Table Of ContentTECHNICAL
REPORT
(¢) 1994 Working-Group on Development Techniques (WOT)
Published by the Working-Group on Development Techniques (WOT),
University of ‘Twente, P.O. Box 217, 7500 AE Enschede, The
Netherlands.
Copyright (a) 1990 by the Horking-Group on Development Techniques
(WOT). Nevertheless, permission is hereby granted for
reproduction of this material, in whole of in part, for
educational, scientific or development-related purposes, except
those Anvoiving commercial sale, provided that a) full citation
gf the source ig given and b) sotification in wetting ts given
Eo the Vorking-Group on Developnent Techniques (ROT).
‘This technical report is the result of four years of research.
Ik is meant for people of the WOT to develop their knowledge
about waterpunping windmills (= windpumps) and especially
about the Dlever 450 windmill. It is also meant fer people in
developing countries vbo have the 1dea to built the Diever
450, To understand the theory and conceptione which are used
in the report the author assumes that the reader has
ouffleient basic knowledge of wind energy. If this is not the
casa the author advises to read first the WoT-publication
‘wind onergy for the third world’ (1it.1).
The report reflects the development of the design and the
results of the tests on the prototype.
The author Le grateful to the people who helped te design the
Diever 450, especially to A. da Roest, A. Schaap, C. Vos, 5.
Vreeland, F. Van Costrum, J. Andringa, 6. Viogman, B. de Jong,
G. Wijbenga and R. van Leeuwen.
Frans Brughuis
may 1996
List of symbols
a
Introduction
1.1. The 12PUS00 windai Ll
1,2. The evaluation of the 12PUS00 windmill
1.8. The requirement list
. The rotor
2:1. The roter dimensions
2.2, The choice of the design tipspend ratio
2.3. The blades
2.4, The power and torque coefficient
2.5, Measurements of the windspeed-rotationapeed
relation
The safety system and the head construction
3.1. General
3.2. The hysteresis systen
3.4. The inelined hinged vane system
3.4, The strength calculations of the
the transmission
‘ety system
4.1. The mechanism
4.2, The construction ang the strength
The pump
5.1. General
5.2. The pumpred forces
5.3, The rotation speed
5.4. The pump dimensions
5.5. The strength calculations of the pumps
5.6. Tests of p-v.c. pumps
5.6.1. The aim of the tests
5.6.2, The test equipment,
5.6.9. The results
5.7, The choice of the p.v-c. pipe as pump cylinder
. The toner
6.1. General
6.2, Forces on the tower top
6.2.1, At operating conditions (v= 12 m/s)
page
3
6.2.2. At storm conditions (v= 40 m/s) a3
6.9. Forces on tha tower construction 50
6.8.4, At operating conditions (v= 12 m/s) 81
6.3.2. At storm conditions (v= 40 m/s) 53
6.4. Stresses in the towsrlegs 34
6.5. The Foundation 38
6.6. Forces on the tower during hoisting 36
7. Froperties and characteristics 58
7.4. The input-output relation 58
7.2, Prediction of the output 61
7.3. Costs and benefits 6
Cenciusions 65
Recommendations ve
Literature 70
appendices:
1. Brawiags of the Diever 450
2. Tha choice of the tipspeed ratio
+ Graphs of the position, the speed and acceleration of the
piston as function of the tine
Results of the measurenents on the test rig
Results of the measurements on the Diever 450 prototype
crank with a variable length
transaission with ball-bearings
Installation af the 12PUS00
SYMBOLS
description
side area head
Piston area
area of the punprod
area of the pumpred iron
projected area
reter area
area of the rising main
aide area rotor (= 7,5% of Ay)
number of blades
corde
arag coefficient
Ligt coefficient
power coefficient
torque coefficient
starting torque cosfficient
retor dianeter
force
admissible force
peak force in the pumprod
punprod force
waterlifting head
blade length
buckting length
power
power output
Mechanica! power of the rotor
power input
torque
starting torque
local cadius
roter radius
vrank Length
resotion forces in
K, L, Wand 8
stroke length
unit
windspard ws
design windspeed m/s
maximum Windspeed ms
rated Windspeed m/s
starting windspeed we
tipspeed w/s
angle of attack
plade angle
angle between actual position of main vane
and its rest pesition
angle of yaw (between rotor axis and wind
direction)
angle between hinge axis and vertical axis
angle between rotor plane and relative flow
epeed,
tipspeed ratio
design tipspesd ratio
local speed ratio at radiue
bydraulic efficiency of the pump
installation
efficiency of the pump installation
mechanical efficiency of the pump
tokal efficiency cf the winépump
efficiency of the transmission
volumetric efficiency of the pump
roter angular speed rad/s
aonsity of ale kayat
density of concrete kant
density of water kgyat
stress Hmm
admissible stress yen
equivalent stress N/mm
minimum stress N/a?
maximon stress Nm
surface stress N/mm?
shear stress N/mm
buckling factor
CHAPTER 1 INTRODUCTTON
In 1979 the WoT designed the 12PUSOO windmill. This windmili
is built in India, indonesia, Bolivia, china, Tanzania and
other countries
After sevea ysars of experiences, in 1986, 1¢ was clear that
the 1270500 design could be improved te get more output and a
Longer life~
Therefore the WOT decided to redesign the windmill which
resulted in a new windmill, the 19PU450, also called the
Diever 480, Biever is the surnane of our oldest and most’ loyal
member .
e
4.1 The 12PUS00 windmitt
The 12Py500 windmill is a
Waterpumping windmil1, 1¢ has
an horizontal-axis rotor with
12 blades and a dianeter
Five meters. The tipspeet-
ratio A (= tipepeed of the
rotorblades divided by the
windspeed, see 1it. 1) is
two. The tower is a welded
construction of angle-irons
and at the top a pipe cf a",
the tonerpipe. The tower has
a height of eix meters, The
tail uf the head construction
carries a windvane ubieb
turns the head around the
towerpipe in order to keep
the cuter perpendicular to
the Hind. The safety system figure 1.1: the 12PUS00
ie half-autonatic. In case of “indnill
a aavere storm it will unlock
automatically tke hal groom the vail after which the head and
rotor turne out of the wind. After the storm the rotor mst be
7
put perpendicular to the wind by hand.
‘The pump is a single-acting piston pump which consists of &
Piston and two valves, one valve in the piston (pistcnvalve)
and cne lower valve (footvalve), see it. 1. The pump has
airchambers to smooth the flow and to reduce the shock forces
in the pumprod.
‘The total weight of the windmill is 400 ky and the material
coats in the tetherlands are about US$ 600
For wore information about the 12PUS90 ese Iit.2 and 3.
1,2 The evaluation of the 12P0500 windn!11
In 1886 the WOT evaluated the 12PUS09 with help of reports of
T. Meyer, Rakish and Hajithia from India and J. Keuper from
Indonesia and wich help of the experiences on the testfiald of
the WOT. Especially the evaluaticn report of 155 installed
12PUSOO windmills Dy mr. Rakish is very detailed and accurate
and therefore helpful.
The conclusions of the evaluation (from mr. Rakish} ware:
Feasibilicy studies are very important before starting to
Antreduce windmills.
- The quality of the fron profiles is often bad Sn developing
countries. Pipes aren't circular, angle-irena aren't
straight, the strength of the iren materials is small, ete.
- The axis of the rotor ien't horizontal but a little bit
sloping (70% of the windmills).
- The blade supports (100% of the windmills) and the blade
tips (308) are cracked,
- There is too mich or to little play between the head and the
towerpipe (70%).
- Sometimes high windspeeds 1ift the head and rotor from the
towerpipe
- The safety system is wrong constructed or installed (80%),
the teeth of the toothed handle wear out too auch.
- The transmission: the crank is welded obliquely
‘the crankpin is bette obliquely te the crank
the crank bearing and the crosshead bearing have too mich
play
‘the wooden crosshead swalls because of rainwater and sticks
Aozide the towerpipe
‘the crosshead wears out because the towerpipe 1s unround of
has @ reugh inner wall
‘the crank is net renovable
the crankholes are eccentric.
- The pump: the airchambers leak often by leaking welds of
washers
‘the washers dry up and scart to leak
‘the bronze bushes for gulding the pumprod wear out
‘the wooden piston swells in the water and sticks inside the
punpoylinder
the piston wears out too fast
bud axial alignment of the pompeylinder and the 1
Other conclusions of the evaluation:
~ The tower is difficult to transport.
~ The tower is toe lew.
- The pumprod pents and rubs against the rising main.
+ The safety system must be full-autonatic. That means that
the rotor turns back in the wind after the storn.
- Wylon for the bearings and sesame-wood for the eross-head is
difficult to optatn.
= The air escapes slowly out of the airchambers. when the
airchamhers are full of water the shock forces in the pump
rod increase much
~ The yaw bearing (nead-towerpipe) 1s tren on tron. 1t
wears out when it has no Erequent lubrification.
~ The windmi1l ts too expensive for peor farners with less
than 2,25 ha, land.
There 1s nv intrest of the local people wnen there isn't
sufficient guidance and participation
1.3 The raguirement list
With help of the results of the evaluation a new List of
requirements ip made:
