土壤水分迁移对地埋管换热器夏季性能的影响
Influence of soil moisture transfer on performance of ground heat exchangers in summer
摘要：
基于一维线热源理论，建立了同时考虑温度和含水量变化的土壤热湿传递线热源模型。针对地源热泵夏季运行工况下地埋管周围土壤温湿度的变化进行了数值模拟，结果显示，水分迁移对土壤含水量的影响主要集中在钻孔内。对模拟结果与一维热湿传递实验结果进行了对比，发现二者具有较高的相似性。数据拟合得到不同土壤初始质量含水量下对普通线热源模型地埋管换热量的修正公式。通过对不同埋深地埋管换热量的加权分析，认为当夏季平均地下水位高于-20 m时，可以不考虑水分迁移引起的换热量偏差。
Abstract：
Based on the one-dimensional linear heat source theory, develops a heat and moisture transfer linear heat source model considering the variety of temperature and moisture content in soil. Simulates the variety of temperature and moisture content in soil around buried pipes in summer running condition. The results indicate that the incidence of moisture transfer in soil is mainly in the borehole. Compares the simulation results with the experimental results of one-dimensional heat and moisture transfer, finds that the two results have comparatively high similarity. Obtains a modified fitting formula for the capacity of the ground heat exchanger from common linear heat source model with different initial mass moisture contents in soil. Calculates and estimates the ground heat exchanger capacity in different depth of soil with weighting method, concludes that the difference of heat exchange rate caused by soil moisture transfer could be ignored when the average underground water level is higher than -20 m in summer.
Keywords:ground heat exchanger, moisture transfer, soil moisture content, heat and moisture transfer, heat exchange rate, ground-source heat pump