The application prospect of hydrogen energy in electric power industry

As a kind of clean renewable energy, hydrogen energy has the characteristics of storage and transport, and has important strategic significance for the sustainable development of the world economy. Hydrogen energy can be converted into electricity through a certain way, and hydrogen fuel is gradually used in generators and fuel cells.

According to the data of the International Energy Agency, the total carbon dioxide emissions generated by power generation in the world in 2014 was 32.3 billion tons, of which China has become the world's largest carbon emissions, and the annual growth of carbon emissions has exceeded the combined volume of North America and Europe.

In recent years, although China's power generation technology has made continuous improvement, such as ultra-high pressure, supercritical and ultra-supercritical units have been launched, fluidized bed combustion and integrated gasification combined cycle power generation technology continues to be used, but the entire power industry still has low energy efficiency and excessive carbon emissions. Therefore, developing a low-carbon economy and promoting the wider application of clean energy is still an arduous task.

As an important green and clean energy, hydrogen energy has the advantages of zero emission, high efficiency, high reliability and remote control. Hydrogen energy is a preferred solution to the world's energy problems and can greatly reduce carbon emissions. Hydrogen energy can not only generate heat energy through combustion, produce mechanical work in thermal engines, but also be used as a raw material in fuel cells, and can be converted into homomorphic hydrogen as a structural material. Since the 1970s, developed countries such as the United States and Japan have accelerated the pace of research on hydrogen power generation technology. At present, power generation through hydrogen energy has entered the stage of construction pilot in some developed countries. But for China's power sector. At present, it is still dominated by thermal power generation, and the application of hydrogen energy technology is less, which has lagged far behind developed countries.

Technical feasibility

Hydrogen energy is the energy released during the reaction of hydrogen and the isotopes deuterium and tritium or the state change of hydrogen. Hydrogen energy can be converted into electrical energy, mechanical energy and heat energy. The conversion from hydrogen energy to electric energy can be realized by hydrogen energy generator and fuel cell.

Hydrogen generator

Hydrogen generator refers to the generator with hydrogen as the raw material, the principle is similar to the traditional internal combustion engine, through the suction, compression, explosion, exhaust process, drive the motor to produce current output. Hydrogen generator is an environmentally friendly power generation equipment, which has the characteristics of no noise, zero emission and strong mobility.

When hydrogen generators are integrated into the power transmission line of the grid, they can cooperate with the hydrogen production device to produce hydrogen by electrolyzing water when the electricity consumption is low, and then generate electricity through hydrogen energy when the electricity consumption is high, so as to realize the rational application of electric energy and reduce resource waste. In 2013, Germany built a 500 kilowatt-level mixed energy pilot power station, the power station uses hydrogen energy as a power storage medium, the hydrogen prepared by electrolysis drives hydrogen generators in the form of combustion, and the electricity generated can directly enter the power transmission network, and can also be used for power stations to continue to electrolyze water.

PEMFC fuel cell

PEMFC fuel cell is one of the research and development focuses in the field of hydrogen energy application. The working principle is the electrochemical reaction of hydrogen and oxygen (or air) to produce water and release electrical energy, that is, the reverse reaction of electrolytic water. The structure and working principle of PEMFC fuel cell is as follows: When the anode and cathode supply hydrogen and oxygen (or air) respectively, under the action of catalyst, hydrogen is oxidized and dissociated into electrons and hydrogen atoms on the anode. Oxygen is reduced on the anode and the electrons react to form water. At the same time, electrons form a current under the connection of the external circuit, releasing electrical energy to the outside.

Compared with traditional fuel cells, energy in PEMFC fuel cells is converted into chemical energy to electric energy, and there is no combustion and heat release in the energy conversion process, thus getting rid of the limitation of the classical heat engine theory - Carnot cycle, and the theoretical utilization rate of hydrogen energy can reach 80%. PEMFC fuel cells have the advantages of fast start-up at room temperature, no electrolyte loss, high specific power and long service life.

Market analysis of hydrogen power generation

PEMFC fuel cells can be used in fixed or mobile power stations, standby peak power stations, standby power supplies, cogeneration systems and other power generation equipment. The commercialization prospects of small PEMFC hydrogen generators are also widely optimistic, and PEMFC hydrogen generators with capacity of 3 kW, 5 kW, 10 kW and even 200 kW grade combined heat and power have been applied in hotels, restaurants, commercial buildings and other places.