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采用能量平衡方程和P1阶微分近似法建立了由超细玻璃纤维和反射屏组成的管道多层隔热系统稳态传热的数学模型。利用该模型分析了反射屏层数、反射屏发射率、反射屏位置、温度等因素对系统隔热性能的影响。分析结果表明,系统的隔热性能随着反射屏层数的增加而提高,但是提高幅度逐渐减小,存在一个最佳的反射屏层数;反射屏的发射率强烈地影响系统的隔热性能,采用低发射率的反射屏对于提高系统隔热性能有着重要作用;反射屏位置对系统隔热性能有较大影响,将反射屏靠近高温面布置能获得更好的隔热效果。
The steady-state heat transfer mathematical model of multi-layer pipe insulation system consisting of ultrafine glass fiber and reflective screen was established by energy balance equation and P1-order differential approximation method. The model was used to analyze the influence of factors such as reflector layer number, reflectance emissivity, reflector position and temperature on the thermal insulation performance of the system. The results show that the thermal insulation performance of the system increases with the increase of the number of reflective screens, but the increase rate decreases gradually, and there is an optimal number of reflective screen layers. The emissivity of reflective screen strongly affects the thermal insulation performance of the system The use of low-emissivity reflective screens plays an important role in improving the thermal insulation performance of the system. The position of the reflective screen has a significant impact on the thermal insulation performance of the system. The reflective screen can achieve better thermal insulation effect when placed near the high-temperature surface.