[Post=100]<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt;"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">4.2 </span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">协调管理方面<span lang="EN-US"><p></p></span></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">1</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、合理安排检修顺序。汽封改造,低压缸<span lang="EN-US">10</span>道隔板外送加工所需时间长,要安排先揭低压缸上盖,及时吊出低压隔板,保证低压隔板外送加工的时间。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">2</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、施工过程中充分发挥业主的协调管理作用,避免工期不必要的浪费。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">3</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、提前购置了汽封间隙调整装置,并于开工前在现场安装调试完毕,保证厂家货到现场即可安装、调整,为汽封改造工作的顺利推进创造有利条件。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">4</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、高中压间轴封改造后汽封漏汽量较设计值小,预计可能引起高中压缸正胀差增大,导致机组动静碰磨,在大修过程中,从高压调节阀后的疏水母管上接出新蒸汽,必要时送到汽缸夹层,提高汽缸夹层的平均温度,减小高中压缸正胀差。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">5</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、货到现场后,安排专人对汽封块的几何尺寸进行认真复查,确保每块汽封均能正确装配到位。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt -0.1pt; TEXT-INDENT: 10pt; LINE-HEIGHT: 20pt; mso-para-margin-left: -.01gd;"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">4.3 </span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">运行方面应采取的措施<span lang="EN-US"><p></p></span></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt -0.1pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0; mso-para-margin-left: -.01gd;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">1</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、汽封改造后通流间隙较厂家设计值小,开、停机、变工况过程中极易发生动静碰磨事故,引发机组轴系振动,因此,运行方面应采取以下措施:<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">2</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、制定详细的《<span lang="EN-US">A</span>级检修后汽轮机启动措施》,严格控制各项启动参数及冲转暖机时间,并下发到各值认真学习。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">3</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">、机组冷态升速过程若振动突然增大或者缓慢增大,都应立即打闸停机,投盘车<span lang="EN-US">4</span>小时、转子临时弯曲恢复,原因分析清楚后才能再次开机,严禁降速暖机。因为对汽轮机转子来讲,摩擦可以产生抖动、涡动等现象,但实际有影响的主要是转子热弯曲。动静摩擦时圆周上各点的摩擦程度是不同的,由于重摩擦侧温度高于轻摩擦侧,导致转子径向截面上温度不均匀,局部加热造成转子热弯曲,产生一个新的不平衡力作用到转子上引起振动。根据转速的高低,振动特征分两种情况:<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><b><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">a.</span></b><b><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">转速低于临界转速时的摩擦振动<span lang="EN-US"><p></p></span></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">如图中,转子原来的不平衡为<span lang="EN-US">OA</span>,振动高点<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt; tab-stops: 336.0pt;"><line id="_x0000_s1027" from="270pt,7.8pt" to="297pt,31.2pt" style="Z-INDEX: 2; LEFT: 0px; POSITION: absolute; TEXT-ALIGN: left; flip: x;"><stroke endarrow="block"></stroke></line><oval id="_x0000_s1026" style="MARGIN-TOP: 0px; Z-INDEX: 1; LEFT: 0px; MARGIN-LEFT: 261pt; WIDTH: 81pt; POSITION: absolute; HEIGHT: 78pt; TEXT-ALIGN: left;"><textbox style="mso-next-textbox: #_x0000_s1026;"><table cellspacing="0" cellpadding="0" width="100%"><tbody><tr><td style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent;"><div><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="mso-spacerun: yes;"><font face="Times New Roman"> </font></span><span style="FONT-FAMILY: MingLiU;">ω</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman"><span style="mso-spacerun: yes;"> </span>O</font></span></p></div></td></tr></tbody></table></textbox></oval><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">为<span lang="EN-US">H</span>,由于滞后角小于<span lang="EN-US">90°</span>,振动高点<span lang="EN-US">H</span>是摩擦<span lang="EN-US"><span style="mso-tab-count: 1;"> </span>A<p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt;"><line id="_x0000_s1031" from="333pt,0" to="378pt,23.4pt" style="Z-INDEX: 6; LEFT: 0px; POSITION: absolute; TEXT-ALIGN: left;"></line><line id="_x0000_s1028" from="297pt,0" to="333pt,23.4pt" style="Z-INDEX: 3; LEFT: 0px; POSITION: absolute; TEXT-ALIGN: left; flip: y;"><stroke endarrow="block"></stroke></line><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">重点,该点温度高于对面一侧,受热弯曲的影响<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt; tab-stops: 385.5pt right 415.3pt;"><line id="_x0000_s1030" from="297pt,7.8pt" to="378pt,7.8pt" strokeweight=".5pt" style="Z-INDEX: 5; LEFT: 0px; POSITION: absolute; TEXT-ALIGN: left;"><stroke endarrow="block"></stroke></line><line id="_x0000_s1032" from="333pt,7.8pt" to="378pt,31.2pt" style="Z-INDEX: 7; LEFT: 0px; POSITION: absolute; TEXT-ALIGN: left; flip: y;"></line><line id="_x0000_s1029" from="297pt,7.8pt" to="333pt,31.2pt" style="Z-INDEX: 4; LEFT: 0px; POSITION: absolute; TEXT-ALIGN: left;"><stroke endarrow="block"></stroke></line><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">在此方向产生一个热不平衡<span lang="EN-US">OH</span>, <span lang="EN-US">OH </span>与<span lang="EN-US">OA</span>合<span lang="EN-US"><span style="mso-tab-count: 1;"> </span>A1<span style="mso-tab-count: 1;"> </span><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">成为一个新的不平衡<span lang="EN-US">OA<sub>1</sub></span>。<span lang="EN-US">OA<sub>1</sub></span>较原不平衡 <span lang="EN-US">OA<p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt; tab-stops: 337.5pt;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">逆转了一个角度并且大于 <span lang="EN-US">OA</span>,造成动静摩擦进<span lang="EN-US"><span style="mso-tab-count: 1;"> </span>H<p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">一步加剧,形成恶性循环,转子弯曲越来越大,<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 20pt;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">很可能造成大轴弯曲事故。<span lang="EN-US"><span style="mso-tab-count: 1;">
</span><span style="mso-spacerun: yes;"> </span></span>低于临界转速的动静摩擦振动<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 23.6pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 1.96;"><b><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">b.</span></b><b><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">工作转速时的摩擦振动<span lang="EN-US"><br/></span></span></b><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;"> 目前,汽轮发电机组的工作转速一般都高于各转子一阶临界转速,而低于二阶临界转速,工作转速下二阶不平衡与其引起的振动之间的滞后角仍小于<span lang="EN-US">90°</span>,如果摩擦发生在对二阶不平衡比较敏感的区段,如转轴的端部,激起了比较大的二阶不平衡分量,那么仍可能发生比较严重的摩擦振动。<span lang="EN-US"><br/></span> 如果摩擦引起的热弯曲与原不平衡反相,则振动呈减小趋势,一段时间后摩擦消失,动静接触点脱离,径向温差减小,振动恢复原状,此时在原不平衡作用下又会发生摩擦,如此反复,汽封显得相对比较<span lang="EN-US">“</span>耐磨<span lang="EN-US">”</span>,振幅发生时间长、波动幅度大,<span lang="EN-US"><br/><span style="mso-spacerun: yes;"> </span></span>由此可见,在机组转速低于一阶临界转速时发生振动,采用降速暖机以期减小机组振动的方法是不对的,正确的做法是立即打闸停机,连续盘车至转子完全恢复原始弯曲值时重新启机。<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt -0.1pt; LINE-HEIGHT: 20pt; mso-para-margin-left: -.01gd;"><b><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;"><span style="mso-spacerun: yes;"> </span><span style="mso-spacerun: yes;"> </span></span></b><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">总之,只要我们付出<span lang="EN-US">100</span>%的努力,接触式汽封的改造风险是可以避免的。<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体;">5 </span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体;">改造后机组的运行情况<span lang="EN-US"><p></p></span></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><chsdate wst="on" isrocdate="False" islunardate="False" day="4" month="10" year="2005"><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">2005</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">年<span lang="EN-US">10</span>月<span lang="EN-US">4</span>日</span></chsdate><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">8</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">:<span lang="EN-US">50</span>分,#<span lang="EN-US">8</span>机开始冲转,现场听音检查发现高压后、中压后轴封处有金属磨擦的声音,中压后轴封处的磨擦声较高压后后轴封处大,升速过临界过程中轴振变化平稳,动静磨擦未引发大的轴系振动,到<span lang="EN-US">3000r/min</span>定速后,#<span lang="EN-US">2</span>轴振<span lang="EN-US">X</span>方向最大达<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".08" unitname="mm"><span lang="EN-US">0.08mm</span></chmetcnv>,其余轴振均小于<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".05" unitname="mm"><span lang="EN-US">0.05mm</span></chmetcnv>。机组并网带负荷后#<span lang="EN-US">2</span>轴振不稳定,随工况变化而上下波动,最大达<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="True" sourcevalue=".095" unitname="mm"><span lang="EN-US">0.095 mm</span></chmetcnv>。到目前为止,轴系振动共发生了三次大的波动,从<chsdate wst="on" isrocdate="False" islunardate="False" day="9" month="10" year="2005"><span lang="EN-US">10</span>月<span lang="EN-US">9</span>日</chsdate>上午最后一次波动后,振动已趋于稳定,#<span lang="EN-US">2</span>轴振<span lang="EN-US">X</span>方向最大达<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".09" unitname="mm"><span lang="EN-US">0.09mm</span></chmetcnv>,其余轴振均小于<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".05" unitname="mm"><span lang="EN-US">0.05mm</span></chmetcnv>。<b style="mso-bidi-font-weight: normal;"><span lang="EN-US"><p></p></span></b></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 20pt; mso-char-indent-count: 2.0;"><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体;">从其它指标上看,高中压缸绝胀、胀差、低压缸胀差、推力瓦温度与改造前相比差别不大。相似工况下,高压内缸内外壁温差较改造前低<span lang="EN-US">8</span>~<span lang="EN-US">10</span>℃,一段抽汽温度较改造前低<span lang="EN-US">4</span>~<span lang="EN-US">5</span>℃,证明改造后轴封漏汽较以前小,汽封改造后经济性方面的定量指标待做热力试验确定。<span lang="EN-US"><p></p></span></span></p>[/Post] |