Working medium heat pump concentration and rectification system and process

Abstract

The system comprises a primary concentration kettle, a secondary concentration kettle, a rectifying tower, a rectifying tower reflux tank, a compressor, a primary concentration kettle reboiler, a secondary concentration kettle reboiler, a rectifying tower reboiler, a rectifying tower condenser, a rectifying tower tail gas condenser, an electronic expansion valve and a rectifying tower reflux pump, a rarefied liquid raw material enters a first-stage concentration kettle and a second-stage concentration kettle to be concentrated, an excellent concentrated solution product is obtained at the bottom of the second-stage concentration kettle to be discharged, evaporated steam at the tops of the first-stage concentration kettle and the second-stage concentration kettle enters a rectifying tower to be rectified, a high-purity solvent product is obtained at the top of the rectifying tower, a high-purity heavy component material is obtained at the bottom of the rectifying tower, and a working medium heat pump provides a cold source and a heat source for a reboiler and a condenser. The invention provides two processes and three excellent products which can be carried out at the same time, and energy conservation, consumption reduction and emission reduction are well realized.

Description

Technical Field

[0001] The invention relates to chemical equipment and technology, and in particular to a working fluid heat pump concentration and distillation system and technology. Background Art

[0002] Energy consumption in chemical industry processes has always been an issue that companies attach great importance to. Concentration and distillation are the unit operations that consume the most energy in the chemical industry. About 70% of the energy consumption in the chemical industry is used for concentration and distillation.

[0003] In the traditional concentration and distillation process, steam or heat medium is generally used to provide heat to the reboiler, and steam is mostly cooled by air or water cooling. While consuming a large amount of steam, a large amount of cold water or refrigerant is also consumed. High-temperature steam mostly comes from steam boilers, which use coal or natural gas as the combustion medium, releasing a large amount of CO2, which is not in line with the energy-saving and carbon-reduction policies advocated by the country. From the perspective of energy consumption, the heat released by steam condensation is taken away by cooling water and finally released into the atmosphere through cooling towers, which greatly wastes heat and consumes electricity. Therefore, chemical energy-saving technology has become an imminent key technology under the current policy environment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to solve the problems existing in the above-mentioned background technology and provide a working fluid heat pump concentration and distillation system and process that can simultaneously perform concentration and distillation processes and provide three excellent products, thereby achieving energy saving, consumption reduction and emission reduction.

[0005] The technical solution adopted in the present invention is: A working fluid heat pump concentration and distillation system, comprising a primary concentration kettle, a secondary concentration kettle, a distillation tower, a distillation tower reflux tank, a compressor, a primary concentration kettle reboiler, a secondary concentration kettle reboiler, a distillation tower reboiler, a distillation tower condenser, a distillation tower tail gas condenser, an electronic expansion valve and a distillation tower reflux pump; The raw material enters the first concentration kettle through the first feed port, a part of the discharge from the bottom of the first concentration kettle is connected to the third feed port of the first concentration kettle reboiler through a pipeline, another part of the discharge from the bottom of the first concentration kettle is connected to the second feed port of the second concentration kettle through a pipeline, the third discharge port of the first concentration kettle reboiler is returned to the first concentration kettle through a pipeline connection, the evaporation steam from the top of the first concentration kettle is connected to the shell side inlet of the second concentration kettle reboiler through the first feed pipe, the evaporation steam from the top of the second concentration kettle is connected to the fifth feed port of the distillation tower through the second feed pipe, the shell side outlet of the second concentration kettle reboiler is also connected to the sixth feed port of the distillation tower through the third feed pipe, a part of the discharge from the bottom of the second concentration kettle is connected to the fourth feed port of the second concentration kettle reboiler through a pipeline, and then returned to the second concentration kettle from the fourth discharge port of the second concentration kettle reboiler, and another part of the discharge from the bottom of the second concentration kettle is discharged as a concentrated liquid product through the first discharge pipe; The top vapor of the distillation tower is connected to the distillation tower condenser through the first gas phase pipe, the second gas phase pipe of the distillation tower condenser is connected to the distillation tower tail gas condenser, the third gas phase pipe of the distillation tower tail gas condenser is connected to the waste gas treatment system or emptying, the condensate of the distillation tower condenser and the distillation tower tail gas condenser is connected to the distillation tower reflux tank through a pipeline, the bottom distillate of the distillation tower reflux tank is connected to the inlet end of the distillation tower reflux pump through the first distillate pipe, a part of the distillate at the outlet end of the distillation tower reflux pump is returned to the distillation tower through the second distillate pipe, another part of the distillate at the outlet end of the distillation tower reflux pump is discharged as a top product through the second discharge pipe, a part of the bottom kettle liquid of the distillation tower is connected to the sixth feed inlet of the distillation tower reboiler, and another part of the bottom kettle liquid of the distillation tower is discharged as a bottom product of the distillation tower through the third discharge pipe; After being pressurized and heated by the compressor, the refrigerant working fluid is output and connected to the shell side inlet of the first-stage concentrator reboiler through the first working fluid gas phase pipe, the shell side outlet of the first-stage concentrator reboiler is connected to the shell side inlet of the distillation tower reboiler through the first working fluid liquid phase pipe, the shell side outlet of the distillation tower reboiler is connected to one end of the electronic expansion valve through the second working fluid liquid phase pipe, the other end of the electronic expansion valve is connected to the working fluid inlet of the distillation tower condenser through the third working fluid liquid phase pipe, and the outlet of the working fluid of the distillation tower condenser is returned to the compressor through the second working fluid gas phase pipe.

[0006] The working fluid heat pump concentration and distillation system of the present invention described above comprises a two-stage concentration kettle, a two-stage concentration kettle reboiler, a distillation tower and a distillation reboiler, and can provide a variety of high-quality products such as a concentrated liquid product, a distillate product from the top of the distillation tower, and a distillation tower bottom kettle liquid; the system of the present invention described above also uses a working fluid heat pump system to provide heating energy for the first-stage concentration kettle reboiler and the distillation tower reboiler, and to provide cooling energy for the distillation tower condenser, and the evaporation steam from the top of the first-stage concentration kettle also provides heating energy for the second-stage concentration kettle reboiler.

[0007] A concentration and distillation process based on the above working medium heat pump concentration and distillation system comprises: (1) The dilute liquid raw material to be concentrated is fed into a primary concentration kettle. The refrigerant is pressurized and heated by a compressor to provide a heating source for the primary concentration kettle reboiler. The primary concentration kettle reboiler circulates and heats the raw material in the primary concentration kettle, so that the raw material in the primary concentration kettle is heated and concentrated; (2) the concentrated liquid at the bottom of the first concentration kettle is sent to the second concentration kettle, and the evaporation steam at the top of the first concentration kettle enters the distillation tower after passing through the reboiler of the second concentration kettle. The evaporation steam at the top of the first concentration kettle provides a heating source for the reboiler of the second concentration kettle, and the reboiler of the second concentration kettle circulates and heats the concentrated liquid in the second concentration kettle, so that the concentrated liquid in the second concentration kettle is heated and concentrated; (3) After the concentrate in the secondary concentration kettle is concentrated to meet the concentration requirements, the concentrate product is discharged from the discharge pipe at the bottom of the kettle; (4) The vapor from the top of the first-stage concentration kettle and the second-stage concentration kettle enters the distillation tower for distillation. A distillation tower reboiler is arranged at the bottom of the distillation tower. The distillation tower reboiler heats the distilled liquid in the distillation tower in a circulation manner. The heating heat source of the distillation tower reboiler is provided by the working fluid after the compressor is pressurized and heated; (5) A high-purity solvent is obtained at the top of the distillation tower, and a high-purity heavy component material is obtained at the bottom of the distillation tower; (6) The high-temperature gaseous working medium output by the compressor is pressurized and heated, and then passes through the first-stage concentrator reboiler and the distillation tower reboiler for heat exchange, and then passes through the electronic expansion valve for throttling and cooling to become a liquid working medium. The liquid working medium exchanges heat with the distillation tower condenser, and the liquid working medium is evaporated into a gaseous working medium, which enters the compressor and repeats the cycle.

[0008] In the above technical solution, the bottom temperature of the first-stage concentration kettle in step (1) is ≤125°C.

[0009] In the above technical solution, the heat exchange temperature range of the reboiler of the first-stage concentrator in step (1) is 60-125°C.

[0010] In the above technical solution, the heat exchange temperature range of the reboiler of the distillation tower in step (4) is 60-125°C.

[0011] In the above technical solution, in step (4), the bottom temperature of the distillation tower is ≤125°C.

[0012] In the above technical solution, the working fluid in step (6) is R245fa, R134a, R1233zd or R515b.

[0013] In the above technical solution, the heat source of the reboiler of the secondary concentrator in step (2) is the evaporation steam from the top of the primary concentrator.

[0014] In the above technical solution, the compression ratio of the compressor in step (6) is 1.5-8.0, and the temperature rise range is 25-90°C.

[0015] In the above technical solution, the first-stage concentrator reboiler, the second-stage concentrator reboiler and the distillation tower reboiler are shell-and-tube heat exchangers, and the distillation tower condenser and the distillation tower tail gas condenser are also shell-and-tube heat exchangers.

[0016] In the above technical solution, the compressor in step (6) is a screw compressor, a centrifugal compressor or a Roots compressor.

[0017] In the above technical solution, the distillation tower is a packed tower or a plate tower.

[0018] The essential features and remarkable effects of the present invention are: The present invention provides a highly safe and stable working fluid heat pump concentration and distillation system and process, which has the following substantial characteristics: 1) The system concentrates and distills the materials. The process uses a working fluid heat pump for heating and cooling, which is highly efficient and energy-saving; 2) The material to be processed first enters the two-stage concentration kettle for concentration, and through double-effect concentration, a qualified concentrated liquid product is obtained at the bottom outlet of the concentration kettle; 3) The solvent evaporated from the double-effect concentrator enters the distillation tower for distillation to obtain a high-purity solvent product; 4) The working fluid enters the compressor in gaseous state, is compressed and heated, and becomes high-temperature working fluid vapor; 5) The high-temperature working fluid steam at the compressor outlet exchanges heat with the first-stage concentrator reboiler and the distillation tower reboiler in turn, heating the process materials to vaporize them, and the working fluid steam releases heat and condenses into liquid; 6) After throttling, the liquid working medium becomes a low-temperature working medium. The low-temperature working medium condenses the steam at the top of the distillation tower into liquid in the condenser of the distillation tower. The working medium absorbs heat and evaporates into steam. The steam working medium returns to the compressor, and the cycle is repeated.

[0019] Significant effects: The working fluid heat pump concentration and distillation system and process of the present invention utilizes a non-flammable refrigerant as the working fluid, obtains heat supplement through compressor pressurization, and the working fluid provides heat for the reboiler of the first-stage concentration kettle and the reboiler of the distillation tower, so that the process medium evaporates continuously, and the working fluid itself condenses into a liquid phase after releasing heat. The throttled low-temperature working fluid continues to provide cooling capacity for the condenser of the distillation tower, so that the steam at the top of the distillation tower is condensed into liquid, and the working fluid itself absorbs heat and evaporates into a gas phase. The cycle is repeated, and a high-concentration concentrated liquid can be obtained at the bottom of the second-stage concentration kettle, and at the same time, a high-purity light component solvent can be obtained at the top of the distillation tower, and a high-purity heavy component solvent can be obtained in the bottom of the distillation tower. Compared with the traditional technology of directly using steam to heat the evaporator or distillation tower reboiler and using circulating cooling water to cool the top condenser, the present invention uses a working fluid heat pump cycle to recover a large amount of evaporation and condensation heat from the top of the distillation tower, and circulates it for heating the reboiler. The small amount of heat lost in the system is obtained by compressor pressurization and temperature increase, which greatly improves the efficiency of thermal energy utilization, greatly reduces energy consumption, and can achieve a very high energy efficiency ratio with a small amount of electricity, which is ultimately reflected in the greatly reduced operating cost of the concentration and distillation system. At the same time, the present invention uses a non-flammable working fluid, which is more safe and has good operating stability than the traditional direct process medium steam direct compression. The present invention provides a concentration and distillation system and process for energy saving, consumption reduction and emission reduction in the chemical industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION Example

[0021] As shown in the figure, this embodiment is a working fluid concentration and distillation device, including a first-level concentration kettle 1, a second-level concentration kettle 2, a distillation tower 3, a distillation tower reflux tank 4, a compressor 5, a first-level concentration kettle reboiler 7, a second-level concentration kettle reboiler 8, a distillation tower reboiler 9, a distillation tower condenser 10, a distillation tower tail gas condenser 11, an electronic expansion valve 12, and a distillation tower reflux pump 13.

[0022] The first-level concentrator 1 has a first feed port 21 and a first discharge port 26, the second-level concentrator 2 has a second feed port 27 and a second discharge port 28, the first-level concentrator reboiler 7 has a third feed port 22 and a third discharge port 23, the second-level concentrator reboiler 8 has a fourth feed port 24 and a fourth discharge port 25, the distillation tower 3 has a fifth feed port 31, a sixth feed port 32 and a fifth discharge port 33, and the distillation tower reboiler 9 has a sixth feed port 34 and a sixth discharge port 35.

[0023] The raw material enters the primary concentration kettle through the feed port 21, and its temperature can be room temperature or a temperature heated to below the bubble point of the feed liquid by the upstream process; a part of the discharge from the bottom of the primary concentration kettle 1 enters the concentration kettle reboiler 7 through the third feed port 22, and is heated, and then returns to the primary concentration kettle 1; another part of the discharge from the bottom of the primary concentration kettle 1 enters the secondary concentration kettle 2 through the second feed port 27. The evaporation steam of the primary concentration kettle 1 enters the shell side inlet of the secondary concentration kettle reboiler 8 from the top of the kettle through the first feed pipe 91, and the evaporation steam heats the secondary concentration kettle to the maximum extent, and then condenses into a liquid phase or a gas-liquid two-phase, and then enters the distillation tower through the third feed pipe 93 of the distillation tower.

[0024] The evaporated steam of the secondary concentrator 2 directly enters the distillation tower from the top of the kettle through the second feed pipe 92, and a part of the discharge from the bottom of the secondary concentrator 2 enters the secondary concentrator reboiler 8 through the fourth feed port 24 to be heated, and then returns to the secondary concentrator 2; another part of the discharge from the bottom of the secondary concentrator 2 is discharged as a concentrated liquid product through the first discharge pipe 94.

[0025] The top steam of the distillation tower 3 enters the distillation tower condenser 10 through the first gas phase pipe 95, and exchanges heat with the working fluid in the pipe process in the distillation tower condenser. The top steam of the distillation tower is condensed into gas-liquid two-phase, and the uncondensed gas phase enters the distillation tower tail gas condenser 11 through the second gas phase pipe 99, and continues to condense in the tail gas condenser 11. The uncondensed small amount of non-condensable gas is emptied or enters the waste gas treatment system through the third gas phase pipe 100. The condensed liquid of the process steam in the distillation tower condenser 10 and the condensation tower tail gas condenser 11 enters the distillation tower reflux tank 4. The distillate in the reflux tank 4 enters the distillation tower reflux pump 13 through the first distillate pipe 96, and a part of the distillate at the outlet of the reflux pump 13 is returned to the distillation tower 3 through the second distillate pipe 97 as reflux, and the other part of the distillate is discharged through the second discharge pipe 98 as the top product. A portion of the bottom liquid of the distillation tower 3 enters the distillation tower reboiler 9 through the sixth feed inlet 34, in which the bottom liquid is heated and partially vaporized and returned to the bottom of the distillation tower 3; another portion of the bottom liquid of the distillation tower 3 is discharged as the distillation tower bottom product through the third discharge pipe 101.

[0026] A refrigerant is used as a working fluid to be pressurized and heated by a compressor 5. The high-temperature working fluid vapor enters the first-stage concentrator reboiler 7 through the first working fluid gas phase pipe 81. After heat exchange with the process medium on the tube side of the reboiler 7, the working fluid vapor releases heat and condenses into a liquid or a gas-liquid two-phase, and enters the distillation tower reboiler 9 through the first working fluid liquid phase pipe 82. After heat exchange with the distillation tower bottom liquid on the tube side of the reboiler 9, the working fluid temperature is reduced and enters the electronic expansion valve 12 through the second working fluid liquid phase pipe 83. The working fluid is reduced in pressure and temperature by the electronic expansion valve 12 to become a low-temperature liquid working fluid, and then enters the distillation tower condenser 10 through the third working fluid liquid phase pipe 84. Here, the working fluid exchanges heat with the process steam on the shell side of the distillation tower condenser 10. The low-temperature liquid working fluid absorbs heat and vaporizes to become a gaseous working fluid. The gaseous working fluid returns to the compressor through the second working fluid gas phase pipe 85 and enters the next working fluid heat exchange cycle. Example

[0027] This embodiment is a working fluid heat pump concentration and distillation process, which uses the working fluid heat pump concentration and distillation system of Example 1 to concentrate and distill a methanol-containing solution. The process is as follows: Figure 1 As shown, the methanol distillation tower adopts a vacuum tower, the tower bottom temperature is 83°C, the first concentration kettle adopts normal pressure operation, the kettle top temperature is 93°C, the second concentration kettle adopts vacuum operation, the kettle top temperature is 84°C, and the working fluid R245 fa is used as the heat pump working fluid: The crude material containing methanol is fed into the first-stage concentration kettle, heated for evaporation, so that the top temperature of the kettle reaches 93°C, and the steam enters the reboiler of the second-stage concentration kettle for heat exchange; After the liquid in the first concentration kettle reaches a certain concentration, it is sent to the second concentration kettle for heating and evaporation, so that the top temperature of the kettle reaches 83°C, and the steam enters the distillation tower; after the concentrated liquid at the bottom of the second concentration kettle reaches a certain concentration, it will be continuously discharged; The steam from the first concentration kettle exchanges heat with the reboiler of the second concentration kettle and then enters the distillation tower. The steam from the second concentration kettle also enters the distillation tower for distillation. The superheated working fluid steam (R245fa, temperature 108℃) at the outlet of the screw compressor is used to exchange heat with the circulating liquid at the bottom of the first-stage concentrator in the reboiler. The working fluid steam is condensed (vaporization rate 15%), and the circulating liquid in the first-stage concentrator is continuously heated and vaporized and returned to the kettle. The condensed working fluid continues to enter the reboiler of the distillation tower to exchange heat with the circulating liquid at the bottom of the tower. The working fluid is completely condensed into liquid (103°C). The steam heated and vaporized at the bottom of the distillation tower continuously flows from the bottom of the tower to the top of the tower, and continuously exchanges gas-liquid mass transfer with the reflux liquid. The temperature at the bottom of the distillation tower reaches 83°C. The liquid working medium is throttled by the electronic expansion valve (43°C) and enters the condenser of the distillation tower to exchange heat with the steam at the top of the distillation tower. The steam at the top of the tower is condensed to 48°C and then enters the reflux tank. Part of the liquid in the reflux tank flows back to the top of the tower, and part is output as a product. The liquid working fluid evaporates into working fluid vapor (45°C), and the working fluid vapor returns to the compressor, repeating steps 4) to 6). Example

[0028] This embodiment is a working fluid heat pump concentration and distillation process, which uses the working fluid heat pump concentration and distillation system of Example 1 to concentrate and distill the ethanol-containing solution. The process is as follows: Figure 1 As shown, the ethanol distillation tower adopts a vacuum tower, the tower bottom temperature is 84°C, the first concentration kettle adopts normal pressure operation, the kettle top temperature is 93°C, the second concentration kettle adopts vacuum operation, the kettle top temperature is 84°C, and the working fluid R245 fa is used as the heat pump working fluid: The crude material containing methanol is fed into the first-stage concentration kettle, heated for evaporation, so that the top temperature of the kettle reaches 93°C, and the steam enters the reboiler of the second-stage concentration kettle for heat exchange; After the liquid in the first concentration kettle reaches a certain concentration, it is sent to the second concentration kettle for heating and evaporation, so that the top temperature of the kettle reaches 84°C, and the steam enters the distillation tower; after the concentrated liquid at the bottom of the second concentration kettle reaches a certain concentration, it will be continuously discharged; The steam from the first concentration kettle exchanges heat with the reboiler of the second concentration kettle and then enters the distillation tower. The steam from the second concentration kettle also enters the distillation tower for distillation. The superheated working fluid steam (R245fa, temperature 108℃) at the outlet of the screw compressor is used to exchange heat with the circulating liquid at the bottom of the first-stage concentrator in the reboiler. The working fluid steam is condensed (vaporization rate 15%), and the circulating liquid in the first-stage concentrator is continuously heated and vaporized and returned to the kettle. The condensed working fluid continues to enter the reboiler of the distillation tower to exchange heat with the circulating liquid at the bottom of the tower. The working fluid is completely condensed into liquid (105°C). The steam heated and vaporized at the bottom of the distillation tower continuously flows from the bottom of the tower to the top of the tower, and continuously exchanges gas-liquid mass transfer with the reflux liquid. The temperature at the bottom of the distillation tower reaches 83°C. The liquid working medium is throttled by the electronic expansion valve (51°C) and enters the condenser of the distillation tower to exchange heat with the steam at the top of the distillation tower. The steam at the top of the tower is condensed to 61°C and then enters the reflux tank. Part of the liquid in the reflux tank flows back to the top of the tower, and part is output as a product. The liquid working fluid evaporates into working fluid vapor (53°C), and the working fluid vapor returns to the compressor, repeating steps 4) to 6).

Claims

1. A working fluid heat pump concentration and distillation system, characterized in that: It includes a primary concentration kettle, a secondary concentration kettle, a distillation tower, a distillation tower reflux tank, a compressor, a primary concentration kettle reboiler, a secondary concentration kettle reboiler, a distillation tower reboiler, a distillation tower condenser, a distillation tower tail gas condenser, an electronic expansion valve and a distillation tower reflux pump; The raw material enters the first concentration kettle through the first feed port, a part of the discharge from the bottom of the first concentration kettle is connected to the third feed port of the first concentration kettle reboiler through a pipeline, another part of the discharge from the bottom of the first concentration kettle is connected to the second feed port of the second concentration kettle through a pipeline, the third discharge port of the first concentration kettle reboiler is returned to the first concentration kettle through a pipeline connection, the evaporation steam from the top of the first concentration kettle is connected to the shell side inlet of the second concentration kettle reboiler through the first feed pipe, the evaporation steam from the top of the second concentration kettle is connected to the fifth feed port of the distillation tower through the second feed pipe, the shell side outlet of the second concentration kettle reboiler is also connected to the sixth feed port of the distillation tower through the third feed pipe, a part of the discharge from the bottom of the second concentration kettle is connected to the fourth feed port of the second concentration kettle reboiler through a pipeline, and then returned to the second concentration kettle from the fourth discharge port of the second concentration kettle reboiler, and another part of the discharge from the bottom of the second concentration kettle is discharged as a concentrated liquid product through the first discharge pipe; The top vapor of the distillation tower is connected to the distillation tower condenser through the first gas phase pipe, the second gas phase pipe of the distillation tower condenser is connected to the distillation tower tail gas condenser, the third gas phase pipe of the distillation tower tail gas condenser is connected to the waste gas treatment system or emptying, the condensate of the distillation tower condenser and the distillation tower tail gas condenser is connected to the distillation tower reflux tank through a pipeline, the bottom distillate of the distillation tower reflux tank is connected to the inlet end of the distillation tower reflux pump through the first distillate pipe, a part of the distillate at the outlet end of the distillation tower reflux pump is returned to the distillation tower through the second distillate pipe, another part of the distillate at the outlet end of the distillation tower reflux pump is discharged as a top product through the second discharge pipe, a part of the bottom kettle liquid of the distillation tower is connected to the sixth feed inlet of the distillation tower reboiler, and another part of the bottom kettle liquid of the distillation tower is discharged as a bottom product of the distillation tower through the third discharge pipe; After being pressurized and heated by the compressor, the refrigerant working fluid is output and connected to the shell side inlet of the first-stage concentrator reboiler through the first working fluid gas phase pipe, the shell side outlet of the first-stage concentrator reboiler is connected to the shell side inlet of the distillation tower reboiler through the first working fluid liquid phase pipe, the shell side outlet of the distillation tower reboiler is connected to one end of the electronic expansion valve through the second working fluid liquid phase pipe, the other end of the electronic expansion valve is connected to the working fluid inlet of the distillation tower condenser through the third working fluid liquid phase pipe, and the outlet of the working fluid of the distillation tower condenser is returned to the compressor through the second working fluid gas phase pipe.

2. A concentration and distillation process based on the working fluid heat pump concentration and distillation system according to claim 1, characterized in that: include: (1) The dilute liquid raw material to be concentrated is fed into a primary concentration kettle. The refrigerant is pressurized and heated by a compressor to provide a heating source for the primary concentration kettle reboiler. The primary concentration kettle reboiler circulates and heats the raw material in the primary concentration kettle, so that the raw material in the primary concentration kettle is heated and concentrated; (2) The concentrated liquid at the bottom of the first concentration kettle is sent to the second concentration kettle, and the evaporation steam at the top of the first concentration kettle enters the distillation tower after passing through the reboiler of the second concentration kettle. The evaporation steam at the top of the first concentration kettle provides a heating source for the reboiler of the second concentration kettle, and the reboiler of the second concentration kettle cyclically heats the concentrated liquid in the second concentration kettle, so that the concentrated liquid in the second concentration kettle is heated and concentrated; (3) After the concentrate in the secondary concentration kettle is concentrated to meet the requirements, the concentrate product is discharged from the discharge pipe at the bottom of the kettle; (4) The vapor from the top of the first-stage concentration kettle and the second-stage concentration kettle enters the distillation tower for distillation. A distillation tower reboiler is arranged at the bottom of the distillation tower. The distillation tower reboiler heats the distilled liquid in the distillation tower in a circulation manner. The heating heat source of the distillation tower reboiler is provided by the working fluid after the compressor is pressurized and heated; (5) A high-purity solvent is obtained at the top of the distillation tower, and a high-purity heavy component material is obtained at the bottom of the distillation tower; (6) The high-temperature gaseous working medium output by the compressor is pressurized and heated, and then passes through the reboiler of the first-stage concentrator and the reboiler of the distillation tower for heat exchange, and then passes through the throttling and cooling of the electronic expansion valve to become a liquid working medium. The liquid working medium then exchanges heat with the condenser of the distillation tower, and the liquid working medium is evaporated into a gaseous working medium, and the gaseous working medium enters the compressor, and the cycle continues.

3. The concentration and distillation process according to claim 2, characterized in that: In the step (1), the bottom temperature of the first-stage concentrator is ≤125°C, and the heat exchange temperature range of the reboiler of the first-stage concentrator is 60-125°C.

4. The concentration and distillation process according to claim 2, characterized in that: In the step (4), the heat exchange temperature of the distillation tower reboiler is in the range of 60-125°C, and the bottom temperature of the distillation tower is ≤125°C.

5. The concentration and distillation process according to claim 2, characterized in that: The working fluid in step (6) is R245fa, R134a, R1233zd or R515b.

6. The concentration and distillation process according to claim 2, characterized in that: In the step (2), the heat source of the reboiler of the secondary concentrator is the gas phase output of the primary concentrator.

7. The concentration and distillation process according to claim 2, characterized in that: In step (6), the compression ratio of the compressor is 1.5-8.0, and the temperature rise range is 25-90°C.

8. The concentration and distillation process according to claim 2, characterized in that: The first-stage concentration kettle reboiler, the second-stage concentration kettle reboiler and the distillation tower reboiler are shell-and-tube heat exchangers, and the distillation tower condenser and the distillation tower tail gas condenser are also shell-and-tube heat exchangers.

9. The concentration and distillation process according to claim 2, characterized in that: The compressor in step (6) is a screw compressor, a centrifugal compressor or a Roots compressor.

10. The concentration and distillation process according to claim 2, characterized in that: The distillation tower is a packed tower or a plate tower.

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