Experimental investigation on lowering the environmental hazards and improving the performance patterns of solar flat plate collectors by employing the internal longitudinal fins and nano additives

Designing and testing low-cost solar water heater using date palm fibers and starch

Solar water heaters are a type of renewable energy technology that converts solar energy into heat to warm water. Solar water heaters are becoming increasingly popular due to their eco-friendliness, cost-effectiveness, and low maintenance requirements. In this study, low-cost solar collectors were developed using date palm waste (dried leaves) as thermal insulation. Date palm waste is a readily available and abundant resource in many regions, and using it in solar collectors can help reduce waste and promote sustainability. Two solar collectors were fabricated using crushed date palm waste, with one collector using the waste alone and the other mixed with starch. Tests were conducted in accordance with the European standard EN 12975-2-2006 and modeled the thermal behavior of the collectors. The results obtained showed that the prototypes of solar collectors performed well and exhibited behavior comparable to that of a commercial solar collector, with a production cost up to three times less. The use of date palm waste as thermal insulation in solar collectors is an innovative approach that aligns with the principles of sustainability and environmental friendliness. Furthermore, it was found that the leveled heating cost (LCOH) and the simple payback period (SPP) were 0.952 US$ kWh-1 and 2.472 years for the prototype without starch and 0.926 US$ kWh-1 and 2.397 years for the prototype with starch.

Recent progress on flat plate solar collectors equipped with nanofluid and turbulator: state of the art

This paper reviews the impacts of employing inserts, nanofluids, and their combinations on the thermal performance of flat plate solar collectors. The present work outlines the new studies on this specific kind of solar collector. In particular, the influential factors upon operation of flat plate solar collectors with nanofluids are investigated. These include the type of nanoparticle, kind of base fluid, volume fraction of nanoparticles, and thermal efficiency. According to the reports, most of the employed nanofluids in the flat plate solar collectors include Al2O3, CuO, and TiO2. Moreover, 62.34%, 16.88%, and 11.26% of the utilized nanofluids have volume fractions between 0 and 0.5%, 0.5 and 1%, and 1 and 2%, respectively. The twisted tape is the most widely employed of various inserts, with a share of about one-third. Furthermore, the highest achieved flat plate solar collectors' thermal efficiency with turbulator is about 86.5%. The review is closed with a discussion about the recent analyses on the simultaneous use of nanofluids and various inserts in flat plate solar collectors. According to the review of works containing nanofluid and turbulator, it has been determined that the maximum efficiency of about 84.85% can be obtained from a flat plate solar collector. It has also been observed that very few works have been done on the combination of two methods of employing nanofluid and turbulator in the flat plate solar collector, and more detailed work can still be done, using more diverse nanofluids (both single and hybrid types) and turbulators with more efficient geometries.

Performance analysis of a serrated absorber plate solar air heater with paraffin wax storage

The study aims to examine the thermal performance of solar air heaters employing two different absorber plates under two different configurations. The experiments have been conducted in the summer climatic conditions of Moradabad City, India. A total of about 04 models of solar air heaters have been developed. The experimental investigation has been done using a flat-plate absorber and a serrated geometric absorber (with and without using the tested phase change material) to estimate the thermal performance. Notably, 03 different mass flow rates (i.e., 0.01 kg/s, 0.02 kg/s, and 0.03 kg/s) have been used to investigate the heat transfer coefficient, instantaneous efficiency, and daily efficiencies. Results of the study showed that Model-4 is the best among all the tested models that provide an average exhaust temperature of about 46 °C after sunset. The optimum daily average efficiency has been obtained at about 63% at 0.03 kg/s. The efficiency of a serrated plate-type SAH without using phase change material is about 23% higher than that of a conventional system, while it is about 19% higher than that of a conventional SAH using phase change material. Overall, the modified system is suitable for moderate-temperature applications, like agricultural drying and space heating.

Experimental performance enhancement of a flat plate solar collector using straight and twisted flow inserts

The thermal performance of a flat plate solar collector (FPSC) is limited minimum due to higher heat loss of the collector and poor heat exchange with the heat transfer fluid. The current study investigates the effect of single-slit twisted tape (TT), double-slit TT, and double-slit straight tape passive-insert devices on enhancing the heat transfer of the FPSC at a constant water flow of 0.025 kg/s. Double-slit inserts have a higher heat transfer area and reduced hydraulic diameter than conventional single-slit TT inserts. The double-slit TT insert creates more fluid mixing and turbulence in the flow than a single-slit TT. The convective heat transfer coefficient for double-slit TT, single-slit TT, and the double-slit straight insert is 47.7%, 26.9%, and 8.7% higher than FPSC with the plain absorber. Double-slit TT inserts are observed with improved energy and exergy efficiency by 23.9% and 46.2% compared to conventional collectors without a flow insert. The average energy efficiency of FPSC without inserts is 48.2%, whereas the double-slit TT is 66.5%. The pressure drop is higher for the collector with inserts than for the collector without inserts, which leads to a little more pump power. Thus, passive inserts help to augment heat transfer in the FPSC.

Performance analysis of sustainable solar energy operated ejector refrigeration system with the combined effect of Scheffler and parabolic trough collectors to lower greenhouse gases

The work aims to analyse an ejector refrigeration system powered with solar energy through serially connected collectors to lower greenhouse gases. The collectors chosen for the work are Scheffler and parabolic collectors with an area of 2.5 m² and 6 m², respectively. The steam generated by the collectors is stored temporarily in a 15-l storage tank. The thermic fluid transfers heat between the steam storage tank and refrigerant, and thus the generator temperature increases. This design was intended as an alternate for a traditional 3.5 kW room air conditioner with substantially lower energy consumption. This modified system consumed lesser energy input of about 20-30% than conventional air conditioners. Further, for the same specification, the ejector system has consumed less power of about 2.475 kW than the traditional refrigeration system.

Experimental Investigation on Mechanical Properties of Glass Fiber Hybridized Natural Fiber Reinforced Penta-Layered Hybrid Polymer Composite

This article investigates and presents the upshots observed in the brook of hybrid composites especially, the current investigation focuses on the impact of fiber composition, sequence, and stacking pattern on composite mechanical Features. Five varied stacking sequences of hybrid composites encompassing laminates are used to create four classes of fiber with jute/bamboo/glass by utilizing a conscientious hand lay-up process with glass fiber-laced mats as their peripheral layer. For examination, fiber sequences are arranged in the combination of GJBJG, GBJBG, GJGJG, and GBGBG, where G, J, and B refer to glass fiber, jute fiber, and bamboo fiber, respectively. The position of fiber in the core layer is kept in a perpendicular direction with respect to adjacent piles which might be jute or bamboo fiber and the best position of fiber is considered due to the stacking order. Stress and strain were linear in the load versus deflection curves, and all of the samples failed quickly, it is observed that the sample containing a higher or considerable number of bamboo fiber layers exhibited increased strain and toughness. In comparison to other samples, embolism of glass fiber as the main and covering layer expressed a higher impact on the mechanical properties of the composites is observed in this investigation. The shattered sample morphology demonstrated that the matrix and reinforcements were compatible.

Experimental Investigation to Utilize Adsorption and Absorption Technique to Reduce CO2 Emissions in Diesel Engine Exhaust Using Amine Solutions

Due to the increased demand for global transportation needs, a long-range diesel engine is considered an important prime mover to fulfill the transportation demand. The major problem addressed by the diesel engines is it liberates harmful emissions and it also increases global warming. CO2 is considered an important greenhouse gas and it has to be controlled by diesel engines. In this research, extensive experimental work is done to identify a suitable solution to control CO2 emissions. For five different mole concentrations (0.1 to 0.5), three types of amino solutions (L-alanine, L-aspartic acid, and L-arginine) were prepared. By passing diesel exhaust through each solution, CO2 absorption is investigated. For CO2 absorption, an appropriate CO2 control system is built and tested. The tests were carried out in a diesel engine which is a naturally aspirated single-cylinder engine with a water-cooled system. It was possible to obtain an effective CO2 reduction of up to 90%, as well as a simultaneous reduction in HC and CO.

Investigation on Efficient Removal of Fluoride from Ground Water Using Activated Carbon Adsorbents

Groundwater seems to be the most significant natural source of potable water for millions of individuals. Fluoride pollution in groundwater is a big problem in Tamil Nadu’s Dharmapuri area. According to a survey done in a school in the Dharmapuri area, dental and skeletal fluoroses afflict almost 75% of school kids. There is no proven or recommended cost-effective strategy for lowering fluoride levels in the home. This study proposes cost-effective and efficient natural treatment approaches for lowering fluoride levels. In this experiment, fluorides in groundwater are eliminated to a suitable extent utilizing natural adsorbents. Neem stem charcoal (activated carbon), neem leaves powder, dry coconut husk, coconut shell charcoal (activated carbon), and rice husk powder are natural adsorbents. The adsorbents were utilized at different concentrations until the best concentration was found. The ideal concentration removes the bulk of fluoride from groundwater and delivers adequate treatment. People could adopt this cost-effective procedure because just a few components are enough. As per the Bureau of Indian Standards, the concentration should not exceed 1.5 ppm, and it should not be lesser than 1 ppm; keeping this in mind, the neem stem charcoal which has higher efficiency in removing fluoride can be used in extensive environments, but in this selected place, it reduces the concentration even below 1 ppm, which relays below the standard level. As a result, adopting these procedures helps prevent dental and skeletal fluoroses, which is common among young people.

Experimental thermal performance and enviroeconomic analysis of serpentine flow channeled flat plate solar water collector

The thermal performance of a flat plate solar water collector (FPSWC) depends on the amount of solar energy absorbed by the absorber, the quantity of heat transferred to the heat transfer fluid (HTF), and the fluid residence time in the collector. In this real-time experimental study, the thermal efficiency of the serpentine flow channeled FPSWC is compared with that of a conventional collector. The heat transfer coefficients (HTC) and heat loss coefficients of both configurations are evaluated at three different water mass flow rates (0.0083 kg/s, 0.0167 kg/s, and 0.025 kg/s). The results show that the serpentine flow channeled collector offers higher energy and exergy efficiencies of 78.9% and 6.47%, respectively, at a mass flow rate of 0.025 kg/s due to the continuous surface contact of the HTF with the absorber plate. The conventional collector yields energy and exergy efficiencies of 66.28% and 4.58%, respectively, at similar operating conditions. The peak HTC of the serpentine flow collector is 210 W/m²K, which is 27.3% higher than that of the conventional collector at a maximum flow rate. The maximum HTC is observed at a higher mass flow rate and lower absorber temperature. The heat loss increases when solar radiation intensity increases; the HTC reaches its peak value at the maximum solar radiation intensity. The proposed collector shows a cleaner production of hot water with a lower payback period when compared to a conventional collector, as evident from the enviroeconomic analysis. The findings can contribute to more successful deployments of solar thermal systems.