Alkaline water electrolysis hydrogen production three-tower purification control method and system

Abstract

The invention discloses a three-tower purification control method and system for hydrogen production by alkaline electrolysis of water, zero consumption of hydrogen, reduction of loss and improvement of purification efficiency are realized through three-tower drying and full utilization of product gas to regenerate a drying tower, and the three towers can be automatically switched according to actual conditions through an automatic control system and setting of three-tower working logic, so that the production efficiency is improved. The device has an automatic drainage function, the workload of personnel is reduced, the reliability of the device is improved, and in the purification process, the two towers perform dehydration at the same time, so that the purity of hydrogen is improved.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen production, and in particular to a three-tower purification control method and system for producing hydrogen by alkaline water electrolysis. Background Art

[0002] With the increasing consumption of fossil fuels, their reserves are decreasing, and environmental pollution, climate warming and other problems are becoming increasingly prominent. Under the background of dual carbon, clean energy is accelerating its development. There is an urgent need for new energy-containing energy sources with abundant reserves that do not rely on fossil fuels. Hydrogen is such an ideal new energy-containing energy source. Hydrogen production by water electrolysis is a method of producing hydrogen by electrolyzing water. It is one of the important ways to utilize renewable energy on a large scale. Among them, alkaline water electrolysis hydrogen production technology is the most mature, with low price and good safety. The technical route of alkaline water electrolysis hydrogen production is that the alkali solution in the electrolyzer produces hydrogen and oxygen under the action of direct current. The hydrogen enters the gas-alkali solution separator, gas cooler, gas-water separator through the pipeline in turn, and enters the hydrogen purification system for purification treatment to finally obtain the product hydrogen that meets the demand.

[0003] Traditional hydrogen drying usually uses molecular sieves as adsorbents. Molecular sieve adsorption is physical adsorption. When the adsorption is saturated, it needs to be heated and regenerated before it can be adsorbed again. The purification device contains two drying towers, one for adsorption and the other for regeneration. Part of the hydrogen after drying is blown through the regeneration tower and then discharged. This drying method will cause hydrogen consumption and waste during use, and because only one drying tower is working, the purity of the hydrogen after drying is relatively low.

[0004] In summary, a three-tower purification control method and system for producing hydrogen by alkaline water electrolysis is needed to solve the shortcomings of the prior art. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a three-tower purification control method and system for producing hydrogen by alkaline water electrolysis, aiming to solve the above problems.

[0006] To achieve the above object, the present invention provides the following technical solution: a three-tower purification control method for producing hydrogen by alkaline water electrolysis, comprising the following steps:

[0007] Step S1: deoxygenation, the raw hydrogen passes through a deoxygenation tower and a palladium catalyst to react impurity oxygen with hydrogen to generate water, thereby obtaining deoxygenated hydrogen;

[0008] Step S2: Cooling and preliminary dehydration, the deoxygenated hydrogen enters the cooling tower, absorbs excess water, and enters the gas-liquid separator for preliminary dehydration;

[0009] Step S3: The automatic control unit controls adsorption drying and regeneration. The hydrogen after preliminary dehydration enters the drying tower and is deeply dried by the molecular sieve in the drying tower. When the molecular sieve in the drying tower is saturated with adsorption, hot blowing regeneration and cold blowing regeneration are performed;

[0010] Step S4: Detection and control: perform purity detection on hydrogen through an analyzer, determine whether the purity of hydrogen meets the requirements, and control whether hydrogen is discharged to the main vent pipe.

[0011] Optionally, the drying tower in step S3 includes a main drying tower and a standby drying tower, and the operation is divided into four cycles: a first stage, a second stage, a third stage and a fourth stage;

[0012] The first stage steps are as follows:

[0013] Step A1: The main drying tower performs adsorption dehydration, and the standby drying tower performs standby;

[0014] Step A2: The standby drying tower performs adsorption dehydration, and the main drying tower performs hot blowing regeneration;

[0015] Step A3: The standby drying tower continues to adsorb and dehydrate, and the main drying tower performs cold blowing regeneration;

[0016] Step A4: The main drying tower and the standby drying tower are kept in standby.

[0017] Optionally, the second stage steps are as follows:

[0018] Step B1: The standby drying tower starts adsorption and dehydration, and the main drying tower performs hot blowing regeneration;

[0019] Step B2: The standby drying tower continues to adsorb and dehydrate, and the main drying tower continues to regenerate by cold blowing;

[0020] Step B3: The main drying tower and the standby drying tower are kept in standby.

[0021] Optionally, the third stage steps are as follows:

[0022] Step C1: The standby drying tower starts adsorption and dehydration, and the main drying tower performs hot blowing regeneration;

[0023] Step C2: The standby drying tower continues to adsorb and dehydrate, and the main drying tower continues to regenerate by hot blowing;

[0024] Step C3: The standby drying tower continues to adsorb and dehydrate, and the main drying tower continues to regenerate by cold blowing;

[0025] Step C4: The main drying tower and the standby drying tower are kept in standby.

[0026] Optionally, the standby drying tower includes a first drying tower and a second drying tower, and the fourth stage steps are as follows:

[0027] Step D1: The first drying tower starts adsorption and dehydration, the second drying tower performs heat blowing regeneration, and the main drying tower starts adsorption and dehydration;

[0028] Step D2: the first drying tower continues to adsorb and dehydrate, the second drying tower continues to heat-blow regeneration, and the main drying tower continues to adsorb and dehydrate;

[0029] Step D3: The first drying tower continues to adsorb and dehydrate, the second drying tower performs cold blowing regeneration, and the main drying tower continues to adsorb and dehydrate.

[0030] Optionally, the automation control unit is controlled in the following manner:

[0031] Step E1: adjusting parameters through human-computer interaction;

[0032] Step E2: Collect system data in real time through sensors and detection instruments, and monitor and analyze the collected data in real time;

[0033] Step E3: Fault judgment and processing. When the system is abnormal, the fault judgment is automatically performed and the corresponding processing procedure is started according to the fault type.

[0034] Optionally, the dried hydrogen in step S4 is passed through a precision filter to remove dust, and then the purity of the hydrogen is tested by a micro-oxygen analyzer and a dew point analyzer.

[0035] An alkaline water electrolysis hydrogen production three-tower purification control system adopts an alkaline water electrolysis hydrogen production three-tower purification control method, including: a deoxygenation tower, a gas-liquid separator, a drying tower, a cooler, a regenerative electric heater, a valve, an analyzer and an automatic control unit;

[0036] Deoxygenation tower, used to remove impurity oxygen in raw hydrogen;

[0037] Gas-liquid separator, used to separate water from hydrogen;

[0038] Drying tower, used to deeply dehydrate hydrogen and improve its purity;

[0039] A cooler, used to reduce the temperature of hydrogen and separate hydrogen and water;

[0040] Regeneration electric heater, used in hot-blow regeneration process, heater hydrogen;

[0041] Valves, used to control the flow of hydrogen to ensure the normal operation of the system;

[0042] Analyzer for real-time detection of hydrogen purity and dew point;

[0043] Automatic control unit, used for automatic switching of the working status of the three drying towers.

[0044] Optionally, the automatic control unit also includes an automatic drainage unit for automatically draining the accumulated water generated after the adsorption operation of the drying tower.

[0045] Beneficial effects of the present invention:

[0046] 1. In the present invention, through three-tower drying, the product gas is fully utilized to regenerate the drying tower, achieving zero consumption of hydrogen, reducing losses, and improving purification efficiency;

[0047] 2. In the present invention, the three-tower working logic is set through the automatic control system, so that the three towers can automatically switch according to the actual situation and have an automatic drainage function, which reduces the workload of personnel and improves the reliability of the device;

[0048] 3. In the present invention, during the purification process, the two towers simultaneously carry out dehydration, which is beneficial to improving the purity of hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The present invention is a flow chart of a method.

[0050] Figure 2 A system structure diagram of the present invention.

[0051] Figure 3 It is a schematic diagram of the working state of a drying tower of the present invention.

[0052] In the figure: 1. Deoxidation tower; 2. Cooling tower; 3. First drying tower; 4. Second drying tower; 5. Main drying tower DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] like Figure 1 As shown, a three-tower purification control method for producing hydrogen by alkaline water electrolysis includes the following contents:

[0055] The outlet hydrogen of the gas-water separation system first enters the deoxidizer 1, where the impurity oxygen in the raw hydrogen reacts with hydrogen to generate water under the catalytic action of the palladium catalyst. After the impurity oxygen is removed, the water is separated and removed by the cooling condenser 2, and then enters the adsorption drying tower for dehumidification. The operating pressure of the purification system is adjusted by the pressure regulating valve, and finally the dust is removed by the precision filter to obtain the pure hydrogen product.

[0056] The drying tower is filled with molecular sieves. In the desorption state, the gas inlet and outlet are switched, and the gas flow direction is reversed. The electric heating works only in desorption. The three drying towers include the first drying tower 3, the second drying tower 4 and the main drying tower 5, corresponding to Figure 2 The A, B, and C drying towers in the system take turns to perform the process of adsorption + regeneration desorption + cold blowing, so that the outlet gas always meets the purity requirements.

[0057] In conjunction with the instruction manual Figure 3 , the four stages are explained in detail:

[0058] Phase 1

[0059] (1) Drying tower T201AB standby - T201C adsorption dehydration (first 1200 minutes)

[0060] The raw hydrogen after deoxygenation is cooled by cooler E201. As the temperature decreases, the gas dew point decreases, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV201F and enters the drying tower T201C for drying and dehydration. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203B and hand valves V203, V204AB, precision filter F201, orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and dew point analyzer before being fed back to the three-way valve ZV201. The qualified product gas enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatic) (Manual valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV201F, XV203B are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0061] (2) Drying tower T201AB adsorption dehydration-T201C hot blowing regeneration (first 1200 minutes + 30 minutes)

[0062] The raw hydrogen after deoxygenation is cooled by cooler E201. When the temperature is lowered, the gas dew point is lowered, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV200 and enters the drying tower T201A for drying and dehydration. The dry hydrogen is heated by the electric heater E203. The dehydrated hydrogen passes through the pneumatic shut-off valve XV202B and enters the drying tower T201C (inlet b and outlet a), and passes through the pneumatic shut-off valve XV201D Then it enters the cooler E202, and after entering the regeneration gas-liquid separator V202, the pneumatic shut-off valve XV201A is opened and then it enters the drying tower T201B for dehydration and drying. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203A and the manual valves V202, V204AB, the precision filter F201, the orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and the dew point analyzer before being fed back to the three-way valve ZV201. If the gas is qualified, it enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatic) (Hand valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV200, XV202B, XV201D, XV201A, XV203A are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0063] (3) Drying tower T201A standby T201B adsorption dehydration - T201C hot blowing regeneration (first 1200 minutes + 30 minutes + 240 minutes)

[0064] The raw hydrogen after deoxygenation is cooled by cooler E201. When the temperature is lowered, the gas dew point is lowered, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV200 and enters the drying tower T201A for drying and dehydration. The dry hydrogen is heated by the electric heater E203. The dehydrated hydrogen passes through the pneumatic shut-off valve XV202B and enters the drying tower T201C (inlet b and outlet a), and passes through the pneumatic shut-off valve XV201D Then it enters the cooler E202, and after entering the regeneration gas-liquid separator V202, the pneumatic shut-off valve XV201A is opened and then it enters the drying tower T201B for dehydration and drying. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203A and the manual valves V202, V204AB, the precision filter F201, the orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and the dew point analyzer before being fed back to the three-way valve ZV201. If the gas is qualified, it enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatics) (Hand valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV200, XV202B, XV201D, XV201, AXV203A are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0065] (4) Drying tower T201A standby T201B adsorption dehydration - T201C cold blowing regeneration (first 1200 minutes + 30 minutes + 240 minutes + 180 minutes)

[0066] The raw hydrogen after deoxygenation is cooled by cooler E201. When the temperature is lowered, the gas dew point is lowered, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV201F and enters the drying tower T201C. The T201C tower is cooled by cold blowing with the cooled hydrogen. The cold blowing gas passes through the electric heater E203 (without heating) and the hydrogen dried by T201A (channel). Open XV201G and cool it. After secondary cooling in device E202, it enters the regeneration gas-liquid separator V202, opens the pneumatic shut-off valve XV201A, and after drying and dehydration by T201B, the dehydrated hydrogen passes through the pneumatic shut-off valve XV203A and manual valves V202, V204AB, precision filter F201, orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and dew point analyzer before being fed back to the three-way valve ZV201. If the gas is qualified, it enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatic) (Hand valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV201F, XV202B, XV201G, XV201A, XV203A are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0067] (5) Drying tower T201A is on standby, T201B is for adsorption dehydration, and T201C is on standby (first 1200 minutes + 30 minutes + 240 minutes + 180 minutes + 750 minutes).

[0068] The raw hydrogen after deoxygenation is cooled by cooler E201. As the temperature decreases, the gas dew point decreases, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV201E and enters the drying tower T201B for drying and dehydration. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203A and hand valves V202, V204AB, precision filter F201, orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and dew point analyzer before being fed back to the three-way valve ZV201. The qualified product gas enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatic) (manual valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV201E, XV203A are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0069] Phase II

[0070] (1) Drying tower T201A adsorption dehydration T201B hot blowing regeneration - T201C adsorption dehydration (first 30 minutes).

[0071] The raw hydrogen after deoxygenation is cooled by cooler E201. When the temperature is lowered, the gas dew point is lowered, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV200 and enters the drying tower T201A for drying and dehydration. The dry hydrogen is heated by the electric heater E203. The dehydrated hydrogen passes through the pneumatic shut-off valve XV202A and enters the drying tower T201B (inlet b and outlet a), and then passes through the pneumatic shut-off valve XV201C. After entering the cooler E202 and the regenerated gas-liquid separator V202, the pneumatic shut-off valve XV201B is opened and then the hydrogen enters the drying tower T201C for dehydration. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203B and the manual valves V203, V204AB, the precision filter F201, the orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and the dew point analyzer. After being fed back to the three-way valve ZV201, the qualified product gas enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatics) (Hand valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV200, XV202A, XV201C, XV201B, XV203B are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0072] (2) Drying tower T201A adsorption dehydration T201B hot blowing regeneration - T201C adsorption dehydration (first 30 minutes + 240 minutes).

[0073] The raw hydrogen after deoxygenation is cooled by cooler E201. When the temperature is lowered, the gas dew point is lowered, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV200 and enters the drying tower T201A for drying and dehydration. The dry hydrogen is heated by the electric heater E203. The dehydrated hydrogen passes through the pneumatic shut-off valve XV202A and enters the drying tower T201B (inlet b and outlet a), and passes through the pneumatic shut-off valve XV201C Then it enters the cooler E202, and after entering the regeneration gas-liquid separator V202, the pneumatic shut-off valve XV201B is opened and then it enters the drying tower T201C for dehydration and drying. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203B and the manual valves V203, V204AB, the precision filter F201, the orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and the dew point analyzer before being fed back to the three-way valve ZV201. If the gas is qualified, it enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatics) (Hand valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV200, XV202A, XV201C, XV201B, XV203B are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0074] (3) Drying tower T201A adsorption dehydration T201B cold blowing regeneration - T201C adsorption dehydration (first 30 minutes + 240 minutes + 180 minutes).

[0075] The raw hydrogen after deoxygenation is cooled by cooler E201. When the temperature is lowered, the gas dew point is lowered, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV201E and enters the drying tower T201B. The cooled hydrogen is used to cool the T201B tower. The cold blown gas passes through the electric heater E203 (without heating), and the hydrogen dried by T201A (channel) is opened XV201G and then cooled. After secondary cooling in device E202, it enters the regeneration gas-liquid separator V202, opens the pneumatic shut-off valve XV201B, and after drying and dehydration by T201C, the dehydrated hydrogen passes through the pneumatic shut-off valve XV203B and hand valves V203, V204AB, precision filter F201, orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and dew point analyzer before being fed back to the three-way valve ZV201. If the gas is qualified, it enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatic) (Hand valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV201E, XV202A, XV201G, XV201B, XV203B are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0076] (4) Drying tower T201AB standby - T201C adsorption dehydration (first 30 minutes + 240 minutes + 180 minutes + 750 minutes)

[0077] The raw hydrogen after deoxygenation is cooled by cooler E201. As the temperature decreases, the gas dew point decreases, and the excess water is analyzed out. It enters the deoxygenation liquid separator V201 for preliminary dehydration. The hydrogen out of the gas-liquid separation gas passes through the pneumatic shut-off valve XV201F and enters the drying tower T201C for drying and dehydration. The dehydrated hydrogen passes through the pneumatic shut-off valve XV203B and hand valves V203, V204AB, precision filter F201, orifice flowmeter FT201, and is tested by the micro-oxygen analyzer and dew point analyzer before being fed back to the three-way valve ZV201. The qualified product gas enters the downstream through N1 and N2, and the unqualified product gas is discharged to the vent main through N1 and N3. (Other pneumatic) (Manual valves V201, V202, V203, V204AB, V206AB, V208, V211AB are in the open state, pneumatic valves XV201F, XV203B are in the open state, the root valve of the safety valve instrument is in the open state; the rest of the valves are in the closed state).

[0078] The operating status of the third stage is the same as that of the first stage (2)(3)(4)(5).

[0079] The fourth stage has the same operating conditions as the second stage (1)(2)(3)(4).

[0080] The present invention uses three-tower drying to fully utilize product gas to regenerate the drying tower, thereby achieving zero consumption of hydrogen, reducing losses, and improving purification efficiency. The automatic control system is used to set the working logic of the three towers so that the three towers can automatically switch according to actual conditions and have an automatic drainage function, thereby reducing the workload of personnel and improving the reliability of the device. During the purification process, the two towers are dehydrated at the same time, which is beneficial to improving the purity of the hydrogen.

[0081] like Figure 2 As shown, a three-tower purification control system for alkaline water electrolysis hydrogen production adopts the three-tower purification control method for alkaline water electrolysis hydrogen production according to claim 1, characterized in that it includes: a deoxygenation tower, a gas-liquid separator, a drying tower, a cooler, a regenerative electric heater, a valve, an analyzer and an automatic control unit;

[0082] Deoxygenation tower, used to remove impurity oxygen in raw hydrogen;

[0083] Gas-liquid separator, used to separate water from hydrogen;

[0084] Drying tower, used to deeply dehydrate hydrogen and improve its purity;

[0085] A cooler, used to reduce the temperature of hydrogen and separate hydrogen and water;

[0086] Regeneration electric heater, used in hot-blow regeneration process, heater hydrogen;

[0087] Valves, used to control the flow of hydrogen to ensure the normal operation of the system;

[0088] Analyzer for real-time detection of hydrogen purity and dew point;

[0089] Automatic control unit, used for automatic switching of the working status of the three drying towers.

[0090] The automatic control unit also includes an automatic drainage unit for automatically draining the accumulated water generated after the adsorption operation of the drying tower.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-tower purification control method for producing hydrogen by alkaline water electrolysis, characterized in that: The following steps are involved: Step S1: deoxygenation, the raw hydrogen passes through a deoxygenation tower and a palladium catalyst to react impurity oxygen with hydrogen to generate water, thereby obtaining deoxygenated hydrogen; Step S2: Cooling and preliminary dehydration, the deoxygenated hydrogen enters the cooling tower, absorbs excess water, and enters the gas-liquid separator for preliminary dehydration; Step S3: The automatic control unit controls adsorption drying and regeneration. The hydrogen after preliminary dehydration enters the drying tower and is deeply dried by the molecular sieve in the drying tower. When the molecular sieve in the drying tower is saturated with adsorption, hot blowing regeneration and cold blowing regeneration are performed; Step S4: Detection and control: perform purity detection on hydrogen through an analyzer, determine whether the purity of hydrogen meets the requirements, and control whether hydrogen is discharged to the main vent pipe.

2. The three-tower purification control method for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The drying tower in step S3 includes a main drying tower and a standby drying tower, and the operation is divided into four cycles: the first stage, the second stage, the third stage and the fourth stage; The first stage steps are as follows: Step A1: The main drying tower performs adsorption dehydration, and the standby drying tower performs standby; Step A2: The standby drying tower performs adsorption dehydration, and the main drying tower performs hot blowing regeneration; Step A3: The standby drying tower continues to adsorb and dehydrate, and the main drying tower performs cold blowing regeneration; Step A4: The main drying tower and the standby drying tower are kept in standby.

3. The three-tower purification control method for producing hydrogen from alkaline water electrolysis according to claim 2, characterized in that: The steps of the second stage are as follows: Step B1: The standby drying tower starts adsorption and dehydration, and the main drying tower performs hot blowing regeneration; Step B2: The standby drying tower continues to adsorb and dehydrate, and the main drying tower continues to regenerate by cold blowing; Step B3: The main drying tower and the standby drying tower are kept in standby.

4. The three-tower purification control method for producing hydrogen from alkaline water electrolysis according to claim 3, characterized in that: The third stage steps are as follows: Step C1: The standby drying tower starts adsorption and dehydration, and the main drying tower performs hot blowing regeneration; Step C2: The standby drying tower continues to adsorb and dehydrate, and the main drying tower continues to regenerate by hot blowing; Step C3: The standby drying tower continues to adsorb and dehydrate, and the main drying tower continues to regenerate by cold blowing; Step C4: The main drying tower and the standby drying tower are kept in standby.

5. The three-tower purification control method for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The standby drying tower includes a first drying tower and a second drying tower, and the fourth stage steps are as follows: Step D1: The first drying tower starts adsorption and dehydration, the second drying tower performs heat blowing regeneration, and the main drying tower starts adsorption and dehydration; Step D2: the first drying tower continues to adsorb and dehydrate, the second drying tower continues to heat-blow regeneration, and the main drying tower continues to adsorb and dehydrate; Step D3: The first drying tower continues to adsorb and dehydrate, the second drying tower performs cold blowing regeneration, and the main drying tower continues to adsorb and dehydrate.

6. The three-tower purification control method for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The automation control unit is controlled in the following ways: Step E1: Adjust parameters through human-computer interaction; Step E2: Collect system data in real time through sensors and detection instruments, and monitor and analyze the collected data in real time; Step E3: Fault judgment and processing. When the system is abnormal, the fault judgment is automatically performed and the corresponding processing procedure is started according to the fault type.

7. The three-tower purification control method for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The hydrogen gas dried in step S4 is dedusted by a precision filter and then tested for hydrogen purity by a micro oxygen analyzer and a dew point analyzer.

8. A three-tower purification control system for hydrogen production by alkaline water electrolysis, using the three-tower purification control method for hydrogen production by alkaline water electrolysis according to claim 1, characterized in that: include: Deoxidation tower, gas-liquid separator, drying tower, cooler, regenerative electric heater, valve, analyzer and automation control unit; Deoxygenation tower, used to remove impurity oxygen in raw hydrogen; Gas-liquid separator, used to separate water from hydrogen; Drying tower, used to deeply dehydrate hydrogen and improve its purity; A cooler, used to reduce the temperature of hydrogen and separate hydrogen and water; Regeneration electric heater, used in hot-blow regeneration process, heater hydrogen; Valves, used to control the flow of hydrogen to ensure the normal operation of the system; Analyzer for real-time detection of hydrogen purity and dew point; Automatic control unit, used for automatic switching of the working status of the three drying towers.

9. The three-tower purification control system for producing hydrogen from alkaline water electrolysis according to claim 8, characterized in that: The automatic control unit also includes an automatic drainage unit for automatically draining the accumulated water generated after the drying tower adsorption operation.

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