Solar seawater desalination device for evaporation driven by immersed heat pipe

Abstract

The invention provides a solar seawater desalination device for evaporation driven by an immersed heat pipe, 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 is provided with an evaporation cylinder and a condensation cylinder which are coaxially nested, the evaporation cylinder is sleeved with the condensation 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, heat pipe condensation sections of the heat pipes are located in the water body in the evaporation barrel, and heat pipe evaporation sections extend out of the evaporation barrel; feeding seawater forms a seawater liquid film on the outer surface of the evaporation barrel; condensation latent heat released by the condensation section of the heat pipe is transmitted to the seawater liquid film through the water body, the seawater liquid film is heated, and generated water vapor is condensed on the inner wall face of the condensation cylinder to generate fresh water. According to the device, solar radiation is absorbed through the heat pipe evaporation section, photo-thermal conversion is achieved, energy is supplied to the device, high integration of heat collection, heat transfer and heat supply links of the device is achieved in the mode that the heat pipe condensation section is internally arranged, and the heat loss of the device is effectively reduced.

Description

Technical Field

[0001] The present invention relates to a seawater desalination device, and more particularly to a solar seawater desalination device driven by an immersed heat pipe for evaporation, belonging to the technical field of solar seawater desalination. Background Art

[0002] With the rapid growth of the population and the rapid development of the economy, the demand for fresh water is more urgent. The use of seawater desalination technology can effectively alleviate the problem of fresh water shortage. However, traditional seawater desalination technologies such as multi-stage flash distillation, multi-effect distillation, reverse osmosis, etc. require a large initial investment for remote areas, need professional technical personnel to operate, have high requirements for infrastructure, and are difficult to be popularized in remote and economically underdeveloped areas. These areas often have rich solar energy resources. For example, solar seawater desalination devices have attracted much attention because of their simple water production process, local materials availability, low investment and operation and maintenance costs, flexible configuration, and no consumption of fossil energy. However, due to the relatively low water production per unit of solar collector area, its large-scale application is limited. Among them, in traditional solar seawater desalination devices, water vapor often condenses on the inner surface of the cover plate, reducing the absorption of solar radiation by the device. When using a solar collector to supply heat to the device, there is a large heat loss in the heat exchange process with the water body to be heated, the heat exchange pipeline is long and complex, the heat response time is slow, the structure of the heat supply from the heat source and the heat used for evaporation does not match, and the sensible heat of fresh water and concentrated seawater and the latent heat of condensation of water vapor are not recycled, etc., which all restrict the water production performance of solar seawater desalination devices. Summary of the Invention

[0003] In view of this, the present invention provides a solar seawater desalination device driven by an immersed heat pipe for evaporation, which realizes the conversion of light heat into energy supply for the device by absorbing solar radiation through the evaporation section of the heat pipe, and realizes the highly integrated heat collection, heat transfer, and heat supply links of the device by the internal placement of the condensation section of the heat pipe, effectively reducing the heat loss of the device.

[0004] The technical solution of the present invention is as follows: A solar seawater desalination device driven by an immersed heat pipe for evaporation, comprising: a seawater desalination unit and a heat pipe unit;

[0005] The seawater desalination unit has an evaporation cylinder and a condensation cylinder nested coaxially. The condensation cylinder is sleeved outside the evaporation cylinder, and a closed evaporation and condensation cavity is formed between the two;

[0006] The heat pipe unit includes a plurality of heat pipes. The condensation section of the heat pipe is located in the water body inside the evaporation cylinder, and the evaporation section of the heat pipe extends out of the evaporation cylinder;

[0007] The feed seawater forms a seawater liquid film on the outer surface of the evaporation cylinder; the latent heat of condensation released by the condensation section of the heat pipe 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 surface of the condensation cylinder to generate fresh water.

[0008] As a preferred embodiment of the present invention, a parabolic reflecting surface is axially arranged inside the heat pipe evaporation section, so that the internal space of the heat pipe evaporation section is separated into region A and region B by the parabolic reflecting surface;

[0009] Region A is the region between the parabolic surface of the parabolic reflecting surface and the inner surface of the corresponding heat pipe evaporation section; Region B is the region between the back surface of the parabolic reflecting surface and the inner surface of the corresponding heat pipe evaporation section;

[0010] Region A and region B are communicated at the lower end and the upper end of the heat pipe evaporation section, and region B is the return channel; Both region A and region B are filled with working fluid.

[0011] As a preferred embodiment of the present invention, light-absorbing particles are distributed in the working fluid in region A.

[0012] As a preferred embodiment of the present invention, the light-absorbing particles are dark-colored porous light-absorbing particles.

[0013] As a preferred embodiment of the present invention, both the condensation cylinder and the evaporation cylinder are conical.

[0014] As a preferred embodiment of the present invention, the heat pipe condensation sections are arranged in a staggered manner of high and low and immersed in the water body of the evaporation cylinder.

[0015] As a preferred embodiment of the present invention, the seawater desalination unit includes a regenerative coil and a liquid distribution pipe;

[0016] A regenerative coil is spirally arranged on the inner surface of the condensation cylinder;

[0017] The regenerative coil is communicated with a liquid distribution pipe arranged circumferentially on the outer surface of the upper end of the evaporation cylinder;

[0018] Liquid distribution holes are circumferentially distributed on the liquid distribution pipe;

[0019] The feed seawater enters the liquid distribution pipe through the regenerative coil and flows out through the liquid distribution holes on the liquid distribution pipe to form a seawater liquid film on the outer surface of the evaporation cylinder.

[0020] As a preferred embodiment of the present invention, a heat exchange coil B is arranged in a fresh water tank for collecting fresh water condensed on the inner surface of the condensation cylinder, and a feed seawater pipe B provided with a water pump B is communicated with the heat exchange coil B;

[0021] A heat exchange coil A is arranged in a concentrated seawater tank for collecting unevaporated concentrated seawater, and a feed seawater pipe A provided with a water pump A is communicated with the heat exchange coil A;

[0022] The upper half of the inner surface of the condensation cylinder is spirally provided with an upper layer regenerative coil, and the lower half of the inner surface of the condensation cylinder is spirally provided with a lower layer regenerative coil;

[0023] An upper liquid distribution pipe is arranged circumferentially on the outer surface of the upper end of the evaporation cylinder, and a lower liquid distribution pipe is arranged circumferentially on the outer surface of the middle position of the evaporation cylinder;

[0024] A plurality of liquid distribution holes are arranged circumferentially on both the upper liquid distribution pipe and the lower liquid distribution pipe;

[0025] The heat exchange coil A is communicated with the lower regenerative coil, and the lower regenerative coil is communicated with the lower liquid distribution pipe; the heat exchange coil B is communicated with the upper regenerative coil, and the upper regenerative coil is communicated with the upper liquid distribution pipe.

[0026] As a preferred embodiment of the present invention, a pipe support platform is arranged in the evaporation cylinder, and the heat pipe condensation sections of a plurality of heat pipes are placed on the pipe support platform and immersed in the water body, and the heat pipe evaporation sections extend out of the evaporation cylinder.

[0027] As a preferred embodiment of the present invention, the pipe support platform is a stepped columnar structure, and a plurality of heat pipes are arranged at intervals circumferentially on each step surface of the pipe support platform.

[0028] Beneficial effects:

[0029] (1) The solar seawater desalination device of the present invention uses the heat pipe unit to provide heat source for the seawater desalination unit, that is, the driving energy of the seawater desalination unit comes from the water body in the evaporation cone cylinder; and the heat of the water body comes from the latent heat of condensation released by the heat pipe condensation section in the water body after absorbing solar radiation. By the way of arranging the heat pipe condensation section inside, the highly integrated heat collection, heat transfer and heat supply links of the device are realized, effectively reducing the heat loss of the device; avoiding the problem of poor evaporation effect caused by the mismatch between the energy supply and demand of the water body heating area and the heat using area of the evaporation surface when the solar radiation is converged by the concentrating device and transmitted from top to bottom to the water body.

[0030] (2) In the solar seawater desalination device of the present invention, the heat pipe condensation section is used to heat the water body in the evaporation cone cylinder, so that the heat transfer direction of the device is the same as the heat and mass transfer direction, improving the energy utilization efficiency of the device.

[0031] (3) In the solar seawater desalination device of the present invention, the latent heat of condensation released by the water vapor on the inner surface of the condensation cylinder, the sensible heat of fresh water and concentrated seawater are used to preheat the feed seawater, increasing the temperature of the seawater entering the device and reducing the heat taken away by the products of the desalination device; at the same time, the rapid heat transfer property of the heat pipe phase change medium is used to supply energy for 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.

[0032] (4) In the solar desalination device of the present invention, the feed seawater after being heated by fresh water and concentrated seawater is respectively introduced into the liquid distribution pipes on the upper and middle parts of the evaporation surface, realizing the staged evaporation of the preheated feed seawater and ensuring the matching of the seawater liquid film evaporation area and the feed seawater.

[0033] (5) In the solar desalination device of the present invention, the regenerative coil is spirally attached to the inner surface of the condensation cylinder, increasing the condensation area of the gas-liquid binary mixed gas in the desalination device. At the same time, the feed seawater absorbs the latent heat of condensation and the temperature rises, shortening the temperature rise time of the falling film evaporation process and facilitating evaporation mass transfer.

[0034] (6) In the solar 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 pipe rack platform for placing the heat pipe is in a stepped shape, so that the distribution and quantity of the heat pipes can be matched according to the liquid film area and the heat area to be evaporated, avoiding the structural mismatch between the heat supply amount of the heat source and the evaporation heat consumption in the conical desalination process.

[0035] (7) In the solar desalination device of the present invention, both the condensation cylinder and the evaporation cylinder are conical, and the evaporation cylinder and the condensation cylinder are arranged obliquely relative to each other on the surface, reducing the flow path of the water vapor in the evaporation and condensation cavity along the heat and mass transfer direction, delaying the disturbance of the air flow in the evaporation and condensation cavity caused by the floating of the water vapor, and reducing the heat transfer resistance; the device is gradually expanding from top to bottom, creating conditions for realizing staged water inlet in different areas of the evaporation surface and ensuring the effective evaporation area.

[0036] (8) In the solar desalination device of the present invention, the evaporation cylinder and the condensation cylinder are in a coaxial nested structure, which can realize multi-effect operation and make the condensation area of each effect of the device larger than the evaporation area, effectively recovering and utilizing the latent heat of condensation of the water vapor and improving the water production rate of the device.

[0037] (9) In the solar desalination device of the present invention, there are dark porous light-absorbing particles in the working fluid of the heat pipe evaporation section. The dark 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 porous light-absorbing particles reduces the escaping light and improves the photothermal conversion efficiency of the working fluid; in addition, the light-absorbing particles float and tumble when heated to generate bubbles, increasing the evaporation area of the working fluid. At the same time, the particle collision enables the working fluid in the heat pipe evaporation section and the working fluid condensed and flowing back in the heat pipe condensation section to be quickly mixed and circulated for evaporation. Description of the Drawings

[0038] Figure 1 is the overall structural sectional view of the device of the present invention;

[0039] Figure 2 is the three-dimensional view of the device structure of the present invention;

[0040] Figure 3It is a schematic structural diagram of the seawater desalination unit in the device of the present invention;

[0041] Figure 4 It is a schematic structural diagram of the heat pipe unit in the device of the present invention;

[0042] Figure 5 It is a schematic structural diagram of the heat pipe in the present invention;

[0043] Figure 6 It is a sectional view of the evaporation section of the heat pipe in the present invention;

[0044] Figure 7 It is an arrangement diagram of the heat pipes in the present invention;

[0045] Figure 8 It is a schematic structural diagram of the pyramid-shaped solar seawater desalination device;

[0046] Figure 9 It is an arrangement diagram of the heat pipes in the pyramid-shaped solar seawater desalination device for heating the water body.

[0047] Among them, 1 - condensation cone; 2 - upper regenerative coil; 3 - evaporation cone; 4 - lower regenerative 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 - evaporation section of heat pipe; 12 - parabolic reflector; 13 - heat exchange coil B; 14 - fresh water tank; 15 - fresh water outlet pipe; 16 - heat insulation layer; 17 - lower liquid distribution pipe; 18 - liquid distribution holes; 19 - pipe support platform; 20 - water body; 21 - condensation section of heat pipe; 22 - upper liquid distribution pipe; 23 - solar rays; 24 - return channel. Specific embodiments

[0048] The present invention will be further described below in conjunction with the drawings and embodiments.

[0049] In this embodiment, based on the basic idea of reducing heat loss during the floating and transmission process of water vapor and the rapid heat transfer property of the heat pipe using a phase change medium, a solar seawater desalination device driven by an immersion heat pipe for evaporation is designed. This seawater desalination device can improve the problems of reduced light transmittance caused by the condensation of water vapor at the cover plate and large heat transfer resistance and much heat loss caused by the long floating distance of water vapor in a traditional solar distiller.

[0050] The solar seawater desalination device includes: a seawater desalination unit and a heat pipe unit; the seawater desalination unit has an evaporation cylinder and a condensation cylinder nested coaxially, where the condensation cylinder is coaxially sleeved outside the evaporation cylinder, and a closed annular space is formed between the two, and this annular space is the evaporation and condensation cavity.

[0051] The heat pipe unit is used to provide heat to the seawater desalination unit; the heat pipe unit includes a plurality of heat pipes, and the heat pipe condensation section 21 of each heat pipe is located in the water body 20 inside the evaporation cylinder (that is, the heat pipe condensation section 21 is immersed in the water body 20 inside the evaporation cylinder); in this solution, the heat required by the seawater desalination unit comes from the latent heat of condensation released in the water body 20 where the heat pipe condensation section 21 is located after the heat pipe unit absorbs solar radiation; thus, it can avoid the problem of poor evaporation effect caused by the mismatch between the energy supply and demand of the water body heating area and the heat using area of the evaporation surface when traditional solar radiation is concentrated by the concentrator and transmitted from top to bottom to the water body.

[0052] The outer circumferential surface of the evaporation cylinder is provided with a water-absorbing material; the feed seawater is distributed on the outer circumferential surface of the evaporation cylinder through the liquid distribution holes on the liquid distribution pipe (which can also be understood as an annular water distributor), and after being absorbed by the water-absorbing material on the outer circumferential surface of the evaporation cylinder, a liquid film is formed on the outer circumferential surface of the evaporation cylinder. The seawater liquid film on the outer surface of the evaporation cylinder is heated (the heat provided by the heat pipe unit) and evaporated, and the generated water vapor condenses on the inner surface of the condensation cylinder with a lower temperature to generate fresh water.

[0053] In this solution, by placing the heat pipe condensation section 21 inside the water body 20 of the evaporation cylinder, the water body 20 absorbs the latent heat of condensation released by the heat pipe condensation section 21 and transfers the heat to the seawater liquid film on the outer wall surface of the evaporation cylinder. The seawater liquid film is heated and evaporated, and the generated water vapor condenses on the inner wall surface of the condensation cylinder with a lower temperature. The heat pipe condensation section 21 is immersed in the evaporation water body 20, making the heat collection, heat exchange, and heat supply links of the device integrated, with the characteristics of simple structure, short heat transfer distance, and small heat loss.

[0054] The seawater desalination unit and the heat pipe unit will be introduced in detail below.

[0055] As Figures 1 - 3 shown, the seawater desalination unit includes: a condensation cylinder, an evaporation cylinder, a regenerative coil, and a liquid distribution pipe; as an example, both the condensation cylinder and the evaporation cylinder are conical, that is, the condensation cylinder is a condensation conical cylinder 1, and the evaporation cylinder is an evaporation conical cylinder 3; the regenerative coil is used to recover and utilize the latent heat of condensation of water vapor to preheat the feed seawater.

[0056] Specifically: The condensation conical cylinder 1 and the evaporation conical cylinder 3 are coaxially nested structures (the generatrices of the two are parallel), the condensation conical cylinder 1 is coaxially sleeved outside the evaporation conical cylinder 3, and an annular space is formed between the two; the lower opening of the annular space is closed by an annular plate, thereby forming an evaporation-condensation cavity. Both the condensation conical cylinder 1 and the evaporation conical cylinder 3 are conical, so that the surfaces of the condensation conical cylinder 1 and the evaporation conical cylinder 3 are arranged obliquely relative to each other, reducing the flow path of water vapor in the evaporation-condensation cavity along the heat and mass transfer direction, delaying the disturbance of the air flow in the evaporation-condensation cavity caused by the floating of water vapor, reducing the heat transfer resistance, and improving the energy utilization efficiency of the device.

[0057] As an example, both the condensation conical cylinder 1 and the evaporation conical cylinder 3 are conical cylinders, asFigures 1 - 4 As shown; as another example, both the condensation cone 1 and the evaporation cone 3 are in the shape of a quadrangular pyramid, as Figure 8 and Figure 9 shown, and at this time, a pyramid-shaped solar seawater desalination device is formed.

[0058] As an example, a heat preservation layer 16 is provided at the lower end of the annular space formed by the condensation cone 1 and the evaporation cone 3 to reduce heat dissipation loss. It can be understood that: the annular plate provided at the lower end opening of the annular space formed by the condensation cone 1 and the evaporation cone 3 has a heat preservation layer 16.

[0059] The inner surface of the condensation cone 1 is spirally arranged (adhered) with a heat recovery coil; the heat recovery coil is communicated with a liquid distribution pipe arranged circumferentially on the outer circumferential surface at the upper end of the evaporation cone 3; liquid distribution holes are distributed circumferentially on the liquid distribution pipe. The feed seawater (i.e., the seawater to be desalinated) first enters the heat recovery coil (used to absorb the latent heat of condensation of water vapor on the inner surface of the condensation cone 1 during the operation of the device), and then enters the liquid distribution pipe, and flows out through the liquid distribution holes on the liquid distribution pipe to form a seawater liquid film on the outer surface of the evaporation cone 3; the seawater liquid film absorbs heat and the temperature rises, and the generated water vapor condenses on the inner surface of the condensation cone 1 with a lower temperature to generate fresh water.

[0060] Furthermore, the seawater desalination unit further includes: a concentrated seawater tank 9 and a fresh water tank 14; wherein the fresh water tank 14 is used to collect the fresh water condensed on the inner surface of the condensation cone 1; the concentrated seawater tank 9 is used to collect the unevaporated concentrated seawater. Specifically: a water retaining ring 5 is provided on the annular plate at the lower end of the annular space formed by the condensation cone 1 and the evaporation cone 3, and the part between the water retaining ring 5 and the condensation cone 1 is the condensation fresh water collection area, and the part between the water retaining ring 5 and the evaporation cone 3 is the unevaporated concentrated seawater collection area; the condensation fresh water collection area is communicated with the fresh water tank 14 through a fresh water outlet pipe 15, and the fresh water condensed on the inner surface of the condensation cone 1 is collected by the fresh water tank 14 through the fresh water outlet pipe 15; the unevaporated concentrated seawater collection area is communicated with 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.

[0061] On this basis, as an example, before the feed seawater enters the heat recovery coil, the feed seawater is preheated respectively by the recycled concentrated seawater in the concentrated seawater tank 9 and the fresh water in the fresh water tank 14 to realize the recovery and utilization of the sensible heat of the recycled concentrated seawater and fresh water; and the sensible heat of the concentrated seawater and fresh water is respectively recovered and utilized to preheat the feed seawater in different areas of the evaporation surface.

[0062] Specifically: as Figure 3As shown in the figure, a heat exchange coil A7 is provided in the concentrated seawater tank 9, and the feed seawater pipe A provided with a water pump A8 is communicated with the heat exchange coil A7; a heat exchange coil B13 is provided in the fresh water tank 14, and the feed seawater pipe B provided with a water pump B is communicated with the heat exchange coil B13. The regenerative coil provided on the inner surface of the condensation cone 1 includes an upper regenerative coil 2 spirally provided on the upper half of the inner surface of the condensation cone 1 and a lower regenerative coil 4 spirally provided on the lower half of the inner surface of the condensation cone 1; the liquid distribution pipe provided on the outer circumferential surface of the evaporation cone 3 along the circumferential direction includes an upper liquid distribution pipe 22 at the upper end and a lower liquid distribution pipe 17 at the middle position (here, the "middle position" refers to the position between the top and the bottom, and does not limit the exact middle in the height direction). A plurality of liquid distribution holes 18 are provided along the circumferential direction on both the upper liquid distribution pipe 22 and the lower liquid distribution pipe 17.

[0063] The heat exchange coil A7 is communicated with the lower regenerative coil 4, and the lower regenerative coil 4 is communicated with the lower liquid distribution pipe 17; the heat exchange coil B13 is communicated with the upper regenerative coil 2, and the upper regenerative coil 2 is communicated with the upper liquid distribution pipe 22. The feed seawater in the feed seawater pipe A exchanges heat with the water body in the concentrated seawater tank 9 in the heat exchange coil A7, and then enters the lower liquid distribution pipe 17 through the lower regenerative coil 4; the feed seawater in the feed seawater pipe B exchanges heat with the water body in the fresh water tank 14 in the heat exchange coil B13, and then enters the upper liquid distribution pipe 22 through the upper regenerative coil 2; thus, the sensible heat contained in the water bodies in the concentrated seawater tank 9 and the fresh water tank 14 can be recovered and utilized. By recovering the sensible heat of the concentrated seawater, the feed seawater forming the seawater liquid film to be evaporated at the lower part with a larger evaporation surface is preheated, and by recovering the sensible heat of the fresh water, the feed seawater forming the seawater liquid film to be evaporated at the upper part with a smaller evaporation surface is preheated, thereby improving the thermal energy utilization efficiency and the fresh water production rate of the device.

[0064] As Figure 4 and Figure 7 shown in the figure, the heat pipe unit includes a plurality of heat pipes and a pipe support platform 19; the heat pipe includes a heat pipe evaporation section 11 and a heat pipe condensation section 21. The pipe support platform 19 is located inside the evaporation cone 3, and the evaporation cone 3 provided with the pipe support platform 19 is a closed structure, and the enclosed space therein is a water body 20 (it can be understood that: the evaporation cone 3 is a hollow conical structure with a closed bottom, the pipe support platform 19 is located inside the evaporation cone 3, and then the remaining space inside the evaporation cone 3 is filled with the water body 20). A plurality of heat pipes are provided on the pipe support platform 19, wherein the heat pipe condensation section 21 is immersed in the water body 20, and the heat pipe evaporation section 11 extends out of the evaporation cone 3, that is, the heat pipe evaporation section 11 extends out of the evaporation cone 3 from the bottom surface of the evaporation cone 3.

[0065] As an example, the condensation sections 21 of the heat pipes are arranged in an interleaved manner and immersed in the water body 20 of the evaporation cone 3, below the inner surface of the evaporation cone 3. One implementation is that the pipe support platform 19 is a stepped columnar structure, which can be understood as formed by successively docking several cylindrical shapes with gradually increasing diameters from top to bottom; several heat pipes are arranged at intervals along the circumferential direction on each step surface of the pipe support platform 19; thus, several heat pipes are distributed in a stepped manner inside the evaporation cone 3 (specifically, the condensation sections 21 of the heat pipes are arranged in a staggered manner with different heights), and the diameters of the cylindrical shapes gradually increase from top to bottom, and the number of heat pipes arranged along the circumferential direction also increases. And this arrangement ensures that the condensation sections 21 of the heat pipes are directly below the inner wall surface of the evaporation cone 3, ensuring that the heat transfer from the latent heat of condensation of the heat pipe condensation section absorbed by the water body in the evaporation cone 3 to the evaporation cone wall surface closest in distance, avoiding the problems of slow thermal response time and large thermal inertia of the device caused by the heat being absorbed by the entire heated water body.

[0066] The heat pipes are distributed in a scattered manner on the stepped pipe support platform 19. To ensure that the solar radiation absorbed by the evaporation sections 11 of the heat pipes can supply heat to different evaporation area regions in the device, the number of heat pipes is adjusted according to the evaporation area and the volume of the hot water body, and the staggered distribution ensures that the evaporation sections 11 of the heat pipes can all receive solar radiation. At the same time, by using the staggered arrangement of the condensation sections 21 of the heat pipes in the water body, the temperature gradient of the water body is reduced, realizing local heating in the water body.

[0067] As Figure 5 shown, a parabolic reflecting surface 12 is axially arranged inside the evaporation section 11 of the heat pipe, dividing the internal space of the evaporation section 11 of the heat pipe into two parts on the left and right by the parabolic reflecting surface 12, namely the region A between the parabolic surface (concave surface) of the parabolic reflecting surface 12 and the inner surface of the corresponding evaporation section 11 of the heat pipe, and the region B between the back surface (convex surface) of the parabolic reflecting surface 12 and the inner surface of the corresponding evaporation section 11 of the heat pipe; region A and region B are connected at the lower end and the upper end (the docking end of the evaporation section 11 of the heat pipe and the condensation section 21 of the heat pipe) of the evaporation section 11 of the heat pipe, and region B is the return channel 24. Both region A and region B are filled with the working fluid 10, and light-absorbing particles are distributed in the low-boiling-point working fluid 10 in region A and at the junction of the condensation section 21 and the evaporation section 11 of the heat pipe; as an example, the working fluid 10 is a low-boiling-point working fluid with a boiling point lower than 60 °C, and the light-absorbing particles are dark-colored porous particles.

[0068] As Figure 6 shown, the solar rays a, b are incident on the edge and surface of the parabolic reflecting surface 12, and after reflection, they converge and are absorbed by the low-boiling-point working fluid 10 containing light-absorbing particles; the rays c, d are directly incident into the low-boiling-point working fluid and are absorbed by the light-absorbing particles, and the light-absorbing particles absorb solar radiation in the low-boiling-point working fluid to form multiple dot matrix heat sources.

[0069] As Figure 5As shown, the low-boiling working fluid 10 containing light-absorbing particles absorbs solar rays 23, heats up, rises in temperature, evaporates, and the light-absorbing particles tumble and generate bubbles in the low-boiling working fluid 10, increasing the evaporation area of the low-boiling working fluid 10. The vapor generated by the low-boiling working fluid 10 condenses in the condensation section 21 of the heat pipe, then flows down along the heat pipe wall, enters the evaporation section 11 of the heat pipe through the return channel 24, and continues to absorb solar rays 23, heat up, and evaporate, thus cycling.

[0070] This solar desalination device is driven by a heat pipe. The heat pipe evaporation section absorbs solar radiation to achieve photo-thermal conversion. The working fluid in the heat pipe evaporation section 11 is heated and evaporated. The latent heat of condensation released after the vapor of the working fluid condenses in the heat pipe condensation section 21 is transferred to the water body in the evaporation cylinder through the pipe wall. The working fluid that condenses in the heat pipe condensation section 21 flows back along the inner wall of the pipe to the heat pipe evaporation section 11 under the action of gravity and absorbs heat and evaporates again. The water body in the evaporation cylinder continuously absorbs the latent heat of condensation released by the heat pipe condensation section 21, rises in temperature, and transfers the heat to the seawater liquid film in the hydrophilic material on the outer wall surface of the evaporation cylinder through heat conduction and heat convection. The seawater liquid film heats up, and the generated water vapor condenses on the inner wall surface of the condensation cylinder with a lower temperature to form fresh water.

[0071] The working principle of this solar desalination device is described in more detail as follows:

[0072] The low-boiling working fluid 10 containing light-absorbing particles in the heat pipe evaporation section 11 absorbs solar radiation, heats up, rises in temperature, and evaporates. The vapor of the low-boiling 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 wall of the heat pipe condensation section 21. The low-boiling working fluid that condenses in the heat pipe condensation section 21 flows down along the heat pipe wall and returns to the heat pipe evaporation section 11 to absorb heat and evaporate again.

[0073] The water body 20 in the evaporation cone 3 continuously absorbs the latent heat of condensation released by the vapor of the low-boiling working fluid, rises in temperature, and transfers the heat to the seawater liquid film in the hydrophilic material on its outer surface through the evaporation cone 3. The seawater liquid film absorbs heat and rises in temperature. The generated water vapor condenses on the inner surface of the condensation cone cylinder 1 with 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 7 through the concentrated seawater outlet pipe 6.

[0074] During the operation of the device, the feed seawater can also be preheated in the heat exchange coil and the regenerative heat exchange coil, realizing the recovery and utilization of the sensible heat of fresh water and concentrated seawater and the latent heat of water vapor condensation. Specifically: The feed seawater is respectively sucked by pump A8 and pump B into heat exchange coil A7 located in the concentrated seawater tank 9 and heat exchange coil B13 located in the fresh water tank 14, and exchanges heat with the concentrated seawater in the concentrated seawater tank 9 and the fresh water in the fresh water tank 14; then it enters the lower regenerative heat exchange coil 4 and the upper regenerative heat exchange coil 2 spirally attached to the inner surface of the condensation cone 1 respectively, absorbs the latent heat of water vapor condensation on the inner surface of the condensation cone 1, and then enters the lower liquid distribution pipe 17 and the upper liquid distribution pipe 22 in sequence, and flows out through the liquid distribution holes 18 to form a seawater liquid film in the hydrophilic material on the outer surface of the evaporation cone 3, thereby realizing the staged water inlet and energy matching of the device.

[0075] In practical applications, according to different fresh water production requirements, multiple devices can be connected in series and parallel to achieve modular operation.

[0076] In addition, in practical applications, the heating strategy is adjusted according to the water volume of the device, with more heating for large water bodies and less heating for small water bodies, reflecting the matching relationship between the heating side and the user side, making the supply and demand balanced and reducing heat loss.

[0077] The above content is a further detailed description of the present invention in combination with specific embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A solar seawater desalination device driven by an immersion heat pipe for evaporation, characterized in that, Comprising: A seawater desalination unit and a heat pipe unit; The seawater desalination unit has an evaporation cylinder and a condensation cylinder nested coaxially. The condensation cylinder is sleeved outside the evaporation cylinder, and a closed evaporation and condensation cavity is formed between the two; The heat pipe unit includes a plurality of 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 evaporation cylinder; 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 temperature rises, and the generated water vapor condenses on the inner wall surface of the condensation cylinder to generate fresh water.

2. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 1, characterized in that A parabolic reflecting surface (12) is axially arranged inside the heat pipe evaporation section (11), so that the internal space of the heat pipe evaporation section (11) is divided into area A and area B by the parabolic reflecting surface (12); Area A is the area between the parabolic surface of the parabolic reflecting surface (12) and the inner surface of the corresponding heat pipe evaporation section (11); Area B is the area between the back surface of the parabolic reflecting surface (12) and the inner surface of the corresponding heat pipe evaporation section (11); Area A and area B communicate at the lower end and upper end of the heat pipe evaporation section (11), and area B is the return channel (24); Both area A and area B are filled with the working fluid (10).

3. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 2, characterized in that Light-absorbing particles are distributed in the working fluid (10) in area A.

4. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 3, characterized in that, The light-absorbing particles are dark-colored porous particles.

5. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 1, wherein, Both the condensation cylinder and the evaporation cylinder are conical.

6. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 5, characterized in that, The heat pipe condensation sections (21) are arranged in a staggered manner in height and immersed in the water body (20) of the evaporation cylinder.

7. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to any one of claims 1-6, characterized in that, The seawater desalination unit includes a regenerative coil and a liquid distribution pipe; A regenerative coil is spirally arranged on the inner surface of the condensation cylinder; The regenerative coil communicates with the liquid distribution pipe arranged circumferentially on the outer surface of the upper end of the evaporation cylinder; Liquid distribution holes are distributed circumferentially on the liquid distribution pipe; The feed seawater enters the liquid distribution pipe through the regenerative coil, and flows out through the liquid distribution holes on the liquid distribution pipe to form a seawater liquid film on the outer surface of the evaporation cylinder.

8. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 5 or 6, characterized in that, A heat exchange coil B (13) is arranged in the fresh water tank (14) for collecting the fresh water condensed on the inner surface of the condensation cylinder. The feed seawater pipe B provided with a water pump B communicates with the heat exchange coil B (13); A heat exchange coil A (7) is arranged in the concentrated seawater tank (9) for collecting the unevaporated concentrated seawater. The feed seawater pipe A provided with a water pump A (8) communicates with the heat exchange coil A (7); The upper half of the inner surface of the condensation cylinder is spirally provided with an upper-layer regenerative coil (2), and the lower half of the inner surface of the condensation cylinder is spirally provided with a lower-layer regenerative coil (4); An upper-layer liquid distribution pipe (22) is arranged circumferentially on the outer surface of the upper end of the evaporation cylinder, and a lower-layer liquid distribution pipe (17) is arranged circumferentially on the outer surface of the middle position of the evaporation cylinder; A number of liquid distribution holes (18) are arranged circumferentially on both the upper-layer liquid distribution pipe (22) and the lower-layer liquid distribution pipe (17); The heat exchange coil A (7) is communicated with the lower regenerative heat exchange coil (4), and the lower regenerative heat exchange coil (4) is communicated with the lower liquid distribution pipe (17); the heat exchange coil B (13) is communicated with the upper regenerative heat exchange coil (2), and the upper regenerative heat exchange coil (2) is communicated with the upper liquid distribution pipe (22).

9. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to any one of claims 1-6, characterized in that, A pipe support platform (19) is arranged in the evaporation cylinder, and the heat pipe condensation sections (21) of a plurality of heat pipes are placed on the pipe support platform (19) and immersed in the water body (20), and the heat pipe evaporation sections (11) extend out of the evaporation cylinder.

10. The solar seawater desalination device driven by an immersion heat pipe for evaporation according to claim 9, wherein, The pipe support platform (19) is of a stepped columnar structure, and a plurality of heat pipes are arranged at intervals along the circumferential direction on each step surface of the pipe support platform (19).

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