53:071 Hydraulics and HydrologyProject #1

Pelton TurbineMarian Muste, Gokhan Kirkil and George Constantinescu

Problem StatementA children’s museum in Colorado has purchased a small Pelton turbine for its new display on renewable energy.

Problem StatementThe 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 ObjectivesYour 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 InformationThe 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 InformationThe 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 ComponentDetermine 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).

Principley

A

x

VEntering jet

j

Exiting jet(nil velocity)

A

r

z

Torqueon shaft

Controlsurface

Nozzle

Turbineshaft

NTTPhydr 2

available

hydrhydr P

P

availableavailable QHP

VIPelec

hydr

elecelec P

P

elechydrtotal *

Centrifugal turbine:high speed jet hits the blades of theturbine and as a result of momentum transfer the turbine shaft rotates with a certain frequency

Laboratory Apparatus

B- Available Head (psi)

C- Turbine Torque (lb-in)

D- Turbine Speed (rpm)

E- Generator Speed (Hz)

F- Generator Voltage (volts)

G- Generator Current (amps)

K- Hydraulic BreakJ-

Discharge controlling valve

A- ElectricalLoads

H- Generator Switch

Laboratory Objective 1Determine 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 ProceduresPart-1-Electrical generation part

1. TA sets the discharge and initial measuring speed with the brake off.

2. Turn on the generator switch and bring generator to 60Hz using the input flow valve.

3. Apply the first electrical load to generator. As power line frequency drops, in order to maintain 60 Hz open input valve slowly.

4. Measure the rotational speed (rpm) of the shaft (N), residual torque (T) (lb-in), voltage (V) (volts) and the current (I) (amps).

5. Measure the head on the weir (H1) and record the reference point (H0). This is needed to measure the discharge

6. Repeat steps 3-5 as second, third and fourth loads are added to the system.

Data Sheet -1Data Acquisition Data Reduction

OperationH0

[ft]H1

[ft]Havail.

[psi]T

[lb-in]N

[rpm]Q

[cfs]Pavailable

[lbf*ft/sec]Phydr

[lbf*ft/sec]Hyd. Effic.

[%]

4 Bulbs 0.919

3 Bulbs 0.919

2 Bulbs 0.919

1 Bulb 0.919

Data Acquisition Data Reduction

Operation Voltage[volts]

Current[amps]

Pelec

[lbf*ft/sec]Elec. Efficiency

[%]

Overall Efficiency

[%]

4 Bulbs

3 Bulbs

2 Bulbs

1 Bulb

Data Analysis-1Determine 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 2Determine energy conversion efficiency (hydraulic) curves of the turbine for 2 operational discharges.

Laboratory ProceduresPart-2 Determine hydraulic efficiency curve for the turbine1. TA sets the first discharge and initial measuring speed

with the brake off.2. Tighten the friction hand-wheel (this reduces the

rotational speed) and record the torque and rotational speed.

3. Repeat Step 2 with ∆N ≈ 50-100 rpm until the rotational speed reaches about 500 rpm

4. Measure the head on the weir (H1) and record the reference point (H0)

5. TA adjusts to a lower discharge. Read the new initial rotational speed with the brake off.

6. Repeat Steps 2 to 57. Plot hydraulic efficiency vs. rotational speed for the

two discharges

Data Sheet -2Data Acquisition Data Reduction

H0

[ft]H1

[ft]Havail

[psi]T[lb-in]

N [rpm]

Q [cfs]

Pavailable

[lb*ft/sec]Phydr

[lb*ft/sec]Hyd. Effic

[%]

Run 1 0.919

Run 2 0.919

Data Analysis-2Determine 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

0

20

40

60

80

100

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

rotational speed (rpm)

effic

ienc

y

Q=0.35 cfs Q=0.11 cfs

Project ReportProvide 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).