3 absorbs the latent heat of condensation from the heat pipe condensation sections and transfers the heat to the nearest evaporation cone wall, avoiding the problem of slow thermal response time and high thermal inertia caused by the heat being absorbed by the entire heated water body.

[0043] The heat pipes are arranged at varying heights on the stepped tube rack 19. To ensure that the solar radiation absorbed by the heat pipe evaporation section 11 can heat different evaporation areas within the device, the number of heat pipes is adjusted and staggered according to the evaporation area and the volume of the hot water supply, ensuring that all heat pipe evaporation sections 11 can receive solar radiation. At the same time, the heat pipe condensation sections 21 are arranged at varying heights within the water body, reducing the water temperature gradient and achieving targeted heating within the water body.

[0044] like Figure 5 As shown, a parabolic reflector 12 is axially arranged inside the heat pipe evaporation section 11, dividing the internal space of the heat pipe evaporation section 11 into two parts: region A, between the parabolic surface (concave surface) of the parabolic reflector 12 and the corresponding inner surface of the heat pipe evaporation section 11; and region B, between the back surface (convex surface) of the parabolic reflector 12 and the corresponding inner surface of the heat pipe evaporation section 11. Regions A and B are connected at the lower and upper ends of the heat pipe evaporation section 11 (the junction of the heat pipe evaporation section 11 and the heat pipe condensation section 21), and region B is a reflux channel 24. Both regions A and B are filled with working fluid 10. Light-absorbing particles are distributed in the low-boiling-point working fluid 10 in region A and at the junction of the heat pipe condensation section 21 and the heat pipe evaporation section 11. As an example, the working fluid 10 is a low-boiling-point working fluid with a boiling point below 60°C, and the light-absorbing particles are dark-colored porous particles.

[0045] like Figure 6 As shown, sunlight rays a and b are incident on the edge and surface of the parabolic reflector 12, and after reflection, they converge and are absorbed by the low-boiling-point working fluid 10 containing light-absorbing particles; sunlight rays c and d are directly incident on the low-boiling-point working fluid and are absorbed by the light-absorbing particles. The light-absorbing particles absorb solar radiation in the low-boiling-point working fluid to form multiple lattice heat sources.

[0046] like Figure 5 As shown, the low-boiling-point working fluid 10 containing light-absorbing particles absorbs sunlight 23 and is heated to evaporate. The light-absorbing particles are heated and tumble in the low-boiling-point working fluid 10 to generate bubbles, which increases the evaporation area of ​​the low-boiling-point working fluid 10. The vapor generated by the low-boiling-point working fluid 10 is condensed in the heat pipe condensing section 21 and flows down the heat pipe wall through the return channel 24 into the heat pipe evaporation section 11 to continue absorbing sunlight 23 and evaporating to increase its temperature. This cycle continues.

[0047] This solar-powered seawater desalination device is driven by a heat pipe. It achieves photothermal conversion by absorbing solar radiation through the heat pipe evaporation section. The working fluid in the heat pipe evaporation section 11 is heated and evaporates. The latent heat of condensation released by the working fluid vapor after condensation in the heat pipe condensation section 21 is transferred to the water in the evaporation cylinder through the pipe wall. The working fluid condensed in the heat pipe condensation section 21 flows back to the heat pipe evaporation section 11 under the action of gravity and absorbs heat to evaporate again. Meanwhile, the water in the evaporation cylinder continuously absorbs the latent heat of condensation released by the heat pipe condensation section 21 and its temperature rises. The heat is transferred through the evaporation cylinder to the seawater liquid film in the hydrophilic material on its outer wall through heat conduction and heat convection. The seawater liquid film is heated and its temperature rises. The generated water vapor condenses on the inner wall of the condensation cylinder at a lower temperature to generate fresh water.

[0048] The working principle of this solar-powered seawater desalination device will be described in more detail below: The low-boiling-point working fluid 10 containing light-absorbing particles in the heat pipe evaporation section 11 absorbs solar radiation and is heated to evaporate. The vapor of the low-boiling-point working fluid 10 flows to the heat pipe condensation section 21 under the action of pressure difference and condenses. The released latent heat of condensation is transferred to the water body 20 in the evaporation cone 3 through the pipe wall of the heat pipe condensation section 21. The low-boiling-point working fluid condensed in the heat pipe condensation section 21 flows down the heat pipe wall under the action of gravity and returns to the heat pipe evaporation section 11 to absorb heat and evaporate again.

[0049] The water 20 inside the evaporation cone 3 continuously absorbs the latent heat of condensation released by the low-boiling-point working liquid vapor, and transfers the heat to the seawater film in the hydrophilic material on its outer surface through the evaporation cone 3. The seawater film absorbs heat and its temperature rises, and the generated water vapor condenses on the inner surface of the condensation cone 1 at a lower temperature to form fresh water. The fresh water is collected by the fresh water tank 14 through the fresh water outlet pipe 15, and the unevaporated concentrated seawater is collected by the concentrated seawater tank 9 through the concentrated seawater outlet pipe 6.

[0050] During operation, the feed seawater can be preheated in the heat exchange coils and regenerator coils, enabling the recovery and utilization of the sensible heat and latent heat of condensation of water vapor in both fresh and concentrated seawater. Specifically, the feed seawater is drawn into the heat exchange coil A7 in the concentrated seawater tank 9 and the heat exchange coil B13 in the freshwater tank 14 by pumps A8 and B, respectively, for heat exchange with the concentrated seawater in the concentrated seawater tank 9 and the freshwater in the freshwater tank 14. Then, it enters the lower regenerator coil 4 and the upper regenerator coil 2, which are spirally attached to the inner surface of the condensing cone 1, to absorb the latent heat of condensation of water vapor on the inner surface of the condensing cone 1, and then sequentially enters the lower liquid distribution pipe 17 and the upper liquid distribution pipe 22. After flowing out through the liquid distribution hole 18, it forms a seawater liquid film in the hydrophilic material on the outer surface of the evaporation cone 3, thereby achieving staged water intake and energy matching for the device. In practical applications, multiple devices can be connected in series and parallel to achieve modular operation, depending on different freshwater production needs.

[0051] Furthermore, in practical applications, the heating strategy is adjusted according to the size of the water body in the device, with more heat supplied to larger water bodies and less heat supplied to smaller water bodies. This reflects the matching relationship between the heating side and the user side, resulting in a balance between supply and demand and reduced heat loss.

[0052] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A solar-powered seawater desalination device with submerged heat pipe-driven evaporation, characterized in that, include: Seawater desalination unit and heat pipe unit; The seawater desalination unit has an evaporator and a condenser nested on the same axis. The condenser is fitted outside the evaporator, forming a closed evaporation-condensation chamber between the two. The heat pipe unit includes several heat pipes, the heat pipe condensation section (21) of the heat pipe is located in the water body (20) inside the evaporation cylinder, and the heat pipe evaporation section (11) extends out of the evaporation cylinder; The feed seawater forms a seawater liquid film on the outer surface of the evaporator; the latent heat of condensation released by the heat pipe condensation section (21) is transferred to the seawater liquid film through the water body (20), the seawater liquid film is heated and the generated water vapor condenses on the inner wall of the condenser to generate fresh water; The heat pipe evaporation section (11) is provided with a parabolic reflector (12) along the axial direction, so that the internal space of the heat pipe evaporation section (11) is divided into region A and region B by the parabolic reflector (12); Region A is the area between the parabolic reflector (12) and the inner surface of the corresponding heat pipe evaporation section (11); Region B is the area between the back surface of the parabolic reflector (12) and the inner surface of the corresponding heat pipe evaporation section (11); Region A and Region B are connected at the lower and upper ends of the heat pipe evaporation section (11), and Region B is a reflux channel (24); both Region A and Region B are filled with working fluid (10). Both the condenser and the evaporator are conical; the heat pipe condenser section (21) is arranged at different heights and is immersed in the water body (20) of the evaporator.

2. The solar seawater desalination device with submerged heat pipe driven evaporation as described in claim 1, characterized in that, Light-absorbing particles are distributed in the working fluid (10) within region A.

3. The solar seawater desalination device with submerged heat pipe driven evaporation as described in claim 2, characterized in that, The light-absorbing particles are dark-colored porous particles.

4. The solar seawater desalination device with submersible heat pipe driven evaporation as described in any one of claims 1-3, characterized in that, The seawater desalination unit includes a regenerative coil and a liquid distribution pipe; The inner surface of the condenser cylinder is spirally provided with a heat recovery coil; The regenerative coil is connected to the liquid distribution pipe arranged circumferentially on the outer surface of the upper end of the evaporator. The liquid distribution pipe has liquid distribution holes distributed circumferentially. The feed seawater enters the distribution pipe through the regenerating coil and flows out through the distribution holes on the distribution pipe to form a seawater liquid film on the outer surface of the evaporator.

5. The solar seawater desalination device with submerged heat pipe driven evaporation as described in claim 4, characterized in that, A freshwater tank (14) for collecting freshwater generated by condensation on the inner surface of the condenser is equipped with a heat exchange coil B (13), and a seawater inlet pipe B equipped with a water pump B is connected to the heat exchange coil B (13). The concentrated seawater tank (9) used to collect unevaporated concentrated seawater is equipped with a heat exchange coil A (7), and the feed seawater pipe A, which is equipped with a water pump A (8), is connected to the heat exchange coil A (7). The upper half of the inner surface of the condenser cylinder is spirally provided with an upper heat recovery coil (2), and the lower half of the inner surface of the condenser cylinder is spirally provided with a lower heat recovery coil (4). An upper liquid distribution pipe (22) is provided on the outer surface of the upper end of the evaporator along the circumference, and a lower liquid distribution pipe (17) is provided on the outer surface of the middle position of the evaporator along the circumference. Both the upper liquid distribution pipe (22) and the lower liquid distribution pipe (17) are provided with a number of liquid distribution holes (18) along the circumference. The heat exchange coil A (7) is connected to the lower heat return coil (4), and the lower heat return coil (4) is connected to the lower liquid distribution pipe (17); the heat exchange coil B (13) is connected to the upper heat return coil (2), and the upper heat return coil (2) is connected to the upper liquid distribution pipe (22).

6. The solar seawater desalination device with submersible heat pipe driven evaporation as described in any one of claims 1-3, characterized in that, The evaporator is provided with a tube rack (19), and the heat pipe condensation section (21) of several heat pipes is placed on the tube rack (19) and immersed in water (20). The heat pipe evaporation section (11) extends out of the evaporator.

7. The solar seawater desalination device with submerged heat pipe driven evaporation as described in claim 6, characterized in that, The tube rack platform (19) is a stepped columnar structure, and several heat pipes are arranged circumferentially on each step surface of the tube rack platform (19).

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