第5章 热工控制对象动态特性分析

1、Q1Q Q1 1FdhdtQQ)(21010Q0000020hQ02211QQQQhh21QQdtdhFKQ 1KSRhQ 2hQ 2SSSRKhdtdhFRdtdhFRhK（放大系数）时间常数SSRKKFRT)(1)()(TSKssHKhdtdhT传函为则有sTsKsHt001)()时的阶跃响应为（当TsCsCsTsTKsH11)(21000201)11(KTTKCKC)1 ()()111()(100tTeKthTssKsH0)(Kh0)(hK稳态值以起始稳态为准的最后控制阀开度阶跃变化)(0h)(h0)1)()1 ()(110tTtTeheKth)(632. 0632. 0)(0hKThT

2、hTKdttdht)()(00)(h0)()(tdttdhhTdhd)(1)(000是表示自衡能力的说明KKKh0max)(dtdhTKdtdhdtdhtt0max0)()(TKTK00则KTKKT111和dhdGC FdhdG FdhFdhdhdGCCRFRTssdGFdh1FRTKRKTKdtdhsst00FKFRKRdtdhsst000则为水槽液位）为出水量，（hQdQdhRs22表示。tQh2stthQQhR1122sssRKK0)(Kh)(h原因是：,FRTs)(101010起始斜率相同tTtTsstTeFKeFRRKeTKdtdh0)(sRKh)(hKQKQ101000000201

3、0hQQ0tt 0tt 00,022QQ所以KQdtdhFQQdtdhF121得FKdtdh0tFKdtFKth00)(0积分环节称为飞升时间，则令sTssHKFTsFKssHsFKssHaa1)()(1)()()()(000)()(aaaaaTtaaTKTKThKTFKFTtFKThTTa代入上式得即其中时，当0aTatTFKFKdtdh10000FKdtdhRKhdtdhFRss和sR01sR0111ssaaRRTT或FKKFTa或放大系数时间常数KTTsKsG1)(0)0()(CCK0111)(63. 0)(ttTtcty，则的时间延迟时间scesTKsG1)(简单，精度低。0)0()(

4、ccK0000102012100)()( 1)( 1 )()111 ()()1()(11)(1)(KcettKtceTsKsCKsTKCKCeTsCsCsCesTsTKsesTKsCesTKsGcccTtTtcTscscsccscsctettcctctccTt,1,0)()()()(*则和求两边取对数得则cccTtTtTtTtTtcTttcTttcetceetcetccccc)(1ln)(1ln-)(1)(11)(1)(2*21*12*1*2*1*2121)(263. 0)(*39. 0)(*)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln122121121221221

5、1ttTtctctctcttTtctcTtttcTttcTtccccc代入212112122121211221111221121121121121111112)4943. 09416. 0(4473. 019416. 04943. 09416. 04943. 069. 0ln63. 0ln39. 0ln63. 0ln63. 0)(*39. 0)(*)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)(*1ln)()(*1ln)(*1ln)(*1ln)()(*1ln)(*1lntttttttttctct

6、ctctcttcttctctcttcttctcttctctcttttctctctttTtcTttcTtccc代入将代入将) 1)(1()(21sTsTKsGtTtTtTtTeTTTeTTTctctcKceTTTeTTTKtcTsKTTTTsKTTTsKsCKTTTCKTTTCKCTsCTsCsCsTsTsTTKsGsRsC212111221121*11221121212211211223121212312121211)()()()()1 ()(1111)(111)1)(1()()()(PPPPtTtTtTtTtTtTeTTeTTTeTTeTTTdttcdeTTeTTdttdcdttcd2121

7、21112112111211212*2112112*2*21)(101)(1)(11)(0)(令212121212121212121122121)11(lnlnln11)()(21TTTTTTtTTtTTTTTTtTtTTTTTTTTTepppptTtTpp)()()(121ln2112121122ln1122ln1221*2112212121212122121211TTeTTTTTTTTTTeTTTeTTTtcPBTTTTTTTTTTTTTTTTTTTTTTp注：线段)()(1)(1)(111)()(122121122121212122212121121211221122112ln112ln

8、112*TTTTTTTTTTTTTTTTTTTTTTTTTTppTTTTTTTTTTTTTTeTTeTTtctgtgtc为拐点处斜率：)()(1)()(;1221211221212121122112121122TTTTTTTTTTTTpTTTTTTTTTTTTTTTTBCtgtAEtgPBBC由图知：2112212221211221212121121212)(1)()()()()(121122121122121TTTTTTTTTTTTBCTTTTTTTTTTTTBCTTTTTTTTTTTTTTTTT得）分子分母同除以（得分子分母同乘)()()(ln()1)(1()()(1)ln(21212112121211221211121)ln(112112121212121212112212121TTTTTTTTTTTTTTTTTTTTTeTTTTTTTTTTTTTTTTTTTTTTTTAE注：关系表与21TTAE值。求得定由实测解方程组值；对应的关系查表得与根据值；及做切线得过拐点方法：确定212121212121)(TTAEkTTTTBCTTAETTAEAEBCPTT02