| Ground source heat pump as an efficient, energy saving, green, advanced technology, are being widely studied and applied. Heat exchanger as part of its core components, the size of its heat capacity directly affects the unit's efficiency. Therefore, the optimization of heat exchanger, becomes extremely important.Soil is a typical porous medium, the composition of the solid skeleton and pore. Saturated zone in the soil, groundwater filled the pore space, water in the pores, the fluid flow caused by heat transfer, enhanced heat transfer.In this paper, a non-flow heat exchanger heat transfer characteristics of the study, measured the thermal conductivity of soil, numerical and experimental methods used to simulate 40℃,45℃,50℃temperature distribution of three conditions may out of the heat exchanger temperature distribution around the center of symmetry for the approximate rule of graphics, with water temperature, the higher the temperature, the greater the temperature difference between imports and exports, for more heat. Numerical simulation and experimental results are basically consistent numerical model is verified the correctness and credibility.Second, the establishment of the fluid, and heat the surrounding soil heat penetration coupled physical mathematical model to simulate the heat exchanger and the fluid flow, heat exchanger and heat the soil and soil temperature. Simplified and made as follows:the soil is homogeneous, isotropic saturated porous media, groundwater flow through porous constant one-way. Groundwater seepage from a different speed, different water temperatures, with different porosity and different soil type, soil temperature of several factors distribution, obtained significant effect of seepage on the temperature field, the greater the flow velocity, heat transfer is more obvious; water temperature the more low, the smaller the radius of thermal effect, heat transfer capability; porosity, the more conducive to heat transfer; loose soil Peclet number greater than the number of compacted soil in Peclet number, so that loose soil heat transfer capacity than Soil compaction stronger convection, heat transfer larger, stronger heat transfer capability. These results provide a theoretical reference to engineering practice, conducive to the development of ground source heat pump. |
