Experimental and Numerical Simulations Predictions Comparison of Power and Efficiency in Hydraulic Turbine

On-site power and mass flow rate measurements were conducted in a hydroelectric power plant (Mexico). Mass flow rate was obtained using Gibson's water hammer-based method. A numerical counterpart was carried out by using the commercial CFD software, and flow simulations were performed to principal components of a hydraulic turbine: runner and draft tube. Inlet boundary conditions for the runner were obtained from a previous simulation conducted in the spiral case. The computed results at the runner's outlet were used to conduct the subsequent draft tube simulation. The numerical results from the runner's flow simulation provided data to compute the torque and the turbine's power. Power-versus-efficiency curves were built, and very good agreement was found between experimental and numerical data.

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Predictions of Flow Separation at the Valve-Seat for Steady-State Port-Flow Simulation

Volume 2: Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development; Keynote Papers ◽

10.1115/icef2014-5667 ◽

2014 ◽

Cited By ~ 1

Author(s):

Tao Fang ◽

Satbir Singh

Keyword(s):

Steady State ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Flow Separation ◽

Combustion Engine ◽

Flow Simulation ◽

Valve Lift ◽

Valve Seat ◽

Mesh Density

Steady-state port-flow simulations with static valve lift are often utilized to optimize the performance of intake system of an internal combustion engine. Generally, increase in valve lift results in higher mass flow rate through the valve. But in certain cases, mass flow rate can actually decrease with increased valve lift, caused by separation of turbulent flow at the valve-seat. Prediction of this phenomenon using computational fluid dynamics (CFD) models is not trivial. It is found that the computational mesh significantly influences the simulation results. A series of steady-state port flow simulation are carried out using a commercial CFD code. Several mesh topologies are applied for the simulations. The predicted results are compared with available experimental data from flow bench measurements. It is found that the flow separation and reduction in mass flow rate with increased valve lift can be predicted when high mesh density is used in the proximity of the valve seat and the walls of the intake port. Higher mesh density also gives better predictions of mass flow rate compared to the experiments, but only for high valve lifts. For low valve lifts, the error in predicted flow rate is close to 13%.

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EXPERIMENTAL AND NUMERICAL INVESTIGATION OF METASTABLE FLOW OF REFRIGERANT R-22 THROUGH CAPILLARY TUBE

THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING ◽

10.32852/iqjfmme.vol18.iss1.72 ◽

2018 ◽

Vol 18 (1) ◽

pp. 41-62

Author(s):

Esam M Abed ◽

Ammar A K Fathi

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Capillary Tube ◽

Numerical Data ◽

Design And Optimization ◽

Metastable Region ◽

Ansys Cfx ◽

Commercial Code ◽

Suction Line

This study presents an experimental investigation of metastable region take place forrefrigerant flow through adiabatic and non-adiabatic capillary tube of window type airconditioner. Large numbers of experiments are carried out to explain the effect of length ofstraight and helical capillary tube on metastable region under adiabatic and non-adiabaticconditions. for the case of adiabatic capillary tube, three different length are selected(70,100 and 150) cm and two helical capillary tube, the length of each tube is 100 cm withtwo coil diameters (2 and 6) cm. For the non-adiabatic capillary tube, the straight capillarytube suction line is 150 cm while the length of non-adiabatic helical capillary tube is 200 cmwith 8 cm coil diameter. The results show that the length is the most influence parameterson beginning of metastable region. In addition the helical coil tube effect on the beginningof metastable region. As well as for the adiabatic and non-adiabatic capillary tube it isconcluded that mass flow rate is the main parameters on beginning of metastable region.Also effect of length and coiling on both pressure drop and mass flow rate are discussed.The CFD commercial code, ANSYS CFX 16.1 based on finite volume method using Kturbulencemodel considering the homogeneous flow between phases applied to straightcapillary tube. The present numerical data has been validated with the present workexperimental data and with other researchers. A good agreement is obtained which can belead to use ANSYS CFX 16.1 in the design and optimization of capillary tube in airconditioner.

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Hydraulic flow rate increase maneuver for ichthyofauna repulsion in bulb-type generating units – Jirau Hydroelectric Power Plant

Periódico Eletrônico Fórum Ambiental da Alta Paulista ◽

10.17271/1980082717420213049 ◽

2021 ◽

Vol 17 (4) ◽

Author(s):

Tania Machado da Silva ◽

Wllyane Silva Figueiredo ◽

Luiz Fabrício Zara

Keyword(s):

Power Plant ◽

Flow Rate ◽

Rate Increase ◽

Draft Tube ◽

Hydroelectric Power Plant ◽

Small Fish ◽

Hydroelectric Power ◽

Two Stage ◽

Hydraulic Flow ◽

Flow Rate Increase

Several repulsion systems have been developed to minimize the confinement of ichthyofauna in draft tubes. In this perspective, this study intends to analyze the efficiency of the hydraulic flow rate increase maneuver, using a hydroacoustic system for real-time monitoring of the movement of the ichthyofauna confined within the draft tube of the generating units of Jirau Hydroelectric Power Plant. It is located on the Madeira River, in Rondônia, Brazil. We analyzed footage of 105 machine shutdowns taken between 2019 and 2020 at Jirau Hydroelectric Power Plant that used the hydraulic flow rate increase maneuver as a strategy to repulse ichthyofauna. Also, the footage of 7 two-stage shutdowns in the year 2020 was analyzed, the first stage without the maneuver and the second with the maneuver. The follow-up of 105 shutdowns demonstrate that approximately 85% of the footage showed little or no movement of ichthyofauna in the draft tube, with images of movements showing patterns characteristic of small fish (~97%). Furthermore, the quantitative evaluation of the two-stage maneuver indicated a reduction of approximately 91% in the movement of ichthyofauna after the hydraulic flow rate increase maneuver. Thus, the increase in the rate of the hydraulic flow procedure, developed by Jirau Energia, proved to be an innovative and efficient strategy in reducing extensive social and environmental impacts and in favoring positive economic impacts.

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Design of an Innovative Solar Updraft Aeration System for Fish Ponds in the Developing World Using Thermofluidic Computational Modelling

Volume 6B: Energy ◽

10.1115/imece2016-66286 ◽

2016 ◽

Author(s):

Ali Ebrahimi Khabbazi ◽

Shakya Sur ◽

Ahmed Mahmoud ◽

Elan Pavlov ◽

Amy M. Bilton

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Draft Tube ◽

Solar Thermal ◽

Fish Ponds ◽

Resource Constrained ◽

Aeration System ◽

Convective Circulation ◽

Patch Length

This paper introduces an innovative design concept for a low-cost solar-thermal aeration system for fish ponds which is amenable to implementation in resource-constrained settings. In its most basic form, the system consists of a metallic solar thermal collector and a heat transfer column (referred to as conduction element in this paper), which induces convective circulation by dissipating heat to the cooler, deeper layers of the pond. As a result of the circulation, oxygen generated by phytoplankton at the top of the pond is distributed throughout the water column, preventing oxygen losses to the atmosphere due to surface supersaturation and increasing the overall dissolved oxygen (DO) content in the pond. This paper presents a design study to evaluate different system configurations. Thermofluidic numerical models were implemented to systematically analyze and compare the mass flow rate through the draft tube induced by convection. Furthermore, parametric studies were performed to evaluate the effect of the insulation patch length and the aluminum plate thickness on the overall performance of the device (i.e. the induced mass flow rate through the draft tube). It was found that the two-fin configuration with split conduction elements was superior to the central rod design in terms of performance. In addition, it was found that depending on the insulation patch length, the induced mass flow rates can be increased up to 5 times. The results from the computational models indicate that the device can induce the convective circulation in order to improve the DO content at deep levels of the ponds and has potential to improve aquaculture productivity in resource-constrained settings. The results from this study will be used to configure systems for future field evaluations that will be performed in fish ponds in Bangladesh.

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STUDY OF THE PROCESS OF EROSION OF A MICRO HYDROELECTRIC POWER PLANT (HPP) TURBINES IN THE FORM OF A HYDROCYCLONE

Periódico Tchê Química ◽

10.52571/ptq.v17.n36.2020.542_periodico36_pgs_527_541.pdf ◽

2020 ◽

Vol 17 (36) ◽

pp. 527-541

Author(s):

Kassymbekov ZHUZBAY ◽

Alimova KULYASH ◽

Kassymbekov GALIMZHAN

Keyword(s):

Power Plant ◽

Abrasive Wear ◽

Water Purification ◽

Flow Simulation ◽

Hydroelectric Power Plant ◽

Hydraulic Turbine ◽

Solid Particles ◽

Hydroelectric Power Station ◽

Experimental Sample ◽

Hydroelectric Power

One of the severe problems of a hydroelectric power plant (HPP) is providing a hydroelectric unit with purified water with the required pressure. Otherwise, the central working bodies - hydraulic turbines - are subjected to abrasive wear and quickly fail. Abrasive wear reduces the efficiency and life of the turbine and causes problems in operation and maintenance. This research aimed to study the degree of abrasive wear (erosion rate) of the surface of a blade hydraulic turbine of a micro HPP during water purification using a hydrocyclone and to ensure its rational layout based on the studies. Investigation of damage to the turbine surface from the dynamic impact was carried out by computer modeling of the process using the Autodesk Simulation CFD program, with different versions of the hydrocyclone body and testing of an experimental sample. Additional software SolidWorks (flow simulation) was used to check the calculations. It was found that the forms of particle hardness in water significantly affect the rate and magnitude of erosion, and a different design of the treatment body in the form of a hydrocyclone in different ways ensures the separation of the flow into phases. A rational scheme for installing a hydraulic turbine inside a hydrocyclone was selected, which provides the required power characteristic of a mini hydroelectric power station and other necessary parameters. The highest degree of water purification from solid impurities (94%) was achieved using the configuration option in a cylindrical-conical design with a rotational water inlet into the hydrocyclone. The location of the hydraulic turbine inside a hydrocyclone of a certain design and the tangential supply of water to the blades of the hydraulic turbine significantly protects the surface of the unit from the effects of solid particles. Their service life can be increased without additional investment in the restoration of the unit.

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