共查询到17条相似文献,搜索用时 250 毫秒
1.
通过对某地源热泵现场测试孔的热物性测试,由热响应测试仪器测得现场埋置岩土中U形换热器循环介质的进出水温度、流量等相关参数,并利用线热源模型计算了岩土综合导热系数、钻孔内热阻相关参数,为该地区地源热泵系统设计提供正确的设计参数。 相似文献
2.
文章以天津填海造陆地区某项目4种冷热源比选方案为基础,进行了能源利用合理性评价与冷热源形式经济性评价。确定冷热源方案为垂直埋管地源热泵系统后,完成岩土热响应试验,通过对地质情况分析、原始温度测试、地埋管换热孔进出水温度变化情况分析,计算出岩土导热系数。 相似文献
3.
地埋管换热器热响应测试与模拟研究 总被引:1,自引:0,他引:1
对48m深双U型地埋管进行热响应测试,并使用线热源模型对实验数据进行分析。计算得到该测试地点土壤导热系数为1.44W/(m.K),进水温度为37℃时,每米井深散热量为91.14W/m。在实验的基础上,建立地埋管全尺寸换热模型,该模型水流进口条件与实验一致,土壤导热系数、地下初始温度等均为实验测得数据。以换热量比较,模拟结果与实验结果相差6.8%。在验证模型精度的基础上,对50m、60m、70m埋深的单U及双U型换热器进行模拟比较。进水温度为36.85℃时,对于单U型管,单位井深换热量分别为59.19W/m、56.23W/m、53.40W/m;对于双U型管,单位井深换热量分别为94.16W/m、90.00W/m、85.93W/m。不同深度的地埋管,双U型换热性能优于单U型,散热量约高37%,但是单U型管出水温度低于双U型管。 相似文献
4.
5.
6.
7.
U型管地热换热器热作用半径的数值模拟 总被引:2,自引:0,他引:2
针对竖直U型埋管地热换热器土壤传热范围的问题,建立了U型埋地换热器三维非稳态传热模型。U型管与土壤间的传热受诸多因素的影响,本文采用CFD软件FLUENT对U型管的进口温度、进口流速、运行时间、土壤初始温度以及土壤热物性在夏季不同工况下对U型管热作用半径的影响进行了数值模拟研究。本文得出的结果可以用来指导地源热泵工程的设计。 相似文献
8.
《建筑热能通风空调》2016,(8)
结合岩土热响应试验,对岩土热响应试验结果的获取方法进行了分析对比,得出无功循环方式获取土壤平均温度和线热源法计算导热系数已完全满足工程需要。对双U形式不同管径不同深度的地埋管换热器取同一计算条件对换热性能进行了比较,得出120 m深时DN32双U管换热性能较DN25双U管提高20%~35%,而150 m深时,仅提高3%左右;同一管径条件下,增大换热孔孔深延米换热量的数值随之减小。结合现场试验对影响因素进行了分析,得出无功循环初始平均温度随流体流速增大而减小,计算导热系数随初始平均温度增大而减小,延米换热量随初始平均温度增大而增大;计算导热系数随回填材料导热系数增大而增大,增长至一定值后趋于稳定,延米换热量随之呈先增后减曲线变化;延米换热量数值受换热孔深增大而减小,且随管径变小影响越来越小。 相似文献
9.
10.
介绍了垂直埋管地下换热器的传热模型,并对常熟市某国际会议中心项目垂直地埋管换热系统利用恒温法进行了热响应测试和分析。通过整理和分析试验数据,获得了单孔的换热能力和地层的导热系数等参数,为地源热泵设计和施工提供了基础资料。 相似文献
11.
Analytical and semi-analytical solutions for short-time transient response of ground heat exchangers
Short-time transient temperature response of ground heat exchangers in ground source heat pump systems is of considerable interest as this has important bearing on the aggregate design length of the U-tube heat exchangers. Recent analytical solutions take into account the thermal capacity of the aggregate fluid mass in the system representing the U-tubes as an equivalent single core. This however is limited to only homogenous media. In this paper, Laplace domain solutions have been obtained for the equivalent single core of the U-tube in grouted boreholes. Both the average fluid temperature and borehole boundary temperature have been obtained using Gaver–Stehfest numerical inversion algorithm from these solutions. The temperature values obtained match the results of finite elements models of the actual U-tube geometry of the grouted borehole. With this solution it is possible to obtain both borehole boundary temperatures and the usual water temperature values. Results of this work show that the ‘early time’ borehole boundary temperature data can be analyzed for measurement of the thermal conductivity of the medium in thermal response tests. This approach would reduce the duration of the thermal response test in single strata subsurface ground zone. This solution also can be incorporated in the building energy simulation programs. 相似文献
12.
本文采用恒热流法对某地源热泵系统工程进行土壤热响应测试,数据处理采用线热源模型,线性关系推导法得到测试结果。现场钻孔埋设单U型、双U型地埋管换热器,钻井深度有80m、100m,比较不同埋管形式下测试出的单位井深换热量、土壤导热系数、钻孔热阻及土壤热扩散率之间的关系,并分析结果差异的原因,为实际设计提供可靠依据。 相似文献
13.
Dipl.-Geol. Kathrin Menberg Dr. Hagen Steger Dr. Roman Zorn Dipl.-Phys. Manfred Reuß Dipl.-Phys. Markus Pröll Dr. Peter Bayer Jun.-Prof. Dr. Philipp Blum 《Grundwasser》2013,18(2):103-116
For the planning and design of borehole heat exchangers systems, the knowledge of the thermophysical ground parameters is essential. In this study, several methods for the determination of thermal conductivity were used on a borehole for a ground source heat pump system. Thermal conductivity was measured on core samples using laboratory tests and likewise a Thermal Response Test (TRT) was carried out. In addition, several ground parameters, such as water content and carbonate content, were determined by laboratory tests. With these parameters the thermal conductivity was then calculated using different theoretical models. The best agreement between measured and calculated values for thermal conductivities was obtained using the geometric mean. The mean error of these calculations in this study is about 12 %. Thus, the accuracy of the calculation of thermal conductivity is lower than the accuracy of the laboratory tests or TRTs, but it nevertheless represents a simple and more accurate method than parameter estimations based on published values. 相似文献
14.
地下换热器传热模型是地源热泵系统长期运行性能预测的基础。基于合理的简化处理,在柱坐标下建立了一种新的单孔及多孔竖埋U形换热器一维非稳态传热数值模型,并给出了求解算法。该模型基于任意时变冷热负荷,预测换热器进出水温及地温。用3组单孔实测数据进行了验证,出口水温模拟值与实测值最大绝对偏差为0.8℃,说明模型可靠准确。全年逐时动态模拟消耗机时不足1 min。综观计算功能、准确性及快速性,本模型可以作为地源热泵地下换热器设计分析的强有力的工具。 相似文献
15.
16.
垂直U型管式埋地换热器热阻分析 总被引:1,自引:0,他引:1
本文介绍了土壤源热泵垂直埋管式换热器的三种不同简易计算模型,引入不同的导热形状因子,并利用G函数来确定管井井壁的温度。通过地源热泵的设计软件分析了回填材料与管材的热物性、管井与U型管以及它们之间的几何特征对管井热阻的影响。 相似文献