燃煤熱水鍋爐水動(dòng)力計(jì)算

1、1.設(shè)計(jì)數(shù)據(jù)序號(hào)名 稱符號(hào)單位計(jì)算公式數(shù)值1-1額定熱功率QMW設(shè)計(jì)給定141-2額定壓力PMPa設(shè)計(jì)給定1.01-3額定出水溫度tr設(shè)計(jì)給定1151-4額定回水溫度th設(shè)計(jì)給定701-5出回水溫差tt= trth=11570451-6循環(huán)流量Gkg/hG=0.86×106Q/t=0.86×106×14/45267.6×1032.水動(dòng)力回路3.結(jié)構(gòu)特性序號(hào)名稱符號(hào)單位下降管1回路2回路3回路4回路5回路1管子內(nèi)徑dmm253(273×10)56.5(63.5×3.5)45(51×3)123(133×5)2根 數(shù)n/

2、16628313213彎頭阻力系數(shù)1/0.10.10.10.10.20.14出入口阻力系數(shù)2/1.81.81.81.295折算摩擦阻力系數(shù)1/m0.060.350.470.146長(zhǎng)度lm3.432.391.61.462.040.57沿程阻力系數(shù)3/0.210.840.750.690.960.078總阻力系數(shù)/2.112.742.741.469下降管流通截面積fjm20.050210上升管流通截面積fsm20.16540.14470.011911截面比f(wàn)j/ (fs1+ fsc)/0.28312回路高度hm3.72.61.13.713下集箱內(nèi)徑djxmm305(325×10)1)1:2

3、0°20°59°60°140°140° 1:00.10.20.3為水轉(zhuǎn)向角度，見附圖。2)2:1.83)3=l, :d mm45(51×3)50(57×3.5)53(60×3.5)63(70×3.5)100(108×4)123(133×5)147(159×6)203(219×6)0.470.400.380.300.170.140.110.074. 水動(dòng)力計(jì)算序號(hào)名稱符號(hào)單位計(jì)算公式數(shù)值11回路上升管流速ws1m/s假設(shè)0.521回路上升管阻力Ps1PaPs

4、1=1ws12/2=2.74×103×0.52/2 34332回路上升管流速ws2m/sws2= ws1fs1/(fs2+fs3+fs4)=0.5×0.1654/0.14470.5742回路上升管阻力Ps2PaPs2=2ws22/2=2.74×103×0.572/24455上升管總阻力PsPaPs =Ps1+Ps2=343+44578865回路上升管阻力PscPaPsc=Ps78875回路上升管流速wscm/swsc =2Psc /(c)1/2=2×788/(1.46×103) 1/21.048單側(cè)回水量Gkg/h0.5 G

5、=0.5×267. 6×103133. 8×1039前管板流量Gckg/hGc =3600fscwsc=3600×103×0.0119×1.0444.55×10310單側(cè)循環(huán)水量G0kg/hG0=3600fs1ws1+ Gc =3600×103×0.1654×0.5+44.55×103342.3×10311單根下降管流量Gjkg/hGj= G0G=342.3×103133.8×103208.5×10312引射系數(shù)u/u1= Gj/ G=208.5

6、×103/133.8×1031.55813噴口內(nèi)徑dpmm取定8114噴口流通截面積fpm2fp =(/4 )dp 2=(3.14/4)×0.08125.15×10-315下集箱流通截面積fjxm2fjx =(/4 )djx 2=(3.14/4)×0.305273.0×10-316噴口流速wpm/swp= G/(3600fp)=133.8×103/(3600×103×5.15×10-3)7.2217噴口壓降PpPaPp=1.11wp2/2=1.11×103×7.222/228

7、93118引射動(dòng)壓PysPaPys=Pp( fp/ fjx)1.76+0.705 fp/( fjxfp) u21.81( fp/ fjx)(1+ u)2=28931×(5.15×10-3)/(73.0×10-3)1.76+0.705×(5.15×10-3)/(73.0×10-35.15×10-3)×1.55821.81×(5.15×10-3)/(73.0×10-3) ×(1+1.558)2215219下降管流速wjm/swj= Gj/(3600fj)=208.5×1

8、03/(3600×103×0.0502)1.1520下降管阻力PjPaPj=jwj2/2=2.11×103×1.152/2139521回路總阻力PPaP=Pj+Ps=1395+788218322校核(PysP)/P×100%=(21522183)/2183×100%1.4%5. 集箱效應(yīng)序號(hào)名稱符號(hào)單位計(jì)算公式數(shù)值1下集箱內(nèi)徑djxm 325×100.3052下集箱最大縱向流速wjxzm/swjxz= G0/3600(/4)djx2=342.3×103/3600×103×(3.14/4)

9、5;0.30521.303靜壓轉(zhuǎn)換系數(shù)A/端部引入0.84集箱靜壓下偏差PjxPaPjx=(2/3A)wjxz2/2=(2/3)×0.8×103×1.302/2450.75重位壓頭偏差PzwPa經(jīng)計(jì)算取406最小水力不均勻系數(shù)min/min =1(Pjx+Pzw)/ Ps1/2=1(450.7-40)/7881/20.697上升管最小流速wsminm/swsmin =min ws=0.69×0.50.358集箱靜壓上偏差Pjx"PaPjx"=(1/3)Awjxz2/2=(1/3)×0.8×103×1.30

10、2/2225.39最大水力不均勻系數(shù)max/max =1+(Pjx+Pzw)/ Ps1/2=1 +(225.3-40)/7881/21.1110上升管最大流速wsmaxm/swsmin =max ws =1.11×0.50.566.射流尺寸序號(hào)名稱符號(hào)單位計(jì)算公式數(shù)值1射流直徑dshmu0.5時(shí); dsh=1.55dp(1+u)=1.55×0.081×(1+1.558)0.3212校核/dsh(0.321)djx(0.305)3噴口至下降管入口距離lcmdshdjx，且u0.5時(shí)；取=45°lc=1.42dp(0.37+u)=1.42×0.08

11、1×(0.37+1.558)0.2217.高溫管板冷卻與擾動(dòng) 水冷壁前端上升管流量max Gc=1.11×44.55×103kg/h=49.45×103kg/h（考慮集箱效應(yīng)），占循環(huán)水量的百分?jǐn)?shù)為49.45×103/（342.3×103）×100%=14.4%。8.安全性校核(1)爐膛最大熱負(fù)荷:qmax1.3 ql=1.3×109=142 kW/m2 取qmax155kW/m2，dn=0.0565m，取t90 ，當(dāng)p=0.3MPa(低壓運(yùn)行)時(shí)，由文獻(xiàn)1繪制圖表1：允許最小流速ws= 0.40 m/s, 考慮角度修正=30°，放大1.05倍，ws= 0.42 m/s ，ws<wsmax，滿足安全要求。圖 1(2)爐膛最小熱負(fù)荷:qmin0.7ql=0.7×109=76.3 kW/m2 取qmin80kW/m2