CN116024592A - A kind of electrolytic hydrogen production system and electrolytic hydrogen production method - Google Patents

Abstract

The invention discloses an electrolysis hydrogen production system and an electrolysis hydrogen production method. The electrolytic hydrogen production system includes: an electrolytic cell, a first gas-liquid separator and a second gas-liquid separator; the cathode side of the electrolytic cell communicates with the first gas-liquid separator; the anode side of the electrolytic cell communicates with the second gas-liquid separator The electrolytic hydrogen production system also includes a first lye input pipeline, which is respectively connected to the first gas-liquid separator, the second gas-liquid separator and the electrolytic cell; also includes: the third gas-liquid separator and the fourth gas-liquid separator Separator; the cathode side of the electrolytic cell communicates with the third gas-liquid separator; the anode side of the electrolytic cell communicates with the fourth gas-liquid separator; the electrolytic hydrogen production system also includes a second lye input pipeline, respectively connected to the Three gas-liquid separators, the fourth gas-liquid separator and the first lye input pipeline; the ratio of the capacity of the first gas-liquid separator to the capacity of the third gas-liquid separator is greater than 3:1; the second gas-liquid separation The ratio of the capacity of the tank to the capacity of the fourth gas-liquid separator is greater than 3:1.

Description

A kind of electrolytic hydrogen production system and electrolytic hydrogen production method

technical field

The invention relates to the technical field of hydrogen production, in particular to an electrolytic hydrogen production system and an electrolytic hydrogen production method.

Background technique

Hydrogen is an energy carrier with both material and energy attributes, and plays an important role in industrial production, electric energy carrier, electrosynthetic fuel, heating and transportation, involving various fields of energy, and in global decarbonization has a high potential market value. Renewable energy such as wind power is intermittent, cyclical, and regional, and there are challenges for large-scale energy storage across seasons. Using renewable energy to electrolyze water to produce hydrogen is an ideal large-scale, long-term energy storage method. At the same time, hydrogen is also an important fuel and chemical raw material in the fields of transportation, industry, electricity, and construction.

Among the mature electrolyzed water hydrogen production technologies, the alkaline electrolyzed water hydrogen production technology is relatively mature, the process is relatively simple, and the cost is relatively low, but the bottleneck lies in the relatively low working current density (less than 0.5A/cm ² ), the efficiency of the electrolyzer (60-75%) still needs to be improved. Counting from low power start-up, the load operating range of the electrolyzer is only 15%-100%. The operating load is very low at low power, and the multi-equipment coordination control strategy is complicated in a large-scale state , The volume is large, and it takes a long time from normal temperature to the temperature corresponding to the rated power. Taking the temperature corresponding to the outlet of the electrolyzer at the rated power as 95°C as an example, the lye equipment with a hydrogen production capacity of 500Nm ³ /h starts at normal temperature to The time required for 95°C is close to 3-4 hours. During this process, the hydrogen production of the rated power cannot be achieved, and the consumption of electric energy is the same as that of the rated power operation. This has caused a large amount of waste of electric energy, and at the same time the time required for the hydrogen production to reach the required output has increased, further increasing the consumption of electric energy. In addition, when the temperature does not reach the temperature corresponding to the rated power, the hydrogen needs to be vented, so this part of the vented hydrogen also causes waste.

Therefore, a solution is needed to shorten the time of the low power period during cold start, so as to reduce the power consumption during the low power period and reduce the waste of hydrogen.

Contents of the invention

In view of the above problems, the present invention provides an electrolytic hydrogen production system and an electrolytic hydrogen production method to solve the problem of electric energy waste in low power periods during cold start of electrolytic hydrogen production.

The invention provides an electrolytic hydrogen production system, comprising: an electrolytic cell, a first gas-liquid separator, and a second gas-liquid separator; the cathode side of the electrolytic cell and the first gas-liquid separator pass through the first gas-liquid The liquid output pipeline is connected; the anode side of the electrolytic cell is communicated with the second gas-liquid separator through the second gas-liquid output pipeline; the electrolytic hydrogen production system also includes a first lye input pipeline, the The first lye input pipeline is respectively connected to the first gas-liquid separator, the second gas-liquid separator and the electrolytic cell; the electrolytic hydrogen production system also includes: a third gas-liquid separator and a first Four gas-liquid separators; the cathode side of the electrolytic cell communicates with the third gas-liquid separator through the third gas-liquid output pipeline; the anode side of the electrolytic cell communicates with the fourth gas-liquid separator It is communicated through the fourth gas-liquid output pipeline; the electrolytic hydrogen production system also includes a second lye input pipeline, and the second lye input pipeline communicates with the third gas-liquid separator and the fourth gas-liquid separator respectively. Gas-liquid separator and the first lye input pipeline; the ratio of the capacity of the first gas-liquid separator to the capacity of the third gas-liquid separator is greater than 3:1; the second gas-liquid separation The ratio of the capacity of the tank to the capacity of the fourth gas-liquid separator is greater than 3:1.

Optionally, the electrolytic cell has a cathode side outlet, the cathode side outlet is close to the cathode of the electrolytic cell, and the cathode side outlet is suitable for the alkali liquor and the gas generated on the cathode side to flow out of the electrolytic cell; The cathode side outlet of the tank communicates with the mixing inlet of the first gas-liquid separator through the first gas-liquid output pipeline; the electrolytic cell has an anode side outlet, and the anode side outlet is close to the anode of the electrolytic cell, the The anode side outlet is suitable for the alkali liquor and the gas generated on the anode side to flow out of the electrolytic cell; the anode side outlet of the electrolytic cell is connected to the mixing inlet of the second gas-liquid separator through the second gas-liquid output pipeline; The electrolytic cell also includes a lye inlet, and the first lye input pipeline communicates with the lye inlet and the lye outlet of the first gas-liquid separator, and simultaneously communicates with the lye inlet and the second gas-liquid separator. The alkali liquor outlet of the second gas-liquid separator.

Optionally, the mixing inlet of the third gas-liquid separator communicates with the first gas-liquid output pipeline through the third gas-liquid output pipeline; the mixing inlet of the fourth gas-liquid separator passes through the The fourth gas-liquid output pipeline communicates with the second gas-liquid output pipeline; the first lye input pipeline is provided with a second lye input pipeline inlet, and the second lye input pipeline communicates with the The lye outlet of the third gas-liquid separator and the inlet of the second lye input pipeline are simultaneously connected to the lye outlet of the fourth gas-liquid separator and the inlet of the second lye input pipeline.

Optionally, the electrolytic hydrogen production system further includes: a first gas scrubbing device and a second gas scrubbing device; the gas inlet of the first gas scrubbing device communicates with the gas of the first gas-liquid separator through the first gas scrubbing pipeline Outlet; the lye outlet of the first gas scrubber is connected to the lye inlet of the first gas-liquid separator through the first liquid return pipeline; the gas inlet of the second gas scrubber is through the second gas scrubber The gas outlet of the second gas-liquid separator is connected; the lye outlet of the second gas scrubber is connected with the lye inlet of the second gas-liquid separator through the second liquid return pipeline.

Optionally, the gas inlet of the first gas scrubbing device is connected to the gas outlet of the third gas-liquid separator through a third gas scrubbing pipeline; the alkali liquor outlet of the first gas scrubbing device is connected through a third liquid return pipe The road is connected with the lye inlet of the third gas-liquid separator; the gas inlet of the second gas scrubber is connected with the gas outlet of the fourth gas-liquid separator through the fourth gas scrubbing pipeline; the second gas scrubber The lye outlet of the device is connected to the lye inlet of the fourth gas-liquid separator through the fourth liquid return pipeline.

Optionally, the first gas-liquid output pipeline is provided with a first regulating valve close to the first gas-liquid separator; the second gas-liquid output pipeline is close to the second gas-liquid separator. The second regulating valve is provided on the side; the third gas-liquid output pipeline is provided with a third regulating valve; the fourth gas-liquid output pipeline is provided with a fourth regulating valve; the third liquid return pipeline is provided with The fifth regulating valve; the fourth liquid return pipeline is provided with a sixth regulating valve; the second lye input pipeline is provided with a seventh regulated valve near the entrance of the second lye input pipeline.

Optionally, the first lye input pipeline is provided with a variable frequency lye pump near the lye inlet side of the electrolytic cell.

Optionally, an lye cooler is arranged between the frequency conversion lye pump and the lye inlet.

Optionally, the electrolytic hydrogen production system further includes: a first gas cooler and a second gas cooler; the first gas cooler communicates with the gas outlet of the first scrubbing device; the second gas cooler communicates with The gas outlet of the second scrubber.

Optionally, the electrolytic hydrogen production system further includes: a water tank; the water tank communicates with the first gas scrubber to replenish water for the first gas scrubber; the water tank communicates with the first gas scrubber on a pipeline There is a water pump.

The present invention also provides an electrolytic hydrogen production method using the electrolytic hydrogen production system provided by the present invention; the electrolytic hydrogen production system has two working modes, and in the first working mode, it includes the following steps: opening the first alkali liquid input pipeline; control the circulating flow of alkali liquor between the electrolytic cell and the first gas-liquid separator, and simultaneously control the circulating flow of alkali liquor between the electrolytic cell and the second gas-liquid separator; The first gas-liquid separator separates the hydrogen from the lye; the oxygen is separated from the lye from the second gas-liquid separator; in the second working mode, the following steps are included: opening the first lye input pipe road, and open the second lye input pipeline, so that the second lye input pipeline is communicated with the first lye input pipeline; Circulating flow between the liquid separators, while controlling the circulating flow of alkali liquor between the electrolytic cell and the fourth gas-liquid separator; separating the hydrogen gas from the alkali liquor from the third gas-liquid separator; The gas-liquid separator separates the oxygen from the lye.

Optionally, the electrolytic hydrogen production system uses the first working mode when the lye input flow of the electrolytic cell is greater than 1/3 of the rated lye input flow of the electrolytic cell; the electrolytic hydrogen production system When the lye input flow of the electrolytic cell is less than 1/3 of the rated lye input flow of the electrolytic cell, the second working mode is used.

The beneficial effects of the present invention are:

In the electrolytic hydrogen production system of the present invention, by setting the third gas-liquid separator and the fourth gas-liquid separator, the ratio of the capacity of the first gas-liquid separator to the capacity of the third gas-liquid separator is greater than 3:1, and the second The ratio of the capacity of the gas-liquid separator to the capacity of the fourth gas-liquid separator is greater than 3:1, which can realize two sets of gas-liquid separation cycles, that is, the electrolytic cell-the first gas-liquid separator and the second gas-liquid separator The large-capacity (high-flow) circulation of the electrolytic cell-the third gas-liquid separator and the small-capacity (low flow) circulation of the fourth gas-liquid separator. Therefore, in the cold start process, that is, the low-power period of the low-temperature electrolytic cell, a small-capacity (low-flow) cycle can be used, and the flow of lye corresponds to low power. Because the flow is low at this time, the heat exchange with the external environment is less , the heat dissipation is low, and at the same time, the power supply to the electrolytic cell is the power supply that meets the rated power state. The heat production of the electrolytic cell is mainly affected by the heat generation of the electrode, so the heat production of the electrolytic cell is not reduced, which can improve the electrolytic cell. The speed of heating up shortens the time of low power period during cold start and reduces the waste of electric energy during low power period. From the low power period to the rated power, the frequency conversion pump can be adjusted according to the temperature of the electrolytic tank to adjust the flow of lye, so that the flow of lye and the temperature of the electrolytic tank can be adjusted linearly. When the temperature of the electrolytic cell meets the temperature requirement corresponding to the rated power, a large-capacity (high-flow) cycle is adopted, and the flow of the lye corresponds to the rated power, and the flow and temperature are linearly adjusted. It can be adjusted to the rated power state in time to meet the production demand.

In the electrolytic hydrogen production method of the present invention, using the electrolytic hydrogen production system provided by the present invention, different large-capacity cycles and small-capacity cycles can be realized respectively through the control of pipeline flow, so as to cope with different power periods. Therefore, the time of the low-power period during cold start can be shortened through the small-capacity cycle, and the waste of electric energy during the low-power period can be reduced. And it can be adjusted to the rated power state of the large-capacity cycle in time to meet the production demand.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

Fig. 1 is the schematic diagram of the electrolytic hydrogen production system of comparative example;

Fig. 2 is a schematic diagram of an electrolytic hydrogen production system according to an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

comparative example

Referring to FIG. 1 , FIG. 1 is a schematic diagram of an electrolytic hydrogen production system of a comparative example, in which hollow arrows indicate the flow direction of gas, and solid arrows indicate the flow direction of lye. An electrolytic hydrogen production system 100 includes an electrolytic cell 110 , a first gas-liquid separator 121 and a second gas-liquid separator 122 .

The electrolytic cell 110 has a cathode-side outlet. The cathode side outlet is close to the cathode of the electrolytic cell 110 (cathode position is not shown in the figure), and the cathode side outlet is suitable for the alkali liquor and the gas (hydrogen) generated on the cathode side to flow out of the electrolytic cell. The cathode side outlet of the electrolytic cell is connected to the inlet of the first gas-liquid separator 121 . Hydrogen is produced at the negative electrode of the electrolytic cell 110, and enters the first gas-liquid separator 121 with the lye flowing out of the electrolytic cell, and is separated from the first gas-liquid separator 121 to the first gas scrubber 131, and the first gas scrubber 131 will scrub The degassed gas is discharged backward, and the remaining alkali liquor flows back to the first gas-liquid separator 121 . The first gas-liquid separator 121 feeds the lye back to the electrolytic cell 110 through the lye input pipeline to continue circulation.

The electrolytic cell 110 has an anode-side outlet. The anode side outlet is close to the anode of the electrolytic cell 110 (the position of the anode is not shown in the figure), and the anode side outlet is suitable for the alkali liquor and the gas (oxygen) generated on the anode side to flow out of the electrolytic cell. The anode side outlet of the electrolytic cell is connected to the inlet of the second gas-liquid separator 122 through the second gas-liquid output pipeline 142 . Oxygen is produced at the anode of the electrolytic cell 110, and enters the second gas-liquid separator 122 with the lye flowing out of the electrolytic cell, and is separated from the second gas-liquid separator 122 to the second gas scrubber 132, and the second gas scrubber 132 will scrub The degassed gas is discharged backwards, and the remaining alkali liquor flows back to the second gas-liquid separator 122 . The second gas-liquid separator 122 feeds the lye back to the electrolytic cell 110 through the lye input pipeline.

The electrolytic cell 110 has an inlet for circulating lye, the inlet is located in the middle of the electrolytic cell, and the lye input pipeline communicates with the inlet, and communicates with the liquid outlet of the first gas-liquid separator 121 and the liquid of the second gas-liquid separator 122 At the outlet, the lye flowing out of the first gas-liquid separator 121 and the second gas-liquid separator 122 merges into the lye input pipeline and enters the electrolytic cell to form a mixed circulation. A lye pump 140 is provided on the side of the lye input pipeline close to the electrolyzer to provide lye circulation power. An lye cooler 150 is arranged between the lye pump 140 and the electrolyzer 110 to control the temperature of the lye entering the electrolyzer 110 .

In such an electrolytic hydrogen production system, at cold start, the temperature of the electrolyzer is relatively low, and the electrolysis rate is relatively low, while the consumption of electric energy is the same as that of the rated power operation. This has caused a large amount of waste of electric energy, and at the same time the time required for the hydrogen production to reach the required output has increased, further increasing the consumption of electric energy.

Example 1

Referring to Fig. 2, Fig. 2 is a schematic diagram of an electrolytic hydrogen production system according to an embodiment of the present invention, in which hollow arrows indicate the gas flow direction, and solid arrows indicate the lye flow direction. This embodiment provides an electrolytic hydrogen production system 200, including:

Electrolyzer 210 , first gas-liquid separator 221 and second gas-liquid separator 222 . The cathode side of the electrolytic cell 210 communicates with the first gas-liquid separator 221 through a first gas-liquid output pipeline. The anode side of the electrolytic cell 210 communicates with the second gas-liquid separator 222 through a second gas-liquid output pipeline. The electrolytic hydrogen production system 200 also includes a first lye input pipeline, which is respectively connected to the first gas-liquid separator 221 , the second gas-liquid separator 222 and the electrolytic cell 210 .

The electrolytic hydrogen production system further includes: a third gas-liquid separator 223 and a fourth gas-liquid separator 224 . The cathode side of the electrolytic cell 210 communicates with the third gas-liquid separator 223 through a third gas-liquid output pipeline. The anode side of the electrolytic cell 210 communicates with the fourth gas-liquid separator 224 through a fourth gas-liquid output pipeline. The electrolytic hydrogen production system 200 also includes a second lye input pipeline, which is respectively connected to the third gas-liquid separator 223 , the fourth gas-liquid separator 224 and the first lye input pipeline.

The ratio of the capacity of the first gas-liquid separator 221 to the capacity of the third gas-liquid separator 223 is greater than 3:1.

The ratio of the capacity of the second gas-liquid separator 222 to the capacity of the fourth gas-liquid separator 224 is greater than 3:1.

In the electrolytic hydrogen production system 200 of this embodiment, by setting the third gas-liquid separator 223 and the fourth gas-liquid separator 224, the ratio of the capacity of the first gas-liquid separator 221 to the capacity of the third gas-liquid separator 223 is greater than 3:1, the ratio of the capacity of the second gas-liquid separator 222 to the capacity of the fourth gas-liquid separator 224 is greater than 3:1, and two sets of gas-liquid separation cycles can be realized, that is, the electrolytic cell 210-the first gas-liquid Large capacity (high flow) circulation of separator 221 and second gas-liquid separator 222 and small capacity (low flow) circulation of electrolytic cell 210-third gas-liquid separator 223 and fourth gas-liquid separator 224. Thereby can adopt small capacity (low flow rate) circulation in the cold start process, promptly electrolyzer 210 low-temperature period of low power, the lye flow corresponds to when low power, because the flow rate is low at this moment, the heat exchange with external environment is comparatively small. less heat dissipation, and at the same time, the power supply to the electrolytic cell 210 is the power supply that meets the rated power state, and the heat production of the electrolytic cell 210 is mainly affected by the heat generation of the electrodes, so the heat production of the electrolytic cell is not reduced, so that it can be Increase the heating speed of the electrolytic cell 210, shorten the time of the low power period during cold start, and reduce the waste of electric energy during the low power period. When the temperature of the electrolytic cell 210 meets the temperature requirement corresponding to the rated power, a large-capacity (high-flow) cycle is adopted, the flow of the lye corresponds to the rated power, and the flow and temperature are linearly adjusted. It can be adjusted to the rated power state in time to meet the production demand.

In this embodiment, the electrolytic cell 210 has a cathode side outlet, the cathode side outlet is close to the cathode of the electrolytic cell 210 , and the cathode side outlet is suitable for the alkali liquor and the gas generated on the cathode side to flow out of the electrolytic cell 210 . The cathode side outlet of the electrolytic cell 210 is connected to the mixing inlet of the first gas-liquid separator 221 through the first gas-liquid output pipeline. The electrolytic cell 210 has an anode side outlet close to the anode of the electrolytic cell 210 , the anode side outlet is suitable for the alkali liquor and the gas generated on the anode side to flow out of the electrolytic cell 210 . The anode side outlet of the electrolytic cell 210 is connected to the mixing inlet of the second gas-liquid separator 222 through the second gas-liquid output pipeline. Electrolyzer 210 also comprises lye inlet, and the lye outlet that the first lye input pipeline communicates with lye inlet and the first gas-liquid separator 221 communicates with the lye outlet of lye inlet and the second gas-liquid separator 222 simultaneously .

Further, the mixing inlet of the third gas-liquid separator 223 communicates with the first gas-liquid output pipeline through the third gas-liquid output pipeline. The mixing inlet of the fourth gas-liquid separator 224 communicates with the second gas-liquid output pipeline through the fourth gas-liquid output pipeline. The first lye input pipeline is provided with the second lye input pipeline inlet, and the second lye input pipeline is connected with the lye outlet of the third gas-liquid separator 223 and the second lye input pipeline inlet, and communicates with the second lye input pipeline inlet simultaneously. The lye outlet of the four gas-liquid separators 224 and the second lye input pipeline inlet.

In this embodiment, the electrolytic hydrogen production system 200 further includes: a first scrubbing device 231 and a second scrubbing device 232 . The gas inlet of the first gas scrubbing device 231 is connected to the gas outlet of the first gas-liquid separator 221 through a first gas scrubbing pipeline. The lye outlet of the first scrubber 231 is connected to the lye inlet of the first gas-liquid separator 221 through the first liquid return pipeline. The gas inlet of the second gas scrubbing device 232 is connected to the gas outlet of the second gas-liquid separator 222 through a second gas scrubbing pipeline. The lye outlet of the second scrubber 232 is connected to the lye inlet of the second gas-liquid separator 222 through the second liquid return pipeline.

Further, the gas inlet of the first gas scrubbing device 231 is connected to the gas outlet of the third gas-liquid separator 223 through a third gas scrubbing pipeline. The lye outlet of the first scrubber 231 is connected to the lye inlet of the third gas-liquid separator 223 through the third liquid return pipeline. The gas inlet of the second gas scrubbing device 232 is connected to the gas outlet of the fourth gas-liquid separator 224 through a fourth gas scrubbing pipeline. The lye outlet of the second scrubber 232 is connected to the lye inlet of the fourth gas-liquid separator 224 through the fourth liquid return pipeline.

In different embodiments, the first gas-liquid separator 221 and the third gas-liquid separator 223 are connected to the gas pipeline of the first gas scrubber 231, and can be connected to different inlets through pipelines, or can be connected through When the lines are joined together, they go into the same inlet. Similarly, the second gas-liquid separator 222 and the fourth gas-liquid separator 224 are connected to the gas pipeline of the second gas scrubber 232, and can be connected to different inlets through pipelines, or can be connected through pipelines. Once together, enter the same entrance. The lye inlet and mixing inlet of each gas-liquid separator are different inlets.

In this embodiment, a first regulating valve a is provided on the side of the first gas-liquid output pipeline close to the first gas-liquid separator 221 .

The side close to the first gas-liquid separator 221 means that since the third gas-liquid output pipeline communicates with the first gas-liquid output pipeline, the connecting point of the two pipelines is used as the calibration point, which is close to the first gas-liquid separator 221. side.

A second regulating valve b is provided on the side 222 of the second gas-liquid output pipeline close to the second gas-liquid separator.

The side close to the second gas-liquid separator 222 means that since the fourth gas-liquid output pipeline communicates with the second gas-liquid output pipeline, the connecting point of the two pipelines is used as the calibration point, which is close to the second gas-liquid separator 222. side.

The third gas-liquid output pipeline is provided with a third regulating valve c.

The fourth gas-liquid output pipeline is provided with a fourth regulating valve d.

The third liquid return line is provided with a fifth regulating valve e.

The fourth liquid return line is provided with a sixth regulating valve f.

A seventh regulating valve g is arranged near the inlet of the second lye input pipeline. Since the second lye input pipeline is respectively connected to the third gas-liquid separation device 223 and the fourth gas-liquid separation device 224, after the confluence, it is connected to the first lye input pipeline, near the entrance of the second lye input pipeline is Refers to, with the confluence point as the calibration point, the side close to the inlet of the second lye input pipeline (the first lye input pipeline), that is, the pipeline section after confluence.

Through the setting of the above-mentioned regulating valves, it is possible to control the working mode of the electrolytic hydrogen production system 200 , that is, different working states through the switching cooperation of the regulating valves. For example:

Close the third regulating valve c, the fourth regulating valve d, the fifth regulating valve e, the sixth regulating valve f and the seventh regulating valve g, and open the first regulating valve a and the second regulating valve b. At this time, the lye circulates between the electrolytic cell 210 and the first gas-liquid separator 221, and at the same time circulates between the electrolytic cell 210 and the second gas-liquid separator 222. The electrolytic hydrogen production system 200 is in a large-capacity cycle, that is, the first Operating mode.

Open the third regulating valve c, the fourth regulating valve d, the fifth regulating valve e, the sixth regulating valve f and the seventh regulating valve g, and close the first regulating valve a and the second regulating valve b. At this time, the lye circulates between the electrolytic cell 210 and the third gas-liquid separator 223, and at the same time circulates between the electrolytic cell 210 and the fourth gas-liquid separator 224. The electrolytic hydrogen production system 200 is in a small-capacity cycle, that is, the second Operating mode.

From the first working mode to the second working mode, those skilled in the art can adjust the variable frequency pump and the flow of lye according to the temperature of the electrolytic cell 210, so that the flow of lye and the temperature of the electrolytic cell 210 present a state of linear adjustment , and then decide which working mode the electrolytic cell 210 is in, so as to cope with different working states of the electrolytic cell 210 .

In this embodiment, a variable frequency lye pump 240 is provided near the lye inlet side of the electrolytic cell 210 in the first lye input pipeline. Through the frequency conversion lye pump 240 , the lye circulation flow state in the electrolytic hydrogen production system 200 can be controlled in different working modes to cope with different working states of the electrolytic cell 210 .

Further, an lye cooler 250 is arranged between the frequency conversion lye pump 240 and the lye inlet. Through the arrangement of the lye cooler 250 , the temperature of the lye entering the electrolytic cell 210 can be further controlled, so as to cope with different working states of the electrolytic cell 210 .

In some embodiments, the electrolytic hydrogen production system 200 further includes: a first gas cooler (not shown in the figure) and a second gas cooler (not shown in the figure). The first gas cooler communicates with the gas outlet of the first gas scrubber 231 . The second gas cooler communicates with the gas outlet of the second gas scrubber 232 . The temperature of the gas produced externally by the electrolytic hydrogen production system 200 is controlled by a cooler to meet production standards.

In some embodiments, the electrolytic hydrogen production system further includes: a water tank; the water tank communicates with the first gas scrubber 231 to replenish water for the first gas scrubber 231 . A supplementary water pump is provided on the pipeline connecting the water tank to the first scrubber 231 . The supplementary water flow rate of the first scrubber 231 is controlled by the supplementary water pump.

Example 2

This embodiment provides an electrolytic hydrogen production method, using the electrolytic hydrogen production system provided in the above-mentioned embodiment 1. The electrolytic hydrogen production system has two working modes. In the first working mode, the following steps are included:

Open the first lye input pipeline.

The alkaline liquid is controlled to circulate between the electrolytic tank and the first gas-liquid separator, and the alkaline liquid is controlled to circulate between the electrolytic tank and the second gas-liquid separator.

From the first gas-liquid separator, the hydrogen is separated from the lye.

Oxygen is separated from lye from the second gas-liquid separator.

In the second working mode, the following steps are included:

The first lye input pipeline is opened, and the second lye input pipeline is opened, so that the second lye input pipeline communicates with the first lye input pipeline.

The alkali liquor is controlled to circulate between the electrolytic cell and the third gas-liquid separator, while the alkali liquor is controlled to circulate and flow between the electrolytic cell and the fourth gas-liquid separator.

From the third gas-liquid separator, the hydrogen is separated from the lye.

Oxygen is separated from lye from the fourth gas-liquid separator.

Specifically, it can be, for example:

Close the third regulating valve, the fourth regulating valve, the fifth regulating valve, the sixth regulating valve and the seventh regulating valve, and open the first regulating valve and the second regulating valve. At this time, the alkali liquor circulates between the electrolytic cell and the first gas-liquid separator, and at the same time circulates between the electrolytic cell and the second gas-liquid separator. The electrolytic hydrogen production system is in a large-capacity cycle, that is, the first working mode.

Open the third regulating valve, the fourth regulating valve, the fifth regulating valve, the sixth regulating valve and the seventh regulating valve, and close the first regulating valve and the second regulating valve. At this time, the alkali liquor circulates between the electrolytic cell and the third gas-liquid separator, and at the same time, circulates between the electrolytic cell and the fourth gas-liquid separator. The electrolytic hydrogen production system is in a small-capacity cycle, that is, the second working mode.

Those skilled in the art can decide which working mode to use according to the temperature of the electrolytic cell to deal with different working states of the electrolytic cell. For example, in this embodiment, the electrolytic hydrogen production system uses the first working mode when the input flow rate of alkali solution to the electrolytic cell is greater than 1/3 of the rated input flow rate of alkaline solution to the electrolytic cell. The electrolytic hydrogen production system uses the second working mode when the lye input flow of the electrolyzer is less than 1/3 of the rated lye input flow of the electrolyzer.

The flow rate of lye in the electrolysis hydrogen production system can be, for example, 20L/h-500L/h, and the rated value is 500L/h. When the flow rate is below 167L/h, use the second working mode; when the flow rate is above 167L/h, use the first working mode. The flow of lye can be controlled by the lye pump or lye pump group in the system, or it can be controlled by combining the opening and closing degrees of different valves with the lye pump or lye pump group.

In the electrolytic hydrogen production method of this embodiment, using the electrolytic hydrogen production system provided in the above-mentioned embodiment 1, different large-capacity cycles and small-capacity cycles can be realized respectively through the control of pipeline flow, so as to cope with different power periods. Therefore, the time of the low-power period during cold start can be shortened through the small-capacity cycle, and the waste of electric energy during the low-power period can be reduced. And it can be adjusted to the rated power state of the large-capacity cycle in time to meet the production demand.

In order to illustrate the beneficial effect of the solution of the present invention, a 10Nm ³ /h electrolytic hydrogen production system is taken as an example, and the electrolytic hydrogen production system of Example 1 is compared with the electrolytic hydrogen production system of the comparative example. The results are shown in Table 1 :

Table 1 Comparison of heating time

According to Table 1, it can be seen that compared with the comparative example, the heating time in the scheme of Example 1 is reduced no matter whether it is from 25°C-60°C or from 25°C-80°C, and the total energy consumption is reduced by 1kw.h. It can be proved that the electrolytic hydrogen production system provided by the present invention can shorten the time of low power period during cold start and reduce the waste of electric energy during low power period

The technical solutions disclosed in the present invention have been described above through examples. It is believed that those skilled in the art can understand the present invention through the description of the above embodiments. Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. An electrolytic hydrogen production system, characterized in that, comprising: An electrolytic cell, a first gas-liquid separator and a second gas-liquid separator; the cathode side of the electrolytic cell and the first gas-liquid separator communicate through the first gas-liquid output pipeline; the anode of the electrolytic cell One side communicates with the second gas-liquid separator through a second gas-liquid output pipeline; the electrolytic hydrogen production system also includes a first lye input pipeline, and the first lye input pipeline communicates with the a first gas-liquid separator, said second gas-liquid separator, and said electrolytic cell; The electrolytic hydrogen production system also includes: a third gas-liquid separator and a fourth gas-liquid separator; the cathode side of the electrolytic cell communicates with the third gas-liquid separator through a third gas-liquid output pipeline; The anode side of the electrolytic cell communicates with the fourth gas-liquid separator through a fourth gas-liquid output pipeline; the electrolytic hydrogen production system also includes a second lye input pipeline, and the second lye input The pipelines are respectively connected to the third gas-liquid separator, the fourth gas-liquid separator and the first lye input pipeline; The ratio of the capacity of the first gas-liquid separator to the capacity of the third gas-liquid separator is greater than 3:1; The ratio of the capacity of the second gas-liquid separator to the capacity of the fourth gas-liquid separator is greater than 3:1. 2. The electrolytic hydrogen production system according to claim 1, characterized in that, The electrolytic cell has a cathode side outlet close to the cathode of the electrolytic cell, the cathode side outlet is suitable for lye and gas generated on the cathode side to flow out of the electrolytic cell; the cathode side of the electrolytic cell The outlet communicates with the mixing inlet of the first gas-liquid separator through the first gas-liquid output pipeline; The electrolytic cell has an anode side outlet close to the anode of the electrolytic cell, the anode side outlet is suitable for the lye and the gas generated on the anode side to flow out of the electrolytic cell; the anode side of the electrolytic cell The outlet communicates with the mixing inlet of the second gas-liquid separator through the second gas-liquid output pipeline; The electrolytic cell also includes a lye inlet, and the first lye input pipeline communicates with the lye inlet and the lye outlet of the first gas-liquid separator, and simultaneously communicates with the lye inlet and the second gas-liquid separator. The alkali liquor outlet of the second gas-liquid separator. 3. The electrolytic hydrogen production system according to claim 2, characterized in that, The mixing inlet of the third gas-liquid separator communicates with the first gas-liquid output pipeline through the third gas-liquid output pipeline; The mixing inlet of the fourth gas-liquid separator communicates with the second gas-liquid output pipeline through the fourth gas-liquid output pipeline; The first lye input pipeline is provided with a second lye input pipeline inlet, and the second lye input pipeline communicates with the lye outlet of the third gas-liquid separator and the second lye input The pipeline inlet is simultaneously connected with the lye outlet of the fourth gas-liquid separator and the inlet of the second lye input pipeline. 4. The electrolytic hydrogen production system according to claim 3, further comprising: a first scrubber and a second scrubber; The gas inlet of the first gas scrubber is connected to the gas outlet of the first gas-liquid separator through the first gas scrubber; the alkali liquor outlet of the first gas scrubber is connected to the gas outlet through the first liquid return pipeline. The lye inlet of the first gas-liquid separator; The gas inlet of the second gas scrubber is connected to the gas outlet of the second gas-liquid separator through the second gas scrubber; the alkali liquor outlet of the second gas scrubber is connected to the gas outlet through the second liquid return pipeline. The alkali liquor inlet of the second gas-liquid separator. 5. The electrolytic hydrogen production system according to claim 4, characterized in that, The gas inlet of the first gas scrubber is connected to the gas outlet of the third gas-liquid separator through the third gas scrubber; the alkali liquor outlet of the first gas scrubber is connected to the gas outlet through the third liquid return pipeline. The lye inlet of the third gas-liquid separator; The gas inlet of the second gas scrubber is connected to the gas outlet of the fourth gas-liquid separator through the fourth gas scrubber; the lye outlet of the second gas scrubber is connected to the The lye inlet of the fourth gas-liquid separator. 6. The electrolytic hydrogen production system according to claim 5, characterized in that, The first gas-liquid output pipeline is provided with a first regulating valve on a side close to the first gas-liquid separator; The second gas-liquid output pipeline is provided with a second regulating valve on the side close to the second gas-liquid separator; The third gas-liquid output pipeline is provided with a third regulating valve; The fourth gas-liquid output pipeline is provided with a fourth regulating valve; The third liquid return pipeline is provided with a fifth regulating valve; The fourth liquid return pipeline is provided with a sixth regulating valve; A seventh regulating valve is provided near the inlet of the second lye input pipeline. 7. The electrolytic hydrogen production system according to claim 6, characterized in that, The first lye input pipeline is provided with a variable frequency lye pump near the lye inlet side of the electrolytic cell. 8. The electrolytic hydrogen production system according to claim 7, characterized in that, An lye cooler is arranged between the frequency conversion lye pump and the lye inlet. 9. A method for producing hydrogen by electrolysis, characterized in that, Use the electrolytic hydrogen production system as described in any one of claims 1-8; The electrolytic hydrogen production system has two working modes, In the first working mode, the following steps are included: Open the first lye input pipeline; Controlling the lye to circulate between the electrolyzer and the first gas-liquid separator, while controlling the lye to circulate between the electrolyzer and the second gas-liquid separator; From the first gas-liquid separator, the hydrogen is separated from the lye; Oxygen is separated from lye from the second gas-liquid separator; In the second working mode, the following steps are included: Opening the first lye input pipeline, and opening the second lye input pipeline, so that the second lye input pipeline communicates with the first lye input pipeline; Controlling the lye to circulate between the electrolyzer and the third gas-liquid separator, while controlling the lye to circulate between the electrolyzer and the fourth gas-liquid separator; From the third gas-liquid separator, the hydrogen is separated from the lye; Oxygen is separated from alkali liquor from the fourth gas-liquid separator. 10. The electrolytic hydrogen production method according to claim 9, characterized in that The electrolytic hydrogen production system uses the first working mode when the lye input flow rate of the electrolyzer is greater than 1/3 of the rated lye input flow rate of the electrolyzer; The electrolytic hydrogen production system uses the second working mode when the input flow rate of the lye to the electrolytic cell is less than 1/3 of the rated lye input flow rate to the electrolytic cell.

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