Energy-saving and environmentally friendly electrolytic hydrogen production system and electrolytic hydrogen production method

Abstract

The present invention belongs to the technical field of hydrogen production by electrolysis of water, and specifically relates to an energy-saving and environmentally friendly electrolysis hydrogen production system and electrolysis hydrogen production method. The electrolysis hydrogen production system includes: a cooler, a high-level tank, a raw water conveying device, an electrolyzer, an oxygen circulation pump, an oxygen liquid separator, a hydrogen circulation pump, and a hydrogen gas-liquid separator. The electrolyte at room temperature and pressure is fed to the high-pressure electrolyzer through intermittent pressure conversion, and a high-temperature and high-pressure gas-liquid mixture is produced through direct current electrolysis, which can save energy for high-pressure liquid transportation and gas compression and pressurization; the high-temperature and high-pressure electrolyte is cooled by natural evaporation under reduced pressure and condensed and recovered to save material consumption, and only the electricity and water required for the electrolysis process are consumed during the production process; after the electrolyte is evaporated and concentrated, it is crystallized through an evaporator to remove the impurities accumulated in the electrolyte, so that the electrolysis process can be carried out continuously and stably. The entire process only produces high-pressure pure oxygen and hydrogen and trace impurities, and no other auxiliary energy is consumed, thereby realizing energy saving and environmental protection in the process.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by electrolysis of water, and in particular relates to an energy-saving and environment-friendly hydrogen production system and method by electrolysis. Background Art

[0002] In the current hydrogen production system by electrolysis of seawater, the electrolysis reaction generates a large amount of heat and high-pressure gas, so a cooling medium is needed to cool the electrolyte through a heat exchanger, which wastes a lot of energy. Intermittently delivering raw water to the high-pressure electrolysis system through a high-pressure delivery pump consumes energy and the equipment is easily damaged.

[0003] In order to solve the above problems, the present invention is proposed. Summary of the invention

[0004] The present invention can fully utilize the heat released during the electrolysis process to carry out environmentally friendly treatment of materials, and cool them by themselves without the need to increase additional cooling capacity. At the same time, the gas pressure energy generated by the rapid expansion of the volume of gas generated by liquid electrolysis is utilized to transport the electrolytic materials at high pressure, thereby achieving the purpose of energy saving and environmental protection.

[0005] The first aspect of the present invention provides an energy-saving and environmentally friendly electrolytic hydrogen production system, which includes the following equipment: a cooler 1, a high-level tank 2, a raw water conveying device 3, an electrolytic cell 4, an oxygen circulation pump 5, an oxygen-liquid separator 6, a hydrogen circulation pump 7, and a hydrogen gas-liquid separator 8;

[0006] The connection relationship of the above devices is as follows:

[0007] The raw water pipeline 01 is connected to the shell side material inlet of the cooler 1, the shell side material outlet and the tube side material outlet of the cooler 1 are both connected to the inlet of the high level tank 2, and the outlet of the high level tank 2 is connected to the inlet of the raw water conveying equipment 3;

[0008] The outlet of the raw water delivery device 3 is connected to the anode inlet 41 of the electrolytic cell 4 through the raw water delivery device outlet pipeline 31 and the first anode input pipeline 02 and the second anode input pipeline 03. The second anode input pipeline 03 is provided with an oxygen circulation pump 5.

[0009] The outlet of the raw water delivery device 3 is also connected to the cathode inlet 42 of the electrolytic cell 4 through the raw water delivery device outlet pipeline 31 and the first cathode input pipeline 04 and the second cathode input pipeline 05. The second cathode input pipeline 05 is provided with a hydrogen circulation pump 7;

[0010] The anode outlet 43 of the electrolytic cell 4 is connected to the middle of the oxygen-liquid separator 6, and the bottom outlet of the oxygen-liquid separator 6 is connected to the anode inlet 41 of the electrolytic cell 4 through the first oxygen liquid discharge pipeline 06 and the second anode input pipeline 03. The bottom outlet of the oxygen-liquid separator 6 is also connected to the material inlet of the cooler 1 tube side through the second oxygen liquid discharge pipeline 07 and the circulation pipeline 08. The top of the oxygen-liquid separator 6 is an oxygen discharge outlet;

[0011] The cathode outlet 44 of the electrolyzer 4 is connected to the middle of the hydrogen liquid separator 8, and the bottom outlet of the hydrogen liquid separator 8 is connected to the cathode inlet 42 of the electrolyzer 4 through the first hydrogen liquid discharge pipeline 09 and the second cathode input pipeline 05. The bottom outlet of the hydrogen liquid separator 8 is also connected to the material inlet of the cooler 1 tube side through the second hydrogen liquid discharge pipeline 010 and the circulation pipeline 08. The top of the hydrogen liquid separator 8 is a hydrogen discharge outlet.

[0012] Preferably, valves are provided on the second oxygen liquid discharge pipeline 07 and the second hydrogen liquid discharge pipeline 010, respectively.

[0013] Preferably, the raw water conveying equipment 3 is a water storage tank; the oxygen outlet of the oxygen-liquid separator 6 is connected to the water storage tank through an air intake pipeline 011, an air intake valve 012 is provided on the air intake pipeline 011, and an exhaust valve 013 is also provided on the water storage tank. A water outlet valve 014 is provided at the bottom of the water storage tank, and a water inlet valve 015 is provided at the inlet of the water storage tank connected to the outlet of the high-level tank 2.

[0014] Preferably, the electrolytic hydrogen production system further comprises: an evaporator 9; the circulation pipeline 08 is connected to the inlet of the evaporator 9, the steam outlet at the top of the evaporator 9 is connected to the material inlet of the cooler 1 tube side, and the upper electrolyte outlet of the evaporator 9 is connected to the inlet of the high-level tank 2;

[0015] The evaporator 9 is located above the header tank 2 .

[0016] Preferably, the cooler 1 is located above the high-level tank 2, the raw water conveying equipment 3 is located below the high-level tank 2 and the outlet of the raw water conveying equipment 3 is flush with the upper and middle parts of the hydrogen gas-liquid separator 8 and the oxygen liquid separator 6, the electrolyzer 4 is located at the bottom of the entire system, the heights of the inlet of the second hydrogen liquid discharge pipeline 010 and the inlet of the second oxygen liquid discharge pipeline 07 are both higher than the anode outlet 43 and the cathode outlet 44 of the electrolyzer 4, and the heights of the hydrogen circulation pump 7 and the oxygen circulation pump 5 are both lower than the heights of the inlet of the second hydrogen liquid discharge pipeline 010 and the inlet of the second oxygen liquid discharge pipeline 07.

[0017] A second aspect of the present invention provides an energy-saving and environmentally friendly method for producing hydrogen by electrolysis, the method using the hydrogen production system by electrolysis according to any one of the first aspects, the method comprising the following steps:

[0018] Raw water at room temperature and pressure continuously enters from the lower part of the shell side of the cooler 1 through the raw water pipeline 01 and flows out from the upper part to keep the shell side filled with supplemented raw water. Part of the high-temperature and high-pressure electrolyte separated by the hydrogen gas-liquid separator 8 is connected to the material inlet of the tube side of the cooler 1 through the second hydrogen liquid discharge pipeline 010 and the circulation pipeline 08. Part of the high-temperature and high-pressure electrolyte separated by the oxygen liquid separator 6 is connected to the material inlet of the tube side of the cooler 1 through the second oxygen liquid discharge pipeline 07 and the circulation pipeline 08. The condensed raw water enters the header tank 2 together with the shell side raw water after heat exchange;

[0019] A portion of the raw water discharged from the header tank 2 is transported to the anode inlet 41 of the electrolytic cell 4 through the raw water transport device 3 and the oxygen circulation pump 5, while another portion is transported to the cathode inlet 42 of the electrolytic cell 4 through the raw water transport device 3 and the hydrogen circulation pump 7;

[0020] The electrolyte in the electrolytic cell 4 is electrolyzed to produce high-pressure oxygen and hydrogen, and a large amount of heat is released, causing the temperature to rise rapidly. A part of the electrolyte and the high-temperature and high-pressure oxygen mixture enters the oxygen-liquid separator 6 through the anode outlet 43 of the electrolytic cell 4 under the transportation of the oxygen circulation pump 5 for gas-liquid separation, while another part of the electrolyte and the high-temperature and high-pressure hydrogen mixture enters the hydrogen-liquid separator 8 through the cathode outlet 44 of the electrolytic cell 4 under the transportation of the hydrogen circulation pump 7 for gas-liquid separation; the oxygen and hydrogen separated by the oxygen-liquid separator 6 and the hydrogen-liquid separator 8 are respectively transported out through their respective oxygen outlets and hydrogen outlets for purification treatment;

[0021] Most of the high-temperature and high-pressure electrolyte after gas-liquid separation in the oxygen-liquid separator 6 enters the electrolytic cell 4 through the first oxygen liquid discharge pipeline 06, the second anode input pipeline 03, and the anode inlet 41 to continue to participate in the circulating electrolysis, and most of the high-temperature and high-pressure electrolyte after gas-liquid separation in the hydrogen gas-liquid separator 8 enters the electrolytic cell 4 through the first hydrogen liquid discharge pipeline 09, the second cathode input pipeline 05, and the cathode inlet 42 to continue to participate in the circulating electrolysis.

[0022] Preferably, when the raw water delivery device 3 is a water storage tank, the method further comprises the following steps:

[0023] When the liquid level in the water storage tank reaches the lower limit, the air inlet valve 012 and the water outlet valve 014 are closed, and then the exhaust valve 013 is opened. After the pressure in the water storage tank drops to normal pressure, the water inlet valve 015 is opened to allow the raw water in the high-pressure tank 2 to fill the water storage tank. Then, the water inlet valve 015 and the exhaust valve 013 are closed, and the air inlet valve 012 is opened to increase the pressure in the water storage tank and maintain the pressure balance between the water storage tank and the oxygen-liquid separator 6. Then, the water outlet valve 014 is opened to continuously replenish raw water to the inlets of the oxygen circulation pump 5 and the hydrogen circulation pump 7 to maintain the electrolyte level.

[0024] When the liquid level in the water storage tank reaches the lower limit again, the above-mentioned operation is repeated to achieve automatic entry of the raw material water at room temperature and pressure into the high-pressure electrolysis system for preheating without the need for a high-pressure pump to transport it.

[0025] Preferably, when the electrolytic hydrogen production system further comprises: an evaporator 9, the method further comprises the following steps:

[0026] The high-temperature and high-pressure electrolyte entering the evaporator 9 through the circulation pipeline 08 is vaporized in the evaporator 9 and then becomes water vapor. It enters the top of the cooler 1 through the top steam outlet and is condensed into liquid by the raw water. It enters the high-level tank 2 together with the shell-side raw water after heat exchange.

[0027] After the high temperature and high pressure electrolyte is evaporated and concentrated under reduced pressure in the evaporator 9, the upper layer of electrolyte intermittently flows back to the high level tank 2 through the upper layer electrolyte outlet, and the crystallized or deposited impurities in the lower layer are cleaned regularly.

[0028] Preferably, the temperature of the electrolyte in the electrolytic cell 4 is controlled to be 100-200° C. by controlling the valve openings on the second oxygen liquid discharge pipeline 07 and the second hydrogen liquid discharge pipeline 010;

[0029] By controlling the opening of two valves at the upper oxygen outlet of the oxygen-liquid separator 6 and the upper hydrogen outlet of the hydrogen-liquid separator 8, the pressure of the two separation systems of the oxygen-liquid separator 6 and the hydrogen-liquid separator 8 is kept balanced and the pressure of the electrolytic cell 4 is adjusted to 0.5-10.0 MPa;

[0030] The liquid levels of the oxygen-liquid separator 6 and the hydrogen-liquid separator 8 are adjusted by adjusting the opening of the water outlet valve 014 .

[0031] The raw water mentioned in this article refers to the fresh water normally added to the system, including pure water, seawater, brine and even wastewater, especially seawater. The electrolyte refers to the raw water mixed with electrolytes or catalysts and then entering the electrolytic cell for electrolysis.

[0032] In this article, the liquid obtained by mixing the raw water in the high-level tank 2 with a small amount of electrolyte is also called raw water.

[0033] The above technical solutions can be freely combined under the premise of no contradiction.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. In the scheme of the present application, the electrolyte at room temperature and pressure is fed to the high-pressure electrolyzer through intermittent pressure conversion, and a high-temperature and high-pressure gas-liquid mixture is produced through direct current electrolysis, which can save energy for high-pressure liquid transportation and gas compression and pressurization; the high-temperature electrolyte is naturally evaporated and condensed and recovered through decompression to save material consumption, and only the electricity and water required for the electrolysis process are consumed during the production process; after the electrolyte is evaporated and concentrated, it is crystallized through an evaporator to remove the impurities accumulated in the electrolyte, so that the electrolysis process can be carried out continuously and stably. The entire process only produces high-pressure pure oxygen and hydrogen and trace impurities, and no other auxiliary energy is consumed, thereby achieving energy saving and environmental protection in the process.

[0036] 2. The specific features of this application are as follows:

[0037] The high-temperature and high-pressure electrolyte cools itself by evaporating under reduced pressure, without the need for additional energy required for cooling the electrolyte;

[0038] High temperature and high pressure electrolyte is used to preheat the material through heat exchange to reach the minimum temperature required for electrolysis;

[0039] The high temperature and high pressure electrolyte is evaporated under reduced pressure, concentrated and crystallized to remove impurities from the electrolyte liquid and then recycled;

[0040] The high-temperature and high-pressure electrolyte is evaporated under reduced pressure, and the condensed steam condensate and the concentrated electrolyte rich in electrolyte are refluxed for further electrolysis, thereby reducing material consumption and avoiding environmental pollution;

[0041] The material preheated by the high-temperature and high-pressure electrolyte through heat exchange can be raw water that meets the requirements after treatment, or it can be waste water rich in impurities. The waste water can be preheated and evaporated under reduced pressure and condensed to obtain raw water that meets the requirements, thereby achieving environmentally friendly treatment of waste water;

[0042] Through intermittent pressure balancing operation, the normal pressure raw water can automatically enter the high-pressure electrolysis system without the need for high-pressure pump transportation, thereby saving energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The figure is a flow chart of the electrolysis hydrogen production system according to the first embodiment.

[0044] Figure 2 This is a flow chart of the electrolysis hydrogen production system according to the second implementation scheme.

[0045] Figure 3This is a flow chart of the electrolysis hydrogen production system according to the implementation scheme of Comparative Example 1.

[0046] Figure 1-3 In the figure, A represents raw water, B represents oxygen, and C represents hydrogen.

[0047] List of reference numerals:

[0048] 1. Cooler, 2. High-level tank, 3. Raw water conveying equipment, 31. Raw water conveying equipment outlet pipeline, 4. Electrolyzer, 41. Anode inlet, 42. Cathode inlet, 5. Oxygen circulation pump, 6. Oxygen liquid separator, 7. Hydrogen circulation pump, 8. Hydrogen gas-liquid separator, 01. Raw water pipeline, 02. First anode input pipeline, 03. Second anode input pipeline, 04. First cathode input pipeline, 05. Second cathode input pipeline, 06. First oxygen liquid discharge pipeline, 07. Second oxygen liquid discharge pipeline, 08. Circulation pipeline, 09. First hydrogen liquid discharge pipeline, 010. Second hydrogen liquid discharge pipeline, 011. Air intake pipeline, 012. Air intake valve, 013. Exhaust valve, 014. Water outlet valve, 015. Water inlet valve. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below in conjunction with embodiments.

[0050] Those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the art or the product specifications are used. If the manufacturer of the materials or equipment used is not specified, they are all conventional products that can be purchased.

[0051] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" to another element, it may be directly connected to the other element, or there may be intermediate elements. In addition, the "connection" used herein may include wireless connection.

[0052] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two. The terms "inside", "upper", "lower", etc., indicating positions or state relationships, are based on the positions or state relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operate in a specific position, and therefore cannot be understood as limiting the present invention.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "provided with" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention will be understood according to specific circumstances.

[0054] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0055] Example 1

[0056] An energy-saving and environmentally friendly electrolytic hydrogen production system, the electrolytic hydrogen production system comprising the following equipment: a cooler 1, a high-level tank 2, a raw water conveying device 3, an electrolytic tank 4, an oxygen circulation pump 5, an oxygen liquid separator 6, a hydrogen circulation pump 7, and a hydrogen gas-liquid separator 8;

[0057] The connection relationship of the above devices is as follows:

[0058] The raw water pipeline 01 is connected to the shell side material inlet of the cooler 1, the shell side material outlet and the tube side material outlet of the cooler 1 are both connected to the inlet of the high level tank 2, and the outlet of the high level tank 2 is connected to the inlet of the raw water conveying equipment 3;

[0059] The outlet of the raw water delivery device 3 is connected to the anode inlet 41 of the electrolytic cell 4 through the raw water delivery device outlet pipeline 31 and the first anode input pipeline 02 and the second anode input pipeline 03. The second anode input pipeline 03 is provided with an oxygen circulation pump 5.

[0060] The outlet of the raw water delivery device 3 is also connected to the cathode inlet 42 of the electrolytic cell 4 through the raw water delivery device outlet pipeline 31 and the first cathode input pipeline 04 and the second cathode input pipeline 05. The second cathode input pipeline 05 is provided with a hydrogen circulation pump 7;

[0061] The anode outlet 43 of the electrolytic cell 4 is connected to the middle of the oxygen-liquid separator 6, and the bottom outlet of the oxygen-liquid separator 6 is connected to the anode inlet 41 of the electrolytic cell 4 through the first oxygen liquid discharge pipeline 06 and the second anode input pipeline 03. The bottom outlet of the oxygen-liquid separator 6 is also connected to the material inlet of the cooler 1 tube side through the second oxygen liquid discharge pipeline 07 and the circulation pipeline 08. The top of the oxygen-liquid separator 6 is an oxygen discharge outlet;

[0062] The cathode outlet 44 of the electrolyzer 4 is connected to the middle of the hydrogen liquid separator 8, and the bottom outlet of the hydrogen liquid separator 8 is connected to the cathode inlet 42 of the electrolyzer 4 through the first hydrogen liquid discharge pipeline 09 and the second cathode input pipeline 05. The bottom outlet of the hydrogen liquid separator 8 is also connected to the material inlet of the cooler 1 tube side through the second hydrogen liquid discharge pipeline 010 and the circulation pipeline 08. The top of the hydrogen liquid separator 8 is a hydrogen discharge outlet.

[0063] The second oxygen liquid discharge pipeline 07 and the second hydrogen liquid discharge pipeline 010 are respectively provided with valves.

[0064] The electrolytic hydrogen production system also includes: an evaporator 9; the circulation pipeline 08 is connected to the inlet of the evaporator 9, the steam outlet at the top of the evaporator 9 is connected to the material inlet of the cooler 1 tube side, and the upper electrolyte outlet of the evaporator 9 is connected to the inlet of the high-level tank 2;

[0065] The evaporator 9 is located above the header tank 2 .

[0066] The cooler 1 is located above the high-level tank 2, the raw water conveying equipment 3 is located below the high-level tank 2 and the outlet of the raw water conveying equipment 3 is flush with the upper and middle parts of the hydrogen gas-liquid separator 8 and the oxygen liquid separator 6, the electrolyzer 4 is located at the bottom, the heights of the inlet of the second hydrogen liquid discharge pipeline 010 and the inlet of the second oxygen liquid discharge pipeline 07 are both higher than the anode outlet 43 and the cathode outlet 44 of the electrolyzer 4, for example, more than one meter, and the heights of the hydrogen circulation pump 7 and the oxygen circulation pump 5 are both lower than the heights of the inlet of the second hydrogen liquid discharge pipeline 010 and the inlet of the second oxygen liquid discharge pipeline 07.

[0067] The flow chart of the electrolysis hydrogen production system of the first embodiment is as follows Figure 1As shown, the raw water conveying equipment 3 is a water storage tank; the oxygen outlet of the oxygen-liquid separator 6 is connected to the water storage tank through an air intake pipeline 011, an air intake valve 012 is provided on the air intake pipeline 011, and an exhaust valve 013 is also provided on the water storage tank. A water outlet valve 014 is provided at the bottom of the water storage tank, and a water inlet valve 015 is provided at the inlet of the water storage tank connected to the outlet of the high-level tank 2.

[0068] The flow chart of the electrolysis hydrogen production system of the second embodiment is as follows Figure 2 As shown, the evaporator 9 can be omitted. The circulation pipeline 08 is directly connected to the high-level tank 2.

[0069] An energy-saving and environmentally friendly method for producing hydrogen by electrolysis, the method using the hydrogen production system by electrolysis according to any one of the first aspects, the method comprising the following steps:

[0070] Raw water at room temperature and pressure continuously enters from the lower part of the shell side of the cooler 1 through the raw water pipeline 01 and flows out from the upper part to keep the shell side filled with supplemented raw water, and part of the high-temperature and high-pressure electrolyte separated by the hydrogen gas-liquid separator 8 is connected to the material inlet of the tube side of the cooler 1 through the second hydrogen liquid discharge pipeline 010 and the circulation pipeline 08, and part of the high-temperature and high-pressure electrolyte separated by the oxygen liquid separator 6 is connected to the material inlet of the tube side of the cooler 1 through the second oxygen liquid discharge pipeline 07 and the circulation pipeline 08, and enters the high-level tank 2 together with the shell side raw water after heat exchange;

[0071] A portion of the raw water discharged from the header tank 2 is transported to the anode inlet 41 of the electrolytic cell 4 through the raw water transport device 3 and the oxygen circulation pump 5, and another portion of the raw water discharged from the header tank 2 is transported to the cathode inlet 42 of the electrolytic cell 4 through the raw water transport device 3 and the hydrogen circulation pump 7;

[0072] The electrolyte in the electrolytic cell 4 is electrolyzed to produce high-pressure oxygen and hydrogen, and a large amount of heat is released, causing the temperature to rise rapidly. A part of the electrolyte and the high-temperature and high-pressure oxygen mixture enters the oxygen-liquid separator 6 through the anode outlet 43 of the electrolytic cell 4 under the transportation of the oxygen circulation pump 5 for gas-liquid separation, while the other part of the electrolyte and the high-temperature and high-pressure hydrogen mixture enters the hydrogen-liquid separator 8 through the cathode outlet 44 of the electrolytic cell 4 under the transportation of the hydrogen circulation pump 7 for gas-liquid separation; the oxygen and hydrogen separated by the oxygen-liquid separator 6 and the hydrogen-liquid separator 8 are respectively transported out through their respective oxygen outlets and hydrogen outlets for purification treatment;

[0073] Most of the high-temperature and high-pressure electrolyte after gas-liquid separation in the oxygen-liquid separator 6 enters the electrolytic cell 4 through the first oxygen liquid discharge pipeline 06, the second anode input pipeline 03, and the anode inlet 41 to continue to participate in the circulating electrolysis, and most of the high-temperature and high-pressure electrolyte after gas-liquid separation in the hydrogen gas-liquid separator 8 enters the electrolytic cell 4 through the first hydrogen liquid discharge pipeline 09, the second cathode input pipeline 05, and the cathode inlet 42 to continue to participate in the circulating electrolysis.

[0074] Preferably, when the raw water delivery device 3 is a water storage tank, the method further comprises the following steps:

[0075] When the liquid level in the water storage tank reaches the lower limit, the air inlet valve 012 and the water outlet valve 014 are closed, and then the exhaust valve 013 is opened. After the pressure in the water storage tank drops to normal pressure, the water inlet valve 015 is opened to allow the raw water in the high-pressure tank 2 to fill the water storage tank. Then, the water inlet valve 015 and the exhaust valve 013 are closed, and the air inlet valve 012 is opened to increase the pressure in the water storage tank and maintain the pressure balance between the water storage tank and the oxygen-liquid separator 6. Then, the water outlet valve 014 is opened to continuously replenish raw water to the inlets of the oxygen circulation pump 5 and the hydrogen circulation pump 7 to maintain the electrolyte level.

[0076] When the liquid level in the water storage tank reaches the lower limit again, the above-mentioned operation is repeated to achieve automatic entry of the raw material water at room temperature and pressure into the high-pressure electrolysis system for preheating without the need for a high-pressure pump to transport it.

[0077] Preferably, when the electrolytic hydrogen production system further comprises: an evaporator 9, the method further comprises the following steps:

[0078] The high-temperature and high-pressure electrolyte entering the evaporator 9 through the circulation pipeline 08 is vaporized in the evaporator 9 and then becomes water vapor. It enters the top of the cooler 1 through the top steam outlet and is condensed into liquid by the raw water. It enters the high-level tank 2 together with the shell-side raw water after heat exchange.

[0079] After the high temperature and high pressure electrolyte is evaporated and concentrated under reduced pressure in the evaporator 9, the upper layer of electrolyte intermittently flows back to the high level tank 2 through the upper layer electrolyte outlet, and the crystallized or deposited impurities in the lower layer are cleaned regularly.

[0080] Preferably, the raw water stored in the high-level tank 2 during the production process is at normal pressure and the temperature is less than 100° C., and the temperature of the electrolyte in the electrolytic cell 4 is controlled to be 100-200° C., preferably 140-150° C., by controlling the valve openings on the second oxygen liquid discharge pipeline 07 and the second hydrogen liquid discharge pipeline 010;

[0081] By controlling the opening of two valves at the upper oxygen outlet of the oxygen-liquid separator 6 and the upper hydrogen outlet of the hydrogen-liquid separator 8, the pressure of the two separation systems of the oxygen-liquid separator 6 and the hydrogen-liquid separator 8 is kept balanced and the pressure of the electrolytic cell 4 is adjusted to 0.5-10.0 MPa, preferably 2.5-4.0 MPa;

[0082] The liquid levels of the oxygen-liquid separator 6 and the hydrogen-liquid separator 8 are adjusted by adjusting the opening of the water outlet valve 014 .

[0083] The raw water mentioned in this article refers to the fresh water normally added to the system, including pure water, seawater, brine and even wastewater, especially seawater. The electrolyte refers to the raw water mixed with electrolytes or catalysts and then entering the electrolytic cell for electrolysis.

[0084] Comparative Example 1

[0085] The flow chart of the electrolytic hydrogen production system of this embodiment is as follows Figure 3 As shown, the raw water delivery device 3 is a high-pressure pump. The head of the high-pressure pump is preferably above 300m. Compared with the solution of Example 1, the solution of Comparative Example 1 consumes energy and the equipment is easily damaged.

Claims

1. An energy-saving and environmentally friendly electrolytic hydrogen production system, characterized in that: The electrolytic hydrogen production system comprises the following equipment: a cooler (1), a high-level tank (2), a raw water conveying device (3), an electrolytic cell (4), an oxygen circulation pump (5), an oxygen liquid separator (6), a hydrogen circulation pump (7), and a hydrogen gas-liquid separator (8); The connection relationship of the above devices is as follows: The raw water pipeline (01) is connected to the shell-side material inlet of the cooler (1), the shell-side material outlet and the tube-side material outlet of the cooler (1) are both connected to the inlet of the high-level tank (2), and the outlet of the high-level tank (2) is connected to the inlet of the raw water conveying equipment (3); The outlet of the raw water delivery device (3) is connected to the anode inlet (41) of the electrolytic cell (4) through the outlet pipeline (31) of the raw water delivery device and the first anode input pipeline (02) and the second anode input pipeline (03), and the second anode input pipeline (03) is provided with an oxygen circulation pump (5); The outlet of the raw water delivery device (3) is also connected to the cathode inlet (42) of the electrolytic cell (4) through the raw water delivery device outlet pipeline (31) and the first cathode input pipeline (04) and the second cathode input pipeline (05), and the second cathode input pipeline (05) is provided with a hydrogen circulation pump (7); The anode outlet (43) of the electrolytic cell (4) is connected to the middle of the oxygen-liquid separator (6); the bottom outlet of the oxygen-liquid separator (6) is connected to the anode inlet (41) of the electrolytic cell (4) through a first oxygen liquid discharge pipeline (06) and a second anode input pipeline (03); the bottom outlet of the oxygen-liquid separator (6) is also connected to the material inlet of the cooler (1) tube side through a second oxygen liquid discharge pipeline (07) and a circulation pipeline (08); the top of the oxygen-liquid separator (6) is an oxygen discharge outlet; The cathode outlet (44) of the electrolyzer (4) is connected to the middle of the hydrogen gas-liquid separator (8), the bottom outlet of the hydrogen gas-liquid separator (8) is connected to the cathode inlet (42) of the electrolyzer (4) through the first hydrogen liquid discharge pipeline (09) and the second cathode input pipeline (05), the bottom outlet of the hydrogen gas-liquid separator (8) is also connected to the material inlet of the cooler (1) tube side through the second hydrogen liquid discharge pipeline (010) and the circulation pipeline (08), and the top of the hydrogen gas-liquid separator (8) is a hydrogen discharge outlet; The raw water conveying equipment (3) is a water storage tank; the oxygen outlet of the oxygen-liquid separator (6) is connected to the water storage tank through an air intake pipeline (011), an air intake valve (012) is provided on the air intake pipeline (011), and an air exhaust valve (013) is also provided on the water storage tank. A water outlet valve (014) is provided at the bottom of the water storage tank, and a water inlet valve (015) is provided at the inlet of the water storage tank connected to the outlet of the high-level tank (2).

2. The energy-saving and environmentally friendly electrolysis hydrogen production system according to claim 1 is characterized in that: The second oxygen liquid discharge pipeline (07) and the second hydrogen liquid discharge pipeline (010) are respectively provided with valves.

3. The energy-saving and environmentally friendly electrolysis hydrogen production system according to claim 1 is characterized in that: The electrolytic hydrogen production system further comprises: an evaporator (9); the circulation pipeline (08) is connected to the inlet of the evaporator (9); the steam outlet at the top of the evaporator (9) is connected to the material inlet of the tube side of the cooler (1); the upper electrolyte outlet of the evaporator (9) is connected to the inlet of the high-level tank (2); The evaporator (9) is located above the high-level tank (2).

4. The energy-saving and environmentally friendly electrolytic hydrogen production system according to claim 1 is characterized in that: The cooler (1) is located above the high-level tank (2), the raw water conveying equipment (3) is located below the high-level tank (2), and the outlet of the raw water conveying equipment (3) is flush with the middle and upper parts of the hydrogen gas-liquid separator (8) and the oxygen gas-liquid separator (6), the electrolyzer (4) is located at the lowest part, the heights of the inlet of the second hydrogen liquid discharge pipeline (010) and the inlet of the second oxygen liquid discharge pipeline (07) are both higher than the anode outlet (43) and cathode outlet (44) of the electrolyzer (4), and the heights of the hydrogen circulation pump (7) and the oxygen circulation pump (5) are both lower than the heights of the inlet of the second hydrogen liquid discharge pipeline (010) and the inlet of the second oxygen liquid discharge pipeline (07).

5. An energy-saving and environmentally friendly method for producing hydrogen by electrolysis, characterized in that: The method uses the electrolysis hydrogen production system according to any one of claims 1 to 4, and the method comprises the following steps: Raw water at room temperature and pressure continuously enters the lower part of the shell side of the cooler (1) through the raw water pipeline (01) and flows out from the upper part to keep the shell side filled with supplementary raw water. Part of the high-temperature and high-pressure electrolyte separated by the hydrogen gas-liquid separator (8) is connected to the material inlet of the tube side of the cooler (1) through the second hydrogen liquid discharge pipeline (010) and the circulation pipeline (08). Part of the high-temperature and high-pressure electrolyte separated by the oxygen liquid separator (6) is connected to the material inlet of the tube side of the cooler (1) through the second oxygen liquid discharge pipeline (07) and the circulation pipeline (08). The condensed raw water enters the header tank (2) together with the shell side raw water after heat exchange. A portion of the raw water discharged from the header tank (2) is transported to the anode inlet (41) of the electrolytic cell (4) through the raw water transport device (3) and the oxygen circulation pump (5), while another portion is transported to the cathode inlet (42) of the electrolytic cell (4) through the raw water transport device (3) and the hydrogen circulation pump (7); The electrolyte in the electrolytic cell (4) is electrolyzed to produce high-pressure oxygen and hydrogen, releasing a large amount of heat, causing the temperature to rise rapidly. A portion of the electrolyte and the high-temperature and high-pressure oxygen mixture are transported by the oxygen circulation pump (5) through the anode outlet (43) of the electrolytic cell (4) and enter the oxygen liquid separator (6) for gas-liquid separation, while another portion of the electrolyte and the high-temperature and high-pressure hydrogen mixture are transported by the hydrogen circulation pump (7) through the cathode outlet (44) of the electrolytic cell (4) and enter the hydrogen gas-liquid separator (8) for gas-liquid separation. The oxygen and hydrogen separated by the oxygen liquid separator (6) and the hydrogen gas-liquid separator (8) are transported out through their respective oxygen outlets and hydrogen outlets for purification. Most of the high-temperature and high-pressure electrolyte after gas-liquid separation in the oxygen-liquid separator (6) enters the electrolytic cell (4) through the first oxygen liquid discharge pipeline (06), the second anode input pipeline (03), and the anode inlet (41) to continue to participate in the circulating electrolysis, and most of the high-temperature and high-pressure electrolyte after gas-liquid separation in the hydrogen-gas-liquid separator (8) enters the electrolytic cell (4) through the first hydrogen liquid discharge pipeline (09), the second cathode input pipeline (05), and the cathode inlet (42) to continue to participate in the circulating electrolysis.

6. The energy-saving and environmentally friendly electrolytic hydrogen production method according to claim 5, characterized in that: When the raw water conveying device (3) is a water storage tank, the method further comprises the following steps: When the liquid level in the water storage tank reaches the lower limit, the air inlet valve (012) and the water outlet valve (014) are closed, and then the exhaust valve (013) is opened. After the pressure in the water storage tank drops to normal pressure, the water inlet valve (015) is opened to allow the raw water in the high-pressure tank (2) to fill the water storage tank. Then, the water inlet valve (015) and the exhaust valve (013) are closed, and the air inlet valve (012) is opened to increase the pressure in the water storage tank and maintain the pressure balance between the water storage tank and the oxygen-liquid separator (6). Then, the water outlet valve (014) is opened to continuously replenish raw water to the inlets of the oxygen circulation pump (5) and the hydrogen circulation pump (7) to maintain the electrolyte level. When the liquid level in the water storage tank reaches the lower limit again, the above-mentioned operation is repeated to achieve automatic entry of the raw material water at room temperature and pressure into the high-pressure electrolysis system for preheating without the need for a high-pressure pump to transport it.

7. The energy-saving and environmentally friendly electrolytic hydrogen production method according to claim 5, characterized in that: When the electrolytic hydrogen production system further comprises: an evaporator (9), the method further comprises the following steps: The high-temperature and high-pressure electrolyte entering the evaporator (9) through the circulation pipeline (08) is vaporized in the evaporator (9) and becomes water vapor, which enters the top of the cooler (1) through the top steam outlet and is condensed into liquid by the raw water, and enters the high-level tank (2) together with the shell-side raw water after heat exchange; After the high-temperature and high-pressure electrolyte is evaporated, cooled and concentrated in the evaporator (9), the upper electrolyte intermittently flows back to the high-level tank (2) through the upper electrolyte outlet, while the crystallized or deposited impurities in the lower layer are regularly cleaned.

8. The energy-saving and environmentally friendly electrolytic hydrogen production method according to claim 5, characterized in that: The temperature of the electrolyte in the electrolytic cell (4) is controlled to be 100-200° C. by controlling the valve openings on the second oxygen liquid discharge pipeline (07) and the second hydrogen liquid discharge pipeline (010); By controlling the valve opening of the oxygen outlet at the upper part of the oxygen-liquid separator (6) and the hydrogen outlet at the upper part of the hydrogen-gas-liquid separator (8), the pressure of the two separation systems of the oxygen-liquid separator (6) and the hydrogen-gas-liquid separator (8) is kept balanced and the pressure of the electrolytic cell (4) is adjusted to 0.5-10.0 MPa; The liquid levels of the oxygen-liquid separator (6) and the hydrogen-liquid separator (8) are adjusted by adjusting the opening of the water outlet valve (014).

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