Abstract: A cogeneration system including an engine, which drives a generator to generate electricity, a cooling/heating unit, which includes at least one compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, to establish a heat pump type refrigerant cycle, and a refrigerant over-heating unit to supply heat of cooling water used to cool the engine to a suction-side refrigerant line of the compressor of the cooling/heating unit, and to supply heat of exhaust gas discharged from the engine to the suction-side refrigerant line of the compressor and to a discharge-side refrigerant line of the compressor. In accordance with the cogeneration system, it is possible to maximize absorption of the waste heat of the engine while preventing compressor malfunction, and thus, to increase the refrigerant condensing temperature of the indoor heat exchanger. Thus, an enhancement in heating performance is achieved.

Abstract: A cogeneration system including an engine, which drives a generator to generate electricity, a cooling/heating unit, which comprises at least one compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, to establish a heat pump type refrigerant cycle, and an exhaust heat consuming heating unit to supply heat of exhaust gas discharged from the engine to a heat exchanging zone of the indoor heat exchanger of the cooling/heating unit, and thus, to heat a confined space. Since waste heat generated from the engine is directly used in the cooling/heating unit, an enhancement in indoor heating efficiency is achieved.

Abstract: A cogeneration system including a pre-heater to pre-heat outdoor air blown toward the outdoor heat exchanger during a heating operation of a heat pump type air conditioner, an auxiliary evaporator to evaporate a refrigerant emerging from the outdoor heat exchanger during the heating operation of the heat pump type air conditioner, and waste heat recovering means to transfer waste heat of the engine to at least one of the pre-heater and the auxiliary evaporator. The cogeneration system exhibits a high energy efficiency.