L D College of Engineering
Mechanical Engineering Department
Experiment No: 9
Performance test on Pelton turbine
Relevant CO: CO3
Objectives:
To study working of Pelton Turbine
To determine output of Pelton wheel.
To determine efficiency of Pelton wheel
Theory:
The Pelton Turbine Test rig is supplied as a complete set to conduct experiments on
model pelton turbine in engineering colleges and technical institutions. It has been
specially designed to conduct experiments in metric units. The test rig mainly consists
of (1) Pelton Turbine (2) flow measuring units consisting of a venturimeter and
pressure gauges and (3) piping system (4) A suitable capacity sump tank.
General Description
The unit essentially consists of casing with a large circular transparent window kept at
the front for the visual inspection of the impact of the jet on buckets a bearing pedestals
rotor assembly of shaft, runner and brake arrangement is provided to load the turbine.
The input to the turbine can be controlled by adjusting the spear position by means of a
hand wheel fitted with indicator arrangement. The water inlet pressure gauge and for
the measurement of speed, use a hand tachometer.
Constructional Specification:
1. CASING: It is made of a close grained cast iron having a large circular transparent
window.
2. RUNNER: It is made of cast gunmetal disc fitted with accurately finished gun
metal buckets and electroplated
3. SHAFT: It is made of Stainless steel for rust free special steel operation and of
sample size for high strength
4. NOZZLE: It is made of gunmetal designed for smooth flow.
5. SPEAR: of stainless steel designed for efficient operation.
6. SPEAR SPINDLE: It is made of stainless steel of liberal size.
7. INLET BEND: It is made of cast iron, which accommodates the indicator bracket.
8. BALL BEARINGS: It is made of double row deep groove rigid type in the casing
and double rows self aligning type in the pedestal both of liberal size.
9. BRAKE ARRANGEMENT: It Consists of a machined and polished brake drum with
cooling water pipes, internal water scoop, discharge pipe, standard cast iron
dead weights, spring balance, rope brake etc., arranged for loading the turbine
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
L D College of Engineering
Mechanical Engineering Department
10. FINISHING: It is of high standard suitable for the laboratory used in technical
institutions
Technical Specification:
PELTON WHEEL TURBINE
Rates Supply Head : 25.0 Meters
Discharge : 500 lpm
Normal Speed : 1000 rpm
Power output : 1 HP (0.7457 kW)
Jet Diameter : 22mm (Maximum)
Pitch Circle Diameter : 260 mm
Jet Ratio : 12 appx.
No. of Buckets : 18 Nos.
Brake Drum diameter: 300 mm
Rope diameter : 15 mm
SUPPLY PUMPSET
Power required : 5 HP (3.7 kW)
Rated Head : 30 Meters
Discharge : 500 LPM
Normal Speed : 2870 rpm
Size : 60mm X 50mm
Type : Centrifugal, Single suction volute, Highspeed
Make: Kirloskar : 538+
FLOW MEASURING UNIT
Size of Venturimeter : 50 mm.
Diameter ratio : 0.5916
Area ratio : 0.35
Throat Diameter : 29.58 mm
Inlet Cone angle of Venturimeter: 20˚
Outlet Cone angle of Venturimeter: 10˚
Pressure Gauge : 0-4 kg/Cm2 -2 Nos
STARTING UP
1. Check whether all the joints are perfectly matched.
2. Check whether all the electric connection is correct.
3. See that the gauges are mounted on the correct position and their cocks closed.
Procedure:
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
L D College of Engineering
Mechanical Engineering Department
Pour adequate water in the sump. Make sure before starting that the pipe
linesare free from foreign matter. Also note whether all the joints are water tight
and perfectly matched. Start the pump with closed gate valve.
The spear in the turbine inlet should bearings and bush bearings in the units are
properly lubricated.
Then slowly open the gate valve situated above the turbine and open the cock
fitted to the pressure gauge and so that the pump develops the rated head. If
thepump develops the required head, slowly open the turbine spear by rotating
the hand wheel until the turbine attains the normal rated speed.
Run the turbine at the normal speed for about 15 minutes and carefully note the
following:
a) Operation of the bearings, temperature rise, noise etc.,
b) Vibration of the unit.
c) Steady constant speed and speed fluctuations if any.
In addition to this, on the sump side note the operation of the stuffing box. (The
stuffing box should show an occasional drip of water. If the gland is over
tightened, the leakage stops but the packing will heat up burn and damage the
shaft.).
If the operation of the above parts is normal, load the turbine slowly and take
readings. To load the turbine standard dead weights are provided with figures
stamped on them to indicate their weights. Open the water inlet valve and allow
some cooling water through the brake drum when the turbine runs under load,
so that the heat generated by the brake drum is carried away by the cooling
water.
Do not suddenly load the turbine, load the turbine gradually and at the sametime
open the spear to run the turbine at normal speed.
Diagram ofPelton Wheel Turbine:
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
L D College of Engineering
Mechanical Engineering Department
OBSERVATION TABLE 1: Fully open Nozzle position ofPelton Turbine
Sr. Nozzle Mass Spring Net Mass Input Speed Venturi Venturi Torque Input Output Efficiency
No. Opening added on balance Acting on Head H (rpm) meter meter T (N.m) Power Power %
the drum Reading S the drum in kg/cm2 reading in reading in (kW) (kW)
M (kg) (kg) M-S (kg) difference difference
in kg/cm2 in kg/cm2
1.
2.
3.
4.
Fully Opening
5.
6.
7.
8.
9.
10.
L D College of Engineering
Mechanical Engineering Department
OBSERVATION TABLE 2: Fully open Nozzle position ofPelton Turbine
Sr. Nozzle Mass Spring Net Mass Input Speed Venturi Venturi Torque Input Output Efficiency
No. Opening added on balance Acting on Head H (rpm) meter meter T (N.m) Power Power %
the drum Reading S the drum in kg/cm2 reading in reading in (kW) (kW)
M (kg) (kg) M-S (kg) difference difference
in kg/cm2 in kg/cm2
1.
2.
3.
4.
Half Opening
5.
6.
7.
8.
9.
10.
L D College of Engineering
Mechanical Engineering Department
To Shut Down:
Before switching off the supply pump set, first remove all the dead weights onthe hanger. Close
the cooling inlet water gate valve.
Slowly close the spear to its full closed position.
Then close the gate valve just above the turbine.
Pressure Gauge cock and Venturi meter cocks should be closed in order to isolate the pump set
when the turbine is working under load.
If the electric line trips off when the turbine is working first unload the turbine, close all the
valves and cocks. Start the electric motor against, when the line gets the power and then
operate the turbine by opening the valve in the order said above.
Formulas for Calculation:
Pressure Conversion 1 kg/cm2 = 98066.5 Pa
Brake power BP (kW)
2𝜋𝑁𝑇
𝐵𝑃 (𝑘𝑊 ) =
60000
Where, N = Turbine speed in RPM
T = Torque in Nm
= (Net brake load in kg * gravitational constant * Effective radius of the brake
drum in meters)
Or
T = ((M+m)-S) x gx Re
Where, M=Mass added on the drum in kg
m= Mass of rope & hanger =1 kg
S= Spring Scale reading in kg
Re = (D/2) + t in m = 0.165 m
D= brake drum diameter = 0.3 m
t = rope diameter = 0.015 m
g = gravitational constant 9.81 m/s2
Input Power in IP (kW)
𝜌𝑔𝑄𝐻 𝑝𝑄
𝐼𝑃 (𝑘𝑊 ) = =
1000 1000
Where ρ g H = p = Pressure exerted at inlet to nozzle in N/m 2
Q = Volume flow rate in m3/s
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
L D College of Engineering
Mechanical Engineering Department
𝑝1−𝑝2
𝐶𝑑 𝐴2 √2 ( )
𝜌
𝑄=
𝐴2 2
√(1 − )
𝐴1 2
Where
Cd = Venturimeter Discharge Coefficient = 0.98
A1 = Inlet Area of Venturimeter
d1 = Inlet diameter of Venturimeter = 50 mm = 0.050 m
A2 = Throat Area of Venturimeter
d2 = Throat diameter of Venturimeter = 29.58 mm = 0.02958 m
p1 - p2 = Venturimeter pressure difference
(1-indicate inlet and 2- indicate throat pressure)
Overall efficiency
𝑂𝑢𝑡𝑝𝑢𝑡 𝑃𝑜𝑤𝑒𝑟(𝐵𝑟𝑎𝑘𝑒 𝑝𝑜𝑤𝑒𝑟)
𝜂=
𝐼𝑛𝑝𝑢𝑡 𝑃𝑜𝑤𝑒𝑟
Graphs to be plotted:
1. Graph 1: x-axis is Speed, Y-axis is output power and efficiency for fully open nozzle Position
2. Graph 2: x-axis is Speed, Y-axis is output power and efficiency for half open nozzle Position
Conclusions
Quiz:
1. What do you mean by an impulse turbine?
2. Why is a pelton wheel suitable for high head only?
3. What is the specific speed range of a pelton wheel
4. What is meant by a speed ratio of a pelton wheel?
5. A nozzle of 50 mm diameter delivers a stream of water that strikes a flat plate which is held
Normal to the axis of stream. If the issuing jet has a velocity of 18m/s, make calculation
for:
(i) Force exerted on the plate if held stationary.
(ii) Force exerted on the plate,
(iii)work done/second, and the jet efficiency if the plate moves in the direction of jet at6m/s
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
L D College of Engineering
Mechanical Engineering Department
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
L D College of Engineering
Mechanical Engineering Department
Rubric wise marks obtained:
Criteria % 10 9-8 7-6 5
Correct answers Correct answers Correct answers
Correct answers
Knowledge 30 90% or more by between 70- between 50-
less than 50%.
student. 89%. 69%.
Proper formatting Only formatting
A few required Several elements
and well is improper
elements are missing
attempted quiz (Location of
Quality of (labeling/ (content in
20 and case study figures/tables,
report notations) are paragraph, labels,
with use of pencil and
missing. figures, tables).
excellentreported scale).
Average Poor report
work Good
Participation
Moderately Focused limited
Participation 25% Excellent
30 focused attention attention in the Less
type focused attention
on exercise. exercise. Participation
in the exercise.
Submission late Submission late Submission late
Timely
Punctuality 20 by one by two by more than two
Submission
laboratory. laboratories. laboratories.
Criteria % Level of Marks Multiplication Total Remarks
Knowledge 30 0.3 *_____
Quality of 20 0.2*_____
report
Participation 30 0.3*_____
Punctuality 20 0.2*______
Total Marks
Fluid Mechanics and hydraulic machines (3141906)
Prof N K Patel: Course Coordinator
