燃用稻壳流化床锅炉的燃烧特性研究

The Study on Combustion Characteristics of RiceHuskFired Fluidized Bed Boiler

本文介绍了在热态流化床试验台上进行的燃用稻壳的试验结果。着火试验表明：稻壳极易着火，最低着火温度仅为３４０℃，在流化床床温达到４００℃左右时，即可投入稻壳稳定着火。着火初期挥发份析出迅速，燃烧剧烈，但燃尽时间长。燃烧试验表明：稻壳燃烧主要集中在流化床的稀相区，稀相区床温明显高于密相区。稀相区中部燃烧强度最大。合理的燃烧应具备的条件是：流化风速为１ｍ／ｓ～２ｍ／ｓ，流化数为３～７，１、２次风量配比为７∶３左右。稻壳流化床燃烧过程中，挥发份析出迅速，但焦炭很难燃尽，燃烧效率可高达９７％。试验结果为工程用的稻壳流化床燃烧锅炉设计和运行提供了理论依据和实践经验。

お? This paper reports the experimental results of ignition characteristics and burn out characteristics of rice husk in fluidized bed combustion test rig and analyzes the results.Ignition experiment shows that rice husk can be ignited easily at the lowest temperature of 340 ℃.Rice husk may be ignited well when fed into fluidized bed at the bed temperature of 400 ℃,and its devolatilization is prompt,but burn out is difficult.Combustion test shows:the combustion intensity is concentrated in dilute phase zone,so the temperature here is higher than that in the density phase zone.In our experimental conditions,the combustion intensity in middle zone of the bed is strongest.Reasonable parameter is list below,velocity 1 m/s～2 m/s,dimensions fluidization number 3～7 and air split 7∶3.Although rice husk char burns out difficultly,the combustion efficiency is still 97% high.All these results are very useful to design and operate rice huskfired fluidized bed boiler in engineering.