Publications
Experimental Study of Different Size of Nanoparticles on the Performance of Solar Collector
Jan 30, 2025Journal Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
Publisher Maral Mahmood Husain
DOI https://doi.org/10.37934/arfmts.132.2.275284
Issue 2
Volume 132
Flat plate solar collectors play a vital role in energy sources. In this study, alumina nanoparticles have been used to improve the thermal performance of the solar collector. The effect of nanoparticles' size has been studied. In this study, three different sizes of nanoparticles are considered. The average size of nanoparticles was 25 nm in 0.5 vol. % Al2O3-water (Nanofluid 1), while 0.5 vol.% Al2O3-water (Nanofluid 2) owns 10nm average size of Al2O3. The third nanofluid (Nanofluid 3, 0.5 vol.% Al2O3-water) includes nanoparticles with average size of 50nm—the concentrations of nanoparticles equal to 0.5 vol. %. The experimentation undergoes Iraqi conditions in three selected months (January-February-March) during the daylight (9 A.M.-4 P.M.). The optimum size of nanoparticles is the one that gives a higher collector efficiency. The efficiency of FPSC of Nanofluid 2 outperforms Nanofluid 1 and Nanofluid 3 by 4.02% and 9.04%, respectively. Additionally, the effect of different flow rates (0.003, 0.007, 0.022, and 0.076) kg/s were studied. Increasing the flow rate would increase the heat flow of the fluid. However, these increments are highly sensitive to the size of nanoparticles. The results clarify that increasing the size of nanoparticles negatively influences the performance of solar collectors. This is due to the effect of agglomerations and sedimentations of nanoparticles. The maximum increment in efficiency was 32.3% for the 10 nm particle size.
An Experimental Study on Electricity Generator Emissions and Their Environmental Impact in Kirkuk City
Jul 10, 2024Journal Advances in Mechanical and Materials Engineering
Publisher Maral Mahmood Husain
DOI https://doi.org/10.7862/rm.2024.11
Issue 1
Volume 41
This article evaluated the environmental impact of emissions from private electric generators, focusing on the amount of toxic gas they contribute to the surrounding environment. In the research, the number of generators used in the study was fifteen diesel-powered generators confined within specific residential areas in the city of Kirkuk (Iraq). The study included a field survey and measurements using air pollution standards. The amounts of HCl, H 2 S, SO 2, NO 2, NO, CO 2, CO, O 2, temperature, and relative humidity in the exhaust gases to illustrate the pollutants and compare them to the normal case were measured. It was found that the concentrations varied depending on the generators' parameters and they were high. The diffraction values were distinguished in location A4 (generator manufacturing company–Scania, generating capacity 250 kVA, voltage 200 V, number of residential units consumed-500), which was characterized by higher concentrations of contaminants than in the standard case. In the remaining cases, this was due to a variety of factors, including the generator's operational age and the higher number of houses it served compared to its generating capacity, which exceeded its design limit.
Design a model for producing fresh water using a refrigeration cycle supported by wind and solar energy
Jul 5, 2024Journal International Journal of Machine Tools and Maintenance Engineering
Publisher Maral M Hussein
Issue 2
Volume 5
Water scarcity, droughts, low rainfall rates, and depletion of groundwater to compensate for the water shortage, all lead to thousands of wells being out of service because of drought, and cause the spread of the phenomenon of desertification that threatens the social and economic stability of many societies in the world. Accordingly, there is an urgent need to find additional sources of water security. The water shortage requires researchers to work to find new sources of fresh water, either from the air or through the desalination of salt water. But both methods are expensive. However, obtaining water through desalination requires a constant source of salty water, while extracting fresh water from atmospheric air can be obtained anywhere on Earth. The atmosphere is a renewable and abundant source of water. The moisture content of the air exceeds ten grams per cubic meter, even in desert areas, and this huge amount of water in the atmospheric air remains constant. According to research, the process of condensing water vapor from the air to obtain pure water is not new, but it is considered high cost. However, the idea of using renewable energies (solar and wind energy) to provide the free energy necessary for the operation of the proposed water extraction systems is correct, making this a worthwhile solution for securing the water necessary for drinking and domestic consumption. In this research, we studied obtaining water from atmospheric air by using renewable energies (solar energy in providing the energy needed for an absorption refrigeration circuit, and wind energy in operating a compressor for a Freon refrigeration circuit). This is done through the evaporators of these two circuits that are placed in a tunnel through which flows the air that, upon contact with the cooling coils (evaporators), experiences a temperature drop below the dew point, and thus the water vapor it contains condenses. The effect of changes in input parameters on the amount of water extracted was studied.
The effect of basic building materials and their paving shapes on the thermal performance of walls in Iraqi residential buildings
Jan 9, 2024Journal International Journal of Mechanical and Thermal Engineering
Publisher Maral M Hussein
DOI https://doi.org/10.22271/27078043.2024.v5.i1a.51
Issue 1
Volume 5
Iraq's high climatic temperature affects buildings' thermal performance, leading to increased electrical energy consumption due to population growth. Researchers are exploring methods to reduce this consumption, such as heat gain reduction, heat transfer prevention, thermal insulators, high-thermal resistance materials, positive building design, useful orientation, and clean energies. The study investigates solar heat transfer in Iraqi air-conditioned spaces using nine models to analyze the impact of building elements on residential walls and their cross-section shape. The aim is to determine the best model for the Iraqi climate and the optimal approach for achieving optimal solar heat transfer. The study reveals that Model A has negative thermal performance, while Model C and I offer superior thermal performance. Model C offers 47.34% energy savings and Model I 43.99%, aligning with the global trend for green buildings and low energy expenditure in Iraqi residential unit.
A Comparison between Exhaust Gas and Electrical Grid Heating of a Diffusion Absorption Refrigerator
Feb 1, 2021Journal IOP Conference Series: Materials Science and Engineering
Publisher Maral M Hussein
DOI :10.1088/1757-899X/1094/1/012092
Issue 1
Volume 1094
A considerable quantity of waste energy in the exhaust system could be reutilized and added in a vehicle to run auxiliary systems, and contribute to improving the overall efficiency of the system. In the current work, a comparison between the conventional electrical grid and exhaust gas heating of an absorption refrigeration system was performed experimentally. A heat exchanger was fabricated to recover the wasted exhaust gas energy of internal combustion engine and operate the generator portion of a diffusion type refrigeration absorption system. The components performance of the absorption refrigerator was analyzed and estimated thermodynamically as a function of type energy source. The results revealed that the components temperatures were rapidly responded in case of the exhaust gas energy with the maximum and minimum steady state temperatures of the generator and evaporator of 140 o C and 1.1 o C, respectively. The steady state values of the COP can be reached from electrical grid, and the exhaust gas energy sources of the refrigerated system were 0.083 and 0.072, respectively. The key conclusion to be drawn is that the proposed system can be used to recycle the waste heat for refrigeration purpose; yet, with low COP values.