A seawater hydrogen production system without alkali liquid circulation

Abstract

The present invention belongs to the technical field of hydrogen production by electrolysis of seawater, and particularly relates to a seawater hydrogen production system without alkali liquid circulation, comprising: an in-situ desalination chamber located at the top and an electrolytic water chamber located at the bottom, the in-situ desalination chamber and the electrolytic water chamber being connected through a seawater evaporation purification connecting component; the top two sides of the in-situ desalination chamber are respectively connected with a seawater inlet pipe and a seawater discharge pipe; the middle two sides of the electrolytic water chamber are respectively connected with an oxygen outlet pipe and a hydrogen outlet pipe; after entering through the seawater inlet pipe, the seawater flows through the outer side of the electrolytic water chamber and absorbs the heat generated by electrolysis in the electrolytic water chamber, and the heat causes part of the seawater to generate steam, which enters the electrolytic water chamber through the seawater evaporation purification connecting component for electrolysis, and the other part of the seawater flows out from the seawater discharge pipe. The device has a simple structure and a small volume, and can be used for direct hydrogen production by electrolysis of seawater, and the electrolytic water chamber only has seawater inlet and outlet and hydrogen / oxygen output, and there is no alkali liquid circulation, and the operation is simple and easy to maintain.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen production by seawater electrolysis, and in particular relates to a seawater hydrogen production system without alkali liquid circulation. Background Art

[0002] Hydrogen energy, as a clean, carbon-free, flexible and efficient secondary energy source and industrial raw material, has broad application prospects.

[0003] The currently industrialized water electrolysis hydrogen production technology (such as alkaline water electrolysis and proton exchange membrane water electrolysis) still uses fresh water as raw material, but my country is short of fresh water resources. With the explosive growth of hydrogen energy demand in the future, the shortage of fresh water resources will become one of the main limiting factors of the water electrolysis industry.

[0004] There are two technical routes for hydrogen production using seawater as raw material: indirect seawater hydrogen production and in-situ seawater hydrogen production. Among them, indirect seawater electrolysis requires two key processes: seawater desalination and electrolysis. The cost of hydrogen production is high and the engineering construction is difficult. In-situ seawater hydrogen production omits the seawater desalination treatment process. Although it can greatly shorten the process flow, direct seawater electrolysis hydrogen production faces serious problems such as chlorine evolution side reaction, catalyst deactivation, and scaling.

[0005] At present, the most widely used water electrolysis hydrogen production technology is alkaline water electrolysis technology, which has been industrialized, with low investment cost and long service life. Due to the existence of electrode polarization, electrolyzer component resistance and interface resistance, part of the electrical energy is inevitably released in the form of heat during the electrolysis process, and a large amount of electrolyte circulation is required to remove the heat. The electrolyte circulation process of alkaline electrolysis technology has the problem of alkali seepage and environmental pollution, and complex maintenance of alkaline fluid is required. In addition, the use of high-concentration alkali solution has strict sealing and alkali resistance requirements for the supporting equipment of the circulation system, which increases the system cost. In addition, the degree of integration is low and the volume is large, which makes it difficult to be used in the future. The use of seawater electrolysis hydrogen production is mainly combined with offshore photovoltaic and offshore wind power. Therefore, a seawater hydrogen production system without alkali solution circulation is urgently needed to solve the problem. Summary of the invention

[0006] The purpose of the present invention is to provide a seawater hydrogen production system without alkali liquid circulation to solve the above problems.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A seawater hydrogen production system without alkali liquid circulation, comprising: an in-situ desalination chamber located at an upper portion and a water electrolysis chamber located at a lower portion, wherein the in-situ desalination chamber is connected to the water electrolysis chamber via a seawater evaporation purification connecting component;

[0009] The top two sides of the in-situ desalination chamber are respectively connected with a seawater inlet pipe and a seawater discharge pipe;

[0010] The two sides of the middle of the water electrolysis chamber are respectively connected with an oxygen outlet pipe and a hydrogen outlet pipe;

[0011] After entering through the seawater inlet pipe, seawater flows through the outer side of the electrolytic water chamber and absorbs the heat generated by electrolysis in the electrolytic water chamber. The heat causes part of the seawater to generate steam, which enters the electrolytic water chamber for electrolysis through the seawater evaporation and purification connecting component, and the other part of the seawater flows out from the seawater discharge pipe.

[0012] Preferably, the in-situ desalination chamber comprises a seawater inlet insulation plate and a seawater outlet insulation plate, the inlet end of the seawater inlet insulation plate is connected to the seawater inlet pipe, the seawater evaporation purification connecting component is located between the seawater inlet insulation plate and the seawater outlet insulation plate, the outlet end of the seawater inlet insulation plate is connected to the water inlet end of the electrolysis water chamber, and the water inlet end of the seawater outlet insulation plate is connected to the water outlet end of the electrolysis water chamber.

[0013] Preferably, the seawater inlet insulation plate includes a first seawater inlet, the inlet end of the first seawater inlet is connected to the outlet end of the seawater inlet pipe, the outlet end of the first seawater inlet is connected to the inlet end of the first seawater matrix flow channel, the outlet end of the first seawater matrix flow channel is connected to the inlet end of the first seawater outlet, and the outlet end of the first seawater outlet is connected to the inlet end of the electrolysis water chamber.

[0014] Preferably, the seawater outlet insulation plate includes a second seawater inlet, the inlet end of the second seawater inlet is connected to the outlet end of the electrolysis water chamber, the outlet end of the second seawater inlet is connected to the inlet end of the second seawater matrix flow channel, the outlet end of the second seawater matrix flow channel is connected to the inlet end of the second seawater outlet, and the outlet end of the second seawater outlet is connected to the inlet end of the seawater discharge pipe.

[0015] Preferably, the seawater evaporation purification connecting component includes a water-proof membrane, a hydrophilic membrane and a hydrophobic breathable membrane arranged in sequence, the water-proof membrane is fixedly connected to the side wall of the insulation board at the seawater inlet end, the hydrophobic breathable membrane is fixedly connected to the side wall of the insulation board at the seawater outlet end, and the bottom end of the hydrophilic membrane extends into the electrolytic water chamber.

[0016] Preferably, the water electrolysis chamber comprises a device sealing plate, in which an anode plate, a cathode plate and an alkaline solution electrolysis unit are fixedly connected; the alkaline solution electrolysis unit is located between the anode plate and the cathode plate;

[0017] The bottom end of the hydrophilic membrane extends into the alkaline solution electrolysis part;

[0018] A third seawater matrix flow channel is provided between the inner wall of the device sealing plate and the anode plate, and the water inlet end of the third seawater matrix flow channel is connected to the first seawater outlet through a third seawater inlet;

[0019] The third seawater matrix flow channel is connected to the cathode plate through a third seawater outlet;

[0020] The anode plate is provided with an oxygen outlet for communicating with the alkaline solution electrolysis part, one end of the oxygen outlet is connected to the oxygen generation end of the alkaline solution electrolysis part, and the other end of the oxygen outlet is connected to the oxygen outlet pipe, and the oxygen outlet pipe is arranged through the side wall of the sealing plate of the device.

[0021] Preferably, a fourth seawater matrix flow channel is provided between the cathode plate and the inner wall of the device sealing plate, the water inlet end of the fourth seawater matrix flow channel is connected to the third seawater outlet through a fourth seawater inlet, and the water outlet end of the fourth seawater matrix flow channel is connected to the second seawater inlet through a fourth seawater outlet;

[0022] The cathode plate is provided with a hydrogen outlet for communicating with the alkali solution electrolysis part;

[0023] One end of the hydrogen outlet is connected to the hydrogen generation end of the alkali solution electrolysis part, and the other end of the hydrogen outlet is connected to the hydrogen outlet pipe, and the hydrogen outlet pipe is arranged through the side wall of the device sealing plate.

[0024] Preferably, the alkaline solution electrolysis part comprises an anode catalytic electrode and a cathode catalytic electrode, the anode catalytic electrode and the cathode catalytic electrode are respectively located on both sides of the hydrophilic membrane, the anode catalytic electrode is arranged close to the anode plate, an anode gas diffusion layer is arranged between the anode plate and the anode catalytic electrode, and an anode sealing gasket for sealing is sleeved outside the anode catalytic electrode and the anode gas diffusion layer; the anode gas diffusion layer is communicated with the oxygen outlet;

[0025] The cathode catalytic electrode is arranged close to the cathode plate, a cathode gas diffusion layer is arranged between the cathode catalytic electrode and the cathode plate, a cathode sealing gasket for sealing is arranged between the cathode gas diffusion layer and the outer side of the cathode catalytic electrode, and the cathode gas diffusion layer is connected to the hydrogen outlet.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] When in use, seawater enters through the seawater inlet pipe and then flows through the outer side of the electrolytic water chamber and absorbs heat generated by electrolysis in the electrolytic water chamber. The heat causes part of the seawater to generate steam, which enters the electrolytic water chamber for electrolysis through the seawater evaporation purification connecting component, and the other part of the seawater flows out from the seawater discharge pipe. Oxygen and hydrogen are generated by electrolysis in the electrolytic water chamber, which are discharged into a collecting device through the oxygen outlet pipe and the hydrogen outlet pipe, respectively. The device has a simple structure and a small volume, and can be used for direct electrolysis of seawater to produce hydrogen. The hydrogen purity is high, and seawater directly enters the electrolytic water chamber without deep treatment. The electrolytic water chamber only has seawater inlet and outlet and hydrogen / oxygen output, and there is no alkali liquid circulation, which is simple to operate and easy to maintain. The electrolytic cell provided by the present invention uses normal temperature seawater for heat extraction and temperature control, thereby eliminating the refrigerant energy consumption required for cooling a conventional electrolytic cell. The temperature difference between the high-temperature seawater and the normal temperature seawater after heat extraction is utilized to realize the in-situ desalination of seawater in the electrolytic cell, and the generated fresh water supplements the water consumed by electrolysis. The in-situ desalination process of seawater utilizes the waste heat of the electrolytic cell, and no additional energy consumption is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative labor:

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the in-situ desalination chamber structure of the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the water electrolysis chamber of the present invention;

[0032] Figure 4 It is a cross-sectional view of the structure of the present invention;

[0033] Figure 5 It is a schematic diagram of the principle of the present invention;

[0034] Among them, 1. In-situ desalination chamber; 11. Hydrophilic membrane; 12. Waterproof membrane; 13. Hydrophobic breathable membrane; 14. Seawater inlet end insulation board; 140. Seawater inlet pipe; 141. First seawater inlet; 142. First seawater matrix flow channel; 143. First seawater outlet; 15. Seawater outlet end insulation board; 150. Seawater discharge pipe; 151. Second seawater outlet; 152. Second seawater matrix flow channel; 153. Second seawater inlet; 2. Water electrolysis chamber; 21. Anode catalytic electrode; 22. Cathode catalytic electrode anode; 23, anode gas diffusion layer; 24, cathode gas diffusion layer; 25, anode plate; 250, oxygen outlet pipe; 251, oxygen outlet; 252, third seawater inlet; 253, third seawater matrix flow channel; 254, third seawater outlet; 26, cathode plate; 260, hydrogen outlet pipe; 261, hydrogen outlet; 262, fourth seawater outlet; 263, fourth seawater matrix flow channel; 264, fourth seawater inlet; 27, device sealing plate; 28, anode sealing gasket; 29, cathode sealing gasket. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Reference Figures 1 to 5 The present invention discloses a seawater hydrogen production system without alkali liquid circulation, comprising: an in-situ desalination chamber 1 located at the upper part and a water electrolysis chamber 2 located at the lower part, wherein the in-situ desalination chamber 1 is connected with the water electrolysis chamber 2 through a seawater evaporation purification connecting component;

[0038] The top sides of the in-situ desalination chamber 1 are connected with a seawater inlet pipe 140 and a seawater discharge pipe 150 respectively;

[0039] The two sides of the middle of the water electrolysis chamber 2 are connected with an oxygen outlet pipe 250 and a hydrogen outlet pipe 260 respectively;

[0040] After entering through the seawater inlet pipe 140, seawater flows through the outside of the electrolytic water chamber 2 and absorbs the heat generated by electrolysis in the electrolytic water chamber 2. The heat causes part of the seawater to generate steam, which enters the electrolytic water chamber 2 for electrolysis through the seawater evaporation purification connecting component, and the other part of the seawater flows out from the seawater discharge pipe 150.

[0041] When in use, seawater enters through the seawater inlet pipe 140 and flows through the outside of the electrolytic water chamber 2 and absorbs the heat generated by electrolysis in the electrolytic water chamber 2. The heat causes part of the seawater to generate steam and enter the electrolytic water chamber 2 for electrolysis through the seawater evaporation purification connecting component. The other part of the seawater flows out through the seawater discharge pipe 150. Oxygen and hydrogen are generated by electrolysis in the electrolytic water chamber 2 and are discharged to the collection device through the oxygen outlet pipe 250 and the hydrogen outlet pipe 260 respectively. The device has a simple structure and a small volume, and can be used for direct electrolysis of seawater to produce hydrogen. The purity of hydrogen is high. High, seawater does not need deep treatment and directly enters the water electrolysis chamber 2, and the water electrolysis chamber 2 only has seawater in and out and hydrogen / oxygen output, no alkali liquid circulation, simple operation and easy maintenance, the electrolytic cell provided by the present invention adopts normal temperature seawater for heat extraction and temperature control, eliminating the refrigerant energy consumption required for cooling the conventional electrolytic cell; the temperature difference between the high-temperature seawater and the normal temperature seawater after heat extraction is utilized to realize the in-situ desalination of seawater in the electrolytic cell, and the fresh water produced supplements the water consumed by electrolysis, and the in-situ desalination process of seawater utilizes the waste heat of the electrolytic cell, without additional energy consumption.

[0042] A further optimized solution is provided, in which the in-situ desalination chamber 1 comprises a seawater inlet insulation plate 14 and a seawater outlet insulation plate 15, the inlet end of the seawater inlet insulation plate 14 is connected to the seawater inlet pipe 140, the seawater evaporation purification connecting component is located between the seawater inlet insulation plate 14 and the seawater outlet insulation plate 15, the outlet end of the seawater inlet insulation plate 14 is connected to the inlet end of the electrolytic water chamber 2, and the inlet end of the seawater outlet insulation plate 15 is connected to the outlet end of the electrolytic water chamber 2.

[0043] A further optimized solution is that the seawater inlet end insulation plate 14 includes a first seawater inlet 141, the inlet end of the first seawater inlet 141 is connected to the outlet end of the seawater inlet pipe 140, the outlet end of the first seawater inlet 141 is connected to the inlet end of the first seawater matrix flow channel 142, the outlet end of the first seawater matrix flow channel 142 is connected to the inlet end of the first seawater outlet 143, and the outlet end of the first seawater outlet 143 is connected to the inlet end of the electrolytic water chamber 2.

[0044] To further optimize the solution, the seawater outlet insulation plate 15 includes a second seawater inlet 153, the inlet end of the second seawater inlet 153 is connected to the outlet end of the electrolytic water chamber 2, the outlet end of the second seawater inlet 153 is connected to the inlet end of the second seawater matrix flow channel 152, the outlet end of the second seawater matrix flow channel 152 is connected to the inlet end of the second seawater outlet 151, and the outlet end of the second seawater outlet 151 is connected to the inlet end of the seawater discharge pipe 150.

[0045] According to a further optimized solution, the seawater evaporation purification connecting component includes a water-proof membrane 12, a hydrophilic membrane 11 and a hydrophobic breathable membrane 13 arranged in sequence, the water-proof membrane 12 is fixedly connected to the side wall of the insulation plate 14 at the seawater inlet end, the hydrophobic breathable membrane 13 is fixedly connected to the side wall of the insulation plate 15 at the seawater outlet end, and the bottom end of the hydrophilic membrane 11 extends into the electrolytic water chamber 2.

[0046] The device is divided into an upper in-situ desalination chamber 1 and a lower water electrolysis chamber 2. The two chambers are directly connected via a hydrophilic membrane 11 and are provided with a communicating seawater flow channel.

[0047] The in-situ desalination chamber 1 comprises a water-proof membrane 12, a hydrophilic membrane 11, a hydrophobic breathable membrane 13, a seawater inlet insulation plate 14 and a seawater outlet insulation plate 15; the seawater inlet insulation plate 14, the water-proof membrane 12, the hydrophilic membrane 11, the hydrophobic breathable membrane 13 and the seawater outlet insulation plate 15 are tightly fitted in sequence, wherein the seawater inlet insulation plate 14 and the seawater outlet insulation plate 15 are provided with a seawater flow channel on the inner side, wherein the hydrophilic membrane 11 extends to the electrolytic water chamber 2 below.

[0048] A first seawater inlet 141, a first seawater matrix flow channel 142, and a first seawater outlet 143 are provided on the inner side of the seawater inlet insulation plate 14; a second seawater inlet 153, a second seawater matrix flow channel 152, and a second seawater outlet 151 are provided on the inner side of the seawater outlet insulation plate 15; the first seawater inlet 141 is connected to the seawater inlet pipe 140; and the second seawater outlet 151 is connected to the seawater discharge pipe 150.

[0049] The hydrophilic membrane 11 is preferably a polyethersulfone microporous membrane or a polyacrylonitrile microporous membrane with a pore size of 0.2 micrometers to 10 micrometers and a thickness of 80 to 180 micrometers.

[0050] The water-blocking membrane 12 is preferably a nonporous polytetrafluoroethylene membrane, a nonporous polyvinylidene fluoride membrane, a nonporous polypropylene membrane, or a nonporous polyethylene membrane.

[0051] The hydrophobic breathable membrane 13 is preferably a polytetrafluoroethylene microporous membrane, a polyvinylidene fluoride microporous membrane, a polypropylene microporous membrane, or a polyethylene microporous membrane.

[0052] Further optimizing the scheme, the water electrolysis chamber 2 includes a device sealing plate 27, in which the anode plate 25, the cathode plate 26 and the alkaline solution electrolysis part are fixedly connected; the alkaline solution electrolysis part is located between the anode plate 25 and the cathode plate 26;

[0053] The bottom end of the hydrophilic membrane 11 extends into the alkaline solution electrolysis part;

[0054] A third seawater matrix flow channel 253 is provided between the inner wall of the device sealing plate 27 and the anode plate 25, and the water inlet end of the third seawater matrix flow channel 253 is connected to the first seawater outlet 143 through the third seawater inlet 252;

[0055] The third seawater matrix flow channel 253 is connected to the cathode plate 26 through the third seawater outlet 254;

[0056] The anode plate 25 is provided with an oxygen outlet 251 for communicating with the alkaline solution electrolysis part. One end of the oxygen outlet 251 is connected to the oxygen generation end of the alkaline solution electrolysis part, and the other end of the oxygen outlet 251 is connected to the oxygen outlet pipe 250. The oxygen outlet pipe 250 is set through the side wall of the device sealing plate 27.

[0057] Further optimizing the scheme, a fourth seawater matrix flow channel 263 is provided between the cathode plate 26 and the inner wall of the device sealing plate 27, the water inlet end of the fourth seawater matrix flow channel 263 is connected to the third seawater outlet 254 through the fourth seawater inlet 264, and the water outlet end of the fourth seawater matrix flow channel 263 is connected to the second seawater inlet 153 through the fourth seawater outlet 262;

[0058] The cathode plate 26 is provided with a hydrogen outlet 261 for communicating with the alkali solution electrolysis part;

[0059] One end of the hydrogen outlet 261 is connected to the hydrogen generation end of the alkali solution electrolysis part, and the other end of the hydrogen outlet 261 is connected to the hydrogen outlet pipe 260, and the hydrogen outlet pipe 260 is set through the side wall of the device sealing plate 27.

[0060] Further optimized solution, the alkaline solution electrolysis part includes an anode catalytic electrode 21 and a cathode catalytic electrode 22, the anode catalytic electrode 21 and the cathode catalytic electrode 22 are respectively located on both sides of the hydrophilic membrane 11, the anode catalytic electrode 21 is arranged close to the anode plate 25, an anode gas diffusion layer 23 is arranged between the anode plate 25 and the anode catalytic electrode 21, and an anode sealing gasket 28 for sealing is sleeved on the outer side of the anode catalytic electrode 21 and the anode gas diffusion layer 23; the anode gas diffusion layer 23 is connected to the oxygen outlet 251;

[0061] The cathode catalytic electrode 22 is arranged close to the cathode plate 26, and a cathode gas diffusion layer 24 is arranged between the cathode catalytic electrode 22 and the cathode plate 26. A cathode sealing gasket 29 for sealing is arranged between the cathode gas diffusion layer 24 and the outer side of the cathode catalytic electrode 22, and the cathode gas diffusion layer 24 is connected to the hydrogen outlet 261.

[0062] The water electrolysis chamber 2 is formed by an anode plate 25, an anode gas diffusion layer 23, an anode catalytic electrode 21, a hydrophilic membrane 11, a cathode catalytic electrode 22, a cathode gas diffusion layer 24, and a cathode plate 26 which are tightly fitted in sequence; to ensure the sealing of the anode and the cathode, an anode sealing gasket 28 is provided around the anode gas diffusion layer 23 and the anode catalytic electrode 21, and a cathode sealing gasket 29 is provided around the cathode catalytic electrode 22 and the cathode gas diffusion layer 24; a device sealing plate 27 is arranged outside the anode plate 25 and the cathode plate 26, and a seawater flow channel is arranged between the anode plate 25 / cathode plate 26 and the inner wall of the device sealing plate 27.

[0063] The anode plate 25 is provided with an oxygen outlet 251, a third seawater inlet 252, a third seawater matrix flow channel 253, and a third seawater outlet 254, wherein the oxygen outlet 251 is connected to the oxygen outlet pipe 250, and the third seawater inlet 252 is connected to the first seawater outlet 143 of the in-situ desalination chamber 1; the cathode plate 26 is provided with a hydrogen outlet 261, a fourth seawater inlet 264, a fourth seawater matrix flow channel 263, and a fourth seawater outlet 262, wherein the hydrogen outlet 261 is connected to the hydrogen outlet pipe 260, and the fourth seawater outlet 262 is connected to the second seawater inlet 153 of the in-situ desalination chamber 1; the third seawater outlet 254 of the anode plate 25 is connected through the fourth seawater inlet 264 of the cathode plate 26; the fourth seawater outlet 262 is connected to the second seawater inlet 153.

[0064] The hydrophilic membrane 11 penetrates the in-situ desalination chamber 1 and the water electrolysis chamber 2 , and a potassium hydroxide solution with a mass content of 30% is stored in the membrane pores of the hydrophilic membrane 11 .

[0065] The electrolysis device is connected to a DC power supply to carry out the seawater electrolysis process. The alkaline electrolyte is a KOH solution with a mass fraction of 30%. The seawater used is taken from the Yellow Sea. The seawater in the seawater buffer tank passes through a security filter and is pumped into the electrolytic cell through a seawater inlet pipe 140. The seawater inlet temperature is 20 degrees Celsius and the inlet flow rate is 80 ml / min.

[0066] Normal temperature seawater first enters the in-situ desalination chamber 1, flows through the first seawater inlet 141, the first seawater matrix flow channel 142, and the first seawater outlet 143 in sequence, then enters the electrolytic water chamber 2 through the third seawater inlet 252, flows through the third seawater matrix flow channel 253 of the anode plate 25, then enters the fourth seawater matrix flow channel 263 of the cathode plate 26 through the third seawater outlet 254 and the fourth seawater inlet 264, then returns to the in-situ desalination chamber 1 through the fourth seawater outlet 262 and the second seawater inlet 153, then flows along the second seawater matrix flow channel 152 to the second seawater outlet 151, and is discharged through the seawater discharge pipe 150. The seawater flows through the water inlet side of the in-situ desalination chamber 1, the outer side of the anode plate of the electrolysis water chamber 2, the outer side of the cathode plate of the electrolysis water chamber 2, and the water outlet side of the in-situ desalination chamber 1 in sequence. The seawater completes partial desalination treatment in the in-situ desalination chamber. The generated desalinated desalinated water enters the hydrophilic membrane 11 and mixes with the original potassium hydroxide solution in the membrane to form an electrolyte. The electrolyte enters the electrolytic cell chamber below due to gravity to undergo a water electrolysis process. When the seawater flows through the electrolysis water chamber, it takes away the waste heat generated by the water electrolysis process, thereby realizing the heat extraction and temperature control process of the seawater.

[0067] The principle of the seawater in-situ desalination process is as follows: after entering the in-situ desalination chamber 1, the normal temperature seawater (i.e., low temperature seawater) first contacts the water-isolating membrane 12 of the in-situ desalination chamber, and then flows through the outer electrode plate of the water electrolysis chamber 2, whereby heat exchange between the water electrolysis chamber 2 and the seawater occurs. The excess heat generated by ohmic loss during the process of hydrogen production by water electrolysis is taken away by the seawater to form high temperature seawater; the high temperature seawater then flows back to the in-situ desalination chamber 1 and contacts the hydrophobic breathable membrane 13. Since the hydrophobic breathable membrane 13, the hydrophilic membrane 11, and the water-isolating membrane 12 are tightly fitted together, the high temperature seawater on the hydrophilic membrane 11 side and the water-isolating membrane 12 side are There is a temperature difference between the high-temperature seawater and the low-temperature seawater. The vapor pressure difference caused by the temperature difference causes some water molecules in the high-temperature seawater to pass through the hydrophobic porous membrane in gaseous form and condense in the middle hydrophilic membrane 11 to form desalinated water. The desalinated water is dissolved with the alkaline electrolyte inside the hydrophilic membrane 11 and flows into the electrolysis water chamber 2 under the action of gravity to replenish the water consumed by electrolysis. The driving force for the in-situ desalination of seawater essentially comes from the waste heat generated in the process of electrolysis of water. In addition, in the present invention, the heat released by the condensation of steam is recovered by the low-temperature seawater just entering the electrolytic cell, thereby avoiding the heat loss and the impact of the discharge of high-temperature seawater on the marine ecology.

[0068] The above-mentioned seawater hydrogen production device without alkali liquid circulation has a current density of 0.7A / cm when the single cell voltage is 1.9V. 2 The purity of the produced hydrogen is 99.2%, and there is no obvious performance degradation after 300 hours of continuous operation.

[0069] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0070] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A seawater hydrogen production system without alkali liquid circulation, characterized in that: include: An in-situ desalination chamber (1) located at the upper part and an electrolytic water chamber (2) located at the lower part, wherein the in-situ desalination chamber (1) is connected to the electrolytic water chamber (2) via a seawater evaporation purification connecting component; The top two sides of the in-situ desalination chamber (1) are respectively connected with a seawater inlet pipe (140) and a seawater discharge pipe (150); The two sides of the middle of the water electrolysis chamber (2) are respectively connected with an oxygen outlet pipe (250) and a hydrogen outlet pipe (260); After entering through the seawater inlet pipe (140), the seawater flows through the outside of the water electrolysis chamber (2) and absorbs heat generated by electrolysis in the water electrolysis chamber (2). The heat causes part of the seawater to generate steam, which enters the water electrolysis chamber (2) through the seawater evaporation purification connection component for electrolysis, and the other part of the seawater flows out through the seawater discharge pipe (150); The in-situ desalination chamber (1) comprises a seawater inlet insulation plate (14) and a seawater outlet insulation plate (15); the water inlet end of the seawater inlet insulation plate (14) is connected to the seawater inlet pipe (140); the seawater evaporation purification communication component is located between the seawater inlet insulation plate (14) and the seawater outlet insulation plate (15); the water outlet end of the seawater inlet insulation plate (14) is connected to the water inlet end of the electrolysis water chamber (2); and the water inlet end of the seawater outlet insulation plate (15) is connected to the water outlet end of the electrolysis water chamber (2); The seawater evaporation purification communication component comprises a water-isolating membrane (12), a hydrophilic membrane (11) and a hydrophobic breathable membrane (13) which are arranged in sequence, the water-isolating membrane (12) is fixedly connected to the side wall of the seawater inlet end insulation board (14), the hydrophobic breathable membrane (13) is fixedly connected to the side wall of the seawater outlet end insulation board (15), and the bottom end of the hydrophilic membrane (11) extends into the electrolytic water chamber (2); The water electrolysis chamber (2) comprises a device sealing plate (27), in which an anode plate (25), a cathode plate (26) and an alkaline solution electrolysis unit are fixedly connected; the alkaline solution electrolysis unit is located between the anode plate (25) and the cathode plate (26); The bottom end of the hydrophilic membrane (11) extends into the alkaline solution electrolysis section; A third seawater matrix flow channel (253) is provided between the inner wall of the device sealing plate (27) and the anode plate (25), and the water inlet end of the third seawater matrix flow channel (253) is connected to the first seawater outlet (143) of the seawater inlet end insulation plate (14) through a third seawater inlet (252); The third seawater matrix flow channel (253) is in communication with the cathode plate (26) via a third seawater outlet (254); A fourth seawater matrix flow channel (263) is provided between the cathode plate (26) and the inner wall of the device sealing plate (27); the water inlet end of the fourth seawater matrix flow channel (263) is connected to the third seawater outlet (254) via a fourth seawater inlet (264); and the water outlet end of the fourth seawater matrix flow channel (263) is connected to the second seawater inlet (153) of the seawater outlet end insulation plate (15) via a fourth seawater outlet (262); The alkaline solution electrolysis unit comprises an anode catalytic electrode (21) and a cathode catalytic electrode (22), wherein the anode catalytic electrode (21) and the cathode catalytic electrode (22) are respectively located on both sides of the hydrophilic membrane (11).

2. The seawater hydrogen production system without alkali liquid circulation according to claim 1 is characterized in that: The seawater inlet insulation plate (14) comprises a first seawater inlet (141), the inlet end of the first seawater inlet (141) is connected to the outlet end of the seawater inlet pipe (140), the outlet end of the first seawater inlet (141) is connected to the inlet end of a first seawater matrix flow channel (142), the outlet end of the first seawater matrix flow channel (142) is connected to the inlet end of the first seawater outlet (143), and the outlet end of the first seawater outlet (143) is connected to the inlet end of the electrolytic water chamber (2).

3. The seawater hydrogen production system without alkali liquid circulation according to claim 1 is characterized in that: The water inlet end of the second seawater inlet (153) of the seawater outlet insulation plate (15) is connected to the water outlet end of the electrolytic water chamber (2), the water outlet end of the second seawater inlet (153) is connected to the water inlet end of the second seawater matrix flow channel (152), the water outlet end of the second seawater matrix flow channel (152) is connected to the water inlet end of the second seawater outlet (151), and the water outlet end of the second seawater outlet (151) is connected to the water inlet end of the seawater discharge pipe (150).

4. The seawater hydrogen production system without alkali liquid circulation according to claim 1 is characterized in that: The anode plate (25) is provided with an oxygen outlet (251) for communicating with the alkaline solution electrolysis section. One end of the oxygen outlet (251) is communicated with the oxygen generation end of the alkaline solution electrolysis section, and the other end of the oxygen outlet (251) is communicated with the oxygen outlet pipe (250). The oxygen outlet pipe (250) is arranged to penetrate the side wall of the device sealing plate (27).

5. The seawater hydrogen production system without alkali liquid circulation according to claim 4 is characterized in that: The cathode plate (26) is provided with a hydrogen outlet (261) for communicating with the alkaline solution electrolysis unit; One end of the hydrogen outlet (261) is connected to the hydrogen generation end of the alkali solution electrolysis part, and the other end of the hydrogen outlet (261) is connected to the hydrogen outlet pipe (260), and the hydrogen outlet pipe (260) is arranged to penetrate the side wall of the device sealing plate (27).

6. The seawater hydrogen production system without alkali liquid circulation according to claim 5 is characterized in that: The anode catalytic electrode (21) is arranged close to the anode plate (25); an anode gas diffusion layer (23) is arranged between the anode plate (25) and the anode catalytic electrode (21); an anode sealing gasket (28) for sealing is sleeved on the outside of the anode catalytic electrode (21) and the anode gas diffusion layer (23); the anode gas diffusion layer (23) is in communication with the oxygen outlet (251); The cathode catalytic electrode (22) is arranged close to the cathode plate (26), a cathode gas diffusion layer (24) is arranged between the cathode catalytic electrode (22) and the cathode plate (26), a cathode sealing gasket (29) for sealing is arranged on the outside of the cathode gas diffusion layer (24) and the cathode catalytic electrode (22), and the cathode gas diffusion layer (24) is connected to the hydrogen outlet (261).

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