Cogeneration system

Abstract

A cogeneration system ( 10 a ) of the present disclosure includes an internal combustion engine ( 21 ), a first power generator ( 22 ), a first coolant circuit ( 23 ), a first heat exchanger ( 24 ), a second coolant circuit ( 25 ), a Rankine cycle power generation apparatus ( 26 ), and an exhaust gas supply path ( 40 ). The Rankine cycle power generation apparatus ( 26 ) includes a pump ( 27 ), an evaporator ( 28 ), an expander ( 29 ), a second power generator ( 30 ), and a condenser ( 31 ). The evaporator ( 28 ) heats and evaporates a working fluid with exhaust gas from the internal combustion engine ( 21 ). The exhaust gas supply path ( 40 ) delivers the exhaust gas from the internal combustion engine ( 21 ) to the evaporator ( 28 ) without allowing the exhaust gas to exchange heat with a liquid. The condenser ( 31 ) has a flow path ( 31 a ) through which the first coolant flows and which forms a part of the first coolant circuit ( 23 ).

What is claimed is: 
     
         1 . A cogeneration system comprising:
 an internal combustion engine;   a first power generator driven by the internal combustion engine;   a first coolant circuit comprising a cooler that cools the internal combustion engine with a first coolant;   a first heat exchanger comprising a part of the first coolant circuit to cool the first coolant with a second coolant;   a second coolant circuit comprising a flow path through which the second coolant flows and which is formed in the first heat exchanger;   a Rankine cycle power generation apparatus comprising a pump that pumps a working fluid, an evaporator that heats and evaporates the working fluid pumped by the pump with exhaust gas from the internal combustion engine, an expander driven by expansion of the working fluid evaporated in the evaporator, a second power generator coupled to and driven by the expander, and a condenser that cools and condenses the working fluid expanded in the expander with the first coolant or the second coolant; and   an exhaust gas supply path that delivers the exhaust gas discharged from the internal combustion engine to the evaporator without allowing the exhaust gas to exchange heat with a liquid, wherein   the condenser has a flow path through which the first coolant flows and which forms a part of the first coolant circuit or a flow path through which the second coolant flows and which forms a part of the second coolant circuit.   
     
     
         2 . The cogeneration system according to  claim 1 , wherein the condenser has the flow path through which the first coolant flows and which forms a part of the first coolant circuit and is disposed downstream of the cooler and upstream of an inlet of the first heat exchanger for the first coolant in a flow direction of the first coolant. 
     
     
         3 . The cogeneration system according to  claim 1 , wherein
 the condenser has the flow path through which the first coolant flows and which forms a part of the first coolant circuit, and   the condenser and the cooler are disposed in parallel downstream of an outlet of the first heat exchanger for the first coolant in a flow direction of the first coolant.   
     
     
         4 . The cogeneration system according to  claim 1 , further comprising a third heat exchanger that cools the exhaust gas flowing out of the evaporator with the first coolant or the second coolant, wherein
 the third heat exchanger has a flow path through which the first coolant flows and which forms a part of the first coolant circuit or a flow path through which the second coolant flows and which forms a part of the second coolant circuit.   
     
     
         5 . The cogeneration system according to  claim 4 , wherein
 the condenser has the flow path through which the second coolant flows and which forms a part of the second coolant circuit,   the third heat exchanger has the flow path through which the second coolant flows and which forms a part of the second coolant circuit, and   the condenser, the first heat exchanger, and the third heat exchanger are disposed in order of the condenser, the first heat exchanger, and the third heat exchanger in a flow direction of the second coolant.   
     
     
         6 . The cogeneration system according to  claim 1 , further comprising:
 an air-cooling circuit having an air-cooled heat radiator; and   a switching valve disposed in the first coolant circuit or the second coolant circuit to switch between a state where the first coolant or the second coolant flowing out of the condenser flows only in the first coolant circuit or the second coolant circuit and a state where the first coolant or the second coolant flowing out of the condenser passes through the air-cooled heat radiator and returns to the condenser.