携热介质对中深层无干扰地热单井换热性能影响分析OA

Actively promoting the application of deep geothermal energy for heating is an important measure to implement the national"dual carbon"strategy.To explore the influence of heat-carrying media on the heat extraction performance of non-disruptive geothermal single wells and optimize injection conditions to enhance thermal recovery efficiency,this paper,based on the actual operating conditions of a deep geothermal well in a certain area of Shanxi Province,uses numerical simulation method to analyze the temperature field distribution in the surrounding rock and soil layers of the wellbore and the outlet temperature and instantaneous heat exchange rate under four different injection flow rates of 30,40,50,and 60 m3/h for water and carbon dioxide as two different media.The results show that the thermal influence radius of the surrounding strata of the wellbore is 10 m,It is recommended to use a central pipe material with a low thermal conductivity within the range of 0 to 200 meters to reduce heat loss.After running for 120 days,the outlet temperature and heat exchange rate of both media gradually decrease and then stabilize as the heat extraction process progresses.When the injection flow rate of the medium water changes from 30 m3/h to 60 m3/h,the final outlet temperature drops from 26.42℃to 19.12℃,a reduction of 27.63%.When the injection flow rate of the medium carbon dioxide changes from 30 m3/h to 60 m3/h,the final outlet temperature rises from 20.34℃to 27.91℃,an increase of 37.22%.Overall,water has a better heat exchange effect than carbon dioxide,but its heat exchange efficiency is lower at high flow rates,making it suitable for low-flow conditions.Carbon dioxide,due to its low viscosity,shows better heat exchange performance at higher injection flow rates and is suitable for high-flow conditions.