HyTran Training Hill Chart

HyTran Training (Basic Course)

Processing Hill ChartsForHytran Transient Analysis17/5/2015Prepared by:Sabin MaharjanAnil Kutuwo17/5/2015ContentIntroduction to Hill Chart ProcessingHill Diagram Pre ProcessingProcessing Hill Chart Data

27/5/201527/5/2015Introduction to Hill Chart ProcessingHill Charts or DiagramsGraphical representation of the turbine flow data and the power output obtained from model tests.Essential for modeling the turbine boundary condition.Defined by various definitions adopted by the turbine manufacturer.The parameters most generally used are:Unit Discharge vs Unit SpeedUnit Torque vs Unit SpeedUnit Power vs Unit SpeedUnit Discharge with efficiency curves vs Unit Speed

37/5/2015Introduction to Hill Chart Processing contd..

D=Diameter of the turbine runner (m)N=Rotational speed (rpm)Q=Discharge (m3/s)Hn=Net head (m) P=Power Output (kW)T=Torque (Nm)47/5/2015Introduction to Hill Chart Processing contd.. Why Hill Chart ProcessingEssential for modeling the turbine boundary condition.The relationship between the net head and discharge has to be specified to simulate a turbine in a transient state. Flow through a turbine depends upon various parameters. Curves representing the relationship between these parameters are described as the turbine characteristics.AssumptionLittle information about above mentioned parameters are available during transient state conditions.Therefore, steady state turbine characteristics are assumed to be valid during the transient state as well57/5/2015Introduction to Hill Chart Processing contd..

67/5/2015Introduction to Hill Chart Processing contd..

77/5/2015Hill Diagram Pre ProcessingThe Hill diagram must be processed before Hytran can model the turbine boundary condition.ObjectiveTo calculate turbine behavior in terms of the turbine head and torque during the transient state.87/5/2015Hill Diagram Pre Processing contd.Plotting the Hill ChartX-axisUnit Speed (from zero beyond runaway speed because during steady state model tests, unit speed cannot exceed the runaway speed for a particular net head and gate opening. During transient state, the speed may exceed the runaway speed for a short duration.)Y-axiscould be Unit Discharge, Unit Torque, Unit Power or Efficiency

On plot, extrapolate the gate curve for the full range of the unit speed (from zero to beyond the runaway speed).

97/5/2015Hill Diagram Pre Processing contd.How to ExtrapolateFor Low Unit Speedextrapolate the gate curves by following the general trend of curves.For Higher unit speed rangeextrapolate the gate curve beyond the runaway speed and negative Y axis. Use whatever information you may have from published curves, actual data, experience etc., to extend the gate curves in this region.This is the most difficult procedure and yet the most crucial for modeling the turbine behavior just prior to the wicket gate fully closing.

107/5/2015Hill Diagram Pre Processing contd.Gate Curve RepresentationThe gate curves are usually labeled as an opening size in percentage.The aim is to extract data for gate openings from 100% to 0% opening in step of 10%, i.e., 11 curves are required.Largest gate opening means the 100% open curve. The zero curve represents the zero opening.Try to get this information from the turbine supplier.

117/5/2015Hill Diagram Pre Processing contd.Extracting the Raw Hill Chart DataSelect a range of Unit Speed values from a low value to beyond the runaway speed.Two procedures can be adopted for the extracting of raw data:Q and T values vs N laying on the original labeled curvesQ and T values vs N laying on the interpolated percentage opening curves

The Hill Diagram processing software can carry out the actual interpolation to find the values for the percentage openings. In both cases however, the zero opening gate curve must be drawn.

127/5/2015Hill Diagram Pre Processing contd.Tabulated FormatEnter the Q1 and T1 vs N1 data onto an Excel spreadsheet in the following format--------------------- Max to zero Gate Openings from Max -------------------------N1 32.53 28.5 24.0 21.0 18.0 15.03 12.0 9.0 6.0 3.0 0.02 0.625 0.595 0.520 0.470 0.410 0.345 0.270 0.210 0.130 0.060 0.0305 0.625 0.600 0.530 0.475 0.415 0.350 0.275 0.220 0.135 0.060 0.03010 0.635 0.600 0.530 0.475 0.415 0.350 0.275 0.220 0.135 0.060 0.03015 0.630 0.600 0.525 0.470 0.414 0.345 0.275 0.215 0.133 0.060 0.030..52 0.115 0.060 0.050 0.025 -0.010 -0.110 -0.130 -0.155 -0.160 -0.165 -0.17054 0.090 0.030 -0.005 -0.010 -0.035 -0.125 -0.140 -0.150 -0.165 -0.170 -0.175.. Etc137/5/2015Hill Diagram Pre Processing contd.Smooth out dataPlot Q and T vs N gate data onto Excel graph and smooth out the gate curves.Excel spreadsheet data can be pasted into a text file for the next stage of the processing.147/5/2015Processing Hill Chart DataRaw data processingTo read the raw Hill Chart data by the Hytran, it must be processed by using a software HillDiagram.HillDiagram provided by the Hytran package HillDiagram can be used. It reads the raw Q and T vs N data, interpolates to find the gate curves corresponding to the 100% ,90% 10% 0% openings. This data is then processed to produce the turbine characteristics.

157/5/2015Processing Hill Chart Data ContdOther Data RequiredTurbine dataRated discharge QR (m3/s)Rated head HR (m)Rated speed NR (rpm)Rated Torque TR (m3/s )Runner diameter D (m)167/5/2015Processing Hill Chart Data ContdConversion FactorConversion factors may be applied to convert the raw Q,T and N into the standard units.Wicket Gate Opening LabelsThese may be the original data provided. The largest opening is assumed to be the maximum opening and the smallest one is the fully closed gate position. Equivalent openings corresponding to the nominated percentage openings. The maximum open position is assumed to be the 100% opened position and the fully closed position is assumed to be the 0% opening. The other positions must be the 90%, 80%, 70% 60%, 50%, 40%, 30%, 20%, 10% positions. A total of 11 gate values MUST be provided.HillDiagram Software will interpolate within the given gate settings to find the 100%, 90%, ..20%, 10%, 0% gate settings.

177/5/2015Processing Hill Chart Data ContdTo Run HillDiagram SoftwareGo toStart/Programs/Hytran Solutions/HillDiagramSelect from the menu Process Hill Diagram and enter the name of the data file (*.dat).The output file is the *.lis file with all the steps of the processing involved and a *.cha file which Hytran can read.

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Turbine .cha file197/5/2015Processing Hill Chart Data ContdProcessed Hill Chart Adjustment.The rows are WH and WB values representing the turbine characteristic for the various gate openings. The rows are the values for each gate opening (Maximum to minimum opening) for the angles from -9 to +90 digress. There are 34 values.Typically the plots of WH and WB will be similar to the diagram below.


217/5/2015Processing Hill Chart Data ContdSmooth Gate ClosureThe zero gate curve is an approximation only and is selected as almost closed allowing flow past the gate up until the closing time at which the flow is abruptly brought to rest resulting in a possible rise in pressure. The aim is to introduce a smooth transition of the flow to zero as the gates are changed.


237/5/2015Processing Hill Chart Data ContdTurbine WH and WB Characteristics Curve

247/5/2015Processing Hill Chart Data ContdStreeters Horizontal InterpolationThe characteristic curves

are stored in 2 matrices as WH and WB. There are 11 gate openings from 100% to 0% in steps of 10%: the maximum gate opening is regarded as No 1 while the zero opening is No 11. For each gate opening, The WH and WB values are plotted against tan-1(/a) from -9 0 to 900 in steps of 30 giving a total of 34 points defining the turbine characteristic for each gate opening. The WH curve is shown below.


267/5/2015Processing Hill Chart Data ContdFurther AdjustmentZero Gate Curve RepresentationAny problems are likely to occur just prior to the turbine wicket gates fully closing. The closer the zero gate curve is to Zero, the better results. Using the closing adjustment can be used to give a smooth discharge to override any deficiencies in the final gate closing.Extrapolation beyond the Runaway SpeedAnother area of experimentation is the extrapolation of the Q1 and T1 curves beyond the runaway speed.

277/5/2015Use the Hill Diagram file in HytranAfter completing above mentioned process and applying required adjustment the .cha file produced by Hill Diagram can be used in Hytran Software to input data for Franscis Turbine.

287/5/2015Trouble ShootingSince there is a significant amount of extrapolation to obtain data from the original Hill Chart, it is very likely some trial and error adjustments will be required. In most cases, the troublesome area is the location of the small gate and zero gate openings producing the maximum transients. The shorter the gate closure time, the more important it is to have the gate drawn at correct positions.

297/5/2015Guidelines for AdjustmentsThe gate opening should be adjusted on the originally Hill Chart and reprocessed as it affects both the WH and WB curve.However, it has been found useful to simple change the WH and WB curves to calibrate test and Hytran results as it is less time consuming. Changing the WH will require a change in the WB as well.Use Excel to open a *.cha file and set the cells to read the WH and WB values. Plot both the WH and WB characteristic curves. By visual observation of the curves, make adjustments.By changing the WH first will help to correct the transient heads (together with gate area adjustments). The WB can then be adjusted to correct the torque and speed curves.Check the WH and WB curves are the Correct shapeSpacing of the WH and WB curves of curves at small gate openings and anglesTo reduce the speed drop after gate closure, raise the Torque curve (WB) at low angels (-9 to 12)For low gate closure times, particularly when the penstocks have been reduced in diameter to produce very high velocities at the turbine, the gate closure rates are crucial. Also the servo position and gate area should be accurate.

307/5/2015THANK YOU317/5/2015

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HyTran Training Hill Chart