摘要
借鉴岩土热响应试验,基于向地埋管施加定加热功率的现场测量方法,设计小型地埋管换热试验系统,采用基于无限长线热源的两参数估算法对岩土热物性参数(土壤热导率、土壤单位体积热容)进行估算,分析地埋管周围土壤温度场分布。介绍试验系统流程及主要试验装置。分别在加热功率为35、45、55、80 W,循环水质量流量为90 kg/h条件下,测试地埋管进出口循环水平均温度随测试时间的变化,估算土壤热导率、土壤单位体积热容,测试地埋管两侧土壤温度场分布。一定加热功率下,地埋管进出口循环水平均温度随测试时间先快速上升,然后趋于平缓。加热功率越大,初期地埋管进出口循环水平均温度上升速率越大,达到稳定状态的时间越长,地埋管进出口循环水平均温度越高。不同加热功率条件下,土壤单位体积热容均保持在106J/(m^3·K)量级,说明计算结果可靠。随着加热功率的增大,土壤热导率总体上呈逐渐增大的趋势。在相同加热功率下,随着远离地埋管,土壤温度呈下降趋势。随着加热功率的增大,地埋管的热影响半径逐渐增大。
Referencing the geoteehnieal thermal response test,a small-scale buried pipe heat exchange test system is designed based on the on-site measurement method of applying fixed heating power to the buried pipe. The geotechnical thermal physical parameters （soil thermal conductivity and soil unit volume heat capacity） are estimated by using two parameters estimation method based on infinite long line heat somme, and the distribution of soil temperature field around the bin-led pipe is analyzed. The test system process and main test devices are introduced. Under the condition that the heating power is 35,45,55 and 80 W respectively, and the circulating water mass flow rate is 90 kg/h, the variation of the average temperature of the circulating water in the inlet and outlet of the buried pipe with the test time is tested, the soil thermal conductivity and the soil unit volume heat capacity are estimated, and the distribution of soil temperature field on both sides of buried pipe is tested. Under certain heating power, the average temperature of circulating water in the inlet and outlet of the buried pipe rises rapidly first, then it tends to gentle. The higher the heating power, the higher the average temperature rise rate of the circulating water in the inlet and outlet of the initial stage buried pipe, the longer the time to reach steady state,and the higher the average temperature of the circulating water in the inlet and outlet of the buried pipe. Soil unit volume heat capacity is maintained at 106 J/（m3 · K）,indicating that the calculation results are reliable. With the increase of heating power, the soil thermal conductivity generally increases gradually, and the soil unit volume heat capacity decreases gradually. Under the same heating power, the soil temperature shows a downward trend with the distance from the buried pipe. With the increase of heating power,the thermal influence radius of the buried pipe increases gradually.
作者
刘朝阳
孙心明
胡平放
雷飞
朱娜
邢路
LIU Chaoyang;SUN Xinming;HU Pingfang;LEI Fei;ZHU Na;XING Lu
出处
《煤气与热力》
2018年第9期5-9,共5页
Gas & Heat
基金
国家自然科学基金(51678262)
住建部科学技术项目计划(2016-K1-004)
关键词
换热试验
地埋管
岩土热物性参数
热影响半径
heat exchange test
buried pipe
geotechnical thermal physical parameters
thremal influence radius
