保温层厚度的计算方法xin[共3页]

1、管管 道道 保保 温温 层层 厚厚 度度 的的 计计 算算 方方 法法(三三种种方方法法) (一).通过控制保温层外表面温度的方法计算 管道内介质的温度 t=95输入 主保温层外表面温度 tw1=34.66 保温层平均温度 tp=64.83 保温材料在tp温度下的导热系数 W/m1=0.048输入 管道外径 mdw=0.219输入 管道周围空气温度tk=28输入 管道外的风速 m/s=4输入 保温层表面到周围空气的放热系数 W/(m2k)h=25.53 设管道主保温层外径为d1:d1/dwln(d1/dw)=0.1556 令d1/dwln(d1/dw)=xlnx查表得：xlnx=0.1556输

2、入 x=1.147输入 则保温层厚度为 : m=0.0161 (二).通过控制最大热损失的方法计算 管道内介质的温度 t=95输入 保温层平均温度 tp=70输入 保温材料的导热系数 W/m1=0.048输入 管道外径 mdw=0.219输入 管道周围空气温度tk=28输入 保温层表面到周围空气的放热系数 W/(m2k)h=0.034 单位表面允许最大散热量 qq=93 设管道主保温层外径为d1:d1=0.3527 则保温层厚度为 : m= 0.0668 注:当预先定出管道或设备的表面最大允许散 热损失时,其保温层的经济厚度为: 1=0.0037 (三).通过控制温度降时的保温层厚度计算 管道

3、内的介质流量 kg/hG=35输入 介质平均比热 kj/(kg)C=896输入 介质始端温度 t1=95输入 介质终端温度 t2=70输入 管道输送长度 mL=1000输入 平面保温层到周围空气的放热系数 W/(m2k)h1= 0.344 输入 管道支吊架局部保温系数K1=1.2输入 当(t1-tk)/(t2-tk)2时TRUE 设管道主保温层外径为d1:d1=0.2290 则保温层厚度为 : m=0.0050 当(t1-tk)/(t2-tk)2时FALSE 设管道主保温层外径为d1:d1=0.2227 则保温层厚度为 : m=0.0018 (四).直埋管道的保温层厚度计算 土壤的导热系数 W

4、/mt=1.74 土壤层温度 tt=5 埋管深度 mh=1.2 设管道主保温层外径为d1:d1=0.0442 则保温层厚度为 : m=-0.0874 备 注 tw1=33.4+0.028(t50) (或者根据工艺要求直接输入) tp=(t+tw1)/2 h=11.63+6.950.5 d1/dwln(d1/dw)=21(t-tw1)/hdw(tw1-tk) 见后面附表1 见后面附表1 =(d1-dw)/2=(x-1)dw/2 此计算方法计算保温层厚度时,外表面温度未知,平均温度查附表2 查附表3 查附表4 ln(d1/dw)=23.141(t-tk)/qh 1=2.69dw1.211.35tw

5、11.73/q1.5 室内取0.086,室外取0.344 吊架室内1.10,室外1.15;支架室内1.15,室外1.20 当(t1-tk)/(t2-tk)2时,用下面公式计算： ln(d1/dw)=23.141(tp-tk)LK1/GC(t1-t2)h1 =(d1-dw)/2 当(t1-tk)/(t2-tk)2时，用下面公式计算： ln(d1/dw)=23.141(t2-tk)LK1/GC(t1-tk)h1 =(d1-dw)/2 一般可取1.74W/m 一般可取5 管管 道道 保保 温温 层层 厚厚 度度 的的 计计 算算 方方 法法(三三种种方方法法) lnd1=1(tw1-tt)ln(dw

6、)+1(t-tw1)ln(4h)/t(tw1-tt)+1(t-tw1) =(d1-dw)/2 x与与xlnx函函数数表表(当当x=15时时的的xlnx)值值 xxlnxxxlnxxxlnxxxlnxx 10.0001.420.4992.141.632.863.0023.58 1.0050.0051.430.5122.151.6482.873.0213.59 1.010.010051.440.5262.161.6652.883.0453.6 1.0150.015151.450.5392.171.6812.893.0653.61 1.020.02021.460.5522.181.6992.93.0

7、853.62 1.0250.2531.470.5652.191.722.913.1043.63 1.030.03041.480.582.21.7352.923.133.64 1.0350.03561.490.5942.211.7562.933.153.65 1.040.04071.50.6072.221.7712.943.173.66 1.0450.0461.510.6222.231.7912.953.193.67 1.050.05121.520.6372.241.8052.963.213.68 1.0550.05651.530.652.251.8252.973.243.69 1.060.06

8、171.540.6652.261.8412.983.253.7 1.0650.0671.550.6792.271.8612.993.273.71 1.070.07241.560.6952.281.8833.293.72 1.0750.07771.570.7082.291.8993.013.313.73 1.080.08311.580.7222.31.923.023.343.74 1.0850.08851.590.7372.311.9353.033.363.75 1.090.09461.60.7512.321.9553.043.383.76 1.0950.09941.610.7652.331.9

9、73.053.43.77 1.10.10481.620.7822.341.993.063.423.78 1.1050.111.630.7992.352.0073.073.443.79 1.110.11621.640.8152.362.0273.083.463.8 1.1150.121.1.650.8272.372.0423.093.483.81 1.120.127.1.660.8422.382.0623.13.53.82 1.1250.13271.670.8562.392.083.113.533.83 1.130.1381.680.8722.42.13.123.553.84 1.1350.14

10、31.690.8892.412.123.133.573.85 1.140.14921.70.9022.422.143.143.593.86 1.1450.15451.710.9162.432.163.153.613.87 1.150.16071.720.9322.442.183.163.643.88 1.1550.16651.730.9492.452.1953.173.663.89 1.160.17211.740.9652.462.2173.183.683.9 1.1650.17721.750.982.472.2333.193.73.91 1.170.18461.760.9942.482.25

11、53.23.723.92 1.1750.1891.771.0112.492.273.213.743.93 1.180.1951.781.0292.52.293.223.763.94 1.1850.2011.791.042.512.313.233.783.95 1.190.2071.81.0592.522.3283.243.813.96 1.1950.2131.811.0812.532.3443.253.833.97 1.20.2181.821.0892.542.373.263.853.98 1.2050.251.831.1082.552.3853.273.883.99 1.210.231.84

12、1.1212.562.4053.283.94 1.2150.2361.851.1382.572.4253.293.924.01 1.220.2421.861.1522.582.4443.33.944.02 1.2250.2451.871.1692.592.4623.313.964.03 1.230.25451.881.1852.62.483.323.984.04 1.2350.2611.891.2052.612.5033.3344.05 1.240.2661.91.222.622.5213.344.034.06 1.2450.2721.911.2342.632.543.354.054.07 1

13、.250.2791.921.2512.642.563.364.074.08 1.2550.2851.931.272.652.583.374.094.09 1.260.2911.941.2882.662.63.384.124.1 1.2650.2981.951.3022.672.623.394.144.11 1.270.341.961.3182.682.643.44.164.12 1.2750.3091.971.3352.692.663.414.184.13 1.280.3161.981.3512.72.683.424.24.14 1.2850.3221.991.3692.712.73.434.

14、234.15 1.290.32821.3862.722.723.444.254.16 1.2950.3342.011.4012.732.743.454.274.17 1.30.342.021.4192.742.763.464.34.18 1.310.3542.031.4392.752.783.474.324.19 1.320.3672.041.4552.762.83.484.344.2 1.330.382.051.4712.772.823.494.364.21 1.340.3892.061.4882.782.843.54.384.22 1.350.4052.071.5072.792.863.5

15、14.44.23 1.360.4172.081.522.82.883.524.424.24 1.370.4322.091.5422.812.9013.534.454.25 1.380.4452.11.5592.822.9213.544.474.26 1.390.4572.111.5792.832.943.554.54.27 1.40.472.121.5922.842.9613.564.524.28 1.410.4852.131.612.852.983.574.554.29 xlnxxxlnx 4.574.36.27 4.594.316.29 4.624.326.32 4.644.336.35

16、4.664.346.38 4.684.356.4 4.714.366.42 4.734.376.44 4.754.386.46 4.774.396.48 4.84.46.52 4.824.416.54 4.844.426.57 4.864.436.6 4.884.446.62 4.914.456.64 4.934.466.67 4.964.476.7 4.984.486.72 54.496.74 5.034.56.77 5.054.516.79 5.074.526.81 5.094.536.83 5.124.546.86 5.154.556.9 5.174.566.92 5.194.576.9

17、4 5.214.586.97 5.244.596.99 5.264.67.02 5.284.617.05 5.314.627.07 5.334.637.1 5.354.647.12 53.74.657.14 5.44.667.16 5.434.677.19 5.454.687.21 5.474.697.24 5.54.77.26 5.534.717.28 5.554.727.32 5.574.737.35 5.64.747.38 5.624.757.4 5.644.767.42 5.664.777.45 5.684.787.47 5.714.797.5 x与与xlnx函函数数表表(当当x=15

18、时时的的xlnx)值值 5.744.87.52 5.764.817.55 5.784.827.58 5.814.837.6 5.834.847.63 5.854.857.65 5.884.867.68 5.914.877.7 5.934.887.73 5.954.897.76 5.984.97.78 6.014.917.8 6.034.927.83 6.054.937.85 6.074.947.86 6.14.957.9 6.134.967.92 6.154.977.95 6.174.988 6.194.998.02 6.2258.05 6.25 附附表表2: 保保 温温 层层 平平 均均 温

19、温 度度 tp 周围空气温度() 介 质 温 度 100150200250300350400 257095125150175205230 156590120145170200225 06080110135160190215 -155575105130155185210 附附表表3-1: 季季 节节 运运 行行 工工 况况 允允 许许 最最 大大 散散 热热 损损 失失 设备、管道及附件外表面温度50100150200250300 允许最大散热损失116163203244279308 附附表表3-2: 常常 年年 运运 行行 工工 况况 允允 许许 最最 大大 散散 热热 损损 失失 设备、管道

20、及附件外表面温度 323(50)373(100) 423(150) 473(200) 523(250) 573(250) 允许最大散热损失5893116140163186 附附表表4: 保保 温温 层层 表表 面面 热热 阻阻 公称直径 (mm) 室内室外 介质温度t()介质温度t() 100200300400500100200300 圆 筒 面 放 热 阻 力 R2 (m2K/w) 250.3010.2580.2150.1980.1890.1030.0950.086 320.2750.2320.1980.1630.1380.0950.0860.077 400.2580.2150.1810.1

21、550.1290.0860.0770.069 500.1980.1630.1380.120.1030.0690.060.052 1000.1550.1290.1120.0950.0770.0520.0430.043 1250.1290.1120.0950.0770.0690.0430.0340.034 1500.1030.0860.0770.0690.060.0340.0260.026 2000.0860.0770.0690.060.0520.0340.0260.026 2500.0770.0690.060.0520.0430.0260.0170.017 3000.0690.060.0520.0430.0430.0260.0170.017 3500.060.052