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In arid and semi-arid regions with low relative humidity, it is difficult to obtain drinking water from the air humidity. The water supply in Mashhad faces many challenges. The water production from atmospheric humidity is one method of supplying water in Mashhad. The aim of this study was to investigate a small-scale hybrid atmospheric water generator (AWG) that utilizes a desiccant wheel to adsorb and desorb air humidity. The proposed AWG was mathematically modeled in order to determine its efficiency and performance. A complete energy, exergy, and economic (3E) analyses were conducted on the proposed system. In order to validate the mathematical model, a numerical simulation was performed using the ANSYS 2022R1 software. The water generation rate, energy consumption, specific energy consumption, and energy-exergy efficiency of the proposed system were presented in months. According to the results, the WGR is highest in July at 156 L day−1 and lowest in December at 23 L day−1. Additionally, July and December had the highest and lowest SECs during the year, with 1.5 kWh L−1 and 10 kWh L−1, respectively. Additionally, July and December recorded the highest and lowest energy and exergy efficiencies, respectively, with 22.1%, 1.25% and 4.8%, 0.14%. [ABSTRACT FROM AUTHOR]

In this paper, the effect of gasoline fumigation on the performance, emission, energy and exergy balance of a direct injection diesel engine is experimentally investigated. Gasoline fumigation is induced at three different ratios based on energy. In the present study, computer-controlled injection using LabVIEW software is attempted for gasoline fumigation and common rail is used to inject at the same pressure always. The characteristics of the engine are studied with and without fumigation. Results reveal that gasoline fumigation increases the energy and exergy efficiency to about 5% at medium and high loads. For all the operating points, the percentage of energy and exergy transfer through the exhaust gases decreases by an average of 2.6% using gasoline fumigation. Fumigation decreases diesel fuel consumption by 33.53%, CO2 emissions by 5.8%, NOx by 10.4% and smoke by 13-17% during full load at 30% of gasoline fumigation. Also, fumigation increases brake thermal efficiency by 3.78%, CO emissions from 0.2 to 0.96% by volume and UBHC emissions from 51 to 205 ppm during full load at 30% of gasoline fumigation. Results show that the gasoline fumigation replaces diesel and reduces both nitrogen oxides and smoke. [ABSTRACT FROM AUTHOR]

The present work seeks to address the forced convection heat transfer behaviour of a double-pass solar air heater system (DPSAHS) provided with asymmetric channel flow configuration used for solar drying of agro-products. Outdoor experiments were performed on a DPSAHS having a constant channel depth ratio of 1.5. Thermal response of the DPSAHS under different influencing parameters such as flow rate, channel depth, and thermophysical properties of the working fluid was experimentally determined. The influence of ambient parameters such as solar intensity, ambient temperature, wind speed, and relative humidity on the thermodynamic behaviour of the DPSAHS was also investigated. Among which, solar intensity and ambient temperature were found to be the major parameters influencing the energy and exergy efficiency followed by wind speed. Relative humidity was found to have the least percentage contribution towards the thermal characteristics of the system. Overall thermal efficiency and exergy efficiency were found to vary in the range of 20-41% and 5.6-18% at two different mass flow rates of 0.02 kg s−1 and 0.03 kg s−1, respectively. The results also inferred that the influence of thermophysical property variation on the thermodynamic performance depends upon the operating temperature range and on the nature of working fluid. Air temperature in the lower channel was found to be an average 3 °C higher than that of upper channel passage corresponding to two different mass flow rates. Hence, the thermodynamic behaviour of DPSAHS was found to be strongly influenced by the variation in channel depth, ambient parameters, and mass flow rate. The obtained experimental results were also compared with the available literatures. [ABSTRACT FROM AUTHOR]

Depletion of non-renewable energy sources are at elevated manner due to the rapid growth of industrialization and transportation sector in last few decades and leads to further energy demand. Biodiesels especially second-generation fuels from non-edible oil resources are alternate sources for replacement of diesel fuel in CI engines due to their considerable environmental benefits. In the present work, non-edible feedstock of Calophyllum inophyllum seed oil (tamanu oil) is used for biodiesel production. Transesterification method is used for preparation of biodiesel in the existence of methanol with NaOH as catalyst. The copper nanoparticles are synthesized by electrochemical method, and it is characterized by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). XRD and SEM results confirm the presence of copper nanoparticle and size of around 30 nm. This paper aims to investigate the effects of the copper additive nanoparticles with biodiesel blends on the engine performance, combustion and emission characteristics of single-cylinder direct-injection diesel engine and compared that with diesel fuel. The results showed that the addition of nano-additives enhances brake thermal efficiency and reduces specific fuel consumption compared to biodiesel blends but slightly lower than diesel. Combustion characteristics also are enhanced by improved oxidation reaction inside the combustion chamber which resulted in higher heat release rate. The emissions of HC, NOx and O2 are significantly reduced for nano-additive blends compared to diesel but increased CO2 emission was observed. It is noticed that higher CO2 emission and substantial reduction of unused O2 emissions from engine fueled with nano-additive are evident for enhanced oxidation and better combustion. Energy and exergy analysis of the diesel engine is carried out to estimate the effect of using nanoparticle additive with biodiesel. [ABSTRACT FROM AUTHOR]