Journal articles: 'Shallow geothermal energy system'

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García-Gil, Alejandro, Miguel Mejías Moreno, Eduardo Garrido Schneider, Miguel Ángel Marazuela, Corinna Abesser, Jesús Mateo Lázaro, and José Ángel Sánchez Navarro. "Nested Shallow Geothermal Systems." Sustainability 12, no. 12 (June 24, 2020): 5152. http://dx.doi.org/10.3390/su12125152.

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The long-term sustainability of shallow geothermal systems in dense urbanized areas can be potentially compromised by the existence of thermal interfaces. Thermal interferences between systems have to be avoided to prevent the loss of system performance. Nevertheless, in this work we provide evidence of a positive feedback from thermal interferences in certain controlled situations. Two real groundwater heat pump systems were investigated using real exploitation data sets to estimate the thermal energy demand bias and, by extrapolation, to assess the nature of thermal interferences between the systems. To do that, thermal interferences were modelled by means of a calibrated and validated 3D city-scale numerical model reproducing groundwater flow and heat transport. Results obtained showed a 39% (522 MWh·yr−1) energy imbalance towards cooling for one of the systems, which generated a hot thermal plume towards the downgradient and second system investigated. The nested system in the hot thermal plume only used groundwater for heating, thus establishing a positive symbiotic relationship between them. Considering the energy balance of both systems together, a reduced 9% imbalance was found, hence ensuring the long-term sustainability and renewability of the shallow geothermal resource exploited. The nested geothermal systems described illustrate the possibilities of a new management strategy in shallow geothermal energy governance.

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Roka, Rajendra, António Figueiredo, Ana Vieira, and José Cardoso. "A systematic review on shallow geothermal energy system: a light into six major barriers." Soils and Rocks 46, no. 1 (December 1, 2022): e2023007622. http://dx.doi.org/10.28927/sr.2023.007622.

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Shallow geothermal energy systems (SGES) are being widely recognized throughout the world in the era of renewable energy promotion. The world is aiming to promote and implement the concept of nearly zero energy consumption in the building sector. Shallow geothermal energy systems have huge potential to meet the heating and cooling demand of a building with low carbon emissions. However, the shallow geothermal system exploration rate and its global contribution to renewable energy used in the buildings sector is yet relatively low. Therefore, this study explores specific barriers which hinder the promotion of shallow geothermal energy systems through a systematic review of the literature. The study was carried out by investigating published papers indexed in Scopus and Web of science core collection databases. The selected papers are focused on shallow geothermal energy systems and barriers to their promotion. Only review and research articles types were included in the analysis and constrained to the topic of closed-loop shallow geothermal energy systems. This system’s promotion has been influenced by the lack of legislation, little knowledge about the conductivity of soil and by high initial investment cost at its topmost. The least influencing barrier is considered to be the heating and cooling efficiency of shallow geothermal energy systems.

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Li, Man, and Xiao Wang. "Study on Public Policy for the Application of Shallow Geothermal Energy into Building Energy Efficiency." Applied Mechanics and Materials 368-370 (August 2013): 1285–88. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.1285.

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At present, in China, shallow geothermal energy has been widely used in energy efficiency of building, but the question of policy mechanisms reduce the rate of new energy promotion.This paper compares the differences between the domestic and foreign shallow geothermal energy policy through the comparison gets the revelation of shallow geothermal energy policy, and combines with the development situation and utilization goal, in the end gives the recommendations for policy system of shallow geothermal.

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Johnston, Ian. "Geothermal energy: shallow sources." Proceedings of the Royal Society of Victoria 126, no. 2 (2014): 25. http://dx.doi.org/10.1071/rs14025.

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Below a depth of around 5 to 8 metres below the surface, the ground displays a temperature which is effectively constant and a degree or two above the weighted mean annual air temperature at that particular location. In Melbourne, the ground temperature at this depth is around 18°C with temperatures at shallower depths varying according the season. Further north, these constant temperatures increase a little; while for more southern latitudes, the temperatures are a few degrees cooler. Shallow source geothermal energy (also referred to as direct geothermal energy, ground energy using ground source heat pumps and geoexchange) uses the ground and its temperatures to depths of a few tens of metres as a heat source in winter and a heat sink in summer for heating and cooling buildings. Fluid (usually water) is circulated through a ground heat exchanger (or GHE, which comprises pipes built into building foundations, or in specifically drilled boreholes or trenches), and back to the surface. In heating mode, heat contained in the circulating fluid is extracted by a ground source heat pump (GSHP) and used to heat the building. The cooled fluid is reinjected into the ground loops to heat up again to complete the cycle. In cooling mode, the system is reversed with heat taken out of the building transferred to the fluid which is injected underground to dump the extra heat to the ground. The cooled fluid then returns to the heat pump to receive more heat from the building.

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Fu, Ying, Chao Yu Zhang, and Bo Zhang. "Benefits Analysis and Utilization Strategy for Development of Shallow Geothermal Energy: A Case Study of Tianjin." Advanced Materials Research 616-618 (December 2012): 1640–46. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.1640.

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As a renewable energy, shallow geothermal energy has received extensive concerns in China, and is regarded as an important means to relieve the pressure in energy supply, meet the greenhouse gas control obligations and establish a low-carbon economy system. In recent years, a series of policies and regulations for promoting the utilization of shallow geothermal energy has been issued. This paper firstly makes an analysis of the patterns and the growing trend of shallow geothermal energy utilization, and then establishes the analysis paradigms of the economic, environmental and social benefits of its utilization, taking Tianjin as a case. Finally, a policy system to promote the utilization of shallow geothermal energy is proposed.

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Yin, Hongmei, Likai Hu, Yang Li, Yulie Gong, Yanping Du, Chaofan Song, and Jun Zhao. "Application of ORC in a Distributed Integrated Energy System Driven by Deep and Shallow Geothermal Energy." Energies 14, no. 17 (September 2, 2021): 5466. http://dx.doi.org/10.3390/en14175466.

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This study presents a distributed integrated energy system driven by deep and shallow geothermal energy based on forward and reverse cycle for flexible generation of cold, heat and electricity in different scenarios. By adjusting the strategy, the system can meet the demand of heat-electricity in winter, cool-electricity in summer and electricity in transition seasons. The thermodynamic analysis shows that the thermal efficiency of the integrated energy system in the heating and power generation mode is 16% higher than that in the cooling and power generation mode or the single power generation mode. Meanwhile, the annual heat-obtaining quantity of the system is reduced by 11% compared with that of the independent power generation system, which effectively alleviates the imbalance of the temperature field of the shallow geothermal reservoir. In terms of net power generation, the integrated energy system can generate approximately 31% more electricity than the conventional independent cooling and heating system under the same cooling and heating capacity. An integrated system not only realizes the comprehensive supply of cold and thermal ower by using clean geothermal efficiency, but also solves the temperature imbalance caused by the attenuation of a shallow geothermal temperature field. It provides a feasible way for carbon emission reduction to realize sustainable and efficient utilization of geothermal energy.

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Tan, Li Li, and Peng Huo. "Shallow Geothermal Energy in the Application of Building Energy Saving in Shijiazhuang." Advanced Materials Research 977 (June 2014): 178–81. http://dx.doi.org/10.4028/www.scientific.net/amr.977.178.

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In recent years,with the low carbon environmental protection consciousness into the social and economic,shallow geothermal energy which is one of the clean energy of is applied widely.This paper states the conditions of resource utilization and collecting technology in Shijiazhuang.It also states the present development situation and the application examples of Shallow Geothermal Energy heat source heating (cold) system , which can provide beneficial reference data.

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Aquino, Andrea, Flavio Scrucca, and Emanuele Bonamente. "Sustainability of Shallow Geothermal Energy for Building Air-Conditioning." Energies 14, no. 21 (October 28, 2021): 7058. http://dx.doi.org/10.3390/en14217058.

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Geothermal heat pumps have a widespread diffusion as they are able to deliver relatively higher energy output than other systems for building air-conditioning. The exploitation of low-enthalpy geothermal energy, however, presents crucial sustainability issues. This review investigates the primary forms of the environmental impact of geothermal heat pumps and the strategies for their mitigation. As life-cycle analyses shows that the highest impacts arise from installation and operation stages, most optimization studies focus on system thermodynamics, aiming at maximizing the energy performance via the optimization in the design of the different components interacting with the ground and serviced building. There are environmental studies of great relevance that investigate how the climate and ground properties affect the system sustainability and map the most suitable location for geothermal exploitation. Based on this review, ground-source heat pumps are a promising technology for the decarbonization of the building sector. However, a sustainable design of such systems is more complex than conventional air-conditioning systems, and it needs a holistic and multi-disciplinary approach to include the broad environmental boundaries to fully understand the environmental consequences of their operation.

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Yue, Chao Jun, and Zhan Shi Liu. "Zonation for Development of Shallow Geothermal Energy in Urban Area of Kaifeng City and some Relevant Suggestions." Applied Mechanics and Materials 587-589 (July 2014): 355–60. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.355.

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Through studying the current development condition of shallow geothermal energy in urban area of Kaifeng City and the corresponding data of geological exploration, by taking into account the various factors influencing the applicability of different heat exchange systems, and by means of GIS and AHP, a comprehensive evaluation and preliminary zonation for the development of shallow geothermal energy in urban Kaifeng are carried out . The research result indicates that the development of ground heat exchange system in the whole urban area of Kaifeng City is feasible and applicable. Furthermore, some suggestions about the development and utilization of shallow geothermal energy in the area are put forward.

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Schwarz, Hans, Nikola Jocic, and David Bertermann. "Development of a Calculation Concept for Mapping Specific Heat Extraction for Very Shallow Geothermal Systems." Sustainability 14, no. 7 (April 1, 2022): 4199. http://dx.doi.org/10.3390/su14074199.

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Horizontal shallow geothermal applications are easy to install, and their installation process is less liable to legislation than other geothermal systems. Due to a lack of planning guidance, the opportunity to implement such systems is often overlooked, although geothermal installations are urgently needed as a sustainable energy source. To give a foundation for including very shallow geothermal systems in local heat supply planning, potential maps are crucial. To enable their utilization in energy use plans or similar elaborations for municipalities, location-specific and system-specific heat extractions are required. Since applicable standards are not available, it is nearly impossible to provide aggregate propositions, which are essential for potential maps. In this study, a concept was evolved for deriving very shallow geothermal potential maps with location-specific and system-specific heat extraction values. As a basis, VDI 4640 Part 2 information regarding heat extraction and respective climate zone references was utilized. Furthermore, climate information and a soil map were needed to apply the concept to the study area. The application of the concept in an Austrian study area resulted in appropriate potential maps. Moreover, this concept is similarly applicable in other areas of interest.

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Lyu, Weihua, Xianting Li, Shuai Yan, and Sihang Jiang. "Utilizing shallow geothermal energy to develop an energy efficient HVAC system." Renewable Energy 147 (March 2020): 672–82. http://dx.doi.org/10.1016/j.renene.2019.09.032.

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Vicidomini, Maria, and Diana D’Agostino. "Geothermal Source Exploitation for Energy Saving and Environmental Energy Production." Energies 15, no. 17 (September 2, 2022): 6420. http://dx.doi.org/10.3390/en15176420.

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Many European and some other developed countries have addressed the use of geothermal energy systems as a renewable source of energy worthy of investment and development. Geothermal energy is a non-intermittent and potentially inexhaustible source that can be used for energy saving and environmental energy production, as well as to provide heating and cooling to buildings, by increasing the energy efficiency of conventional systems. This editorial paper collects the most significant and recent studies, dealing with geothermal source exploitation, the possible role of geothermal systems in the building retrofit measures, the use of shallow geothermal sources, and specific aspects of systems that exploit geothermal energy.

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Shuang, You, Li Xiangyu, Gao Yu, and Tang Wendi. "An Assessment Methodology of Shallow Geothermal Energy Projects." Open Fuels & Energy Science Journal 7, no. 1 (December 31, 2014): 169–75. http://dx.doi.org/10.2174/1876973x01407010169.

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Combination of theoretical and numerical analysis, an assessment approach of shallow geothermal energy project is proposed. A case study on Chongqing is carried out to verify the methods. According to the theoretical calculation, the heat transfer power per meter of typical boreholes in Chongqing is 40 W/m for cooling and 50 W/m for heating. The numerical model of 100m borehole heat exchanger (BHE) of ground sourced heat pump (GSHP) system is built, two sets of heating and cooling loads are input to calculate the ground thermal response, the results show that the thermal unbalance ratio equals to 1.5 would ensure the safe and reliable long time operation of GSHP system. By comparing the single and group borehole model, the heat transfer efficiency of BHE is not influenced by adjacent boreholes with 6m drilling spacing, the temperature distribution among boreholes almost uniform after a year running, however, the increase of cumulative temperature of the ground reaches 2.2°C after five years running.

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Cocchi, Silvia, Sonia Castellucci, and Andrea Tucci. "Modeling of an Air Conditioning System with Geothermal Heat Pump for a Residential Building." Mathematical Problems in Engineering 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/781231.

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The need to address climate change caused by greenhouse gas emissions attaches great importance to research aimed at using renewable energy. Geothermal energy is an interesting alternative concerning the production of energy for air conditioning of buildings (heating and cooling), through the use of geothermal heat pumps. In this work a model has been developed in order to simulate an air conditioning system with geothermal heat pump. A ground source heat pump (GSHP) uses the shallow ground as a source of heat, thus taking advantage of its seasonally moderate temperatures. GSHP must be coupled with geothermal exchangers. The model leads to design optimization of geothermal heat exchangers and to verify the operation of the geothermal plant.

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Wang, Qian Kun, Zhan Liang Zu, and Si Lun Liu. "Study on the Use of Geothermal Energy in Large Space Stadium." Applied Mechanics and Materials 368-370 (August 2013): 1415–20. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.1415.

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With the development of economy and the rising of public awareness on environmental issues, building energy consumption, especially the energy consumption of public buildings represented by large space stadiums, has received an increasing public attention. Geothermal energy, as a green energy, is widely used in large public buildings as a replacement of traditional energies. This article compares the respective economic and environmental benefits of ground source heat pump system and traditional air-conditioning system. First of all, the article discusses the feasibility of building geothermal wells and utilizing geothermal energy in large space stadiums. Then, the article illustrates the determination of the parameters of the geothermal wells and geothermal utilization strategy (deep + shallow geothermal) through software stimulation on Dest. Finally, the article evaluates the environmental and economic effect of geothermal energy system applied in large space stadium.

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Zhang, Qing, Weiya Ge, Junyuan Jia, Fujin Tian, Xiaojun Chang, Huaixue Xing, and Ting Lei. "Recoverable Resource Prediction of Shallow Geothermal Energy in Small Towns Using the Finite Volume Method: Taking the Central Urban Area of Danyang City, Jiangsu Province, as an Example." Mathematical Problems in Engineering 2019 (April 9, 2019): 1–14. http://dx.doi.org/10.1155/2019/4154836.

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The ground-coupled ground-source heat pump (GSHP) system is a common method for shallow geothermal energy exploitation and utilization. GSHP has a great heat exchange rate and wide application range. In order to effectively exploit shallow geothermal energy in the central urban area of Danyang City, Jiangsu Province, based on finite volume method, it is adopted to simulate the amount of recoverable shallow geothermal energy in the study area through ground-coupled heat exchange. The simulation is conducted on the development trend of thermal transport and thermal balance in the study area from early June 2015 to the end of May 2025 to obtain the temperature distribution at different times. Under the presupposed working conditions, with the operation of a ground-coupled GSHP, thermal accumulation occurs in parts of the study area. To mitigate the problem of thermal accumulation, two schemes are proposed: (1) adding auxiliary cooling towers and (2) increasing the amount heated domestic water in spring and autumn. Both schemes mitigate thermal accumulation. For Scheme 1, the total heat supply for shallow geothermal energy in the central urban area of Danyang City in winter is 2.91 × 106 kW, and the total heat release in summer is 3.53 × 106 kW. For Scheme 2, the total heat release in summer is 3.52 × 106 kW and the total heat supply in winter is 2.90 × 106 kW. A ground-coupled GSHP system has significant applicability in the central urban area of Danyang City, where shallow geothermal energy has good exploitation prospects.

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He, Yujiang, and Xianbiao Bu. "Performance of Hybrid Single Well Enhanced Geothermal System and Solar Energy for Buildings Heating." Energies 13, no. 10 (May 14, 2020): 2473. http://dx.doi.org/10.3390/en13102473.

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The energy reserves in hot dry rock and hydrothermal systems are abundant in China, however, the developed resources are far below the potential estimates due to immature technology of enhanced geothermal system (EGS) and scattered resources of hydrothermal systems. To circumvent these problems and reduce the thermal resistance of rocks, here a shallow depth enhanced geothermal system (SDEGS) is proposed, which can be implemented by fracturing the hydrothermal system. We find that, the service life for SDEGS is 14 years with heat output of 4521.1 kW. To extend service life, the hybrid SDEGS and solar energy heating system is proposed with 10,000 m2 solar collectors installed to store heat into geothermal reservoir. The service life of the hybrid heating system is 35 years with geothermal heat output of 4653.78 kW. The novelty of the present work is that the hybrid heating system can solve the unstable and discontinuous problems of solar energy without building additional back-up sources or seasonal storage equipment, and the geothermal thermal output can be adjusted easily to meet the demand of building thermal loads varying with outside temperature.

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Motamedi, Yaser, Nikolas Makasis, Arul Arulrajah, Suksun Horpibulsuk, and Guillermo Narsilio. "Thermal performance of the ground in geothermal pavements." E3S Web of Conferences 205 (2020): 06015. http://dx.doi.org/10.1051/e3sconf/202020506015.

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Shallow geothermal energy utilises the ground at relatively shallow depths as a heat source or sink to efficiently heat and cool buildings. Geothermal pavement systems represent a novel concept where horizontal ground source heat pump systems (GSHP) are implemented in pavements instead of purpose-built trenches, thus reducing their capital costs. This paper presents a geothermal pavement system segment (20m × 10m) constructed and monitored in the city of Adelaide, Australia, as well as thermal response testing (TRT) results. Pipes have been installed in the pavement at 0.5 m depth, and several thermistors have been placed on the pipes and in the ground. A TRT has been performed with 6kW heating load to achieve an understanding of the thermal response of the system as well as to estimate the effective thermal conductivity of the ground. The results show that the conventional semi-log method may be applicable to determine the thermal conductivity for geothermal pavements. The geothermal heat exchanger at shallow depth is considerably under the influence of the ambient temperature; however, it is still acceptable for exchanging the heat within the ground. It is also concluded that the impact radius of heat exchanger in geothermal pavement during the TRT is around 0.5m in the vertical and horizontal directions for this case study.

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Choi, Hanna, Jaeyeon Kim, Byoung Ohan Shim, and Dong-hun Kim. "Characterization of Aquifer Hydrochemistry from the Operation of a Shallow Geothermal System." Water 12, no. 5 (May 13, 2020): 1377. http://dx.doi.org/10.3390/w12051377.

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The use of shallow geothermal energy systems utilizing groundwater temperature for the air-conditioning of buildings is increasing worldwide. The impact of these systems on groundwater quality has become crucial for environmental regulations and system design. For the long-term operation of geothermal systems, it is important to evaluate their influence on the geochemical properties of groundwater, including precipitation and dissolution of secondary minerals. This research was conducted in a real-scale geothermal system, consisting of a groundwater heat pump (GWHP). Hydrochemical data were obtained from samples collected from an aquifer before heating, during heating, and before cooling operations of the GWHP. The Langelier Saturation Index and Ryznar Stability Index were calculated, and the saturation index was simulated with the PHREEQC program. Evidence from water table variation, temperature change, and 87 Sr/ 86 Sr isotope distribution showed that groundwater flows from a well located on the northwest side of the geothermal well. The saturation index values showed that the pristine groundwater favors carbonate dissolution, however, manganese oxides are more sensitive to temperature than carbonate minerals. In addition, mineral precipitation and dissolution were found to vary with depth and temperature.

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Rybach, Ladislaus. "Global Status, Development and Prospects of Shallow and Deep Geothermal Energy." International Journal of Terrestrial Heat Flow and Applications 5, no. 1 (April 2, 2022): 20–25. http://dx.doi.org/10.31214/ijthfa.v5i1.79.

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Geothermal heat pump systems (GHP), producing from shallow resources, are the spearhead of geothermal achievement and development. Global heat delivery grew exponentially to 600 PJ in 2020. GHP is the fastest growing segment in geothermal technology and one of the fastest growing application of renewable energy technologies worldwide. Other, various direct-use applications like space heating, bathing and swimming/wellness, industrial, agricultural (especially greenhouses) and aquacultural applications are based on deep, hydrothermal resources. These varieties produced worldwide 420 PJ heat in 2020; the average linear growth was, from 1995 on, about 10 % per year. It can be expected that this trend continues. Power generation, also from deep, hydrothermal resources, develops slowly but steadily, with an average growth-rate of 5 % per year, producing 95.0 TWh in 2020 in 30 countries. When comparing with other renewable power plant technologies (hydro, biomass, solar PV, wind), geothermal falls far behind – both in installed capacity (GWe) and in production (TWh). Only the annual availability of geothermal electricity is the highest among the renewables (60 %). Low geothermal productivity and growth-rate is due to extensive investments for solar PV and wind, which are by orders of magnitude higher than for geothermal power. The technology of Enhanced Geothermal Systems (EGS), based on deep, petrothermal resources, could be a game-changer. Requirements, problems and research goals to find solutions are presented.

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Zhang, Hua, Shuren Hao, Qing Yang, Zihong Wang, Wujun Dong, and Liangliang Guo. "Study on Storage Conditions and Suitability Zoning of Shallow Floor Energy in Nanchang City." Geofluids 2021 (October 23, 2021): 1–16. http://dx.doi.org/10.1155/2021/4230048.

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In the context of China’s carbon summit strategy, as renewable clean energy, the development and utilization of shallow geothermal energy has broad prospects. Based on the analysis of the occurrence conditions of shallow geothermal energy in Nanchang City, the suitability zoning of the ground source heat pump project in Nanchang City is studied by using the analytic hierarchy process. The results show that Nanchang is very suitable for the construction of the ground source heat pump system. Among them, the suitable area of the groundwater ground source heat pump is 252.17 km2, the basically suitable area is 133.64 km2, and the unsuitable area is 124.29 km2. The suitable area of the buried pipe ground source heat pump is 180.49 km2, the basically suitable area is 320.82 km2, and the unsuitable area is 8.79 km2. The evaluation results can provide a basis for the development and utilization of shallow geothermal energy in Nanchang.

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Wang, Yi-Tong, Shuang You, Xiao-Xu Hou, and Zheng Yi. "Estimation of shallow geothermal potential to meet heating demand in a building scale." Thermal Science 27, no. 1 Part B (2023): 607–14. http://dx.doi.org/10.2298/tsci2301607w.

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The heat exchanger can use shallow geothermal energy to provide regional heating and cooling demand in winter and summer. In this paper, a large-scale public building is taken as the example, and the energy system in the building is taken as the research object. Firstly, through the collection of geothermal drilling geographic information and geothermal data, the geothermal reserves and geothermal recoverable resources are evaluated. Secondly, the cooling and heating demand of the building is calculated by using HVAC simulation software. Then, the heat transfer capacity of a single pile is evaluated and the layout scheme of the underground heat exchange pile foundation of the building is given. The actual heating effect of the heat exchange pile foundation system is explored, and the heat transfer characteristics of heat exchange pile foundation under different working conditions are compared and analyzed. Finally, reasonable suggestions for the arrangement of heat exchange pile foundation are given.

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NAGAI, Niro. "Advances and Opportunities in Air-conditioning System Utilizing Shallow Geothermal Energy." International Conference on Business & Technology Transfer 2018.8 (2018): 58–59. http://dx.doi.org/10.1299/jsmeicbtt.2018.8.0_58.

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Lyu, Weihua, Xianting Li, Baolong Wang, and Wenxing Shi. "Energy saving potential of fresh air pre-handling system using shallow geothermal energy." Energy and Buildings 185 (February 2019): 39–48. http://dx.doi.org/10.1016/j.enbuild.2018.12.037.

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Du, Ruiqing, Dandan Jiang, and Yong Wang. "Experimental Investigation on Thermal Performance of Double-U-tube Heat Exchanger Using CuO/water Nanofluid as Heat Transfer Fluid." E3S Web of Conferences 165 (2020): 01022. http://dx.doi.org/10.1051/e3sconf/202016501022.

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By applying the shallow ground energy to supply building heating and cooling, the geothermal heat exchanger systems were considered as an energy-efficient building service system. In this study, the CuO/water nanofluid was employed as circuit fluids of the geothermal heat exchanger system, and the thermal performance of the heat exchanger was investigated. The results showed that the heat transfer process of CuO/water nanofluid became stable earlier than that water. Furthermore, the heat transfer rate of nanofluid was higher than that of water when the heat transfer process plateaued.

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Su, Chuan Yang, Gang Chen, and Qing Zhang. "Experimental Study on Pumping and Recharging of Groundwater-Source Heat Pump System in Fuzhou Basin." Advanced Materials Research 805-806 (September 2013): 574–79. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.574.

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Groundwater-source heat pump is a new kind of energy conservation and environmental protection air conditioning technology, which is playing a significant role in the development and utilization of the shallow geothermal energy.This paper takes Fuzhou basin as the research object, analyses its regional hydrogeological characteristics, finding Min River terrace and plains are the suitable areas to carry out the tests. On the basis of pumping and recharging experiments, the paper works out the recharging ability, the suitable pumping and recharging wells quantitative proportion of Fuzhou basin main aquifers and the well spacing design parameters between pumping and recharging wells, which provides some scientific evidences for the development of shallow geothermal energy and for the rational application of groundwater-source heat pump technology.

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Shah, Archan, Moncef Krarti, and Joe Huang. "Energy Performance Evaluation of Shallow Ground Source Heat Pumps for Residential Buildings." Energies 15, no. 3 (January 29, 2022): 1025. http://dx.doi.org/10.3390/en15031025.

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This paper evaluates the energy performance of shallow ground source heat pumps using the state-of-art whole building energy simulation tool. In particular, the paper presents a systematic and easy to implement approach to model the energy performance of shallow and helical ground heat exchangers and assess their energy efficiency benefits to heat and cool buildings. The modeling approach is based on the implementation of G-functions, generated using a validated numerical model, in a state-of-art whole building energy simulation tool. Both the numerical model and the simulation tool are applied to assess the energy performance of various shallow geothermal systems designed to meet heating and cooling needs for detached single-family homes in California. Specifically, a series of sensitivity analyses is conducted to determine the energy performance of the shallow geothermal systems in 16 locations representing all California climate zones. It is found that the suitability and the efficiency of the shallow geothermal systems vary widely and depend on several factors including their design specifications as well as the climate conditions. Compared with conventional air-to-air heat pumps, the shallow ground source heat pumps can be more energy efficient in most climate zones in California except those locations with extreme weather conditions resulting in either heating or cooling only operation. Moreover, configurations of shallow ground source heat pumps with 16 boreholes with 6.7 m (22 ft) depth are found to be cost-effective in several California climate zones.

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Sowiżdżał, Anna. "Geothermal Systems—An Overview." Energies 15, no. 17 (September 1, 2022): 6377. http://dx.doi.org/10.3390/en15176377.

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This editorial aims to summarize 10 articles (7 scientific papers and 3 review papers) that contributed to the Special Issue “Geothermal Systems—An Overview”. This Special Issue contains information on both shallow and deep geothermal systems, and analyzes geothermal resources (low and high temperature) in various locations around the world.

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Carlini, M., S. Castellucci, E. Allegrini, and A. Tucci. "Down-Hole Heat Exchangers: Modelling of a Low-Enthalpy Geothermal System for District Heating." Mathematical Problems in Engineering 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/845192.

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In order to face the growing energy demands, renewable energy sources can provide an alternative to fossil fuels. Thus, low-enthalpy geothermal plants may play a fundamental role in those areas—such as the Province of Viterbo—where shallow groundwater basins occur and conventional geothermal plants cannot be developed. This may lead to being fuelled by locally available sources. The aim of the present paper is to exploit the heat coming from a low-enthalpy geothermal system. The experimental plant consists in a down-hole heat exchanger for civil purposes and can supply thermal needs by district heating. An implementation in MATLAB environment is provided in order to develop a mathematical model. As a consequence, the amount of withdrawable heat can be successfully calculated.

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Kljajić, Miroslav V., Aleksandar S. Anđelković, Vaclav Hasik, Vladimir M. Munćan, and Melissa Bilec. "Shallow geothermal energy integration in district heating system: An example from Serbia." Renewable Energy 147 (March 2020): 2791–800. http://dx.doi.org/10.1016/j.renene.2018.11.103.

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Messervey, Thomas, Marco Calderoni, Angel Font, Mikel Borras, Ray Sterling, David Martin, and Zia Lennard. "Introducing GEOFIT: Cost-Effective Enhanced Geothermal Systems for Energy Efficient Building Retrofitting." Proceedings 2, no. 15 (September 21, 2018): 557. http://dx.doi.org/10.3390/proceedings2150557.

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GEOFIT, “Deployment of novel GEOthermal systems, technologies and tools for energy efficient building retrofitting,” is a recently launched 4-year H2020 project funded by the Innovation and Networks Executive Agency (INEA) under the call topic LCE-17-2017: Easier to install and more efficient geothermal systems for retrofitting buildings. GEOFIT is a part of INEA’s Energy Portfolio Low Carbon Economy (LCE), Renewable Energy Technologies (RET) and brings together 24 partners from 10 European countries to work on the development of novel and smart shallow geothermal systems. This paper introduces the project.

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Hou, Jikun, Xingqi Luo, and Lei Zhang. "Establishment of Evaluation Model for Shallow Geothermal Energy Resource Development Potential Based on Characteristic of Geotemperature." Earth Sciences Research Journal 24, no. 3 (October 12, 2020): 317–25. http://dx.doi.org/10.15446/esrj.v24n3.89513.

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The potential analysis of geothermal energy based on geothermal characteristics requires research of the regional shallow geothermal energy. Then, an evaluation model can be constructed. Taking Weinan City as an example, this paper studied the depth and temperature characteristics of the constant zone of subsurface temperature, the vertical variation characteristic of geotemperature, and the horizontal distribution characteristic of geotemperature in Weinan City. Based on the analysis of geotemperature characteristic, the analytic hierarchy process was used to construct the zoning evaluation system of the suitability of ground source, groundwater source, and surface water source. Then, the suitability of Weinan city was comprehensively zoned by the zoning evaluation system. The heat capacity and heat-exchange power of the heat pump system at the groundwater source were calculated based on the zoning results, and the heat-exchange power of the ground-coupled heat pump was obtained. According to the evaluation index, the development potential of shallow geothermal energy resources was evaluated. Through the experimental analysis, applying the model in this paper, it can be seen that the heat pump system has great potential for heating in winter and cooling in summer. The area is 50.79 km2. The area of the potential middle region of the buried pipe heat pump is 135.74 km2, and the potential of the ground source heat pump system is low. The potential area of the ground source heat pump is 82.14 km2. Upon comparing the model results with the current results, it was found that the consistency between the two is high.

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Bertermann, David, Johannes Müller, Simon Freitag, and Hans Schwarz. "Comparison between Measured and Calculated Thermal Conductivities within Different Grain Size Classes and Their Related Depth Ranges." Soil Systems 2, no. 3 (September 1, 2018): 50. http://dx.doi.org/10.3390/soilsystems2030050.

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In the field of the efficiency of very shallow geothermal energy systems, there is still a significant need for research activity. To ensure the proper exploitation of this energy resource, the decisive geophysical parameters of soil must be well-known. Within this study, thermal conductivity, as a fundamental property for evaluating the geothermal potential of very shallow geothermal systems, was analyzed and measured with a TK04 device. A dataset, consisting of various geophysical parameters (thermal conductivity, bulk density, water content, and porosity) determined for a large range of different textural soil classes, was collated. In a new approach, the geophysical properties were visualized covering the complete grain size range. The comparison between the measured and calculated thermal conductivity values enabled an investigation with respect to the validity of the different Kersten equations. In the course of this comparison, the influence of effective bulk density was taken into account. In conclusion, both Kersten formulas should be used as recommended and regular bulk density corresponded better to the reference dataset representing the outcomes of the TK04 laboratory measurement. Another objective was to visualize the relation of thermal conductivities within their corresponding textural classes and the validity of Kersten formulas for various bulk densities, depths, and soils. As a result, the accessibility to information for expedient recommendations about the feasibility of very shallow geothermal systems will be improved. Easy, accessible know-how of the fundamentals is important for a growing renewable energy sector where very shallow geothermal installations can also cover heating and cooling demands.

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Shi, Yan, Fu Gang Wang, Guan Hong Feng, Hai Long Tian, and Hong Wu Lei. "Numerical Simulation and Parameter Analysis on Low-Temperature Geothermal System in Homogeneous Porous Medium." Applied Mechanics and Materials 409-410 (September 2013): 578–83. http://dx.doi.org/10.4028/www.scientific.net/amm.409-410.578.

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According to the mass and energy conservation principle of simulation program TOUGH2 used for non-isothermal multi-phase fluid and heat flow in porous and fractured media, the heat transport mathematical model of low-temperature shallow geothermal system is set up in homogeneous porous medium. The fundamental scientific issues on heat transfer characteristics and distribution of transient temperature field of heat exchange wells in summer is discussed in this paper. In addition, the significance and correlation between the changes of hydrogeology parameters and temperature field of the soil is analyzed. So as to the practical application of geothermal energy development can be guided by the achievements of the research.

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Belliardi, Marco, Linda Soma, Rodolfo Perego, Sebastian Pera, Eloisa Di Sipio, Angelo Zarrella, Laura Carnieletto, et al. "A method for the sustainable planning and management of ground source heat pump systems in an urban environment, considering the effects of reciprocal thermal interference." Open Research Europe 2 (May 12, 2022): 58. http://dx.doi.org/10.12688/openreseurope.14665.1.

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The “Most Easy, Efficient and Low Cost Geothermal Systems for Retrofitting Civil and Historical Buildings” (GEO4CIVHIC) project aims to accelerate the deployment of shallow geothermal systems for heating and cooling purposes when retrofitting existing and historical buildings. Analyzing the implementation process of borehole heat exchangers (BHEs), allows the understanding of how to promote the long-term sustainability of shallow geothermal energy systems. The thermal interference between BHE systems represents a problem, especially due to the increasing deployment of this technology and its spread in densely built-up areas. The main goals of this paper are: a) to analyze the design phase of a BHE system in order to prevent mutual thermal interference, b) to propose a model that encloses phases to adopt an integrated approach for preventing long term thermal interferences, c) to give technical and management suggestions to minimize thermal interference between closed-loop geothermal systems. The method developed follows the following steps: 1) literature review to determine what are the main drivers for thermal interference between shallow geothermal systems, in the context of the GEO4CIVHIC project case study sites; 2) to create a conceptual model to limit thermal interference at both design and operational phases; 3) to apply the developed method to real and virtual case studies in countries with different regulatory frameworks and to test its main strengths and weaknesses. The application of this conceptual model to specific case studies provides evidence of critical planning and operational characteristics of GSHP systems and allows the identification of measures to mitigate impacts of thermal interference to be identified.

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Floridia, Giovanni, Salvatore Urso, Giuseppe Maria Belfiore, and Marco Viccaro. "Thermal and Mechanical Improvement of Filling Mixture for Shallow Geothermal Systems by Recycling of Carbon Fiber Waste." Energies 15, no. 16 (August 10, 2022): 5806. http://dx.doi.org/10.3390/en15165806.

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The reuse of waste materials such as carbon fiber (CF) as filling additive for closed-loop vertical geothermal probes in shallow geothermal systems has been evaluated as a new grout mixture for the improvement of geothermal energy systems efficiency and a sustainable supply of raw materials from special waste. The study evaluates the improvement in both thermal exchange characteristics and mechanical properties of the filling grout for geothermal purposes through the addition of 5% of CF to standard (ST) materials currently on the market. Uniaxial and flexural tests investigating the material response after 14 and 28 days from sample preparation on samples of both standard and mixed grout material as well as non-stationary hot wire method were used to define the thermal conductivity for both the standard and innovative mixtures. The experimental analysis provides evidence for increasing the thermal conductivity by about 3.5% with respect to standard materials. Even the mechanical properties are better in the innovative mixture, being the compressive strength 187% higher and flexural strength 81% higher than standard materials. The obtained results become useful for the optimization of low enthalpy geothermal systems and mostly for the design of the vertical heat exchange system in terms of depth/number of installed probes. Principally, thermal conductivity improvements result in a reduction of about 24% of the geothermal exchanger’s length, affecting the economic advantages in the implementation of the entire system. A simple analysis of the reuse of CF waste shows the reduction of industrial waste and the simultaneous elimination of disposal costs, defining new perspectives for industrial waste management. This research provides essential elements for the development of a circular economy and is well integrated with the European challenges about the End of Waste process and reduction of environmental impact, suggesting new perspectives for economic development and sectorial work.

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Lorente Rubio, Carlos, Jorge Luis García-Alcaraz, Juan Carlos Sáenz-Diez Muro, Eduardo Martínez-Cámara, Agostino Bruzzone, and Julio Blanco-Fernández. "Environmental Impact Comparison of Geothermal Alternatives for Conventional Boiler Replacement." Energies 15, no. 21 (November 1, 2022): 8163. http://dx.doi.org/10.3390/en15218163.

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In the transition towards a sustainable world with a “green horizon” (something that is also of great importance to the policy of energy self-sufficiency in housing and self-consumption), geothermal energy is seen as quite a feasible alternative for single-family homes. This article focuses on a comparison between the environmental impact and life cycle analysis of three alternatives and provides a base case for the replacement of a conventional type of boiler with a geothermal one for a typical house located in a Mediterranean climate. The first alternative (A) consists of a horizontal catchment system through a field of geothermal probes. The second alternative (B) is a shallow water catchment system, open type, with the return of water to a nearby river. The third option studied (C) is also a shallow water catchment system but with the water, return injected into a well downstream to the underground water flow. The study shows that alternatives A and B have the least environmental impact in most of the categories studied. The total amortization periods for the three alternatives and the base case differ by almost two years, with alternative A taking 6.99 years and alternative C costing 8.82 years.

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David, I., and M. Visescu. "Analytical solution for estimating the influence of a pre-existing ground water flow on a geothermal heat production-injection well system." International Review of Applied Sciences and Engineering 2, no. 1 (June 1, 2011): 13–17. http://dx.doi.org/10.1556/irase.2.2011.1.2.

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Abstract Geothermal energy source is the heat from the Earth, which ranges from the shallow ground (the upper 100 m of the Earth) to the hot water and hot rock which is a few thousand meters beneath the Earth's surface. In both cases the so-called open systems for geothermal energy resource exploitation consist of a groundwater production well to supply heat energy and an injection well to return the cooled water, from the heat pump after the thermal energy transfer, in the underground. In the paper an analytical method for a rapid estimation of the ground water flow direction effect on the coupled production well and injection well system will be proposed. The method will be illustrated with solutions and images for representative flow directions respect to the axis of the production/injection well system.

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Zhang, Qing, Yunfeng Li, Jian Hua, Xiaonan Niu, Lili Hou, Zongfang Chen, and Weiya Ge. "Assessment of Energy Potential and Benefit under the Ground Source Heat Pump Air Conditioning System in Anqing Area of Eastern China." Geofluids 2021 (November 9, 2021): 1–14. http://dx.doi.org/10.1155/2021/3271884.

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Now ground source heat pump is a more efficient way to develop and utilize shallow geothermal energy because it is clean and environmentally friendly and has a relatively low energy cost. In order to optimize the planning layout and geographical space development in the eastern new town of Anqing city, which can realize the transformation and upgrading of real space and urban sustainable development, the exploration for shallow geothermal energy will be carried out in this area, so as to find out the comprehensive thermophysical parameters of the shallow rock-soil body and the heat transfer capacity of the vertical heat exchanger, etc. This paper takes the CBD in the eastern new town of Anqing as an example to provide the basis for the feasibility construction of the ground source heat pump project in the study area and evaluate the economic and environmental benefits of the expected project. According to the simulation test data of 5 working conditions of 4 geothermal exploration holes in the study area, we can clearly know that the energy cost per square meter of the ground source heat pump is 11.8 yuan for a building of one hundred thousand square meters in which the heat removal power is expected to be 9481 kW in summer and 3070 kW in winter. And the annual emission of carbon dioxide, sulfur dioxide, nitrogen oxides, suspended dust, and other air pollutants to the atmosphere can be reduced by 1442.5 t, and the solid waste ash and slag can be reduced by 59.7 t. The annual environmental treatment cost will be saved by 166000 yuan.

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Ninikas, Konstantinos, Nicholas Hytiris, Rohinton Emmanuel, and Bjorn Aaen. "Heat energy from a shallow geothermal system in Glasgow, UK: performance evaluation design." Environmental Geotechnics 7, no. 4 (July 1, 2020): 274–81. http://dx.doi.org/10.1680/jenge.17.00033.

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Liang, Jyun-De, Bo-Hao Huang, Yuan-Ching Chiang, and Sih-Li Chen. "Experimental investigation of a liquid desiccant dehumidification system integrated with shallow geothermal energy." Energy 191 (January 2020): 116452. http://dx.doi.org/10.1016/j.energy.2019.116452.

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Sipio, Galgaro, Carli, Greggio, Mantovan, and Sukha. "How Different Natural Energy Sources Affect the Shallow Geothermal Suitability in Urban Areas: The South Africa Case Study." Proceedings 30, no. 1 (November 21, 2019): 22. http://dx.doi.org/10.3390/proceedings2019030022.

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In recent years, the overall worldwide demand for energy has been increasing due to the constant growth of both global population and industrialization, which is particularly intensifying in emerging countries (China, India, South Africa, Brazil) and recently industrialized ones (i.e., Mexico, Turkey). In this framework, the exploitation of shallow geothermal energy through heat geo-exchange systems, as borehole heat exchangers (closed loop systems) or groundwater systems (open loop systems) coupled with a heat pump (Ground Source Heat Pump—GSHP), is really appealing, due to its versatility and energy efficiency. The heat exchanged with the underground, a reliable and green thermal energy source, is used mainly for heating and cooling of residential, industrial or commercial buildings and greenhouses. Several technologies are available and combinations with other local renewable energy sources are also possible, representing very interesting efficient and environmentally friendly solutions to be adopted in urban areas. The integration of different natural energy sources brings significant advantages, such as the reduction of CO2 emissions, the mitigation of the subsurface urban heat island effect, the minimization of electricity consumption. However, the underground suitability to low enthalpy geothermal systems is strictly related to the climatic, geological, hydrogeological, geothermal and thermophysical properties, typical of the area under investigation. The evaluation of these parameters allows to assess the amount of heat at disposal and the possibility to exchange it. On one hand, it is necessary to select and collect the data related to the factors that better characterize the ground behavior from the point of view of the heat exchange capacity. On the other, it is essential to integrate them in thematic maps created by Geographic Information System (GIS) tools, providing a preliminary evaluation of the territory suitability to geo-exchange and supporting the land use geothermal management both for closed and open loop systems. A preliminary representation of low-enthalpy geothermal resources suitability maps for Johannesburg, Durban and Cape Town, the three main urbanized cities of South Africa, representing the geological and climatic national variability of the country, is here presented. From a methodological point of view, these maps are created by assigning to each value of the descriptive parameters selected (i.e., lithology, type of aquifer, thermal conductivity, average annual air and ground temperature) a corresponding quantitative value, assessing its different attitude for thermal purposes. In this way, one of the first contribution to the suitability of geothermal energy resources in South Africa is obtained.

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Xu, Chenghua, Dandan Yu, and Zujiang Luo. "Recharge Sources and Genetic Model of Geothermal Water in Tangquan, Nanjing, China." Sustainability 13, no. 8 (April 16, 2021): 4449. http://dx.doi.org/10.3390/su13084449.

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This paper introduces a method to study the origin of geothermal water by analysis of hydrochemistry and isotopes. In addition, the genetic mechanism of geothermal water (GTW) is revealed. The study of the origin of geothermal water is useful for the sustainability of geothermal use. As an example, Tangquan is abundant in GTW resources. Elucidating the recharge sources and formation mechanism of the GTW in this area is vitally important for its scientific development. In this study, the GTW in Tangquan was systematically investigated using hydrochemical and isotopic geochemical analysis methods. The results show the following. The GTW and shallow cold water in the study area differ significantly in their hydrochemical compositions. The geothermal reservoir has a temperature ranging from 63 to 75 °C. The GTW circulates at depths of 1.8–2.3 km. The GTW is recharged by the infiltration of meteoric water at elevations of 321–539 m and has a circulation period of approximately 2046–6474 years. The GTW becomes mixed with the shallow cold karst water at a ratio of approximately 4–26% (cold water) during the upwelling process. In terms of the cause of its formation, the geothermal system in the study area is, according to analysis, of the low-medium-temperature convective type. This geothermal system is predominantly recharged by precipitation that falls in the outcropping carbonate area within the Laoshan complex anticline and is heated by the terrestrial heat flow in the area. The geothermal reservoir is composed primarily of Upper Sinian dolomite formations, and its caprock is made up of Cambrian, Cretaceous, and Quaternary formations. Through deep circulation, the GTW migrates upward along channels formed from the convergence of northeast–east- and north–west-trending faults and is mixed with the shallow cold water, leading to geothermal anomalies in the area.

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Ramos-Escudero, Adela, M. Socorro García-Cascales, and Javier F. Urchueguía. "Evaluation of the Shallow Geothermal Potential for Heating and Cooling and Its Integration in the Socioeconomic Environment: A Case Study in the Region of Murcia, Spain." Energies 14, no. 18 (September 12, 2021): 5740. http://dx.doi.org/10.3390/en14185740.

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In order to boost the use of shallow geothermal energy, reliable and sound information concerning its potential must be provided to the public and energy decision-makers, among others. To this end, we developed a GIS-based methodology that allowed us to estimate the resource, energy, economic and environmental potential of shallow geothermal energy at a regional scale. Our method focuses on closed-loop borehole heat exchanger systems, which are by far the systems that are most utilized for heating and cooling purposes, and whose energy demands are similar throughout the year in the study area applied. The resource was assessed based on the thermal properties from the surface to a depth of 100 m, considering the water saturation grade of the materials. Additionally, climate and building characteristics data were also used as the main input. The G.POT method was used for assessing the annual shallow geothermal resource and for the specific heat extraction (sHe) rate estimation for both heating and, for the first time, for cooling. The method was applied to the Region of Murcia (Spain) and thematic maps were created with the outputting results. They offer insight toward the thermal energy that can be extracted for both heating and cooling in (MWh/year) and (W/m); the technical potential, making a distinction over the climate zones in the region; the cost of the possible ground source heat pump (GSHP) installation, associated payback period and the cost of producing the shallow geothermal energy; and, finally, the GHG emissions savings derived from its usage. The model also output the specific heat extraction rates, which are compared to those from the VDI 4640, which prove to be slightly higher than the previous one.

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Okiyi, I. M., S. I. Ibeneme, E. Y. Obiora, S. O. Onyekuru, A. I. Selemo, and M. O. Olorunfemi. "Evaluation of geothermal energy resources in parts of southeastern sedimentary basin, Nigeria." Ife Journal of Science 23, no. 1 (May 3, 2021): 195–211. http://dx.doi.org/10.4314/ijs.v23i1.17.

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Residual aeromagnetic data of parts of Southeastern Nigerian sedimentary basin were reduced to the equator and subjected to magnetic vector inversion and spectral analysis. Average depths of source ensembles from spectral analysis were used to compute depth to magnetic tops (Z), base of the magnetic layer (Curie Point t Depth (CPD)), and estimate geothermal gradient and heat flow required for the evaluation of the geothermal resources of the study area. Results from spectral analysis showed depths to the top of the magnetic source ranging between 0.45 km and 1.90 km; centroid depths of 4 km - 7.87 km and CPD of between 6.15 km and 14.19 km. The CPD were used to estimate geothermal gradients which ranged from 20.3°C/km to 50.0°C/km 2 2 and corresponding heat flow values of 34.9 mW/m to 105 mW/m , utilizing an average thermal conductivity -1 -1 of 2.15 Wm k . Ezzagu (Ogboji), Amanator-Isu, Azuinyaba, Nkalagu, Amagunze, Nta-Nselle, Nnam, Akorfornor environs are situated within regions of high geothermal gradients (>38°C/Km) with models delineated beneath these regions using 3D Magnetic Vector Inversion, having dominant NW-SE and NE-SW trends at shallow and greater depths of <1km to >7 km bsl. Based on VES and 2D imaging models the geothermal system in Alok can be classified as Hot Dry Rock (HDR) type, which may likely have emanated from fracture systems. There is prospect for the development of geothermal energy in the study area. Keywords: Airborne Magnetics, Magnetic Vector Inversion, Geothermal Gradient, Heat Flow, Curie Point Depth, Geothermal Energy.

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Jamali, Muhammad Afzal, Muhammad Hassan Agheem, Akhtar Hussain Markhand, Shahid Ali Shaikh, Asfand Yar Wali Arain, Mujeeb Ur Rehman Khaskhely, Ali Ghulam Sahito, Kashif Ahmed Memon, and Waqarullah Hassan Mujtaba. "Exploration of Shallow Geothermal Energy Aquifers by Using Electrical Resistivity Survey in Laki Range Jamshoro district Sindh, Pakistan." International Journal of Economic and Environmental Geology 12, no. 1 (June 8, 2021): 46–52. http://dx.doi.org/10.46660/ijeeg.vol12.iss1.2021.561.

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Geothermal water is increasingly used around the world for its exploitation. Bulk electrical resistivity differences can bring significant information on variation of subsurface geothermal aquifer characteristics. The electrical resistivity survey was carried out in Laki range in lower Indus basin in the study area to explore the subsurface geothermal aquifers. The Schlumberger electrode configuration with range from 2 m to 220 m depth was applied. Three prominent locations of hot springs were selected including Laki Shah Saddar, Lalbagh and Kai hot spring near Sehwan city. After processing resistivity image data, two hot water geothermal aquifers were delineated at Laki Shah Sadder hot springs. The depth of first aquifer was 56 m and its thickness 38 m in the limestones. The depth of second aquifer of 190 m and with thickness of 96 m hosted in limestone. In Lalbagh hot springs two geothermal aquifers were delineated on the basis of apparent resistivity contrast, the depth of first aquifer zone in sandstone was in sandstone 15 m and thickness 12 m, while the depth of second aquifer was 61m and thickness was 35m. In Kai hot springs two hot water geothermal aquifers were delineated. The depth of first geothermal aquifer was 21m and thickness was 18 m and the depth of second aquifer was 105 m and thickness was 61m present in sandstone lithology. Present work demonstrates the capability of electrical resistivity images to study the potential of geothermal energy in shallow aquifers. These outcomes could potentially lead to a number of practical applications, such as the monitoring or the design of shallow geothermal systems.

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Zeh, Robin, Björn Ohlsen, David Philipp, David Bertermann, Tim Kotz, Nikola Jocić, and Volker Stockinger. "Large-Scale Geothermal Collector Systems for 5th Generation District Heating and Cooling Networks." Sustainability 13, no. 11 (May 27, 2021): 6035. http://dx.doi.org/10.3390/su13116035.

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Low temperature district heating and cooling networks (5GDHC) in combination with very shallow geothermal energy potentials enable the complete renewable heating and cooling supply of settlements up to entire city districts. With the help of 5GDHC, heating and cooling can be distributed at a low temperature level with almost no distribution losses and made useable to consumers via decentralized heat pumps (HP). Numerous renewable heat sources, from wastewater heat exchangers and low-temperature industrial waste heat to borehole heat exchangers and large-scale geothermal collector systems (LSC), can be used for these networks. The use of large-scale geothermal collector systems also offers the opportunity to shift heating and cooling loads seasonally, contributing to flexibility in the heating network. In addition, the soil can be cooled below freezing point due to the strong regeneration caused by the solar irradiation. Multilayer geothermal collector systems can be used to deliberately generate excessive cooling of individual areas in order to provide cooling energy for residential buildings, office complexes or industrial applications. Planning these systems requires expertise and understanding regarding the interaction of these technologies in the overall system. This paper provides a summary of experience in planning 5GDHC with large-scale geothermal collector systems as well as other renewable heat sources.

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Zhang, Zhening, Jindong Sun, Zhenxing Zhang, Xinxin Jia, and Yang Liu. "Numerical Research and Parametric Study on the Thermal Performance of a Vertical Earth-to-Air Heat Exchanger System." Mathematical Problems in Engineering 2021 (July 23, 2021): 1–16. http://dx.doi.org/10.1155/2021/5557280.

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The earth-to-air heat exchanger (EAHE) system, as a clean and efficient shallow geothermal energy application technology, has obvious effects in reducing the energy consumption of passive low-energy buildings. The traditional horizontal EAHE system is difficult to apply and popularize due to its large occupation, unfavorable shallow soil temperature, and difficulty in timely centralized discharge of condensed water. This paper proposes a new type of vertical earth-to-air heat exchanger (VEAHE) system. The VEAHE system has a number of advantages such as smaller occupation, efficient geothermal energy utilization, and centralized discharge of condensed water. In order to evaluate the influence of different parameters on the thermal performance of the VEAHE system, a mathematical model of the VEAHE system was developed. And, the data calculated by the model highly tallied with the experimental data. The results showed that laying thermal insulation layers at the outlet of risers will effectively restrain the interference of downcomers to risers. It is advisable to set thickness and length of the insulation layer at 30 mm and 3 m. Considering the compromise between thermal performance and construction costs of the VEAHE system, the length of the ducts at 30–50 m and the diameter at 150–250 mm are recommended. The air supply volume of a single shaft can reach 500–1200 m3/h as the air velocity reaches 3–7 m/s.

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Christodoulides, Paul, Ana Vieira, Stanislav Lenart, João Maranha, Gregor Vidmar, Rumen Popov, Aleksandar Georgiev, Lazaros Aresti, and Georgios Florides. "Reviewing the Modeling Aspects and Practices of Shallow Geothermal Energy Systems." Energies 13, no. 16 (August 18, 2020): 4273. http://dx.doi.org/10.3390/en13164273.

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Shallow geothermal energy systems (SGES) may take different forms and have recently taken considerable attention due to energy geo-structures (EGS) resulting from the integration of heat exchange elements in geotechnical structures. Still, there is a lack of systematic design guidelines of SGES. Hence, in order to contribute towards that direction, the current study aims at reviewing the available SGES modeling options along with their various aspects and practices. This is done by first presenting the main analytical and numerical models and methods related to the thermal behavior of SGES. Then, the most important supplementary factors affecting such modeling are discussed. These include: (i) the boundary conditions, in the form of temperature variation or heat flow, that majorly affect the predicted thermal behavior of SGES; (ii) the spatial dimensions that may be crucial when relaxing the infinite length assumption for short heat exchangers such as energy piles (EP); (iii) the determination of SGES parameters that may need employing specific techniques to overcome practical difficulties; (iv) a short-term vs. long-term analysis depending on the thermal storage characteristics of GHE of different sizes; (v) the influence of groundwater that can have a moderating effect on fluid temperatures in both heating and cooling modes. Subsequently, thermo-mechanical interactions modeling issues are addressed that may be crucial in EGS that exhibit a dual functioning of heat exchangers and structural elements. Finally, a quite lengthy overview of the main software tools related to thermal and thermo-hydro-mechanical analysis of SGES that may be useful for practical applications is given. A unified software package incorporating all related features of all SGES may be a future aim.

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Nowamooz, Hossein, Saeid Nikoosokhan, and Cyrille Chazallon. "Seasonal thermal energy storage in shallow geothermal systems: thermal equilibrium stage." E3S Web of Conferences 9 (2016): 07003. http://dx.doi.org/10.1051/e3sconf/20160907003.

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Journal articles on the topic 'Shallow geothermal energy system'

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