CN105948152A - Seawater distilling and desalting device floating on sea surface and desalting method - Google Patents

Abstract

The invention discloses a sea surface floating seawater distillation and desalination device and a desalination method, belonging to the field of seawater desalination. The seawater distillation and desalination device of the present invention includes a seawater container and a distillation hood arranged on the seawater container, and also includes a water storage tank, a water supply mechanism, a drainage mechanism and an electric power system. The seawater container is fixed below the distillation hood, and the seawater container and The distillation hoods are connected, and the bottom of the distillation hood is an annular sump, and the water in the sump flows into the water storage tank through the drainage pipe; the water supply mechanism is used to transport seawater into the seawater container, and the drainage mechanism is used to drain the water from the water storage tank. The fresh water is discharged, and the power system provides electricity for the water supply mechanism and the drainage mechanism through wind power generation and/or hydropower generation. The invention performs seawater desalination through distillation, has high desalination efficiency, and converts various energy sources into electric energy by itself, can be directly used independently on the sea surface, has a stable structure, and is suitable for development and utilization on islands and reefs.

Description

Sea surface floating seawater distillation and desalination device and desalination method

technical field

The invention relates to the technical field of seawater desalination, more specifically, to a sea surface floating seawater distillation and desalination device and a desalination method.

Background technique

Water is the source of life and the foundation of economic and social development. With economic development and social progress, the demand and quality of fresh water resources will continue to increase. my country has a coastline of 18,000 kilometers, among which there are 6,961 islands with an area of more than 500 square meters. They are not only bases for marine fishing, offshore aquaculture and marine resource protection, but also military bases and border defenses with strategic significance for national defense. outpost. Most of these islands lack fresh water resources, and the water quality often does not meet sanitary standards; some islands have no fresh water at all, and they mainly rely on supply ships to supply fresh water, which is expensive and easily affected by weather conditions. Some very remote islands still have power shortage and no supply. Using traditional fossil fuels (coal, oil) to solve the energy problem of seawater desalination not only easily destroys the ecosystem of the island, but also has high operation and maintenance costs.

As an important maritime strategic base, the South my country Sea of China needs to continuously improve various infrastructure works. However, due to the scarcity of fresh water resources, it is necessary to transport water resources from the inland to meet the water demand of the island. As mentioned above, if other energy sources are used for seawater desalination, it is easy to destroy the ecological balance on the island, and various resources still need to be transported from the inland, instead of using local materials for seawater desalination, this problem is common in all islands and reefs question.

After searching, it is found that there are many seawater desalination schemes in the prior art. For example, Patent No. 201420809193.0 records a container-type solar seawater desalination device, which is mainly composed of solar photovoltaic power generation device, seawater pretreatment device, reverse osmosis device, deep It consists of a boron removal device and an intelligent control device. The solar cell array is connected and installed on the top of the container in a certain way, and other devices are integrated and installed in the container through pipelines or wires. The device uses solar energy to desalinate seawater, but if the water demand on the islands and reefs is to be met, a larger place is needed to place the device, and the area of the islands and reefs itself is small, so there is a certain demand contradiction.

Chinese Patent No. 201410300763.8 discloses a high-efficiency distillation seawater desalinator, including a desalinator cylinder, a seawater inlet is provided on one side of the top of the desalinator cylinder, one side of the seawater inlet is connected to a flow equalizing pipe, and the other side of the seawater inlet is connected to a sedimentation tank. The flow equalizing pipe is arranged on the top of the desalinator cylinder, and the spray nozzle is arranged on the flow equalizing pipe. The heat exchange tube assembly is arranged inside the desalinator cylinder, and the heat exchange tube assembly includes multiple sets of heat exchange tube bundles. On the lower side of the flow equalizing tube, a fresh water guide tube is provided at the bottom of the desalinator cylinder, and a fresh water outlet is provided at the bottom of the fresh water guide tube. The device uses heat exchange tubes to speed up the distillation process to improve the efficiency of seawater desalination, but how to generate electricity on the island is also a big problem. If it is on an isolated island, it is difficult to transmit electricity from the inland, so the device cannot be implemented. .

Contents of the invention

1. The technical problem to be solved by the invention

The purpose of the present invention is to overcome the deficiency that the seawater desalination device in the prior art cannot be used independently on the sea surface, and provides a sea surface floating seawater distillation and desalination device and desalination method. The present invention performs seawater desalination through distillation, with high desalination efficiency and It converts various energy sources into electric energy by itself, which can be directly used independently on the sea surface, has a stable structure, and is suitable for development and utilization on islands and reefs.

2. Technical solution

In order to achieve the above object, the technical scheme provided by the invention is:

A sea surface floating seawater distillation and desalination device of the present invention comprises a seawater container and a distillation hood arranged on the seawater container, and also includes a water storage tank, a water supply mechanism, a drainage mechanism and an electric power system, and the seawater container is fixed on the distillation hood Below, the seawater container is connected with the distillation hood, and the bottom of the distillation hood is an annular sump, and the water in the sump flows into the water storage tank through the drainage tube; the water supply mechanism is used to transport seawater into the seawater container, and the drainage mechanism is used to The fresh water in the water storage tank is discharged, and the power system provides electric energy for the water supply mechanism and the drainage mechanism through wind power generation and/or hydropower generation.

As a further improvement of the present invention, the distillation hood is in the shape of a spherical crown, and the sump at the bottom thereof is connected to the seawater container through a transition ring.

As a further improvement of the present invention, the cross-section of the sump is arc-shaped, and the arc-shaped opening faces upward; at least 3 drainage tubes are evenly spaced along the circumference of the sump, and the interface between the drainage tube and the sump is located at the the bottom of the sink.

As a further improvement of the present invention, the water storage tank is circular, and a counterweight is fixed at the bottom of the water storage tank, and the counterweight is attached to the bottom surface of the water storage tank in a circular circumferential direction.

As a further improvement of the present invention, the bottom of the water storage tank is convex in an arc shape, and the thickness of the center of the counterweight is the largest, and gradually decreases toward the outer edge.

As a further improvement of the present invention, the upper surface of the water storage tank is a planar structure, and the diameter of the center point of the water storage tank is greater than its height.

As a further improvement of the present invention, the power system includes a power storage module, a wind generator and/or a water flow generator, the wind generator is fixed on the water storage tank through a supporting plate, and the water flow generator is fixed on the water storage tank At the bottom, the electricity generated by the wind generator and/or the water current generator is stored in the power storage module, which provides power for the water supply mechanism and drainage mechanism through the power storage module.

As a further improvement of the present invention, the water supply mechanism includes a first water pump, a first controller, a first upper water level detector and a first lower water level detector, and the first upper water level detector and the first lower water level detector The detectors are arranged at different positions and heights of the seawater container to detect the water level information in the seawater container, and transmit the detection signal to the first controller, and the first controller controls the action of the first water pump.

As a further improvement of the present invention, the drainage mechanism includes a second water pump, a second controller, a second upper water level detector and a second lower water level detector, and the second upper water level detector and the second lower water level The detectors are arranged at different heights of the water storage tank to detect the water level information in the water storage tank, and transmit the detection signal to the second controller, and the second controller controls the action of the second water pump to pump out the fresh water.

A seawater desalination method of the present invention adopts a sea surface floating seawater distillation and desalination device in the above scheme to carry out seawater desalination.

3. Beneficial effect

Compared with the prior art, the technical solution provided by the invention has the following beneficial effects:

(1) A sea surface floating type seawater distillation and desalination device of the present invention arranges a water storage tank on the sea surface, stores the seawater distilled by the upper distillation hood into the lower water storage tank, the structure is combined up and down, and the location space is larger application, can directly desalinize seawater; in addition, the system is directly installed in the sea, does not need to occupy land space, and can also generate electricity to provide drainage power by itself, so that resources can be used reasonably, and will not produce pollution, energy saving and environmental protection; in addition, in The water storage tank is equipped with a counterweight to ensure the stability of the water storage tank, the structure design is reasonable, and the principle is simple;

(2) In the sea surface floating seawater distillation and desalination device of the present invention, the set distillation hood is in the shape of a spherical cap, and the bottom of the distillation hood is provided with an annular sump, so that the steam condenses into water droplets on the distillation hood and flows along the spherical cap. The shaped wall flows into the sump, and then flows into the water storage tank through the drainage pipe; when the water level in the seawater container is low, the water pump automatically injects water into it, the structure layout is reasonable, and the distilled fresh water can be directly drunk;

(3) A sea surface floating type seawater distillation and desalination device of the present invention, the power system includes a power storage module, a wind generator and/or a water current generator, the power storage module is used to store electricity, and the wind power generator can generate electricity by sea wind , The water flow generator uses the water flow to generate electricity, and when the two are used together, it has sufficient power.

Description of drawings

Fig. 1 is a structural representation of a sea surface floating seawater distillation and desalination device of the present invention;

Fig. 2 is the structural representation of water supply mechanism among the present invention;

Fig. 3 is a schematic diagram of the setting structure of the counterweight in the present invention.

Explanation of the symbols in the schematic diagram: 101, distillation hood; 102, transition ring; 103, sump; 104, drainage tube; 105, seawater container; 106, ventilation pipe; 107, water storage tank; 108, earrings; 109, counterweight block; 201, the first suction pipe; 202, the first water pump; 203, the water inlet pipe; 204, the first controller; 205, the first upper water level detector; 206, the first lower water level detector; 207, the solenoid valve ; 208, the first drainage pipe; 301, the power storage module; 302, the circuit packaging tube; 303, the current generator; 304, the supporting plate; 305, the wind generator; 401, the second water pipe; ; 403, the second drain pipe; 404, the second controller; 405, the second upper water level detector; 406, the second lower water level detector.

detailed description

In order to further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings and embodiments.

Example 1

In conjunction with Fig. 1, a sea surface floating seawater distillation and desalination device of this embodiment includes a seawater container 105 and a distillation cover 101 arranged on the seawater container 105, the distillation cover 101 is made of a transparent heat-conducting material, which may be a tempered glass cover, On the one hand, it is beneficial to the heat absorption and evaporation of seawater, and on the other hand, it can prevent it from breaking after being hit. In this embodiment, a water storage tank 107, a water supply mechanism, a drainage mechanism and an electric power system are also provided, wherein the upper surface of the water storage tank 107 is a planar structure, and the diameter of the passing center point of the water storage tank 107 is greater than its height, also That is, the transverse length of the section passing through the center is greater than the longitudinal height, so its center of gravity is relatively stable and not easy to overturn.

A ventilation pipe 106 is arranged on the upper surface of the water storage tank 107. The upper part of the ventilation pipe 106 is an inverted U shape, which can ensure the balance of internal air pressure on the one hand and ensure the smooth progress of the pumping and drainage action; on the other hand, prevent seawater from entering through the ventilation pipe 106. In the water storage tank 107, it has a certain blocking effect.

The seawater container 105 in this embodiment is fixed below the distillation hood 101, the seawater container 105 communicates with the distillation hood 101, the bottom of the distillation hood 101 is an annular sump 103, and the water in the sump 103 flows into the water storage tank through the drainage pipe 104 107 in. In order to allow the water flow to enter the water storage tank 107 quickly, the distillation hood 101 is arranged in the shape of a spherical crown, and the sump 103 at the bottom thereof is connected to the seawater container 105 through the transition ring 102 . Because the distillation hood 101 is in the sea, its temperature is lower than the temperature in the air, and the water vapor will condense into small water droplets after encountering the distillation hood 101. If the top of the distillation hood 101 is set as a plane shape, the small water droplets will directly drop to the In the seawater container 105, by setting the distillation hood 101 as a spherical crown, the height of the side wall gradually decreases due to the excessive arc, and the small water droplets will slide down along the side wall, and finally flow into the sump 103, with a simple structure Reasonable, to achieve the purpose of distillation separation.

Further, the cross section of the water collection tank 103 is set to be arc-shaped, and the arc-shaped opening faces upward, so the water flow will flow along the arc-shaped wall of the water collection tank 103 to the bottom. Further, there are at least three drainage pipes 104 evenly distributed along the circumference of the water collection tank 103, and the interface between the drainage pipes 104 and the water collection tank 103 is located at the bottom of the water collection tank 103, so the desalinated water flow will enter the storage tank in time. In the water tank 107.

Although there are many methods of seawater desalination in ordinary technology, the principle is mostly to transport water vapor to another chamber and condense to form desalinated water. It is difficult to directly carry out seawater distillation and fresh water in the same large-scale connected chamber. In this embodiment, the distillation hood and the sump are skillfully combined, which solves a major technical difficulty in the prior art.

For the sake of structural stability, the volume of the seawater container 105 is not greater than 1/5 of the volume of the water storage tank 107, so as to prevent the seawater container 105 from tilting due to unstable center of gravity. The main purpose of the present invention is to desalinize seawater on the sea surface, but there is a big problem that the sea surface has large waves, and the sump in the present invention is connected with the seawater container 105, once the device has a large inclination, Then the water causes the undesalinated seawater in the seawater container 105 to enter the sump and lose its own desalination effect.

Based on the above problems, the water storage tank 107 provided in this embodiment is circular, and the bottom is curved downward, and the counterweight 109 is fixed at the bottom of the water storage tank 107. Referring to Fig. 3, the counterweight 109 is circularly attached to the circumference. Attached to the bottom surface of the water storage tank 107, that is, to ensure that the center of gravity is located at the lower position on the central axis of the water storage tank 107, the thickness of the center of the counterweight 109 is the largest, and gradually decreases outward. Because the counterweight 109 is provided, the water storage tank 107 also has a certain draft in the vacant state. Even if there is a certain wave, the water storage tank 107 more rises and falls with the waves instead of shaking left and right. In this way, the water storage tank 107 is prevented from tilting, and the unsalinated seawater in the seawater container 105 is guaranteed not to enter the sump 103 . Two earrings 108 are symmetrically arranged on the side wall of the water storage tank 107, and ropes are inserted in the ear rings 108 to limit the position of the water storage tank 107 to prevent being washed away by water waves.

In order to continuously perform distilled seawater desalination, a water supply mechanism is provided on the water storage tank 107, and the water supply mechanism is used to deliver seawater into the seawater container 105 to form automatic water intake. The drainage mechanism is used to discharge the fresh water in the water storage tank 107, and the power system provides electric energy for the water supply mechanism and the drainage mechanism through wind power generation and/or hydropower generation. The water supply mechanism and the drainage mechanism are provided with a controller and a water level detector, rely on the power system to provide power, and automatically perform pumping actions according to changes in the water level for distillation and desalination. This setting is highly automated, does not require manual operation, and is suitable for independent use.

Example 2

A sea surface floating seawater distillation and desalination device of this embodiment has the same basic structure as that of Embodiment 1, except that the power system in this embodiment includes a power storage module 301, a wind power generator 305 and/or a water flow Generator 303, in order to ensure sufficient power supply, both are set in the system at the same time in this embodiment. Wherein, the wind-driven generator 305 is fixed above the water storage tank 107 through the supporting plate 304, that is, the wind-driven generator 305 is fixed on the outer edge of the upper surface of the water storage tank 107, and is distributed along the circumferential direction of the water storage tank 107, which is easy to accept blows from all directions. For incoming wind, a plurality of wind generators 305 can be installed, and the specific number can be set according to needs, and there is no specific limitation.

Wherein the water current generator 303 is fixed on the bottom of the water storage tank 107, and is also distributed along the circumferential direction of the water storage tank 107, and the water current generator 303 is arranged below the bottom surface of the water storage tank 107, because the water storage tank 107 will hinder the flow of water, And being arranged at its lower part enables the water flow generator 303 to obtain a better water flow impact effect and improve power generation efficiency. The electricity generated by the wind generator 305 and the water current generator 303 is stored in the power storage module 301 , and the power for pumping and draining water is provided for the water supply mechanism and the drainage mechanism through the power storage module 301 . In order to prevent the electric wires from being corroded by seawater, the electric wires are wrapped by the circuit packaging tube 302 . The power storage module 301 is arranged on the upper surface of the water storage tank 107 and is treated with waterproofing.

Example 3

Referring to Fig. 2, a sea surface floating seawater distillation and desalination device of this embodiment has the same basic structure as that of Embodiment 2, except that the water supply mechanism includes a first water pump 202, a first controller 204, a first The upper water level detector 205 and the first lower water level detector 206, the first water pump 202 are connected with the first water suction pipe 201, and the first water suction pipe 201 is inserted into external seawater. The water outlet of the first water pump 202 is connected to the water inlet pipe 203 , and the water inlet pipe 203 extends into the seawater container 105 to input the pumped seawater into the seawater container 105 .

The first upper water level detector 205 and the first lower water level detector 206 are arranged at different positions and heights of the seawater container 105 to detect the water level information in the seawater container 105, the first upper water level detector 205 is arranged on the top of the seawater container 105, the first The lower water level detector 206 is arranged in the lower part of the seawater container 105. When the first lower water level detector 206 detects that the seawater is lower than this position, the detection signal is transmitted to the first controller 204, and the first controller 204 controls the first The water pump 202 starts pumping water; when the first upper water level detector 205 detects a water level signal, it transmits the signal to the first controller 204 to control the first water pump 202 to stop pumping water. When the lower water level detector 206 detects that the water level drops to this height every four consecutive times, the counter attached to the 206 sends a signal to the solenoid valve 207, and automatically drains this part of the remaining water through the drain on the seawater container 105 . A first drain pipe 208 is arranged on the drain port, and a solenoid valve 207 is arranged on the first drain pipe 208. The solenoid valve 207 is connected with the first controller 204, and the solenoid valve 207 is controlled by the first controller 204 to discharge the remaining water in real time. Drain.

When the fresh water in the water storage tank 107 is full, it needs to be transported to other places for use. Therefore, a drainage mechanism needs to be provided to transport the fresh water away. The drainage module can be an opening, and the water can be pumped away through an external water pump, or a water pump can be directly installed in the system to drain water directly to the outside.

This embodiment adopts the second method, and the drainage mechanism includes a second water pump 402 , a second controller 404 , a second upper water level detector 405 and a second lower water level detector 406 . The water outlet of the second water pump 402 goes deep into the bottom of the water storage tank 107 through the second water pipe 401 , and the water outlet of the second water pump 402 drains water to the outside through the second water pipe 403 .

The second upper water level detector 405 and the second lower water level detector 406 are arranged at different heights of the water storage tank 107 to detect the water level information in the water storage tank 107, and the second upper water level detector 405 is arranged on the top of the water storage tank 107, When the second upper water level detector 405 detects that the water is full, it transmits the detection signal to the second controller 404, and starts the second water pump 402 to start draining water.

The second lower water level detector 406 is arranged near the bottom position in the water storage tank 107. When the second lower water level detector 406 detects the no-water signal, it transmits the detection signal to the second controller 404 to control the second water pump 402. Pumping is stopped, thereby automating the entire process.

Example 4

The features of the above-mentioned embodiments in the present invention can be combined with each other, and are not limited to the features described in the embodiments. For above-mentioned characteristics, the present invention also provides a kind of seawater desalination method, and its steps are as follows:

Step 1. Place the sea surface floating seawater distillation and desalination device in the seawater, tie the rope on the earring 108 to the fixed pile on land, and complete the preparation work;

Step 2. The wind power generator 305 in the wind blowing power system generates power, and the water generator 303 generates power under the impact of the water flow. The generated power is stored in the power storage module 301. When the power reaches the set value, it starts to provide power for the system ;

Step 3, after power supply, the first lower water level detector 206 in the water supply module detects low water level information, and the signal is transmitted to the first controller 204, which controls the first water pump 202 to pump water into the seawater container; when the first upper water level is detected After the device 205 detects the water-full signal, the first water pump 202 stops pumping water and begins to distill and desalinate seawater;

By sunlight, the evaporated water forms small drops on the distillation hood, and flows into the sump along the distillation hood, and then enters the water storage tank 107; after the seawater in the seawater container evaporates to the position of the first lower water level detector 206 , perform the second water injection, and continue the distillation; after three times of distillation, the remaining seawater in the seawater container has a relatively high salt content, the first controller 204 automatically opens the electromagnetic valve 207, and the remaining seawater is discharged from the first drain pipe 208; Then start pumping water by controlling the first water pump 202, and circulate with this;

Step 4. After the second upper water level detector 405 detects the water flow information, the second water pump 402 starts pumping water to the outside to transport the desalinated seawater outward. When the water level reaches the position of the second lower water level detector 406, the second The second water pump 402 stops pumping water, and the process of steps 3 and 4 is repeated.

The seawater desalination device is installed on the sea surface, does not occupy land space, and the whole seawater desalination process does not require human intervention, and has a high degree of automation; since the power of the entire system relies on self-generated power, it will not emit any pollutants and will not affect seawater Inner ecological environment, environmental protection and energy saving.

In the present invention, if only the distillation and desalination mechanism is set on the sea surface, the waves on the sea surface will easily cause the water storage tank to topple over. Even if it is only tilted at a certain angle, the seawater in the seawater container will enter into the sump, and then flow into the In the water storage tank, the desalinated water is not as much as the inflowing seawater, and seawater desalination is impossible at all, which is why the existing distillation and desalination devices can only be installed on land, because it is difficult to overcome the wave factor at sea.

In the present invention, the water storage tank is combined with the counterweight structure, and the stability of the water storage tank is ensured by increasing the gravity. Even if there is a relatively large wind and wave, the water storage tank generally only rises and falls with the waves, and does not move left and right. Shaking, it has a better stabilizing effect in a relatively calm sea.

The above schematically describes the present invention and its implementation, which is not restrictive, and what is shown in the drawings is only one of the implementations of the present invention, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by it, without departing from the inventive concept of the present invention, without creatively designing a structural mode and embodiment similar to the technical solution, it shall all belong to the protection scope of the present invention .

Claims (10)

1. an offshore floating formula sea water by distillation desalting plant, including sea container (105) be arranged on sea container (105) On distillation cover (101), it is characterised in that: also include water storage cylinder (107), water supply mechanism, drainage mechanism and power system, Described sea container (105) is fixed on distillation cover (101) lower section, and sea container (105) is connected with distillation cover (101) Logical, distillation cover (101) bottom is the water leg (103) of annular, and the water in water leg (103) is flowed by drainage tube (104) Enter in water storage cylinder (107)；Described water supply mechanism is for carrying sea water in sea container (105), and drainage mechanism is for storage Fresh water in water vat (107) is discharged, and power system is that water supply mechanism, drainage mechanism carry by wind-power electricity generation and/or hydroelectric generation For electric energy.

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 1, it is characterised in that: described distillation Cover (101) is spherical, and the water leg (103) bottom it is connected with sea container (105) by transition rings (102).

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 2, it is characterised in that: described water leg (103) cross section is arc, and arc opening is upward；At least 3 drains are distributed along water leg (103) circumference uniform intervals Manage (104), and the seam of drainage tube (104) and water leg (103) is positioned at the bottom of water leg (103).

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 1, it is characterised in that: described water storage cylinder (107) being circular, water storage cylinder (107) bottom is fixed with balancing weight (109), the circumferential circular attaching of this balancing weight (109) In water storage cylinder (107) bottom surface.

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 4, it is characterised in that: described water storage cylinder (107) convex under the camber of bottom, balancing weight (109) center thickness is maximum, and gradually decreases to outer.

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 1, it is characterised in that: described water storage The upper surface of cylinder (107) is planar structure, and the diameter crossing central point of water storage cylinder (107) is more than its height.

7. according to a kind of offshore floating formula sea water by distillation desalting plant according to any one of Claims 1 to 5, it is characterised in that: Described power system includes power storage module (301), wind-driven generator (305) and/or water flow generator (303), described wind-force Electromotor (305) is fixed on water storage cylinder (107) by supporting plate (304), and water flow generator (303) is fixed on water storage cylinder (107) bottom, wind-driven generator (305) and/or water flow generator (303) produce electric power and are stored in power storage module (301), By power storage module (301) be water supply mechanism, drainage mechanism provide power.

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 7, it is characterised in that: described water supplying machine Structure includes the first suction pump (202), the first controller (204), level switch (205) and first time water level detecting on first Device (206), on described first, level switch (205) and first time level switch (206) are arranged on sea container (105) Diverse location height sentence the water level information in detection sea container (105), and detection signal is passed to the first controller (204) action of the first suction pump (202), is controlled by the first controller (204).

A kind of offshore floating formula sea water by distillation desalting plant the most according to claim 7, it is characterised in that: described draught engine Structure includes the second suction pump (402), second controller (404), level switch (405) and second time water level detecting on second Device (406), on described second, level switch (405) and second time level switch (406) are arranged on water storage cylinder (107) Differing heights sentence the water level information in detection water storage cylinder (107), and detection signal is passed to second controller (404), Fresh water is extracted out by the action being controlled the second suction pump (402) by second controller (404).

10. a method for desalting seawater, it is characterised in that: use right to remove a kind of offshore floating according to any one of 1～9 Formula sea water by distillation desalting plant carries out desalinization.