固体表面黑度的测定.doc

固体表面黑度的测定一、实验目的1、巩固辐射换热理论。2、用真空辐射法测定固体表面的黑度，掌握实验方法。3、确定黑度与温度的关系。二、实验原理当一物体放在另一物体的空腔内如图所示，且空腔内不存在吸收热辐射的界质时（如空气），披此以辐射方式进行热交换，其辐射换热量由下列计算： （1）式中：F1试件外表面积（m2）；试件外径为38mm，管长290mm；F2外壳之内表面积（m2）；内壳内径为100mm，管长290mm；C0绝对黑度的辐射系数C0=5.67W/m2K4；T1、T2分别为试件外表面和试壳内表面的绝对温度；1、2分别为试件和外壳的黑度。当F1、F2为已知，由实验测得Q12、T1、T2分别借助于固定在试件外表面和外壳内表面之镍铬考铜热电偶通过电位差计测得，由测得热电势查出对应的温度值，即为被测表面的实际温度，本实验装置的外壳内表面涂有碳黑，取2=0.96，根据式（1）内包物体表面黑度1可由下式算出： （2） 三、实验装置和仪器本实验共有四个系统：1、密封法兰2、外壳3、试件4、加热器1、加热系统：包括调压器、电加热器、电流表、电压表。图1 原理图2、真空系统：包括真空泵、真空保持阀、真空表、以及本体密封装置。3、热电偶测温系统：包括外壳及试件上的热电偶、电位差计、冷暖瓶4、循环水系统：包括循环水泵、水箱、溢水管、流量调节阀。测试系统图如下：四、实验步骤1、将水箱内注满净水图二 测试系统1、真空表 2、本体 3、保暖瓶 4、水泵 5、真空泵6、水箱 7、真空保持阀 8、流量调节网 9、溢水管2、冷暖瓶内注入适量冰水混合物，将热电偶丝浸在其中。3、打开真空保持阀、开启真空泵，使系统中形成真空。4、开启冷却水泵使本体与水箱之间形成强制水循环，本体内的水位由流量调节阀控制在水浸过本体外壳上法兰盘510mm为宜。5、一切正常后，按通加热器电源电源，并调整送入装置内的电流在46安，不得超过6.5安。6、每隔10分钟记录一次数据，填入表中，进行计算，以稳定后的数值作为实验结果。五、数值表年 月 日测量次数电压V电流A真空mmHG水温试件外表面外壳内表面计算得黑度1备注热电势mV对应温度热电势mV对应温度六、注意事项及说明1、本体内电加热器，用调压器控制电流在6.5安以下，不得超出此数值，以免损坏设备。2、进行实验时，应首先接好地线（在仪器车盘上）。3、表盘上的标牌中旋纽开关的“内”是指试件测温，“外”是指外壳测温。4、实验完毕后，先停本体加热器电源，然后停真空泵（停用真空泵时，先关闭真空保持阀，再开通大气阀。最后停真空泵电源）。七、实验结果的整理1、计算不同温度下的1值。2、画出1=f(T)的曲线。3、对实验结果进行分析和讨论。八、热电偶分度表镍铬-银硅（镍铅）热电偶分度表（参考端温度为0）分度号：EA-2测量端0123456789温度热 电 偶 （毫伏）-50-40-30-20-10-0-3.11-2.50-1.89-1.27-0.64-0.00-2.56-1.95-1.33-0.70-0.06-2.62-2.01-1.39-0.77-0.13-2.68-2.07-1.46-0.83-0.19-2.74-2.13-1.52-0.89-0.26-2.81-1010-1.58-0.96-0.32-2.87-2.26-1.64-1.02-0.38-2.93-2.32-1.70-1.080.45-2.99-2.33-1.77-1.14-0.51-3.05-2.44-1.88-1.21-0.58+01020304050607080900.000.651.311.982.662.354.054.765.486.210.070.721.382.052.733.424.124.035.566.290.130.781.442.122.803.494.194.905.636.360.200.851.512.182.873.564.264.985.706.430.260.911.572.252.943.634.335.055.786.510.330.981.642.323.003.704.415.125.856.580.391.051.702.383.073.774.485.205.926.650.461.111.772.453.143.844.555.275.996.730.521.181.842.522.213.914.625.346.076.300.951.241.912.593.283.984.695.416.146.871001101201301401501601701801906.957.698.439.189.9310.6911.4612.2413.0313.347.037.778.509.2510.0010.7711.5412.3213.1113.927.107.848.589.3310.0810.8511.6212.4013.1914.007.177.918.659.4010.1610.9211.6912.4813.2714.087.257.998.739.4810.2311.0011.7712.5513.3614.167.348.068.609.5510.3111.0811.8512.6313.4414.257.408.138.889.6310.3811.1511.9312.7113.5214.347.478.218.959.7010.4611.2312.0012.7913.6014.437.548.289.039.7810.5411.3112.0812.8713.6814.507.628.359.109.8510.6111.3812.1612.9513.7614.5820021022023024025026027028029014.6615.4816.3017.1217.9518.7619.5920.4221.2422.0714.7415.5616.3817.2018.6718.8419.6720.5021.3222.1514.8215.6416.4617.2818.1118.9219.7520.5821.4122.2314.0915.7216.5417.3718.1919.0119.8420.6621.4922.3214.9815.8016.6217.4518.2819.0919.9220.7421.5722.4015.0615.8916.7117.5318.3619.1720.0020.8321.6533.4815.1415.9716.7917.6218.4419.2620.0920.9121.7322.5715.2216.0516.8617.7018.5219.3420.1720.9921.8222.6515.3016.1316.9517.7818.6019.4220.2521.0721.9022.7315.3816.2117.0317.8718.6819.5120.3421.1521.9822.8130031032033034035036037038039022.9023.7424.5925.4426.3027.1528.0128.8829.7530.6122.9323.8324.6825.5326.3827.2428.1028.9729.8330.7023.0723.9124.7625.6126.4727.3228.1929.0629.9230.7923.1524.0024.8526.0026.5527.4128.2729.1430.0030.8723.2324.0824.9825.7826.6427.4928.3629.0030.0930.9623.3224.1725.0225.8626.7327.5828.4529.3230.1731.0523.4024.2525.1025.9526.8127.6628.5429.4030.2631.1323.4924.3425.1926.0326.9027.7528.6229.4930.3431.2223.5724.4225.2726.1226.9827.8328.7129.5830.4331.3023.6624.5125.3626.2127.0727.9228.8029.6630.5231.3940041042043044045046047048049031.4832.3433.2134.0734.9435.8136.6737.5438.4139.2831.5732.4333.3034.1635.0335.9036.7637.6338.5039.3731.6632.5233.3934.2535.1235.9836.8437.7138.5839.4531.7432.6033.4934.3335.2036.0736.9337.8033.6739.5431.8332.6933.5634.4235.2936.1537.0237.8938.7639.6331.9232.7833.6534.5135.3836.2437.1137.9838.8539.7232