scholarly journals Long-Term Thermal Performance of Group of Energy Piles in Unsaturated Soils under Cyclic Thermal Loading

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4122
Author(s):  
Abubakar Kawuwa Sani ◽  
Rao Martand Singh
Keyword(s):  
Thermal Load ◽  
Unsaturated Soils ◽  
Thermal Loading ◽  
Numerical Study ◽  
Continuous Heating ◽  
Carrier Fluid ◽  
Heating And Cooling ◽  
First Case ◽  
Energy Piles

Geothermal energy piles (GEPs) are an environmentally friendly heat exchange technology that dualizes the role of the structural foundation pile for load support and in meeting the building heating/cooling need. Energy loops made from high-density polyethylene, which allow heat carrier fluid circulation, are fitted into the pile foundation elements to extract or inject and store heat energy in the soil surrounding the pile. This paper reports the results of a numerical study investigating the long-term behaviour of a group of energy piles embedded in unsaturated soils (sand and clay) under continuous cyclic heating and cooling load. Additionally, two scenarios were investigated where: (1) the whole GEPs were heated and cooled collectively; (2) alternate piles were heated and cooled. It was found that the trend of temperature magnitude at all the observed locations decreases with time as a result of the continuous heating and cooling cycles. Furthermore, subjecting alternate GEPs to the heating and cooling cycles result in lower temperature development in comparison to thermally activating all the GEPs in the group. This is attributed to the applied thermal load, which is 0.5 times that considered in the first case. However, this might not be the case where equal thermal load is applied on the GEPs in the two cases investigated.

Feasibility study of collective heating and cooling based on foundation pile heat exchangers in Vejle (Denmark)

2020 ◽  
pp. qjegh2020-114
Author(s):  
D. Cerra ◽  
M. Alberdi-Pagola ◽  
T.R. Andersen ◽  
K.W. Tordrup ◽  
S.E. Poulsen
Keyword(s):  
Energy Demand ◽  
District Heating ◽  
Demand Model ◽  
Heating And Cooling ◽  
Energy Piles ◽  
Geophysical Investigations ◽  
Foundation Pile ◽  
Long Term Performance ◽  
Term Performance

We assess the feasibility of a collective district heating and cooling network based on a foundation pile heat exchanger in a new urban area in Vejle, Denmark. A thermogeological model for the area is developed based on geophysical investigations and borehole information. In tandem with a building energy demand model, the subsurface thermal properties serve as the input for a newly developed computational temperature model for collective heating and cooling with energy piles. The purpose of the model is to estimate the long-term performance and maximum liveable area that the energy piles are able to support. We consider two case studies where residential and office buildings dominate the building mass. We find that three to four floors can be supplied with heating and cooling from the energy piles, depending on the use and design of the buildings.

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.

scholarly journals COVID-19 Response in Thailand and Its Implications on Future Preparedness

2021 ◽  
Vol 18 (3) ◽  
pp. 1089
Author(s):  
Wijitbusaba Marome ◽  
Rajib Shaw
Keyword(s):  
Early Stage ◽  
Health Resources ◽  
Holistic Approach ◽  
Disaster Risk ◽  
Community Level ◽  
Multilateral Cooperation ◽  
First Case ◽  
Multiple Dimensions ◽  
Economic And Social Impacts

Thailand has been affected by COVID-19, like other countries in the Asian region at an early stage, and the first case was reported as early as mid-January 2020. Thailand’s response to the COVID-19 pandemic has been guided by the “Integrated Plan for Multilateral Cooperation for Safety and Mitigation of COVID-19”. This paper analyses the health resources in the country and focuses on the response through community-level public health system and legislative measures. The paper draws some lessons on future preparedness, especially with respect to the four priorities of Sendai Framework for Disaster Risk Reduction. At the end, the paper puts some key learning for future preparedness. While Thailand’s response to COVID-19 has been effective in limiting the spread of the disease, it falls short at being able to address the multiple dimensions of the crisis such as the economic and social impacts. The socioeconomic sectors have been hardest hit, with significant impact on tourism sectors. Sociopolitical system also plays an important role in governance and decision-making for pandemic responses. The analysis suggests that one opportunity for enhancing resilience in Thailand is to strive for more multilevel governance that engages with various stakeholders and to support grassroots and community-level networks. The COVID-19 pandemic recovery is a chance to recover better while leaving no one behind. An inclusive long-term recovery plan for the various impacted countries needs to take a holistic approach to address existing gaps and work towards a sustainable society. Furthering the Health Emergency Disaster Risk Management (HEDRM) Framework may support a coordinated response across various linked sectors rather than straining one particular sector.

scholarly journals Hypocalcemic cardiomyopathy after parathyroidectomy in a patient with uremia: A case report and literature review

2020 ◽  
Vol 48 (7) ◽  
pp. 030006052094211
Author(s):  
Wei Zhang ◽  
Feng Xue ◽  
Quandong Bu ◽  
Xuemei Liu
Keyword(s):  
Heart Failure ◽  
Case Report ◽  
Secondary Hyperparathyroidism ◽  
Calcium Supplementation ◽  
Severe Heart Failure ◽  
Cardiac Complications ◽  
Refractory Heart Failure ◽  
First Case ◽  
Insight Into

Hypocalcemia is a rare, but reversible, cause of dilated cardiomyopathy. Although cardiomyopathy may cause severe heart failure, calcium supplementation can reverse heart failure. We report here a patient with uremia and secondary hyperparathyroidism, who was complicated by persistent hypocalcemia and refractory heart failure. The cardiac failure was refractory to treatment with digitalis and diuretics, but dramatically responded to calcium therapy and restoration of normocalcemia. As a result, the patient was eventually diagnosed with hypocalcemic cardiomyopathy. To the best of our knowledge, this is the first case of this disease to be reported in a patient with uremia. Findings from our case may help clinicians to better understand hypocalcemic cardiomyopathy. Our case might also provide new insight into long-term cardiac complications and prognoses of patients undergoing parathyroidectomy due to secondary hyperparathyroidism.

Experimental and numerical study of size effect on long-term drying behavior of concrete: influence of drying depth

2016 ◽  
Vol 49 (10) ◽  
pp. 4029-4048 ◽  
Author(s):  
H. Samouh ◽  
A. Soive ◽  
E. Rozière ◽  
A. Loukili
Keyword(s):  
Size Effect ◽  
Numerical Study ◽  
Drying Behavior

Impact of Thermal Loading on Waste Package Material Performance

1994 ◽  
Vol 353 ◽  
Author(s):  
D. Stahl ◽  
J. K. McCoy ◽  
R. D. McCright
Keyword(s):  
Thermal Load ◽  
Thermal Loading ◽  
Steel Corrosion ◽  
Yucca Mountain ◽  
Microbiologically Influenced Corrosion ◽  
Corrosion Performance ◽  
Kinetic Relation ◽  
Reference Case ◽  
Time Exponent ◽  
High Thermal Load

AbstractThis report focuses on the prediction of materials performance for the carbon steel corrosion-allowance container as a function of thermal loading for the potential repository at Yucca Mountain. Low, intermediate and high thermal loads were evaluated as to their performance given assumptions regarding the temperature and humidity changes with time and the resultant depth of corrosion penetration. The reference case involved a kinetic relation for corrosion that was utilized in a sensitivity analysis to examine the impacts of time exponent, pitting, and microbiologically-influenced corrosion. As a result of this study, the high thermal load appears to offer the best corrosion performance. However, other factors must be considered in making the final thermal loading decision.

Experimental and numerical study on the in-plane behaviour of concrete-filled steel tubular arches with long-term effects

2021 ◽  
Vol 169 ◽  
pp. 108507
Author(s):  
Xu Han ◽  
Bing Han ◽  
Huibing Xie ◽  
Wutong Yan ◽  
Qi Ma
Keyword(s):  
Numerical Study ◽  
Long Term Effects

Numerical Simulation of Heat Transfer in Laminar Natural Convection of Mixed Newtonian-Non-Newtonian and Pure Non-Newtonian Nanofluids in a Square Enclosure

2021 ◽  
pp. 1-44
Author(s):  
Ajay Vallabh ◽  
P.S. Ghoshdastidar
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Base Fluid ◽  
Volume Fraction ◽  
Numerical Study ◽  
Transfer Model ◽  
Nanoparticle Concentration ◽  
Left Wall ◽  
Square Enclosure ◽  
First Case

Abstract This paper presents a steady-state heat transfer model for the natural convection of mixed Newtonian-Non-Newtonian (Alumina-Water) and pure Non-Newtonian (Alumina-0.5 wt% Carboxymethyl Cellulose (CMC)/Water) nanofluids in a square enclosure with adiabatic horizontal walls and isothermal vertical walls, the left wall being hot and the right wall cold. In the first case the nanofluid changes its Newtonian character to Non-Newtonian past 2.78% volume fraction of the nanoparticles. In the second case the base fluid itself is Non-Newtonian and the nanofluid behaves as a pure Non-Newtonian fluid. The power-law viscosity model has been adopted for the non-Newtonian nanofluids. A finite-difference based numerical study with the Stream function-Vorticity-Temperature formulation has been carried out. The homogeneous flow model has been used for modelling the nanofluids. The present results have been extensively validated with earlier works. In Case I the results indicate that Alumina-Water nanofluid shows 4% enhancement in heat transfer at 2.78% nanoparticle concentration. Following that there is a sharp decline in heat transfer with respect to that in base fluid for nanoparticle volume fractions equal to and greater than 3%. In Case II Alumina-CMC/Water nanofluid shows 17% deterioration in heat transfer with respect to that in base fluid at 1.5% nanoparticle concentration. An enhancement in heat transfer is observed for increase in hot wall temperature at a fixed volume fraction of nanoparticles, for both types of nanofluid.

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