Hydrogen purification system, regeneration control method and hydrogen production system

Abstract

This invention relates to the field of hydrogen purification technology, providing a hydrogen purification system, a regeneration control method, and a hydrogen production system. The hydrogen purification system includes: a deoxygenation module; at least three dryers, each with its first end connected to the deoxygenation module and its second end connected to a discharge branch; a purging branch, with its inlet end connected to the discharge branch and its outlet end connected to the second ends of all dryers, the purging branch including a heating branch capable of heating hydrogen; a cooling branch, with both ends connected to the first ends of all dryers, used for cooling hydrogen; a first detection device located in the cooling branch and used to detect the dew point value of the hydrogen; and a control unit connected to the purging branch, the cooling branch, and the first detection device, respectively, and controlling the heating branch to shut down based on the dew point value. The purging time can be controlled based on the moisture content within the dryers, which, compared to timed purging in related technologies, ensures purging quality while saving operating energy.

Description

Technical Field

[0001] This invention relates to the field of hydrogen purification technology, and in particular to a hydrogen purification system, a regeneration control method, and a hydrogen production system. Background Technology

[0002] Electrolysis of water is one of the most widely used methods for producing hydrogen at present. The hydrogen produced during the electrolysis of water contains trace amounts of oxygen and a large amount of water vapor. Therefore, in order to improve the purity of hydrogen, it is usually necessary to purify the hydrogen through a hydrogen purification system.

[0003] In related technologies, hydrogen purification systems typically include a deoxygenation module and a drying module. The deoxygenation module removes trace amounts of oxygen from the hydrogen, while the drying module removes water vapor. To achieve repeated recycling, the drying module usually includes three dryers: one in operation, one in regeneration, and one in regeneration gas dehumidification, with these states switching cyclically. The dryer in operation dries the hydrogen discharged from the deoxygenation module. A portion of the dried hydrogen is then used as regeneration gas to purge the regeneration dryer, removing any remaining water vapor. After exiting the regeneration dryer, the water-vapor-containing hydrogen enters a cooler for cooling, where some of the water vapor condenses and is discharged. The cooled hydrogen then enters the regeneration gas dehumidification dryer for further drying, and the dried hydrogen proceeds downstream.

[0004] In the aforementioned technologies, when purging a dryer in the regeneration process with regeneration gas, the purging time is usually fixed and cannot be adjusted based on operating conditions. For example, when the purification system is running at low load, the purging time may be too long, leading to increased energy consumption; when the purification system is running at high load, the purging time may be too short, resulting in a higher dew point value and lower purity of the product hydrogen. Summary of the Invention

[0005] This invention provides a hydrogen purification system, a regeneration control method, and a hydrogen production system to address the shortcomings of existing technologies where the purging time is usually a fixed value and cannot be adjusted based on operating conditions, thereby achieving the effect of dynamically adjusting the purging time according to changes in system load.

[0006] This invention provides a hydrogen purification system, comprising:

[0007] The deoxygenation module is used to remove oxygen from hydrogen gas;

[0008] At least three dryers, each having a first end connected to the deoxygenation module and a second end connected to the discharge branch;

[0009] The purge branch has its inlet end connected to the outlet branch, and its outlet end connected to the second end of all the dryers. The purge branch includes a heating branch capable of heating hydrogen.

[0010] A cooling branch, with both ends connected to the first end of all the dryers, is used to cool hydrogen gas.

[0011] A first detection device is installed in the cooling branch and is used to detect the dew point value of hydrogen.

[0012] The control unit is connected to the purging branch, the cooling branch, and the first detection device, respectively, and controls the heating branch of the purging branch to shut down based on the dew point value.

[0013] According to a hydrogen purification system provided by the present invention, the purging branch further includes a low-temperature purging branch connected in parallel with the heating branch, and the control unit controls the opening of the low-temperature purging branch based on the dew point value.

[0014] According to a hydrogen purification system provided by the present invention, the hydrogen purification system further includes a second detection device, which is disposed in the cooling branch and used to detect the temperature value of hydrogen. The second detection device is connected to the control unit, and the control unit controls the low-temperature purging branch to close based on the temperature value.

[0015] And / or, it also includes a heat recovery unit, which includes exothermic and absorbent flow channels capable of heat exchange, the absorbent flow channel of the heat recovery unit being connected in series with the heating branch, and the exothermic flow channel of the heat recovery unit being connected in series with the cooling branch.

[0016] According to the hydrogen purification system provided by the present invention, a fifth detection device is further included. The fifth detection device is disposed at the outlet end of the discharge branch and is used to detect the product dew point value of hydrogen. The fifth detection device is connected to the control unit, and the control unit controls the opening of the heating branch and the cooling branch of the purging branch based on the product dew point value.

[0017] According to a hydrogen purification system provided by the present invention, a venting valve, a delivery control valve, and a sixth detection device are respectively connected to the control unit. The sixth detection device is located at the outlet end of the discharge branch and is used to detect the oxygen content of the hydrogen product. The control unit controls the opening and closing of the venting valve and the delivery control valve based on the product dew point value and the product oxygen content.

[0018] According to a hydrogen purification system provided by the present invention, the purge branch is provided with a flow control valve and a third detection device. The third detection device is used to detect the flow rate of hydrogen in the purge branch. Both the flow control valve and the third detection device are connected to the control unit. The control unit controls the opening degree of the flow control valve based on the flow rate.

[0019] According to a hydrogen purification system provided by the present invention, a regenerated hydrogen emission branch is further included. The outlet end of the emission branch is provided with an emission control valve. The first end of the regenerated hydrogen emission branch is connected to the second end of all the dryers, and the second end of the regenerated hydrogen emission branch is connected to the outlet end of the emission control valve.

[0020] According to a hydrogen purification system provided by the present invention, the discharge branch further includes a fourth detection device, which is disposed at the inlet end of the discharge control valve and is used to detect the pressure value of hydrogen. Both the fourth detection device and the discharge control valve are connected to the control unit, and the control unit controls the opening degree of the discharge control valve based on the pressure value.

[0021] According to a hydrogen purification system provided by the present invention, a venting valve, a delivery control valve, a fifth detection device, and a sixth detection device are respectively connected to the control unit. The fifth detection device and the sixth detection device are both located at the outlet end of the discharge branch and are used to detect the product dew point value and product oxygen content of hydrogen, respectively. The control unit controls the opening and closing of the venting valve and the delivery control valve based on the product dew point value and the product oxygen content.

[0022] According to a hydrogen purification system provided by the present invention, the deoxygenation module includes a heat exchanger, a first heater, a deoxygenator, and a first cooler. The heat exchanger includes a heat-exchanging channel and a heat-absorbing channel. The heat-absorbing channel of the heat exchanger, the first heater, the deoxygenator, the heat-exchanging channel of the heat exchanger, and the first cooler are connected in series. The exhaust port of the first cooler is connected to the first end of all the dryers.

[0023] According to a hydrogen purification system provided by the present invention, a self-regulating control valve is further included. The first cooler is arranged in a vertical direction, and the self-regulating control valve is provided at the condensate outlet of the bottom end cap of the first cooler.

[0024] According to a hydrogen purification system provided by the present invention, the dryer is arranged vertically, with a first end of the dryer located at the top of the dryer so that the hydrogen to be dried can enter the dryer from the top, and a second end of the dryer located at the bottom of the dryer so that the regenerated hydrogen can enter the dryer from the bottom.

[0025] The present invention also provides a regeneration control method, implemented based on a hydrogen purification system, comprising:

[0026] During the process of purging the dryer through the purging branch, the dew point value of the hydrogen discharged from the cooling branch is obtained. The purging branch and the cooling branch are respectively connected to the two ends of the dryer. The purging branch is used to supply hydrogen to the dryer, and the cooling branch is used to cool the hydrogen discharged from the dryer.

[0027] When the dew point value is determined to be less than or equal to the preset dew point value, the heating branch of the purging branch is shut off.

[0028] The present invention also provides a hydrogen production system, including the hydrogen purification system described above or using the regeneration control method described above.

[0029] The hydrogen purification system provided by this invention can eliminate trace amounts of oxygen in hydrogen by incorporating a deoxygenation module and can dry and dehydrate hydrogen by incorporating a dryer. A purging branch allows a portion of the hydrogen in the discharge branch to be exported and heated, then introduced into the second end of the dryer in regeneration mode. The hydrogen purges the dryer in regeneration mode, removing moisture and discharging it from the first end of the dryer. The discharged hydrogen enters a cooling branch for cooling, causing moisture to condense and precipitate. The hydrogen discharged through the cooling branch then enters the dryer in regeneration dehumidification mode for further drying. The dried hydrogen is then discharged from the second end of the dryer in regeneration dehumidification mode to the discharge branch.

[0030] The first detection device can detect the dew point value of hydrogen discharged from the dryer in the regeneration state. The control unit can control the heating branch of the purging branch to be shut down based on the dew point value. Specifically, when the dew point value is lower than the preset dew point threshold, it means that the moisture content after the hydrogen purges the dryer is low, that is, the dryer in the regeneration state has met the drying requirements at this time, so the heating branch of the purging branch can be shut down.

[0031] With this configuration, the hydrogen purification system provided by the present invention controls the heating branch of the purging branch to be shut down based on the dew point value of hydrogen obtained by the first detection device. This allows the purging time to be controlled based on the moisture content in the dryer, which can be dynamically adjusted according to the system load. Compared with the timed purging method in related technologies, this method ensures purging quality and saves operating energy.

[0032] The regeneration control method provided by this invention controls the heating branch of the purging branch to shut down based on the dew point value of the acquired hydrogen gas. This allows the purging duration to be controlled based on the moisture content in the dryer, which can be dynamically adjusted according to the system load. Compared with the timed purging method in related technologies, this method ensures purging quality and saves operating energy.

[0033] The hydrogen production system provided by this invention includes the hydrogen purification system described above or uses the regeneration control method described above, and therefore has corresponding advantages. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a hydrogen purification system provided in some embodiments of the present invention.

[0036] Figure label:

[0037] 1. Deaerator module; 101. Heat exchanger; 102. First heater; 103. Deaerator; 104. First cooler; 105. Self-regulating control valve; 2. Purge branch; 201. Heating branch; 201-1. Second heater; 201-2. Heating control valve; 202. Low-temperature purging branch; 202-1. Purge control valve; 203. Flow control valve; 204. Third detection device; 205. Purge inlet valve; 3. Cooling branch; 301. 1. Control valve; 302. Second control valve; 303. Second cooler; 4. Discharge branch; 401. Discharge control valve; 402. Fourth detection device; 5. First detection device; 6. Dryer; 7. Heat recovery unit; 8. Regenerated hydrogen discharge branch; 801. Regenerated hydrogen discharge valve; 9. Second detection device; 10. Venting valve; 11. Conveying control valve; 12. Fifth detection device; 13. Sixth detection device; 14. Hydrogen feed valve; 15. Hydrogen discharge valve. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0039] The following is combined Figure 1 The hydrogen purification system provided in the embodiments of the present invention is described.

[0040] Specifically, the hydrogen purification system includes a deoxygenation module 1, a dryer 6, a purging branch 2, a cooling branch 3, a first detection device 5, and a control unit.

[0041] The deoxygenation module 1 is used to remove oxygen from hydrogen. For example, the deoxygenation module 1 can utilize the principle of redox reaction to react trace amounts of oxygen in hydrogen with hydrogen to produce water under the action of a catalyst.

[0042] The number of dryers 6 is set to at least three, with the first end of each dryer 6 connected to the deoxygenation module 1 and the second end of each dryer 6 connected to the discharge branch 4. Optionally, the dryers 6 are filled with molecular sieves for absorbing moisture from the hydrogen. When there are three dryers 6, during the operation of the hydrogen purification system, one of the three dryers 6 is in working condition, one is in regeneration condition, and the other is in regeneration gas dehumidification condition. When there are more than three dryers 6, during the operation of the hydrogen purification system, at least two of the following three conditions must be met: the number of dryers 6 in working condition, the number of dryers 6 in regeneration condition, and the number of dryers 6 in regeneration gas dehumidification condition. Optionally, the discharge branch 4 is used to connect to a downstream hydrogen processing system.

[0043] The purge branch 2 is capable of heating hydrogen. The inlet end of the purge branch 2 is connected to the outlet branch 4, allowing a portion of the hydrogen from the outlet branch 4 to enter the purge branch 2. The outlet end of the purge branch 2 is connected to the second end of all dryers 6, allowing the hydrogen heated by the purge branch 2 to enter any one of the dryers 6. The purge branch 2 includes a heating branch 201 capable of heating hydrogen.

[0044] Cooling branch 3 is used to cool hydrogen. Both ends of cooling branch 3 are connected to the first end of dryer 6 so that hydrogen discharged from the first end of either dryer 6 can be cooled by cooling branch 3 before entering the other dryer 6.

[0045] The first detection device 5 is located in the cooling branch 3 and is used to detect the dew point value of hydrogen. Optionally, the first detection device 5 is located at the outlet end of the cooling branch 3. Optionally, the first detection device 5 is a dew point meter.

[0046] The control unit is connected to purge branch 2, cooling branch 3, and the first detection device 5, respectively. The control unit controls the heating branch 201 of purge branch 2 to shut down based on the dew point value. The control unit can be the control system of the hydrogen purification system.

[0047] The following is for reference. Figure 1The operation process of the hydrogen purification system provided in this embodiment is described. For clarity, definitions are used. Figure 1 The three dryers 6 in the middle are, from left to right, the first dryer 6, the second dryer 6, and the third dryer 6. The following is an example with the first dryer 6 in working condition, the second dryer 6 in regeneration condition, and the third dryer 6 in regeneration gas dehumidification condition. The specific operation process is as follows:

[0048] The hydrogen to be purified first enters the deoxygenation module 1, where trace amounts of oxygen are removed. Hydrogen exiting the deoxygenation module 1 enters the first dryer 6 through its first end, where it is dried and dehydrated. Hydrogen exiting the second end of the first dryer 6 enters the discharge branch 4, which transports it downstream. A portion of the hydrogen from the discharge branch 4 enters the purging branch 2, where it is heated and introduced into the second end of the second dryer 6 to purge the dryer and remove moisture. The hydrogen carrying moisture from the second dryer 6 exits from its first end and enters the cooling branch 3 for cooling, where the moisture condenses and precipitates. Hydrogen gas discharged through cooling branch 3 enters the third dryer 6 from the first end of the third dryer 6, where it is dried. The dried hydrogen gas then exits from the second end of the third dryer 6 to the discharge branch 4. When the first dryer 6 cannot meet the drying requirements of the hydrogen gas, the three dryers 6 switch states: specifically, the first dryer 6 switches to regeneration state, the second dryer 6 switches to regeneration gas dehumidification state, and the third dryer 6 switches to working state.

[0049] During the purging process, the first detection device 5 can detect the dew point value of the hydrogen gas discharged from the second dryer 6, and the control unit can control the heating branch 201 of the purging branch 2 to shut down based on the dew point value. Specifically, when the dew point value of the hydrogen gas discharged from the second dryer 6 is lower than the preset dew point threshold, it indicates that the moisture content of the purging hydrogen gas discharged from the second dryer 6 is low, that is, the second dryer 6 has met the drying requirements at this time, so the heating branch 201 of the purging branch 2 can be shut down.

[0050] With this configuration, the hydrogen purification system provided in this embodiment of the invention controls the shutdown of the heating branch 201 of the purging branch 2 based on the dew point value of hydrogen obtained by the first detection device 5. This allows for control of the purging duration based on the moisture content within the dryer 6, enabling dynamic adjustment according to the system load. Compared to timed purging in related technologies, this configuration ensures purging quality while saving operating energy. Furthermore, the dryer 6 is vertically positioned during operation, with its first end at the top and its second end at the bottom. In operation, hydrogen flows from the first end to the second end of the dryer 6; in regeneration, hydrogen flows from the second end to the first end. This feeding method, which reverses the hydrogen diffusion characteristics during drying and follows the water vapor diffusion characteristics during regeneration, enhances mass transfer.

[0051] In some embodiments provided by the present invention, the purging branch 2 further includes a low-temperature purging branch 202 connected in parallel with the heating branch 201. The control unit controls the heating branch 201 to shut down and controls the low-temperature purging branch 202 to turn on based on the dew point value.

[0052] In this embodiment, when the purging branch 2 purges the dryer 6 in the regeneration state, the control unit first controls the heating branch 201 to open and the low-temperature purging branch 202 to close. Part of the hydrogen from the discharge branch 4 enters the heating branch 201 of the purging branch 2 as regeneration gas, where it is heated. The heated hydrogen then enters the dryer 6 in the regeneration state and performs high-temperature purging, which helps to expel moisture from the dryer 6 more quickly. When the control unit determines that the dew point value transmitted by the first detection device 5 is lower than a preset dew point threshold, it indicates that the dryer 6 meets the drying conditions. The control unit then controls the heating branch 201 to close and the low-temperature purging branch 202 to open. At this time, some of the hydrogen gas discharged from the discharge branch 4 enters the low-temperature purging branch 202, and then enters the dryer 6 in the regeneration state for purging. Since the hydrogen gas discharged from the discharge branch 4 is not heated, its temperature is low. Therefore, the hydrogen gas entering the dryer 6 in the regeneration state through the low-temperature purging branch 202 can perform low-temperature purging on the dryer 6, so that the dryer 6 can be cooled down quickly.

[0053] In some embodiments of the present invention, the hydrogen purification system further includes a second detection device 9. The second detection device 9 is disposed in the cooling branch 3 and is used to detect the temperature value of the hydrogen, specifically the temperature value of the hydrogen discharged from the dryer 6 in the regeneration state. Optionally, the second detection device 9 may be a temperature transmitter or a temperature sensor. Optionally, refer to... Figure 1As shown, the second detection device 9 is located at the inlet end of the cooling branch 3. The second detection device 9 is connected to the control unit. The control unit controls the low-temperature purge branch 202 to close based on the temperature value. In addition, the closure of the low-temperature purge branch 202 indicates that the dryer has completed regeneration, and the control unit can then control the cooling branch 3 to close.

[0054] In this embodiment, when the control unit determines that the temperature value transmitted by the second detection device 9 is lower than the preset temperature threshold, it indicates that the temperature of the dryer 6 has met the conditions and regeneration is complete. The control unit then controls the low-temperature purging branch 202 to close.

[0055] With this configuration, the hydrogen purification system controls the closure of the low-temperature purging branch 202 based on the temperature value of the hydrogen discharged from the regenerated dryer 6. This reduces the problem of energy waste caused by excessively long cold blowing time or insufficient cooling due to insufficient cold blowing time. It can quickly cool down the dryer 6 while ensuring low energy consumption costs.

[0056] Optionally, refer to Figure 1 As shown, the purge branch 2 includes purge inlet valves 205. The number of purge inlet valves 205 is the same as the number of dryers 6 and corresponds one-to-one. The purge branch 2 is connected to each dryer 6 through the corresponding purge inlet valve 205. The purge inlet valve 205 is connected to the control unit. During the purge process, the control unit controls the purge inlet valve 205 corresponding to the dryer 6 in the regeneration state to open, and the other purge inlet valves 205 to close.

[0057] Optionally, the heating branch 201 includes a heating control valve 201-2 and a second heater 201-1 connected in series. The second heater 201-1 can be an electric heater, a steam heater, or a thermal oil heater. The heating control valve 201-2 is connected to a control unit, which controls the opening and closing of the heating control valve 201-2. For example, when the dryer 6 in the regeneration state needs hot blowing, the control unit controls the heating control valve 201-2 to open.

[0058] Furthermore, when the second heater 201-1 is an electric heater, the heating branch 201 also includes a temperature detection device installed at the outlet of the second heater 201-1. The control unit is connected to the temperature detection device and controls the power of the second heater 201-1 based on the temperature value detected by the temperature detection device so that the temperature of the hydrogen meets the hot blowing requirements.

[0059] Optionally, the low-temperature purging branch 202 includes a purging control valve 202-1. The purging control valve 202-1 is connected to a control unit, which controls the opening and closing of the purging control valve 202-1. For example, when the dryer 6 in regeneration mode requires cold purging, the control unit controls the heating control valve 201-2 to close and controls the purging control valve 202-1 to open. Alternatively, the heating control valve 201-2 and the purging control valve 202-1 can be combined into a three-way valve. By switching the state of the three-way valve, either the heating branch 201 or the low-temperature purging branch 202 can be connected to the discharge branch 4.

[0060] In some embodiments provided by the present invention, the cooling branch 3 includes a first control valve 301, a second cooler 303, and a second control valve 302 arranged in series. The number of both the first control valve 301 and the second control valve 302 is the same as the number of dryers 6. The first control valve 301 is located at the inlet end of the cooling branch 3, meaning the inlet end of the cooling branch 3 is connected to the first end of each dryer 6 via a corresponding first control valve 301. The second control valve 302 is located at the outlet end of the cooling branch 3, meaning the outlet end of the cooling branch 3 is connected to the first end of each dryer 6 via a corresponding second control valve 302. Both the first control valve 301 and the second control valve 302 are connected to a control unit. During the operation of the hydrogen purification system, the control unit controls the opening of the first control valve 301 corresponding to the dryer 6 in the regeneration state and the opening of the second control valve 302 corresponding to the dryer 6 in the regeneration gas dehumidification state. The remaining first control valve 301 and second control valve 302 are closed. In this way, the hydrogen gas containing water vapor discharged from the dryer 6 in the regeneration state can be cooled by the second cooler 303 and then enter the dryer 6 in the regeneration gas dehumidification state.

[0061] In some embodiments of the present invention, the hydrogen purification system further includes a heat recovery unit 7. The heat recovery unit 7 includes a heat-exchanging channel and a heat-absorbing channel. The heat-exchanging channel of the heat recovery unit 7 is connected in series with the heating branch 201, and the heat-absorbing channel of the heat recovery unit 7 is connected in series with the cooling branch 3. Specifically, in the heating branch 201, the heat-absorbing channel of the heat recovery unit 7 is connected in series upstream of the second heater 201-1, and in the cooling branch 3, the heat-exchanging channel of the heat recovery unit 7 is connected in series upstream of the second cooler 303. This configuration allows the hydrogen discharged from the regenerated dryer 6 to preheat the hydrogen in the heating branch 201, thereby achieving heat recovery and reducing the energy consumption of the hydrogen purification system.

[0062] In some embodiments of the present invention, the hydrogen purification system further includes a fifth detection device 12. The fifth detection device 12 is located at the outlet end of the discharge branch 4, for example, at the outlet end of the discharge control valve 401. The fifth detection device 12 is used to detect the product dew point value of the hydrogen; for example, the fifth detection device 12 can be a dew point meter. The fifth detection device 12 is connected to a control unit, which controls the opening of the purge branch 2 and the cooling branch 3 based on the product dew point value.

[0063] Specifically, when the control unit determines that the product dew point value is higher than the target dew point value, it indicates that the dryer 6 currently in operation can no longer meet the drying requirements for hydrogen. Therefore, the control unit controls the purge branch 2 to open and the cooling branch 3 to regenerate the dryer 6. The operating status of the purge branch 2 and the cooling branch 3 after they are opened can be controlled by the control unit based on the dew point value detected by the first detection device 5 and the temperature value detected by the second detection device 9, as described above, and will not be repeated here.

[0064] With this configuration, the hydrogen purification system can automatically determine whether to activate the purging branch 2 and the cooling branch 3 based on the product dew point value of the hydrogen discharged from the discharge branch 4, so as to purge the dryer 6 which is in operation. This eliminates the need for manual intervention, thereby increasing the automation level of the hydrogen purification system.

[0065] In some embodiments of the present invention, the hydrogen purification system further includes a vent valve 10, a delivery control valve 11, and a sixth detection device 13, all connected to the control unit. The sixth detection device 13 is located at the outlet end of the discharge branch 4, for example, at the outlet end of the discharge control valve 401. The sixth detection device 13 is used to detect the oxygen content of the hydrogen product. For example, the sixth detection device 13 can be an oxygen analyzer. The control unit controls the opening and closing of the vent valve 10 and the delivery control valve 11 based on the product dew point value and the product oxygen content.

[0066] Specifically, when the control unit determines that the product dew point value is higher than the target dew point value or the product oxygen content is higher than the target oxygen content, it controls the delivery control valve 11 to close and controls the vent valve 10 to open, so as to release the substandard hydrogen. When the hydrogen quality meets the standard, the control unit controls the delivery control valve 11 to open and controls the vent valve 10 to close, so as to deliver the hydrogen downstream.

[0067] In some embodiments of the present invention, the purge branch 2 is equipped with a flow control valve 203 and a third detection device 204. For example, both the flow control valve 203 and the third detection device 204 are located at the inlet end of the purge branch 2. The third detection device 204 is used to detect the flow rate of hydrogen in the purge branch 2, that is, the flow rate of hydrogen discharged from the discharge branch 4 to the purge branch 2. The third detection device 204 can be a flow meter. The flow control valve 203 is used to control the flow rate of hydrogen discharged from the discharge branch 4 to the purge branch 2. Both the flow control valve 203 and the third detection device 204 are connected to a control unit, which controls the opening degree of the flow control valve 203 based on the flow rate value.

[0068] Specifically, in this embodiment, during the purging process, the control unit sets the target flow rate of the regenerated gas based on the load of the hydrogen purification system. The control unit controls the opening degree of the flow control based on the target flow rate and the flow rate obtained by the third detection device 204, so that the actual flow rate of the regenerated gas meets the actual flow rate requirement.

[0069] In some embodiments provided by this invention, the discharge branch 4 includes a hydrogen discharge valve 15, the number of which is the same as the number of dryers 6, and there is a one-to-one correspondence between them. The discharge branch 4 is connected to each dryer 6 through a corresponding hydrogen discharge valve 15. When a dryer 6 is in operation, the corresponding hydrogen discharge valve 15 is opened. The hydrogen discharge valve 15 can be connected to a control unit and its opening and closing can be controlled by the control unit.

[0070] In some embodiments of the present invention, the hydrogen purification system further includes a regenerated hydrogen discharge branch 8, and a discharge control valve 401 is provided at the outlet end of the discharge branch 8. The first end of the regenerated hydrogen discharge branch 8 is connected to the second end of all the dryers 6, and the second end of the regenerated hydrogen discharge branch 8 is connected to the outlet end of the discharge control valve 401. The second end of the dryer 6 in the regenerated gas dehumidification state is connected to the outlet end of the discharge control valve 401 through the regenerated gas discharge branch 4. By setting the discharge control valve 401, on the one hand, the pressure of hydrogen in the hydrogen purification system can be adjusted to maintain the stability of the hydrogen purification system; on the other hand, the pressure difference between product hydrogen and regenerated hydrogen can be balanced to ensure that the regenerated hydrogen can be discharged smoothly.

[0071] Optionally, the regenerated hydrogen emission branch 8 includes a regenerated hydrogen emission valve 801, the number of which corresponds to the number of dryers 6. That is, the regenerated hydrogen emission branch 8 is connected to each dryer 6 via a corresponding regenerated hydrogen emission valve 801. The regenerated hydrogen emission valve 801 is connected to a control unit. During normal operation of the hydrogen purification system, the control unit controls the regenerated hydrogen emission valve 801 corresponding to the dryer 6 in the regenerated gas dehumidification state to open, and the remaining regenerated hydrogen emission valves 801 to close. Simultaneously, it controls the hydrogen discharge valve 15 corresponding to the dryer 6 in the working state to open, and the remaining hydrogen discharge valves 15 to close.

[0072] In some embodiments of the present invention, the discharge branch 4 further includes a fourth detection device 402. The fourth detection device 402 is located at the inlet of the discharge control valve 401 and is used to detect the pressure value of hydrogen. For example, the fourth detection device 402 is a pressure transmitter or a pressure sensor. Both the fourth detection device 402 and the discharge control valve 401 are connected to a control unit, which controls the opening degree of the discharge control valve 401 based on the pressure value. For example, when the control unit determines that the pressure value is higher than the target pressure value, it controls the opening degree of the discharge control valve 401 to increase; when the control unit determines that the pressure value is lower than the target pressure value, it controls the opening degree of the discharge control valve 401 to decrease.

[0073] In some embodiments provided by the present invention, the deoxygenation module 1 includes a heat exchanger 101, a first heater 102, a deoxygenator 103, and a first cooler 104. The heat exchanger 101 includes a heat-exporting flow channel and a heat-absorbing flow channel capable of heat exchange. The heat-absorbing flow channel of the heat exchanger 101, the first heater 102, the deoxygenator 103, the heat-exporting flow channel of the heat exchanger 101, and the first cooler 104 are connected in series. The exhaust port of the first cooler 104 is connected to the first end of all the dryers 6.

[0074] In this embodiment, during the deoxygenation process, hydrogen enters the heat absorption channel of heat exchanger 101 to absorb heat from the hydrogen discharged from deoxygenator 103, then passes through a heater to a preset temperature before entering deoxygenator 103 for deoxygenation. Deoxygenator 103 contains a deoxygenation catalyst, where trace amounts of oxygen in the hydrogen react with some of the hydrogen to form water. Hydrogen discharged from deoxygenator 103 enters the heat release channel of heat exchanger 101 for pre-cooling, then enters the first cooler 104 for further cooling. Water in the hydrogen condenses and precipitates in the first cooler 104. Hydrogen discharged from the first cooler 104 then enters the dryer 6 for further drying. Furthermore, by placing the first heater 102 outside the deoxygenator 103, the heating method of the first heater 102 becomes more flexible; for example, the first heater 102 can be a steam heater, a hot oil heater, or an electric heater.

[0075] Optionally, if the first heater 102 is an electric heater, the deoxygenation module 1 further includes a temperature detection device disposed at the outlet of the first heater 102. Both the temperature detection device and the first heater 102 are connected to the control unit. The control unit controls the heating power of the first heater 102 based on the temperature value detected by the temperature detection device, so that the first heater 102 can heat the hydrogen to the target temperature.

[0076] Optionally, the hydrogen purification system also includes hydrogen feed valves 14. The number of hydrogen feed valves 14 is the same as the number of dryers 6 and corresponds one-to-one. The deoxygenation module 1 is connected to each dryer 6 through a corresponding hydrogen feed valve 14. The hydrogen feed valve 14 is connected to a control unit. When the hydrogen purification system is running, the control unit controls the opening of the hydrogen feed valve 14 corresponding to the dryer 6 in operation, so that the hydrogen discharged from the deoxygenation module 1 can enter the dryer 6 in operation.

[0077] In some embodiments of the present invention, the hydrogen purification system further includes a self-regulating control valve 105. The first cooler 104 is arranged vertically, and the condensate outlet of the bottom end cap of the first cooler 104 is equipped with the self-regulating control valve 105. With this configuration, the self-regulating control valve 105 can automatically adjust its opening according to the pressure changes caused by changes in the liquid level in the bottom end cap of the first cooler 104. This allows for automatic drainage while maintaining a certain liquid seal to prevent hydrogen leakage from the condensate outlet. Specifically, the first cooler 104 is a cooler with a gas-liquid separation function; for example, the end of the first cooler 104 is equipped with an extended end cap for liquid storage. Thus, an additional gas-liquid separator is unnecessary.

[0078] Optionally, the second cooler 303 is arranged vertically, and a self-regulating control valve 105 is provided at the condensate outlet sealed at the bottom of the second cooler 303. With this configuration, the self-regulating control valve 105 can automatically adjust its opening according to the pressure changes caused by changes in the liquid level in the bottom end cap of the second cooler 303. This allows for automatic drainage while maintaining a certain liquid seal to prevent hydrogen leakage from the condensate outlet. Specifically, the second cooler 303 is a cooler with a gas-liquid separation function. For example, the end of the second cooler 303 is provided with an extended end cap for liquid storage. Thus, an additional gas-liquid separator is unnecessary.

[0079] In some embodiments of the present invention, the dryer 6 is vertically arranged, with its first end located at the top to allow the hydrogen to be dried to enter from the top, and its second end located at the bottom to allow the regenerated hydrogen to enter from the bottom. By allowing the hydrogen to enter the dryer 6 from the top and exit from the bottom, hydrogen and water vapor can be better separated, thereby improving the drying effect. During regeneration, allowing the regenerated hydrogen to enter the dryer 6 from the bottom and exit from the top helps to remove moisture from the dryer 6, thus improving the regeneration effect.

[0080] This invention also provides a regeneration control method based on a hydrogen purification system, for example, based on the hydrogen purification system described in the above embodiments.

[0081] Specifically, regeneration control methods include:

[0082] Step 1: During the purging process of dryer 6 via purge branch 2, obtain the dew point value of the hydrogen discharged via cooling branch 3. Purge branch 2 and cooling branch 3 are connected to the two ends of dryer 6, respectively. Purge branch 2 supplies hydrogen to dryer 6, and cooling branch 3 cools the hydrogen discharged from dryer 6.

[0083] Specifically, the number of dryers 6 is set to at least three. The first end of each dryer 6 is connected to the deoxygenation module 1, and the second end of each dryer 6 is connected to the discharge branch 4. With three dryers 6, during the operation of the hydrogen purification system, one of the three dryers 6 is in working condition, one is in regeneration condition, and the other is in regeneration gas dehumidification condition. Optionally, the discharge branch 4 is connected to a downstream hydrogen processing system. The purge branch 2 can heat the hydrogen. The inlet end of the purge branch 2 is connected to the discharge branch 4 so that a portion of the hydrogen from the discharge branch 4 enters the purge branch 2. The outlet end of the purge branch 2 is connected to the second end of all dryers 6 so that the hydrogen heated by the purge branch 2 can enter any one of the dryers 6. The cooling branch 3 is used to cool the hydrogen. Both ends of the cooling branch 3 are connected to the first end of each dryer 6 so that the hydrogen discharged from the first end of each dryer 6 can be cooled by the cooling branch 3 before entering another dryer 6. The first detection device 5 is located in the cooling branch 3 and is used to detect the dew point value of hydrogen. Optionally, the first detection device 5 is located at the outlet end of the cooling branch 3. Optionally, the first detection device 5 is a dew point meter.

[0084] The second step is to shut down the heating branch 201 of the purging branch 2 when the dew point value is determined to be less than or equal to the preset dew point value.

[0085] Specifically, the control unit is connected to the purge branch 2, the cooling branch 3, and the first detection device 5, respectively. The control unit controls the heating branch 201 of the purge branch 2 to shut down based on the dew point value. The control unit can be the control system of the hydrogen purification system.

[0086] With this configuration, the regeneration method provided in this embodiment of the invention controls the heating branch 201 of the purging branch 2 to be shut down based on the dew point value of the acquired hydrogen gas. This allows the purging duration to be controlled based on the moisture content in the dryer 6, which can be dynamically adjusted according to the system load. Compared with the timed purging method in related technologies, this method ensures purging quality and saves operating energy consumption.

[0087] Furthermore, the regeneration control method also includes: obtaining the temperature value of hydrogen in the cooling branch 3, and controlling the opening of the low-temperature purging branch 202 based on the dew point value, and controlling the closing of the low-temperature purging branch 202 based on the temperature value.

[0088] Specifically, the second detection device 9 is installed in the cooling branch 3, and is used to detect the temperature of the hydrogen gas, specifically the temperature of the hydrogen gas discharged from the dryer 6 in the regeneration state. The purging branch 2 includes a heating branch 201 and a low-temperature purging branch 202 connected in parallel; the heating branch 201 is used to heat the hydrogen gas. The control unit controls the low-temperature purging branch 202 to open based on the dew point value and to close based on the temperature value. The specific operation process has been discussed above and will not be repeated here.

[0089] Furthermore, the regeneration control method also includes: obtaining the product dew point value of hydrogen at the discharge end of the discharge branch 4, and controlling the purging branch 2 and the cooling branch 3 to open when it is determined that the product dew point value is higher than the target dew point value.

[0090] Specifically, when the product dew point value is determined to be higher than the target dew point value, it indicates that the dryer 6 currently in operation can no longer meet the drying requirements for hydrogen. Therefore, the control unit can control the purge branch 2 and the cooling branch 3 to regenerate the dryer 6. The operating status of the purge branch 2 and the cooling branch 3 after they are opened can be controlled by the control unit based on the dew point value detected by the first detection device 5 and the temperature value detected by the second detection device 9, as described above, and will not be repeated here.

[0091] With this setup, the regeneration control method can automatically determine whether to activate the purging branch 2 and cooling branch 3 based on the product dew point value of the hydrogen discharged from the discharge branch 4, so as to purge the dryer 6 which is in operation. This eliminates the need for manual intervention, thereby increasing the automation level of the hydrogen purification system.

[0092] This invention also provides a hydrogen production system.

[0093] Specifically, the hydrogen production system includes the hydrogen purification system described above, or uses the regeneration control method described above.

[0094] It should be noted that the hydrogen production system includes a hydrogen purification system or uses a regeneration control method, which also has corresponding advantages, which will not be elaborated further.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen purification system, characterized by, The hydrogen gas purification system comprises: a deoxidizing module (1) for removing oxygen from hydrogen gas; at least three dryers (6), each of which has a first end connected to the deoxidizing module (1) and a second end connected to a discharge branch (4); a purge branch (2) having an inlet end connected to the discharge branch (4) and an outlet end connected to the second ends of all the dryers (6), the purge branch (2) comprising a heating branch (201) capable of heating hydrogen gas; a cooling branch (3) having two ends connected to the first ends of all the dryers (6), the cooling branch (3) being used for cooling hydrogen gas; a first detection device (5) arranged in the cooling branch (3) and used for detecting a dew point value of hydrogen gas; a control unit connected to the purge branch (2), the cooling branch (3) and the first detection device (5) respectively, and capable of controlling the heating branch (201) of the purge branch (2) to be closed based on the dew point value; the purge branch (2) further comprises a low-temperature purge branch (202) arranged in parallel with the heating branch (201), and the control unit is capable of controlling the low-temperature purge branch (202) to be opened based on the dew point value.

2. The hydrogen purification system of claim 1, wherein, The hydrogen gas purification system further comprises a second detection device (9) arranged in the cooling branch (3) and used for detecting a temperature value of hydrogen gas, the second detection device (9) is connected to the control unit, and the control unit is capable of controlling the low-temperature purge branch (202) to be closed based on the temperature value. And / or, the hydrogen gas purification system further comprises a heat recovery device (7) comprising an exothermic flow channel and an endothermic flow channel capable of exchanging heat, the endothermic flow channel of the heat recovery device (7) is connected in series to the heating branch (201), and the exothermic flow channel of the heat recovery device (7) is connected in series to the cooling branch (3).

3. The hydrogen purification system of claim 1, wherein, The hydrogen gas purification system further comprises a fifth detection device (12) arranged at an outlet end of the discharge branch (4) and used for detecting a product dew point value of hydrogen gas, the fifth detection device (12) is connected to the control unit, and the control unit is capable of controlling the heating branch (201) of the purge branch (2) to be opened and the cooling branch (3) to be opened based on the product dew point value.

4. The hydrogen purification system of claim 3, wherein, The hydrogen gas purification system further comprises a bleed valve (10), a delivery control valve (11) and a sixth detection device (13) connected to the control unit respectively, the sixth detection device (13) is arranged at the outlet end of the discharge branch (4) and used for detecting a product oxygen content of hydrogen gas, and the control unit is capable of controlling the opening and closing of the bleed valve (10) and the opening and closing of the delivery control valve (11) based on the product dew point value and the product oxygen content.

5. The hydrogen purification system according to any one of claims 1 to 4, characterized in that, The purge branch (2) is provided with a flow control valve (203) and a third detection device (204), the third detection device (204) is used for detecting the flow value of hydrogen in the purge branch (2), the flow control valve (203) and the third detection device (204) are connected with the control unit, and the control unit controls the opening degree of the flow control valve (203) based on the flow value.

6. The hydrogen purification system of any one of claims 1-4, wherein, The exhaust branch (4) is further provided with an exhaust control valve (401), a first end of a regenerated hydrogen discharge branch (8) is connected with the second ends of all the dryers (6), and a second end of the regenerated hydrogen discharge branch (8) is connected with an outlet end of the exhaust control valve (401).

7. The hydrogen purification system of claim 6, wherein, The exhaust branch (4) further comprises a fourth detection device (402) arranged at an inlet end of the exhaust control valve (401) and used for detecting a pressure value of hydrogen, and the fourth detection device (402) and the exhaust control valve (401) are connected with the control unit, and the control unit controls the opening degree of the exhaust control valve (401) based on the pressure value.

8. The hydrogen purification system of any one of claims 1-4, wherein, The deoxidizing module (1) comprises a heat exchanger (101), a first heater (102), a deoxidizer (103) and a first cooler (104), the heat exchanger (101) comprises a heat releasing flow channel and a heat absorbing flow channel capable of heat exchange, the heat absorbing flow channel of the heat exchanger (101), the first heater (102), the deoxidizer (103), the heat releasing flow channel of the heat exchanger (101) and the first cooler (104) are sequentially connected in series, and an exhaust port of the first cooler (104) is connected with the first ends of all the dryers (6).

9. The hydrogen purification system of claim 8, wherein, The first cooler (104) is arranged in a vertical direction, and a condensate outlet of a bottom head of the first cooler (104) is provided with a self-operated control valve (105).

10. The hydrogen purification system of any one of claims 1-4, wherein, The dryer (6) is arranged vertically, the first end of the dryer (6) is arranged at the top of the dryer (6) so that the hydrogen to be dried can enter the dryer (6) from the top, and the second end of the dryer is arranged at the bottom of the dryer (6) so that the regenerated hydrogen can enter the dryer (6) from the bottom.

11. A regeneration control method characterized by comprising: The hydrogen purification system is implemented based on any one of claims 1-10, comprising: In the process of purging the dryer (6) by the purge branch (2), the dew point value of the hydrogen discharged by the cooling branch (3) is obtained, wherein the purge branch (2) and the cooling branch (3) are connected to the two ends of the dryer (6) respectively, the purge branch (2) is used for providing hydrogen to the dryer (6), and the cooling branch (3) is used for cooling the hydrogen discharged by the dryer (6); When it is determined that the dew point value is less than or equal to a preset dew point value, the heating branch (201) of the purge branch (2) is closed; When it is determined that the dew point value is less than or equal to a preset dew point value, the heating branch (201) of the purge branch (2) is closed; A temperature value of the hydrogen in the cooling branch (3) is acquired, and the low-temperature purge branch (202) is controlled to be opened based on the dew point value, and the low-temperature purge branch (202) is controlled to be closed based on the temperature value.

12. A hydrogen production system, characterized by, The hydrogen purification system as claimed in any one of claims 1-10 or the regeneration control method as claimed in claim 11 is used.

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