Storage unit, control method, and system for carbon dioxide gas-liquid-phase-change energy storage system

A carbon dioxide gas-liquid-phase-change energy storage system, comprising a storage unit, wherein the storage unit comprises:

• an energy storage container, configured to store carbon dioxide in a gas state and carbon dioxide in a liquid state;
• a condenser, connected to the energy storage container and configured to condense the carbon dioxide in the gas state into the carbon dioxide in the liquid state;
• an energy storage pressure-maintaining flow path, wherein the energy storage pressure-maintaining flow path, the energy storage container and the condenser form a closed-loop connection;
• wherein during an energy storage phase and an interval period between the energy storage phase and an energy release phase of the carbon dioxide gas-liquid-phase-change energy storage system, the carbon dioxide in the gas state inside the energy storage container is capable of flowing through the energy storage pressure-maintaining flow path to the condenser where the carbon dioxide in the gas state is condensed into the carbon dioxide in the liquid state, and then the carbon dioxide in the liquid state flows back to the energy storage container, to maintain a pressure of the energy storage container stable within a design pressure range during the energy storage phase and the interval period between the energy storage phase and the energy release phase.

A control method for a storage unit of a carbon dioxide gas-liquid-phase-change energy storage system:

• wherein the storage unit comprises:
• an energy storage container, configured to store carbon dioxide in a gas state and carbon dioxide in a liquid state;
• a condenser, connected to the energy storage container and configured to condense the carbon dioxide in the gas state into the carbon dioxide in the liquid state;
• an energy storage pressure-maintaining flow path, wherein the energy storage pressure-maintaining flow path, the energy storage container and the condenser form a closed-loop connection;
• wherein during an energy storage phase and an interval period between the energy storage phase and an energy release phase of the carbon dioxide gas-liquid-phase-change energy storage system, the carbon dioxide in the gas state inside the energy storage container is capable of flowing through the energy storage pressure-maintaining flow path to the condenser where the carbon dioxide in the gas state is condensed into the carbon dioxide in the liquid state, and then the carbon dioxide in the liquid state flows back to the energy storage container, to maintain a pressure of the energy storage container stable within a design pressure range during the energy storage phase and the interval period between the energy storage phase and the energy release phase;
• wherein the method further comprises;
• the energy storage phase, wherein, during the energy storage phase, the carbon dioxide in the gas state inside the energy storage container flows through the energy storage pressure-maintaining flow path to the condenser where the carbon dioxide in the gas state is condensed into the carbon dioxide in the liquid state, then the carbon dioxide in the liquid state flows back to the energy storage container, to maintain the pressure of the energy storage container stable within the design pressure range during the energy storage phase.