Compressed carbon dioxide energy storage system and method combined with air separation technology

A compressed carbon dioxide energy storage system combined with an air separation technology, comprising:

• a gaseous carbon dioxide storage tank (14), a liquid carbon dioxide storage tank (21), an energy storage assembly, an energy release assembly and an air separation assembly, wherein the energy storage assembly and the energy release assembly are respectively disposed between the gaseous carbon dioxide storage tank (14) and the liquid carbon dioxide storage tank (21);
• the energy storage assembly comprises a preheater (15), a first compressor (16) and a condenser (20) sequentially connected in that order, the first compressor (16) is configured to compress carbon dioxide, and the condenser (20) is configured to condense the carbon dioxide;
• the energy release assembly comprises a first evaporator (22), a first turbine (26) and a first cooler (27) sequentially connected in that order, an output axis of the first turbine (26) is connected to an input axis of a generator (G), the generator (G) is configured to generate electric energy, and the first cooler (27) is configured to cool carbon dioxide entering the gaseous carbon dioxide storage tank (14);
• and the air separation assembly comprises an air pretreatment component and a separation column (9), the separation column (9) is connected to an output end of the air pretreatment component, the separation column (9) is configured to separate air to generate nitrogen, oxygen, and waste nitrogen, the nitrogen and the oxygen each are a cold source, and the waste nitrogen is a heat source;
• wherein the cool source is supplied to the condenser (20), the first cooler (27) and the air pretreatment component individually through pipelines (38), the heat source is supplied to the preheater (15) and the first evaporator (22) individually through the pipelines (38), and the electric energy generated on the generator (G) is supplied to the air pretreatment component;
• wherein the air pretreatment component comprises a second compressor (2), a second cooler (3), a gas-liquid separator (4) and a first expansion valve (8), and the second compressor (2), the second cooler (3) and the gas-liquid separator (4) are connected;
• a gas phase outlet of the gas-liquid separator (4) is connected to the first expansion valve (8), and an input end of the separation column (9) is connected to the first expansion valve (8);
• and the second compressor (2) is configured to pressurize and heat the air, the second cooler (3) is configured to cool the air, the gas-liquid separator (4) is configured to separate liquid water and the carbon dioxide from gaseous air, and the first expansion valve (8) is configured to expand and cool the gaseous air;
• and
• wherein the cool source is connected to a cooling inlet of the second cooler (3) through the pipelines (38), a cooling outlet of the second cooler (3) is vented, and the generator (G) is electrically connected to the second compressor (2).