A novel composite-medium solution for pile geothermal heat exchangers with spiral coils. (February 2016)

• Record Type: Journal Article
• Authors: Wang, Deqi; Lu, Lin; Cui, Ping
• Is Part Of: International journal of heat and mass transfer. Volume 93(2016:Feb.)
• Page Start: 760
• Page End: 769
• Publication Date: 2016-02
• Subjects: Composite medium -- Ground heat exchanger -- Energy pile -- Ground-coupled heat pump system -- Spiral coil; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2015.10.055
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: A new transient analytical model for pile geothermal heat exchangers. A numerical model has been established to validate this new analytical model. Study the effect of thermal properties of pile and soil on pile. Abstract: This paper presents a new transient analytical model for describing the heat transfer process of pile geothermal heat exchangers with spiral coils (PGHE-SC). A numerical model has been established based on the finite element method to validate this new analytical model, which shows a good agreement between the two models. The temperature responses for different heat transfer conditions were calculated and are discussed. When the thermal conductivities of pile is twice as the one of soil, the dimensionless temperature at middle of the pile is 0.3832 which almost twice as the temperature response of homogeneous case. The results indicate that the thermal difference between pile and soil is an important factor influencing PGHE-SC simulation/design. As this new model not only successfully takes the limited length of an energy pile into consideration but also distinguishes thermal properties in its modeling process, it may provide a desirable and better design tool for the PGHE-CS.