Hydraulic Machinery - Sree Chaitanya College Of ... · Web viewHydraulic (or Water) turbines...

SREE CHAITANAYA COLLEGE OF ENGINEERING , KARIMNAGAR

EXPERIMENT 4

PERFORMANCE TEST ON COMPUTARIZED KAPLAN TURBINE 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

Hydraulic (or Water) turbines are the machines which use the energy of water (Hydro-Power) and convert it into mechanical energy. Thus the turbine becomes the prime mover to run the electrical generators to produce the electricity, Viz., Hydro-electric power.The turbines are classified as Impulse & Reaction types. In impulse turbine, the head of water is completely converted into a jet, which impulses the forces on the turbine. In reaction turbine, it is the pressure of the following water, which rotates the runner of the turbine. Of many types of turbine, the Pelton wheel, most commonly used, falls into the category of impulse turbines. While Francis & Kaplan falls in category of impulse reaction turbines.

Normally, Pelton wheel (impulse turbine) requires high heads & low discharge, while the Francis & Kaplan (reaction turbines) require relatively low heads and high discharge. These corresponding heads and discharges are difficult to create in laboratory size turbine from the limitation of the pumps availability in the market. Nevertheless, at least the performance characteristics could be obtained within the limited facility available in the laboratories. Further, understanding various elements associated with any particular turbine are possible with this kind of facility.

ii Specifications

Diameter of Impeller : 153mm Impeller Material : Gun Metal Diameter of venturimeter inlet, D : 100mm Diameter of venturimeter throat, d : 50mm Run-away speed : 2000 RPM (approx.) Maximum head : 12 m (approx.)

iii Test Setup Description

While the impulse turbine is discussed elsewhere in standard textbooks, Kaplan turbine, the reaction type which is of present concern consists of main components such as propeller (runner) scroll casing and draft tube. Between the scroll casing and the runner, the water turns through right angle into axial direction and passes through the runner and thus rotating the runner shaft. The runner has four blades which can be turned about their own axis so that the DEPARTMENT OF MECHANICAL ENGINEERING MFHM LAB


angle inclination may be adjusted while the turbine in motion. When runner blade angles are varied, high efficiency can be maintained over wide range of operating conditions. In the other words even at parts loads, when a low discharge is following through the runner, a high efficiency can be attained in case of Kaplan turbine, whereas this provision does not exist in Francis and propeller turbines where, the runner blade angles are fixed and integral with hub.

The actual experimental facility supplied consists of a centrifugal pump set, turbine unit, sump tank, Venturimeter arranged in such a way that the whole unit works on re circulating water system. The centrifugal pump set supplies the water from the sump tank to the turbine through butterfly valve which has the marking to the meter the known quantity of water. The water after passing through the turbine units enters the same tank through the draft tube. The water then flows back to the turbine unit through the venturimeter for the measurement of flow rate.

The loading of the turbine is achieved by electrical AC generator connected to blub bank. The provision for measurement electrical energy by energy meter, turbine speed (digital RPM indicator), Head on the turbine (pressure gauge), are built-in on to the control panel.

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

DEPARTMENT OF MECHANICAL ENGINEERING MFHM LAB


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√2g HV

√ A12−A2

2m3/s

Where,A1=Venturimeter Inlet Area∈m2

A2=VenturimeterT hroat 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 =10 hHV =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. Efficiency of the Kaplan turbine ________________



KAPLAN TURBINE


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