Gas-Tight Heat Storage Tank With Volume Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current heat storage systems for solar power plants face challenges such as large volume requirements, gas management issues, and oxidation risks, leading to high operating costs and complexity, especially when operating at high temperatures or with oxidation-sensitive media.
Innovation Solution
A heat storage device with a gas-tight container and means for volume compensation, such as a flexible cover or buffer container, to manage volume fluctuations without using inert gases, and the use of sulfur-based heat storage media with additives to control vapor pressure and melting point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If large heat storage units are used to enable uninterrupted operation of solar power plants, then the operating duration is improved, but the volume and space requirements increase significantly
Solution Approach 1:
The patent changes the physical parameters of the heat storage medium by using molten salts with specific melting points and thermal properties. The composition of the molten salt (e.g., mixtures of nitrates, chlorides, or sulfates) is optimized to achieve desired operating temperatures and thermal capacity, allowing efficient heat storage in a reduced volume
Solution Approach 2:
The system uses composite heat storage media comprising mixtures of different salts (e.g., sodium nitrate, potassium nitrate, calcium chloride) that combine to provide optimal thermal properties. The container structure also employs composite materials including refractory linings, insulation layers, and structural alloys to enhance thermal efficiency and reduce required storage volume
2Strength
If gas is used to occupy unoccupied volume in the container to avoid negative pressure, then the structural integrity is improved, but the device complexity increases due to pressure control requirements
Solution Approach 1:
The patent introduces an inert gas atmosphere (typically nitrogen or argon) above the molten salt in the container. This inert layer prevents oxidation of the heat storage medium and controls the vapor pressure environment, eliminating the need for complex active pressure control systems while maintaining container integrity
Solution Approach 2:
The system allows the molten salt itself to self-regulate the gas space pressure through thermal expansion and contraction. The vapor pressure of the molten salt and the compressibility of the overlying inert gas automatically balance pressure fluctuations without requiring external control mechanisms
3Reliability
If nitrogen is used as inert gas to prevent oxidation of heat storage medium, then the reliability is improved, but the operating costs increase due to gas procurement and management
Solution Approach 1:
The patent employs an inert gas atmosphere (nitrogen or argon) in the headspace of the container to prevent oxidation of the molten salt heat storage medium. This simple approach provides reliable oxidation protection without requiring complex gas management systems
Solution Approach 2:
The system utilizes the natural vapor pressure equilibrium of the molten salt with the overlying inert gas to automatically manage gas composition. Any small amounts of gas evolution or consumption are self-balanced by the compressible inert atmosphere, eliminating the need for active gas monitoring or replenishment systems
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
Enables safe and efficient heat storage and retrieval at high temperatures, reducing the need for inert gases and complex gas management systems, while minimizing operating costs and maintaining system integrity.
Implementation Method 1
a heat storage medium 3 that absorbs heat to store heat and releases heat to use the stored heat
Implementation Method 2
the volumes occupied by the heat storage medium change due to thermal expansion of the heat storage medium
Implementation Method 3
heat is transferred from a heat carrier to a heat storage medium in a heat exchanger
Data Source
Figure 1.1~3
Figure 4~5
Figure 6~7
AI summary
The invention relates to a device for storing heat, comprising a heat storage medium, which for storing heat takes up heat and for using the stored heat gives off heat, and a tank for receiving the heat storage medium, wherein the tank is closed by a gas-tight covering, and means for volume equalization are comprised, in order to equalize an increase in volume of the heat storage medium (3) as a result of an increase in temperature and a decrease in volume as a result of a decrease in temperature. The invention also relates to a method for storing heat, in which, for storing heat, heat is transferred to a heat storage medium or, for using heat, heat is removed from the heat storage medium and passed to the heat transfer medium, wherein the heat storage medium is held in a tank, which is closed by a gas-tight covering, wherein an expansion of the volume of the heat storage medium (3) is equalized by an increase in the volume of the tank (1), or by heat storage medium (3) flowing out of the tank (1) into a buffer tank (21; 63, 65), and a decrease in the volume of the heat storage medium (3) is equalized by a reduction in the volume of the tank (1) or by heat storage medium (3) flowing out of the buffer tank (21; 63, 65) into the tank (1).