The new type of dual vortex low-speed circulating fluidized bed boiler is a new generation of low-speed circulating fluidized bed boiler developed by the Zhengzhou Institute of Circulating Fluidized Bed Boiler at Tsinghua University, using the latest technological achievements of Tsinghua University. This type of boiler has achieved significant technological breakthroughs in vortex fluidized combustion technology, vortex separation structure design and parametric design technology, and material return technology while inheriting the original technological advantages. For national patented products. The characteristics of the boiler: 1. The boiler has a high thermal efficiency, reaching over 88%, and the combustion efficiency is generally above 98%, with significant energy-saving effects. 2. Less harmful gas emissions. Adding limestone desulfurization to the fluidized bed can control SO2 emissions within the GB13271 emission standard range (200mg/Nm3). 3. The boiler adopts a low flow rate design, with a large cross-sectional area in the dilute phase zone of the furnace and low smoke velocity. 4. There are temperature control points in the dense phase zone, dilute phase zone, and inlet and outlet of the separator of the boiler. And it has an over temperature alarm function, and the stoker adjusts the air coal ratio according to the temperature at each point. The furnace temperature can be controlled within the range of 850 ℃ -900 ℃. 5. Coal has a wide adaptability. Not only can smokeless coal, bituminous coal, lignite, and lean coal be used, but also inferior fuels such as coal gangue, gasification slag, and chain slag can be used. Waste slag can be comprehensively utilized, and the carbon content of slag is generally below 2%. 6. This product adopts low-temperature combustion technology, effectively reducing the generation of harmful gases. NOx emissions can meet the requirements of GB13271 emission standard 200mg/m3 without using denitrification equipment.