Recently, the first and largest 200 thousand ton / year ethylene cracking furnace with completely independent intellectual property rights achieved a successful one-off start-up and finished its performance assessment in Sinopec Zhenhai Refining & Chemical Company (ZRCC). Tianhua Institute of Chemical Machinery & Automation (Tianhua Institute) once participated in the research and development of this ethylene cracking furnace. It marks the further upgrading of China's packaged technology of ethylene independent innovation.
As one of the three project research units, Tianhua Institute is specifically responsible for the development and design of the quenching boiler system and combustion system. During the design of the critical rapid-cooling heat exchanger, the R&D personnel of Tianhua Institute adopted the most advanced linear structure which enabled the heat exchanger have advantages such as large tube diameter, low mass flow velocity, low resistance drop, low outlet temperature, low steam output, high energy saving and low consumption, and eliminate the need of mechanical coke cleaning operation. The design of key combustion system adopts the side burning and bottom burning combined heating. Fuel classification, gas recirculation and low oxygen multi-point combustion technology are used for both side burning and bottom burning. The bottom burner also adopts the air door automatic control system.
With advanced design tools and test means, Tianhua Institute's technicians make the developed quenching boiler system and combustion system meet or exceed the requirements for the guaranteed values of the process package. After the bottom burner adopts the air door automatic control system, the furnace can operate under the optimum oxygen content, which improves the heat efficiency of the furnace and reduces the labor intensity of the operator. Especially, the NOx emission of the Low NOx burners provided by Tianhua Institute is about 80mg/Nm^3, which is lower than the national environmental protection standard 100 mg/Nm^3.