集群地埋管换热器分区运行策略研究

发布时间：2018-01-24 05:49

本文关键词： 地热换热器负荷不平衡热/冷量累积分区运行　出处：《山东建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：地源热泵作为一种节能环保的新技术得到了推广和使用,但是随着运行时间增长也出现了一些问题:在夏季负荷大于冬季负荷的热带地区和冬季负荷大于夏季负荷的严寒地区,由于冬夏季取放热负荷不平衡,长期运行后会导致地埋管群中心区域有多余的热/冷量累积,土壤温度严重偏离初始温度,系统的运行效率下降。分区运行方法是最近提出的一种能够减缓地埋管群中心区域热/冷量累积的新方法,目前该技术不够完善,还在探索之中。本文以夏季负荷大与冬季负荷为例,基于集群有限长线热源模型,以地热换热器内部区域冬夏季负荷趋于相对平衡为目标,结合冬夏季各运行月负荷情况提出多种分区运行策略,之后分别从夏冬季负荷比、土壤热物性参数和钻孔间距等方面研究分析12×12管群布置的地源热泵系统运行到第20年夏季结束时的地下土壤温度场分布。结果表明,夏冬季负荷比小于1.5:1时,不采用分区运行方式也能保证地源热泵系统正常运行;夏冬季负荷在1.5:1~2.0:1之间时,建议考虑采用大负荷季节运行所有埋管,小负荷季节停止运行外围一圈埋管(即策略二)的分区运行方法;夏冬季负荷比、钻孔间距和土壤体积比热越大、土壤导热系数越小,采用分区运行策略后中心区域累积的热量越少;通过对各分区策略的地下土壤温度分布进行分析,钻孔间距、土壤导热系数和土壤体积比热较小时,建议采用大负荷季节运行所有埋管,小负荷季节停止运行外围两圈埋管(即策略三)的分区运行方法;而当钻孔间距、土壤导热系数和土壤体积比热较大时,建议采用大负荷季节运行所有埋管,小负荷季节停止运行外围一圈埋管(即策略二)的分区运行方法。
[Abstract]:As a new energy saving and environmental protection technology, ground-source heat pump has been popularized and used. However, with the increase of operating time, there are some problems: in the tropical areas where the summer load is larger than the winter load, and in the severe area where the winter load is larger than the summer load, because of the imbalance of the heat transfer load in winter and summer. Long-term operation will lead to the accumulation of excess heat / cooling in the central area of the buried pipe group, and the soil temperature will deviate from the initial temperature seriously. The operation efficiency of the system is decreased. The partition operation method is a new method which can slow down the accumulation of heat / cold rate in the central area of the buried pipe group recently, but the technology is not perfect at present. This paper takes the heavy load in summer and the load in winter as an example, based on the cluster finite line heat source model, taking the relative balance of winter and summer load in the inner region of geothermal heat exchanger as the goal. Combined with the monthly load of each operation in winter and summer, the paper puts forward a variety of zonal operation strategies, and then respectively from summer to winter load ratio. The distribution of the ground temperature field of the geothermal heat pump system arranged by 12 脳 12 pipe group up to the end of the 20th summer is studied and analyzed from the aspects of soil thermal properties parameters and borehole spacing. The results show that the temperature field of the ground source heat pump system is very important. When the load ratio is less than 1.5: 1 in summer and winter, the normal operation of ground source heat pump system can be ensured without using the zonal operation mode. When the load in summer and winter is between 1.5: 1 and 2.0: 1, it is suggested to consider the method of running all buried pipes in heavy load season and stopping one circle of buried pipe (strategy II) in small load season. The load ratio in summer and winter, the larger the borehole spacing and the specific heat of soil volume, the smaller the thermal conductivity of the soil, and the less heat accumulated in the central area after adopting the zonal operation strategy. Based on the analysis of soil temperature distribution in different subzone strategies, the borehole spacing, soil thermal conductivity and specific heat of soil volume are small, and it is suggested that all buried pipes should be operated in heavy load season. The partition operation method of two-circle buried pipe (i.e. strategy III) in small load season; However, when the borehole spacing, soil thermal conductivity and specific heat of soil volume are large, it is suggested that all buried pipes should be operated in the heavy load season and the surrounding buried pipes (i.e. strategy 2) in the small load season.
【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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