THE BURNT TURBOCHARGE BLADE TIPS

We had a request for technical support onboard a major shipping company’s vessel about serious trouble with turbocharge last week. We carried out dismantling and inspecting this turbocharge. Affer dismantling it, we find that all blade tips are seriously burnt (see fig1)

Fig 1. The burnt turbocharge blade tips

Beside that some blades of nozzle are also burnt (see figure 2)

Fig 2. The burnt nozzle blades

We conducted simultaneous processing in two steps.

1. Finding the correct root cause of the trouble

The root cause of the phenomenon is too high temperature of exhaust gas. As you know: An overabundance of heat is never a desired condition for any engine components, and turbochargers are of course no exception. And like any other engine component, turbochargers are designed to function within a specified range of temperatures – exceed that you have trouble with your turbocharge.

Of course, there are many causes of high exhaust gas temperature. You can refer following some causes.

1. When exhaust temperature of some cylinder increases:

• tappet clearance increases.
• increase in piston clearance leading to blowpast in decrease in compression pressure. hence incomplete combustion and increase in exhaust temperature.
• leaky exhaust valve
• leaky fuel injector
• in case of main engine, scavenge fire can also lead to high exhaust temperature.

2. When exhaust temperature of all cylinder increases:

• turbocharger fouling;
• air filter of turbocharger fouled;
• air cooler chocked on water side
• air side fouled of air cooler;
• fuel oil temperature decreases leading to problem in atomization;
• governor problem;

There are so many causes which make you feel confuse. We have to find the correct root cause.

2. Inspecting and renewing spare parts

You can see following figures

Figure 3. Renewing rotor (turbine and compressor)

Fig 4. Renewing the nozzle

We hope this insight is useful – if you are experiencing any similar issues or have any further questions, get in touch and visit us: https://mtbshiprepair.com/  we’d be happy to help.