A new, patented concept for a small cogeneration system is introduced in this paper. A small turbogas driven generator is inserted into the cold air duct of a condensing heating boiler for domestic use. The electric production takes place only when heating is active in winter. The turbogas exhaust and the cooling air are ingested by the burner of the boiler giving to the electric unit a nearly unitary efficiency. The generator is very small when compared to the total power of the system. The heat to electric power ratio is more than twenty. In this way it is possible to run the turbogas-generator unit always at full power. Even if the turbogas needs a biennial replacement, the economical balance of the system is very convenient. In addition, the heating boiler does not necessitate of an external electric power supply. Therefore, it will run even in case of black-out. The reliability of the original heating boiler is preserved. In fact, in case of turbogas failure, the heating boiler is identical to the traditional unit. The simultaneous production of electrical and thermal energy from a single fuel source increases efficiency and reduces greenhouse gas emissions.
Micro.cogeneration, domestic, heating boiler, micro-turbine
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