阅读说明：本技术 一种紧凑型蒸馏装置和系统及其应用 (Compact distillation device and system and application thereof ) 是由 黄志强 陈运良 郑开云 张天博 蒋励 叶晶 于 2019-10-24 设计创作，主要内容包括：本发明提供一种紧凑型蒸馏装置和系统及其应用,包括在加热室上部设置原料水进口,供原料水进入加热室进行加热蒸发；在加热室的侧壁底部设置浓缩污水出口,通过加热室的加热蒸发后浓缩形成的污水从浓缩污水出口排出；在加热室的顶部设置带有蒸汽出口的蒸馏隔板,蒸馏隔板在原料水进口的上方,经过加热室加热蒸发的水蒸汽经过蒸汽出口进入加热室上层,并在蒸馏隔板上形成冷凝水,冷凝水通过蒸馏隔板上部设置的净水出口排出。本发明结构简单、易操作、低能耗；通过采用原料水直接进入高温段及控制每级紧凑型蒸馏装置较小的温差的设计方案,提高了系统的利用效率；且无需添加阻垢剂等添加剂,既解决了结垢和腐蚀的问题,又可有效地保留水质的纯净度。(The invention provides a compact distillation device and a system and application thereof, comprising a raw material water inlet arranged at the upper part of a heating chamber, wherein the raw material water enters the heating chamber for heating and evaporation; a concentrated sewage outlet is formed in the bottom of the side wall of the heating chamber, and sewage formed by concentration after heating and evaporation in the heating chamber is discharged from the concentrated sewage outlet; the top of the heating chamber is provided with a distillation clapboard with a steam outlet, the distillation clapboard is arranged above the raw material water inlet, the steam evaporated by heating in the heating chamber enters the upper layer of the heating chamber through the steam outlet, condensed water is formed on the distillation clapboard, and the condensed water is discharged through a purified water outlet arranged at the upper part of the distillation clapboard. The invention has simple structure, easy operation and low energy consumption; by adopting the design scheme that raw material water directly enters the high-temperature section and the smaller temperature difference of each stage of compact distillation device is controlled, the utilization efficiency of the system is improved; and additives such as scale inhibitors and the like are not required to be added, so that the problems of scaling and corrosion are solved, and the purity of water quality can be effectively kept.)

1. A compact distillation apparatus, characterized in that the apparatus is provided with a heating chamber (9), and comprises at least one raw material water inlet (4) arranged on the side wall of the heating chamber (9) and at least one concentrated sewage outlet (5) arranged at the bottom of the side wall, a distillation partition plate (13) with a steam outlet (14) is arranged at the top of the heating chamber, the distillation partition plate (13) is arranged above the raw material water inlet (4), the steam heated and evaporated by the heating chamber (9) enters the upper layer of the heating chamber (9) through the steam outlet (14) and forms condensed water on the distillation partition plate (13), and the condensed water is discharged through a purified water outlet (3) arranged at the upper part of the distillation partition plate (13).

2. A compact rectifying unit according to claim 1, characterized in that said heating chamber (9) is provided at its bottom with heat conducting fins (15).

3. A compact rectifying unit according to claim 2, characterized in that said heat conducting fins (15) are hollow tubes fixed to the bottom plate of said heating chamber (9), the hollow portions of said heat conducting fins (15) being in communication with an external heat source.

4. A compact rectifying unit according to claim 1, characterized in that said raw material water inlet (4) is connected to a raw material water draft tube (16) inside said heating chamber (9), said raw material water draft tube (16) being adapted to introduce raw material water into said heating chamber (9).

5. A compact rectifying unit according to claim 4, characterized in that said raw water draft tube (16) is provided with several nozzles.

6. A compact rectifying unit according to claim 1, characterized in that said vapor outlet (14) is located slightly higher than the vapor-free outlet of said rectifying partition (13), said rectifying partition (13) forming a convex shape with said vapor outlet (14).

7. A compact rectifying unit according to claim 6, characterized in that a demister is arranged at said steam outlet (14).

8. A compact rectifying unit according to claim 1, characterized in that said thick sewage outlet (5) is connected to a thick sewage draft tube (17), said thick sewage draft tube (17) guiding the thick sewage out of said thick sewage outlet (5).

9. A compact rectifying unit according to claim 8, characterized in that said thick matter draft tube (17) is provided with a plurality of small openings for collecting the thick matter.

10. A compact distillation system comprising a stack of two or more compact distillation apparatuses according to any one of claims 1 to 9, a heat source being provided below the lowest stage of said compact distillation apparatuses; a final condensing unit (10) is provided on the uppermost compact distillation unit to cool the vapor in the uppermost compact distillation unit; 1-grade heat conducting fins (15-1) in a 1-grade heating chamber (9-1) of the 1-grade compact distillation device heat raw material water which flows into a 1-grade raw material water guide pipe (16-1) from a 1-grade raw material water inlet (4-1) and then uniformly flows into the 1-grade heating chamber (9-1), formed water vapor is output through a 1-grade steam outlet (14-1) on a 1-grade steam partition plate (13-1), is condensed on the 1-grade steam partition plate (13-1) after heat transfer is carried out on 2-grade heat conducting fins (15-2) in a 2-grade heating chamber (9-2) of a 2-grade compact distillation device, and flows out from a 1-grade purified water outlet (3-1) after being collected; the concentrated sewage deposited after being heated in the 1-level heating chamber (9-1) is uniformly collected from the bottom of the 1-level heating chamber through a 1-level concentrated sewage guide pipe (17-1) and is conveyed to a 1-level concentrated sewage outlet (5-1) discharge system; 2-stage compact distillation apparatus — the uppermost-stage compact distillation apparatus repeats the operation of the 1-stage compact distillation apparatus; the heat source of the heater passes through the compact distillation devices of all stages from bottom to top, heat exchange is carried out on raw material water in the compact distillation devices of all stages, and the compact distillation device of the uppermost stage is condensed by the final stage condensation device (10).

11. A compact distillation system according to claim 10, wherein the compact distillation apparatus is fixed by welding or flange.

12. A compact distillation system according to claim 10, wherein said heat source is an external heat source or a regenerative heat source.

13. A compact distillation system according to claim 10 or 12, wherein the heat source is a 0-stage steam heating unit, and the bottom of the 0-stage steam heating unit is provided with a condensed water outlet.

14. A compact distillation system according to claim 10, wherein the top of the final condensing unit is provided with a non-condensable gas discharge.

15. A method of using compact distillation systems according to any one of claims 10 to 14 in parallel, wherein 1-stage compact distillation apparatus to N-stage compact distillation apparatus are connected in series between said heat source and said final condensation apparatus;

raw material water is put into a 1-level raw material water inlet of the 1-level compact distillation device, the raw material water is heated by the heat source through the 1-level heat conducting fins of the 1-level compact distillation device, steam generated by heating the raw material water passes through the 1-level steam outlet and is condensed on the upper part of the 1-level distillation partition plate, and condensed water flows out through the 1-level purified water outlet; the evaporated and concentrated water is discharged from the 1-stage concentrated sewage outlet;

steam on the distillation partition of the N-1 stage compact distillation unit heats the N stage compact distillation unit, and the using method of the N-1 stage compact distillation unit is repeated;

and the steam on the distillation partition plate of the N-stage compact distillation device is condensed by the final stage condensation device and then discharged.

16. A method of parallel application of compact distillation systems as claimed in claim 15, wherein said 1-stage clean water outlet and said 1-stage concentrated wastewater outlet preheat feed water from said 1-stage feed water inlet via a regenerative means.

17. A method of parallel application of compact distillation systems as claimed in claim 15 or 16, wherein said clean water outlet of each stage and said concentrated wastewater outlet of each stage preheat feed water from said feed water inlet of each stage via a recuperating means.

18. A method for parallel application of compact distillation systems according to claim 16 or 17, wherein said recuperator is no more than said compact distillation apparatus.

19. A method of using a compact distillation system according to any one of claims 10 to 14 in series, wherein 1-stage compact distillation apparatus to N-stage compact distillation apparatus are connected in series between said heat source and said final condensation apparatus;

raw material water is put into a 1-level raw material water inlet of the 1-level compact distillation device, the raw material water is heated by the heat source through the 1-level heat conducting fins of the 1-level compact distillation device, steam generated by heating the raw material water passes through the 1-level steam outlet and is condensed on the upper part of the 1-level distillation partition plate, and condensed water is discharged through the 1-level purified water outlet; the evaporation concentrated water flows into the 2-stage raw water inlet of the 2-stage compact distillation device from the 1-stage concentrated sewage outlet;

the steam on the distillation partition of the N-1 stage compact distillation unit heats the N stage compact distillation unit, and the using method of the N-1 stage compact distillation unit is repeated;

and the steam on the distillation partition plate of the N-stage compact distillation device is condensed by the final-stage condensing device and then discharged, and the N-stage concentrated sewage outlet discharges concentrated sewage.

20. A method of using a compact distillation system in series as claimed in claim 19 wherein said clean water outlet from each stage preheats said feed water from stage 1 via a recuperator.

21. A method for tandem application of a compact distillation system according to claim 20, wherein said recuperator is no more than said compact distillation apparatus.

22. Use of a compact distillation system, characterized in that the use according to claims 15-18 and claims 19-21 are used simultaneously.

Technical Field

The invention relates to the technical field of distillation, in particular to a multi-effect distillation technology.

Background

Water is the root of human survival, and fresh water resources are being exhausted globally at present, and become the biggest threat to human survival. China all occupies 1/3 of the world with insufficient water resource quantity, and is listed as one of 13 water-poor countries by united nations. One survey showed that over 420 cities in 661 cities across the country had water shortage, about 70 billionths of a cubic meter. The vast sea accounts for about 71 percent of the surface area of the earth, is a huge treasury and has huge development potential. The utilization of seawater resources and the utilization of seawater chemical resources have very wide prospects.

Seawater is an inexhaustible resource, and the total volume of the seawater is about 137 hundred million cubic kilometers. Due to shortage of fresh water resources, the world countries are vigorously developing seawater desalination technology. In China, the research on seawater desalination starts in the last 50 th century, and currently, industrialized large-scale seawater desalination methods mainly comprise nanofiltration-reverse osmosis, multiple-effect evaporation, multi-stage flash evaporation and the like. Wherein, the low-temperature multi-effect distillation method, the multi-stage flash evaporation method and the reverse osmosis membrane method are the main global technologies. Generally speaking, the low-temperature multi-effect distillation method has the advantages of energy conservation, low requirement on seawater pretreatment, high quality of desalted water and the like; the reverse osmosis membrane method has the advantages of low investment, low energy consumption and the like, but the requirement on seawater pretreatment is high; the multistage flash evaporation method has the advantages of mature technology, reliable operation, large device yield and the like, but the energy consumption is higher. The seawater desalination technologies have respective advantages and disadvantages and occupy respective application fields.

The quality of the desalinated water of the multi-stage evaporation method is best, the desalinated water can be directly drunk, and the energy consumption is one of the core parameters for evaluating the multi-stage evaporation method seawater desalination technology. The reduction of energy consumption is a constantly striving goal of the multi-stage evaporation technology.

Disclosure of Invention

In order to solve the above technical problems, the present invention aims to provide a compact distillation apparatus and system with simple structure, easy operation and low energy consumption, and the application thereof.

The invention provides a compact distillation device, which is characterized by comprising a heating chamber 9, at least one raw material water inlet 4 arranged on the side wall of the heating chamber 9 and at least one concentrated sewage outlet 5 arranged at the bottom of the side wall, wherein a distillation partition plate 13 with a steam outlet 14 is arranged at the top of the heating chamber 9, the distillation partition plate 13 is arranged above the raw material water inlet 4, the steam heated and evaporated by the heating chamber 9 enters the upper layer of the distillation partition plate 13 through the steam outlet 14, condensed water is formed on the distillation partition plate 13, and the condensed water is discharged through a purified water outlet 3 arranged at the upper part of the distillation partition plate 13.

Preferably, the bottom of the heating chamber 9 is provided with a plurality of heat conducting fins 15, and the heat conducting fins 15 increase the heating area of the distillation apparatus and also uniformly heat the raw material water in the heating chamber 9, so that the raw material water in the heating chamber 9 can be rapidly and uniformly heated and evaporated in a short time.

Preferably, the heat conducting plate 15 is a hollow pipe fixed on the bottom plate of the heating chamber 9, and the hollow part of the heat conducting plate 15 is communicated with an external heat source. The hollow heat conducting fin contributes to further increase of the heat exchange surface, so that the heat exchange effect is improved, and the water making quantity of the distillation device is improved.

Preferably, the raw material water inlet 4 is connected to a raw material draft tube 16 inside the heating chamber 9, and the raw material water draft tube 16 can introduce the raw material water into the heating chamber 9. The raw material draft tube 16 can introduce the raw material water into each position of the heating chamber 9, so that the raw material water can be uniformly distributed in the heating chamber 9.

Preferably, the raw material draft tube 16 is provided with a plurality of nozzles. The design of the spout helps the raw water to enter the heating chamber 9 quickly and uniformly.

Preferably, the distillation partition 13 is provided with a plurality of steam outlets 14. The plurality of steam outlets can accelerate the generation and ascending of steam and also facilitate the efficiency of forming condensed water by distillation.

Preferably, the steam outlet 14 is arranged slightly higher than the steam-free outlet of the distillation partition 13, and the distillation partition 13 and the steam outlet 14 form a convex shape. The bulge of the steam outlet not only helps the condensation of the ascending steam, but also can isolate the situation that the condensed water and the heated steam are in hedging because the condensed water flows back to the steam outlet, thereby improving the distillation effect of the distillation device.

Preferably, a demister is arranged at the steam outlet 14.

Preferably, the concentrated sewage outlet 5 is connected with a concentrated sewage guide pipe 17, and the concentrated sewage guide pipe 17 guides the concentrated sewage out of the concentrated sewage outlet 5.

Preferably, the thick sewage guide pipe 17 is provided with a plurality of guide ports, so that the thick sewage precipitated and accumulated at different parts of the heating chamber 9 can be conveniently and rapidly collected and discharged from the thick sewage outlet 5.

The invention also provides a compact distillation system, which comprises more than two compact distillation devices which are superposed, wherein a heat source is arranged below the lowest compact distillation device; a final condensing unit 10 is provided on the uppermost compact distillation unit to cool the vapor in the uppermost compact distillation unit; the 1-level heat conducting fin 15-1 in the 1-level heating chamber 9-1 of the 1-level compact distillation device heats the raw material water which flows into the 1-level raw material water guide pipe 16-1 from the 1-level raw material water inlet 4-1 and then uniformly flows into the 1-level heating chamber 9-1, the formed water vapor is output through the 1-level steam outlet 14-1 on the 1-level steam partition plate 13-1, and is condensed on the 1-level steam partition plate 13-1 after heat transfer is carried out on the 2-level heat conducting fin 15-2 in the 2-level heating chamber 9-2 of the 2-level compact distillation device, and flows out from the 1-level clean water outlet 3-1 after being collected. The concentrated sewage deposited after being heated in the 1-level heating chamber 9-1 is uniformly collected from the bottom of the 1-level heating chamber through a 1-level concentrated sewage guide pipe 17-1 and is conveyed to a 1-level concentrated sewage outlet 5-1 discharge system; 2-stage compact distillation apparatus — the uppermost-stage compact distillation apparatus repeats the operation of the 1-stage compact distillation apparatus; the heat source of the heater passes through the compact distillation devices at all stages from bottom to top, and exchanges heat with the raw material water in the compact distillation devices at all stages, and the compact distillation device at the uppermost stage is condensed by the final condensation device 10.

Preferably, the compact distillation device is fixed by welding or flange.

Preferably, the heat source may be an external heat source or a regenerative heat source.

Preferably, the heat source is a 0-level steam heating device, and a condensed water outlet can be arranged at the bottom of the 0-level steam heating device.

Preferably, the top of the final condensation device is provided with a non-condensable gas outlet.

The invention also provides a parallel application method of the compact distillation system, which is characterized in that 1-stage compact distillation device to N-stage compact distillation devices are sequentially connected between the heat source and the final-stage condensing device;

raw material water is put into a 1-level raw material water inlet of the 1-level compact distillation device, the raw material water is heated by the heat source through the 1-level heat conducting fins of the 1-level compact distillation device, steam generated by heating the raw material water passes through the 1-level steam outlet and is condensed on the upper part of the 1-level distillation partition plate, and condensed water flows out through the 1-level purified water outlet; the evaporated and concentrated water is discharged from the 1-stage concentrated sewage outlet;

steam on the distillation partition of the N-1 stage compact distillation unit heats the N stage compact distillation unit, and the using method of the N-1 stage compact distillation unit is repeated;

and the steam on the distillation partition plate of the N-stage compact distillation device is condensed by the final stage condensation device and then discharged.

Preferably, the raw water at the raw water inlet of the 1-level is preheated by the 1-level purified water outlet and the 1-level concentrated sewage outlet through a heat recovery device.

Preferably, the raw material water at each level of raw material water inlet is preheated by the pure water outlet and the concentrated sewage outlet through a heat recovery device.

Preferably, the heat regenerator is not more than the compact distillation unit.

The heat source can be a heat source of photo-thermal equipment, can be various waste heat sources, can be a steam heat source of a nuclear power plant, a boiler combustion steam heat source, a low-pressure cylinder steam extraction of a steam turbine of the power plant, a supercritical carbon dioxide heat source and terrestrial heat of a supercritical carbon dioxide cycle power generation system and the like, and can be flue gas, water vapor, carbon dioxide, helium, liquid metal, molten salt and any other heating media.

The condensing working medium of the condenser is water working medium or air with the temperature not higher than the environmental temperature, and can be river water, seawater, river water or circulating water of an air cooling tower and the like.

The present invention may also provide a method for the tandem application of compact distillation systems, characterized in that 1-stage compact distillation apparatus to N-stage compact distillation apparatus are connected in sequence between the heat source and the final condensing apparatus;

raw material water is put into a 1-level raw material water inlet of the 1-level compact distillation device, the raw material water is heated by the heat source through the 1-level heat conducting fins of the 1-level compact distillation device, steam generated by heating the raw material water passes through the 1-level steam outlet and is condensed on the upper part of the 1-level distillation partition plate, and condensed water is discharged through the 1-level purified water outlet; the evaporation concentrated water flows into the 2-stage raw water inlet of the 2-stage compact distillation device from the 1-stage concentrated sewage outlet;

the steam on the distillation partition of the N-1 stage compact distillation unit heats the N stage compact distillation unit, and the using method of the N-1 stage compact distillation unit is repeated;

and the steam on the distillation partition plate of the N-stage compact distillation device is condensed by the final-stage condensing device and then discharged, and the N-stage concentrated sewage outlet discharges concentrated sewage.

Preferably, the purified water outlets of all stages preheat the raw material water of stage 1 through a heat recovery device.

Preferably, the heat regenerator is not more than the compact distillation unit.

In addition, the invention also provides a series and parallel application method of the compact distillation system, and the whole distillation system or a part of the distillation system is alternately used in the series and parallel methods.

The raw material water of the invention can comprise river water, river water and seawater, and can also comprise engineering silt water, domestic sewage, industrial wastewater of chemical industry, mines, textiles and the like, thus having a wide application range. River water, seawater and river water can reach the standard of direct drinking after being desalted by the distillation device and the system; the industrial wastewater of engineering silt water, domestic sewage, chemical industry, mine, textile and the like can realize the effect of reaching the standard of pollutant discharge and recycling water resources after being desalted by the distillation plant and the system, thereby obtaining great economic benefit and social effect.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention has simple structure, convenient disassembly and assembly and convenient operation, and can effectively achieve the effect achieved by the complex prior art.

2. The raw material water of the system is in a non-flowing state when being heated, is different from the spraying state in the prior art, has small flow resistance of each stage, does not scour, abrade or shake the heat conducting fins, and effectively inhibits the scaling and corrosion problems of the raw material water in equipment; raw material water directly enters a high-temperature section, and the utilization efficiency of the system is improved by a design scheme of controlling smaller temperature difference of each stage of compact distillation device; additives such as scale inhibitors and the like are not required to be added, the problems of scaling and corrosion in the prior art are solved, and the purity of water can be effectively kept.

3. The invention can be used for the aspects of distilled water, seawater desalination, sewage treatment and the like, and has a wide application range.

4. Compared with a multi-effect distillation method, the method is applied to projects such as seawater desalination and the like, has low water making ratio and obviously reduced energy consumption, and has obvious technical advantages.

Drawings

FIG. 1 is a schematic view of a compact distillation apparatus;

FIG. 2 is a schematic view of a compact distillation system;

FIG. 3 is a schematic view of a heating chamber;

FIG. 4 is a schematic diagram of a parallel process for compact distillation systems;

FIG. 5 is a schematic diagram of a compact distillation system series process;

FIG. 6 is a schematic diagram of a compact distillation system series-parallel process.

In the figure:

1. condensation working medium inlet

2. Outlet for condensed working medium

3(.3-1, 3-2.. 3.N) water purification outlet (1-level water purification outlet, 2-level water purification outlet.. 3.N level water purification outlet)

4, (4-1, 4-2.... 4-N) raw material water inlet (1-grade raw material water inlet, 2-grade raw material water inlet,... N-grade raw material water inlet)

5, (5-1, 5-2.. 5-N) concentrated sewage outlet (1-level concentrated sewage outlet, 2-level concentrated sewage outlet, N-level concentrated sewage outlet)

6. Heat regeneration device

7. Heat source working medium inlet

8. Outlet of heat source

9, (9-1, 9-2.. 9-N) heating chamber (1-stage heating chamber, 2-stage heating chamber,. 9.. N-stage heating chamber)

10. Final stage condensing device

11. Raw material water header

12. Raw material water pump

13. Distillation baffle (1-stage distillation baffle, 2-stage distillation baffle, a

14. Steam outlet

15. Heat conducting fin

16. Raw material water diversion pipe (1 grade raw material water diversion pipe, 2 grade raw material water diversion pipe, N grade raw material water diversion pipe.)

17. Dense sewage flow guide pipe (1 level dense sewage flow guide pipe, 2 level dense sewage flow guide pipe, N level dense sewage flow guide pipe.)

18. A water-water heat regenerative device.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The invention can be used in the environments of distilled water, seawater desalination, sewage treatment and the like, and has a wide application range.

A compact distillation apparatus is used as shown in fig. 1. The device is provided with a seawater inlet 4 at the upper part of a heating chamber 9, so that seawater enters the heating chamber 9 for heating and evaporation; a concentrated sewage outlet 5 is arranged at the lower part of the heating chamber 9, and sewage formed by concentration after heating and evaporation of the heating chamber 9 is discharged from the concentrated sewage outlet 5; as shown in fig. 3, a distillation partition plate 13 with a steam outlet 14 is provided at the top of the heating chamber 9, the distillation partition plate 13 is provided above the seawater inlet 4, the steam heated and evaporated by the heating chamber 9 enters the upper layer of the heating chamber through the steam outlet 14, and condensed clean water is formed on the distillation partition plate 13, and the condensed clean water is discharged through the clean water outlet 3 provided at the upper part of the distillation partition plate 13. The steam outlet 14 is slightly higher than the non-steam outlet of the distillation partition plate 13, the distillation partition plate 13 and the steam outlet 14 form a convex shape, so that condensed purified water can be conveniently collected at the non-steam outlet of the distillation partition plate 13, and the condensed purified water is discharged from the purified water outlet 3. A demister is installed at the steam outlet 14 for removing bubbles in the steam. As shown in fig. 2, the bottom of the heating chamber 9 is provided with a plurality of heat conducting fins 15 to increase the heat transfer effect of the heating chamber 9. As shown in fig. 2, the heat conducting fin 15 is a hollow circular tube, and is fixed on the bottom plate of the heating chamber, and the hollow part of the heat conducting fin 15 is set to be communicated with an external heat source, so that the heat below enters the heat conducting fin 15, and the heat is exchanged to the seawater in the heating chamber 9 through the heat conducting fin 15. As shown in fig. 2, the raw material water inlet 4 is connected to a raw material water guide pipe 16, and the raw material water guide pipe 16 is used for carrying and conveying the raw material water entering from the raw material water inlet 4, so that the raw material water is uniformly distributed in the heating chamber 9. The concentrated sewage outlet 5 is connected with a concentrated sewage guide pipe 17, and the concentrated sewage guide pipe is used for bearing and conveying the deposited concentrated sewage to the concentrated sewage outlet 5.

The compact distillation system comprises a plurality of compact distillation devices which are stacked, and the specific method comprises the following steps:

the compact distillation devices at all levels are welded and fixed, and the heaters are connected below the compact distillation device at 1 level to provide corresponding heat sources. The heat source heats the seawater flowing into the 1-level heating chamber 9-1 from the 1-level seawater inlet 4-1 through the 1-level heat conducting sheet 15-1 in the 1-level heating chamber 9-1 of the 1-level compact distillation device, the formed water vapor is output through the 1-level vapor outlet 14-1 on the 1-level vapor partition 13-1, and is condensed on the 1-level vapor partition 13-1 after heat transfer is carried out on the 2-level heat conducting sheet 15-2 in the 2-level heating chamber 9-2 of the 2-level compact distillation device, and the water vapor flows out from the 1-level purified water outlet 3-1 after being collected. The concentrated sewage deposited after heating in the 1-level heating chamber 9-1 is uniformly collected from the bottom of the 1-level heating chamber through a 1-level concentrated sewage guide pipe 17-1 and is conveyed to a 1-level concentrated sewage outlet 5-1 discharge system. The 2-stage compact distillation device-the uppermost-stage compact distillation device repeats the operation of the 1-stage compact distillation device, a final-stage condensing device 10 is arranged on the uppermost-stage compact distillation device, a condensing working medium is led in from a condensing working medium inlet 1 to cool steam in the uppermost-stage compact distillation device, the condensing working medium is led out from a condensing working medium outlet 2, and a non-condensable gas discharge port is arranged at the top of the final-stage condensing device 10 to prevent the non-condensable gas released by seawater in the distillation process from gathering to reduce the efficiency of equipment. The seawater at the level 1 seawater inlet 4-1 is pumped in by a raw material water header 11 through a raw material water pump 12.