Thermal Storage Power Plant With Separate Circuits for Turbine Stability
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Solution Overview
Problem
Existing power plants face challenges in efficiently storing and converting electrical energy due to fluctuations in energy demand, as traditional energy storage methods like batteries and pumped storage require significant infrastructure and are inefficient in maintaining constant turbine steam temperatures, leading to material stresses and reduced efficiency.
Innovation Solution
A power plant design featuring separate heat storage fluid and working fluid circuits, where thermal energy is transferred via heat exchangers to a working fluid that drives turbines at a constant temperature, allowing for efficient energy storage and conversion without the need for high-pressure steam and minimizing material stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If electrical energy is stored as heat energy using a thermal storage body, then energy storage capacity is improved, but the temperature of the thermal storage fluid varies significantly during operation, causing material stresses and reduced reliability
Solution Approach 1:
The system is divided into two separate circuits: a heat storage fluid circuit and a working fluid circuit. The heat storage fluid circuit handles thermal energy storage with variable temperatures, while the working fluid circuit maintains constant temperature for turbine operation. This segmentation allows each circuit to optimize its function independently, resolving the contradiction between energy storage capacity and operational stability.
Solution Approach 2:
A heat exchanger serves as an intermediary between the heat storage fluid circuit and the working fluid circuit. It transfers thermal energy from the heat storage fluid to the working fluid without direct mixing, allowing the working fluid to receive heat at a controlled, constant temperature regardless of fluctuations in the heat storage fluid temperature. This mediator protects the turbine system from temperature variations while enabling efficient energy transfer.
2Use of energy by moving object
If the thermal storage fluid is heated to high temperatures for efficient energy storage, then energy density is improved, but material stresses increase and manufacturing complexity increases
Solution Approach 1:
The system separates the high-temperature heat storage function from the turbine operation function. The heat storage fluid circuit can operate at high temperatures for efficient energy storage, while the working fluid circuit operates at lower, more manageable temperatures suitable for standard turbine materials. This segmentation allows high energy density without proportionally increasing manufacturing complexity.
Solution Approach 2:
The heat exchanger acts as a thermal intermediary that decouples the temperature requirements of the two circuits. It enables the heat storage fluid to reach high temperatures for efficient storage while transferring heat to the working fluid at controlled temperatures, reducing material stress and simplifying manufacturing requirements for the turbine components.
3Productivity
If the working fluid temperature is allowed to vary to match thermal storage temperature, then energy conversion efficiency is improved, but turbine reliability decreases due to material stresses
Solution Approach 1:
The heat exchanger serves as a thermal mediator that enables efficient heat transfer from the heat storage fluid to the working fluid while maintaining a constant working fluid temperature. This allows the system to capture thermal energy effectively without subjecting the turbine to temperature fluctuations, thus maintaining both efficiency and reliability.
Solution Approach 2:
The system changes the temperature parameter of the working fluid to remain constant despite variations in heat storage fluid temperature. By controlling the working fluid temperature independently through the heat exchanger, the system achieves reliable turbine operation while still enabling efficient energy conversion from the thermal storage system.
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 solution enables stable and efficient energy storage and conversion, reducing material stresses and maintaining turbine efficiency while allowing for high-pressure operation of the working fluid circuit, thus effectively addressing the challenges of fluctuating energy demand.
Implementation Method 1
Each thermal storage unit (1) comprises an electrical heater (10) for converting electrical energy into thermal energy
Implementation Method 2
at least one thermal storage body (30, 31) for receiving and storing thermal energy from the electrical heater (10)
Implementation Method 3
a heat exchanger (50) for receiving thermal energy from the thermal storage body (30, 31)
Implementation Method 4
the heat exchanger comprising heat exchange tubes (51) for conducting a heat storage fluid (40)
Implementation Method 5
The heat exchanger can be designed in terms of the length and cross section of its tubes in such a way that the heat storage fluid evaporates as it flows through the heat exchanger
Implementation Method 6
liquid water is converted into water vapor
Implementation Method 7
driving at least a first turbine (120) and generating electrical energy from a rotational movement provided by the turbine
Data Source
Figure 1~2
Figure 3
AI summary
A power plant for generating electrical energy comprises at least one thermal storage device (100) for storing electrical energy into thermal energy, comprising: an electrical heater (10) for converting electrical energy into thermal energy; a thermal storage body (30, 31) for absorbing and storing thermal energy of the electric heater (10); a heat exchanger (50) for absorbing heat energy from the heat storage body (30, 31). In addition, the power plant includes a turbine (120) and a generator (123). A thermal storage fluid circuit (130) is connected to the heat exchanger (50) or heat exchangers (50) and a working fluid circuit (140) is connected to the turbine (120). A fluid circuit heat exchanger (131) transfers heat from the heat storage fluid to a working fluid in the working fluid circuit (140).