NTU Journal of Renewable Energy

The present study aims to evaluate and analyze the gas turbine power generation unit (K3) in the Kirkuk gas power station under actual weather conditions of (2017), which is located south of Kirkuk in the district of Taza. The (K3) unit has a production capacity estimated at (255 MW) at maximum load; the unit consists of a gas turbine and an air compressor connected to the generator via a common shaft and operates in the Joule-Brighton simple cycle. The current study dealt with the analysis of the energy and exergy for the mentioned unit based on the law of conservation of mass, the first law, the second law in terms of the influence of each of the factors (ambient temperature, compression ratio, and relative humidity). Two methods were used to simulate the working data; the first is simulation programming by Excel, and the other is by using CHEMCAD software; the average data have been used in the simulation process for each month in that year to evaluate the performance of the unit K3. The simulation results showed that the combustion chamber represents the most important part in the exergy destruction, and the largest energy rate can be obtained from fuel as chemical, and the results of both methods showed maximum energy and energy efficiency was around (37.67%) and (36.89%), respectively.

The increase of energy demand and environmental contaminations hearten the utilization of alcohol-based as a alternatives fuels in spark ignition (SI) engine. The fusel oil is a byproduct developed from a fermentation process with higher alcohol content. It has high-octane and slight exhaust emissions, there for it takes important place between the substitutes fuels. During this study, effect of used mixtures of pure low octane gasoline & fusel oil on engine exhaust emissions & performance have been estimated after water removal from fusel oil. A single-cylinder, four-stroke SI engine has been used in this tests. The inspections execute at different speeds. The test fuels mixed by fusel oil at ratio of 5%, 10%, 20%, and 30%. In each speed, the engine’s performance & emissions size have been conducted. During the investigations, it have been observed that the brake power (BP) and specified fuel consuming (SFC) rises as the size of fusel oil risen in the mixture.

Here we give a comprehensive overview of the current situation and trends used in the field of waste-to-energy technology (WTE) and the feasibility of the various current technologies used in the conversion process, as well as the advantages and disadvantages of each used technology in terms of benefit, cost and impact on the environment, this research also provides recent statistics on the amount of electrical energy produced from waste-to-energy conversion technology (WTE) in some leading Arab and global countries in this field. We also review the global scenario for countries producing this type of renewable energies.

The purpose of this research is to determine the performance of a close type parabolic trough collector (CTPTC) by varying the design and operating parameters on a sunny day. It was carried out at Iraq's Renewable Energy Unit in Hawija. Use water as working fluid (WF) at a mass flow rate of 0.00083, 0.0011, 0.00138 and 0.00166 Kg/s. The concentration ratio of 10, 14, 18 and 22 are used. The fuzzy technique was used to analyze the system's performance, where the theoretical analysis was carried out according to ASHRAE 93-1986 (RA-91). The findings demonstrated that theoretical efficiency reaches a maximum of 58 % when the mass flow is greatest, and the concentration ratio is minimum. Simultaneously, the practical efficiency increases to 38% under the same circumstances.

Bioremediation is a friendly and cheap way to remove minerals from the environment. Research has been conducted over the past five decades, an enormous amount of information has been collected about the types of different bio- sorbents and their mechanism of mineral absorption. More research is needed to explore new bio-sorbent materials from the environment. Moreover, a deep insight needed not only into the method of demineralization but also its effective recovery. So that it can be get in usable form. Use of biomass to remove heavy metals which are absorbed simultaneously treating large quantities of sewage. No need for highly selective chemical additives to absorb and remove certain minerals operates over a wide range of conditions including temperature, pH, and presence other metal ions. Easy and cheaper absorption of minerals associated with biomass are essential to reduce the volume of waste or production of toxic substances.

On February 25, 2022 at 08:39:29 Local Time an unexpected earthquake with a magnitude of 6.1 Mw struck the Western part of Sumatera, onshore, and located on the blind fault. It is very likely that the earthquake was from Angkola Fault, but there is still a possibility that there are still other active faults in this area that have not been mapped yet. The areas that were affected by the earthquake are Pasaman, West Pasaman, Limapuluh Kota, Padang Pariaman and Agam regencies. The focal mechanism from BMKG show that the dominant mechanism of this earthquake was the right lateral (dextral) strike slip. The worst devastation was in West Pasaman and the damage from this earthquake was wide spread. An estimated 6627 houses have been destroyed and 70 mosques were damaged, 41 offices were devastated, 208 schools and educational institutions, 25 medical infrastructures, and 5 bridges were damaged. An on-site post-event survey was carried out to investigate the effects. We conduct mapping ground ruptures and cracking in an effort to find surface expression of fault rupture. Right after the main shock, a few seismometers were deployed near the epicenter to monitor the aftershocks. By using macro seismic observation, micro seismic measurement, and impact documentation, we also find collateral impact that is flash flood and soil landslide which broken some access points. The destructive earthquake is a reminder of the serious future seismic threats to comply implementation of the Building Codes.

One of the main obstacles facing solar chimney systems is their low efficiency which contributed to the decrease in the construction of solar chimneys in the world. The current article presents a novel proposal to enhance the efficiency of solar chimneys by using solar panels. In this new system, the solar cells are fixed in the mid-distance between the chimney base and the glass cover. Therefore, the air can move above and below the solar cells to accelerate the photovoltaic cells' cooling and obtain higher air velocity.

The results also showed that the photovoltaic cell location determines its temperature, where high temperatures characterized the solar panels fixed in the middle. In contrast, the solar cells that are placed on the ends were at lower temperatures. The outcomes also confirmed that the air velocity in the new design still depends on weather conditions, and the results show that the chimney base is the ideal location for the turbine, and the air velocity rises during the day to reach its maximum value at 1 p.m. The highest recorded air velocity was 1.8 m/s in February at 1 p.m. High-efficiency values were recorded in the early morning because of the solar cells' low temperatures for the tested months. The highest recorded electrical efficiency value was 17.8% in December. In contrast, the lowest recorded electrical efficiency was 10.6% in February at 1 p.m.

Trombe photovoltaic wall is well known for its ability to supply the building with thermal and electrical energy at the same time. The increase in the temperature of the solar panels leads to a decrease in electrical efficiency. The use of DC fans and water as a medium for cooling the panels improved thermal and electrical efficiency and enhanced the comfort conditions inside the building. The results showed that the Trombe wall with DC fans could reduce the demand for the rudder by Increasing the heat inside the building, as it reached the highest thermal efficiency at 37.5%. As for the system equipped with a heat exchanger recorded the highest electrical efficiency of 14%. Finally, the results showed that the use of DC fans improves the overall efficiency of the photovoltaic Trombe wall system.