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Show 3 Recent growth in the natural gas pipeline industry has contributed to the increasing popularity of these engines, both because of their direct use on the pipelines and due to the cleaner-burning and cost-effective nature of the fuel. These engines were first applied to drive high speed pipeline compressors in the early 1960's. They have since become larger and more fuelefficient as a result of developments in aircraft turbofan engines from which many of the land-based units are derived. Most of the modern pipeline units are in the 3 MW to 25 MW size range, and are base-loaded with an average of 5000 to 6000 operating hours per year. Over 1000 MW have been installed since 1988 due to a general expansion of the gas industry, and the near future will see additional units installed to replace older equipment. The other major user of gas turbines is the electric power industry, which has traditionally installed aero-derivative engines for reserve or intermittent duty to back up the larger hydro, nuclear or coal-fired generating plants. These units, mostly installed during the 1970's, are often fired on liquid fuel (No.2 distillate) and are operated for only a few hundred hours annually. Reliability and low first cost are more important than fuel efficiency in these applications. However the availability of low-cost natural gas will result in the increasing use of turbines in high load factor combined cycles for electricity production. These will compete with the traditional sources such as coal-fired and nuclear power plants. The combined cycle arrangement supplements a simple cycle gas turbine with a secondary steam turbine, supplied with steam derived from the hot exhaust air of the primary gas turbine. A typical 35% efficient engine can thus produce additional electricity at an overall thermal efficiency of 50 percent. If a nearby large industrial complex requiring steam for process or space heating is available, additional efficiencies can be realized by cogeneration, using any excess steam from the combined cycle. Cogeneration systems will employ units across the full size range (1 to 150 MW) and represent the major growth potential for gas turbines in Canada. Approximately 1000 MW of cogen capacity is being planned for 1995/96, with possibly an additional 2000 MW to be installed by year 2000. At that time there will also be an opportunity to construct large coal gasification plants to provide medium-BTU synthetic gas to fuel very large 200 MW gas turbines. |