Application of high-performance voltage monitoring scheme in water electrolysis hydrogen production industry
● Electrolysis of water to hydrogen industry
With the continuous advancement of carbon peak and carbon neutrality policies, hydrogen energy, as a clean, efficient, sustainable and high-quality secondary energy, is ushering in rapid development. According to relevant third-party data, my country's annual hydrogen production will be about 43.8 million tons in 2023, making it the world's largest hydrogen producer.Here we mainly discuss the way of green energy hydrogen production, which is a way of using renewable energy such as wind power, hydropower, photovoltaics, etc. to electrolyze water to produce hydrogen. It has the advantages of high hydrogen purity and no greenhouse gas and harmful gas emissions. With the rapid development of renewable energy and the continuous decline in the cost of hydrogen production equipment, water electrolysis hydrogen production has become the main development direction of hydrogen production in the future. According to forecasts, the global green hydrogen share will increase from 1% to 34% in 2030, and the demand will exceed 30 million tons, with an average annual compound growth rate of 81%.
● Key issues for the industry
The electrolysis water hydrogen production system generally includes an electrolyzer, a hydrogen purification device, a hydrogen compressor, a hydrogen storage tank, etc. Among them, the electrolyzer is a device that generates an electrochemical reaction through direct current to decompose water into hydrogen and oxygen, and is the core of the hydrogen production system. Whether the voltage of the electrolysis chamber is normal or not reflects the operating conditions of the electrolyzer and the active state of the cathode and anode, affects the purity and efficiency of hydrogen production by electrolysis, and is an important parameter affecting the safe operation and working energy consumption of the electrolyzer.If the chamber voltage is too high, it will accelerate the corrosion and wear of the electrolyzer, reduce its service life, and also reduce the electrolysis rate, affecting the efficiency of hydrogen production. It may even cause problems such as excessive pressure and high temperature inside the electrolyzer, increasing the risk of explosion or leakage of the electrolyzer.If the chamber voltage is too low, the speed of the electrolysis reaction slows down, the time required for hydrogen production increases, and the working efficiency will be greatly reduced. Too low voltage will also cause problems such as reduced products, increased impurities, and impure crystals, which seriously affect the purity of hydrogen production. In addition, too low voltage may also cause problems such as short circuits, leading to risks such as spark explosions. Therefore, how to achieve real-time and accurate detection of multi-channel voltages of electrolyzers of different specifications has become the focus of the electrolytic hydrogen production industry.Traditional solutions usually use multimeters and PLCs for voltage inspections, which have problems such as low safety, low efficiency, and inconvenience in use:Low safety: The current of the electrolyzer is usually kiloamperes or even ten thousand amperes, and the temperature is about 90°C. If a manual multimeter is used for close contact measurement, it is extremely dangerous.Low efficiency: Taking a 1000Nm3 alkaline electrolyzer as an example, the number of chambers is generally 280. Manual inspections with multimeters require measurement one by one, and it is impossible to monitor and record all chamber voltage data in real time, which is inefficient.High cost and inconvenience in use: If PLC automatic measurement is used, there is a problem of high cost, and the subsequent data analysis needs to be programmed using professional software, which is inconvenient to use.
● NGI high-performance voltage monitoring solution
NGI has been deeply involved in the hydrogen energy industry chain for many years and has launched the N1200 multi-channel high-performance voltage inspection instrument, which can be widely used in electrolyzer and fuel cell voltage inspection tests.Safe and reliableDesign a high-reliability signal isolation circuit to ensure the independence and integrity of the voltage acquisition data. The use of a dedicated shielded harness can effectively reduce the interference of the complex environment of the electrolytic cell on the sampling voltage signal, and realize remote sampling of the cell voltage without the need for on-site near-end measurement. After on-site measurement, the measurement distance of the inspection instrument is ≥15m.High precision and high synchronizationDesign a high-precision signal acquisition and conditioning circuit with a voltage accuracy of up to ±1mV, which can achieve high-precision detection of the cell voltage, with a temperature coefficient as low as 50ppm/℃, and an error of less than 0.05% per 10℃. The 200-channel data synchronization update time is up to 10ms, which is convenient for users to sample and analyze in real time.High integrationThe 19-inch 1U standard chassis supports up to 200 acquisition channels and supports dual network port expansion channels to match larger specifications such as 1000Nm3 and 3000Nm3.Powerful data analysis functionThe standard host computer software collects, displays, and analyzes the voltage data of each channel, supports display modes such as bar graphs and lists, and displays the highest voltage value and corresponding channel, the lowest voltage value and corresponding channel, the average voltage value and other data in real time. It supports voltage drop detection for each channel, supports data storage and query, and is convenient for users to save and analyze.