Waste heat negative-pressure low-temperature strong brine evaporation and desalination system coupled with electrolytic bath

Abstract

The utility model discloses a coupling electrolytic bath waste heat negative pressure low temperature evaporation desalination strong brine system, which comprises a reboiler, a Venturi structure, a condenser, a brine tank and a condensate water tank, the reboiler is provided with an alkali liquor heat exchange inlet pipe and an alkali liquor heat exchange outlet pipe, the Venturi structure is respectively communicated with the reboiler and the condenser, and the condensate water tank is communicated with the condenser. A strong brine preheating pipe is connected between the condenser and the brine tank, the condenser is connected with the reboiler through a strong brine evaporating pipe, a first booster pump is arranged on the strong brine preheating pipe, a condensate water circulating pipe is connected between the condensate water tank and the Venturi structure, and a second booster pump is arranged on the condensate water circulating pipe. And a second booster pump is arranged on the condensate water circulating pipe. According to the utility model, the waste heat generated by the work of the electrolytic bath can be used as a heat source for evaporating the strong brine, and the boiling evaporation temperature of the strong brine is reduced through the Venturi structure, so that the energy required for heating the strong brine to the evaporation temperature is reduced, and further, the consumption of extra energy is reduced, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of brine desalination technology, specifically to a low-temperature evaporation desalination system for concentrated brine using waste heat from a coupled electrolytic cell under negative pressure. Background Technology

[0002] Globally, 97% of the water is saltwater, and only 3% is freshwater. Of that, 2.5% of the freshwater is covered by glaciers, mountains, or other forms of permafrost. Usable freshwater accounts for only 0.3% of the total global water volume. Therefore, freshwater resources are extremely precious.

[0003] Alkaline electrolysis technology is currently the most mature and widely used technology in the field of water electrolysis. Its basic principle for hydrogen production is that, under the influence of an electric current, water is decomposed into hydrogen and oxygen through an electrochemical reaction. Subsequently, hydrogen and oxygen are released at the cathode and anode of the electrolytic cell, respectively. During water electrolysis, the raw water is decomposed and gradually consumed; approximately 0.9 liters of raw water are required to produce one standard cubic meter of hydrogen. To maintain continuous production, raw water needs to be constantly replenished to the system. As the demand and scale of hydrogen production in electrolytic cells continue to expand, the consumption of raw water is also increasing. Simultaneously, the total waste heat generated during water electrolysis for hydrogen production is also considerable.

[0004] To utilize brine, existing technologies involve desalination, where energy is exchanged for fresh water. The primary energy required for desalination includes thermal and electrical energy. Under normal pressure, thermal energy is used to heat the concentrated brine until it boils and evaporates. The water vapor is then condensed in a condenser, converting it into fresh water. Electrical energy powers the pumps, brine pumps, vacuum pumps, and other components in the equipment.

[0005] However, existing concentrated brine dilution equipment requires high energy consumption and is costly. Utility Model Content

[0006] To overcome the shortcomings of existing technologies, this utility model provides a coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine. It can utilize the waste heat generated by the operation of the electrolytic cell as a heat source for the evaporation of concentrated brine, and reduce the boiling and evaporation temperature of concentrated brine through a Venturi structure, thereby reducing the energy required to heat the concentrated brine to the evaporation temperature, and thus reducing the consumption of additional energy and lowering production costs.

[0007] The technical solution adopted by this utility model to solve its technical problem is:

[0008] A coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine includes a reboiler, a Venturi structure, a condenser, a brine tank, and a condensate tank. The reboiler is equipped with an alkali heat exchange inlet pipe and an alkali heat exchange outlet pipe, which are respectively connected to the outlet and inlet of the electrolytic cell. The Venturi structure connects the reboiler and the condenser. A concentrated brine preheating pipe connects the condenser and the brine tank. The condenser is connected to the reboiler via a concentrated brine evaporation pipe. A first booster pump is installed on the concentrated brine preheating pipe. A condensate circulation pipe connects the condensate tank and the Venturi structure, and a second booster pump is installed on the condensate circulation pipe.

[0009] As a further improvement to the above technical solution, the Venturi structure includes a hollow tube, a nozzle disposed at one end of the hollow tube, a converging tube and a diverging tube sequentially connected to the other end of the hollow tube, and a negative pressure suction tube connected to the bottom of the hollow tube. The nozzle is connected to the condensate circulation pipe, the diverging tube is connected to the condenser, and the negative pressure suction tube is connected to the reboiler.

[0010] As a further improvement to the above technical solution, the nozzle, the hollow tube, the converging tube, and the diverging tube are arranged coaxially.

[0011] As a further improvement to the above technical solution, the condenser is provided with a reflux interface, which is connected to the condensate tank through a condensate reflux pipe, and a condensate valve is provided on the condensate reflux pipe.

[0012] As a further improvement to the above technical solution, the reboiler is equipped with a temperature sensor and a pressure sensor.

[0013] As a further improvement to the above technical solution, the reboiler is also equipped with a level gauge, which is connected to the reboiler through two level connection flanges, which are located above and below the side of the reboiler, respectively.

[0014] As a further improvement to the above technical solution, the bottom of the reboiler is provided with a drain port, which is connected to the brine tank through a drain pipe, and a drain valve is provided on the drain pipe.

[0015] As a further improvement to the above technical solution, a check valve and a concentrated brine valve are provided on the concentrated brine evaporation tube.

[0016] As a further improvement to the above technical solution, a flow meter is also installed on the concentrated brine evaporation tube.

[0017] As a further improvement to the above technical solution, the reboiler is an axe-type reboiler.

[0018] The beneficial effects of this utility model are as follows: This utility model provides a coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine. A first booster pump sequentially pumps concentrated brine from the brine tank through a concentrated brine preheating pipe, a condenser, and a concentrated brine evaporation pipe into the reboiler. High-temperature alkaline solution from the electrolytic cell enters the reboiler through an alkaline heat exchange inlet pipe, and after heat exchange, flows back to the electrolytic cell through an alkaline heat exchange outlet pipe. The waste heat from the high-temperature alkaline solution in the electrolytic cell directly provides heat to the reboiler. Simultaneously, a second booster pump pumps condensate from the condensate tank into the Venturi structure at a high flow rate through a condensate circulation pipe. Through the Venturi effect, a negative pressure is generated within the reboiler. Under this negative pressure condition... The boiling point of concentrated brine is lowered, allowing the concentrated brine in the reboiler to boil and evaporate at a lower temperature. The water vapor produced by evaporation enters the condenser through the Venturi structure and is condensed into condensate. The condensate is discharged from the condenser. As the concentrated brine in the reboiler continues to evaporate, its concentration gradually increases. The condensate is continuously discharged to achieve the desalination process of concentrated brine. Thus, the waste heat generated by the electrolytic cell can be used as the heat source for the evaporation of concentrated brine. The Venturi structure lowers the boiling and evaporation temperature of the concentrated brine, reducing the energy required to heat the concentrated brine to the evaporation temperature. This reduces additional energy consumption and lowers production costs. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a structural schematic diagram provided by an example of this utility model;

[0021] Figure 2 yes Figure 1 A schematic diagram of the Venturi structure.

[0022] Figure reference numerals: 1-Reboiler, 2-Venturi structure, 3-Condenser, 4-Brine tank, 5-Condensate tank, 6-Alkali heat exchanger inlet pipe, 7-Alkali heat exchanger outlet pipe, 8-Concentrated brine preheating pipe, 9-Concentrated brine evaporation pipe, 10-First booster pump, 11-Condensate circulation pipe, 12-Second booster pump, 13-Condensate return pipe, 14-Condensate valve, 15-Temperature sensor, 16-Pressure sensor, 17-Level gauge, 18-Drain pipe, 19-Drain valve, 20-Check valve, 21-Concentrated brine valve, 22-Flow meter, 101-Level connection flange, 201-Hollow tube, 202-Nozzle, 203-Converging tube, 204-Diverging tube, 205-Negative pressure suction pipe. Detailed Implementation

[0023] The following will clearly and completely describe the concept, specific structure, and technical effects of this utility model in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are all within the scope of protection of this utility model. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this utility model can be combined interactively without contradicting each other.

[0024] Reference Figure 1 This utility model provides a coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination concentrated brine system, including a reboiler 1, a Venturi structure 2, a condenser 3, a brine tank 4, and a condensate tank 5. The reboiler 1 is provided with an alkali heat exchange inlet pipe 6 and an alkali heat exchange outlet pipe 7, which are respectively connected to the outlet and inlet of the electrolytic cell (not shown in the attached figure). The Venturi structure 2 is connected to the reboiler 1 and the condenser 3. A concentrated brine preheating pipe 8 is connected between the condenser 3 and the brine tank 4. The condenser 3 is connected to the reboiler 1 through a concentrated brine evaporation pipe 9. A first booster pump 10 is provided on the concentrated brine preheating pipe 8. A condensate circulation pipe 11 is connected between the condensate tank 5 and the Venturi structure 2. A second booster pump 12 is provided on the condensate circulation pipe 11.

[0025] During operation, the first booster pump 10 is turned on. The first booster pump 10 pumps concentrated brine from the brine tank 4 through the concentrated brine preheating pipe 8, condenser 3, and concentrated brine evaporation pipe 9 into the reboiler 1. The high-temperature alkaline solution from the electrolytic cell enters the reboiler 1 through the alkaline solution heat exchange inlet pipe 6, and after heat exchange, flows back to the electrolytic cell through the alkaline solution heat exchange outlet pipe 7. The residual heat of the high-temperature alkaline solution in the electrolytic cell directly provides heat to the reboiler 1. Simultaneously, the second booster pump 12 is turned on. The second booster pump 12 pumps condensate from the condensate tank 5 into the Venturi structure 2 at a high flow rate through the condensate circulation pipe 11. Through the Venturi effect, a negative pressure is generated in the reboiler 1. Under this negative pressure condition, the concentrated brine... The lower boiling point allows the concentrated brine in reboiler 1 to boil and evaporate at a lower temperature. The water vapor produced by evaporation enters condenser 3 through venturi structure 2 and is condensed into condensate. The condensate is discharged from condenser 3. As the concentrated brine in reboiler 1 continues to evaporate, its concentration gradually increases. The condensate is continuously discharged, thus achieving the desalination process of the concentrated brine. In this way, the waste heat generated by the electrolytic cell can be used as the heat source for the evaporation of concentrated brine. Furthermore, the venturi structure 2 lowers the boiling and evaporation temperature of the concentrated brine, reducing the energy required to heat the concentrated brine to the evaporation temperature. Consequently, this reduces the consumption of additional energy and lowers production costs.

[0026] Reference Figure 2 In some preferred embodiments, the Venturi structure 2 includes a hollow tube 201, a nozzle 202 disposed at one end of the hollow tube 201, a converging tube 203 and a diverging tube 204 connected sequentially to the other end of the hollow tube 201, and a negative pressure suction tube 205 connected to the bottom of the hollow tube 201. The nozzle 202 is connected to the condensate circulation pipe 11, the diverging tube 204 is connected to the condenser 3, and the negative pressure suction tube 205 is connected to the reboiler 1.

[0027] Understandably, the condensate in the condensate circulation pipe 11 is injected at high speed into the hollow pipe 201 through the nozzle 202. The water flow accelerates in the converging pipe 203. According to the Venturi effect, the increased flow velocity leads to a decrease in pressure, forming a local negative pressure area at the connection between the converging pipe 203 and the expanding pipe 204. At this time, the negative pressure area will draw the water vapor generated by evaporation in the reboiler 1 into the hollow pipe 201 through the negative pressure suction pipe 205. The water vapor and the high-speed water flow are fully mixed at the end of the converging pipe 203 to form a gas-liquid mixture. The flow velocity of the gas-liquid mixture in the expanding pipe 204 decreases and the pressure recovers, allowing the gas-liquid mixture to smoothly enter the condenser 3 and be condensed into condensate.

[0028] Furthermore, the nozzle 202, hollow tube 201, converging tube 203, and diverging tube 204 are coaxially arranged, which can reduce the impact of the gas-liquid mixture on the tube wall, reduce energy loss caused by turbulence, reduce flow velocity fluctuations, and ensure pressure stability.

[0029] Furthermore, the negative pressure suction pipe 205 is connected to the reboiler 1 via a Venturi negative pressure connection flange, the converging pipe 203 and the expanding pipe 204 are connected via a throat pipe, and the expanding pipe 204 is connected to the condenser 3 via a Venturi positive pressure connection flange.

[0030] In some preferred embodiments, the condenser 3 is provided with a reflux port, which is connected to the condensate tank 5 through a condensate reflux pipe 13, and a condensate valve 14 is provided on the condensate reflux pipe 13.

[0031] It is understandable that the condensed water is returned to the condensate tank 5 through the condensate return pipe 13, forming a closed-loop circulation system, thereby reducing the need for condensate replenishment. Furthermore, the condensate return flow rate can be adjusted through the condensate valve 14.

[0032] In some preferred embodiments, the reboiler 1 is equipped with a temperature sensor 15 and a pressure sensor 16. The temperature sensor 15 is used to monitor the internal temperature of the reboiler 1 and adjust the flow rate of the high-temperature alkaline solution by temperature changes to ensure maximum waste heat utilization efficiency. The pressure sensor 16 is used to monitor the internal pressure of the reboiler 1 to avoid abnormal evaporation rate of concentrated brine due to pressure fluctuations and improve the stability of the system.

[0033] Furthermore, a level gauge 17 is also installed on the reboiler 1. The level gauge 17 is connected to the reboiler 1 through two level connection flanges 101. The two level connection flanges 101 are located above and below the side of the reboiler 1, respectively. They can monitor the upper and lower limits of the concentrated brine level in real time to avoid the concentrated brine level in the reboiler 1 being too high or too low. Moreover, the flange connection method facilitates the disassembly and assembly of the level gauge 17.

[0034] In some preferred embodiments, the bottom of the reboiler 1 is provided with a drain port, which is connected to the brine tank 4 through a drain pipe 18. A drain valve 19 is provided on the drain pipe 18. By opening and closing the drain valve 19, the concentrate in the reboiler 1 can be periodically discharged through the drain pipe 18 and returned to the brine tank 4, thereby reducing the environmental pollution caused by the direct discharge of high-concentration wastewater.

[0035] In some preferred embodiments, a check valve 20 and a concentrated brine valve 21 are provided on the concentrated brine evaporation tube 9.

[0036] It is understandable that by setting the check valve 20, the backflow of concentrated brine can be prevented, ensuring the stable operation of the condenser 3. By setting the concentrated brine valve 21, the flow rate of concentrated brine into the reboiler 1 can be precisely adjusted, avoiding the loss of control of the liquid level in the reboiler 1 due to excessive instantaneous flow. Moreover, it can be shut off during the maintenance and repair of the reboiler 1 to avoid the risk of concentrated brine entering the reboiler 1 and causing injury to maintenance personnel.

[0037] Furthermore, a flow meter 22 is also installed on the concentrated brine evaporation tube 9. The flow meter 22 can accurately monitor the flow rate of concentrated brine entering the reboiler 1, which facilitates the adjustment of the concentrated brine valve 21.

[0038] In some preferred embodiments, the reboiler 1 is an axe-type reboiler 1. The axe-type reboiler 1 adopts a wide-bottomed vessel design to provide ample separation space for concentrated brine. Through the synergistic effect of gravity settling and inertial separation, the water vapor flow rate generated by the evaporation of concentrated brine is high. At the same time, the flat bottom structure of the axe-type reboiler 1 can reduce the accumulation of salt crystals. With the help of the drain pipe 18, it can efficiently discharge the concentrated high-salt waste liquid or solid precipitate, reducing the risk of scaling. The modular design of the axe-type reboiler 1 facilitates quick docking with components such as the Venturi structure 2 and the condenser 3, reducing the complexity of pipeline connections.

[0039] The above is a detailed description of the preferred embodiments of the present utility model. However, the present utility model is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present utility model. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine, characterized in that, The device includes a reboiler, a Venturi structure, a condenser, a brine tank, and a condensate tank. The reboiler is equipped with an alkali heat exchange inlet pipe and an alkali heat exchange outlet pipe, which are respectively connected to the outlet and inlet of the electrolytic cell. The Venturi structure connects the reboiler and the condenser. A concentrated brine preheating pipe connects the condenser and the brine tank. The condenser is connected to the reboiler through a concentrated brine evaporation pipe. A first booster pump is installed on the concentrated brine preheating pipe. A condensate circulation pipe connects the condensate tank and the Venturi structure, and a second booster pump is installed on the condensate circulation pipe.

2. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The Venturi structure includes a hollow tube, a nozzle disposed at one end of the hollow tube, a converging tube and a diverging tube connected in sequence to the other end of the hollow tube, and a negative pressure suction tube connected to the bottom of the hollow tube. The nozzle is connected to the condensate circulation pipe, the diverging tube is connected to the condenser, and the negative pressure suction tube is connected to the reboiler.

3. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 2, characterized in that, The nozzle, the hollow tube, the converging tube, and the diverging tube are arranged coaxially.

4. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The condenser is equipped with a reflux port, which is connected to the condensate tank via a condensate reflux pipe. A condensate valve is installed on the condensate reflux pipe.

5. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The reboiler is equipped with a temperature sensor and a pressure sensor.

6. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The reboiler is also equipped with a level gauge, which is connected to the reboiler via two level connection flanges, located above and below the side of the reboiler, respectively.

7. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The bottom of the reboiler is provided with a drain port, which is connected to the brine tank through a drain pipe, and a drain valve is provided on the drain pipe.

8. The coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The concentrated brine evaporation tube is equipped with a check valve and a concentrated brine valve.

9. A coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, A flow meter is also installed on the concentrated brine evaporation tube.

10. A coupled electrolytic cell waste heat negative pressure low-temperature evaporation desalination system for concentrated brine according to claim 1, characterized in that, The reboiler is an axe-type reboiler.

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