A Caterpillar that goes to sea

Caterpillar has introduced a diesel genset module built around its C175-16 power unit and designed specifically for offshore applications. It is available in 60 Hz packages with a 1.83 MW rating at 1200 rpm.

The package was designed to offer a larger unit rating, higher power density, lower emissions and reduced installation costs for shallow water and jackup rigs. Meeting US EPA Tier 2 and IMO II requirements, the genset is intended to meet the current needs of the drilling industry, and to be the new standard for future offshore drilling rigs.

The C175 model has successfully completed rigorous field reliability demonstrations in real-world applications spanning the globe, achieving more than 100 000 hours of reliable oeration, over 60,000 of them in generator set applications. The C175 is optimised for a variety of applications, including the stringent demands of power generation for offshore drilling.

The C175-16's fuel system utilises a high pressure fuel pump and control valve that deliver multiple precise injections within a single combustion event. This results in lower emissions, improved performance and reduced fuel consumption. Driven by the ADEM™ A4 controller, the engine management system features full redundancy and is said to provide superior performance, even in the most demanding environments.

The high efficiency close coupled generator is designed to match the performance and output characteristics of the C175 standard package. It offers Class F insulation and an IP23 enclosure. The 0.7 power

factor, form wound generator, features permanent magnet excitation (PMG).

The air system delivers cooler combustion air at the cross-flow cylinder heads, allowing for higher power density and emission reduction. A new generation of turbochargers was designed for the C175, providing a 5% efficiency boost and longer life when compared to traditional turbochargers. A newly designed cooling system cools only the parts of the engine that require cooling, resulting in increased efficiency and lower heat rejection. This method of temperature control allows customers to reduce overall installation costs by using smaller radiators or heat exchangers, as well as smaller engine room ventilation ducting and fans.

The lubrication system utilises Cat high efficiency oil filters that optimise the recommended oil change interval to 1000 hours. It may be possible to extend this further with the use of Cat S·O·SSM analysis.