The importance of surface air temperature fluctuations on long-term performance of vertical ground heat exchangers

2016 ◽  
Vol 6 ◽  
pp. 35-44 ◽  
Author(s):  
Asal Bidarmaghz ◽  
Guillermo A. Narsilio ◽  
Ian W. Johnston ◽  
Stuart Colls
Keyword(s):  
Air Temperature ◽  
Heat Exchangers ◽  
Surface Air Temperature ◽  
Temperature Fluctuations ◽  
Ground Heat Exchangers ◽  
Vertical Ground ◽  
Long Term Performance ◽  
Term Performance

WARMING ISSUES ASSOCIATED WITH THE LONG TERM SIMULATION OF HOUSING USING CFD ANALYSIS

2016 ◽  
Vol 11 (2) ◽  
pp. 57-74 ◽  
Author(s):  
Aiman Albatayneh ◽  
Dariusz Alterman ◽  
Adrian W. Page ◽  
Behdad Moghtaderi
Keyword(s):  
Air Temperature ◽  
Cfd Simulation ◽  
Heating And Cooling ◽  
And Performance ◽  
External Volume ◽  
Cooling Loads ◽  
Long Term Performance ◽  
Term Performance

The determination of internal building air temperature has an impact on the design and performance of a building in measuring thermal comfort and heating and cooling loads. There is software to assist with measuring internal building air temperature such as Autodesk CFD simulation. However, the use of Autodesk CFD simulation for the analysis appears to have an issue with simulations extending over a long term (i.e. months or years) as the internal air temperature in a building keeps rising with time. This paper addresses the challenges encountered using CFD simulation in the modelling of a building for long term performance. A new method to overcome the issue of the progressive rising of internal air temperature using two external air boundaries, one for the external volume (sky boundary) and the other surrounding the building, is suggested in the paper.

Thermal Energy Storage in Soils at Temperatures Reaching 90°C

2000 ◽  
Vol 122 (1) ◽  
pp. 3-8 ◽  
Author(s):  
A. Gabrielsson ◽  
U. Bergdahl ◽  
L. Moritz
Keyword(s):  
High Temperature ◽  
Renewable Energy Sources ◽  
Soft Clay ◽  
Construction Costs ◽  
Temperature Range ◽  
Ground Heat Exchangers ◽  
Heat Transfer Capacity ◽  
Long Term Performance ◽  
Term Performance

Using soil and groundwater for heat storage offers an opportunity to increase the potential for renewable energy sources. For example, solar heating in combination with high temperature storage, e.g., using ducts in the ground, has the potential of becoming an environment friendly and economically competitive form of heat supply. Technology is developed to reduce ground construction costs and to ensure that adequate attention is paid to the geotechnical potentials and limitations of such systems, in the temperature range between neutral ground temperature up to 90°C. Investigations of real plants and in the laboratory have given valuable knowledge on the thermal effects on clayey soils as well as on the surroundings of high temperature stores in soft clay. The operational function of heat stores, with respect to heat transfer capacity of ground heat exchangers and heat losses, can be predicted with good agreement. For the uppermost part of the temperature range, long term performance, cost verification and thermal endurance of materials involved including the storage medium, is recommended using a full-scale demonstration plant. [S0199-6231(00)00901-1]

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance

Long-term performance of the Hancock bioprosthetic conduit for aortic root replacement

2008 ◽  
Vol 56 (S 1) ◽  
Author(s):  
CC Badiu ◽  
W Eichinger ◽  
D Ruzicka ◽  
I Hettich ◽  
S Bleiziffer ◽  
...  
Keyword(s):  
Aortic Root ◽  
Aortic Root Replacement ◽  
Long Term Performance ◽  
Term Performance
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