Compressed-Gas Heat Storage Staging for Lower Mass at High Pressure
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Solution Overview
Problem
Existing compressed-air energy storage systems require significant mass and cost due to the design of heat storage and recovery devices, which are subjected to high pressures, limiting their economic viability.
Innovation Solution
A compressed-gas energy storage system utilizing a combination of direct and indirect heat storage and recovery devices, where direct heat exchange occurs in lower-pressure stages and indirect heat exchange with a cooling loop is used in high-pressure stages, reducing the mass and cost of the system while maintaining efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If direct heat storage and recovery devices are used in high-pressure compression stages, then heat exchange efficiency is improved, but device mass and cost increase significantly
Solution Approach 1:
The compression process is divided into multiple stages with different pressure levels. Direct heat storage devices are used only in low-pressure stages where they are feasible, while indirect heat storage devices are used in high-pressure stages where direct devices would be too heavy and expensive. This segmentation allows the system to optimize heat exchange efficiency in low-pressure stages while controlling mass and cost in high-pressure stages.
Solution Approach 2:
Different heat storage device types are assigned to different compression stages based on local pressure conditions. Low-pressure stages receive direct heat storage devices for efficient heat exchange, while high-pressure stages receive indirect heat storage devices to avoid excessive mass and cost. This local quality differentiation resolves the contradiction by matching device characteristics to operating conditions.
2Use of energy by moving object
If direct heat storage and recovery devices are used throughout all compression stages, then energy recovery efficiency is improved, but system cost increases
Solution Approach 1:
The compression system is segmented into multiple stages, each equipped with appropriate heat storage devices. Direct heat storage devices are deployed in low-pressure stages where they provide good energy recovery efficiency at reasonable cost, while indirect heat storage devices are used in high-pressure stages where direct devices would be prohibitively expensive. This segmentation maintains overall energy recovery efficiency while controlling system cost.
Solution Approach 2:
The system changes the operating parameters (pressure levels) across different compression stages and matches appropriate heat storage device types to each stage. By varying the device type according to pressure parameters, the system achieves good energy recovery efficiency without incurring the high costs associated with using direct heat storage devices throughout all stages.
3Weight of stationary object
If indirect heat storage and recovery devices are used in all stages, then device mass is reduced, but heat exchange efficiency decreases
Solution Approach 1:
The compression system is divided into stages where indirect heat storage devices are used in high-pressure stages to reduce mass, while direct heat storage devices are used in low-pressure stages to maintain heat exchange efficiency. This segmentation ensures that mass reduction is achieved where it matters most (high-pressure stages) while efficiency is preserved where indirect devices would be less effective (low-pressure stages).
Solution Approach 2:
Different heat storage device types are assigned to different compression stages based on local pressure conditions and efficiency requirements. Direct heat storage devices are used in low-pressure stages where they provide superior heat exchange efficiency, while indirect devices are used in high-pressure stages where mass reduction is prioritized. This local quality approach resolves the contradiction by optimizing for different criteria in different locations.
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
The system achieves reduced size, mass, and cost of heat storage and recovery devices, enhancing the overall efficiency and economic feasibility of compressed-air energy storage.
Implementation Method 1
a heat exchanger without direct contact for heat exchange between the compressed gas and a heat transfer fluid
Implementation Method 2
a second heat storage and recovery means comprising second heat storage particles, the second heat storage and recovery means being configured for direct heat exchange between the second heat storage particles and the heat transfer fluid
Implementation Method 3
compressing at least once a gas in a compression line comprising at least two compression stages
Implementation Method 4
expanding the heated compressed gas in an expansion means
Data Source
AI summary
The present invention relates to a compressed-gas energy storage and recovery system and method, comprising:a gas compression line (1) with at least two compression stages (3), each comprising a heat storage device downstream from a compression means (100, 101, 102),in a compression stage (3), the heat storage device comprises a heat storage means (200, 201) for exclusively direct heat exchange between the compressed gas and heat storage particles, andin another compression stage (3), the heat storage device comprises a cooling loop, with an exchanger (800) for heat exchange between the compressed gas and a heat transfer fluid, and a heat storage means (203) for direct heat exchange between the heat storage particles and the heat transfer fluid.