Cummins Inc. has announced the launch of an upgraded 60 Hz natural gas generator set, powered by an 18-cylinder multi-turbo natural gas engine, as part of its 91 L gas product range. Cummins said the new gen-set offers outputs of 1.54 to 2 MWe for both prime and standby power applications and it delivers low emissions levels — down to 0.5g/hp-h NOx without aftertreatment — and meets the transient requirements of ISO 8528-5 G1.
The upgraded unit is also designed for fuel flexibility, being able to produce electricity from pipeline natural gas or other alternative gaseous fuels such as oilfield gas methane numbers as low as 40 MN.
“We have invested in the development of the new QSV91 gas series to ensure strong product performance, application flexibility, fuel flexibility, low emissions and robust load handling,” said Peter Schroeck, general sales manager for Cummins North and Central America. “The multi-turbo design provides optimal transient response as well as high altitude and ambient temperature capability. It offers superior performance and efficiency, providing dependable power to satisfy a wide range of operational and environmental requirements. Balancing key technologies allows us to develop the best solution for our customers.”
The gen-set is based on the QSV91 gas engine, an 18-cylinder, vee-configuration, lean-burn engine with a bore and stroke of 180 x 200 mm and an overall displacement of 91.6 L. The engine has a cast iron block with replaceable wet cylinder liners, and a forged steel crankshaft and connecting rods. Engine breathing is enhanced by four-valve cylinder heads and four High Efficiency Low Flow (HELF) turbochargers from Cummins Turbo Technologies. Engineered to provide optimal transient response as well as high altitude and ambient temperature capability, the turbos incorporate graphite-filled steel ring seals on the compressor outlet tubes for increased durability
The new gen-set is also equipped with an intake air cleaner system with four filter elements supplied by Cummins Filtration. The engine lubrication system includes an ac-driven prelube pump, oil makeup system, lube oil cooler and engine oil immersion heater in the sump.
The engine drives a brushless, four-pole revolving field alternator with permanent magnet exciter and a stator and bearing temperature monitoring system that is Modbus capable for remote monitoring. Engine and generator functions are operated through a Cummins PowerCommand 3.3 controller with HMI320 display, which is also available in a remote option. A new generator interface box is compatible with the CM2358 engine control module, the company said.
The QSV91 gas series is engineered to minimize voltage, frequency deviation and operational time-to-recover, achieving 100% load shed without shutdown, Cummins said. It can deliver electrical efficiencies as high as 38.3%, the company said.
The gen-set has also been developed to function in extreme environments and is capable of operating in ambient temperatures of up to 131°F and at 4921 ft. above sea level, making it suitable for a wide range of industries and applications, Cummins said.