基于吸收式换热的深层地热集中供热系统能效分析

ENERGY EFFICIENCY ANALYSIS OF DEEP GEOTHERMAL ENERGY DISTRICT HEATING SYSTEM BASED ON ABSORPTION HEAT EXCHANGERS

结合深层地热温度高、稳定性好的特点,提出基于吸收式换热的深层地热集中供热新系统,并对其热力性能及经济性进行分析。结果表明：远低于地热水温的一次网回水有助于热源站采用换热器高效利用深层地热能。当一次网输热距离为15 km时,新型供热系统的产品效率为22.94%,一次能源利用率为121.6%,供热成本为62.25$/GJ,投资回收期不足7 a。与常规燃气锅炉供热系统相比,新型供热系统每年可降低燃气消耗量约54%,供热成本约25.6%;提升产品效率约11.8%,一次能源利用率约63.2%。

In view of characteristics such as higher temperature and more stable output,a new deep geothermal energydistrict heating system based on absorption heat exchangers is proposed and analyzed from the perspective ofthermodynamics and economics. The results showed that the lower temperature return water of the primary heatingnetwork which is much lower than geothermal water temperature contributes to efficiently utilize deep geothermal energyin heating station. When the heat transmission distance of the primary heating network is 15 km,product exergyefficiency,primary energy efficiency,heating cost and investment recovery period of the new district heating system areabout 22.94%,121.6%,62.25 $/GJ,seven years. Comparing with the conventional district heating system based onnatural gas heating boilers,the new district heating system can reduce annual natural gas consumption by about 54%,heating costs by about 25.6%,and increase product exergy efficiency by about 11.8%,primary energy efficiency byabout 63.2%.