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标题: 《集控值班员》理论题 [打印本页]
作者: 华电之声    时间: 2008-4-24 10:23
标题: 《集控值班员》理论题
<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">25</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;;">．轴流风机喘振有何危害？如何防止风机喘振？</span></p><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;;">答：当风机发生喘振时，风机的流量周期性的反复，并在很大范围内变化，表现为零甚至出现负值。风机流量的这种正负剧烈的波动，由于流量的波动很大而发生汽流的猛烈撞击，使风机本身产生剧烈振动，同时风机工作的噪声加剧。大容量的高压头风机产生喘振的危害很大，可能导致设备和轴承德损坏、造成事故，直接影响了锅炉的安全运行。</span></p><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;;">为防止风机喘振，可采用如下措施：</span></p><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;;">（</span><span lang="EN-US"><font face="Times New Roman">1</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;;">）保持风机在稳定区域工作。因此，管路中应选择</span><span lang="EN-US"><font face="Times New Roman">-Q</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;;">特性曲线没有驼峰的风机；如果风机的性能曲线有驼峰，应使风机一直保持在稳定区域工作。</span></p><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;;">（</span><span lang="EN-US"><font face="Times New Roman">2</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;;">）采用再循环。使一部分排出的气体再引回风机入口，不使风机流量过小而处于不稳定区工作。</span></p><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;;">（</span><span lang="EN-US"><font face="Times New Roman">3</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;;">）加装放气阀。当输送流量小于或接近喘振的临界流量时，开启放气阀，放掉部分气体，降低管系压力，避免喘振。</span></p><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;;">（</span><span lang="EN-US"><font face="Times New Roman">4</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;;">）采用适当调节方法，改变风机本身的流量。如采用改变转速、叶片的安装角等方法，避免风机的工作点落入喘振区。</span></p><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;;">（</span><span lang="EN-US"><font face="Times New Roman">5</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;;">）当二台风机并联运行时，应尽量调节其出力平衡，防止偏差过大。</span></p>
作者: zdfbzdfb    时间: 2010-4-3 20:41
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<td class="infoleft leftcolor" valign="top" rowspan="3"><span></span> <span><img style="MARGIN: 5px="5px"  0px" src="skins/Default/star/level04.gif"/></span> <span></span><br style="HEIGHT: 10px"/><span>等级：四年级</span> <span>帖子：<b class="green"><font color="#008000">28</font></b></span> <span>积分：200</span> <span>威望：0</span> <span>精华：0</span> <span>注册：<font color="#9d9d9b" size="2">2010-4-3 19:28:48</font></span> </td>
<td class="inforight" valign="top"><b style="LINE-HEIGHT: 15px; FONT-SIZE: 12px"></b>&nbsp;&nbsp; <img alt="发贴心情" src="skins/Default/topicface/face1.gif"/><font size="2"><font color="#afafaf"><font face="Arial"><span style="LINE-HEIGHT: 20px" class="font10">ost By：2010-4-3 20:40:30</span><br/><br/></font></font></font>
<div style="LINE-HEIGHT: 150%; WORD-WRAP: break-word; FONT-SIZE: 14px; OVERFLOW: hidden; WORD-BREAK: keep-all" id="textstyle_2">感谢发帖，辛苦了，谢谢分享。</div></td></tr></tbody></table>
<table style="TABLE-LAYOUT: fixed; WORD-BREAK: break-all" class="bbslist border" cellspacing="0" cellpadding="0">
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<td class="infoleft leftcolor" valign="top" rowspan="3"><span></span> <span><img style="MARGIN: 5px="5px"  0px" src="skins/Default/star/level04.gif"/></span> <span></span><br style="HEIGHT: 10px"/><span>等级：四年级</span> <span>帖子：<b class="green"><font color="#008000">28</font></b></span> <span>积分：200</span> <span>威望：0</span> <span>精华：0</span> <span>注册：<font color="#9d9d9b" size="2">2010-4-3 19:28:48</font></span> </td>
<td class="inforight" valign="top"><b style="LINE-HEIGHT: 15px; FONT-SIZE: 12px"></b>&nbsp;&nbsp; <img alt="发贴心情" src="skins/Default/topicface/face1.gif"/><font size="2"><font color="#afafaf"><font face="Arial"><span style="LINE-HEIGHT: 20px" class="font10">ost By：2010-4-3 20:40:30</span><br/><br/></font></font></font>
<div style="LINE-HEIGHT: 150%; WORD-WRAP: break-word; FONT-SIZE: 14px; OVERFLOW: hidden; WORD-BREAK: keep-all" id="textstyle_2">感谢发帖，辛苦了，谢谢分享。</div></td></tr></tbody></table>感谢楼主的发帖，辛苦了，谢谢分享。



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