【作者】 于子望；

【导师】 张延军；

【作者基本信息】 吉林大学 ， 地质工程， 2009， 硕士

【摘要】 当今社会能源问题已经成为的一个重大问题,人们正不断的开发新能源来缓解由于能源紧缺所带来的压力。其中桩埋管作为地源热泵的一种新的埋管方式,又以其环保、节能、运行可靠等特点在国外得到了广泛的应用。它把地下U型管换热器埋于建筑物混凝土桩基中,使其与建筑结构相结合,充分地利用了建筑物的面积,通过桩基与周围大地形成换热,从而减少了钻孔和埋管费用。这种技术的推广将为绿地面积小、容积率高的建筑物提供新的应用空间,十分适合我国的国情。然而有关其考虑地下水渗流的力场和温度场的耦合研究较为落后,并且大都是应用于石油天然气开发和核废料的储存等领域,而有关于地源热泵地下系统尤其是桩埋管换热器THM耦合的则需要进一步的理论和试验研究。基于此,本文在自然基金《地能转换桩-土水系统的THM耦合效应机理研究》(No.40472134)的支持下,对这种新的地能换热装置在热流固耦合理论下的力学、导热特性展开了理论和试验研究。通过室内试验对不同换热管类型的桩进行竖向的荷载测定,分析桩中换热装置对桩的强度的影响。在桩中分别加入U型管、螺旋管,制作出七个桩来模拟埋管换热桩。对实验结果进行了对比分析,得到了考虑U型管总截面积的理论桩身强度与实际值之间的近线性关系。基于V.C.Mei传热模型对桩埋管导热过程进行了初步研究并给定了起在各个接触面的边界条件。探讨了TH耦合的理论模型,考虑了地下水流动的影响下,建立桩埋管换热地下温度场的数值模型,通过大量的三维水-热耦合计算模拟研究,得出了温度场扩散范围随流速变化的走势。在此基础上,推导建立了THM(Thermo-hydro-mechanical)三场耦合的数学模型,并应用其模拟某桩埋管换热的工程试验,分析了模型参数在热-流-力三场耦合下的特性及其规律。更多还原

【Abstract】 Along with science’s and technology’s rapid development, society’s unceasing progress, the energy question became now a society’s major issue already. People are unceasingly developing new energy alleviates. The heat pump which takes one kind through the consumption few high grade energy and rose the quantity of heat from the low temperature level to the high temperature level special installment has received people’s favor. And the ground source heat pump also by its characteristics of environmental protection, the energy conservation, the movement reliable and so on obtained the widespread application in overseas. Along with the energy structure’s continual readjustment, the public environmental consciousness’s unceasing enhancement, this technology will certainly to have a bigger development.In the ground source heat pump’s family, the heat exchanger pile installation belongs to the new technology. Through install each kind of tubular exchanger installment underground ,it keep off the earth supports and protections, ground reinforcement and transform the shallow layer low temperature geothermal energy.It has the pile foundation and the ground source heat pump function together in advance. This also saves the drill hole working procedure, saves the operating charges and use building ledger wall’s area effective. This kind of technology’s promotion will be provides the new application space for the small green space area, the volume fraction high building and very suits our country’s national condition. It will certainly to become the new application direction.The heat exchanger pile model is based on the Fourier heat conduction law in the early time which had not considered that the flowing of ground water and the convection and the machinery disseminate the function, moreover, because all theories are the drill hole bury the heat interchanger, also had never considered the heat interchanger’s temperature stress field and the bias field. Generally only uses the simple compound unstable state heat conduction which neglect mechanics field, using a thermal conductivity added value describes in the ground caloric coupling method the moisture content and the air transport process function are bound to bring the big error obviously which the corresponding result will be lead heat interchanger’s size to be big and will affect the normal operation of project. And domestic and foreign started some related THM coupling research in the 1990s is applies in petroleum natural gas development and nuclear waste storage and so on. Their fundamental research was the crevasse rock mass coupling question and had does not have THM coupling research of ground place source heat pump underground system particularly the heat exchanger pile.Based on above this article under the support of the natural fund "Heat Transform Pile– Hydro-Soil system’s THM Coupling effect Mechanism Research" (No.40472134) did theory and the experimental study the mechanics and heat conduction character of this kind of new heat-exchanger pile under heat flow solid coupling theory .In this experiment it did not consider that limits side. It carried on the vertical load determination to the different tube type in pile and analyzed the influence of heat-exchanger rig to the pile intensity. Joined the U tube and the spiral pipes to manufacture seven piles, for normal reinforced concrete simulation pile (did not increase any tube) to take the contrast to be tender, two join a U tube, two join three U tubes and two join a spiral pipe. It had analyzed to the experimental result, obtained the relations of the theory supporting capacity and the actual supporting capacity with respect to the U tube quantity.With summarize the theory of predecessor’s heat transfer model, it has conducted the preliminary study based on the V.C.Mei heat transfer model to the heat exchanger pile. This model was builded on conservation of energy’s foundation and constituted by the system energy balance conbined with heat conductivity equation. It was obtained through a series of suppositions and was assigned boundary condition in each contact face.It was discussed the TH coupling theoretical model which had considered the ground water influence, established the the numerical model of heat exchanger pile installation underground temperature field and analyzed law of development to temperature field under the different ground water speed of flow law of development to temperature field. Through the massive hydro-thermal coupling research, the proportion relationship between temperature field and time was found. It also has contrasted the temperature change rule of different observation point and obtained the temperature proportional relationship under the different ground water flow speed.It was established the THM three coupling mathematical models from the distortion field, the equation of continuity and in the energy- conservation equation in the foundation of several front chapter of experiments and theories. Then the model was used to simulated a heat exchanger pile engineering test which did in Sweden Lausanne by Lyesse Laloui et al. Model serviceability will be established by contrast of simulate and the experimental value. A large number of iterations of numerical simulation work was done by change the model’s parameter condition and did some classified contrast and analysis. The contrastive analysis was also done to the stress causes by heat transfer and by the building load. It was also analyzed the stress strain of the pile and surround soil as well as the temperature field development rule considers the THM coupling.This paper’s research will rationalize the type, quantity design of heat transfer tube in pile and quantity design more rationalize and provide rationale and technology for the heat transfer model, the hydro- thermal coupling, the thermal- mechanic coupling as well as the THM coupling and the parameter about the heat exchanger pile.更多还原