500 kW Horizontal Tubular Hydro Turbine Set

Overview

How it works

In a tubular turbine the shaft is horizontal or slightly inclined, and water flows through the runner in a nearly straight line. With no spiral casing or sharp bends, hydraulic losses stay low, and the powerhouse can be shallower than for a vertical set. This is why tubular units are widely used on low-head schemes.

Our 500 kW set

The set is rated at 500 kW for sites with a head below 25 m. The runner is stainless steel, which helps resist wear and cavitation in silt-bearing water. Flow, speed, generator type, voltage and frequency are set for each project, because they depend on the actual head and flow at your weir or outlet.

Head variation

On low-head schemes a change of a few meters in water level has a large effect on output. For this reason the design is checked against the head at both low and high river levels.

Where it is used

Low-head tubular sets are found on river barrages, irrigation canal drops, the outlets of reservoirs and the tailwater of existing structures. They are a common choice where building a deep vertical powerhouse would be costly.

Installation and site

Gate, valve and trash-rack arrangement, governor and control cabinet scope, and grid synchronization requirements are set for each site. The equipment is manufactured and tested in our factory and prepared for shipment. Drawings for the water passage, foundations and powerhouse are provided so your civil team can build to the right dimensions. The quotation lists each item that is in or out of scope, and our engineers can support installation and commissioning.

Tubular, Kaplan or axial flow?

The horizontal tubular set is built for low head and large flow, below 25 m. The water travels in a nearly straight line through the runner, which means fewer elbows, less head loss and a flatter powerhouse than a vertical Kaplan. It is a good match for run-of-river plants on weirs, irrigation dams and canal falls.

Next to the 200 kW Kaplan set at about 10 m head, the tubular is larger at 500 kW and built for sites with much more flow; the Kaplan is a vertical machine with a deeper pit. Next to the 100 kW axial flow set, it is five times the power and is an engineered plant rather than a village unit. The key design question is head variation: river levels change with season, and a fixed-blade runner loses efficiency away from its design point. If your head swings by more than about 30 percent, double regulation with adjustable blades is the better choice. A site survey with river level records is the best way to decide.