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In Gran Canaria, the integration of renewable technologies is being investigated to address intermittency in power generation. The future Chira-Soria pumped-storage hydroelectric power plant (PHES), planned for 2030, will be key in harnessing the island's hydro potential. In addition, hydrogen storage is being explored as a viable solution. This method uses electrolysis of water to produce hydrogen during energy surplus, storing it to generate electricity when there is low renewable production. This approach mitigates intermittency, stabilizes the energy system and reduces dependence on fossil fuels. The combination of the Chira-Soria PHES with hydrogen storage will ensure a sustainable and reliable energy supply, contributing to the transition to a cleaner and more resilient energy matrix. The studies seek to optimize this technology, maximizing its efficiency to promote the sustainable development of Gran Canaria and reduce greenhouse gas (GHG) emissions. • H 2 storage reduces emissions by 12.36% vs. PHES; 36.02% vs. no integration. • PHES plant with H 2 storage maximizes surplus renewable energy and system reliability. • H 2 storage optimizes emissions reduction and resource use in an island power system. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to introduce an innovative method for diagnosing bearing issues in turbines using statistical control charts, with the aim of improving diagnostic abilities, leading to enhanced operational reliability and extended turbine lifespan. Methods: The proposed method employs a data-driven strategy, utilizing statistical control charts to monitor crucial parameters linked to bearing health in real-time. This enables the detection of subtle deviations from typical operating conditions. Results: Experimental results demonstrate the value of statistical control charts in detecting and monitoring bearing faults, showcasing their potential to transform predictive maintenance in industrial machinery. Conclusion: The method offers clear advantages over traditional approaches that depend on periodic inspections or subjective assessments, providing a systematic and proactive approach to early fault detection. By addressing the shortcomings of traditional inspection methods, the proposed method enables real-time tracking and early detection of faults, leading to improved operational reliability and extended turbine lifespan. [ABSTRACT FROM AUTHOR]

This research examines the development of a turbine for a supercritical organic Rankine cycle (ORC) power generation system. The study details the design, manufacturing, and performance evaluation of a 100 kWe-class power generation turbine equipped with a magnetic bearing. Furthermore, a supercritical ORC power-generation system is constructed to evaluate the turbine performance. The turbine featured an overall expansion ratio of 9 with a two-stage centrifugal design, and it was integrated with the generator and magnetic bearings within a unified sealed-type casing. To ensure continuous electric power generation, internal turbine cooling devices were installed, and the evaporator connection pipes are modified. The performance tests demonstrate that the turbine produces 100 kW of electric power with an efficiency rate of 75 %. Comparison between the test results and numerical analysis confirms their good agreement. This research elucidates the considerations essential for the development of supercritical ORC turbines. [ABSTRACT FROM AUTHOR]

Water distribution networks (WDNs) are significant users of energy and contributors to greenhouse gas emissions. Energy recovery strategies (ERSs) have potential for switching WDNs to a renewable energy source, thereby assisting with the transition to net-zero emissions and reducing the dependency of water utilities on power-grids. To address the current lack of understanding of the potential for ERSs to achieve these goals, this work presents a holistic review, which considers all available devices, i.e. turbines, pumps as turbines, and other alternative strategies, such as the GreenValves, as well as all the kinds of application in the literature. Besides describing the latest most significant achievements in the context of ERSs, the review also identifies the most common issues and proposes several future research directions, including the need for a better test and comparison of the various available solutions in field applications, and more thorough analyses of the socio/political problems hampering their diffusion. [ABSTRACT FROM AUTHOR]

In 2019, more than 16% of the globe's total production of electricity was provided by hydroelectric power plants. The core of a typical hydroelectric power plant is the turbine. Turbines are subjected to high levels of pressure, vibration, high temperatures, and air gaps as water passes through them. Turbine blades weighing several tons break due to this surge, a tragic accident because of the massive damage they cause. This research aims to develop predictive models to accurately predict the status of hydroelectric power plants based on real stored data for all factors affecting the status of these plants. The importance of having a typical predictive model for the future status of these plants lies in avoiding turbine blade breakage and catastrophic accidents in power plants and the resulting damages, increasing the life of these plants, avoiding sudden shutdowns, and ensuring stability in the generation of electrical energy. In this study, artificial neural network algorithms (RNN and LSTM) are used to predict the condition of the hydropower station, identify the fault before it occurs, and avoid it. After testing, the LSTM algorithm achieved the greatest results with regard to the highest accuracy and least error. According to the findings, the LSTM model attained an accuracy of 99.55%, a mean square error (MSE) of 0.0072, and a mean absolute error (MAE) of 0.0053. [ABSTRACT FROM AUTHOR]

Researches have shown that the use of a continuous detonation afterburner can improve the propulsion performance of aero engine. However, backpropagation pressure waves (BPW) generated by the pressure gain of detonation will affect the internal flow and performance of turbine. This article simulates BPW through a custom function, and investigates the effects of BPW amplitude, rotation frequency, and propagation mode on turbine performance through three-dimensional simulation. The results show that as the pressure amplitude of the BPW increases, the pressure oscillation at each section of the turbine increases and a local subcritical flow state will appear, leading to the decrease of turbine flowrate and turbine power, as well as an intensification of instantaneous turbine power fluctuations. As the rotation frequency of the BPW increases, the pressure oscillation at each section of the turbine gradually decreases. The flowrate and power of the turbine do not change much, but turbine efficiency gradually decreases. Compared to the aligned mode, the turbine performs better under the influence of BPW in misaligned mode. Compared to the single-wave mode, the fluctuation of transient turbine power is lower under the influence of BPW in the multiwave mode excluding collision mode. Finally, the constraints of equal flowrate region and equal turbine power line on the peak-to-peak value of the BPW were analyzed when the joint operation of the turbine and compressor was not affected. The rotation frequency and mode of BPW will affect the flowrate region and power line. [ABSTRACT FROM AUTHOR]

Fonseca, M.; McMahon, A.; Erickson, R.; Kelly, C.; Tiggelaar, J., II, and Graham, B., 2024. Effects of the Block Island Wind Farm on benthic and epifaunal communities. Journal of Coastal Research, 40(6), 1037–1054. Charlotte (North Carolina), ISSN 0749-0208. This study reports on monitoring surveys conducted at three of the five commercially operating turbines in U.S. waters off Block Island, Rhode Island, U.S.A., with an emphasis on the final, fourth year of a Bureau of Ocean Energy Management sampling program. The monitoring focused on changes to sediments and infaunal and epifauna species abundance, richness, and diversity caused by the presence of the turbine structure. As anticipated, based on a comparison with other study results, far-field changes in benthic conditions were not evident. Clear changes to the seabed sediments and faunal composition manifested only in the immediate footprint of the turbine foundations. Aside from a localized and sustained shift in particle size, little evidence of a temporally or spatially progressive pattern (as a function of distance away from the turbines) of change in seabed physical and biological composition, or on the turbine structures themselves, was found. The lack of a systematic pattern of influence suggests that many of the intra- and interannual differences may be attributed to natural fluctuations, especially the epifauna on the turbine structures. Notably, the faunal dynamics suggest a community in constant flux and, as seen in other studies, lacking a trend toward the formation of a climax community, which is characterized by stable faunal composition. For these dynamic communities, future sampling may consider using a fixed station, repeated measures approach, as has been done in similarly dynamic, intertidal communities to manage these scales of habitat variability. [ABSTRACT FROM AUTHOR]

Turbine blades recovered from the Apollo Saturn V rocket F-1 engines were examined to determine an appropriate conservation protocol. Significant corrosion damage was observed in the turbine blades which appear to be made of a nickel based γ–γ′ superalloy. Pitting corrosion appears to have breached the surface of the turbine blades, and subsequently a form of dealloying corrosion preferentially attacked the γ′ phase. This corrosion left behind a thin network of interconnected γ phase, causing a severe loss of density of the blades and fragility of the blades. The particular alloy used for these turbine blades does not appear to be a known production alloy and may have been developed specifically for use in the F-1 rocket engines, with an increased concentration of refractory (Mo, Nb) elemental additions. The analytical results helped conservators determine a suitable treatment protocol for more than 400 blades and 100 fragments from four recovered turbines. [ABSTRACT FROM AUTHOR]

The use of surge tanks in hydroelectric projectss is very important to prevent pipes from breaking. Hydroelectric dam construction is very costly, and therefore it is important to protect them against shock waves caused by disconnecting and connecting the flow control valves leading to the turbines. In this study, the rigid column theory and its governing equations are introduced, and then they are solved by the finite difference numerical method. The MS Excel software is used for ease of work, and pressure and velocity fluctuation graphs are provided in the surge tank. Results show that rigid column theory can be implemented easily to find water head and velocity fluctuations in the surge tank. The amplitude of water head fluctuations decreased with the increase in shaft diameter, indicating the positive effect of larger diameter. A 50% increase in the diameter of the vertical shaft does not appreciably change the velocity fluctuations. With increasing friction factor (f), the frequency of the head and velocity decreases. Meanwhile, for increasing f = 0.011 to f = 0.022, the amplitude of the head and velocity is diminished. [ABSTRACT FROM AUTHOR]

Turbine generators play a pivotal role in efficiently converting gas internal energy into electrical energy, finding extensive applications in diverse green energy and power equipment. The adoption of a high-speed direct-drive structure eliminates mechanical losses associated with the reducer between the turbine and generator, enhancing system efficiency and compactness. However, this configuration introduces challenges in design and manufacturing. This article explores the various application scenarios of high-speed direct-drive power generation systems, examining their roles in organic Rankine cycle power generation, gas turbine power generation, supercritical CO2 power generation, vehicle exhaust turbine power generation, and natural gas pressure reduction power generation. Considering the high-speed, high-pressure, high-temperature, and high-efficiency challenges in turbine power generation systems, the key technologies are reviewed including high-speed bearings, rotor dynamics, high-speed motors, high-frequency variable frequency technology, sealing technology, axial force adjustment, thermal management, turbine aerodynamic design, and system control strategies. The article further delves into the current research and development status of high-speed direct-drive power generation systems across different application scenarios. Finally, the article presents prospects for the future development of efficient, reliable and widely adaptable high-speed direct-drive generators, offering valuable insights for researchers and practitioners in the field. [ABSTRACT FROM AUTHOR]

This article deals with the possibility of using 3D-printed models as an input for the production of a mould for cast iron castings. This new progressive process is significantly faster (with sufficient accuracy) compared to the current way of making models for moulds. The need to create a wooden model is removed by this process. The quality of this wooden model was highly dependent on the experience and qualifications of the worker. This article describes the manufacturing process of the model and mould in detail. The key dimensions of the final parts are compared with the model and, thus, the accuracy of the chosen procedure is verified. A 3D-printing technology known as Multi Jet Fusion (MJF) was used to produce the model. The material used for the production of the model is polyamide PA12 with 40% glass fibre filling. This material has sufficient structural and strength properties to be used for the given application. Taking into account the dimensions of the part and the printing space of the printer, it was necessary to structurally modify and divide the part. The inlet cone of a turbine is used as an example This cone is produced from grey cast iron as standard. [ABSTRACT FROM AUTHOR]

The highly loaded design method of helium compressors can effectively solve the difficulty in compressing helium in High Temperature Gas-cooled Reactors (HTGR). But it also causes obviously different attack angle characteristics of blade surface loads in a highly loaded helium compressor compared to air compressors. This difference inevitably affects separation characteristics and flow loss within the compressor. In the current study, the effects of highly loaded design methods and changes in attack angle on the separation characteristics of the compressor cascade are analyzed by applying a numerical simulation method first. Then, the influence of Mach number on the loss characteristics of the cascade for a highly loaded helium compressor is systematically analyzed. Finally, the effect of differences in the material properties of working fluid on the separation characteristics is discussed. The results indicate that the proportion of secondary flow loss to the total loss in highly loaded compressor cascades is 2.46 times larger than that in conventionally loaded ones. While the properties of working fluid have an effect on the performance of the compressor cascade, their effects on the weight factor of vortex loss are highly limited. [ABSTRACT FROM AUTHOR]

Hydroelectricity was born in the last decades of the nineteenth century, benefiting from the pre-existing achievements of hydraulic technologies, and taking advantage of new developments in electric generators. It has experienced a very rapid development under the pressure of growing industrial energy demand, and needs related to the development of cities. Some regions such as the Alps or the Great Lakes basin in North America have experienced rapid development since the last decade of the nineteenth century. For a long time, city–hydroelectric plant couples allowed the development of local electricity systems, until the development of interconnected networks made it possible to efficiently share the hydroelectric resource, and to guarantee its security of supply. Gradually, large rivers became the object of chain development of low-chute plants, while the middle course of these rivers were the site for large and very large dams. Many environmental, political and human problems must be taken into account in the analysis of the past and future development of hydroelectricity, which is the most abundant source of renewable electrical energy.

In order to more accurately analyze the influence of the interaction between the aero-engine combustion chamber and the turbine, this paper establishes a combustion chamber-turbine cross-component model based on a high-pressure first-stage guide vane thermal shock test device for numerical research. The SST k-ω turbulence model, non-premixed combustion model and P1 radiation model are selected, and the test conditions are used as boundary conditions to carry out fluid-solid coupling unsteady calculation in ANSYS FLUENT. The numerical results are in good agreement with the experimental results. The complex flow field information between the combustion chamber and the turbine is obtained by analyzing the numerical results. It is found that there is an interaction between the combustion chamber and the turbine. The results show that the hot spot at the outlet of the combustion chamber will cause a stronger thermal shock to the downstream of the high-pressure first-stage guide vane during the migration process. The influence of the high-pressure first-stage guide vane on its upstream can be traced back to the position 0.3 times the chord length from the outlet of the combustion chamber.

This paper presents the leakage characteristics of stepped labyrinth seals, considering the impact of rotation in the circumferential direction. Two types of casing, honeycomb and solid lands, were applied to the labyrinth seal, and a numerical study was performed with a wide operating range of the rotational speed, pressure ratio and clearance. The effect of the rotational speed on the sealing performance was analyzed for each clearance size through a parametric study. Regardless of the casing type, the flow function decreased as the rotational speed increased, and the smaller the clearance was, the more the leakage performance was affected by the rotation effect. In particular, it was confirmed that the honeycomb seal had a stronger tendency to decrease the flow function due to the rotation than the solid seal. The honeycomb seal allowed a larger leakage flow in comparison to the solid seal, and the rotational speed played an important role when the clearance was small or moderate. However, when the clearance became large, the leakage flow of the two seal types became almost the same, and the rotational effect became marginal. [ABSTRACT FROM AUTHOR]

Traditional exhaust-gas turbocharging exhibits hysteresis under variable working conditions. To achieve rapid-intake supercharging, this study investigates the synergistic coupling process between the detonation and diesel cycles using gasoline as fuel. A numerical simulation model is constructed to analyze the detonation characteristics of a pulse-detonation combustor (PDC), followed by experimental verification. The comprehensive process of the flame's deflagration-to-detonation transition (DDT) and the formation of the detonation wave are discussed in detail. The airflow velocity, DDT time, and peak pressure of detonation tubes with five different blockage ratios (BR) are analyzed, with the results imported into a one-dimensional GT-POWER engine model. The results indicate that the generation of detonation waves is influenced by flame and compression wave interactions. Increasing the airflow does not shorten the DDT time, whereas increasing the BR causes the DDT time to decrease and then increase. Large BRs affect the initiation speed of detonation in the tube, while small BRs impact the DDT distance and peak pressure. Upon connection to the PDC, the transient response rate of the engine is slightly improved. These results can provide useful guidance for improving the transient response characteristics of engines. [ABSTRACT FROM AUTHOR]

At present, hydraulic transmission loaders have high automatic adaptability and convenient operation, but their transmission efficiency is low, and the intelligent degree of energy consumption regulation is limited. Strengthening the research of locking device in torque converter is an important measure to effectively reduce energy consumption. Therefore, the research uses MATLAB software and torque converter parameters to build the external characteristic curves of the engine and torque converter, and builds the dynamic model based on the working principle and locking process of the lockup clutch. The research and experimental analysis are carried out from three aspects of the lockup dynamic process of the torque converter, the lock‐up and unlocking conditions, and the change of the lockup oil pressure of the clutch. The results show that the speed difference range between pump wheel and turbine (233.08–365.44 rpm) is much lower than that of other cases (409.68–616.23 rpm) when the engine and torque converter are matched. And the fuel rate is the highest when the throttle opening of the loader is 70%, about 38%. The above results show that the locking structure of the hydraulic torque converter of the loader can effectively reduce the working vibration and improve the service life and fuel rate. And its energy‐saving application effect has an important enlightening effect on the performance optimization and resource utilization of construction machinery, and provides new ideas for improvement. [ABSTRACT FROM AUTHOR]

A coaxial counter-rotating rotor (CCRR), which has two rotors rotating in the opposite directions on the same axis, is seen as a promising technology for low-cost floating tidal current/ocean current power generation using single-point mooring, as the torques of the front and rear rotors are cancelled. In the evaluation and design of such turbines, there is a need for an accurate analysis method with a low computational load that considers the strong mutual induction between the two rotors placed close together. An individual rotor mutual induction (IRMI) method was developed in this study, aiming to significantly reduce the calculation time of conventional computational fluid dynamics (CFD), considering the mutual induction that are not considered in conventional modified blade element and momentum methods. In this method, the basic characteristics of the front and rear rotors are calculated in advance using full-model CFD. In calculations for the CCRR, in addition to these individual characteristics of each rotor, the interaction between the rotors is considered using the actuator disk model CFD calculated in advance. The condition where the torques of the front and rear rotors are cancelled is determined at the same time. This method was used to analyze models in which the front and rear rotors were approximately the same diameter and placed close together (10% of the rotor diameter). A comparison with the mixing plane model CFD revealed that they agree quite well when mutual induction is considered, although both the power and thrust are overcalculated when it is ignored. The simulation time of the IRMI would be almost counter-proportional to the numbers of TSR conditions to solve as compared with the CFD with the MP model. [ABSTRACT FROM AUTHOR]

In this research, the computational fluid dynamics (CFD) approaches using ANSYS Fluent solver was employed to evaluate new designs of the delta-shaped bladed Darrieus hydrokinetic turbines (DHKT) employing NACA0012 hydrofoils. The 2-bladed models with four different designs (MD1-MD4) of varying blade characteristics and cross-sectional areas were simulated. The models were positioned fully submerged inside a water flow domain and were forced to rotate with different rotational speeds by utilizing the sliding mesh technique under a constant upstream velocity of 1.5 m/s. The results using a Shear Stress Transport (SST) k-ω turbulence model were compared with previous studies. The optimum model designs were shown to be the models with twisted blades and reduced and constant cross-sectional areas (MD3 and MD4). The 3-bladed models with similar blade characteristics (MD7 and MD8) were continuously tested and compared with the 2-bladed models. The 2-bladed models performed better during the higher range of tip speed ratio (λ), whereas 3-bladed models were outstanding at the lower range. Based on the work using CFD approaches in this paper, the MD4 model was shown to be the most appropriate design to operate under the specified conditions. [ABSTRACT FROM AUTHOR]

Flow inside the axial test turbine VT-400 is measured by using a standard methodology of Particle Image Velocimetry (PIV). The studied area lies between the stator and rotor wheel in meridional plane. This area covers both: the regular flow near hub and the endwall secondary structures as well. Regular structure of wakes and jets past stator blades is observed in terms of mean velocities and turbulence intensity. The fluctuations are close to isotropy and the energy distribution across length-scales exhibits almost Kolmogorov scaling. Near the hub, we observe secondary vortices. Despite the positive radial ejections in that regions, these secondary vortices drift towards the hub, they dissipate energy and circulation and their core grows in size. [Display omitted] • Particle Image Velocimetry measurement in Stereo configuration inside test axial turbine. • Meridional (i.e. axial × radial) plane past the stator wheel endwall at underloaded, nominal and overloaded regime. • Observation of wakes and jets; wake/jet amplitude do not follow velocity magnitude; periodicity corresponds to geometry of stator wheel. • Fluctuations in region of wakes and jets up to 10%; spatial spectra follows Kolmogorov law with depletion at the wake periodicity. • Secondary flow contain radial ejections and secondary vortices of single orientation; these vortices drift towards the hub. [ABSTRACT FROM AUTHOR]

A comparative experimental study of the structure and properties of 25Kh1M1FA steel rotor metal from a PT-60-90 turbine is conducted after operation for approximately 400 thousand hours and appearance of a crack in the axial channel, and from a PT-60-130 turbine after additional thermal aging equivalent 600 thousand hours at a live steam temperature of 555°C. Despite the absence of obvious signs of recrystallization within the metal microstructure, after ageing there is a significant, up to ~1.5 times, decrease in metal hardness and other short-term strength mechanical properties. Weakening is not related to the diameter and distance between relatively large (over 1 μm) particles. A negative effect of decreasing molybdenum content in solid solution on strength is demonstrated. Stress-rupture strength for 100 thousand hours at 525°C decreases by a factor of 1.4, due to which the value of the guaranteed service life of a PT-60-130 turbine rotor after ageing at 650°C decreases from 1.7 × 105 to 1 × 105 h. Brittle failure resistance increases, i.e., the metal critical brittleness temperature decreases from 56 to 42°C. It is found that appearance of a crack in an axial channel is not necessarily accompanied by a large degree of bainitic component spheroidization (more than 3 points). A reduction in PT-60-90 turbine rotor metal hardness to a lower permissible level of 180 HB occurs after about 50 thousand hours, which indicates that the PT-60-90 turbine may be operated up to 450 thousand hours. [ABSTRACT FROM AUTHOR]

The supercritical CO2 (sCO2) power cycle could improve efficiencies for a wide range of thermal power plants. The sCO2 turbine generator plays an important role in the sCO2 power cycle by directly converting thermal energy into mechanical work and electric power. The operation of the generator encounters challenges, including high temperature, high pressure, high rotational speed, and other engineering problems, such as leakage. Experimental studies of sCO2 turbines are insufficient because of the significant difficulties in turbine manufacturing and system construction. Unlike most experimental investigations that primarily focus on 100 kW‐ or MW‐scale power generation systems, we consider, for the first time, a small‐scale power generator using sCO2. A partial admission axial turbine was designed and manufactured with a rated rotational speed of 40,000 rpm, and a CO2 transcritical power cycle test loop was constructed to validate the performance of our manufactured generator. A resistant gas was proposed in the constructed turbine expander to solve the leakage issue. Both dynamic and steady performances were investigated. The results indicated that a peak electric power of 11.55 kW was achieved at 29,369 rpm. The maximum total efficiency of the turbo‐generator was 58.98%, which was affected by both the turbine rotational speed and pressure ratio, according to the proposed performance map. [ABSTRACT FROM AUTHOR]

In the current study, three airfoils--PSU94-097, SD6060, and S2055--were analyzed for their aerodynamic performance across Reynolds numbers (Re) ranging from 50,000 to 500,000, typical for Small Wind Turbine (SWT) blade airfoils. Results indicated that as Re increased, the aerodynamic efficiency of all modified airfoils improved. Optimal thickness-to-camber ratios (t/c) of 1.50-2.25, 2.25-3, and 0.60-1.50 for SD6060, S2055, and PSU94-097 airfoils, respectively, contributed to enhanced efficiency. PSU94-097-modified airfoil demonstrated the highest lift-todrag ratio (CL/CD) of 151.60 at Re of 500,000. Peak CL/CD values for SD6060-modified and S2055-modified airfoils were 109.87 and 97.13, respectively. PSU94-097-modified, SD6060-modified, and S2055-modified airfoils attained peak lift coefficients (CL) of 1.534, 1.219, and 1.174, respectively. PSU94-097-modified airfoil also showed the highest peak CL across Re ranging from 50,000 to 500,000. Percentage increase in peak CL/CD across Re range of 50,000 to 500,000 was 15.8%, 16.08%, 24.43%, 17.12%, 17.30%, 17.98%, and 20.22% for PSU94-097-modified airfoil; 27.87%, 2.03%, 13.77%, 15.83%, 15.14%, 17.95%, and 17.73% for SD6060-modified airfoil; and 16.70%, 7.11%, 5.77%, 7.25%, 11.40%, 9.99%, and 6.04% for S2055-modified airfoil. In addition to enhancing the aerodynamic efficiency of airfoils and consequently increasing electricity production in wind turbines, optimizing the t/c reduces the material needed for wind turbine construction. This not only lowers the cost but also minimizes environmental impact by using fewer resources. Thus, these modifications are environmentally beneficial, contributing to sustainable development alongside improving wind turbine efficiency. [ABSTRACT FROM AUTHOR]

The good operation of the automation systems with which the small hydropower plants are equipped has an important contribution to the optimal operation of these small hydropower plants. Outdated, inefficient automation must be replaced with modern, computer-based control in order to obtain the best possible efficiency. Such a modernized automatic control system was implemented at the small hydropower plant Leşu. The automatic control and command system fully ensures monitoring and automatic commands for the efficient and safe operation of the hydropower plant, including in failure conditions. The supervision and control of the plant's operations is done centrally, from the hydropower plant's control room through the automation system. [ABSTRACT FROM AUTHOR]

The transportation industry consumes most of the fossil fuel and releases enormous amount of Co2 which leads to global warming. Hence there is always a need for generating green energy for replacing fossil fuel-based transportation. The recent booming of electrical vehicle is considered as alternative but still they are using the power for charging synthesized by burning fossil fuels. If the wind energy of a moving car is used to generate electrical power, then the charging frequency can be reduced and there by indirectly reduce the consumption of fossil fuel. Moreover, the main disadvantage of electric car is frequent charging. If a system to generate power by using wind energy in moving car, it could supplement the power requirement. Hence, we have designed a prototype spoiler integrated with inbuilt turbine and motor to supplement the power requirement by utilizing wind energy of a moving electric car.

The rapid penetration of intermittent renewable power puts pressure on the stability and reliability of power grids. To address this tissue, coal-fired power plants play an increasingly important role in providing the peak shaving service. Moreover, the high-level layout of turbine can significantly reduce the amount of high temperature resistant materials and thus improve the economics of ultra-supercritical coal-fired power plants. The exergy and exergy economic models were developed to obtain the performance of ultra-supercritical coal-fired power plants with high-level layout of turbine under load-cycling operation conditions. By analyzing the exergy economic of coal-fired power plants under different loads, and the distribution of irreversibilities was obtained. The results show that the exergy efficiency of the high pressure turbine can be improved by optimizing the parameters. Moreover, the cost of electricity per unit with the high-level layout is 0.332 4 yuan/(kW⋅h). The exergy price of electricity generation decreases with the increase of load.

In the realm of gas turbine engine technology, turbine blades are persistently subjected to extreme thermal conditions due to prolonged exposure to high-temperature gases. Given this operating environment, devising effective cooling strategies is paramount for ensuring the turbine’s safety and longevity. Despite the critical nature of this issue, existing literature scarcely addresses cooling channels that incorporate factors like variable cross-sectional attributes and rotational effects. In this study, Computational Fluid Dynamics (CFD) and numerical methodologies were employed to analyze the flow mechanism and performance of three distinct cooling channels characterized by variable cross-sectional features. The results indicate a marginal thermal performance improvement of up to 3% for U-shaped cooling channels, specifically at a Reynolds number of 20,000, in comparison to Net cooling channels. Conversely, jet impingement channels outperform U-shaped channels by an impressive margin of over 11%. Additionally, at a Reynolds number of 60,000, jet impingement cooling channels manifest a significant upsurge of nearly 25% in the ratio between average Nusselt number, and the reference Nusselt number when compared with U-shaped and Net cooling channels.

The energy sector faces a pressing need for significant transformation to curb CO2 emissions. For instance, Czechia and Germany have taken steps to phase out fossil thermal power plants by 2038, opting instead for a greater reliance on variable renewable energy sources like wind and solar power. Nonetheless, thermal power plants will still have roles, too. While the conventional multistage axial turbine design has been predominant in large-scale power plants for the past century, it is unsuitable for small-scale decentralized projects due to complexity and cost. To address this, the study investigates less common turbine types, which were discarded as they demonstrated lower efficiency. One design is the Elektra turbine, characterized by its velocity compounded radial re-entry configuration. The Elektra turbine combines the advantages of volumetric expanders (the low rotational speed requirement) with the advantages of a turbine (no rubbing seals, no lubrication in the working fluid, wear is almost completely avoided). Thus, the research goal of the authors is the implementation of a 10 kW-class ORC turbine driving a cost-effective off-the-shelf 3000 rpm generator. The paper introduces the concept of the Elektra turbine in comparison to other turbines and proposes this approach for an ORC working fluid. In the second part, the 1D design and 3D–CFD optimization of the 7 kW Elektra turbine working with Hexamethyldisiloxane (MM) is performed. Finally, CFD efficiency characteristics of various versions of the Elektra are presented and critically discussed regarding the originally defined design approach. The unsteady CFD calculation of the final Elektra version showed 46% total-to-static isentropic efficiency. [ABSTRACT FROM AUTHOR]

The global energy consumption has surged from the minimal requirements of primitive societies to today's extensive needs, which are being met primarily by fossil fuels. However, the environmental impact of these fuels, emitting greenhouse gases and contributing to global warming, prompts a reevaluation. Renewable energy is becoming an essential alternative energy source, and wind energy is one of the viable options. This study investigates the viability of wind energy in Northern Nigeria as a safer alternative to fossil fuel-based energy generation. Comprehensive wind data of two decades was obtained for six stations across three geographical zones in Northern Nigeria, detailing hourly readings at 10-meter and 80-meter heights. The study determined monthly and yearly wind speeds, as well as wind power density (WPD) at 10 meters per station. Results unveiled the regional distribution of mean wind speed, ranging from the highest in Jos (9.9 m/s) to the lowest in Yola (1.86 m/s). Employing diverse wind turbine models, including Acciona 70/1500 class I, GE 1.6-100, and Samsung 2.5/90, the study evaluated the Annual Energy Output and Net Capacity Factor. Notably, Jos exhibited the highest WPD (1402 W/m²), contrasting with Yola's lowest (15.9 W/m²) at 80 meters. The findings indicate that Sokoto, Kano and Jos possess enough potential capable of generating electricity for integration into the national grid, while the remaining stations hold sufficient wind energy potential suitable for powering irrigation devices and other agricultural activities. It is recommended that the areas with high potential for wind energy should be harnessed into the national grid by the Government by providing funds to actualise this project on a large scale for the nation. [ABSTRACT FROM AUTHOR]

Copyright of Adab Al-Kufa is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, numerical simulation methods are adopted to explore the influencing factors of a Ceramic Catalytic Turbine (CCT) for reduced exhaust pollution from vehicles during the warm-up stage. Also, an analysis is conducted regarding the potential effects of turbulence on the catalytic reaction mechanism and the sensitivity of relevant parameters to the Arrhenius equation. It is found out that the air-fuel ratio inside the engine has a considerable effect on the reactions of CCT, with the conversion efficiency of each emission species sharply reduced under fuel-rich conditions. At 600K, the conversion efficiency declines by 11.3% for C3H6, 12.26% for CO, and 3.64% for NO. At 700K, the conversion efficiency is reduced by 6.7% for C3H6, 11.56% for CO, and 6.44% for NO. Despite increasing the concentration of reaction gas components, a high flow rate makes little difference to the reaction itself. At the same rotational speed of the turbine, the conversion rate of harmful components drops with an increase in flow rate due to the increase in space velocity. When the flow rate is constant and the temperature is kept in the control zone of chemical kinetics, the conversion efficiency of the catalytic reaction is enhanced at a higher rotational speed. Differently, when the temperature is in the control zone of mass transport and the flow rate is constant, the conversion efficiency decreases as the turbine accelerates. In practical terms, reducing activation energy within a controllable range is equivalent to further reducing the light-off temperature of the catalyst. Meanwhile, this may disrupt the convergence of numerical calculations because the catalytic reactions could occur at around the light-off temperature. [ABSTRACT FROM AUTHOR]

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The substantial portion areas are customarily habituated across the world is electricity. In need of electricity generation, no equipment, instruments, motor, or any machinery is functioning. The paper portrays consequently footsteps energy carries on exploited and it draws upon non-conventional sources of energy resources. There are many types of electricity generation i.e., solar power, wind conversion system, thermal, hydro-electricity, nuclear energy. Renewable energy and Non-Renewable Energy Sources are inherent notions in the Electricity generation system. The Walking Footsteps are and untapped natural resources. While employing the Walking Footsteps energy its more concise amount of cost means that it’s modest and innocuous for human. The metamorphosis technology is intermingled that electrical energy can proselytize to mechanical energy using footsteps walking of human beings. The consequent equipment’s efficacious used for procedure of footsteps is as supervening like pipe arrangement, nozzle type, unidirectional valve, water reservoir, turbine motor of any type, and DC motor. The occupied conformance is accomplished be pertinent pressure which is strive on the water reservoir; water flows amidst the direction of nozzle into the turbine and generates electrical energy. This type of electrical energy is kept stored in the energy battery storage. There is very much load disturbance in the consumers terminal so that there will be causing global warming and load shedding. This paper defines having advantages of the global warming and load shedding in best way of cleaner the cost-effective way. [ABSTRACT FROM AUTHOR]

Among the most efficient sources of renewable energy and a potential significant source of electricity is wind energy. Wind energy is perfect for dependable energy systems since it can produce electricity at any time of day. Wind power is a dependable source that may produce renewable energy sources continuously and sustainably. However, there are several drawbacks to wind energy, including as the high initial building costs, the requirement for immovable property, and the challenge of locating ideal locations. In reading, a machine learning (ML)-based scheme is used to forecast the output of wind energy. We suggested a technique for precisely predicting WPs using machine learning techniques. The major goals of this inquiry are to forecast wind production and collect data on daily wind speed control. Only the daily mean wind velocity values were analysed to see if the wind energy estimates provided by the wind speed data were sufficient. The results demonstrated that machine learning techniques could anticipate long-term wind energy values using previous wind data. The results also demonstrate that the machine is designed to find spots that diverge from previously learnt sites so that they can be added to models [ABSTRACT FROM AUTHOR]

This research work aimed at optimizing tuning parameters for the regulation of speed and power of Francis turbine. Here prototype calculations are used to model the Francis turbine. Here PID controllers are used to optimize the parameters of torque, power and time. Block diagram with control functions of turbine, actuator, generator and PID controller are employed here. Response of tuning of parameters of power and time are noted here for optimal models. Finally slow runner Francis turbine has selected for running with optimal speed and power. [ABSTRACT FROM AUTHOR]

This work presents mathematical modelling of moist air condensation process in a fuel cell turbine. A condensation model based on the classical nucleation theory and the Hertz–Knudsen droplet growth model is established. The numerical approach is validated through experimental results of the MS nozzle and a fuel cell turbine, and the simulation fits the experimental data well. Influences of inlet temperature and pressure on condensation process in the turbine is examined. Results show that increase of inlet temperature apparently weakens condensation and inlet heating can be realized by arranging a gas-to-gas heat exchanger in the air supply subsystem without consuming additional energy. Moreover, at the same mass flow rate increase of inlet pressure reduces the expansion ratio, thereby curbing the condensation. Compared with the matching scheme of a bypass valve, turbocharger matching with a back-pressure valve allows higher inlet pressure to be achieved and can effectively suppress the condensation. • An electric turbocharger for 100 kW PEMFC system is designed, manufactured and evaluated. • A numerical model on condensation occurring in turbine is established. • Inflow heating is beneficial to suppressing the condensation. • Adding back-pressure valves to the turbine can help diminish the condensation. [ABSTRACT FROM AUTHOR]

Harnessing energy from descending greywater (GW) in tall buildings (TBs) is an innovative concept that combines water management with renewable energy generation and applying simulation methods. This study proposes a novel approach to enhancing sustainable energy recovery in TBs by capitalizing on the kinetic energy inherent in descending GW. Greywater, derived from non-toilet fixtures such as showers, bathroom sinks, and washing machines, offers a readily accessible source of potential energy due to its gravity-driven flow through the plumbing system. This gravitational potential energy could feasibly be converted into useable electricity through the incorporation of specialized energy-recovery mechanisms, such as turbines, hydroelectric generators, and piezoelectric devices. The study addresses the technical, economic and environmental aspects of implementing this idea in TBs. It describes the challenges of system integration, maintenance requirements and adherence to regulatory standards, as well as the potential benefits in terms of water conservation and reduced reliance on conventional energy sources, through a comprehensive analysis encompassing modeling, experimental validation and feasibility assessments. The research offers insights into the potential viability of harnessing downward-flowing GW as an alternative and sustainable green energy resource.

Abstract The supercritical CO2 (sCO2) power cycle could improve efficiencies for a wide range of thermal power plants. The sCO2 turbine generator plays an important role in the sCO2 power cycle by directly converting thermal energy into mechanical work and electric power. The operation of the generator encounters challenges, including high temperature, high pressure, high rotational speed, and other engineering problems, such as leakage. Experimental studies of sCO2 turbines are insufficient because of the significant difficulties in turbine manufacturing and system construction. Unlike most experimental investigations that primarily focus on 100 kW‐ or MW‐scale power generation systems, we consider, for the first time, a small‐scale power generator using sCO2. A partial admission axial turbine was designed and manufactured with a rated rotational speed of 40,000 rpm, and a CO2 transcritical power cycle test loop was constructed to validate the performance of our manufactured generator. A resistant gas was proposed in the constructed turbine expander to solve the leakage issue. Both dynamic and steady performances were investigated. The results indicated that a peak electric power of 11.55 kW was achieved at 29,369 rpm. The maximum total efficiency of the turbo‐generator was 58.98%, which was affected by both the turbine rotational speed and pressure ratio, according to the proposed performance map.