管道保溫層厚度的計算方法

1、管管 道道 保保 溫溫 層層 厚厚 度度 的的 計計 算算 方方 法法(三三種種方方法法)(一).通過控制保溫層外表面溫度的方法計算管道內(nèi)介質(zhì)的溫度 t=150輸入主保溫層外表面溫度 tw1=36.2保溫層平均溫度 tp=93.1保溫材料在tp溫度下的導(dǎo)熱系數(shù) W/m1=0.041輸入管道外徑 mdw=0.133輸入管道周圍空氣溫度tk=25輸入管道外的風(fēng)速 m/s=4輸入保溫層表面到周圍空氣的放熱系數(shù) W/(m2k)h=25.53設(shè)管道主保溫層外徑為d1:d1/dwln(d1/dw)=0.2454令d1/dwln(d1/dw)=xlnx查表得：xlnx=0.2454輸入x=1.225輸入則保

2、溫層厚度為 : m=0.0150(二).通過控制最大熱損失的方法計算管道內(nèi)介質(zhì)的溫度 t=150輸入保溫層平均溫度 tp=80輸入保溫材料的導(dǎo)熱系數(shù) W/m1=0.041輸入管道外徑 mdw=0.133輸入管道周圍空氣溫度tk=0輸入保溫層表面到周圍空氣的放熱系數(shù) W/(m2k)h=0.034單位表面允許最大散熱量 qq=116設(shè)管道主保溫層外徑為d1:d1=0.2806則保溫層厚度為 : m=0.0738注:當(dāng)預(yù)先定出管道或設(shè)備的表面最大允許散熱損失時,其保溫層的經(jīng)濟(jì)厚度為:1=0.0013(三).通過控制溫度降時的保溫層厚度計算管道內(nèi)的介質(zhì)流量 kg/hG=35輸入介質(zhì)平均比熱 kj/(k

3、g)C=896輸入介質(zhì)始端溫度 t1=95輸入介質(zhì)終端溫度 t2=70輸入管道輸送長度 mL=1000輸入平面保溫層到周圍空氣的放熱系數(shù) W/(m2k)h1=0.344輸入管道支吊架局部保溫系數(shù)K1=1.2輸入當(dāng)(t1-tk)/(t2-tk)2時TRUE設(shè)管道主保溫層外徑為d1:d1=0.1398則保溫層厚度為 : m=0.0034當(dāng)(t1-tk)/(t2-tk)2時FALSE設(shè)管道主保溫層外徑為d1:d1=0.1350則保溫層厚度為 : m=0.0010(四).直埋管道的保溫層厚度計算土壤的導(dǎo)熱系數(shù) W/mt=1.74土壤層溫度 tt=5埋管深度 mh=1.2設(shè)管道主保溫層外徑為d1:d1=

4、0.0185則保溫層厚度為 : m=-0.0573備 注tw1=33.4+0.028(t50) (或者根據(jù)工藝要求直接輸入)tp=(t+tw1)/2h=11.63+6.950.5d1/dwln(d1/dw)=21(t-tw1)/hdw(tw1-tk)見后面附表1見后面附表1=(d1-dw)/2=(x-1)dw/2此計算方法計算保溫層厚度時,外表面溫度未知,平均溫度查附表2巖棉0.036-0.041查附表4查附表3ln(d1/dw)=23.141(t-tk)/qh1=2.69dw1.211.35tw11.73/q1.5室內(nèi)取0.086,室外取0.344吊架室內(nèi)1.10,室外1.15;支架室內(nèi)1.

5、15,室外1.20當(dāng)(t1-tk)/(t2-tk)2時,用下面公式計算：ln(d1/dw)=23.141(tp-tk)LK1/GC(t1-t2)h1=(d1-dw)/2當(dāng)(t1-tk)/(t2-tk)2時，用下面公式計算：ln(d1/dw)=23.141(t2-tk)LK1/GC(t1-tk)h1=(d1-dw)/2管管 道道 保保 溫溫 層層 厚厚 度度 的的 計計 算算 方方 法法(三三種種方方法法)一般可取1.74W/m一般可取5lnd1=1(tw1-tt)ln(dw)+1(t-tw1)ln(4h)/t(tw1-tt)+1(t-tw1)=(d1-dw)/20.0335704x與與xlnx

6、函函數(shù)數(shù)表表(當(dāng)當(dāng)x=15時時的的xlnx)值值xxlnxxxlnxxxlnxxxlnxxxlnx10.0001.420.4992.141.632.863.0023.584.571.0050.0051.430.5122.151.6482.873.0213.594.591.010.010051.440.5262.161.6652.883.0453.64.621.0150.015151.450.5392.171.6812.893.0653.614.641.020.02021.460.5522.181.6992.93.0853.624.661.0250.2531.470.5652.191.722.9

7、13.1043.634.681.030.03041.480.582.21.7352.923.133.644.711.0350.03561.490.5942.211.7562.933.153.654.731.040.04071.50.6072.221.7712.943.173.664.751.0450.0461.510.6222.231.7912.953.193.674.771.050.05121.520.6372.241.8052.963.213.684.81.0550.05651.530.652.251.8252.973.243.694.821.060.06171.540.6652.261.

8、8412.983.253.74.841.0650.0671.550.6792.271.8612.993.273.714.861.070.07241.560.6952.281.8833.293.724.881.0750.07771.570.7082.291.8993.013.313.734.911.080.08311.580.7222.31.923.023.343.744.931.0850.08851.590.7372.311.9353.033.363.754.961.090.09461.60.7512.321.9553.043.383.764.981.0950.09941.610.7652.3

9、31.973.053.43.7751.10.10481.620.7822.341.993.063.423.785.031.1050.111.630.7992.352.0073.073.443.795.051.110.11621.640.8152.362.0273.083.463.85.071.1150.121.1.650.8272.372.0423.093.483.815.091.120.127.1.660.8422.382.0623.13.53.825.121.1250.13271.670.8562.392.083.113.533.835.151.130.1381.680.8722.42.1

10、3.123.553.845.171.1350.1431.690.8892.412.123.133.573.855.191.140.14921.70.9022.422.143.143.593.865.211.1450.15451.710.9162.432.163.153.613.875.241.150.16071.720.9322.442.183.163.643.885.261.1550.16651.730.9492.452.1953.173.663.895.281.160.17211.740.9652.462.2173.183.683.95.311.1650.17721.750.982.472

11、.2333.193.73.915.331.170.18461.760.9942.482.2553.23.723.925.351.1750.1891.771.0112.492.273.213.743.9353.71.180.1951.781.0292.52.293.223.763.945.41.1850.2011.791.042.512.313.233.783.955.431.190.2071.81.0592.522.3283.243.813.965.451.1950.2131.811.0812.532.3443.253.833.975.471.20.2181.821.0892.542.373.

12、263.853.985.51.2050.251.831.1082.552.3853.273.883.995.531.210.231.841.1212.562.4053.283.945.551.2150.2361.851.1382.572.4253.293.924.015.571.220.2421.861.1522.582.4443.33.944.025.61.2250.2451.871.1692.592.4623.313.964.035.621.230.25451.881.1852.62.483.323.984.045.641.2350.2611.891.2052.612.5033.3344.

13、055.661.240.2661.91.222.622.5213.344.034.065.681.2450.2721.911.2342.632.543.354.054.075.711.250.2791.921.2512.642.563.364.074.085.741.2550.2851.931.272.652.583.374.094.095.761.260.2911.941.2882.662.63.384.124.15.781.2650.2981.951.3022.672.623.394.144.115.811.270.341.961.3182.682.643.44.164.125.831.2

14、750.3091.971.3352.692.663.414.184.135.851.280.3161.981.3512.72.683.424.24.145.881.2850.3221.991.3692.712.73.434.234.155.911.290.32821.3862.722.723.444.254.165.931.2950.3342.011.4012.732.743.454.274.175.951.30.342.021.4192.742.763.464.34.185.981.310.3542.031.4392.752.783.474.324.196.011.320.3672.041.

15、4552.762.83.484.344.26.031.330.382.051.4712.772.823.494.364.216.051.340.3892.061.4882.782.843.54.384.226.071.350.4052.071.5072.792.863.514.44.236.11.360.4172.081.522.82.883.524.424.246.131.370.4322.091.5422.812.9013.534.454.256.151.380.4452.11.5592.822.9213.544.474.266.171.390.4572.111.5792.832.943.

16、554.54.276.191.40.472.121.5922.842.9613.564.524.286.221.410.4852.131.612.852.983.574.554.296.25xxlnx4.36.274.316.294.326.324.336.354.346.384.356.44.366.424.376.444.386.464.396.484.46.524.416.544.426.574.436.64.446.624.456.644.466.674.476.74.486.724.496.744.56.774.516.794.526.814.536.834.546.864.556.

17、94.566.924.576.944.586.974.596.994.67.024.617.054.627.074.637.14.647.124.657.144.667.164.677.194.687.214.697.244.77.264.717.284.727.324.737.354.747.384.757.44.767.424.777.454.787.474.797.5x與與xlnx函函數(shù)數(shù)表表(當(dāng)當(dāng)x=15時時的的xlnx)值值4.87.524.817.554.827.584.837.64.847.634.857.654.867.684.877.74.887.734.897.764.97

18、.784.917.84.927.834.937.854.947.864.957.94.967.924.977.954.9884.998.0258.05附附表表2:保保 溫溫 層層 平平 均均 溫溫 度度 tp周圍空氣溫度()介 質(zhì) 溫 度10015020025030035040025709512515017520523015659012014517020022506080110135160190215-155575105130155185210附附表表3-1:季季 節(jié)節(jié) 運(yùn)運(yùn) 行行 工工 況況 允允 許許 最最 大大 散散 熱熱 損損 失失設(shè)備、管道及附件外表面溫度50100150200250

19、300允許最大散熱損失116163203244279308附附表表3-2:常常 年年 運(yùn)運(yùn) 行行 工工 況況 允允 許許 最最 大大 散散 熱熱 損損 失失設(shè)備、管道及附件外表面溫度323(50)373(100) 423(150) 473(200) 523(250) 573(250) 623(350)允許最大散熱損失5893116140163186209附附表表4:保保 溫溫 層層 表表 面面 熱熱 阻阻公稱直徑(mm)室內(nèi)室外介質(zhì)溫度t()介質(zhì)溫度t()100200300400500100200300400圓 筒 面 放 熱 阻 力 R2 (m2K/w)250.3010.2580.2150.

20、1980.1890.1030.0950.0860.077320.2750.2320.1980.1630.1380.0950.0860.0770.069400.2580.2150.1810.1550.1290.0860.0770.0690.06500.1980.1630.1380.120.1030.0690.060.0520.0431000.1550.1290.1120.0950.0770.0520.0430.0430.0341250.1290.1120.0950.0770.0690.0430.0340.0340.0261500.1030.0860.0770.0690.060.0340.0260.0260.0262000.0860.0770.0690.060.0520.0340.0260.0260.0