Ag-based nanofluidic system to enhance heat transfer fluids for concentrating solar power: Nano-level insights

Gómez‐Villarejo, Roberto; Martín, Elisa I.; Navas, Javier; Sánchez‐Coronilla, Antonio; Aguilar, Teresa; Gallardo, Juan Jesús; Alcántara, Rodrigo; Santos, Desiré De los; Carrillo‐Berdugo, Iván; Fernández‐Lorenzo, Concha

doi:10.1016/j.apenergy.2017.03.003

Cited by 58 publications

(24 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the isobaric specific heat of solids is generally lower than that of fluids, it is reasonable to expect that the suspension of solids could cause a decrease in isobaric specific heat values [39,62,63]. However, other authors have reported an increase in isobaric specific heat values when a nanomaterial is suspended within a fluid [14,16,64]. This is typically explained by an internal structure [65,66], which is created by a interaction between the nanomaterial and base fluid.…”

Section: Isobaric Specific Heatmentioning

confidence: 99%

Boron nitride nanotubes-based nanofluids with enhanced thermal properties for use as heat transfer fluids in solar thermal applications

Gómez‐Villarejo

Estellé

Navas

2020

Solar Energy Materials and Solar Cells

Self Cite

View full text Add to dashboard Cite

Nanofluids are considered as promising alternative in heat exchange processes to the classical fluids, which usually present poor thermal properties. One interesting application for nanofluids is as heat transfer fluid in solar thermal applications plants. Boron nitride nanotubes present interesting thermophysical properties for use in nanofluids. Therefore, nanofluids based on boron nitride nanotubes were prepared by a two-step method, dispersing this nanomaterial in a heat transfer fluid typically used. Stability, rheological and thermal properties of the nanofluids were analysed. To check the stability, ultraviolet-visible spectroscopy and particle size and -potential measurements were performed for a month, obtaining that the nanofluids were stable. Furthermore, surface tension was measured and no significant differences were observed with regard to the base fluid. In a variable range of temperature, nanofluids show Newtonian behaviour with a slight increase in viscosity. Besides, the boron nitride nanotubes caused an increase in thermal conductivity of up to 33% with regard to the base fluid. The use of these nanofluids also led to an improvement in the heat transfer coefficient under turbulent flow conditions of up to 18%. Finally, the analysis of the outlet temperature in solar thermal applications shows that these nanofluids are a promising alternative in this application.

show abstract

Section: Isobaric Specific Heatmentioning

confidence: 99%

Boron nitride nanotubes-based nanofluids with enhanced thermal properties for use as heat transfer fluids in solar thermal applications

Gómez‐Villarejo

Estellé

Navas

2020

Solar Energy Materials and Solar Cells

Self Cite

View full text Add to dashboard Cite

show abstract

“…An increase in thermal conductivity is known to lead to more efficient heat transfer [59], and the suspension of nanomaterials in a fluid increases its thermal conductivity [17,19,20,60]. Thus, the thermal conductivity of the nanofluids was measured at 30, 50 and 70 ºC following the procedure described above.…”

Section: Accepted Manuscript 23mentioning

confidence: 99%

“…For example, Gao et al [12] reported increases in thermal conductivity of up to 4.6%, 18%, and 6.8% using graphene nanoplatelets in ethylene glycol, a 1:1 mixture of deionized water and ethylene glycol and deionized water, respectively. In addition, metal oxide [6,11,[16][17][18] and metallic nanoparticles [19,20] have been widely analysed for suspension in the base fluid.…”

Section: Introductionmentioning

confidence: 99%

“…Yasinskiy et al [6] reported an increase in thermal conductivity of up to 25.8% for TiO 2 -based nanofluids. In addition, enhancements have been reported of up to 6% and 13% for Ag and Cu-based nanofluids using a heat transfer fluid typically used in Concentrating Solar Power [19,20]. Nowadays, advanced nanomaterials are being used in nanofluid technology.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental analysis of water-based nanofluids using boron nitride nanotubes with improved thermal properties

Gómez‐Villarejo

Aguilar

Hamze

et al. 2019

Journal of Molecular Liquids

Self Cite

View full text Add to dashboard Cite

Nowadays, the use of nanofluids as alternative to commonly-used industrial heat transfer fluids is a topic of increasing interest. Analysing the improved efficiency of heat transfer processes according to advanced nanomaterials and obtaining stable nanofluids is one of the most interesting challenges. This paper presents a study of nanofluids based on boron nitride nanotubes and using an aqueous solution of Triton X-100 (which acts as a surfactant) as the base fluid. UV-vis spectroscopy, particle size measurements (size between 150-170 nm) and  potential (at about -25 mV) showed that stable nanofluids were obtained. Surface tension measurements were also performed. The surface tension of water was weakly affected by the presence of any amount of nanoparticles and was mainly governed by the presence of surfactant. The rheological properties of the fluids were also analysed, as were their isobaric specific heat and thermal conductivity values. A Newtonian behaviour was observed for the base fluid and the nanofluids, with no significant increase in viscosity. The isobaric specific heat increased by 8% and thermal conductivity by 10 % compared with the base fluid.Thus, the results obtained are interesting because while thermal properties improved with nanoparticle content, rheological behaviour did not change. Consequently, the nanofluids studied in the current paper do not raise the pressure drop and pumping power significantly and may therefore be a good option for thermal system applications. HighlightsStable nanofluids based on boron nitride nanotubes were prepared and analysed Isobaric specific heat increased by 8% and thermal conductivity by 10 % Newtonian behaviour was found for nanofluids with no significant increase in viscosity Surface tension was mainly governed by the presence of Triton X-100 as surfactant Rheological behaviour is not changed with nanoparticle content

show abstract

“…Both these cases result in the loss of a significant portion of absorbed thermal energy to the surrounding environment [147,149]. By the use of optimum value of nanoparticle volume fraction, up to 10% improvement in overall efficiency of solar power plants is reported and thus the electricity production cost can be expected to reduce accordingly [147,151]. However, the use of nanofluids comes with some difficulties which should be addressed, namely agglomeration and instability, high pumping power required due to enhanced viscosity, complex manufacturing processes, high capital costs, etc.…”

Section: Nanoparticle-laden Heat Transfer Fluid (Nanofluids)mentioning

confidence: 99%

Technological Advances to Maximize Solar Collector Energy Output: A Review

Salvi

Bhalla

Taylor

et al. 2018

Journal of Electronic Packaging

View full text Add to dashboard Cite

Since it is highly correlated with quality of life, the demand for energy continues to increase as the global population grows and modernizes. Although there has been significant impetus to move away from reliance on fossil fuels for decades (e.g., localized pollution and climate change), solar energy has only recently taken on a non-negligible role in the global production of energy. The photovoltaics (PV) industry has many of the same electronics packaging challenges as the semiconductor industry, because in both cases, high temperatures lead to lowering of the system performance. Also, there are several technologies, which can harvest solar energy solely as heat. Advances in these technologies (e.g., solar selective coatings, design optimizations, and improvement in materials) have also kept the solar thermal market growing in recent years (albeit not nearly as rapidly as PV). This paper presents a review on how heat is managed in solar thermal and PV systems, with a focus on the recent developments for technologies, which can harvest heat to meet global energy demands. It also briefs about possible ways to resolve the challenges or difficulties existing in solar collectors like solar selectivity, thermal stability, etc. As a key enabling technology for reducing radiation heat losses in these devices, the focus of this paper is to discuss the ongoing advances in solar selective coatings and working fluids, which could potentially be used in tandem to filter out or recover the heat that is wasted from PVs. Among the reviewed solar selective coatings, recent advances in selective coating categories like dielectric-metal-dielectric (DMD), multilayered, and cermet-based coatings are considered. In addition, the effects of characteristic changes in glazing, absorber geometry, and solar tracking systems on the performance of solar collectors are also reviewed. A discussion of how these fundamental technological advances could be incorporated with PVs is included as well.

show abstract

Ag-based nanofluidic system to enhance heat transfer fluids for concentrating solar power: Nano-level insights

Cited by 58 publications

References 58 publications

Boron nitride nanotubes-based nanofluids with enhanced thermal properties for use as heat transfer fluids in solar thermal applications

Boron nitride nanotubes-based nanofluids with enhanced thermal properties for use as heat transfer fluids in solar thermal applications

Experimental analysis of water-based nanofluids using boron nitride nanotubes with improved thermal properties

Technological Advances to Maximize Solar Collector Energy Output: A Review

Contact Info

Product

Resources

About