Pointe Monnier, Mauritius

The Central Electricity Board (CEB) of Mauritius improved the performance as well as reduced the operating costs of their power plant by having a turbocharger retrofit. “The result was very satisfying: improved performance, less operating costs due to lower fuel consumption and reduced emissions,” says Mr. Manoj Kumar Jahajeeah, Officer-in-Charge of the Production Department at the Central Electricity Board, Mauritius.

The Pointe Monnier power station is located on Rodrigues Island, about 600 km northeast of the Mauritius main island. The Wärtsilä 6L32 engine, with an output of 2.5 MW, is the primary baseload generating set because of its generating capacity, generally producing more than 30% of the total monthly electricity generation on the island.

Mr. Jahajeeah describes the plant operations before the turbocharger retrofit: “Within one year from the commissioning, we started to have problems with the turbocharger, which resulted in high exhaust gas temperatures. On several occasions over the years we have had the turbocharger dismantled and mechanically cleaned and overhauled; only to see temperatures starting to rise again shortly after.”

Wärtsilä’s professional installation services

In June 2016, the turbocharger was severely damaged and replaced by a spare one. CEB complained about the performance of the turbocharger to its engineering procurement contractor, BWSC, who offered a retrofit of a newer and better turbocharger that would not only reduce the exhaust gas temperatures and turbocharger speed, but also improve the engine performance.

No problems were encountered during the installation phase, and Wärtsilä’s engineers were professional and knew exactly what should be done. “Wärtsilä’s staff were trustworthy and performed extremely well. They also provided technical advice to the CEB personnel on site. The transfer of knowledge and technology went well, and our technicians and engineers got proper training,” explained Mr. Jahajeeah.

Significant benefits

According to Mr. Jahajeeah, the new turbocharger has fulfilled CEB’s expectations. The exhaust gas temperatures are lower compared to the same load as before the retrofit. Lower temperatures mean better combustion and lower emissions regarding NOx.

With the new turbocharger, the Specific Fuel Oil Consumption was reduced by 8g/kWh, which was higher than expected. This is clear proof that the engine is more efficient with the new turbocharger. Furthermore, lower exhaust gas temperatures and improved engine operating parameters, such as charge air temperature and pressure, contribute to maintaining the thermal load of the engine at a correct level. “It’s easy to recommend a turbocharger retrofit to other customers with similar needs. Based on the fuel savings at an average engine load factor of 75%, the payback time for our investment is 15 months.,” concludes Mr. Manoj Kumar Jahajeeah.

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