1、2006-3-52006-3-5 (4)有效平均溫差計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，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)機計算

4、估選風(fēng)機型號根據(jù)風(fēng)機的選擇原則，估選風(fēng)機為：F36R4型風(fēng)機4臺，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)機的轉(zhuǎn)數(shù)為60Vn=兀D60Vn=兀D=265轉(zhuǎn)/分兀x3.6計算全風(fēng)壓。空冷器的全風(fēng)壓由通過管束的靜壓降和風(fēng)機的動壓頭組成。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)機動壓頭：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)機的效率n1=0.69皮帶傳動效率n2=0.86電機的效率n3=0.95風(fēng)機的軸功率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