Measurement of the Flow in a 170 MW Hydraulic Turbine Recording the Pressure-Time Rise in One Section of the Penstock

2006 ◽  
Author(s):  
F. Sierra ◽  
J. Kubiak ◽  
G. Urquiza ◽  
A. Adamkoski ◽  
W. Janicki ◽  
...  
Keyword(s):  
Flow Rate ◽  
Flow Simulation ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
Measuring System ◽  
Recirculation Region ◽  
Flow Recirculation ◽  
Pressure Time ◽  
On Line ◽  
Region Size

The objective of the present work is to evaluate the performance of a hydraulic turbine by means of the measurement of flow using the Gibson method based on recording pressure–time rise in one section of the penstock and relate it to the pressure in the upper reservoir to which the penstock is connected. Volumetric flow is determined by integration of the time function of a differential pressure (between the section and the inlet to the penstock). Flow measurement was possible this way because the influence of penstock inlet was negligible as far as an error of the measurement is concerned. The paper presents the results obtained with this method for the case of a 170 MW hydraulic turbine. The length of the penstock was 300 m. Previous experience and a standard IEC-41-1991 were the criteria adopted and applied. An efficient and fast acquisition system including a 16 bit card was used. The flow rate was calculated using a computer program developed and tested on several cases. The results obtained with the Gibson method were used for calibration of the on-line flow measuring system based on the Winter-Kennedy principles. This last method is used for continuous monitoring of the turbine flow rate. Having calculated the flow rate and output power the efficiency is calculated for any operating conditions. A curve showing the best operating conditions based on the highest efficiency is presented and discussed. Flow simulation allowed having an estimation of a flow recirculation region size.

Effect of Fuel Composition on Emissions From a Low-Swirl Burner

2007 ◽  
Author(s):  
Daniel Sequera ◽  
Ajay K. Agrawal
Keyword(s):  
Gas Turbines ◽  
Bluff Body ◽  
Swirling Flow ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Recirculation Region ◽  
Fuel Composition ◽  
High Hydrogen ◽  
Flow Recirculation

Lean Premixed Combustion (LPM) is a widely used approach to effectively reduce pollutant emissions in advanced gas turbines. Most LPM combustion systems employ the swirling flow with a bluff body at the center to stabilize the flame. The flow recirculation region established downstream of the bluff-body brings combustion products in contact with fresh reactants to sustain the reactions. However, such systems are prone to combustion oscillations and flame flashback, especially if high hydrogen containing fuels are used. Low-Swirl Injector (LSI) is an innovative approach, whereby a freely propagating LPM flame is stabilized in a diverging flow field surrounded by a weakly-swirling flow. The LSI is devoid of the flow recirculation region in the reaction zone. In the present study, emissions measurements are reported for a LSI operated on mixtures of methane (CH4), hydrogen (H2), and carbon monoxide (CO) to simulate H2 synthetic gas produced by coal gasification. For a fixed adiabatic flame temperature and air flow rate, CH4 content of the fuel in atmospheric pressure experiments is varied from 100% to 50% (by volume) with the remainder of the fuel containing equal amounts of CO and H2. For each test case, the CO and nitric oxide (NOx) emissions are measured axially at the combustor center and radially at several axial locations. Results show that the LSI provides stable flame for a range of operating conditions and fuel mixtures. The emissions are relatively insensitive to the fuel composition within the operational range of the present experiments.

scholarly journals Numerical Study on Performance Characteristics of Draft Tube of Mixed Flow Hydraulic Turbine

2012 ◽  
Vol 10 ◽  
pp. 48-52
Author(s):  
Ruchi Khare ◽  
Vishnu Prasad
Keyword(s):  
Coming Out ◽  
Draft Tube ◽  
Numerical Study ◽  
Flow Simulation ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
Francis Turbine ◽  
Mixed Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Overall Performance

Draft tube is an important component of the hydraulic reaction turbine and affects the overall performance of turbine to a large extent. The flow inside the draft tube is complex because of the whirling flow coming out of runner and its diffusion along the draft tube. The kinetic energy coming out of runner is recovered in draft tube and part of recovery meets the losses. In the present work, the computational fluid dynamics (CFD) has been used for flow simulation in complete mixed flow Francis turbine for performance analysis for energy recovery, losses and flow pattern in an elbow draft tube used in Francis turbine at different operating conditions. The overall performance of the turbine at some typical operating regimes is validated with the experimental results and found to be in close comparison.DOI: http://dx.doi.org/10.3126/hn.v10i0.7103 Hydro Nepal Vol.10 January 2012 48-52

Detection of Unsteady Flow in a Kaplan Hydraulic Turbine Using Machine Mechanical Model and Rotor Measured Vibrations

2012 ◽  
Author(s):  
Paolo Pennacchi ◽  
Andrea Vania ◽  
Steven Chatterton ◽  
Ezio Tanzi
Keyword(s):  
Unsteady Flow ◽  
Flow Rate ◽  
Mechanical Model ◽  
Turbine Unit ◽  
Draft Tube ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
Design Stage ◽  
System Response ◽  
Model Based

Hydraulic stability is one of the key problems during the design stage of hydraulic turbines. Despite of modern computational tools that help to define dangerous operating conditions and optimize runner design, hydraulic instabilities may fortuitously arise during the turbine life, as a consequence of variable and different operating conditions at which a hydraulic turbine can be subject. In general, the presence of unsteady flow reveals itself in two different ways: at small flow rate, the swirling flow in the draft tube conical inlet occupies a large portion of the inlet and causes a strong helical vortex rope; at large flow rate conditions the unsteady flow starts midway and causes a breakdownlike vortex bubble, followed by weak helical waves. In any case, hydraulic instability causes mechanical effects on the runner, on the whole turbine and on the draft tube, which may eventually produce severe damages on the turbine unit and whose most evident symptoms are vibrations. This notwithstanding, condition monitoring systems seldom are installed on this purpose in hydraulic power plants and no examples are reported in literature about the use of model-based methods to detect hydraulic instability onset. In this paper, by taking the advantage of a testing campaign performed during the commissioning of a 23 MW Kaplan hydraulic turbine unit, a rotordynamic model-based method is proposed. The turbine was equipped by proximity and vibration velocity probes, that allowed measuring lateral and axial vibrations of the shaft-line, under many different operating conditions, including also some off-design ones. The turbine mechanical model, realized by means of finite beam elements and considering lateral and axial degrees of freedom, is used to predict turbine unit response to the unsteady flow. Mechanical system response is then compared to the measured one and the possibility to detect instability onset, especially in real-time, is discussed.

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

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Laura Castro ◽  
Gustavo Urquiza ◽  
Adam Adamkowski ◽  
Marcelo Reggio
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Draft Tube ◽  
Flow Simulation ◽  
Numerical Data ◽  
Hydroelectric Power Plant ◽  
Hydraulic Turbine ◽  
Hydroelectric Power ◽  
Spiral Case

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.

scholarly journals The Influence of Transient Regimes on Unsteady Vortex Phenomena in the Model of the Draft Tube of the Hydraulic Turbine

2019 ◽  
Vol 14 (4) ◽  
pp. 55-68
Author(s):  
D. A. Suslov ◽  
I. V. Litvinov ◽  
S. I. Shtork ◽  
E. U. Gorelikov
Keyword(s):  
Flow Rate ◽  
Swirling Flow ◽  
Draft Tube ◽  
Maximum Level ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
Rotor Speed ◽  
Precessing Vortex Core ◽  
Transient Regimes ◽  
Partial Load

This article is devoted to study the swirling flow with the formation of the precessing vortex core (PVC) in the cone of the model of the draft tube of the hydraulic turbine. The experiments were carried out on the aerodynamic set-up both in stationary and in transient regimes of operation of the hydraulic turbine. The hydraulic turbine operating conditions were varied by continuously changing the flow rate at a constant rotor speed. The formation of the PVC in the flow and the maximum level of pressure pulsations in the regime modeling the partial load regime of a turbine are revealed. The boundaries of the occurrence of the PVC effect are determined with varying rotor speed and air flow rate. It was found that the dependence of the PVC lifetime in transition regimes correlate with the transition time. It was shown that the velocity profiles in transient conditions change quasistatically between the operation regime with partial loading of the turbine and the regime of the highest efficiency of the turbine.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Optimal Tuner Selection for Kalman Filter-Based Aircraft Engine Performance Estimation

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Donald L. Simon ◽  
Sanjay Garg
Keyword(s):  
Kalman Filter ◽  
Estimation Error ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Performance Estimation ◽  
Experimental Simulation ◽  
Tuning Parameter ◽  
Estimation Accuracy ◽  
On Line

A linear point design methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multivariable iterative search routine that seeks to minimize the theoretical mean-squared estimation error. This paper derives theoretical Kalman filter estimation error bias and variance values at steady-state operating conditions, and presents the tuner selection routine applied to minimize these values. Results from the application of the technique to an aircraft engine simulation are presented and compared with the conventional approach of tuner selection. Experimental simulation results are found to be in agreement with theoretical predictions. The new methodology is shown to yield a significant improvement in on-line engine performance estimation accuracy.

On-Line Monitoring System for Monitoring SO2 in Fumes (1) — Monitoring Subsystem for SO2 Mass Concentration

2011 ◽  
Vol 422 ◽  
pp. 296-299
Author(s):  
Shi Long Wang ◽  
Li Na Wang ◽  
Hong Bo Wang ◽  
Yong Hui Cai
Keyword(s):  
Flow Velocity ◽  
Monitoring System ◽  
Flow Rate ◽  
Mass Concentration ◽  
National Monitoring ◽  
Monitoring Result ◽  
Short Period ◽  
On Line ◽  
Working Principle

In order to achieve the target of controlling SO2 emissions in fumes in a short period of time in China, a SO2 on-line monitoring system (CEMS) has been developed by the authorased on the principle of electrochemistry. This system consists of two subsystems: (1) SO2 mass concentration monitoring and (2) SO2 flow velocity and flow rate monitoring. In the paper, the procedure of system and working principle and method of SO2 mass concentration monitoring subsystem are described in detail (SO2 flow velocity and flow rate monitoring subsystem is described by another paper).Two subsystems work synchronously to monitor and calculate the SO2 emissions, then the on-line monitoring of SO2 emissions is achieved. Through experiment and testing, monitoring result of the system is stable and reliable, which has reached the national monitoring standards and passed the appraisal.

scholarly journals Chemical–Electrochemical Process Concept for Lead Recovery from Waste Cathode Ray Tube Glass

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1546
Author(s):  
Árpád Imre-Lucaci ◽  
Melinda Fogarasi ◽  
Florica Imre-Lucaci ◽  
Szabolcs Fogarasi
Keyword(s):  
Flow Rate ◽  
Current Density ◽  
Complete Recovery ◽  
Electrochemical Process ◽  
Operating Conditions ◽  
General Effect ◽  
Optimal Operating ◽  
Recirculation Flow ◽  
Lead Recovery ◽  
Cathode Ray Tube

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.

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