中深层同轴套管井取热损失分析与内管保温影响研究  

Analysis on thermal extraction loss and inner pipe insulation influence of medium-deep coaxial deep borehole heat exchanger

作　　者：刘博洋 刘俊 张育平 张廷会 周聪 LIU Boyang;LIU Jun;ZHANG Yuping;ZHANG Tinghui;ZHOU Cong(Shaanxi Zhongmei New Energy Company Ltd.,Shaanxi Union Research Center of University and Enterprise for Geothermal Resource Exploration and Low-carbon Utilization,Xi’an 710054,China;Shaanxi Coal Geology Group Company Ltd.,Key Laboratory of Coal Resources Exploration and Comprehensive Utilization,Ministry of Natural Resources,Xi’an 710021,China)

机构地区：[1]陕西中煤新能源有限公司、陕西省“四主体一联合”地热资源勘查与低碳利用校企联合研究中心,陕西西安710054 [2]陕西省煤田地质集团有限公司自然资源部煤炭资源勘查与综合利用重点实验室,陕西西安710021

出　　处：《区域供热》2023年第5期1-9,共9页District Heating

基　　金：陕西省秦创原“科学家+工程师”队伍建设项目(2022KXY-039);陕西省科协青年人才托举计划项目(NYHB202218);陕西省国有资本经营预算科技创新专项资金项目(2022-10)。

摘　　要：针对中深层同轴套管井存在的热损失现象,开展了取热损失分析,并探究内管保温对套管井换热性能和机组选型的影响。研究结果表明:套管井底部取热量高于实际取热量,在热提取期间的取热损失比基本不随时间发生变化。在套管井运行流速较低、地质参数较高和套管井长度较大的条件下,取热损失更大,但仍具有取热潜力。内管保温可以提升套管井的换热性能,且当套管井承担更多供热负荷的情况下,内管保温作用更明显。对内管进行保温后,运行流量的减小会导致套管井出口温度升高、入口温度降低,故对内管保温的套管井进行供热能力评估时,应综合进、出口水温对运行要求和能效的影响来决定,采用小流量运行时应考虑进行大温差热泵机组选型。In this paper,from the viewpoint of heat loss in medium-deep coaxial deep borehole heat exchanger(MCDBHE),analysis on the heat loss is carried out.Moreover,the effect of inner pipe insulation on heat transfer performance of MCDBHE and heat pump unit selection is investigated.The results show that the thermal extraction capacity in the pipe bottom is higher than the actual capacity.The thermal extraction loss ratio hardly changes with operating time.In the condition of lower operating velocity,higher geological parameters and longer pipe length,MCDBHE has much more heat loss,indicating a thermal extraction potential.Insulating inner pipe could improve heating performance of MCDBHE and the effect of the insulation was more obvious for putting a higher heating load on MCDBHE.After insulating inner pipe,decreasing operating flow rate would result in a higher outlet temperature and lower inlet temperature.Thus,the comprehensive effects of inlet and outlet temperatures of MCDBHE on both operating requirement and energy performance should be considered when evaluating thermal extraction capacity of MCDBHE with insulated inner pipe.If a lower operating flow rate was determined,large temperature difference heat pump unit should be taken into account.

关 键 词：中深层 地热 同轴 换热 保温 

分 类 号：TU83[建筑科学—供热、供燃气、通风及空调工程]