A dynamic experimental study on the evaporative cooling performance of porous building materials

Zhang, Lei; Meng, Qinglin; Feng, Yanshan; Chen, Yuanrui

doi:10.1007/s00231-017-2009-4

Cited by 6 publications

(3 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermal efficiency of the designed PVT collector at the different flow rates. directly measured during the experiments, uncertainty analysis was performed are as follows [40]: where the uncertainty of each parameter was calculated by the following expression.…”

Section: Experimental Data and Model Verificationmentioning

confidence: 99%

Temperature distribution and efficiency assessment of different PVT water collector designs

2018

View full text Add to dashboard Cite

The aim of this work was to study different hybrid photovoltaic-thermal (PVT) collectors. Numerical simulation of the collectors was carried out using a 3-dimensional computational fluid dynamic (CFD) model. A set of experiments was conducted using a box-type PVT collector to validate the obtained computed data. Simulation results for water outlet temperature, especially at the lower flow rates, were closer to the measured data compared with average module surface temperature. Based on the simulation results, the spiral flow designs of heat exchanger provided the most uniform temperature distribution for module surface and the highest temperature gradient was observed with the direct flow designs. A hot zone was generated on the module surface of the direct flow box-type collector and the results indicated that the hot zone was considerably declined using cross-fins inside the box-type heat exchanger. The highest heat transfer to the ambient occurred with the spiral flow design and the box type heat exchanger presented a relatively low heat losses. The cross-fined box type and the spiral flow designs of the PVT collector had the highest electrical efficiencies at the different test conditions.

show abstract

Section: Experimental Data and Model Verificationmentioning

confidence: 99%

Temperature distribution and efficiency assessment of different PVT water collector designs

2018

View full text Add to dashboard Cite

show abstract

“…The results revealed that the proposed system can be used effectively and economically in changeable weather. A study examining the evaporative cooling performance of porous building materials using a special wind tunnel device was introduced by Zhang et al [14]. It was found that the total thermal resistance of the wet sample is almost doubled with respect to the dry sample, indicating an improvement in the performance of insulation.…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study of a Novel System Used for Cooling the Protection Helmet

Saleh,

Kanaan

2023

Energies

View full text Add to dashboard Cite

In this study, a novel experimental model was proposed, built, and tested to present an efficient and simple method for cooling protective helmets. The system was based on an evaporative cooling technique in which water is used as a coolant sprayed over a canvas covering the outer helmet’s surface. A solar fan was provided to enhance the evaporation rate. The experimental results were used with the main laws of heat and mass to evaluate evaporation and heat transfer rates. The proposed system was compared by other two cases, the uncovered dry helmet and the wet-covered one without using the fan. The inner and outer surface temperatures reached were characterized by a good level of stability and by being compatible with human comfort conditions. The addition of the wet cover led to a temperature drop in both the outer and inner surfaces of the helmet by about 9 degrees, and the addition of the fan led to an additional drop of about 5 degrees. There were increases in the cooling rate by 63.3% by adding the wet cover and by 131.7% after adding the fan. The system is characterized by free power consumption and simplicity in implementation.

show abstract

“…As regards the influence of sepiolite addition on the thermal behavior of renders, in general it can be stated that the evaporation process occurring on a porous surface could produce a significant thermal insulation effect [14]. Some authors also highlighted that porous additives, such as metakaolin admixtures, lower the final thermal conductivity for the increased porosity of the matrix [15].…”

Section: Introductionmentioning

confidence: 99%

Effect of pore modulating additives-sepiolite and colloidal nano silica-on physical, mechanical and durability properties of lime-based renders

et al. 2022

View full text Add to dashboard Cite

In hot-humid climates, porous external surfaces of the buildings with high water sorption capabilities could contribute to the surface temperatures reduction through the release of latent heat by evaporative cooling. On the other hand, compact and low permeable finishing materials could have mechanical and durability benefits respect to the underlying supports, for example reducing the permeability to degrading agents. In this paper, the properties of lime base coat renders with pore modulating additives (sepiolite and colloidal nano silica) have been surveyed to evaluate their effectiveness in water absorption, thermal performance, and the fulfilment of mechanical requirements for the application on the external side of the walls. A traditional lime–sand formulation was taken as reference. After preliminary tests on workability and shrinkage, the optimal mix designs were selected and the samples were subjected to several mechanical and thermo-hygrometric tests, before and after accelerated aging. The results allowed demonstrating that the use of sepiolite in substitution of sand, enhances the render ductility, thermal resistance and water uptake but worsens its mechanical stability, increasing the shrinkage effects and slightly reducing the ultimate strength values. The addition of colloidal nano silica, either to lime–sepiolite or to lime–sand renders, fails to produce any improvement in their either physical or mechanical behavior. Mixed formulations (lime–sand with sepiolite and nano silica) behave as simple lime–sand solutions, showing optimal compressive and flexural strength but reduced water uptake capabilities. This demonstrates that the presence of sand prevails in the performance of the render, and that the adoption of other additives doesn’t worth the cost for the benefit presented.

show abstract

A dynamic experimental study on the evaporative cooling performance of porous building materials

Cited by 6 publications

References 41 publications

Temperature distribution and efficiency assessment of different PVT water collector designs

Temperature distribution and efficiency assessment of different PVT water collector designs

An Experimental Study of a Novel System Used for Cooling the Protection Helmet

Effect of pore modulating additives-sepiolite and colloidal nano silica-on physical, mechanical and durability properties of lime-based renders

Contact Info

Product

Resources

About