scholarly journals Numerical analysis of a heat exchanger pile response in a Brazilian subtropical region

2020 ◽  
Vol 205 ◽  
pp. 05004
Author(s):  
Roberto Pimentel de Sousa Júnior ◽  
Renato Pinto da Cunha

Ground-coupled heat exchanger systems have been used as acclimatization systems for residential and commercial buildings in many countries. Brazil is the ninth largest consumer of electrical energy in the world, for this reason, local researchers are investigating the use of the energy piles in order to reduce the consumption of electricity. Thermal response tests have been carried out on a heat exchanger pile at the geotechnical experimental site of the University of São Paulo in São Carlos city, a region of subtropical climate. Simultaneously, using the thermal properties obtained in these tests, numerical analysis has been performed to investigate the heat exchange performance of energy piles installed in this site. For this numerical analysis, the effect of soil and concrete properties, pile geometry and the flow rate on the pile thermal response were evaluated. The current paper presents the results obtained by the analysis of 67 models tested to found an optimal configuration of an energy pile through the software COMSOL, using Heat Transfer and Non-Isothermal Pipe Flow modules. From this work, it was observed that the optimal configuration was obtained for a turbulent flow condition in piles in the heat exchanger pipes.

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.


Author(s):  
Adéla Macháčková ◽  
Radim Kocich ◽  
Marian Bojko ◽  
Zuzana Klečková

2021 ◽  
pp. 1-19
Author(s):  
Muhammad Ahmad Jamil ◽  
Talha S. Goraya ◽  
Haseeb Yaqoob ◽  
Muhammad Wakil Shahzad ◽  
Syed M. Zubair

2011 ◽  
Vol 71-78 ◽  
pp. 3729-3732
Author(s):  
Ming Zhou ◽  
Zhi Guo Xie ◽  
Xin Tang Wang

The computational model of numerical analysis of a suspended pre-stressed steel reticulated shell subjected to fire load is established with using the software Marc. Based on the model presented here, numerical analysis of thermal response and structural response of the pre-stressed steel structure are computed. The different space height and different rise-span ratio are considered for analysis of response temperature, displacements and stresses of the pre-stressed lattice shell under fire for one fire source. It is also shown that displacement of the node right above the inner cable is the maximum among the four nodes presented here as the fire source is located at the position right below the second-ring cable of the structure. It is concluded that the influence degree of space height of the structure on the fire response of the structure is not great, but rise-span ratio has obvious and great effect on displacements and stresses of the pre-stressed steel structure with large span in fire.


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