Compressor Rotor Deterioration Detection Using a Sacrificial Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The rotor of a centrifugal compressor is prone to deterioration such as embrittlement and corrosion due to high stress and exposure to the working fluid, leading to defects like stress corrosion cracking, which existing detection methods fail to adequately address.
Innovation Solution
A compressor system with a sacrificial member, comprising a C-ring portion made of the same metal material as the rotor, exposed to the compressed fluid and strained by the pressure, and a strain gauge to monitor the strain, allowing for detection of deterioration and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a CMAS probe is disposed inside the compressor to detect erosion and corrosion, then the state of material deterioration can be monitored, but the detection is limited to electrical resistance changes and cannot detect various modes of deterioration including stress corrosion cracking
Solution Approach 1:
The patent uses a sacrificial member that is a copy of the rotor material (same metal material) to simulate the actual deterioration conditions. This copy is subjected to the same working fluid and stress conditions, allowing comprehensive detection of various deterioration modes including stress corrosion cracking, embrittlement, and corrosion that cannot be detected by electrical resistance alone
Solution Approach 2:
The strain gauge acts as an intermediary device that converts physical strain into measurable electrical signals. By placing the strain gauge on the sacrificial member, it indirectly measures the deterioration state through strain changes, enabling detection of multiple deterioration modes beyond what direct electrical resistance measurement can achieve
2Measurement precision
If the rotor is directly monitored to detect deterioration, then accurate real-time data can be obtained, but the detection system becomes complex and may interfere with the rotor's normal operation
Solution Approach 1:
The patent employs a sacrificial member that is disposable and can be easily replaced. This member undergoes the same deterioration processes as the rotor but can be removed and inspected without disassembling the rotor, significantly simplifying the detection system while maintaining accurate deterioration monitoring
Solution Approach 2:
The detection function is segmented from the rotor itself into a separate sacrificial member. This segmentation allows the rotor to operate normally without monitoring interference, while the sacrificial member independently experiences the same working conditions and can be monitored using simple strain gauges
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 effectively detects various modes of deterioration and defects in the rotor by simulating the conditions experienced by the rotor, providing accurate estimation of the rotor's condition and determining the need for inspection and repair.
Implementation Method 1
a strain gauge to monitor the strain
Data Source
AI summary
A compressor system includes: a compressor provided with a rotor and a stator forming, by covering the rotor, a flow path of a fluid to be compressed; and a sacrificial member disposed in an accommodation space in communication with the flow path. The sacrificial member includes a portion to be measured disposed in the accommodation space and strained by a pressure of the fluid.