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SREE CHAITANAYA COLLEGE OF ENGINEERING , KARIMNAGAR

EXPERIMENT 3

PERFORMANCE TEST ON COMPUTARIZED FRANCIS TURINE TEST

RIG ELECTRICAL LOADINGOBJECTIVE

To study the performance characteristics of turbine under unit quantities

To obtain constant head characteristics

To obtain constant speed characteristics

THEORY

Francis turbine is a inward mixed flow reaction turbine. In a Francis turbine, water enters

the runner at its outer periphery and flows out axially at its centre. This arrangement provides a

large discharge area with the given diameter of the runner. A part of the net available energy of

the water is converted into kinetic energy and the rest of the major portion remains as pressure

energy, as water enters the runner. The runner rotates due to reaction pressure caused by the

pressure difference at the runner entry and exit.

The principal component parts of Francis Turbine are:

Scroll Casing It’s a spiral shaped closed passage of gradually reducing cross-sectional area, enclosing

the runner. Its function is to distribute the flow uniformly along the periphery of the

runner in such a way that the velocity remains constant at every point.

Guide MechanismThere are two main functions of the guide mechanism (a) To regulate the quantity of

water supplied to the runner and (b) To adjust the direction of flow so that there is

minimum shock at the entrance to runner blades. It consists of a series of guide vanes of

aerofoil section fixed between to rings, in the form of a wheel known as guide wheel.

Each guide vane can be rotated about its pivot centre, which is connected to a regulating

ring by means of a link and lever. By operating the regulating ring the guide vanes can

be rotated, varying the width of the passage between adjacent vanes, thus altering both

the flow angle as well as the quantity of flow.

DEPARTMENT OF MECHANICAL ENGINEERING MFHM LAB


Runner

The runner consists of a series of curved vanes arranged evenly around the

circumference, in the annular space between two plates. It may be cast in one piece or

made of separate steel plates welded together. The runner vanes are so shaped that water

enters radially at the outer periphery and leaves it axially at the inner periphery. This

change in the direction of flow from radial to axial as it passes over the curved vanes

changes the angular momentum of the fluid thereby producing the torque, which rotates

the runner. The runner is keyed to shaft of the turbine.

Draft Tube

It is a gradually expanding closed passage connecting the runner to the tailrace

(collecting tank). The lower end of the draft tube is always kept submerged in water.

The function of a draft tube is to convert the high kinetic energy of flow at runner exit

into pressure energy, thus increasing the efficiency of the turbine. It also enables the

turbine to be installed above the tail race level without any loss of head.

EXPERIMENTAL SETUP

Supply Pump / Motor Capacity : 10HP, 3Ph, 440V, 50Hz, AC

Electrical Supply : 3 Ph, 440V, AC, 32A, with Neutral & Earth

Alternator make : Kirloskar

Alternator capacity : 3KVA

Loading : AC Alternator connected with electrical switches

Speed Measurement : Digital speed indicator with proximity sensor

Pressure Measurement : Digital dual pressure indicator connected to sensor

Outlet Pressure Measurement : Digital pressure indicator connected to sensor

Power Output Measurement : Digital AC wattmeter

Discharge Measurement : Venturimeter [Cd=0.98 ] Computer Interface : RS 485 converter

Lab view application software



SPECIFICATIONS

Diameter of Impeller : 153mm

Impeller Material : Stainless Steel

Diameter of venturimeter inlet, D : 100mm

Diameter of venturimeter throat, d : 50mm

Guide vane material : Gun metal

Run-away speed :1900 rpm (approx.)

Maximum flow of water :1200 LPM (approx.)

Maximum head :14 m (approx.)

PROCEDURE

When all the instrumentation along with its accessories is readily connected it is just enough to

follow the instructions framed below:

1. Before switching on the MCB ensure that all the loading switches and the solenoid valve

switches are maintained at OFF position

2. Now switch ON the M.C.B. All the indicators mounted on the control panel board starts

displaying some random values.

3. Now open the butterfly valve of the turbine setup say Francis or Kaplan on which the

performance test is to be carried out initially and shut the valve completely on which the

test is not conducted.

4. Engage the belt of one particular turbine with the alternator and adjust the guide vane to

required opening position say full, half, One-fourth or One-third if you are operating for

Francis turbine or adjust the gate opening to required position say full, half, One-fourth

or One-third if you are operating for Kaplan turbine.

5. Meanwhile switch on the computer and the control panel & keep it ready with the

observation menu

6. For the application software Computerized Francis & Kaplan turbine, in the computer

follow the route, Start > Programs > Computerized Francis & Kaplan Turbine >

Application or directly select the short cut icon on the desktop.

7. Now start the pump by pressing the starter button on the pump starter. Now water start

flowing to the turbine through venturimeter and the setup becomes operational.

8. Now on software screen click on the COMM SET option as shown in the figure.



9. Now Computer port setting dialog box will open as shown in the figure. Now select the

required connected port and press OK.

10. Now select the turbine type from the option given in the application software say Francis

or Kaplan. Once the turbine type is selected one could hear a sound of solenoid valve

valve opening for the selected turbine type.

11. After selecting the turbine type, select the type of experiment to be conducted in the

particular turbine from the option given in the application software say Constant

Head/pressure operation or Constant Speed Operation.

12. After selecting the required type of turbine and the type of experiment to be conducted

for the performance test click on START TEST option on the application software

screen a dialog box with the file name will be displayed as shown in the figure



Now select the required file path and press OK. In the data indicator tab of the software

all the values will start indicating as shown in the control panel.

13. Once all the values are displayed on the software as per the values indicated in the digital

indicators of the control panel click LOG DATA and all the data will be logged in the

data tabulation tab of the software along with performance graphs

14. Log different values at different loading condition by clicking the same icon.

15. As the test is running, the computer will carry out all the Calculations and

Tabulations. Repeat the same procedure for other condition say for different guide vanes

opening for Francis turbine whereas for different gate opening for Kaplan turbine.

16. After logging the data for different condition unload the turbine by putting OFF the

loading bulbs by using the software if the loads are being applied using software or put it

OFF manually if the load is being applied by using the loading switches.

17. To save the data click on the STOP TEST option on the software and then click on the

SAVE TO EXCEL option on the software

18. An Excel Sheet opens with all the logged values along with the performance graph.

19. To save the file go to FILE > SAVE AS > FILE NAME > OK



20. After the completion of the expirement put OFF the supply pump and SHUT the valves.

NoteSoftware is running Software is running continuously Software is not running

8. Constants and Nomenclature

Pi Venturimeter Inlet Pressure Kg /cm2

Pt Venturimeter Throat Pressure Kg /cm2

PV Vacuum Pressure (Outlet pressure) Kg /cm2

D1 Venturimeter Inlet Diameter m

D2 Venturimeter Throat Diameter m

A1 Venturimeter Inlet Area m2

A2 Venturimeter Throat Area m2

H v Venturimeter Head m

h Venturimeter Inlet and Throat Pressure Difference m

Cd Coefficient of Discharge No unit

Q Discharge m3/sg Acceleration due to gravity m /s2

N Turbine Speed RPM

H Head on Turbine m

W Specific Weight of Water N /m3

BPElectric Brake Power Electric KW

BPShaft Brake Power Shaft KW

H Hydraulic Hydraulic Input to Turbine KW

NU Unit Speed No unit

PU Unit Power No unit

QU Unit Discharge No unit

NS Specific Speed No unit

ηTurbine Turbine Efficiency No unit

LIST OF FORMULAE

Turbine Break Power, ( BP )



BPElectric=n x1000 x60 x60

Energy Meter Constant x TimeKW

Where,n=No of blinks /revolution¿energy meter

BPShaft=BPElectric

Transmission EfficienyKW

Discharge, (Q )

Q=C d xA1 x A2 x√2 g HV

√ A12−A2

2m3/s

Where,A1=Venturimeter Inlet Area∈m2

A2=VenturimeterT h roat Area∈m2

Cd=Coefficient of Disc h arge

g=Acceleration due¿ gravity∈m / s2

P I=Venturimeter Inlet Pressure∈Kg /cm2

PT=Venturimeter T hroat Pressure∈Kg /cm2

HV =Head on Venturimeter∈mHV =10hHV =10 [P I−PT ]

Head on the Turbine, H

H=10 (PI+( PV

760 )) Where, H=Head onTurbine∈mP I=Venturimeter Inlet Pressure∈Kg /cm2

PV =Vacuum Pressure [Outlet Pressure ]∈Kg /cm2

Hydraulic Input to the Turbine in W

Phyd=WQH

Where,W =Specific Weig ht of Water ∈N /m3

Q=Disc h arge∈m3/sH=Head onTurbinein m



Turbine Efficiency

% ηTurbine=BPPHyd

x100

Where,BP=Brake Power∈KWPHyd=Hydraulic Input ¿ turbine∈KW

Unit quantities under unit head

Unit Speed

NU= N

H12

Where,N=Turbine Speed∈RPMH=Head onTurbine∈m

Unit Power

Pu=P

H32

Where,P=Brake Power of Sh aft∈KWH=Head onTurbine∈m

Unit Discharge

Qu=Q

H12

Where,Q=Disc h arge∈m3/sH=Head onTurbine∈m

Specific speed

N S=N P

12

H54

Where,N=Turbine Speed∈RPMP=Brake Power of Sh aft∈KWH=Head onTurbine∈m

Percentage Full Load



% Full Load=Part load BPMaxload BP

x100

GRAPHS OF FRANCIS AND KAPLAN

For constant head characteristics Turbine efficiency Vs Unit speed Unit power Vs Unit speed Unit discharge Vs Unit speed

For constant speed characteristics Turbine efficiency Vs Percentage of full load Efficiency Vs discharge BPSHAFT Vs discharge

PRECAUTIONS

Do not start pump set if the supply voltage is less than 300v (phase to phase voltage).

Do not forget to give electrical earth and neutral connections correctly. Otherwise, the

RPM Indicator gets burnt if connections are wrong.

Frequently, atleast once in three months, grease all visual moving parts.

Initially, fill-in the tank with clean water free from foreign material. Change the water

once in a month.

Atleast every week, operate the unit for five minutes to prevent any clogging of the

moving parts.

To start and stop the supply pump, always keep Gate valve (Butterfly valve) closed.

Gradual opening and closing of the Gate valve is recommended for smooth operation.

Handle the switches gently.

After the experiment is over, switch off all the indicators.



Constant Head/Pressure Operation

Sl.No. Turbine Type

Type of Experiment

Blade / Guide

Opening

Inlet Pressure

(kg/cm^2)

Throat Pressure

(kg/cm^2)

Delivery Pressure

(kg/cm^2)

Outlet Pressure

(kg/cm^2)

Speed (RPM)

Discharge(Cu m/s)

1 Francis Turbine

Constant Pressure Full

2 Francis Turbine


3 Francis Turbine


4 Francis Turbine


5 Francis Turbine


6 Francis Turbine


Turbine Output Shaft Input Turbine Specific Unit Unit Unit % Full



Head (m) Power (W) Power (W) Power (W) Efficiency (%) Speed Ns Speed Nu Discharge

Qu Power Pu Load

Constant Speed Operation



Sl.No. Turbine Type Type of Experiment

Blade / Guide Opening

Inlet Pressure (kg/cm^2)

Throat Pressure

(kg/cm^2)

Delivery Pressure(kg/cm^2)

Outlet Pressure(kg/cm^2)

1 Francis Turbine Constant Speed Full2 Francis Turbine Constant Speed Full3 Francis Turbine Constant Speed Full4 Francis Turbine Constant Speed Full5 Francis Turbine Constant Speed Full6 Francis Turbine Constant Speed Full

Speed (RPM)

Discharge(Cu m/s)

Turbine Head (m)

Output Power (W)

Shaft Power (W)

Input Power (W)

Turbine Efficiency (%)

% Full Load



Constant Head/ Pressure Operation

Sl.No. Turbine Type

Type of Experiment

Blade / Guide

Opening

Inlet Pressure

(kg/cm^2)

Throat Pressure

(kg/cm^2)

Delivery Pressure

(kg/cm^2)

Outlet Pressure

(kg/cm^2)

Speed (RPM)

Discharge(Cu m/s)

1 Kaplan Turbine


2 Kaplan Turbine


3 Kaplan Turbine


4 Kaplan Turbine


5 Kaplan Turbine


6 Kaplan Turbine




Turbine Head (m)

Output Power (W)

Shaft Power (W)

Input Power (W)

Turbine Efficiency

(%)

Specific Speed Ns

Unit Speed Nu

Unit Discharge

Qu

Unit Power Pu

% Full Load

Constant Speed Operation

Sl.No. Turbine Type Type of Experiment

Blade / Guide Opening

Inlet Pressure (kg/cm^2)

Throat Pressure (kg/cm^2)

Delivery Pressure(kg/cm^2)

Outlet Pressure(kg/cm^2)

1 Kaplan Turbine Constant Speed Full








Speed (RPM)

Discharge(Cu m/s)

Turbine Head (m)

Output Power (W)

Shaft Power (W)

Input Power (W)

Turbine Efficiency (%)

% Full Load

RESULT:



1. Efficiecy of the francis turbine _________________

FRANCIS TURBINE



KAPLAN TURBINE


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