非饱和带在水源热泵工程中的导热特性研究

发布时间：2018-04-21 16:43

本文选题：地下水源热泵 + 非饱和带　；参考：《沈阳建筑大学》2013年硕士论文

【摘要】：地下水源热泵系统是一种利用浅层地能的既可供热又可制冷的高效节能空调系统,在全球范围内应用越来越广泛。然由于热泵技术的不成熟,造成地下水源热泵工程在运行过程中常造成回灌困难、“热贯通”及环境污染等一系列问题。地下水源热泵回灌过程经常在非饱和带的渗透量较大且渗透效果良好,故准确掌握地下水源热泵工程运行过程非饱和带水位和温度场的变化特性尤为重要。否则地下水源热泵工程运行时不仅会使热泵工程运行效率降低,能源造成浪费,对环境也会构成一定危害。为全面掌握非饱和带在水源热泵工程运行中的导热特性,提高地下水源热泵工程运行效率,本为以沈阳城区为例,对不同岩性条件下的热泵运行导热特性进行研究。首先,本文通过收集沈阳城区今年水文地质条件,确定不同地区岩性特征,确定不同区域砂土特性。根据砂土岩性特征,在沈阳城区选取13个热泵工程,收集热泵工程场区在2011年不同时间段内不同深度处的温度值,对不同深度、不同时段的抽灌井水温恢复幅度与速率进行监测和分析,研究地下水源热泵工程采暖后场区地下水温恢复特性。研究表明,地下水温度随地层埋深增加不断升高,在25m-35m深度范围内地下水温度处于稳定,称为恒温带。根据各监测点温度值建立沈阳城区恒温带温度分区图,为试验取样和建立模型提供条件和依据。为研究砂土在回灌过程中的导热特性,本文采用室内试验的方法,分别测取不同岩性条件下砂土的导热特性和机械弥散特性。砂土导热特性的研究,文章应用热探针法,测取了不同含水率条件下砂土导热系数。研究表明,热导率值随着含水率的增大而增大,在含水率h15%状态下砂土导热系数基本处于稳定状态,故导热系数在砂土非饱和状态下对热弥散度影响不大。为测取不同回灌条件下热弥散度变化特性,本文通过建立水平土柱模型,应用一维非饱和砂土热量运移定解方程,室内测取不同回灌温度条件下粗砂、中砂和细砂热弥散度并对其变化特性进行分析研究。试验表明,同一回灌温度条件下,中砂热弥散度最大,粗砂次之,细砂最小；对于同一类型砂土,不同回灌水温度条件下热弥散度随温度升高呈上升趋势；热泵工程布井过程应准确掌握热弥散度的变化特性,优化布井提高热泵效率。其次,为验证本次试验的可行性和准确性,本次选取鑫淼酒店和红田美林居两个热泵工程两个运行热泵工程,对热泵工程监测数值与试验数据条件下的模拟值进行对比分析。经分析试验数据条件下模拟数值与实际工程监测值之间差值较小,表明本次试验数据误差较小,试验数据准确可靠。最后,为提高本次使用的实用性,试验完成后选取沈阳城区在建工程千缘商会大厦热泵工程和乐天游乐场热泵工程。通过沈阳城区砂土岩性分区图和地温分区图,选取相应的热弥散度试验数值,应用软件模拟两个在建土程运行过程中温度场的变化特性,对实际工程的可行性和可靠性进行分析论证,提出合理的布井方案。
[Abstract]:The underground water source heat pump system is a kind of high efficiency and energy saving air conditioning system, which can be used both for heating and refrigeration in shallow ground. It is widely used in the world. However, because of the immature heat pump technology, the underground water source heat pump engineering often causes a series of problems, such as recharge difficulties, "heat through" and environmental pollution. The permeability of underground water source heat pump is often large and has good penetration effect in the unsaturated zone. Therefore, it is very important to grasp the change characteristics of the water level and temperature field of the underground water source heat pump engineering. Otherwise, the operation efficiency of the heat pump project will not only reduce the efficiency of the heat pump, but the energy will cause the wave. Fee, to the environment can also constitute a certain hazard.
In order to master the heat conduction characteristics of the unsaturated zone in the operation of water source heat pump, and to improve the operating efficiency of the underground water source heat pump, this paper takes the urban area of Shenyang as an example to study the heat conduction characteristics of the heat pump under different lithologic conditions.
First, by collecting the hydrological and geological conditions of Shenyang city this year, this paper determines the characteristics of different regions and determines the characteristics of sandy soil in different regions. According to the characteristics of sand and soil, 13 heat pump projects are selected in the urban area of Shenyang to collect the temperature values at different depths of different time periods in different time periods of the heat pump field area in 2011, and to different depths and different periods. The water temperature recovery amplitude and rate of the pumping well are monitored and analyzed. The characteristics of the groundwater temperature recovery in the field area of the ground water source heat pump project are studied. The study shows that the groundwater temperature increases continuously with the ground depth, and the water temperature in the 25m-35m depth is stable, which is called the constant temperature zone. According to the temperature value of each monitoring point, Shenyang is established. The temperature zoning map of the urban constant temperature zone provides the conditions and basis for the test sampling and the establishment of the model.
In order to study the thermal conductivity of sand in the process of recharge, the thermal conductivity and mechanical dispersion characteristics of sand under different lithologic conditions were measured in this paper.
Research on thermal conductivity of sand soil, the thermal conductivity of sand under different water content has been measured by the thermal probe method. The study shows that the thermal conductivity increases with the increase of water content, and the thermal conductivity of sand is basically in the stable state under the condition of water content h15%, so the influence of the number of thermal conductivity on the thermal dispersion under the unsaturated state of sand is not. Big.
In order to measure the variation characteristics of the thermal dispersion under different recharge conditions, by establishing a horizontal soil column model and applying the heat transfer equation of one dimension unsaturated sand, the coarse sand, the heat dispersion of medium sand and fine sand under different recharge temperatures were measured and analyzed. The experiment showed that under the same recharge temperature condition, the thermal dispersion of sand and fine sand was analyzed. The heat dispersion of the medium sand is the largest, the coarse sand is the second and the fine sand is the smallest. For the same type of sand, the thermal dispersion of the heat heat pump should be increased with the temperature rising, and the heat pump project should accurately grasp the change characteristic of the heat mass and optimize the well heat pump efficiency.
Secondly, in order to verify the feasibility and accuracy of the test, two heat pump projects of two heat pump projects in Xin Miao Hotel and red field Merrill are selected, and the simulated values of the heat pump engineering monitoring values and the experimental data are compared and analyzed. The difference between the simulated value and the actual project monitoring value under the condition of the analysis test data is analyzed. It shows that the error of the test data is small, and the test data is accurate and reliable.
At last, in order to improve the practicability of this use, the heat pump project of Shenyang urban area, the heat pump project of Qian Yuan chamber of Commerce building and the music field heat pump project are selected. The corresponding thermal dispersion test values are selected through the zoning map of sand soil lithology and the ground temperature zoning map of Shenyang City, and the application software is used to simulate the temperature of two processes during the running process of the soil construction process. The feasibility and reliability of the actual project are analyzed and demonstrated, and a reasonable well pattern is put forward.

【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU83

【参考文献】