Water electrolysis hydrogen production system with waste heat utilization function
By introducing a combined design of a hydrogen separation tank, a first heat exchanger, an electrolyzer, and an oxygen separation tank into the water electrolysis hydrogen production system, combined with low-temperature waste heat utilization components and an ORC low-temperature waste heat power generation system, the problem of heat loss in electrolyte temperature regulation is solved, and rapid heating and efficient heat utilization are achieved.
Patent Information
- Application Number
- CN202422835125.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-11-20
AI Technical Summary
In the prior art, the inlet temperature of the electrolytic cell, the inlet temperature of the alkali solution of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the inlet temperature of the electrolytic cell, the electrolyte temperature needs to be cooled by heat exchange, resulting in heat loss.
A water electrolysis hydrogen production system with waste heat utilization function is adopted. Through the combined design of hydrogen separation tank, first heat exchanger, electrolyzer and oxygen separation tank, low-temperature waste heat utilization components and ORC low-temperature waste heat power generation system are used to achieve rapid heating of the electrolyzer and effective utilization of heat.
It improves the heat utilization rate, saves cooling water, realizes the rapid heating of the electrolytic cell and the efficient use of heat, and solves the problem of heat loss in the temperature regulation of the electrolyte.
Smart Images
Figure CN223357777U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electrolytic hydrogen production, in particular to a water electrolytic hydrogen production system with waste heat utilization function. Background Art
[0002] Water electrolysis is a relatively convenient method for producing hydrogen. Direct current is passed through an electrolytic cell filled with electrolyte. Water molecules undergo an electrochemical reaction at the electrodes, decomposing into hydrogen and oxygen. Specifically, high-purity hydrogen is produced by directly electrolyzing the water in the electrolyte. When power is applied, hydrogen is produced at the cathode and oxygen at the anode of the electrolytic cell. The hydrogen enters the hydrogen / water separator, while the oxygen is discharged into the atmosphere.
[0003] In the water electrolysis hydrogen production system, in order to make the electrolyzer have a higher hydrogen production efficiency, the electrolyzer needs to be kept at a higher temperature for reaction. Currently, the temperature of the alkaline water electrolysis hydrogen production system is about 90°C, the temperature of the PEM water electrolysis hydrogen production system is about 60°C, and the temperature of the SOEC water electrolysis hydrogen production system is about 800°C. At the same time, because part of the current will be converted into heat energy to increase the temperature of the electrolyzer, the inlet temperature of the electrolyzer electrolyte must be lower than the reaction temperature and remain stable.
[0004] To reduce the electrolyte inlet temperature, the current solution is to introduce a heat exchanger at the electrolyzer inlet and use a cooling water circulation system to cool the electrolyte at the outlet of the water electrolysis hydrogen production system, so that it meets the lower inlet temperature requirement during circulation. However, this technical drawback is that the cooling water circulation system in this solution causes a large amount of heat loss, and the hydrogen production system, especially the SOEC water electrolysis hydrogen production system, with a temperature of approximately 800°C, is not effectively utilized. Utility Model Content
[0005] In view of the technical problem that in the existing electrolytic hydrogen production technology, the electrolyte temperature at the electrolyzer inlet needs to be cooled by heat exchange, resulting in heat loss, the utility model provides a water electrolysis hydrogen production system with waste heat utilization function, which solves the problem of low heat utilization rate in the water electrolysis hydrogen production system and saves cooling water.
[0006] The technical solution of the utility model is:
[0007] A water electrolysis hydrogen production system with waste heat utilization includes a hydrogen separation tank, a first heat exchanger, an electrolyzer and an oxygen separation tank. The hydrogen separation tank is provided with a liquid inlet on the side, a hydrogen exhaust pipe is provided on the top of the hydrogen separation tank, a liquid discharge port at the bottom of the hydrogen separation tank is connected to a heat medium inlet of the first heat exchanger through a first pipeline, and an oxygen outlet of the electrolyzer is connected to a steam inlet on the side of the oxygen separation tank through a second pipeline. The system also includes a second heat exchanger, the heat medium outlet of the first heat exchanger is connected to the heat medium inlet of the second heat exchanger through a third pipeline, the heat medium outlet of the second heat exchanger is connected to an alkali solution inlet of the electrolyzer through a fourth pipeline, the hydrogen outlet of the electrolyzer is connected to the cold medium inlet of the second heat exchanger through a fifth pipeline, and the cold medium outlet of the second heat exchanger is connected to the steam inlet on the side of the hydrogen separation tank through a sixth pipeline.
[0008] Furthermore, a low-temperature waste heat utilization component is provided on the fifth pipeline, and the heat source inlet of the low-temperature waste heat utilization component is connected to the hydrogen outlet of the electrolyzer through a pipeline, and the heat source outlet of the low-temperature waste heat utilization component is connected to the cold medium inlet of the second heat exchanger through a pipeline.
[0009] Furthermore, the low-temperature waste heat utilization component is an ORC low-temperature waste heat power generation system.
[0010] Furthermore, a three-way valve is installed on the third pipeline, and the outlet of the three-way valve is connected to the fourth pipeline through the seventh pipeline. This is because during the electrolytic cell heating process, when the first and second heat exchangers are not in operation due to the need for rapid temperature increase, the three-way valve opens to the seventh pipeline, allowing the electrolytic cell to reach the rated temperature as quickly as possible.
[0011] Furthermore, the height of the second heat exchanger and the sixth pipeline are both higher than the height of the steam inlet on the side of the hydrogen separation tank, so as to ensure that the liquid initially condensed after heat exchange in the second heat exchanger can flow into the hydrogen separation tank under the action of gravity.
[0012] Furthermore, a circulation pump is provided on the first pipeline.
[0013] The beneficial effect of the present invention is that the water electrolysis hydrogen production system with waste heat utilization provided by the present invention can further heat exchange the hydrogen (gas-liquid two-phase) produced by the electrolytic cell in the hydrogen production system with the cooled alkali liquid at the inlet of the electrolytic cell, so that the lower temperature hydrogen and the alkali liquid exchange heat, further reducing the temperature of the alkali liquid, saving the cooling water consumption of the first heat exchanger, improving the heat utilization rate, and having the effect of waste heat utilization. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0015] Figure 1 This is a structural diagram of Example 1 of the specific implementation method of the present utility model.
[0016] Figure 2 This is a structural diagram of Example 2 of the specific implementation method of the present utility model.
[0017] In the figure, 1-hydrogen separation tank, 2-liquid inlet, 3-first pipeline, 4-circulation pump, 5-first heat exchanger, 6-third pipeline, 7-seventh pipeline, 8-electrolyzer, 9-second pipeline, 10-oxygen separation tank, 11-fifth pipeline, 12-fourth pipeline, 13-second heat exchanger, 14-three-way valve, 15-sixth pipeline, 16-hydrogen exhaust pipe, 17-low-temperature waste heat utilization component. DETAILED DESCRIPTION
[0018] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will be combined with the drawings of the embodiments of the present invention to clearly and completely describe the technical solutions of the embodiments of the present invention. Obviously, the embodiments described 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 without making creative efforts should fall within the scope of protection of the present invention.
[0019] Example 1
[0020] Combine Figure 1 The utility model provides a water electrolysis hydrogen production system with waste heat utilization, including a hydrogen separation tank 1, a first heat exchanger 5, an electrolyzer 8 and an oxygen separation tank 10. The hydrogen separation tank 1 is provided with a liquid inlet 2 on the side, a hydrogen exhaust pipe 16 is provided on the top of the hydrogen separation tank 1, and the liquid discharge port at the bottom of the hydrogen separation tank 1 is connected to the heat medium inlet of the first heat exchanger 5 through a first pipeline 3. A circulating pump 4 is provided on the first pipeline 3. The oxygen outlet of the electrolyzer 8 is connected to the steam inlet on the side of the oxygen separation tank 10 through a second pipeline 9.
[0021] The utility model also includes a second heat exchanger 13. The hot medium outlet of the first heat exchanger 5 is connected to the hot medium inlet of the second heat exchanger 13 through a third pipeline 6. The hot medium outlet of the second heat exchanger 13 is connected to the alkali solution inlet of the electrolyzer 8 through a fourth pipeline 12. The hydrogen outlet of the electrolyzer 8 is connected to the cold medium inlet of the second heat exchanger 13 through a fifth pipeline 11. The cold medium outlet of the second heat exchanger 13 is connected to the steam inlet on the side of the hydrogen separation tank 1 through a sixth pipeline 15.
[0022] A three-way valve 14 is installed on the third pipeline 6, and the outlet of the three-way valve 14 is connected to the fourth pipeline 12 through the seventh pipeline 7. The purpose of this valve is that when the temperature of the electrolytic cell 8 is rising, due to the need for rapid temperature increase, the first heat exchanger 5 and the second heat exchanger 13 are not in operation. The three-way valve 14 opens to the seventh pipeline 7, allowing the inside of the electrolytic cell 8 to reach the rated temperature as quickly as possible.
[0023] The height of the second heat exchanger 13 and the sixth pipeline 15 are both higher than the height of the steam inlet on the side of the hydrogen separation tank 1. Their function is to ensure that part of the liquid that is initially condensed after heat exchange in the second heat exchanger can flow into the hydrogen separation tank under the action of gravity.
[0024] The first heat exchanger 5 and the second heat exchanger 13 used in the present invention are both conventional industrial heat exchanger structures. The cold medium of the first heat exchanger 5 is water. For example, the first heat exchanger 5 is a shell and tube heat exchanger, and the second heat exchanger 13 is a plate heat exchanger. Both have four interface ends: a cold medium inlet, a cold medium outlet, a hot medium inlet, and a hot medium outlet.
[0025] The working process of this utility model is:
[0026] The electrolyte alkali liquid enters the hydrogen separation tank 1 from the liquid inlet 2, is discharged from the bottom, and is pumped to the first heat exchanger 5 by the circulation pump 4 for preliminary heat exchange and cooling before entering the second heat exchanger 13. The cold medium of the second heat exchanger 13 is the hydrogen gas in the gas-liquid two-phase of the electrolyte in the electrolytic cell 8. The hydrogen gas has a low temperature and further reduces the temperature of the alkali liquid after heat exchange with the alkali liquid, so that it drops to the temperature required by the process, saving the amount of cooling water in the first heat exchanger 5 and saving heat. The oxygen gas in the gas-liquid two-phase produced by electrolysis enters the oxygen separation tank 10 to separate the liquid and collect the oxygen.
[0027] Example 2
[0028] Combine Figure 2, Example 2 is different from Example 1 in that the water electrolysis hydrogen production system adopts a SOEC water electrolysis hydrogen production system. The temperature of the SOEC water electrolysis hydrogen production system is about 800°C. A low-temperature waste heat utilization component 17 is provided on the fifth pipeline 11. The low-temperature waste heat utilization component is an ORC low-temperature waste heat power generation system. The heat source inlet of the low-temperature waste heat utilization component 17 is connected to the hydrogen outlet of the electrolyzer 8 through a pipeline, and the heat source outlet of the low-temperature waste heat utilization component 17 is connected to the cold medium inlet of the second heat exchanger 13 through a pipeline.
[0029] The drawn gas-liquid two-phase hydrogen gas first enters the ORC low-temperature waste heat power generation system to generate electricity. The generated electricity can be used for low-voltage electricity consumption of the system. For a water electrolysis hydrogen production system with a capacity of 100MW, the waste heat is calculated as 10MW at 10%. The power generation efficiency of the low-temperature waste heat power generation system is calculated at 10%, and the power generation capacity can reach 1MW.
[0030] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall fall within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall fall within the scope of protection of the present invention.
Claims
1. A water electrolysis hydrogen production system with waste heat utilization, comprising a hydrogen separation tank, a first heat exchanger, an electrolyzer, and an oxygen separation tank, wherein a liquid inlet is provided on the side of the hydrogen separation tank, a hydrogen exhaust pipe is provided on the top of the hydrogen separation tank, a liquid discharge port at the bottom of the hydrogen separation tank is connected to the heat medium inlet of the first heat exchanger through a first pipeline, and the oxygen outlet of the electrolyzer is connected to the steam inlet on the side of the oxygen separation tank through a second pipeline, characterized in that: It also includes a second heat exchanger, the hot medium outlet of the first heat exchanger is connected to the hot medium inlet of the second heat exchanger through a third pipeline, the hot medium outlet of the second heat exchanger is connected to the alkali solution inlet of the electrolyzer through a fourth pipeline, the hydrogen outlet of the electrolyzer is connected to the cold medium inlet of the second heat exchanger through a fifth pipeline, and the cold medium outlet of the second heat exchanger is connected to the steam inlet on the side of the hydrogen separation tank through a sixth pipeline.
2. The water electrolysis hydrogen production system with waste heat utilization according to claim 1, characterized in that: The fifth pipeline is provided with a low-temperature waste heat utilization component, the heat source inlet of the low-temperature waste heat utilization component is connected to the hydrogen outlet of the electrolyzer through a pipeline, and the heat source outlet of the low-temperature waste heat utilization component is connected to the cold medium inlet of the second heat exchanger through a pipeline.
3. The water electrolysis hydrogen production system with waste heat utilization as claimed in claim 2, characterized in that: The low-temperature waste heat utilization component is the ORC low-temperature waste heat power generation system.
4. The water electrolysis hydrogen production system with waste heat utilization according to claim 1, characterized in that: A three-way valve is provided on the third pipeline, and an outlet of the three-way valve is connected to the fourth pipeline through the seventh pipeline.
5. The water electrolysis hydrogen production system with waste heat utilization as claimed in claim 1, characterized in that: The heights of the second heat exchanger and the sixth pipeline are both higher than the height of the steam inlet on the side of the hydrogen separation tank.
6. The water electrolysis hydrogen production system with waste heat utilization according to claim 1, characterized in that: A circulation pump is provided on the first pipeline.