地下水动力学条件对地下水源热泵系统的约束研究

发布时间：2018-06-07 19:35

本文选题：地温能 + 水源热泵　；参考：《合肥工业大学》2015年硕士论文

【摘要】：浅层地温能,作为清洁、环保、可再生的新型能源,具有广阔的开发利用前景。浅层地温能开发,将为有效地缓解化石能源的紧张局面和环境压力、提高节能减排效果,提供一重要支撑路径。浅层地温能利用途径,主要有地下热交换热泵(常称为地源热泵)系统、地下水源热泵系统；相对而言,地下水源热泵系统,效率较高、运行成本也相对较低。当目标含水层属地下水资源开发利用层位时,地下水源热泵一般要采取“地下水抽采～能量交换～回灌”的循环过程,以求在尽量减少工程运行对地下水资源数量与质量影响的前提下,合理利用地下水体中所赋存的热能。而地下水源热泵所依赖的地下水“抽～回”系统,其运行的稳定性、效率与成本及其对水资源影响程度等,直接受到地下水动力学条件的制约。依托安徽省内己建8处地下水源热泵工程,开展热泵系统运行稳定性、效率与成本及其对水资源影响程度的调查、监测；综合8处水源热泵工程的水文地质条件,选取泾县医院和利辛县人民医院2处工程实例为代表,由地下水-热运移机理,借助TOUGH2软件,建立水-热运移数值模拟模型,定量研究热泵运行对地下水流动力场与温度场的影响程度、范围与过程,开展地下水动力学条件对地下水源热泵系统的约束研究。研究结果表明：在地下水源热泵建设与运行过程中,存在多处水量损失,包括建井损失、洗井损失、线路损失、回灌损失、检修期间放水量、间歇期末运行初期放水量、节假日末运行初期放水量等。其中,洗井损失占总抽水量比例最大,泾县医院洗井损失水量占总抽水量的33.3%,利辛县人民医院洗井损失水量占总抽水量的85.7%；含水层渗透系数,与热泵工程对水资源影响效果关系密切,泾县医院热泵工程渗透系数为25m/d,利辛县人民医院热泵工程渗透系数为7m/d,泾县医院较利辛县人民医院热泵工程回灌损失水量少2%,且在系统运行周期末抽水井和回灌井水位影响范围分别小16.55km2和0.25km2；热泵工程的水量损失导致水位稳定延迟,含水层渗透系数越小延迟作用越明显；地下水源热泵系统运行过程中,对周边地下水温度场也将造成一定的影响。
[Abstract]:Shallow geothermal energy, as a clean, environmental protection, renewable new energy, has a broad prospect of development and utilization. The development of shallow geothermal energy will provide an important supporting path for effectively relieving the tension and environmental pressure of fossil energy and improving the effect of energy saving and emission reduction. There are mainly ground heat exchange heat pump system and ground water source heat pump system in shallow layer. In contrast, the efficiency of ground water source heat pump system is higher and the operating cost is relatively low. When the target aquifer belongs to the horizon of groundwater resources development and utilization, the groundwater source heat pump generally adopts the cycle process of "groundwater extraction ~ energy exchange ~ recharge". On the premise of minimizing the influence of engineering operation on the quantity and quality of groundwater resources, the thermal energy stored in underground water can be reasonably utilized. However, the stability, efficiency and cost of groundwater pumping system, which are relied on by ground water source heat pump, are directly restricted by the dynamic conditions of groundwater. Based on 8 underground water source heat pump projects built in Anhui Province, the operation stability, efficiency and cost of the heat pump system and its influence on water resources are investigated and monitored, and the hydrogeological conditions of 8 water source heat pump projects are synthesised. Two engineering examples, Jingxian Hospital and Lixin people's Hospital, are selected as representatives. The numerical simulation model of water-heat transport is established by means of TOUGH2 software. The influence degree, scope and process of heat pump operation on the force field and temperature field of groundwater flow are studied quantitatively, and the constraint of groundwater dynamic condition on groundwater source heat pump system is studied. The results show that there are many water losses during the construction and operation of the groundwater source heat pump, including well building loss, well washing loss, line loss, recharge loss, water release during overhaul, and initial water release at the end of intermittent operation. At the end of the holidays, the amount of water released at the initial stage of operation, etc. Among them, washing loss accounts for the largest proportion of the total pumping capacity, Jing county hospital accounts for 33.3% of the total pumping capacity, and Lixin people's Hospital accounts for 85.7% of the total pumping capacity; aquifer permeability coefficient, Is closely related to the effect of heat pump engineering on water resources, The permeability coefficient of heat pump project in Jinxian county hospital is 25m / d, and the permeability coefficient of heat pump project in Lixin county people's hospital is 7m / d. The water loss of heat pump project in Jing county hospital is 2 times less than that in Lixin people's hospital, and pumping well and recharge water at the end of system operation cycle. The influence range of well water level is small 16.55km2 and 0.25km2, respectively. The water loss of heat pump project results in the delay of water level stabilization. The smaller the aquifer permeability coefficient is, the more obvious the delayed effect is, and the lower the aquifer permeability coefficient is, the more obvious the effect will be on the temperature field of the surrounding groundwater during the operation of the groundwater source heat pump system.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU831;P641.2

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