Investigation of the effect of physical factors on exergy efficiency of a photovoltaic thermal (PV/T) with air cooling

Thermal photovoltaic systems are used to harness solar energy to generate electricity and thermal at the same time. In this technology, electrical efficiency is very low compared to thermal efficiency; as the cell surface temperature rises, the electrical efficiency decreases, so one of the ways to achieve high efficiency is exergy analysis. Exergy analysis of a process or system shows how much of the ability to perform the work or input exergy has been consumed by that process or system. In this research, an ordinary thermal photovoltaic panel with air cooling has been examined for exergy. To do this, it has identified the effective performance variables from a mechanical point of view, which are inlet air temperature, inlet air flow, and length (number of modules that are connected in series). The effect of changing each of the variables based on Saveh weather conditions has been simulated using MATLAB software. The results show that the exergy efficiency of the panel decreases with the inlet air temperature increasing. It was also observed that the optimal airflow is 0012 (kg/s) and will have the highest efficiency per 8.8 m length.http://www.hindawi.com/journals/ijpMechanical and Aeronautical Engineerin

Influence of injection pressure on the dual-fuel mode in CI engines fueled with blends of ethanol and tamanu biodiesel

DATA AVAILABILITY : The data used to support the findings of this study are included within the article.The acceleration of global warming is primarily attributable to nonrenewable energy sources such as conventional fossil fuels. The primary source of energy for the automobile sector is petroleum products. Petroleum fuel is depleting daily, and its use produces a significant amount of greenhouse emissions. Biofuels would be a viable alternative to petroleum fuels, but a redesign of the engine would be required for complete substitution. The use of CNG in SI engines is not new, but it has not yet been implemented in CI engines. This is due to the fuel having a greater octane rating. The sole use of CNG in a CI engine results in knocking and excessive vibration. This study utilizes CNG under dual-fuel conditions when delivered through the intake manifold. In a dual-fuel mode, compressed natural gas (CNG) is utilized as the secondary fuel and a blend of 90% tamanu methyl ester and 10% ethanol (TMEE10) is used as the primary fuel. The injection pressure (IP) of the primary fuel changes between 200 and 240 bar, while the CNG induction rate is kept constant at 0.17 kg/h. The main combustion process is governed by the injection pressure of the pilot fuel. It could be affecting factors such as the vaporization characteristics of the fuel, the homogeneity of the mixture, and the ignition delay. Originally, tamanu methyl ester (TME) and diesel were used as base fuels in the investigation. As a result of its inherent oxygen content, TME emits more NOx than diesel. The addition of 10% ethanol to TME (TMEE10) marginally reduces NOx emissions in a CI mode because of its high latent heat of vaporization characteristics. Under peak load conditions, NOx emissions of TMEE10 are 6.2% lower than those of neat TME in the CI mode. Furthermore, the experiment was conducted using TMEE10 as the primary fuel and CNG as the secondary fuel. In the dual-fuel mode, the TMEE10 blend showed higher combustion, resulting in an increase in performance and a significant decrease in emission characteristics. As a result of the CNG’s high-energy value and rapid burning rate, the brake thermal efficiency (BTE) of TMEE10 improves to 29.09% compared to 27.09% for neat TME. In the dual-fuel mode of TMEE10 with 20.2% CNG energy sharing, the greatest reduction in fuel consumption was 2.9%. TMEE10 with CNG induction emits 7.8%, 12.5%, and 15.5% less HC, CO, and smoke, respectively, than TME operation.http://www.hindawi.com/journals/ijce/am2023Mechanical and Aeronautical Engineerin

Influences of hydrogen addition from different dual- fuel modes on engine behaviors

Compression ignition (CI) engines have good performance but more exhaust emissions. Dual fuel (DF) engines have better performance and lower emissions compared to CI mode. Also, the scarcity of fossil fuels made the researchers to find alternative fuels to power CI engines. Therefore, the present work aims to use hydrogen (H2) and honne oil biodiesel (BHO) to investigate the performance of CI engines in DF mode. Also, it aims to compare the performance of CI engines in various DF modes, namely induction, manifold injection, and port injection. First, the CI engine was fuelled completely by diesel fuel and BHO. The data were gathered when the engine ran at a constant engine speed of 1500 rpm and at 80% load. Second, the CI engine was operated in various DF modes and data were generated. CI engine operation in DF mode was smooth with biodiesel and H2. The brake thermal efficiency (BTE) of 32% and 31.1% was reported with diesel and biodiesel, respectively, for manifold injection due to low energy content and high viscosity of biodiesel. These values were higher than CI mode and other DF modes. Fuel substitution percentage for DF manifold injection was 60% and 57% with diesel and biodiesel, respectively. Smoke, hydrocarbon (HC), and carbon monoxide (CO) emissions were lower than conventional mode, but a reverse trend was observed for oxides of nitrogen (NOx) emissions. Heat release rate (HRR) and peak pressure (PP) were higher than conventional mode due to the fast combustion rate of hydrogen. The shortest ignition delay (ID) period was noticed for traditional diesel fuel, but it was longer for BHO biodiesel due to its higher viscosity and lower cetane number. On the contrary, the presence of hydrogen led to an increment in the combustion duration (CD) owing to the scarcity of oxygen in CD. Consequently, the paper clearly showed that the injection way of hydrogen plays a respectable role in the engine characteristics.https://wileyonlinelibrary.com/journal/ese3hj2023Mechanical and Aeronautical Engineerin

Utilization of animal solid waste for electricity generation in the northwest of Iran 3E analysis for one-year simulation

DATA AVAILABILITY : The data used to support the findings of this study are available from the corresponding author upon request.Today, the use of renewable energy is increasing day by day. The most susceptible to renewable energy is biomass energy because it depends directly on the size of the population and does not have the problems of other renewable energies such as lack of access day and night and constant change throughout the year. For this reason, animal solid waste has been used in the research to supply electrical energy to the study area. In this regard, the amount of animal waste is considered as a source of biomass input energy. HOMER software was used to simulate the system under study. To better compare the competitiveness of this energy, photovoltaic systems and wind turbines have been used as different scenarios of electrical energy production in the study area. The results of scenario analysis showed that in all designed systems, the highest amount of energy production was in July and was related to the hottest season of the year. Among hybrid systems, the biomass system has a higher priority than other systems due to the minimum cost of energy production and total net present cost (NPC). The amount of exhaust gas from the biomass system reached 53.5 kg/yr and the biomass-wind and biomass-wind-solar systems reached 52.5 kg/yr and 52.2 kg/yr, respectively. The surplus generated electricity also increases from 2.91% to 6.65% from the biomass-wind system to the biomass-with-solar system.http://www.hindawi.com/journals/ijceam2023Mechanical and Aeronautical Engineerin

Performance comparison of single-slope solar still loaded with various nanofluids

Nanofluids are great heat transfer carriers for collecting thermal energy in solar thermal applications. In the present study, a theoretical study of single-slope solar still (passive type) has been carried out by incorporating CuO, Al2O3, Ag, Fe2O3, and SiC-water nanofluids at different volume concentrations (0.02, 0.05, 0.08, 0.12, and 0.2). This analysis has been carried out with an optimum water depth of 0.02m as obtained from the experimental and theoretical studies. In order to validate the model, the experiments were conducted on solar still and then performance of still was compared. The analytical expression of the characteristic equation using Runga-Kutta ODE, for passive single slope solar still was found to be in good agreement with experiments carried out in Patiala, India. The total deviation for both experimental and theoretical distillate output of a still for a day was found to be 12.24%. Daily production for Al2O3-water-based nanofluid was found to be (14.22%) higher than simple solar still without nanofluid, followed by CuO (10.82%), Ag (8.11%), Fe2O3 (7.63%) and SiC (7.61%).http://wileyonlinelibrary.com/journal/ese3dm2022Mechanical and Aeronautical Engineerin

A novel long term solar photovoltaic power forecasting approach using LSTM with Nadam optimizer : a case study of India

Solar photovoltaic (PV) power is emerging as one of the most viable renewable energy sources. The recent enhancements in the integration of renewable energy sources into the power grid create a dire need for reliable solar power forecasting techniques. In this paper, a new long-term solar PV power forecasting approach using long short-term memory (LSTM) model with Nadam optimizer is presented. The LSTM model performs better with the time-series data as it persists information of more time steps. The experimental models are realized on a 250.25 kW installed capacity solar PV power system located at MANIT Bhopal, Madhya Pradesh, India. The proposed model is compared with two time-series models and eight neural network models using LSTM with different optimizers. The obtained results using LSTM with Nadam optimizer present a significant improvement in the forecasting accuracy of 30.56% over autoregressive integrated moving average, 47.48% over seasonal autoregressive integrated moving average, and 1.35%, 1.43%, 3.51%, 4.88%, 11.84%, 50.69%, and 58.29% over models using RMSprop, Adam, Adamax, SGD, Adagrad, Adadelta, and Ftrl optimizer, respectively. The experimental results prove that the proposed methodology is more conclusive for solar PV power forecasting and can be employed for enhanced system planning and management.https://wileyonlinelibrary.com/journal/ese3hj2023Mechanical and Aeronautical Engineerin

Assessment on performance and emission characteristics of the CRDI engine fueled with ethanol/diesel blends in addition to EGR

In this research, the CRDI engine characteristics were analyzed with the aid of exhaust gas recirculation rate (EGR) adoption fueled with ethanol blends. The test fuels were the various blends with ethanol, such as (10% of ethanol + 90% of diesel) E10D90 (20% of ethanol + 80% of diesel), E20D80, and (30% of ethanol + 70% of diesel) E30D70. From the results, it was revealed that performance characteristics were reduced when using a higher concentration of the alcohols mixed with diesel fuel. The blend E30D70 showed that brake thermal efficiency (BTE) without EGR drops by 3.8%, increased by 9.14% of BSFC, a 9.25% decrease in oxides of nitrogen emissions, and slightly decreased CO and HC emissions compared to baseline diesel operation at 60% load condition. The blend E10D90 with 20% EGR shows the highest BTE of 8.87% when compared with base fuel, due to proper fuel mixture taking place in the inlet manifold. The results indicate that the engine runs smoothly, and E30D70 has chosen an optimum blend. A further experiment was performed using E30D70 with different rates of exhaust gas recirculation system. The addition of exhaust gas recirculation with E30D70 in the common rail diesel engine exhibits oxides of nitrogen emission, but in contrast, it was noticed to have inferior performance characteristics and drastically decreased HC and CO emissions. The hydrocarbon emission decreased E10D90, E20D80, and E30D70 at 60% load condition by 21.42%, 37.38%, and 48.76%, respectively. The blends E10D90, E20D80, and E30D70 decreased carbon dioxide by 7.9%, 30.08%, and 31.98%, respectively. The maximum reduction of NOx emission was observed at about 51.06% at an EGR rate of 20% with E30D70.http://www.hindawi.com/journals/ijceam2023Mechanical and Aeronautical Engineerin

Evaluation of the Safety of High-Salt Wastewater Treatment in Coal Chemical Industry Based on the AHP Fuzzy Method

Aim. Epichlorohydrin (ECH) is a widely used chemical product. The production of glycerol has its irreplaceable advantages. With the development of biodiesel industry, it will become the main trend of ECH production in the future. Methods. A vacuum evaporation device is built to investigate the effect of evaporation on the treatment of this kind of high-salt wastewater, and the feasibility of the thermodynamic equation of the simulation process is verified. Process. An AHR fuzzy mathematics evaluation algorithm is used to compare experimental values with simulated numerical values in brine. Results and Conclusions. In the multieffect evaporation process simulation with glycerin-containing brine, the amount of salt precipitated by unit steam energy is arranged in order from more to less than that of seven-effect parallel flow evaporation, is greater than five-effect parallel flow evaporation, and is larger than three-effect parallel flow evaporation, which shows that the increase of validity number is beneficial to the utilization of heat

Modeling and Analysis of Energy/Exergy for Absorber Pipes of Linear Parabolic Concentrating Systems

In this paper, the physical parameters of the absorber pipe of a linear parabolic collector have been investigated. The types of solar collectors, specifically the linear parabolic collector, have been comprehensively studied. Then, the mathematical model of heat transfer in the absorber pipe of the collector has been presented based on valid references. Numerical solutions of the equations related to the absorber pipe were performed by MATLAB software, and the effects of the physical parameters of the absorber pipe on its efficiency were investigated. The results show that increasing the length of the absorber pipe causes a nonlinear decrease in the efficiency of the absorber pipe. One of the important results is the increase in fluid temperature due to the increase in the diameter of the adsorbent tube, which increases the diameter of the fluid temperature by 60 K, in which the parameter increases the efficiency by 0.38%

Thermal and Environmental Analysis Solar Water Heater System for Residential Buildings

Due to the reduction of fossil resources, the replacement of renewable energy sources such as solar energy has become mandatory. Solar energy does not contain pollution and widely available in all parts of the world, especially in warm regions. Our country (IRAN) is geographically located in a hot and dry region, and with more than 280 sunny days per year, one of the nonpower applications of solar energy is heating space and water consumption of the building using solar thermal energy. Solar water heaters can be used to heat the water used in buildings, which is the main purpose of this study. Water heating consumes an average of 20% to 30% of the total energy consumption in the residential building. Therefore, using solar water heaters annually can provide 70% of the energy needed for water heating. The system designed in this research is able to provide 75% of the hot water consumption needs. If an auxiliary heat source is used next to this system, all hot water needs of the building can be met throughout the year. In this case, as much as 237.3 kWh, energy will be saved from fossil energy sources