Novel Experimental Device to Monitor the Ground Thermal Exchange in a Borehole Heat Exchanger

Abstract

Ground source heat pump (GSHP) systems are becoming popular in space heating and cooling applications. Despite this fact, in most countries, the role of this energy is not as important as it should be nowadays according to its capabilities for energy generation without CO2 emissions, mainly due to the lack of technical knowledge about GSHP performance. The analysis of the physical processes that take part in the geothermal exchanges is necessary to allow the optimal exploitation of the geothermal resources. For all the above, an experimental geothermal device was built in the laboratory to control the phenomena that take place in a borehole heat exchanger (BHE). A 1-m high single-U heat exchanger was inserted in the center of a polyethylene container which also included granular material (surrounding ground) and the grouting material. Temperature sensors were situated in different positions of the experimental setup. Physical processes are evaluated to finally validate the model. Numerous applications can be developed from the experimental BHE. In this research, the determination of the thermal conductivity of the material used as medium was carried out. Results of this parameter were also compared with the ones obtained from the use of the KD2 Pro device.

A Low-cost Automatic System for Long-term Observations of Soil Temperature

“…DS18B20 sensors are used in engineering projects (e.g. for temperature monitoring in hydrotechnical devices [25], studies of concrete properties [26], industrial pipelines [27], geothermal installations [28,29], environmental temperature (e.g. measurements of substrate temperature [5,12,[14][15][16][30][31][32]) and in karst hydrogeology [17].…”

Determination of the Selected Wells Operational Power with Borehole Heat Exchangers Operating in Real Conditions, Based on Experimental Tests

“…Sáez Blázquez et al proposed an experimental novel device that provides an inexpensive, less time-consuming and reliable approach to measuring thermal conductivity. This approach can replace or supplement well-known but expensive methods such as the thermal response test (TRT) [67]. A very extensive review on TRTs of ground-coupled heat pump systems can be found in the work of Zhang et al covering both in situ research and mathematical models [68].…”

Assessment of Ground Regeneration around Borehole Heat Exchangers between Heating Seasons in Cold Climates: A Case Study in Bialystok (NE, Poland)

“…By comparing these experimental data with the model describing the heat exchange between the liquid and the ground, it is possible to estimate the thermal properties of the ground [57,[59][60][61][62]. Sáez Blázquez et al [63] proposed a new experimental device that provides an inexpensive, less time-consuming, and reliable approach to measuring thermal conductivity. This approach may replace or supplement well-known but expensive methods such as the thermal response test (TRT).…”