scholarly journals Energy-Pile Model Verification

2020 ◽  
Author(s):  
Ondřej Šikula ◽  
◽  
Richard Slávik ◽  
Jan Eliáš ◽  
Jakub Oravec ◽  
...  
Keyword(s):  
Heat Conduction ◽  
Low Cost ◽  
Energy Performance ◽  
Model Verification ◽  
Transient Phenomenon ◽  
Conduction Model ◽  
Energy Pile ◽  
Heating And Cooling ◽  
Energy Piles ◽  
Pile Model

Equipping the foundation piles with a liquid circuit pipeline makes it possible to use the advantageous ther-mal capacity of the soil for heating and cooling buildings at low cost. The energy performance of the energy-pile in a soil is a transient phenomenon dependent on many parameters, which could be investigate by a computational model. The contribution deals with the description and verification of a new numerical computational software based on a simplified 2D and 2D rotational symmetrical heat conduction model being developed for energy-piles modeling.

scholarly journals An Evaluation of the Mathematical Models of Energy Piles

2020 ◽  
Vol 28 (1) ◽  
pp. 44-48
Author(s):  
Jakub Oravec ◽  
Ondřej Šikula ◽  
Iva Nováková
Keyword(s):  
Mathematical Models ◽  
Current Trend ◽  
Energy Performance ◽  
Point Of View ◽  
Analytical Models ◽  
Energy Pile ◽  
Heating And Cooling ◽  
Energy Piles ◽  
Alternative Sources ◽  
The Individual

AbstractA current trend is to reduce the energy performance of buildings by using alternative sources for heating and cooling. One of the most promising, and so far unprecedented sources of heating and cooling, is the use of energy from the earth using the thermally-activated foundation piles of a building, the so-called energy piles. The paper deals with an overview and comparison of computer-aided analytical models of energy piles. The individual analytical models are compared (categorized) from the point of view of their physical complexity, computational costs, and thus their usability for the purpose of optimizing energy-pile equipment or assessing the long-term energy efficiency of an energy pile field. Selected mathematical models were algorithmized, and the results obtained were compared with a more robust numerical solution performed using CalA 4 software.

scholarly journals Validation of the simplified heat conduction model of EN ISO 52016-1

2021 ◽  
Vol 2069 (1) ◽  
pp. 012136
Author(s):  
G De Luca ◽  
I Ballarini ◽  
F G M Bianco Mauthe Degerfeld ◽  
V Corrado
Keyword(s):  
Heat Conduction ◽  
Finite Difference ◽  
Input Data ◽  
Internal Surface ◽  
Building Energy ◽  
Energy Performance ◽  
Building Energy Efficiency ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Wide Range

Abstract The issue of improving the building energy efficiency led to the development of calculation methods for the building energy performance assessment. To overcome the low accessibility to detailed input data, the recently introduced EN ISO 52016-1 hourly method is based on assumptions and simplifications chosen to allow a sufficient accuracy in the outcomes with a low amount of input data. Among these assumptions, a simplified mass distribution in the envelope components is considered. In the present work, the hypothesis of the simplified heat conduction model introduced by the EN ISO 52016-1 technical standard and an improved solution provided by its Italian National Annex were evaluated. In particular, the accuracy in the prediction of the internal surface temperature was assessed in comparison with a detailed finite difference conduction algorithm. The validation was performed for 5 opaque component test cases, covering a wide range of areal heat capacity values, by considering both internal and external thermal constraints (e.g. variation of the air temperature). For the structures and boundary conditions considered, results reveal that the standard algorithm allows to predict the internal surface temperatures with a valuable level of accuracy compared to the finite difference algorithm.

scholarly journals Simulation of the thermo-hydraulic response of energy piles in unsaturated soils

2020 ◽  
Vol 205 ◽  
pp. 05002
Author(s):  
Fatemah Behbehani ◽  
John S. McCartney
Keyword(s):  
Heat Transfer ◽  
Unsaturated Soils ◽  
Cumulative Effect ◽  
Degree Of Saturation ◽  
Soil Layers ◽  
Energy Pile ◽  
Axial Capacity ◽  
Coupled Heat Transfer ◽  
Heating And Cooling ◽  
Energy Piles

This paper focuses on the simulation of the coupled heat transfer and water flow in unsaturated soil layers surrounding a solitary energy pile undergoing heating and cooling cycles typical of a field-scale energy pile. The results indicate that heating leads to drying of the soil surrounding the energy pile, which has been shown in previous studies to result in an increase in axial capacity. During cooling, the degree of saturation was observed to recover to the value present before the start of heating initially, however, it will not recover in the following years. Which will lead to a cumulative effect after several cycles of heating and cooling. Heating and cooling cycles lead to an overall reduction in the thermal conductivity of the subsurface, reducing the heat transfer from the energy pile but also leading to greater storage of heat in the subsurface surrounding the pile.

Effect of Ground Mineralogy on Energy Pile Performance in Dense Sand

2016 ◽  
Vol 846 ◽  
pp. 325-330
Author(s):  
Abraham Kazzaz ◽  
Itai Einav ◽  
Gwénaëlle Proust ◽  
Yi Xiang Gan
Keyword(s):  
Research Effort ◽  
Cost Effective ◽  
Element Model ◽  
Quartz Content ◽  
Element Analysis ◽  
Energy Pile ◽  
Dense Sand ◽  
Heating And Cooling ◽  
Energy Piles ◽  
Significant Research

Geothermal energy piles have emerged as a cost effective and efficient solution for heating and cooling buildings through renewable energy. Although significant research effort has been dedicated to investigating the performance of these systems, the effect of ground mineralogy has received little attention. This study examines the likely performance of energy piles in dense sand with varying mineralogy. A 3D thermal discrete element model is used to determine the dry thermal conductivity of quartz, feldspar and mica rich sand. This is then used in a 2D finite element analysis to estimate the dissipation/extraction capacity of the soil surrounding a typical energy pile. A 35% increase in quartz content is predicted to result in 51% improvement in the thermal performance of a pile.

scholarly journals Apparatus development for contact mechanics of energy pile-soil interface

2020 ◽  
Vol 205 ◽  
pp. 05009
Author(s):  
Dan Zhang ◽  
Yulong Gao ◽  
Guangya Wang ◽  
Guanzhong Wu
Keyword(s):  
Mechanical Behavior ◽  
Normal Stress ◽  
Contact Mechanics ◽  
Earth Pressure ◽  
Hoop Strain ◽  
Energy Pile ◽  
Heating And Cooling ◽  
Fiber Technology ◽  
Pile Model ◽  
Soil Interface

An Energy Pile-Soil Interface Characteristic Apparatus (EPSICA) was developed to investigate the contact mechanics of the pile-soil interface. In the center of the apparatus, there is an energy pile model, around which different soil can be filled to simulate pile in different subsoil. The soil can be saturated. By applying loads on the top of the soil, the different depths were simulated. The temperature of energy piles was controlled by the cycling fluid with a water bath. The Pt100 sensors were installed in the pile and soil to measure the temperature changes. The miniature earth pressure cells were installed on the pile surface to measure the normal stress of the pile-soil interface. The FBG quasi-distributed optical fiber technology was used to measure the hoop strain to evaluate the circumferential deformation of the pile model. Taking the sand foundation as an example, the mechanical behavior of pile-soil contact behavior during the heating and cooling cycle was studied based on the temperature of pile and soil, normal stress of pile-soil interface and hoop strain of pile. The developed apparatus provides a new method for the study of thermos-mechanical behavior of energy pile.

scholarly journals Relationship between construction parameters and thermal loads in a building without internal gains

2021 ◽  
Author(s):  
José Alberto Díaz Angulo ◽  
Silvia Soutullo ◽  
Emanuela Giancola ◽  
José Antonio Ferrer
Keyword(s):  
Building Materials ◽  
Low Cost ◽  
Energy Performance ◽  
Operating Conditions ◽  
Influential Factor ◽  
Thermal Loads ◽  
Heating And Cooling ◽  
Cost System ◽  
Cooling Loads ◽  
Available Information

The analysis of building characteristics indicates that there are some uncertainties influencing its energy performance: Environment, volumetry or operating conditions. It is important to have a low-cost system that performs this analysis and energy management by optimizing the coupling between production and consumption. Knowing the relationship between the annual thermal needs with different construction parameters can help to define this system and allow understanding the expected heating and cooling consumption based on easily available information. In this work, a numerical methodology has been applied to estimate the thermal loads of a building without internal gains. For this purpose, a simulation environment has been developed to execute a sensitivity analysis through the interconnection between TRNSYS 16.1 and GenOpt programs. Volumetry, building materials according to Spanish regulations and percentage of external windows are evaluated as analysis variables of the parametric study. Heating, and cooling loads have been calculated to quantify their influence: Older regulations imply higher annual loads; the increase in building height and area reduces the annual thermal loads and higher percentages of glazing on the external façades imply higher annual demands, particularly in the east and west orientations; the variation of the envelope results in the most influential factor. Finally, a statistical study has been performed to assess the annual trends: Heating trends point to more stability with two defined intervals, while cooling trends are more asymmetric.

Energy Performance of Sustainable Roofing Systems

2013 ◽  
Author(s):  
David J. Sailor ◽  
Prem Vuppuluri
Keyword(s):  
Energy Use ◽  
Green Roof ◽  
Green Roofs ◽  
Energy Performance ◽  
Office Building ◽  
Solar Photovoltaic ◽  
Conduction Model ◽  
Exterior Surface ◽  
Photovoltaic Array ◽  
Heating And Cooling

This study presents efforts to analyze how sustainable roofing technologies can contribute to the energy budget of buildings, and the resulting implications for heating and cooling energy use. The data analyzed in this study were obtained from a field experiment performed on a four story warehouse/office building in Portland, Oregon USA. The building’s roof includes a 216 panel, 45.6 kW solar photovoltaic array in combination with 576 m2 of vegetated green roofing. While most of the surface consists of green roof shaded by photovoltaic panels, the roof also has test patches of dark membrane, white membrane and un-shaded green-roofing. Interior and exterior surface temperatures were monitored over a period of two years and heat flux into the building is estimated using a finite difference conduction model. On average, the black roof membrane was the only roof that caused a net heat gain into the building in the summer. In the winter, all four roofing technologies resulted in net heat losses out of the building. Both the PV-shaded and un-shaded green-roofs indicated a net heat loss out of the interior of the building during both the summer and winter. This latter effect is largely a result of green-roof evaporative cooling — which can benefit air conditioning demand in summer but may be undesirable during heating-dominated seasons.

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