面向多年冻土区路基的主动型压缩式制冷装置研究

Active Compression Refrigeration Device for Subgrade in Permafrost Region

针对我国多年冻土区交通工程普遍面临的冻土退化和路基融沉问题,基于新能源制冷技术,开发路基专用主动型制冷装置,实现在暖季实时控制路基热量收支平衡。根据冻土退化防治技术要求,结合多年冻土区新能源分布条件,并对比制冷方法,采用太阳能光伏驱动压缩式制冷技术进行制冷。针对冻土退化的大深度和分散性特征,制作用于路基工程的由压缩机、冷凝器、蒸发器、毛细管组成的压缩式制冷管,其中蒸发器型式为立式柱状的螺旋形铜管。应用该主动型压缩式制冷装置的制冷试验结果表明:在0~5℃正温环境下,装置蒸发器制冷温度整体呈先降低、后稳定的规律,在竖直方向由上至下逐渐降低,平均值可达-20℃,且不受环境温度影响;在制冷作用下试验箱土体温度逐渐降低,降温幅度随着与蒸发器距离的增大而减小,装置起到有利的“冷源”作用。可见,主动型压缩式制冷装置具有季节匹配性好和制冷温度低的技术优势。

To solve such problems as permafrost degradation and subgrade settlement in transport engineering in the permafrost regions of China, a special active refrigeration device for subgrade was developed based on new energy refrigeration technology to realize the real-time control of heat balance in warm season. According to the technical requirements for the prevention and control of permafrost degradation , combined with the distribution conditions of new energy in permafrost regions and compared with existing refrigeration methods, compression refrigeration driven by solar photovoltaic technology was proposed. In view of the deep and dispersive characteristics of permafrost degradation, compression refrigeration tube for subgrade engineering was manufactured, consisting of compressor, condenser, evaporator and capillary, in which the evaporator was a screw-type copper tube with vertical columnar form. The refrigeration test results of the active compression refrigeration device show that the refrigeration temperature of the evaporator decreases first and then stabilizes, and gradually decreases from top to bottom in the vertical direction. The average refrigeration temperature can reach -20 ℃ in a positive-temperature environment of 0~5 ℃, and it is not affected by the ambient temperature. Under the action of refrigeration , the soil temperature around the test device decreases gradually, and its dropping range decreases with the increase of the distance from the evaporator. The device plays as an advantageous role of “cold source”. It can be seen that the proposed active compression refrigeration device has the technical advantages of good seasonal matching and low refrigeration temperature.