太阳能集热-辐射制冷复合表面及其试制与性能分析

PRELIMINARY MANUFACTURE AND ANALYSIS OF A SPECTRAL SELECTIVITY SURFACE FOR BOTH SOLAR HEATING AND RADIATIVE COOLING

提出一种可以兼顾太阳能集热和辐射制冷的光谱选择性复合表面，其在太阳辐射波段（0．2～3．0μm）和辐射制冷“大气窗口”波段（8．0～13．0μm）具有高吸收（发射）率，而在除此之外的其余波段（3．0～8．0μm、13．0～25．0μm）具有低吸收（发射）率。笔者初步实现该复合表面的制备，对样品进行光谱测试表明其在太阳辐射波段和“大气窗口”波段的平均吸收（发射）率分别为0．92和0．80，其余波段平均吸收（发射）率为0．55，具有一定的光谱选择性。通过实例计算，对该复合表面与单独太阳能集热表面、单独辐射制冷表面和理想复合表面之间在太阳能集热效率、辐射制冷平衡温度和辐射制冷功率等关键性能参数进行对比分析。

The surface for both solar heating and radiative cooling was proposed. It has a high spectral absorptivity （emissivity） in solar radiation band and atmospheric window band （i.e., 0.2-3.0 μm and 8.0-13.0 μm）, as well as a low absorptivity（emissivity） in the band aside from the solar radiation and atmospheric window wavelengths （i.e., 3.0-8.0 μm or above 13.0 μm）. A type of composite surface sample was also trial-manufactured with the use of blue titaniumpolyethylene terephthalate （BTPT）. Sample tests show that the BTPT composite surface has clear spectral selectivity in the spectra of solar heating and radiation cooling wavelengths. More specifically, absorptivity （emissivity）of the BTPT composite surface in the three spectrum smentioned above is 0.92, 0.80 and 0.55, respectively. Numerical analysis was conducted to evaluate the solar heating and radiative cooling performance of the BTPT composite surface. Comparisons among the BTPT composite surface and three other typical surfaces, namely, normal solar heating surface, normal radiative cooling surface, and ideal composite surface were also performed.