Water electrolysis hydrogen production oxygen pressure energy recycling system

Abstract

The utility model relates to a water electrolysis hydrogen production oxygen pressure energy recycling system. The system comprises a water electrolysis system and an oxygen-driven power generation system, the oxygen-driven power generation system comprises an oxygen pipeline, an oxygen emptying pipeline and an expansion generator; the expansion generator is arranged between the oxygen pipeline and the oxygen emptying pipeline; and the oxygen pipeline is connected with the electrolyzed water system. According to the utility model, the expansion generator is additionally arranged on the oxygen pipeline of the electrolyzed water system, and the pressure of byproduct oxygen can be utilized to push the expansion generator to do work to generate electric energy, so that the purpose of directly recycling oxygen pressure energy is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen production by electrolyzing water, and particularly to a system for recycling the pressure energy of oxygen in hydrogen production by electrolyzing water. Background Art

[0002] At present, the main hydrogen production devices by electrolyzing water are alkaline hydrogen production by electrolyzing water and proton exchange membrane hydrogen production by electrolyzing water. The alkaline electrolyzed water technology uses an aqueous solution of KOH or NaOH as an electrolyte. Under the action of direct current, water is decomposed into hydrogen and oxygen.

[0003] Currently, common electrolyzers often use low-pressure electrolyzers, and the pressures of the electrolyzed hydrogen and oxygen are both 1.6 MPa (a similar pressure value process is also adopted for proton exchange membrane hydrogen production by electrolyzing water). Hydrogen is sent as a product to downstream purification for storage or use, while oxygen (oxygen that is not recycled and utilized is called waste oxygen) is depressurized to atmospheric pressure and discharged to the atmosphere after gas-liquid separation. This not only wastes the oxygen product but also wastes the pressure energy of oxygen, making the oxygen and its pressure energy unable to be effectively utilized, resulting in great waste.

[0004] Therefore, how to recycle and utilize the pressure energy of oxygen has become an urgent problem to be solved. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a system for recycling the pressure energy of oxygen in hydrogen production by electrolyzing water, so as to solve the problem of recycling and utilization of the pressure energy of the by-product oxygen in the hydrogen production device by electrolyzing water and avoid the direct waste of the by-product oxygen by discharging it directly.

[0006] To achieve the above purpose, the utility model provides a system for recycling the pressure energy of oxygen in hydrogen production by electrolyzing water. The system includes an electrolyzed water system and an oxygen-driven power generation system; the oxygen-driven power generation system includes an oxygen pipeline, an oxygen vent pipeline, and an expansion generator; the expansion generator is arranged between the oxygen pipeline and the oxygen vent pipeline; the oxygen pipeline is connected to the electrolyzed water system.

[0007] Optionally, the oxygen pipeline is connected to the inlet of the expansion generator.

[0008] Optionally, the outlet of the expansion generator is connected to the oxygen vent pipeline.

[0009] Optionally, the expansion generator is a turboexpander generator.

[0010] Optionally, the electrolyzed water system includes an electrolyzer, the electrolyzer is connected with a hydrogen separator and an oxygen separator, the hydrogen separator is connected with a hydrogen scrubber, the oxygen separator is connected with an oxygen scrubber, the oxygen scrubber is connected with a gas-liquid separation tank, and the gas-liquid separation tank is connected with the oxygen pipeline.

[0011] Optionally, a first heat exchanger is connected between the hydrogen separator and the hydrogen scrubbing tower.

[0012] Optionally, a second heat exchanger is connected between the oxygen separator and the oxygen scrubbing tower.

[0013] Optionally, the oxygen-driven power generation system further includes a pressure regulating assembly disposed on the oxygen pipeline.

[0014] Optionally, the oxygen-driven power generation system further includes a voltage stabilizing assembly disposed on the oxygen vent pipeline.

[0015] Optionally, the expansion generator is connected to a power-consuming unit.

[0016] By the above technical solution, in the present utility model, an expansion generator is added to the oxygen pipeline of the electrolytic water system, and the pressure of the by-product oxygen can be used to drive the expansion generator to do work and generate electric energy, so as to achieve the purpose of recycling the oxygen pressure energy.

[0017] Other features and advantages of the present utility model will be described in detail in the following specific implementation section. Description of the Drawings

[0018] The drawings are used to provide a further understanding of the present utility model, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the present utility model, but do not constitute a limitation to the present utility model. In the drawings:

[0019] Figure 1 is the system for recycling the oxygen pressure energy in the electrolytic water hydrogen production of the present utility model.

[0020] Description of the Reference Numerals

[0021] 1 - Electrolytic water system; 2 - Oxygen-driven power generation system; 3 - Electrolytic cell; 4 - Hydrogen separator; 5 - Oxygen separator; 6 - First heat exchanger; 7 - Second heat exchanger; 8 - Hydrogen scrubbing tower; 9 - Oxygen scrubbing tower; 10 - Gas-liquid separation tank; 11 - Expansion generator; 12 - Oxygen pipeline; 13 - Oxygen vent pipeline. Specific Implementation

[0022] The following will describe in detail the specific implementation of the present utility model with reference to the drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present utility model, and is not used to limit the present utility model.

[0023] A system for recycling the oxygen pressure energy in the electrolytic water hydrogen production, as Figure 1As shown in the figure, the system includes an electrolyzed water system 1 and an oxygen-driven power generation system 2; the oxygen-driven power generation system 2 includes an oxygen pipeline 12, an oxygen vent pipeline 13, and an expansion generator 11; the expansion generator 11 is arranged between the oxygen pipeline 12 and the oxygen vent pipeline 13; the oxygen pipeline 12 is connected to the electrolyzed water system 1.

[0024] In the oxygen pipeline of the present utility model is directly connected to the expansion generator, the pressure of the by-product oxygen can be utilized to drive the expansion generator to do work and directly generate electric energy. After the oxygen drives the expansion generator to do work and generate electricity, the pressure drops to a slightly positive pressure and then enters the oxygen vent pipeline for venting, so as to achieve the purpose of directly recovering and utilizing the oxygen pressure energy. At the same time, the present utility model reduces the complexity of the system and improves the overall reliability of the system.

[0025] In one embodiment, the oxygen pipeline 12 is connected to the intake port of the expansion generator 11.

[0026] In one embodiment, the outlet of the expansion generator 11 is connected to the oxygen vent pipeline 13.

[0027] In one embodiment, the expansion generator is a turbine expansion generator.

[0028] In one embodiment, the electrolyzed water system 1 includes an electrolytic cell 3, the electrolytic cell 3 is connected to a hydrogen separator 4 and an oxygen separator 5, the hydrogen separator 4 is connected to a hydrogen scrubber 8, the oxygen separator 5 is connected to an oxygen scrubber 9, the oxygen scrubber 9 is connected to a gas-liquid separation tank 10, and the gas-liquid separation tank 10 is connected to the oxygen pipeline 12.

[0029] In one embodiment, a first heat exchanger 6 is connected between the hydrogen separator 4 and the hydrogen scrubber 8, and a second heat exchanger 7 is connected between the oxygen separator 5 and the oxygen scrubber 9.

[0030] In one embodiment, the oxygen-driven power generation system 2 further includes a pressure regulating component (not shown in the figure), the pressure regulating component can be a pressure regulating valve, and the pressure regulating component is arranged on the oxygen pipeline 12 to regulate the oxygen pressure entering the expansion generator to be 1.6 ± 0.1 MPa.

[0031] In one embodiment, the oxygen-driven power generation system 2 further includes a voltage stabilizing component (not shown in the figure), the voltage stabilizing component can be a voltage stabilizing valve, and the voltage stabilizing component is arranged on the oxygen vent pipeline 13 to stabilize the oxygen pressure output from the expansion generator to below 0.2 MPa.

[0032] In one embodiment, the oxygen pressure on the oxygen pipeline 12 is 1.6 ± 0.1 MPa, which can drive the expansion generator to do work and generate electricity.

[0033] In one embodiment, the oxygen pressure in the oxygen vent pipeline 13 is lower than 0.2 MPa, and it can be vented through the oxygen vent pipeline.

[0034] In one embodiment, the expansion generator 11 is connected to an electricity-consuming unit (not shown in the figure). The electric energy generated by the expansion generator of the present utility model can be used by the electricity-consuming unit, and the electricity-consuming unit can generally be for domestic lighting electricity, office electricity, etc.

[0035] The present utility model will be further illustrated by examples below, but the present utility model is not limited thereby.

[0036] Example

[0037] A system for recycling the oxygen pressure energy in hydrogen production by electrolyzing water includes an electrolytic water system 1 and an oxygen-driven power generation system 2; the electrolytic water system 1 includes an electrolytic cell 3, the electrolytic cell 3 is connected to a hydrogen separator 4 and an oxygen separator 5, the hydrogen separator 4 is connected to a hydrogen scrubber 8, a first heat exchanger 6 is connected between the hydrogen separator 4 and the hydrogen scrubber 8, the oxygen separator 5 is connected to an oxygen scrubber 9, a second heat exchanger 7 is connected between the oxygen separator 5 and the oxygen scrubber 9, and the oxygen scrubber 9 is connected to a gas-liquid separation tank 10;

[0038] The oxygen-driven power generation system 2 includes an oxygen pipeline 12, an oxygen vent pipeline 13, and an expansion generator 11; the expansion generator 11 is arranged between the oxygen pipeline 12 and the oxygen vent pipeline 13; the oxygen pipeline 12 is connected to the inlet of the expansion generator 11, and the outlet of the expansion generator 11 is connected to the oxygen vent pipeline 13; the oxygen pipeline 12 is connected to the gas-liquid separation tank 10; a pressure regulating component is arranged on the oxygen pipeline 12, and a voltage stabilizing component is arranged on the oxygen vent pipeline 13; the expansion generator 11 is connected to an electricity-consuming unit.

[0039] The recycling method of the system for recycling the oxygen pressure energy in hydrogen production by electrolyzing water in this example includes:

[0040] The electrolytic cell 3 generates oxygen (containing a small amount of hydrogen) at about 1.8 MPa, which is subjected to gas-liquid separation by the oxygen separator 5, washed by the oxygen scrubber 9, and then subjected to gas-liquid separation again by the gas-liquid separation tank 10 to remove most of the moisture. At this time, the oxygen pressure is about 1.6 MPa. Then, the oxygen enters the expansion generator 11 through the oxygen pipeline 12 for power generation. The internal energy of the oxygen is converted into the kinetic energy of the generator and then into electric energy. After the oxygen pressure is reduced to a lower pressure (not exceeding 0.2 MPa), it is vented through the oxygen vent pipeline 13, and the generated electric energy is used by the electricity-consuming unit.

[0041] The preferred embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present utility model, various simple modifications can be made to the technical solutions of the present utility model, and these simple modifications all fall within the protection scope of the present utility model.

[0042] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present utility model will not separately describe various possible combination methods.

[0043] Furthermore, any combination can be made among various different embodiments of the present utility model, as long as it does not violate the idea of the present utility model, and it should also be regarded as the content disclosed by the present utility model.

Claims

1. A system for recycling oxygen pressure energy from water electrolysis to produce hydrogen, characterized in that: The system comprises a water electrolysis system (1) and an oxygen driven power generation system (2); The oxygen-driven power generation system (2) comprises an oxygen pipeline (12), an oxygen venting pipeline (13) and an expansion generator (11); the expansion generator (11) is arranged between the oxygen pipeline (12) and the oxygen venting pipeline (13); and the oxygen pipeline (12) is connected to the water electrolysis system (1).

2. The recycling system according to claim 1, characterized in that: The oxygen pipeline (12) is connected to the air inlet of the expansion generator (11).

3. The recycling system according to claim 1, characterized in that: The gas outlet of the expansion generator (11) is connected to the oxygen venting pipeline (13).

4. The recycling system according to claim 1, characterized in that: The expansion generator is a turbine expansion generator.

5. The recycling system according to claim 1, characterized in that: The water electrolysis system (1) comprises an electrolytic cell (3), the electrolytic cell (3) being connected to a hydrogen separator (4) and an oxygen separator (5), the hydrogen separator (4) being connected to a hydrogen scrubber (8), the oxygen separator (5) being connected to an oxygen scrubber (9), the oxygen scrubber (9) being connected to a gas-liquid separation tank (10), and the gas-liquid separation tank (10) being connected to the oxygen pipeline (12).

6. The recycling system according to claim 5, characterized in that: A first heat exchanger (6) is connected between the hydrogen separator (4) and the hydrogen scrubbing tower (8).

7. The recycling system according to claim 5, characterized in that: A second heat exchanger (7) is connected between the oxygen separator (5) and the oxygen washing tower (9).

8. The recycling system according to claim 1, characterized in that: The oxygen-driven power generation system (2) further comprises a pressure regulating component, wherein the pressure regulating component is arranged on the oxygen pipeline (12).

9. The recycling system according to claim 1, characterized in that: The oxygen-driven power generation system (2) further comprises a voltage stabilizing component, wherein the voltage stabilizing component is arranged on the oxygen venting pipeline (13).

10. The recycling system according to claim 1, characterized in that: The expansion generator (11) is connected to an electricity-using unit.

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