The Core Value of the Equipment Health Index (EHI) in Air Compressor Management
The Equipment Health Index (EHI) is a comprehensive, quantifiable metric for assessing the operational condition of industrial equipment. In compressed air systems, the EHI translates complex operating data into an intuitive health score, enabling maintenance teams to shift from “reactive maintenance” to “predictive maintenance,” thereby effectively reducing the risk of unplanned downtime and extending equipment life.
Core monitoring parameters: vibration, temperature, and pressure
To construct a robust EHI model for air compressors, it is essential to rely on the real-time acquisition of key physical parameters. The following three parameters form the foundation for assessing the health status of an air compressor:
- Vibration:It reflects mechanical faults such as rotor imbalance, bearing wear, or poor gear meshing. High-frequency vibration data are crucial for the early detection of mechanical damage.
- Temperature:This includes exhaust gas temperature, lubricating oil temperature, and motor stator temperature. Abnormally elevated temperatures typically indicate a failure of the cooling system, inadequate lubrication, or increased internal friction.
- Pressure:It covers intake pressure, exhaust pressure, and oil pressure. Pressure fluctuations or an increased pressure differential may indicate a clogged filter element, valve leakage, or abnormal pipeline resistance.
Analysis of Weight Coefficient Allocation and the EHI Calculation Formula
Since different parameters exhibit varying degrees of sensitivity and influence on air compressor faults, it is necessary to introduce weighting coefficients for comprehensive calculation. The general EHI calculation logic is as follows:
EHI = (Wv × Sv) + (Wt × St) + (Wp × Sp)
- Wv, Wt, Wp:These represent the weight coefficients for vibration, temperature, and pressure, respectively. In general, vibration provides the highest early‑warning value for mechanical faults, and its weight coefficient is typically greater than those for temperature and pressure. The specific values must be calibrated based on the equipment type and the historical failure database.
- Sv, St, Sp:These are the normalized health scores (0–100) for vibration, temperature, and pressure. By setting thresholds, the measured physical parameters are mapped to health scores. For example, when the exhaust temperature exceeds the safety threshold, the temperature score decreases exponentially.
Application Cases and Development Trends for 2025–2026
As industrial IoT and edge computing technologies mature, air compressor condition monitoring is expected to become highly intelligent between 2025 and 2026.
Typical use case scenario: Cluster management of air compressor rooms in a large manufacturing park
In a centralized gas-supply project at a large manufacturing complex, management has implemented an intelligent monitoring system based on the EHI model. By deploying high-frequency vibration sensors and wireless temperature–pressure transmitters across multiple air compressors, the system calculates the EHI value of each unit in real time.
- Dynamic Weight Adjustment:The system employs machine learning algorithms to dynamically adjust the weighting coefficients for temperature and pressure based on seasonal ambient temperatures and load variations, thereby enhancing the accuracy of the EHI score.
- Predictive Intervention:When the EHI of a particular air compressor drops to the warning threshold, the system automatically determines that the primary cause is a decline in the vibration score and identifies an abnormality in the motor’s drive-end bearing. The maintenance team scheduled its replacement during a planned shutdown, thereby preventing an unexpected outage during peak production hours.
- Energy-Efficiency Coordinated Optimization:By integrating EHI data, the central control system prioritizes the operation of air compressors with high health indices and superior energy efficiency ratios, designating high-EHI units as the main workhorses while de‑loading or scheduling maintenance for low‑EHI units, thereby achieving a significant improvement in the overall energy efficiency of the compressor room.
In the future, the equipment health index will go beyond the condition assessment of individual units and be deeply integrated into the enterprise’s asset performance management system, serving as the core data foundation for the entire lifecycle management of air compressors.