在“双碳”背景下，中深层地热能供暖技术在推动建筑领域节能降碳方面发挥着越来越重要的作用。中深层同轴套管式换热器作为“无干扰”开采地热能的核心部件，其结构参数深刻影响着地热井取热能力。为此，利用COMSOL数值模拟软件建立了外套管内壁配装螺旋肋片的同轴套管换热器数值模型，并利用Gnielinski、Konakov等关联式进行了验证分析；采用响应曲面法探讨了肋片高度、厚度、数量、螺旋角及其交互作用对换热器换热性能、流动阻力的影响，并利用满意度函数法对肋片结构设计参数进行了优化。研究结果表明：当肋片高度为6 mm，厚度为2 mm，数量为16个，螺旋角为15°时，总体满意度为0.75，性能评价标准（performance evaluation criterion, PEC）为1.32，该结构下的努塞尔数Nu较普通中深层同轴套管换热器提升了39.00%；在地热井动态换热性能分析中，采用新型同轴套管换热器的地热井累积提取热量较普通地热井提升了12.87%。研究成果可为增强中深层同轴套管换热器适用性提供新思路、新方法，也可为同类型中深层同轴套管换热器设计提供借鉴。

Under the background of double carbon, the medium-deep geothermal energy heating technology plays an increasingly important role in promoting energy conservation and carbon reduction in the construction field. As the core component of 'non-interference' geothermal energy exploitation, the structural parameters of the middle and deep coaxial casing heat exchanger have a profound impact on the heat extraction capacity of geothermal wells. Therefore, the numerical model of the coaxial tube heat exchanger with spiral fins on the inner wall of the outer tube was established by COMSOL numerical simulation software, and the correlation of Gnielinski and Konakov was used for verification and analysis. The effects of fin height, thickness, number, helix angle and their interaction on the heat transfer performance and flow resistance of the heat exchanger were discussed by using the response surface method. The parameter optimization of the structural parameters of the coaxial tube heat exchanger was carried out by using the satisfaction function method. The results show that when the fin height is 6 mm, the thickness is 2 mm, the number is 16, and the helix angle is 15°, the overall satisfaction is 0.75, the performance evaluation criterion(PEC) is 1.32, and the Nu under this structure is 39.00% higher than that of the ordinary mid-deep coaxial casing heat exchanger. In the analysis of the dynamic heat transfer performance of geothermal wells, the cumulative extracted heat of geothermal wells using the new coaxial casing heat exchanger is 12.87% higher than that of ordinary geothermal wells. The research results can provide new ideas and methods for enhancing the applicability of medium-deep coaxial casing heat exchangers, and can also provide reference for the design of the same type of medium-deep coaxial casing heat exchangers.