Production method and production device of polyethylene naphthalate

The invention provides a production method and a production device of polyethylene naphthalate. The device comprises a first ester exchange reactor, a second ester exchange reactor, a flash evaporation reactor, a first polymerization reactor, a second polymerization reactor, a first gas-liquid separation tower, a second gas-liquid separation tower, a first ethylene glycol condensation unit, a second ethylene glycol condensation unit and a third ethylene glycol condensation unit, the first ester exchange reactor internally comprises n cavities which are communicated with one another, the second ester exchange reactor internally comprises m cavities which are communicated with one another, and n and m are greater than or equal to 3; by utilizing the device, the utilization rate of reaction raw materials can be improved, and continuous production of high-viscosity PEN is realized. 本发明提供一种聚萘二酸乙二醇酯的生产方法及生产装置，该装置包括依次连通的第一酯交换反应器、第二酯交换反应器、闪蒸反应器、第一聚合反应器、第二聚合反应器以及第一气液分离塔、第二气液分离塔、第一乙二醇冷凝单元、第二乙二醇冷凝单元、第三乙二醇冷凝单元；所述第一酯交换反应器