What is rated head of turbine?
Rated head (hr) – is the net head at which the full-gate output of the turbine produce the generator rated output in kilowatts. The turbine nameplate rating usually is given at this head.
What are the different heads in turbine?
There are two main types of hydro turbines: impulse and reaction. The type of hydropower turbine selected for a project is based on the height of standing water—referred to as “head”—and the flow, or volume of water, at the site.
What is head in hydraulic turbine?
Head is the change in water levels between the hydro intake and the hydro discharge point. It is a vertical height measured in metres. The more head you have the higher the water pressure across the hydro turbine and the more power it will generate.
What is difference between gross head and net head?
In the case of a reaction turbine, the gross head is the difference between head race and tailrace water level as shown in figure (b). The net or effective head is the head of water available at the point of entry to the turbine ..
What is head loss equation?
In fluid dynamics, the Darcy–Weisbach equation is an empirical equation, which relates the head loss, or pressure loss, due to friction along a given length of pipe to the average velocity of the fluid flow for an incompressible fluid. The equation is named after Henry Darcy and Julius Weisbach.
Which turbine requires more head?
Explanation: Pelton turbine is an impulse turbine only energy available is kinetic energy which is proportional to head, hence it requires high head.
What is hydraulic head for a small dam?
The hydraulic head is equivalent to the water level in a static (non-flowing) water body. In its simplest form hydraulic head is a measurement of the height of a static water column above an arbitrary point, usually expressed in meters (or feet in the US).
How do you find effective head?
In a hydro plant this will obviously depend on the volume flow rate of the moving water – the number of cubic metres (m3) per second passing through the plant, usually represented by the symbol Q (think ‘Quantity’); g = acceleration due to gravity and H is ‘effective head’ of water.
What is the general formula for calculating hydraulic head?
HYDROLOGY | Ground and Surface Water It represents the mechanical energy per unit weight of the fluid in the system. Hydraulic head is defined as h = hp + hz, where h is the hydraulic head, hp is the pressure head, and hz is the elevation head. All three quantities have the dimension [L].
What is the head of a dam?
Head: Vertical change in elevation, expressed in feet or meters, between the head (reservoir) water level and the tailwater (downstream) level. Headwater: The water level above the powerhouse or at the upstream face of a dam.
What is head flow?
Head is the height at which a pump can raise water up, that’s it, it’s that simple. Connect a tube to the discharge of a pump and measure the water height, that the head of the pump.
What is head hydrogeology?
Hydraulic head (often simply referred to as “head”) is an indicator of the total energy available to move ground water through an aquifer. Hydraulic head is measured by the height to which a column of water will stand above a reference elevation (or “datum”), such as mean sea level.
What is high and low head?
Figure 15 Types of hydroelectric installation: low, medium and high head. Hydroelectric installations can be classified as low, medium or high head. The boundaries are fuzzy, but high head usually implies an effective head of appreciably more than 100 metres and low head less than perhaps 10 metres.
What is the head in low head plant?
Head is the vertical height measured between the hydro intake water level and the water level at the point of discharge. Using only a low head drop in a river or tidal flows to create electricity may provide a renewable energy source that will have a minimal impact on the environment.
Which type of turbine is most suitable if head is high and volume is low?
Kaplan turbines are the best choice if they will operate on a low head ranging from 2 to 70 m , high water flow rate ranging from 70 to 1000 m 3 / s and net power up to 200 MW.
What is head loss in a penstock?
The head loss in penstock comprises of friction loss (hf) due to resistance offered by penstock inner surface and other losses. As the head loss at trash rack is not dependent on the flow velocity in the penstock and is not considered for the optimum design of penstock.
How do you calculate net head?
The net head is defined as the gross head minus all pipe losses due to friction and turbulence and is used to calculate the available power capacity of the water resource. To determine the net head, the river’s gross head must be measured and pipe loses calculated.
What is the net head HNET in hydraulic turbine?
Net head is basically defined as the head available at the inlet of the turbine. Net head is also simply called as effective head. When water will flow from head race to the turbine, there will be some losses of head due to friction between water and penstock.