This paper presents a detailed review of shell materials that have the potential to be used for high temperature thermal energy storage (TES) applications, particularly in conjunction with concentrated solar power (CSP) plants. This paper considers shell materials that are thermally stable at more than 300 °C and have successfully been used to encapsulate a phase change material (PCM). The current review does not consider the thermal performance of the shell material and PCM combinations that have been studied. Using these constraints several feasible materials were identified including: steel (carbon and stainless), nickel (and nickel alloy), sodium silicate, silicon dioxide, calcium carbonate and titanium dioxide. These materials have the potential to encapsulate high temperature PCMs and thus provide a suitable method of high temperature TES.

Review on shell materials used in the encapsulation of phase change materials for high temperature thermal energy storage

The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in the later part of the twentieth century This is evident from the increased number of studies related to nanofluids published annually The increasing attention on nanofluids is primarily due to their enhanced thermophysical properties and their ability to be incorporated into a wide range of thermal applications ranging from enhancing the effectiveness of heat exchangers used in industries to solar energy harvesting for renewable energy production Owing to the increasing number of studies relating to nanofluids, there is a need for a holistic review of the progress and steps taken in 2019 concerning their application in heat transfer devices This review takes a retrospective look at the year 2019 by reviewing the progress made in the area of nanofluids preparation and the applications of nanofluids in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling This review aims to update readers on recent progress while also highlighting the challenges and future of nanofluids as the next-generation heat transfer fluids Finally, a conclusion on the merits and demerits of nanofluids is presented along with recommendations for future studies that would mobilise the rapid commercialisation of nanofluids

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An updated review of nanofluids in various heat transfer devices

The drastic rise in global warming and the fossil fuel consumption have resulted in destruction of the ecological balance, reduction of the environmental quality, and demotion of the sustainable development. The utilization of biofuels have been paid much attention to by researchers and policy makers due to its benefits and indisputable contributions to protect the living environment. Free fatty acid-rich rice bran oil which is unsuitable for food purposes could be a good candidate for biofuel production. Accordingly, rice bran oil-based biofuels (straight oil and its biodiesel) as promising alternative fuels to petrodiesel were reviewed in this article from the sources, components, and physicochemical perspectives. In addition, biodiesel production from rice bran oil using various methods and catalysts was thoroughly detailed. The oxidative stability of rice bran biodiesel as a function of the storage time was also discussed. The application of rice bran oil-based biofuels to diesel engines was completely analyzed and critically discussed based on engine performance, combustion, and emissions characteristics. The effects of using rice bran oil-based biofuels on the lubricating oil degradation, deposit formation, wear, and sound intensity of diesel engines were explained in detail. Finally, the economic aspects of using rice bran oil and its biodiesel as fuels were also assessed. As a conclusion, the blend containing 20% rice bran oil biodiesel and 80% petrodiesel fuel, both in volume, could be the most effective composition considering the techno-economic aspects of diesel engines; meanwhile the remaining blends appeared to be improper for the existing diesel engines.

Rice bran oil-based biodiesel as a promising renewable fuel alternative to petrodiesel: a review.

Experimental investigation on the performance, combustion and exhaust emission characteristics of a compression-ignition engine fueled with cottonseed oil biodiesel/diethyl ether/diesel fuel blends

Nanofluids are broadly employed in heat transfer mediums to enhance their efficiency and heat transfer capacity. Thermophysical properties of nanofluids play a crucial role in their thermal behavior. Among various properties, the dynamic viscosity is one of the most crucial ones due to its impact on fluid motion and friction. Applying appropriate models can facilitate the design of nanofluidics thermal devices. In the present study, various machine learning methods including MPR, MARS, ANN-MLP, GMDH, and M5-tree are used for modeling the dynamic viscosity of CuO/water nanofluid based on the temperature, concentration, and size of nanostructures. The input data are extracted from various experimental studies to propose a comprehensive model, applicable in wide ranges of input variables. Moreover, the relative importance of each variable is evaluated to figure out the priority of the variables and their influences on the dynamic viscosity. Finally, the accuracy of the models is compared by employing the statistical criteria such as R-squared value. The models’ outputs disclosed that employing ANN-MLP approach leads to the most precise model. R-square value and average absolute percent relative error (AAPR) value of the model by using ANN-MLP model are 0.9997 and 1.312%, respectively. According to these values, ANN-MLP is a reliable approach for predicting the dynamic viscosity of the studied nanofluid. Additionally, based on the relative importance of the input variables, it is concluded that concentration has the highest relative importance; while the influence of size is the lowest one.

Comparing various machine learning approaches in modeling the dynamic viscosity of CuO/water nanofluid

Carbon nanotubes are one of the major research areas in the field of nanotechnology, due to its mechanical and electro-conductive properties in the field of engineering and medical sciences. This p...

Synthesis and characterisation of multi-walled carbon nanotubes (MWCNTs)

Vegetable oils are now considered to be a potential alternative that can be used in place of partial or total substitution of diesel fuels. In this study, we used Di-ethyl ether as an oxygenated additive to investigate the possible use of higher percentages of biodiesel in an unmodified diesel engine. Neem oil was selected for biodiesel production. The tests were performed at a steady-state condition in a single-cylinder constant speed DI diesel engine. The combustion process involved in diesel engine would be improved and the particulate matter would be reduced if these biodiesels are blended. An experimental investigation is carried out to establish the emission characteristics of a direct injection diesel engine using Di-ethyl ether as additive in Neat Neem oil Biodiesel.Emissions of hydro carbon oxides of nitrogen and carbon monoxide significantly reduced by adding Di-ethyl ether into neem oil biodiesel at 10 and 20% on volume basis.

Effect of diethyl ether blended with neem oil methyl esters in CI engine

This work is a performance study that investigated the nanorefrigerant CuO/AL2O3-R22 used in a refrigerator without any remodelling of the system. The refrigerator performance was then inve...

Performance study of a domestic refrigerator using CuO/AL2O3-R22 nanorefrigerant as a working fluid

Conventional fluids such as water, ethylene glycol and mineral oils are normally used as heat transfer fluids. Various techniques are applied to enhance the heat transfer. Heat exchange of the coolant moving through the vehicle radiators is of incredible significance for the advancement of fuel utilisation. In this experiment, the heat transfer performance of the automobile radiator is evaluated experimentally. For this we have taken two different combinations of nanoparticles. Aluminium oxide (Al2O3) and magnesium oxide (MgO) nanoparticles are added to the base fluid (80% water + 20% ethylene glycol) at two concentrations 0.12% and 0.4% volume concentration considering the best pH for longer stability. Similarly, another combination with aluminium oxide (Al2O3) and titanium oxide (TiO2) at the same volume concentrations of 0.12% and 0.4% in the base fluid is also prepared. Furthermore, this increases nanoparticle concentration, air velocity and nanofluid velocity and enhances the overall heat tra...

M. Anish

Papers

Synthesis and characterisation of multi-walled carbon nanotubes (MWCNTs)

Effect of diethyl ether blended with neem oil methyl esters in CI engine

Performance study of a domestic refrigerator using CuO/AL2O3-R22 nanorefrigerant as a working fluid

Enhancing heat transfer rate in a car radiator by using Al2O3 nanofluid as a coolant

Measurement of temperature-dependent thermal conductivity, viscosity and density of ZnO-Theminol 55 Nanofluids