Hydrogen purification system and hydrogen purification process of hydrogen production device by electrolysis of water

Abstract

The embodiment of the application provides a hydrogen purification system and a hydrogen purification process of a water electrolysis hydrogen production device, the hydrogen purification system comprises a primary cooler and at least two first coolers and at least two dryers, an integrated cooler which integrates the functions of cooling, gas-liquid separation and liquid collection is designed, the integrated cooler is adopted for the primary cooler and / or the first cooler, the number of devices of the hydrogen purification system is reduced, the floor area of the hydrogen purification system is reduced, the burden of the dryers is reduced, the working condition switching of the drying valve is realized through reasonable design of the communication structure of the valve, the dryer, the primary cooler and the first cooler, regeneration of the drying agent is carried out while hydrogen is dried, and therefore continuous production can be realized, and the working efficiency is relatively high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by water electrolysis, and in particular to a hydrogen purification system of a hydrogen production by water electrolysis device and a hydrogen purification process. BACKGROUND

[0002] When hydrogen is produced by water electrolysis, the hydrogen gas separated from the hydrogen production system also contains trace amounts of oxygen and a large amount of water vapor, and therefore needs to be further purified by a hydrogen purification system.

[0003] In the current hydrogen purification system of a hydrogen production by water electrolysis device, the hydrogen gas is first subjected to gas-liquid separation by a gas-liquid separator, then subjected to oxygen removal by a deoxygenator, then subjected to one-stage cooling and condensation by a cooler, then subjected to gas-liquid separation by another gas-liquid separator, then subjected to gas-liquid separation by another gas-liquid separator, then subjected to two-stage cooling and condensation by another cooler, then subjected to drying by a dryer, and then divided into two paths, one of which enters a product pipeline and the other of which is used as regeneration gas to regenerate the drying agent in another dryer. The waste liquid separated by each gas-liquid separator is immediately discharged into a water collector, which is subjected to timed discharge.

[0004] The current hydrogen purification system of a hydrogen production by water electrolysis device has a large number of devices and occupies a large area. The water produced in the two-stage cooling and condensation process enters the dryer along with the gas, increasing the burden on the dryer. The timed discharge process of the water collector is accompanied by the discharge and waste of hydrogen.

[0005] Therefore, how to improve the hydrogen purification system of a hydrogen production by water electrolysis device is a technical problem to be solved by those skilled in the art. SUMMARY

[0006] To solve the above technical problems, the present application provides a hydrogen purification system of a hydrogen production by water electrolysis device, which comprises an integrated cooler, wherein the integrated cooler comprises a shell, a heat exchange tube bundle located in the shell, an upper combined head located at the upper end of the shell, a lower combined head located at the lower end of the shell, a split plate located in the upper combined head, a C port and a D port provided on the upper combined head, a cooling medium inlet and a cooling medium outlet provided on the shell, and a liquid discharge port provided on the lower combined head.

[0007] The height of the lower combined head is greater than the height of the upper combined head, the heat exchange tube bundle comprises first-stage heat exchange tubes and second-stage heat exchange tubes, the inner cavity of the upper combined head comprises a first sub-cavity and a second sub-cavity, the first sub-cavity and the second sub-cavity are separated by the split plate, the first sub-cavity is in communication with the upper end of the first-stage heat exchange tubes, the second sub-cavity is in communication with the upper end of the second-stage heat exchange tubes, the D port is in communication with the first sub-cavity, and the C port is in communication with the second sub-cavity.

[0008] An embodiment of the hydrogen purification system of the hydrogen production device by water electrolysis, the hydrogen purification system comprises a deoxidizer and a primary cooler, the primary cooler adopts the integrated cooler, the D port of the primary cooler is in communication with the hydrogen outlet of the deoxidizer, and a demister is arranged in the second sub-cavity of the primary cooler.

[0009] An embodiment of the hydrogen purification system of the hydrogen production device by water electrolysis, the hydrogen purification system comprises at least two first coolers and at least two dryers, the first coolers adopt the integrated cooler, the number of the dryers is the same as that of the first coolers, each of the dryers is provided with an A port and a B port, the A port of each of the dryers is in communication with the D port of one of the first coolers, and a demister is arranged in the first sub-cavity and the second sub-cavity of the first cooler.

[0010] An embodiment of the hydrogen purification system of the hydrogen production device by water electrolysis, the hydrogen purification system comprises a plurality of valves, the plurality of valves can switch the C port of the first cooler to be in communication with the C port of the primary cooler or the C port of another first cooler, and can switch the B port of the dryer to be in communication with the product pipeline or the B port of another dryer.

[0011] An embodiment of the hydrogen purification system of the hydrogen production device by water electrolysis, a lower baffle is arranged in the lower combined head, the upper end of the lower baffle is connected with the lower tube plate at the lower end of the heat exchange tube bundle, a flow space is formed between the lower end of the lower baffle and the wall part of the lower combined head, and the lower ends of the first-stage heat exchange tubes and the second-stage heat exchange tubes are located on the two sides of the lower baffle, respectively.

[0012] An embodiment of the hydrogen purification system of the hydrogen production device by water electrolysis, the lower combined head is provided with an upper liquid level port and a lower liquid level port, which are used as measuring ports of a liquid level meter, the upper liquid level port is higher than the lower liquid level port, and the lower liquid level port is higher than the liquid discharge port.

[0013] The application also provides a hydrogen purification process of a hydrogen production device by water electrolysis, in which the hydrogen is cooled, gas-liquid separated and collected at the bottom of the integrated cooler of the hydrogen purification system, the hydrogen passes through the tube side of the integrated cooler, and the cooling medium passes through the shell side of the integrated cooler.

[0014] An embodiment of the hydrogen purification process, the hydrogen purification system is provided with two first coolers and two dryers, in the previous time period, the I dryer is in a drying working condition and the II dryer is in a regeneration working condition, in the next time period, the I dryer is in a regeneration working condition and the II dryer is in a drying working condition, and the two conditions are switched in a reciprocating cycle; the dryer in the drying working condition dries the hydrogen, and the dryer in the regeneration working condition regenerates the drying agent.

[0015] One embodiment of the hydrogen purification process, the hydrogen purification system is provided with three first coolers and three dryers, in the previous time period, I dryer is in the main drying condition, II dryer is in the regeneration condition, III dryer is in the auxiliary drying condition, in the next time period, I dryer is in the regeneration condition, II dryer is in the auxiliary drying condition, III dryer is in the main drying condition, in the next time period, I dryer is in the auxiliary drying condition, II dryer is in the main drying condition, III dryer is in the regeneration condition, and so on; the dryer in the main drying condition dries the hydrogen gas from the first cooler communicated with the C port of the first cooler, the dryer in the regeneration condition regenerates the hydrogen gas, and the dryer in the auxiliary drying condition dries the hydrogen gas from the first cooler communicated with the A port of the dryer in the regeneration condition.

[0016] One embodiment of the hydrogen purification process, when the liquid level meter detects that the liquid level in the lower combined head is at the height of the upper liquid level port, the drain port is opened, and when the liquid level meter detects that the liquid level in the lower combined head is at the height of the lower liquid level port, the drain port is closed.

[0017] The present application has the following technical effects:

[0018] (1) Fewer equipment and smaller floor area.

[0019] (2) The integrated cooler utilizes inertial separation, gravity separation and mechanical separation of the demister to achieve good gas-liquid separation effect, and makes the condensate generated along the heat exchange tube flow directly into the bottom of the inner cavity of the lower combined head, or is removed by the upper demister and returned to the bottom of the inner cavity of the lower combined head, so that the condensate basically does not enter the dryer with the gas, reducing the burden of the dryer.

[0020] (3) The integrated cooler, on the one hand, adopts a double-tube design to increase the flow rate and prevent condensate from accumulating on the surface of the tube wall, and on the other hand, the condensate generated by the first heat exchange tube is separated and the liquid on the surface of the tube wall of the second heat exchange tube is further reduced, so that the overall heat exchange efficiency is high.

[0021] (4) A water seal is formed at the drain port during the draining process, avoiding waste of hydrogen gas caused by hydrogen gas flowing out with the liquid.

[0022] (5) The working condition switching of the dryer can be realized by opening and closing different valves, and the control difficulty is low.

[0023] (6) While drying hydrogen, the desiccant is also regenerated, thus enabling continuous production and high working efficiency. Attached Figure Description

[0024] Figure 1 A schematic flowchart of one embodiment of the hydrogen purification system provided in this application;

[0025] Figure 2 for Figure 1 Enlarged view of the intermediate stage cooler;

[0026] Figure 3 for Figure 1 Enlarged view of the first cooler in the middle;

[0027] Figure 4 for Figure 1 A schematic diagram of the hydrogen flow path when dryer I is in main drying mode, dryer II is in regeneration mode, and dryer III is in auxiliary drying mode.

[0028] Figure 5 for Figure 1 A schematic diagram of the hydrogen flow path when dryer I is in regeneration mode, dryer II is in auxiliary drying mode, and dryer III is in main drying mode.

[0029] Figure 6 for Figure 1 A schematic diagram of the hydrogen flow path when dryer I is in auxiliary drying mode, dryer II is in main drying mode, and dryer III is in regeneration mode.

[0030] The annotations in the attached figures are explained as follows:

[0031] 1 is a gas-liquid separator, 2 is a deaerator, 3 is a primary cooler, 4 is the first cooler (I), 5 is the first cooler (II), 6 is the first cooler (III), 7 is the dryer (I), 8 is the dryer (II), 9 is the dryer (III), 10 is a level gauge, 11 is a filter, 12 is a tube shell, 13 is a heat exchange tube bundle, 14 is a baffle plate, 15 is an upper tube sheet, 16 is a lower tube sheet, 17 is an upper combined end cap, 18 is a lower combined end cap, 19 is a baffle plate, 20 is a cooling medium inlet, 21 is a cooling medium outlet, 22 is a drain port, 23 is a demister, 24 is a lower baffle plate, 25 is an upper level port, 26 is a lower level port, V1-V12 are shut-off valves, and V13 is a regulating valve. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1As shown, the hydrogen purification system of the water electrolysis hydrogen production device comprises a primary cooler 3 and at least two first coolers (three in the figure, labeled 4, 5, and 6). The primary cooler 3 and / or the first coolers (labeled 4, 5, and 6) are integrated coolers that integrate the functions of cooling, gas-liquid separation, and liquid collection.

[0034] In the past, the functions of cooling, gas-liquid separation, and liquid collection were separately implemented by heat exchangers, gas-liquid separators, and liquid collectors, which required separate spaces, resulting in a large number of devices and a large floor area for the hydrogen purification system. The present application integrates the functions of cooling, gas-liquid separation, and liquid collection into the same device to form an integrated cooler, reducing the number of devices and the floor area of the hydrogen purification system.

[0035] As shown in FIGS. Figure 2 and Figure 3 In this embodiment, the integrated cooler comprises a shell 12, a heat exchange tube bundle 13 located in the shell 12, an upper tube plate 15 located at the upper end of the heat exchange tube bundle 13, a lower tube plate 16 located at the lower end of the heat exchange tube bundle 13, an upper combined head 17 located at the upper end of the shell 12, a lower combined head 18 located at the lower end of the shell 12, a split baffle 19 located in the upper combined head 17, C and D ports provided in the upper combined head 17, a cooling medium inlet 20 and a cooling medium outlet 21 provided in the shell 12, and a liquid discharge port 22 provided in the lower combined head 18. Optionally, a baffle 14 can be provided in the shell 12. Optionally, a lower baffle 24 can be provided in the lower combined head 18. Optionally, a demister 23 can be provided in the upper combined head 17.

[0036] The height of the lower combined head 18 is greater than the height of the upper combined head 17. The lower combined head 18 and the upper combined head 17 comprise an arc segment and a straight cylinder segment, and the arc segment is provided at one end of the straight cylinder segment.

[0037] The heat exchange tube bundle 13 comprises first-stage heat exchange tubes and second-stage heat exchange tubes. The inner cavity of the upper combined head 17 comprises a first sub-cavity and a second sub-cavity, which are separated by the split baffle 19. The first sub-cavity is in communication with the upper ends of the first-stage heat exchange tubes, and the second sub-cavity is in communication with the upper ends of the second-stage heat exchange tubes.

[0038] The D port is in communication with the first sub-cavity, and the C port is in communication with the second sub-cavity. The liquid discharge port 22 is positioned as low as possible in the lower combined head 18.

[0039] The lower end of the lower baffle 24 is connected to the lower tube plate 16, and the lower end of the lower baffle 24 forms a flow space with the wall of the lower combined head 18. The lower ends of the first-stage heat exchange tubes and the second-stage heat exchange tubes are located on both sides of the lower baffle 24.

[0040] Wherein, the first stage cooler 3 with integrated cooler structure and the demister 23 of the first cooler (4, 5, 6) with integrated cooler structure are different. For the first stage cooler 3, as shown in the figure, only the second sub-cavity is provided with the demister 23. For the first cooler, as shown in the figure, the first sub-cavity and the second sub-cavity are both provided with the demister 23. Figure 2 Figure 3

[0041] In operation, the cooling medium passes through the shell side (outside the heat exchange tube bundle 13) of the integrated cooler, and the hydrogen gas passes through the tube side (inside the heat exchange tube bundle 13) of the integrated cooler. More specifically, for the first stage cooler 3, the hydrogen gas enters from the D port and is discharged from the C port. For the first cooler (4, 5, 6), in some modes, the hydrogen gas enters from the C port and is discharged from the D port, and in some modes, the hydrogen gas enters from the D port and is discharged from the C port. Hereinafter, the working process of the integrated cooler is described by taking the hydrogen gas entering from the D port as an example:

[0042] After the hydrogen gas enters the integrated cooler from the D port, it enters the first sub-cavity and exchanges heat with the cooling medium outside the heat exchange tube to be cooled and condensed;

[0043] The cooled and condensed hydrogen gas carries liquid droplets from the lower end of the first heat exchange tube into the inner cavity of the lower combined head 18. In the inner cavity of the lower combined head 18, the liquid droplets are separated from the gas flow under the action of inertial force and gravity and are deposited at the bottom of the inner cavity of the lower combined head 18. The separated gas flow passes through the flow space between the lower partition plate 24 and the wall of the lower combined head 18, turns to the other side of the lower partition plate 24, and then turns back upward to the second heat exchange tube. The liquid droplets in the upwardly turned gas flow are further separated under the action of gravity and are deposited at the bottom of the inner cavity of the lower combined head 18. The lower partition plate 24 prolongs the residence time of the gas flow in the inner cavity of the lower combined head 18, avoids the collision and mixing of the upwardly turned gas flow with the gas flow just coming out of the first heat exchange tube, and improves the gas-liquid separation effect;

[0044] When the gas flow passes through the second heat exchange tube, it exchanges heat with the cooling medium outside the heat exchange tube to be cooled and condensed again. Since the liquid in the first heat exchange tube has been basically separated, the liquid film on the inner wall of the second heat exchange tube is thin and has a high heat exchange efficiency. The condensed water droplets flow down the tube wall to the bottom of the inner cavity of the lower combined head 18. Then, the gas flow flows into the second sub-cavity of the upper combined head 17 from the upper end of the second heat exchange tube. Some liquid droplets carried by the gas flow are further captured by the demister 23 in the second sub-cavity. After that, the gas flow is discharged from the C port. The liquid droplets captured by the demister 23 flow down the tube wall to the bottom of the inner cavity of the lower combined head 18. The demister 23 improves the gas-liquid separation effect;

[0045] ​​The liquid drops are concentrated at the bottom of the inner cavity of the lower combination head 18. When the liquid level exceeds a certain value, the liquid discharge port 22 is opened to discharge the liquid.

[0046] From the above working process, it can be seen that the integrated cooler has the functions of cooling, gas-liquid separation and liquid collection.

[0047] Preferably, the upper liquid level port 25 and the lower liquid level port 26 can be arranged on the lower combination head 18. The upper liquid level port 25 is higher than the lower liquid level port 26, and the lower liquid level port 26 is higher than the liquid discharge port 27. The upper liquid level port 25 and the lower liquid level port 26 serve as the measuring ports of the liquid level gauge 10. Two probes of the liquid level gauge 10 are respectively arranged in the upper liquid level port 25 and the lower liquid level port 26. When the liquid level gauge 10 detects that the liquid level in the lower combination head 18 is located at the upper liquid level port 25, the liquid discharge port 22 is opened to discharge the liquid. When the liquid level gauge 10 detects that the liquid level in the lower combination head 18 is located at the lower liquid level port 26, the liquid discharge port 22 is closed. In this way, the liquid discharge port 22 always maintains a certain water seal state during the liquid discharge process, so that hydrogen gas will not be discharged with the liquid flow, thereby avoiding the waste of hydrogen gas.

[0048] As shown in Figure 1 , the hydrogen purification system further comprises a gas-liquid separator 1 and a deoxidizer 2. The hydrogen inlet of the deoxidizer 2 is in communication with the hydrogen outlet of the gas-liquid separator 1, and the D port of the first cooler 3 is in communication with the hydrogen outlet of the deoxidizer 2, that is, the gas-liquid separator 1, the deoxidizer 2 and the first cooler 3 are sequentially connected in series. In operation, the hydrogen gas discharged from the hydrogen production and separation system first passes through the gas-liquid separator 1 for gas-liquid separation, then passes through the deoxidizer 2 for deoxidation, and then enters the first cooler 3 for cooling and gas-liquid separation. In the deoxidizer 2, the gas flow is first preheated by the electric resistance heater, and then enters the catalyst layer to react with oxygen under the action of the catalyst to form water vapor, thereby achieving the purpose of deoxidation.

[0049] As shown in Figure 1 , the hydrogen purification system further comprises at least two dryers (7, 8, 9 in the figure). The dryers are provided with A ports and B ports. The number of dryers is the same as the number of first coolers. The A port of each dryer is in communication with the D port of a first cooler.

[0050] As shown in Figure 1 , the hydrogen purification system further comprises a plurality of valve members (V1-V12 in the figure). These valve members can switch the C port of the first cooler to be in communication with the C port of the first cooler or the C port of another first cooler, and can also switch the B port of the dryer to be in communication with the product pipeline or the B port of another dryer. In this way, the working condition switching of the dryers can be realized.

[0051] When two dryers are provided, i.e. the I dryer 7 and the II dryer 8, each dryer has two working conditions, one is a drying working condition, and the other is a regeneration working condition. The dryer in the drying working condition dries the hydrogen. The dryer in the regeneration working condition regenerates the drying agent of the hydrogen. In operation, in the last time period, the I dryer 7 is in the drying working condition, and the II dryer 8 is in the regeneration working condition; in the next time period, the I dryer 7 is in the regeneration working condition, and the II dryer 8 is in the drying working condition, and so on.

[0052] When three dryers are provided, i.e. the I dryer 7, the II dryer 8 and the III dryer 9, each dryer has three working conditions, one is a main drying working condition, one is a regeneration working condition, and one is an auxiliary drying working condition. The dryer in the main drying working condition dries the hydrogen from the first cooler which communicates with the C port of the primary cooler 3. The dryer in the regeneration working condition regenerates the drying agent of the hydrogen. The dryer in the auxiliary drying working condition dries the hydrogen from the first cooler which communicates with the A port of the dryer in the regeneration working condition. In operation, in the last time period, the I dryer 7 is in the main drying working condition, the II dryer 8 is in the regeneration working condition, and the III dryer 9 is in the auxiliary drying working condition; in the next time period, the I dryer 7 is in the regeneration working condition, the II dryer 8 is in the auxiliary drying working condition, and the III dryer 9 is in the main drying working condition; in the next time period, the I dryer 7 is in the auxiliary drying working condition, the II dryer 8 is in the main drying working condition, and the III dryer 9 is in the regeneration working condition, and so on. That is to say, the switching cycle of the same dryer is: from the main drying working condition to the regeneration working condition, from the regeneration working condition to the auxiliary drying working condition, and from the auxiliary drying working condition to the main drying working condition.

[0053] Hereinafter, the working process is described by taking the example of providing three dryers, i.e. the I dryer 7, the II dryer 8 and the III dryer 9, and three first coolers, i.e. the I first cooler 4, the II first cooler 5 and the III first cooler 6:

[0054] As Figure 4As shown, in the last time period, the V2, V4, V8, V10, V11 valves are opened, and the V1, V3, V5, V6, V7, V9, V12 valves are closed, as shown by the blue arrows in the figure. The hydrogen gas from the first cooler 3 enters the first cooler 4 through the V4 valve from the C port of the first cooler 4, and is subjected to secondary cooling and gas-liquid separation in the first cooler 4. Then, the hydrogen gas from the D port of the first cooler 4 enters the dryer 7 through the A port of the dryer 7, and is subjected to drying in the dryer 7. Then, the hydrogen gas from the B port of the dryer 7 is divided into two paths after passing through the V8 valve. One path (about 75%-85%) enters the product pipeline through the V13 regulating valve, and the V13 regulating valve adjusts the gas flow. The other path (about 15%-25%) enters the second dryer 8 through the V10 valve as regeneration gas from the B port of the second dryer 8, and is subjected to regeneration of the drying agent in the second dryer 8 after being heated. Then, the hydrogen gas from the A port of the second dryer 8 enters the second cooler 5 from the D port of the second cooler 5, and is subjected to cooling and gas-liquid separation in the second cooler 5. Then, the hydrogen gas from the C port of the second cooler 5 enters the third cooler 6 through the V2 valve from the C port of the third cooler 6, and is subjected to cooling and gas-liquid separation in the third cooler 6. Then, the hydrogen gas from the D port of the third cooler 6 enters the third dryer 9 from the A port of the third dryer 9, and then enters the product pipeline through the V11 valve from the B port of the third dryer 9.

[0055] Figure 4 In the mode shown, the second cooler 5 and the third cooler 6 sequentially cool and separate the regeneration gas, and the third dryer 9 dries the regeneration gas to meet the product requirements, so that the regeneration gas can be returned to the product pipeline.

[0056] Figure 4 In the mode shown, the first dryer 7 is in the main drying working condition, the second dryer 8 is in the regeneration working condition, and the third dryer 9 is in the auxiliary drying working condition.

[0057] As Figure 5As shown, in the next time period, V1, V6, V8, V9, V12 are opened, V2, V3, V4, V5, V7, V10, V11 are closed, as shown by the blue arrows in the figure, the hydrogen gas from the first cooler 3 enters the III first cooler 6 through the V6 valve from the C port of the III first cooler 6, and is subjected to secondary cooling and gas-liquid separation in the III first cooler 6, then enters the III dryer 9 through the A port of the III dryer 9 from the D port of the III first cooler 6, and is subjected to drying in the III dryer 9, then is divided into two paths after exiting the B port of the III dryer 9 through V12, one path enters the product pipeline through the V13 regulating valve, and the other path enters the I dryer 7 through the V8 valve from the B port of the I dryer 7 as regeneration gas, is heated to regenerate the drying agent in the I dryer 7, then enters the I first cooler 4 from the D port of the I first cooler 4 from the A port of the I dryer 7, is subjected to cooling and gas-liquid separation in the I first cooler 4, then enters the II first cooler 5 through the V1 valve from the C port of the II first cooler 5 from the C port of the I first cooler 4, is subjected to cooling and gas-liquid separation in the II first cooler 5, then enters the II dryer 8 from the A port of the II dryer 8 from the D port of the II first cooler 5, and then returns to the product pipeline through the V9 valve from the B port of the II dryer 8.

[0058] Figure 5 In the mode shown, the I first cooler 4 and the II first cooler 5 sequentially cool and gas-liquid separate the regeneration gas, and the II dryer 8 dries the regeneration gas, so that the regeneration gas meets the product requirements, thereby being able to return to the product pipeline.

[0059] Figure 5 In the mode shown, the I dryer 7 is in a regeneration working condition, the II dryer 8 is in an auxiliary drying working condition, and the III dryer 9 is in a main drying working condition.

[0060] As Figure 6As shown, in the next time period, V3, V5, V7, V10 and V12 are opened, and V1, V2, V4, V6, V8, V9 and V11 are closed, as shown by the blue arrows in the figure. The hydrogen gas from the first cooler 3 enters the second first cooler 5 through the V5 valve from the C port of the second first cooler 5, is subjected to secondary cooling and gas-liquid separation in the second first cooler 5, and then enters the second dryer 8 through the A port of the second dryer 8 from the D port of the second first cooler 5, is subjected to drying in the second dryer 8, and then is divided into two paths after passing through the V10 from the B port of the second dryer 8, one of which enters the product pipeline through the V13 regulating valve, and the other of which enters the third dryer 9 through the V12 valve from the B port of the third dryer 9 as regeneration gas, regenerates the drying agent in the third dryer 9, and then enters the third first cooler 6 from the D port of the third first cooler 6 from the A port of the third dryer 9, is subjected to cooling and gas-liquid separation in the third first cooler 6, and then enters the first cooler 4 through the V3 valve from the C port of the first cooler 4 from the C port of the third first cooler 6, is subjected to cooling and gas-liquid separation in the first cooler 4, and then enters the first dryer 7 from the A port of the first dryer 7 from the D port of the first cooler 4, and then returns to the product pipeline through the V7 valve from the B port of the first dryer 7.

[0061] Figure 6 In the mode shown, the third first cooler 6 and the first cooler 4 sequentially cool and gas-liquid separate the regeneration gas, the first dryer 7 dries the regeneration gas, so that the regeneration gas meets the product requirements, and thus can be returned to the product pipeline.

[0062] Figure 6 In the mode shown, the first dryer 7 is in the auxiliary drying working condition, the second dryer 8 is in the main drying working condition, and the third dryer 9 is in the regeneration working condition.

[0063] The hydrogen purification system further comprises a filter 11. The hydrogen in the product pipeline is further filtered by the filter 11 and then sent to a product container.

[0064] As can be seen from the above working process, the hydrogen purification system can realize switching of the working conditions of the dryers by only opening and closing different valves, and has low control difficulty. Moreover, the hydrogen purification system can regenerate the drying agent while drying the hydrogen, so that continuous production can be realized, and the working efficiency is high.

[0065] In summary, the hydrogen purification system provided by the embodiments of the present application has the following technical effects:

[0066] (1) Fewer devices and smaller floor area.

[0067] (2) The integrated cooler utilizes inertial separation, gravity separation and mechanical separation of the demister to achieve a good gas-liquid separation effect, and makes the condensate produced flow downward along the heat exchange tube and basically not enter the dryer with the gas, thereby reducing the burden of the dryer.

[0068] (3) The integrated cooler adopts a double-tube-pass design to increase the flow rate and prevent the condensate on the surface of the tube wall from accumulating, and the condensate produced in the first heat exchange tube pass is further reduced after gas-liquid separation in the second heat exchange tube pass, so the overall heat exchange efficiency is high; on the other hand, the continuous cooling and dehumidifying capacity of each device is effectively utilized to reduce the heat exchange area of the primary cooler and the first cooler.

[0069] (4) A water seal is formed at the drain outlet during the draining process, thereby avoiding waste of hydrogen due to the hydrogen being discharged with the liquid flow.

[0070] (5) The working condition of the dryer can be switched by opening and closing different valves, and the control difficulty is low.

[0071] (6) The hydrogen is dried while the desiccant is regenerated, thereby enabling continuous production and having a high work efficiency.

[0072] The above describes the principles and implementation modes of the present application by using specific examples, and the above example is only used to help understand the method and core idea of the present application. It should be noted that those skilled in the art can make some improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A hydrogen purification system for a water electrolysis hydrogen production apparatus, characterized in that, The hydrogen purification system includes an integrated cooler, which includes a shell (12), a heat exchange tube bundle (13) located inside the shell (12), an upper combined head (17) located at the upper end of the shell (12), a lower combined head (18) located at the lower end of the shell (12), a partition plate (19) located inside the upper combined head (17), ports C and D provided on the upper combined head (17), a cooling medium inlet (20) and a cooling medium outlet (21) provided on the shell (12), and a drain port (22) provided on the lower combined head (18). The height of the lower combined head (18) is greater than the height of the upper combined head (17). The heat exchange tube bundle (13) includes a first heat exchange tube and a second heat exchange tube. The inner cavity of the upper combined head (17) includes a first sub-cavity and a second sub-cavity. The first sub-cavity and the second sub-cavity are separated by the partition plate (19). The first sub-cavity is connected to the upper end of the first heat exchange tube, and the second sub-cavity is connected to the upper end of the second heat exchange tube. The D port is connected to the first sub-cavity, and the C port is connected to the second sub-cavity.

2. The hydrogen purification system of the water electrolysis hydrogen production apparatus according to claim 1, characterized in that, The hydrogen purification system includes a deoxygenator (2) and a primary cooler (3). The primary cooler (3) is an integrated cooler. The D port of the primary cooler (3) is connected to the hydrogen outlet of the deoxygenator (2). A demister (23) is provided in the second compartment of the primary cooler (3).

3. The hydrogen purification system of the water electrolysis hydrogen production apparatus according to claim 2, characterized in that, The hydrogen purification system includes at least two first coolers and at least two dryers. The first coolers are integrated coolers. The number of dryers is the same as the number of first coolers. Each dryer has an A port and a B port. The A port of each dryer is connected to the D port of one of the first coolers. Demisters (23) are provided in the first compartment and the second compartment of the first cooler.

4. The hydrogen purification system of the water electrolysis hydrogen production apparatus according to claim 3, characterized in that, The hydrogen purification system includes multiple valves, which can switch the C port of the first cooler to connect with the C port of the first-stage cooler (3) or to the C port of another first cooler, and can also switch the B port of the dryer to connect with the product pipeline or to the B port of another dryer.

5. The hydrogen purification system of the water electrolysis hydrogen production apparatus according to any one of claims 1-4, characterized in that, The lower assembly head (18) is provided with a lower partition plate (24). The upper end of the lower partition plate (24) is connected to the lower tube sheet (16) at the lower end of the heat exchange tube bundle (13). The lower end of the lower partition plate (24) and the wall of the lower assembly head (18) form a flow space. The lower ends of the first heat exchange tube and the lower ends of the second heat exchange tube are located on both sides of the lower partition plate (24).

6. The hydrogen purification system of the water electrolysis hydrogen production apparatus according to any one of claims 1-4, characterized in that, The lower combined end cap (18) is provided with an upper liquid level port (25) and a lower liquid level port (26) for use as measuring ports of a liquid level gauge (10). The upper liquid level port (25) is higher than the lower liquid level port (26), and the lower liquid level port (26) is higher than the drain port (22).

7. A hydrogen purification process for a water electrolysis hydrogen production device, implemented based on the hydrogen purification system according to any one of claims 1-6, characterized in that, The hydrogen is cooled, separated into gas and liquid, and the separated droplets are collected at the bottom of the integrated cooler in the hydrogen purification system. The hydrogen flows through the tube side of the integrated cooler, and the cooling medium flows through the shell side of the integrated cooler.

8. The hydrogen purification process of the water electrolysis hydrogen production device according to claim 7, implemented based on the hydrogen purification system according to claim 4, is characterized in that, The hydrogen purification system is equipped with two first coolers and two dryers. In the previous time period, dryer I (7) is in drying mode and dryer II (8) is in regeneration mode. In the next time period, dryer I (7) is in regeneration mode and dryer II (8) is in drying mode, and so on in a cycle. The dryer in drying mode dries hydrogen, and the dryer in regeneration mode regenerates the desiccant inside by hydrogen.

9. The hydrogen purification process of the water electrolysis hydrogen production device according to claim 7, implemented based on the hydrogen purification system according to claim 4, is characterized in that, The hydrogen purification system includes a primary cooler (3). The hydrogen purification system is equipped with three primary coolers and three dryers. In the previous time period, dryer I (7) is in the main drying condition, dryer II (8) is in the regeneration condition, and dryer III (9) is in the auxiliary drying condition. In the next time period, dryer I (7) is in the regeneration condition, dryer II (8) is in the auxiliary drying condition, and dryer III (9) is in the main drying condition. In the next time period, dryer I (7) is in the auxiliary drying condition, dryer II (8) is in the main drying condition, and dryer III (9) is in the regeneration condition. This cycle repeats. The dryer in the main drying condition dries the hydrogen coming out of the primary cooler connected to port C of the primary cooler (3). The dryer in the regeneration condition regenerates the desiccant inside by hydrogen. The dryer in the auxiliary drying condition dries the hydrogen coming out of the primary cooler connected to port A of the dryer in the regeneration condition.

10. The hydrogen purification process of the water electrolysis hydrogen production device according to claim 7, implemented based on the hydrogen purification system according to claim 6, is characterized in that, When the level gauge (10) detects that the liquid level in the lower combined head (18) is at the height of the upper liquid level port (25), the drain port (22) is opened; when the level gauge (10) detects that the liquid level in the lower combined head (18) is at the height of the lower liquid level port (26), the drain port (22) is closed.

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