Exergy and Energy Analysis of Wind-Thermal System

Current wind systems are intermittent and cannot be used as the baseload energy source. The research on the concept of wind power using direct thermal energy conversion and thermal energy storage, called wind powered Thermal Energy System (WTES), opened the door to a new energy system called Wind-thermal, which is a strategy for developing baseload wind power systems. The thermal energy is generated from the rotating energy directly at the top of the tower by the heat generator, which is a simple and light electric brake. The rest of the system is the same as the tower type concentrated solar power (CSP). This paper’s results suggest that the energy and exergy performance of the WTES (62.5% and 29.8%) is comparable to that of conventional wind power, which must be supported by the backup thermal plants and grid enhancement. This cogeneration nature of the WTES system makes this system suitable for using wind power as a direct heat source in several heat-demanding processes such as chemical production. Also, the light heat generator reduces some issues of wind power, such as noise and vibration, which are two main bottlenecks of the wind power technology.

Exergy and Energy Analysis of a CHP System with a Gas Turbine and a Horizontal Axis Wind Turbine

The combined heating and power (CHP) system is among the most effective ways to increase energy and exergy efficiencies, reduce fuel consumption, and reduce operational costs. In this study, the combination of an electricity and heat CHP system with the prime movers of a gas turbine and a horizontal axis wind turbine under the strategy of providing electric charge has been investigated. This study aims to evaluate the effect of the wind turbine on the system. The Blade Element Momentum Theory (BEM) is used to model the wind turbine under different wind speeds, pitch angle, and tip speed ratios to show their effect on the gas turbine system under different combustion chamber temperatures and pressure ratios. The results show that the proposed CHP system has significant advantages over the separate production system. It is shown that the best operating condition for the wind turbine is at the wind speed of 12 m/s, the pitch angle of 5°, and the tip speed ratio of 3. Moreover, the wind speed and tip speed ratio effects become considerable at the high-pressure ratios of more than ten and the combustion chamber temperature below 1250°C on the total system's exergy efficiency. Also, compared to the separate production mode, operational costs and fuel consumption are reduced by about 55% and 60%, respectively. Finally, taking into account the interest rate, the payback period will be equal to 5.4 years.

Life Cycle Assessment of A Hydrocarbon-based Electrified Cleaning Agent

The electrified cleaning agent requires a moderate volatilization rate, low ozone-depleting substances value, non-flammable, non-explosive and other characteristics. This study performed a whole life cycle assessment on a hydrocarbon-based electrified cleaning agent. The life cycle model is cradle-to-grave, and the background data sets include power grid, transportation, high-density polyethylene, chemicals, etc. The analysis shows that the global warming potential (GWP) of the life cycle of 1 kg of electrified cleaning agent is 2.08 kg CO2 eq, acidification potential (AP) is 9.49E-03 kg SO2 eq, eutrophication potential (EP) is 1.18E-03 kg PO43-eq, respirable inorganic matter (RI) is 2.13E- 03 kg PM2.5 eq, ozone depletion potential (ODP) is 4.91E-05 kg CFC-11 eq, photochemical ozone formation potential (POFP) is 2.89E-02 kg NMVOC eq, ionizing radiation-human health potential (IRP) is 3.16E-02 kg U235 eq, ecotoxicity (ET) is 2.69E-01 CTUe, human toxicity-carcinogenic (HT-cancer) is 4.32E-08 CTUh, and human toxicity-non-carcinogenic (HT-non cancer) is 2.31E-07 CTUh. The uncertainty of the results is between 3.46-9.95%. The four processes of tetrachloroethylene production, D40 solvent oil production, tetrachloroethylene environmental discharge during product use, and electricity usage during product disposal have substantial effects on each LCA indicator, so they are the focus of process improvement. Changes in power consumption during production and transportation distance of raw materials have little effect on total carbon emissions. Compared with the production process of single-solvent electrified cleaning agent tetrachloroethylene and n-bromopropane, the production of the electrified cleaning agent developed in this study has its own advantages in terms of carbon footprint and other environmental impact indicators. Carbon emissions mainly come from the power consumption of each process, natural gas production and combustion, and other energy materials for heating. It is recommended to use renewable raw materials instead of crude oil to obtain carbon credits based on geographical advantages, and try to use production processes with lower carbon emissions, while the exhaust gas from the traditional production process is strictly absorbed and purified before being discharged.

Enhance the Output Power of a Shaded Solar Photovoltaic Arrays with Shade Dispersion based TCT Configuration

Partial shading has a negative impact on the performance parameters of a Solar Photovoltaic (PV) array, because it shades certain panels while leaving others un-shaded. This article focuses on modeling, comparing and performance assessment of 6×6, 6×5 and 5×6 size shadowed solar PV arrays under different partial shading cases in the MATLAB/ Simulink software. For this purpose, the simulation of series-parallel (SP), Total-Cross-Tied (TCT) and proposed shade dispersion based TCT (SD-TCT) type of array configurations was carried out under few shading cases. The proposed SD-TCT was designed using the shades dispersion technique, which is based on a number logic approach. In this technique, in order to effectively remove the row-current mismatches in the TCT PV array configuration, the shaded and un-shaded modules in an array were re-arranged, so that the shading on modules expands across the whole array. The physical placement of the TCT array modules has been reordered in accordance with the proposed number logic pattern exclusive of altering the electrical links among the panels. The simulation results showed that the performance of the SD-TCT type was superior to that of conventional array configurations.

Pyrolysis-Gas Chromatography/Mass Spectrometry Analysis of Oils from Different Sources

Regenerated gutter oil (i.e., waste oil) accounts for 10% of the edible oil market, which has caused serious food safety issues. Currently, there is no standard protocol for the identification of the gutter oil. In this study, the pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) method was employed to analyze eleven oil samples including edible vegetable oils (tea oil, corn oil, olive oil, sunflower oil, peanut oil and blend vegetable oil) and waste oils (used frying oil, lard, chicken fat, inferior oil and kitchen waste grease). Three factors of pyrolysis temperature, reaction time and sample volume were investigated to optimize the analytical parameters. The optimal pyrolysis conditions were determined to be 600°C, 1 min and an injection volume of 0.3 μL. Five characteristic components (tetradecane, z,z-9,12-octadecadienoic acid, decanoic acid-2-propenyl ester, 17-octadecenoic acid, and z-9-octadecenoic acid) were found in all oil samples. The existence of C11-C16 olefins in the pyrolytic products of the animal fats and the other low-quality oils could be utilized to distinguish vegetable oils from gutter oils.

Information Technology, Artificial Intelligence and Machine Learning in Smart Grid – Performance Comparison between Topology Identification Methodology and Neural Network Identification Methodology for the Branch Number Approximation of Overhead Low-Voltage Broadband over Power Lines Network Topologies

Broadband over Power Lines (BPL) networks that are deployed across the smart grid can benefit from the usage of machine learning, as smarter grid diagnostics are collected and analyzed. In this paper, the neural network identification methodology of Overhead Low-Voltage (OV LV) BPL networks that aims at identifying the number of branches for a given OV LV BPL topology channel attenuation behavior is proposed, which is simply denoted as NNIM-BNI. In order to identify the branch number of an OV LV BPL topology through its channel attenuation behavior, NNIM-BNI exploits the Deterministic Hybrid Model (DHM), which has been extensively tested in OV LV BPL networks for their channel attenuation determination, and the OV LV BPL topology database of Topology Identification Methodology (TIM). The results of NNIM-BNI towards the branch number identification of OV LV BPL topologies are compared against the ones of a newly proposed TIM-based methodology, denoted as TIM-BNI.

Technical Overview of the Net Metering in Lebanon

In order to realize the best practices to allow the individuals participate in renewable energy production, a collection of legislation was ratified, and a set of decisions was introduced to encourage the prosumer concept. This notion, which is called Net Metering (NEM), is a billing mechanism that credits PV solar system owners for the energy injected to the grid. Lebanon adopts the NEM policy to reduce the demand and boost the grid through increasing the generation capacity. The decline of solar equipment cost encourages people to subscribe to the NEM service by utilizing the PV solar systems. The implementation of the NEM service provides the customers with leverage over their electricity bills. However, connecting the home micro grid into the vast grid is not easy. It imposes many technical challenges which are discussed in this article.