关键词: 集中供热, 水热型地热, 节能减排, 大温差输热, 喷射式换热, 供热负荷

Abstract: To deal with the problems of short economic heating radius，small heating scale and low utilization efficiency of hydrothermal geothermal resources existing in the conventional hydrothermal geothermal heating mode， a new hydrothermal geothermal central heating system based on enhanced ejector heat exchangers is proposed according to the characteristics of both hydrothermal geothermal resources and ejector heat exchangers. The results show that the new heating mode is of a lower primary return water temperature，which facilitates mounting the temperature difference between supply and return water，utilizing hydrothermal geothermal heat and recovering waste heat in flue gas. Comparing with the conventional central heating system based on gas-fired boilers，the new hydrothermal geothermal central heating system can increase the energy efficiency of fossil fuel by about 86.0%，boost the product exergy efficiency（PEE）of the system by about 9.7%，reduce the heating cost by about 32.47 yuan/GJ ，and save natural gas consumption by about 70%.The cost- effective distance of the new hydrothermal geothermal central heating system reaches 55.2 km，which could be used to resolve the space distribution mismatching between the hydrothermal geothermal heat fields and the heating load center.

Key words: district heating, hydrothermal geothermal heat, energy saving and emission reduction, large temperature difference heat transmission, enhanced ejector heat exchanger, heating load