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干旱区地理 ›› 2022, Vol. 45 ›› Issue (3): 836-846.doi: 10.12118/j.issn.1000-6060.2021.355

• 地表过程研究 • 上一篇    下一篇

兰州新区浅层地温能赋存条件及土壤源热泵系统适宜性分析

范斌1,4(),丁宏伟2(),张霖鑫1,4,张凌鹏1,4,张永军3,4   

  1. 1.甘肃省地矿局第二地质矿产勘查院,甘肃 兰州 730020
    2.甘肃省地质矿产勘查开发局,甘肃 兰州 730000
    3.甘肃省地质环境监测院,甘肃 兰州 730050
    4.甘肃省地下水工程及地热资源重点实验室,甘肃 兰州 730050
  • 收稿日期:2021-08-08 修回日期:2021-12-19 出版日期:2022-05-25 发布日期:2022-05-31
  • 通讯作者: 丁宏伟
  • 作者简介:范斌(1986-),男,硕士,高级工程师,主要从事地热地质、水文地质等方面的研究. E-mail: 362428520@qq.com
  • 基金资助:
    甘肃省职工技术创新补助资金项目(201912);甘肃省地下水工程及地热资源重点实验室开放基金项目(20190512)

Occurrence conditions of shallow geothermal energy and suitability analysis of soil source heat pump system in Lanzhou New District

FAN Bin1,4(),DING Hongwei2(),ZHANG Linxin1,4,ZHANG Lingpeng1,4,ZHANG Yongjun3,4   

  1. 1. The Second Institute of Geology and Minerals Exploration, Gansu Provincial Bureau of Geology and Minerals Exploration and Development, Lanzhou 730020, Gansu, China
    2. Gansu Provincial Bureau of Geology and Minerals Exploration and Development, Lanzhou 730000, Gansu, China
    3. Gansu Geological Environment Monitoring Institute, Lanzhou 730050, Gansu, China
    4. Gansu Provincial Key Laboratory of Groundwater Engineering and Geothermal Resources, Lanzhou 730050, Gansu, China
  • Received:2021-08-08 Revised:2021-12-19 Online:2022-05-25 Published:2022-05-31
  • Contact: Hongwei DING

摘要:

浅层地温能的开发利用有助于优化区域能源结构、节约常规化石能源、减少CO2排放。为掌握兰州新区浅层地温能的适宜性特点,对该类资源的开发规划和政府决策提供科学依据,以兰州新区建成区和规划区为研究对象,在分析区内浅层地温能赋存条件的基础上,依据掌握的多年实际勘查资料和测试数据,通过综合运用改进的层次分析法、综合指数法,对兰州新区440 km2的区域进行了土壤源热泵系统适宜性评价分析。结果表明:(1) 兰州新区拥有较为优异的浅层地温能赋存条件,区内地层结构简单且分布稳定,岩土体综合热导率、比热容、地温梯度均较高,十分有利于土壤源热泵系统的应用;而受到含水层富水性弱、水质差等因素的影响,地下水源热泵系统适宜性差。(2) 基于层次分析法建立的适宜性评价模型共划分3个属性准则和7个要素指标,采用指数标度分别构建了各层次的判断矩阵,并全部高精度通过一致性检验,同时优化了各要素参数的无量纲化方法,构建的评价模型更符合实际。(3) 研究区内对于土壤源热泵适宜性影响较大的要素主要是平均热导率和地温梯度。评价显示兰州新区土壤源热泵系统适宜、较适宜区总面积359.46 km2,占评价区总面积的81.70%,主要分布于秦王川盆地平原区,其余丘陵山区地带不适宜土壤源热泵系统的建设。评价结果对兰州新区乃至其他地质条件类似地区土壤源热泵系统的开发利用规划具有指导意义。

关键词: 浅层地温能, 土壤源热泵, 层次分析法, 适宜性, 兰州新区

Abstract:

Exploitation of shallow geothermal energy can optimize regional energy structure, save fossil fuel resources, and reduce carbon dioxide emissions. Understanding the subsurface characteristics which determine the suitability of an area for shallow geothermal energy is essential to provide a scientific basis for development planning and government decision-making. This study examines the conditions for shallow geothermal energy in both the existing built-up area and planned area of Lanzhou New District (440 km2 in total) in Gansu Province of northwest China, based on many years’ actual exploration and test data. An objective evaluation of the applicability of soil source heat pump (SSHP) systems was undertaken using an improved analytic hierarchy process (AHP) and the comprehensive index method. The results are that: (1) Lanzhou New District has generally excellent conditions for shallow geothermal energy utilizing SSHP systems. Specifically, the area has a simple and stable stratigrafic structure, high thermal conductivity, high specific heat capacity, and relatively high geothermal gradient. However, there are some unfavorable factors for developping groundwater source heat pump systems in the district, include a weak water-rich property aquifer and poor water quality. (2) The suitability evaluation model is based on an AHP divided into three attribute criteria and seven element indexes. This approach avoids some discrepancies inherent in a traditional judgement matrix constructed with the 1-9 scale proposed by Saaty. In this study, the judgement matrices for target layer and attribute criterion layer were constructed using an index scale, obtaining the weight of each factor to the target. Simultaneously, dimensionless parameters for each factor were optimized to make the model more efficient and give the evaluation result higher credibility. (3) The key factors affecting the suitability of SSHP are the average thermal conductivity and the geothermal gradient, which in this area are 1.807-2.676 W·m-1·K-1 and 0.30-0.40 ℃·km-1, respectively. The evaluation shows that “suitable” and “relatively suitable” areas for SSHP in the Lanzhou New District amount to 359.46 km2, which is 81.70% of the extent of the study area. Those suitable areas are chiefly located on the plains of Qinwangchuan Basin; other hilly and mountainous areas are less suitable for the installation of SSHP systems. Changing the traditional judgement matrix approach to this improved AHP-based evaluation process gives more accurate results more efficiently. The specific evaluation results of this study have clear practical value in guiding development planning for deployment of SSHP systems in Lanzhou New District and other comparable areas.

Key words: shallow geothermal energy, soil source heat pump, analytic hierarchy process (AHP), suitability, Lanzhou New District