European Journal of Energy Research

Modelling thePerformanceof DoublePassSolar Air Collectors

Maytham H. Machi — 2025-01-30

This study presents a detailed investigation into the thermal performance of double-pass solar air collectors (DPSACs) through a combination of experimental testing and theoretical modelling. DPSACs are widely recognized for their ability to enhance heat transfer and reduce energy losses, making them suitable for applications such as drying and space heating. Experimental measurements were conducted under outdoor conditions focusing on key operational parameters such as mass flow rates (MFR) and solar radiation intensity. A theoretical model was developed and validated against experimental data, achieving high agreement with R²values of 0.989 for outlet temperature and 0.917 for thermal efficiency. Results indicate that increasing MFRs initially improves thermal efficiency by enhancing convective heat transfer. However, higher MFRs reduce the outlet air temperature, as shorter air residence times limit the transfer of heat to the air. Solar radiation was found to have a pronounced effect at lower MFRs, emphasizing the need for optimal MFR selection to balance efficiency and temperature output. The study highlights a preferred operating range of 0.01–0.025 kg/s for maintaining efficient thermal performance under varying solar intensities. The validated model provides a robust framework for predicting the performance of DPSACs under diverse conditions.

Dynamic Simulation of a Hybrid Energy System for Powering a Water Treatment Facility in McCallum, Newfoundland and Labrador

Fatemeh Kafrashi — 2024-12-31

Clean water, a basic human need, is in short supply in McCallum, Newfoundland and Labrador, primarily due to lead contamination, forcing residents to rely on collected rainwater. Reverse Osmosis (RO) has been identified as the most suitable desalination method because of its lower energy requirements and high effectiveness in treating lead-contaminated water. Powering the RO system with renewable energy sources (RES) offers a promising solution for this remote, off-grid area, currently powered by a diesel generator. The proposed hybrid energy system (HES) provides not only the most economically optimal configuration but also greater reliability. The system consists of a 3.6 kW solar array, a 2-kW wind turbine, a 3-kW DC diesel generator, and a 680 Ah 48 V battery bank to supply the single-phase water treatment system, which includes a 0.3 kW resistive load, lighting, and two asynchronous machines rated at 0.5 hp and 0.75 hp, respectively. A dynamic simulation of the proposed system, based on calculation done in Kafrashi and Iqbal [1], is presented in this paper. All system components are modeled in MATLAB/Simulink. Simulation results show expected dynamics in the system. Results indicate proper system operation with reasonable within-range system voltage and current during normal operation.

Design of a Solar Air Heating Collector from Steel Cans

Abdlmanam S. A. Elmaryami — 2024-12-31

Numerous research works have examined the efficiency of both single- and double-pass solar air heaters. These investigations cover the pressure drop in ducts, flow phenomena, heat transfer enhancement, and solar air heater design. Recycled aluminum cans are used as the absorbing material in this project’s experimental work, which is based on an energy analysis of a solar air heating collector. The tops and bottoms of the cans will be drilled out, and they will be assembled into vertical columns through which air flows. The sun heats the cans with black paint. The air rising through the can’s columns absorbs the solar heat. A single-pass solar air heating collector with a single cover has been created. The effectiveness of the most important design and environmental parameters, such as mass flow rate and ambient temperature, on the model’s performance, was examined. Temperatures at the inlet and outlet, as well as thermal heat flow, were calculated. All of the can columns receive room air from a manifold at the bottom, and heated air is collected and distributed back to the room by a manifold akin to the one at the top of the collector. An efficient collector combines a large amount of heat transfer area from the cans to the air with uniform air distribution throughout the collector. The creation and testing of an effective single-glass air solar collector with an absorber plate composed of recyclable aluminum cans (RAC) are detailed in this project. This collector was created as a suggestion on how to construct air solar collector absorber plates at a reasonable cost by recycling recyclable materials. The collector’s absorber plate was made up of eight airflow channels with a circular cross-section made of 54 recyclable aluminum cans. Seven reusable cans, each with an absorptance of 0.903, were painted black using an opaque black paint that was widely available.

Synthesis and Characterization of Biodiesel from Non-Edible Seed Oils Extracted from Cameroon Bioresources

Juliette Salamatou — 2024-09-03

This work aimed at valorizing non-edible seed oils from some plants found in Cameroon videlicet Acacia hockii (AH), Garcinia livingstonei (GL) and Moringa oleifera (MO), through production of biodiesel. Two extraction methods used were; the Soxhlet extraction and surfactant assisted extraction with sodium dodecyl sulphate (SDS) as surfactant. The extracted oils were characterized using physicochemical parameters. The characterized oils were used to synthesize biodiesels via acid and base catalyzed transesterification reactions. The purification of the biodiesels was done using chromatographic columns. The biodiesels obtained were also characterized using physicochemical analysis in a manner similar to the oils with additional parameters like cold f low properties, f lammability, ignition qualities and cetane number determinations. Qualitative analysis was realized using the Fourier Transformed Infrared Spectrophotometer (FT-IR). The Soxhlet extraction method gave higher yields for all the plants with MO being the highest, compared to the surfactant assisted extractions. The results from the physicochemical properties of the oils were as follows: specific gravity, 0.876 g/mL, 0.843 g/mL and 0.865 g/mL for AH, GL, and MO. The free fatty acid contents of the oils were 0.436% FFA, 0.547% FFA and 1.60% FFA for AH, GL, and MO respectively. The saponification values gave 143.03 mgKOH/g, 72.93 mgKOH/g, 126.22 mgKOH/g for AH, GL and MO in that order. Iodine values for the oils were 46.54 mgI2/g, 22.41 mgI2/g, 68.10 mgI2/g for AH, GL, and MO, respectively. The peroxide values gave 10.05 meq/kg, 8.50 meq/kg, 8.0 meq/kg for AH, GL, and MO, respectively. The kinematic viscosities were 21.0 mm2/s, 22.0 mm2/s and 43.0 mm2/s for AH, GL, and MO, respectively. The acid catalyzed reaction gave greater crude yields of 90.00% for all three plants while the base catalyzed reaction gave, 87.00% (AH), 84.00% (GL) and 74.00% (MO). The purified biodiesel samples had the following acid numbers: 0.028% FFA for BAH, 0.022% FFA for BGL, and 0.028% FFA for BMO. The kinematic viscosities values for biodiesel were 4.00 mm2/s, 4.23 mm2/s, and 5.22 mm2/s for BAH, BGL, and BMO, respectively. The cetane numbers of the synthesized biodiesel samples were 142.73 (BAH), 167.29 (BGL), and 82.40 (BMO). The IR spectra of the biodiesels corroborated the chemical make-up of biodiesel. Hence non-edible seed oils from the Cameroon rich bioresources can be valorized in biodiesel synthesis and other forms of green energy production in Cameroon and beyond.