High-salt-content wastewater evaporation heat exchange system

Abstract

The invention discloses a high-salt-content wastewater evaporation heat exchange system which comprises an evaporation raw water tank, a horizontal pipe heat exchanger, an evaporation salt precipitation tank, a steam compressor, a condensate water barrel, a salt centrifugal machine and a filtrate barrel. The evaporation salting-out tank is provided with a salting-out circulating pipeline for communicating inside and outside; the salting-out circulating pump is used for driving high-salinity wastewater in the salting-out circulating pipeline and raw water introduced through the raw water inlet pipeline to flow into the evaporation salting-out tank from the first passage, and driving saturated salt slurry in the evaporation salting-out tank to enter the salting-out circulating pipeline; the steam compressor is used for compressing unsaturated secondary steam which is generated by the self-evaporation salt precipitation tank and input through the first steam pipeline and then conveying saturated high-temperature and high-pressure steam to the second steam pipeline; the filtrate return pipeline is communicated with the salting-out circulating pipeline, so that the filtrate flows back into the salting-out circulating pipeline again. According to the invention, the reutilization of heat at the later stage of the process is realized, the energy utilization rate is high, the energy waste is less, and the operation cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to an evaporation heat exchange system for high-salt wastewater. Background Art

[0002] With the rapid development of industry, a large amount of high-salt wastewater is generated in the industrial production process. This type of wastewater is highly corrosive, biodegradable and environmentally polluting. Traditional wastewater treatment methods are difficult to meet the treatment requirements of high-salt wastewater. Among them, high-salt wastewater treatment can use evaporation and crystallization technology to evaporate the salt in the wastewater and achieve water-salt separation. However, the current evaporation and crystallization treatment system has low thermal utilization rate and cannot fully utilize the heat in the latter part of the process, resulting in large energy waste and high operating costs.

[0003] In view of this, it is necessary to provide a high-salinity wastewater evaporation heat exchange system to overcome the above-mentioned defects. Summary of the invention

[0004] The purpose of the present invention is to provide a high-salt wastewater evaporation heat exchange system, aiming to improve the problem of low thermal utilization rate of existing evaporation crystallization treatment systems, improve heat circulation efficiency, and reduce operating costs.

[0005] In order to achieve the above object, the present invention provides a high-salinity wastewater evaporation heat exchange system, comprising:

[0006] An evaporation raw water tank, wherein the evaporation raw water tank is connected to a raw water inlet pipeline, and the raw water inlet pipeline is provided with an evaporation inlet pump;

[0007] A transverse tube heat exchanger, wherein the transverse tube heat exchanger comprises a first passage and a second passage for heat exchange; the raw water inlet pipeline is connected to the first passage;

[0008] An evaporative salt precipitation tank, wherein the evaporative salt precipitation tank is provided with a salt precipitation circulation pipeline connecting the inside and the outside; the salt precipitation circulation pipeline is provided with a salt precipitation circulation pump, and both ends are respectively connected with the two ends of the first passage; the salt precipitation circulation pump is used to drive the high-salt wastewater in the salt precipitation circulation pipeline and the raw water introduced through the raw water inlet pipeline to flow from the first passage into the evaporative salt precipitation tank, and drive the saturated salt slurry in the evaporative salt precipitation tank into the salt precipitation circulation pipeline;

[0009] A steam compressor, the steam compressor is connected to the upper part of the evaporation salt precipitation tank through a first steam pipeline, and is connected to one end of the second passage through a second steam pipeline; the steam compressor is used to compress the unsaturated secondary steam generated from the evaporation salt precipitation tank and input through the first steam pipeline, and then transport saturated high-temperature and high-pressure steam to the second steam pipeline;

[0010] a condensed water tank, the condensed water tank being connected to an end of the second passage away from the second steam pipeline to receive high-temperature condensed water formed after the saturated high-temperature and high-pressure steam in the second passage exchanges heat with the first passage;

[0011] A salt centrifuge, wherein the salt centrifuge is connected to the salt precipitation circulation pipeline through a salt slurry discharge branch, so that part of the saturated salt slurry in the salt precipitation circulation pipeline that has not flowed into the first passage is subjected to solid-liquid separation in the salt centrifuge;

[0012] The filtrate bucket is used to receive the filtrate separated by the salt centrifuge, and is connected to the salt precipitation circulation pipeline through a filtrate reflux pipeline, so that the filtrate can flow back into the salt precipitation circulation pipeline.

[0013] In a preferred embodiment, the system further comprises:

[0014] A plate preheater, the plate preheater being connected to an end of the raw water inlet pipeline away from the evaporation raw water tank, the evaporation inlet pump being used to pump the raw water in the evaporation raw water tank into the plate preheater through the raw water inlet pipeline;

[0015] The condensed water bucket is also connected to the plate preheater via a condensed water discharge branch, so that the high-temperature condensed water in the condensed water discharge branch can be subjected to countercurrent heat exchange with the raw water in the raw water inlet pipeline.

[0016] In a preferred embodiment, the system further comprises:

[0017] A thickener is arranged on the salt slurry discharge branch and is used to increase the salt crystal ratio of the salt slurry in the salt slurry discharge branch; the salt centrifuge is connected to the bottom of the thickener; the filtrate barrel is connected to the upper part of the thickener through a supernatant recovery pipeline and is also used to receive the supernatant located at the upper part of the thickener.

[0018] In a preferred embodiment, a thickener jacket is provided on the outside of the thickener, a heat exchange passage is provided in the thickener jacket, and the raw water inlet pipeline is connected to the heat exchange passage.

[0019] In a preferred embodiment, the raw water inlet pipeline includes an inlet main line connected to the evaporation raw water tank and a first branch and a second branch. The raw water in the first branch enters the cross-tube heat exchanger after heat exchange with the plate preheater and the condensate discharge branch.

[0020] In a preferred embodiment, the first branch is further provided with a heat exchange bypass at both ends of the plate preheater, and the raw water entering from the front end of the first branch can enter the cross-tube heat exchanger through the plate preheater or the heat exchange bypass; the raw water of the second branch enters the plate preheater or the heat exchange bypass after passing through the heat exchange passage to exchange heat with the salt slurry in the thickener.

[0021] In a preferred embodiment, the middle of the filtrate reflux pipeline is also connected to an evaporation mother liquor discharge pipeline, and the evaporation mother liquor discharge pipeline is used to discharge part of the filtrate in the filtrate barrel into the evaporation mother liquor pool.

[0022] In a preferred embodiment, the system further includes: a steam supplementary pipeline, which is connected between the steam generator and the second steam pipeline and is used to transport the saturated high-temperature and high-pressure steam generated by the steam generator to the second steam pipeline.

[0023] The high-salt wastewater evaporation and heat exchange system provided by the present invention pumps the high-temperature salt-containing wastewater in the salt precipitation circulation pipeline into the evaporation and salt precipitation tank for evaporation and crystallization through a salt precipitation circulation pump, and enables the generated unsaturated secondary steam to enter the steam compressor for compression to obtain high-quality saturated high-temperature and high-pressure steam, and then in the cross-tube heat exchanger, the wastewater in the salt precipitation circulation pipeline is heated by heat exchange to form a wastewater operation loop, which reduces energy demand compared with the prior art; in addition, the higher temperature and saturated filtrate in the filtrate barrel will flow back to the salt precipitation circulation pipeline, and the heat in the filtrate barrel will also be brought into the evaporation and salt precipitation tank, thereby realizing the reuse of heat in the latter stage of the process, with high energy utilization rate, less energy waste and reduced operation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic diagram of the pipeline of the high-salinity wastewater evaporation heat exchange system provided by the present invention;

[0026] Figure 2 FIG. 1 is a schematic diagram of temperature changes of wastewater as it flows through various locations in an exemplary embodiment.

[0027] Numbers in the figure: 100, high-salinity wastewater evaporation heat exchange system;

[0028] 10. Evaporation raw water tank; 20. Horizontal tube heat exchanger; 30. Evaporation salt separation tank; 40. Steam compressor; 50. Condensate bucket; 60. Salt centrifuge; 70. Filtrate bucket; 80. Plate preheater; 90. Thickener; 91. Thickener jacket;

[0029] 101, raw water inlet pipeline; 1010, water inlet main pipeline; 1011, first branch pipeline; 1012, second branch pipeline; 1013, heat exchange bypass pipeline;

[0030] 102, evaporation water inlet pump; 201, salt precipitation circulation pipeline; 202, salt precipitation circulation pump; 301, first steam pipeline; 302, second steam pipeline; 401, condensate discharge branch; 501, salt slurry discharge branch; 601, filtrate reflux pipeline; 602, evaporation mother liquor discharge pipeline; 603, evaporation mother liquor pool; 604, filtrate collection pipeline; 701, steam replenishment pipeline; 702, steam generator; 801, supernatant recovery pipeline. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and beneficial technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining the present invention, not for limiting the present invention.

[0032] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0033] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0034] In an embodiment of the present invention, a high-salt wastewater evaporation and heat exchange system 100 is provided, which is used to evaporate and crystallize the high-salt wastewater after pretreatment (hardness removal, silicon removal, mud removal, etc.) to precipitate crystalline salt, facilitate subsequent solid-liquid separation, achieve a certain degree of heat recycling, and reduce operating costs.

[0035] like Figure 1-Figure 2 As shown, the high-salinity wastewater evaporation heat exchange system 100 includes: an evaporation raw water tank 10, a cross-tube heat exchanger 20, an evaporation salt precipitation tank 30, a steam compressor 40, a condensed water barrel 50, a salt centrifuge 60 and a filtrate barrel 70.

[0036] In this embodiment, the evaporation raw water tank 10 is used to receive and store high-salinity wastewater, and is connected to a raw water inlet pipeline 101, and the raw water inlet pipeline 101 is provided with an evaporation inlet pump 102. The evaporation inlet pump 102 is used to drive the high-salinity wastewater in the evaporation raw water tank 10 to other devices through the raw water inlet pipeline 101. At this time, the temperature of the high-salinity wastewater (also called raw water) is room temperature.

[0037] The cross-tube heat exchanger 20 includes a first passage and a second passage (not shown) for heat exchange. The first passage and the second passage are synchronously bent and countercurrently arranged in the cross-tube heat exchanger 20 to improve the heat exchange efficiency. The raw water inlet pipeline 101 is connected to the first passage, that is, low-temperature raw water enters the first passage through the raw water inlet pipeline 101.

[0038] The evaporation salting tank 30 includes an evaporation chamber and a heating chamber connected to each other internally, and is provided with a salting circulation pipeline 201 which is connected to the evaporation chamber and the heating chamber from the outside. The evaporation salting tank 30 is an evaporation crystallization device, and the high-temperature saline wastewater evaporates in the heating chamber at the bottom thereof to form saturated saline wastewater, and then continues to evaporate to precipitate crystallized salt (such as sodium chloride, potassium chloride, etc.), and the steam (i.e., unsaturated secondary steam) generated during the evaporation process is accumulated in the evaporation chamber at the top. Among them, the salting circulation pipeline 201 is arranged on the outside of the evaporation salting tank 30, one end of which is connected to the bottom of the evaporation salting tank 30 to receive the saturated saline wastewater and its crystallized salt at the bottom of the evaporation salting tank 30, and the other end is connected to the middle of the evaporation salting tank 30 to transport the high-temperature saline wastewater to the inside of the evaporation salting tank 30.

[0039] Specifically, the salt-precipitating circulation pipeline 201 is provided with a salt-precipitating circulation pump 202. The salt-precipitating circulation pump 202 is used to drive the wastewater and the salt slurry mixed with crystallized salt to circulate in the salt-precipitating circulation pipeline 201 and the evaporation salt-precipitating tank 30. The two ends of the salt-precipitating circulation pipeline 201 are respectively connected to the two ends of the first passage. That is, the salt-precipitating circulation pipeline 201 is divided into two sections, one section connects the middle of the evaporation salt-precipitating tank 30 with one end of the first passage, and the other section connects the bottom of the evaporation salt-precipitating tank 30 with the other end of the first passage. It should be noted that the raw water inlet pipeline 101 is also connected to the first passage, so the low-temperature saline wastewater entering through the raw water inlet pipeline 101 also enters the salt-precipitating circulation pipeline 201 through the first passage, and flows unidirectionally to the middle of the evaporation salt-precipitating tank 30, and the low-temperature saline wastewater forms high-temperature saline wastewater after heat exchange in the cross-tube heat exchanger 20, thereby replenishing the high-temperature evaporation liquid in the evaporation salt-precipitating tank 30.

[0040] Therefore, the salt precipitation circulation pump 202 is used to drive the high-salt wastewater in the salt precipitation circulation pipeline 201 and the raw water introduced through the raw water inlet pipeline 101 to flow from the first passage to the evaporation salt precipitation tank 30, and to drive the saturated salt slurry in the evaporation salt precipitation tank 30 into the salt precipitation circulation pipeline 201, so that the liquid in the salt precipitation circulation pipeline 201 continuously flows in one direction, and the saturated salt slurry and crystallized salt can be extracted from the bottom of the evaporation salt precipitation tank 30, and raw water can be replenished to the evaporation salt precipitation tank 30.

[0041] The steam compressor 40 is connected to the upper part of the evaporation salt precipitation tank 30 through the first steam pipeline 301, and is connected to one end of the second passage through the second steam pipeline 302. The high-temperature salt-containing wastewater in the evaporation salt precipitation tank 30 will produce a large amount of unsaturated steam during the evaporation and crystallization process, and these unsaturated steam (also called unsaturated secondary steam) will enter the steam compressor 40 through the first steam pipeline 301. At the same time, the wastewater at the bottom of the evaporation salt precipitation tank 30 will form a saturated salt solution after the water evaporates, and then precipitate crystallized salt.

[0042] Therefore, the steam compressor 40 is used to compress the unsaturated secondary steam generated by the self-evaporation salt precipitation tank 30 and input through the first steam pipeline 301, converting electrical energy into thermal energy, thereby converting the unsaturated secondary steam entering from the first steam pipeline 301 into high-quality saturated high-temperature and high-pressure steam, and then transporting the saturated high-temperature and high-pressure steam to the second steam pipeline 302, and finally making the saturated high-temperature and high-pressure steam in the second passage exchange heat with the liquid in the first passage. It should be noted that the specific structure of the steam compressor 40 and its steam compression principle can refer to the prior art, and the present invention will not be repeated here.

[0043] The condensed water bucket 50 is connected to one end of the second passage away from the second steam pipeline 302 to receive the high-temperature condensed water formed after the saturated high-pressure and high-temperature steam in the second passage exchanges heat with the first passage. That is, after the saturated high-temperature and high-pressure steam (gas state) in the second passage exchanges heat, the temperature is reduced and condenses from the gas state to the liquid state to form high-temperature condensed water (liquid state). The high-temperature condensed water is discharged from the second passage and then flows into the condensed water bucket 50, and the high-temperature condensed water can be reused.

[0044] Furthermore, the high-salinity wastewater evaporation heat exchange system 100 also includes a plate preheater 80 .

[0045] The plate preheater 80 is connected to one end of the raw water inlet pipeline 101 away from the evaporation raw water tank 10, and the evaporation inlet pump 102 is used to pump the raw water in the evaporation raw water tank 10 into the plate preheater 80 through the raw water inlet pipeline 101. The condensed water bucket 50 is also connected to the plate preheater 80 through the condensed water discharge branch 401, so that the high-temperature condensed water in the condensed water discharge branch 401 and the raw water in the raw water inlet pipeline 101 are countercurrently exchanged. That is, the high-temperature condensed water and the raw water are first heat exchanged to increase the temperature of the raw water before entering the salt precipitation circulation pipeline 201, and reduce the energy consumption in the cross-tube heat exchanger 20, so as to realize the reuse of the heat of the condensed water and reduce the operating cost.

[0046] In an embodiment of the present invention, the salt centrifuge 60 is connected to the salt analysis circulation pipeline 201 through the salt slurry discharge branch 501, so that the partially saturated salt slurry in the salt analysis circulation pipeline 201 that has not yet flowed into the first passage is separated into solid and liquid in the salt centrifuge 60. Among them, the salt slurry discharge branch 501 is connected to the bottom of the evaporation salt analysis tank 30, and is staggered with the vertical section of the salt analysis circulation pipeline 201, so that the traditional "salt leg" structure can be omitted, the overall height of the salt analysis tank is reduced, and the skid-mounted assembly is realized. That is, the salt centrifuge 60 separates the solid and liquid by centrifugation, thereby separating the crystallized salt, and the remaining is the filtrate in a saturated state. The filtrate is connected to the filtrate barrel 70 through the filtrate collection pipeline 604, so that the saturated salt solution separated by the salt centrifuge 60 enters the filtrate barrel 70 through the filtrate collection pipeline 604.

[0047] Furthermore, the high-salinity wastewater evaporation heat exchange system 100 also includes a thickener 90. The thickener 90 is arranged on the salt slurry discharge branch 501, and is used to increase the concentration of the salt slurry in the salt slurry discharge branch 501, that is, to further increase the proportion of crystallized salt in the salt slurry. The salt centrifuge 60 is connected to the bottom of the thickener 90. The filtrate barrel 70 is connected to the upper part of the thickener 90 through the supernatant recovery pipeline 801, and is also used to receive the supernatant overflowing from the upper part of the thickener 90 to realize the thickening function of the thickener. It should be noted that the specific structure and implementation principle of the thickener 90 can refer to the prior art, and the present invention is not limited here.

[0048] The filtrate barrel 70 is used to receive the filtrate separated by the salt centrifuge 60 and the supernatant overflowing from the top of the thickener 90, and is connected to the salt precipitation circulation pipeline 201 through the filtrate reflux pipeline 601, so that the filtrate and the supernatant can flow back into the salt precipitation circulation pipeline 201.

[0049] Furthermore, a thickener jacket 91 is provided outside the thickener 90. A heat exchange passage (not shown in the figure) is provided inside the thickener jacket 91. The raw water inlet pipeline 101 can be connected to the heat exchange passage.

[0050] Specifically, the raw water inlet pipeline 101 includes a water inlet main 1010 connected to the evaporation raw water tank 10, a first branch 1011 and a second branch 1012. The raw water in the first branch 1011 enters the cross-tube heat exchanger 20 after passing through the plate preheater 80 and the condensed water discharge branch 401 for heat exchange. The raw water in the second branch 1012 exchanges heat with the salt slurry in the thickener 90 through the heat exchange passage. That is, one end of the heat exchange passage is connected to the end of the second branch 1012, and the other end is connected to the middle of the first branch 1011 (the connection point is located at the front end of the plate preheater 80 and the heat exchange bypass 1013).

[0051] Specifically, the raw water inlet pipeline 101 is divided into at least two branches. The raw water of the first branch 1011 first enters the plate preheater 80 to exchange heat with the high-temperature condensed water. The raw water of the second branch 1012 can then enter the plate preheater 80 or other flushing pipelines after exchanging heat with the salt slurry in the heat exchange passage.

[0052] The first branch 1011 is further provided with a heat exchange bypass 1013 at both ends of the plate preheater 80, and the raw water entering from the inlet of the first branch 1101 can enter the cross-tube heat exchanger 20 through the plate preheater 80 or the heat exchange bypass 1013. That is, the raw water of the first branch 1011 can enter the cross-tube heat exchanger 20 directly through the heat exchange bypass 1013 without passing through the plate preheater 80 or flushing other pipelines.

[0053] It should be noted that, depending on the system operation conditions, it can be chosen whether to utilize the heat of the salt slurry in the thickener 60, that is, whether to exchange heat with it. However, regardless of whether heat is exchanged with it, the raw water must pass through the plate preheater 80 (or the heat exchange bypass 1013) before entering the cross-tube heat exchanger or other flushing pipeline 20.

[0054] It can be understood that the raw water of the evaporation raw water tank 10 has at least four flow modes: one is to enter the cross tube heat exchanger 20 after primary preheating from the first trunk 1011 through the plate preheater 80; the second is to enter the cross tube heat exchanger 20 after secondary preheating from the second branch 1012 through the thickener jacket 91 of the thickener 90 and the plate preheater 80; the third is to flush other pipelines with cold water from the first trunk 1011 through the heat exchange bypass 1013 or directly enter the cross tube heat exchanger 20; the fourth is to enter the heat exchange bypass 1013 after preheating from the second trunk 1012 through the thickener jacket 91 of the thickener 90 and then flush other pipelines with hot water or enter the cross tube heat exchanger 20. Therefore, the pipeline design of the present invention can control the flow direction of the raw water according to the use requirements, save the design of additional flushing pipelines, and realize cold water / hot water flushing.

[0055] In one embodiment, the middle of the filtrate return pipeline 601 is also connected to an evaporation mother liquor discharge pipeline 602. The evaporation mother liquor discharge pipeline 602 is used to discharge part of the filtrate in the filtrate barrel 70 into the evaporation mother liquor pool 603, and the saturated salt solution in the filtrate barrel 70 can be placed in the evaporation mother liquor pool 603 for temporary storage or for other purposes.

[0056] In one embodiment, the high-salinity wastewater evaporation heat exchange system 100 further includes a steam supplementary pipeline 701. The steam supplementary pipeline 701 is connected between the steam generator 702 and the second steam pipeline 302, and is used to transport the saturated high-temperature and high-pressure steam generated by the steam generator 702 to the second steam pipeline 302. That is, when the entire system starts to operate or the steam in the pipeline is insufficient, the saturated high-temperature and high-pressure steam is supplemented through the steam generator 702.

[0057] It should be noted that each pipeline can realize on-off control, drive liquid flow and other functions through its own valve or pump structure; it can also realize the switching and joint use of multiple pipelines by opening and closing the valves of different pipelines in different combinations. In order to make the drawings more concise and clear, the present invention does not specifically describe the valves, pumps, detection devices, stirring devices and other auxiliary structures of each pipeline and each device in the above description.

[0058] In summary, the high-salt wastewater evaporation and heat exchange system 100 provided by the present invention pumps the high-temperature salt-containing wastewater in the salt precipitation circulation pipeline 201 into the evaporation and salt precipitation tank 30 for evaporation and crystallization through the salt precipitation circulation pump 202, and enables the generated unsaturated secondary steam to enter the steam compressor 40 for compression to obtain high-quality saturated high-temperature and high-pressure steam, and then in the cross-tube heat exchanger 20, the wastewater in the salt precipitation circulation pipeline 201 is heated by heat exchange to form a wastewater operation loop, which reduces energy demand compared with the prior art; in addition, the higher temperature and saturated filtrate in the filtrate barrel 70 will flow back to the salt precipitation circulation pipeline 201, and will also bring the heat in the filtrate barrel 70 into the evaporation and salt precipitation tank 30, thereby realizing the reuse of heat in the latter stage of the process, with high energy utilization rate, less energy waste, and reduced operating costs.

[0059] The present invention is not limited to what is described in the specification and implementation modes, and therefore additional advantages and modifications can be easily realized by those skilled in the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described herein.

Claims

1. A high-salinity wastewater evaporation heat exchange system, characterized in that: include: An evaporation raw water tank, wherein the evaporation raw water tank is connected to a raw water inlet pipeline, and the raw water inlet pipeline is provided with an evaporation inlet pump; A transverse tube heat exchanger, wherein the transverse tube heat exchanger comprises a first passage and a second passage for heat exchange; the raw water inlet pipeline is connected to the first passage; An evaporative salt precipitation tank, wherein the evaporative salt precipitation tank is provided with a salt precipitation circulation pipeline connecting the inside and the outside; the salt precipitation circulation pipeline is provided with a salt precipitation circulation pump, and both ends are respectively connected with the two ends of the first passage; the salt precipitation circulation pump is used to drive the high-salt wastewater in the salt precipitation circulation pipeline and the raw water introduced through the raw water inlet pipeline to flow from the first passage into the evaporative salt precipitation tank, and drive the saturated salt slurry in the evaporative salt precipitation tank into the salt precipitation circulation pipeline; A steam compressor, the steam compressor is connected to the upper part of the evaporation salt precipitation tank through a first steam pipeline, and is connected to one end of the second passage through a second steam pipeline; the steam compressor is used to compress the unsaturated secondary steam generated from the evaporation salt precipitation tank and input through the first steam pipeline, and then transport saturated high-temperature and high-pressure steam to the second steam pipeline; a condensed water tank, the condensed water tank being connected to an end of the second passage away from the second steam pipeline to receive high-temperature condensed water formed after the saturated high-temperature and high-pressure steam in the second passage exchanges heat with the first passage; A salt centrifuge, wherein the salt centrifuge is connected to the salt precipitation circulation pipeline through a salt slurry discharge branch, so that part of the saturated salt slurry in the salt precipitation circulation pipeline that has not flowed into the first passage is subjected to solid-liquid separation in the salt centrifuge; The filtrate bucket is used to receive the filtrate separated by the salt centrifuge, and is connected to the salt precipitation circulation pipeline through a filtrate reflux pipeline, so that the filtrate can flow back into the salt precipitation circulation pipeline.

2. The high-salinity wastewater evaporation heat exchange system according to claim 1, characterized in that: Also includes: A plate preheater, the plate preheater being connected to an end of the raw water inlet pipeline away from the evaporation raw water tank, the evaporation inlet pump being used to pump the raw water in the evaporation raw water tank into the plate preheater through the raw water inlet pipeline; The condensed water bucket is also connected to the plate preheater via a condensed water discharge branch, so that the high-temperature condensed water in the condensed water discharge branch can be subjected to countercurrent heat exchange with the raw water in the raw water inlet pipeline.

3. The high-salinity wastewater evaporation heat exchange system according to claim 2, characterized in that: Also includes: A thickener is arranged on the salt slurry discharge branch and is used to increase the salt crystal ratio of the salt slurry in the salt slurry discharge branch; the salt centrifuge is connected to the bottom of the thickener; the filtrate barrel is connected to the upper part of the thickener through a supernatant recovery pipeline and is also used to receive the supernatant located at the upper part of the thickener.

4. The high-salinity wastewater evaporation heat exchange system according to claim 3, characterized in that: A thickener jacket is arranged outside the thickener, and a heat exchange passage is arranged inside the thickener jacket; the raw water inlet pipeline is connected to the heat exchange passage.

5. The high-salinity wastewater evaporation heat exchange system according to claim 4, characterized in that: The raw water inlet pipeline includes a water inlet trunk line connected to the evaporation raw water tank and a first branch and a second branch. The raw water in the first branch enters the cross-tube heat exchanger after heat exchange with the plate preheater and the condensate discharge branch.

6. The high-salinity wastewater evaporation heat exchange system according to claim 5, characterized in that: The first branch is also provided with a heat exchange bypass at both ends of the plate preheater. The raw water entering from the front end of the first branch can enter the cross-tube heat exchanger through the plate preheater or the heat exchange bypass; the raw water of the second branch enters the plate preheater or the heat exchange bypass after passing through the heat exchange passage to exchange heat with the salt slurry in the thickener.

7. The high-salinity wastewater evaporation heat exchange system according to claim 1, characterized in that: The middle part of the filtrate reflux pipeline is also connected to an evaporation mother liquor discharge pipeline, and the evaporation mother liquor discharge pipeline is used to discharge part of the filtrate in the filtrate barrel into the evaporation mother liquor pool.

8. The high-salinity wastewater evaporation heat exchange system according to claim 1, characterized in that: Also includes: A steam replenishment pipeline is connected between the steam generator and the second steam pipeline and is used to transport the saturated high-temperature and high-pressure steam generated by the steam generator to the second steam pipeline.

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