| Ground-coupled heat pump technology has been gaining increasing popularity in residential and commercial buildings, since it is environment-friendly, causing less energy than their conventional alternatives. The ground source heat pump system effectively combines heat pump system with heating and air-conditioning system, besides it utilizes the earth as heat source. When it runs, the heat exchangers extract or inject thermal energy from or into the ground so that it realizes the seasonal energy diversion. The ground source heat pump system is one of green air-conditioning systems in the 21th century.With the national policy of building new energy-efficient village, the ground source heat pump with new pipe columns called single-row ground source heat pump has been put forward in this paper. Compared to single-tube ground source heat pump, it has a greater capacity to undertake larger heat or cold loads. It is appropriate to apply in vast area, and the soil temperature field has a better recovery performance, which is superior to tube group type.The certain building mentioned in the article was selected in Harbin suburb in order to validate the feasibility of this type of system in severe cold area. Long-term numerical simulation of this system was carried out by FLUENT software. We established the mathematical model of each subsystem, containing the physical and mathematical model of heat exchanger, heat pump units, target room and fan coil system, single-value conditions as well. According to the first year's and years'simulation results of this system, we got the thermal equilibrium analysis of soil field by theoretical analysis of total and unit heat extraction capacity, COP of heat pump, etc.Then we made the judgment of the feasibility of single-row ground source heat pump system applied in cold area, and then the relevant improvement measures were presented. On the other hand, analogy simulations were performed in typical cities of Beijing and Wuhan and the relevant operation parameters were made according to the different climate and geological conditions. In the end, the applicable area of single-row ground source heat pump came out. All of our research results would provide theoretical guidance for applying and popularizing the technology of this heat pump system.Because of the imbalance between heat and cooling load in severe cold area, the average soil temperature gradually decreases and the performance of heat pump units and the whole system also become lower as time goes, all of which is unfavorable for the system's long-term use. While if appropriate measures to compensate for the heat imbalance were took, from initial investment and operational costs, the single-row ground source heat pump system would have significant friendly environmental effects and bright development prospects. |
