TSA dehydration system and method suitable for large-scale wind-solar hydrogen production

Abstract

The invention relates to the technical field of hydrogen purification, and discloses a TSA dehydration system and method suitable for large-scale wind and light hydrogen production, and the system comprises the following modules: an adsorption module which is composed of a plurality of drying towers and is used for adsorbing moisture in upstream crude hydrogen; the regeneration treatment module comprises a regeneration gas heater, a regeneration gas heat exchanger, a regeneration gas cooler and a regeneration gas gas-liquid separator which are sequentially connected in series and are respectively used for regeneration gas heating, heat exchange of hot-state and cold-state regeneration gas, regeneration gas cooling and gas-water separation, and the regeneration treatment module is provided with a regulating valve for controlling the gas taking amount of the regeneration gas; a valve control module; a monitoring module; and a main control module. Four operation modes are divided according to the real-time crude hydrogen flow, mode switching is executed only when an adsorption time sequence period is finished and dew point monitoring and temperature monitoring both meet qualified conditions, and therefore the number of online towers of an adsorption unit is adjusted along with the change of the crude hydrogen flow, and adaptation to the change of the crude hydrogen flow under the wind-solar hydrogen production condition is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen purification, in particular to a TSA dehydration system and method suitable for large-scale wind-solar hydrogen production. BACKGROUND

[0002] With the continuous expansion of wind power and photovoltaic power generation, the wind-solar hydrogen production technology of using renewable energy to produce hydrogen by electrolysis of water has gradually become an important way of hydrogen production. The electrolysis device in the wind-solar hydrogen production process will be affected by external conditions such as wind speed and light during operation, resulting in frequent changes in the crude hydrogen output between different working conditions such as low load, medium load and high load. The crude hydrogen produced by electrolysis contains a certain amount of water, which needs to be reduced in water content through a drying process before entering the subsequent storage and application link. The TSA (Temperature Swing Adsorption) dehydration technology is widely used in wind-solar hydrogen production systems because of its stable adsorption performance through adsorption-regeneration cycle. With the scale of renewable energy hydrogen production increasing, the hydrogen production of a single hydrogen production device is increasing, and the dehydration unit needs to be able to adapt to large-scale hydrogen flow changes and maintain the product dew point to meet the subsequent use requirements.

[0003] The existing wind-solar hydrogen dehydration system mostly uses the TSA drying method with fixed number of towers, fixed time sequence or limited regeneration and adsorption period, and the running mode is usually not adjusted with the change of crude hydrogen flow, resulting in insufficient adsorption time at high load, idle adsorption capacity at low load, and possible switching due to failure to meet the required conditions of adsorption, regeneration or cold blowing, so that the drying tower cannot match the fluctuating output of the front-end electrolytic hydrogen production device, and therefore it is difficult to adjust the number of online drying towers and the running state of the drying tower according to the real-time crude hydrogen flow, resulting in that the dehydration system is difficult to adapt to the continuous change of crude hydrogen flow under wind-solar hydrogen production. SUMMARY

[0004] In view of the shortcomings of the prior art, the present application provides a TSA dehydration system and method suitable for large-scale wind-solar hydrogen production, which adjusts the number of online drying towers and the running state of the drying tower according to the real-time crude hydrogen flow, solving the problem that the dehydration system is difficult to adapt to the continuous change of crude hydrogen flow under wind-solar hydrogen production.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: a TSA dehydration system suitable for large-scale wind-solar hydrogen production, comprising the following modules:

[0006] The adsorption module is composed of multiple drying towers and is used for adsorbing water in the upstream crude hydrogen;

[0007] The regeneration treatment module comprises a regeneration gas heater, a regeneration gas heat exchanger, a regeneration gas cooler and a regeneration gas gas-liquid separator connected in series, and is respectively used for regeneration gas heating, heat state and cold state regeneration gas heat exchange, regeneration gas cooling and gas-water separation, and the regeneration treatment module is provided with an adjusting valve for controlling the regeneration gas taking amount;

[0008] The valve control module comprises a program-controlled valve group for switching the drying tower adsorption, cold blowing, regeneration and secondary adsorption states, and comprises a program-controlled valve group for switching the gas flow path in different online tower number modes;

[0009] The monitoring module comprises a dew point analyzer, a temperature transmitter, a crude hydrogen flow meter, a regeneration gas flow meter and a gas-liquid separator liquid level monitoring and drainage assembly;

[0010] The main control module is in signal connection with the monitoring module and the valve control module, and is used for controlling the valve control module to switch the adsorption mode according to the design capacity yield threshold values Q1, Q2 and Q3 of a single drying tower, in combination with the dew point qualified index and the regeneration temperature qualified index, wherein Q3 is the maximum design adsorption capacity of a single tower, Q2 is 60-80% of the normal adsorption capacity of a single tower, and Q1 is 30-50% of the normal adsorption capacity of a single tower; the real-time crude hydrogen flow is compared with Q1, Q2 and Q3, and the adsorption mode comprises a four-tower high-yield mode, a four-tower high-efficiency mode, a three-tower medium-load mode and a two-tower low-load mode.

[0011] Preferably, the adsorption module is composed of four drying towers, in the four-tower high-yield mode, the real-time crude hydrogen flow Q≥Q3, the main control module controls two drying towers to adsorb in parallel, one drying tower to regenerate, one drying tower to cold blow, and switches the operation states of the drying towers in turn according to the adsorption time sequence and the dew point monitoring result.

[0012] Preferably, in the four-tower high-efficiency mode, the real-time crude hydrogen flow Q2

[0013] Preferably, in the three-tower medium-load mode, the real-time crude hydrogen flow Q1≤Q

[0014] Preferably, in the two-tower low-load mode, the real-time crude hydrogen flow Q

[0015] Preferably, the main control module controls the timing of mode switching at the end of the current adsorption timing cycle, and the switching needs to meet the real-time crude hydrogen flow continuously matching the yield threshold range corresponding to the target mode, and the water dew point analyzer feedback adsorption effect is qualified, and the temperature transmitter feedback regeneration and cold blowing effect is qualified.

[0016] Preferably, the main control module controls the logic of mode switching: based on the real-time crude hydrogen flow obtained by the crude hydrogen flow meter to determine whether it is in a certain yield threshold interval, combined with the dew point monitoring to determine whether the adsorption state is qualified, and combined with the temperature monitoring to determine whether the regeneration and cold blowing state is qualified, and finally execute the switching at the end of the adsorption timing cycle.

[0017] Preferably, the main control module controls the sequence of mode switching: when the hydrogen yield gradually decreases, switch in the order of four-tower high-yield mode, four-tower high-efficiency mode, three-tower medium-load mode, and two-tower low-load mode, and the dry towers switched out are kept in qualified standby state; when the hydrogen yield gradually increases, switch in the order of two-tower low-load mode, three-tower medium-load mode, four-tower high-efficiency mode, and four-tower high-yield mode, and the dry towers switched in directly adapt to the working state of the target mode, and the product hydrogen dew point always meets the standard during the switching process.

[0018] Preferably, the dry tower switched out does not participate in the cycle period, is used to reduce the molecular sieve thermal stress and mechanical wear, and can perform molecular sieve inspection or replacement during the switching-out period, and meets the cold blowing temperature reduction condition when switched out.

[0019] Preferably, a TSA dehydration method suitable for large-scale wind-solar hydrogen production includes the following steps:

[0020] S1, according to the design capacity of a single dry tower, set three yield threshold values Q1, Q2, Q3, and clearly Q≥Q3 corresponds to four-tower high-yield mode, Q2

[0021] S2, real-time acquisition of crude hydrogen flow, dew point of each dry tower top outlet gas, dry tower bottom outlet temperature, regeneration gas heating temperature, regeneration gas flow, gas-liquid separator liquid level, and current adsorption timing data, and control drainage according to the liquid level signal;

[0022] S3, continuously compare the real-time crude hydrogen flow with Q1, Q2, Q3, and determine whether the adsorption effect is qualified through dew point data and whether the regeneration and cold blowing effect is qualified through temperature data, to determine the target mode and switching timing;

[0023] S4, when the hydrogen production decreases, the main control module switches the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode and the two-tower low-load mode in sequence through the valve control module, and the cut-out drying tower remains in a qualified standby state; when the hydrogen production increases, the two-tower low-load mode, the three-tower medium-load mode, the four-tower high-efficiency mode and the four-tower high-yield mode are switched in sequence, and the cut-out drying tower is in a standby state meeting the cold blowing condition;

[0024] S5, after switching, the dew point, regeneration temperature and crude hydrogen flow are continuously monitored, if any index is unqualified, the timing parameters are immediately adjusted or switched back to the original adaptive mode, forming a product quality closed-loop control to ensure that the outlet hydrogen dew point meets the standard.

[0025] The application provides a TSA dehydration system and method suitable for large-scale wind-solar hydrogen production.

[0026] 1. The application divides into four operation modes according to real-time crude hydrogen flow, and makes mode switching only at the end of the adsorption timing cycle and when the dew point monitoring and temperature monitoring meet the qualified conditions, so that the number of online adsorption units is adjusted according to the crude hydrogen flow; under different working conditions such as low load, medium load and high load, the number and operation state of the drying towers are changed to match the fluctuating output of the front-end hydrogen production device, realizing the adaptation to the change of crude hydrogen flow under wind-solar hydrogen production conditions.

[0027] 2. The application enables different numbers of drying towers to participate in adsorption under different crude hydrogen flow conditions: and the drying towers not participating in the cycle are cut out as standby towers; during the cutting-out period, the drying towers do not undergo adsorption, regeneration and cold blowing cycle, thereby reducing the temperature cycle and flow impact on the molecular sieve, prolonging the service life of the molecular sieve and the valve device involved in the switching action; at the same time, the state of the standby tower when it is cut out is a qualified regeneration state, which is ready for use at any time when production is needed.

[0028] 3. The application reduces the number of drying towers participating in the cycle in the low-load and medium-load modes, reduces the workload of the regeneration gas heater, regeneration gas heat exchanger and regeneration gas cooler of the regeneration treatment unit, thereby reducing the regeneration heating consumption; at the same time, since the cut-out drying tower does not participate in adsorption, regeneration and cold blowing after meeting the cold blowing temperature reduction condition, the molecular sieve can be checked or replaced during the cutting-out period, decoupling the maintenance operation and hydrogen production operation, reducing the shutdown demand and improving the operation stability, thereby reducing the maintenance cost and regeneration energy consumption.

[0029] 4, The application obtains the dew point of the outlet gas of each adsorption tower by the dew point analyzer, and uses the dew point qualified criterion as the condition for the adsorption tower to exit the adsorption state, monitors the regeneration and cold blowing temperature by the temperature transmitter, and uses the regeneration and cold blowing qualified criterion as the next state switching condition, so that the adsorption tower is switched to regeneration only when the adsorption reaches the set dew point requirement, the regenerated tower is switched to cold blowing only when the temperature meets the set requirement, the cold blowing tower is switched to adsorption only when the temperature drops to the set range, and the closed loop quality control is realized by continuously monitoring the dew point, regeneration temperature and crude hydrogen flow after mode switching, when any index does not meet the requirement, the timing is adjusted or the previous mode is restored, the dew point of the outlet hydrogen gas is continuously maintained in the set range, and the unremoved moisture is avoided to enter the product gas pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The system architecture diagram of the application;

[0031] Figure 2 The method flow chart of the application;

[0032] Figure 3 The four-tower high-yield mode flow chart of the application;

[0033] Figure 4 The four-tower high-efficiency mode flow chart of the application;

[0034] Figure 5 The three-tower medium-load mode flow chart of the application;

[0035] Figure 6 The two-tower low-load mode flow chart of the application. DETAILED DESCRIPTION

[0036] The technical solutions of the application will be described clearly and completely below with reference to the drawings of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0037] Please refer to the drawings of the application Figure 1 - the drawings of the application Figure 6 The embodiment of the application provides a TSA dehydration system suitable for large-scale wind-solar hydrogen production, which comprises the following modules:

[0038] The adsorption module is composed of multiple drying towers and is used for adsorbing the moisture in the upstream crude hydrogen;

[0039] The regeneration treatment module comprises a regeneration gas heater, a regeneration gas heat exchanger, a regeneration gas cooler and a regeneration gas gas-liquid separator connected in series, and is used for regeneration gas heating, hot and cold regeneration gas heat exchange, regeneration gas cooling and gas-water separation, and the regeneration treatment module is provided with an adjusting valve for controlling the regeneration gas quantity;

[0040] The valve control module comprises a program-controlled valve group for switching the drying tower adsorption, cold blowing, regeneration and secondary adsorption states, and a program-controlled valve group for switching the gas flow path in different online tower number modes;

[0041] The monitoring module comprises a dew point analyzer, a temperature transmitter, a crude hydrogen flow meter, a regeneration gas flow meter and a gas-liquid separator liquid level monitoring and drainage assembly;

[0042] The main control module is connected with the monitoring module and the valve control module, and is used for controlling the valve control module to switch the adsorption mode according to the design capacity threshold Q1, Q2 and Q3 of a single drying tower, in combination with the dew point qualified index and the regeneration temperature qualified index, wherein Q3 is the maximum design adsorption capacity of a single tower, Q2 is 60-80% of the normal adsorption capacity of a single tower, and Q1 is 30-50% of the normal adsorption capacity of a single tower; the real-time crude hydrogen flow is compared with Q1, Q2 and Q3, and the adsorption mode includes a four-tower high-yield mode, a four-tower high-efficiency mode, a three-tower medium-load mode and a two-tower low-load mode.

[0043] By adopting the above scheme, the adsorption module adsorbs the moisture in the upstream crude hydrogen through the structure composed of multiple drying towers, the regeneration treatment module sequentially completes the regeneration gas heating, hot and cold regeneration gas heat exchange, regeneration gas cooling and gas-water separation for the regeneration gas used for regenerating the drying tower through the sequential connection of the regeneration gas heater, the regeneration gas heat exchanger, the regeneration gas cooler and the regeneration gas gas-liquid separator, and the adjusting valve for controlling the regeneration gas quantity arranged in the regeneration treatment module controls the regeneration gas quantity in the regeneration working condition;

[0044] The valve control module switches the states of the drying tower adsorption, cold blowing, regeneration and secondary adsorption through the program-controlled valve group for switching the states and the program-controlled valve group for switching the gas flow path in different online tower number modes, so that the multiple drying towers switch between the adsorption, cold blowing, regeneration and secondary adsorption states according to the predetermined adsorption mode between the adsorption module and the regeneration treatment module, and the online tower number can be adjusted in the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode and the two-tower low-load mode;

[0045] The monitoring module monitors the dew point of the outlet of the drying tower, the temperature of the bottom of the drying tower and the regenerated gas, the crude hydrogen flow, the wet regenerated gas flow and the liquid level of the gas-liquid separator through the dew point analyzer, the temperature transmitter, the crude hydrogen flowmeter, the regenerated gas flowmeter and the gas-liquid separator liquid level monitoring and drainage assembly, and provides the main control module with real-time data of the adsorption effect, the regeneration temperature, the regenerated gas working condition and the liquid level drainage state.

[0046] The main control module sets the yield thresholds Q1, Q2 and Q3 according to the design capacity of a single drying tower, and takes Q3 as the maximum design adsorption capacity of a single tower, Q2 as 60-80% of the normal adsorption capacity of a single tower, and Q1 as 30-50% of the normal adsorption capacity of a single tower, wherein Q2 and Q3 can be adjusted according to actual conditions. In the running process, the real-time crude hydrogen flow obtained through the crude hydrogen flowmeter is compared with Q1, Q2 and Q3. When the real-time crude hydrogen flow is in different threshold intervals, the main control module issues control instructions to the valve control module in combination with the dew point qualified index and the regeneration temperature qualified index, selects one of the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode or the two-tower low-load mode, and controls the adsorption, cold blowing, regeneration and secondary adsorption states of each drying tower and the online tower number in the corresponding adsorption mode, so that the drying tower switches the adsorption mode according to the real-time crude hydrogen flow under the premise of meeting the dew point qualified index and the regeneration temperature qualified index, and realizes the matching between crude hydrogen adsorption dehydration and regenerated gas treatment working condition.

[0047] The adsorption module is composed of four drying towers. When the four-tower high-yield mode is adopted, the real-time crude hydrogen flow Q≥Q3, the main control module controls two drying towers to adsorb in parallel, one drying tower to regenerate, and one drying tower to cold blow, and switches the running states of the drying towers in turn according to the adsorption time sequence and the dew point monitoring result.

[0048] Through the above scheme, under the working condition of real-time crude hydrogen flow Q≥Q3, two drying towers are used to adsorb in parallel to provide an adsorption flux matching the crude hydrogen flow, one drying tower is used for regeneration to restore its adsorption capacity, and one drying tower is used for cold blowing to cool the tower body to a temperature suitable for being put into adsorption again after regeneration. When the adsorption time sequence progresses to a predetermined stage and the dew point monitoring result shows that the outlet dew point of the current adsorption drying tower is close to the set limit, the main control module switches the drying tower in the adsorption state to the regeneration or cold blowing state in turn, and switches the drying tower that has completed cold blowing to the adsorption state, so that the two adsorption drying towers, one regeneration drying tower and one cold blowing drying tower are switched in turn based on the adsorption time sequence and the dew point monitoring result in the four-tower high-yield mode, so that each drying tower completes the adsorption, regeneration and cold blowing process under high load conditions, and continuously performs crude hydrogen adsorption dehydration under the premise of ensuring that the outlet dew point is constrained by the dew point monitoring result.

[0049] In the four-tower high-efficiency mode, real-time crude hydrogen flow Q2QQ3, one drying tower performs primary adsorption on crude hydrogen, one drying tower performs secondary adsorption on the regenerated gas from the top of the gas-liquid separation device, one drying tower is regenerated, one drying tower is cold blown, and the regenerated gas after secondary adsorption is merged into the product gas pipeline.

[0050] By adopting the above scheme, in the four-tower high-efficiency mode, real-time crude hydrogen flow Q2QQ3, one drying tower performs primary adsorption on crude hydrogen, so that the moisture in the upstream crude hydrogen is adsorbed in the drying tower; at the same time, one drying tower performs secondary adsorption on the regenerated gas from the top of the gas-liquid separation device, and further adsorbs and processes the residual moisture in the regenerated gas, and the regenerated gas after secondary adsorption is merged into the product gas pipeline, so that the regenerated gas originally used for regeneration is utilized as part of the product gas after completing the regeneration and being subjected to secondary adsorption; in this process, one drying tower is regenerated to desorb the moisture enriched in the molecular sieve in the previous adsorption process, so as to restore the adsorption capacity of the drying tower, and the other drying tower is cold blown to cool the drying tower after regeneration, so that the temperature of the drying tower is restored to the working temperature suitable for participating in primary adsorption or secondary adsorption again, so that in the four-tower high-efficiency mode corresponding to real-time crude hydrogen flow Q2QQ3, through one drying tower performing primary adsorption on crude hydrogen, one drying tower performing secondary adsorption on the regenerated gas from the top of the gas-liquid separation device and merging the regenerated gas after secondary adsorption into the product gas pipeline, and one drying tower being regenerated and one drying tower being cold blown, the primary adsorption process of crude hydrogen and the secondary adsorption process of regenerated gas are cooperatively utilized, and the primary adsorption and secondary adsorption are continuously performed in the process of the drying tower rotating to complete adsorption, regeneration and cold blowing.

[0051] In the three-tower medium-load mode, real-time crude hydrogen flow Q1Q2, one drying tower is adsorbed, one drying tower is regenerated, one drying tower is cold blown, and the remaining one drying tower is cut out as a standby tower.

[0052] By adopting the above scheme, in the three-tower medium load mode, the real-time crude hydrogen flow Q1≤Q<Q2 is used as the working condition for starting the three-tower medium load mode, one dry tower in the adsorption state adsorbs the crude hydrogen under the working condition to remove water from the crude hydrogen; meanwhile, one dry tower in the regeneration state desorbs the water adsorbed in the previous cycle to restore the adsorption capacity of the dry tower in the current cycle, and the other dry tower in the cold blowing state cools the dry tower after regeneration to restore the temperature of the dry tower to a working condition temperature suitable for subsequent adsorption or regeneration; through the combination of adsorption by one dry tower, regeneration by one dry tower, and cold blowing by one dry tower, a cycle connection between adsorption, regeneration, and cold blowing is formed at the real-time crude hydrogen flow Q1≤Q<Q2, and the remaining one dry tower is cut out as a standby tower, so that the dry tower does not participate in the adsorption, regeneration, and cold blowing cycle in the three-tower medium load mode, thereby realizing the adsorption processing capacity matched with the real-time crude hydrogen flow Q1≤Q<Q2 by reducing the number of dry towers participating in the cycle in the medium load condition, and maintaining the continuous operation of adsorption, regeneration, and cold blowing while keeping one dry tower as a standby tower.

[0053] In the two-tower low load mode, the real-time crude hydrogen flow Q<Q1, one dry tower adsorbs, one dry tower sequentially regenerates and cold blows, and the other two dry towers are cut out as standby towers, and the cold blowing gas bypasses the regeneration gas heat exchange device and enters the regeneration gas cooling device under the two-tower low load mode through the program control valve.

[0054] By adopting the above scheme, in the two-tower low load mode, the real-time crude hydrogen flow Q<Q1 is used as the condition for starting the two-tower low load mode, one dry tower in the adsorption state undertakes the task of adsorbing and removing water from low-flow crude hydrogen, and the other dry tower in the same mode first regenerates to desorb the water adsorbed in it, and then in the cold blowing stage, the regenerated dry tower is cooled by introducing cold blowing gas, so that the dry tower has the temperature condition for participating in adsorption again after the sequential execution of regeneration and cold blowing; the remaining two dry towers are cut out as standby towers in the two-tower low load mode, so that these two dry towers do not participate in the adsorption, regeneration, and cold blowing cycle under the condition of Q<Q1, thereby forming a basic adsorption-regeneration-cold blowing rotation relationship by only one dry tower adsorbing and one dry tower sequentially regenerating and cold blowing in the low load condition, and by switching the cold blowing gas to bypass the regeneration gas heat exchange device and directly enter the regeneration gas cooling device through the program control valve, the cold blowing gas cools the dry tower performing regeneration and cold blowing through the regeneration gas cooling device in the two-tower low load mode, thereby realizing adsorption processing matched with low-flow crude hydrogen under the condition of Q<Q1 corresponding to the two-tower low load mode, and maintaining the continuous performance of the regeneration and cold blowing process in the mode.

[0055] The time boundary of the mode switching controlled by the main control module is the end of the current adsorption timing cycle, and the switching needs to meet the real-time crude hydrogen flow continuously matching the production threshold range corresponding to the target mode, and the adsorption effect feedback by the water dew point analyzer is qualified, and the regeneration and cold blowing effect feedback by the temperature transmitter is qualified.

[0056] By adopting the above scheme, the main control module first takes the end of the current adsorption timing cycle as the time boundary of triggering mode switching, ensures that mode switching occurs after a complete adsorption timing, and judges whether the real-time crude hydrogen flow continuously matches the production threshold range corresponding to the target mode, establishes mode switching on the premise that the crude hydrogen flow has stabilized in a certain load range, and combines the adsorption effect qualified signal fed back by the water dew point analyzer and the regeneration and cold blowing effect qualified signal fed back by the temperature transmitter, allows switching from the current mode to the target mode only when the adsorption effect and the regeneration and cold blowing effect both meet the preset requirements, ensures that the switched drying tower is in a qualified regeneration state, thereby, through the joint constraints of time conditions, flow conditions, and adsorption and regeneration and cold blowing effect conditions, the mode switching is executed under the condition that the current adsorption timing is completed, the crude hydrogen flow matches the target mode, and the adsorption, regeneration and cold blowing processes all meet the qualified criteria, avoids mode switching when the adsorption is not completed, the regeneration or cold blowing does not meet the requirements, or the crude hydrogen flow temporarily fluctuates, and guides the connection between each adsorption mode according to the established order.

[0057] The logic of the mode switching controlled by the main control module is that the real-time crude hydrogen flow obtained based on the crude hydrogen flow meter is judged to be in a certain production threshold range, the adsorption state is judged to be qualified in combination with the dew point monitoring, and the regeneration and cold blowing state is judged to be qualified in combination with the temperature monitoring, and finally the switching is executed at the end of the adsorption timing cycle.

[0058] Through adoption of the above scheme, the logic of the main control module controlling mode switching is: judging whether it is in a certain production threshold interval based on the real-time crude hydrogen flow obtained by the crude hydrogen flow meter, combining with the dew point monitoring to judge whether the adsorption state is qualified, and combining with the temperature monitoring to judge whether the regeneration and cold blowing state is qualified, and finally executing switching at the end of the adsorption timing cycle. Under this logic, the main control module first uses the real-time crude hydrogen flow signal of the crude hydrogen flow meter to determine the production threshold interval of the current operating condition to determine the production threshold interval to which the target adsorption mode belongs. On this basis, whether the dew point of the drying tower outlet in the adsorption state is in the adsorption effect qualified range is judged through the dew point monitoring to confirm whether the adsorption state is qualified, and whether the temperature of the drying tower in the regeneration and cold blowing state meets the qualified requirement of the regeneration and cold blowing effect is judged through the temperature monitoring to confirm whether the regeneration and cold blowing state is qualified, to ensure that the cut-out drying tower is in the qualified regeneration state. Only when the production threshold interval corresponding to the real-time crude hydrogen flow is consistent with the target mode and the adsorption state, the regeneration and cold blowing state are all determined to be qualified by the dew point monitoring and the temperature monitoring, the main control module executes mode switching at the time node of the end of the adsorption timing cycle. Thus, the mode switching process takes the real-time crude hydrogen flow, the dew point monitoring and the temperature monitoring as the premise, and changes the mode after completing the current adsorption timing, which combines the production threshold interval judgment with the adsorption, regeneration and cold blowing state judgment from the process, to avoid mode switching when the adsorption state is not qualified or the regeneration and cold blowing state is not qualified.

[0059] The sequence of the main control module controlling mode switching is: when the hydrogen production gradually decreases, the four-tower high-production mode, the four-tower high-efficiency mode, the three-tower medium-load mode and the two-tower low-load mode are switched in turn, and the cut-out drying tower remains in the qualified standby state. When the hydrogen production gradually increases, the two-tower low-load mode, the three-tower medium-load mode, the four-tower high-efficiency mode and the four-tower high-production mode are switched in turn, and the cut-in drying tower directly adapts to the working state of the target mode. The product hydrogen dew point always meets the standard during the switching process.

[0060] By adopting the above scheme, when the hydrogen production gradually decreases, the main control module reduces the number of online drying towers in turn according to the sequence of four-tower high-yield mode, four-tower high-efficiency mode, three-tower medium-load mode and two-tower low-load mode, and processes the drying tower that exits the current mode as a qualified standby state at each switching step, so that the switched-out drying tower remains in a state that can be put into use again after exiting; when the hydrogen production gradually increases, the main control module increases the number of online drying towers in turn according to the sequence of two-tower low-load mode, three-tower medium-load mode, four-tower high-efficiency mode and four-tower high-yield mode, and takes the drying tower in the qualified standby state as the switching-in object, so that the switched-in drying tower can directly adapt to the working state of the target mode, thereby, in the whole process of the hydrogen production from high to low and then to high, through the mode switching sequence based on the change direction of the hydrogen production and the cooperation of the switched-out tower remaining in the qualified standby state and the switched-in tower directly adapting to the working state of the target mode, the dew point control of the product hydrogen during switching between different modes always meets the requirement that the dew point of the product hydrogen always meets the standard during the switching process.

[0061] The switched-out drying tower does not participate in the cycle period, is used to reduce the thermal stress and mechanical wear of the molecular sieve, and can perform molecular sieve inspection or replacement during the switching-out period, and meets the cold blow cooling condition when switching out.

[0062] By adopting the above scheme, the drying tower is no longer subjected to the cycle period of repeated alternation of adsorption, regeneration and cold blow, so that the molecular sieve avoids frequent temperature fluctuations between adsorption and regeneration and the thermal stress of the molecular sieve caused thereby, and the start-stop and switching operations related to the cycle no longer occur, thereby reducing the mechanical wear of the molecular sieve and components associated therewith; on this basis, the time window of the switched-out state of the drying tower is utilized to perform molecular sieve inspection or replacement operation on the molecular sieve in the drying tower during the switching-out period; when the high-yield mode is switched to the medium-load mode, the switched-out tower is a tower that has completed cold blow, and does not need to be cooled, and can directly perform molecular sieve replacement or maintenance, and can be put into use at any time;

[0063] When the medium-load mode is switched to the low-load mode, the switched-out tower is a tower that has completed regeneration, and the temperature is still relatively high; if the molecular sieve needs to be maintained or replaced at this time, the tower can only be naturally cooled, but the tower can be put into use without any problem, because on the one hand, the switched-out hot tower can be naturally cooled, and on the other hand, when the medium-load mode is switched, the timing of the tower corresponds to cold blow, which can also cool the tower, and the tower is cooled to a qualified state before adsorption.

[0064] A TSA dehydration method suitable for large-scale wind-solar hydrogen production, comprising the following steps:

[0065] S1, according to the design capacity of a single drying tower, three yield threshold values Q1, Q2 and Q3 are set, and Q≥Q3 corresponds to a four-tower high-yield mode, Q2

[0066] S2, by collecting crude hydrogen flow, outlet gas dew point of each drying tower top, drying tower bottom outlet temperature, regeneration gas heating temperature, regeneration gas flow, gas-liquid separator liquid level and current adsorption timing data in real time, and controlling drainage according to the liquid level signal;

[0067] S3, continuously compare the real-time crude hydrogen flow with Q1, Q2 and Q3, and determine whether the adsorption effect is qualified through dew point data and whether the regeneration and cold blowing effect is qualified through temperature data, to determine the target mode and switching time;

[0068] S4, when the hydrogen yield decreases, the main control module switches according to the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode and the two-tower low-load mode in turn, and the cut-out drying tower remains in a qualified standby state; when the hydrogen yield increases, it is switched according to the two-tower low-load mode, the three-tower medium-load mode, the four-tower high-efficiency mode and the four-tower high-yield mode in turn, and the cut-out drying tower is in a standby state that meets the cold blowing condition;

[0069] S5, continuously monitor the dew point, regeneration temperature and crude hydrogen flow after switching, and if any index is unqualified, immediately adjust the timing parameters or switch back to the original adaptive mode, form a product quality closed-loop control, and ensure that the outlet hydrogen dew point meets the standard.

[0070] By using the above scheme, in step S1, yield threshold values Q1, Q2 and Q3 are set according to the design capacity of a single drying tower, and Q≥Q3, Q2

[0071] In step S2, by collecting crude hydrogen flow, outlet gas dew point of each drying tower top, drying tower bottom outlet temperature, regeneration gas heating temperature, regeneration gas flow, gas-liquid separator liquid level and current adsorption timing data in real time, and controlling drainage according to the liquid level signal, the basic measurement data for subsequent judgment of yield threshold interval, adsorption effect and regeneration and cold blowing effect is provided;

[0072] In step S3, the real-time crude hydrogen flow is continuously compared with Q1, Q2 and Q3, and whether the adsorption effect is qualified is determined by the dew point data, and whether the regeneration and cold blowing effects are qualified is determined by the temperature data, so as to determine the target mode and switching time, so that the selection of the target mode and the determination of the switching time are simultaneously constrained by the yield threshold condition and the adsorption, regeneration and cold blowing effect conditions;

[0073] In step S4, when the hydrogen yield decreases, the main control module switches in sequence according to the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode and the two-tower low-load mode through the valve control module, and the dry tower cut out is kept in a qualified standby state, and when the hydrogen yield increases, the switching is in sequence according to the two-tower low-load mode, the three-tower medium-load mode, the four-tower high-efficiency mode and the four-tower high-yield mode, and the dry tower cut out is kept in a standby state meeting the cold blowing condition, so that the corresponding four-tower high-yield mode, four-tower high-efficiency mode, three-tower medium-load mode and two-tower low-load mode in different yield threshold intervals are transitioned in a predetermined order, and the dry tower that can be cut in is kept in a qualified standby state during the switching process;

[0074] In step S5, after completing the mode switching, the dew point, regeneration temperature and crude hydrogen flow are continuously monitored, and when any index is unqualified, the main control module immediately adjusts the timing parameters or switches back to the original adaptive mode, so as to realize product quality closed-loop control based on real-time monitoring and mode adjustment, so as to ensure that the outlet hydrogen dew point meets the standard.

[0075] Embodiment

[0076] A week of seven days is selected as the description object, 24h is selected as the cycle period, and the hydrogen production changes within seven days are fluctuated according to the process from maximum to minimum and then gradually recovered to maximum, as shown in Table 1:

[0077]

[0078] Table 1 Switching of high yield to low yield process

[0079] The first day hydrogen production Q≥Q3, the system is in high yield mode, that is, two towers are adsorbed at the same time, one tower is heated and regenerated, and one tower is cold blown. The working state of each tower is shown in Table 2:

[0080]

[0081] Table 2 Working state of each tower

[0082] Note 1: The percentage in the bracket after adsorption represents the assumed adsorption saturation degree, and the same below (when two towers are adsorbed at the same time, due to different previous timing, the adsorption mass transfer front faces of the two towers are inconsistent, and the adsorption amounts are different);

[0083] Note 2: The confirmation of adsorption drying process timing should be determined according to the conditions of crude hydrogen, molecular sieve properties, etc. The timing in the table is the assumed state timing, and the same applies below.

[0084] When the hydrogen production decreases to the range of Q2 < Q < Q3, the process switching time can be selected at any time point of 6, 12, 18, 24 h in the actual application process. In this specification, the process switching is taken as an example at the 24 h point, that is, it is assumed that the yield fluctuates and the process switches the next day.

[0085] Before process switching, the current process state of the four towers and the working state after switching are first determined: at the 24 h time point, the states of A, B, C, and D towers are cold blowing, adsorption (50%), adsorption (100%), and regeneration, respectively. Therefore, after switching to the high-efficiency mode, the states of A, B, C, and D towers are secondary adsorption (20%), adsorption (100%), regeneration, and cold blowing, respectively.

[0086] Secondly, the confirmation of the working quality indicators of each tower under the current timing should be determined: whether the cold blowing process is completed is determined by the bottom temperature instrument of A tower; whether the adsorption process is normal is determined by the water dew point analyzer at the top of B tower and C tower (the dew point of B tower should be consistent with the product gas dew point; the dew point index of C tower has a slight upward trend, but is still within the qualified range); whether the regeneration process is completed is determined by the bottom temperature instrument of D tower and the temperature maintenance time. After all the above indicators are normal, the process switching program can be executed.

[0087] Finally, the working state and quality indicators of each tower after the switching are completed should be paid attention to, and if the product quality is unqualified, the high-yield mode should be switched back in time.

[0088] The above three switching steps should be executed in any switching process.

[0089] The working state of each tower after switching to the high-efficiency mode is shown in Table 3. One tower is adsorbed, one tower is secondary adsorbed, one tower is heated and regenerated, and one tower is cold blown.

[0090]

[0091] Table 3 Working state of each tower in high-efficiency mode the next day

[0092] When the hydrogen production continues to decrease to the range of Q1≤Q<Q2, the switching to the medium load mode can be prepared. As before, the time of the process switching can be selected at any of 6, 12, 18, 24 h in the actual application process, and the switching of the process is taken as an example at the 24 h point in the description. In addition, the working state and working quality of the four drying towers also need to be confirmed. At the 24 h point, the states of the four towers A, B, C, and D are cold blowing, adsorption (20%), adsorption (100%), and regeneration, respectively. After the working quality of each tower is confirmed to be qualified by using the temperature and water dew point instruments, the switching to the medium load mode can be performed, and at this time, the tower A is selected to be cut out, and the states of the towers B, C, and D are adsorption (100%), regeneration, and cold blowing, respectively. When the tower A is cut out, it has been in the cold blowing qualified standby state, and can be put into the adsorption state at any time according to the needs, which greatly guarantees the adsorption redundancy of the device.

[0093] After the switching to the medium load mode, the working states of the towers are shown in Table 4. One tower is adsorbed, one tower is heated and regenerated, and one tower is cold blown.

[0094]

[0095] Table 4 Working states of the towers in the medium load mode on the third day

[0096] When the hydrogen production continues to decrease to the range of Q<Q1, the switching to the low load mode can be prepared. In the actual application process, the time of the process switching can be selected at any of 8, 16, 24 h, and the switching of the process is taken as an example at the 24 h point in the description. In addition, the working state and working quality of the three drying towers also need to be confirmed. At the 24 h point, the states of the towers B, C, and D are cold blowing, adsorption (100%), and regeneration, respectively. After the working quality of each tower is confirmed to be qualified by using the temperature and water dew point instruments, the switching to the low load mode can be performed, and at this time, the tower D is selected to be cut out, and the states of the towers B and C are adsorption (100%) and regeneration + cold blowing, respectively. When the tower D is cut out, it has been in the regeneration qualified state, and although the cold blowing has not been performed, the tower D can be naturally cooled and cooled down after being cut out. In addition, when the process is switched from the low load to the medium load, the first working state of the tower D is the cold blowing stage, and the tower D can also complete the cooling process.

[0097] When the hydrogen production gradually increases to the range of Q1≤Q<Q2, it can be prepared to switch to the medium load mode. In the actual application process, the time of process switching can be selected at any time point of 12, 24 h, and in this description, the process switching at the 24 h point is taken as an example. In addition, the working state and working quality of the two drying towers also need to be confirmed. At the 24 h time point, the states of the B and C towers are respectively regeneration + cold blow and adsorption (100%). After confirming that the working quality of each tower is qualified by using the temperature and water dew point instruments, the medium load mode can be switched, and at this time, the D tower is selected to be switched in. As described before, after natural cooling, the first time sequence when the D tower is switched in is the cold blow process, which can ensure the complete cooling of the D tower. At this time, the states of the B and C towers are respectively adsorption (100%) and regeneration.

[0098] After switching to the low load mode, the working states of each tower are shown in Table 5. One tower is adsorbed, and one tower is regenerated + cold blown.

[0099]

[0100] Table 5 Working states of each tower in the low load mode on the fourth day

[0101] After switching to the medium load mode, the working states of each tower are shown in Table 6. One tower is adsorbed, one tower is regenerated, and one tower is cold blown.

[0102]

[0103] Table 6 Working states of each tower in the medium load mode on the fifth day

[0104] When the hydrogen production gradually increases to the range of Q2<Q≤Q3, it can be prepared to switch to the high efficiency mode. Similarly, in the actual application process, the time of process switching can be selected at any time point of 8, 16, 24 h, and in this description, the process switching at the 24 h point is taken as an example. In addition, the working state and working quality of the three drying towers also need to be confirmed. At the 24 h time point, the states of the B, C and D towers are respectively cold blow, adsorption (100%) and regeneration. After confirming that the working quality of each tower is qualified by using the temperature and water dew point instruments, the high efficiency mode can be switched, and at this time, the A tower is selected to be switched in. As described before, the A tower is in the cold blow qualified state, and can be ready to switch to the adsorption state at any time. At this time, the states of the B, C and D towers are respectively adsorption (100%), regeneration and cold blow.

[0105] After switching to the high efficiency mode, the working states of each tower are shown in Table 7. One tower is adsorbed, one tower is regenerated, one tower is cold blown, and one tower is secondary adsorbed.

[0106]

[0107] Table 7 Working states of each tower in the high efficiency mode on the sixth day

[0108] When the hydrogen production gradually increases to the range of Q≥Q3, it is ready to switch to the high production mode. Similarly, the time of process switching can be selected at any of 6, 12, 18, 24 h during actual application, and the process switching at the 24 h point is taken as an example in the description. In addition, the working state and quality of the four drying towers also need to be confirmed. At the 24 h point, the states of the A, B, C, and D towers are cold blowing, secondary adsorption (20%), adsorption (100%), and regeneration, respectively. After confirming that the working quality of each tower is qualified by using temperature and water dew point instruments, the high production mode can be switched.

[0109] The working states of the towers after switching to the high production mode are shown in Table 8. Two towers are adsorbing, one tower is regenerating, and one tower is cold blowing.

[0110]

[0111] Table 8 Working states of the towers in the high production mode on the seventh day

[0112] So far, the variable adsorption tower number TSA dehydration system has completed the sequential switching of different working processes, i.e., the high production mode, the high efficiency mode, the medium load mode, the low load mode, the medium load mode, the high efficiency mode, and the high production mode, within one week. It can be seen that as wind energy, solar energy, and other fluctuating power sources gradually become the main power sources for electrolytic water hydrogen production, and the scale of hydrogen production is also increasingly large, the variable adsorption tower number TSA dehydration system can effectively match the continuous fluctuations in hydrogen production caused by the inherent fluctuations of wind and light, and provide an effective solution for matching the front-end fluctuating hydrogen production with the rear-end purification and drying device in the scenario of renewable energy hydrogen production.

[0113] Although embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A TSA dewatering system suitable for large-scale wind-solar hydrogen production, characterized in that, The application relates to a hydrogen drying system. The system comprises the following modules: An adsorption module composed of multiple drying towers for adsorbing moisture in upstream crude hydrogen; A regeneration treatment module comprising a regeneration gas heater, a regeneration gas heat exchanger, a regeneration gas cooler and a regeneration gas gas-liquid separator connected in series for heating regeneration gas, heat exchange between hot and cold regeneration gas, cooling regeneration gas and gas-water separation, and the regeneration treatment module is provided with an adjusting valve for controlling the regeneration gas flow rate; A valve control module comprising a program-controlled valve group for switching the drying tower adsorption, cold blowing, regeneration and secondary adsorption states, and comprising a program-controlled valve group for switching the gas flow path in different online tower number modes; A monitoring module comprising a dew point analyzer, a temperature transmitter, a crude hydrogen flow meter, a regeneration gas flow meter and a gas-liquid separator liquid level monitoring and drainage assembly; 2. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 1, characterized in that, A main control module connected with the monitoring module and the valve control module for controlling the valve control module to switch the adsorption mode according to the design capacity threshold values Q1, Q2 and Q3 of a single drying tower, the dew point qualified index and the regeneration temperature qualified index, wherein Q3 is the maximum design adsorption capacity of a single tower, Q2 is 60-80% of the normal adsorption capacity of a single tower and Q1 is 30-50% of the normal adsorption capacity of a single tower; the real-time crude hydrogen flow is compared with Q1, Q2 and Q3, and the adsorption mode comprises a four-tower high yield mode, a four-tower high efficiency mode, a three-tower medium load mode and a two-tower low load mode.

3. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 2, characterized in that, The adsorption module is composed of four drying towers, in the four-tower high yield mode, the real-time crude hydrogen flow Q is greater than or equal to Q3, the main control module controls two drying towers to adsorb in parallel, one drying tower to regenerate and one drying tower to cold blow, and the operation states of the drying towers are switched in sequence according to the adsorption time sequence and the dew point monitoring result.

4. The TSA dewatering system for large-scale wind-solar hydrogen production according to claim 2, wherein, In the four-tower high efficiency mode, the real-time crude hydrogen flow Q2 is less than Q and Q is less than Q3, one drying tower adsorbs crude hydrogen, one drying tower secondarily adsorbs regeneration gas from the top of a gas-liquid separation device, one drying tower regenerates and one drying tower cold blows, and the regeneration gas after secondary adsorption is combined into a product gas pipeline.

5. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 2, characterized in that, In the three-tower medium load mode, the real-time crude hydrogen flow Q1 is less than or equal to Q and Q is less than Q2, one drying tower adsorbs, one drying tower regenerates and one drying tower cold blows, and the remaining one drying tower is switched out as a standby tower.

6. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 1, wherein, In the two-tower low load mode, the real-time crude hydrogen flow Q is less than Q1, one drying tower adsorbs, one drying tower regenerates and cold blows in sequence, and the other two drying towers are switched out as standby towers, and the cold blowing gas is switched by a program-controlled valve to bypass the regeneration gas heat exchange device and enter the regeneration gas cooling device in the two-tower low load mode.

7. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 1, wherein, The switching time of the main control module is when the current adsorption time sequence cycle ends, and the switching needs to meet the condition that the real-time crude hydrogen flow continuously matches the yield threshold range corresponding to the target mode, and the adsorption effect is qualified according to the dew point analyzer feedback and the regeneration and cold blowing effects are qualified according to the temperature transmitter feedback. The logic of the main control module for mode switching is that the real-time crude hydrogen flow obtained by a crude hydrogen flow meter is used to determine whether it is in a certain yield threshold interval, the adsorption state is determined to be qualified or not in combination with the dew point monitoring, and the regeneration and cold blowing states are determined to be qualified or not in combination with the temperature monitoring, and finally the switching is executed at the end of the adsorption time sequence cycle.

8. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 1, wherein, The main control module controls the sequence of mode switching: when the hydrogen production gradually decreases, the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode, and the two-tower low-load mode are switched in turn, and the switched-out drying towers remain in a qualified standby state; when the hydrogen production gradually increases, the two-tower low-load mode, the three-tower medium-load mode, the four-tower high-efficiency mode, and the four-tower high-yield mode are switched in turn, and the switched-in drying towers directly adapt to the working state of the target mode, and the product hydrogen dew point always meets the standard during the switching process.

9. The TSA dewatering system suitable for large-scale wind-solar hydrogen production according to claim 1, wherein, The switched-out drying towers do not participate in the cycle period, are used to reduce the thermal stress and mechanical wear of the molecular sieve, and can perform molecular sieve inspection or replacement during the switching-out period, and meet the cold-blowing cooling condition when switched out.

10. A TSA dewatering method suitable for large scale wind-solar hydrogen production, characterized in that, The TSA dewatering system according to any one of claims 1-9, comprising the following steps: S1, according to the design capacity of a single drying tower, set three yield thresholds Q1, Q2, Q3, and clearly Q≥Q3 corresponds to the four-tower high-yield mode, Q2<Q<Q3 corresponds to the four-tower high-efficiency mode, Q1≤Q<Q2 corresponds to the three-tower medium-load mode, and Q<Q1 corresponds to the two-tower low-load mode; S2, by real-time acquisition of crude hydrogen flow, dew point of each drying tower top outlet gas, drying tower bottom outlet temperature, regeneration gas heating temperature, regeneration gas flow, gas-liquid separator liquid level, and current adsorption timing data, and according to the liquid level signal to control drainage; S3, continuously compare the real-time crude hydrogen flow with Q1, Q2, and Q3, and at the same time, determine whether the adsorption effect is qualified through dew point data, and whether the regeneration and cold-blowing effect is qualified through temperature data, to determine the target mode and switching time; S4, when the hydrogen production decreases, the main control module switches according to the four-tower high-yield mode, the four-tower high-efficiency mode, the three-tower medium-load mode, and the two-tower low-load mode in turn through the valve control module, and the switched-out drying towers remain in a qualified standby state; when the hydrogen production increases, the two-tower low-load mode, the three-tower medium-load mode, the four-tower high-efficiency mode, and the four-tower high-yield mode are switched in turn, and the switched-out drying towers are in a standby state that meets the cold-blowing condition; S5, continuously monitor the dew point, regeneration temperature, and crude hydrogen flow after switching, and if any index is unqualified, immediately adjust the timing parameters or switch back to the original adaptation mode, form a product quality closed-loop control, and ensure that the outlet hydrogen dew point meets the standard.

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