Position Control of the Hydraulically Actuated Francis Turbine Inlet Guide Vane

Author(s):  
Paladugu Venkaiah ◽  
Bikash Kr. Sarkar

Development of the renewable source of energy has become an area of interest due to increasing power demand and fixed fossil fuels in the universe. To increase efficiency of the renewable source of energy like, hydro power become important. In the present work, adaptive feedforward fuzzy PID controller has been developed for position control of the electrohydraulic actuation turbine IGV system. Electrohydraulic turbine governing systems are superior to the electromechanical governing system due to the high power availability, very good controllability, self lubrication property etc. NACA 0012 aerofoil blade configuration has been considered for the turbine IGV system due to the less lift force which lead to the less effort required to governing action. Low cost proportional valve control electrohydraulic system configuration has been considered. Simulation study has been carried in Matlab Simulink environment. The system IGV position control has been studied for step, sinusoidal and arbitrary position demand.

Author(s):  
Angela Sodemann ◽  
Yaoyu Li ◽  
Xin Wu ◽  
Rick Lancaster ◽  
Mark Rucker ◽  
...  

Fast and accurate positioning of Inlet Guide Vane (IGV) is critical for flow regulation in centrifugal air compressors, especially for surge avoidance control. Both transport delay and external disturbance are present for IGV position control on a compressed air system. A Smith Predictor based control scheme with the process-model modification is applied to this problem. The adopted control scheme can both compensate for the time delay and effectively reject step disturbances present in the IGV system. Simulation was conducted using simple PI controller and a PI controller with the Smith Predictor with process-model modification. It showed that the proposed control scheme can achieve zero steady-state error with the presence of external disturbance and the settling time was shortened. Robust stability and performance of the system was discussed.


Author(s):  
Vinod J ◽  
Bikash Kumar Sarkar

Hydropower system has great attention due to the cheapest and simplest renewable power generation, available potential and environmental concern. Francis turbine has wide operating range compare to other hydro turbine runner. Electrohydraulic Francis turbine inlet guide vane system has advantages like, high power density, self-lubrication property, very good controllability and rugged. Francis turbine inlet guide vane system consists of inlet guide vane actuation system, ring inlet guide blade arrangement, and controller. The main challenges with the electrohydraulically actuated inlet guide vane system are nonlinear characteristic, parametric uncertainty, and external disturbances. Further with respect to the real-life application of the electrohydraulic actuator piston seal damage may occur due to fitting problem of the seal, impurities in the hydraulic oil, high temperature of the hydraulic oil and so on. Recently some researchers are reported on modelling accuracy, accurate controller design and stability analysis. In the present study mathematical model of the Francis turbine has been developed based on velocity diagram to capture effect of water flow dynamics on turbine power generation with the consideration of Euler’s equation of turbo machinery. Detailed mathematical model of the inlet guide vane actuating system has been integrated with Francis turbine model. Artificial neural network 2 degree-of-freedom proportional integral derivative controller has been developed for Francis turbine power/speed control. The controller performance has been studied with the consideration of actuator piston seal damage. The controller performance has been studied with 30%, 60%, and 90% step increase of power demand. The controller performance also has been studied with 0.005 and 0.05 Hz frequency sinusoidal power demand. The proposed controller performance has been compared with conventional proportional integral derivative controller through various performance indexes. The proposed controller performances also have been compared with recently reported work due to step increase of torque and step decreases of power demand.


Author(s):  
Zygfryd Domachovski ◽  
Merek Dzida

The gas turbine efficiency drops quickly at part load as it is very dependant on turbine firing temperature. Therefore in combined cycle power plants the inlet guide vane is adjusted to maintain the high combustion chamber exhaust temperature. Simulations on influence of the inlet guide vane position control on combined cycle power plant transients have been carried out.


2021 ◽  
Vol 11 (10) ◽  
pp. 4681
Author(s):  
Mohammad Ebrahim Bajgholi ◽  
Gilles Rousseau ◽  
Martin Viens ◽  
Denis Thibault

This paper presents the results of a project aimed at evaluating the performance of ultrasonic techniques for detecting flaws in Francis turbine runners. This work is the first phase of a more ambitious program aimed at improving the reliability of inspection of critical areas in turbine runners. Francis runners may be utilized to supply power during peak periods, which means that they experience additional load stress associated with start and stop sequences. Inspection during manufacturing is then of paramount importance to remove as much as feasible all flaw initiation sites before the heat treatment. This phase one objective is to collect initial data on a simplified mock-up and then to compare the experimental ultrasonic data with the results of simulations performed by CIVA, a computer simulation package. The area of interest is the region with the highest stress between the blade and the web. A welded T-joint coupon made of UNS S41500 was manufactured to represent this high-stress area. During the FCAW welding process, ceramic beads were embedded in the weld to create discontinuities whose size is in the critical range to initiate a crack. Inspection of the material was carried out by various nondestructive testing (NDT) methods namely conventional pulse-echo, phased array, total focusing method (TFM). With these results, detection rates were obtained in order to compare the effectiveness of each method.


Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 172
Author(s):  
Hengtao Shi

Recently, a new type of low-loss variable inlet guide vane (VIGV) was proposed for improving a compressor’s performance under off-design conditions. To provide more information for applications, this work investigated the effect of the Reynolds number and clearance flow on the aerodynamic characteristics of this new type of VIGV. The performance and flow field of two representative airfoils with different chord Reynolds numbers were studied with the widely used commercial software ANSYS CFX after validation was completed. Calculations indicate that, with the decrease in the Reynolds number Rec, the airfoil loss coefficient ω and deviation δ first increase slightly and then entered a high growth rate in a low range of Rec. Afterwards, a detailed boundary-layer analysis was conducted to reveal the flow mechanism for the airfoil performance degradation with a low Reynolds number. For the design point, it is the appearance and extension of the separation region on the rear portion; for the maximum incidence point, it is the increase in the length and height of the separation region on the former portion. The three-dimensional VIGV research confirms the Reynolds number effect on airfoils. Furthermore, the clearance leakage flow forms a strong stream-wise vortex by injection into the mainflow, resulting in a high total-pressure loss and under-turning in the endwall region, which shows the potential benefits of seal treatment.


Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 101
Author(s):  
Leonardo Acho

The main objective of this paper is to present a position control design to a DC-motor, where the set-point is externally supplied. The controller is conceived by using vibrational control theory and implemented by just processing the time derivative of a Hall-effect sensor signal. Vibrational control is robust against model uncertainties. Hence, for control design, a simple mathematical model of a DC-Motor is invoked. Then, this controller is realized by utilizing analog electronics via operational amplifiers. In the experimental set-up, one extreme of a flexible beam attached to the motor shaft, and with a permanent magnet fixed on the other end, is constructed. Therefore, the control action consists of externally manipulating the flexible beam rotational position by driving a moveable Hall-effect sensor that is located facing the magnet. The experimental platform results in a low-priced device and is useful for teaching control and electronic topics. Experimental results are evidenced to support the main paper contribution.


Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Zhenlin Li ◽  
Xin Zhou ◽  
Zizhe Wang

In order to effectively improve hydraulic performance of centrifugal pump on off-conditions, the hydraulic design of inlet guide vane (IGV) was completed by adopting two dimensional theory in-house code based on one kind of IS series of centrifugal pump, which can achieve pre-whirl regulation of centrifugal pump. During design process the trailing edge of vane is assumed as equal velocity moment condition, and the distribution of vane setting angle along meridional streamline is also given as a quartic function firstly, the camber line is then drawn by point-by-point integration method and thickened at both sides along circumferential direction. With local vortex dynamics diagnosis theory, the optimal improvement of vane space shape can be finished by adjusting the design parameters of vane setting angle distribution coefficient ap. The full flow passage numerical simulations of centrifugal pump with IGV device are completed to analyze the influence of pre-whirl regulation on hydraulic performance of centrifugal pump under various pre-whirl angles. The results show that the pre-whirl regulation can improve the hydraulic performance of centrifugal pump on off-conditions. Under the positive pre-whirl regulation conditions, the best efficient point shift to small flow rate zone, and under the negative pre-whirl regulation conditions it moves to large flow rate zone. Compared with the pump without IGV device at the same flow rate condition of 0.8Q (Q the design flow rate), the hydraulic efficiency of centrifugal pump with IGV device improves obviously and reaches up to 1.43%. Meanwhile compared with that installed with the straight vanes designed based on the traditional theory, the inner flow field of centrifugal pump with the designed vanes improves and the overall hydraulic efficiency of centrifugal pump is somewhat increased.


Author(s):  
J. D. Hughes ◽  
G. J. Walker

Data from a surface hot-film array on the outlet stator of a 1.5 stage axial compressor are analyzed to look for direct evidence of natural transition phenomena. An algorithm is developed to identify instability waves within the Tollmien Schlichting (T-S) frequency range. The algorithm is combined with a turbulent intermittency detection routine to produce space∼time diagrams showing the probability of instability wave occurrence prior to regions of turbulent flow. The paper compares these plots for a range of blade loading, with free-stream conditions corresponding to the maximum and minimum inflow disturbance periodicity produced by inlet guide vane clocking. Extensive regions of amplifying instability waves are identified in nearly all cases. The implications for transition prediction in decelerating flow regions on axial turbomachine blades are discussed.


2016 ◽  
Vol 28 (4) ◽  
pp. 676-689 ◽  
Author(s):  
Biraj Singh Thapa ◽  
Chirag Trivedi ◽  
Ole Gunnar Dahlhaug

Sign in / Sign up

Export Citation Format

Share Document