Early Detection of Injection Underperformance During PoC Operation
Customer Profile
- Customer: International ship owner operating main-fleet commercial vessels
- Asset: Auxiliary engines (two identical units)
- Engine make & model: Doosan MAN 5L23/30H
- Rated Power: 620 kW @ 720 RPM
- Engine Type :Four-stroke diesel generator
- Industry: Marine – Commercial Shipping
Context
Vib360 was installed on the vessel as a Proof of Concept (PoC) as part of an evaluation of advanced condition-monitoring technologies.
During normal vessel operation and routine daily use of the system, Vib360 identified a subtle but persistent anomaly in the torsional behaviour associated with a specific firing event.
At the time the anomaly was raised:
- No OEM alarms were active
- Exhaust gas temperatures were within acceptable limits
- Engine operation was considered normal by ship staff
The indication was therefore system-initiated and not prompted by any reported fault or performance concern.
This provided an opportunity to validate Vib360’s ability to identify early-stage injection underperformance during real operation, rather than during targeted testing.
Problem Statement
Injection degradation is typically detected only at a late stage through Exh Gas Temp deviation, smoke, or alarm activation.
Early detection was required to avoid secondary thermal and mechanical stress.
Objective of Vib360 Assessment
- Validate early-stage injection anomaly raised by the system
- Confirm physics-based, repeatable diagnosis
- Enable corrective action prior to escalation
Measurement Setup
- Flywheel-mounted Magnetic Pickup Unit (MPU)
- Continuous torsional vibration and angular acceleration monitoring through Intelligent Controller
- Data analysed under comparable load conditions over multiple days
Physics-Based Findings
- Repeatable torsional irregularities linked to specific firing events
- Increased cycle-to-cycle angular acceleration variability
- Harmonic distortion patterns consistent with delayed or inconsistent injection
Mechanical / Operational Interpretation
Injection underperformance alters combustion torque timing and magnitude, producing measurable torsional harmonic distortion.
The observed signatures were consistent with progressive injector degradation.
Action Taken
- Targeted injector inspection
- Injector servicing during planned maintenance
Outcome and Value
- Issue detected before alarms or performance loss
- Avoided secondary component stress
- Maintenance executed in a controlled manner
Technical Significance
Demonstrates Vib360’s ability to autonomously detect early-stage injection degradation during normal operation, supporting CBM decisions.