CN114105240A

CN114105240A - Solar energy distillation sea water desalination

Info

Publication number: CN114105240A
Application number: CN202111446387.XA
Authority: CN
Inventors: 张永学; 鲁博辉; 张金亚; 罗孟熙
Original assignee: China University of Petroleum Beijing
Current assignee: China University of Petroleum Beijing
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-03-01
Anticipated expiration: 2041-11-30
Also published as: CN114105240B

Abstract

The application provides a solar energy distillation sea water desalination system, includes: a distillation subsystem and a heat supply subsystem; the distillation subsystem includes: the system comprises a low-temperature seawater storage tank, an immersion cooling tank and a tubular distiller arranged in the immersion cooling tank; the low-temperature seawater in the low-temperature seawater storage tank enters the immersion cooling tank through a seawater pipeline and is preheated by heat emitted when the tubular distiller distills the seawater to obtain high-temperature seawater, and the high-temperature seawater enters the tubular distiller to be distilled to obtain fresh water; the heating subsystem includes: a solar heat collector and a phase-change heat storage tank; when the solar radiation is sufficient, the solar heat collector heats the heat exchange fluid in the solar heat collector, and the heated heat exchange fluid is input into the tubular distiller and the phase change heat storage tank through the heat exchange pipeline; when the sun is not sufficiently irradiated, the phase change heat storage tank inputs the stored heat exchange fluid into the tubular distiller through the heat exchange pipeline. The seawater desalination device can utilize the latent heat of condensation of water vapor and the heat in the phase change heat storage tank to desalt the seawater.

Description

Solar energy distillation sea water desalination

Technical Field

The invention belongs to the technical field of solar energy utilization and seawater desalination, and particularly relates to a solar distillation seawater desalination system based on a phase change heat storage technology.

Background

In the process of ocean resource development, fresh water shortage is always a development bottleneck, and seawater desalination is an ideal choice for being developed nearby. At present, a plurality of seawater desalination technologies exist, wherein compared with seawater desalination technologies such as multi-stage flash evaporation, multi-effect distillation, electrodialysis, reverse osmosis and the like, solar seawater distillation is a very promising method by virtue of the advantages of low cost, simple structure, low salinity of produced water and the like.

However, the conventional solar distillation system still has a series of non-negligible problems in the actual operation process: firstly, the latent heat of condensation of water vapor is dissipated into the environment, which results in a large amount of heat energy loss; secondly, the normal operation of the system is influenced by the inherent intermittency of solar energy and the fluctuation of environmental factors such as weather and the like, so that the water yield is unstable; when operating at atmospheric pressure, the water vaporization temperature is higher, resulting in lower water production. Therefore, reasonable transformation on the existing solar distillation seawater desalination system is urgently needed to avoid unnecessary waste of heat energy, improve the stability of system operation and increase the water yield as much as possible.

Disclosure of Invention

To the problem among the prior art, the application provides a solar energy distillation sea water desalination system, can utilize the latent heat of condensation of vapor and the heat in the phase transition heat storage jar to carry out sea water desalination.

In order to solve the technical problem, the application provides the following technical scheme:

in a first aspect, the present application provides a solar distillation seawater desalination system comprising: a distillation subsystem and a heat supply subsystem;

the distillation subsystem includes: the system comprises a low-temperature seawater storage tank, an immersion cooling tank and a tubular distiller arranged in the immersion cooling tank;

the low-temperature seawater in the low-temperature seawater storage tank enters the immersion cooling tank through a seawater pipeline and is preheated by heat emitted when the tubular distiller distills the seawater to obtain high-temperature seawater, and the high-temperature seawater enters the tubular distiller to be distilled to obtain fresh water;

the heating subsystem includes: a solar heat collector and a phase-change heat storage tank;

when the solar radiation is sufficient, the solar heat collector heats the heat exchange fluid in the solar heat collector, and the heated heat exchange fluid is input into the tubular distiller and the phase-change heat storage tank through a heat exchange pipeline; when the sun irradiation is insufficient, the phase change heat storage tank inputs the stored heat exchange fluid into the tubular distiller through the heat exchange pipeline.

Further, the solar distillation seawater desalination system, the distillation subsystem still includes:

a high-temperature seawater storage tank for storing the high-temperature seawater;

and a first circulating water pump for pumping the high-temperature seawater from the high-temperature seawater storage tank and inputting the high-temperature seawater to the tubular still through the seawater pipeline.

and the fresh water storage tank is connected with the tubular distiller through a fresh water pipeline and is used for receiving and storing the fresh water.

and the vacuum pump is used for maintaining negative pressure in the tubular distiller, the fresh water storage tank and the high-temperature seawater storage tank so as to reduce the distillation boiling point of seawater and improve the distillation efficiency.

and the filter is arranged on a seawater pipeline between the seawater inlet and the low-temperature seawater storage tank and is used for primarily filtering impurities in seawater.

Further, in the solar distillation seawater desalination system, the bottom of the tubular distiller is provided with a heat insulation material so as to maintain the distillation efficiency of seawater.

Further, the solar distillation seawater desalination system, the heating subsystem still includes:

and the second circulating water pump is used for inputting the heated heat exchange fluid into the tubular distiller and/or the phase change heat storage tank through the heat exchange pipeline.

Further, the solar distillation seawater desalination system also comprises: a power supply subsystem, the power supply subsystem comprising:

and the photovoltaic panel is used for absorbing solar energy and converting the solar energy into electric energy so as to drive the first circulating water pump, the second circulating water pump and the vacuum pump.

Further, the solar energy distillation seawater desalination system, the power supply subsystem still includes:

a power controller and a storage battery;

the power controller is used for inputting the electric energy into the storage battery with preset power, and the storage battery drives the first circulating water pump, the second circulating water pump and the vacuum pump.

and the circuit switch is used for switching on and/or switching off the circuit between the power controller and the storage battery.

The solar distillation seawater desalination system can preheat seawater by using the latent heat of condensation of water vapor, supplies heat to a tubular distiller in a distillation subsystem by using a phase change heat storage tank when the sun is not sufficiently irradiated, reduces the evaporation temperature of the seawater by using the negative pressure of a vacuum pump so as to improve the water yield, and selects a proper vacuum pump and a circulating water pump by reasonably adjusting the opening of a valve so that the whole system is in dynamic balance.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a general block diagram of a solar distillation seawater desalination system in an embodiment of the present application;

FIG. 2 is a view showing an internal structure of a tubular still according to an embodiment of the present application.

[ notation ] to show

1. A seawater inlet; 2. a valve; 3. a filter; 4. a low temperature seawater storage tank; 5. a valve; 6. a seawater inlet of the immersion cooling tank; 7. a tubular still; 8. immersing a cooling tank; 9. a fresh water discharge port; 10. a mechanical pressure gauge; 11. a seawater outlet of the immersion cooling tank; 12. the right end surface of the tubular distiller; 13. a seawater outlet of the immersion cooling tank; 14. a tubular distiller seawater inlet; 15. an overflow port of the tubular distiller; 16. an outlet of the U-shaped heat exchange tube; 17. an inlet of the U-shaped heat exchange tube; 18. a fresh water storage tank; 19. a vacuum pump; 20. a high temperature seawater storage tank; 21. a water circulating pump; 22. a valve; 23. a valve; 24. a valve; 25. a solar heat collector; 26. a water circulating pump; 27. a valve; 28. a valve; 29. a valve; 30. a phase change heat storage tank; 31. a circuit switch; 32. a circuit switch; 33. a circuit switch; 34. a battery; 35. a power controller; 36. a photovoltaic panel; 37. a water storage tank; 38. a U-shaped heat exchange tube; 39. a thermal insulation material; 40. a seawater pipeline; 41. a fresh water pipeline.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In one embodiment, referring to fig. 1, in order to desalinate seawater by using latent heat of condensation of water vapor and heat in a phase-change heat storage tank, the present application provides a solar distillation seawater desalination system, comprising: a distillation subsystem and a heat supply subsystem.

The distillation subsystem includes: a low-temperature seawater storage tank 4, an immersion cooling tank 8 and a tubular distiller 7 arranged in the immersion cooling tank 8; wherein, the low-temperature seawater in the low-temperature seawater storage tank 4 enters the immersion cooling tank 8 through a seawater pipeline (label) and is preheated by the heat emitted when the tubular distiller 7 distills the seawater to obtain high-temperature seawater, and the high-temperature seawater enters the tubular distiller 7 to be distilled to obtain fresh water;

the heating subsystem includes: a solar heat collector 25 and a phase change heat storage tank 30; when the sun is sufficiently irradiated, the solar heat collector 25 heats the heat exchange fluid therein, and inputs the heated heat exchange fluid into the tubular distiller 7 and the phase change heat storage tank 30 through a heat exchange pipeline (reference number); when the sun is not sufficiently irradiated, the phase change heat storage tank 30 inputs the stored heat exchange fluid to the tubular still 7 through the heat exchange pipeline.

In an embodiment, referring to fig. 1, the solar distillation seawater desalination system provided by the present application further comprises: and a power supply subsystem. The power supply subsystem includes: and a photovoltaic panel 36 for absorbing solar energy and converting the solar energy into electric energy to drive the circulating water pump 21, the circulating water pump 26 and the vacuum pump 19.

In one embodiment, the power supply subsystem further comprises: a power controller 35 and a battery 34; the power controller 35 is configured to input electric energy into the battery 34 with a predetermined power, and the battery 34 drives the circulating water pump 21, the circulating water pump 26, and the vacuum pump 19.

In one embodiment, the power supply subsystem further comprises: and a circuit switch for switching on and/or off the circuit between the power controller 35 and the battery 34.

It can be understood that the solar distillation seawater desalination system provided by the application is realized based on a phase change heat storage technology, and the distillation subsystem, the heat supply subsystem and the power supply subsystem are described in detail as follows:

firstly, a seawater inlet 1, a valve 2, a filter 3, a low-temperature seawater storage tank 4, a valve 5, an immersion cooling tank 8, a tubular distiller 7, a mechanical pressure gauge 10, a fresh water storage tank 18, a high-temperature seawater storage tank 20, a plurality of valves, pipelines (which may include a seawater pipeline, a fresh water pipeline and an air pipeline), a vacuum pump 19 and a circulating water pump 21 in a distillation subsystem are shown in fig. 1 and 2.

In the distillation subsystem, low temperature seawater flows in from seawater inlet 1, enters low temperature seawater storage tank 4 through primary filtration of filter 3 under the control of valve 2, and enters submerged cooling tank 8 through submerged cooling tank seawater inlet 6 under the control of valve 5. Wherein the filter 3 is provided on the sea water line 40 between the sea water inlet 1 and the low temperature sea water storage tank 4.

The low-temperature seawater in the submerged cooling tank 8 is preheated by the latent heat of condensation of water vapor in the tubular still 7, and the preheated seawater may flow into the high-temperature seawater storage tank 20 (for storing the preheated seawater) and then pumped into the tubular still 7 by the circulating water pump 21. In other words, the circulating water pump 21 draws the high-temperature seawater from the high-temperature seawater storage tank 20 and inputs it to the pipe still 7 through the seawater pipe 40. The term "high-temperature seawater" as used herein means that the temperature thereof is increased relative to "low-temperature seawater". Finally, the high-temperature heat exchange fluid (which can be but is not limited to distilled water) heats the seawater in the tubular distiller 7 through heat exchange of a U-shaped pipe in the tubular distiller 7, so that the vapor flows upwards to meet the low-temperature top and then quickly releases latent heat to be condensed into liquid to form fresh water, and the fresh water enters the fresh water storage tank 18 through the tank wall under the action of gravity to be stored, thereby completing the seawater desalination process. Wherein the fresh water storage tank 18 is connected to the pipe still 7 via a fresh water line 41.

In one embodiment, the bottom of the pipe still 7 is provided with insulation to maintain the temperature of the pipe still 7 and thus the distillation efficiency of the seawater. In addition, when the seawater in the tubular still 7 is excessive, the seawater therein will flow back to the high temperature seawater storage tank 20 through the overflow port 15. The vacuum pump 19 can maintain the negative pressure in the tubular still 7, the fresh water storage tank 18 and the high-temperature seawater storage tank 20, and the power of the vacuum pump 19 can be adjusted by changing the indication of the mechanical pressure gauge 10. So as to reduce the distillation boiling point of the seawater and improve the distillation efficiency. The circulating water pump 21 powers the flow of seawater in the distillation subsystem to ensure that the seawater in the pipeline can flow normally.

In conclusion, the distillation subsystem can heat the seawater in the tubular distiller 7, realize the negative pressure distillation of the seawater under the action of the vacuum pump 19, and improve the efficiency of seawater desalination.

Secondly, a solar heat collector 25, a phase change heat storage tank 30, valves, pipelines (which may include a seawater pipeline, a fresh water pipeline and an air pipeline) and a circulating water pump 26 in the heating subsystem are shown in fig. 1.

When the sun is sufficiently illuminated, the high temperature heat exchange fluid (which may be, but is not limited to, distilled water) in the heating subsystem is output from the solar collector 25 by the circulating water pump 26. Wherein, a part of high-temperature heat exchange fluid directly enters the tubular distiller 7, and the high-temperature heat exchange fluid returns to the solar heat collector 25 after exchanging heat with seawater through the U-shaped pipe, and is heated by the solar heat collector 25 for a new circulation; the other part of the high-temperature heat exchange fluid enters the phase-change heat storage tank 30 to store heat in the phase-change material, and after heat storage is completed, the high-temperature heat exchange fluid returns to the solar heat collector 25 again and is heated by the solar heat collector 25 to perform a new cycle.

When the solar radiation is less, the heat energy provided by the solar heat collector 25 is only used for maintaining the normal operation of the distillation subsystem, the high-temperature heat exchange fluid flowing out of the solar heat collector 25 only enters the tubular distiller 7, exchanges heat with the seawater in the tubular distiller 7 through the U-shaped pipe, returns to the solar heat collector 25 again after the heat exchange is completed, and is heated by the solar heat collector 25 for a new circulation.

When the sun is not sufficiently irradiated, the high-temperature heat exchange fluid in the solar heat collector 25 enters the heat exchange coil in the phase-change heat storage tank 30 through the circulating water pump 26, enters the tubular distiller 7 after exchanging heat with the high-temperature phase-change material, exchanges heat with the seawater in the tubular distiller 7 through the U-shaped pipe, returns to the phase-change heat storage tank 30 after heat exchange is finished, and is circulated for a new time. That is, the circulating water pump 26 may input the heated distilled water to the pipe still 7 and/or the phase change heat storage tank 30 through the heat exchange pipeline.

In summary, the heat supply subsystem can continuously heat the heat exchange fluid to exchange heat with the seawater.

And thirdly, the photovoltaic panel 36, the power controller 35, the circuit switch 31, the circuit switch 32 and the battery 34 in the power supply subsystem are shown in fig. 1. When the sun is sufficiently irradiated, the electric energy generated by the photovoltaic panel 36 in the power supply subsystem is converted by the power controller 35 and is stored in the battery 34 partially, and the part supplies power to the circulating water pump 21, the circulating water pump 26 and the vacuum pump 19. When the sun is less irradiated, the electric energy generated by the photovoltaic panel 36 is converted by the power controller 35 to supply energy only for the circulating water pump 21, the circulating water pump 26 and the vacuum pump 19, and is not input into the battery 34 for storage. When the sun irradiation is insufficient, the energy required for the circulating water pump 21, the circulating water pump 26, and the vacuum pump 19 is supplemented by the battery 34. Wherein the power controller 35 is used to control the output power of the electric energy, and the circuit switch 31 is used to switch on/off the circuit. In summary, the power supply subsystem can utilize the photovoltaic panel to convert solar energy into electric energy, and continuously supplies power to the vacuum pump and the circulating water pump.

From the above description, the solar distillation seawater desalination system provided by the application can preheat seawater by using the latent heat of condensation of water vapor, supply heat to the tubular distiller in the distillation subsystem by using the phase change heat storage tank when the sun is not sufficiently irradiated, reduce the evaporation temperature of seawater by using the negative pressure of the vacuum pump so as to improve the water yield, and select a proper vacuum pump and a proper circulating water pump by reasonably adjusting the opening degree of the valve so that the whole system is in a dynamic balance. Wherein, the heat supply subsystem provides high-temperature hot fluid for the distillation subsystem to heat the distilled seawater. The power supply subsystem is vacuum pump and circulating water pump energy supply, and the vacuum pump can ensure to be the negative pressure in the distillation subsystem, reduces the evaporating temperature of sea water, and then improves fresh water aquatic water yield, and circulating water pump can ensure that high temperature heat transfer fluid lasts the circulation flow between distillation subsystem and heat supply subsystem. The three subsystems are independently connected and cooperatively operate in function, so that the solar technology, the seawater distillation technology and the phase change heat storage technology can be reasonably and organically integrated, and the stable and uninterrupted efficient seawater desalination for 24 hours can be realized under the negative pressure distillation type method.

In the specific implementation, three cases can be divided: sufficient sun exposure (e.g., in sunny conditions), weak sun exposure (e.g., in cloudy conditions), and insufficient sun exposure (e.g., in cloudy conditions).

The sun irradiation is sufficient: when the solar energy supply is sufficient, the

valves

22, 24, 27 and 28 are opened, and the

valves

23 and 29 are closed. The circuit switch 32 and the circuit switch 33 are opened, and the circuit switch 31 is closed. The high temperature heat exchange fluid in the solar collector 25 flows out under the action of the circulating water pump 26, and a part of the high temperature heat exchange fluid continuously enters the pipe still 7 through the valve 27 to distill seawater, and then returns to the solar collector 25 through the valve 22. The other part is used for storing heat for the phase change heat storage tank through a valve 28, the heat is returned to the solar heat collector 25 through a valve 24 after being stored, the solar heat collector 25 is used for heating the heat, and the heat supply subsystem enters a new cycle. After the electric energy generated by the photovoltaic panel 36 in the power supply subsystem passes through the power controller 35, a part of the electric energy supplies power to the vacuum pump 19, the circulating water pump 21 and the circulating water pump 26, and the other part of the electric energy charges the battery 34.

② the solar radiation is weaker: when the solar energy supply is less, the normal operation of the whole solar distillation seawater desalination system can be maintained only, and the valve 22 and the valve 27 are opened, and the valve 23, the valve 24, the valve 28 and the valve 29 are closed. Circuit switch 32 is opened and circuit switches 31 and 33 are closed. The high-temperature heat exchange fluid is output from the solar heat collector 25 through the circulating water pump 26, enters the tubular distiller 7 through the valve 27 to be distilled into seawater, and then returns to the solar heat collector 25 through the valve 22, and the heating subsystem carries out a new circulation. After passing through the power controller 35, the power generated by the photovoltaic panel 36 in the power supply subsystem is only used for supplying power to the vacuum pump 19, the circulating water pump 21 and the circulating water pump 26.

Sun irradiation is insufficient: when the solar energy is not supplied enough, the valve 23, the valve 28 and the valve 29 are opened, and the valve 22, the valve 24 and the valve 27 are closed. The high-temperature heat exchange fluid required by the seawater distillation subsystem is provided by the phase-change heat storage tank 30, the high-temperature heat exchange fluid flows out of the phase-change heat storage tank 30 through the valve 29 and enters the tubular distiller 7 to distill seawater, and after heat exchange is completed, the high-temperature heat exchange fluid enters the phase-change heat storage tank 30 through the valve 23, the circulating water pump 26 and the valve 28 to be heated, and then enters a new cycle. All of the electric power required for the vacuum pump 19, the circulating water pump 21, and the circulating water pump 26 is supplied from the battery 34.

Compared with the prior art, the solar energy distillation seawater desalination system that this application provided's beneficial effect includes at least:

1. the utilization efficiency of heat energy is high: most of the heat energy of the solar heat collector is used for seawater distillation, and the heat energy taken away by fresh water and the heat dissipation loss account for a small amount.

2. The distillation subsystem has simple structure: the single-stage tubular distiller is adopted, the latent heat of condensation of water vapor is used for preheating seawater, and compared with a three-stage or even multi-stage distiller, the single-stage tubular distiller has the advantages of better economy and lower installation and maintenance difficulty.

3. The solar energy technology, the seawater distillation technology and the phase change heat storage technology are reasonably integrated, and the seawater can be stably and uninterruptedly desalinated for 24 hours.

4. The water yield of the fresh water is improved, and the internal pressure of the tubular distiller is reduced through the vacuum pump, so that the evaporation temperature of the seawater is reduced, and the seawater is easier to evaporate.

5. The system can independently operate in an isolated island environment, does not need additional energy input after initial construction, only needs simple maintenance in the later period, and has certain universality and popularization.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the embodiment of the method implemented by the device, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to part of the description of the method embodiment.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

Although embodiments of the present description provide method steps as described in embodiments or flowcharts, more or fewer steps may be included based on conventional or non-inventive means. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the presence of additional identical or equivalent elements in a process, method, article, or apparatus that comprises the recited elements is not excluded.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment. In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an embodiment of the specification. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

The above description is only an example of the embodiments of the present disclosure, and is not intended to limit the embodiments of the present disclosure. Various modifications and variations to the embodiments described herein will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present specification should be included in the scope of the claims of the embodiments of the present specification.

Claims

1. A solar distillation seawater desalination system, comprising: a distillation subsystem and a heat supply subsystem;

the distillation subsystem includes: a low-temperature seawater storage tank (4), an immersion cooling tank (8) and a tubular distiller (7) arranged in the immersion cooling tank (8);

the low-temperature seawater in the low-temperature seawater storage tank (4) enters the immersion cooling tank (8) through a seawater pipeline and is preheated by heat emitted when the tubular distiller (7) distills the seawater to obtain high-temperature seawater, and the high-temperature seawater enters the tubular distiller (7) and is distilled to obtain fresh water;

the heating subsystem includes: a solar heat collector (25) and a phase change heat storage tank (30);

when the solar radiation is sufficient, the solar heat collector (25) heats the heat exchange fluid therein, and the heated heat exchange fluid is input to the tubular distiller (7) and the phase-change heat storage tank (30) through a heat exchange pipeline; when the sun is not sufficiently irradiated, the phase change heat storage tank (30) inputs the stored heat exchange fluid to the tubular distiller (7) through the heat exchange pipeline.

2. The solar distillation seawater desalination system of claim 1, wherein the distillation subsystem further comprises:

a high-temperature seawater storage tank (20) for storing the high-temperature seawater;

a first circulating water pump (21) which draws the high-temperature seawater from the high-temperature seawater storage tank (20) and inputs it to the tubular still (7) through the seawater line.

3. The solar distillation seawater desalination system of claim 2, wherein the distillation subsystem further comprises:

a fresh water storage tank (18) connected to the tubular still (7) by a fresh water line for receiving and storing the fresh water.

4. The solar distillation seawater desalination system of claim 3, wherein the distillation subsystem further comprises:

a vacuum pump (19) for maintaining a negative pressure in the tubular still (7), the fresh water storage tank (18) and the high temperature seawater storage tank (20) to reduce a distillation boiling point of seawater and improve distillation efficiency.

5. The solar distillation seawater desalination system of claim 1, wherein the distillation subsystem further comprises:

and the filter (3) is arranged on a seawater pipeline between the seawater inlet and the low-temperature seawater storage tank (4) and is used for primarily filtering impurities in seawater.

6. Solar distillative desalination system according to claim 1, characterized in that the bottom of the tubular still (7) is provided with insulation to maintain the distillation efficiency of the seawater.

7. The solar distillation seawater desalination system of claim 1, wherein the heating subsystem further comprises:

and the second circulating water pump (26) is used for inputting the heated heat exchange fluid to the tubular distiller (7) and/or the phase change heat storage tank (30) through the heat exchange pipeline.

8. The solar distillation seawater desalination system of claim 1, further comprising: a power supply subsystem, the power supply subsystem comprising:

and the photovoltaic panel (36) is used for absorbing solar energy and converting the solar energy into electric energy so as to drive the first circulating water pump (21), the second circulating water pump (26) and the vacuum pump (19).

9. The solar distillation seawater desalination system of claim 8, wherein the power supply subsystem further comprises:

a power controller (35) and a battery (34);

the power controller (35) is used for inputting the electric energy into the storage battery (34) with preset power, and the storage battery (34) drives the first circulating water pump (21), the second circulating water pump (26) and the vacuum pump (19).

10. The solar distillation seawater desalination system of claim 9, wherein the power supply subsystem further comprises:

a circuit switch for switching on and/or off the circuit between the power controller (35) and the battery (34).