空冷器的設(shè)計(jì)講解

1、2006-3-52006-3-5 (4)有效平均溫差計(jì)算空氣出口溫度按照熱平衡的方法求取空氣的出口溫度。t=t+=35+2iV.C.p10139797.2.6*9*2.9*4*1005*1.093=64.97對(duì)數(shù)平均溫差Tm=(135t=t+=35+2iV.C.p10139797.2.6*9*2.9*4*1005*1.093=64.97對(duì)數(shù)平均溫差Tm=(13564.97)(6035)113564.971n6035=43.72溫度效率64.9735P=0.3014035溫度相關(guān)系數(shù)R=M=2.50查3.28得Ft=0.96有效平均溫差41二尸1Tm=43.72x0.96=41.97(5)傳熱面

2、積Q10139797RK-AT-358.96*41.97m=673.07m2實(shí)際選用面積余量C=FA義NA-AR義100%二193*4673.07673.07*100%=15.87%5管程壓力降管內(nèi)壓力降Pi=2ftp.Gi2/P,0*/*。4=2*0.00331*160.42/5.822*2*9/0.02/1000=26.32kpa式中：汽相分率yav=0.5(y1+y2)=0.5*(1+0.37)=0.7兩相綜合重度ptp=1/(1-yav)/pl+yav/pv)=1/(1-0.7)/638.1+0.7/3.9996)=5.822kg/m3兩相綜合粘度：Lp=ptp%y/pv+%(1-ya

3、v)/pl=5.822*0.00000987*0.7/3.9996+0.00000987*(1-0.7)/638.1=0.00000987氣相雷諾數(shù)Reg=di.G/口用=0.02*160.4/0.00000987=325030摩擦系數(shù)：ftp=0.079*Re-0.25=0.079*325030-0.25=0.00331管箱壓力降：APr=Gi2/2Ptp.Cn=160.42/2/5.822*1.6/1000=7.07kPa其中：Cn與管程數(shù)有關(guān)，當(dāng)管程數(shù)等于大于2時(shí)，取Cn=1.6管程總壓力降：APf=Api+APr=26.32+7.07=33.39kPa.管內(nèi)總壓降小于允許值。6風(fēng)機(jī)計(jì)算

4、估選風(fēng)機(jī)型號(hào)根據(jù)風(fēng)機(jī)的選擇原則，估選風(fēng)機(jī)為：F36R4型風(fēng)機(jī)4臺(tái)，葉輪直徑為3.6m.由于控制噪音的需要，葉尖速度選為50米秒，故風(fēng)機(jī)的轉(zhuǎn)數(shù)為60Vn=兀D60Vn=兀D=265轉(zhuǎn)/分兀x3.6計(jì)算全風(fēng)壓。空冷器的全風(fēng)壓由通過管束的靜壓降和風(fēng)機(jī)的動(dòng)壓頭組成。通過管束的壓力降%靜壓降：GP,=FNrmaxstB2pdrG、次1=37.86(max)-0.316(1)-0.927(1)0.315)!dSr20.026x6.610.06350.0635=37.86()0.316.(-rz)-0.927-()0.315=0.9311.95x10-50.02580.0635GmaxGmax=6.61kg

5、/m2,s2.6x26.1*4x1.093x0.528*4Pst=0.931x6x6.612x1.093=94.35pa風(fēng)機(jī)動(dòng)壓頭：U2PD=-2BRUB=JB0.785xD2xnfFVo=LBUNF=9x2.9x2.6*2=135.72m3/s67.86U=6.67m/sB0.785x3.62x2Pn=x1.093=24.31paD2全風(fēng)壓為：H=4Pst+APD=94.35+24.31=118.66pa風(fēng)機(jī)的效率n1=0.69皮帶傳動(dòng)效率n2=0.86電機(jī)的效率n3=0.95風(fēng)機(jī)的軸功率118.66*135.72*0118.66*135.72*0.5*273+350.69273+20*1.01/1000=13.3kW0-二Fn273+20l1電機(jī)功率為(H)(V)N=o-nnn123生旦.F273+20l該裝置海拔50米，F(xiàn)l=1.01N二=16.3