岩土热响应散热修正瞬态模拟及关键参数研究

A THERMAL-DISSIPATION-CORRECTED TRANSIENT SIMULATION ON TRT AND KEY PARAMETERS STUDY

提出一种带散热修正的地埋管储热的TRNSYS瞬态计算模型,考虑管道散热及地表空气对流散热损失;在山东省滨州市进行实地热响应测试,通过对实验测试井供回水温度的模拟,验证模型准确性。同时,模拟分析循环流量、加热功率等关键参数对岩土导热系数、钻孔热阻、延米换热量辨识精度的影响。研究结果表明,测试持续时间对岩土导热系数辨识精度影响高达24.88%,其次分别是加热功率、初始舍弃时间、循环流量、回填材料导热系数。加热功率对延米换热量影响最高达75.01%。

Based on the duct ground heat storage model on TRNSYS software,a thermal-dissipation-corrected transient model which takes the heat dissipation from ground and testing tube surfaces into consideration is established. An experimental platform is built for in-situ thermal response test(in-situ TRT)in Shandong Province and the presented model is verified by in-situ TRT for similar inlet and outlet temperatures of borehole heat exchanger(BHE).Furthermore,the key parameters,such as injected heat power,circulation flowrate,etc. are analyzed to study the influences on identified soil thermal conductivity,borehole thermal resistance and heat flow per unit length. It is showed that test duration has largest 24.88% impact on identification precision of soil thermal conductivity,followed by injected heat power,abandoned initial time,the circulation flowrate and backfill material conductivity;The injected heat power has the biggest influence on heat flow per unit length of 75.01% than testing results.