地下水源热泵取水引起颗粒运动的理论分析

Theoretical Analysis on Mobilization of Aquifer Particles Induced by Groundwater Source Heat Pump Pumping

摘要:

对地下水源热泵取水引起含水层颗粒运动进行了理论研究，包括颗粒受力分析和脱离方式两个方面。以天津市一个典型含水层为例，对该含水层的临界水力坡度和临界渗流速度进行了计算，并结合热泵取水量、含水层厚度和井径尺寸等参数进行了分析。结果表明在取水量相同的条件下，含水层厚度与井径尺寸对颗粒的运动有直接影响。为解决井壁坍塌和井壁周围颗粒重组等问题提供了理论依据。

Abstract:

The mobilization theory of aquifer particles induced by groundwater heat pump(GWSHP) pumping is theoretically studied in this work, which includes analysis of forces working on the particles and the releasing mechanism. A case study, which represents a kind of typical aquifer in Tianjin, is carried out. Such parameters as water discharge, aquifer thickness and borehole diameter are analyzed based on the calculated values of critical hydraulic gradient and the critical seepage velocity. The present studies indicate that the particle mobilization is directly influenced by the aquifer thickness and the borehole diameter under the same water discharge. It is aimed to provide some theoretical basis to solve the problems of borehole collapse and particle regrouping in the GWSHP’s long-term operation.