Metodika automatického měření a vyhodnocování teplot v hlubinných vrtech

Abstract

This dissertation deals with issue of designing a comprehensively solved methodology focused on description, measurement and evaluation of certain thermo-physical rock environment parameters (i. e., coefficient of thermal conductivity, coefficient of thermal resistance, and an uninfluenced temperature) at performing so-called TRT experiments. At their evaluation, the main aim is to find relationships for a geoscience viewpoint (i. e., viewpoints of geography, geomorphology, and geology for certain examined locality), a relevant analytical or a numerical mathematical description, and results of in-situ TRT tests, including principal and supplemental procedures. In case of evaluating data acquired by this way, there are used and discussed – due to the given maths description – not only some simpler analytical approaches (based on conventional Kelvin line-source theory and on related theories), but also complicated analytical ones (i. e., descriptions of thermal resistances inside a borehole by Hellström, and control equations of temperature processes inside the borehole, namely in dependencies on geometry of a borehole heat exchanger and its configuration by Eskilson & Claesson). In this context, some samples using numerical approaches (based on methods of finite elements and finite differences) are also introduced to creating advanced and complex models within a multiphysical modelling by using COMSOL Multiphysics and FEFLOW. In the practical part of this dissertation (related to the designed methodology for performance and evaluation of the TRT experiments), there are discussed not only applicable practical approaches to measuring temperature profiles (by using temperature sensors of Pt1000 and Dallas DS18B20, and by using an optical cabel), but also designed fixed 4-procedure sequence (i. e., measuring an uninfluenced temperature profile, performing the TRT test with the first data evaluation stage, measuring influenced temperature profiles, and the second data evaluation stage), gradually applied to 13 performances of the TRT experiment and 12 performances of the TRT test (i. e., with no supplemental procedures); detailed description centred on performing and evaluating the TRT experiment is introduced to the locality of Ovčárna pod Pradědem. Generally, results of the TRT experiments – directly related to the certified methodology, see [1] – can serve as a methodological material for practical design and dimensioning of vertical borehole heat exchangers (connected to ground-water heat pumps), and their performance optimization in dependencies on features of the rock environment and planned heat energy consumption for a certain locality.