Temperature-controlled hydrogen purification system and purification regeneration method

Abstract

The present application belongs to the field of hydrogen purification, and particularly relates to a temperature control type hydrogen purification system and a purification regeneration method. The system comprises a water tank, a refrigerator unit and an electric heater, at least one adsorption tower, a circulating water pump, a purge gas buffer tank, a purge pipeline and a control unit. The adsorption tower is of a jacket structure, and a coil pipe is arranged in the jacket. The inlet and outlet of the coil pipe are connected with the water tank to form a circulating water loop, so that the temperature in the adsorption tower is kept at 20-30 DEG C. The purge gas buffer tank is used for receiving and temporarily storing hydrogen obtained in the step of pressure reduction after normal discharge. The control unit is used for adjusting the pressure in the water tank to change the saturated vapor pressure of water, so that heat supply is realized in the same water body in the daily constant temperature adsorption and the regeneration stage. In the regeneration stage, the program control is adopted, which comprises constant temperature at a constant speed, constant temperature at a constant speed and constant temperature at a constant speed. In the normal production, the present application keeps the optimum adsorption temperature in the adsorption process, and when the adsorption tower needs to be regenerated, online regeneration is realized to avoid loss caused by discharge and reduce the production cost.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen purification, and in particular to a temperature-controlled hydrogen purification system and purification and regeneration method. Background Technology

[0002] Pressure swing adsorption (PSA) is a separation method based on the selective adsorption of different components in a gas mixture by an adsorbent. Adsorption and regeneration are achieved through periodic pressure changes. This technology is widely used in hydrogen purification, capable of extracting high-purity hydrogen (up to 99.999%) from various hydrogen-containing feedstocks such as methanol purge gas, natural gas, and coke oven gas. The resulting hydrogen can be used in fuel cells, laboratories, and high-end markets such as electronic chips. For high-end markets, some difficult-to-remove components, such as oxygen and argon, are the main factors limiting the product's quality. Factors affecting the adsorption capacity of the adsorbent include the impurity content of the feedstock gas, the load of the production unit, and the adsorption temperature. Controlling the adsorption temperature has a significant impact on hydrogen purification, especially under high-load operating conditions. Excessively high temperatures reduce the adsorbent's ability to adsorb impurity gases, causing impurities to break through the adsorption bed and affecting hydrogen purity; conversely, excessively low temperatures affect adsorbent regeneration, preventing the effective removal of some strongly adsorbed components, leading to their accumulation in the adsorbent and also affecting hydrogen purity. Through production and operation practice, it has been found that the adsorption effect is best when the temperature is around 20~30℃, which can effectively reduce the content of impurities such as oxygen and argon, and the recovery rate is correspondingly the highest.

[0003] During normal production, the adsorbent can recover most of its activity through conventional regeneration processes such as depressurization and purging. The purging process is completed by using hydrogen gas from the forward depressurization step, which is then buffered in the purging gas buffer tank S2, and then used to purge the adsorption tower T1 that needs to be regenerated.

[0004] However, in actual operation, the adsorbent often faces the problem of performance degradation, leading to a decrease in product purity and recovery rate. The main reasons for adsorbent deactivation and contaminant penetration into the bed include excessively high production loads. Overloading the unit accelerates the accumulation of impurities (especially highly adsorbent substances such as heavy hydrocarbons) within the adsorbent micropores, making complete desorption difficult with conventional regeneration. Additionally, impurities such as moisture and heavy hydrocarbons carried in the feed gas are highly detrimental to adsorbents (especially molecular sieves). Moisture and heavy hydrocarbons are difficult to desorb at normal operating temperatures, gradually clogging the adsorbent pores. Therefore, conventional pressure-reducing purging regeneration has limited desorption capacity for highly adsorbent impurities. These substances gradually accumulate within the adsorbent pores, ultimately leading to a significant decrease in adsorbent adsorption capacity, reduced product hydrogen recovery rate, and increased production costs.

[0005] Currently, there are two main industrial methods for dealing with adsorbent deactivation:

[0006] Replacement with new adsorbent: The deactivated adsorbent is removed from the tower and replaced with a new adsorbent. This method requires the unit to be shut down, which is time-consuming. The cost of adsorbent procurement (especially when relying on imports, the cycle is long and the cost is high) and the labor loading and unloading costs are high. At the same time, it will cause production interruption and waste of hydrogen resources.

[0007] Hot nitrogen purging regeneration: This method uses heated nitrogen to purge and regenerate the adsorption tower. While it can reduce downtime, it has several drawbacks: First, commonly used low-pressure nitrogen may contain trace amounts of moisture, carbon dioxide, oxygen, and other impurities, which can cause secondary pollution to the adsorbent or affect the regeneration effect during the regeneration process. Second, after regeneration, the system is filled with nitrogen, requiring a large amount of hydrogen to replace it until the product gas is qualified. This process not only prolongs the start-up time but also requires the initial unqualified product gas to be vented, resulting in hydrogen waste and economic losses.

[0008] In summary, existing technologies cannot simultaneously achieve the following under normal production conditions: precise temperature control of the adsorption section at 20–30°C; online, nitrogen-free, and zero-venting regeneration of the adsorbent after deactivation; and regeneration without interrupting the operation of other adsorption towers or introducing secondary pollution. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a temperature-controlled hydrogen purification system and purification and regeneration method, which maintains the optimal adsorption temperature during normal production and performs online regeneration when the adsorption tower needs to be regenerated, avoiding venting losses and reducing production costs.

[0010] The technical solution of this invention is:

[0011] The first aspect of this invention provides a temperature-controlled hydrogen purification system, comprising: a water tank, a refrigeration unit and an electric heater, at least one adsorption tower, a circulating water pump, a purge gas buffer tank, a purge pipeline, and a control unit. The refrigeration unit and the electric heater are respectively connected to the water tank for cooling or heating the water in the tank. The adsorption tower has a jacketed structure with a coil inside the jacket. The inlet and outlet of the coil are connected to the water tank to form a circulating water loop, so as to maintain the temperature inside the adsorption tower at 20°C to 30°C. The circulating water pump is located in the circulating water loop and is used to drive the water to circulate between the coil and the water tank. The purge gas buffer tank is used to receive and temporarily store the hydrogen obtained in the forward depressurization step. The purge pipeline connects the purge gas buffer tank and the adsorption tower and is used to pass the temporarily stored hydrogen as a regeneration gas into the adsorption tower to be regenerated. The control unit is used to adjust the pressure inside the water tank to change the saturated vapor pressure of the water, thereby achieving daily constant temperature adsorption and regeneration stage heating in the same water body. The regeneration stage adopts a program control of constant-rate heating-stage constant temperature-constant-rate cooling.

[0012] Furthermore, the circulating water circuit is equipped with a temperature-controlled flow regulating valve and a temperature-controlled online flow meter to control the circulating water volume of a single adsorption tower at 2 t / h to 3 t / h.

[0013] Furthermore, the water tank is equipped with an online temperature gauge, which is connected to the chiller unit, electric heater, cold water regulating valve, and chilled water inlet shut-off valve to form a closed-loop temperature control; the water tank is also equipped with an online pressure gauge, which is connected to the pressure replenishment regulating valve and the venting regulating valve to stabilize the pressure in the water tank at a set value.

[0014] Furthermore, the coil is arranged in a double helix within the jacket, and fins are uniformly distributed on its outer surface.

[0015] Furthermore, the purging pipeline is equipped with a purging flow regulating valve and an online purging flow meter to control the hydrogen flow rate during the regeneration purging stage.

[0016] Furthermore, the exhaust side of the adsorption tower is equipped with a regeneration exhaust manual valve and an online temperature gauge after purging, which are used to monitor the temperature of the regeneration exhaust gas and control the timing of emission.

[0017] Furthermore, an online temperature gauge is installed on the main water supply pipe after heat exchange between the coil and the water tank to monitor the return water temperature entering the water tank in real time, ensuring that the environment inside the adsorption tower is within the range of 20℃~30℃.

[0018] Furthermore, the water tank is equipped with an online water level gauge, which is connected to the water supply regulating valve to automatically maintain the water level in the tank within a set range.

[0019] A second aspect of the present invention provides a temperature-controlled hydrogen purification and regeneration method for the above-mentioned system, comprising the following steps:

[0020] (1) Normal adsorption stage: Start the chiller or electric heater to control the water temperature in the water tank at 20℃~30℃. The circulating water pump sends the constant temperature water into the jacket coil of the adsorption tower to keep the adsorbent at the optimal adsorption temperature.

[0021] (2) Preparation for adsorption tower regeneration: Close all inlet and outlet valves of the adsorption tower to be regenerated, and release pressure through the regeneration exhaust valve to reduce the pressure inside the tower to 0.05MPa;

[0022] (3) Regeneration heating stage: Start the electric heater and control it in a closed loop at a heating rate of ≤30℃ / h, and heat it up to 100℃ for 2 hours, 150℃ for 1 hour, and 220℃ in sequence.

[0023] (4) Regeneration purging stage: When the online temperature gauge of the water tank displays 220℃, open the regeneration air supply valve and the regeneration air exhaust valve, and set the online purging flow meter to automatic. Initially, use 200 Nm³ / h. 3 Purge at a low flow rate of / h until the online temperature gauge shows ≥210℃ after purging and the cumulative temperature is ≥1h;

[0024] (5) Regeneration and cooling stage: Set the online purging flow meter to 500 Nm 3 The temperature is controlled in a closed loop by the online temperature gauge of the water tank at a cooling rate of ≤30℃ / h, and then successively cooled to 120℃ for 1h, 60℃ for 1h, until the online temperature gauge of the water tank is ≤20℃ and the online temperature gauge after purging is ≤30℃, thus completing the regeneration.

[0025] Furthermore, the entire process of heating, maintaining temperature, and cooling is automatically controlled by online temperature gauges in the water tank, after heat exchange, after purging, and the control unit, ensuring that the temperature change rate does not exceed 30℃ / min.

[0026] The advantages and positive effects of this invention are:

[0027] 1. The present invention adopts a constant-rate heating and cooling method and a staged constant temperature method during regeneration, which effectively prevents the adsorbent from pulverizing due to excessively rapid heating or cooling, and at the same time ensures the best regeneration effect of the adsorbent.

[0028] 2. During regeneration, the present invention uses the purge gas generated during operation for regeneration purging, which avoids the need to introduce regeneration nitrogen to replace the system and also avoids waste caused by product gas purging.

[0029] 3. This invention changes the saturated vapor pressure of water by adjusting the pressure inside the water tank, so that the temperature control system can maintain a constant temperature during daily use to ensure the adsorption effect, and can also provide a heat source for regeneration when the adsorbent effect deteriorates. This achieves two goals at once, saving investment costs and floor space.

[0030] 4. This invention uses the refrigeration unit E1 and the electric heater E2 in cooperation and utilizes the dead zone to not only accurately control the water temperature, but also prevent energy waste caused by the simultaneous operation of the refrigeration unit E1 and the electric heater E2, thus ensuring stable production operation.

[0031] 5. The adsorption tower of the present invention adopts a jacket structure, which can effectively avoid the adsorbent from becoming ineffective due to water leakage from the coil, thus ensuring the safety of the adsorbent.

[0032] 6. The adsorption tower of the present invention is equipped with a double coil structure and fins are evenly arranged to increase the contact area between the coil and the inner wall of the adsorption tower, ensuring that the adsorbent is heated evenly, thereby better ensuring the quality of the product. Attached Figure Description

[0033] Figure 1 : A schematic diagram of the process flow of this invention;

[0034] Figure 2 : Schematic diagram of the internal structure of the adsorption tower of the present invention;

[0035] Figure 3 : A flowchart of the adsorbent regeneration process of this invention.

[0036] Among them: E1-Refrigeration unit, E2-Electric heater, S1-Water tank, S2-Purge gas buffer tank, T1-Adsorption tower, P1-Circulating water pump, 1-Refrigerated water supply pipeline, 2-Refrigerated circulation pipeline, 3-Refrigerated water return pipeline, 4-Medium pressure nitrogen pipeline, 5-Vent pipeline, 6-Relief pipeline, 7-Make-up water pipeline, 8-Water supply pipeline before pump, 9-Main water supply pipeline, 10-Water supply branch pipeline, 11-Water supply branch pipeline after heat exchange, 12-Main water supply pipeline after heat exchange, 13-Purge main pipeline, 14-Purge branch pipeline, 15-Exhaust branch pipeline, 16-Exhaust main pipeline, 17-Coil, 18-Fin, V1-Water supply manual valve, V2-Return water manual valve, V3-Regeneration gas supply manual valve, V4- Regeneration exhaust hand valve, V5-chilled water inlet hand valve, V6-chilled water return hand valve, TV1-cold water regulating valve, TV2-cold water circulation regulating valve, PV1-pressure replenishment regulating valve, PV2-venting regulating valve, SV1-safety valve, LV1-water replenishment regulating valve, XV1-chilled water inlet shut-off valve, PIC1-water tank online pressure gauge, PI1-adsorption tower online pressure gauge, FV1-temperature control flow regulating valve, FV2-purge flow regulating valve, FIC1-temperature control online flow meter, FIC2-purge online flow meter, LIC1-water tank online level gauge, TI1-heat exchange online temperature gauge, TI2-purge online temperature gauge, TIC1-water tank online temperature gauge. Detailed Implementation

[0037] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0038] like Figure 1The temperature-controlled hydrogen purification system shown includes an adsorption tower T1, a water tank S1, a purge gas buffer tank S2, a refrigeration unit E1, an electric heater E2, a circulating water pump P1, and a purging system. The electric heater E2 is installed inside the water tank S1. The lower left side of the water tank S1 is connected to the inlet of the refrigeration unit E1 via a chilled water return pipeline 3. The outlet of the refrigeration unit E1 is connected to the upper left port of the water tank S1 via a chilled water supply pipeline 1. A chilled water inlet manual valve V5 and a chilled water inlet shut-off valve XV1 are sequentially installed on the chilled water return pipeline 3. A cold water regulating valve TV1 and a chilled water return manual valve V6 are sequentially installed on the chilled water supply pipeline 1. A chilled circulation pipeline 2 connects the chilled water return pipeline 3 and the chilled water supply pipeline 1, and a cold water circulation regulating valve TV2 is installed on the chilled circulation pipeline 2. An online temperature gauge TIC1 is installed on the lower left side of the water tank. An online pressure gauge PIC1 is installed on the top of the water tank S1. One end of the medium-pressure nitrogen pipeline 4, the vent pipeline 5, the discharge pipeline 6, and the water supply pipeline 7 are connected sequentially to the top of the water tank S1. The other end of the medium-pressure nitrogen pipeline 4 is connected to the medium-pressure nitrogen network. A pressure regulating valve PV1 is installed on the medium-pressure nitrogen pipeline 4. The other ends of the vent pipeline 5 and the discharge pipeline 6 are discharged into the air. A vent regulating valve PV2 is installed on the vent pipeline 5. A safety valve SV1 is installed on the discharge pipeline 6. The other end of the water supply pipeline 7 is connected to the high-pressure water network. A water supply regulating valve LV1 is installed on the water supply pipeline 7. An online level gauge LIC1 is installed on the lower right side of the water tank S1.

[0039] The medium-pressure nitrogen pipeline 4 installed on the water tank serves two purposes: First, during normal production, it replenishes the water tank with medium-pressure nitrogen to a pressure of 0.05 MPa to prevent air from entering and causing corrosion. Second, when the adsorption tower needs regeneration, it increases the water tank pressure to prevent water from vaporizing during heating. When the adsorption tower needs regeneration, the water temperature needs to be raised to 220°C. At atmospheric pressure, water exceeds its boiling point, preventing the water pump from operating. Therefore, medium-pressure nitrogen is introduced into the water tank, increasing the pressure to 3.5 MPa. At this pressure, the boiling point of water reaches 245°C, meeting the requirement that water will not vaporize when heated to 220°C.

[0040] The water tank is connected to the inlet of the circulating water pump P1 via the pre-pump water pipeline 8 at the bottom right side. The outlet of the circulating water pump P1 is connected to one end of multiple water supply branch pipes 10 via the main water supply pipe 9. A temperature-controlled flow regulating valve FV1 and a temperature-controlled online flow meter FIC1 are installed sequentially on the main water supply pipe 9. The other end of the water supply branch pipe 10 is connected to one end of the coil 17 inside the adsorption tower T1. A water delivery manual valve V1 is installed on the water supply branch pipe 10. The other end of the coil 17 is connected to the heat exchange water supply main pipe 12 via the heat exchange water supply branch pipe 11. A return water manual valve V2 is installed on the heat exchange water supply branch pipe 11. The other end of the heat exchange water supply main pipe 12 is connected to the upper right port of the water tank S1. A heat exchange online temperature meter TI1 is installed on the heat exchange water supply main pipe 12.

[0041] The purging system includes a purging flow regulating valve FV2, a purging online flow meter FIC2, a purging online temperature meter TI2, an adsorption tower online pressure gauge PI1, a regeneration gas supply manual valve V3, and a regeneration exhaust manual valve V4. The top port of the purging gas buffer tank S2 is connected to one end of each purging branch pipe 14 via a purging main pipe 13. The other end of the purging branch pipe 14 is connected to the top gas port of the adsorption tower T1. The regeneration gas supply manual valve V3 and the adsorption tower online pressure gauge PI1 are installed sequentially on the purging branch pipe 14. The bottom gas port of each adsorption tower T1 is connected to the exhaust main pipe 16 via an exhaust branch pipe 15. The purging online temperature meter TI2 and the regeneration exhaust manual valve V4 are installed sequentially on each exhaust branch pipe 15. The exhaust main pipe 16 is connected to the fuel gas main pipe.

[0042] The online temperature gauge TIC1 signal is connected to the chiller unit E1, the electric heater E2, the chilled water regulating valve TV1, and the chilled water inlet shut-off valve XV1, respectively, and is used to control the temperature inside the water tank.

[0043] The online pressure gauge PIC1 of the water tank is connected to the pressure regulating valve PV1 and the venting regulating valve PV2 to maintain the pressure inside the water tank S1.

[0044] The online level gauge LIC1 is connected to the water supply regulating valve LV1 via a signal to automatically control the liquid level in the water tank.

[0045] The online temperature-controlled flow meter FIC1 is connected to the temperature-controlled flow regulating valve FV1 for automatic control of circulating water flow.

[0046] The online purge flow meter FIC2 is connected to the purge flow regulating valve FV2 to control the purge gas volume during the regeneration of adsorption tower T1.

[0047] The adsorption tower T1 has a jacketed structure, with two coils 17 wound at intervals inside the jacket. Multiple fins 18 are evenly arranged on the coils 17 to increase the contact area between the coils 17 and the inner wall of the adsorption tower.

[0048] The working principle and specific operating steps of this invention are as follows:

[0049] During normal production, the purge flow regulating valve FV2 is closed, and all regeneration air supply valves V3 and V4 of the adsorption towers are closed. The online pressure gauge PIC1 for the water tank is set to automatic, with the tank pressure set to 0.05 MPa. This is achieved through the pressure compensation regulating valve PV1 and the venting regulating valve PV2 to prevent air from entering the tank and causing corrosion. The chiller unit E1 is set to automatic, with a water temperature of 26℃ and a dead zone of 2℃. The electric heater E2 is also set to automatic, with a water temperature of 24℃ and a dead zone of 2℃. Specifically, when the water temperature exceeds 28℃, the chiller unit E1 starts, cooling to 24℃ and then stopping. When the water temperature falls below 22℃, the electric heater E2 starts, heating to 26℃ and then stopping. This ensures that the water temperature in tank S1 operates between 22℃ and 28℃, while preventing the chiller unit E1 and the electric heater E2 from operating simultaneously, thus avoiding resource waste. When starting the chiller unit E1, open the chilled water inlet manual valve V5, the chilled water inlet shut-off valve XV1, and the chilled water return manual valve V6. Control the chilled water flow rate through the chilled water regulating valve TV1 and the chilled water circulation regulating valve TV2, thereby controlling the temperature in the water tank. Open the supply water manual valve V1 and return water manual valve V2 of each branch, start the circulating water pump P1, and set the online flow meter FIC1 to automatic. The flow rate setpoint is set according to the number of adsorption towers to ensure that the circulating water volume of each adsorption tower is 2t~3t / h. Monitor the temperature through the online temperature meter TI1 after heat exchange to ensure that the water temperature after heat exchange is between 20~30℃.

[0050] When the adsorption effect of adsorption tower T1 deteriorates, resulting in unqualified product indicators or a significant decrease in recovery rate, online regeneration is initiated. The purge gas used for regeneration is the purge gas generated during the operation of other adsorption towers T1 by depressurization. Specifically, without affecting the regeneration effect of other adsorption towers T1, a stream is drawn from the purge gas buffer tank S2 as the purge gas for the regenerated adsorption tower T1. The specific steps are as follows: First, one adsorption tower T1 is switched out according to the tower switching procedure, while the other adsorption towers T1 continue operating online. The regeneration exhaust valve V4 at the bottom of the switched-out adsorption tower T1 is opened, and after the pressure is reduced to 0.05 MPa via PI1, the regeneration exhaust valve V4 is closed.

[0051] The purge flow regulating valve FV2 is closed, and the regeneration air supply valve V3 and regeneration exhaust valve V4 of all adsorption towers are closed. Close the water supply valve V1 and return valve V2 of the operating adsorption towers, and open the water supply valve V1 and return valve V2 of the adsorption towers requiring regeneration. Set the online pressure gauge PIC1 of the water tank to automatic, increasing the water tank pressure to 3.5 MPa. At this pressure, the boiling point of water is 242.6℃; temperatures below this will not cause the water to turn into steam during heating. Start the regeneration program, which will automatically regenerate according to the following steps: The electric heater E2 is started, and the heating rate is controlled by the online temperature gauge TIC1 at a rate of 30℃ / h. When the temperature reaches 100℃, it is held at 100℃ for 2 hours, then the temperature continues to rise at a rate of 30℃ / h. When the temperature reaches 150℃, it is held for another 1 hour, then the temperature continues to rise at a rate of 30℃ / h to 220℃, and then held at that temperature. When the temperature displayed on the online temperature gauge TIC1 reaches 220℃, open the regeneration air supply valve V3 and the regeneration exhaust valve V4, and put the online purging flow meter FIC2 into automatic mode. Control the purging flow rate to 200 Nm through the purging flow regulating valve FV2. 3 At a low flow rate of / h, purging is performed. The purpose of purging is firstly to ensure more uniform heating of the adsorbent in adsorption tower T1, and secondly to observe the heating effect of the adsorbent using the online temperature gauge TI2 after purging. The second purpose of purging is to blow out impurities precipitated from the heated adsorbent from the adsorption tower, thus achieving regeneration. Timing begins when the temperature on the online temperature gauge TI2 reaches 210℃. If the cumulative time exceeding 210℃ is greater than 1 hour, regeneration is complete, and the cooling process begins. The set flow rate on the online flow meter FIC2 is adjusted, and the purging rate is controlled to 500 Nm³ using the purging flow regulating valve FV2. 3 The cooling rate is controlled by the online temperature gauge TIC1 at a rate of 30℃ / h. When the temperature reaches 120℃, it is maintained at 120℃ for 1 hour. The temperature is then increased at a rate of 30℃ / h until it drops to 60℃, where it is maintained for another hour. The temperature is then decreased at a rate of 30℃ / h until it reaches 20℃, where it is maintained. If the temperature does not reach 20℃ after all electric heaters E2 are turned off, the refrigeration unit E1 is started to continue cooling, maintaining the water temperature at approximately 20℃. When the temperature on the online temperature gauge TI2 after purging reaches below 30℃, the cooling of adsorption tower T1 is complete. The above steps are repeated for other unregenerated adsorption towers T1 until all adsorption towers T1 are fully regenerated.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept, and these all fall within the protection scope of the present invention.

Claims

1. A temperature-controlled hydrogen purification system, characterized by, It comprises: a water tank (S1); a refrigeration unit (E1) and an electric heater (E2) connected with the water tank (S1) respectively for cooling or heating the water in the water tank; at least one adsorption tower (T1) with a jacket structure, a coil pipe (17) arranged in the jacket, the inlet and outlet of the coil pipe (17) connected with the water tank (S1) to form a circulating water circuit so that the temperature in the adsorption tower (T1) is kept at 20-30℃; a circulating water pump (P1) arranged in the circulating water circuit for driving the water to circulate between the coil pipe (17) and the water tank (S1); a purge gas buffer tank (S2) for receiving and temporarily storing the hydrogen obtained in the step of sequentially releasing and reducing pressure; a purge pipeline connecting the purge gas buffer tank (S2) with the adsorption tower (T1) for feeding the temporarily stored hydrogen into the adsorption tower (T1) to be regenerated as a regeneration gas; a control unit for adjusting the pressure in the water tank (S1) to change the saturated vapor pressure of the water so as to realize daily constant temperature adsorption and heat supply in the regeneration stage in the same water body; the regeneration stage adopts a program control of constant speed temperature rising-stage constant temperature-constant speed temperature falling.

2. The temperature-controlled hydrogen purification system of claim 1, wherein, The circulating water circuit is provided with a temperature control flow regulating valve (FV1) and a temperature control online flow meter (FIC1) for controlling the circulating water quantity of a single adsorption tower at 2-3 t / h.

3. The temperature-controlled hydrogen purification system of claim 1 or 2, wherein, The water tank (S1) is provided with an online temperature meter (TIC1) which is signal connected with the refrigeration unit (E1), the electric heater (E2), a cold water regulating valve (TV1) and a refrigeration water inlet cut-off valve (XV1) to form a closed loop temperature control; the water tank (S1) is also provided with a water tank online pressure meter (PIC1) which is signal connected with a pressure regulating valve (PV1) and a venting regulating valve (PV2) for stabilizing the pressure in the water tank at a set value.

4. The temperature-controlled hydrogen purification system of claim 1, wherein, The coil pipe (17) is arranged in a double helix in the jacket and the outer surface is uniformly provided with fins (18).

5. The temperature-controlled hydrogen purification system of claim 1, wherein, The purge pipeline (14) is provided with a purge flow regulating valve (FV2) and a purge online flow meter (FIC2) for controlling the hydrogen flow in the regeneration and purge stage.

6. The temperature-controlled hydrogen purification system of claim 1, wherein, The exhaust side of the adsorption tower (T1) is provided with a regeneration exhaust hand valve (V4) and a post-purge online temperature meter (TI2) for monitoring the temperature of the regeneration exhaust gas and controlling the discharge timing.

7. The temperature-controlled hydrogen purification system of claim 1, wherein, The water total pipeline (12) after heat exchange between the coil pipe (17) and the water tank (S1) is provided with a post-heat exchange online temperature meter (TI1) for real-time monitoring of the return water temperature entering the water tank to ensure that the environment in the adsorption tower (T1) is in the range of 20-30℃.

8. The temperature-controlled hydrogen purification system of claim 1, wherein, The water tank (S1) is provided with a water tank online liquid level meter (LIC1) which is signal connected with a water supply regulating valve (LV1) to automatically maintain the water level of the water tank in a set range.

9. A temperature-controlled hydrogen gas purification regeneration method using the system according to any one of claims 1 to 8, characterized by, It comprises the following steps: (1) normal adsorption stage: start the refrigeration unit (E1) or the electric heater (E2) to control the water temperature of the water tank (S1) at 20-30℃, the circulating water pump (P1) sends the constant temperature water into the jacket coil pipe (17) of the adsorption tower (T1) to keep the adsorbent at the optimum adsorption temperature; (2) Adsorption tower regeneration preparation: close all valves of inlet and outlet of the adsorption tower (T1) to be regenerated, release pressure through the regeneration exhaust hand valve (V4), and reduce the pressure in the tower to 0.05 MPa; (3) Regeneration temperature rising stage: start the electric heater (E2), and control in a closed loop at a temperature rising rate of ≤30 ℃ / h, and sequentially rise to 100 ℃, keep constant for 2 h, 150 ℃, keep constant for 1 h, and 220 ℃, keep constant; (4) Regeneration purge phase: when the water tank online temperature table (TIC1) shows 220℃, open the regeneration air supply hand valve (V3) and the regeneration exhaust hand valve (V4), and automatically cast the purge online flow table (FIC2) at first 200Nm 3 / h small flow purge, until the online temperature table (TI2) after purging ≥210℃ and accumulates ≥1h; (5) Regeneration cooling stage: Set the purge online flow meter (FIC2) to 500 Nm 3 / h, still closed-loop controlled by the water tank online temperature meter (TIC1) at a cooling rate of ≤30 ℃ / h, sequentially cooled to 120 ℃ constant temperature for 1 h, 60 ℃ constant temperature for 1 h, until the water tank online temperature meter (TIC1) ≤20 ℃ and the post-purging online temperature meter (TI2) ≤30 ℃, completing regeneration.

10. The regeneration method according to claim 9, characterized by, The whole process of temperature rising, constant keeping and temperature falling is automatically controlled by the water tank online temperature table (TIC1), the heat exchange online temperature table (TI1) and the purging online temperature table (TI2) and the control unit, so that the temperature change rate is ensured to be not more than 30 ℃ / min.

Images