Development of modified bentonite slurry for use in subsurface thermal storage and insulation

开发用于地下蓄热和隔热的改性膨润土浆料

• 批准号: 485018-2015
• 负责人: Guo, PeiJun
• 金额: $ 1.82万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=584656
• 关键词: Development; modified; bentonite; slurry; use

The use of ground source heat pumps (GSHPs) as an energy sink/source to save energy required for building heating and cooling has been increasing in recent years. According to Canadian Geothermal Coalition, the market in Canada for these heat pumps has been expanding approximately 44% per year from 2005 to 2009. As a result, innovative approaches/technologies are in high-demand to make the GSHPs more efficient and economical in industrial scale. In addition, because of environmental concerns about the potential for contamination of underlying ground water, jurisdictions commonly require boreholes in a GSHPs system be filled with nearly impervious bentonite grout. The thermal and hydraulic properties of such bentonite grout has significant impact on the economic and safe operation of GSHPs. Enhanced bentonite grout with high thermal conductivity allows more thermal energy to be transferred to or from the surrounding soil and hence increases the efficiency of the system. At the same time, materials with low thermal conductivity and low permeability are also required as insulation for subsurface storage of thermal energy. This research will develop new composite bentonite grouts that meet different requirements on thermal and hydraulic properties for ground source heat pumps. A theoretical study will be performed to help find the optimal combination of different types of additives with bentonite, while a series of laboratory tests will be carried out to verify the optimal combination of different types of additives. The findings will then be examined and verified in a large testing tank prior to full-scale field implementation. The expected outcomes of the project will accommodate the industry needs, and provide valuable tools to appropriately deal with special issues related to the design and safe operation of ground source heat pumps, which are considered to be more economical and able to reduce potential negative environmental impact.

近年来，使用地源热泵（GSHPs）作为能量汇/源以节省建筑物加热和冷却所需的能量已经增加。根据加拿大地热联盟的数据，从2005年到2009年，加拿大的热泵市场每年增长约44%。因此，迫切需要创新方法/技术，以使GSHPs在工业规模上更加有效和经济。此外，由于对潜在地下水污染的环境关注，司法管辖区通常要求GSHP系统中的钻孔填充几乎不透水的膨润土灌浆。膨润土浆液的热工和水力性能对地源热泵的经济和安全运行有重要影响。具有高导热性的增强型膨润土灌浆允许更多的热能传递到周围土壤或从周围土壤传递，从而提高系统的效率。同时，还需要具有低导热性和低渗透性的材料作为热能地下储存的绝缘材料。本研究将开发新型复合膨润土浆液，以满足地源热泵对热力性能和水力性能的不同要求。将进行理论研究，以帮助找到不同类型的添加剂与膨润土的最佳组合，同时将进行一系列实验室测试，以验证不同类型的添加剂的最佳组合。然后，在全面实地实施之前，将在一个大型试验池中对调查结果进行检查和核实。该项目的预期成果将满足行业需求，并提供有价值的工具，以适当处理与地源热泵设计和安全运行有关的特殊问题，这些问题被认为更经济，能够减少潜在的负面环境影响。