First voyage energy-saving and French power co-start supercritical carbon dioxide thermal power generation project.




On June 15, Shouhang Energy Saving and EDF held a launching ceremony for the research and development project of supercritical carbon dioxide cycle photothermal power generation technology in Beijing. This is an international cooperation in the field of photothermal power generation. The two sides will jointly develop high-efficiency photothermal power generation technology by virtue of their respective technology accumulation in the field of photothermal power generation, aiming to reduce the cost of photothermal power generation. DUFOUR, Counselor Jean-Phillipe of the French Embassy, Zhang Juejing, President of the China Chamber of Commerce of Electrical and Mechanical Services, former Counselor of the State Council, Shi Dinghuan, Chairman of the China Renewable Energy Society, Du Ozawa, Dean of the Institute of Science and Technology of North China Electric Power University, and other guests and relevant leaders of Shouhang Energy Conservation Company and EDF attended the launching ceremony and made important speeches.



Figure: Special guests and the first flight energy conservation, EDF leadership jointly launched the project

DUFOUR, Jean-Phillipe Counselor of the French Embassy, Mr. Shi Dinghuan, former Counselor of the State Council, and Chairman of the China Renewable Energy Society, all expressed their deep congratulations on the launch of the project. At the same time, they also said that EDF is the world leader in energy, and Shouhang Energy Saving is a major manufacturer of air cooling equipment in China and a Chinese leader in photothermal technology. This project is a strong combination of complementary advantages between the two sides, which is a promising cooperation and an important contribution to the world's climate and environmental change.



Figure: French Embassy Counsellor Jean-Phillipe DUFOUR



Figure: Shi Dinghuan, former Counsellor of the State Council and President of China Renewable Energy Society

Supercritical carbon dioxide Brayton cycle power generation technology is currently one of the most cutting-edge photothermal power generation technologies. On May 25, 2018, the Chinese Society of Electrical Engineering issued the ''Ten Major Engineering and Technical Problems in the Field of Energy and Power'', supercritical CO2 solar thermal power generation Technology is listed as one of them. Supercritical CO2 is a gaseous and liquid fluid, the density is close to the liquid, the viscosity is close to the gas, the diffusion coefficient is about 100 times of the liquid. Its characteristics are that the critical conditions are easy to reach, the chemical properties are not active, colorless, tasteless, non-toxic, safe, cheap, high purity, and easy to obtain.

There are two types of solar power generation: photovoltaic power generation and photothermal power generation.

Photovoltaic power generation is the use of sunlight to irradiate semiconductor materials and generate current through the photoelectric effect. Photovoltaic power generation is difficult to store large-scale energy, and silicon energy consumption is very large.

Photothermal power generation uses the radiant energy of solar energy to heat the working medium through the concentrator and heat absorber, and then generates electricity through the heat engine.

The supercritical CO2 Brayton cycle only needs to provide a temperature of 500 to 800 degrees Celsius, which is a temperature that can be easily achieved by applying existing solar concentrator and heat absorber technology.

Due to the high density of supercritical CO2 and simple circulation, the unit is light in weight and small in size (only 1/10 of that of steam turbine); The installation, maintenance and operation costs are low. Can be used for cooling, the efficiency can be greater than 50%; High power density and large power range (10MW to hundreds of MW) can be used as the main power station. Supercritical CO2 units are now close to commercialization. At present, the cycles used for solar thermal power generation are mainly subcritical Rankine cycle and Stirling cycle, with efficiency of 35% ~ 45%.

The performance improvement of the supercritical CO2 Brayton cycle can be significantly higher than that of the commercial steam cycle, and can be used as a new generation of replacement products, which can make solar thermal power generation cheaper. The research and development project starts with a simple supercritical CO2 Brayton cycle, step by step to tap the potential, improve system performance, and increase the use of technical measures that can greatly improve efficiency:(1) increase the turbine inlet temperature: from 500 degrees Celsius to 700 degrees Celsius or higher. (2) The compression process is completed in two steps. That is, there is a main compressor and a shunt compressor. (3) Use compressor intercooling. (4) The turbine is also divided into two stages and reheats the discharged working medium. (5) The compressor and the turbine are of the split shaft type, so that each of them operates at an optimized speed. (6) Increase the bottom cycle, such as the Rankine cycle or the supercritical CO2 cycle in series. Its excellent characteristics and the possible subversion of power generation technology have been more and more widely recognized, and the speed of its technology research and development and commercial application process is gradually accelerating.

The cooperation between the first flight energy saving and EDF is a strong alliance. each should give full play to its advantages and jointly carry out various research work. This is in line with the country's sustainable development orientation, the idea of continuous innovation and development of the photothermal industry, and the common interests of EDF and Shouhang Energy Saving Company.



Photo: Special guests take photos with leaders of Shouhang Energy Conservation and EDF

EDF (Electricite De France), founded in 1946, is one of the world's leading power companies and has become one of the world's leading power companies. As a large company with world-class industrial competitiveness in nuclear, thermal, hydropower and renewable energy, EDF can provide integrated solutions including power investment, engineering design, and power management and distribution.

Beijing Shouhang Aiqiwei Energy Saving Technology Co., Ltd. is a joint-stock high-tech enterprise that develops energy-saving technology for the purpose of energy conservation and environmental protection. It is an A- share listed company on the Shenzhen Stock Exchange of China. It is a well-known domestic power station air-cooling manufacturer and a domestic first-class photothermal technology integration supplier. He has undertaken many scientific and technological projects and won national scientific and technological awards. Shouhang Energy Saving has built the third 10MW molten salt tower solar thermal power station in the world and the first 10MW molten salt tower solar thermal power station in Asia. For the national demonstration project already under construction, the 100MW molten salt tower solar thermal power station will be completed in the second half of this year. The achievement of these scientific research conditions and demonstration projects of photothermal power plants provides extremely valuable conditions for the research and development of supercritical carbon dioxide Brayton cycle photothermal power generation technology.