Our solution
Shock pulse transducers installed in the bearing housings, both on the turbine and the compressor side, are connected by coaxial cables to a multichannel measuring and display module. A vibration transducer monitors the overall movement. The readings can also be captured with a portable instrument like Leonova Diamond or Leonova Emerald. You get an instant, user-friendly condition evaluation on a green-yellow-red scale. The system gives immediate results such as maximized up-time, increased profitability, and reduced cost.
The concept of air compression and expansion has been used in a variety of applications: gas turbines, steam turbines, wind energy, turbocharging of diesel engines, and is commonly used in the maritime industry.
A turbocharger comprises a turbine and a compressor connected by a common shaft, supported on a bearing system.
The turbocharger converts waste energy into compressed air that it pushes into the engine. This allows the engine to produce more power and torque and improves the overall efficiency of the combustion process.
The turbocharger has two bearings, one on the compressor side and one on the turbine side. The bearings are either of roller bearing type or sleeve bearing type.
A breakdown of a turbocharger is very costly. Direct costs are primary and secondary material damages. Indirect costs are off-hire of the ship, penalties due to late arrival to port because of decreased speed, and bad will in front of passengers. Therefore, condition monitoring of turbochargers is very important when it comes to monitoring the condition of the turbocharger and planning their maintenance to eliminate any unplanned stops.
Typical faults and trends
While in good condition, turbocharger bearings produce very stable shock pulse readings. Due to the high rpm, the fatigue of these bearings results in a fairly rapid damage development. A few weeks´ warning time can be expected, but it is advisable to replace the bearing at the first opportunity after an increase in the shock level. Vibration above all increases on the turbine side when the compressor is fouled and needs cleaning. Combustion residues on nozzle vanes and turbine blades cause a considerable drop in compressor efficiency.
Bearing damage
The bearing can be damaged due to, for example, normal wear, poor lubrication oil, or incorrect mounting. If the turbocharger runs until the bearing breaks down due to any of the above reasons, this will cause the turbocharger to stop, and the bearing will have to be replaced before startup. Bearing damage might also cause secondary damage to the turbine and the compressor.
Rotor imbalance
Rotor imbalance means that the turbocharger starts to vibrate. This is because the blades have dirt deposit causing these vibrations. If the turbocharger is run toward a rotor breakdown, this will cause the turbocharger to stop. The rotor will have to be replaced, and most probably, secondary damages will have to be fixed.
The solution
1) Turbine bearing 2) Blower bearing 3) Turbine vibration
A breakdown is very costly, mainly due to material costs. The time from a worsened condition to a breakdown is much shorter compared to many other applications due to the very high speed at which turbochargers are run. An online solution is, therefore, often preferred when monitoring the condition of turbochargers.
Suggested methods
Roller bearing types
SPM monitoring of the bearings with the SPM® method. Vibration monitoring on the housing for measuring the impeller condition.
Sleeve bearing types
Vibration monitoring
For trending and alert handling, SPM Instrument supplies units that give 4-20 mA output for connecting to local PLC. A solution with the Condmaster® Ruby software can also be implemented.
