Ship cogeneration system using waste heat of LNG engine ship recovered through economizer

A ship cogeneration system using waste heat of an LNG engine ship recovered through an economizer, the ship cogeneration system comprising:

• a first organic Rankine cycle (100) configured to use high-temperature and high-pressure steam as a heat source and to use fresh water as a heat sink, the high-temperature and high-pressure steam being generated by the economizer (300) which is mounted on a side of an exhaust port of the LNG engine ship and which uses an exhaust gas, as a heat source, generated from a main engine so as to heat-exchange with water so that the high-temperature and high-pressure steam is generated, the fresh water being heat-exchanged through a seawater heat exchanger (200);
• and
• a second organic Rankine cycle (100′) configured to use a fluid as a heat source and to use the fresh water as the heat sink, the fluid being used as a heat source in the first organic Rankine cycle and then discharged, the fresh water being used as the heat sink in the first organic Rankine cycle and then discharged,
• wherein the first organic Rankine cycle comprises:
• a first evaporator (110) configured to use the high-temperature and high-pressure steam, as the heat source, generated by the economizer;
• a first turbine generator (120) configured to generate electric power by being rotated by a refrigerant that is evaporated by the first evaporator and then discharged;
• a first condenser (130) configured to liquefy the refrigerant discharged from the first turbine generator by using the fresh water, as the heat sink, heat-exchanged through the seawater heat exchanger;
• and
• a first circulation pump (140) configured to compress the refrigerant discharged from the first condenser and to provide the compressed refrigerant to the first evaporator,
• the second organic Rankine cycle comprises:
• a second evaporator (110′) configured to use the fluid as a heat source, the fluid being used as the heat sink in the first evaporator and then discharged;
• a second turbine generator (120′) configured to generate electric power by being rotated by the refrigerant that is evaporated by the second evaporator and then discharged;
• a second condenser (130′) configured to liquefy the refrigerant discharged from the second turbine generator by using the fluid as the heat sink, the fluid being used as the heat sink in the first condenser and then discharged;
• and
• a second circulation pump (140′) configured to compress the refrigerant discharged from the second condenser and to provide the compressed refrigerant to the second evaporator,
• further comprises a third heat exchanger (600) configured to heat-exchange the refrigerant discharged from the second condenser by using the refrigerant which is discharged from the first turbine generator and which has a high-temperature, the heat exchanger being configured to provide the refrigerant discharged from the second condenser and heat-exchanged to the second circulation pump (140′), and
• further comprises a third circulation pump (410) configured to circulate the fluid discharged from the second evaporator to the economizer.