Compressor Thermal Shield Reduces Casing Creep
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multistage gas compressors, particularly in CAES systems, face issues with high thermal and mechanical stresses due to the significant temperature increase of the gas during compression, leading to potential creep deformation and material degradation, especially when using less performing materials like low alloy steel for the outer casing.
Innovation Solution
A thermal shield arrangement is implemented between the compressor bundle and casing to reduce heat transfer, comprising thermal barriers and insulating materials like ceramic powders, which slows down the heating of the casing and prevents visco-plastic deformation, allowing for longer operational intervals and using less performing materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If no thermal shield is used, then heat transfer from compressor bundle to casing is efficient for cooling, but the casing reaches high steady state temperatures causing thermo-mechanical stresses and creep deformation
Solution Approach 1:
A thermal shield arrangement is introduced as an intermediary component between the compressor bundle and the compressor casing. This thermal shield acts as a mediator that reduces the direct thermal coupling, thereby lowering the steady state temperature of the casing while maintaining the operational integrity of the compressor bundle.
Solution Approach 2:
The patent converts the harmful effect of heat transfer (which causes high casing temperatures and structural degradation) into a beneficial outcome by using the thermal shield to control and redirect heat flow. The heat that would otherwise damage the casing is now managed to protect the casing while still allowing efficient thermal management.
2Temperature
If thermal shield arrangement is added, then casing temperature and thermal-mechanical stresses are reduced, but device complexity increases
Solution Approach 1:
The thermal shield arrangement is implemented as a segmented structure with multiple shields positioned at different locations within the compressor. This segmentation allows the thermal management function to be distributed and optimized at different stages of heat transfer, reducing the overall thermal load on the casing while maintaining a manageable structural complexity.
Solution Approach 2:
The thermal shields are strategically positioned at specific locations where heat transfer to the casing is most problematic. This local application of thermal shielding focuses the complexity reduction where it is most needed, rather than uniformly increasing complexity throughout the entire compressor structure.
3Duration of action of moving object
If thermal shield is implemented, then allowable operative time intervals are extended, but manufacturing complexity increases
Solution Approach 1:
The thermal shields are designed as relatively simple, potentially replaceable components that can be manufactured using cost-effective methods. Their simpler construction compared to the main compressor structure allows for easier manufacturing and potential replacement if needed, extending the operative time intervals without significantly increasing overall manufacturing complexity.
4Use of energy by moving object
If thermal shield reduces heat transfer, then energy content of compressed gas increases, but heat dissipation from gas decreases
Solution Approach 1:
The thermal shield arrangement extracts and intercepts a portion of the heat energy from the compressed gas before it can be fully transferred to the casing. This extracted heat energy remains within the gas stream, thereby increasing the energy content of the compressed gas delivered to the outlet, while the shield prevents this energy from being lost to the casing and environment.
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 thermal shield arrangement effectively reduces thermal-mechanical stresses, prevents creep deformation, and increases the energy content of the compressed gas, enhancing the efficiency of CAES systems by maintaining higher gas temperatures for energy conversion.
Implementation Method 1
A thermal shield is arranged between the compressor casing and the compressor bundle. The thermal shield arrangement reduces or slows down the thermal transfer from the compressor bundle towards the compressor casing.
Implementation Method 2
The gas processed by the compressor is ingested at an inlet pressure and delivered at a higher outlet pressure, the pressure increase being obtained by conversion of mechanical power into potential pressure energy stored in the gas flow. The process provokes a temperature increase of the processed gas.
Implementation Method 3
The heat is transferred from the gas to the diaphragms 121 and therefrom to the casing 101.
Data Source
AI summary
A compressor includes a compressor bundle and an outer casing. Between the outer casing and the compressor bundle a thermal shield is provided, for reducing thermal stress and visco-plastic deformation of the casing under severe operating conditions.