CASE59 · Manufacturing · Compressor efficiency degradation
Separating compressor equipment deterioration from operating-condition effects
Unit-level specific energy identifies persistently inefficient candidates. Matched pressure and load comparisons precede mechanical inspection, maintenance and remeasurement.
01 · CASE ANALYSIS
Compare energy with air output
Specific energy = compressor power in kW / airflow in Nm³/h, yielding kWh/Nm³. High kW alone does not establish poor efficiency if a machine delivers more air.
The source listed inspection of inefficient units and diagnosis/restoration of deterioration separately from header-pressure control and staging.
02 · CASE ANALYSIS
System context
Annual analysis found one or two idling machines through the seasons, pressures around 8.3–9.0 kg/cm² and roughly two units operating above demand at around 74% mean load.
Source air-production yield was approximately 7.0 m³/kWh versus a stated theoretical reference of 8.0–8.3 m³/kWh. Higher yield is favorable; it is reciprocal to energy-per-air-volume intensity.
| Domain | Items | Possible interpretation |
|---|---|---|
| Intake | Filters, temperature and pressure | Restriction or density effect |
| Compression | Elements, internal leaks and lubrication | Mechanical performance |
| Cooling | Inter/aftercoolers and cooling supply | Temperature/heat-transfer effect |
| Pressure network | Discharge, check valves and filter ΔP | Unnecessary pressure ratio |
| Control | Loading/unloading, VSD and setpoints | Part-load/unloaded loss |
| Measurement | Flow, power and pressure sensors | False efficiency outlier |
03 · CASE ANALYSIS
Do not diagnose mechanical failure from an unmatched KPI
Higher discharge pressure or frequent unloading can worsen specific energy even in a mechanically healthy compressor. Compare similar flow, pressure and load-factor regions.
Only persistent deviations after operating-condition checks justify detailed equipment inspection.
04 · CASE ANALYSIS
Inspect causes and verify restoration
Review intake filters/conditions, compression elements and internal leaks, lubrication, cooling, discharge valves, control settings and meter validity.
After action, remeasure under comparable conditions. A completed maintenance work order does not itself demonstrate restored energy performance.
| Question | Activity |
|---|---|
| How many machines? | Staging and loading/unloading: CASE52 |
| What service pressure? | Header/terminal control: CASE54 |
| Which units are efficient? | Matched specific-energy comparison |
| Why does one unit deteriorate? | Inspection, restoration and retest: CASE59 |
05 · CASE ANALYSIS
Manage long-term drift
Build unit-specific normal ranges or load/pressure curves and track sustained deviations. Retain post-maintenance performance history.
The case does not publish an isolated final annual savings amount for the inspection activity.
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