同轴套管式深井换热器的换热性能分析

同轴套管式深井换热器是一种开采地热能的有效方式,为了提高其换热器的换热性能,采用有限体积分析方法,开展了同轴套管式深井换热器传热性能研究。通过建立近地热源区域的同轴套管式深井换热器三维传热模型,分析了入口流速、入口温度以及保温管距井底距离等关键因素对换热器采热功率的影响,结果表明:入口流速由0.1 m/s增加到1 m/s,采出温度降低了9.82 K,采热功率增加了7倍;入口温度从288 K增加到308 K,采出温度增加了13.61 K,采热功率下降了17.2%;距井底900 mm距离降低到 100 mm,采出温度增加1.91 K,采热功率增加了6.57%。

Analysis of Heat Exchange Performance of Coaxial Casing Deep Well Heat Exchanger

Coaxial casing deep well heat exchanger is an effective way to extract geothermal energy. In order to improve its heat transfer performance, this paper adopts the finite volume analysis method to carry out the research on the heat transfer performance of the coaxial casing deep well heat exchanger. By establishing a three-dimensional heat transfer model of the coaxial casing deep well heat exchanger in the near-ground heat source area, the influence of key factors, such as inlet flow velocity, inlet temperature and the distance between the insulation pipe and the bottom of the well, on the heat recovery power of the heat exchanger is analyzed. The results show that when the inlet flow rate increases from 0.1 m/s to 1 m/s, the outlet temperature decreases by 9.82 K, and the heat recovery power increases by 7 times; when the inlet temperature increases from 288 K to 308 K, the outlet temperature increases by 13.61 K, and the heat recovery power decreases by 17.20%; the distance down to the bottom of the well from 900 mm to 100 mm, the outlet temperature increases by 1.91 K, and the heat recovery power increases by 6.57%.