Method and system for carbon dioxide energy storage in a power generation system
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Solution Overview
Problem
Existing power generation systems using carbon dioxide as a working fluid are inefficient in storing and releasing energy, as condensing gaseous CO2 into liquid at the triple point pressure only yields a portion of the energy and is not optimized for energy retrieval.
Innovation Solution
A CO2 energy storage system that includes a storage tank for a CO2 slurry of dry ice and liquid CO2 at the triple point, with a pump to increase the slurry pressure above the triple point pressure and a contactor to mix high-pressure CO2 slurry with gaseous CO2, facilitating efficient condensation of CO2 into liquid for enhanced energy generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If gaseous CO2 is condensed into liquid CO2 within the storage tank at the triple point pressure, then the CO2 can be stored in liquid form, but only a portion of the energy contained in the system is yielded and the process is inefficient
Solution Approach 1:
The patent changes the pressure parameter from triple point pressure to a higher pressure (e.g., 73-150 atm) to enable more efficient energy storage and retrieval. This parameter change allows CO2 to be stored as a liquid at higher density and enables the turbine to extract more energy during the expansion process, resolving the contradiction between energy efficiency and energy retrieval productivity.
Solution Approach 2:
The system performs preliminary compression of CO2 to high pressure before storage, preparing the working fluid in advance for more efficient energy extraction. By pre-compressing the CO2 to a state where it can be stored as a dense liquid at higher pressure, the system maximizes the energy potential available for subsequent turbine expansion and energy generation.
2Ease of operation
If CO2 is stored at triple point pressure, then the storage conditions are simplified, but the energy yield is limited and not optimized for energy retrieval
Solution Approach 1:
The patent modifies the storage pressure parameter from the triple point pressure (5.1 atm) to a significantly higher pressure (73-150 atm). This parameter change increases the energy density and thermodynamic potential of the stored CO2, enabling higher power output during turbine expansion while maintaining operational simplicity through automated high-pressure storage systems.
3Productivity
If the CO2 condensation process is optimized for energy yield, then more energy can be retrieved, but the system complexity increases
Solution Approach 1:
The patent combines the compression, storage, and expansion functions into an integrated high-pressure CO2 energy storage system. By merging these functions and using CO2's unique thermodynamic properties at high pressure, the system achieves efficient energy retrieval without proportionally increasing complexity, as the same high-pressure condition serves multiple purposes in the energy cycle.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances power plant efficiency and increases electricity generation by promoting efficient heat transfer and condensation of CO2, leading to improved performance of the CO2 turbine and increased energy retrieval.
Implementation Method 1
a pump to increase the pressure of the slurry to a pressure above the triple point pressure
Implementation Method 2
a contactor to mix high-pressure CO2 slurry with gaseous CO2, facilitating efficient condensation of CO2 into liquid
Implementation Method 3
promoting efficient heat transfer and condensation of CO2
Data Source
AI summary
A CO2 energy storage system includes a storage tank that stores a CO2 slurry, including dry ice and liquid CO2, at CO2 triple point temperature and pressure conditions. The storage system also includes a first pump coupled in flow communication with the storage tank. The first pump is configured to receive the CO2 slurry from the storage tank and to increase a pressure of the CO2 slurry to a pressure above the CO2 triple point pressure. The energy storage system further includes a contactor coupled in flow communication with the first pump. The contactor is configured to receive the high pressure CO2 slurry from the pump and to receive a first flow of gaseous CO2 at a pressure above the CO2 triple point pressure. The gaseous CO2 is contacted and then condensed by the melting dry ice in the slurry to generate liquid CO2.