Good Case Study About Engineering

The project was to test the salinity of the water in the hotwell. On checking the salinity meter, the readings were unexpectedly high at 500ppm from the normal 0.5 to 2ppm. One possible explanation would be the failure of the meter. The problem that the team faced is that the engineer that had left did not leave any indication of the meter being faulty. This led to the team having to inspect the hotwell to find out what could have caused the problem.
On inspecting the hotwell, there was thick formation of dark sludge, which showed that the water was high levels of salinity. There were cracked tubes which had been the channel through which sea water got to the auxiliary boiler water. The hotwell also had some mud and sand. There was no clue of the cause of the sand and how it entered the hotwell. The possible cause of the cracked tubes was fatigue because the condenser had been there for a period of over 15 years. This did not, however, explain the reason why the condenser had sludge and sand. There was unexpected discovery that one of the plate coolers had been maintained during the previous trip. The reason fro this is that the sea suction had not been transferred from low to high and that that there were high sediments that had been sucked into the ships from the sea water.
The solution was to seal the cracks so that no water could be sucked further. The hotwell was cleaned and blown twice daily for four weeks running. The system was also given a new water feed till the problem was under control.
A slight leak was found at the boiler furnace. This was found after the regular maintenance of the boiler when it was discovered that one of the smoke tubes had leakage. Perhaps important information that should be known is that the vessel was being transferred enroute Devonport to Melbourne. The loading and discharging takes roughly 16 hours.
When the first and second engineers were preparing the vessel for further inspection, there was the notice of the poor management of boiler water. This caused corrosion and thinning to the tube. This is an important and significant cause of the leaks that affected the boiler. There was the need to ensure that the problem was well defined and working effectively and well. The thinning of the materials causes the boiler to crack. Poor management of the boiler water was confirmed to be the problem of the cracks.
One of the solutions proposed was to ensure that there was correct PH of the water used in the boiler. There was need to undertake maintenance of the equipment. There were also new designs for the smoke tubes which were to be followed in the design. This would help in the management of the smoke. The modification proposed included rotating the outlet and inlet by 60%. The new designs gave better inner circulation of currents.
The repairs were assessed with ultrasound testing to ensure no cracks were present. There was firing with the correct recommendations with the presence of the manufacturer’s representative. This ensured that the vessel would wok effective.
This is a scenario of failure of the burner in main boiler 2. The boiler shut down after some time. There are two generators that are running in the system. After assessing the systems, there were many attempts to restart the system on HFO which did not make through. The vessel was changed so that it could not use diesel but it was not making through.
On close scrutiny, it was discovered that the burner started and stopped working intermittently. This sometimes happened after the second minute. There was also a high temperature observed at the combustion air fans.
The solution that was proposed was to increase the burner stop points as much as possible from the switch points. Another solution was the raise of the burner set point at 0.2 to 0.3 above the control set point.
With this solution, it meant that the burner only stopped all the time when there was minimum load in the burner. It is evident that the load is reduced when it comes above the switch point. The increased starting pressure will effectively help the burner work effectively. When the burner ignites, pressure of the boiler is set to be below the switch point. This is controlled by the PID controllers which will keep burners operating in low load until the boiler reaches the “stop” switch point. The burner start point should be checked well so that the controllers will not send the wrong signals and have the boiler stop working. The parameters of the increased start and burner stop will reduce the number of starts and stops of the burner.
Conclusion