A water electrolysis hydrogen drying system and method

Abstract

The present invention provides a water electrolysis hydrogen drying system and method, comprising an air inlet, a product gas outlet, a first adsorption tower connected between the air inlet and the product gas outlet, and a second adsorption tower, wherein the adsorption cycles of the first adsorption tower and the second adsorption tower are switched at intervals, so that in any adsorption cycle, when one of the adsorption towers is in an adsorption state, the other adsorption tower is in a heating regeneration or cooling state; when hydrogen enters the air inlet, part of the hydrogen enters the adsorption tower in the adsorption state, and flows out from the air outlet of the adsorption tower after being dried by an adsorbent in the adsorption tower, so that the dried hydrogen flows out from the product gas outlet; another part of the hydrogen enters a heater for heating, and the heated hydrogen enters the adsorption tower in the heating regeneration state, so that the moisture on the adsorbent flows out from the air outlet of the adsorption tower in the form of water vapor together with the heated hydrogen; the present invention reduces equipment manufacturing costs, simplifies the process, and avoids ineffective heat loss.

Description

Technical Field

[0001] The invention relates to the field of water electrolysis hydrogen equipment, and in particular to a water electrolysis hydrogen drying system and a method thereof. Background Art

[0002] The existing water electrolysis hydrogen drying scheme mainly adopts a three-tower process. The hydrogen produced by the water electrolyzer is deoxygenated, cooled, and separated from gas and water, and then flows through a three-way program-controlled valve, a gas-water separator, and a cooler, and enters from the lower end interface of adsorption tower A. Under the adsorption and drying effect of the adsorbent, the water vapor contained in the hydrogen is adsorbed and dried by the adsorbent. The dried hydrogen flows out from the upper end interface of adsorption tower A and is divided into two paths by a pneumatic three-way program-controlled valve. One path goes to adsorption tower B, and the other path enters the product gas pipeline after passing through a pneumatic regulating valve.

[0003] As part of the dry hydrogen flowing out of adsorption tower A enters adsorption tower B, the heater element in adsorption tower B is automatically started, the hydrogen is heated by the electric heater, and then flows through the bed of the adsorption tower. The moisture adsorbed on the adsorption tower contacts with the hot hydrogen, and is desorbed from the adsorbent in the form of water vapor, and flows out through the lower interface of adsorption tower B together with the hydrogen.

[0004] Subsequently, the hot mixed gas of hydrogen and water vapor enters the adsorption tower C and contacts the cooler therein. The mixed gas of hydrogen and water vapor is cooled, and the condensed water flows into the gas-water separator in the adsorption tower C together with the hydrogen and is separated from the hydrogen. The condensed water is automatically discharged through the drain valve.

[0005] The above-mentioned water electrolysis hydrogen drying scheme has the following main defects:

[0006] 1. Each adsorption tower is equipped with a cooler and a gas-water separator, which results in a large number of equipment and high manufacturing costs.

[0007] 2. The electric heating element is arranged in the adsorption tower, which makes the subsequent maintenance of the adsorption tower inconvenient and the structure of the adsorption tower complicated.

[0008] 3. For adsorption devices with large processing capacity, since the electric heating element is set in the adsorption tower, part of the space in the adsorption tower cannot be filled with adsorbent, which will cause the size of the adsorption tower to become larger and increase the difficulty and cost of container manufacturing.

[0009] 4. When the diameter of the adsorption tower becomes larger, because an electric heating element is installed in the center of the adsorption tower, the closer the distance to the center of the adsorption tower is, the higher the temperature of the adsorbent will be, and the farther away from the center of the adsorption tower, the lower the temperature will be, resulting in uneven radial temperature distribution of the adsorbent, affecting the regeneration effect and ultimately the adsorption effect.

[0010] 5. Because the electric heating element is set in the adsorption tower, the heat of the electric heater element needs to be taken away every time the cold blow is performed, which will increase the energy loss and increase the cold blow time. Summary of the invention

[0011] The object of the present invention is to provide a water electrolysis hydrogen drying system and method thereof which can reduce equipment manufacturing cost, simplify the process and avoid ineffective heat loss.

[0012] In order to solve the above technical problems, the present invention provides a method for drying hydrogen from water electrolysis, comprising an air inlet, a product gas outlet, a first adsorption tower connected between the air inlet and the product gas outlet, and a second adsorption tower, and the adsorption cycles of the first adsorption tower and the second adsorption tower are switched at intervals, so that in any adsorption cycle, when one of the adsorption towers is in an adsorption state, the other adsorption tower is in a heating regeneration or cooling state;

[0013] The air inlet, the adsorption tower in the adsorption state and the product gas outlet are connected in sequence to form a drying flow path;

[0014] A heater is connected between the air inlet and the product gas outlet, so that the air inlet, the heater and the adsorption tower in the heating regeneration state are connected in sequence to form a regeneration flow path;

[0015] When hydrogen enters the air inlet, part of the hydrogen enters the adsorption tower in the adsorption state, and flows out from the gas outlet of the adsorption tower after being dried by the adsorbent in the adsorption tower, so that the dried hydrogen flows out from the product gas outlet; the other part of the hydrogen enters the heater for heating, and the heated hydrogen enters the adsorption tower in the heating regeneration state, so that the moisture on the adsorbent flows out from the gas outlet of the adsorption tower together with the heated hydrogen in the form of water vapor. When the adsorption tower in the heating regeneration state is regenerated, the hydrogen flowing to the heater is switched to the bypass pipeline, and the regenerated adsorption tower is cooled. After cooling to the set temperature, the adsorption tower is switched to the adsorption state.

[0016] Furthermore, a cooler and a gas-liquid separator are connected between the air inlet pipe and the product gas outlet, and one side of the cooler is connected to the gas outlet end of the adsorption tower, so that the adsorption tower in a heated regeneration state, the cooler and the gas-liquid separator are connected in sequence to form a condensation flow path.

[0017] Furthermore, a heat exchanger is provided between the air inlet and the heater, and the condensation flow path flows through the heat exchanger.

[0018] Furthermore, a drainage pipe outlet for discharging condensed water is connected to one side of the gas-liquid separator, and the gas-liquid separator is connected to the air inlet end of the adsorption tower so that the hydrogen after gas-liquid separation enters the adsorption tower in an adsorption state.

[0019] Furthermore, a temperature detection element is provided at the outlet of the heater, so that when the temperature detection element detects that the temperature at the outlet is lower than a set temperature, the heater starts heating and raising the temperature.

[0020] Furthermore, a pneumatic regulating valve is connected between the air inlet pipe opening and the air inlet end of the adsorption tower to adjust the air intake volume of the adsorption tower.

[0021] Furthermore, a filter is connected to a side of the product gas outlet close to the adsorption tower, so that the hydrogen flows out from the product gas outlet after being filtered by the filter.

[0022] Furthermore, a flow meter is connected between the air inlet and the heater to detect the flow of hydrogen entering the heater.

[0023] The invention also discloses a water electrolysis hydrogen drying system, which is used by the water electrolysis hydrogen drying method.

[0024] The beneficial effects of the present invention are:

[0025] 1. The three-tower process is simplified to a two-tower process. At the same time, the built-in coolers of the three adsorption towers are simplified to one external cooler for common use, and the built-in gas-liquid separators of the three adsorption towers are simplified to one external gas-liquid separator for common use, reducing the number of equipment and simplifying the process.

[0026] 2. The heater is independently arranged outside the adsorption tower, which reduces the number of components, simplifies the process, simplifies the structure of the adsorption tower simultaneously, and avoids the heat loss of the cooler to the heater.

[0027] 3. For adsorption devices with large processing capacity, the size of the adsorption tower can be reduced and the manufacturing difficulty can be reduced.

[0028] 4. Since the heater is arranged outside the adsorption tower and multiple adsorption towers share the same heater, when the hydrogen is heated by the heater, the problem of uneven radial heating when heating inside the adsorption tower will not occur.

[0029] 5. Simplify the process and avoid ineffective heat loss of the heater, thereby reducing energy loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention.

[0031] Figure numerals: 1. Air inlet; 2. Product gas outlet; 3. First adsorption tower; 4. Second adsorption tower; 5. Heater; 6. Cooler; 7. Gas-liquid separator; 8. Drain pipe; 9. Bypass line; 10. Temperature detection element; 11. Pneumatic control valve; 12. Filter; 13. Flow meter; 14. Heat exchanger. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0033] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0034] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0035] like Figure 1 The present invention provides a method for drying hydrogen from water electrolysis, comprising an air inlet 1, a product gas outlet 2, a first adsorption tower 3 and a second adsorption tower 4 connected between the air inlet 1 and the product gas outlet 2, and the adsorption cycles of the first adsorption tower 3 and the second adsorption tower 4 are switched at intervals, so that in any adsorption cycle, when one of the adsorption towers is in an adsorption state, the other adsorption tower is in a heating regeneration or cooling state;

[0036] The air inlet 1, the adsorption tower in the adsorption state and the product gas outlet 2 are sequentially connected to form a drying flow path;

[0037] A heater 5 is connected between the air inlet port 1 and the product gas outlet 2, so that the air inlet port 1, the heater 5 and the adsorption tower in the heating regeneration state are sequentially connected to form a regeneration flow path;

[0038] When hydrogen enters the air inlet pipe 1, part of the hydrogen enters the adsorption tower in the adsorption state, and flows out from the gas outlet of the adsorption tower after being dried by the adsorbent in the adsorption tower, so that the dried hydrogen flows out from the product gas outlet 2; another part of the hydrogen enters the heater 5 for heating, and the heated hydrogen enters the adsorption tower in the heating regeneration state, so that the moisture on the adsorbent flows out from the gas outlet of the adsorption tower together with the heated hydrogen in the form of water vapor. When the adsorption tower in the heating regeneration state is regenerated, the hydrogen flowing to the heater 5 is switched to the bypass line 9, and the regenerated adsorption tower is cooled. After cooling to the set temperature, the adsorption tower is switched to the adsorption state.

[0039] Among them, the switching of the air intake path between the first adsorption tower and the second adsorption tower, the switching between the drying flow path and the regeneration flow path, and the flow paths between the various devices are all controlled and switched by opening and closing valves at different positions.

[0040] It is worth mentioning that the adsorption cycles of the first adsorption tower and the second adsorption tower in this scheme are switched at intervals. Specifically, when the first adsorption tower is adsorbing, the second adsorption tower is heated and regenerated, and when the second adsorption tower is adsorbing, the first adsorption tower is heated and regenerated.

[0041] In particular, in this solution, the hydrogen entering from the air inlet is subjected to pre-deoxygenation, cooling, and gas-water separation treatments.

[0042] In one embodiment of the present scheme, the bottom of the adsorption tower has an air inlet end, and the top of the adsorption tower has an air outlet end, so that after the hydrogen enters the adsorption tower, it can naturally pass through the dry adsorption of the adsorbent by the way of gas rising.

[0043] Preferably, a cooler 6 and a gas-liquid separator 7 are connected between the air inlet pipe 1 and the product gas outlet 2, and one side of the cooler 6 is connected to the gas outlet end of the adsorption tower, so that the adsorption tower in a heated regeneration state, the cooler 6 and the gas-liquid separator 7 are connected in sequence to form a condensation flow path.

[0044] Specifically, after the hydrogen heated by the heater enters the adsorption tower in the heating regeneration state, the water on the adsorbent therein is evaporated by the heat, so that the water vapor and hydrogen flow out from the gas outlet of the adsorption tower together, and then the mixed gas of water vapor and hydrogen enters the cooler for cooling and condensation, so that the water vapor forms condensed water. At this time, the condensed water and hydrogen flow through the gas-liquid separator, and the hydrogen is separated and removed by the gas-liquid separator to improve the dehydration effect of the adsorbent during the heating regeneration process.

[0045] In a preferred embodiment of the present scheme, a heat exchanger 14 is provided between the air inlet pipe port 1 and the heater 5, and the condensation flow path flows through the heat exchanger 14, so that the hot gas output from the adsorption tower in the heating regeneration state provides part of the heat after passing through the heat exchanger 14. At the same time, when the hydrogen flows through the heat exchanger 14 from the air inlet pipe port 1, it can be initially heated by the heat exchanger 14 to reduce the heating energy consumption.

[0046] Preferably, a drain pipe 8 for discharging condensed water is connected to one side of the gas-liquid separator 7, and the gas-liquid separator 7 is connected to the air inlet end of the adsorption tower so that the hydrogen after gas-liquid separation enters the adsorption tower in an adsorption state.

[0047] Specifically, after the gas-liquid separator separates the condensed water from the hydrogen, the condensed water is discharged from the drain pipe outlet, while the hydrogen re-enters the adsorption tower in the adsorption state, thereby avoiding hydrogen waste and ensuring the drying effect of the hydrogen.

[0048] Preferably, a temperature detection element 10 is provided at the outlet of the heater 5, so that when the temperature detection element 10 detects that the temperature at the outlet is lower than the set temperature, the heater 5 starts heating and raising the temperature.

[0049] Specifically, the temperature at the heater outlet is detected in real time by a temperature detection element to ensure that a certain degree of heat is maintained when the hydrogen passes through the heater and enters the adsorption tower, thereby improving the effect of the adsorbent being heated to release water.

[0050] During actual use, the user needs to first set the temperature of the temperature detection element so that when the temperature detection element detects that the heater outlet temperature is lower than the set temperature, the temperature detection element will feedback a signal to the heater, so that the heater receives the signal to start and heat up to increase the temperature at the heater outlet.

[0051] At the same time, the user can also set an upper limit temperature value for the temperature detection element, so that when the heater outlet temperature is higher than the upper limit temperature value, a feedback signal is sent to the heater. At this time, the heater can stop or maintain the current temperature to avoid the heater heating up for too long and causing increased energy consumption.

[0052] In one embodiment of the present solution, the temperature detection element may be an infrared temperature sensor.

[0053] Preferably, a pneumatic regulating valve 11 is connected between the air inlet pipe port 1 and the air inlet end of the adsorption tower to adjust the air intake volume of the adsorption tower.

[0054] Specifically, the flow rate of dry hydrogen entering the adsorption tower is controlled by adjusting the pneumatic regulating valve, and the flow rate of hydrogen entering the heater is then synchronously controlled to ensure that the adsorption tower in the heating regeneration state has sufficient hydrogen for regeneration.

[0055] Preferably, a filter 12 is connected to the side of the product gas outlet 2 close to the adsorption tower, so that the hydrogen flows out from the product gas outlet 2 after being filtered by the filter 12 .

[0056] Specifically, after water is adsorbed by the adsorbent, the dry hydrogen needs to be filtered through a filter before entering the product gas outlet to ensure that the final hydrogen has good quality.

[0057] In one embodiment of the present solution, a program-controlled valve is connected to one side of the filter close to the adsorption tower.

[0058] Preferably, a flow meter 13 is connected between the air inlet port 1 and the heater 5 to detect the flow rate of hydrogen entering the heater 5 .

[0059] Specifically, when the hydrogen flow entering the adsorption tower or heater is controlled by a pneumatic regulating valve, the hydrogen flow at the heater can be clearly indicated by observing the detection value of the flow meter, so as to avoid too much or too little hydrogen entering the adsorption tower in the regenerated state, resulting in poor regeneration effect of the adsorption tower or waste of hydrogen.

[0060] The invention also discloses a water electrolysis hydrogen drying system, which is used by the water electrolysis hydrogen drying method.

[0061] The water electrolysis hydrogen drying system of this scheme is used in accordance with the following process when it is actually used (taking the adsorption in the first adsorption tower and the regeneration in the second adsorption tower as an example):

[0062] After the hydrogen produced by the water electrolyzer is deoxygenated, cooled, and separated from gas and water, the hydrogen enters the air inlet port 1 and is divided into two paths through the pneumatic regulating valve 11. One path enters from the air inlet end of the first adsorption tower 3 after passing through the pneumatic regulating valve 11. Under the adsorption and drying of the adsorbent, the water vapor contained in the hydrogen is adsorbed and dried by the adsorbent. The dried hydrogen flows out from the air outlet end of the first adsorption tower 3, passes through the program-controlled valve, and is filtered by the filter 12 before entering the product gas outlet 2.

[0063] The other hydrogen gas enters the heater 5 after being measured by the flow meter 13. The heated hydrogen gas enters from the air inlet end of the second adsorption tower 4, and then contacts the adsorption bed in the second adsorption tower 4. The moisture adsorbed on the adsorption bed contacts with the hot hydrogen gas, and is desorbed from the adsorbent in the form of water vapor, and flows out through the air outlet end of the second adsorption tower 4 together with the hydrogen gas.

[0064] Subsequently, the hot mixed gas of hydrogen and water vapor passes through the cooler 6 and the chiller 9, so that the mixed gas of hydrogen and water vapor is cooled, and the condensed water precipitated from the mixed gas flows into the gas-liquid separator 7 together with the hydrogen and is separated from the hydrogen. The separated hydrogen merges with the hydrogen entering the first adsorption tower 3 and re-enters the adsorption tower, and the condensed water separated at the gas-liquid separator 7 is discharged through the drain pipe 8.

[0065] The heater 5 is controlled by the temperature at the heater outlet. When the temperature detection element 10 detects that the temperature at the outlet is lower than the set value, the heater 4 automatically starts heating and raising the temperature.

[0066] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A method for drying hydrogen from water electrolysis, characterized in that: The invention comprises an air inlet (1), a product gas outlet (2), a first adsorption tower (3) and a second adsorption tower (4) connected between the air inlet (1) and the product gas outlet (2), wherein the adsorption cycles of the first adsorption tower (3) and the second adsorption tower (4) are switched at intervals, so that in any adsorption cycle, when one of the adsorption towers is in an adsorption state, the other adsorption tower is in a heating regeneration or cooling state; The air inlet (1), the adsorption tower in the adsorption state, and the product gas outlet (2) are connected in sequence to form a drying flow path; A heater (5) is connected between the air inlet pipe opening (1) and the product gas outlet (2), so that the air inlet pipe opening (1), the heater (5) and the adsorption tower in a heated regeneration state are sequentially connected to form a regeneration flow path; When hydrogen enters the air inlet (1), part of the hydrogen enters the adsorption tower in the adsorption state, and flows out from the gas outlet of the adsorption tower after being dried by the adsorbent in the adsorption tower, so that the dried hydrogen flows out from the product gas outlet (2); another part of the hydrogen enters the heater (5) for heating, and the heated hydrogen enters the adsorption tower in the heating regeneration state, so that the moisture on the adsorbent flows out from the gas outlet of the adsorption tower in the form of water vapor together with the heated hydrogen. When the adsorption tower in the heating regeneration state is regenerated, the hydrogen flowing to the heater (5) is switched to the bypass pipeline (9), and the regenerated adsorption tower is cooled. After cooling to a set temperature, the adsorption tower is switched to the adsorption state; A cooler (6) and a gas-liquid separator (7) are connected between the air inlet (1) and the product gas outlet (2), and one side of the cooler (6) is connected to the gas outlet of the adsorption tower, so that the adsorption tower in a heating and regeneration state, the cooler (6) and the gas-liquid separator (7) are connected in sequence to form a condensation flow path. After the hydrogen heated by the heater enters the adsorption tower in a heating and regeneration state, the water on the adsorbent therein evaporates due to the heat, so that the water vapor and the hydrogen flow out from the gas outlet of the adsorption tower together. Subsequently, the mixed gas of the water vapor and the hydrogen enters the cooler for cooling and condensation, so that the water vapor forms condensed water. At this time, the condensed water and the hydrogen flow through the gas-liquid separator, and the hydrogen is separated and removed by the gas-liquid separator. A heat exchanger (14) is provided between the air inlet port (1) and the heater (5), and the condensation flow path flows through the heat exchanger (14); A temperature detection element (10) is provided at the outlet of the heater (5), so that when the temperature detection element (10) detects that the temperature at the outlet is lower than a set temperature, the heater (5) starts heating and raising the temperature.

2. The method for drying hydrogen from water electrolysis according to claim 1, characterized in that: A drainage pipe opening (8) for discharging condensed water is connected to one side of the gas-liquid separator (7), and the gas-liquid separator (7) is connected to the air inlet end of the adsorption tower so that hydrogen after gas-liquid separation enters the adsorption tower in an adsorption state.

3. The method for drying hydrogen from water electrolysis according to claim 1, characterized in that: A pneumatic regulating valve (11) is connected between the air inlet pipe opening (1) and the air inlet end of the adsorption tower, and is used to adjust the air intake volume of the adsorption tower.

4. The method for drying hydrogen from water electrolysis according to claim 1, characterized in that: A filter (12) is connected to the side of the product gas outlet (2) close to the adsorption tower, so that the hydrogen flows out from the product gas outlet (2) after being filtered by the filter (12).

5. The method for drying hydrogen from water electrolysis according to claim 1, characterized in that: A flow meter (13) is connected between the air inlet pipe opening (1) and the heater (5) for detecting the flow rate of hydrogen entering the heater (5).

6. A water electrolysis hydrogen drying system, characterized in that: The method for drying hydrogen by water electrolysis is used according to any one of claims 1 to 5.

Images