title: Novel wireless sensor system for dynamic characterization of borehole heat exchangers.
abstract: The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE) is presented. The system, by means of two special valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the sensor along its way through the BHE U-tube. This sensor system is intended to improve the conventional thermal response test (TRT) and it allows the collection of information about the thermal characteristics of the geological structure of subsurface and its influence in borehole thermal behaviour, which in turn, facilitates the implementation of TRTs in a more cost-effective and reliable way.
authors.affiliation: Department of Electronic Engineering, Universidad de Valencia, Campus de Burjassot, CP 46100 Valencia, Spain. julio.martos@uv.es
authors.forename: Julio
authors.initials: J
authors.lastname: Martos
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Montero
authors.forename: José
authors.initials: J
authors.lastname: Torres
authors.forename: Jesús
authors.initials: J
authors.lastname: Soret
authors.forename: Guillermo
authors.initials: G
authors.lastname: Martínez
authors.forename: Raimundo
authors.initials: R
authors.lastname: García-Olcina