For over a hundred years, the core action of human power generation has only been four words: boiling water. From coal, natural gas to nuclear energy, water ultimately needs to be burned into high-temperature and high-pressure steam to drive the turbine to rotate. On September 16th, this century old technological route was rewritten in Yantai, Shandong - the world's first commercial demonstration project of molten salt coupled supercritical carbon dioxide cycle power generation, Ruicarbon, started construction at Huaneng Shandong Bajiao Power Plant. The protagonist is no longer water vapor, but carbon dioxide, which is often regarded as a greenhouse gas.

No longer just boiling water

To take on this responsibility, carbon dioxide must first transform. When the temperature exceeds 31 degrees Celsius and the pressure rises above 73 atmospheres, it enters a supercritical state: it has a high density like a liquid and can carry a huge amount of thermal energy; Like a gas, it has low viscosity and minimal flow resistance, and the entire cycle process does not undergo phase change, thus reducing phase change heat loss.

Compared to traditional thermal power units that use steam as the circulating working fluid, supercritical carbon dioxide generators directly drive power generation with supercritical carbon dioxide, which has the characteristics of higher efficiency, smaller size, and stronger flexibility. The world's first commercial supercritical carbon dioxide generator unit has been put into commercial operation in Liupanshui, Guizhou, verifying that this path is feasible. The Ruicarbon project, which has started construction this time, plans to build the world's largest 50 MW supercritical carbon dioxide power generation unit, equipped with a 100 MW/400 MWh molten salt energy storage system, with a working fluid temperature of 550 degrees Celsius. After completion, it will be the world's largest and highest parameter supercritical carbon dioxide power cycle technology demonstration project.

Molten salt as a power bank

Rui Carbon is mainly composed of three parts: molten salt energy storage system, supercritical carbon dioxide cycle power generation system, and steam generation system. It innovatively adopts an integrated mode of molten salt energy storage and carbon dioxide power generation.

When the electricity consumption is low, the project uses the surplus electricity from the two ultra supercritical cogeneration units of Huaneng Shandong Bajiao Power Plant to heat molten salt. The electricity is then converted into heat energy and stored, like a super sized power bank; During peak electricity consumption, high-temperature molten salt releases heat, heats carbon dioxide, and drives the unit to generate electricity. The waste heat then enters the steam generation system for external heating and steam supply. Energy storage, power generation, heating, and steam supply are linked together in a chain, greatly improving the comprehensive utilization efficiency of energy. The long-standing dilemma of using heat to determine electricity for coal-fired power units has also been loosened.

Give the power grid a regulator

Wind power and photovoltaics rely on the weather to make a living, and their output fluctuates between high and low. The power grid needs more sensitive regulation capabilities than ever before. Supercritical carbon dioxide power generation units can achieve continuous smooth regulation from 0 to 100% load, with a regulation rate about four times that of traditional coal-fired power units, and can quickly respond to the peak shaving needs of the power grid; Under the same capacity and parameter conditions, the efficiency is 3 to 5 percentage points higher than traditional technologies, and the equipment structure is compact, with almost zero water consumption. It has unique competitiveness in special application scenarios such as limited space areas and the Shago Desert Base.

As a demonstration project of the Central Enterprise Innovation Alliance for Carbon Energy Power, Rui Carbon Number is invested and constructed by Huaneng Shandong Branch and operated and managed by Huaneng Octagonal Power Plant, which will significantly enhance the deep regulation and heating guarantee capabilities of coal-fired power units.keywords:New energy information network

Supercritical carbon dioxide power cycle technology is a transformative thermal power generation technology and a forward-looking strategic technology that China Huaneng focuses on cultivating. The demonstration project is planned to be put into operation within 2027, providing valuable practical experience for the large-scale application of new energy storage technologies in multiple scenarios, and serving as a Chinese model for the low-carbon transformation of the global energy structure and the enhancement of renewable energy consumption capacity.Editor/Yang Meiling