Flow rate measurements in hydropower plants using the pressure-time method – Experiences and improvements

2019 ◽  
Vol 68 ◽  
pp. 101584 ◽  
Author(s):  
Adam Adamkowski ◽  
Waldemar Janicki ◽  
Zbigniew Krzemianowski ◽  
Mariusz Lewandowski
Keyword(s):  
Flow Rate ◽  
Hydropower Plants ◽  
Pressure Time

scholarly journals Contributions to the development of a methodology for determining the flow rate

2019 ◽  
Vol 112 ◽  
pp. 02008
Author(s):  
Cristian Purece ◽  
Valeriu Panaitescu ◽  
Irina Alina Chera Anghel
Keyword(s):  
Flow Rate ◽  
Operating Characteristics ◽  
Wireless Data ◽  
In Situ Tests ◽  
Small Hydropower ◽  
Actual Operating ◽  
Wireless Data Transmission ◽  
Hydropower Plants ◽  
Data Transmission System

The implementation of the requirements of the European Parliament Directive 2009/28 / EC requires efficient use of the water supply of a hydropower plants installation in order to obtain a higher amount of electricity by producing the same volume of water. In order to achieve efficient utilization of the energy of the water is necessary framing the operation of hydropower plants in the ranges of head course and the electric power so that the energy conversion is carried out in the optimum efficiency characteristic operation of the system. In order to determine as accurately the actual operating characteristics of a hydro-unit, in situ tests are required to determine the actual operating parameters of the hydro-unit. These parameters, the flow rate is the parameter that requires the most complex methodologies to determine. The paper presents a way of improvement but also a simplification of the methodology for in situ determination of the flow to small hydropower plants by using a mobile frame that has implemented a wireless data transmission system.

Improved Discharge Measurement Using the Pressure-Time Method in a Hydropower Plant Curved Penstock

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Adam Adamkowski ◽  
Zbigniew Krzemianowski ◽  
Waldemar Janicki
Keyword(s):  
Velocity Field ◽  
Flow Rate ◽  
Cross Sections ◽  
Hydropower Plant ◽  
National Standard ◽  
Problem Solution ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
International Standard ◽  
Pressure Time

One of the basic flow rate measurement methods applied in hydropower plants and recommended by the International Standard IEC 60041–1999 and American National Standard ASME PTC 18–2002 is the pressure-time method, generally known as Gibson method. The method consists in determining the flow rate (discharge) by integration of the recorded time course of pressure difference variations between two cross sections of the hydropower plant penstock. The accuracy of measurement depends on numerous factors and, according to the International Standard, generally is confined within the range 1.5–2.3%. Following the classical approach, the pressure-time method applicability is limited to straight cylindrical pipelines with constant diameters. However, the International Standard does not exclude application of this method to more complex geometries, i.e., curved pipeline (with elbows). It is obvious that a curved pipeline causes deformation of the uniform velocity field in pipeline cross sections, which subsequently causes aggravation of the accuracy of the pressure-time method flow rate measurement results. The influence of a curved penstock application on flow rate measurements by means of the considered method is discussed in this paper. The special calculation procedure for the problem solution has been developed. The procedure is based on the FLUENT computational fluid dynamic solver. Computations have been carried out in order to find the so-called equivalent value of the geometric pipe factor F required when using the pressure-time method. An example of application of this method to a complex geometry (two elbows in a penstock) is presented. The systematic uncertainty caused by neglecting the effect of the elbows on velocity field deformation has been estimated.

scholarly journals Evaluation of the Hydroelectric Potential of the TokounouWaterfall, Kankan Prefecture, Guinea

2021 ◽  
pp. 1-6
Author(s):  
Faya Oulare ◽  
Fodé Cisse ◽  
Ansoumane Sakouvogui ◽  
Amadou Sidibe ◽  
Mamby Keita
Keyword(s):  
Flow Rate ◽  
Rural Areas ◽  
Electrical Energy ◽  
Small Hydropower ◽  
Hydro Power ◽  
Hydropower Plants ◽  
Energy Needs ◽  
Useful Power ◽  
Hydro Power Potential

This study is a continuation of the work of evaluation and valuation of the hydro power potential of Small hydropower plants in Guinea. With a total hydroelectric potential estimated at 6000 MW, Guinea generally suffers from a lack of electrical energy, especially in rural areas where nearly 70% of the populations live and less than 15% of this population is connected to the grid. Electricity of the country, which has the negative consequence of the misuse of wood as a source of energy. Hence the need for this study, which aims to assess the hydroelectric potential of the Tokounou waterfall in Kankan prefecture. The main results obtained relate to : the turbine flow rate, the net head, the useful power, the dimensions of the loading basin, the characteristics of the penstock and the choice of turbine. Proposals for the use of the estimated hydroelectric potential have been made, which could improve the energy needs of the locality.

scholarly journals The Influence of Changing Hydropower Potential on Performance Parameters of Pumps in Turbine Mode

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2103 ◽  
Author(s):  
Martin Polák
Keyword(s):  
Flow Rate ◽  
Water Distribution ◽  
Distribution Networks ◽  
Small Scale ◽  
Operational Parameters ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Total Head ◽  
Hydropower Potential ◽  
Water Turbines

Pumps as turbines (PAT) are used as an alternative to water turbines in small hydropower plants. The same devices can also be used for energy recovery in water distribution networks. They can replace pressure reduction valves that often lead to energy loss. However, PATs lack the parts that regulate flow so that when a hydropower potential change occurs, efficiency is reduced, as is economic gain. This article summarizes the influence of changing hydropower potential on PAT efficiency and presents comparisons of experimental results with the commonly used predictive model stemming from the theory of physical similarity, which presumes constant PAT efficiency. Our research indicates that the deviation between the model and the real power output calculation at varying potentials was minimal. Similarly, the affine parabola can be used to determine the relationship between total head and flow rate. Other relationships differ from reality the more the PAT efficiency changes. The flow rate and total head dependence on shaft speed are the main factors when setting the optimum operational parameters at varying hydropower potentials. Therefore, a change in efficiency must be included in predictive calculations to correctly optimize PAT operation. The problem is that a change in efficiency cannot be reliably predicted in advance, especially in the case of small-scale devices. For this reason, further research on the issue of changes in PAT efficiency is necessary.

Improvement of Forecasting Method of Recession Characteristics of River Flow Rate into a Dam by using Estimation of Steady State

2020 ◽  
pp. 1-10
Author(s):  
Tomonari Kawai ◽  
Katsuhiro Ichiyanagi ◽  
Takuo Koyasu ◽  
Kazuto Yukita ◽  
Yasuyuki Goto
Keyword(s):  
Steady State ◽  
State Estimation ◽  
Flow Rate ◽  
River Flow ◽  
System Operation ◽  
Forecasting Accuracy ◽  
Hydropower Plants ◽  
Dam Management ◽  
Forecasting Method

This paper describes an application of neural networks for forecasting the flow rate upper district of dams for hydropower plants. The forecasting of recession characteristics of the river flow after rainfalls is important with respect to system operation and dam management. We present a method for improving the precision of forecasting flow rate upper district of dams by utilizing steady-state estimation and recession time constant of the river flow. A case study was carried out on the upper district of the Yahagi River in Central Japan. It is found from our investigations that the forecasting accuracy is improved to 18.6% from 25.8% with a forecasted error of the total amount of river flow by using steady-state estimation.

scholarly journals Uncertainty analysis of liquid flow rate measurement with the pressure-time method

Measurement ◽  
2021 ◽  
pp. 109866
Author(s):  
Adam Adamkowski ◽  
Waldemar Janicki ◽  
Mariusz Lewandowski ◽  
Edson da Costa Bortoni
Keyword(s):  
Uncertainty Analysis ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Pressure Time

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.

Designing of Micro Gravitational Vortex Turbine’s Vortex Pool

2017 ◽  
Author(s):  
Wajiha Rehman ◽  
Masooma Ijaz ◽  
Asma Munir
Keyword(s):  
Cross Section ◽  
Flow Rate ◽  
Turbine Blades ◽  
Vortex Formation ◽  
Vortex Generation ◽  
Geometrical Characteristics ◽  
Novel Technology ◽  
Hydropower Plants ◽  
Low Head ◽  
Micro Level

Water is one of the major sources of renewable energy and many hydropower plants are working across the world but they require specific values of head and flow rate for their operation and optimum results. There are many sites where limited head and flow rate is available but these resources cannot be exploited due to inefficient technologies. Gravitational vortex turbine (GVT) is a novel technology that is suitable for micro-level power production where low head and flow rate is available. It consists of two main parts: vortex pool for vortex generation and turbine blades. This paper focuses on parametrical analysis of GVT to determine the geometrical characteristics which gives the best performance. These parameters would address; effect of velocity and symmetry of vortex with the ratio of upper diameter of funnel (D) to outlet diameter (d), effect of the angle of rectangular inlet passage on the vortex formation. It will also analyze flow in rectangular passage with constant cross section vs. converging cross section. All of these parameters have major impact on the velocity and symmetry of flow. Results show that outlet of the funnel should be 40% of the upper diameter while highest velocity was achieved when rectangular passage was at 60 degrees with pre-rotational plate at 30 degrees.

scholarly journals Reformulation of the pressure-time method for application without flow rate cut-off

Measurement ◽  
2021 ◽  
pp. 110583
Author(s):  
MJ Cervantes ◽  
G Dunca ◽  
B Mulu ◽  
PP Jonsson
Keyword(s):  
Flow Rate ◽  
Pressure Time
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