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Products > Combined Cycle > THERMOFLEX > Sample 4

Reciprocating Engine with Cogeneration of Steam

Besides icons that cover the entire GT PRO gas turbine library, THERMOFLEX also shares the RECIPRO library of over 350 reciprocating engine specs from major vendors including CAT, Cummins, Deutz, Jenbacher, MTU, Wartsilla, Waukesha. This model uses a gas fired reciprocating engine in a small CHP plant to generate process steam by capturing heat from the engine cooling loop and from the exhaust stream. Process steam at 75 psia/5.2 bar is generated directly by heat recovery from the exhaust gasses, but the cooling jackets can only make low-pressure steam by flashing a percentage of the hot, pressurized cooling water in a flash tank. This low-pressure steam is then compressed in a steam compressor, which consumes about 8% of the engine's power, but allows useful steam output from the plant to be increased by about 80%. The steam compressor consumes electric power, thereby reducing the electric efficiency from 42.8% for the engine alone, to 39.1% for the whole plant. However, this small plant has a high total (CHP) efficiency of 85.5% and provides 2.5MW of net electric output.