title: Ground Thermal Diffusivity Calculation by Direct Soil Temperature Measurement. Application to very Low Enthalpy Geothermal Energy Systems.
abstract: This paper presents a methodology and instrumentation system for the indirect measurement of the thermal diffusivity of a soil at a given depth from measuring its temperature at that depth. The development has been carried out considering its application to the design and sizing of very low enthalpy geothermal energy (VLEGE) systems, but it can has many other applications, for example in construction, agriculture or biology. The methodology is simple and inexpensive because it can take advantage of the prescriptive geotechnical drilling prior to the construction of a house or building, to take at the same time temperature measurements that will allow get the actual temperature and ground thermal diffusivity to the depth of interest. The methodology and developed system have been tested and used in the design of a VLEGE facility for a chalet with basement at the outskirts of Huelva (a city in the southwest of Spain). Experimental results validate the proposed approach.
authors.affiliation: Escuela Técnica Superior de Ingeniería, Universidad de Huelva, Ctra. Palos de la Ftra.-Huelva s/n, Huelva 21819, Spain. andujar@uhu.es.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Andújar Márquez
authors.affiliation: Escuela Técnica Superior de Ingeniería, Universidad de Huelva, Ctra. Palos de la Ftra.-Huelva s/n, Huelva 21819, Spain. bohorquez@uhu.es.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Martínez Bohórquez
authors.affiliation: Escuela Técnica Superior de Ingeniería, Universidad de Huelva, Ctra. Palos de la Ftra.-Huelva s/n, Huelva 21819, Spain. sergio.gomez@dimme.uhu.es.
authors.forename: Sergio
authors.initials: S
authors.lastname: Gómez Melgar
keywords: ground temperature probe; ground thermal diffusivity; instrumentation system; soil temperature; very low enthalpy geothermal energy