[转帖]流化床锅炉爆燃原因分析
<P align=center><STRONG><SPAN>流化床锅炉爆燃原因分析</SPAN></STRONG></P><STRONG><SPAN></SPAN></STRONG><SPAN><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p><P class=MsoNormal><B><SPAN><FONT face="Times New Roman">1 </FONT></SPAN></B><B><SPAN>可燃气体爆燃</SPAN></B><B><SPAN><o:p></o:p></SPAN></B></P>
<P class=MsoNormal><SPAN><SPAN><FONT face="Times New Roman"> </FONT></SPAN></SPAN><SPAN>为防止炉膛内正压物料泄漏</SPAN><SPAN><FONT face="Times New Roman">,CFB</FONT></SPAN><SPAN>锅炉采用膜式水冷壁结构</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>炉膛封闭严密。正常燃烧过程中</SPAN><SPAN><FONT face="Times New Roman">, </FONT></SPAN><SPAN>床上热物料的可燃成份约占</SPAN><SPAN><FONT face="Times New Roman">3%</FONT></SPAN><SPAN>～</SPAN><SPAN><FONT face="Times New Roman">5%</FONT></SPAN><SPAN>。在一些应急情况下</SPAN><SPAN><FONT face="Times New Roman">,CFB</FONT></SPAN><SPAN>锅炉可进入临时压火状态</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>压火时间甚至能达到</SPAN><SPAN><FONT face="Times New Roman">24h</FONT></SPAN><SPAN>。压火时整个锅炉处于封闭状态</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>床体物料温度保持在</SPAN><SPAN><FONT face="Times New Roman">900℃</FONT></SPAN><SPAN>左右</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>炉内为缺氧氛围，此时物料中的大量碳会缺氧氧化生成</SPAN><SPAN><FONT face="Times New Roman">CO</FONT></SPAN><SPAN>；当压火时间过长床温下降时</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>要在床体上添加高挥发份的烟煤维持床温</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>高温下烟煤的挥发分析出</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>增加了炉膛中可燃气体的浓度。因此长时间的压火</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>使得在烟道、风室、风道内聚集了较高浓度的可燃气体。锅炉热态启动时</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>引风机的启动能排除炉膛和烟道内的部分可燃气体</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>但是由于床料的阻隔</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>风室及风道内的气体被引风机抽出的极少</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>当一次风机启动时</SPAN><SPAN><FONT face="Times New Roman">, </FONT></SPAN><SPAN>如果风道、风室内还保持有较高浓度的可燃气体，就会推动风室及风道内的可燃气体流向床体，如果可燃气体和一次风中形成的混合气体达到爆炸浓度</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>遇到</SPAN><SPAN><FONT face="Times New Roman">900℃</FONT></SPAN><SPAN>的高温物料时就会引发爆燃。</SPAN><SPAN><o:p></o:p></SPAN></P>
<P class=MsoNormal><B><SPAN><FONT face="Times New Roman">2 </FONT></SPAN></B><B><SPAN>残存点火油引起的爆燃。</SPAN></B><B><SPAN><o:p></o:p></SPAN></B></P>
<P class=MsoNormal><SPAN><SPAN><FONT face="Times New Roman"> </FONT></SPAN></SPAN><SPAN>采用床下点火的</SPAN><SPAN><FONT face="Times New Roman">CFB</FONT></SPAN><SPAN>锅炉</SPAN><SPAN><FONT face="Times New Roman">,,</FONT></SPAN><SPAN>点火不成功时会有一部分点火油沉积在风室内，如果点火吹扫时间不够或残油处理不当</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>再次点燃时</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>就可能造成油气爆燃。</SPAN><SPAN><o:p></o:p></SPAN></P>
<P class=MsoNormal><B><SPAN><FONT face="Times New Roman">3 </FONT></SPAN></B><B><SPAN>尾部积灰可燃物引起爆燃</SPAN></B><B><SPAN><o:p></o:p></SPAN></B></P>
<P class=MsoNormal><SPAN><SPAN><FONT face="Times New Roman"> </FONT></SPAN></SPAN><SPAN>锅炉运行过程中</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>尾部烟道会产生大量积灰</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>尤其是在水平烟道部位更为严重。</SPAN><SPAN><FONT face="Times New Roman">CFB</FONT></SPAN><SPAN>锅炉的积灰含碳量较高，某些调整不好的锅炉甚至高达</SPAN><SPAN><FONT face="Times New Roman">20%</FONT></SPAN><SPAN>以上</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>在由可燃气体引燃的情况下</SPAN><SPAN><FONT face="Times New Roman">,</FONT></SPAN><SPAN>积灰中的碳粉能够产生爆燃。</SPAN><SPAN><o:p></o:p></SPAN></P>
<P class=MsoNormal><B><SPAN><FONT face="Times New Roman">4. </FONT></SPAN></B><B><SPAN>入炉煤水分过大引起爆燃</SPAN></B><B><SPAN><o:p></o:p></SPAN></B></P>
<P><SPAN><SPAN> </SPAN></SPAN><SPAN><FONT face=宋体>正常运行的</FONT></SPAN><SPAN>CFB</SPAN><SPAN><FONT face=宋体>锅炉，在入炉煤水分突然剧增的状态下，炉膛中部的锥形缺氧区会形成较高浓度的水煤气，当这部分水煤气处于爆炸浓度范围内时，会形成爆燃，这在</FONT></SPAN><SPAN>135MWe</SPAN><FONT face=宋体><SPAN>和更小容量的锅炉上都曾出现过。</SPAN><SPAN><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><SPAN><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></SPAN></P>
<P align=center></o:p></SPAN> </P> 学习了，，。，， 入炉煤水分过大引起爆燃，这个不清楚，能专门介绍下吗？ 想去看看！怎么成这个样子了？1 都是乱码呀。 锅炉启动一定要进行大风量的吹扫，一旦点火不成功，也要进行吹扫，防止可燃气体聚集爆燃。 若果是热态启动，更应注意风机的启动顺序，加大氧量的监视，严禁缺氧下启动风机，CO可燃气体爆燃。 怎么看啊！乱码了！ 这么了，看不了是乱码？
页:
[1]