地热驱动的双温热力站系统及其变工况性能  

Investigation into geothermal-driven dual-temperature district heating substation and its performance under variable conditions

作　　者：李天成 石文星[1,2] 王宝龙[1,2] LI Tiancheng;SHI Wenxing;WANG Baolong(School of Architecture,Tsinghua University,Beijing 100084,China;Beijing Key Laboratory of Indoor Air Quality Evaluation and Control,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学建筑学院,北京100084 [2]清华大学室内空气质量评价与控制北京市重点实验室,北京100084

出　　处：《西安工程大学学报》2024年第5期9-18,共10页Journal of Xi’an Polytechnic University

基　　金：国家重点研发计划项目(2022YFC3801502)。

摘　　要：高温地热能是宝贵的可再生能源供热资源,降低地热水回水温度是发挥地热供热潜力、扩大供热面积的重要途径。鉴于既有建筑普遍采用散热器等高温供热末端,而新建建筑多采用地暖等低温供热末端,二者的需求供水温度不同,对此提出了单吸收式热泵+双换热器的地热能驱动双温热力站系统,以制取高、低温末端用双温热水,并尽可能降低地热水回灌温度。模拟分析表明:在地热出水为100℃,二次网高、低温末端供热量相同且供水温度分别为50℃和35℃条件下设计的双温热力站,可将地热水回水温度降至20.1℃,相比于采用2个换热器串联的热力站,其地热水的回水温度可降低14.9℃、流量可降低18.6%,系统的COP提升11%,具有显著的节能优势。变工况分析表明:低温供热末端的应用有利于进一步降低地热水回灌水温,增加向末端用户的供热量,并提高双温热力站系统的COP。High-temperature geothermal energy is precious renewable resource for heating.Reducing the return temperature of geothermal water is an important way to maximize geothermal heating potential and expand the heating area.Considering that existing buildings generally use high-temperature radiators and other heating terminals,while newly constructed buildings mostly use low-temperature floor heating terminals,the required supply water temperatures for these two types differ.In response to this,a geothermal energy-driven dual-temperature district heating substation system with a single absorption heat pump and two heat exchangers is proposed.This system aims to produce dual-temperature hot water for both high-and low-temperature heating terminals and reduce the return temperature of geothermal water.Simulation results show that when the geothermal outlet water is 100℃,and the secondary network's high-and low-temperature terminal supply water temperatures are 50℃and 35℃respectively,the return temperature of geothermal water in the dual-temperature district heating substation one can be reduced to 20.1℃.Compared to a substation using two serial heat exchangers,the proposed one can lower the geothermal water return temperature by 14.9℃,reduce the geothermal water flow rate by 18.6%,and improve COP by 11%,demonstrating significant energy-saving advantages.Variable working condition analysis indicates that promoting the use of low-temperature heating terminals helps further reduce the return temperature of geothermal water,increase the heat supply to users,and improve the COP of the dual-temperature district heating substation.

关 键 词：地热能 双温热力站 吸收式热泵 变工况 集中供热 

分 类 号：TU833.1[建筑科学—供热、供燃气、通风及空调工程]