CN206720784U - A kind of novel seawater desalting device - Google Patents

Abstract

It the utility model is related to a kind of novel seawater desalting device, heat exchange plate is divided into starting sheet, terminates plate and intermediate plate A, intermediate plate B, each plate general structure is identical, starting sheet and end plate are located at both ends respectively, intermediate plate A, intermediate plate B are positioned at centre, and arrange alternately, in pairs, it is fixed and clamped between all plates by screw rod and nut, the confined space needed for desalinization is formed between plate.The utility model has the advantage of：The gap region as evaporative condenser, heat exchange efficiency height, and the plate cleaning easy to disassemble successively being divided into by plate, prevents heat exchanger can not normal use because of fouling etc.；Hydrothermal area is relative with evaporating area, preferably realizes the exchange of heat；With condensing zone, possess the ability of condensation fresh water, be fresh water from heat exchanger outflow, without other equipment；The copper shell of Conventional plate-type fresh water generator can be saved, space has been saved, reduced cost.

Description

A new type of seawater desalination device

technical field

The utility model relates to the field of a heat exchanger used for medium distillation, in particular to a novel plate type seawater desalination device.

Background technique

Seawater desalination is an effective way to ensure the continuous and stable supply and replenishment of freshwater for ships and marine engineering. Distillation seawater desalination technology has been greatly developed due to its advantages of using the waste heat of the main engine of the ship as a heat source, no special treatment for seawater inflow, high-quality water produced, and easy maintenance.

In the invention patent with the patent number 201510621244.6, a plate heat exchanger is mentioned, including a front end plate, a rear end plate, and a plate arranged between the front end plate and the rear end plate and arranged parallel to the front end plate, each plate There are sealing rings on both sides of the adjacent plate. After the same sealing ring on one side of the adjacent plate cooperates, a seawater cavity and a steam cavity are formed, and the same sealing ring on the other side forms a seawater evaporation cavity; During the process, steam enters the evaporation chamber, seawater enters the seawater chamber, and gradually increasing seawater flows into the seawater evaporation chamber. Both sides of each seawater evaporation chamber are steam chambers, which can effectively remove the seawater in the seawater evaporation chamber. Evaporation, the water vapor generated by the evaporation of seawater flows to the condensing device through the opening on the sealing ring, and is guided to the fresh water collection device through the condensing device. The above-mentioned patent mentions a device that uses seawater evaporation to produce fresh water. It adopts a plate structure to improve the efficiency of seawater evaporation. However, the device does not include a condensation device, so fresh water cannot be directly produced, and the seawater areas on both sides are in contact with the steam The regions are not completely aligned, and the efficiency needs to be improved.

Utility model content

The technical problem to be solved by the utility model is to provide a new high-efficiency plate-type seawater desalination device integrating evaporation and condensation.

In order to solve the above technical problems, the technical solution of this utility model is: a new type of seawater desalination device. The tight plates are pressed tightly to form a closed space between adjacent plates, and the closed space includes alternately arranged first inter-plate gaps and second inter-plate gaps;

The plates include a start plate, several middle plates A, some middle plates B and an end plate, the front of the start plate is facing the outside of the device body, and its reverse side is attached to the front of the middle plate A to form a gap between the first plates ; The middle plate A and the middle plate B are arranged alternately, wherein, the back of the middle plate A is attached to the front of the middle plate B to form a second gap between the plates; the back of the middle plate B and the front of the middle plate A Bonding to form a first inter-panel gap; the front of the end plate is bonded to the reverse side of the middle plate B to form a first inter-panel gap;

Wherein, the first inter-plate gap includes an upper cold water area and a lower hot water area that are independent and sealed; the second inter-plate gap sequentially includes a condensation area, a separation area, and an evaporation area that are connected to each other from top to bottom. The cold water area is opposite to the condensation area, and the hot water area is opposite to the evaporation area.

Further, there is also a channel for the medium to flow between the plates,

The starting board, the middle board A and the middle board B are provided with cold water inlet holes and cold water outlet holes, and the cold water inlet and outlet holes are located in the area surrounded by the cold water area on the plate; the front of the middle board B is surrounded by cold water The inlet and outlet holes are provided with a small sealing ring to form a cold water circulation channel that communicates with the cold water area but not with the condensation area;

The starting plate, the middle plate A and the middle plate B are provided with hot water inlet holes and hot water outlet holes, and the hot water inlet and outlet holes are located in the area surrounded by the hot water area on the plate; the middle plate A small sealing ring is provided around the hot water inlet and outlet holes on the front side, forming a hot water circulation channel that communicates with the hot water area but not with the evaporation area;

Sea water inlet holes are provided on the starting board, middle board A and middle board B, and the sea water inlet holes are located in the area surrounded by the hot water area on the plate, and the front of the middle board B surrounds the sea water inlet holes. There is a small sealing ring, forming a seawater channel that communicates with the evaporation area but not with the hot water area;

The initial plate, the middle plate A and the middle plate B are provided with a fresh water output hole at the bottom of the condensation zone, the fresh water output hole is located in the area surrounded by the condensation zone, and the front of the middle plate A is provided with a fresh water output hole around the fresh water output hole. A small sealing ring is formed to form a fresh water output channel that communicates with the condensation zone in the gap between the second plates and does not communicate with the gap between the first plates;

Wherein, the medium in the cold water circulation channel is cold sea water, and the medium in the hot water circulation channel is jacket water.

Further, the seawater inlet holes have a pair of symmetrically arranged, and the pair of seawater inlet holes are symmetrically opened on the middle plate A and the middle plate B at positions corresponding to the two sides of the bottom of the evaporation zone, and the middle plate B A small opening sealing ring is installed around the seawater inlet hole on the front side, and the small opening sealing ring has an opening towards the center of the evaporation area.

Further, the channel also includes a concentrated brine channel located under the evaporation zone and the hot water zone, which is formed by superimposing the concentrated brine holes at the corresponding positions at the bottom of each plate.

Further, the front side of the middle plate A has a first sealing ring group, and the first sealing ring group includes the first main sealing ring used to surround and form the first inter-plate gap and is installed in the area surrounded by the first main sealing ring. The large sealing ring A used to surround the cold water area and the large sealing ring B used to surround the hot water area;

The front side of the middle plate B has a second sealing ring group, and the second sealing ring group includes a second main sealing ring used to surround and form a gap between the second plates and a sealing ring installed in the area surrounded by the second main sealing ring. To divide the sealing strip A and sealing strip B of the condensation zone, the separation zone and the evaporation zone, the evaporation zone is an open space at the upper end formed by the seal strip A, and the separation zone and the condensation zone are sequentially arranged in the evaporation zone above and separated by sealing strip B above the opening of the evaporation zone.

Further, the sealing strip B is in the shape of a strip that slopes symmetrically downward from both ends to the middle and forms a low-lying strip in the middle.

Further, the two sides corresponding to the separation zone of each plate have guide corrugations, and the guide corrugations on both sides extend obliquely downward from the middle position of the separation zone to the outside, and the extending direction does not contact the evaporation zone.

Further, the middle plate A and the middle plate B are also provided with gas communication holes, and the gas communication holes are located in the enclosed space and outside the area surrounded by the hot water area and the cold water area.

The utility model has the advantages of:

(1) The airtight space required for seawater desalination is formed by the plate and the sealing ring (strip), and there is no need to add a shell, which not only saves materials but also saves space.

(2) The gaps formed by the plates provide space for seawater desalination, the heat exchange efficiency is high, and the plates are easy to disassemble and clean to prevent the heat exchanger from being unable to use normally due to fouling; the hot water area is opposite to the evaporation area, more Good heat exchange; it has a condensation zone and the ability to condense fresh water, and the flow out of the heat exchanger is fresh water, no other equipment is required.

(3) The heat exchanger also has a cold water circulation channel, a hot water circulation channel, a seawater circulation channel, and a fresh water output channel. Various media flow fully in the heat exchanger to realize heat exchange. Among them, the cold water circulation channel The medium is cold sea water, and the medium in the hot water circulation channel is jacket water, which makes full use of the waste heat of the jacket water on board and saves resources.

(4) The functional areas on the plate are surrounded by sealing rings, among which the main sealing ring forms the gap between the plates, and the sealing rings isolate the functional areas on the same gap between the plates from each other, separating each functional area tightly and conveniently. Disassembly and assembly; only one side of each plate is provided with a sealing ring, which is convenient for processing.

(5) The hole group is set on the plate as a channel, and there is no need to independently set up a pipe as a medium channel, which facilitates the flow of the medium and reduces consumables. The channel is sealed with a sealing ring in the gap between the plates that is not connected, replacing the traditional pipe.

(6) Concentrated brine channel guides seawater with high salinity after evaporation of fresh water out of the heat exchanger to prevent salt from accumulating in the heat exchanger, causing blockage and reducing production efficiency.

(7) The function of the sealing strip B is to separate the separation area and the condensation area in the gap between the plates. Its structure is just enough to make the fresh water condensed in the condensation area gather towards the middle low-lying area, and finally flow into the fresh water output channel.

(8) The role of the guiding corrugations is to separate the salt in the seawater during the seawater evaporation process, and make the seawater with more salty flow into the concentrated brine channel at the bottom along with the guiding corrugations, and finally flow out.

Description of drawings

Fig. 1 is a schematic side view of the best embodiment of a novel seawater desalination device of the present invention.

Fig. 2 is a schematic front view of the middle plate A of the best embodiment of a new seawater desalination device of the present invention.

Fig. 3 is a schematic front view of the middle plate B of the best embodiment of a new seawater desalination device of the present invention.

Fig. 4 is a schematic front view of the starting plate of the best embodiment of a novel seawater desalination device of the present invention.

Fig. 5 is a schematic front view of the end plate of the best embodiment of a new seawater desalination device of the present invention.

Fig. 6 is a working principle diagram of the best embodiment of a novel seawater desalination device of the present invention.

In the picture:

1-middle plate A, 11-main sealing ring A, 12-sealing ring B,

13-sealing ring A, 14-small sealing ring, 15-opening small sealing ring,

2-Middle plate B, 21-Main sealing ring B, 22-Sealing strip B,

23-sealing strip A, 3-start plate, 4-end plate,

5-compression plate, 6-bolt, 7-through rod,

8-the gap between the second plates, 9-the gap between the first plates, 10-the cold water inlet hole,

20-cold water outlet hole, 30-fresh water outlet hole, 40-gas communication hole,

50-hot water inlet hole, 60-hot water outlet hole, 70-sea water inlet hole,

80-concentrated brine hole, 90-guide corrugation; L-cold water area,

R-hot water zone, C-condensation zone, S-separation zone,

E - Evaporation zone.

detailed description

As shown in Figure 1, the utility model discloses a new type of seawater desalination device, including the device body, which is formed by superimposing several plates in a face-to-face fastening manner, and then compressed with a compression plate 5 at the beginning and end ends , a closed space is formed between adjacent plates, and the closed space includes alternately arranged first inter-plate gaps 9 and second inter-plate gaps 8, and the plates include:

A starting plate 3 is located at the beginning of the device body and has a front side and a back side. The front side is facing the outside of the device body, and is pressed against the starting end pressure plate, and its back side is facing the inside of the device body to form a gap between the first plates;

An end plate 4, located at the end of the device body, has a front side and a back side, the front side faces to the outside of the device body to form a terminal surface of the heat exchanger, and its back side faces to the inside of the device body to form a first inter-plate gap;

A plurality of intermediate boards A1 are arranged between the starting board 3 and the ending board 4, and have a front side and a back side, the front side is used to form the first inter-panel gap, and the back side is used to form the second inter-panel gap;

A plurality of middle boards B2 are arranged between the start board 3 and the end board 4, and are arranged alternately with the middle board A1. A gap between the plates, the opposite side of which is buckled with the front of the middle plate A to form a second gap between the plates;

The start board 3 and the end board 4 are located at both ends, the middle board A1 and the middle board B2 are located in the middle, and they are arranged alternately and in pairs; the reverse side of the starting board 3 is buckled with the front side of the first middle board A1 to form the first A gap between the boards, the front of the end board 4 is buckled with the reverse side of the last middle board B2 to form the final first gap between the boards, and the boards are installed in parallel and closely, so the airtight space required for seawater desalination can be formed, so that The copper shell of the traditional plate water generator is omitted, which saves space and reduces costs.

The enclosed space is divided into several functional areas by rubber mats; among them,

The gap between the first plates includes the upper cold water area L and the lower hot water area R which are sealed independently of each other, which are separated and formed by the first sealing ring group on the front of the middle plate A1. As shown in Figure 2, the first sealing ring group includes The main seal ring A11 forming the gap between the first plates, and the large seal ring A13 installed in the area surrounded by the main seal ring A11 to surround the cold water zone L and the large seal ring B12 to surround the hot water zone B;

The gap between the second plates includes the interconnected condensation area C, separation area S, and evaporation area E from top to bottom, which are separated and formed by the second seal ring group on the front of the middle plate B2, as shown in Figure 3, the second seal The ring group includes the main sealing ring B21 used to surround the gap between the second plates and the sealing strip A23 and sealing strip installed in the area surrounded by the main sealing ring B21 to divide the condensation zone C, separation zone S and evaporation zone E B22, the evaporation area E is a space with an open upper end surrounded by the sealing strip A23, the separation area S and the condensation area C are sequentially arranged above the evaporation area E, separated by the sealing strip B22 above the opening of the condensation area C;

Among them, there are symmetrical guide corrugations 90 on both sides of each plate, and the guide corrugations 90 on both sides extend from the middle position of the separation zone to the outside obliquely downward, and the extension direction does not contact the evaporation zone E, which is convenient for entraining salt during the evaporation process. Part of the steam settles and flows out of the evaporation zone E along with the guide corrugated flow;

In the first inter-plate gap and the second inter-plate gap, the cold water area L is opposite to the area surrounded by the condensation area C, and is located at the same position on both sides of any middle plate, and the hot water area R is opposite to the area surrounded by the evaporation area E, located at Same location on both sides of any midplane.

When seawater reaches a certain temperature, it will boil and produce water vapor. The distillation method of seawater desalination is just using this physical phenomenon to achieve seawater desalination. The hot water zone R has a high-temperature heat exchange medium, and the evaporation zone E has seawater to be evaporated. There is only one plate between them, which can achieve better heat transfer. The cold water zone L has a low-temperature heat exchange medium, and the condensation zone There is only one plate between C, and similarly, better heat transfer can be achieved between the two areas; under the action of the high-temperature heat exchange medium in the hot water area R, the seawater in the evaporation area E will boil at a certain temperature Water vapor is generated, and the water vapor passes through the separation zone S and rises to the condensation zone C. Since the cold water zone L has a low-temperature heat exchange medium and is opposite to the condensation zone C, the water vapor is condensed under the action of the low-temperature medium. form fresh water.

As shown in Figure 2-5, since the body of the device is composed of several plates superimposed on each other, in order to facilitate the circulation of media in each functional area, the plates are also provided with channels for the flow of media, including

The cold water circulation channel is composed of a cold water inlet channel and a cold water outlet channel. The cold water inlet and outlet channels are connected to the cold water area L, pass through the condensation area C and are not connected to the condensation area C; its specific structure is: the starting plate 3, the middle The plate A1 and the middle plate B2 are provided with a cold water inlet hole 10 and a cold water outlet hole 20. The cold water inlet and outlet holes 10 and 20 are located in the area surrounded by the cold water area L on the plate, and the cold water inlet and outlet holes on the adjacent front and rear plates 10 and 20 are superimposed on each other to initially form cold water inlet and outlet channels respectively; the front of the middle plate B2 surrounds the cold water inlet and outlet holes 10 and 20 with a small sealing ring 14 respectively, forming a communication with the cold water area L and not with the condensation area C Complete cold water circulation channel;

The hot water circulation channel is composed of a hot water inlet channel and a hot water outlet channel. The hot water inlet and outlet channels are connected to the hot water area R, pass through the evaporation area E and are not connected to the evaporation area E; its specific structure is: The initial plate 3, the middle plate A1 and the middle plate B2 are provided with a hot water inlet hole 50 and a hot water outlet hole 60, and the hot water inlet and outlet holes 50 and 60 are located in the area surrounded by the hot water area R on the plate; The hot water inlet and outlet holes 50 and 60 on the front and rear plates are superimposed on each other to initially form hot water inlet and outlet channels; the front of the middle plate A1 is respectively provided with a small sealing ring 14 around the hot water inlet and outlet holes 50 and 60 to form A complete hot water circulation channel that communicates with the hot water area R but not with the evaporation area E;

The seawater channel, the seawater channel is connected with the evaporation area E, passes through the hot water area R and does not communicate with the hot water area R; its specific structure is: the starting plate 3, the middle plate A1 and the middle plate B2 are provided with seawater inlet holes 70. The seawater inlet hole 70 is located in the area surrounded by the hot water area R on the plate. The seawater inlet holes 70 on the adjacent front and rear plates are superimposed on each other to initially form a seawater channel. The front of the middle plate A1 is surrounded by a seawater inlet hole 70. A small sealing ring 14 is formed to form a complete seawater channel that communicates with the evaporation zone E but not with the hot water zone R; It is arranged symmetrically on the middle plate A1 and the middle plate B2, corresponding to the two sides of the bottom of the evaporation area E, so as to facilitate the diffusion of seawater from the two sides of the bottom to the middle and upper part, and the front of the middle plate B2 is surrounded by the seawater inlet hole 70 and is equipped with small openings. Sealing ring 15, small opening The sealing ring 15 has an opening towards the center of the evaporation area, which guides the inflowing medium and facilitates the medium to flow toward the center.

The fresh water output channel is located at the bottom of the condensation area C and only communicates with the condensation area C. The specific structure is: the initial plate 3, the middle plate A1 and the middle plate B2 are provided with a fresh water output hole 30, and the fresh water output hole 30 is located in the condensation area C. In the surrounding area, the condensation area C is isolated by the sealing strip B22, and the condensation area C is above the sealing strip B23. The sealing strip B22 is in the shape of a strip that slopes symmetrically downward from both ends to the middle and forms a low-lying belt in the middle. The fresh water output hole 30 is located at the corresponding position of the low-lying area, and the fresh water drained by the sealing strip B can completely flow into the fresh water output hole 30; the fresh water output holes 30 on the adjacent front and rear plates are superimposed on each other to initially form a fresh water output channel. A small sealing ring 14 is provided around the fresh water output hole 30 on the front of the middle plate A1, finally forming a complete fresh water output channel that communicates with the condensation area in the gap between the second plates and does not communicate with the gap between the first plates.

Among them, the medium in the cold water circulation channel is cold sea water, and the medium in the hot water circulation channel is jacket water, and the jacket water on other equipment is used to preheat to save energy and reduce costs.

Since the seawater evaporates to separate the concentrated brine, the channel also includes a concentrated brine channel located under the evaporation zone and the hot water zone, which is formed by superimposing the concentrated brine holes 80 at the corresponding positions at the bottom of each plate, which is convenient for entraining a large amount of salty seawater Separates and flows out during evaporation.

In addition to the above-mentioned medium flow holes, the middle plate A1 and the middle plate B2 are also provided with gas communication holes 40. The gas communication holes 40 are located in the area surrounded by the main sealing ring of any middle plate, and are located in the hot water zone R and the cold water zone L. Outside the area, it is convenient for water vapor to freely disperse and absorb condensation in the gaps between the plates, and it is convenient to use a vacuum pump to create a vacuum inside the heat exchanger, reduce the boiling point of seawater, and improve production efficiency. Specifically, the gas communication holes 40 are opened in the middle plate A1, In the area where the separation area S of B2 is located and on both sides of the area where the condensation area C is located, it is also set up on both sides of the area surrounded by the middle plate A1 and the cold water area L of B2.

The plate of the device body is positioned by the piercing rod 7, so that the front and rear are superimposed, and the two ends are pressed by the pressure plate 5, and the bolt 6 is used to connect and fix the pressure plate 5, thereby compressing the device body; the front pressure plate 5 and the starting plate 3 are buckled together As shown in Figure 4, the medium holes on the starting plate 3 are completely consistent with the middle plate A1, and there is a small sealing ring 14 around each medium hole on the front to ensure the tightness when the medium enters and exits the device body. OK, no leakage; the rear end plate 5 is buckled with the reverse side of the end plate 4, leaving no gap between the two, as shown in Figure 5, there is no medium hole on the end plate 4, and the front side has the same hole as the middle plate A1. rubber pads to facilitate the formation of the final first inter-panel gap.

When the heat exchanger is working, since the plates of the device body communicate with each other through the gas communication holes 90, the vacuum pump can be used to first reduce the air pressure, thereby reducing the evaporation temperature of seawater;

As shown in Figure 6, the first is the evaporation process. The jacket water of the main engine continuously enters through the hot water inlet hole 50. Since there is no small sealing ring 14 around the hot water inlet hole 50 of the middle plate A1, the jacket water diffuses to the middle plate A1 Evaporation zone E, while continuing to move forward, because there are small sealing rings 14 around the hot water inlet hole 50 and hot water outlet hole 60 of the middle plate B2, the cylinder jacket water only flows through the evaporation zone E and diffuses to the next set of middle plate A1 The hot water area R circulates alternately to the end plate 4. Finally, in the same way, the hot water outlet channel composed of the hot water outlet holes 60 flows out; the seawater to be evaporated that continuously enters the heat exchanger at the same time as the jacket water, the The seawater enters continuously through the seawater inlet hole 70. Since there is a small sealing ring 14 at the seawater inlet hole 70 on the middle plate A1, the seawater only flows through the hot water area R and flows into the gap between the second plates at the same time. Because the middle plate B2 There is a small opening sealing ring 15 around the Shanghai water inlet hole 70, and the seawater diffuses to the evaporation area E of the middle plate B2 along with the opening of the small opening sealing ring 15, and also continues to flow forward, and so circulates until the end plate. During this process, the middle plate A1 and the middle plate B2 are alternately arranged, the heat of the jacket water is transferred to the seawater through the plates, and the seawater gradually heats up to the evaporation temperature under the pressure, and then turns into water vapor, and rises to the separation zone S .

Separation process: seawater is heated and turned into water vapor, rising to the separation zone S, and salt will be entrained in the water vapor. During the rising process, this part of the water vapor will drip and separate due to the action of gravity, and the guide corrugation 90 in the separation zone S Under the action of , the concentrated brine bypasses the evaporation zone E, flows down from both sides, flows through the concentrated brine hole 80, and is discharged to the overboard; at the same time, due to the large amount of steam in this area, part of the steam communicates with the gas in this area. The holes 90 are evenly dispersed into the other inter-plate gaps.

Condensation process: Since the left and right sides of the condensation zone C formed by the sealing strip B13 are not closed, the steam passing through the separation zone S enters the condensation zone C; there is cold seawater in the cold water zone L separated from the condensation zone C, and the cold seawater is formed by The cold water inlet hole 10 continuously enters the device body. Since there is no small sealing ring 14 around the cold water inlet hole 10 of the middle plate A1, the cold seawater diffuses to the cold water area and flows into the gap between the second plates at the same time. Because the cold water inlet hole of the middle plate B2 There is a small sealing ring 14 around 10, so the cold sea water only flows through the cold water inlet hole 10 of the middle plate B2 without spreading, and continues to spread to the next cold water area L, and repeats this until the end plate 4, and flows through the cold water outlet in the same way The cold water outlet channel that hole 20 forms flows out. During this process, the cold seawater exchanges heat with the water vapor through the plates, and the water vapor condenses into fresh water, which flows to the fresh water output hole 30 under the action of gravity, and then directly enters the fresh water tank through the fresh water output hole 30. Part of the seawater flowing out of the cold water outlet hole 20 is directly discharged overboard, and part of it flows to the seawater inlet hole 70, and is used as seawater to be evaporated. The process of water vapor liquefaction has played a role in preheating the cold seawater, and the temperature of the seawater has increased. , which is beneficial for seawater to be heated to evaporate.

Supplementary Note: Both the condensation area C and the evaporation area E on the plate are equipped with herringbone corrugations. On the one hand, it can promote the formation of turbulent flow of liquid or gas flowing through both sides, so that the heat exchange is more sufficient and the heat exchange efficiency is improved; on the other hand, Can increase steel plate rigidity. The plate separation area S is provided with inclined guide corrugations 90 in the horizontal direction, so that the liquid droplets in it are easy to attach and separate during the rising process of water vapor, which saves the practical filter screen in the traditional plate water generator; Plate stiffness.

The basic principles and main features of the present utility model have been shown and described above. Those skilled in the industry should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (8)

1. A novel sea water desalination device is characterized in that: the device comprises a device body, wherein a plurality of plates are overlapped in a face-to-face buckling manner, the start end and the tail end of each plate are tightly pressed by a pressing plate, a closed space is formed between every two adjacent plates, and the closed space comprises first plate-to-plate gaps and second plate-to-plate gaps which are alternately arranged;

the plate comprises an initial plate, a plurality of middle plates A, a plurality of middle plates B and a finishing plate, wherein the front surface of the initial plate faces the outer side of the device body, and the back surface of the initial plate is attached to the front surface of the middle plate A to form a first plate gap; the middle plates A and the middle plates B are arranged in an alternating mode, wherein the back surfaces of the middle plates A are attached to the front surfaces of the middle plates B to form second plate gaps; the back surface of the middle plate B is attached to the front surface of the middle plate A to form a first plate gap; the front surface of the end plate is attached to the back surface of the middle plate B to form a first plate gap;

the first inter-plate gap comprises an upper cold water area and a lower hot water area which are independent and sealed; the second inter-plate gap sequentially comprises a condensation area, a separation area and an evaporation area which are communicated with each other from top to bottom, the cold water area is opposite to the condensation area, and the hot water area is opposite to the evaporation area.

2. The novel seawater desalination device of claim 1, which is characterized in that: the plates are also provided with channels for medium to flow between,

cold water inlet holes and cold water outlet holes are formed in the starting plate, the middle plate A and the middle plate B, and the cold water inlet holes and the cold water outlet holes are located in an area surrounded by a cold water area on the plate; a circle of small sealing rings are arranged on the front surface of the middle plate B around the cold water inlet and outlet holes to form a cold water circulating channel communicated with the cold water area but not communicated with the condensation area;

hot water inlet holes and hot water outlet holes are formed in the starting plate, the middle plate A and the middle plate B and are positioned in an area surrounded by a hot water area on the plate; the front surface of the middle plate A is provided with a circle of small sealing rings around the hot water inlet and outlet holes to form a hot water circulating channel communicated with the hot water area but not communicated with the evaporation area;

the starting plate, the middle plate A and the middle plate B are provided with seawater inlet holes, the seawater inlet holes are positioned in the area surrounded by the hot water area on the plate, the front surface of the middle plate B is provided with a circle of small sealing rings around the seawater inlet holes, and a seawater channel communicated with the evaporation area but not communicated with the hot water area is formed;

the starting plate, the middle plate A and the middle plate B are provided with fresh water output holes positioned at the bottom of the condensation area, the fresh water output holes are positioned in the area surrounded by the condensation area, the front surface of the middle plate A is provided with a circle of small sealing rings around the fresh water output holes, and a fresh water output channel communicated with the second plate-to-plate gap condensation area but not communicated with the first plate-to-plate gap is formed;

the medium in the cold water circulation channel is cold seawater, and the medium in the hot water circulation channel is cylinder liner water.

3. The novel seawater desalination device of claim 2, wherein: the seawater inlet holes are symmetrically arranged in a pair, the seawater inlet holes are symmetrically arranged on the middle plate A and the middle plate B and correspond to two sides of the bottom of the evaporation area, the front surface of the middle plate B is provided with a small opening sealing ring around the seawater inlet holes, and the small opening sealing ring is provided with an opening facing the center of the evaporation area.

4. The novel seawater desalination device of claim 2, wherein: the channel also comprises a strong brine channel positioned below the evaporation area and the hot water area, and is formed by superposing strong brine holes positioned at corresponding positions at the bottom of each plate in front and back.

5. The novel seawater desalination device of claim 1, which is characterized in that:

the front surface of the middle plate A is provided with a first sealing ring group, and the first sealing ring group comprises a first main sealing ring used for surrounding and forming a first plate-to-plate gap, a large sealing ring A arranged in a region surrounded by the first main sealing ring and used for surrounding and forming a cold water region, and a large sealing ring B used for surrounding and forming a hot water region;

the front surface of the middle plate B is provided with a second sealing ring group, the second sealing ring group comprises a second main sealing ring for surrounding and forming a gap between the second plates, and a sealing strip A and a sealing strip B which are arranged in an area surrounded by the second main sealing ring and used for dividing a condensation area, a separation area and an evaporation area, the evaporation area is a space with an opening at the upper end formed by surrounding the sealing strip A, and the separation area and the condensation area are sequentially arranged above the evaporation area and are separated by the sealing strip B above the opening of the evaporation area.

6. The novel seawater desalination device of claim 5, wherein: the sealing strip B is in a strip shape which is symmetrically inclined downwards from two ends to the middle part and forms a low-lying zone in the middle.

7. The novel seawater desalination device of claim 1, which is characterized in that: the two sides of each plate corresponding to the separation area are provided with guide ripples, the guide ripples at the two sides extend from the middle position of the separation area to the outer oblique lower side, and the extending direction of the guide ripples is not contacted with the evaporation area.

8. The novel seawater desalination device of claim 1, which is characterized in that: and the middle plate A and the middle plate B are also provided with gas communication holes, and the gas communication holes are positioned in the closed space and are positioned outside the surrounded areas of the hot water area and the cold water area.