Modeling turbine kaplan in heliciel guide vanes draft tube turbine
Tutorial example small hydropower plant design 1/3:

Chapter Summary hydroelectric turbines::

 

1: Power of the site 2: Propeller turbine design

 

1: Power of the site: In this tutorial example, we take the case of the development of a site which has an average flow of 12 m3/sec with a drop height of about 4 meters.

Evaluate the power of undeveloped site:

Ph hydraulic power in watts, of the site depends:

  • The difference in height of fall H in meters, between the surfaces of the upstream and downstream basin.
  • The flow rate Q in m3/sec, through the system.

implantation des turbines de type bulbes helices kaplan

with :

  • ρ water density (1000 kg/m3)
  • Section =fluid passage section (area swept by the turbine) m²
  • g (9.81 m/s²)
  • Q turbine flow in m3/s
  • H Head m
Hydraulic raw power of our site can be evaluated : 12 X 4 X 9.81 X 1000 = 470 880 Watts (471 Kw). We will see that because of the various losses, the electrical power produced will be lower. The division of power produced by the raw power, give the overall performance of our system.
2: Design of the propeller turbine.
As stated in the proposed method, nous commencerons par calculer notre hélice optimum pour le débit de 8 m3/sec. For this we use the HELICIEL software to obtain performance and 3D models of blades that we will build.

projet turbine

fluide turbine

ptofil naca

helice kaplan 4 pales

point de fonctionnement turbine

la section balayée par l'hélice

enter the basic parameters:

  • Blade tip radius=1000mm
  • Radius blade root= 60% (600mm)
  • Chord blade root= 738 mm
  • Blade tip Chord= 1138 mm
  • Click "linearize" in the distribution area of chords to get a straight blade.
  • In this example we want a distribution chord giving a slightly curved blade. To achieve exactly the same distribution as this example, we can directly enter the equation for distribution of our cords in three fields provided for this purpose. Our equation is: -0.0031457 r² + 6.033248 r -1749.469 , Enter these values ​​and click "Apply equation chords".(cords values ​​and the equation may be slightly altered during the application of the equation)
If you have previously entered speed 6 m/sec, You should get a flow rate (top left in speed counter) 12.064.m3/sec like this:

debit de tubine

option carenage de l'hélice de turbine hydroelectrique

Ticking the option Duct relaunch calculation of the propeller..
Heliciel will build the optimum twist and evaluate the performance of our turbine based on a series of speed rotations tested and will stop on the optimum rotation speed, here we got a performance propeller, 0,47 at 53,19 revolutions per minute::

turbine hydraulique

The optimum twist suitable for this operating point and the 3D model of our propeller was built. Our performance could be improved by changing the width and distribution of cords to get close to the Betz limit, but suffice 0.47 in this tutorial trying to keep it simple and fast.

We could start manufacturing the blade editing 3D IGS file... but optimizations will follow, as the introduction of a tangential velocity by the distributor(guide vanes), and creating a draft tube ...Take care to save your project, because we'll come back later.. We will now use the results of this turbine configuration for following: evaluate the effect of a tangential introduction upstream of the propeller caused by a guide vanes

 

Chapter Summary hydroelectric turbines::