Taking a large public building in a hot summer and cold winter area as the research object
a simulation model of shallow medium deep geothermal cascade utilization coupled heating was built based on TRNSYS software. The operating characteristics of the shallow medium deep coupled heating system during the heating season were analyzed and compared with a single medium deep geothermal cascade utilization heating system and a shallow ground source heat pump system. The results show that the coupled system is superior to a single deep or shallow geothermal heating system in terms of end heat transfer
geothermal return water temperature
heat pump unit COP
and system energy utilization efficiency. The system is more stable and adaptable. The average energy utilization efficiency of the system reaches 0.95
verifying the feasibility of the coupled system operation.
AIRA R, FERNÁNDEZ-SEARA J, DIZ R, et al. Experimental analysis of a ground source heat pump in a residential installation after two years in operation[J]. Renewable energy, 2017, 114: 1214-1223.
XI S P, WANG X.Analysis of temperature field and stress field around vertical u-tube exchange used in ground source heat pump[J]. Advanced materials research, 2014, 3383(1008/1009): 1097-1100.
KOHL T, BRENNI R, EUGSTER W.System performance of a deep borehole heat exchanger[J]. Geothermics, 2002, 31(6): 687-708.
DENG J W, HE S, WEI Q P, et al.Field test and optimization of heat pumps and water distribution systems in medium-depth geothermal heat pump systems[J]. Energy and buildings, 2020, 209: 109724.
ALIYU M D, CHEN H P.Sensitivity analysis of deep geothermal reservoir: effect of reservoir parameters on production temperature[J]. Energy, 2017, 129: 101-113.
ZARE V.A comparative thermodynamic analysis of two tri-generation systems utilizing low-grade geothermal energy[J]. Energy conversion and management, 2016, 118: 264-274.