A New Method Based on Thermal Response Tests for Determining Effective Thermal Conductivity and Borehole Resistivity for Borehole Heat Exchangers

Sapińska-Śliwa, Aneta; Rosen, Marc A.; Gonet, Andrzej; Kowalczyk, Joanna; Śliwa, T.

doi:10.3390/en12061072

Cited by 12 publications

(13 citation statements)

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“…geothermal boreholes, one can be tempted to determine the value of the BHEs work with varying loads. The way to determine BHE's energy effici form a Thermal Response Test [19]. TRT allows for the determination o thermal conductivity.…”

Section: Borehole Heat Exchangers At Agh Ust In Krakowmentioning

confidence: 99%

“…One of the most important tests performed to understand the properties of rocks, and simultaneously the appropriate selection of borehole heat exchanger's design is the Thermal Response Test-TRT [17,18]. The main parameters which can be determined using TRT are effective thermal conductivity and borehole resistance [19]. Currently, Thermal Response Tests are being conducted in an increasingly advanced form [20,21].…”

Section: Introductionmentioning

confidence: 99%

“…Each of them has a different design. Thermal Response Tests are ongoing to identify the most energy-efficient design and the optimal operating parameters, primarily the flow rate of the heat carrier [19]. An energy pile was also studied in the Laboratory.…”

Section: Introductionmentioning

confidence: 99%

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Geothermal Boreholes in Poland—Overview of the Current State of Knowledge

et al. 2021

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Geothermal energy can be useful after extraction from geothermal wells, borehole heat exchangers and/or natural sources. Types of geothermal boreholes are geothermal wells (for geothermal water production and injection) and borehole heat exchangers (for heat exchange with the ground without mass transfer). The purpose of geothermal production wells is to harvest the geothermal water present in the aquifer. They often involve a pumping chamber. Geothermal injection wells are used for injecting back the produced geothermal water into the aquifer, having harvested the energy contained within. The paper presents the parameters of geothermal boreholes in Poland (geothermal wells and borehole heat exchangers). The definitions of geothermal boreholes, geothermal wells and borehole heat exchangers were ordered. The dates of construction, depth, purposes, spatial orientation, materials used in the construction of geothermal boreholes for casing pipes, method of water production and type of closure for the boreholes are presented. Additionally, production boreholes are presented along with their efficiency and the temperature of produced water measured at the head. Borehole heat exchangers of different designs are presented in the paper. Only 19 boreholes were created at the Laboratory of Geoenergetics at the Faculty of Drilling, Oil and Gas, AGH University of Science and Technology in Krakow; however, it is a globally unique collection of borehole heat exchangers, each of which has a different design for identical geological conditions: heat exchanger pipe configuration, seal/filling and shank spacing are variable. Using these boreholes, the operating parameters for different designs are tested. The laboratory system is also used to provide heat and cold for two university buildings. Two coefficients, which separately characterize geothermal boreholes (wells and borehole heat exchangers) are described in the paper.

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Section: Borehole Heat Exchangers At Agh Ust In Krakowmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Geothermal Boreholes in Poland—Overview of the Current State of Knowledge

et al. 2021

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“…Sapinska-Sliwa et al [117] focused on borehole heat exchangers. They developed a new method based on thermal response tests based on resistivity equations.…”

Section: Energy Efficiency In Industrymentioning

confidence: 99%

Toward an Efficient and Sustainable Use of Energy in Industries and Cities

et al. 2019

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Several countries have recently realized that the present development paradigm is not sustainable from an environmental and energy point of view. The growing awareness of the population regarding environmental issues is pushing governments worldwide more and more to promote policies aiming at limiting harmful effects of human development. In particular, the rapid increase of the global temperature, especially in the polar regions, and the management of human wastes, mainly plastic in seas, are some of the main points to be addressed by these novel policies. Several actions must be implemented in order to limit such issues. Unfortunately, the recent COP 24 Conference was not successful, but hopefully an agreement will be established in 2020 at the COP 26 Conference. The effort performed by policymakers must be mandatorily supported by the scientific community. In this framework, this paper aims at showing that countries worldwide are trying to negotiate an agreement to increase energy efficiency and reduce greenhouse gas (GHG) emissions. In addition, in this paper all the researchers reported can provide quantitative measures of the actions to be implemented in order to address a sustainable and efficient use of energy. Here, innovations in terms of novel efficient and environmentally friendly technologies mainly based on renewable energy sources have been also investigated. The study also highlights different sectors that have been involved for this aim, such as energy conversion systems, urban areas, mobility, sustainability, water management, social aspects, etc. In this framework, specific conferences are periodically organized in order to provide a forum for discussion regarding these topics. In this area the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference is the most ordinary conference. The 13th Sustainable Development of Energy, Water and Environment Systems Conference was held in Palermo, Italy in 2018. The current Special Issue of Energies, precisely dedicated to the 13th SDEWES Conference, is based on three main topics: energy policy and energy efficiency in urban areas, energy efficiency in industry and biomass and other miscellaneous energy systems.

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“…The purpose of this article is to determine the effect of temperature measurement frequency during the TRT on its results. Temperature measurements, as well as the measurement of other parameters during the test, e.g., differential pressure [36], can be recorded at different frequencies (averaged). The article analyzes how it affects the calculated value of effective thermal conductivity λ eff in BHE, which is a basic parameter determined during TRT.…”

Section: Introductionmentioning

confidence: 99%

Method of Averaging the Effective Thermal Conductivity Based on Thermal Response Tests of Borehole Heat Exchangers

et al. 2020

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This work concerns borehole heat exchangers and their testing using apparatus for thermal response tests. In the theoretical part of the article, an equation was derived from the known equation of heat flow, on which the interpretation of the thermal response test was based. The practical part presents the results of several measurements taken in the AGH Laboratory of Geoenergetics. They were aimed at examining the potential heat exchange capacity between the heat carrier and rock mass. Measurement results in the form of graphs are shown in relation to the examined, briefly described wells. Result analysis made it possible to draw conclusions regarding the interpretation of the thermal response test. The method of averaging the measurement results was subjected to further study. The measuring apparatus recorded data at a frequency of one second, however such accuracy was too large to be analyzed efficiently. Therefore, an average of every 1 min, every 10 min, and every 60 min was proposed. The conclusions stemming from the differences in the values of effective thermal conductivity in the borehole heat exchanger, resulting from different data averaging, were described. In the case of three borehole heat exchangers, ground properties were identical. The effective thermal conductivity λeff was shown to depend on various borehole heat exchanger (BHE) designs, heat carrier flow geometry, and grout parameters. It is important to consider the position of the pipes relative to each other. As shown in the charts, the best (the highest) effective thermal conductivity λeff occurred in BHE-1 with a coaxial construction. At the same time, this value was closest to the theoretical value of thermal conductivity of rocks λ, determined on the basis of literature. The standard deviation and the coefficient of variation confirmed that the effective thermal conductivity λeff, calculated for different time intervals, showed little variation in value. The values of effective thermal conductivity λeff for each time interval for the same borehole exchanger were similar in value. The lowest values of effective thermal conductivity λeff most often appeared for analysis with averaging every 60 min, and the highest—for analysis with averaging every 1 min. For safety reasons, when designing (number of BHEs), safer values should be taken for analysis, i.e., lower, averaging every 60 min.

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A New Method Based on Thermal Response Tests for Determining Effective Thermal Conductivity and Borehole Resistivity for Borehole Heat Exchangers

Cited by 12 publications

References 35 publications

Geothermal Boreholes in Poland—Overview of the Current State of Knowledge

Geothermal Boreholes in Poland—Overview of the Current State of Knowledge

Toward an Efficient and Sustainable Use of Energy in Industries and Cities

Method of Averaging the Effective Thermal Conductivity Based on Thermal Response Tests of Borehole Heat Exchangers

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