Novel water electrolysis hydrogen production system

Abstract

The utility model discloses a novel water electrolysis hydrogen production system which comprises an electrolytic bath, the hydrogen production system is provided with one or more material coolers for cooling and separating gas-liquid mixed materials at the downstream of the electrolytic bath equipment, and each material cooler comprises a heat source inlet end, a gas outlet end and a liquid outlet end. The liquid outlet ends are connected to the corresponding liquid collecting tanks, the gas outlet ends are connected to downstream gas treatment equipment or a user side, and cooled liquid materials in the liquid collecting tanks are conveyed to the electrolytic bath for recycling. A large alkali liquor separator is omitted, so that the equipment investment and the occupied area are reduced, and the separation process is simplified; a hydrogen / oxygen washing tower is omitted, so that the equipment investment and the occupied area are reduced; therefore, not only is the occupied use area of equipment saved, but also the cost is greatly reduced compared with equipment such as a washing tower and the like.

Description

Technical Field

[0001] This utility model relates to the field of water electrolysis for hydrogen production technology, and specifically to a novel water electrolysis for hydrogen production system. Background Technology

[0002] In the technical field of hydrogen production systems using electrolyzers, such as in prior art application number CN202111291730.8, the hydrogen-alkali mixture and the oxygen-alkali mixture produced after electrolysis in the electrolyzer enter their respective hydrogen separators and oxygen separators. Subsequently, the mixture is washed in hydrogen and oxygen scrubbing towers, during which water replenishment, alkali removal, and cooling are performed. The washed liquid (containing alkali solution) re-enters the hydrogen and oxygen separators, and the separated hydrogen and oxygen then enter their respective hydrogen and oxygen coolers. The cooled condensate again enters the hydrogen and oxygen separators. Finally, the qualified hydrogen and oxygen, after cooling, enter their respective hydrogen and oxygen purification devices, while the unqualified hydrogen and oxygen are vented.

[0003] However, existing technologies have significant drawbacks. First, in terms of equipment configuration, large-scale alkali separators and hydrogen / oxygen scrubbing towers are required. These large-scale devices are necessary because the separation and treatment process requires effective separation of the mixed liquid and thorough washing, alkali removal, and cooling of the gas. However, this results in a substantial increase in equipment investment, occupies a large space, leads to a large footprint, and makes the separation process relatively complex, increasing the difficulty of operation and management.

[0004] Secondly, regarding the separation method, existing technologies use gas-liquid separators, relying solely on gravity settling to achieve gas-liquid separation, followed by washing. The limitation of this separation method lies in the inability to precisely control the temperature of the produced gas and the separated liquid. This is due to the inherent limitations of gravity settling separation, which primarily utilizes the density difference between gas and liquid for separation, making precise temperature control difficult. For downstream gas users, this imprecise temperature control is undesirable. Unstable gas temperatures can affect the normal operation of downstream equipment and may even reduce the gas's effectiveness and safety.

[0005] In view of the above, it is necessary to propose a new type of water electrolysis hydrogen production system to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to overcome the defects in the existing technology and provide a more efficient, economical, and easy-to-control electrolytic cell gas separation and treatment solution, so as to make up for the many drawbacks in terms of equipment investment, floor space, separation process, and temperature control.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] A novel water electrolysis hydrogen production system includes an electrolyzer. Downstream of the electrolyzer, one or more material coolers are provided for cooling and separating a gas-liquid mixture. Each material cooler includes a heat source inlet, a gas outlet, and a liquid outlet. The liquid outlet is connected to a corresponding liquid collection tank, and the gas outlet is connected to downstream gas processing equipment or a user. The cooled liquid material in the liquid collection tank is transported back to the electrolyzer for recycling.

[0009] Furthermore, the downstream process routes of the electrolyzer include a hydrogen treatment route and an oxygen treatment route. Each of the hydrogen treatment route and the oxygen treatment route is equipped with a primary liquid collection tank. The bottom outlets of the primary liquid collection tanks of the two downstream process routes are connected to a secondary collection tank. The outlet of the secondary collection tank is connected to the alkaline solution inlet of the electrolyzer via a circulation pump.

[0010] Furthermore, the material coolers on the hydrogen processing route and / or oxygen processing route sequentially include a primary cooler and a secondary cooler. The gas outlet of the primary cooler is connected to the heat source inlet of the secondary cooler, and the gas outlet of the secondary cooler is connected to downstream gas processing equipment or the user end. The liquid outlets of the primary cooler and the secondary cooler are connected in parallel to a liquid collection tank.

[0011] Furthermore, the multiple liquid outlets in the hydrogen and oxygen processing routes are connected to the same primary liquid collection tank, and the two primary liquid collection tanks in the hydrogen and oxygen processing routes are connected to the secondary collection tank.

[0012] Furthermore, each material cooler in the hydrogen processing route and oxygen processing route is equipped with a corresponding primary liquid collection tank, and the outlet end of each primary liquid collection tank is connected to a secondary collection tank.

[0013] Furthermore, a bottom connecting pipe is provided between the liquid primary collection tanks of the hydrogen processing route and the oxygen processing route.

[0014] Furthermore, the cooling medium of the primary cooler is circulating water or chilled water, and the cooling medium of the secondary cooler is circulating water or chilled water.

[0015] Furthermore, the gas outlet temperature of the primary cooler is 60±5℃; the gas outlet temperature of the secondary cooler is 40±5℃ when using circulating water cooling, and 15±5℃ when using chilled water cooling.

[0016] Furthermore, the bottom outlet pipe of the primary liquid collection tank is equipped with a temperature control valve, a temperature sensor, and a pressure sensor; an oxygen-hydrogen analyzer or a hydrogen-oxygen analyzer can also be installed on this basis; the primary liquid collection tank is equipped with a first temperature sensor and a pressure sensor, and the pipeline entering the secondary collection tank is equipped with a second temperature sensor and a pressure sensor. The temperature feedback data from the second temperature sensor is used as the basis for the opening ratio of each temperature control valve.

[0017] Furthermore, both the hydrogen processing route and the oxygen processing route are equipped with vent pipes at their ends, and the distance between the vent pipes of the two routes is not less than 10m (designed in accordance with national standards and specifications).

[0018] The advantages and beneficial effects of this utility model are as follows:

[0019] 1. All coolers can use circulating cooling water or chilled water as the cooling medium. If a lower hydrogen outlet temperature (15°C) is required, chilled water can be used in the secondary cooler according to the system requirements. By cooling the gas-liquid mixture, the material temperature can be controlled as needed, avoiding the drawbacks of existing technologies that rely solely on gravity separation.

[0020] 2. The elimination of the large alkali separator reduces equipment investment and floor space, and simplifies the separation process; the elimination of the hydrogen / oxygen scrubbing tower also reduces equipment investment and floor space. This not only saves on equipment floor space, but also significantly reduces costs compared to equipment such as scrubbing towers.

[0021] 3. The temperature of the alkaline solution entering the electrolytic cell can be adjusted according to the needs of the electrolytic cell equipment operation, thereby effectively ensuring the electrolysis efficiency in the electrolytic cell. Attached Figure Description

[0022] Figure 1 This is one of the process diagrams of a novel water electrolysis hydrogen production system according to this utility model;

[0023] Figure 2 This is the second schematic diagram of a novel water electrolysis hydrogen production system according to this utility model;

[0024] In the diagram: 1. Electrolytic cell; 2. Material cooler; 3. Heat source inlet; 4. Gas outlet; 5. Liquid outlet; 6. Liquid collection tank; 7. Hydrogen processing route; 8. Oxygen processing route; 9. Primary liquid collection tank; 10. Secondary collection tank; 11. Circulating pump; 12. Primary cooler; 13. Secondary cooler; 14. Bottom connecting pipe; 15. Circulating water cooling; 16. Chilled water; 17. Temperature control valve; 18. First temperature sensor; 19. Second temperature sensor; 20. Vent pipe. Detailed Implementation

[0025] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0026] Example 1:

[0027] A novel water electrolysis hydrogen production system includes an electrolyzer 1. Downstream of the electrolyzer 1, one or more material coolers 2 are provided for cooling and separating a gas-liquid mixture. The material cooler 2 includes a heat source inlet 3, a gas outlet 4, and a liquid outlet 5. The liquid outlet 5 is connected to a corresponding liquid collection tank 6, and the gas outlet 4 is connected to downstream gas processing equipment or a user end. The cooled liquid material in the liquid collection tank 6 is transported back to the electrolyzer 1 for recycling.

[0028] like Figure 1 As shown, the downstream process routes of the electrolyzer 1 include a hydrogen treatment route 7 and an oxygen treatment route 8. Preferably, liquid primary collection tanks 9 are respectively provided on the hydrogen treatment route 7 and the oxygen treatment route 8. The bottom outlets of the liquid primary collection tanks 9 of the two downstream process routes are connected to a secondary collection tank 10. The outlet of the secondary collection tank 10 is connected to the alkaline inlet of the electrolyzer 1 via a circulation pump 11. In this embodiment, temperature control valves 17 are further provided on the bottom outlet pipes of the liquid primary collection tanks 9. A first temperature sensor 18 is provided on the liquid primary collection tanks 9, and a second temperature sensor 19 is provided on the pipeline entering the secondary collection tank 10. The temperature feedback data from the second temperature sensor 19 is used as the basis for the opening ratio of each temperature control valve 17. In actual use, due to the high cooling requirements of customers for hydrogen, a lower temperature cooling medium is used. After two-stage heat exchange, the temperature of the condensed alkali solution is also lower. As a result, the temperature of the primary liquid collection tank 9 on the hydrogen processing route 7 is lower than that on the oxygen processing route 8. This creates conditions for temperature control of the secondary collection tank 10. If the alkali solution is separated only by gravity, its temperature will remain at the temperature when it leaves the electrolyzer 1. With repeated cycles of entering and leaving the electrolyzer 1, the temperature of the electrolyzer 1 will inevitably rise cumulatively, which will negatively affect the efficiency of hydrogen production by electrolysis. It may even cause the temperature of the electrolyzer 1 body to rise abnormally, accelerating the aging of the gaskets between the bipolar plates.

[0029] Of course, as another improved structure parallel to the above, only one liquid collection tank 6 can be set up, that is, the liquid outlet end 5 of all material coolers 2 is connected to this liquid collection tank 6. This embodiment has the advantage of reducing the number of liquid collection tanks 6, thus also bringing the advantage of lower equipment cost. The difference is that, compared with the above method, it is not convenient to control the temperature of the alkali solution. All the cooled alkali solution flows into the same liquid collection tank 6, and the natural mixing temperature is more random and not convenient for precise control.

[0030] In this embodiment, it is understood that the number of material coolers 2 is not limited and can be increased or decreased according to design needs. Specifically, taking two material coolers 2 as an example, as a way, the material coolers 2 on the hydrogen processing route 7 and the oxygen processing route 8 each include a primary cooler 12 and a secondary cooler 13 in sequence.

[0031] As another approach, if the customer has high requirements for the temperature of hydrogen and needs to reduce the temperature of hydrogen to a lower level, a three-stage cooler or more can be added to the hydrogen processing route 7. In contrast, there are no high requirements for the temperature of oxygen, so the number of material coolers 2 on the oxygen processing route 8 can be reduced, and only the alkaline solution entrained in the gas needs to be separated. Alternatively, only one material cooler 2 can be set up, so the configuration can be flexibly set according to the customer's needs.

[0032] The following example illustrates two material coolers 2 on both the hydrogen processing route 7 and the oxygen processing route 8, meaning that each route has a primary cooler 12 and a secondary cooler 13. When connected, the gas outlet 4 of the primary cooler 12 on each route is connected to the heat source inlet 3 of the secondary cooler 13. The gas outlet 4 of the secondary cooler 13 is connected to downstream gas processing equipment or the user end. The liquid outlets 5 of the primary cooler 12 and the secondary cooler 13 are connected in parallel to the liquid collection tank 6.

[0033] Example 2:

[0034] This embodiment is based on Embodiment 1, specifically, as follows: Figure 1As shown, multiple liquid outlets 5 in the hydrogen processing route 7 and oxygen processing route 8 converge and connect to the same primary liquid collection tank 9. The two primary liquid collection tanks 9 of the hydrogen processing route 7 and oxygen processing route 8 converge and connect to the secondary collection tank 10. Due to the different cooling requirements of the gases in the two processing routes, the temperatures of the cooling alkaline solutions in the hydrogen alkaline solution collection tank and the oxygen alkaline solution collection tank are not the same (according to Example 1, we already know that the cooling requirement is higher in the hydrogen processing route 7, so the temperature of the hydrogen alkaline solution collection tank is lower than that of the oxygen alkaline solution collection tank). During use, the temperature can be adjusted according to the temperature of the electrolyzer 1. When the temperature of the electrolyzer 1 is high, more liquid can be used in the hydrogen alkaline solution collection tank, while the amount of liquid used in the oxygen alkaline solution collection tank can be reduced, thereby lowering the operating temperature of the electrolyzer 1; conversely, the amount of liquid used in the oxygen alkaline solution collection tank can be increased. By modulating and mixing the two primary liquid collection tanks 9, the temperature of the secondary collection tank 10 can be controlled.

[0035] Specifically, temperature control valves 17 are installed on the bottom outlet pipe of the primary liquid collection tank 9, and a first temperature sensor 18 is installed on the primary liquid collection tank 9. A second temperature sensor 19 is installed on the pipeline entering the secondary collection tank 10. The temperature feedback data of the second temperature sensor 19 is used as the basis for the opening ratio of each temperature control valve 17. In actual use, temperature sensors, pressure sensors, and hydrogen-oxygen analyzers installed on the hydrogen processing route 7 and oxygen-hydrogen analyzers installed on the oxygen processing route can be added to further achieve precise control and ensure product quality.

[0036] The second temperature sensor 19 serves as a downstream temperature sensor, used to detect temperature data in real time and output corresponding electrical signals; the valve openings of the two upstream temperature control valves 17 are adjustable to control the flow rate; a PID controller is also provided, whose input port is electrically connected to the second temperature sensor 19, used to receive the actual temperature signal transmitted from the temperature sensor, compare it with the preset temperature value, and obtain the temperature deviation; based on the temperature deviation, the control signal is calculated using the PID algorithm.

[0037] The output of the PID controller is connected to the control mechanism of two temperature control valves 17 (hereinafter referred to as the first valve and the second valve). Based on the calculated control signal, the controller controls the opening of the first valve and the second valve according to the preset opening ratio rule to adjust the flow rate into the downstream and make the downstream temperature tend to the preset temperature value. The preset opening ratio rule is determined based on experimental data or theoretical models to ensure that the downstream temperature is accurately controlled by the coordinated adjustment of the opening of the two valves under different operating conditions.

[0038] Furthermore, a bottom connecting pipe 14 is provided between the primary liquid collection tanks 9 of the hydrogen processing route 7 and the oxygen processing route 8. When the liquid levels of the two primary liquid collection tanks 9 differ significantly, the control valve on the bottom connecting pipe 14 can be opened to balance the liquid levels on both sides.

[0039] Example 3:

[0040] The difference between this embodiment and Embodiment 2 is that in the hydrogen processing route 7 and the oxygen processing route 8, each material cooler 2 is equipped with a corresponding primary liquid collection tank 9, and the outlet of each primary liquid collection tank 9 is connected to the secondary collection tank 10. For example... Figure 2 As shown, two gas-connected material coolers 2 are respectively installed on the hydrogen processing route 7 and the oxygen processing route 8. The liquid outlet ends 5 of the four material coolers 2 are connected in parallel and are respectively connected to the corresponding primary liquid collection tanks 9. As shown in the figure, there are four primary liquid collection tanks 9. Then the four primary liquid collection tanks 9 are connected to the secondary collection tank 10.

[0041] Based on the customer's temperature requirements for raw materials, such as a requirement of 15°C for hydrogen and no requirement for oxygen, the oxygen can be vented. Therefore, the specific control can be implemented according to the usage requirements. Taking hydrogen as an example, hydrogen processing route 7 is cooled by circulating cooling water through primary cooler 12 (other cooling media, such as chilled water, ethylene glycol cooling water, Freon refrigeration system, etc., can also be used as needed in actual use), controlling the outlet temperature of primary cooler 12 to 60°C. Secondary cooler 13 can be cooled by either circulating cooling water or chilled water 16. If circulating cooling water is used, the outlet temperature can be reduced to 40°C, and if chilled water 16 is used, it can be reduced to about 15°C. Similarly, oxygen processing route 8 on the oxygen side can also be selectively used in the same way.

[0042] It is understood that this embodiment can also use the temperature sensor and temperature control valve as in Embodiment 2 to regulate the temperature of the secondary collection tank 10. In this case, three temperature ranges can be formed in the four primary liquid collection tanks 9: the temperatures of the primary coolers 12 of hydrogen processing route 7 and oxygen processing route 8 are approximately the same, forming one temperature range of about 60°C; simultaneously, the secondary cooler 13 of hydrogen processing route 7 can be controlled at 15°C, forming the second temperature range; and the secondary cooler 13 of oxygen processing route 8 can be controlled at 40°C, forming the third temperature range. Therefore, the temperature of the secondary collection tank 10 can be controlled more precisely by controlling the opening of the temperature control valve through the temperature sensor.

[0043] Furthermore, both the hydrogen treatment route 7 and the oxygen treatment route 8 are equipped with vent pipes 20 at their ends, and the distance between the vent pipes 20 of the two routes is not less than 10m (designed in accordance with national standards and specifications).

[0044] In actual use, at least two or more material coolers 2 should be used to replace the hydrogen separator (and oxygen separator) in the original separation system. Depending on the client's requirements for hydrogen temperature, if it is <40 degrees Celsius, the first and second cooling water can be circulating cooling water; if it is <15 degrees Celsius, the second cooling should be done with 7-degree Celsius chilled water 16. The refrigeration method can be electric refrigeration or bromine refrigeration.

[0045] Since oxygen customers do not require cooling, both coolers at the oxygen end can be cooled by circulating water 15, and chilled water is not considered under any circumstances 16, thus saving electricity.

[0046] The specific work process is as follows:

[0047] (1) Utilizing the cooling and separation principle of the electrolytic cooler, the hydrogen-alkali mixture and the oxygen-alkali mixture generated by electrolysis in electrolytic cell 1 first enter the primary hydrogen cooler for primary cooling until the alkali is cooled to a reasonable temperature for entering electrolytic cell 1 (e.g., 60°C). After cooling, the alkali sinks into the hydrogen-alkali collection tank 1. The gas-liquid mixture from the primary hydrogen cooler is cooled by the secondary hydrogen cooler to the gas temperature required by the gas outlet of the original gas-liquid separation device (e.g., 40°C or 15°C). The alkali after secondary cooling sinks into the hydrogen-alkali collection tank 2. The same applies to the oxygen side.

[0048] (2) The alkaline solutions collected by hydrogen alkaline solution collection tank 1, hydrogen alkaline solution collection tank 2, oxygen alkaline solution collection tank 1 and oxygen alkaline solution collection tank 2 flow into the total alkaline solution collection tank, and then enter the electrolytic cell 1 after being circulated by the alkaline solution circulation pump 11, forming the corresponding alkaline solution circulation.

[0049] (3) After secondary cooling, qualified hydrogen and oxygen enter their respective hydrogen purification devices and oxygen purification devices, while unqualified hydrogen and oxygen are released into the air.

[0050] Advantages after improvement:

[0051] (1) All coolers can use circulating cooling water as the cooling medium. If there is a lower requirement for the hydrogen outlet temperature (15°C), chilled water 16 can be used at the secondary cooler according to the system requirements.

[0052] (2) The large alkaline separator was eliminated, reducing equipment investment and floor space, and simplifying the separation process;

[0053] (3) The hydrogen / oxygen scrubbing tower was eliminated, reducing equipment investment and floor space.

[0054] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A novel water electrolysis hydrogen production system, comprising an electrolyzer, characterized in that, The hydrogen production system has one or more material coolers downstream of the electrolyzer for cooling and separating the gas-liquid mixture. The material cooler includes a heat source inlet, a gas outlet, and a liquid outlet. The liquid outlet is connected to a corresponding liquid collection tank, and the gas outlet is connected to downstream gas processing equipment or a user end. The cooled liquid material in the liquid collection tank is transported to the electrolyzer for recycling.

2. The novel water electrolysis hydrogen production system according to claim 1, characterized in that, The downstream process route of the electrolyzer includes a hydrogen treatment route and an oxygen treatment route. Each of the hydrogen treatment route and the oxygen treatment route is equipped with a primary liquid collection tank. The bottom outlets of the primary liquid collection tanks of the hydrogen treatment route and the oxygen treatment route are connected to a secondary collection tank. The outlet of the secondary collection tank is connected to the alkaline solution inlet of the electrolyzer through a circulation pump.

3. A novel water electrolysis hydrogen production system according to claim 2, characterized in that, The material coolers on the hydrogen and / or oxygen processing routes sequentially include a primary cooler and a secondary cooler. The gas outlet of the primary cooler is connected to the heat source inlet of the secondary cooler, and the gas outlet of the secondary cooler is connected to downstream gas processing equipment or the user end. The liquid outlets of the primary and secondary coolers are connected in parallel to a liquid collection tank.

4. A novel water electrolysis hydrogen production system according to claim 3, characterized in that, The multiple liquid outlets in the hydrogen and oxygen processing routes are connected to the same primary liquid collection tank, and the two primary liquid collection tanks in the hydrogen and oxygen processing routes are connected to the secondary collection tank.

5. A novel water electrolysis hydrogen production system according to claim 3, characterized in that, Each material cooler in the hydrogen and oxygen processing routes is equipped with a corresponding primary liquid collection tank, and the outlet of each primary liquid collection tank is connected to a secondary collection tank.

6. A novel water electrolysis hydrogen production system according to claim 4 or 5, characterized in that, A bottom connecting pipe is installed between the liquid primary collection tanks of the hydrogen processing route and the oxygen processing route.

7. A novel water electrolysis hydrogen production system according to claim 3, characterized in that, The cooling medium of the primary cooler is circulating water or chilled water, and the cooling medium of the secondary cooler is circulating water or chilled water.

8. A novel water electrolysis hydrogen production system according to claim 7, characterized in that, The gas outlet temperature of the primary cooler is 60±5℃; the gas outlet temperature of the secondary cooler is 40±5℃ when using circulating water cooling, and 15±5℃ when using chilled water cooling.

9. A novel water electrolysis hydrogen production system according to claim 2, characterized in that, The bottom outlet pipe of the liquid primary collection tank is equipped with a temperature control valve, a temperature sensor, a pressure sensor, and an oxygen-hydrogen analyzer or a hydrogen-oxygen analyzer. The liquid primary collection tank is equipped with a first temperature sensor and a pressure sensor. The pipeline entering the secondary collection tank is equipped with a second temperature sensor and a pressure sensor. The temperature feedback data from the second temperature sensor is used as the basis for the opening ratio of each temperature control valve.

10. A novel water electrolysis hydrogen production system according to claim 2, characterized in that, Both the hydrogen processing route and the oxygen processing route are equipped with vent pipes at their ends, and the distance between the vent pipes of the two routes is not less than 10m.

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