Hydrogen dehydration system

Abstract

The utility model relates to the technical field of hydrogen production through water electrolysis, and discloses a hydrogen dehydration system which comprises a dehydration unit, a product output unit, a heating unit and a regenerated product separation unit, wherein the dehydration unit comprises at least three dehydration towers and a plurality of raw material feeding switch valves; the product output unit comprises a hydrogen header pipe; the heating unit comprises a regeneration heater; the regeneration heater is connected with the dehydration unit and the product output unit; and the regenerated product separation unit is connected with the dehydration unit. According to the hydrogen dehydration system provided by the utility model, the serial and parallel connection modes of the dehydration towers are flexibly adjusted through the switching of the switch valves, the hydrogen dehydration system can be flexibly adapted to hydrogen with different gas volumes obtained by hydrogen production through upstream alkaline water electrolysis and hydrogen with different water volumes, the purity of the product hydrogen is high, and almost no hydrogen is wasted in the system operation process; and hydrogen drying and drying agent regeneration can be simultaneously carried out and flexibly switched.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen production by electrolysis of water, and in particular to a hydrogen dehydration system. Background Art

[0002] Hydrogen produced by water electrolysis contains trace amounts of oxygen and a large amount of water vapor. In order to obtain high-purity hydrogen, it is necessary to purify the hydrogen produced by water electrolysis. In recent years, large-scale hydrogen production projects coupled with renewable energy (wind power / photovoltaic power generation) have been gaining momentum. However, due to the discontinuity and instability of wind / photovoltaic resources, the power generation load fluctuates greatly. Due to the limitation of the hydrogen production capacity of a single alkaline electrolyzer (no more than 1000Nm 3 / h), the hydrogen production device generally has multiple electrolyzers operating in parallel. When the power generation load fluctuates, it can be matched by starting and stopping the corresponding number of electrolyzers, but the back-end "many-in-one" hydrogen purification system (that is, multiple electrolyzers, 1 purification system, usually 4 in 1 or 6 in 1) cannot adapt to the high operational flexibility of the front-end hydrogen production device, resulting in poor subsequent dehydration effect. Traditional hydrogen and purification systems cannot adapt to the high operational flexibility of large-scale water electrolysis to produce hydrogen under multiple scenarios of renewable energy (wind power / photovoltaic power generation) (sufficient or scarce wind / light resources).

[0003] At present, the dehydration system for hydrogen purification does not have flexible operating elasticity, is difficult to match the front-end hydrogen production equipment, does not have high operating elasticity and high hydrogen purification processing capacity, and has low dehydration efficiency, generally high engineering costs, and serious energy waste.

[0004] Therefore, there is an urgent need to provide a new hydrogen dehydration system that can flexibly adapt to the processing of different gas volumes and hydrogen with different water contents obtained by upstream alkaline water electrolysis. Utility Model Content

[0005] The utility model provides a hydrogen dehydration system to address the problems that the existing water electrolysis hydrogen dehydration system has poor operational flexibility, is difficult to match the front-end hydrogen production device, cannot flexibly adapt to process different gas volumes and hydrogen with different water contents produced upstream, and the dehydration efficiency needs to be improved.

[0006] In order to achieve the above-mentioned object, the utility model provides a hydrogen dehydration system, which includes a dehydration unit, a product output unit, a heating unit and a regeneration product separation unit; wherein:

[0007] The dehydration unit comprises at least three dehydration towers and a plurality of raw material feed switch valves, which are used to remove water vapor entrained in the hydrogen to be purified to obtain product hydrogen; wherein the raw material feed switch valve is used to control the hydrogen to be purified to enter at least one of the dehydration towers, or to control the hydrogen to be purified to enter a plurality of the dehydration towers connected in series, in parallel, or in a combination of series and parallel;

[0008] The product output unit comprises a hydrogen main pipe, which is connected to the dehydration unit and is used to transport the product hydrogen to outside the system;

[0009] The heating unit comprises a regeneration heater, which is connected to the dehydration unit and the product output unit and is used to heat part of the product hydrogen from the hydrogen main pipe, and then transport the heated hydrogen to the dehydration unit to desorb and regenerate the desiccant in the optional dehydration tower, and obtain a regenerated product;

[0010] The regeneration product separation unit is connected to the dehydration unit and is used to perform gas-liquid separation on the regeneration product to obtain condensed water and regeneration tail gas, and then the regeneration tail gas is transported to an optional dehydration tower in the dehydration unit for drying and merged into the hydrogen main pipe.

[0011] Preferably, when a plurality of the dehydration towers are connected in series or in a series-parallel mixed manner, the series connection is in a sequential series manner.

[0012] Preferably, the dehydration tower is not provided with a heating device.

[0013] Preferably, each of the dehydration towers is independently connected to the hydrogen main pipe through a product hydrogen discharge switch valve, and the product hydrogen is controlled to enter the hydrogen main pipe through the product hydrogen discharge switch valve.

[0014] Preferably, each of the dehydration towers is independently connected to the regeneration heater via a regeneration hydrogen feed switch valve, and the regeneration hydrogen feed switch valve controls the heated hydrogen from the regeneration heater to enter at least one of the dehydration towers to desorb and regenerate the desiccant.

[0015] Preferably, each of the dehydration towers is independently connected to the regeneration product separation unit via a regeneration product discharge switch valve, and the regeneration product obtained by the desorption regeneration is controlled by the regeneration product discharge switch valve to enter the regeneration product separation unit.

[0016] Preferably, each of the dehydration towers is independently connected to the regeneration product separation unit through a regeneration tail gas feed switch valve, and the regeneration tail gas generated by the regeneration product separation unit is controlled by the regeneration tail gas feed switch valve to enter at least one of the dehydration towers for drying.

[0017] Preferably, each of the dehydration towers is independently connected to the hydrogen main pipe through a dry regeneration tail gas discharge switch valve, and the dry regeneration tail gas discharge switch valve is used to control the dried regeneration tail gas to flow into the hydrogen main pipe.

[0018] Preferably, the regeneration product separation unit comprises a regeneration primary liquid separator tank, a regeneration cooler and a regeneration secondary liquid separator tank which are connected in sequence.

[0019] Preferably, in the hydrogen main pipe, along the product hydrogen delivery direction, a regulating valve is arranged after the connection position between the hydrogen main pipe and the regeneration heater, and the regulating valve is used to interlock and adjust the product hydrogen flow entering the regeneration heater, and to adjust the pressure drop to promote the dried regeneration tail gas to merge into the hydrogen main pipe.

[0020] Through the above technical solution, the hydrogen dehydration system provided by the utility model can achieve the following beneficial effects:

[0021] 1) The hydrogen dehydration system provided by the utility model is provided with at least three dehydration towers, which can adapt to hydrogen from upstream under various conditions (for example, just after startup, after running for a period of time, near shutdown stage), efficiently remove water vapor entrained in hydrogen, and improve the purity of product hydrogen;

[0022] 2) The hydrogen dehydration system provided by the utility model can flexibly adjust the series and parallel connection modes of the dehydration towers by switching the switch valve, and can flexibly adapt to the different gas volumes of hydrogen obtained by the upstream alkaline water electrolysis hydrogen production and flexibly adapt to the hydrogen containing different water contents, and flexibly deal with the complex material conditions appearing in the upstream;

[0023] 3) The hydrogen dehydration system provided by the utility model can reduce the waste of hydrogen during the operation of the system, and adopts part of the product hydrogen as the regeneration gas. This regenerated hydrogen can enter at least one dehydration tower for regeneration. After the regeneration is completed, it continues to enter the dehydration tower for regeneration tail gas (hydrogen) drying after gas-liquid separation and returns to the hydrogen main pipe to avoid hydrogen waste; hydrogen drying and desiccant regeneration can be carried out simultaneously and flexibly switched. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a hydrogen dehydration system according to one embodiment of the utility model.

[0025] Description of Reference Numerals

[0026] 1. The first dehydration tower 2. The second dehydration tower 3. The third dehydration tower

[0027] 4. The fourth dehydration tower 5. Regeneration heater 6. Regeneration first-stage liquid separation tank

[0028] 7. Regeneration cooler 8. Regeneration secondary liquid separation tank 9. First product hydrogen discharge switch valve

[0029] 10. First regeneration hydrogen feed switch valve 11. First dry regeneration tail gas discharge switch valve

[0030] 12. Second product hydrogen discharge switch valve 13. Second regenerated hydrogen feed switch valve

[0031] 14. Second drying and regeneration tail gas discharge switch valve 15. Third product hydrogen discharge switch valve

[0032] 16. The third regeneration hydrogen feed switch valve 17. The third dry regeneration tail gas discharge switch valve

[0033] 18. Fourth product hydrogen discharge switch valve 19. Fourth regeneration hydrogen feed switch valve

[0034] 20. Fourth drying and regeneration tail gas discharge switch valve 21. Second raw material feed switch valve

[0035] 22. Fourth raw material feed switch valve 23. Sixth raw material feed switch valve

[0036] 24. The eighth raw material feed switch valve 25. The first raw material feed switch valve

[0037] 26. First regeneration product discharge switch valve 27. First regeneration tail gas feed switch valve

[0038] 28. Third raw material feed switch valve 29. Second regeneration product discharge switch valve

[0039] 30. Second regeneration tail gas feed switch valve 31. Fifth raw material feed switch valve

[0040] 32. Third regeneration product discharge switch valve 33. Third regeneration tail gas feed switch valve

[0041] 34. Seventh raw material feed switch valve 35. Fourth regeneration product discharge switch valve

[0042] 36. Fourth regeneration tail gas feed switch valve 37. Hydrogen main pipe

[0043] 38. Control valve DETAILED DESCRIPTION

[0044] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0045] The utility model provides a hydrogen dehydration system, which comprises a dehydration unit, a product output unit, a heating unit and a regeneration product separation unit; wherein:

[0046] The dehydration unit comprises at least three dehydration towers and a plurality of raw material feed switch valves, which are used to remove water vapor entrained in the hydrogen to be purified to obtain product hydrogen; wherein the raw material feed switch valve is used to control the hydrogen to be purified to enter at least one of the dehydration towers, or to control the hydrogen to be purified to enter a plurality of the dehydration towers connected in series, in parallel, or in a combination of series and parallel;

[0047] The product output unit comprises a hydrogen main pipe, which is connected to the dehydration unit and is used to transport the product hydrogen to outside the system;

[0048] The heating unit comprises a regeneration heater, which is connected to the dehydration unit and the product output unit and is used to heat part of the product hydrogen from the hydrogen main pipe, and then transport the heated hydrogen to the dehydration unit to desorb and regenerate the desiccant in the optional dehydration tower, and obtain a regenerated product;

[0049] The regeneration product separation unit is connected to the dehydration unit and is used to perform gas-liquid separation on the regeneration product to obtain condensed water and regeneration tail gas, and then the regeneration tail gas is transported to an optional dehydration tower in the dehydration unit for drying and merged into the hydrogen main pipe.

[0050] In the specific implementation manner provided by the utility model, the dehydration unit includes at least three dehydration towers, so as to meet the basic requirements of adjusting the connection relationship between the dehydration towers, realizing the operation of a single dehydration tower or the simultaneous operation of multiple dehydration towers in series, parallel or a series-parallel mixed mode. In the utility model, there is no limit on the upper limit of the number of dehydration towers in the dehydration unit, and the upper limit of the number of dehydration towers can be flexibly set according to the different gas amounts of hydrogen and different water amounts of hydrogen obtained by the upstream alkaline water electrolysis hydrogen production of the system, and the number of dehydration towers in the hydrogen dehydration operation state and the specific series-parallel connection relationship can be adjusted.

[0051] In the specific implementation of the utility model, the dehydration tower is defined broadly, and any dehydration tower in the art that can be used for dehydration of hydrogen from water electrolysis can be used. The specifications of each dehydration tower and the desiccant loaded can be the same or different. In the utility model, preferably, the specifications of each dehydration tower and the desiccant loaded are the same, and main towers and auxiliary towers of different sizes are not provided, which is more conducive to simultaneous hydrogen dehydration and desiccant regeneration.

[0052] In the specific implementation manner provided by the utility model, the hydrogen dehydration system adopts an external regeneration heater to heat the regenerated hydrogen, and a set of heating units is used to heat the regenerated hydrogen and regenerate the desiccant in each dehydration tower, thereby reducing the heating energy consumption and heating cost during the regeneration process. Preferably, the dehydration tower is not provided with a heating device.

[0053] In the specific implementation manner provided by the utility model, preferably, when a plurality of the dehydration towers are connected in series or in a series-parallel mixed manner, the series connection adopts a sequential series connection manner.

[0054] In the present use of new type, the sequential series connection means that during the process of series feeding, the material does not skip a dehydration tower between the first dehydration tower and the last dehydration tower. For example, in the case where four dehydration towers are provided in the dehydration unit, they are recorded as the first dehydration tower, the second dehydration tower, the third dehydration tower and the fourth dehydration tower from front to back. When three of the dehydration towers are selected for series connection, the sequential series connection can adopt the mode of sequentially connecting the first dehydration tower, the second dehydration tower and the third dehydration tower in series, or the mode of sequentially connecting the second dehydration tower, the third dehydration tower and the fourth dehydration tower in series, or the mode of sequentially connecting the fourth dehydration tower, the first dehydration tower and the second dehydration tower in series, etc., all of which belong to the sequential series connection. However, for example, the mode of sequentially connecting the first dehydration tower, the third dehydration tower and the fourth dehydration tower in series, or the mode of sequentially connecting the fourth dehydration tower, the first dehydration tower and the third dehydration tower in series, etc., these modes do not belong to the sequential series connection. In the present utility model, the sequential series connection adopts the mode of sequential series connection, which is more conducive to simplifying the complexity of the system circuit and facilitating control.

[0055] In the specific implementation manner provided by the utility model, preferably, each of the dehydration towers is independently connected to the hydrogen main pipe through a product hydrogen discharge switch valve, and the product hydrogen is controlled to enter the hydrogen main pipe through the product hydrogen discharge switch valve.

[0056] In the present invention, preferably, each of the dehydration towers is correspondingly configured with at least one product hydrogen discharge switch valve to achieve flexible control of whether the dehydration product produced by each dehydration tower enters or does not enter the hydrogen main pipe.

[0057] In the specific implementation manner provided by the utility model, the definition of the regeneration heater is relatively broad, and any device capable of heating hydrogen (used as regeneration gas) to the temperature required for desiccant regeneration can be used.

[0058] In the specific implementation manner provided by the utility model, preferably, each of the dehydration towers is independently connected to the regeneration heater through a regeneration hydrogen feed switch valve, and the heated hydrogen from the regeneration heater is controlled by the regeneration hydrogen feed switch valve to enter at least one of the dehydration towers to desorb and regenerate the desiccant.

[0059] In the present invention, preferably, each of the dehydration towers is correspondingly provided with at least one regeneration hydrogen feed switch valve, so as to flexibly select the dehydration tower that needs to regenerate the desiccant for desorption regeneration according to specific operating conditions.

[0060] In the specific implementation manner provided by the utility model, preferably, each of the dehydration towers is independently connected to the regeneration product separation unit through a regeneration product discharge switch valve, and the regeneration product obtained by the desorption regeneration is controlled by the regeneration product discharge switch valve to enter the regeneration product separation unit.

[0061] In the present invention, preferably, each of the dehydration towers is correspondingly configured with at least one regeneration product discharge switch valve, so that each of the dehydration towers can be regenerated and the regeneration product can be transported to the regeneration product separation unit.

[0062] In the specific embodiment provided by the utility model, preferably, each of the dehydration towers is independently connected to the regeneration product separation unit through a regeneration tail gas feed switch valve, and the regeneration tail gas generated by the regeneration product separation unit is controlled by the regeneration tail gas feed switch valve to enter at least one of the dehydration towers for drying.

[0063] In the utility model, preferably, each of the dehydration towers is correspondingly configured with at least one regeneration tail gas feed switch valve, so that each of the dehydration towers can be used to dry and dehydrate the regeneration tail gas, thereby realizing flexible selection of a specific dehydration tower for drying and dehydrating the regeneration tail gas according to specific operating conditions.

[0064] In the specific implementation manner provided by the utility model, preferably, each of the dehydration towers is independently connected to the hydrogen main pipe through a dry regeneration tail gas discharge switch valve, and the dry regeneration tail gas discharge switch valve is used to control the dried regeneration tail gas to flow into the hydrogen main pipe.

[0065] In the present invention, preferably, each of the dehydration towers is correspondingly configured with at least one drying and regeneration tail gas discharge switch valve.

[0066] In the specific implementation mode provided by the utility model, preferably, the regeneration product separation unit comprises a regeneration first-stage liquid separator, a regeneration cooler and a regeneration second-stage liquid separator connected in sequence. The regeneration product first enters the regeneration first-stage liquid separator for gas-liquid separation, and the hydrogen with a small amount of water vapor obtained above the regeneration first-stage liquid separator enters the regeneration cooler to continue to remove moisture, and then the product enters the regeneration second-stage liquid separator for gas-liquid separation, and the condensed water coming out from the bottom of the regeneration second-stage liquid separator, the condensed water coming out from the bottom of the regeneration cooler, and the condensed water coming out from the bottom of the regeneration first-stage liquid separator are combined and discharged from the system, and the regeneration tail gas (hydrogen) obtained above the regeneration second-stage liquid separator enters an optional dehydration tower for drying.

[0067] In the specific implementation manner provided by the utility model, preferably, in the hydrogen main pipe, along the product hydrogen delivery direction, a regulating valve is arranged after the connection position between the hydrogen main pipe and the regeneration heater, and the regulating valve is used to interlock and adjust the product hydrogen flow entering the regeneration heater, and to adjust the pressure drop to promote the dried regeneration tail gas to merge into the hydrogen main pipe.

[0068] In the specific implementation manner provided by the utility model, preferably, in the hydrogen main pipe, along the product hydrogen delivery direction, the position where the dried regenerated tail gas enters the hydrogen main pipe is located after the position of the regulating valve.

[0069] In the specific implementation manner provided by the utility model, auxiliary equipment such as flow control valves, liquid level control valves, and pressure control valves may also be provided on the lines connecting the various devices, and may be provided in a conventional manner in the art according to the needs of logistics regulation, and the utility model has no special limitation on this.

[0070] The following combination Figure 1 A hydrogen dehydration system according to an embodiment of the present invention is shown, and the system and the working process are described.

[0071] In one embodiment of the present invention, Figure 1 As shown, the hydrogen dehydration system includes a dehydration unit A, a product output unit B, a heating unit C and a regeneration product separation unit D; wherein,

[0072] The dehydration unit A includes four dehydration towers (used to illustrate an embodiment of the utility model, and does not limit the number of dehydration towers), which are respectively recorded as the first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4 (the specifications of the four dehydration towers and the water absorbent loaded are the same); wherein the first dehydration tower 1 is correspondingly provided with a first raw material feed switch valve 25, the second dehydration tower 2 is correspondingly provided with a third raw material feed switch valve 28, the third dehydration tower 3 is correspondingly provided with a fifth raw material feed switch valve 31, and the fourth dehydration tower 4 is correspondingly provided with a seventh raw material feed switch valve 34; on the series circuit of the first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4, the second raw material feed switch valve 21, the fourth raw material feed switch valve 22, the sixth raw material feed switch valve 23 and the eighth raw material feed switch valve 24 are sequentially provided between two adjacent towers;

[0073] The product output unit B includes a hydrogen main pipe 37; the heating unit C includes a regeneration heater 5; the regeneration product separation unit D includes a regeneration primary liquid separator 6, a regeneration cooler 7 and a regeneration secondary liquid separator 8 connected in sequence;

[0074] In the hydrogen main pipe 37, a regulating valve 38 is provided after the connection position between the hydrogen main pipe 37 and the regeneration heater 5 along the product hydrogen delivery direction;

[0075] The first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4 are respectively provided with a first product hydrogen discharge switch valve 9, a second product hydrogen discharge switch valve 12, a third product hydrogen discharge switch valve 15 and a fourth product hydrogen discharge switch valve 18, and are connected to the hydrogen main pipe 37 through the above-mentioned product hydrogen discharge switch valves;

[0076] The hydrogen main pipe 37 is connected to the gas inlet of the regeneration heater 5 through a branch line;

[0077] The first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4 are respectively provided with a first regeneration hydrogen feed switch valve 10, a second regeneration hydrogen feed switch valve 13, a third regeneration hydrogen feed switch valve 16 and a fourth regeneration hydrogen feed switch valve 19, and are connected to the heating gas outlet of the regeneration heater 5 through the above-mentioned regeneration hydrogen feed switch valves;

[0078] The first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4 are respectively provided with a first regeneration product discharge switch valve 26, a second regeneration product discharge switch valve 29, a third regeneration product discharge switch valve 32, and a fourth regeneration product discharge switch valve 35, and are connected to the feed port of the regeneration primary liquid separation tank 6 through the above-mentioned regeneration product discharge switch valves;

[0079] The first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4 are respectively provided with a first regeneration tail gas feed switch valve 27, a second regeneration tail gas feed switch valve 30, a third regeneration tail gas feed switch valve 33 and a fourth regeneration tail gas feed switch valve 36, and the discharge port of the regeneration secondary liquid separation tank 8 is connected through the above-mentioned regeneration tail gas feed switch valve;

[0080] The first dehydration tower 1, the second dehydration tower 2, the third dehydration tower 3 and the fourth dehydration tower 4 are respectively provided with a first drying and regeneration tail gas discharge switch valve 11, a second drying and regeneration tail gas discharge switch valve 14, a third drying and regeneration tail gas discharge switch valve 17, and a fourth drying and regeneration tail gas discharge switch valve 20, and are connected to the hydrogen main pipe 37 through the above-mentioned regeneration tail gas discharge switch valve, and the connection position is located after the position of the regulating valve 38 (along the product hydrogen delivery direction);

[0081] The regulating valve 38 is interlocked to adjust the flow rate of the product hydrogen entering the regeneration heater 5 , and is used to adjust the pressure drop to promote the dried regeneration tail gas to flow into the hydrogen main pipe 37 .

[0082] Working process example 1:

[0083] The gas volume of water-containing hydrogen (water content 3-4wt%) from the deoxygenation device upstream of the system is 12000Nm 3 / h, the hydrogen processing capacity of a single dehydration tower is 4000Nm 3 / h, the processing requirements of the upstream hydrogen to be dehydrated cannot be met by the operation of a single tower or two towers in series. The system of the utility model is adopted, and the three-tower series mode is selected. By opening the first raw material feed switch valve 25, the second raw material feed switch valve 21, and the fourth raw material feed switch valve 22, the hydrogen to be dehydrated enters the first dehydration tower 1, the second dehydration tower 2, and the third dehydration tower 3 in sequence (the operating temperature of the three dehydration towers is 20-30°C, and the operating pressure is 1.5-1.7MPa), and the water vapor entrained in the hydrogen is removed;

[0084] When the water content of the hydrogen at the outlet of the third dehydration tower 3 is less than 10 ppm, the product hydrogen is transported to the hydrogen main pipe 37 and then to the outside of the system through the opened third product hydrogen discharge switch valve 15;

[0085] A stream of product hydrogen (accounting for 10-30wt% of the total amount of product hydrogen) is separated from the hydrogen main pipe 37 as regeneration hydrogen for regeneration of the first dehydration tower 1, the second dehydration tower 2, and the third dehydration tower 3. The hydrogen is first heated by the regeneration heater 5, and the hot hydrogen coming out of the heater 5 enters the first dehydration tower 1, the second dehydration tower 2, and the third dehydration tower 3 through the opened first regeneration hydrogen feed switch valve 10, the second regeneration hydrogen feed switch valve 13, and the regeneration hydrogen feed switch valve 16 respectively for regeneration of the three dehydration towers (the regeneration temperature of the three towers is 240-260°C, and the regeneration pressure is 1.5-1.7MPa). After that, the regeneration product (hydrogen entrained with water vapor) is separated into gas and liquid through the regeneration first-stage separator tank 6 through the opened first regeneration product discharge switch valve 26, the second regeneration product discharge switch valve 29, and the regeneration product discharge switch valve 32. The hydrogen with a small amount of water vapor enters the regeneration cooler 7 to continue to remove moisture, and then the product enters the regeneration secondary liquid separator 8 for gas-liquid separation. The condensed water coming out from the bottom of the regeneration secondary liquid separator 8, the condensed water coming out from the bottom of the regeneration cooler 7, and the condensed water coming out from the bottom of the regeneration primary liquid separator 6 are combined and discharged out of the system. The regenerated tail gas (hydrogen) obtained above the regeneration secondary liquid separator 8 enters the fourth dehydration tower 4 through the opened fourth regeneration tail gas feed switch valve 36 for drying (drying temperature is 20-30°C, drying pressure is 1.5-1.7MPa). When the water content of the hydrogen at the outlet of the fourth dehydration tower 4 is less than 10ppm, it enters the hydrogen main pipe 37 through the opened fourth dry regeneration tail gas discharge switch valve 20 and is transported outside the system; the regulating valve 38 is interlocked and adjusts the product hydrogen flow entering the regeneration heater 5, and adjusts the pressure drop to promote the dried regeneration tail gas to merge into the hydrogen main pipe 37.

[0086] For hydrogen with the above gas volume and water content, the purity of the hydrogen product after dehydration can be greater than 99.999%, with almost no hydrogen waste.

[0087] Working process example 2:

[0088] The gas volume of water-containing hydrogen (water content 3-4wt%) from the deoxygenation device upstream of the system is 3000Nm 3 / h, the hydrogen processing capacity of a single dehydration tower is 4000Nm 3 / h, using the system of the utility model, any dehydration tower can be used for treatment, and the raw material feed switch valve 25 is opened to enter the first dehydration tower 1 alone, or the first raw material feed switch valve 25, the third raw material feed switch valve 28, and the fifth raw material feed switch valve 31 are opened at the same time to enter the first dehydration tower 1, the second dehydration tower 2, and the third dehydration tower 3 (operating temperature is 20-30°C, operating pressure is 1.5-1.7MPa) connected in parallel to remove water vapor entrained in hydrogen;

[0089] When the water content of hydrogen at the outlet of the first dehydration tower 1 (for the case of three towers in parallel, it also includes the outlet of the second dehydration tower 2 and the outlet of the third dehydration tower 3) is less than 10ppm, the product hydrogen is transported to the hydrogen main pipe 37 and sent out of the system through the opened first product hydrogen discharge switch valve 9 (for the case of three towers in parallel, it also includes the second product hydrogen discharge switch valve 12 and the third product hydrogen discharge switch valve 15);

[0090] The hydrogen main pipe 37 can separate a stream of product hydrogen as regeneration hydrogen for the regeneration of the aforementioned dehydration tower 1 (for the case of three towers in parallel, it also includes the second dehydration tower 2 and the third dehydration tower 3). For the regeneration process, taking the dehydration tower 1 as an example, the hydrogen is first heated by the regeneration heater 5, and the hot hydrogen coming out of the heater 5 enters the first dehydration tower 1 through the opened first regeneration hydrogen feed switch valve 10 for regeneration of the dehydration tower (the regeneration temperature of the three towers is 240-260°C, and the regeneration pressure is 1.5-1.7MPa), and then the regeneration product (hydrogen with water vapor) is separated from the gas and liquid through the regeneration first liquid separator 6 through the opened first regeneration product discharge switch valve 26. The hydrogen with a small amount of water vapor obtained above the regeneration first liquid separator 6 enters the regeneration cooler 7 to continue to remove moisture, and then the product enters The regenerated tail gas (hydrogen) obtained above the regenerated secondary liquid separator 8 enters the fourth dehydration tower 4 for drying (drying temperature is 20-30°C, drying pressure is 1.5-1.7MPa) through the opened fourth regenerated tail gas feed switch valve 36. When the water content of the hydrogen at the outlet of the fourth dehydration tower 4 is less than 10ppm, it enters the hydrogen main pipe 37 through the opened fourth dry regenerated tail gas discharge switch valve 20 and is transported to the outside of the system; the regulating valve 38 is interlocked to adjust the product hydrogen flow entering the regeneration heater 5, and the pressure drop is adjusted to promote the dried regenerated tail gas to enter the hydrogen main pipe 37;

[0091] Similarly, dehydration tower 2 and dehydration tower 3 can also perform the regeneration process, separation of regeneration products and drying of regeneration tail gas by adjusting the corresponding switch valves;

[0092] For the above-mentioned hydrogen volume and water content, a single tower or three towers in parallel can be used to dehydrate hydrogen less than the processing capacity of a single tower (wherein three towers in parallel can achieve continuous operation). For the above-mentioned hydrogen volume and water content, the purity of the dehydrated product hydrogen can be greater than 99.999%, with almost no hydrogen waste.

[0093] By adopting the hydrogen dehydration system provided by the utility model, the series and parallel connection modes of the dehydration towers can be flexibly adjusted by switching the switch valve, and the hydrogen with different gas amounts obtained by the upstream alkaline water electrolysis hydrogen production and the hydrogen containing different water amounts can be flexibly adapted. The product hydrogen has high purity, and there is almost no hydrogen waste during the operation of the system. Hydrogen drying and desiccant regeneration can be carried out simultaneously and flexibly switched.

[0094] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A hydrogen dehydration system, characterized in that: The system comprises a dehydration unit, a product output unit, a heating unit and a regeneration product separation unit; wherein, The dehydration unit comprises at least three dehydration towers and a plurality of raw material feed switch valves, which are used to remove water vapor entrained in the hydrogen to be purified to obtain product hydrogen; wherein the raw material feed switch valve is used to control the hydrogen to be purified to enter at least one of the dehydration towers, or to control the hydrogen to be purified to enter a plurality of the dehydration towers connected in series, in parallel, or in a combination of series and parallel; The product output unit comprises a hydrogen main pipe, which is connected to the dehydration unit and is used to transport the product hydrogen to outside the system; The heating unit comprises a regeneration heater, which is connected to the dehydration unit and the product output unit and is used to heat part of the product hydrogen from the hydrogen main pipe, and then transport the heated hydrogen to the dehydration unit to desorb and regenerate the desiccant in the optional dehydration tower, and obtain a regenerated product; The regeneration product separation unit is connected to the dehydration unit and is used to perform gas-liquid separation on the regeneration product to obtain condensed water and regeneration tail gas, and then the regeneration tail gas is transported to an optional dehydration tower in the dehydration unit for drying and merged into the hydrogen main pipe.

2. The system according to claim 1, wherein: When a plurality of the dehydration towers are connected in series or in a series-parallel mixed manner, the series connection is in a sequential series connection manner.

3. The system according to claim 1, wherein: The dehydration tower is not provided with a heating device.

4. The system according to claim 1, wherein: Each of the dehydration towers is independently connected to the hydrogen main pipe through a product hydrogen discharge switch valve, and the product hydrogen is controlled to enter the hydrogen main pipe through the product hydrogen discharge switch valve.

5. The system according to claim 1, wherein: Each of the dehydration towers is independently connected to the regeneration heater via a regeneration hydrogen feed switch valve, and the regeneration hydrogen feed switch valve controls the heated hydrogen from the regeneration heater to enter at least one of the dehydration towers to desorb and regenerate the desiccant.

6. The system according to claim 1, wherein: Each of the dehydration towers is independently connected to the regeneration product separation unit through a regeneration product discharge switch valve, and the regeneration product obtained by the desorption regeneration is controlled by the regeneration product discharge switch valve to enter the regeneration product separation unit.

7. The system according to claim 1, wherein: Each of the dehydration towers is independently connected to the regeneration product separation unit through a regeneration tail gas feed switch valve, and the regeneration tail gas generated by the regeneration product separation unit is controlled by the regeneration tail gas feed switch valve to enter at least one of the dehydration towers for drying.

8. The system according to claim 1, wherein: Each of the dehydration towers is independently connected to the hydrogen main pipe through a dry regeneration tail gas discharge switch valve, and the dry regeneration tail gas discharge switch valve is used to control the dried regeneration tail gas to flow into the hydrogen main pipe.

9. The system according to claim 1, wherein: The regeneration product separation unit comprises a regeneration primary liquid separation tank, a regeneration cooler and a regeneration secondary liquid separation tank which are connected in sequence.

10. The system according to claim 1, wherein: In the hydrogen main pipe, a regulating valve is arranged after the connection position between the hydrogen main pipe and the regeneration heater along the conveying direction of the product hydrogen. The regulating valve is used to interlock and adjust the product hydrogen flow entering the regeneration heater, and to adjust the pressure drop to promote the dried regeneration tail gas to flow into the hydrogen main pipe.

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