Model of transparent heat source tower and its application optimization in the severe cold region

Utilizing a heat source tower (HST) to increase the ground temperature has good technical and economic advantages for ground source heat pump system (GSHP) in extremely cold regions. This paper proposes a novel transparent heat source tower (THST), which replaces the conventional shell with a transparent one to harness solar radiation and increase the temperature of the circulating water. The mathematical model as well as the TRNSYS module of the THST were developed and imported into the transient simulation model. Under the meteorological parameters of Shenyang, China and a certain circulating water flow rate in the THST, an experimental platform was established. The proposed new model is applied to the GSHP and simulated in TRNSYS. The results showed that the average solar heat exchange of the THST accounted for 8.6 % of the total heat absorbed, and the average increase of the THST effluent temperature was 0.4°C compared to the ordinary HST. The optimal water vapor ratio of the THST was between 0.55 and 0.6. The COP of the new system in a typical case reaches 3.57, which is 16.2 % higher than that of the GSHP. After 10 years of simulation, the soil temperature with the transparent heat source tower − ground source heat pump (THST-GSHP) is 4.35 °C higher than GSHP, effectively mitigating the soil heat imbalance problem.