A desalination heat pump rectification system for organic salt-containing aqueous solution

Abstract

The application provides a kind of organic salt-containing aqueous solution desalination heat pump rectification system, through evaporator rough concentration, then through forced circulation evaporator desalination, reheat pump rectification, solve the problem of difficult treatment and high energy consumption of salt-containing organic solution, the heat pump system reduces the steam consumption, reduces energy consumption compared with traditional process, saves operating cost.

Description

Technical Field

[0001] This invention relates to the application of heat pump distillation in the chemical industry, specifically a heat pump distillation system for desalinating organic saline aqueous solutions. Background Technology

[0002] Distillation columns are the most widely used separation equipment in industrial production processes such as chemical, pharmaceutical, and environmental protection. These large pieces of equipment, typically over ten meters high, are also among the most energy-intensive units. Improving the performance of the distillation process will be crucial for companies to reduce operating costs and increase economic efficiency.

[0003] Existing distillation systems not only consume a lot of energy, but also lack desalination capabilities. If the salt in the raw solution is not treated, the following problems will occur: 1. It will easily cause severe blockage of the tower, making continuous production impossible; 2. The salt generated during the distillation process cannot be separated from the solution in a timely and effective manner, and the quality of the finished product cannot meet the specifications.

[0004] Therefore, there is an urgent need to design and develop an energy-saving distillation system suitable for desalinating organic saline aqueous solutions. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide an organic salt-containing aqueous solution desalination heat pump distillation system.

[0006] The technical solution adopted in this invention is as follows: A heat pump distillation system for desalinating organic saline aqueous solutions, comprising a preheating module, an evaporator, a vapor-liquid separator, a forced circulation evaporator, a crystallizer, a thickener, a centrifuge, a mother liquor tank, and a distillation column.

[0007] The preheating module has a raw liquid inlet and a raw liquid outlet. The raw liquid inlet is connected to a raw liquid feed pipe, and the raw liquid outlet is connected to the raw material inlet of the evaporator. The first steam outlet of the evaporator is connected to the steam inlet of the vapor-liquid separator.

[0008] The liquid outlet of the vapor-liquid separator is connected to the second inlet of the evaporator and the first liquid inlet of the crystallizer via a first pump body. The second liquid outlet of the crystallizer is connected to the first inlet of the forced circulation evaporator via a forced circulation pump. The first outlet of the forced circulation evaporator is connected to the second inlet of the crystallizer. The third outlet of the crystallizer is connected to the inlet of the thickener via a third pump body. The first liquid outlet of the thickener is connected to the mother liquor tank. The second outlet of the thickener is connected to the centrifuge. The liquid outlet of the centrifuge is connected to the liquid inlet of the mother liquor tank. Its solid outlet is connected to a crystallized salt discharge pipe. The liquid outlet of the mother liquor tank is connected to the second inlet of the forced circulation evaporator via a fourth pump body. The inlet of the distillation column is connected to the steam outlet of the vapor-liquid separator and the steam outlet of the crystallizer.

[0009] Preferably, the preheating module includes a first preheating unit with liquid inlet and outlet connected in sequence and a second preheating unit with live steam inlet. The raw liquid inlet of the first preheating unit is the raw liquid inlet of the preheating module, and the raw liquid outlet of the second preheating unit is the raw liquid outlet of the preheating module. The second preheating unit includes a four-stage preheater.

[0010] Preferably, it also includes a condensate tank, and the first preheating unit includes a raw liquid inlet and outlet connected in sequence to a primary preheater, a secondary preheater, and a tertiary preheater, wherein the raw liquid inlet is the liquid inlet of the primary preheater;

[0011] The second steam outlet of the evaporator and the second steam outlet of the forced circulation evaporator are both connected to the first steam inlet at the top of the condensate tank. The condensate outlet of the condensate tank is connected to the condensate inlet of the secondary preheater through the fifth pump body. The steam outlet of the condensate tank is connected to the steam inlet of the tertiary preheater. The condensate outlet of the tertiary preheater is connected to the condensate outlet of the condensate tank.

[0012] Preferably, the liquid outlet of the evaporator is connected to the second inlet of the evaporator and the first liquid inlet of the crystallization separator via the first pump body.

[0013] Preferably, the system also includes a gas scrubbing tower, the inlet of which is connected to the steam outlet of the vapor-liquid separator and the steam outlet of the crystallization separator, and the first outlet of the gas scrubbing tower is connected to the inlet of the distillation tower.

[0014] Preferably, the second liquid outlet of the gas scrubbing tower is connected to the third inlet of the crystallizer via the second pump body.

[0015] Preferably, it also includes a reboiler, wherein the second liquid outlet of the distillation column is connected to the liquid inlet of the reboiler, the vapor outlet of the distillation column is connected to the vapor inlet of the compressor, the output port of the compressor is connected to the vapor inlet of the reboiler and the third inlet of the forced circulation evaporator, the third inlet of the forced circulation evaporator is connected to the second outlet of the forced circulation evaporator, and the second outlet of the forced circulation evaporator is connected to the third inlet of the evaporator.

[0016] Preferably, the liquid outlet of the reboiler is connected to the liquid inlet of the primary preheater in the preheating module via a sixth pump body.

[0017] Preferably, the crystallizer has a salt leg sight glass for observing the crystallization situation inside the crystallizer, and a first discharge pipe and a second discharge pipe are formed between the third pump body and the third outlet of the crystallizer and the inlet of the thickener, respectively. The first discharge pipe and / or the second discharge pipe have pipe sight glasses for observing the crystallization situation inside the discharge pipe.

[0018] Preferably, the evaporator is a falling film evaporator, the vapor-liquid separator is a falling film separator, and the second inlet of the evaporator is located at the top of the evaporator.

[0019] The beneficial effects of this invention are as follows: by using an evaporator for coarse concentration, followed by a forced circulation evaporator for desalination, and then heat pump distillation, the problems of difficult treatment and high energy consumption of salt-containing organic solutions are solved. The heat pump system reduces steam consumption, which reduces energy consumption compared to traditional processes and saves operating costs.

[0020] The heated raw material enters the tube side of the evaporator for heating and evaporation. After evaporation, the material vapor enters the vapor-liquid separator. The separated material vapor enters the crystallizer and the gas scrubbing tower. The separated liquid is pumped by a pump, with part of it being pumped to the top of the evaporator and part to the crystallizer. The material passing through the crystallizer enters the forced circulation evaporator and then is pumped back to the crystallizer and finally enters the thickener. The clear liquid from the thickener enters the mother liquor tank directly, and the rest enters the centrifuge. After centrifugation, the liquid material enters the mother liquor tank, and the solid crystal salt is directly discharged. The material vapor entering the gas scrubbing tower enters the distillation tower. In the distillation tower, the liquid flows into the reboiler, and the gas rises to the top of the tower and enters the compressor for pressurization and heating, providing heat to the reboiler, the forced circulation evaporator, and the evaporator. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0022] Figure 1 This is a flow chart of the heat pump distillation process of the present invention;

[0023] In the diagram, 1. Primary preheater; 2. Secondary preheater; 3. Tertiary preheater; 4. Quaternary preheater; 5. Condensate tank; 6. Evaporator; 7. Vapor-liquid separator; 8. Forced circulation evaporator; 9. Crystallization separator; 10. Gas scrubbing tower; 11. Thickener; 12. Centrifuge; 13. Mother liquor tank; 14. Distillation column; 15. Reboiler; 16. Compressor; 17. Fifth pump body; 18. First pump body; 19. Forced circulation pump; 20. Second pump body; 21. Third pump body; 22. Fourth pump body; 23. Sixth pump body. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0026] The directional and positional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side," are merely for reference to the accompanying drawings. Therefore, the directional and positional terms used are for illustrating and understanding this invention, and not for limiting the scope of protection of this invention.

[0027] A heat pump distillation system for desalinating organic saline aqueous solutions includes a preheating module, an evaporator 6, a vapor-liquid separator 7, a forced circulation evaporator 8, a crystallizer 9, a thickener 11, a centrifuge 12, a mother liquor tank 13, and a distillation column 14.

[0028] The preheating module has a raw liquid inlet and a raw liquid outlet. The raw liquid inlet is connected to a raw liquid feed pipe, and the raw liquid outlet is connected to the raw material inlet of the evaporator 6. The first steam outlet of the evaporator 6 is connected to the steam inlet of the vapor-liquid separator 7.

[0029] The liquid outlet of the vapor-liquid separator 7 is connected to the second inlet of the evaporator 6 and the first liquid inlet of the crystallizer 9 via the first pump body 18. The second liquid outlet of the crystallizer 9 is connected to the first inlet of the forced circulation evaporator 8 via the forced circulation pump 19. The first outlet of the forced circulation evaporator 8 is connected to the second inlet of the crystallizer 9. The third outlet of the crystallizer 9 is connected to the inlet of the thickener 11 via the third pump body 21. The first liquid outlet of the thickener 11 is connected to the mother liquor tank 13. The second outlet of the thickener 11 is connected to the centrifuge 12. The liquid outlet of the centrifuge 12 is connected to the liquid inlet of the mother liquor tank 13. Its solid outlet is connected to a crystallized salt discharge pipe. The liquid outlet of the mother liquor tank 13 is connected to the second inlet of the forced circulation evaporator 8 via the fourth pump body 22. The inlet of the distillation column 14 is connected to the steam outlet of the vapor-liquid separator 7 and the steam outlet of the crystallizer 9.

[0030] By using the above setup, the process involves coarse concentration in an evaporator, followed by desalination in a forced circulation evaporator, and then heat pump distillation. This solves the problems of difficult and high energy consumption in the treatment of salty organic solutions. The heat pump system reduces steam consumption, thus reducing energy consumption and saving operating costs compared to traditional processes.

[0031] In this process, most of the salt in the organic saline solution is discharged as crystallized salt through evaporation and crystallization, and the remaining mother liquor is returned to the forced circulation evaporation system. The organic aqueous solution is then purified to the required concentration through a distillation column. The main purpose of the evaporator and forced circulation evaporator is to evaporate and crystallize the raw materials, the thickener is to increase the salt content of the material in the thickener, and the centrifuge is to separate the solid-liquid mixture.

[0032] The heated raw material enters the tube side of the evaporator for heating and evaporation. After evaporation, the material vapor enters the vapor-liquid separator. The separated material vapor enters the crystallizer and the gas scrubbing tower. The separated liquid is pumped by a pump, with part of it being pumped to the top of the evaporator and part to the crystallizer. The material passing through the crystallizer enters the forced circulation evaporator and then is pumped back to the crystallizer and finally enters the thickener. The clear liquid from the thickener enters the mother liquor tank directly, and the rest enters the centrifuge. After centrifugation, the liquid material enters the mother liquor tank, and the solid crystal salt is directly discharged. The material vapor entering the gas scrubbing tower enters the distillation tower. In the distillation tower, the liquid flows into the reboiler, and the gas rises to the top of the tower and enters the compressor for pressurization and heating, providing heat to the reboiler, the forced circulation evaporator, and the evaporator.

[0033] In this embodiment, the liquid outlet of the mother liquor tank 13 is connected to the pipeline between the crystallizer 9 and the inlet of the forced circulation pump 19 via the fourth pump body 22, thereby achieving communication with the second inlet of the forced circulation evaporator 8, simplifying the system connection structure and optimizing space occupation.

[0034] The preheating module includes a first preheating unit with a liquid inlet and outlet connected in sequence, and a second preheating unit with a live steam inlet. The raw liquid inlet of the first preheating unit is the raw liquid inlet of the preheating module, and the raw liquid outlet of the second preheating unit is the raw liquid outlet of the preheating module. The second preheating unit includes a four-stage preheater 4. It also includes a condensate tank 5. The first preheating unit includes a raw liquid inlet and outlet connected in sequence to a first-stage preheater 1, a second-stage preheater 2, and a third-stage preheater 3. The raw liquid inlet is the liquid inlet of the first-stage preheater 1.

[0035] The second steam outlet of evaporator 6 and the second steam outlet of forced circulation evaporator 8 are both connected to the first steam inlet at the top of condensate tank 5. The condensate outlet of condensate tank 5 is connected to the condensate inlet of secondary preheater 2 through fifth pump body 17. The steam outlet of condensate tank 5 is connected to the steam inlet of tertiary preheater 3. The condensate outlet of tertiary preheater 3 is connected to the condensate outlet of condensate tank 5.

[0036] With the above settings, the second preheating unit heats up the raw liquid by exchanging heat between live steam and the raw liquid for the start-up of the system. The first preheating unit uses the heat recovery of steam and condensate inside the system as a heat source to heat up the raw liquid. Compared with the method of using live steam as the only heat source, this greatly saves the energy consumption of the system.

[0037] Specifically, the primary preheater exchanges heat between the raw material and heavy components (derived from reboiler 15), utilizing the heat from the heavy components to heat the raw material and cool the heavy components. The secondary preheater exchanges heat between the raw material and the condensate from the material steam, utilizing the heat from the condensate to heat the raw material and cool the condensate. The tertiary preheater exchanges heat between the raw material and the material steam, utilizing the heat from the material steam to heat the raw material and condense the material steam. The quaternary preheater exchanges heat between the raw material and live steam to bring the raw material to the designed feed temperature.

[0038] Among them, the primary preheater 1, the secondary preheater 2, the tertiary preheater 3 and the quaternary preheater 4 are one of the following: tubular heat exchanger, spiral plate heat exchanger, wound tube heat exchanger and plate heat exchanger. Those skilled in the art can set them up according to the actual needs of use.

[0039] The liquid outlet of the evaporator 6 is connected to the second inlet of the evaporator 6 and the first liquid inlet of the crystallizer 9 via the first pump body 18.

[0040] With this setup, the liquid evaporated by the evaporator is further recycled back to itself and the crystallizer, which improves the crystallization efficiency and the final desalination and distillation yield of the system.

[0041] Meanwhile, in this embodiment, the liquid outlet of the vapor-liquid separator and the liquid outlet of the evaporator are both connected to the liquid inlet of the first pump body, which further simplifies the system connection structure and saves energy.

[0042] It also includes a gas scrubbing tower 10, the inlet of which is connected to the steam outlet of the gas-liquid separator 7 and the steam outlet of the crystallization separator 9, and the first outlet of the gas scrubbing tower 10 is connected to the inlet of the distillation tower 14.

[0043] By setting up a gas scrubbing tower before the secondary steam evaporated from the system re-enters the distillation tower, foaming of the material can be effectively avoided.

[0044] The second liquid outlet of the gas scrubbing tower 10 is connected to the third inlet of the crystallizer 9 via the second pump body 20.

[0045] With this setup, liquid will accumulate at the bottom of the gas scrubbing tower during the process of spraying liquid for gas scrubbing. The liquid at the bottom of the gas scrubbing tower will be pumped into the crystallizer for evaporation through the second pump, which further saves energy and materials in this system while improving efficiency.

[0046] It also includes a reboiler 15, the second liquid outlet of the distillation column 14 is connected to the liquid inlet of the reboiler 15, the steam outlet of the distillation column 14 is connected to the steam inlet of the compressor 16, the output port of the compressor 16 is connected to the steam inlet of the reboiler 15 and the third inlet of the forced circulation evaporator 8, the third inlet of the forced circulation evaporator 8 is connected to the second outlet of the forced circulation evaporator 8, and the second outlet of the forced circulation evaporator 8 is connected to the third inlet of the evaporator 6.

[0047] This setting allows the extracted material to reach the set concentration. After the compressor pressurizes and heats the material vapor at the top of the distillation column, it provides heat to the reboiler, forced circulation evaporator, and evaporator, reducing the consumption of live steam and further saving the energy consumption of the system.

[0048] The liquid outlet of the reboiler 15 is connected to the liquid inlet of the first-stage preheater 1 in the preheating module via the sixth pump body 23.

[0049] With this setup, the heavy components are fed from the reboiler into the primary preheater, enabling the primary preheater to exchange heat between the raw liquid and the heavy components, and to use the heat from the heavy components to heat the raw liquid and cool the heavy components, thus saving on the consumption of live steam.

[0050] The crystallizer 9 has a salt leg sight glass for observing the crystallization situation inside the crystallizer 9. The third pump body 21 forms a first discharge pipe and a second discharge pipe between the third outlet of the crystallizer 9 and the inlet of the thickener 11, respectively. The first discharge pipe and / or the second discharge pipe have pipe sight glasses for observing the crystallization situation inside the discharge pipe.

[0051] This setup allows for observation of crystal content via the salt leg sight glass and pipe sight glass of the crystallizer. When the required discharge level is reached, the crystals are conveyed to the thickener. When the crystal content is between 40% and 60% (by volume), the slurry enters a centrifuge for centrifugal separation to obtain crystals. The centrifugal mother liquor enters a mother liquor tank and is then pumped back to the forced circulation evaporation system. When the system's evaporation rate significantly decreases, the mother liquor is discharged.

[0052] In this embodiment, the first pump body, the second pump body, the third pump body, the fourth pump body, and the fifth pump body are respectively one of a piston compressor, a screw compressor, a centrifugal compressor, and a linear compressor.

[0053] The evaporator 6 is a falling film evaporator, the vapor-liquid separator 7 is a falling film evaporator, and the second inlet of the evaporator 6 is located at the top of the evaporator 6.

[0054] With this setup, the falling film evaporator and falling film separator have the advantages of high heat transfer efficiency, strong adaptability, small footprint, and easy maintenance, which can further save energy consumption of this system.

[0055] In this embodiment, the primary preheater 1 and the distillation column 14 are both connected to the first collection channel, the secondary preheater 2 is connected to the mother liquor collection channel, the mother liquor tank 13 is connected to the second inlet of the forced circulation evaporator 8 and the centrifugal mother liquor discharge channel through the fourth pump body 22, and the reboiler 15 is connected to the steam condensate discharge channel.

[0056] Example 1

[0057] A 25℃ methylhydrazine saline solution first exchanges heat with the heavy components in the primary preheater 1. The heated raw material then passes through the secondary preheater 2, tertiary preheater 3, and quaternary preheater 4, reaching a temperature of 112℃. The heated raw material then enters the tube side of evaporator 6 for heating and evaporation, concentrating the sodium chloride to approximately 20% concentration. The material vapor enters the vapor-liquid separator 7, and the separated material vapor enters the crystallizer 9. The separated liquid is pumped by pump 18, with part entering the top of evaporator 6 and part entering the crystallizer 9. The material passing through the crystallizer 9 enters the forced circulation evaporator 8 for concentration and crystallization to remove sodium chloride, then returns to the crystallizer 9 and finally enters the thickener 11. When the crystal content is 4... 0%-60% (by volume) of the material enters centrifuge 12. The clarified portion of the material after passing through the thickener directly enters mother liquor tank 13. After centrifugation, the liquid material enters mother liquor tank 13, while the solid crystalline salt is directly discharged. The liquid in mother liquor tank 13 is pumped into forced circulation evaporator 8. The material vapor entering gas scrubbing tower 10 then enters distillation tower 14. In distillation tower 14, the liquid flows into reboiler 15, and the gas rises to the top of the tower and enters compressor 16 for pressurization and heating, providing heat to reboiler 15, forced circulation evaporator 8, and evaporator 6. Water with a methylhydrazine concentration of less than 0.1% is collected from the top of the tower, and a methylhydrazine aqueous solution with a water concentration of less than 55% is collected from the bottom of the tower. In Example 1, evaporator 6 is a falling film evaporator, and vapor-liquid separator 7 is a falling film separator.

[0058] Example 2

[0059] As shown in Table 1 below, by calculating the energy consumption of the present invention and conventional distillation, it is found that the present invention consumes 8t of steam per hour, 600t of circulating water per hour, a pump power of 254KW, and a compressor power of 1120KW. Conventional distillation consumes 14t of steam per hour, 1100t of circulating water per hour, and a pump power of 132KW. With steam costing 250 yuan per ton, circulating water costing 0.5 yuan per ton, and electricity costing 0.7 yuan per kilowatt, the annual operating cost of the present invention is calculated to be 23.48 million yuan, while the annual operating cost of conventional distillation is 9.83 million yuan. The present invention can save 6.34 million yuan in operating costs per year.

[0060] Table 1

[0061]

[0062] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A heat pump distillation system for desalinating organic saline aqueous solutions, characterized in that: Includes a preheating module, evaporator, vapor-liquid separator, forced circulation evaporator, crystallizer, thickener, centrifuge, mother liquor tank, and distillation column. The preheating module has a raw liquid inlet and a raw liquid outlet. The raw liquid inlet is connected to a raw liquid feed pipe, and the raw liquid outlet is connected to the raw material inlet of the evaporator. The first steam outlet of the evaporator is connected to the steam inlet of the vapor-liquid separator. The liquid outlet of the vapor-liquid separator is connected to the second inlet of the evaporator and the first liquid inlet of the crystallizer via a first pump body. The second liquid outlet of the crystallizer is connected to the first inlet of the forced circulation evaporator via a forced circulation pump. The first outlet of the forced circulation evaporator is connected to the second inlet of the crystallizer. The third outlet of the crystallizer is connected to the inlet of the thickener via a third pump body. The first liquid outlet of the thickener is connected to the mother liquor tank. The second outlet of the thickener is connected to the centrifuge. The liquid outlet of the centrifuge is connected to the liquid inlet of the mother liquor tank. Its solid outlet is connected to a crystallized salt discharge pipe. The liquid outlet of the mother liquor tank is connected to the second inlet of the forced circulation evaporator via a fourth pump body. The inlet of the distillation column is connected to the steam outlet of the vapor-liquid separator and the steam outlet of the crystallizer. The preheating module includes a first preheating unit with liquid inlet and outlet connected in sequence and a second preheating unit with live steam inlet; It also includes a condensate tank. The first preheating unit includes a raw liquid inlet and outlet connected in sequence to a primary preheater, a secondary preheater, and a tertiary preheater. The raw liquid inlet is the liquid inlet of the primary preheater. The second steam outlet of the evaporator and the second steam outlet of the forced circulation evaporator are both connected to the first steam inlet at the top of the condensate tank. The condensate outlet of the condensate tank is connected to the condensate inlet of the secondary preheater through the fifth pump body. The steam outlet of the condensate tank is connected to the steam inlet of the tertiary preheater. The condensate outlet of the tertiary preheater is connected to the condensate outlet of the condensate tank. The liquid outlet of the evaporator is connected to the second inlet of the evaporator and the first liquid inlet of the crystallization separator via the first pump body; It also includes a gas scrubbing tower, the inlet of which is connected to the steam outlet of the gas-liquid separator and the steam outlet of the crystallization separator, and the first outlet of the gas scrubbing tower is connected to the inlet of the distillation tower. The second liquid outlet of the gas scrubbing tower is connected to the third inlet of the crystallizer via the second pump body; It also includes a reboiler, the second liquid outlet of the distillation column is connected to the liquid inlet of the reboiler, the steam outlet of the distillation column is connected to the steam inlet of the compressor, the output port of the compressor is connected to the steam inlet of the reboiler and the third inlet of the forced circulation evaporator, the third inlet of the forced circulation evaporator is connected to the second outlet of the forced circulation evaporator, and the second outlet of the forced circulation evaporator is connected to the third inlet of the evaporator.

2. The organic salt-containing aqueous solution desalination heat pump distillation system according to claim 1, characterized in that: The raw liquid inlet of the first preheating unit is the raw liquid inlet of the preheating module, and the raw liquid outlet of the second preheating unit is the raw liquid outlet of the preheating module. The second preheating unit includes a four-stage preheater.

3. The organic salt-containing aqueous solution desalination heat pump distillation system according to claim 1, characterized in that: The liquid outlet of the reboiler is connected to the liquid inlet of the first-stage preheater in the preheating module via the sixth pump body.

4. The organic salt-containing aqueous solution desalination heat pump distillation system according to claim 1, characterized in that: The crystallizer has a salt leg sight glass for observing the crystallization process inside the crystallizer. The third pump body forms a first discharge pipe and a second discharge pipe between the third outlet of the crystallizer and the inlet of the thickener, respectively. The first discharge pipe and / or the second discharge pipe have pipe sight glasses for observing the crystallization process inside the discharge pipe.

5. The organic salt-containing aqueous solution desalination heat pump distillation system according to claim 1, characterized in that: The evaporator is a falling film evaporator, the vapor-liquid separator is a falling film separator, and the second inlet of the evaporator is located at the top of the evaporator.

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