A NUMERICAL METHOD AND ITS APPLICATION TO INVESTIGATE THE THERMAL PERFORMANCE OF AN EARTH TO FLUID PIPE SYSTEM
The earth to fluid pipe (ETFP) system can be applied for air cooling in the fields of gas turbine intake and green building, for heat storage in the field of solar energy utilization and for heat release in developing geothermal energy. Two types of physical model of the heat transfer process in the ETFP system were established for numerical investigating the thermal performance of the system. The method to determine the heat affected zone which is necessary for numerical calculation was proposed. The applications of this ETFP system in typical fluid cooling and heat storage processes have been studied. The effect of the system characteristics such as pipe length, diameter, buried depth, fluid velocity and soil properties on the thermal performance as well as the mutual effect among pipes was investigated. As a result, the thermal parameters of the system were predicted accurately by means of numerical simulation, which indicates that the proposed method and adopted models were reliable. The heat released from the hot fluid was stored in the soil with a finite region. There were strong correlations between the heat capacity of the system and the soil or fluid properties. The method and results can provide guidance for the study and operation of the ETFP system in heat storage or fluid cooling engineering.