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 an 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 a 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 a 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 a heat sink, heat-exchanged through the seawater heat exchanger;
• and
• a 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 a 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 a heat sink, the fluid being used as a heat sink in the first condenser and then discharged;
• and
• a 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 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 circulation pump (140′), and
• further comprises a circulation pump (410) configured to circulate the fluid discharged from the second evaporator to the economizer.