Abstract:

The ceramic regenerative air preheater uses corrosion-resistant honeycomb ceramics as the heat accumulator, breaks through the dew point corrosion barrier, and deeply recovers the waste heat of the fired heater flue gas. Application examples show that energy saving targets for fired heaters with exhaust gas temperatures below 90 ℃ and thermal efficiencies greater than 95% can be achieved. Exhaust gas temperature is adjustable online, which can be controlled within the target range of 70～90 ℃, and can dynamically match the load change of the fired heater and the seasonal change of environmental temperature. The 8-way reversing damper can ensure the synchronous commutation of flue gas and air, with intrinsic safe, “zero leakage” and low-frequency. The annual commutation frequency is about 66,000 times when switch time is 480 s. Multiple 8-way reversing dampers are arranged in parallel, and are automatically sequenced controlled by DCS or PLC. The new example shows that the exhaust gas temperature of the working group ceramic regenerative air preheater dynamically changes in the range of 47～57 ℃ when switch time is 480 s, crossing the acid dew point of 100 ℃ and the water dew point of 55 ℃.

Key words: fired heater, dew point corrosion, honeycomb ceramics, regenerative air preheater, 8-way damper, air temperature after preheating, exhaust gas temperature, switch time

摘要：

陶瓷蓄热式空气预热器以耐腐蚀的蜂窝陶瓷为蓄热体，突破露点腐蚀障碍，深度回收加热炉烟气余热。应用案例表明：可以实现排烟温度低于90℃、热效率大于95%的加热炉节能目标。排烟温度在线可调，可控制在70～90℃的目标范围内，可以动态匹配加热炉的负荷变化和环境温度的四季变化。八通换向挡板可确保烟气和空气的同步、低频换向，换向时间为480 s时，年换向频率约6.6万次，实现零泄漏。多个八通换向挡板并联布置，由DCS(集散控制系统)或PLC(可编程逻辑控制器)自动顺序控制。新实施例显示：换向时间为480 s时，工作组陶瓷蓄热式空气预热器排烟温度在47～57℃区间内动态循环变化，穿越了100℃的酸露点和55℃的水露点。

关键词: 加热炉, 露点腐蚀, 蜂窝陶瓷, 蓄热式空气预热器, 八通换向挡板, 空气预热温度, 排烟温度, 换向时间