泗河冲洪积扇松散岩土体地温场自恢复能力研究

Study on Geothermal Field Recovery Ability of Soil in Alluvialproluvial Fan in Sihe River

摘要:

泗河冲洪积扇区域分布厚层松散岩土体，浅层地温能开发利用潜力巨大，查明地温场的温度自恢复能力并分析其影响因素，对地源热泵工程换热器的设计具有重要参考价值。笔者开展了多组现场热响应试验，并采用高精度测温线缆，长期监测地埋管换热器周边不同岩性、不同深度岩土体温度变化情况，以查明其变化规律。研究表明：在同种工况下，砂性土的温度恢复能力要远强于粘性土，地温的恢复主要发生在负荷停止的初期。研究区粘性土温度自恢复能力差，岩土体热物性参数、地下水径流条件、埋管循环水温度、气温及变温带深度是影响地温场恢复能力的因素。

Abstract:

The rock and soil mass with great thickness distributed in the alluvialproluvial fan in Sihe River. Shallow geothermal energy has enormous exploitation and utilization potentiality. Finding out the temperature selfrecovery capacity of the rock and soil mass and analyzing the influencing factors will provide important reference for engineering design of groundsource heat pumps. Many groups of thermal response tests have been carried out. By adopting highprecision temperature measuring cables, changes in the temperature of the rock and soil mass with different lithologies and different depths around the ground heat exchanger have been monitored in a long period. It is showed that the temperature recovery ability of sandy soil is much stronger than that of cohesive soil under the same conditions, and the recovery of soil temperature mainly occurs at the early stage of load stopping. The cohesive soil in the study area has bad temperature selfrecovery capacity, main factors that influence the geothermal field selfrecovery include thermophysical parametersof the rock and soil, runoff conditions of underground water, buried pipe circulating water temperature, air temperature and the depth of temperature changing zones.