下图是管式加热炉,工艺要求其出口温度恒定,现要以出口温度为被控量,以加热油料流量为操纵量,根据所给两种干扰来源,分别选取一副变量,设计相应的串级控制系统,画出工艺图,并选择阀的气开气关形式及调节器的正反作用。1）燃油流量及压力的波动是生产中的主要干扰。 2）燃油压力较稳定，生产中经常需要变换原料油。

<span lang="EN-US" style="font-size:14.0pt;font-family: 宋体;mso-bidi-font-family:&quot;Times New Roman&quot;;mso-font-kerning:1.0pt;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA">1</span><span style="font-size:14.0pt;font-family:宋体;mso-bidi-font-family:&quot;Times New Roman&quot;; mso-font-kerning:1.0pt;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN; mso-bidi-language:AR-SA">）<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539565651713f73c9c78a7314cb4bfd7ba8e680b52cb.png" alt="上传图片"></span><br/><p class="MsoNormal"><span style="font-size:14.0pt;font-family:宋体;mso-ascii-font-family: &quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;">调节阀选择气开阀，因为</span><span lang="EN-US" style="font-size:14.0pt">K_V</span><span style="font-size: 14.0pt;font-family:宋体;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family: &quot;Times New Roman&quot;">为“</span><span lang="EN-US" style="font-size:14.0pt">+</span><span style="font-size:14.0pt;font-family:宋体;mso-ascii-font-family:&quot;Times New Roman&quot;; mso-hansi-font-family:&quot;Times New Roman&quot;">”，燃油流量</span><span style="font-size: 14.0pt;font-family:宋体">↑—<span lang="EN-US">&gt;</span>流量<span lang="EN-US">F</span>↑<span lang="EN-US">, </span>所以<span lang="EN-US">K_P2</span>选“<span lang="EN-US">+</span>” ，根据负反馈原则，所以<span lang="EN-US">K_C2</span>选“<span lang="EN-US">-</span>”，流量调节器为反作用调节器；当<span lang="EN-US">F</span>↑—<span lang="EN-US">&gt;T</span>↑<span lang="EN-US">,</span>所以<span lang="EN-US">K_P1</span>选“<span lang="EN-US">+”</span>，则<span lang="EN-US">K_C1</span>选“<span lang="EN-US">-</span>”<span lang="EN-US">,</span>所以温度调节器也为反作用调节器。<span lang="EN-US"><o:p></o:p></span></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;font-family:宋体">2)</span><span lang="EN-US" style="font-size:14.0pt;mso-no-proof:yes"> &nbsp;<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539565676737e617b4c28bcf4614aea8a2205f7b2296.png" alt="上传图片"> &nbsp;&nbsp;</span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;mso-no-proof:yes">&nbsp;<o:p></o:p></span><span style="font-size: 14pt; font-family: 宋体;">调节阀选择气开阀，因为</span><span lang="EN-US" style="font-size: 14pt;">K_V</span><span style="font-size: 14pt; font-family: 宋体;">为“</span><span lang="EN-US" style="font-size: 14pt;">+</span><span style="font-size: 14pt; font-family: 宋体;">”，燃油流量</span><span style="font-size: 14pt; font-family: 宋体;">↑—<span lang="EN-US">&gt;</span>温度<span lang="EN-US">T₂</span>↑<span lang="EN-US">, </span>所以<span lang="EN-US">K_P2</span>选“<span lang="EN-US">+</span>” ，根据负反馈原则，所以<span lang="EN-US">K_C2</span>选“<span lang="EN-US">-</span>”，副温度调节器为反作用调节器；当<span lang="EN-US">T₂</span>↑—<span lang="EN-US">&gt;T₁</span>↑<span lang="EN-US">,</span>所以<span lang="EN-US">K_P1</span>选“<span lang="EN-US">+”</span>，则<span lang="EN-US">K_C1</span>选“<span lang="EN-US">-</span>”<span lang="EN-US">,</span>所以主温度调节器也为反作用调节器。</span></p><p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt"><o:p></o:p></span></p>
1）调节阀选择气开阀，因为KV为“+”，燃油流量↑—>流量F↑, 所以KP2选“+” ，根据负反馈原则，所以KC2选“-”，流量调节器为反作用调节器；当F↑—>T↑,所以KP1选“+”，则KC1选“-”,所以温度调节器也为反作用调节器。 2)      调节阀选择气开阀，因为KV为“+”，燃油流量↑—>温度T2↑, 所以KP2选“+” ，根据负反馈原则，所以KC2选“-”，副温度调节器为反作用调节器；当T2↑—>T1↑,所以KP1选“+”，则KC1选“-”,所以主温度调节器也为反作用调节器。