Modular PCM Thermal Storage With Bidirectional Heat Transfer
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Solution Overview
Problem
Current energy storage technologies, such as solar photovoltaic panels with battery backup, are expensive and limited in addressing peak demand challenges, and existing thermal energy storage systems fail to efficiently manage both hot and cold temperature conditioning due to inefficiencies and limitations in thermal conductivity and single-directional energy fluid flow.
Innovation Solution
A modular thermal-energy storage and transfer system using phase-change materials (PCMs) with a control mechanism to adjust energy fluid flow, enabling flexible and efficient storage and retrieval of thermal energy, and a bi-directional fluid flow design to optimize temperature exchange across multiple chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional air-source refrigeration cycles are used, then heating and cooling functions are provided, but inefficiencies occur during peak summer and winter conditions with high utility charges
Solution Approach 1:
The system performs preliminary action by storing thermal energy during off-peak hours when utility rates are lower. The thermal storage medium accumulates heat or cold energy in advance, allowing the system to meet peak demand without running expensive peak-period equipment, thereby resolving the contradiction between energy efficiency and utility costs.
Solution Approach 2:
A thermal storage medium acts as an intermediary between the utility grid and the building's heating/cooling demand. This mediator absorbs excess thermal energy during off-peak periods and releases it during peak periods, decoupling the building's energy consumption from the utility's peak pricing structure and improving overall energy efficiency.
2Quantity of substance
If load-shifting technologies use solar photovoltaic panels with battery backup, then energy storage is achieved, but the approach is expensive and singular
Solution Approach 1:
The system changes the physical parameter of the thermal storage medium's temperature and phase state to provide both heating and cooling functions. By controlling the temperature of the storage medium and using heat exchangers at different temperature levels, the system delivers dual functionality without requiring separate solar PV and battery systems, reducing complexity and cost.
Solution Approach 2:
The thermal storage system provides multi-functionality by serving both heating and cooling needs through a single integrated system. The same thermal storage medium can be charged during off-peak cooling periods and discharged during peak heating periods, or vice versa, eliminating the need for separate energy storage systems and reducing overall system complexity.
3Adaptability or versatility
If existing energy storage systems store only single-temperature thermal energy, then storage function is provided, but the ability to simultaneously store hot and cold thermal energy is limited
Solution Approach 1:
The thermal storage system is segmented into multiple zones with different temperature levels within the same storage medium. Heat exchangers are positioned at different vertical locations to access different temperature zones, enabling simultaneous extraction of both hot and cold thermal energy from a single storage system, thereby increasing versatility without requiring multiple separate tanks.
Solution Approach 2:
The system transitions from a single-temperature storage approach to a multi-temperature stratified storage approach by utilizing the vertical dimension. Thermal energy is stored in stratified layers at different heights, with colder densities at the bottom and hotter densities at the top, allowing simultaneous access to multiple temperature levels through vertically distributed heat exchangers.
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 provides cost-effective, flexible, and efficient thermal energy storage and transfer capabilities, capable of managing both hot and cold temperature conditioning, optimizing PCM phase change, and adapting to varying energy demands.
Implementation Method 1
phase-change material (PCM) that stores thermal energy. An energy fluid is routed through the ESM, and the temperature of the energy fluid triggers a phase change in the PCM to transfer thermal energy between the PCM and the energy fluid
Implementation Method 2
transfer thermal energy between the PCM and the energy fluid
Data Source
AI summary
The disclosed embodiments disclose a modular seasonal thermal-energy storage and transfer system that includes an energy-storage module (ESM) with a plurality of chambers that contain phase-change material (PCM) that stores thermal energy. An energy fluid is routed through the ESM, and the temperature of the energy fluid triggers a phase change in the PCM to transfer energy between the PCM and the energy fluid. A control mechanism can adjust the flow of the energy fluid through the ESM to efficiently achieve a target temperature change either in the energy fluid (e.g., using the ESM to access stored energy from the PCM) or in the PCM (e.g., use thermal energy in the energy fluid to store energy in the PCM). The disclosed techniques facilitate the charging and use of a flexible, modular year-round hot and cold energy storage.