The invention provides a
supercritical carbon dioxide power generation system and method based on
natural gas waste heat recovery. The
supercritical carbon dioxide power generation system comprises anair separation device, a
combustor, a
carbon dioxide turbine, a heat regenerator, a water separator, a first
carbon dioxide pressurization device, a
carbon dioxide recovery device, a waste-heat-
recovery heat exchanger, a Kalina
turbine, a Kalina heat regenerator, a first mixer, an
ammonia separator, a second mixer, a high-pressure condenser and a gas-liquid separator. According to the
supercritical carbon dioxide power generation system,
natural gas is taken as fuel, and the full capture of carbon dioxide is achieved by adopting an
oxygen-enriched
combustion method; in the carbon dioxide
turbine, carbon dioxide expands to the subcritical state and achieves a higher
expansion ratio than that the supercritical carbon dioxide
Brayton cycle, so that the carbon dioxide turbine can do more workand the
cycle efficiency can be improved; and during the bottom cycle,
waste heat of the supercritical carbon dioxide cycle is recovered by adopting the
Kalina cycle, and the concentration of a working medium changes in the working medium phase-change non-
isothermal process and cycle process, so that the
vaporization process and the heat-source heat release process can be matched well, the
irreversible loss in the heat exchange process can be reduced, and the
waste heat utilization efficiency can be improved.