Patent ID: 8093733

Claim:
A cogeneration system having a generation unit equipped with a generator adapted to be connectable to an AC power feed line between a commercial power network and an electrical load, and an internal combustion engine for driving the generator, comprising: a hot water unit including: a first flow channel that connects a water supply source with a thermal load to supply water from the water supply source to the thermal load; a heat exchanger that is installed in the first flow channel and exchanges heat between the water flowing through the first flow channel and coolant of the engine; a first electromagnetic solenoid valve that is installed in the first channel and regulates flow rate of the water heated by the heat exchanger; a second flow channel connected to the first flow channel to form a bypass between the heat exchanger and the first solenoid valve; a boiler that is installed in the second flow channel and heats water flowing through the second flow channel; and a second electromagnetic solenoid valve that is installed in the second flow channel and regulates flow rate of the water to be heated by the boiler; and an electronic control unit that detects at least one of a temperature of the coolant of the engine and a temperature of water at a joint where the first and second flow channels are joined and controls operation of the first and second solenoid valves based on the detected temperatures.