穷举搜索法确定地下土壤热物性参数及准确性分析
发布时间：2019-03-20 08:48
【摘要】：地源热泵系统可以有效利用浅层地热能,对环境影响小、寿命长、效能系数高,作为一项可再生能源技术近年来得到快速发展。获取准确的地下土壤热物性参数是合理设计地埋管长度、提高系统有效利用率、降低系统初投资的关键,对推广地源热泵技术具有重要意义。恒热流测试法是目前获取地下土壤热物性参数的主要方法,但是,目前研究中针对恒热流测试时间长短的问题尚没有明确定论,测试过程中,通常人为设定测试时间而不是根据现场测试结果准确性决定测试时间,这可能会导致测试结果准确性不高。另外,测试分析过程中采用的优化方法通常仅能得到较为准确的导热系数值,而钻孔内热阻和容积比热计算结果可信度相对较差。针对上述问题,论文提出了利用穷举搜索法确定热物性参数的测试分析方法。论文比较了二参数估计法、三参数估计法以及线热源模型、柱热源模型、实心柱热源模型在计算地下土壤热物性参数方面的结果准确性,发现三参数估计法计算结果较二参数估计法准确,线热源模型计算速度快、准确度较高,更适于工程应用。对穷举搜索法、遗传算法、蚁群算法、复形调优法的计算结果准确性进行了对比分析,并利用实验和实际工程进行检验,表明穷举搜索法较其他几种方法得到的热物性参数更具可信性。开发了地下土壤热物性测试计算软件,该软件在现场进行地下土壤热物性测试时,可实时计算分析热物性参数结果,当得到稳定的测试结果后,自动发出测试停止信号,并输出得到土壤热物性参数最终测试结果,从而避免因人为决断测试时间而可能导致测试结果准确性不高的情况。
[Abstract]:The ground-source heat pump (GSHP) system can utilize the shallow geothermal energy effectively, has little influence on the environment, long life and high efficiency coefficient. As a renewable energy technology, GSHP has been developed rapidly in recent years. Obtaining accurate thermal parameters of underground soil is the key to reasonably design the length of buried pipe, improve the effective utilization ratio of the system and reduce the initial investment of the system. It is of great significance to popularize the technology of ground source heat pump (GSHP). The method of constant heat flow measurement is the main method to obtain the thermal physical parameters of underground soil at present. However, there is no clear conclusion about the length of testing time of constant heat flow in the current research, in the process of testing, there is no clear conclusion about the length of test time. The test time is usually set artificially rather than determined by the accuracy of the field test results, which may lead to low accuracy of the test results. In addition, the optimization method used in the test and analysis is usually only able to obtain more accurate thermal conductivity values, but the reliability of the calculation results of thermal resistance and volume specific heat in borehole is relatively poor. In order to solve the above problems, this paper presents a test and analysis method to determine thermal physical parameters by exhaustive search method. The accuracy of the two-parameter estimation method, the three-parameter estimation method, the linear heat source model, the column heat source model and the solid column heat source model in calculating the thermal physical parameters of underground soil are compared in this paper. It is found that the calculation results of the three-parameter estimation method are more accurate than that of the two-parameter estimation method, and the calculation speed and accuracy of the linear heat source model are faster and more accurate. The accuracy of calculation results of exhaustive search method, genetic algorithm, ant colony algorithm and complex optimization method are compared and analyzed, and the results are tested by experiment and practical engineering. It is shown that the exhaustive search method is more reliable than the other methods in terms of thermophysical parameters. The software for testing and calculating the thermal properties of underground soil is developed. When testing the thermal properties of underground soil on the spot, the software can calculate and analyze the results of thermal properties parameters in real time. When the stable test results are obtained, the test stop signal will be sent out automatically. Finally, the final test results of soil thermal physical parameters are obtained, so as to avoid the situation that the accuracy of test results may not be high due to the artificial determination of test time.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU83
本文编号：2444049
[Abstract]:The ground-source heat pump (GSHP) system can utilize the shallow geothermal energy effectively, has little influence on the environment, long life and high efficiency coefficient. As a renewable energy technology, GSHP has been developed rapidly in recent years. Obtaining accurate thermal parameters of underground soil is the key to reasonably design the length of buried pipe, improve the effective utilization ratio of the system and reduce the initial investment of the system. It is of great significance to popularize the technology of ground source heat pump (GSHP). The method of constant heat flow measurement is the main method to obtain the thermal physical parameters of underground soil at present. However, there is no clear conclusion about the length of testing time of constant heat flow in the current research, in the process of testing, there is no clear conclusion about the length of test time. The test time is usually set artificially rather than determined by the accuracy of the field test results, which may lead to low accuracy of the test results. In addition, the optimization method used in the test and analysis is usually only able to obtain more accurate thermal conductivity values, but the reliability of the calculation results of thermal resistance and volume specific heat in borehole is relatively poor. In order to solve the above problems, this paper presents a test and analysis method to determine thermal physical parameters by exhaustive search method. The accuracy of the two-parameter estimation method, the three-parameter estimation method, the linear heat source model, the column heat source model and the solid column heat source model in calculating the thermal physical parameters of underground soil are compared in this paper. It is found that the calculation results of the three-parameter estimation method are more accurate than that of the two-parameter estimation method, and the calculation speed and accuracy of the linear heat source model are faster and more accurate. The accuracy of calculation results of exhaustive search method, genetic algorithm, ant colony algorithm and complex optimization method are compared and analyzed, and the results are tested by experiment and practical engineering. It is shown that the exhaustive search method is more reliable than the other methods in terms of thermophysical parameters. The software for testing and calculating the thermal properties of underground soil is developed. When testing the thermal properties of underground soil on the spot, the software can calculate and analyze the results of thermal properties parameters in real time. When the stable test results are obtained, the test stop signal will be sent out automatically. Finally, the final test results of soil thermal physical parameters are obtained, so as to avoid the situation that the accuracy of test results may not be high due to the artificial determination of test time.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU83
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相关硕士学位论文 前1条
1 吴迪;穷举搜索法确定地下土壤热物性参数及准确性分析[D];山东建筑大学;2017年
，本文编号：2444049
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