Jenbacher J920 FleXtra gas engines deliver enhanced flexibility, greater efficiency, and lower emissions
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Jenbacher J920 FleXtra gas engines deliver enhanced flexibility, greater efficiency, and lower emissions Acea Produzione SpA, Tor di Valle, Rome, Italy Background Italian utility Acea Produzione SpA, a subsidiary of Acea SpA - one of Italy's principal multi-utilities - supplies energy, water, and other environmental services in southwestern Rome. The utility recently modernized its largest district heating power plant - the 1990 Tor di Valle combined cycle heat and power plant - to improve its operating flexibility and energy efficiency as well as reduce its environmental impact. The district heating power plant originally was constructed as a gas turbine combined cycle (GTCC) plant with heat extraction providing about 120 MW of power and 70 MW of heat to the nearby Torrino area district heating network. Solution The existing district heating power plant modernization resulted into a new 19 MW combined heat and power (CHP) plant with two of GE's 9.5 MW Jenbacher* J920 FleXtra gas engines, plus three 23 MW auxiliary gas boilers, six 215 cubic meter (m3) heat storage tanks, and associated balance of plant systems to connect to the existing district heating system. Jenbacher gas engines, auxiliary gas boilers, and other balance of plant equipment were installed in the existing modernized engine hall. The Jenbacher J920 FleXtra gas engines produce 19 MW of electrical power and about 15 MW of thermal power, achieving more than 80 % total efficiency. The three additional gas boilers can produce another 70 MW of thermal power to cover peak heat load demands. In addition to the gas engines, GE's Distributed Power business supplied related engineering and associated balance-of-plant equipment, while Cefla - an Italian industrial engineering supplier - developed the engineering of the plant, providing project management, ensuring equipment supplies and overseeing installation of the entire plant, including the civil infrastructure. The gas engines are integrated with a thermal energy storage system consisting of six 215 m3 outdoor heat storage tanks. The storage system helps ensure a continuous supply of heat without the need to increase electric power generation in times of low power demand from gas engines. Acea's two Jenbacher J920 FleXtra gas engines are connected to GE's myPlant* Asset Performance Management (APM) platform. The myPlant APM solution actively monitors all key engine parameters and supplies analytics that can predict component life, allowing operators to move from a proactive maintenance schedule to a condition-based maintenance approach. * Indicates a Trademark of the General Electric Company

Results The modernized 19 MW Tor di Valle CHP plant began commercial operation near the end of 2017, supplying electricity to Acea’s nearby sewage treatment plant and Rome’s distribution grid. Heat is used for the local district heating network to supply about 40,000 residential customers in the Torrino area. “The two Jenbacher J920 FleXtra gas engines run only when power and heat demand is high and when the cost of generation is lower than the cost of electricity from the grid,” explains Giovanni Papaleo, head of ACEA Energy Industrial Area. “The engines easily can be shut down within...