摘要
根据试验,新型黑色陶瓷平板集热器的日平均效率为46.1％,按本文的理论分析求得的计算值为46.7％,两者大致相近。黑色陶瓷材料的导热系数比较小,只有铜的1/300。这对整个平板集热器的热性能特带来一定的不利影响。根据分析,在相同条件下,由于黑陶的导热系数比较小,用它制作集热板组装成的平板集热器,其平均板温被抬高6.7℃,相对值为12％,最高为9.8℃。由此,相对降低集热器的日平均效率为1.3％,影响甚小。但由于黑色陶瓷集热板具有很多突出的优点,如不腐蚀,不老化,不退色,不氧化,强度高,耐高温等,因此黑色陶瓷可能是制做平板集热器集热板的良好材料。
The average daily efficiency of a new-type flat-plate collector of black ceramic was measured to be 46.1% in its experiment. But based on the theoretical analysis of this paper, the calculated value of the average daily efficiency obtained was 46. 7%. It should be held that both values are quite approximate. As the thermal conductivity of black ceramic is 1/300 lower than that of copper , it will exert an unfavourable influence on the total performance of the flat-plate collector. That is to say, under similar conditions the temderature of the plate increases 6. 7℃ on the average, its relative value being 12%, and its maximum being 9. 8℃. For this reason, if the average daily efficiendcy of the collector is reduced by 1. 3% approximately, its influence on thermal performance will be little. As the absorber of black ceramic has such obvious advantages as being corrosion - resistant, ageing -resistant, fadeless, oxidation - resistant, highly strong and temperature-resistant,etc. , it is well to say that the black ceramic is a good material for making flat-plate collectors.
