蜂窝陶瓷换热器的预热特性

Preheating Characteristics of Honeycomb Ceramic Heat Exchanger

摘要: 针对高温烟气和空气通过堆积蜂窝陶瓷蓄热体的换热过程，基于单孔蓄热体模型，通过数值模拟研究了流速和换向时间对预热过程中流体温度、蓄热体温度的演变过程，以及换热稳定后所达温度效率的影响。结果表明，在高温烟气进口温度1123.15 K、空气进口温度313.15 K的条件下，当换热时间为60 s时，随着迎面风速从0.75 m/s增加到1.5 m/s，放热期末空气出口温度从1083.83 K下降到1055.05 K，温度效率从95.15%下降到91.59%；当换向时间为90 s时，随着迎面风速从0.75 m/s增加到1.5 m/s，放热期末空气出口温度从1076.25 K下降到1040.37 K，温度效率从94.21%下降到89.78%。在相同的迎面流速下，换向时间越短，蓄热期烟气出口温度越小，放热期空气出口温度和温度效率越高；在相同的换向时间下，进口流速越大，蓄热期烟气出口温度越高，放热期空气出口温度和温度效率越低。蜂窝陶瓷蓄热体中换热过程的热惰性很强，需要经历较长的时间才能趋于稳定。

Abstract: Aiming at the heat exchange process of high-temperature flue gas and air passing through the stacked honeycomb ceramic regenerator, based on the single-hole regenerator model, numerical simulations were carried out to study the effects of flow velocity and switching time on the tem-perature distribution of fluid and honeycomb ceramics during the preheating process, and the ef-fect on the temperature efficiency reached after the heat exchange was stabilized. The results show that under the conditions of high temperature flue gas inlet temperature 1123.15 K and air inlet temperature 313.15 K, when the switching time is 60 s, as the face velocity increases from 0.75 m/s to 1.5 m/s, the air outlet temperature at the end of heat release period changes from 1083.83 K to 1055.05 K, and the temperature efficiency drops from 95.15% to 91.59%, when the switching time is 90 s, as the face velocity increases from 0.75 m/s to 1.5 m/s, the air outlet temperature at the end of heat release period drops from 1076.25 K to 1040.37 K, and the temperature efficiency drops from 94.21% to 89.78%. Under the same face velocity, the shorter the switching time, the lower the flue gas outlet temperature during the heat storage period, and the higher the air outlet temperature and temperature efficiency during the heat release period. Under the same switching time, when the inlet flow rate increases, the flue gas outlet temperature during the heat storage period increases, and the air outlet temperature decreases during the heat release period as well as the temperature efficiency. The thermal inertia of the heat exchange process in the honeycomb ceramic regenerator is very strong, and it takes a long time to stabilize.