砾砂回填条件下地埋管换热器周围温度场试验研究

Experimental Research on Temperature Field around Geothermal Heat Exchanger under Gravel Backfilled Condition

为研究不同工况砾砂回填条件下土壤源热泵地理管换热器周围温度场的变化规律,通过自主设计的可模拟地下水渗流的砂箱试验台,以砾砂为回填材料,测试了多种工况下地埋管换热器周围的温度场,并利用Surfer软件绘制等温线。结果表明,饱和无渗流条件下,温度场呈圆形对称分布,随着热负荷的增加,温度场达到稳定的时间延长;稳定后的温度变化量增加;温度变化明显区域的范围增大。饱和有渗流条件下,温度场沿渗流方向向下偏移,随着渗流速度的增加,温度场达到稳定的时间缩短;上游各点达到稳定后的温度变化量减小,温度变化明显区域的范围缩小;下游各点达到稳定后的温度变化量先增大后减小,温度变化明显区域的范围扩大。研究成果提供了一种温度场测试的新方法。

In order to research the change regulation of temperature field around the soil source heat pump geothermal heat exchanger which is backfilled with gravel under different working conditions,through design the sand box model which is backfilled with gravel and can simulate groundwater seepage,the temperature field around the geothermal heat exchanger under various conditions was test,and the isothermal line was plotted by Surfer software.The results show that under saturation non-seepage condition,temperature field appears circular symmetric distribution.With increase of heat load,the time for temperature attains stable is prolonged,and the stable temperature variation increases as well as the range of temperature variation is also increased.Under saturation seepage condition,temperature filed is offset along the downwards direction of seepage.With increase of seepage velocity,the time for temperature attains stable is shortened,and the stable temperature variation at the upstream point decreases as well as the range of temperature variation is also decreased.The stable temperature variation at the downstream point increases firstly and then decreases.The range of temperature variation is increased.The research results provide a new method for temperature field test.