Crash Course on the Many Types of Hydro Turbines

There are two general types of hydro turbines that are used for hydropower generation. And these types of hydro turbines may also refer to the mode as to how the turbines are set, for example you have the vertical axis water turbine.

Though the production may be small scale or for large scale energy production, there still exists a differentiation among the many types of turbines.

When you talk of the water turbines, then these will refer to the rotary engines that are designed to take the energy from the moving water. First developed in the 19th century, these were initially used for industries but right now these are used and maximized for power generation.

The two kinds of hydro turbines for use in many industries now are "the reaction and impulse turbines". It is not at all times that both turbines may be found in one project. In most cases, there is only one kind of turbine that is used, and the type of turbine selected is based on the height of standing water called as the head and the flow or the volume of the water that can be expected from the site.

There are other factors that come into play in the proper selection of the right turbines, and the list includes how deep the turbine must be set, the efficiency and the cost of the turbine.

What can be expected from the impulse turbine?

For this kind of turbine, it can be expected that the engine will use the velocity of the water in order to move the runner and discharge to the atmospheric pressure.

In the typical operations of this kind of turbine, the water will hit the bucket of the runner. Suction is not present on the downside of the turbine, and water will flow to the bottom of the engine housing the moment it hits the runner. For this kind of turbine, you can encounter the high head and the low flow applications thus the need for another sub-type, the low head hydro turbines.

If you are talking about the working of the impulse turbines, keep in mind that there are two general types used in many industries. The first one is the ‘Pelton wheel’ which incorporates one or more free jets that discharge the water into the aerated space which have an impact on the buckets of the runner.

The other type of impulse turbine is the cross-flow. Physically, this is available in drum shape and utilizes the elongated and the rectangular section nozzle which is directed against the curved vanes on the runner. This specific type of turbine will allow for the water to flow through the blades tow times. On its first pass, the water flows from outside of the blades to the inside. And on the second pass, water starts from the inside and out.

The reaction turbine takes its power from the actions of the pressure and the movement of the water. For this type, there are specific turbines to count on as well including the propeller engine with runner and three to six blades, the straflo, the tube turbine, the Kaplan-type and the Francis-type hydropower turbine.

Discover the Different Types of Water Wheels

Considered to be the relics of the industrial revolution, the water wheels are still making its presence felt. Right now there are a number of people and DIY consumers that are still depending on the water wheels for a number of purposes including commercial applications, for architectural functions or for power generation.

Water wheels are simply machines that are used where free-flowing water is available, and these ‘wheels’ are used to turn the water into useful forms of power. Don’t be surprised to see homes that are equipped with a small-scale waterwheel which is used to sustain the electrical needs of the household.

The earliest designs of these waterwheels incorporate wheels that are made. But succeeding designs of these wheels made use of the metal wheels. But for these two designs, there are blades and buckets that are arranged on the outside of the rim. There are different types of water wheels, depending on how the water is applied to the wheel, relative to the axle.

What is a horizontal water wheel?

For this type of design, the wheel is installed inside the building, just below the working floor. The water is directed into the water wheel which causes the wheel to turn. This is considered as the simplest design amongst the many types of water wheels. Other types of the wheels trace its roots to the horizontal type.

Undershot water wheel as the oldest type

Considered as the oldest and the most common among types of water wheels, this type of wheel is often placed over a river. As the flowing water hits the wheel, the wheel turns and power is generated. Because of this, it is a requirement that this wheel should be installed in a fast-moving river. Though this is considered as the most common application for the water wheel, it should be noted that this is the least efficient among all wheels. But what makes this type appealing is that this is easy to build and has minimal environmental impact.

What is the breast-shot water wheel?

This is a vertically-mounted wheel that is turned by the falling water that hits the buckets that are installed near its edge. This is more efficient than the undershot design, but less efficient than the back shot design. Instead of blades and paddles, this type of wheel makes use of buckets. This is best used on rivers where there is a steady and a high-volume flow of water.

The overshot water wheel and back-shot wheel

A water wheel is known as an overshot model when the falling water hits the paddles or the buckets near the top of the wheel. The buckets collect the water on the side of the wheel, and once that side of the wheel becomes heavy due to the collected water the wheel eventually turns and the wheel will be inverted.

Compared to the other types of wheel designs, this one does not require a heavy volume and a steady flow of water. Then there is the back-shot that combines the efficacies of the breast shot and the overshot. This wheel will work until the water on the pit rises just above the height of the axle. Power can also be sourced at the bottom of the wheel, and does not simply require the weight of the water that falls on the buckets.