This invention provides a
system and method for
cogeneration of building heat and
electric power and that efficiently interfaces a warm
air heating system with a liquid-cooled
electric power generator. The
system and method utilizes an
electric generator that is rated at near the time-averaged
electric power consumption for the building. This generator is operated as the priority source of heat for the building, but normally only when there is a demand for heat in building. In this manner, the generator can run to generate a significant part of the building's electric power but in a manner that is typically supplemented in variable quantities by power from a public
power grid. The
heat output is directed via a liquid
coolant circuit on the generator, as needed, to the warm
air heating unit for the building. The warm
air heating unit blows return air through a cabinet and out to the supply duct(s). The warm liquid
coolant is directed through a primary
heat exchanger in the cabinet. The air is passed over this primary
heat exchanger to provide heat to the building. When heat from primary
heat exchanger is insufficient to heat the building fully, an auxiliary heater, operated typically by burning fuel, supplements the heat through one or more auxiliary heat exchangers arranged in line along the
airflow path with the primary heat exchanger. The blower that directs the
airflow is controlled variably in speed to create the most efficient use of electric power by the blower and a desirable heated air delivery temperature.