Phase-Change Thermal Storage for Stable Building Power Generation
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Solution Overview
Problem
Thermal solar panels face inefficiencies due to the irregularity of thermal energy sources over time, requiring a solution to stabilize and efficiently convert fluctuating thermal energy into electrical energy.
Innovation Solution
A thermal energy transformation installation comprising an energy storage device with a heat transfer fluid tank, a phase change material tank, and a heat pump, which uses a turbogenerator to produce electrical energy from the kinetic energy of a gaseous fluid, and incorporates a phase change material to store thermal energy without significant volume or pressure requirements, allowing for stable energy production and domestic hot water generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If thermal solar panels are used as the thermal energy source, then the installation can capture renewable thermal energy, but the irregularity of thermal energy over time causes unstable electrical energy production
Solution Approach 1:
The system performs preliminary action by storing thermal energy in the FC tank and MCP tank during periods when thermal energy is abundant (such as daytime solar exposure), so that this stored energy can be utilized during periods when thermal energy input is insufficient, thereby stabilizing electrical energy production throughout the day and across seasons.
Solution Approach 2:
The system utilizes phase change of the FC fluid (between liquid and gaseous phases) and the MCP material (between solid and liquid phases) to store and release thermal energy. This parameter change allows the system to buffer thermal energy fluctuations and maintain stable operation of the turbogenerator, resolving the contradiction between renewable energy capture and production stability.
2Quantity of substance
If a large volume FC tank is used to store gaseous fluid, then thermal energy storage capacity increases, but the device volume and pressure requirements increase
Solution Approach 1:
The system employs phase transitions of both the FC fluid (liquid-gas) and the MCP material (solid-liquid) to store thermal energy. The MCP tank stores thermal energy during phase transition without significant volume expansion or pressure increase, as the material changes phase at constant temperature and pressure. This allows high thermal energy storage capacity in a compact volume, resolving the contradiction between storage capacity and device volume.
Solution Approach 2:
The FC tank is positioned within the MCP tank, creating a nested configuration where the smaller FC tank is surrounded by the MCP material. This nested arrangement maximizes the use of available space, allowing the FC fluid to undergo phase changes for thermal storage while the surrounding MCP material provides additional thermal buffering without requiring a larger overall system volume.
3Use of energy by stationary object
If the FC fluid vaporization temperature is kept low (10-70°C) for easy heat pump achievement, then the heat pump energy input decreases, but the electrical energy output and system power are limited
Solution Approach 1:
The MCP material acts as an intermediary thermal storage medium between the heat pump and the FC fluid. The heat pump transfers thermal energy to the MCP material, which then transfers it to the FC fluid. This intermediary arrangement allows the system to accumulate thermal energy over time in the MCP tank, enabling the FC fluid to undergo more extensive phase changes and generate higher electrical power output without requiring the heat pump to operate at high energy input levels continuously.
Solution Approach 2:
The system performs preliminary thermal energy accumulation in the MCP tank before the FC fluid undergoes phase change in the turbogenerator. This preliminary action allows thermal energy to be stored during periods when heat pump input is available, and then released in concentrated form to generate higher power output when needed, resolving the contradiction between low energy input and high power output.
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 installation effectively stabilizes electrical energy production and domestic hot water supply, enabling autonomous energy provision for buildings up to 10000 m2 by efficiently managing thermal energy fluctuations from thermal solar panels, demonstrating improved efficiency and scalability.
Implementation Method 1
a heat pump, suitable for transferring thermal energy from a cold source to the energy storage device in order to heat the FC fluid contained in the FC vessel and/or supply energy to the MCP material
Implementation Method 2
it produces electrical energy from the kinetic energy released by the expansion of the coolant in the gaseous phase under pressure
Implementation Method 3
a first electric generator connected to the FC vessel by a forward path and a fluid return path, the generator being suitable for producing electrical energy from the kinetic energy of the gaseous fluid under pressure
Implementation Method 4
an MCP tank containing a phase change material called MCP material... the use of an MCP tank makes it possible to store much more energy, in particular if a solid/liquid type MCP material is used because the phase change requires little or no additional volume
Implementation Method 5
the energy storage device may also comprise a first heat exchanger element, for example a coil, positioned in or around the MCP tank
Data Source
AI summary
The invention relates to a facility for transforming heat energy, the facility including: an energy-storage device including a vessel (26) of heat-transfer fluid referred to as HT vat containing a heat-transfer fluid HT in pressurised gaseous phase, a PCM vat (19) containing a phase-change material, referred to as PCM material, the PCM vat and the HT vat being positioned relative to one another such as to enable a transfer of heat energy between the PCM material and the HT fluid, a first electric generator (11) connected to the HT vat by a fluid forward channel (14) and a fluid backward channel (13), the generator being suitable for generating power from a kinetic energy of the pressurised gaseous fluid, and a heat pump, suitable for transferring heat energy from a cold source to the energy-storage device in order to heat the HT fluid contained in the HT vat and/or to provide energy to the PCM material. The invention can be used for the general supply of energy, heat, domestic hot water or electricity of a building such as a single-family home, an apartment block, an industrial or service building, etc.