锅炉受热面烧损的原因.doc

<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">锅炉受热面烧损的原因</span><span lang="EN-US"><font face="Times New Roman">&lt;br&gt;&lt;br&gt;</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">锅炉受热面是将烟气中的热量传递给汽、水、空气的界面，在没有汽、水、空气这些冷却介质时，受热面的温度便会很快接近或达到烟温。煤、油正常燃烧可能达到的温度为</span><span lang="EN-US"><font face="Times New Roman">1500</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">℃～</span><chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="1600" unitname="℃"><span lang="EN-US"><font face="Times New Roman">1600</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">℃</span></chmetcnv><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">，高于钢铁的熔点，由此引起的钢材熔融、氧化称为烧损。一台</span><span lang="EN-US"><font face="Times New Roman">670t/h</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">炉为了停炉保养烘干过热器内的积水，错误的点油枪升温，由于当时水冷壁无水，不久水冷壁管被烧穿，当然这样的例子是极个别的。发生在发电厂中受热面烧损离主要是空气预热器及省煤器受热面烧损（也有过电气除尘器烧损的报导），通常称为锅炉尾部烟道再燃烧，或称二次燃烧，见图</span><chsdate wst="on" isrocdate="False" islunardate="False" day="6" month="3" year="2004"><span lang="EN-US"><font face="Times New Roman">4-3-6</font></span></chsdate><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">、图</span><span lang="EN-US"><font face="Times New Roman">4-3-7</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">。一台</span><span lang="EN-US"><font face="Times New Roman">2008t/h</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">锅炉在调试过程中先后于</span><chsdate wst="on" isrocdate="False" islunardate="False" day="13" month="10" year="1995"><span lang="EN-US"><font face="Times New Roman">1995</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">年</span><span lang="EN-US"><font face="Times New Roman">10</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">月</span><span lang="EN-US"><font face="Times New Roman">13</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">日</span></chsdate><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">和</span><span lang="EN-US"><font face="Times New Roman">11</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">月</span><span lang="EN-US"><font face="Times New Roman">20&lt;br&gt;&lt;br&gt;&lt;br&gt;</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">日发生空气预热器着火，两台空预器传热元件遭受不同程度的损坏。究其原因是炉膛内未燃烧的可燃油垢（炭黑和油滴）沉积在尾部受热面上。当温度与氧量条件合适，便自燃起火。紧急停炉后空气预热器停转，从关不严的烟、风挡板漏入空气等，常常是促进油垢着火的原因。</span><span lang="EN-US"><font face="Times New Roman">&lt;br&gt;&lt;br&gt;</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">二、防止尾部烟道再燃烧的措施</span><span lang="EN-US"><font face="Times New Roman">&lt;br&gt;&lt;br&gt;</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">锅炉尾部烟道再燃烧的主要原因是炉膛燃烧恶化，特别是启动和带低负荷期间燃烧不完全，可燃物带至锅炉尾部并在那儿聚集。防范措施包括防止可燃物沉积以及着火后的扑救两部分。通常包括，①油枪投用前应逐个试点火，点火成功后再调试自动点火，避免盲目试点火；②点火不着</span><span lang="EN-US"><font face="Times New Roman">10</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">～</span><span lang="EN-US"><font face="Times New Roman">30s</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">内停枪，最好退出油枪倒出管内存油，以免残油入炉；③用好油枪根部风，保持油枪冷却，维持油枪良好的雾化功能以控制低负荷阶段油雾的完全燃烧；④锅炉点火前，空气预热器蒸汽吹灰、水冲洗（或消防水）装置必须投用（有的水冲洗装置在预热器停转后不能覆盖全部受热面，应该改进）；⑤发现排烟温度异常升高等再燃烧现象时，要及时正确处理确保省煤器与钢结构的冷却，防止事故扩大；⑥长期低负荷燃油要考虑热碱水冲洗方案。</span><span lang="EN-US"><font face="Times New Roman">&lt;br&gt;&lt;br&gt;</font></span></p>