Seawater electrolysis hydrogen production system

Abstract

The invention belongs to the technical field of water electrolysis hydrogen production, and particularly relates to a water electrolysis hydrogen production system. According to the technical scheme, a power supply device generates electricity to provide electric energy; the power supply module supplies power to the electrolytic cell module group; the seawater pretreatment module is used for removing impurities in seawater and heating the filtered seawater into high-temperature steam, and the high-temperature steam subjected to heat exchange through the heat exchanger serves as raw material water to be output outwards; raw material water output outwards is mixed with alkali liquor with set concentration and then conveyed to the electrolytic cell module group through a liquid inlet pump; the electrolytic cell module group electrolyzes the mixed liquid, and gas generated by electrolysis and electrolyte enter the gas-liquid treatment system together; and the gas-liquid processor system is used for separating the electrolytic gas from the electrolyte, and the separated electrolyte circularly enters the electrolytic cell module group. Renewable energy sources such as offshore wind energy and photovoltaic energy are used as power sources, seawater is used as a hydrogen production raw material and a heat exchange medium, and the device has the advantages of being economical, feasible and rich in source.

Description

Technical Field

[0001] The invention belongs to the technical field of water electrolysis hydrogen production, and specifically relates to a water electrolysis hydrogen production system. Background Art

[0002] Globally, the hydrogen energy industry is gradually becoming a key direction in the field of energy transformation and sustainable development. Countries regard the hydrogen energy industry as a strategic industry and strengthen policy guidance.

[0003] At present, the raw water used in water electrolysis hydrogen production equipment has high requirements for water quality. Impurities, dissolved substances and ions in the water will affect the effect of electrolysis and the purity of hydrogen production. Therefore, deionized water or high-purity water treated by pure water equipment is used as the source of raw water. Offshore wind power hydrogen production equipment is located in the marine environment and lacks fresh water resources. Therefore, using seawater as the raw material source and combining offshore wind power as a renewable power source is an economically feasible technical solution. Summary of the invention

[0004] The purpose of the present invention is to provide a seawater electrolysis hydrogen production system in order to fully utilize marine resources.

[0005] The technical solution of the present invention is: a seawater electrolysis hydrogen production system, including: a power supply device, a power module, a seawater pretreatment module, a heat exchanger, a liquid inlet pump, an electrolyzer module group and a gas-liquid processor system.

[0006] The power supply device generates electricity to provide electrical energy.

[0007] The power module is connected to the power supply device and the electrolytic cell module group to provide power for the electrolytic cell module group.

[0008] The seawater pretreatment module includes: a filtering device and a heating device; the filtering device removes most of the impurities in the seawater, such as barnacles, seaweed, etc., to reduce the burden of the electrolysis device and improve the hydrogen production efficiency; the heating device heats the filtered seawater into high-temperature steam, and the high-temperature steam after heat exchange in the heat exchanger is output as raw water.

[0009] The raw water output is mixed with alkaline solution of set concentration and then transported to the electrolytic cell module group through the liquid inlet pump.

[0010] The electrolytic cell module group electrolyzes the mixed liquid, and the gas generated by the electrolysis enters the gas-liquid treatment system together with the electrolyte.

[0011] The gas-liquid processor system is used to separate the electrolytic gas from the electrolyte, and the separated electrolyte is circulated into the electrolytic cell module group.

[0012] On the basis of the above scheme, further, the power supply device utilizes offshore renewable energy to generate electricity, including: offshore wind energy, offshore photovoltaic energy, and offshore wave energy.

[0013] On the basis of the above solution, further, the power supply module includes a rectifier transformer or a high-frequency switching power supply.

[0014] On the basis of the above scheme, further, the heat exchanger, on the one hand, exchanges heat with the high-temperature steam output by the heating device, and sends the liquid seawater after heat exchange to the filtering device; on the other hand, the heat exchanger exchanges heat with the electrolyte separated by the gas-liquid processor system, and the electrolyte after heat exchange is recycled into the electrolytic cell module group to achieve reasonable utilization of waste heat.

[0015] On the basis of the above scheme, further, the gas-liquid processor system includes: a hydrogen separator and an oxygen separator respectively connected to the electrolyzer module group, and the hydrogen and oxygen generated by the electrolysis of the electrolyzer module group are output after passing through the hydrogen separator and the oxygen separator, and are collected, stored or discharged.

[0016] On the basis of the above scheme, further, the electrolyzer module group includes multiple groups of alkaline electrolyzers connected in series and / or in parallel, and the hydrogen outlets of the multiple groups of alkaline electrolyzers connected in series and / or in parallel are collected together to the hydrogen separator, and the oxygen outlets are collected together to the oxygen separator.

[0017] On the basis of the above scheme, further, the power supply device includes a power detection function, which predicts the power generation according to the power generation power of offshore wind energy, offshore photovoltaic energy and offshore wave energy; the electrolytic cell module group controls the start and stop of multiple groups of alkaline electrolytic cells connected in series and / or in parallel according to the power predicted by the power supply device.

[0018] Beneficial effects:

[0019] (1) The present invention uses offshore wind energy, photovoltaic and other renewable energy sources as the power source, and uses seawater as the hydrogen production raw material and heat exchange medium, which has the advantages of being economically feasible and having abundant sources.

[0020] (2) The present invention can realize the prediction of offshore wind power and photovoltaic power according to the power detection device, so as to adjust the start and stop of single / multiple module groups, realize large-scale power regulation, and effectively cope with the power fluctuation of the offshore hydrogen production system; at the same time, it avoids the excessive heat release and high-power carrying capacity problems of a single large-gas-production hydrogen production equipment under low-power conditions, thereby improving the overall energy utilization efficiency.

[0021] (3) The heat exchanger in the present invention exchanges heat with the alkaline electrolytic mixed liquid and recycles it; seawater is used as the heat exchange medium to exchange heat with the high-temperature steam, and the seawater after heat exchange enters through the filtering device as raw water, so as to achieve reasonable utilization of waste heat.

[0022] (4) The present invention is economically feasible, has abundant sources and is highly efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the alkaline electrolytic cells in the electrolytic cell block of the present invention when they are connected in series;

[0025] Figure 3 It is a schematic structural diagram of the alkaline electrolytic cells in the electrolytic cell block of the present invention when they are connected in parallel;

[0026] Figure 4 It is a schematic diagram of the structure when the alkaline electrolytic cells in the electrolytic cell block of the present invention are connected in series and in parallel;

[0027] In the figure: 1-power supply device, 2-power module, 3-filter device, 4-heating device, 5-heat exchanger, 6-alkali solution, 7-liquid inlet pump, 8-electrolyzer module group, 9-hydrogen separator, 10-oxygen separator. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0029] Embodiment 1:

[0030] See attached Figure 1 A seawater electrolysis hydrogen production system includes: a power supply device 1, a power module 2, a seawater pretreatment module, a heat exchanger 5, a liquid inlet pump 7, an electrolyzer module group 8 and a gas-liquid processor system.

[0031] The power supply device 1 uses offshore renewable energy to generate electricity, including offshore wind energy, offshore photovoltaic energy, and offshore wave energy. The power supply device 1 uses a direct current or alternating current output mode.

[0032] The power module 2 is connected to the power supply device 1 and the electrolytic cell module group 8 to provide power for the electrolytic cell module group 8. The power module 2 includes a rectifier transformer or a high-frequency switching power supply. The power module 2 converts the output of the power supply device 1 into direct current of the voltage required by the electrolytic cell module group 8.

[0033] The seawater pretreatment module includes: a filtering device 3 and a heating device 4; the filtering device 3 removes most of the impurities in the seawater, such as barnacles, seaweed, etc., to reduce the burden of the electrolysis device and improve the hydrogen production efficiency; the heating device 4 heats the filtered seawater into high-temperature steam, and the high-temperature steam after heat exchange in the heat exchanger 5 is output as raw water.

[0034] The raw water outputted outward is mixed with the alkaline solution 6 of set concentration and then transported to the electrolytic cell module group 8 through the liquid inlet pump 7.

[0035] See attached Figure 2 , 34. The electrolyzer module group 8 electrolyzes the mixed liquid, and the gas and electrolyte generated by the electrolysis enter the gas-liquid treatment system together. The electrolyzer module group 8 includes multiple groups of alkaline electrolyzers connected in series and / or in parallel, and the hydrogen outlets of the multiple groups of alkaline electrolyzers connected in series and / or in parallel are collected together to the hydrogen separator 9, and the oxygen outlets are collected together to the oxygen separator 10.

[0036] The gas-liquid processor system is used to separate the electrolytic gas from the electrolyte, and the separated electrolyte is circulated into the electrolyzer module group 8. The gas-liquid processor system includes: a hydrogen separator 9 and an oxygen separator 10 respectively connected to the electrolyzer module group 8. The hydrogen and oxygen generated by the electrolysis of the electrolyzer module group 8 are output after passing through the hydrogen separator 9 and the oxygen separator 10, and are collected, stored or emptied. Specifically, the mixture of hydrogen and alkali liquid enters the hydrogen separator 9, and the gas-liquid separation is carried out under the action of gravity. The hydrogen enters the hydrogen scrubber from the upper pipeline, and is cooled and washed by the scrubber to minimize the alkali content and water content in the gas. Finally, the hydrogen is emptied or collected through a membrane regulating valve, and the alkali liquid is returned to the electrolyzer for recycling after heat exchange to ensure the continuous operation of the hydrogen production system; the oxygen and alkali liquid treatment process electrolyzed by the electrolysis module is the same as the above process.

[0037] Preferably, the electrolyzer module group 8 shares a set of gas-liquid processor system, which can automatically adjust the opening of the hydrogen-side pneumatic valve and the oxygen-side pneumatic valve by the alkali liquid flow value measured by the flow meter. When one of the electrolyzers is shut down / failed, the alkali liquid mixed liquid flow rate decreases, and the opening of the pneumatic ball valve at the hydrogen side outlet and the pneumatic ball valve at the oxygen side outlet of the electrolyzer becomes smaller, preventing hydrogen and oxygen from mixing and affecting the life of the electrolyzer.

[0038] Preferably, the heat exchange medium of the heat exchanger 5 is seawater. On the one hand, the heat exchanger 5 exchanges heat with the high-temperature steam output by the heating device 4, and sends the liquid seawater after heat exchange to the filtering device 3, so as to preheat the seawater raw material in advance; on the other hand, the heat exchanger 5 exchanges heat with the electrolyte separated by the gas-liquid processor system, and the electrolyte after heat exchange is recycled into the electrolytic cell module group 8, so as to make rational use of the waste heat.

[0039] Preferably, the power supply device 1 includes a power detection function, and predicts the power generation according to the power generation of offshore wind energy, offshore photovoltaic energy, and offshore wave energy; the electrolyzer module group 8 controls the start and stop of multiple groups of alkaline electrolyzers connected in series and / or in parallel according to the power level predicted by the power supply device 1. The electrolyzer module group 8 can increase or stop the gas production of certain electrolyzers according to the hydrogen production demand and power size, so that multiple electrolyzers correspond to a set of gas-liquid separators, thereby maximizing the use efficiency of the gas-liquid processor.

[0040] Embodiment 2:

[0041] The system described in Example 1 is run:

[0042] Offshore wind power or photovoltaic power is used as the power supply device 1. The power is converted into a direct current that can be used for water electrolysis through a rectifier transformer or a high-frequency switching power supply in the power module 2. The electrolyzer module group 8 adopts an alkaline water electrolysis electrolyzer, and the total hydrogen production scale is 1000Nm3 / h (the power adjustment range is 10-150%). It can be designed as a plurality of electrolyzers with a hydrogen production capacity in parallel or in series, with a maximum gas production capacity of 1500Nm3 / h and a total gas production capacity range of 200-1500Nm3 / h. The equipment operation control is as follows:

[0043] 1) Gas production: 0~220Nm3 / h;

[0044] The 1# electrolytic cell is operated alone, and the process parameters are optimized and adjusted to meet the conditions for stable operation and to ensure that the gas indicators (purity and dew point) meet the standards;

[0045] 2) Gas production: 220Nm3 / h~1000Nm3 / h;

[0046] When the system input energy is within the above range, priority is given to ensuring the operation of electrolytic cell #1, gradually opening electrolytic cell #2 and ensuring the operating load to 100Nm3 / h, and gradually increasing or decreasing the operating load of electrolytic cell #1. When the operating load of electrolytic cell #1 reaches 220Nm3 / h, gradually increase the operating load of electrolytic cell #2.

[0047] When the operating load decreases, priority is given to gradually reducing the load of 2# electrolytic cell to 100Nm3 / h. When the load of 1# electrolytic cell reaches 220Nm3 / h, 2# electrolytic cell is shut down and controlled solely by 1# electrolytic cell.

[0048] 3) Gas production 1000Nm3 / h~1500Nm3 / h When the system input energy is >1000Nm3 / h, the 4 electrolytic cells jointly absorb the wide power fluctuation, and the 5# electrolytic cell participates in the regulation and is adjusted according to step 2.

[0049] During the above operation, the electrolyzer module group 8 can start the nth module in advance according to the hydrogen production demand and power size to achieve rapid startup control of the equipment.

[0050] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A seawater electrolysis hydrogen production system, characterized in that: include: A power supply device (1), a power module (2), a seawater pretreatment module, a heat exchanger (5), a liquid inlet pump (7), an electrolyzer module group (8) and a gas-liquid treatment system; The power supply device (1) generates electricity to provide electrical energy; The power module (2) is connected to the power supply device (1) and the electrolytic cell module group (8) to provide power for the electrolytic cell module group (8); The seawater pretreatment module comprises: a filtering device (3) and a heating device (4); the filtering device (3) removes impurities in the seawater; the heating device (4) heats the filtered seawater into high-temperature steam, and the high-temperature steam after heat exchange in the heat exchanger (5) is output as raw water. The raw water output outward is mixed with an alkali solution (6) of a set concentration and then transported to the electrolytic cell module group (8) via the liquid inlet pump (7); The electrolytic cell module group (8) electrolyzes the mixed liquid, and the gas generated by the electrolysis and the electrolyte enter the gas-liquid processing system together; The gas-liquid processor system is used to separate the electrolytic gas from the electrolyte, and the separated electrolyte is circulated into the electrolytic cell module group (8).

2. A seawater electrolysis hydrogen production system as claimed in claim 1, characterized in that: The power supply device (1) generates electricity using offshore renewable energy, including offshore wind energy, offshore photovoltaic energy, and offshore wave energy.

3. A seawater electrolysis hydrogen production system as claimed in claim 1 or 2, characterized in that: The power supply module (2) comprises a rectifier transformer or a high-frequency switching power supply.

4. A seawater electrolysis hydrogen production system as claimed in claim 1 or 2, characterized in that: On the one hand, the heat exchanger (5) exchanges heat with the high-temperature steam output by the heating device (4) and delivers the liquid seawater after the heat exchange to the filtering device (3); on the other hand, the heat exchanger (5) exchanges heat with the electrolyte separated by the gas-liquid treatment system, and the electrolyte after the heat exchange is recycled into the electrolytic cell module group (8).

5. A seawater electrolysis hydrogen production system as claimed in claim 2, characterized in that: The gas-liquid treatment system comprises: a hydrogen separator (9) and an oxygen separator (10) respectively connected to the electrolyzer module group (8); hydrogen and oxygen generated by electrolysis of the electrolyzer module group (8) are output after passing through the hydrogen separator (9) and the oxygen separator (10) to be collected, stored or discharged.

6. A seawater electrolysis hydrogen production system as claimed in claim 5, characterized in that: The electrolyzer module group (8) comprises a plurality of groups of alkaline electrolyzers connected in series and / or in parallel, the hydrogen outlets of the plurality of groups of alkaline electrolyzers connected in series and / or in parallel are collectively connected to a hydrogen separator (9), and the oxygen outlets are collectively connected to an oxygen separator (10).

7. A seawater electrolysis hydrogen production system as claimed in claim 6, characterized in that: The power supply device (1) includes a power detection function, and predicts the power generation according to the power generation of offshore wind energy, offshore photovoltaic energy, and offshore wave energy; the electrolytic cell module group (8) controls the start and stop of multiple groups of alkaline electrolytic cells connected in series and / or in parallel according to the power level predicted by the power supply device (1).

Images