Page 66 - CARILEC CE Industry Journal_Oct_2019

Upon inspection, it was found that the Locknut the And then there is the rest of the story. In the process of
secures that Adjust screw had not been torqued correctly correcting this maintenance induced maintenance issue,
and was found to be loose (Fig. 38 and 39). This allowed instead of just correcting the timing, the injector was
the adjusting screw to thread-in which changed the replaced. During this replacement, the fuel lines were not
timing of injection. As a result, fuel was extremely corrected properly. This in turn resulted in a fuel leak,
retarded resulting in a low and late combustion. The early which was not detected immediately and ultimately led to
peak is from compression as the “peak firing pressure” a complete crank case lube oil dilution with fuel oil.
was so late is was below compression pressure. This also Therefore a simple maintenance error resulted in
led to the slightly elevated exhaust temperature. significant corrective maintenance actions.

CONCLUSIONS

This paper has presented that comprehensive engine
analysis and monitoring can benefit the operators of large
diesel engines by providing technology that can help avoid
engine failures and optimize engine performance with
targeted corrective actions. This technology is well proven
and is utilized in many other applications (Oil & Gas,
Military, and Power Generation, as well as critical
applications such as Nuclear Emergency Diesel Generators).

By monitoring engines in a comprehensive manner, small
mechanical issues can be identified early on before a
small issue causes a more significant engine failure.
Fig. 38 - Rocker Arm Assembly
The benefits of operating an engine at its optimum
condition saves fuel and reduces emissions as well as
providing the maximum ”up-time” and availability.

Whether the goal or outcome is to reduce fuel
consumption by ensuring optimized operating conditions
or to have the parts and personnel available to perform
maintenance before a failure, even a “minor” one occurs,
the financial benefits can be measured in the hundreds of
thousands of dollars.

The reality is that conducting this type of monitoring and
analysis on a regular basis is not hard or complicated, nor
is it expensive considering the savings present. Whether
companies conduct this “in-house” or collect data and
send it to others for analysis, there are proven benefits to
comprehensive engine analysis.

Fig. 39 - Rocker Arm Assembly

References

Kelleher, Economic and Mechanical Benefits of Utilizing Advanced Diesel Engine Analysis
and Monitoring Techniques, Paper SMC-089-2016, SNAME 2016
C L Haller and E P Kelleher. ‘Practical Integrated Maintenance and Diagnostics
for Medium and Slow Speed Diesel Engines.’

64 CE INDUSTRY Journal