Continuous salt separation type high-concentration brine heat exchange process

Abstract

The present application relates to waste liquid treatment technical field, disclose a kind of continuous salt separation type high concentration brine heat exchange process, comprising the following steps: by original liquid line to first evaporation tank input high concentration brine, concentrated evaporation high concentration brine in first evaporation tank;When first monitoring component monitors the monitoring index value of material liquid in first evaporation tank reaches first threshold value, input salt separation material liquid into relay bucket;Liquid outlet line input salt separation material liquid in relay bucket into second evaporation tank;Salt separation line is sent into centrifugal component after salt separation material liquid of tube heat exchanger heat exchange and carries out salt separation;Through intermittent evaporation concentration and continuous salt separation are carried out simultaneously, can effectively avoid that high concentration brine cannot be concentrated to salt separation state when concentrating evaporation, leading to the problem that high concentration brine is not fully treated, also can avoid the impact of the salt and scale separated when evaporation concentration reaches salt separation state on tank body, leading to the problem that tank body service life is short and subsequent evaporation concentration is affected.

Description

Technical Field

[0001] This invention relates to the field of waste liquid treatment technology, specifically to a continuous salt separation type high-concentration brine heat exchange process. Background Technology

[0002] After heat pump evaporation and concentration, distilled water that meets discharge standards can be extracted from wastewater. This distilled water can be discharged directly, and the remaining concentrate can be discharged to a wastewater treatment plant for further treatment, which can greatly reduce the wastewater treatment costs for enterprises.

[0003] The applicant found some existing technologies for the separation of salts in high-concentration brine, such as patent publication number CN112321048A. Its main technical means is to use a three-stage countercurrent evaporation process with opposite steam and material flow directions to achieve sodium salt precipitation, combined with flash evaporation and cooling to achieve potassium salt precipitation. By controlling the concentration and temperature of the discharged potassium chloride, the two salts are thoroughly separated, improving the purity of the separated product. However, the applicant's analysis revealed that this technical solution has the following drawbacks: during the evaporation and concentration process, scaling inevitably occurs when the salt separation concentration is reached. The precipitated salt easily adheres to the sidewalls of the equipment and cannot be smoothly discharged for collection. Over time, the precipitated salt will deposit at the bottom of the equipment, affecting the efficiency of subsequent evaporation and concentration. To avoid salt separation and scaling, the concentrate cannot be concentrated to the salt separation concentration during the evaporation process. Based on this, the present invention provides a continuous high-concentration brine heat exchange process that can simultaneously achieve evaporation, concentration, and salt separation. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a continuous salt separation high-concentration brine heat exchange process to solve the technical problem that scaling occurs during salt separation of the concentrate, affecting subsequent concentration of the feed solution.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A continuous salt separation high-concentration brine heat exchange process, the process comprising the following steps:

[0007] Step S1: Start the first vacuum assembly to create a negative pressure environment inside the first evaporator and the first refrigerant heat exchanger. At the same time, start the second vacuum assembly to create a negative pressure environment inside the second evaporator, the shell and tube heat exchanger, and the second refrigerant heat exchanger. This will lower the boiling point of the liquid in the evaporation system.

[0008] Step S2: High-concentration brine is introduced into the first evaporator through the raw liquid pipeline, and hot refrigerant that has absorbed heat from the first compressor is also introduced into the first evaporator to concentrate and evaporate the high-concentration brine in the first evaporator. The hot refrigerant undergoes a phase change to become liquid refrigerant, and the first monitoring component in the first evaporator monitors the liquid inside.

[0009] Step S3: The liquid refrigerant is fed into the first refrigerant heat exchanger, and after heat exchange, it is fed into the first compressor to do work, and then enters the first evaporator for concentration and evaporation;

[0010] Step S4: When the first monitoring component detects that the monitoring index value of the liquid in the first evaporator reaches the first threshold, the liquid in the first evaporator is a separable salt liquid. At this time, the liquid inlet pipe is opened to input the separable salt liquid into the relay tank.

[0011] Step S5: The liquid outlet line inputs the separable salt liquid from the relay tank into the second evaporator, and then the liquid outlet line is closed. The separable salt liquid circulates in the circulation line between the second evaporator and the shell and tube heat exchanger.

[0012] Step S6: The hot refrigerant, after absorbing heat from the second compressor, is introduced into the tube heat exchanger to exchange heat with the separable salt liquid entering the tube heat exchanger, and the hot refrigerant undergoes a phase change to become liquid refrigerant.

[0013] Step S7: Open the salt separation pipeline and send the salt separation liquid after heat exchange in the tube heat exchanger into the centrifugal assembly for salt separation. At the same time, the second monitoring assembly in the second evaporator monitors the liquid inside.

[0014] Step S8: When the second monitoring component detects that the monitoring index value of the liquid in the second evaporator reaches the second threshold, the liquid outlet pipeline is opened to input the same amount of separable liquid as the output of the salt separation pipeline into the second evaporator.

[0015] As a further aspect of the present invention, step S2 specifically includes the following steps:

[0016] Step S21: Open the raw material pipeline and input high-concentration brine into the first evaporator;

[0017] Step S22: After the high-concentration brine input is completed, the raw liquid pipeline is closed, and the hot refrigerant that has absorbed the heat of the first compressor is input into the first evaporator to concentrate and evaporate the high-concentration brine in the first evaporator.

[0018] Step S23: The hot refrigerant undergoes a phase change to become a liquid refrigerant;

[0019] Step S24: The first monitoring component in the first evaporator monitors the liquid inside.

[0020] As a further aspect of the present invention: in step S4, after opening the liquid inlet pipeline to input the separable salt liquid into the relay tank, the raw liquid pipeline is opened to input new high-concentration brine into the first evaporator.

[0021] As a further aspect of the present invention, step S8 specifically includes the following steps:

[0022] Step S81: When the salt separation pipeline sends the heat-exchanged salt separation liquid into the centrifugal assembly, when the second detection assembly detects that the monitoring index value of the liquid in the second evaporator reaches the second threshold, the external controller calculates the corresponding liquid output when the monitoring index value of the liquid in the second evaporator reaches the second threshold.

[0023] Step S82: Open the liquid outlet pipeline and input the separable salt liquid into the second evaporator in an amount equal to the liquid output. Then repeat steps S5 to S8.

[0024] As a further aspect of the present invention: the first evaporator is connected to a purification separator, and the steam generated by the concentrated evaporation of the first evaporator is input into the purification separator for purification, and then input into the first refrigerant heat exchanger.

[0025] As a further aspect of the present invention: the first evaporator is connected to the first refrigerant heat exchanger via a first plate heat exchanger, the tube heat exchanger is connected to the second refrigerant heat exchanger via a second plate heat exchanger, and both the first plate heat exchanger and the second plate heat exchanger are connected to cooling pipes.

[0026] As a further aspect of the present invention: both the first compressor and the second compressor are oil-free compressors.

[0027] As a further aspect of the present invention: both the first refrigerant heat exchanger and the second refrigerant heat exchanger are submerged heat exchangers, and both the first refrigerant heat exchanger and the second refrigerant heat exchanger are provided with steam pipes for flowing steam, and the steam pipes are submerged in the refrigerant inside the heat exchanger.

[0028] As a further aspect of the present invention: the second evaporator is connected to a defoamer pipeline and a cleaning water pipeline, and control valves are respectively installed on the defoamer pipeline and the cleaning water pipeline.

[0029] The beneficial effects of this invention are:

[0030] (1) In this invention, the first evaporator is used to evaporate and concentrate in batches. When the liquid is concentrated to the point where it is about to be separated into salts, the first evaporator stops evaporating and concentrating it and puts it into the relay tank for storage. At the same time, the second evaporator is put into the relay tank to store the liquid that can be separated into salts, and then the separation of salts is carried out continuously. That is, the intermittent evaporation and concentration and the continuous separation of salts are carried out simultaneously. This can effectively avoid the problem that the high concentration of brine cannot be concentrated to the point of separation of salts during the concentration and evaporation, resulting in insufficient treatment of the high concentration of brine. It can also avoid the problem that the salt and scale precipitated when the concentration reaches the point of separation of salts will affect the tank body, resulting in a short service life of the tank body and the impact on subsequent evaporation and concentration.

[0031] (2) In this invention, considering that the processing rates of preliminary concentration and salt separation concentration are different, after preliminary concentration to the point of salt separation, this portion of the salt-separable liquid is stored so that it can be used intermittently in the second evaporator for salt separation concentration, so that the high-concentration brine can have enough time to be evaporated and reach sufficient concentration, thereby improving the treatment effect of the high-concentration brine.

[0032] (3) In this invention, the first evaporator is used for intermittent concentration, which is the initial concentration of high-concentration brine. Concentration is stopped when the brine is about to separate into salts. This avoids the problem of salt precipitation in the tank affecting subsequent concentration processes caused by one-time concentration. Attached Figure Description

[0033] The invention will now be further described with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the overall process flow of the present invention;

[0035] Figure 2 This is a schematic diagram of the preliminary concentration process in the first evaporator of the present invention;

[0036] Figure 3 This is a schematic diagram of the salt concentration process in the second evaporator of the present invention.

[0037] In the diagram: 1. First evaporator; 2. Raw liquid pipeline; 3. First refrigerant heat exchanger; 4. First vacuum assembly; 5. First compressor; 6. First plate heat exchanger; 7. Impurity separator; 8. Inlet pipeline; 9. Relay tank; 10. Second evaporator; 11. Outlet pipeline; 12. Circulation pipeline; 13. Shell and tube heat exchanger; 14. Circulation pump; 15. Salt separation pipeline; 16. Second refrigerant heat exchanger; 17. Second compressor; 18. Second plate heat exchanger; 19. Second vacuum assembly; 20. Cooling pipeline; 21. Defoamer pipeline; 22. Cleaning water pipeline. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please see Figures 1-3 As shown, this invention is a continuous salt separation type high-concentration brine heat exchange process, which includes the following steps:

[0040] Step S1: Start the first vacuum assembly 4 to make the first evaporator 1 and the first refrigerant heat exchanger 3 a negative pressure environment. At the same time, start the second vacuum assembly 19 to make the second evaporator 10, the shell and tube heat exchanger 13 and the second refrigerant heat exchanger 16 a negative pressure environment. Then the boiling point of the liquid in the evaporation treatment system will decrease.

[0041] Step S2: High-concentration brine is introduced into the first evaporator 1 through the raw liquid pipeline 2, and hot refrigerant that has absorbed heat from the first compressor 5 is introduced into the first evaporator 1 to concentrate and evaporate the high-concentration brine in the first evaporator 1. The hot refrigerant undergoes a phase change to become liquid refrigerant. At the same time, the first monitoring component in the first evaporator 1 monitors the liquid inside.

[0042] Step S3: The liquid refrigerant is input into the first refrigerant heat exchanger 3, and after heat exchange, it is input into the first compressor 5 to do work, and then enters the first evaporator 1 for concentration and evaporation;

[0043] Step S4: When the first monitoring component detects that the monitoring index value of the liquid in the first evaporator 1 reaches the first threshold, the liquid in the first evaporator 1 is a separable salt liquid. At this time, the liquid inlet pipe 8 is opened to input the separable salt liquid into the relay tank 9.

[0044] Step S5: The liquid outlet pipe 11 inputs the separable salt liquid in the relay tank 9 into the second evaporator 10, and then closes the liquid outlet pipe 11. The separable salt liquid circulates in the circulation pipe 12 between the second evaporator 10 and the shell and tube heat exchanger 13.

[0045] Step S6: The hot refrigerant that has absorbed heat from the second compressor 17 is introduced into the tube heat exchanger 13 to exchange heat with the separable salt liquid entering the tube heat exchanger 13, and the hot refrigerant undergoes a phase change to become liquid refrigerant.

[0046] Step S7: Open the salt separation pipeline 15 and send the salt separation liquid after heat exchange in the tube heat exchanger 13 into the centrifugal assembly for salt separation. At the same time, the second monitoring component in the second evaporator 10 monitors the liquid inside.

[0047] Step S8: When the second monitoring component detects that the monitoring index value of the liquid in the second evaporator 10 reaches the second threshold, the liquid outlet pipe 11 is opened to input the second evaporator 10 with a volume of separable liquid equal to the output volume of the salt separation pipe 15.

[0048] It should be noted that the original liquid pipeline 2, inlet pipeline 8, outlet pipeline 11, circulation pipeline 12 and salt separation pipeline 15 described in this application are all equipped with control valves. The control valves are connected to an external controller to control the opening and closing of each pipeline. A circulation pump 14 is installed on the circulation pipeline 12.

[0049] In one embodiment, both the first vacuum component 4 and the second vacuum component 19 can be vacuum centrifugal pumps or water ring vacuum components, as long as a negative pressure environment can be achieved. This embodiment does not impose specific limitations. The first monitoring component can be a current monitor. When the current monitor detects that the current value of the liquid in the first evaporator 1 reaches a first threshold, the liquid in the tank is about to be separated into salts. The second monitoring component is a liquid level sensor. When the liquid level in the second evaporator 10 drops to a second threshold after the separation pipeline 15 outputs the separationable liquid, the data processing module of the external controller calculates the corresponding drop in liquid level. The liquid output is then adjusted, and the liquid outlet pipe 11 is opened to input a separateable salt liquid into the second evaporator 10 in an amount equal to the liquid output. Of course, the first and second monitoring components can also be other modules with monitoring functions, which will not be elaborated here. The centrifugal component can be a centrifuge or other equipment capable of separating salts, which will not be specifically limited here. The control valve, external controller, vacuum component, monitoring component, circulation pump 14, centrifugal component and other electrical components are all existing technologies. This application has not improved them. Therefore, it is not necessary to disclose their specific mechanical structure and circuit structure, which does not affect the integrity of this application.

[0050] In practical application, the first vacuum component 4 and the second vacuum component 19 work together to create a negative pressure environment in the second evaporator 10, the shell-and-tube heat exchanger 13, and the second refrigerant heat exchanger 16, thus lowering the boiling point of the liquid in the entire evaporation system. Hot refrigerant is introduced into the first evaporator 1 for evaporation and concentration with the high-concentration brine inside. When the first monitoring component detects that the current value of the liquid in the first evaporator 1 reaches a first threshold, the liquid in the first evaporator 1 is in a state of imminent salt separation, and the salt-separable liquid is ready for separation. At this point, the evaporation and concentration in the first evaporator 1 is interrupted, and all the salt-separable liquid is transferred to the relay tank 9 for storage. The evaporation and concentration process in the second evaporator 10 is... The separatory liquid is fed into relay tank 9 and circulates in circulation pipe 12. Upon entering the shell-and-tube heat exchanger 13, it exchanges heat with the hot refrigerant inside. As the separatory liquid begins circulation, it quickly reaches a salt-separation state. Therefore, while circulating, the salt-separation pipe 15 is opened, sending the salt-separated liquid from the shell-and-tube heat exchanger 13 into the centrifugal assembly for further salt separation. Meanwhile, the second monitoring component constantly monitors the liquid in the second evaporator 10. When the monitored index value reaches a second threshold, the outlet pipe 11 is opened, inputting an amount of separatory liquid equal to the output from the salt-separation pipe 15 into the second evaporator 10. The second evaporator 10 continues to evaporate and concentrate; in other words... In the first evaporator 1, evaporation and concentration are carried out in batches. When the liquid is concentrated to the point where it is about to be separated into salts, the first evaporator 1 stops evaporation and concentration and transfers it all to the relay tank 9 for storage. Then, new high-concentration brine is introduced into the first evaporator 1 for evaporation and concentration. When the second evaporator 10 starts circulating evaporation and concentration after the brine stored in the relay tank 9 is introduced, salt separation begins. At this time, the salt separation pipeline 15 is opened simultaneously to send the salt separation liquid after heat exchange in the shell and tube heat exchanger 13 into the centrifugal assembly for salt separation. After a certain amount of salt separation liquid has been output, the relay tank 9 again introduces new salt separation liquid into the second evaporator 10 for heat exchange and salt separation, i.e., intermittent evaporation and concentration. Simultaneous concentration and continuous salt separation effectively avoid the problem of insufficient treatment of high-concentration brine due to the inability of the brine to reach the salt separation state during concentration and evaporation. It also avoids the impact of precipitated salt and scale on the tank when the concentration reaches the salt separation state, which could lead to a short service life of the tank and affect subsequent evaporation and concentration. Furthermore, the processing rates during initial concentration and salt separation concentration are different. After initial concentration to the point of near salt separation, this portion of the salt-separable liquid is stored for intermittent use in the second evaporation tank 10 for salt separation concentration. This allows the high-concentration brine sufficient time to be evaporated and treated, achieving adequate concentration and thus improving the treatment effect of the high-concentration brine.

[0051] like Figures 1-2 As shown, in a preferred embodiment of the present invention, step S2 specifically includes the following steps:

[0052] Step S21: Open the raw liquid pipeline 2 and input high-concentration brine into the first evaporator 1;

[0053] Step S22: After the high-concentration brine input is completed, close the raw liquid pipeline 2 and input the hot refrigerant that has absorbed the heat of the first compressor 5 into the first evaporator 1 to concentrate and evaporate the high-concentration brine in the first evaporator 1.

[0054] Step S23: The hot refrigerant undergoes a phase change to become a liquid refrigerant;

[0055] Step S24: The first monitoring component in the first evaporator 1 monitors the liquid inside.

[0056] In one embodiment, in step S4, after opening the inlet pipe 8 to input the separable salt solution into the relay tank 9, the raw liquid pipe 2 is opened to input new high-concentration brine into the first evaporator 1.

[0057] In practical application, the first evaporator 1 performs intermittent concentration, which is the initial concentration of high-concentration brine. Concentration is stopped when the brine is about to separate into salts. This avoids the problem of salt precipitation and deposition in the tank due to one-time concentration, which would affect subsequent concentration processes.

[0058] like Figures 1-3 As shown, in a preferred embodiment of the present invention, step S8 specifically includes the following steps:

[0059] Step S81: When the salt separation pipeline 15 sends the heat-exchanged salt separation liquid into the centrifugal assembly, when the second detection assembly detects that the monitoring index value of the liquid in the second evaporator 10 reaches the second threshold, the external controller calculates the liquid output corresponding to the monitoring index value of the liquid in the second evaporator 10 reaching the second threshold.

[0060] Step S82: Open the liquid outlet pipe 11 and input the separable salt liquid into the second evaporator 10 in an amount equal to the liquid output, and then repeat steps S5 to S8.

[0061] In one embodiment, when the second detection component is a liquid level sensor, the second threshold is the liquid level height value. This liquid level height value, combined with the size of the second evaporator 10, can correspond to a liquid output volume. In practical applications, there is no need for external sensors to measure each time. The parameters can be preset in advance, and the liquid output volume corresponding to this liquid level height value can be calculated in advance. When the liquid level in the second evaporator 10 drops to the second threshold, the liquid outlet pipe 11 can be directly opened to input the second evaporator 10 with a liquid output volume equal to the liquid output volume corresponding to the second threshold.

[0062] like Figures 1-2As shown, in a preferred embodiment of the present invention, the first evaporator 1 is connected to the impurity removal separator 7. The steam generated by the concentrated evaporation of the first evaporator 1 is input into the impurity removal separator 7 for impurity removal, and then input into the first refrigerant heat exchanger 3.

[0063] In one embodiment, the impurity separator 7 can be a cyclone separator. After the steam generated by evaporation in the first evaporator 1 enters it, the water droplets mixed in will be thrown back into the first evaporator 1 for evaporation. Of course, the impurity separator 7 can also be other structural components capable of removing impurities. This embodiment does not make specific limitations here.

[0064] like Figures 1-3 As shown, in a preferred embodiment of the present invention, the first evaporator 1 is connected to the first refrigerant heat exchanger 3 via the first plate heat exchanger 6, the shell and tube heat exchanger 13 is connected to the second refrigerant heat exchanger 16 via the second plate heat exchanger 18, and both the first plate heat exchanger 6 and the second plate heat exchanger 18 are connected to the cooling pipe 20.

[0065] In practical application, when the refrigerant temperature reaches 45°C after heat exchange, the plate heat exchanger is turned on for subcooling. This is because the internal pressure of the first evaporator 1 and the shell-and-tube heat exchanger 13 increases after prolonged use, resulting in a decrease in heat exchange efficiency. To maintain pressure and ensure a certain degree of subcooling for the refrigerant, the plate heat exchanger can subcool the refrigerant, preventing the compressor pressure from continuously rising and triggering an alarm when the steam processing is unbalanced, thus maintaining the system balance. In addition, when the ambient temperature is too high, the temperature of the chiller unit connected to the cooling pipe 20 will also be too high, resulting in a decrease in the efficiency of chilled water production and a decrease in the system's steam processing efficiency. The plate heat exchanger can increase the subcooling of the system and maintain the system balance.

[0066] like Figures 1-3 As shown, in a preferred embodiment of the present invention, both the first compressor 5 and the second compressor 17 are oil-free compressors; in practical applications, oil-free compressors do not have oil return failures.

[0067] like Figures 1-3 As shown, in a preferred embodiment of the present invention, both the first refrigerant heat exchanger 3 and the second refrigerant heat exchanger 16 are submerged heat exchangers. Both the first refrigerant heat exchanger 3 and the second refrigerant heat exchanger 16 are provided with steam pipes for flowing steam, and the steam pipes are submerged in the refrigerant inside the heat exchanger.

[0068] In one embodiment, the refrigerant liquid level inside the submerged heat exchanger is located at half the height of its inner cavity, and the height of the steam pipe is lower than the refrigerant liquid level. A sight glass is provided on the submerged heat exchanger.

[0069] In practical application, the steam pipe is immersed in refrigerant, with the refrigerant level just submerging the steam pipe. The refrigerant level is controlled by a level sensor installed on the submersible heat exchanger, ensuring that the steam pipe is laid to half the height of the submersible heat exchanger's inner cavity. This achieves the goal of the refrigerant just submerging the steam pipe, preventing the refrigerant level from being too low, which would prevent some of the steam in the steam pipe from not being fully condensed, and also preventing the refrigerant level from being too high, which would cause the compressor to draw in too much incompletely vaporized liquid refrigerant and steam condensate.

[0070] like Figures 1-3 As shown, in a preferred embodiment of the present invention, the second evaporator 10 is connected to a defoamer pipeline 21 and a cleaning water pipeline 22, and control valves are respectively provided on the defoamer pipeline 21 and the cleaning water pipeline 22.

[0071] In practical application, this embodiment allows defoamer to be introduced into the second evaporator 10 through the defoamer pipeline 21, and cleaning water to be introduced through the cleaning water pipeline 22, which can clean the second evaporator 10 and avoid the problem of reduced wastewater evaporation efficiency caused by excessive dirt adhering to the tank wall after long-term use.

[0072] Working principle of the invention: The above embodiments of the invention provide a continuous high-concentration brine heat exchange process. The brine is concentrated in batches by a first evaporator 1. When the brine is concentrated to the point of near-separation, the first evaporator 1 stops evaporation and concentration, and all of it is transferred to a relay tank 9 for storage. Subsequently, new high-concentration brine is introduced into the first evaporator 1 for further evaporation and concentration. Meanwhile, when the second evaporator 10 starts circulating evaporation and concentration after the brine stored in the relay tank 9 has been introduced, separation begins. Simultaneously, the separation pipeline 15 is opened to send the separated brine from the tube heat exchanger 13 into a centrifugal assembly for further separation. After a certain amount of separateable brine has been output, the relay tank 9 again inputs new separateable brine into the second evaporator 10. The liquid undergoes heat exchange and output salt separation, meaning that intermittent evaporation and concentration are carried out simultaneously with continuous salt separation. This effectively avoids the problem of high-concentration brine not being concentrated to the salt separation state during concentration and evaporation, resulting in insufficient treatment of high-concentration brine. It also avoids the problem of precipitated salt and scale affecting the tank when the evaporation concentration reaches the salt separation state, which would lead to a short service life of the tank and affect subsequent evaporation and concentration. Furthermore, the processing rates during initial concentration and salt separation concentration are different. After initial concentration to the point of almost reaching the salt separation state, this portion of the salt-separable liquid is stored for intermittent use in the second evaporation tank 10 for salt separation concentration. This allows the high-concentration brine sufficient time to be evaporated and treated, achieving sufficient concentration, thereby improving the treatment effect of high-concentration brine.

[0073] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A continuous salt-separation high-concentration brine heat exchange process, characterized in that, The process includes the following steps: Step S1: Start the first vacuum assembly (4) to make the first evaporator (1) and the first refrigerant heat exchanger (3) negative pressure environment. At the same time, start the second vacuum assembly (19) to make the second evaporator (10), the shell and tube heat exchanger (13) and the second refrigerant heat exchanger (16) negative pressure environment. Then the boiling point of the liquid in the evaporation treatment system will decrease. Step S2: High-concentration brine is input into the first evaporator (1) through the raw liquid pipeline (2), and hot refrigerant after absorbing heat from the first compressor (5) is input into the first evaporator (1) to concentrate and evaporate the high-concentration brine in the first evaporator (1). The hot refrigerant undergoes a phase change to become liquid refrigerant. At the same time, the first monitoring component in the first evaporator (1) monitors the liquid inside. Step S3: The liquid refrigerant is input into the first refrigerant heat exchanger (3), and after heat exchange, it is input into the first compressor (5) to do work, and then enters the first evaporator (1) for concentration and evaporation; Step S4: When the first monitoring component detects that the monitoring index value of the liquid in the first evaporator (1) reaches the first threshold, the liquid in the first evaporator (1) is a separable salt liquid. At this time, the liquid inlet pipe (8) is opened to input the separable salt liquid into the relay tank (9). Step S5: The liquid outlet pipe (11) inputs the separable salt liquid in the relay tank (9) into the second evaporator (10), and then closes the liquid outlet pipe (11). The separable salt liquid circulates in the circulation pipe (12) between the second evaporator (10) and the shell and tube heat exchanger (13). Step S6: The hot refrigerant that has absorbed the heat from the second compressor (17) is introduced into the tube heat exchanger (13) to exchange heat with the separable salt liquid entering the tube heat exchanger (13), and the hot refrigerant undergoes a phase change to become liquid refrigerant. Step S7: Open the salt separation pipeline (15) and send the salt separation liquid after heat exchange in the tube heat exchanger (13) into the centrifugal assembly for salt separation. At the same time, the second monitoring component in the second evaporator (10) monitors the liquid inside. Step S8: When the second monitoring component detects that the monitoring index value of the liquid in the second evaporator (10) reaches the second threshold, the liquid outlet pipe (11) is opened to input the liquid into the second evaporator (10) in an amount equal to the output amount of the salt separation pipe (15); Step S2 specifically includes the following steps: Step S21: Open the raw liquid pipeline (2) and input high-concentration brine into the first evaporator (1); Step S22: After the high-concentration brine input is completed, the original liquid pipeline (2) is closed, and the hot refrigerant that has absorbed the heat of the first compressor (5) is input into the first evaporator (1) to concentrate and evaporate the high-concentration brine in the first evaporator (1); Step S23: The hot refrigerant undergoes a phase change to become a liquid refrigerant; Step S24: The first monitoring component in the first evaporator (1) monitors the liquid inside; Step S8 specifically includes the following steps: Step S81: When the salt separation pipeline (15) sends the heat-exchanged salt separation liquid into the centrifugal assembly, when the second detection assembly detects that the monitoring index value of the liquid in the second evaporator (10) reaches the second threshold, the external controller calculates the liquid output corresponding to the monitoring index value of the liquid in the second evaporator (10) reaching the second threshold. Step S82: Open the liquid outlet pipeline (11) and input the separable salt liquid into the second evaporator (10) in an amount equal to the liquid output, and then repeat steps S5 to S8.

2. The continuous salt-separation high-concentration brine heat exchange process according to claim 1, characterized in that, In step S4, after opening the inlet pipe (8) to input the separable salt liquid into the relay tank (9), the original liquid pipe (2) is opened to input new high-concentration brine into the first evaporator (1).

3. The continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that, The first evaporator (1) is connected to the impurity removal separator (7). The steam generated by the concentrated evaporation of the first evaporator (1) is input into the impurity removal separator (7) for impurity removal, and then input into the first refrigerant heat exchanger (3).

4. The continuous salt-separation high-concentration brine heat exchange process according to claim 1, characterized in that, The first evaporator (1) is connected to the first refrigerant heat exchanger (3) through the first plate heat exchanger (6), and the tube heat exchanger (13) is connected to the second refrigerant heat exchanger (16) through the second plate heat exchanger (18). Both the first plate heat exchanger (6) and the second plate heat exchanger (18) are connected to the cooling pipeline (20).

5. The continuous salt-separation high-concentration brine heat exchange process according to claim 1, characterized in that, Both the first compressor (5) and the second compressor (17) are oil-free compressors.

6. The continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that, Both the first refrigerant heat exchanger (3) and the second refrigerant heat exchanger (16) are submerged heat exchangers. Both the first refrigerant heat exchanger (3) and the second refrigerant heat exchanger (16) are equipped with steam pipes for flowing steam, and the steam pipes are submerged in the refrigerant inside the heat exchanger.

7. The continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that, The second evaporator (10) is connected to a defoamer pipeline (21) and a cleaning water pipeline (22), and control valves are respectively installed on the defoamer pipeline (21) and the cleaning water pipeline (22).

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