Research On Heat Transfer Of Single U Type Buried Well Group

The utilization of shallow geothermal energy is of great significance for building energy efficiency and building a green building. Soil source heat pump is one of the important technologies in shallow geothermal energy utilization, and the core and application of this technology is the underground pipe heat transfer. In the engineering of buried tube heat exchanger applied in the form of well group, so it is necessary to study the heat transfer of the well, and to understand the basic heat transfer characteristics and laws, and to provide theoretical guidance for engineering practice.Paper firstly in order to research the heat transfer of wells and establish a fast solution model for well group heat transfer, a hybrid solution model based on analytical and numerical calculation is presented, after the establishment of a single borehole heat exchanger heat transfer test-bed for single well heat transfer model is verified, and using the FLUENT software in combination with the heat transfer model of well group to further define the well of three kinds of special position in the square well group("middle well, edge well, corner well"), and the typical well group of physical model is determined and the thermal interference coefficient of the well group are defined.At the same time, the basic heat transfer characteristics of the well group, as well as the influence of seven kinds of factors of buried pipe inlet water temperature and inlet velocity, coefficient of thermal conductivity of soil and backfill material, initial temperature of soil, buried pipe spacing and operation mode on the heat transfer characteristics of the well is mainly studied in this paper under the condition of continuous operation in summer.Finally, the coupling model of the ground source heat pump air conditioning system is established, and the operating characteristics of the soil source heat pump air conditioning system under the dynamic load and the response of the soil temperature field all the year round are studied.The results of the research provide a simple and convenient of buried tube heat transfer model and a simulation method of system model. The basic heat transfer characteristics of the well group, the effect of the seven factors on the heat transfer characteristics of the wells, the annual operating characteristics of the soil source heat pump air conditioning system and the basic law of ground temperature response in the whole year are obtained, and they provides theoretical guidance for the application of the soil source heat pump air conditioning system.