1、自然循環(huán)熱水鍋爐水動(dòng)力計(jì)算例題A1鍋爐規(guī)范 TOC o 1-5 h z 額定供熱量Qsup：7.0MW額定工作壓力P:1.0MPa回水溫度tbac.w：70 C供水溫度thot.w :115c鍋爐為雙鍋筒、橫置式鏈條爐，回水進(jìn)入鍋筒后分別進(jìn)入前墻、后墻、兩側(cè)墻和對(duì)流管束回路中，兩側(cè)水冷壁對(duì)稱布置，前墻和后墻水冷壁在3.2m標(biāo)高下覆蓋有耐火涂料層，如圖A -1所示。圖A-1鍋爐簡(jiǎn)圖A2鍋爐結(jié)構(gòu)特性計(jì)算A2.1前墻回路上升管劃分為三個(gè)區(qū)段，第I區(qū)段為覆蓋有耐火涂料層的水冷壁管， 第R區(qū)段為未覆蓋有耐火涂料層的水冷壁管，第田區(qū)段為爐頂水冷壁（圖A-2）A2.2后墻回路上升管劃分為二個(gè)區(qū)段，第I區(qū)段為

2、覆蓋有耐火涂料層的水冷壁管， 剩下的受熱面作為第n區(qū)段（圖A-3）。A2.3側(cè)墻水冷壁回路上升管不分段（圖A-4）A2.4對(duì)流管束回路不分段，循環(huán)高度取為對(duì)流管束回路的平均循環(huán)高度，并設(shè)對(duì) 流管束高溫區(qū)為上升區(qū)域(共7排)，低溫區(qū)為下降區(qū)(共6排)。對(duì)流管束共 有347根，相應(yīng)的上升管區(qū)域根數(shù)為191根，下降管區(qū)域根數(shù)為1561g(ffl A-5)。對(duì)流管束總的流通截面積 Ao為：Ao=347 義 0.785 義 0.0442 = 0.5274 m 2下降管區(qū)域流通截面積 Adc為：Adc =156 義 0.785 義 0.0442 = 0.2371 m 2下降管區(qū)域流通截面積與對(duì)流管束總的流

3、通截面積比Adc / Ao為：Adc _ 0.2371K = 0.5274=0.450其值在推薦值(0.44 0.48)的范圍內(nèi)圖A-2前墻水冷壁回路圖A-3后墻水冷壁回路圖A4側(cè)墻水冷壁圖A5對(duì)流管束回路A2.5結(jié)構(gòu)特性數(shù)據(jù)如表A-1所示表A-1結(jié)構(gòu)特性數(shù)據(jù)截面積各區(qū)段長(zhǎng)度各區(qū)段高度各區(qū)段彎頭度數(shù)及個(gè) 數(shù)回 路 名 稱回 路 元 件管徑X壁厚管 子 根 數(shù)單根 管子整個(gè) 回路與上 升管 截面 積比Inm總長(zhǎng) 度Inm總高 度InmD XnAAo/1112131h1h2h3h-n-n-nmm xmm/m2m2/mmmmmmmm(o )(o )(0 )前 墻 水上 升管51 X3.5180.00

4、1520.02741.52.564.18.161.022.461.214.6955 o-275-1冷壁下 降 管108 X420.007850.01570.579.124.6965 o-150 o -125 o -1后墻水上 升 管51 X3.5180.001520.02746.142.999.133.012.425.43128-150 o160 -1冷壁下 降 管108 X420.007850.01570.578.165.4330 130 -1側(cè) 墻 水上升管51 X3.5140.001520.02135.005.00冷壁下 降 管108 X420.007850.01570.748.345.

5、0075 1對(duì) 流上升管51 X3.51910.001520.29034.103.7030 o2管束下 降 管51 X3.51560.001520.23710.824.103.7030 2A3各循環(huán)回路局部阻力系數(shù)計(jì)算各循環(huán)回路局部阻力系數(shù)計(jì)算結(jié)果如表A-2所示表A-2各循環(huán)回路局部阻力系數(shù)計(jì)算序號(hào)名稱符 號(hào)單 位計(jì)算公式及數(shù)據(jù)來(lái)源前墻水冷壁后墻水冷壁側(cè)墻水冷壁對(duì)流管束InmInF管1入口阻力系 數(shù)in表 2-4、表 2-60.70.70.70.52出口阻力系 數(shù)out表2-71.01.01.11.03彎頭阻力系 數(shù)bb =K o0.340.20.410.180.244總局部阻力 系數(shù)rs.l

6、crs.lc = in+ out+ b1.041.21.111.181.81.74下降管1入口阻力系 數(shù)in表2-40.50.50.50.52出口阻力系 數(shù)out表2-71.11.11.11.03彎頭阻力系 數(shù)bb =K o0.480.250.210.244總局部阻力 系數(shù)dc.lcdc.lc = in+ out+ b2.081.851.811.74A4各受熱面吸熱量分配qav 為 107.67kW/m 2,爐膛出口溫=220 C ,對(duì)流管束總的受熱面積Ars=138.1m2),對(duì)流管束總吸熱量為3109.46kW(其中吸收來(lái)自爐膛的輻射吸熱量為 輻射熱被對(duì)流管束高溫區(qū)(即上升管區(qū)域)均勻吸收

7、。設(shè)對(duì)流管束高溫區(qū)與低溫區(qū)分界處的煙氣溫度為 lg( out .f - t) - lg( out .conv - t) AoQfr =320.5kW)。設(shè)來(lái)自爐膛的(C),則為:lg( out.f -t)-lg( -t)(A-1)由熱力計(jì)算得，爐膛水冷壁平均熱流密度 度為out.f = 893.6 C ,對(duì)流管束煙氣出口溫度 為Ao=250.9m2,(其中上升管區(qū)域受熱面積為式中：t對(duì)流管束內(nèi)工質(zhì)平均溫度， ct 可取為:t=0.5(t hot.w + tbac.w )= 0.5 乂 (115+70) = 92.5 ( C) 則由式(A-1)得：lg( 893 .6 -92 .5)-lg( 2

8、20 - 92.5 ) _ 250 .9lg( 893 .6 -92 .5 )-lg(-92 .5) - 138.1求得:=383.8 ( C)則對(duì)流管束下降管區(qū)域所吸收的熱量 Qcd為:-outconv383.8-220(kW)Q = Qoutconv =(3109.46-320.5) X=678.19Cd outf - out.conv893.6-220上升管區(qū)域總吸熱量Qcr：Qcr = Q - Q cd=3109.46-678.19=2431.27 (kW)表A-3給出了各受熱面熱量分配結(jié)果。表A-3各受熱面熱量分配結(jié)果名 稱符 號(hào)單 位前墻水冷 壁后墻水冷 壁側(cè)墻水冷壁對(duì)流管束下降管

9、吸熱QdckW000678.19上升管吸熱量第I區(qū)QikW37.24227.21每側(cè)862.11兩側(cè)1724.222431.27第II區(qū)Q2kW444.89912.71第田區(qū)Q3kW521.27A5各回路水循環(huán)計(jì)算A5.1各回路下降管入口水溫的假設(shè)=0.5(thot.w + tbac.w ) = (115+70)/2 = 92.5 ( C)A5.2各回路中循環(huán)流量的假設(shè)假設(shè)四個(gè)回路中循環(huán)流量 Gi、G2、G3所對(duì)應(yīng)的上升管中的流速約為:G1對(duì)應(yīng)上升管水速 Wrs.1約為0.15 (m/s)G2 對(duì)應(yīng)上升管水速 Wrs.2約為0.20 (m/s)G3 對(duì)應(yīng)上升管水速約 Wrs.3為0.35 (m

10、/s)則：Gi= 3600f Wrs.i (i=1 ,2,3) (kg/h)Ars上升管流通截面積，m2;Wrs.i假設(shè)的上升管水速，m/s ;水的密度，kg/m3;Gi與 Wrs.i相對(duì)應(yīng)的流量，kg/h。計(jì)算 時(shí)，對(duì)應(yīng)的溫度t可取為：t= (thot.w + tbac.w)/2 = (115+70)/2 = 92.5( C )=1008.6263-0.2811t-0.t 2 =1008.6263-0.2811 X 92.5-0. X 92.52=963.87各回路中的循環(huán)流量取值如表 A-4所示：表A-4各回路中的循環(huán)流量循環(huán)流量前墻回路后墻回路側(cè)墻回路對(duì)流管束Gi (kg/h)15000

11、1500020000150000G2 (kg/h)200002500025000200000G3 (kg/h)250003000030000250000A5.3各回路水循環(huán)計(jì)算A5.3.1各回路水循環(huán)計(jì)算結(jié)果如表A-5至A-8表A-5前墻水冷壁回路水循環(huán)計(jì)算結(jié)果名 稱符號(hào)單位計(jì)算公式及來(lái)源計(jì)算結(jié)果92.592.592.5回路循環(huán)流量Gkg/h假設(shè)值15000 I2000025000下降管出口水溫Ctout.dc = tin.dc + 860 Qdc/G92.592.592.5下降管平均水溫tav .dcctav .dc =0.5( t in.dc + tout.dc )92.592.592.5

12、下降管中水的平均 密度dckg/ m3dc =1008.6263-0.2811tav .dc-0.002192 t2av.dc963.87963.87963.87下降管中水速Wdcm/sWdc = G/(3600A dc dc)0.2750.3670.459下降管沿程摩擦阻 力系數(shù)dc一0.02180.02110.0207下降管總阻力系數(shù)dc一dc = dc l/din + dc.lc4.074.0043.97下降管流動(dòng)阻力Pa=dc dc W2dc /2148.6260.1402.7下降管重位壓降Pst,dPaPst .dc =h dc g44346.644346.644346.6上升管各段

13、出口水 溫IRmtout .1t out .2t out .3Ctout .1 = + 860Q 1/G=+860 列4 Gt out .2 = tout ,1+860Q 2/G=tout .1+860 x444.89/Gt out .3 = t out ,2 +860Q 3/G=t out .2+860 x521.27/G94.6120.14150.0294.1113.23135.6493.8109.1127.02上升管各段平均水 溫I R mtl t2 t3Ct1 = 0,5( + t out .1)t2 = 0,5(t out .1 + t out .2)t3= 0,5(t out .2

14、+ t out ,3)93.56107.4135.0893.3103.66124.4393.14101.4118.05上升管各段水的平 均密度IRmpr s.1pr s.2pr s.3kg/ m3prs.1=1008.6263-0.2811 t 1-0.002192 t 12prs.2=1008.6263-0.2811 t 2-0.002192 t 2 2Prs.3=1008.6263-0.2811t3-0.002192 t 3 2963.13953.16930.65963.3955.93939.7963.4957.56944.9上升管中平均水溫C=0.5( + t out .3 )120.2

15、6114.07109.76上升管中水的平均 密度rskg/ m3rs= 1008.6263-0.2811-0.002192 t av.r s2942.3948.04951.36上升管中水的平均 流速Wrsm/sWrs = G/(3600A rs rs )0.16140.21380.2664上升管沿程摩擦阻 力系數(shù)rs一0.02780.0270.0264上升管總阻力系數(shù)rs一rs =rsl/din+ rs.lc7.3957.2477.136上升管流動(dòng)阻力Pa=rs rsWrs2 / 290.74157.14240.9上升管各段重位壓 降I R mPst 1Pst.2 Pst.3PaPst .1

16、= h 1 prs.1 gP st. 2 = h2 prs.2 gP st. 3 = h3 prs.3 g9637.323002.2411046.969639.1523069.0511154.379640.323108.411216.0上升管側(cè)總壓差PrsPaPrs = Pfl.rs+Pst 1+ Pst. 2+ P st. 343777.2644019.744205.6下降管側(cè)總壓差PdcPaPdc =Pst.dc-Pfl. dc44197.9344086.4743943.87G (kg/h)圖A-6前墻水冷壁回路水循環(huán)特性曲線表A-6后墻水冷壁回路水循環(huán)計(jì)算結(jié)果名 稱符 號(hào)單位計(jì)算公式及來(lái)

17、源計(jì)算結(jié)果92.592.592.5回路循環(huán)流量r gKg/h假設(shè)值150002500030000下降管出口水溫ctout.dc = t in.dc + 860 Qdc /G92.592.592.5下降管平均水溫tav .dcctav.dc =0.5( tin.dc + tout.dc )92.5192.592.5下降管中水的平 均密度dckg/m3dc =1008.6263-0.2811tav .dc-0. tav.dc963.87963.87963.87下降管中水速WdcM/sWdc = G/(3600A dc dc)0.2750.4590.551下降管沿程摩擦 阻力 系數(shù)dc一0.0218

18、0.02070.0204下降管總阻力系 數(shù)dc一dc = dc |/d in+dc.lc3.633.543.51下降管流動(dòng)阻力Pa=dc dc W2dc /2132.60359.18513.65下降管重位壓降Pst . dcPaPst # =h dc g51343.751343.751343.7上升管各段出口 水溫IRtout .1t out .2Ctout .1= + 860Q 1/G227 21=+860 戔。t out .2= tout .1+860Q2/G,ccc 912.71=tout .1 +860- G105.53157.85100.316131.7199.01125.18上升管

19、各段平均 水溫IRtlt2Ct1 = 0.5( + t out .1)t2 = 0.5(t out .1 + t out .2 )99.01131.6996.41116.0195.75112.1上升管各段水的 平均 密度IRpr s.1pr s.2kg/m3prs.1=1008.6263-0.2811 t 1-0.002192 t 12prs.2=1008.6263-0.2811 t 2-0.002192 t 2 2959.3933.6961.15946.5961.6949.57上升管中平均水 溫c=0.5( + t out .2 )125.18112.10108.8上升管中水的平 均密度rs

20、kg/m3rs= 1008.6263-0.2811-0.002192 tav.r s2939.09949.56952.06上升管中水的平 均流速Wrsm/sWrs = G/(3600A rs rs)0.1620.2670.3194上升管沿程摩擦 阻力系數(shù)rs一0.02760.02630.0259上升管總阻力系 數(shù)rs一rs = rsl/din+ rs.lc8.0177.7477.66上升管流動(dòng)阻力Pa=rs rs Wrs2 / 298.71262.0372.3上升管各段重位 壓降IRPst 1 Pst.2PaPst .1 = h1 prs.1 gP st. 2 = h2 prs.2 g2832

21、6.4322163.6928381.022470.428394.522543.0上升管側(cè)總壓差PrsPaPrs = Pfl. rs+ Pst 1+ Pst. 250588.8451113.451309.86、降管側(cè)總壓器PdcPaPdc = Pst.dc- Pfl. dc51211.150984.550830.051400圖A-7后墻水冷壁回路水循環(huán)特性曲線表A-7側(cè)墻水冷壁回路水循環(huán)計(jì)算結(jié)果名 稱符 號(hào)單位計(jì)算公式及來(lái)源計(jì)算結(jié)果92.592.592.5回路循環(huán)流量Gkg/h假設(shè)值200002500030000下降管出口水溫ctout.dc = t in.dc + 860 Qdc/G92.59

22、2.592.5下降管平均水溫tav .dctav.dc =0.5( tin.dc + tout.dc )92.5 92.592.5下降管中水的平 均密度dckg/m3dc =1008.6263-0.2811tav .dc-0. tav.dc963.87963.87963.87下降管中水速Wdcm/sWdc = G/(3600A dc dc)0.3670.4590.551下降管沿程摩擦 阻力系數(shù)dc一0.02110.02070.0204下降管總阻力系 數(shù)dc一dc= dc l/d in+ dc.lc3.573.5363.51下降管流動(dòng)阻力Pa=dcdc W2dc /2231.87358.9051

23、3.20下降管重位壓降Pst . dcPaPst .dc =h dc g47277.847277.847277.8上升管出口水溫toutCtout = + 860Q/G129.6122.2117.2=+860 86：11G上升管中平均水 溫c=0.5( + t out )111.0107.3104.85上升管中水的平 均密度rskg/m3rs= 1008.6263-0.2811-0.002192 tav.r s2950.4953.2955.05上升管中水的平 均流速Wrsm/sWrs = G/(3600A rs rs)0.2740.3420.410上升管沿程摩擦 阻力系數(shù)rs一0.02630.

24、02580.0254上升管總阻力系 數(shù)rs一rs = rsl/din+ rs.lc4.794.734.68上升管流動(dòng)阻力Pa=rs rs Wrs2 / 2171.38263.88375.52上升管重位壓降PstPaPst = h prs g46616.646754.7546845.2上升管側(cè)總壓差PrsPaPrs = Pfl. rs+ Pst46787.9847018.5947220.72下降管側(cè)總壓差PdcPaPdc = Pst.dc- Pfl. dc47045.946918.8846764.6表A-8對(duì)流管束水循環(huán)計(jì)算結(jié)果名 稱符號(hào)單位計(jì)算公式及來(lái)源計(jì)算結(jié)果92.592.592.5回路循環(huán)

25、流量Gkg/h假設(shè)0250000下降管出口水溫Ct . . = t - A + 860 Qz /Gout.dcin.dcQdc /G96.495.494.83下降管平均水溫tav .dcctav.dc =0.5( tin.dc + tout.dc )94.493.9693.66下降管中水的平均 密度dckg/m3dc =1008.6263-0.2811tav .dc-0. tav.dc962.50962.86963.06下降管中水速Wdcm/sWdc = G/(3600A dc dc)0.1830.2430.304下降管沿程摩擦阻 力系數(shù)dc一0.02830.0272

26、0.0265下降管總阻力系數(shù)dc一dc= dc l/din+ dc.lc4.384.274.21下降管流動(dòng)阻力Pa=dcdc W2dc /270.20121.86187.50下降管重位壓降Pst .dcPaPst .dc =h dc g34936.834949. 034956.4上升管出口水溫toutCtout = + 860Q/G=+860 2431r27 G110.3105.87103.2上升管中平均水溫 上升管中水的平均密度47200ckg/m3=0.5( + t out )103.4100.699.0上升管中水的平均流速）47100 1上升管中程摩擦阻力系數(shù) d 47000 -Wrs4

27、6957m/s6rs= 1008.6263-0.2811-0.002192 t av.r s2Prs ,Jin.dcWrs = G/(3600A rs rs )sA956.20.20=92.5 0c0.15 0.0287958.1959.30.250.02770.0269上升管點(diǎn)阻力系IT 上升管電動(dòng)阻嬴二 上升管甫位壓降rsrsrsl/din+rs.lc46800上升管側(cè)總壓差46700下降管側(cè)總壓差Pa Prs4.41dc，47.d5= 94.32o2.2 金4.24126.6PstPst = hPrsPaPrsprs gPfl. rs + 2幽004705.634777.34753.14

28、34859.34819.834946.51 1 -TPa2000Pde = 24P00.dc-P60003428660634800002圖A-8側(cè)墻水冷壁回路水循環(huán)特性曲線34768.9G (kg/h)圖A-9對(duì)流管束水循環(huán)特性曲線A5.4計(jì)算結(jié)果由各回路水循環(huán)特性曲線， 及工作點(diǎn)的流量，結(jié)果如表可以得到在假設(shè)的下降管入口水溫下,A-9所小?；芈饭ぷ鼽c(diǎn)表A-9工質(zhì)流量匯總表假設(shè)的下降 管入口水溫C前墻Gkg/h后墻GKg/h側(cè)墻 G (kg/h)對(duì)流管束G kg/h總和 Gkg/h一側(cè)兩側(cè)92.521000231502360047200187550278900計(jì)算全爐循環(huán)倍率:鍋爐總的回水量G

29、bac (kg/h)為:Q7000Gbac = 860 一 = 860 X=133778(kg/ h)bacAt(115 -70)K=EG/G bac=278900/133778=2.085由式(4-18)得，當(dāng) K1.0, =thot,w-(thot.w - tbac.w)/k=115-(115-70)/2.085=93.4 C,與假設(shè)的=92.5 C相差在15c以內(nèi)。因此， 計(jì)算有效。A6循環(huán)回路中最低、最高水速的計(jì)算以前墻循環(huán)回路為例A6.1回路中受熱最弱、最強(qiáng)管各段吸熱量計(jì)算回路中受熱最弱、最強(qiáng)管各段吸熱量計(jì)算結(jié)果如表 A-11所示表A -11回路中受熱最弱、最強(qiáng)管各段吸熱量計(jì)算結(jié)果序

30、 號(hào)名稱符號(hào)單 位公式計(jì)算及數(shù)據(jù) 來(lái)源第I區(qū)第H區(qū)第田 區(qū)1平均工況下回路各段吸熱 量QikW37.24444.89521.2 72回路中管子根數(shù)n1818183受熱最弱管最小吸熱不均 勻系數(shù)min0.50.50.54受熱最強(qiáng)管最大吸熱不均 勻系數(shù)max1.31.31.35結(jié)構(gòu)不均系數(shù)c1.01.01.06受熱最弱管吸熱量Qmin, ikW%.?7 mn - c n1.03412.35 814.48 07受熱最強(qiáng)管吸熱量Qmax ,ikW包 ?max r c n2.69032.13 137.64 7A6.2平均工況下管組兩端壓差確定由圖A-6可知，平均工況下管組兩端壓差P=44060 PaA6

31、.3受熱最弱管中兩端壓差計(jì)算管內(nèi)流量(單根管，截面積為A=0.00152 m2)假設(shè)Gi =500(kg/h) , G2 = 800(kg/h) , G3 = 1200(kg/h),兩端壓差計(jì)算結(jié)果見表 A-12。A6.4受熱最強(qiáng)管中兩端壓差計(jì)算管內(nèi)流量(單根管，截面積為A=0.00152 m 2)假設(shè)Gi =1000(kg/h) , G2 = 1400(kg/h) , G3= 1800(kg/h),兩端壓差計(jì)算結(jié)果見表 A-13。表A-12受熱最弱管中兩端壓差計(jì)算結(jié)果名 稱符號(hào)單位計(jì)算公式及來(lái)源假設(shè)流量kg/h假設(shè)流量Gkg/h5008001200下降管入口水溫C93.493.493.4下降

32、管出口水溫Ctout.dc = tin.dc + 860 Qdc/G93.493.493.4上升管各段出口水溫I R mtout .1tout .2tout .3ctout .1 = + 860Q min,1 /Gt out .2=tout.1+860Qmin,2/Gt out .3 = t out .2 +860Qmin,3/G95.18116.43141.3494.51107.80123.3694.14103.0113.37上升管各段平均水 溫IRmt1t2t3ct1 = 0.5( + t out .1)t2 = 0.5(t out .1 + t out .2)t3= 0.5(t out

33、.2+ t out .3)94.29105.81128.8993.96101.15115.5893.7798.57108.19上升管各段水的 平均密度IRmpr s.1pr s.2pr s.3kg/m3prs.1=1008.6263-0.2811 t 1-0.002192 t 12prs.2=1008.6263-0.2811 t 2-0.002192 t 2 2Prs.3=1008.6263-0.2811t3-0.002192 t 3 2962.63954.34935.98962.87957.76946.85962.99959.62952.56上升管中平均水溫C=0.5( + t out .3

34、 )117.37108.38103.39上升管中水的平均 密度rskg/m3rs= 1008.6263-0.2811-0.002192 t av.r s2945.44952.41956.13上升管中水的平均 流速Wrsm/sWrs = G/(3600A o rs)0.09660.15350.2294上升管沿程摩擦阻 力系數(shù)rs一0.03020.02840.0271上升管總阻力系數(shù)rs一rs =rsl/din+rs.lc7.847.517.26上升管流動(dòng)阻力Pa=rs rs Wrs2 / 234.6284.24182.73上升管各段重位壓降IRmPst 1Pst. 2Pst. 3PaPst .1

35、 = h1 prs.1 gP st. 2 = h2 prs.2 gP st. 3 = h3 prs.3 g9632.323030.811110.29634.623113.311239.39635.923158.2 11307.0上升管兩端總壓差PrsPaPrs = + Pst 1+ Pst. 2 + Pst. 343807.944071.444283.8表A-13受熱最強(qiáng)管中兩端壓差計(jì)算結(jié)果名 稱符號(hào)單位計(jì)算公式及來(lái)源假設(shè)流量kg/h100014001800下降管入口水溫c93.493.493.4下降管出口水溫ctout.dc =tin.dc +860 Qdc/G93.493.493.4上升管

36、各段出口水溫Itout .1ctout .1 = + 860Q max,l/G95.7195.0594.69Rtout .2tout.2=tout.1123.35114.79110.04mtout .3+860Q max,2/Gtout.3=tout .2+860Q max,3/G155.72137.92128.02上升管各段平均水溫Itlt1 = 0.5( + t out .1)94.5694.2394.04Rt2ct2 = 0.5(t out .1 + t out .2 )109.53104.92102.36 1mt3t3= 0.5(t out .2 + t out .3)139.5312

37、6.35119.03上升管各段水的平 均密度IR mpr s.1pr s.2pr s.3kg/m3prs.1=1008.6263-0.2811 t 1-0.002192 t 12prs.2=1008.6263-0.2811 t 2-0.002192 t 2 2Prs.3=1008.6263-0.2811t3-0.002192 t 3 2962.45951.54926.73962.68955.0938.11962.80956.88944.11上升管中平均水溫 上升管中水的平均 密度rsC ；kg/m3=0.5( + t out .3 )rs= 1008.6263-0.2811-0.002192

38、t av.r s2124.56939.60115.66946.79110.71 , 950.64上升管中水的平均 流速Wrsm/sWrs = G/(3600A o rs )0.19450.27020.3460上升管沿程摩擦阻 力系數(shù)rs一0.02700.02620.0257上升管總阻力系數(shù)rs一rs = rs|/din+ rs.lc7.257.17.0上升管流動(dòng)阻力Pa=rs rs Wrs2 / 2128.80245.40398.74上升管各段重位壓 降IRmPst 1Pst. 2Pst. 3PaPst .1 = h1 prs.1 gP st. 2 = h 2 prs.2 gP st. 3 =

39、 h3 prs.3 g9630.4522963.1511000.329632.7423046.6 911135.59634.0 223092.1 11206.7上升管側(cè)總壓差PrsPaP rs=+ P st.1 +Pst.2+ Pst. 343722.744060.344331.6W(m/s)A6.5受熱最弱管中工作點(diǎn)時(shí)水速Wrs, min的確定如圖 A-10a 所示，得到 Wrs, min 為 0.1497 (m/s)A6.6受熱最強(qiáng)管中工作點(diǎn)時(shí)水速Wrs, max的確定如圖 A-10b 所示，得至|J Wrs, max 為 0.2702 (m/s)44400443004420044100

40、n msP 44000439004380043700(a)W (m/s)（b）圖A-10受熱最弱（a）、最強(qiáng)管（b）中水速的確定A7過(guò)冷沸騰的校驗(yàn)以前墻回路為例工作絕對(duì)壓力:1.1(MPa)前墻水冷壁管內(nèi)徑：din= 0.044(m),管長(zhǎng)l = 8.16 (m)上升管出口處傾角為：=75 0A7.1管內(nèi)壁熱流密度qn計(jì)算A7.1.1平均工況管管子吸熱量Qp=55.74 kWqn =Qp/( Ttdnl ) = 55.74 / (3.14 X 0.044 X 8.16) = 49.44 (kW/m 2)貝U qn = J x C x qn按第三章3.5.5節(jié)，取J= 0.9。由第三章式(3-30)計(jì)算可得：C =1.225qn = 0.9 X 1.225 義 49.44 = 54.50(kW/m 2)A7.1.2受熱最弱管管子吸熱量Qmin = 27.87 kWqn,min=J C Qmin/(兀 dnl ) = 0.9 X 1.225 義 27.87/(3.14 義 0.044 X 8.16)=27.25 (kW/m 2)A7.1.3受熱最強(qiáng)管管子吸熱量Qmax=72.47kWqn,max=J C Qmax/(兀 dn l ) = 0.9 X 1.2