Water Turbine Research Articles

An efficient CNN-transformer hybrid approach for water turbine unit failure prediction

Water Turbine Unit is the core equipment of water power generation. It is the most important research object in hydroelectric power. The analysis of daily monitoring data of Water Turbines can evaluate its running state and avoid the loss caused by failure. In this paper, A hybrid neural network architecture which CNN combines Transformer is proposed to evaluate the health state of water turbines based on multivariate long time series data. It has two core components: (i) dilated convolution applies to capture low-level and local semantic information, then the output of convolutional layers is divided into subseries-level patches by time, these patches are regarded as input tokens of Transformer layers; (ii) utilizing self-attention of Transformer to extract high-level and global semantic information. Patching design naturally has benefit as follow: (i) local semantic information is retained in Transformer input tokens and high-level semantic confirm to common sense of human understanding through low-level construction; (ii) the length of Transformer input sequence is greatly shorted and attention can be more concentrated compared with point-wise form. Meanwhile, the computation and memory usage reduces at the same time. The experimental result indicates that the hybrid architecture can achieves excellent performance in time series understanding.

Effect of blade materials on the undershot water turbine performance

Undershot waterwheel at low flow with an average discharge of 0.12 m3/s and 613.2 W water horsepower are used to turn the waterwheel. The rotation results obtained with aluminum material is 24 RPM which has a density of 2.71 g/cm3 while the lowest rotation is owned by a galvanic of 20 RPM with a density of 7.49 g/cm3. From the experiment, it was found that the difference between the materials used was due to the different density. The efficiency of waterwheels with aluminum material has the highest value, namely 30%, while the lowest using acrylic material has an efficiency of 23%. For the highest generator efficiency using aluminum material with an efficiency of 4.2%, the second has an efficiency of 3.6% using Aluminum Composite Panel material. Aluminum has the highest efficiency because it has less density than galvanized. In addition, the thickness of aluminum is also very influential, where aluminum has a thickness of 1.14 mm while Galvanized has 0.98 mm.

Modelling and Simulation of 100 kW Pumped Storage Hydro Power System

Renewable energy sources are an attractive alternative option for augmenting the supply that comes from the utility Grid. This is because they are environmentally friendly. However Photovoltaic power generation is intermittent in nature. Hence, it is usually combined with energy storage systems such as batteries. In this study, pumped hydroelectric energy storage is used for supplementing the power produced from the Solar Photovoltaic system especially during peak demands and when the solar irradiance is low especially at night. Thus, the objective of this study is to model and simulate a pumped energy storage hydro system that can provide power supply of up to approximately 100 kW for a 10 hour period to service the night time. The proposed system is modeled using MATLAB Simulink. A total volume of 91836.7 m3 of storage water was calculated to achieve this purpose. Maximum torque of about 90 N/m was attainable when the angular speed of the water turbine was between 1100 and 1200 rpm. Recommendation for further works can be considered to maintain the angular speed of the turbine within this range.

The Effects of Blade Height on the Efficiency of Gravitational Water Vortex Turbine

This paper presents the results of a study on the effect of blade height on the efficiency of a free-vortex water turbine. Laboratory experimentation was conducted to find the shaft power generation and the efficiency of the turbine. Water turbines with six blades and four different heights (208 mm, 248 mm, 288 mm, and 320 mm) were built and tested to determine the most appropriate blade height. The turbines were tested in a conical basin with inlet and outlet diameters of 600 mm and 100 mm and a height of 800 mm, at volume flow rates of 0.0088 m³/s, 0.0105 m³/s, and 0.0108 m³/s. The results showed that the turbine with a blade height of 288 mm was the most appropriate, yielding the highest efficiency of 30,46% at a water flow rate of 0.0108 m³/s.

EFFECTS OF BLADE HEIGHT ON THE EFFICIENCY OF GRAVITATIONAL WATER VORTEX TURBINE

This paper presents the results of a study on the effect of blade height on the efficiency of a free-vortex water turbine. Laboratory experimentation was conducted to determine the turbine's shaft power generation and efficiency. Water turbines with six blades and four different heights (208 mm, 248 mm, 288 mm, and 320 mm) were built and tested to determine the most appropriate blade height. The turbines were tested in a conical basin with inlet and outlet diameters of 600 mm and 100 mm and a height of 800 mm, at volume flow rates of 0.0088 m³/s, 0.0105 m³/s, and 0.0108 m³/s. The results showed that the turbine with a blade height of 288 mm was the most appropriate, yielding the highest efficiency of 30.46% at a water flow rate of 0.0108 m³/s.

Smart IoT Approach for Renewable Energy Monitoring System

Numerous factories, commercial establishments, and private residences require an uninterrupted power supply. The primary source of this supply is often the grid. Industries, businesses, and residential areas needing 24-hour power inevitably require backup systems to ensure continuous operation of essential electronic devices. Typically, diesel generators are employed as backup power sources, utilizing diesel oil to generate electrical energy. While this approach has been successfully employed for many years, it carries a significant drawback. Diesel oil falls under the category of non-renewable energy sources, unable to be regenerated and requiring an extensive period for renewal. Furthermore, diesel generators emit substantial amounts of carbon dioxide into the atmosphere, contributing to air pollution in the vicinity. To address these challenges, a prototype implementing a smart Internet of Things (IoT) approach has been developed. This study introduces the utilization of an Arduino Nano microcontroller, allowing users to control their power supply source, choosing between the grid, solar panels, or water generation. This control process is facilitated through a smartphone application, granting users the ability to manage it remotely, enhancing monitoring capabilities. The system incorporates two environmentally friendly power sources: solar panels and a mini water turbine, both considered safe for ecological balance. The outcomes of this research demonstrate that users can effectively utilize the generated electricity supply for approximately 12 hours, thereby reducing reliance on the grid and harnessing the potential of renewable energy sources.

POTENSI PLTMH DI BENDUNGAN SIDAN, DESA BELOK SIDAN, KABUPATEN BADUNG

The potential of new renewable energy is highly needed to support Clean Energy Bali, and one of the viable energy sources is Micro Hydro Power Plant (PLTMH). The design of the Sidan Dam PLTMH is based on the construction of the Sidan Dam area in Belok Sidan Village, Badung Regency. The planning of the Sidan Dam PLTMH only extends to the construction of the penstock. In this Capstone Project, the design of the Sidan Dam PLTMH utilizes water discharge and head height data from the Sidan Dam planning. This data is used to determine the design, type of water turbine, dimensions of the water turbine, and to determine the appropriate generator capacity. The calculation results indicate that the Sidan Dam PLTMH has a potential capacity of 290.83 kW with a Francis turbine type and a generator capacity of 472.59 Kva. It is estimated to generate an annual energy output of 1,783,396 kWh with a capacity factor 70%.

Experimental Study of Stagger Angle Effect on the Performance of Marine Savonius Vertical Axis Water Turbine

This paper investigates the performance of Savonius vertical axis water turbine by varying its stagger angles. In this study, the shape of the turbine blade is modified based on the Myring equation as well as adding a disturbance in the form of a circular cylinder placed in front of the advancing blade as a barrier. The method used in this research is an experimental study in a water tunnel at a velocity of 0.22 m/s. The turbine has size of 0.4 m in height and 0.4 m in diameter. The experiment results show that the use of a circular cylinder in front of the advancing blade has a significant effect on increasing turbine performance. This can be proven by placing a circular cylinder with , , and where the angular speed achieved is , torque coefficient and the result of maximum power coefficient is about 0.4356.

Effect Analysis of Boiler Feed Water and Exhaust Gas Turbine Generator against Steam Products

Effect Analysis of Boiler Feed Water and Exhaust Gas Turbine Generator against Steam Products

Measurements and Modelling of the Discharge Cycle of a Grid-Connected Hydro-Pneumatic Energy Storage System

Hydro-pneumatic energy storage is a form of compressed-air energy storage that can provide the long-duration storage required for integrating intermittent renewable energies into electrical power grids. This paper presents results based on numerical modelling and laboratory tests for a kilowatt-scale HPES system tested at the University of Malta. This paper presents measurements of the discharge cycle, in which energy stored in compressed air within a pressure vessel is hydro-pneumatically converted back into electricity via a Pelton turbine and fed into the national electricity grid. The tests were conducted using a hydraulic turbine operated under different fixed-turbine rotational speed settings, with the pressure being allowed to decrease gradually during the HPES system’s discharge cycle. The system’s overall efficiency accounted for flow losses, turbine inefficiencies, and electrical losses. The tests showed that this efficiency was practically independent of the compressed-air pressure of specific water turbine runner speeds, despite the water turbine operating at fixed speeds. A numerical model developed in MATLAB Simulink (R2022a) was also presented for use simulating the hydraulic performance of the system during the discharge cycle. The model used secondary loss coefficients for the hydraulic circuit and derived velocity coefficients from computational fluid dynamics (CFD) for the Pelton turbine nozzle. We achieved very good agreement between the predictions based on numerical modelling and the measurements taken during laboratory testing.

Investigation of Cavitated Flow in Water-Lubricated Bearings Considering Surface Roughness, Thermal, and Elastic Effects

Contrary to conventional journal bearings, which operate using oil-based substances, water-lubricated bearings (WLBs) utilize water and, thus, constitute a more environmentally responsible solution. The shipping industry, among others, as already been introduced to this technology with a lot of commercial ships using water-lubricated stern tube systems; in other cases, hydropower plants manage to keep up with the strict environmental regulations by implementing the use of WLBs in water turbines. However, there are a lot of challenges when it comes to transitioning from conventional bearings to water-based ones. Such challenges are caused by the low viscosity of water and lead to phenomena of high complexity. Such phenomena are related but not limited to cavitation and turbulent flow due to the interaction between the lubricating water and bearing surface. In this study, a numerical method will be used to simulate the fluid film and bearing geometries in order to perform a thermo-elastohydrodynamic (TEHD) analysis. The dynamic characteristics of the bearing will be calculated and the results will be discussed. The novelty of the study is evident in but not limited to the determination of the elastic deformation of a WLB during operation, as well as the effect of surface roughness, cavitation, and thermal effects on bearing characteristics.

Analisis variasi pipa penstock terhadap kecepatan inlet turbin pada PLTMH Boonpring menggunakan CFD

The development of renewable energy is a necessity in order to reduce the consumption of fossil energy. One of the alternative technologies to obtain sustainable energy resources is to use a Micro Hydro Power Plant (PLTMH). In order to obtain high-efficiency power, it is necessary to analyze the maximum head and discharge values. In this study, an analysis of variations in the design of the penstock pipe from the forebay was carried out to obtain the highest velocity value for rotating the water turbine. The method used in this research is a simulation using ANSYS Fluent software. Based on the results obtained, the highest velocity values were obtained for penstock numbers 2 and 4. Pipe elevation causes the flow velocity to increase smoothly. The branching at the inlet does not affect the velocity value but increases the possibility of a vortex which is detrimental to the flow leading to the turbine.

Numerical Analysis of Three Vertical Axis Turbine Designs for Improved Water Energy Efficiency

A hydrokinetic turbine with a vertical axis is specifically designed to harvest the kinetic energy from moving water. In this study, three vertical axis water turbines, namely Gorlov, Darrieus, and Savonius turbines, were compared for their efficiency via numerical modeling for steady-state conditions via the ANSYS 2022 R2 Fluent model. The Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) was implemented with an SST k-ω turbulence model. The dynamic mesh technique, which allows modeling according to changes in angular velocity at each time step, was used to simulate flow around the turbines for six different velocities (from 0.5 to 3 m/s). The efficiency of the turbines was compared and the results were analyzed. The pressure, velocity, and turbulence kinetic energy distributions around the rotor were measured at different rotational angles and results indicated a wider operating range for the Darrieus and Gorlov turbines compared to the Savonius turbine. The highest power coefficient of 0.293 was achieved in the model featuring a Darrieus turbine, corresponding to a TSR value of 1.34, compared to 0.208 for the Gorlov and 0.257 for the Savonius turbine, at TSR values of 1.3 and 1.06, respectively. Numerical modeling results pointed to a significantly higher self-starting capacity for the Savonius turbine compared to the others.

Reverse engineering of pump as turbine for CFD analysis

Reverse engineering (RE) using 3D scanning is already a relatively technologically simple and cost-effective method. For water turbines, this is particularly true for RE of larger machines. With microturbines, there is a lot of pressure to minimise costs, even at the cost of reduced accuracy. Using an existing micro-PAT (Pump as Turbine) as an example, we showed the approach to assessing these microturbines, starting with scanning the entire internal flow profile of the turbine, reconstructing the surface into a 3D model, and numerically assessing it using CFD (Computational Fluid Dynamics). A different approach is necessary compared to standard large machines, whose dimensions allow troublefree scanning of the flow parts of the turbine. Using CFD, we assessed the reconstructed geometry of the PAT. Two significant findings were made: the importance of high-quality 3D scanning by combining several cheaper 3D scanners and the necessity for reliable in-situ measurements for a successful CFD validation. Our future focus involves optimising PAT runner geometry in turbine mode to enhance energy production at the site and, at the same time, eliminating existing cavitation.

Analysis of Chilled Water Turbine Inlet Air Cooling Model for Enhancement of Turbine Performance

Analysis of Chilled Water Turbine Inlet Air Cooling Model for Enhancement of Turbine Performance

Thermal-driven osmosis utilizing hollow fiber membranes: Sustainable dye water treatment and electricity extraction

Excessive discharges of chemical dyes have led to severe contamination of seawater, resulting in significant ecological damage. Thermo-osmotic energy conversion technology, which purifies wastewater and generates electricity under temperature gradients, has garnered considerable interest from researchers. However, the operational efficiency of thermo-osmotic energy conversion is inherently limited by the effective membrane area, and conventional systems typically employ flat membranes as separators, resulting in suboptimal performance for the same floorage. In this study, we introduce a novel system that combines thermo-osmotic energy conversion technology with hollow fiber membranes that possess a high effective membrane area, thereby achieving optimized performance. Driven by the temperature gradient, the water in the dye solution condenses outside the membrane and converted from vapor to liquid. The continuous accumulation of condensed water generates pressure and drives a water turbine for sustainable power generation. Our results demonstrate that at temperature gradient of 40 °C, the system can achieve the power output of 16.75 Wm−3 and the freshwater production rate of 70.29 kg m−3 h−1 under ideal conditions. This study presents a novel water-electricity co-production system based on low-grade waste heat recovery for dye solution treatment, which extends the applicability of thermo-osmotic energy conversion technology and improves its practicality.

Optimal blade design of a spherical water turbine

The use of in-pipe water turbines for small-scale energy harvesting from pipe networks is starting to gain popularity. However, limited research have looked into whether adding helical blade turbines would be feasible with a spherical lift base in a water supply network. Three Naca airfoil (0012, 2412, 4412) were used to study the ratio of lift to drag force for each wing, Benefit from Qblade and ANSYS CFX software, and choosing the wing that has the highest ratio. The study investigates the feasibility of improving the design of spherical turbine blades by increasing the ratio of lift to drag. The results show that the Naca airfoil 4412 had the highest lift-to-drag force ratio, which was equal to 19.95. Through the improvement process for the Naca 4412 airfoil, the increase was made by 13.34 %, and the lift-to-drag ratio became 22.61. The study also dealt with the design of a turbine through the improved airfoil. 230 mm. It has the engineering characteristics of the number of helical blades, 5, The measurement of the blade's length chord 15 % of the turbine diameter, and the Angle of Attack, 9.5°

Effect of the Turbulence Model on the Computational Results of a Lucid Spherical Rotor

Due to the excessive increase in the energy demand, renewable energy has become an alternative for electricity production for industrial and domestic needs. Water energy has received significant investment as a sustainable and clean energy source. Lucid spherical rotors, a kind of hydro-power converter, are cross flow rotors designed to be mounted within a pipeline in order to gather excess energy available in gravity-fed water pipelines. This paper focuses on the effect of the numerical model parameters choice, namely the turbulence model, on the Lucid spherical rotor hydrodynamic characteristics. Numerical simulations were carried out through Ansys Fluent software 17.0 using the unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. Four turbulence models: RNG k-ε, Realizable k-ε, SST k-ω and transition SST were tested. Performance characteristics in terms of torque and power coefficients in addition to hydrodynamic features of the flow around the considered rotor were analyzed. The adopted numerical model was validated based on previous experimental findings from the literature. It was found that the realizable k-ε model showed a good agreement with experimental results. Thus, it was adopted for the Lucid spherical rotor simulation. The obtained findings could provide further direction for researchers to use the Lucid spherical water turbine.

Study on the optimum design of cross flow water turbines using RSM with weighted least squares method

In this study, an optimum design method using the response surface method (RSM) was applied to a cross-flow water turbine in which a circular cavity was installed. The efficiency obtained by CFD analysis was used as the objective function. A quadratic equation for the shape parameters obtained using the weighted least-squares method was used to the response surface. For optimal nozzle design, three shape parameters were used: the runner opening angle, nozzle wall exit angle, and radius of curvature of the nozzle wall. In the weighted least-squares method, the weights of the residual between the efficiency obtained from CFD analysis and the value from the response surface were defined as inversely proportional to the root mean square of the difference between the efficiency of the calculation point from CFD and that at the highest efficiency point, such that more accurate optimal values could be estimated. The shape derived using this optimum method achieved high efficiency.

The Effect Of Pitch Ratio On Screw Turbine Performance With Tip Fin

A water turbine is an energy conversion machine that converts water head into shaft movement. In screw-type turbines, performance is influenced by several parameters including outer diameter, inner diameter, rotor length, head angle, number of blades, and pitch distance. This research uses a screw turbine type with a tip fin. The research aims to determine the performance of screw turbines with tip fins on mechanical power and efficiency. The research independent variables consist of pitch ratio and flow rate. The pitch ratio variations used are 1.2; 1.4 and 1.6 while the variations in flow rate used are 3 l/s, 3.5 l/s, and 4 l/s. The method used in this research is experimental. This study's data analysis employed the two-way Anova method with an alpha (α) of 5%. Anova's results show that the P-value of the interaction of the two independent variables, pitch ratio and water discharge, is <0.05, meaning that the independent variables have a significant influence on the performance of the screw turbine. The highest turbine performance results were at a pitch ratio of 1.4 at a water flow rate of 4 l/s resulting in an efficiency value of 34.91% and a mechanical power value of 6.82 watts at a rotational speed of 125 RPM. The lowest turbine performance results at a pitch ratio of 1.2 with a flow rate of 3 l/s resulting in an efficiency of 22.64% and a mechanical power of 3.32 watts at a rotational speed of 56 RPM.