Transcript 53:071 Principles of Hydraulics Laboratory Experiment #1

53:071 Hydraulics and Hydrology
Project #1
Pelton Turbine
Marian Muste, Gokhan Kirkil
and George Constantinescu
Problem Statement
A children’s museum in Colorado has
purchased a small Pelton turbine for its
new display on renewable energy.
Problem Statement
The museum wishes to operate the
turbine (with available flows) and sell
the power on the open market.
You have been hired as a consultant to
the museum.
Project Objectives
Your jobs are:
1.Using the measurements of relevant hydraulic
and electrical variables for various loads in the
power grid of the hydroelectric power system,
determine energy conversion efficiency
(hydraulic, electric and total).
2.Determine energy (kWh) that can be
generated from the laboratory-scale Pelton
turbine, and the revenue it can generate
($/year) for the museum.
Site Information
The effective head
(pressure) for
operations at the
site is about 51.5
psi (Havailable).
Variations in the
forebay elevation
are assumed to be
minor.
Operational Information
The museum will operate the turbine 7
days a week (9 am to 4 pm).
The museum has secured water rights
to divert flows from the South Platte
River. The allotted diversion depends
on the average monthly flow rate in the
river.
Laboratory Component
Determine the energy conversion efficiency
(hydraulic and/or electrical and total) of the
laboratory-scale Pelton turbine for the
proposed operating conditions (Havailable, Q)
under different loads (constant rotational
speed) or under different rotational speeds
(constant discharge).
The project is designed to allow documenting
the efficiency of the energy conversion in a
hydropower plant.
Engineering Analysis Components
Compute the energy produced (kWh/yr)
if operated as planned.
Estimate the revenue that can be
generated if the energy is sold on the
open market ($/year).
Principle
Pavailable  QHavailable
y
A
Phydr  T  2NT
Control
surface
Turbine
shaft
Torque
on shaft
x
z
 hydr 
Phydr
Pavailable
r
Pelec  VI
Vj
Entering jet
Nozzle
A
Exiting jet
(nil velocity)
elec
Pelec

Phydr
Centrifugal turbine:
high speed jet hits the blades of the
total   hydr *elec
turbine and as a result of momentum
transfer the turbine shaft rotates with a certain frequency
Laboratory Apparatus
A- Electrical
Loads
B- Available
Head (psi)
C- Turbine
Torque
(lb-in)
FGenerator
Voltage
(volts)
D- Turbine
Speed (rpm)
E- Generator
Speed (Hz)
J- Discharge
controlling
valve
HGenerator
Switch
G- Generator
Current (amps)
K- Hydraulic
Break
Laboratory Objective 1
Determine energy conversion efficiency
(hydraulic, electric and total) for the
laboratory-scale Pelton turbine for
various loads in the system (10 bulbs)
under constant rotational speed.
Laboratory Procedures
Part-1-Electrical generation part
1.
2.
3.
4.
5.
6.
TA sets the discharge and initial measuring speed with the
brake off.
Turn on the generator switch and bring generator to 60Hz
using the input flow valve.
Apply the first electrical load to generator. As power line
frequency drops, in order to maintain 60 Hz open input valve
slowly.
Measure the rotational speed (rpm) of the shaft (N), residual
torque (T) (lb-in), voltage (V) (volts) and the current (I)
(amps).
Measure the head on the weir (H1) and record the reference
point (H0). This is needed to measure the discharge
Repeat steps 3-5 as second, third and fourth loads are added
to the system.
Data Sheet -1
Data Acquisition
Operation
H0
[ft]
H1
[ft]
4 Bulbs
0.919
3 Bulbs
0.919
2 Bulbs
0.919
1 Bulb
0.919
Data Reduction
Havail.
[psi]
T
[lb-in]
N
[rpm]
Data Acquisition
Operation
4 Bulbs
3 Bulbs
2 Bulbs
1 Bulb
Voltage
[volts]
Q
[cfs]
Pavailable
[lbf*ft/sec]
Phydr
[lbf*ft/sec]
Data Reduction
Current
[amps]
Pelec
[lbf*ft/sec]
Elec. Efficiency
[%]
Overall
Efficiency
[%]
Hyd. Effic.
[%]
Data Analysis-1
Determine the discharge using a
triangular weir formula
Q=2.49(H1-H0)2.48.
Determine Pavail, Phydr, Pelec (lbf-ft/sec)
for four different loads in the systems.
Determine ηhydr, ηelec, ηtotal.
Laboratory Objective 2
Determine energy conversion efficiency
(hydraulic) curves of the turbine for 2
operational discharges.
Laboratory Procedures
Part-2 Determine hydraulic
efficiency curve for the turbine
1.
2.
3.
4.
5.
6.
7.
TA sets the first discharge and initial measuring speed with
the brake off.
Tighten the friction hand-wheel (this reduces the rotational
speed) and record the torque and rotational speed.
Repeat Step 2 with ∆N ≈ 50-100 rpm until the rotational
speed reaches about 500 rpm
Measure the head on the weir (H1) and record the reference
point (H0)
TA adjusts to a lower discharge. Read the new initial
rotational speed with the brake off.
Repeat Steps 2 to 5
Plot hydraulic efficiency vs. rotational speed for the two
discharges
Data Sheet -2
Data Acquisition
H0
[ft]
Run 1
0.919
Run 2
0.919
H1
[ft]
Data Reduction
Havail
[psi]
T
[lb-in]
N
[rpm]
Q
[cfs]
Pavailable
[lb*ft/sec]
Phydr
[lb*ft/sec]
Hyd. Effic
[%]
Data Analysis-2
Determine the discharge using
Q=2.49(H1-H0)2.48.
Determine the hydraulic efficiency of
the turbine.
Plot the rotational speed vs. the
hydraulic efficiency of the turbine for
two discharges.
Sample Result
Efficiency curve
100
60
40
Q=0.35 cfs
Q=0.11 cfs
20
rotational speed (rpm)
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
0
efficiency
80
Project Report
Provide the client (the museum director) with
a concise report that answers the project
objectives
Consultation with Center for Technical
Communication (CTC) is mandatory for this
project (you should show proof that you
consulted with CTC when you submit the
report).