MECHANICAL AND INDUSTRIAL ENGINEERING DEPARTMENT FLUID MACHINARY LABEXPERIMENT NO. 5(KAPLAN TURBINE)AIMTo draw the main (constant head) characteristic curves of the Kaplan Turbine for a given guide vane opening.

Apparatus DescriptionThe artificial head to run the turbine is created by using a hydraulic pump. A single-stage pump is supplying water to the Kaplan Turbine through a penstock. The water enters the guide blade section of the turbine where the static pressure of the water is partly converted into kinetic energy. The water then enters into moving blades of the vertical shaft turbine, through the casing, where further fall of pressure occurs which results into motion of the turbine. The pressure falls below atmospheric value in the draft tube. The discharge of the water is measured using a venturimeter fitted with u-tube manometer. The Brake Power is measured using a rope brake dynamometer and speed is measured by a tachometer.

Specifications:1. 2. 3. 4. 5. Driving motor power: 15 kW Size of impeller of the pump: 25 cm Power of the turbine: 3 kW Head: 8.5 m RPM: 1440

FormulaeN T W Size of Venturimeter (d1) Throat Dia. ( d2) K Speed of the turbine in r.p.m Torque on the brake drum, Net weight Lever Arm, N-m Specific weight of water, 9800 N/m3 250 mm 125 mm A1 A2

A1

2

A2

2

MECHANICAL AND INDUSTRIAL ENGINEERING DEPARTMENT FLUID MACHINARY LABSm H Cd Q H B.P WP Specific gravity of the manometric liquid (mercury) Difference in the heights of the manometers, h1 h2 Coefficient of Discharge Discharge, m3/sec = CdK Net head available at the inlet of the turbine Brake Power, 2 NT/60000 kW Water Power, WQH/1000 kW

Unit QuantitiesUnit Discharge, Qu = Unit Speed, Nu = Unit Power, Pu =

ProcedureThe head of the turbine is maintained constant during the experiment. Set the turbine guide blades at the given opening. Loose the rope of brake dynamometer and open the water tap supplying water for cooling of brake drum. Close the discharge valve of the centrifugal pump. Prime the centrifugal pump and start the motor. Open the discharge valve of the centrifugal pump gently. Let the turbine pick the speed. Load the drum by putting the weight in the balance. Set discharge by adjustment through pump side butterfly valve for the required head in the casing of the turbine. Read pressure head in the casing, speed of the turbine, net load on the drum, discharge head (h) from the manometers in the venturimeter, tailrace level of the water and voltage, current values in the motor. Increase the load on turbine by adding more weight in the balance. Adjust the discharge so that static pressure head in the casing is same as the previous case. Repeat the readings. Take six sets of readings. After completion of the readings remove load on the brake drum by removing weights. Close the discharge valve of the centrifugal pump gently. After the turbine stops, close the cooling water tap. Stop the motor. Repeat experiment by changing the guide vane opening.

MECHANICAL AND INDUSTRIAL ENGINEERING DEPARTMENT FLUID MACHINARY LABObservationsDiameter of brake drum Diameter of the rope Effective Radius of the brake drum, R Diameter of the penstock Velocity head in the penstock Nozzle opening 300 mm 16 mm (Diameter of the brake drum + thickness of the Belt ), m 250 mm Discharge/Area of penstock (Note in the table) _________(1/4,1/2,3/4,Full)

Discharge(Q) Reading No. Manometer reading, h1 Manometer reading, h2 Net head on the Discharge manometer,h (Q), m3/sec (h1 h2), m

Head on turbine (H), WP Reading No. Pressure Gauge Reading, p1, m Velocity head in penstock , (v1)2/2g, m of water Elevation Head, H head, {p1+(v1)2/2g+h1}, w.r.t tailrace m h1, m Water Power, WP, WQH

Brake Power (BP) Reading No. Speed,N(rpm) Dead Weight, m1(kg) Spring Balance Reading, m2(kg) Torque{(m1m2)gR},N-m Brake Power(BP) (2 NT/60000)kW

Unit Quantities Reading No. Efficiency( ) BP/WP Unit Speed, Nu Unit Discharge, Qu Unit Power,Pu

MECHANICAL AND INDUSTRIAL ENGINEERING DEPARTMENT FLUID MACHINARY LABResultsDraw the following graphs for each guide vane opening 1. Unit Discharge as a function of Unit Speed 2. Unit Power as a function of Unit speed 3. Efficiency as a function of Unit Speed Determine the best efficiency point and the corresponding speed and power.

Precautions1. Always close the discharge valve of the centrifugal pump at the start of the experimentation. 2. Prime the pump before starting the motor. 3. The tap supplying the cooling water to brake drum should be opened before starting the turbine. 4. Open the discharge valve of the pump gently. 5. Before switching off the pump, remove all dead weights, close cooling water inlet, close the guide vanes to its full closed position. 6. Never switch off the supply pump when the turbine is running under load.

Discussion1. Discuss the importance of the unit quantities. 2. Discuss the nature of characteristic curves. 3. Explain iso-efficiency curves.