中南丘陵地区地源热泵系统优化设计的模拟研究

发布时间：2018-01-10 02:20

本文关键词：中南丘陵地区地源热泵系统优化设计的模拟研究　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着社会经济高速发展,建筑能耗也迅速增长,能源问题和环境问题渐渐凸显。节能减排政策应运而生。地源热泵作为利用可再生能源的技术,以其环保、节能等特点而得到广泛的应用。然而在实际工程中,部分地源热泵系统并没体现其性能上的优越性,反而因其短暂的使用寿命和较大的初投资而被人诟病。研究者往往将问题的根源归结于土壤的换热性能和土壤热平衡问题,却忽视了管网水力特性对系统运行效率的影响。本文认为管网水力特性与土壤热平衡对地源热泵系统高效运行的作用同等重要。为此,本文以中南丘陵地区某展示馆地源热泵系统为例,采用De ST模拟建筑全年动态负荷;利用TRNSYS16建立仿真模型,研究影响土壤平均温度的因素和其合理的设计范围,并探讨不同因素的影响程度;同时利用Pipe Flow Expert软件建立管网模型,分析管网的水力特性;最后利用TRNSYS16对系统进行建模,模拟系统的长期运行特性及管网阻力与土壤热平衡的关系,并以全年输送系统综合COP为评价指标,对钻井深度、钻井间距、埋管长度和埋管形式进行优化。研究结果表明:1.在地源热泵系统承担的建筑负荷中,负荷率低于40%的时间占到41%;地埋管全年累积负荷不平衡率为67.3%;2.以埋管周围平均温度作为参考标准,如果考虑系统的初投资成本,并不考虑系统的间歇运行,钻井最佳深度为60m-100m,钻井最佳间距为4.0m-5.0m,回填材料的最佳导热系数为1.7-2.1 W/(m·K);对土壤平均温度的影响程度由主到次依次为钻井间距、钻井深度、钻井数量、回填材料导热系数;3.竖直埋管部分的阻力在整个分区总阻力的80%,属于分区管网优化的重点对象;减小机房到埋管区域的管段长度能够有效地减小管网的总阻力;4.对于本系统,以全年地埋管侧输送系统综合COP作为评价指标,在考虑管网水力特性、土壤热平衡及初投资成本的前提下,钻井深度宜为60m-90m,钻井间距宜为4.0m-5.0m。保证钻井深度相同时,双U型埋管的COP高于单U;保证埋管长度相同时,存在一个临界管长,当地埋管长度小于24000m时,宜采用单U埋管,当地埋管长度大于24000m时,则宜采用双U埋管。本文对中南丘陵地区某展示馆地源热泵系统进行模拟研究,为地源热泵系统的优化设计提供理论依据和指导。本文的结论对于类似地区同样适用。
[Abstract]:With the rapid development of economy, energy consumption is also growing rapidly, energy and environmental problems gradually emerged. Energy saving and emission reduction policy came into being. The ground source heat pump as the use of renewable energy technology, with its environmental protection, energy saving features are widely used in practical engineering. However, part of the ground source heat pump system does not reflect its superiority performance on the contrary, because of its short service life and large initial investment and being criticized. Researchers tend to thermal properties and soil heat balance at the root of the problem is due to the soil, but ignore the influence of hydraulic characteristics on the running efficiency of the system. This paper argues that the hydraulic characteristics and soil heat balance of pipe network the operation of GSHP system are equally important role. Therefore, an exhibition hall in the south of GSHP system in hilly area as an example, using the De ST simulation of building annual dynamic negative Holland; using TRNSYS16 to build the simulation model, the influencing factors on the average temperature of the soil and the reasonable range of the design, and to explore the influence of different factors; at the same time model using Pipe Flow Expert software, analysis of hydraulic characteristics of pipe network; finally the use of TRNSYS16 for system modeling, the relationship between long-term operating characteristics and pipe resistance simulation system with the soil heat balance, and to the comprehensive transportation system COP as the evaluation index, the drilling depth, drilling spacing, tube length and tube form were optimized. The results show that: 1. in the construction of the load borne ground source heat pump system, the load is lower than 40% of the time accounted for 41%; annual cumulative buried pipe the load imbalance rate is 67.3% to 2.; the average temperature around the pipe as the reference standard, if we consider the system initial investment cost, does not consider the intermittent operation of the system, the optimal drilling depth For 60m-100m, the optimal drilling spacing is 4.0m-5.0m, the best thermal conductivity of backfill material for 1.7-2.1 W/ (m, K); the degree of impact on the average temperature of the soil from the primary to secondary are drilling spacing, drilling depth, drilling quantity, the thermal conductivity of backfill materials; pipe buried 3. vertical resistance in the whole area total resistance 80%, belonging to the district pipe network optimization focus; the total resistance decreases to room area of the buried pipe pipe length can effectively reduce the network; 4. for this system, the tube side conveying system integrated COP as the evaluation index to the ground, considering the hydraulic characteristics and soil heat balance and the initial investment cost under the premise. Drilling depth should be 60m-90m, wells spacing should be 4.0m-5.0m. to ensure the drilling depth is same, the double U tube COP is higher than that of single U; ensure the tube length is the same, there is a critical length, when the pipe length is less than 24000m When, should adopt the single U pipe, tube length is greater than the 24000m buried local, are advised to adopt double U tube. The simulation results of a museum of GSHP system in hilly area of South China, provide theoretical basis and guidance for the design of the GSHP system. The conclusion of this paper is also applicable to class like area.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU83

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