严寒地区跨季节空气-U形地埋管土壤蓄热特性模拟与实验验证

Simulation and experimental validation of soil seasonal thermal storage characteristics by air-U tube system in severe cold zone

为了解决严寒地区长期使用地埋管地源热泵所引起的土壤温度逐年降低问题,提出利用现有设备实现跨季节空气-土壤蓄热思想,建立了室外空气换热器和竖直U形地埋管换热器的非稳态传热模型。分别对3种运行模式在4种埋深情况下的土壤蓄热特性进行了模拟分析。结果显示,蓄热能效比为8.1～17.0;经综合比较可知,采用50m埋深、第2种模式蓄热更加经济高效。通过实验验证了所建模型的正确性。

In order to solve the problem of the soil temperature decrease year by year around the ground heat exchanger due to long-term operation of ground-source heat pump in severe cold area, presents an idea of airsoil seasonal thermal storage based on the existing ground-source heat pump system, and develops the unsteadystate heat transfer models of outdoor air heat exchanger and vertical U-tube heat exchanger. Simulates and analyses the thermal storage characteristics of soil under the conditions of the three thermal storage modes and four buried depths. The results show that the energy efficiency ratio of thermal storage changes from 8.1 to 17.0. From a comprehensive comparison, concludes that heat storage is more economical and efficient by adopting 50 m buried depth and the second mode. Verifies the model by experiments.