内置式气气换热器在SCR烟气脱硝尿素热解系统中的应用

采用内置式气气换热器的尿素热解过程具有系统简单、能耗低等优点。在详细分析内置式气气换热器技术特点的基础上，提出了采用内置式气气换热器的尿素热解方案并应用于某300MW机组的脱硝系统，将原天然气加热热解工艺改造为内置式气气换热器。改造后运行结果表明，内置式气气换热器每年可减少天然气消耗约360 000 m³（标准状态），减少运行费用90余万元，产生了良好的经济效益。

Application of Built-in Gas-to-Gas Heat Exchanger in the Urea Pyrolysis System for SCR Denifrication

The urea pyrolysis process adopting the gas-to-gas heat exchanger (GGH) is characterized with simple system and low energy consumption. In this paper, based on the detailed analysis on the characteristics of the GGH, a design of GGH for the use in the process of urea pyrolysis is proposed and applied to the retrofit of the denitration system of a 300-MW unit, in which the original pyrolysis by natural gas heating is changed with GGH. The operation results show that the design of GGH can reduce the natural gas consumption by about 360,000 m³ (standard state) and reduce the operating costs by more than RMB 900,000 yuan each year. The retrofit has obtained good economic benefits.