Water electrolysis oxygen generation system and control method thereof

Abstract

The invention discloses a water electrolysis oxygen production system and a control method thereof, the water electrolysis oxygen production system comprises a PEM water electrolysis oxygen production and hydrogen production device and a high temperature proton membrane fuel cell device, a water inlet of the PEM water electrolysis oxygen production and hydrogen production device is connected with ultrapure water, and an oxygen outlet of the PEM water electrolysis oxygen production and hydrogen production device is connected with an oxygen storage tank; a hydrogen outlet of the PEM water electrolysis oxygen and hydrogen production device is connected with a hydrogen inlet of the high-temperature proton membrane fuel cell device, and a direct current input device of the PEM water electrolysis oxygen and hydrogen production device is connected with a direct current output device of the high-temperature proton membrane fuel cell device through the power supply controller; and the high-temperature proton membrane fuel cell device is connected with the air compressor. The method has the characteristics of high efficiency, stability and safety, also has high expandability and flexibility, and can be widely applied to the fields of medical treatment, chemical engineering, environmental protection and the like.

Description

Technical Field

[0001] The invention relates to an oxygen production system, in particular to an oxygen production system by electrolysis of water and a control method thereof. Background Art

[0002] Electrolysis of water to produce hydrogen and oxygen is a clean hydrogen and oxygen production technology, and is an environmentally friendly and efficient method for producing high-purity hydrogen and oxygen. At present, the technical characteristics of the electrolysis of water to produce oxygen system are: using PEM water electrolysis hydrogen and oxygen production technology, the working medium is pure water, which is non-corrosive; direct pressure production of hydrogen, normal pressure water supply (using high differential pressure electrolyzer and system); high current density, miniaturization of the stack, easy integration; fast system response, adaptability to dynamic operation; high gas purity (high-purity hydrogen can directly meet the needs of fuel cells); high efficiency, low energy consumption, long life; high reliability and safety, miniaturization and integration, easy operation and maintenance.

[0003] Through PEM electrolysis water preparation technology, direct current is used to decompose ultrapure water into high-purity oxygen and hydrogen. However, the prepared high-purity hydrogen as fuel has a purity of up to 99.97% (H2O≤0.03%). According to GB / T37244-2018 "Hydrogen for Proton Exchange Membrane Fuel Cell Vehicles", low-temperature proton exchange membrane fuel cells (LT-PEMFCs) technology products have very stringent index requirements for hydrogen sources. In addition to the high purity of hydrogen, the impurity content must be controlled within the ppm level, such as H2O≤5ppm, which is far lower than the water content of hydrogen preparation. Therefore, the prepared high-purity hydrogen cannot be used directly as fuel, and a complex condensing or adsorption hydrogen dehydration device must be added before it can be provided to traditional low-temperature proton exchange membrane fuel cells. If matched with the LT-PEMFC (traditional hydrogen fuel cell) stack system, including high-precision humidifiers and radiators, the volume, energy consumption, and hydrogen consumption of the overall system will be further increased. Summary of the invention

[0004] The purpose of the present invention is to provide a water electrolysis oxygen production system and a control method thereof, which realizes efficient, green and convenient oxygen production by coupling PEM water electrolysis and high-temperature proton membrane fuel cell (HT-PEMFC) technology, and effectively solves the problems of outdoor operations, mobile camping and improving the living environment of residents in plateau areas.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A water electrolysis oxygen production system, characterized in that it comprises a PEM water electrolysis oxygen production and hydrogen production device and a high-temperature proton membrane fuel cell device, wherein the water inlet of the PEM water electrolysis oxygen production and hydrogen production device is connected to ultrapure water, and the oxygen outlet of the PEM water electrolysis oxygen production and hydrogen production device is connected to an oxygen storage tank; the hydrogen outlet of the PEM water electrolysis oxygen production and hydrogen production device is connected to the hydrogen inlet of the high-temperature proton membrane fuel cell device, the direct current input device of the PEM water electrolysis oxygen production and hydrogen production device is connected to the direct current output device of the high-temperature proton membrane fuel cell device through a power controller; and the high-temperature proton membrane fuel cell device is connected to an air compressor.

[0007] Furthermore, in the high temperature proton membrane fuel cell device, the HT-PEMFC stack, the hydrogen heat exchanger and the air heat exchanger are integrated into an integrated structure. The HT-PEMFC stack is connected to a temperature controller and a fan.

[0008] A control method for an electrolytic water oxygen production system, characterized in that the specific steps are as follows:

[0009] 1) The ultrapure water in the water tank is sent to the PEM water electrolysis oxygen and hydrogen production device, and the power controller provides power to the PEM water electrolysis oxygen and hydrogen production device. The oxygen generated by the PEM water electrolysis is sent to the oxygen storage tank, and the generated hydrogen directly enters the high-temperature proton membrane fuel cell device;

[0010] 2) The air compressor delivers air with oxygen into the high-temperature proton membrane fuel cell device, where it undergoes an electrochemical reaction with hydrogen to generate direct current that is fed back to the power controller;

[0011] 3) The supplemented electric energy is output through the power controller to the PEM water electrolysis oxygen and hydrogen production device for hydrogen and oxygen production.

[0012] In the present invention, a main power supply of 220V AC is input to a power controller; a high-temperature proton membrane fuel cell device outputs a DC voltage of 23-39V and an output current of 0-18A, which is input to the power controller as feedback electric energy; the power controller replenishes the feedback electric energy into the power output terminal, rectifies and stabilizes the voltage to a DC 48V voltage to provide power for the PEM water electrolysis oxygen and hydrogen production device, thereby ensuring that hydrogen and oxygen production are controlled in a constant current manner.

[0013] The working status of the PEM water electrolysis oxygen and hydrogen production device is monitored and adjusted in real time through an intelligent control system. The intelligent control system includes sensors, controllers and actuators. The sensors are responsible for collecting water level, temperature and pressure in real time; the controller analyzes and processes the data according to the preset algorithm and issues corresponding control instructions; the actuator adjusts the electrolysis current and flow according to the instructions of the controller to achieve the best oxygen production efficiency.

[0014] The intelligent control system has a fault self-diagnosis function. Once an abnormality is detected, it will promptly issue an alarm and take measures to ensure the safe and stable operation of the system. The intelligent control system is scalable and flexible, and can be modularly configured and upgraded according to actual needs. The intelligent control system automatically adjusts the working state according to changes in external environmental conditions through optimization algorithms to achieve the best energy efficiency ratio.

[0015] The beneficial effects of the present invention are as follows:

[0016] The high-temperature proton membrane fuel cell device has a strong tolerance for hydrogen fuel impurities, and tolerates H2O ≤ 10%, which is much higher than the water content of hydrogen produced by PEM water electrolysis. Therefore, the high-purity hydrogen produced by water electrolysis can be directly used as fuel and injected into the HT-PEMFC stack system as fuel to achieve efficient hydrogen-to-electricity conversion reaction. It not only saves the complex hydrogen dehydration device, but also makes water and heat management simpler, and does not require a humidifier and a high-precision radiator, further reducing the overall efficiency of the system. The present invention can perfectly achieve low-energy water electrolysis to produce oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, a water electrolysis oxygen production system includes a PEM water electrolysis oxygen production hydrogen production device 1 and a high-temperature proton membrane fuel cell device 2, wherein the water inlet of the PEM water electrolysis oxygen production hydrogen production device is connected to ultrapure water 11, and the oxygen outlet of the PEM water electrolysis oxygen production hydrogen production device is connected to an oxygen storage tank 12; the hydrogen outlet of the PEM water electrolysis oxygen production hydrogen production device is connected to the hydrogen inlet of the high-temperature proton membrane fuel cell device, and the DC input device of the PEM water electrolysis oxygen production hydrogen production device is connected to the DC output device of the high-temperature proton membrane fuel cell device through a power controller 3; the high-temperature proton membrane fuel cell device 2 is connected to an air compressor 4.

[0019] In the high temperature proton membrane fuel cell device 2 , the HT-PEMFC stack 21 is integrated with the hydrogen heat exchanger and the air heat exchanger. The HT-PEMFC stack 21 is connected to the temperature controller 22 and the fan 23 .

[0020] In the present invention, direct current is used to decompose pure water into high-purity oxygen and hydrogen. The chemical reaction is as follows: cathode: 2H2O+2e→H2+2OH -

[0021] Anode: 2OH - -2e→H2O+1 / 2O2

[0022] Overall reaction formula: H2O=H2+1 / 2O2

[0023] This system adopts the internationally advanced PEM water electrolysis device preparation and system integration technology.

[0024] In the present invention, the high temperature proton membrane fuel cell device has low requirements for hydrogen purity (more than 70% H2 and 1-2% CO can be adapted). The stack system adopts a high-performance liquid cooling design to integrate the HT-PEMFC stack with the hydrogen heat exchanger and the air heat exchanger to achieve smaller system volume and mass, higher reliability and better performance.

[0025] The high-value-added pure oxygen produced by the PEM electrolysis water oxygen and hydrogen production device is selected for storage in a dedicated oxygen device for people's use. High-purity hydrogen can be directly coupled with a high-temperature proton membrane fuel cell device as a hydrogen source fuel, and through electrochemical reactions with oxygen in the air (as an oxidant), the chemical energy of the fuel is directly and efficiently converted into a continuous supply of electrical energy (direct current). The only excrement of the fuel cell is pure water, which is used as a coolant for the fuel cell system. The excess water returns to the pure water tank and continues to be used as a raw material for oxygen production. The chemical reaction is as follows,

[0026] Anode: 2H2+2O2-→2H2O+4e

[0027] Cathode: O2+4e→2O2-

[0028] Overall reaction formula: 2H2+O2→2H2O

[0029] By feeding back the electrolyzed water power supply, the on-site conversion of electric energy is realized to reduce the overall energy efficiency; it can be used in a timely manner in the form of energy feedback, matched with battery energy storage, or connected to a load for use.

[0030] A control method for an electrolytic water oxygen production system, the specific steps are as follows:

[0031] 1) Ultrapure water 11 is fed into the PEM water electrolysis oxygen and hydrogen production device 1, and the power controller 3 provides power to the PEM water electrolysis oxygen and hydrogen production device. The oxygen generated by the PEM water electrolysis is fed into the oxygen storage tank 12, and the generated hydrogen directly enters the high-temperature proton membrane fuel cell device 2;

[0032] 2) The air compressor 4 delivers air with oxygen into the high-temperature proton membrane fuel cell device 2, where it undergoes an electrochemical reaction with hydrogen to generate direct current that is fed back to the power controller 3;

[0033] 3) The supplemented electric energy is output to the PEM water electrolysis oxygen and hydrogen production device 2 for producing hydrogen and oxygen through the power supply controller.

[0034] In the present invention, a main power supply of 220V AC is input to a power controller; a high-temperature proton membrane fuel cell device outputs a DC voltage of 23-39V and an output current of 0-18A, which is input to the power controller as feedback electric energy; the power controller replenishes the feedback electric energy into the power output terminal, rectifies and stabilizes the voltage to a DC 48V voltage to provide power for the PEM water electrolysis oxygen and hydrogen production device, thereby ensuring that hydrogen and oxygen production are controlled in a constant current manner.

[0035] The working status of the PEM water electrolysis oxygen and hydrogen production device is monitored and adjusted in real time through an intelligent control system. The intelligent control system includes sensors, controllers and actuators. The sensors are responsible for collecting water level, temperature and pressure in real time; the controller analyzes and processes the data according to the preset algorithm and issues corresponding control instructions; the actuator adjusts the electrolysis current and flow according to the instructions of the controller to achieve the best oxygen production efficiency.

[0036] The intelligent control system has a fault self-diagnosis function. Once an abnormality is detected, it will promptly issue an alarm and take measures to ensure the safe and stable operation of the system. The intelligent control system is scalable and flexible, and can be modularly configured and upgraded according to actual needs. The intelligent control system automatically adjusts the working state according to changes in external environmental conditions through optimization algorithms to achieve the best energy efficiency ratio.

[0037] In terms of safety, the system adopts multiple protection measures, including overvoltage protection, overcurrent protection, overheating protection, etc., to ensure that the power supply can be quickly cut off in any abnormal situation to prevent equipment damage or personal injury. In addition, the system also has remote monitoring and fault alarm functions. Operation and maintenance personnel can view the system operation status in real time through the remote terminal, and respond and handle various abnormal situations in a timely manner.

[0038] The present invention is not only efficient, stable and safe, but also highly scalable and flexible. It can be widely used in the fields of medicine, chemical industry, environmental protection, etc., providing reliable oxygen supply and energy solutions for related industries.

Claims

1. A water electrolysis oxygen production system, characterized in that: The invention comprises a PEM water electrolysis oxygen-hydrogen production device (1) and a high-temperature proton membrane fuel cell device (2), wherein the water inlet of the PEM water electrolysis oxygen-hydrogen production device (1) is connected to ultrapure water (11), and the oxygen outlet of the PEM water electrolysis oxygen-hydrogen production device (1) is connected to an oxygen storage tank (12); the hydrogen outlet of the PEM water electrolysis oxygen-hydrogen production device (1) is connected to the hydrogen inlet of the high-temperature proton membrane fuel cell device (2); the direct current input device of the PEM water electrolysis oxygen-hydrogen production device (1) is connected to the direct current output device of the high-temperature proton membrane fuel cell device (2) through a power controller (3); and the high-temperature proton membrane fuel cell device (2) is connected to an air compressor (4).

2. The water electrolysis oxygen production system according to claim 1, characterized in that: In the high-temperature proton membrane fuel cell device (2), the HT-PEMFC stack (21), the hydrogen heat exchanger and the air heat exchanger are an integrated structure.

3. The water electrolysis oxygen production system according to claim 2, characterized in that: The HT-PEMFC stack (21) is connected to a temperature controller (22) and a fan (23).

4. A control method for an electrolytic water oxygen production system, characterized in that: The specific steps are as follows: 1) The water in the pure water tank is sent to the PEM water electrolysis oxygen and hydrogen production device, and the power controller provides power to the PEM water electrolysis oxygen and hydrogen production device. The oxygen generated by the PEM water electrolysis is sent to the oxygen storage tank, and the generated hydrogen directly enters the high-temperature proton membrane fuel cell device; 2) The air compressor delivers air with oxygen into the high-temperature proton membrane fuel cell device, where it undergoes an electrochemical reaction with hydrogen to generate direct current that is fed back to the power controller; 3) The supplemented electric energy is output through the power controller to the PEM water electrolysis oxygen and hydrogen production device for hydrogen and oxygen production.

5. The control method of the water electrolysis oxygen production system according to claim 4, characterized in that: The main power supply is 220V AC input to the power controller; the high-temperature proton membrane fuel cell device outputs a DC voltage of 23~39V and an output current of 0~18A, which is input into the power controller as feedback power; the power controller replenishes the feedback power into the power output end, rectifies and stabilizes the voltage into a DC 48V voltage to provide power for the PEM water electrolysis oxygen and hydrogen production device, ensuring that hydrogen and oxygen production are controlled in a constant current manner.

6. The control method of the water electrolysis oxygen production system according to claim 4, characterized in that: The working status of the PEM water electrolysis oxygen and hydrogen production device is monitored and adjusted in real time through an intelligent control system. The intelligent control system includes sensors, controllers and actuators. The sensors are responsible for collecting water level, temperature and pressure in real time; the controller analyzes and processes the data according to the preset algorithm and issues corresponding control instructions; the actuator adjusts the electrolysis current and flow according to the instructions of the controller to achieve the best oxygen production efficiency.

7. The control method of the water electrolysis oxygen production system according to claim 6, characterized in that: The intelligent control system has a fault self-diagnosis function. Once an abnormality is detected, it will promptly issue an alarm and take measures to ensure the safe and stable operation of the system. The intelligent control system is scalable and flexible, and can be modularly configured and upgraded according to actual needs. The intelligent control system automatically adjusts the working state according to changes in external environmental conditions through optimization algorithms to achieve the best energy efficiency ratio.

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